Search

The availability of parks and urban green spaces has been associated with a number of benefits, including increased physical activity, improvements in mental health, increases in social interactions, improvements to the environment, and increases in property values. The installation of temporary pop-up parks in urban areas is one way for urban communities to obtain these benefits. In this mixed-methods study, quantitative and qualitative data were gathered by researchers, the city council, a local investment company, and community residents that informed the initiation, iteration, and incremental expansion of a series of temporary, summer pop-up parks in the downtown business district of the City of Los Altos in Northern California over a 4-year period (2013–2016). Results showed that the parks were visited by a large, multigenerational group of users who engaged in leisure-time physical activity, shopped at local stores, attended programed events, and socialized with others. Direct observation and survey data gathered in year 2014 also indicated that foot traffic into businesses directly fronting on a pop-up park (n = 8) was higher during a 4-day period when the park was in place, as compared to a similar 4-day period before the park was installed. The majority of downtown business owners/managers reported no decrease in sales compared to the month before the pop-up park was installed. City sales tax data indicated increases in year-on-year sales tax revenue in the summer quarter of 2014 and 2016 compared with the year (2015) when there was no downtown pop-up park. Perspectives of community residents collected before, during, and after the installation of the pop-up parks indicated that the pop-up park created a vibrant space in an otherwise underutilized area that was enjoyed by a variety of people in a host of ways (e.g., children playing, families relaxing, people shopping and eating at downtown stores and restaurants, people of all ages attending scheduled park events). These results informed a number of discussions and meetings between key stakeholders about the pop-up parks, culminating in a temporary park that was held in a new location in 2017 that was substantially larger in size, installed for a longer time period, cost more, and had more scheduled park events. Results from this prospective investigation of the initial impacts of pop-up parks in this urban location provide insights regarding the potential benefits and viability of such temporary parks for residents and businesses alike. [ABSTRACT FROM AUTHOR]

Using data from Korean-American residents (N = 343) in subsidized senior housing in the Los Angeles area, we examined the effect of peer bullying on mental health. About 18% of the sample had been a target of bullying, and over 31% had witnessed someone being bullied. Being a target of bullying was a significant predictor for both depressive symptoms and anxiety, whereas witnessing other residents being bullied was a significant predictor for anxiety only. Findings shed light on the adverse mental health impacts of peer bullying among ethnic minority older residents in senior housing. [ABSTRACT FROM AUTHOR]

Insights from conservation genomics have dramatically improved recovery plans for numerous endangered species. However, most taxa have yet to benefit from the full application of genomic technologies. The mountain yellow-legged frog species complex, Rana muscosa and Rana sierrae, inhabits the Sierra Nevada mountains and Transverse/Peninsular Ranges of California and Nevada. Both species have declined precipitously throughout their historical distributions. Conservation management plans outline extensive ongoing recovery efforts but are still based on the genetic structure determined primarily using a single mitochondrial sequence. Our study used two different sequencing strategies – amplicon sequencing and exome capture – to refine our understanding of the population genetics of these imperiled amphibians. We used buccal swabs, museum tissue samples, and archived skin swabs to genotype frog populations across their range. Using the amplicon sequencing and exome capture datasets separately and combined, we document five major genetic clusters. Notably, we found evidence supporting previous species boundaries within Kings Canyon National Park with some exceptions at individual sites. Though we see evidence of genetic clustering, especially in the R. muscosa clade, we also found evidence of some admixture across cluster boundaries in the R. sierrae clade, suggesting a stepping-stone model of population structure. We also find that the southern R. muscosa cluster had large runs of homozygosity and the lowest overall heterozygosity of any of the clusters, consistent with previous reports of marked declines in this area. Overall, our results clarify management unit designations across the range of an endangered species and highlight the importance of sampling the entire range of a species, even when collecting genome-scale data. [ABSTRACT FROM AUTHOR]

The recognition and delineation of cryptic species remains a perplexing problem in systematics, evolution, and species delimitation. Once recognized as such, cryptic species complexes provide fertile ground for studying genetic divergence within the context of phenotypic and ecological divergence (or lack thereof). Herein we document the discovery of a new cryptic species of trapdoor spider, Promyrmekiaphila korematsui sp. nov. Using subgenomic data obtained via target enrichment, we document the phylogeography of the California endemic genus Promyrmekiaphila and its constituent species, which also includes P. clathrata and P. winnemem. Based on these data we show a pattern of strong geographic structuring among populations but cannot entirely discount recent gene flow among populations that are parapatric, particularly for deeply diverged lineages within P. clathrata. The genetic data, in addition to revealing a new undescribed species, also allude to a pattern of potential phenotypic differentiation where species likely come into close contact. Alternatively, phenotypic cohesion among genetically divergent P. clathrata lineages suggests that some level of gene flow is ongoing or occurred in the recent past. Despite considerable field collection efforts over many years, additional sampling in potential zones of contact for both species and lineages is needed to completely resolve the dynamics of divergence in Promyrmekiaphila at the population–species interface. [ABSTRACT FROM AUTHOR]

