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- Creator:
- Sun, Yifei
- Description:
- Based on a four-point evaluation system consisting of accuracy, consistency, power, and chance to commit type I errors, this study compares Tango's minimum p (MinP) and Stone's maximum relative risk (MaxRR) methods for detecting focused cluster size through simulations in GIS. It reveals that the MinP method is more effective than the MaxRR method. The MinP method exhibits higher levels of accuracy and consistency; and its power and chance to commit type I errors are similar to the MinP method. The MaxRR method has a tendency to underestimate the cluster size, while the MinP method tends to overestimate the cluster size, particularly when the clusters are relatively big and have high relative risk levels. In addition, the MinP method seems to be most effective in revealing the size of clusters when clusters are neither too strong nor too weak. The lowest detection rates for clustering occur when the clustering signal is relatively weak, which is easily understandable. In practice, it might be useful to use both the methods to estimate a range of possible cluster sizes, where the MaxRR method indicates the lower estimate, while the MinP method gives the higher estimate of the cluster size.
- Resource Type:
- Article
- Identifier:
- 1029-4597, 1069-2665, 1026-7050
- Campus Tesim:
- Northridge

- Creator:
- Chong, James and Phillips, G. Michael
- Description:
- In this study, we present an extension to the literature on passive hedge fund replication and its applications by introducing the Eta model, and applying it to hedged mutual funds (HMFs) in an attempt to clone their cumulative returns and assessing the skills of fund managers. Although our replication methodology performed reasonably well for HMFs of certain trading strategies, the clones tend to outperform their respective HMFs, which suggest significant managerial influence that compromises fund performance. Finally, with the aid of the Eta model, we constructed a minimum economic risk portfolio, a long-only portfolio comprising exchange traded funds, with quarterly rebalancing, which nevertheless registered higher cumulative returns than funds with access to long/short strategies, leverage and derivatives. This augurs well for a typical household in that it is possible for them to earn hedge fund returns without hedge fund experience or expertise.
- Resource Type:
- Article
- Identifier:
- 1753-9641, 1753-965X
- Campus Tesim:
- Northridge

- Creator:
- DeShields, Oscar and Kara, Ali
- Description:
- This study examines the communication effectiveness of a spokesperson with an American-Spanish Accent (ASA) and a Mexican-Spanish Accent (MSA) in two different locations of Mexico. These cities were selected based on their high or low exposure of the US culture (that is, high exposure is assumed if the city was close to the US border and/or coastal city). We used Tajfel's Theory to hypothesize the relationship between spokesperson's accent and consumers' purchase intentions in that location. The theory posits that the most influential spokesperson will be the person who speaks with the standard accent for a given region but what is considered standard accent changes based on cultural influences of different groups. To test the hypothesized relationships, we used a sample of 1058 student subjects who observed an advertisement with different accented spokespersons. Consistent with the theory, the results of this study indicate that consumers that are less exposed to the US culture (inland Mexico cities) had more favorable views about the spokesperson that had an MSA than a spokesperson with an ASA. Moreover, consumers in the cities close to the US border and coastal areas had equally favorable views for both accents. The implications for the marketers are discussed.
- Resource Type:
- Article
- Identifier:
- 1479-1862, 0967-3237
- Campus Tesim:
- Northridge
- 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:
- 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:
- 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:
- Hoese, William
- Description:
- Background: Evolutionary trees illustrate relationships among taxa. Interpreting these relationships requires developing a set of “tree-thinking” skills that are typically included in introductory college biology courses. One of these skills is determining relationships among taxa using the most recent common ancestor, yet many students instead use one or more alternate strategies to determine relationships. Several alternate strategies have been well documented and these include using superficial similarity, proximity at the tips of a tree, or the fewest intervening nodes in the tree to group taxa. Results: We administered interviews (n = 16) and pencil-and-paper questionnaires (n = 205), and constructed a valid and reliable assessment that measured how well students determined relationships among taxa on an evolutionary tree. Our questions asked students to consider a focal taxon and identify which of two additional taxa is most closely related to it. We paired the use of most recent common ancestor with one of three alternative strategies (i.e., similarity, proximity, or node-counting) to explicitly test students’ understanding of the relationships among the taxa on each tree. Conclusions: Our assessment enables us to identify students who are effectively distracted by an alternative strategy, those who use the most recent common ancestor inconsistently, or who are guessing in order to determine relationships among taxa. Our 18-question tool (see Additional file 1) can be used for formative assessment of student understanding of how to interpret relationships on evolutionary trees. Because our assessment tests for the same skill throughout, students who answer incorrectly, even once, likely have an incomplete understanding of how to determine relationships on evolutionary trees and should receive follow-up instruction.
- Resource Type:
- Article
- Campus Tesim:
- Fullerton
- Department:
- Department of Biological Sciences
- Creator:
- Hernández-Baz, Fernando, González, Jorge, Coates, R., and Teston, J.A.
- Description:
- A revision of the bibliography, as well as an analysis on the data from the specimen labels of Scena propylea (Druce) (Erebidae: Arctiinae: Euchromiina) deposited in different scientific collections, was carried out and included information from 1894 to 2010. Its geographical distribution is restricted to the Trans-Mexican Volcanic Belt which determines this species as endemic. Data are provided on the biogeography, ecology and biology for this species. Its food plant is Thenardia floribunda (Apocynaceae) which is also endemic to Mexico. From this analysis, we propose the inclusion of both species in the document known as the Norma Oficial Mexicana 059 which encompasses the environmental protection of wild flora and fauna species native to Mexico and their risk categories, as well as the specifications for their inclusion, exclusion or change and a list of all species at risk.
- Resource Type:
- Article
- Identifier:
- Publisher version: http://dx.doi.org/10.1007/s13744-013-0119-3
- Campus Tesim:
- Fresno
- Creator:
- Bieszczad, Andrzej and Bieszczad, Kasia
- Description:
- In this paper, we introduce an enhancement to the Neurosolver, a neuromorphic planner and a problem solving system. The enhanced architecture enables contextual learning. The Neurosolver was designed and tested on severalproblem solving and planning tasks such as re-arranging blocks and controlling a software-simulated artificial rat running in a maze. In these tasks, the Neurosolver learned temporal patterns independent of the context. However in the real world no skill is acquired in vacuum; Contextual cues are a part of every situation, and the brain can incorporate such stimuli as evidenced through experiments with live rats. Rats use cues from the environment to navigate inside mazes. The enhanced architecture of the Neurosolver accommodates similar learning.
- Resource Type:
- Postprint
- Identifier:
- 0302-9743
- Campus Tesim:
- Channel Islands