Search
Search Results
-
The average size and age of chinook salmon (Oncorhynchus tshawytscha) caught in commercial fisheries along the Pacific Coast of North America have decreased substantially in this century. These declines ...
Citation Citation
- Title:
- Changes in size and age at maturity of Columbia River upriver bright fall chinook salmon (Oncorhynchus tshawytscha) : implications for stock fitness, commercial value, and management
- Author:
- Beaty, Roy E.
The average size and age of chinook salmon (Oncorhynchus tshawytscha) caught in commercial fisheries along the Pacific Coast of North America have decreased substantially in this century. These declines might be caused in part by changes in size and age at maturity within the stocks contributing to those fisheries. Upriver Brights (Brights), a stock of fall chinook salmon in the Columbia River, are one of those stocks. The purposes of this study were to (1) determine if average size and age at maturity of Brights have declined, (2) gain a better understanding of the factors that may contribute to such declines, and (3) describe potential consequences of these changes. Data from in-river fisheries suggest that the average weight of mature Brights returning to the Columbia River has decreased approximately 2.7 kg since the 1910s, an average rate of about 0.1 lb·yr⁻¹ (45 g·yr⁻¹ ). Most of the potential biases in these data tend to make this estimate conservative. Insufficient data were available to describe changes in average age at maturity. There are many potential causes for the decline in average size of mature Brights, including factors that affect very early life stages. Other researchers have determined that size at maturity appears to be highly influenced by inheritance, gender, and growth rate. I describe how maternal size can influence -- through time of spawning, choice of spawning site, and egg size -- the viability of the young, which carry the dam's genes for size. The size-related ability to produce viable offspring may have been changed by modifications in the environment. Very little is known about how changes in the natural environment for spawning, incubation, and rearing may have contributed to a decline in average size at maturity. Artificial propagation and rearing, such as at Priest Rapids Hatchery, seems to produce adult Brights that are smaller, younger, and more likely to be male than their natural counterparts. The net result is that the average hatchery fish may have only about 0.80 of the reproductive potential of the average natural fish. Changes in growth conditions in the ocean probably did not contribute to the change in size, although the ocean fisheries of Southeast Alaska and British Columbia appear to select, in the genetic sense, against large size and old age in Brights. Since 1978, in-river commercial fisheries have caught larger Brights and a higher proportion of females than are found in the escapement of the Priest Rapids Hatchery component of the stock, but the fisheries impact the two sexes differently by taking the larger males and the smaller females. The effect on the natural component may differ because of their apparently larger average size. I found no evidence that larger fish or more females were caught when 8-in. minimum restrictions were in effect on gillnet mesh size relative to periods when mesh size was not restricted. Impounding the mainstem during the last 50+ yr may have removed obstacles to migration (e.g., Celilo Falls) that selected for large size in Brights, but that hypothesis could not be tested. The perserverance of larger and older phenotypes in the Bright stock suggests that countervailing selection -- perhaps during spawning, incubation, and/or early rearing -- may have resisted the effects of a century of size- and age-selective fisheries. That resistance, however, may reduce the productivity of the stock. Declines in average size and age at maturity can have undesireable consequences. Lower average size means less biomass landed and lower commercial value. Lower average fecundity and a diminished ability to reproduce in some environments are also expected. Loss of size and age classes may reduce the ability of the stock to adapt to environmental variations. These results are relevant to several management practices. A holistic approach to fishery management issues is necessary to avoid erroneous conclusions based on narrow perspectives. Measuring reproductive potential of the catch and escapement would be superior to the conventional practice of simply counting numbers of fish. Many aspects of artificial propagation can be improved, including broodstock aquisition, mating regimes, and rearing practices. Stock abundance is a major factor in determining the effect of many management practices on the stock. In general, fisheries managers must be mindful that they manage very complex natural systems.