Subsidized senior housing helps many socioeconomically disadvantaged older adults pursue independent living and aging in place. However, cognitive impairment or dementia poses a critical challenge to many residents' ability to live independently and safely. Focusing on Korean American dementia caregivers, a group known to be vulnerable to caregiving burden but understudied, we explored the safety of persons with dementia in senior housing from the perspectives of caregivers. Qualitative data from nine caregivers whose care recipients were current or former residents of subsidized senior housing in Los Angeles were analyzed by the constant comparative method. Major concerns emerged were: (1) fire risks, (2) wandering, (3) physical injury (e.g., self-harm, falls), and (4) potential neglect. Caregivers also mentioned errors in the self-administration of medications, potential financial exploitation, and interpersonal conflicts. These concerns provide implications for services and programs for the safety of persons with dementia who live in senior housing. [ABSTRACT FROM AUTHOR]

Shrimp is one of the most consumed seafood products globally. Antimicrobial drugs play an integral role in disease mitigation in aquaculture settings, but their prevalent use raises public health concerns on the emergence and spread of antimicrobial resistant microorganisms. Vibrio spp., as the most common causative agents of seafood-borne infections in humans, and Enterococcus spp., as an indicator organism, are focal bacteria of interest for the monitoring of antimicrobial resistance (AMR) in seafood. In this study, 400 samples of retail shrimp were collected from randomly selected grocery stores in the Greater Sacramento, California, area between September 2019 and June 2020. The prevalence of Vibrio spp. and Enterococcus spp. was 60.25% (241/400) and 89.75% (359/400), respectively. Subsamples of Vibrio (n = 110) and Enterococcus (n = 110) isolates were subjected to antimicrobial susceptibility testing (AST). Vibrio isolates had high phenotypic resistance to ampicillin (52/110, 47.27%) and cefoxitin (39/110, 35.45%). Enterococcus were most frequently resistant to lincomycin (106/110, 96.36%), quinupristin-dalfopristin (96/110, 87.27%), ciprofloxacin (93/110, 84.55%), linezolid (86/110, 78.18%), and erythromycin (58/110, 52.73%). For both Vibrio and Enterococcus, no significant associations were observed between multidrug resistance (MDR, resistance to ≥3 drug classes) in isolates from farm raised and wild caught shrimp (p > 0.05) and in isolates of domestic and imported origin (p > 0.05). Whole genome sequencing (WGS) of a subset of Vibrio isolates (n = 42) speciated isolates as primarily V. metschnikovii (24/42; 57.14%) and V. parahaemolyticus (12/42; 28.57%), and detected 27 unique antimicrobial resistance genes (ARGs) across these isolates, most commonly qnrVC6 (19.05%, 8/42), dfrA31 (11.90%, 5/42), dfrA6 (9.5%, 4/42), qnrVC1 (9.5%, 4/42). Additionally, WGS predicted phenotypic resistance in Vibrio isolates with an overall sensitivity of 11.54% and specificity of 96.05%. This study provides insights on the prevalence and distribution of AMR in Vibrio spp. and Enterococcus spp. from retail shrimp in California which are important for food safety and public health and exemplifies the value of surveillance in monitoring the spread of AMR and its genetic determinants. [ABSTRACT FROM AUTHOR]

Genetic analysis of intra-host viral populations provides unique insight into pre-emergent mutations that may contribute to the genotype of future variants. Clinical samples positive for SARS-CoV-2 collected in California during the first months of the pandemic were sequenced to define the dynamics of mutation emergence as the virus became established in the state. Deep sequencing of 90 nasopharyngeal samples showed that many mutations associated with the establishment of SARS-CoV-2 globally were present at varying frequencies in a majority of the samples, even those collected as the virus was first detected in the US. A subset of mutations that emerged months later in consensus sequences were detected as subconsensus members of intra-host populations. Spike mutations P681H, H655Y, and V1104L were detected prior to emergence in variant genotypes, mutations were detected at multiple positions within the furin cleavage site, and pre-emergent mutations were identified in the nucleocapsid and the envelope genes. Because many of the samples had a very high depth of coverage, a bioinformatics pipeline, "Mappgene", was established that uses both iVar and LoFreq variant calling to enable identification of very low-frequency variants. This enabled detection of a spike protein deletion present in many samples at low frequency and associated with a variant of concern. [ABSTRACT FROM AUTHOR]

