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- Creator:
- Carlin, Joseph A.
- Description:
- Extreme episodic events have the capacity to transport large amounts of terrestrial material to the coastal ocean. While estuaries and deltas are typically thought to trap most of this material, some escapes these coastal features and is transported to distal depocenters along the continental shelf. Distal shelf depocenters can act as the ultimate sink for event deposits, yet event sedimentation and the impact of terrestrial carbon burial within these shelf deposits remains understudied. Therefore, this study investigated event sedimentation within the Texas Mud Blanket (TMB), a distal shelf depocenter of the Brazos River located in the northwestern Gulf of Mexico. Using a core that was collected from the TMB during a months-long elevated discharge event in late 2015 to early 2016 we applied a multi-proxy approach to delineate the event deposit. We utilized physical sediment properties (fabric, texture, and bulk density), radioisotopes (7Be and 210Pb), and organic geochemical properties (ẟ13C, C/N, and lignin-phenols) to identify a 10 cm event layer at the surface of the core. Within this 10 cm layer, we also distinguished two sub-layers associated with separate extreme discharge periods in the winter and spring, respectively. Using these event layer characteristics, we identified three other earlier potential event deposits in the core that we have attributed to events in 2010, 2007, and 2000–2001. From these results, this study has demonstrated that the TMB may be an archive for event deposits over multi-decadal time periods, in particular the transition from periods of prolonged drought to extreme wetness associated with the Brazos River. This event-dominated sedimentation regime can enhance long-term carbon burial, potentially increasing current estimates of carbon burial significantly in the TMB and other similar distal shelf depocenters. Ultimately this study highlights the potential for distal shelf depocenters as organic carbon burial “hotspots,” and postulates that this role may expand in the future as climate change increases the intensity and frequency of extreme events.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Biological Sciences
- Creator:
- Paig-Tran, E.W. Misty, Lowe, Andrew, Walker, Sean, and Walter, Ryan P.
- Description:
- The cory catfishes (Callichthyidae) are small, South American armored catfishes with a series of dermal scutes that run the length of the fish from posterior to the parieto-supraoccipital down to the caudal peduncle. In this study, we explore the anatomy and functional performance of the armored scutes in the three-striped cory catfish, Corydoras trilineatus . The lateral surface has a dorsal and a ventral row of scutes that interact at the horizontal septum. The scutes have little overlap with sequential posterior scutes (~33% overlap) and a deep ridge in the internal surface that connects to the underlying soft tissue. The internal surface of C. trilineatus scutes is stiffer than the external surface, contrary to the findings in a related species of cory catfish, C. aeneus , which documented a hypermineralized, enamel-like, non- collagenous, hyaloine layer along the external surface of the scute. Clearing and staining of C. trilineatus scutes revealed that the scutes have highly mineralized (~50% mineralization) regions embedded in be- tween areas of low mineralization along the posterior margin. Puncture tests showed that posterior scutes were weaker than both anterior and middle scutes, and scutes attached to the body required 50% more energy to puncture than isolated scutes. Corydoras trilineatus has the strongest armor in areas critical for protecting vital organs and the external armored scute receives synergistic benefits from interactions to the soft underlying tissue, which combine to provide a tough protective armor that still allows for flexible mobility.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Biological Sciences
- Creator:
- Fisher, Koren
- Description:
- Introduction Sedentary behavior (SB) is highly prevalent among older adults, with more than 25% engaging in 6 hours or more of SB daily. SB has been associated with several cardiometabolic biomarkers in younger adults; however, there is a paucity of research in older populations. This study examined associations between patterns of SB and cardiometabolic biomarkers in community-dwelling adults aged 55 years and older. Methods Data were drawn from a convenience sample of 54 community-dwelling individuals (12 males, 42 females; mean age = 72.6 ± 6.8 years, range = 56–89 years). Cardiometabolic biomarkers assessed included systolic (SBP) and diastolic blood pressure (DBP), body mass index, waist circumference, and fasting blood glucose and cholesterol parameters. SB was assessed via accelerometry over a 7-day period, and measures included daily time in SB, number and length of sedentary bouts, the number and length of breaks between sedentary bouts, moderate-to-vigorous physical activity (MVPA), and light physical activity (LPA). Associations between the SB measures and each cardiometabolic risk factor were examined using separate stepwise multiple regression models, controlling for sex, MVPA, and accelerometer wear time. Isotemporal substitution models were used to examine the change in cardiometabolic outcomes when SB is replaced by an equal duration of either LPA or MVPA. Results Adjusted regression analyses showed that daily sedentary time was positively associated with DBP (β = 0.052, ∆R2 = 0.112, p = 0.022) and inversely associated with HDL cholesterol (β = −0.111, ∆R2 = 0.121, p = 0.039). Sedentary bout length was also associated with DBP and HDL cholesterol (β = 0.575, ∆R2 = 0.152, p = 0.007; β = −1.529, ∆R2 = 0.196, p = 0.007, respectively). Replacement of 10 minutes of SB a day with LPA was associated with improved DBP and HDL cholesterol (p ≤ 0.05). No other significant associations (p ≤ 0.05) were found. Conclusion Sitting for prolonged periods of time without interruption is unfavorably associated with DBP and HDL cholesterol. Prospective studies should identify causal relationships and observe specific changes in cardiometabolic profiles in older populations.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Kinesiology
- Creator:
- Lockie, Robert
- Description:
- There has been limited analyses of DI mid-major male basketball players, and no analyses of relationships between athletic abilities and playing time in this population. The purpose of this study was to (1) describe and compare backcourt and frontcourt players from one mid-major team and (2) determine if there were relationships between playing time (total minutes, total games played, minutes per game) and select tests from the NBA Combine (height, body mass, standing reach, and wingspan; countermovement [VJ] and approach [AppVJ vertical jump], lane agility drill, ¾ court sprint, and 83.91-kg bench press). A retrospective analysis of data from the 2018 season for a men's DI team (n = 10) was conducted. Performance testing was completed in the pre-season, and playing time metrics were collated by the team's staff over the season. Players were split into backcourt (n = 6) and frontcourt (n = 4) groups and compared via independent samples t-tests (p < 0.05) and effect sizes (d). Pearson's correlations calculated relationships between playing time metrics and the NBA combine test data (p < 0.05). When compared to the backcourt group, the frontcourt group were significantly taller, heavier, had a greater standing reach and wingspan, and performed poorer in the VJ, AppVJ, and ¾ court sprint (d = 1.49-3.45). There were no significant relationships between playing time and any NBA Combine test (r = -0.363-0.511). Basketball-specific skill may have a larger impact on playing time in this mid-major team. However, the mid-major players in this study may have had above-average athletic abilities as measured by NBA combine testing, limiting correlations with playing time.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Kinesiology
- Creator:
- Wu, Jindong
- Description:
- Urban trees provide various important ecological services, the quantification of which is vital to sustainable urban development and requires accurate estimation of tree biomass. A limited number of allometric biomass equations, however, have been developed for urban species due to the prohibitive cost. Remote sensing has provided cost-effective means for estimating urban forest biomass, although the propagation of error in the estimation process is not well understood. This study aimed to offer a baseline assessment of the feasibility of estimating urban tree biomass with remote sensing-based general equations applicable to broad taxonomic groups by conducting a large urban tree inventory on a university campus. The biomasses of 191 trees of seven species from the inventory, separated into two categories (i.e., evergreen and deciduous), were calculated exclusively with urban-based species-specific allometric equations. WorldView-2 satellite imagery data were acquired to retrieve normalized difference vegetation index (NDVI) values at the location, crown, and stand levels. The results indicated that biomass correlated with NDVI in varying forms and degrees. The general equations at the crown level yielded the most accurate biomass estimates, while the location-level estimates were the least accurate. Crown-level spectral responses provided adequate information for delivering spatially explicit biomass estimation.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Geography and the Environment