-
1272. [Article] Inflammation, immune suppression, and iron status in endurance athletes and the effects of antioxidant supplementation
During extreme exercise, athletes experience increased inflammation that is similar to the acute phase response. Endurance athletes, distance runners in particular, are also more susceptible to compromised ...Citation Citation
- Title:
- Inflammation, immune suppression, and iron status in endurance athletes and the effects of antioxidant supplementation
- Author:
- Hopkins, Dawn Marie Weseli
During extreme exercise, athletes experience increased inflammation that is similar to the acute phase response. Endurance athletes, distance runners in particular, are also more susceptible to compromised iron stores. This study evaluated inflammation, immune function and iron status in athletes completing a 50K ultramarathon. Twenty-two well-trained distance runners, 11 males and 11 females, were randomized in a double blind manner into--1) those who consumed 300 mg vitamin E and 1000 mg vitamin C (500 mg twice daily) or 2) placebos--for six weeks before and one week following a 50K ultramarathon race. Blood samples were obtained on 13 separate occasions throughout the study: before supplementation, during supplementation, the day before the race, pre-race, mid-race, immediately post-race, 2 hours following the race, and daily for six days following the race. Plasma levels of ascorbic acid and α-tocopherol were measured by HPLC with electrochemical detection. Inflammatory cytokines, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) were measured using standard clinical assays. Each subject recorded immune function in an activity log and incidence of illness was tabulated as number of days ill. Ferritin was measured by enzyme immunoassay. Hemoglobin, hematocrit, and total-iron binding capacity (TIBC) and serum total iron were analyzed by standard procedures. Plasma concentrations of ascorbic acid and α-tocopherol increased significantly in supplemented subjects (p<0.0001). Although the ultramarathon race elicited an inflammatory response, antioxidant supplementation did not alter the responses of IL-6 and TNF-α, which both increased from pre-race to mid-race, post- and post-2 h (Scheffe post-hoc analysis, p<0.0001) and returned to pre-race concentrations by 1 day after the race. Male supplemented subjects had lower IL-1β concentrations compared to females consuming the supplement or to males consuming the placebo (ANCOVA, gender/time/treatment interaction; p<0.01) at mid-race (p<0.05 females, p<0.005 males), post 1 and 2 days (all p<0.002). Males had significantly higher ferritin levels than the female subjects (ANOVA, p<0.0001); supplementation resulted in lower ferritin concentrations at post-5 days (p<0.02, ANCOVA treatment time interaction, p<0.005). Supplementation did not reduce the days illness among those consuming antioxidants compared to those consuming the placebos. Ferritin not only increases during inflammation, it also is a measure of iron stores. Females had significantly lower levels of iron than the male subjects for each of the iron parameters measured (hemoglobin and hematocrit both p<0.0001, ferritin p<0.001, TIBC p<0.02) excluding serum total iron. The ferritin concentrations measured in the women were indicative of depleted iron stores (<12 μg/l), and antioxidant supplementation increased hematocrit levels in the female subjects (p<0.05). This investigation indicates that female distance runners need to be aware of an increased susceptibility to iron depletion compared to their male counterparts. Antioxidant supplementation improved hematocrit levels (p<0.05) among female runners and may improve iron status among females with depleted stores. Although other investigations have suggested that antioxidant vitamins decrease exercise induced inflammation, no profound benefit of supplementation was found in this investigation though a response similar to the acute phase response was elicited by the ultramarathon race. Improvements in IL-i and ferritin in response to antioxidant supplementation may indicate that the supplementation was beneficial, but more research is needed to draw definitive conclusions.
-
Prostate cancer is the second leading cause of cancer related death in American men. Epidemiologic studies suggest that cruciferous vegetable intake may lower the risk for many cancers, including prostate ...
Citation Citation
- Title:
- Prostate cancer prevention with broccoli : from cellular to human studies
- Author:
- Clarke, John D.
Prostate cancer is the second leading cause of cancer related death in American men. Epidemiologic studies suggest that cruciferous vegetable intake may lower the risk for many cancers, including prostate and colon. Isothiocyanates (ITC) are phytochemicals derived from cruciferous vegetables such as broccoli, Brussels sprouts, cauliflower, and cabbage that may have health promoting properties. Broccoli and broccoli sprouts are a good source of sulforaphane (SFN), a well studied chemopreventive ITC. SFN is known to inhibit histone deacetylase (HDAC) activity and alter epigenetic endpoints. A key factor in understanding the efficacy of SFN as a chemoprevention agent is to determine the metabolism, distribution and bioavailability of SFN, and the factors that alter these parameters. The present study was undertaken to provide further evidence that SFN can alter HDAC activity, alter prostate cancer cell proliferation, both in vitro and in vivo and expands our understanding of SFN metabolism and tissue distribution. We characterized the effects of SFN in normal (PrEC), benign hyperplasia (BPH1) and cancerous (LnCap and PC3) prostate epithelial cells. We observed that 15 µM SFN differentially induced cell cycle arrest and apoptosis in BPH1, LnCap and PC3 cells but not PrEC cells. SFN treatment also differentially decreased HDAC activity, and Class I and II HDAC proteins, increased acetylated histone H3 at the promoter for P21, induced p21 expression and increased tubulin acetylation in prostate cancer cells. In PrEC cells, SFN caused only a transient reduction in HDAC activity with no change in any other endpoints tested. Therefore, normal prostate cells were refractory to the cytotoxic and epigenetic effects of SFN. In order for SFN to be an effective chemopreventive agent it must be metabolized and reach target tissues. Nrf2 wild-type and Nrf2 knockout (Nrf2-/-) mice were treated with 5 or 20 µmoles of SFN, and SFN metabolites were detected in all tissues tested at 2 and 6 h in a dose dependent manner. Genotype only had marginal effects at 5 µmoles, whereas, at 20 µmoles the female Nrf2-/- mice had dramatically higher