This paper investigates the constant-damage residual displacement ratios Cr (i.e., the ratio of the residual displacement in terms of the maximum inelastic displacement) of single-degree-of-freedom (SDOF) systems with different damage levels. A statistical study aimed at estimating the constant-damage Cr is conducted using the modified Park–Ang damage model when subjected to 228 ground motions recorded in California and organized for the NEHRP soil type, peak ground acceleration and ground motion duration. The effects of soil type, damage model and hysteretic behaviour are highlighted. The results indicate that constant-damage Cr increases when the damage index increases, reaching a limit at a damage index of 0.5. An empirical expression is finally proposed with two-step regression analysis to provide a reliable estimate of constant-damage Cr for SDOF structures. [ABSTRACT FROM AUTHOR]

Pregnant women appear to be more susceptible to infectious diseases than women in reproductive age. According to the California Department of Public Health pregnant women were 9.6-folds more likely to be hospitalized during the 2009 influenza outbreak when compared to non-pregnant women in reproductive age. In contrast, it was reported that of 16,749 COVID-19 patients that were hospitalized in the UK, the probability for pregnant women to require in-patient care due to infection by SARS-CoV-2 was 0.95 versus non-pregnant women. Therefore 9.6/0.95 = 10.10, which brings us to the conclusion that pregnant women are 10.10-folds less likely to be hospitalized for a SARS-CoV-2 infection than for the 2009 H1N1 pandemic. Folic acid supplementation during pregnancy could be the factor that is protecting these patients against SARS-CoV-2 infection. Two independent papers that used informatic simulation proved that folic acid reduced the replication of this virus. One of them showed that folic acid inhibits the furin protease which the virus needs in order to enter its host cell, while the other one explained that folic acid inactivates protease 3CL pro , a protein that the virus needs to replicate. Nonetheless the probability that folic acid blocks two different proteins is very low, therefore the mechanism by which folic acid has apparently protected pregnant women during the COVID-19 pandemic has not been determined. [ABSTRACT FROM AUTHOR]

Growth in the human population and the popularity of outdoor recreation have resulted in increasing interaction between humans and mountain lions (Puma concolor). A questionnaire was used to gauge attitudes, risk perception, and management preferences toward the species among residents near its habitat in Santa Cruz County, California. Attitudes were positive, risk perception moderate, knowledge low, and lethal control measures unpopular. More positive attitudes were found among men, respondents with more education, respondents who recreated often in natural areas, and nature organization members. Older respondents, women, those who recreated less in mountain lion habitat, and those who lived near (but not in) perceived mountain lion habitat demonstrated increased risk perception. Results could help align management actions with public preferences, and guide conservation organizations toward capitalizing on positive attitudes. Both management bodies and conservation organizations should target outreach toward addressing poor knowledge among groups with negative attitudes and higher risk perception. [ABSTRACT FROM AUTHOR]

This study examines the relationship between living arrangements, social capital, and quality of life of elderly Chinese immigrants in the United States. For this purpose, data were collected from 205 Chinese immigrants aged 65 years and above who did not have any cognitive disorders and were living in Los Angeles County. The primary variables considered included demographic data, living arrangements, social capital, and the quality of life. Results showed that the quality of life of elderly Chinese immigrants was significantly influenced by their life with a spouse or children and traits of social capital, such as trust, partnership with the community, and political participation. Findings indicate that trust, partnership, political participation, and living with a spouse or children are closely related to the quality of life of elderly Chinese immigrants. This study highlights the importance of developing a community atmosphere and policy to enhance elderly Chinese immigrants' social participation, trust, and life with family members to further improve their subjective quality of life. Results may have implications for elderly immigrants from other countries, as well. [ABSTRACT FROM AUTHOR]

While Asians are becoming the largest ethnic group in the United States, studies have focused on Asians as a single population. The purpose of this study was to explore the racial and ethnic mental health differences between non-Hispanic Whites and Asians, with an emphasis on understudied subgroups, from the California Health Interview Survey 2011/2012. In this dataset Asians had significantly lower adjusted odds ratios for both mental distress and serious mental illness. However, when Asians were divided into subgroups and compared to Whites, Vietnamese and Japanese subgroups were significantly lower than Whites for mental distress while Koreans were significantly higher. Vietnamese and Chinese were found to have significantly less serious mental illness than Whites in the subgroup analyses. Our results underscore the importance of recognizing that Asian subgroups should not be overlooked, and all Asians should not automatically be treated as a homogenous group. [ABSTRACT FROM AUTHOR]