- Creator:
- Lee, Alice
- Description:
- Objectives: The aims of our study were to describe current hepatitis B prevalence among Vietnamese Americans and to examine predictors of hepatitis B risk in this specific ethnic community. Design: Cross-sectional analysis of data from a community-based screening program. Setting: This analysis was based on hepatitis screening community events in Southern California. Participants: 2508 Vietnamese Americans in Southern California. Outcome measures: Serological tests for hepatitis B surface antigen, hepatitis B surface antibody, and total hepatitis B core antibody were used to classify participants as one of four hepatitis B infection statuses: currently infected, previously infected, susceptible, or immune due to a previous hepatitis B vaccination. Results: Across 2508 participants, 9.0% were currently infected with hepatitis B and 17.7% were at risk for hepatitis B. Females and those reporting a previous hepatitis B vaccination were at significant decreased risk of hepatitis B (OR=0.48, 95% CI 0.33 to 0.69 and OR=0.53, 95% CI 0.31 to 0.93, respectively) whereas those born outside of the USA and with a family history of the disease showed substantial increased risk (OR=13.36, 95% CI 1.62 to 110.05 and OR=4.68, 95% CI 2.66 to 8.22, respectively). Among those who reported a previous hepatitis B vaccination, less than half (42.9%) possessed the protective antibodies that result from a hepatitis B vaccination. Conclusions: Vietnamese Americans remain disproportionately burdened by hepatitis B. Public health efforts that focus on improving hepatitis B awareness and vaccination knowledge and that are tailored to specific high-risk subgroups, such as immigrants and those with infected family members, could help in addressing the disease's burden in this high-prevalence population.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Public Health
- Creator:
- Carlin, Joseph
- Description:
- Continental shelf environments are uniquely situated to capture some of the most dynamic processes on Earth including climatic variability and anthropogenic modifications to coastal systems. Understanding how these processes have affected sediment delivery and accumulation on the shelf in the past may provide insight into potential changes in the future. To address this, we investigated shelf sedimentation within Monterey Bay, California. Sediment cores were collected from four locations throughout the bay to capture both the modern and late Holocene sedimentological record using grain size analysis, and sediment chronologies determined from 210Pb, 137Cs, and 14C. From the grain size results we focused on the total percent sand, and established a Littoral Sand Fraction (LSF) index to assess sediment contribution from the littoral zone as a result coastal erosion. Grain size results from the multicores consistently showed an increase in sand over the past several decades (post 1970s). For the cores located within the bay proximal to three major rivers, the increase in sand corresponded to a general increase in the LSF over the same period. We attributed these trends to increased sediment contributions to the shelf due to accelerated coastal erosion in the region. This accelerated coastal erosion was likely the combined result of dam construction in the mid-twentieth century that limited fluvial supply to the coast, and a shift in climate toward wetter, stormier period. Applying these sediment characteristics back over the past ∼1,000 years we found that dry climatic periods resulted in deposits that were limited in total sand but enriched in littoral material suggesting elevated coastal erosion. During wet periods deposits were enriched in total sand but limited in littoral sand suggesting elevated fluvial supply and low erosion. Compared to the late Holocene record, the previous several decades represent a shift to a new regime, uncharacteristic of deposits over the past millennia, highlighting the impact humans have had on shelf sedimentation.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Geological Sciences
- Creator:
- Yu Bai
- Description:
- During recent years, researchers throughout academia and industry have been advancing the theory, designing, and applications of mobile service computing through the Internet of Things (IoT). Research interest in mobile service computing stems from its performance, security, reliability, and power consumption. Hence, ultra-low power integrated circuits are essential for mobile service computing that can offer the advantages of low power for computational tasks in the IoT that is driven by the restricting constraints of power consumption and autonomy in both computation and idle phases. To attain the benefits of ultra-low power circuits, the energy-consuming and computational intense demands are imposed by the underlying processing and memory devices on which the conventional ultra-low power integrated circuit can benefit substantially from innovative hardware designs. Logic-in-Memory (LIM) architectures are considered as the potential approaches to attain goals within area and energy constraints starting with the lowest layers of the hardware stack. In this paper, we propose and implement the LIM asynchronous computing paradigm for energy-efficient mobile service computing. The results indicate that the proposed design achieves 38% leakage reduction and 30% accuracy improvement compared to the state-of-the-art non-volatile asynchronous circuits. At the system level, we compare our designs with various commercial microprocessors. The experimental results show that the asynchronous processors attain a four-fold throughput increase relative to their synchronous counterparts under these operating constraints. Therefore, the proposed design offers an approach toward tangible benefits of the battery-constrained embedded mobile service computing.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Computer Science
- Creator:
- Lockie, Robert
- Description:
- This study determined the influence of years spent working in custody on fitness measured by a state-specific testing battery (Work Sample Test Battery; WSTB) in deputy sheriffs. Retrospective analysis was conducted on one patrol school class (51 males, 13 females) divided into three groups depending on time spent working in custody: DS24 (<24 months; n = 20); DS2547 (25–47 months; n = 23); and DS48+ (≥48 months; n = 21). These groups were compared to a recruit class (REC; 219 males, 34 females) in the WSTB, which comprised five tasks completed for time: 99-yard (90.53-m) obstacle course (99OC); 165-pound (75-kg) dummy drag; six-foot (1.83-m) chain link fence (CLF) and solid wall (SW) climb; and 500-yard (457.2-m) run (500R). A univariate analysis of covariance (ANCOVA) (controlling for sex and age) with Bonferroni post hoc determined significant between-group differences. DS48+ were slower in the 99OC compared to the REC (p = 0.007) and performed the CLF and SW slower than all groups (p ≤ 0.012). DS24, DS2547, and DS48+ were all slower than REC in the 500R (p ≤ 0.002). Physical training should be implemented to maintain fitness and job-specific task performance in deputy sheriffs working custody, especially considering the sedentary nature of this work.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Kinesiology
- Creator:
- Kirby, Matthew
- Description:
- Records of past climate can inform us on the natural range and mechanisms of climate change. In the arid Pacific southwestern United States (PSW), which includes southern California, there exist a variety of Holocene records that can be used to infer past winter conditions (moisture and/or temperature). Holocene records of summer climate, however, are rare from the PSW. In the future, climate changes due to anthropogenic forcing are expected to increase the severity of drought in the already water stressed PSW. Hot droughts are of considerable concern as summer temperatures rise. As a result, understanding how summer conditions changed in the past is critical to understanding future predictions under varied climate forcings. Here, we present a c. 10.9 kcal BP δ18O(calcite) record from Lake Elsinore, California, interpreted to reflect δ18O(lake water) values as controlled by over-water evaporation from summer-to-early fall. Our results reveal three millennial scale intervals: (1) the highly evaporative Early Holocene (10.55–6.65 kcal BP), (2) the less evaporative Mid-Holocene (6.65–2.65 kcal BP); and (3) the evaporative Late Holocene (2.65–0.55 kcal BP). These results are coupled with an inferred winter precipitation runoff (sand content) record from Kirby et al. (2010). Using these data together, we estimate the duration and severity of centennial-scale Holocene droughts and pluvials (e.g., high δ18O(calcite) values plus low sand content = drought and vice versa). Furthermore, the coupled δ18O(calcite) and sand data provide a generalized Holocene lake level history. The most severe, long-lasting droughts (i.e., maximum summer-to-early fall evaporation and minimum winter precipitation runoff) occur in the Early Holocene. Fewer, less severe, and shorter duration droughts occurred during the Mid-Holocene as pluvials became more common. Droughts return with less severity and duration in the Late Holocene. Notably, the Little Ice Age is characterized as the wettest period during the Late Holocene.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Geological Sciences