levels. The relative abundance of each metabolite was not strikingly different between genders and genotypes, although different ratios between tissues were observed. In the transgenic adenoma of the mouse prostate model dietary SFN, fed as freeze-dried broccoli sprouts, increased SFN content in the prostate and decreased the severity of prostate cancer at 12 and 28 weeks of age. In humans, the differences in metabolism of isothiocyanates between whole food and broccoli supplements have yet to be determined. Two separate human trials were conducted; the first was a randomized 7 day feeding study where subjects consumed either broccoli sprouts or a broccoli supplement, and the second study was a randomized single dose cross-over study with broccoli sprouts, followed by a washout period, then broccoli supplement. In plasma and urine, the total amounts of SFN and erucin (ERN) metabolites were greater and the peak concentration occurred sooner in subjects who consumed broccoli sprouts. Glutathione-S-transferase pi-1 polymorphisms did not affect ITC metabolism. Interconversion of SFN to ERN was observed. Histone deacetylase activity in peripheral blood mononuclear cells was inhibited only in subjects who consumed sprouts. In conclusion, these data provide evidence that SFN alters HDAC activity and protein acetylation in cancerous prostate cells but not normal prostate cells. For the first time we show that SFN is bioavailable to many tissues types, including the prostate and are largely found as SFN metabolites not the parent SFN compound. We also show that the bioavailability of ITCs is markedly lower in human subjects who consume a broccoli supplement. Decreased HDAC activity in the peripheral blood of subjects who consumed sprouts indicates that higher ITC plasma concentrations can alter HDAC activity in vivo. Taken together, these data show that SFN is an effective prostate cancer chemopreventive agent that can easily be utilized in the diet from whole food.
-
1274. [Article] Does Disability Severity Matter? The Daily Lives of Parent Caregivers of Children with Developmental Disabilities
Individuals with disabilities and their parents, even within specific disability diagnoses, have diverse life experiences and trajectories. The current study focuses on parents of individuals with developmental ...Citation Citation
- Title:
- Does Disability Severity Matter? The Daily Lives of Parent Caregivers of Children with Developmental Disabilities
- Author:
- Fenn, Meghann L.
Individuals with disabilities and their parents, even within specific disability diagnoses, have diverse life experiences and trajectories. The current study focuses on parents of individuals with developmental disabilities. Developmental disabilities (DD) are a diverse group of severe chronic conditions evident at birth or acquired during childhood that affect major life activities such as language, mobility, learning, self-help, and independent living; and include conditions such as Down syndrome, attention deficit hyperactive disorder (ADHD), autism spectrum disorders, and general developmental delays. This study builds on previous literature concerning stress, caregiving, and disability by examining the daily lives, experiences, and wellbeing of parents of children with DD. The majority of health and wellbeing research being done in this area focuses on overall or global wellbeing. Comparatively little research has examined the daily lives, experiences, and wellbeing of these parents, who exist within extremely fluid contexts that change daily. Furthermore, this study also aims to build on previous research by considering the severity of the child’s disability, in order to further contextualize and understand the complex levels of influence within these parents’ daily lives. Using data from the second wave of the National Study of Daily Experiences (NSDE), the daily diary project of the National Survey of Midlife in the United States (MIDUS), this study examined these topics further by answering three specific research questions; First, to what extent does the association between daily stressors and same-day positive and negative affect differ for parents of children with and without DD? Second, to what extent does the association between daily positive events and same-day positive and negative affect differ for parents of children with and without DD? And lastly, are these associations further moderated by the severity of the child’s disability? A total of 82 participants (Mean Age = 57.4; 59% female, 96% non-Hispanic White, 79% married, Mean Education = 14 years) were identified as parents of children with DD. A sample of 82 individuals who were parents of typically developing children were identified and matched as a comparison group based on: parent gender, parent age, number of children in the household, child age, whether the target child lives with the parent, parent marital status, and parent educational attainment. Participants completed 8 nightly telephone interviews, which included assessments of their daily stressors and positive events, as well as positive and negative affect. Results from the current study found that the daily lives of individuals with disabilities and their parents are diverse and complex. Compared to their matched counterparts, parents of children with DD experienced significantly greater increases in negative affect associated with the experience of daily stressors. In contract, parents of children with DD exhibited comparable increases in daily positive affect associated with the daily positive experiences. With respect to severity of disability, the longevity of the child’s disability diagnosis, the number of comorbid disability diagnoses, and the number of comorbid mental health diagnoses, did selectively moderate daily experience-wellbeing associations, but not in a symmetric fashion across indicators. Taken together, the daily experiences and daily wellbeing of parents caring for a child with a disability cannot be understood and defined merely by knowing their child’s disability status. Parents of children with DD may be vulnerable because of the chronic stress context of caring for a child with a disability, and they show more reactive patterns of daily wellbeing when experiencing daily stressors, however, they also show resiliency in their daily wellbeing when experiencing daily positive events. The current study attempted to better contextualize and understand the daily lives of caregiving parents by moving beyond a binary definition of disability (yes/no a disability is present), and findings suggest that severity of disability is a complex phenomenon in need of continued empirical investigation.