This study examined the relations between core psychological self-schemas and the subjective well-being (SWB) of Turkish and California (United States) adolescents. The participants were 2,242 high school students (1,123 from Turkey and 1,119 from California). Core psychological self-schemas were measured with the Social and Emotional Health Survey–Secondary (SEHS-S) and SWB was measured by the combination of the Students’ Life Satisfaction Scale (SLSS; cognitive component) and the Positive and Negative Affect Schedule for Children (PANAS-C; affective component). Significant, small effect size differences were found for self-awareness, persistence, family coherence, and behavioral self-control, favoring the Turkish adolescents, and for school support, empathy, and SWB, favoring the California adolescents. Positive associations were found between the social and emotional health self-schemas and SWB for adolescents in both cultures. Multiple regression analyses indicated that self-efficacy, self-awareness, family coherence, and zest were significant predictors of SWB for both the Turkish and California samples. For the California sample only, peer support, gratitude, and optimism were significant predictors. The findings are discussed in the context of individualist and collectivist cultures. [ABSTRACT FROM AUTHOR]

Objective: Hospice is an important method of promoting quality end-of-life (EoL) care, yet its utilization is relatively low in underserved populations. The unique characteristics of a border community-such as a lack of healthcare resources and cultural integration-impact EoL decision making. The aim of our study was to assess the willingness to use hospice care services and its predictors among family caregivers of Latino patients in the United States (U.S.)-Mexico border region of Southern California.Method: This study analyzes secondary data from a home health agency in the U.S.-Mexico border region. Quantitative data were collected via a face-to-face interview with 189 caregivers of patients enrolled in the agency. Bivariate tests and logistic regression were employed to address our study objectives.Results: The majority (83%) of family caregivers were willing to use hospice services for their loved ones. The factors impacting willingness to use hospice services included the primary language of the caregiver (OR = 6.30, CI 95% = 1.68, 23.58); trust in doctors to make the right decisions (OR = 3.77, CI 95% = 1.05, 13.57); and the belief that using hospice care means giving up on life (OR = 0.52, CI 95% = 0.30; 0.88). Caregivers who trusted doctors to make the best decisions for their loved ones and English-speaking caregivers were more willing to utilize hospice services, while caregivers who held a strong belief that hospice care means giving up on life were less likely to consider using hospice care for their loved ones.Significance Of Results: The willingness of family caregivers to use hospice services for their loved ones is influenced by cultural perspectives about hospice care. As the importance of family involvement in EoL care planning has been highlighted, family caregivers' beliefs about hospice care services need to be addressed within their particular cultural context. [ABSTRACT FROM AUTHOR]

Objectives: To examine racial/ethnic/immigration disparities in health and to investigate the relationships among race/ethnic/immigration status, delayed health care, and health of the elderly. Design and Sample: Responses from 13,508 people aged 65 and above were analyzed based on the California Health Interview Survey (CHIS) 2011–2012. Measures: Key variables include race/ethnicity/immigration status, health outcome, and delayed health care. Age, gender, education, work status, and annual family income are used as covariates. Results: The findings indicate that Whites (regardless of country of birth) and U.S.‐born Asians enjoy better health than Latinos, African‐Americans, and Foreign‐born Asians. Foreign‐born Asians and foreign‐born Latinos have the poorest self‐reported health and mental health, respectively. Delayed use of health care is negatively associated with both self‐reported health and mental health status. Conclusions: Health disparities exist among older adult populations; the combined effects of minority and immigrant status can be approximated from the results in this study. Health care accessibility and the quality of care should be promoted in minority/immigrant populations. Public health nurses have a strong potential to aide in reducing health disparities among an aging American population that continues to exhibit increasing racial/ethnic diversity. [ABSTRACT FROM AUTHOR]

Racial-ethnic disparities in physical activity present important challenges to population health. Public parks provide access to free or low-cost physical activity opportunities, but it is unclear to what extent parks are utilized by various race-ethnic groups in diverse urban settings. Here, we examine racial ethnic differences in park use and physical activity among adult residents (n = 7506) living within 1 mi of 50 parks in the city of Los Angeles. In multivariate analyses, we find few differences among race-ethnic groups in terms of their frequency of having visited the park in the past 7 days; however, we find numerous differences in how the groups used the park and in their levels of physical activity: Blacks and English-speaking Latinos were less likely than whites to report being physically active, exercising in the park, and exercising outside the park; Spanish-speaking Latinos were equally likely as whites to report exercising in park but less likely to report exercising outside the park and more likely to report using the parks for social interactions; Asians/Pacific Islanders (PI)/others were more likely than whites to report visiting the park in the past 7 days and using the parks for social interactions. Urban parks appear to be an important resource for physical activity and socialization, in particular among Spanish-speaking Latino and Asians/PI groups. Additional efforts may be needed for other racial-ethnic minorities to experience the same benefits. [ABSTRACT FROM AUTHOR]