- Creator:
- Loyd, Sean
- Description:
- Major hydrocarbon accumulations occur in traps associated with salt domes. Whereas some of these hydrocarbons remain to be extracted for economic use, significant amounts have degraded in the subsurface, yielding mineral precipitates as byproducts. Salt domes of the Gulf of Mexico Basin typically exhibit extensive deposits of carbonate that form as cap rock atop salt structures. Despite previous efforts to model cap rock formation, the details of subsurface reactions (including the role of microorganisms) remain largely unknown. Here we show that cap rock mineral precipitation occurred via closed-system sulfate reduction, as indicated by new sulfur isotope data. 13C-depleted carbonate carbon isotope compositions and low clumped isotope-derived carbonate formation temperatures indicate that microbial, sulfate-dependent, anaerobic oxidation of methane (AOM) contributed to carbonate formation. These findings suggest that AOM serves as an unrecognized methane sink that reduces methane emissions in salt dome settings perhaps associated with an extensive, deep subsurface biosphere.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Geological Sciences
- Creator:
- Galpin, Andrew
- Description:
- Human skeletal muscle fibers exist across a continuum of slow → fast-twitch. The amount of each fiber type (FT) influences muscle performance but remains largely unexplored in elite athletes, particularly from strength/power sports. To address this nescience, vastus lateralis (VL) biopsies were performed on World/Olympic (female, n = 6, “WCF”) and National-caliber (female, n = 9, “NCF”; and male, n = 6, “NCM”) American weightlifters. Participant accolades included 3 Olympic Games, 19 World Championships, 25 National records, and >170 National/International medals. Samples were analyzed for myosin heavy chain (MHC) content via SDS-PAGE using two distinct techniques: single fiber (SF) distribution (%) and homogenate (HG) composition. The main finding was that these athletes displayed the highest pure MHC IIa concentrations ever reported in healthy VL (23±9% I, 5±3% I/IIa, 67±13% IIa, and 6±10% IIa/IIx), with WCF expressing a notable 71±17% (NCF = 67±8%, NCM = 63±16%). No pure MHC IIx were found with SF. Secondary analysis revealed the heavyweights accounted for 91% of the MHC IIa/IIx fibers, which caused a correlation between this FT and body mass. Additionally, when compared to SF, HG overestimated MHC I (23±9 vs. 31±9%) and IIx (0±0 vs. 3±6%) by misclassifying I/IIa fibers as I and IIa/IIx fibers as IIx, highlighting the limitation of HG as a measure of isoform distribution. These results collectively suggest that athlete caliber (World vs. National) and/or years competing in the sport determine FT% more than sex, particularly for MHC IIa. The extreme fast-twitch myofiber abundance likely explains how elite weightlifters generate high forces in rapid time-frames.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Kinesiology
- Creator:
- Lockie, Robert
- Description:
- This study analyzed the effects physical fitness may have on reasons for academy separation in law enforcement recruits. A retrospective analysis was conducted on 401 recruits; 330 recruits graduated (GRAD), and 71 recruits separated at various times during academy. Twenty-eight recruits separated for personal reasons (SEPPR); 18 due to physical training failures (i.e., poor fitness) or injury (SEPFI); and 25 due to academic or scenario failures (SEPAS). Fitness testing occurred prior to academy, and included: Push-ups and sit-ups in 60s; a 75-yard pursuit run (75PR); vertical jump; medicine ball throw; and multistage fitness test (MSFT). A one-way ANOVA with Bonferroni post hoc compared between-group fitness test performance. A multiple stepwise regression calculated whether recruit characteristics or fitness could predict separation. The GRAD group was younger than the SEPAS group (p < 0.01), faster in the 75PR than the SEPFI group (p = 0.02), and completed more MSFT shuttles than the SEPPR and SEPFI groups (p = 0.01). Age predicted GRAD and SEPAS group inclusion; MSFT predicted GRAD, SEPPR, and SEPFI group inclusion. Recruits who had superior high-intensity running capacity (75PR) and aerobic fitness (MSFT) should have a better chance of completing academy. However, this could be influenced by training practices adopted during academy.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Kinesiology
14. The Role of Regional Contrast Changes and Asymmetry in Facial Attractiveness Related to Cosmetic Use
- Creator:
- Peissig, Jessie
- Description:
- This study collected behavioral data for testing how regional contrast changes due to the addition of cosmetics would affect attractiveness ratings. In addition, we used an established model of asymmetry to look for a correlation between changes in attractiveness related to the application of cosmetics to specific regions of the face and changes in symmetry. Using this asymmetry model we compared female faces with and without makeup. Specifically, we used a highly controlled set of grayscale faces in which makeup application was standardized to explore these issues from a perceptual perspective. The human data showed that adding upper eye makeup significantly increased attractiveness ratings. In contrast, increases in contrast to the lower eyes and lips did not lead to increases in attractiveness ratings; application of cosmetics to the lower eyes led to a significant decrease in attractiveness. We found that for the makeup condition that led to increased attractiveness, asymmetry did not change significantly when makeup was applied to the female faces. This suggests a role for mechanisms other than symmetry related to increases in attractiveness related to makeup use in females.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Psychology
- Creator:
- Tomaszewski, Robert
- Description:
- Identifying research gaps and generating research questions are often a first step in developing ideas for writing a research paper or grant proposal. The concept of substance-based bibliometrics uses the counts of substances in the scientific literature to better understand, assess, and clarify the state and impact of information in the chemical sciences. Connecting substances indexed to specific bioactivity or target indicators can lead to assessing the biochemical, biological, and medicinal relevance of substances as well as developing ideas for expanding drug design and discovery through identifying and modifying the structural features of molecules. This study uses Chemical Abstracts through the SciFinder database to count for the occurrence of substances in the scientific literature. The study sets out search strategies for discovering potential research gaps and new ideas through visualization of chemical structures with known bioactivity and target indicators. The author recommends that subject librarians integrate research gap training in their bibliographic instruction classes, particularly to upper-level undergraduate and graduate chemistry students.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Pollak Library
- Creator:
- Lockie, Robert
- Description:
- This study determined relationships between an agency-specific fitness test battery (PT500), and a work sample test battery (WSTB) in law enforcement recruits. Retrospective analysis on 219 males and 34 females from one agency was conducted. The PT500 comprised: push-ups, sit-ups, and mountain climbers in 120 s; pull-ups; and 201 m and 2.4 km runs. The WSTB comprised: 99 yard (90.53 m) obstacle course (99OC); body drag (BD) with a 165 pound (75 kg) dummy; 6 foot (1.83 m) chain link fence (CLF) and solid wall (SW) climb; and 500 yard (457.2 m) run (500R). Partial correlations, controlling for sex, calculated PT500 and WSTB relationships (p < 0.05). Stepwise regression determined whether fitness predicted WSTB performance. The 500R related to all PT500 assessments (r range = -0.127⁻0.574), 99OC related to all bar push-ups and mountain climbers, and BD related to none. The CLF related to sit-ups, pull-ups, and 2.4 km run; SW related to mountain climbers, pull-ups, and 2.4 km run (r range = -0.127⁻-0.315). Push-ups, pull-ups, and 2.4 km run were involved in predictive relationships for 99OC, CLF, SW, and 500R (r² range = 0.217⁻0.500). To perform better in the WSTB and job-specific tasks, developing upper-body strength and aerobic fitness may be beneficial.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Kinesiology
- Creator:
- Ramirez, Maria Soledad
- Description:
- Acinetobacter baumannii is a multidrug resistant nosocomial pathogen that shows an outstanding ability to undergo genetic exchange, thereby acquiring different traits that contribute to its success. In this work, we identified genetic features of an indigo-pigmented A. baumannii strain (Ab33405) that belongs to the clonal complex CC113B/CC79P. Ab33405 possesses a high number of genes coding for antibiotic resistance and virulence factors that may contribute to its survival, not only in the human host, but also in the hospital environment. Thirteen genes conferring resistance to different antibiotic families (trimethoprim, florfenicol, β-lactams, aminoglycosides and sulfonamide) as well as the adeIJK genes and the capsule locus (KL) and outer core locus (OCL) were identified. Ab33405 includes 250 unique genes and a significant number of elements associated with Horizontal Gene Transfer, such as insertion sequences and transposons, genomic islands and prophage sequences. Also, the indigo-pigmented uncommon phenotype that could be associated with the monooxygenase or dioxygenase enzyme coded for by the iacA gene within the iac cluster was probably conferred by insertion of a 18-kb DNA fragment into the iacG gene belonging to this cluster. The Ab33405 genome includes all type VI secretion system genes and killing assays showed the ability of Ab33045 to kill Escherichia coli. In addition, Ab33405 can modulate susceptibility antibiotics when exposed to blue light.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Biological Sciences
- Creator:
- James, Sagil
- Description:
- Dye-Sensitized Solar Cells (DSSC) are third generation solar cells used as an alternative to traditional silicon solar cells. DSSCs are characterized by their durability, easy handling and ability to perform better under diverse lighting conditions which makes them an ideal choice for indoor applications. However, DSSCs suffer from several limitations including low efficiencies, susceptibility to electrolyte leakage under extreme weather conditions, and the need for expensive materials and fabrication techniques which limits their large-scale industrial applications. Addressing these limitations through efficient design and manufacturing techniques are critical in ensuring that the DSSCs transform from the current small-scale laboratory levels to sizeable industrial production. This research attempts to address some of these significant limitations by introducing the concepts of nature-inspired fractal-based design followed by the additive manufacturing process to fabricate cost-effective, flexible counter electrodes for DSSCs. The new conceptual fractal-based design counter electrodes overcome the limitations of conventional planar designs by significantly increasing the number of active reaction sites which enhances the catalytic activity thereby improving the performance. The fabrication of these innovative fractal designs is realized through cost-effective manufacturing techniques including additive manufacturing and selective electrochemical co-deposition processes. The results of the study suggest that the fractal-based counter electrodes perform better than conventional designs. Additionally, the fractal designs and additive manufacturing technology help in addressing the problems of electrolyte leakage, cost of fabrication, and scalability of DSSCs.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Mechanical Engineering
- Creator:
- Ahmed, Wylie
- Description:
- The intracellular environment is a dynamic space filled with various organelles moving in all directions. Included in this diverse group of organelles are vesicles, which are involved in transport of molecular cargo throughout the cell. Vesicles move in either a directed or non-directed fashion, often depending on interactions with cytoskeletal proteins such as microtubules, actin filaments, and molecular motors. How these proteins affect the local fluctuations of vesicles in the cytoplasm is not clear since they have the potential to both facilitate and impede movement. Here we show that vesicle mobility is significantly affected by myosin-II, even though it is not a cargo transport motor. We find that myosin-II activity increases the effective diffusivity of vesicles and its inhibition facilitates longer states of non-directed motion. Our study suggests that altering myosin-II activity in the cytoplasm of cells can modulate the mobility of vesicles, providing a possible mechanism for cells to dynamically tune the cytoplasmic environment in space and time.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Physics
- Creator:
- Yang, Joshua
- Description:
- Background In response to the growing awareness and use of electronic nicotine delivery systems (ENDS), or e-cigarettes, the U.S. Food and Drug Administration asserted its regulatory authority over ENDS in May 2016. Federal, state, and local regulatory action on ENDS may have significant and unique impacts on specialty ENDS retailers, including tobacco and vape shops. The purpose of this study is to describe the commercial motivations of vape shops in minority communities as business entities whose financial interests and actions may be particularly impacted by regulation of ENDS. Methods Specialty tobacco and vape retail stores in three minority communities were identified through an online search and community canvassing. Key informant interviews were conducted with tobacco and vape shop owners or managers discussing the business interests and tactics of selling ENDS for their store. Interview data were coded and analyzed for major themes. Results Interviews with 18 tobacco shops and 9 vape shops were completed. Tobacco shops’ reasons for carrying e-cigarettes were business oriented, focused on maintaining their customer base. In comparison, vape shops opened because of the owner’s positive experiences with e-cigarettes and belief in the potential of e-cigarettes to help people quit or reduce smoking. Tobacco shops mainly see their customers as using e-cigarettes to quit smoking whereas vape shops reported their customers using e-cigarettes for more varied reasons. Tobacco shops are much more limited in their marketing than vape shops, which rely heavily on social media and experimentation with other forms of marketing. Conclusions Tobacco shops and vape shops differ in their rationale and approaches to the business of e-cigarettes. Vape shops engage in a wide range of activities that stabilize their financial interest and increase their influence with customers and within the vape community. In order for regulatory policymaking and tobacco control interventions to maximize effectiveness, the actions of vape shops in promoting ENDS use and influencing policy debates must be taken into account.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Public Health
- Creator:
- Paig-Tran, Erin
- Description:
- Solid-liquid filtration is a ubiquitous process found in industrial and biological systems. Although implementations vary widely, almost all filtration systems are based on a small set of fundamental separation mechanisms, including sieve, cross-flow, hydrosol, and cyclonic separation. Anatomical studies showed that manta rays have a highly specialized filter-feeding apparatus that does not resemble previously described filtration systems. We examined the fluid flow around the manta filter-feeding apparatus using a combination of physical modeling and computational fluid dynamics. Our results indicate that manta rays use a unique solid-fluid separation mechanism in which direct interception of particles with wing-like structures causes particles to “ricochet” away from the filter pores. This filtration mechanism separates particles smaller than the pore size, allows high flow rates, and resists clogging.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Biological Sciences
22. Densities and zonation patterns of native and non-indigenous oysters in southern California bays
- Creator:
- Zacherl, Danielle
- Description:
- Worldwide, artificially armored shorelines can dominate available estuarine habitat. Increases in artificial substrata in southern California, USA, coincide with increased abundances of nonindigenous species. The US west coast Olympia oyster, Ostrea lurida, may be particularly sensitive to changes in natural habitat availability and recently experienced large-scale declines in abundance. Simultaneously, the non-indigenous and often invasive Pacific oyster, Crassostrea gigas, has been introduced along the US West Coast, including into southern California estuaries where its impact is unstudied. We recorded C. gigas and O. lurida densities from October 2010 through July 2017 throughout southern California on several habitat types and as a function of tidal elevation as a critical baseline for evaluating impacts of C. gigas. Ostrea lurida was present in higher proportions than C. gigas in hard substrate-dominated habitats, whether natural or human-introduced. A strong zonation pattern emerged; C. gigas achieved its maximum density above +0.4 m MLLW versus O. lurida at or below +0.2 m MLLW. These data reveal the optimal tidal elevation for placement of a restored O. lurida bed and establish a critical baseline and techniques for evaluating future changes in oyster density.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Biological Sciences
- Creator:
- Yang, Joshua
- Description:
- Background Non-communicable diseases (NCDs) account for over two-thirds of deaths worldwide, and global efforts to address NCDs have accelerated. Current prevention and control efforts rely primarily on individual behavior/lifestyle approaches that place the onus of responsibility for health on the individual. These approaches, however, have not stopped the increasing trend of NCDs worldwide. Thus, there is urgent need for exploring alternative approaches in order to attain the aim of reducing global premature NCDs mortality by 25% by 2025, and meeting the NCD reduction objective in the Sustainable Development Goals. Discussion We suggest the need for a structural approach to addressing the NCDs epidemic that integrates social science and public health theories. We evaluate two overarching principles (empowerment and human rights) and three social determinants of health (labor and employment, trade and industry, and macroeconomics) addressed in the 2013 Global Action Plan for the Prevention and Control of NCDs to demonstrate how a structural approach to NCDs can be incorporated into existing NCD interventions. For each area considered, theoretical considerations for structural thinking are provided and conclude with recommended actions. Conclusion Achieving the global health agenda goals of reducing NCDs mortality will require a shift to a paradigm that embraces concerted efforts to address both behavioral/lifestyle factors and structural dimensions of NCDs.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Public Health
- Creator:
- Lockie, Robert
- Description:
- This study investigated relationships that linear speed and lower-body power have on change-of-direction (COD) speed in collegiate women soccer players. Data from two Division I (n = 39) and one Division II (n = 18) schools were analyzed. Subjects were assessed in: power (vertical jump (VJ); jump height, peak anaerobic power measured in watts (PAPw), power-to-body mass ratio (P:BM); linear speed (10-m sprint); and COD speed (modified T-test (MTT), 505, COD deficit). Independent samples T-tests derived significant between-group differences, with effect sizes (d) calculated. Pearson’s correlations determined relationships between COD speed, linear speed, and power, with regression equations calculated. Division I players demonstrated superior 505, COD deficit, VJ height, PAPw, and P:BM (d = 1.09–2.21). Division II players were faster in the MTT (d = 1.51). For all players, the 505 correlated with the 10-m sprint (r = 0.39–0.53) and VJ height (r = −0.65–0.66), while the COD deficit related to the 10-m sprint (r = −0.77–0.82). The regression data supported these results. Division I players were superior in the 505 and COD deficit, and expressed their power in the 180° 505 task. Division II players should enhance lower-body power and the ability to perform 180° direction changes.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Kinesiology
- Creator:
- Verdugo, Anael
- Description:
- This paper presents a computational study of the stability of the steady state solutions of a biological model with negative feedback and time delay. The motivation behind the construction of our system comes from biological gene networks and the model takes the form of an integro-delay differential equation (IDDE) coupled to a partial differential equation. Linear analysis shows the existence of a critical delay where the stable steady state becomes unstable. Closed form expressions for the critical delay and associated frequency are found and confirmed by approximating the IDDE model with a system of delay differential equations (DDEs) coupled to ordinary differential equations. An example is then given that shows how the critical delay for the DDE system approaches the results for the IDDE model as becomes large.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Mathematics
- Creator:
- Verdugo, Anael
- Description:
- The repressilator is a genetic network that exhibits oscillations. The net-work is formed of three genes, each of which represses each other cyclically, creating a negative feedback loop with nonlinear interactions. In this work we present a computational bifurcation analysis of the mathematical model of the repressilator. We show that the steady state undergoes a transition from stable to unstable giving rise to a stable limit-cycle in a Hopf bifurcation. The nonlinear analysis involves a center manifold reduction on the six-dimensional system, which yields closed form expressions for the frequency and amplitude of the oscillation born at the Hopf. A parameter study then shows how the dynamics of the system are influenced for different parameter values and their associated biological significance.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Mathematics
27. Enhancing Learning Power through First-Year Experiences for Students Majoring in STEM Disciplines
- Creator:
- Koch, Robert
- Description:
- Academic programs targeted for first-time students can help their persistence in STEM majors. Our project, ASCEND STEM, included three first-year experiences (FYEs) designed to offer students the skills that would help them successfully traverse potential barriers to academic success. In the FYEs, we sought to strengthen the learning power, improve the academic achievements, and increase the postsecondary success of first-time, full-time freshmen majoring in a STEM discipline. Two models of FYE were offered in three settings—two scenarios were for engineering majors and the third for science and mathematics majors. Both models tested whether the offering of literacy skill building in the context of discipline knowledge acquisition strengthened learning power (as measured by the Effective Lifelong Learning Inventory) and asked whether this could affect academic success and persistence within the STEM major. We found that either model one, integrating literacy skill building and discipline-based concepts into a single course (the approach used in science and math), or model two, pairing a literacy skill building course with either a discipline-based course or a special group support program (the approach used in engineering), improved learning power. Increases in learning power were a valid predictor of improved grades and persistence in engineering where a highquality control group was available.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Biological Sciences
- Creator:
- Schenk, H. Jochen
- Description:
- Premise of the Study Xylem sap in angiosperms moves under negative pressure in conduits and cell wall pores that are nanometers to micrometers in diameter, so sap is always very close to surfaces. Surfaces matter for water transport because hydrophobic ones favor nucleation of bubbles, and surface chemistry can have strong effects on flow. Vessel walls contain cellulose, hemicellulose, lignin, pectins, proteins, and possibly lipids, but what is the nature of the inner, lumen‐facing surface that is in contact with sap? Methods Vessel lumen surfaces of five angiosperms from different lineages were examined via transmission electron microscopy and confocal and fluorescence microscopy, using fluorophores and autofluorescence to detect cell wall components. Elemental composition was studied by energy‐dispersive X‐ray spectroscopy, and treatments with phospholipase C (PLC) were used to test for phospholipids. Key Results Vessel surfaces consisted mainly of lignin, with strong cellulose signals confined to pit membranes. Proteins were found mainly in inter‐vessel pits and pectins only on outer rims of pit membranes and in vessel‐parenchyma pits. Continuous layers of lipids were detected on most vessel surfaces and on most pit membranes and were shown by PLC treatment to consist at least partly of phospholipids. Conclusions Vessel surfaces appear to be wettable because lignin is not strongly hydrophobic and a coating with amphiphilic lipids would render any surface hydrophilic. New questions arise about these lipids and their possible origins from living xylem cells, especially about their effects on surface tension, surface bubble nucleation, and pit membrane function.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Biological Sciences
- Creator:
- Stapp, Paul
- Description:
- In late 2009, the Catalina Island Conservancy began using fertility control to replace periodic removals to manage an introduced population of American bison (Bison bison) on the island. Through the application of the immunocontraceptive vaccine porcine zona pellucida (PZP), population growth was slowed within 1 year, and halted over time. In response to lingering questions about the use of PZP to manage large, free-ranging wildlife populations, we sought to determine the reversibility of PZP by ceasing the annual application to a subset of 15 bison cows and monitoring for subsequent calf arrival, and to document changes in the timing and length of the breeding season in response to PZP by monitoring breeding behavior and assessing fecal progesterone (FP) levels for all 60 resident cows over a 13-month period. As of June 2017, no new calves had been observed on the island, suggesting that, following repeated annual treatment with PZP (3 or 4 years), bison do not resume normal reproduction for at least 4 or 5 years, and that fewer treatments would be advisable if a faster return to fertility is desired. Based on observations of bull and cow behavior, and FP levels, cows displayed estrous cycles consistently throughout the study period, indicating that bison may ovulate year-round when conception and its consequences, e.g., lactation and presence of calves, are blocked. Because there is little evidence that an extended breeding season would negatively impact the health of bulls or result in large numbers of out-of-season births on Catalina, PZP appears to be a highly effective tool for managing the population of introduced bison on the island. However, the extended period of contraception and breeding activity of both cows and bulls may make PZP less suitable in high-latitude, predator-rich environments where bison conservation remains a top priority.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Biological Sciences