-
1275. [Article] A comparative analysis of factors influencing smoking behaviors of college students, 1963-1987
Cigarette smoking continues to be one of the country's major health concerns. It has been defined as the single largest preventable cause of disease and death in the United States. Although research has ...Citation Citation
- Title:
- A comparative analysis of factors influencing smoking behaviors of college students, 1963-1987
- Author:
- Gray, Nancy L.
Cigarette smoking continues to be one of the country's major health concerns. It has been defined as the single largest preventable cause of disease and death in the United States. Although research has indicated that overall cigarette consumption has decreased in the nation over the past decades, cigarette smoking remains a significant problem among young people in the United States. This fact, coupled with studies indicating that cigarette smoking increases with age into the early twenties suggests that research should be conducted to determine those variables that encourage smoking behavior of late adolescents and young adults. The purpose of the study was to compare the relationship between selected predisposing factors and subsequent smoking behaviors exhibited in 1963 and 1987 respectively. Assessments of smoking behaviors of college students in Oregon in 1963-64 and 1986-87 were conducted to determine relationships between students smoking behaviors and selected socio-demographic variables. Comparisons were made between the resulting data for students in the 1963-64and 1986-87 studies. Aquestionnaire relating to smoking behavior was developed and administered to 3,786 college students attending introductory personal health classes during the 1963-64 school year at four selected colleges in the state of Oregon. During the 1986-87 school year a modified version of the questionnaire was developed and administered to college students attending introductory personal health classes at three of the same four universities that were utilized in the 1963-64 study. Stepwise logistic regression, chi square and descriptive statistics were used to analyze the data. Results indicated that there were significantly more smokers in 1963-64 and their daily consumption rates were significantly higher when compared to 1986-87 data. Although a larger percentage of females were smokers in the total population surveyed in 1963-64, there were more female smokers in the population of smokers in 1986-87. Whereas males consumed significantly more cigarettes per day than did females in 1963-64, there was no significant difference between male and female consumption rates in 1986-87. Significant numbers of smokers in 1986-87 started smoking at an earlier age than did smokers in 1963-64. When separating by gender, this was significant for females but not for males. Peer smoking was listed as the number one reason for starting to smoke by more than half of the respondents in 1986-87 as compared to 40% who listed curiosity in 1963-64. Physical reasons were indicated as the main reason for quitting by ex-smokers in 1963-64 and in 1986-87, over one half of the respondents indicated that they quit because of a concern for their physical health. Stepwise logistic regression equations were used to determine the set of variables that best accounted for smoking status in 1963-64 and 1986-87. Results indicated that the variables which predisposed individuals toward subsequent smoking behavior did differ when comparing the two studies. In 1963-64, an individual with the highest probability of smoking was one who had one or more older sisters who smoked, both parents smoked, father was a high school non-graduate and was from an urban setting. The individual with the lowest probability of smoking in 1963-64 had no older sisters who smoked, mother and father did not smoke, father was a high school graduate and lived in a rural setting. In 1986-87, the only variable to significantly increase the probability of an individual smoking was one or more older brothers who smoked. The following data were collected only for the 1986-87 population of students because questions relating to these issues were not included on the 1963-64 questionnaire. Use of alcohol, marijuana and smokeless tobacco by cigarette smokers was not significantly different when compared to non-smokers. Illicit substance use (cocaine, crack, heroin, quaaludes, etc) was significantly different for cigarette smokers and non-smokers. Smokers were more likely to use illicit substances than were non-smokers. The largest number of smokeless tobacco users were males in the 18-19 age category. Use of alcohol, marijuana and other illicit substances were significantly different for smokeless tobacco users than for non-users. Smokeless tobacco users were more likely to consume more alcohol on a weekly basis and use marijuana and illicit substances on an occasional and regular basis than were non-users of smokeless tobacco.