Background Leadership WalkRounds (WR) are widely used in healthcare organisations to improve patient safety. The relationship between WR and caregiver assessments of patient safety culture, and healthcare worker burnout is unknown. Methods This cross-sectional survey study evaluated the association between receiving feedback about actions taken as a result of WR and healthcare worker assessments of patient safety culture and burnout across 44 neonatal intensive care units (NICUs) actively participating in a structured delivery room management quality improvement initiative. Results Of 3294 administered surveys, 2073 were returned for an overall response rate of 62.9%. More WR feedback was associated with better safety culture results and lower burnout rates in the NICUs. Participation in WR and receiving feedback about WR were less common in NICUs than in a benchmarking comparison of adult clinical areas. Conclusions WR are linked to patient safety and burnout. In NICUs, where they occurred more often, the workplace appears to be a better place to deliver and to receive care. [ABSTRACT FROM AUTHOR]

Ammonia (NH3) is an important trace gas species in the atmosphere that can have negative impacts on human, animal, and ecosystem health. Agriculture has been identified as the largest source of NH3, specifically livestock operations. NH3 emissions from a commercial dairy in California were investigated during June 2008. Cattle were held in open-lot pens, except for young calves in hutches with shelters. Solid manure was stored in the open-lot pens. Liquid manure from feed lanes was passed through a solids settling basin and stored in a holding pond. Passive sensors and open-path Fourier transform infrared spectrometers (OP-FTIR) were deployed around the facility to measure NH3 concentrations. Emissions from pens and the liquid manure system (LMS) were estimated using inverse modeling. Mean emission factors (EFs) for the entire facility were 140.5 ±42.5 g d-1 animal-1 from the passive sampler data and 199.2 ±22.0 g d-1 animal-1 from the OP-FTIR data, resulting in the facility's summer emissions calculated at 265.2 ±80.2 kg d-1 and 375.4 ±27.1 kg d-1, respectively. These EFs are within the range of values reported in the literature. Both concentrations and emissions exhibited a strong diurnal cycle, peaking in the late afternoon. Total facility emissions exhibited significant positive correlations with temperature and wind speed. The findings of this study show that NH3 emissions from a commercial dairy can vary by a factor of 10 or more throughout the day, and EFs can vary by two orders of magnitude when compared to other U.S. dairies, based on literature values. [ABSTRACT FROM AUTHOR]

Copyright of Western North American Naturalist is the property of Monte L. Bean Life Science Museum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Old-growth forests in the American West typically represent fragments of former, more extensive forests that were subjected to nineteenth and twentieth century land-clearing activities, such as logging. These present-day forest fragments are thought to be representative of the former landscape, and thus are capable of serving as living references for guiding restoration of logged forests. Yet how do we determine the extent to which existing old-growth stands represent the former forest, especially when little of the surrounding original vegetation remains? Historic land surveys conducted prior to significant logging can reconstruct the former forest at the stand level, thereby allowing an analysis of old-growth patches within the larger historic landscape. This study utilized original Public Land Surveys to assess the applicability of old-growth stands in Redwood National Park as reference ecosystems. A geographic information system (GIS) and statistical analysis of the nineteenth century forest found that vegetation communities, woody species composition, and ratios of dominant canopy species in unlogged patches were highly representative of the forests that were logged. Significance testing (Ho: μ1 = μ2) revealed p-values greater than 0.10000 in all measures of community and species composition, except for the higher abundance of oak in present-day old-growth ( p-value = 0.0395). The results of this study suggest that the national park should increase efforts to protect old-growth reference ecosystems from further human impacts, and minimize ongoing degradation from edge effects by prioritizing restoration of adjoining second-growth forest. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The San Bernardino shrew, Sorex obscurus parvidens Jackson, 1921, is a population inhabiting the San Bernardino and San Gabriel mountains of southern California. For the past 9 decades, this population has been considered either a subspecies of S. obscurus Merriam, 1895, S. vagrans Baird, 1857, or S. monticola Merriam, 1890; or an undifferentiated population of S. ornatus Merriam, 1895. Aside from the changing taxonomic landscape that contextualizes the genus Sorex, previous study of S. obscurus parvidens has been retarded by the perception of limited available samples (typically, fewer than 8 specimens); misinterpretation of the provenance of specimens identified as S. obscurus parvidens; misunderstanding of the type locality; and inclusion of specimens of this taxon in the type series of another species with which S. obscurus parvidens has been both contrasted and allied at different times. My investigation of S. obscurus parvidens indicates that it is a distinctive population that is morphologically closest to S. ornatus, and it corresponds to the Southern Clade of that species. However, the appropriate names for deep clades within S. ornatus remain uncertain. Until this uncertainty is resolved, S. obscurus parvidens should be considered a distinctive population within S. ornatus; for conservation purposes, it should be recognized as S. ornatus parvidens. [ABSTRACT FROM AUTHOR]