- Creator:
- Rathbun, Matt
- Description:
- A twisted torus knot is a knot obtained from a torus knot by twisting adjacent strands by full twists. The twisted torus knots lie in F, the genus 2 Heegaard surface for S3. Primitive/primitive and primitive/Seifert knots lie in F in a particular way. Dean gives sufficient conditions for the parameters of the twisted torus knots to ensure they are primitive/primitive or primitive/Seifert. Using Dean’s conditions, Doleshal shows that there are infinitely many twisted torus knots that are fibered and that there are twisted torus knots with distinct primitive/Seifert representatives with the same slope in F. In this paper, we extend Doleshal’s results to show there is a four parameter family of positive twisted torus knots. Additionally, we provide new examples of twisted torus knots with distinct representatives with the same surface slope in F.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Mathematics
- Creator:
- Jacobs, Wura
- Description:
- Aim: A binary measurement of type 2 diabetes (T2D) has been found not to influence behaviors. We aimed to examine the influence of other measures of family history such as number of relatives, genetic closeness of relatives, and severity of T2D of family members on nutrition and physical activity behaviors among college students. Methods: Students across four colleges in Texas were sampled. Multiple linear regression models, controlling for covariates, were used to model results. Cross-sectional data were used. Results: More number of relatives with T2D was associated with vegetable consumption (β = 0.131, p = 0.007) and exercise (β = 0.129, p = 0.037). Having relatives with severe T2D was associated with vegetable consumption (β = 0.157, p = 0.002) and exercise (β = 106, p = 0.027). Closer genetic relationship with someone with T2D was associated with increased vegetable consumption (β = 0.107, p = 0.023) and exercise (β = 0.096, p = 0.047). Conclusion: It is likely that the severe complications that may accompany the relatives T2D or having an immediate family member living with T2D may in fact motivate other family members without T2D to modify their attitudes, beliefs, and knowledge about T2D, thus encourage health-protective behaviors.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Public Health
- Creator:
- Lockie, Robert
- Description:
- The close-grip bench press (CGBP) is a variation of the traditional bench press (TBP) that uses a narrower grip (~95% of biacromial distance (BAD)) and has potential application for athletes performing explosive arm actions from positions where the hands are held close to the torso. Limited research has investigated CGBP mechanics compared to the TBP. Twenty-seven resistance-trained individuals completed a one-repetition maximum TBP and CGBP. The TBP was performed with the preferred grip; the CGBP with a grip width of 95% BAD. A linear position transducer measured lift distance and duration; peak and mean power, velocity, and force; distance and time when peak power occurred; and work. Pre-sticking region (PrSR), sticking region, and post-sticking region distance and duration for each lift was measured. A repeated measures ANOVA was used to derive differences between TBP and CGBP mechanics (p < 0.01); effect sizes (d) were also calculated. A greater load was lifted in the TBP, thus mean force was greater (d = 0.16–0.17). Peak power and velocity were higher in the CGBP, which had a longer PrSR distance (d = 0.49–1.32). The CGBP could emphasize power for athletes that initiate explosive upper-body actions with the hands positioned close to the torso.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Kinesiology
- Creator:
- Yang, Joshua
- Description:
- Background:E-cigarette use has been increasing in the United States, though knowledge of potential risks and harms associated with e-cigarette use is low. Marketing of e-cigarettes may serve as a source of information to shape beliefs and attitudes toward e-cigarettes. The purpose of this study was to identify the most common marketing claims made within “vape” and tobacco shops in sales interactions with customers in demographically diverse cities. Methods:Vape and tobacco shops from three diverse cities in Southern California were selected for inclusion in the study. From May 2015 to July 2015, simulated customers asked salespeople in vape and tobacco shops how e-cigarettes compare to conventional cigarettes, and then recorded the resulting claims that were made using a standardized form designed for this purpose. Data were analyzed from January to March 2016. Results:The most frequent claims made by sales staff were that: smoking e-cigarettes helps one quit smoking (57% of the simulated shopping interactions), e-cigarettes come in multiple flavors (54%), and e-cigarettes are healthier than conventional cigarettes (50%). Simulated customer interactions that took place in vape shops included more positive marketing claims than those that occurred in tobacco shops; this relationship approached statistical significance (p = .087). There was a significant relationship between city and the average number of positive e-cigarette claims made (p < .001). Conclusions:A wide range of marketing claims are made about e-cigarettes in retail settings. These may vary by geographic location, community demographics, and type of retail outlet.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Public Health
- Creator:
- Yen, Shu-Chen
- Description:
- High-impact educational practices can promote student involvement and learning outcomes, but are rarely tested in the community college setting—where involvement is a typical challenge to student success. For Family Child Care (FCC) providers, who tend to be older and overworked, higher-education training can be especially difficult. The present study examined the use of learning communities as a high-impact practice in Project Vista Higher Education Academy (PVHEA), a two-year professional development intervention program for Cantonese/Mandarin FCC providers at the East Los Angeles College in California. Quantitative and qualitative data during the inaugural term (January 2012-December 2013) indicated that PVHEA successfully helped FCC providers access and complete college coursework towards Child Development degrees and credentials. Course completion rate reached 100%, and the providers gradually increased course load while maintaining above-average grades. Positive changes were also observed in self-efficacy, aspirations, and professional image. The associated program challenges were discussed.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Child and Adolescent Studies
- Creator:
- Delyser, Dydia
- Description:
- Amid growing attention by geographers to materiality, emotion, and work, we draw together practices of making and communities of enthusiasm to autoethnographically trace the restoration of three Indian motorcycles, revealing restoration as a dynamic aesthetic and political practice that links restorers to communities of enthusiasm as well as to the agentic materiality of the things they restore. Restoration, we show, is a culturally and geographically situated skilled practice that links material agency to labors of love and devotion. Such devotion to things, in turn, suggests a provocative counternarrative to the unsustainable throwaway society of the Anthropocene. Emotional labor, material devotion, and handcraft skill could, we suggest, proffer positive pathways as we endeavor to make, restore, and, indeed, sustain our material world.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Geography and the Environment
- Creator:
- Costa, Pablo
- Description:
- International Journal of Exercise Science 10(3): 354-364, 2017. The aim of this study was to investigate the effects of six months of training with three different number of sets of resistance training on flexibility in young men. Forty-seven men (mean ± SD age = 24 ± 1yrs; body mass = 79.39 ± 9.12 kg; height = 174.5 ± 5.6 cm) were randomly divided into three training groups performing either one set (G1S), three sets (G3S), or five sets (G5S) of all exercises in a resistance training session or a control group (CG). All groups were assessed pre- and post-training for Sit-and-Reach test and range of motion of 10 joints using goniometry. The training protocol included three weekly sessions and was composed of nine exercises performed at a moderate intensity (eight to 12RM). The results demonstrated significant differences pre- to post-training for the Sit-and-Reach test for all training groups; however, only the G5S showed significant differences when compared to the CG (31.04 ± 5.94cm vs. 23.56 ± 6.76cm, respectively; p < 0.05). Of the ten joint movements measured, there were range of motion increases only to shoulder flexion (G1S), shoulder extension (G3S), elbow flexion (G3S), and knee flexion (G3S) when comparing pre- to post-training (p < 0.05). In conclusion, different resistance training volumes improved flexibility for some joints of young men. These findings indicate that performing only resistance training can result in increases in flexibility.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Kinesiology
