Indian Residential Segregation in the Urban Southwest: 1970 and 1980.

ERIC Educational Resources Information Center

Bohland, James R.

1982-01-01

Indian segregation in 11 cities in the Southwest in 1970 and 1980 was less than the segregation of either Blacks or Spanish Americans. Indian segregation declined between 1970 and 1980, but the decline was least in cities experiencing the greatest growth in Indian population. (Author/AM)

Mountain gorilla genomes reveal the impact of long-term population decline and inbreeding.

PubMed

Xue, Yali; Prado-Martinez, Javier; Sudmant, Peter H; Narasimhan, Vagheesh; Ayub, Qasim; Szpak, Michal; Frandsen, Peter; Chen, Yuan; Yngvadottir, Bryndis; Cooper, David N; de Manuel, Marc; Hernandez-Rodriguez, Jessica; Lobon, Irene; Siegismund, Hans R; Pagani, Luca; Quail, Michael A; Hvilsom, Christina; Mudakikwa, Antoine; Eichler, Evan E; Cranfield, Michael R; Marques-Bonet, Tomas; Tyler-Smith, Chris; Scally, Aylwyn

2015-04-10

Mountain gorillas are an endangered great ape subspecies and a prominent focus for conservation, yet we know little about their genomic diversity and evolutionary past. We sequenced whole genomes from multiple wild individuals and compared the genomes of all four Gorilla subspecies. We found that the two eastern subspecies have experienced a prolonged population decline over the past 100,000 years, resulting in very low genetic diversity and an increased overall burden of deleterious variation. A further recent decline in the mountain gorilla population has led to extensive inbreeding, such that individuals are typically homozygous at 34% of their sequence, leading to the purging of severely deleterious recessive mutations from the population. We discuss the causes of their decline and the consequences for their future survival. Copyright © 2015, American Association for the Advancement of Science.

Poaching and human encroachment reverse recovery of African savannah elephants in south-east Angola despite 14 years of peace.

PubMed

Schlossberg, Scott; Chase, Michael J; Griffin, Curtice R

2018-01-01

With populations of African savannah elephants (Loxodonta africana) declining across the continent, assessing the status of individual elephant populations is important for conservation. Angola's elephant population represents a key linkage between the larger populations of Namibia and Botswana. Elephants in Angola were decimated during the 1975-2002 Angolan civil war, but a 2005 survey showed that populations were recolonizing former habitats. Between 2005 and 2015, no research was permitted on elephants in Angola, but elsewhere in Africa many elephant populations experienced a poaching crisis. In 2015, we were able to resume elephant research in Angola. We used aerial surveys and satellite monitoring of collared elephants to determine the current status of elephant populations in Angola and to learn how human populations may be affecting elephant habitat usage. The aerial survey revealed a population of 3,395 ± SE of 797 elephants, but populations had declined 21% from the 2005 estimate. The high number of carcasses observed on the survey suggests that populations may have increased after the 2005 survey but were declining rapidly as of 2015. Satellite-collared elephants avoided areas <6 km from human indicators but preferred areas nearer humans at scales of 6-40 km, suggesting that humans may be displacing elephants from preferred habitats near rivers. Taken together, these results suggest that Angola's elephant population is experiencing intense poaching and may be losing habitat to human settlements. Without action to conserve their populations, Angola's elephants face an uncertain future.

Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines

PubMed Central

Ceballos, Gerardo; Ehrlich, Paul R.; Dirzo, Rodolfo

2017-01-01

The population extinction pulse we describe here shows, from a quantitative viewpoint, that Earth’s sixth mass extinction is more severe than perceived when looking exclusively at species extinctions. Therefore, humanity needs to address anthropogenic population extirpation and decimation immediately. That conclusion is based on analyses of the numbers and degrees of range contraction (indicative of population shrinkage and/or population extinctions according to the International Union for Conservation of Nature) using a sample of 27,600 vertebrate species, and on a more detailed analysis documenting the population extinctions between 1900 and 2015 in 177 mammal species. We find that the rate of population loss in terrestrial vertebrates is extremely high—even in “species of low concern.” In our sample, comprising nearly half of known vertebrate species, 32% (8,851/27,600) are decreasing; that is, they have decreased in population size and range. In the 177 mammals for which we have detailed data, all have lost 30% or more of their geographic ranges and more than 40% of the species have experienced severe population declines (>80% range shrinkage). Our data indicate that beyond global species extinctions Earth is experiencing a huge episode of population declines and extirpations, which will have negative cascading consequences on ecosystem functioning and services vital to sustaining civilization. We describe this as a “biological annihilation” to highlight the current magnitude of Earth’s ongoing sixth major extinction event. PMID:28696295

Relationships between forest songbird populations and managed forests in Idaho

Treesearch

Diane M. Evans; Deborah M. Finch

1994-01-01

Many species of songbirds have experienced population declines. In the eastern U.S. in recent years, but conclusive data on population trends and factors affecting populations in the West are lacking. Few studies have evaluated the importance of surrounding land configuration to songbird abundances. In 1992, we initiated a study in mixed conifer forest in west-central...