Captive breeding of animals is often cited as an important tool in conservation, especially for fishes, but there are few reports of long-term (<50 years) success of captive breeding programs, even in salmonid fishes. Here we describe the captive breeding program for Eagle Lake rainbow trout, Oncorhynchus mykiss aquilarum, which is endemic to the Eagle Lake watershed of northeastern California. The population in Eagle Lake has been dependent on captive breeding for more than 60 years and supports a trophy fishery in the lake. Nevertheless, the basic life history, ecological, and genetic traits of the subspecies still seem to be mostly intact. Although management has apparently minimized negative effects of hatchery rearing, reestablishing a wild population would ensure maintenance of its distinctive life history and its value for future use as a hatchery fish. An important factor that makes reestablishment possible is that the habitat in Eagle Lake is still intact and that Pine Creek, its major spawning stream, is recovering as habitat. With the exception of an abundant alien brook trout ( Salvelinus fontinalis) population in Pine Creek, the habitat factors that led to the presumed near-extinction of Eagle Lake rainbow trout in the early twentieth century have been ameliorated, although the final stages of reestablishment (eradication of brook trout, unequivocal demonstration of successful spawning migration) have still not been completed. The Eagle Lake rainbow trout story shows that long-term captive breeding of migratory salmonid fishes does not necessarily prevent reestablishment of wild populations, provided effort is made to counter the effects of hatchery selection and that natural habitats are restored for reintroduction. Long-term success, however, ultimately depends upon eliminating hatchery influences on wild-spawning populations. Extinction of Eagle Lake rainbow trout as a wild species becomes increasingly likely if we fail to act boldly to protect it and the Eagle Lake watershed. [ABSTRACT FROM AUTHOR]

Over the past 35 years, a trend of decreasing water clarity has been documented in Lake Tahoe, attributable in part to the delivery of fine-grained sediments emanating from upland and channel sources. The overall objective of the research reported here was to determine the amount of fine sediment delivered to Lake Tahoe from each of the 63 contributing watersheds. The research described in this report used combinations of field-based observations of channel and bank stability with measured and simulated data on fine-sediment loadings to estimate fine-sediment loadings from unmonitored basins throughout the Lake Tahoe Basin. Loadings were expressed in the conventional format of mass per unit time but also in the number of particles finer than 20 μm, the latter for future use in a lake-clarity model. The greatest contributors of fine sediment happened to be those with measured data, not requiring extrapolation. In descending order, they are as follows: Upper Truckee River [1,010 tonnes per year (T/year)], Blackwood Creek (846 T/year), Trout Creek (462 T/year), and Ward Creek (412 T/year). Summing estimated values from the contributing watersheds provided an average, annual estimate of fine-sediment (<0.063 mm) loadings to the lake of 5,206 T/year. A total of 7.79E + 19 particles in the 5-20 μm fraction were calculated to enter Lake Tahoe in an average year with the Upper Truckee River accounting for almost 25% of the total. Contributions from Blackwood, Ward, Trout, and Third creeks account for another 23% of these very fine particles. Thus, these five streams making up about 40% of the basin area, account for almost 50% of all fine-sediment loadings to the lake. Contribution of fine sediment from streambank erosion were estimated by developing empirical relations between measured or simulated bank-erosion rates with a field-based measure of the extent of bank instability along given streams. An average, annual fine-sediment loading from streambank erosion of 1,305 T/year was calculated. This represents about 25% of the average, annual fine-sediment load delivered to the lake from all sources. The two largest contributors, the Upper Truckee River (639 T/year) and Blackwood Creek (431 T/year), account for slightly more than 80% of all fines emanating from streambanks, representing about 20% of the fine sediment delivered to Lake Tahoe from all sources. Extrapolations of fine-sediment loadings to the unmonitored watersheds are based on documented empirical relations, yet contain a significant amount of uncertainty. Except for those values derived directly from measured data, reported results should be considered as estimates. [ABSTRACT FROM AUTHOR]

Mitochondrial cytochrome oxidase subunit one (COI) sequence, nuclear microsatellites, and amplified fragment length polymorphisms (AFLPs) were used to evaluate connectivity among nine red abalone ( Haliotis rufescens) populations sampled between August 1998 and November 2003 along approximately 1,300 km of California coastline from Crescent City (41°46′N, 124°12′W) to San Miguel Island (34°02′N, 120°22′W). COI sequences and microsatellite genotypes did not show significant genetic divergence among nine sampled populations. A subset of five populations spanning the geographic range of the study was scored for 163 polymorphic AFLP markers. Of these, 41 loci showed significant divergence ( P < 0.001) among populations. Still, no AFLP markers were diagnostic for any of the study populations, and assignment tests did not consistently assign individuals to the correct population. Although the AFLP data are the first to suggest there is significant genetic differentiation among California red abalone populations, the discordance between the different genetic markers needs further study before unambiguous conclusions can be drawn with respect to connectivity among the populations. [ABSTRACT FROM AUTHOR]