-
Alcoholic liver disease (ALD) continues to be one of the major public health problems in the United States and worldwide. Complicated by factors including gender, polymorphisms of alcohol-metabolizing ...
Citation Citation
- Title:
- Label-free mass spectrometry-driven methods for elucidating adaptive responses of the hepatic mitochondrial proteome in an alcoholic fatty liver disease model
- Author:
- Tzeng, Shin-Cheng
Alcoholic liver disease (ALD) continues to be one of the major public health problems in the United States and worldwide. Complicated by factors including gender, polymorphisms of alcohol-metabolizing enzymes, immunologic factors, exposures to other substances/drugs, hepatic viral infections, nutritional deficiencies, and obesity, ALD is a complex disease that requires a systematic approach to dissect the mechanisms associated with organ dysfunction. Mechanistic knowledge is necessary to shed light on routes that potentially may lead to effective treatments. Proteomics as a discovery tool that may reveal new targets and pathways that can potentially be exploited for developing new preventive strategies and treatments. The mitochondrion is the pivotal organelle linked to disease progression and to the development of ALD. Studies have shown links between mitochondrial dysfunction and ethanol-induced liver injury, but the underlying mechanisms at the molecular level still remain largely unknown. In the present study we evaluated the capability of two label-free mass-spectrometry-driven approaches (i) the intensity-based MS[superscript E] method, and (ii) a spectral counting-based method that uses data-dependent acquisition (DDA). Initially a single- and a three-protein model system were utilized to evaluate differences in the performance characteristics of the two methods. To examine the performance difference of the two methods for proteome characterization, we measured changes in protein levels as a consequence of chronic alcohol consumption in rat liver mitochondria. Our results revealed that the MS[superscript E] approach had better performance in terms of precision, and dynamic range and resulted in superior accuracy for fold change determinations. The MS[superscript E] approach proved to identify more mitochondrial proteins than the two DDA methods. However, the run-to-run reproducibility of the MS[superscript E] method was lower than was observed for the DDA methods. Despite poor linear correlation between approaches, the outcomes of the proteome characterizations were rather consistent as more than half of the significantly altered proteins detected by the MS[superscript E] method were also revealed by at least one of the DDA methods. Collectively, we concluded that both MSE and DDA approaches provide satisfactory performance with the MS[superscript E] approach outperforming the DDA-based methods with respect to accuracy, linearity and dynamic range. Further, we integrated the label-free LC-MS[superscript E] quantification with bioinformatics and knowledge base to profile alteration of the mitochondrial proteome for unraveling the protective effect of MitoQ, a mitochondrial targeted ubiquinone, on ALD. With carefully maintained stability of the LC-MS system, robust proteome datasets with high technical precision were obtained. By taking advantage of the information-rich quantitative proteomic data, we quantitatively categorized the identified proteins and performed pathway analysis for each category independently. Metabolic pathways and associated proteins were highlighted with the guidance of the systems biology approach. In summary, our results indicated that the pathways enriched in response to MitoQ included acyl-CoA synthases and the carnitine shuttle, ketogenesis, the TCA cycle and oxidative phosphorylation. The MitoQ-responsive metabolic network suggested that MitoQ up-regulates fatty acid transportation to counteract accumulation of lipids in the fatty liver. For dissecting the mitochondrial proteome, we develop a "targeted" quantitative approach involving label-free mass spectrometry-based quantification, chemoselective labeling, avidin- biotin based affinity enrichment at both protein and peptide level. The approach was applied to mitochondria exposed to 4-hydroxy-2-nonenal (HNE) for depicting a subset of the mitochondrial proteome susceptible to HNE insult. The utilization of the carbonyl-selective probe, ARP, facilitated labeling of HNE-adducted proteins and enabled avidin affinity enrichment with the biotin moiety. A list of potential protein targets with concentration-dependent response and known HNE modification sites was obtained when combining results from the protein- and peptide-level enrichment workflows. The core list of putative protein targets of HNE adduction may serve as lead for further validation studies towards unraveling the pathogenesis of ALD and emerging treatment modalities using Western blotting or targeted LC-MS methods.