Poaching and human encroachment reverse recovery of African savannah elephants in south-east Angola despite 14 years of peace

PubMed Central

Chase, Michael J.; Griffin, Curtice R.

2018-01-01

With populations of African savannah elephants (Loxodonta africana) declining across the continent, assessing the status of individual elephant populations is important for conservation. Angola’s elephant population represents a key linkage between the larger populations of Namibia and Botswana. Elephants in Angola were decimated during the 1975–2002 Angolan civil war, but a 2005 survey showed that populations were recolonizing former habitats. Between 2005 and 2015, no research was permitted on elephants in Angola, but elsewhere in Africa many elephant populations experienced a poaching crisis. In 2015, we were able to resume elephant research in Angola. We used aerial surveys and satellite monitoring of collared elephants to determine the current status of elephant populations in Angola and to learn how human populations may be affecting elephant habitat usage. The aerial survey revealed a population of 3,395 ± SE of 797 elephants, but populations had declined 21% from the 2005 estimate. The high number of carcasses observed on the survey suggests that populations may have increased after the 2005 survey but were declining rapidly as of 2015. Satellite-collared elephants avoided areas <6 km from human indicators but preferred areas nearer humans at scales of 6–40 km, suggesting that humans may be displacing elephants from preferred habitats near rivers. Taken together, these results suggest that Angola’s elephant population is experiencing intense poaching and may be losing habitat to human settlements. Without action to conserve their populations, Angola’s elephants face an uncertain future. PMID:29538387

Genetic Signatures of Demographic Changes in an Avian Top Predator during the Last Century: Bottlenecks and Expansions of the Eurasian Eagle Owl in the Iberian Peninsula

PubMed Central

Graciá, Eva; Ortego, Joaquín; Godoy, José Antonio; Pérez-García, Juan Manuel; Blanco, Guillermo; del Mar Delgado, María; Penteriani, Vincenzo; Almodóvar, Irene; Botella, Francisco; Sánchez-Zapata, José Antonio

2015-01-01

The study of the demographic history of species can help to understand the negative impact of recent population declines in organisms of conservation concern. Here, we use neutral molecular markers to explore the genetic consequences of the recent population decline and posterior recovery of the Eurasian eagle owl (Bubo bubo) in the Iberian Peninsula. During the last century, the species was the object of extermination programs, suffering direct persecution by hunters until the 70’s. Moreover, during the last decades the eagle owl was severely impacted by increased mortality due to electrocution and the decline of its main prey species, the European rabbit (Oryctolagus cuniculus). In recent times, the decrease of direct persecution and the implementation of some conservation schemes have allowed the species’ demographic recovery. Yet, it remains unknown to which extent the past population decline and the later expansion have influenced the current species’ pattern of genetic diversity. We used eight microsatellite markers to genotype 235 eagle owls from ten Spanish subpopulations and analyse the presence of genetic signatures attributable to the recent population fluctuations experienced by the species. We found moderate levels of differentiation among the studied subpopulations and Bayesian analyses revealed the existence of three genetic clusters that grouped subpopulations from central, south-western and south-eastern Spain. The observed genetic structure could have resulted from recent human-induced population fragmentation, a patchy distribution of prey populations and/or the philopatric behaviour and habitat selection of the species. We detected an old population bottleneck, which occurred approximately 10,000 years ago, and significant signatures of recent demographic expansions. However, we did not find genetic signatures for a recent bottleneck, which may indicate that population declines were not severe enough to leave detectable signals on the species genetic makeup or that such signals have been eroded by the rapid demographic recovery experienced by the species in recent years. PMID:26230922

Copperheads are common when kingsnakes are not: relationships between the abundances of a predator and one of their prey

Treesearch

David A. Steen; Christopher J. W. McClure; William B. Sutton; D. Craig Rudolph; Josh B. Pierce; James R. Lee; Lora L. Smith; Beau B. Gregory; Danna L. Baxley; Dirk J. Stevenson; Craig Guyer

2014-01-01

Common Kingsnakes (formerly known collectively as Lampropeltis getula) are experiencing localized declines throughout the southeastern United States. Because there have been limited studies to determine how snakes regulate prey populations, and because Kingsnake declines may result in ecosystem impacts, we evaluated the hypothesis that Kingsnakes regulate the abundance...