Oak woodlands and savannas are key defining landscapes in the California Floristic Province, making up almost a quarter of the region's forests and woodlands. Two endemic Californian oak species, valley oak ( Quercus lobata Neé) and blue oak ( Quercus douglasii Hook. & Arn.), are widely considered at risk of decline from persistent recruitment failures in the last century. However, decades of research have produced no definitive conclusion about the existence, extent, or causes of this ‘regeneration problem’. Underlying causes of perceived recruitment failure are unclear and could include drivers at distribution-wide to local scales including climate and atmospheric changes, habitat fragmentation, altered herbivore populations, changing fire regimes, exotic plant and animal invasions, livestock grazing, and soil conditions altered by past land uses. We performed meta-analyses of existing stand-scale data from the published and grey literatures on seedling and sapling recruitment in blue and valley oaks throughout each of their distributions. We sought to evaluate whether distribution-wide regeneration ‘problems’ exist for either species and to assess what factors correlate with distribution-wide recruitment patterns. Nearly 80% of sites surveyed for blue oaks but fewer than 50% of sites surveyed for valley oaks contained some evidence of seedling or sapling recruitment. A majority of sites surveyed for both species appear to have insufficient recruitment to replace adult populations, though further demographic work would be required to quantify minimum replacement recruitment rates. Reserve sites were seven times more likely than non-reserve sites to contain valley oak populations with evidence of recruitment. Blue oak recruitment patterns were weakly related to climate and geographical factors and strongly variable at subregional scales. We suggest several lines of additional research that could fill gaps in the existing literature and clarify the patterns emerging from this analysis. [ABSTRACT FROM AUTHOR]

Predator–prey relationships provide an excellent opportunity to study coevolved adaptations. Decades of theoretical and empirical research have illuminated the various behavioral adaptations exhibited by prey animals to avoid detection and capture, and recent work has begun to characterize physiological adaptations, such as immune reactions, metabolic changes, and hormonal responses to predators or their cues. A 2-year study quantified the activity budgets and antipredator responses of adult Belding’s ground squirrels ( Spermophilus beldingi) living in three different California habitats and likely experiencing different predation pressures. At one of these sites, which is visually closed and predators and escape burrows are difficult to see, animals responding to alarm calls remain alert longer and show more exaggerated responses than adults living in two populations that likely experience less intense predation pressure. They also spend more time alert and less time foraging than adults at the other two sites. A 4-year study using noninvasive fecal sampling of cortisol metabolites revealed that S. beldingi living in the closed site also have lower corticoid levels than adults at the other two sites. The lower corticoids likely reflect that predation risk at this closed site is predictable, and might allow animals to mount large acute cortisol responses, facilitating escape from predators and enhanced vigilance while also promoting glucose storage for the approaching hibernation. Collectively, these data demonstrate that local environments and perceived predation risk influence not only foraging, vigilance, and antipredator behaviors, but adrenal functioning as well, which may be especially important for obligate hibernators that face competing demands on glucose storage and mobilization. [ABSTRACT FROM AUTHOR]

The generalization error bounds found by current error models using the number of effective parameters of a classifier and the number of training samples are usually very loose. These bounds are intended for the entire input space. However, support vector machine (SVM), radial basis function neural network (RBFNN), and multilayer perceptron neural network (MLPNN) are local learning machines for solving problems and treat unseen samples near the training samples to be more important. In this paper, we propose a localized generalization error model which bounds from above the generalization error within a neighborhood of the training samples using stochastic sensitivity measure. It is then used to develop an architecture selection technique for a classifier with maximal coverage of unseen samples by specifying a generalization error threshold. Experiments using 17 University of California at Irvine (UCI) data sets show that, in comparison with cross validation (CV), sequential learning, and two other ad hoc methods, our technique consistently yields the best testing classification accuracy with fewer hidden neurons and less training time. [ABSTRACT FROM AUTHOR]

This article discusses the inception of Yosemite National Park and looks at the idea of U.S. national parks as natural monuments. The author traces the history of Yosemite from the time land was set aside looking at the various features of the Yosemite Valley that inspired environmentalists to deem the region worthy to become a preserved area.