-
1277. [Article] Bicyclist Compliance at Signalized Intersections
This project examined cyclist red light running behavior using two data sets. Previous studies of cyclist compliance have investigated the tendencies of cyclists to run red lights on the whole by generalizing ...Citation Citation
- Title:
- Bicyclist Compliance at Signalized Intersections
- Author:
- Thompson, Samson Ray Riley
- Year:
- 2015
This project examined cyclist red light running behavior using two data sets. Previous studies of cyclist compliance have investigated the tendencies of cyclists to run red lights on the whole by generalizing different maneuvers to their end outcome, running a red light. This project differentiates between the different types of red light running and focuses on the most egregious case, gap acceptance, which is when a cyclist runs a red light by accepting a gap in opposing traffic. Using video data, a mathematical model of cyclist red light running was developed for gap acceptance. Similar to other studies, this analysis utilized only information about the cyclist, intersection, and scenario that can be outwardly observed. This analysis found that the number of cyclists already waiting at the signal, the presence of a vehicle in the adjacent lane, and female sex were deterrents to red light running. Conversely, certain types of signal phasing, witnessing a violation, and lack of helmet increased the odds that a cyclist would run the red light. Interestingly, while women in general are less likely to run a red light, those who witnessed a violation were even more prone that men who had witnessed a violation to follow suit and run the red light themselves. It is likely that the differing socialization of women and men leads to different effects of witnessing a previous violator. The analysis also confirmed that a small subset of cyclists, similar to that found in the general population, are more prone to traffic violations. These cyclists are more willing to engage in multiple biking-related risk factors that include not wearing a helmet and running red lights. Although the model has definite explanatory power regarding decisions of cyclist compliance, much of the variance in the compliance choices of the sample is left unexplained. This points toward the influence of other, not outwardly observable variables on the decision to run a red light. Analysis of survey data from cyclists further confirms that individual characteristics not visible to the observer interact with intersection, scenario, and visible cyclist characteristics to result in a decision to comply (or not) with a traffic signal. Furthermore, cyclist characteristics, in general, and unobservable individual characteristics, specifically, play a larger role in compliance decisions as the number of compliance-inducing intersection traits (e.g. conflicting traffic volume) decrease. One such unobservable trait is the regard for the law by some cyclists, which becomes a more important determinant of compliance at simpler intersections. Cyclists were also shown to choose non-compliance if they questioned the validity of the red indication for them, as cyclists. The video and survey data have some comparable findings. For instance, the relationship of age to compliance was explored in both data analyses. Age was not found to be a significant predictor of non-compliance in the video data analysis while it was negatively correlated with stated non-compliance for two of the survey intersections. Gender, while having significant effects on non-compliance in the video dataset, did not emerge as an important factor in the stated non-compliance of survey takers. Helmet use had a consistent relationship with compliance between the video and survey datasets. Helmet use was positively associated with compliance in the video data and negatively associated with revealed non-compliance at two of the survey intersections. When coupled with the positive association between normlessness and stated willingness to run a red light, the relationship between helmet use and compliance solidifies the notion that a class of cyclists is more likely to consistently violate signals. It points towards a link between red light running and individuals who do not adhere to social norms and policies as strictly as others. Variables representing cyclists and motorists waiting at the signal were positively related to signal compliance in the video data. While an increased number of cyclists may be a physical deterrent to red light running, part of the influence on compliance that this variable and the variable representing the presence of a vehicle may be due to accountability of cyclists to other road users. This relationship, however, was not revealed in the stated non-compliance data from the survey. Efforts to increase cyclist compliance may not be worth a jurisdiction's resources since nearly 90% of cyclists in the video data were already compliant. If a problem intersection does warrant intervention, different methods of ensuring bicyclist compliance are warranted depending on the intersection characteristics. An alternative solution is to consider the applicability of traffic laws (originally designed for cars) to bicyclists. Creating separation in how laws affect motorists and cyclists might be a better solution for overly simple types of intersections where cyclists have fewer conflicts, better visibility, etc. than motorists. Education or other messaging aimed at cyclists about compliance is another strategy to increase compliance. Since cyclists appear to feel more justified in running red lights at low-volume, simple-looking intersections, it would probably be prudent to target messaging at these types of intersections. Many cyclists are deterred by high-volume and/or complicated looking intersections for safety reasons. Reminding cyclists of the potential dangers at other intersections may be a successful messaging strategy. Alternatively, reminding cyclists that it is still illegal to run a red light even if they feel safe doing so may be prudent. Additionally, messaging about the purpose of infrastructure such as bicycle-specific signals or lights that indicate detection at a signal may convince cyclists that stopping at the signal is in their best interest and that the wait will be minimal and/or warranted.