Abundance of Grassland Sparrows on Reclaimed Surface Mines in Western Pennsylvania

Treesearch

Jennifer A. Mattice; Daniel W. Brauning; Duane R. Diefenbach

2005-01-01

Grassland songbird populations have experienced some of the most severe declines of any migratory songbird guild in North America and are continuing to disappear from portions of their historic ranges. Habitat loss and degradation have been implicated as primary causes of these declines. However, intensive surface coal mining and subsequent reclamation in western...

Changing places: the impact of rural restructuring on mental health in Australia.

PubMed

Fraser, Cait; Jackson, Henry; Judd, Fiona; Komiti, Angela; Robins, Garry; Murray, Greg; Humphreys, John; Pattison, Pip; Hodgins, Gene

2005-06-01

Significant demographic, social and economic change has come to characterise much of rural Australia, with some authors arguing there are now two sharply differentiated zones, one of growth and one of decline. This restructuring process, which has been similar to other western nations, has had a profound impact upon rural places-socially, economically and physically. Findings from research investigating the relationship between health, place and income inequality suggest that rural 'desertification', which is characterised by decline of the agricultural sector, net population loss and the deterioration of demographic structures, may negatively influence mental health outcomes in these areas. By contrast, the growth in rural areas, which is associated with expanding employment opportunities and the movement of capital and people, may confer positive benefits to mental health. The aim of this study was to investigate differences in mental health and well-being between rural communities experiencing growth and decline as measured by net population change. Utilising a survey methodology, questionnaires were distributed to 20,000 people randomly sampled from the electoral role in rural Australia. We selected four sub-regions from the sample area that were characteristic of areas experiencing population growth and decline in Australia and analysed the results of respondents from these four regions (n = 1334). The analysis provided support for our hypothesis that living in a declining area is associated with poorer mental health status; however, the factors that underpin growth and decline may also be important in influencing mental health. Discussed are the mechanisms by which demographic and social change influence mental health. The findings of this study highlight the diversity of health outcomes in rural areas and suggest that aspects of place in declining rural areas may present risk factors for mental health.

Impact of offspring death on cognitive health in late life: the Cache County study.

PubMed

Greene, Daylee; Tschanz, JoAnn T; Smith, Ken R; Ostbye, Truls; Corcoran, Chris; Welsh-Bohmer, Kathleen A; Norton, Maria C

2014-11-01

Experiencing the death of a child is associated with negative short-term mental health consequences, but less is known about cognitive outcomes and whether such associations extend to late life. We tested the hypothesis that experiencing an offspring death (OD) is associated with an increased rate of cognitive decline in late life. This population-based longitudinal study observed four cognitive statuses spaced 3-4 years apart, linked to an extensive database containing objective genealogic and vital statistics data. Home visits were conducted with 3,174 residents of a rural county in northern Utah, initially without dementia, aged 65-105. Cognitive status was measured with the Modified Mini-Mental State Exam at baseline and at 3-, 7-, and 10-year follow-ups. OD was obtained from the Utah Population Database, which contains statewide birth and death records. In linear mixed models, controlling for age, gender, education, and apolipoprotein E status, subjects who experienced OD while younger than age 31 years experienced a significantly faster rate of cognitive decline in late life, but only if they had an ε4 allele. Reclassifying all OD (regardless of age) according to subsequent birth of another child, OD was only related to faster cognitive decline when there were no subsequent births. Experiencing OD in early adulthood has a long-term association with cognitive functioning in late life, with a gene-environment interaction at the apolipoprotein E locus. Subsequent birth of another child attenuates this association. Copyright © 2014 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

Climate and ecosystem linkages explain widespread declines in North American Atlantic salmon populations.

PubMed

Mills, Katherine E; Pershing, Andrew J; Sheehan, Timothy F; Mountain, David

2013-10-01

North American Atlantic salmon (Salmo salar) populations experienced substantial declines in the early 1990s, and many populations have persisted at low abundances in recent years. Abundance and productivity declined in a coherent manner across major regions of North America, and this coherence points toward a potential shift in marine survivorship, rather than local, river-specific factors. The major declines in Atlantic salmon populations occurred against a backdrop of physical and biological shifts in Northwest Atlantic ecosystems. Analyses of changes in climate, physical, and lower trophic level biological factors provide substantial evidence that climate conditions directly and indirectly influence the abundance and productivity of North American Atlantic salmon populations. A major decline in salmon abundance after 1990 was preceded by a series of changes across multiple levels of the ecosystem, and a subsequent population change in 1997, primarily related to salmon productivity, followed an unusually low NAO event. Pairwise correlations further demonstrate that climate and physical conditions are associated with changes in plankton communities and prey availability, which are ultimately linked to Atlantic salmon populations. Results suggest that poor trophic conditions, likely due to climate-driven environmental factors, and warmer ocean temperatures throughout their marine habitat area are constraining the productivity and recovery of North American Atlantic salmon populations. © 2013 John Wiley & Sons Ltd.