To counter the power of pro-development interests, growth opponents in American communities have increasingly turned to the institutions of direct democracy. This study analyses the effects of one type of direct democracy—voter requirements for new development—on municipal growth. Analysing data from a sample of California communities, we consider the impact of voter requirements on the land use process and outcomes. We find that—in general— voter requirements fail to stop new development; property owners and developers can and do adapt to the constraints created by these direct democracy institutions. We also find, however, that voter requirements change the land use process in important ways. Specifically, they change the way developers interact with interest groups in the community and force developers to compensate current residents for enduring some of the negative aspects of growth. [ABSTRACT FROM AUTHOR]

Analysis of 12 microsatellite loci from 431 mountain lions (Puma concolor) revealed distinct genetic subdivision that was associated with geographic barriers and isolation by distance in California. Levels of genetic variation differed among geographic regions, and mountain lions that inhabited coastal areas exhibited less heterozygosity than those sampled inland. The San Francisco Bay and Sacramento-San Joaquin River Delta, the Central Valley, and the Los Angeles Basin appeared to be substantial barriers to gene flow, and allele frequencies of populations separated by those features differed substantially. A partial barrier to gene flow appeared to exist along the crest of the Sierra Nevada. Estimated gene flow was high among mountain lions inhabiting the Modoc Plateau, the western Sierra Nevada, and northern section of the eastern Sierra Nevada. Southern California mountain lion populations may function as a metapopulation; however, human developments threaten to eliminate habitat and movement corridors. While north-south gene flow along the western Sierra Nevada was estimated to be very high, projected loss and fragmentation of foothill habitat may reduce gene flow and subdivide populations. Preservation of existing movement corridors among regions could prevent population declines and loss of genetic variation. This study shows that mountain lion management and conservation efforts should be individualized according to region and incorporate landscape-level considerations to protect habitat connectivity. [ABSTRACT FROM AUTHOR]

This paper first introduces the key players involved in the deployment of Intelligent Transportation Systems (ITS) technologies in the Los Angeles metropolitan area. The paper then reports the local deployment status of major Advanced Public Transportation Systems (APTS) projects, with a particular emphasis placed on the burgeoning Los Angeles Smart Shuttle Demonstration Project. In addition, the paper analyzes some technical, political, financial and other issues centering around the deployment of APTS technologies in the Los Angeles metropolitan area. [ABSTRACT FROM AUTHOR]

AbstractAptostichus simus is a trapdoor spider endemic to the coastal dunes of central and southern California and, on morphological grounds, is recognized as a single species. Mitochondrial DNA 16S rRNA sequences demonstrate that most populations are fixed for the same haplotype and that the population haplotypes from San Diego County, Los Angeles County, Santa Rosa Island, and Monterey County are extremely divergent (6–12%), with estimated separation times ranging from 2 to 6 million years. A statistical cluster analysis of morphological features demonstrates that this genetic divergence is not reflected in anatomical features that might signify ecological differentiation among these lineages. The species status of these divergent populations of A. simus depends upon the species concept utilized. If a time-limited genealogical perspective is employed, A. simus would be separated at the base into two genetically distinct species. This study suggests that species concepts based on morphological distinctiveness, in spider groups with limited dispersal capabilities, probably underestimate true evolutionary diversity. [ABSTRACT FROM AUTHOR]

Presents abstracts for the 21st annual meeting of the American College of Toxicology in San Diego, California. Mouse bioassay in pharmaceutical testing; Application of immunohistochemistry for the evaluation of immunosuppressive agents; Design of reproductive toxicology protocol for the study of antiandrogens.

The article offers information on the fundamentals of textile testing training program offered by the American Association of Textile Chemists and Colorists (AATCC) to be held on June 20-21, 1991 at California State University in Long Beach. According to the article, the program will showcase demonstrations and discussion on the 35 basic AATCC testing methods for color fastness and physical properties assessment as well as ways on how to properly implement, analyze and interpret the test results. In addition, the author notes that sessions will focus on the concept and methods of visual and instrumental color evaluation and fiber identification and hands-on laboratory simulation.

The article discusses the study conducted which evaluates the effectiveness of a guidance program in the Hayward Union High School District in California. The purpose of the study is to measure the effectivity of this program on imparting guidance information which is significant in making choices such as occupations, education, health, marriage, personal adjustment. A test is administered to high school students that contains information like name of counselor, raw scores on the primary mental abilities and other important data. The findings show that students who are guided by academic interest and have certain vocational choice exhibit knowledge of guidance information.

The article presents information related to the California Irrigation Districts. In 1897, the state of California enacted the Irrigation District Act. Following twelve years of controversy with holders of large tracts of land who were unwilling to improve or market their holdings, the act was amended in 1909 at the behest of legislators who understood the economic principles. To finance the cost of the public improvement works in the Districts, such as dams, water rights, canals, etc., the act provides for the issuance of general obligation municipal bonds, upon approval by the resident voters, the same type of security as those by which school or road district improvements are financed. There is no poll tax or property restriction on voting in a California Irrigation District. The important irrigation systems throughout California during the past thirty-four years have virtually all been acquired under the provisions of this 1909 amendment to the original act of 1897. The great bulk of California's fruit, vegetable and almost endless variety of horticultural and agricultural crops are today grown on the land within these Irrigation Districts.