-
1278. [Article] Factors affecting within-season and between-season breeding dispersal of burrowing owls in California
Dispersal is integral to our understanding of the life history and population biology of many vertebrates, but difficulties in detecting long distance movements have complicated its study. Moreover, studies ...Citation Citation
- Title:
- Factors affecting within-season and between-season breeding dispersal of burrowing owls in California
- Author:
- Catlin, Daniel H.
Dispersal is integral to our understanding of the life history and population biology of many vertebrates, but difficulties in detecting long distance movements have complicated its study. Moreover, studies of factors affecting dispersal are often unable to determine the relative contributions of variables such as nesting success, mate fidelity, and nest site fidelity. I examined the effects of nest depredation on dispersal in comparison to successful nests and nests that failed for other reasons. Additionally, I investigated a suite of biological factors affecting within-season and between-season breeding dispersal by burrowing owls (Athene cunicularia) in California, attempting to partition the effects of these covariates and to deal with long distance detectibility issues. For both types of dispersal, I divided dispersal into two components; dispersal probability and dispersal distance. I used experimental and observational approaches to investigate within-season dispersal in two contrasting environments; a large grassland and an agricultural landscape. I found that the factors affecting dispersal probability and dispersal distance were different, supporting my decision to examine each separately. Of the factors investigated, dispersal probability was influenced most by study area, mate fidelity, and nesting success. The proportion of individuals dispersing tended to be greater for owls that lost their mate due to death or dispersal (60%, 6 of 10) and owls whose nests were depredated (50%, 10 of 20) than for owls that did not lose their mates (33%, 6 of 18) and owls whose nests were successful (17%, 1 of 6), respectively. The results from an experiment where we removed eggs from pairs of owls to simulate nest depredation were consistent with the observational results, suggesting that owls whose nests were depredated may have been more likely to disperse than control owls. The reactions of owls from depredated nests, however, did not appear to differ from those whose nests failed for other reasons. In contrast, owl dispersal distance was most affected by owl gender, and to a lesser degree by study area and nesting success. Dispersal distance was greater for female owls (median = 1575 m, n = 13) than male owls (median = 417 m, n = 11), greater for owls from the grassland area (median= 939 m, n = 9) compared to owls from the agricultural area (median = 829 m, n = 15), and greater for owls whose nests had failed (median = 1018 m, n = 17) than for owls that successfully bred (median 475 m, n = 7). Nest depredation, however, did not appear to increase dispersal distance. The geometric models performed poorly at approximating within-season dispersal distance, indicating that many owls disperse farther than predicted by a "first is best" model. I speculate that the distribution of within-season dispersal distances by burrowing owls is related to the densities of suitable territories and mates, which are more variable than predicted by a geometric model within a breeding season. I used data from band resightings and nesting success (1998-2003) to examine factors related to between-season breeding dispersal by burrowing owls in an agricultural environment. Of the factors investigated, nesting success appeared to have the greatest effect on burrowing owl dispersal. The proportion of individuals dispersing was greater for owls whose nests had failed (68%, 28 of 41) than owls whose nests were successful (27%, 58 of 212). Similarly, dispersal distance was greater for owls whose nest failed (mean = 745 ± 175 m, n = 28) than owls with successful nests (mean = 340 ± 36 m,n = 58). The owls exhibited high rates of nest site and mate fidelity between breeding seasons. There was evidence that previous experience at a breeding site may have reduced dispersal probability and that unpaired owls may have been more likely to disperse and dispersed slightly greater distances than those that retained their mates. Nesting success, however, appeared to be the major factor contributing to burrowing owl breeding dispersal after controlling for nest site and mate fidelity, particularly for male owls. Despite the complexity of the dispersal process, a geometric model provided a reasonably good fit to the distribution of between-season breeding dispersal distances at relatively short distances, but failed to predict a small percentage of long distance dispersals. Geometric models appeared to be a better fit for the distribution of between-season breeding dispersal distances than within-season breeding dispersal distances. Factors affecting within-season dispersal were generally similar to those affecting between-season dispersal. Both within-season and between-season breeding dispersal were affected by nesting success and mate fidelity, but the effects of these factors differed between the two types of breeding dispersal, suggesting that time constraints and competition play a larger role in within-season dispersal than between season dispersal. In addition, both studies supported a difference in dispersal behavior, in which the factors that affected dispersal probability were distinct from those that affected dispersal distance. These results help determine the relative contributions of nesting success, mate fidelity, and nest site fidelity to avian dispersal, offer some evidence that the effects of nest depredation are not distinct from the effects of nest failure in general, and provide further support for the division of dispersal into dispersal probability and dispersal distance.