- Creator:
- Jacobs, Wura
- Description:
- We live in a digital age and this has changed the landscape of health information. With the changing US demographic, otherwise acute diseases morphing into chronic diseases as a result of treatment advancements, and evolving health needs of the population, there is need for increase in available and accessible health information. It is estimated that one in three US adults use the internet to diagnose or learn about a health concern. Nevertheless, a nagging question is whether the Web is reducing or creating disparities in health information availability and use for making health decisions. This study examined factors associated with heath information seeking from the internet, traditional media, and health care professionals among a diverse population of US adults. Data for the analysis was from four cycles (2011–2014) of the Health Information National Trends Survey (HINTS), a national survey of US adults. Controlling for age, race/ethnicity, gender, and socioeconomic status (SES), regression analyses were conducted. STATA 13 was used for analyses. Findings indicated that there is a possibility that while the Web is an easily available source of health information, it could also create inequalities in health information accessibility. The Web should not be considered a substitute for using alternative health information sources. Doing so, might create disproportionate access to health information essential for health decisions.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Public Health
- Creator:
- Kirby, Matthew
- Description:
- Paleoenvironmental records from a southern California coastal saltmarsh reveal evidence for repeated late Holocene coseismic subsidence events. Field analysis of sediment gouge cores established discrete lithostratigraphic units extend across the wetland. Detailed sediment analyses reveal abrupt changes in lithology, percent total organic matter, grain size, and magnetic susceptibility. Microfossil analyses indicate that predominantly freshwater deposits bury relic intertidal deposits at three distinct depths. Radiocarbon dating indicates that the three burial events occurred in the last 2000 calendar years. Two of the three events are contemporaneous with large-magnitude paleoearthquakes along the Newport-Inglewood/Rose Canyon fault system. From these data, we infer that during large magnitude earthquakes a step-over along the fault zone results in the vertical displacement of an approximately 5-km2 area that is consistent with the footprint of an estuary identified in pre-development maps. These findings provide insight on the evolution of the saltmarsh, coseismic deformation and earthquake recurrence in a wide area of southern California, and sensitive habitat already threatened by eustatic sea level rise.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Geological Sciences
- Creator:
- Bursztyn, Natalie
- Description:
- In searching for ways to improve undergraduate success in introductory geoscience courses, the importance of experiential learning in engaging students has become clear—and in geoscience, that is encapsulated best by field trips. However, as general education class sizes increase, so do the cost, liability, and difficulty of running a field trip. A solution for economically and conveniently bringing kinesthetic field experiences to a broader audience lies in the integration of technology through mobile-device games, apps, and augmented reality (AR) field trips. We report here an examination of learning gains at five colleges after intervention with augmented reality field trips to Grand Canyon. The AR field trips cover three topics taught in introductory geoscience courses: geologic time, geologic structures, and hydrologic processes.Results involving nearly 1000 students show that overall gains are similar to control groups, with completion of the AR field trips being a predictor of student learning success in some cases. Prior interest in the geosciences, students’ base-level understanding of the material, and whether or not the student is a science, technology, engineering, and mathematics (STEM) major are strong predictors of improvement in geoscience learning. Gender and ethnicity had no statistical impact on the results, suggesting the AR field trip modules have broad reach across student demographics. Because these modules have been shown elsewhere to increase student interest in learning the geosciences, we advocate their adoption, leading to increases in student learning.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Geological Sciences
- Creator:
- Hofmann, Jim
- Description:
- Molecular clocks based upon amino acid sequences in proteins have played a major role in the clarification of evolutionary phylogenies. Creationist criticisms of these methods sometimes rely upon data that might initially seem to be paradoxical. For example, human cytochrome c differs from that of an alligator by 13 amino acids but differs by 14 amino acids from a much more closely related primate, Otolemur garnettii. The apparent anomaly is resolved by taking into consideration the variable substitution rate of cytochrome c, particularly among primates. This paper traces some of the history of extensive research into the topic of rate heterogeneity in cytochrome c including data from cytochrome c pseudogenes.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Liberal Studies
- Creator:
- Pichler, Shaun
- Description:
- Management and organization research has traditionally focused on employees’ work role and the interface between their work and family roles. We suggest that persons assume a third role in modern society that is relevant to work and organizations, namely the Information and Communication Technology User (ICTU) role. Based on role theory and boundary theory, we develop propositions about the characteristics of this role, as well as how ICTU role characteristics are related to boundary spanning activity, inter-role spillover with the work role, and work role performance. To this end, we first conceptualize the ICTU role and its associations with work and family roles. We then apply identity theory and boundary management theory to advance our understanding of how the ICTU role is related to criteria that are important to individuals and to organizations, namely self-selection into certain types of work roles and positive and negative inter-role spillover. The implications of this role for theory, research, and practice in management and organizations are discussed.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Management
- Creator:
- Schenk, H. Jochen
- Description:
- Vascular plants transport water under negative pressure without constantly creating gas bubbles that would disable their hydraulic systems. Attempts to replicate this feat in artificial systems almost invariably result in bubble formation, except under highly controlled conditions with pure water and only hydrophilic surfaces present. In theory, conditions in the xylem should favor bubble nucleation even more: there are millions of conduits with at least some hydrophobic surfaces, and xylem sap is saturated or sometimes supersaturated with atmospheric gas and may contain surface-active molecules that can lower surface tension. So how do plants transport water under negative pressure? Here, we show that angiosperm xylem contains abundant hydrophobic surfaces as well as insoluble lipid surfactants, including phospholipids, and proteins, a composition similar to pulmonary surfactants. Lipid surfactants were found in xylem sap and as nanoparticles under transmission electron microscopy in pores of intervessel pit membranes and deposited on vessel wall surfaces. Nanoparticles observed in xylem sap via nanoparticle-tracking analysis included surfactant-coated nanobubbles when examined by freeze-fracture electron microscopy. Based on their fracture behavior, this technique is able to distinguish between dense-core particles, liquid-filled, bilayer-coated vesicles/liposomes, and gas-filled bubbles. Xylem surfactants showed strong surface activity that reduces surface tension to low values when concentrated as they are in pit membrane pores. We hypothesize that xylem surfactants support water transport under negative pressure as explained by the cohesion-tension theory by coating hydrophobic surfaces and nanobubbles, thereby keeping the latter below the critical size at which bubbles would expand to form embolisms.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Biological Sciences
- Creator:
- Soper, Daniel
- Description:
- Service level agreement (SLA) negotiations involving cloud-based information technology (IT) service providers and customers are now commonplace. Although historical research on negotiation has often relied on economic foundations, the important nature of IT service levels to organizations' operational effectiveness suggests that negotiation complexities in the context of cloud-based outsourcing (or cloudsourcing) cannot be well understood by relying on economic perspectives alone. To that end, this paper reports on experiments designed to determine the relevance of competing sociotheoretic frameworks as they pertain to IT cloudsourcing negotiations. Contributions include a rigorous examination of hypotheses derived from social exchange theory, equity theory, learning theory, and the win-win theories of negotiation. Additional contributions include the development of methodological constructs (using the Euclidean geometry) that reflect the complex nature of IT cloudsourcing SLAs, i.e., that they are composed of numerous service category contract clauses where negotiation tradeoffs within a service category as well as across service categories are possible. We find strong support for the relevance of the social exchange theory to IT cloudsourcing negotiations, as well as moderate support for the win-win theories of negotiation. Our conclusions provide clear directions for extending our work into the realm of negotiation support systems, and we rely on our findings to conjecture that IT cloudsourcing negotiation is a unique context for sociotheoretic negotiation research due to the inherent importance of information technologies to organizations' operational effectiveness.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Information Systems & Decision Sciences
- Creator:
- Mitra, Sinjini
- Description:
- This paper develops an integrated theoretical framework that links visuo-spatial mental models of Web interface design to user satisfaction, and reports on a controlled experiment aimed at investigating the nature of these mental models. Using data from more than 500 subjects in conjunction with both graphical and statistical analyses, we find that Web users possess a strongly cohesive shared mental model of the way in which a Web interface should be designed. In addition to describing and quantifying this shared visuospatial mental model, this paper also shows how both experience and the physiological properties of the human visual system give rise to such models, and discusses the implications of the results for organizational website design, scientific theory, and future research in this area.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Information Systems & Decision Sciences
- Creator:
- Segal, Nancy
- Description:
- Aim: Epigenetic comparisons within monozygotic twin pairs have enhanced our understanding of nongenetic mechanisms underlying disease etiology. We present epigenetic findings for a unique case of doubly exchanged Colombian male monozygotic twins raised in extremely different environments. Results: Using genome-wide DNA methylation data from cheek swabs from which blood-specific differentially methylated probes had been removed, the individuals grouped by shared genetics rather than shared environment, except for one twin who presented as an outlier. Closer inspection of DNA methylation differences within both reared-apart twin pairs revealed several genes and genetic pathways likely to be influenced by the rearing environment. Conclusion: Together with our previous findings, we suggest that genetics, pre- and postnatal environments contribute to the epigenetic profile, although additional studies are needed to quantify these effects.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Psychology
- Creator:
- Lukaszewski, Aaron
- Description:
- Human life history (LH) strategies are theoretically regulated by developmental exposure to environmental cues that ancestrally predicted LH-relevant world states (e.g., risk of morbidity–mortality). Recent modeling work has raised the question of whether the association of childhood family factors with adult LH variation arises via (i) direct sampling of external environmental cues during development and/or (ii) calibration of LH strategies to internal somatic condition (i.e., health), which itself reflects exposure to variably favorable environments. The present research tested between these possibilities through three online surveys involving a total of over 26,000 participants. Participants completed questionnaires assessing components of self-reported environmental harshness (i.e., socioeconomic status, family neglect, and neighborhood crime), health status, and various LH-related psychological and behavioral phenotypes (e.g., mating strategies, paranoia, and anxiety), modeled as a unidimensional latent variable. Structural equation models suggested that exposure to harsh ecologies had direct effects on latent LH strategy as well as indirect effects on latent LH strategy mediated via health status. These findings suggest that human LH strategies may be calibrated to both external and internal cues and that such calibrational effects manifest in a wide range of psychological and behavioral phenotypes.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Psychology
- Creator:
- Dover, Alison G.
- Description:
- Emphases on high-stakes testing and accountability can undermine teachers' ability to use their professional expertise to respond to the localized needs of their students. For justice-oriented teachers, they also create ideological conflicts, as teachers are forced to navigate increasingly prescriptive curricular mandates. In this article, we examine how justice-oriented veteran social studies teachers in the United States use their disciplinary expertise and professional agency to respond strategically to the influence of the Common Core State Standards on their discipline. We conclude by discussing the implications for preparing candidates to teach for social justice in accountability-driven contexts.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Secondary Education
- Creator:
- Loyd, Sean
- Description:
- Methane cold seep systems typically exhibit extensive buildups of authigenic carbonate minerals, resulting from local increases in alkalinity driven by methane oxidation. Here, we demonstrate that modern seep authigenic carbonates exhibit anomalously low clumped isotope values (Δ47), as much as ∼0.2‰ lower than expected values. In modern seeps, this range of disequilibrium translates into apparent temperatures that are always warmer than ambient temperatures, by up to 50 °C. We examine various mechanisms that may induce disequilibrium behaviour in modern seep carbonates, and suggest that the observed values result from several factors including kinetic isotopic effects during methane oxidation, mixing of inorganic carbon pools, pH effects and rapid precipitation. Ancient seep carbonates studied here also exhibit potential disequilibrium signals. Ultimately, these findings indicate the predominance of disequilibrium clumped isotope behaviour in modern cold seep carbonates that must be considered when characterizing environmental conditions in both modern and ancient cold seep settings.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Geological Sciences
- Creator:
- Distefano, Anthony
- Description:
- Japan is widely perceived to have a low level of HIV occurrence; however, its HIV epidemics also have been the subject of considerable misunderstanding globally. I used a ground truthing conceptual framework to meet two aims: first, to determine how accurately official surveillance data represented Japan's two largest epidemics (urban Kansai and Tokyo) as understood and experienced on the ground; and second, to identify explanations for why the HIV epidemics were unfolding as officially reported. I used primarily ethnographic methods while drawing upon epidemiology, and compared government surveillance data to observations at community and institutional sites (459 pages of field notes; 175 persons observed), qualitative interviews with stakeholders in local HIV epidemics (n = 32), and document research (n = 116). This revealed seven epidemiologic puzzles involving officially reported trends and conspicuously missing information. Ethnographically grounded explanations are presented for each. These included factors driving the epidemics, which ranged from waning government and public attention to HIV, to gaps in sex education and disruptive leadership changes in public institutions approximately every two years. Factors constraining the epidemics also contributed to explanations. These ranged from subsidized medical treatment for most people living with HIV, to strong partnerships between government and a well-developed, non-governmental sector of HIV interventionists, and protective norms and built environments in the sex industry. Local and regional HIV epidemics were experienced and understood as worse than government reports indicated, and ground-level data often contradicted official knowledge. Results thus call into question epidemiologic trends, including recent stabilization of the national epidemic, and suggest the need for revisions to the surveillance system and strategies that address factors driving and constraining the epidemics. Based upon its utility in the current study, ground truthing has value as a conceptual framework for research and shows promise for future theoretical development.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Public Health
- Creator:
- Rathbun, Matt
- Description:
- We characterize cutting arcs on fiber surfaces that produce new fiber surfaces, and the changes in monodromy resulting from such cuts. As a corollary, we characterize band surgeries between fibered links and introduce an operation called generalized Hopf banding. We further characterize generalized crossing changes between fibered links, and the resulting changes in monodromy.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Mathematics