-
1279. [Article] DANCE AS COMMUNICATION: HOW HUMANS COMMUNICATE THROUGH DANCE AND PERCEIVE DANCE AS COMMUNICATION
58 pages. A thesis presented to the Department of Dance and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Arts, Spring 2016.Citation Citation
- Title:
- DANCE AS COMMUNICATION: HOW HUMANS COMMUNICATE THROUGH DANCE AND PERCEIVE DANCE AS COMMUNICATION
- Author:
- Rounds, Samantha
- Year:
- 2016
58 pages. A thesis presented to the Department of Dance and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Arts, Spring 2016.
-
1280. [Article] Assessing equity in health system finance and health care utilization : the case of Chile, and a model to measure health care access
Chile has experienced great success in terms of economic growth in the last decades. This growing economy brings changes in the Chilean health care system. Its health care system was primarily funded by ...Citation Citation
- Title:
- Assessing equity in health system finance and health care utilization : the case of Chile, and a model to measure health care access
- Author:
- Nunez Mondaca, Alicia Lorena
Chile has experienced great success in terms of economic growth in the last decades. This growing economy brings changes in the Chilean health care system. Its health care system was primarily funded by state sources until 1981, when a major reform was introduced that established new rules for the health insurance market. Since then, Chile has a public-private mixed health care system, both in financing and delivery of services. Citizens can choose for coverage between the Public National Health Insurance and the Private Health Insurance system. However, these systems have a common funding source coming from the mandatory contribution of employees, equivalent to 7% of their taxable income with an approximate limit of US$2,800 dollars. One of the more important Chilean health reforms towards the establishment of social guarantees was effective on July 2005, when the Regime of Explicit Health Guarantees, also known as Plan AUGE became effective. Plan AUGE is a health program that benefits all Chileans without discrimination of age, gender, economic status, health care, or place of residence. This plan includes the 69 diseases with higher impact on Chilean population in its different stages, but with feasibility of effective treatments. Changes in the health care system and its last reform brought questions about their impact on the distribution of health care services throughout country. Is Chile moving towards a better and more equitable health care system? The main purpose of this thesis is to investigate equity in health system finance and health care utilization as well as to explore alternative measurement of access to health care in Chile. The first two manuscripts examine equity issues in Chile. The purpose of the first one is to assess equity in health system finance in Chile, accounting for all finance sources. While equity in health system finance has been well studied in OECD countries, there are still few published empirical studies on Latin American health care systems, where there tends to be a wider gap in income-wealth distribution among states. This gap may increase the financial burden for people in the lower spectrum of income groups, which is the main concern in the first manuscript. It will focus on identifying policy variables that may contribute to more equitable distribution of the financial burden in health care. The equity principle we adopt for this study is the ability to pay principle. Based on this, we explore factors that contribute to inequities in the health care system finance and issues about who bears the heavier burden of out-of pocket (OOP) payment, progressivity of OOP payment, and the redistributive effect of OOP payment for health care as a source of finance in the Chilean health care system. Our analysis is based on data from the National Socioeconomic Survey (CASEN), and the 2006 National Survey on Satisfaction and OOP payments. Results from this study provide comprehensive understanding of the financial burden of health care in Chile. This study identified evidence of inequity, in spite of the progressivity of the health care system. Furthermore, our assessment of equity in health system finance identified relevant policy variables such as education, insurance system, and method of payment that should be taken into consideration in the ongoing debates and research in improving the Chilean system. Such findings will also benefit other Latin American countries that are concerned about equity in health system finance. The purpose of the second manuscript was to assess equity in health care utilization in Chile. Secondary data analyses from the National Socioeconomic Survey (CASEN) were performed to estimate the impact of different factors including AUGE in the utilization of health care services. We used a two-part model for the analysis of frequency of health care use in the country. Four other separate two-part models were also specified to estimate the frequency of use of preventive services, general practitioner services, specialty care and emergency care. An assessment of horizontal equity was also included. Results suggest the presence of pro-rich inequities in the use of medical care. The estimation of the two-part model found key factors affecting utilization of health care services such as education and the implementation of the AUGE program. These findings provide timely evidence to policy-makers to understand the current distribution and equity of health care utilization, and to strengthen availability of health services accordingly. The third manuscript was motivated by the previous findings. Its purpose was to explore an alternative measurement for health care access. The majority of studies nowadays use a single proxy to estimate access: the use of health care services. However, we saw many limitations on this approach since it only considers people that are already using the system and ignores those that are not. The final manuscript proposed a model to estimate access to health care services based on communitarian claims. The model identified barriers to health care access as well as the preferences of the community for priority settings.