Geolocator reveals migratory and winter movements of a Prothonotary Warbler

Treesearch

Jared D. Wolfe; Erik I. Johnson

2015-01-01

Prothonotary Warblers (Protonotaria citrea) are Nearctic-Neotropic migrants that have experienced declining populations over the past 50 yr. Determining their migration routes and wintering areas are critical steps in identifying habitats used by species and populations of conservation concern. We captured a male Prothonotary Warbler on its...

Long-term financial burden of breast cancer: experiences of a diverse cohort of survivors identified through population-based registries.

PubMed

Jagsi, Reshma; Pottow, John A E; Griffith, Kent A; Bradley, Cathy; Hamilton, Ann S; Graff, John; Katz, Steven J; Hawley, Sarah T

2014-04-20

To evaluate the financial experiences of a racially and ethnically diverse cohort of long-term breast cancer survivors (17% African American, 40% Latina) identified through population-based registries. Longitudinal study of women diagnosed with nonmetastatic breast cancer in 2005 to 2007 and reported to the SEER registries of metropolitan Los Angeles and Detroit. We surveyed 3,133 women approximately 9 months after diagnosis and 4 years later. Multivariable models evaluated correlates of self-reported decline in financial status attributed to breast cancer and of experiencing at least one type of privation (economically motivated treatment nonadherence and broader hardships related to medical expenses). Among 1,502 patients responding to both surveys, median out-of-pocket expenses were ≤ $2,000; 17% of respondents reported spending > $5,000; 12% reported having medical debt 4 years postdiagnosis. Debt varied significantly by race: 9% of whites, 15% of blacks, 17% of English-speaking Latinas, and 10% of Spanish-speaking Latinas reported debt (P = .03). Overall, 25% of women experienced financial decline at least partly attributed to breast cancer; Spanish-speaking Latinas had significantly increased odds of this decline relative to whites (odds ratio [OR], 2.76; P = .006). At least one privation was experienced by 18% of the sample; blacks (OR, 2.6; P < .001) and English-speaking Latinas (OR, 2.2; P = .02) were significantly more likely to have experienced privation than whites. Racial and ethnic minority patients appear most vulnerable to privations and financial decline attributable to breast cancer, even after adjustment for income, education, and employment. These findings should motivate efforts to control costs and ensure communication between patients and providers regarding financial distress, particularly for vulnerable subgroups.

Declining Fertility and the Use of Cesarean Delivery: Evidence from a Population-Based Study in Taiwan

PubMed Central

Ma, Ke-Zong M; Norton, Edward C; Lee, Shoou-Yih D

2010-01-01

Objective To test the hypothesis that declining fertility would affect the number of cesarean sections (c-sections) on maternal demand, but not medically indicated c-sections. Data Sources The 1996–2004 National Health Insurance Research Database in Taiwan for all singleton deliveries. Study Design Retrospective population-based, longitudinal study. Estimation was performed using multinomial probit models. Principal Findings Results revealed that declining fertility had a significant positive effect on the probability of having a c-section on maternal request but not medically indicated c-section. Conclusions Our findings offer a precautionary note to countries experiencing a fertility decline. Policies to contain the rise of c-sections should understand the role of women's preferences, especially regarding cesarean deliveries on maternal request. PMID:20545781

Indicators of Population Viabllity in Red Spruce, Picea rubens. I. Reproductive Traits and Fecundity

Treesearch

A. Mosseler; J.E. Major; J.D. Simpson; B. Daigle; K. Lange; Y.S. Park; K.H Johnsen; O.P. Rajora

2000-01-01

Red spruce (Picea rubens Sarg.) has experienced a substantial decline across most of its range in eastern North America over the past centmy and probably also in the disjunct Ontario populations where it now occurs only in small isolated stands. Measurements of cone and seed traits from natural populations were used as indicators of the...

Continent-wide tracking to determine migratory connectivity and tropical habitat associations of a declining aerial insectivore.

PubMed

Fraser, Kevin C; Stutchbury, Bridget J M; Silverio, Cassandra; Kramer, Patrick M; Barrow, John; Newstead, David; Mickle, Nanette; Cousens, Bruce F; Lee, J Charlene; Morrison, Danielle M; Shaheen, Tim; Mammenga, Paul; Applegate, Kelly; Tautin, John

2012-12-22

North American birds that feed on flying insects are experiencing steep population declines, particularly long-distance migratory populations in the northern breeding range. We determine, for the first time, the level of migratory connectivity across the range of a songbird using direct tracking of individuals, and test whether declining northern populations have higher exposure to agricultural landscapes at their non-breeding grounds in South America. We used light-level geolocators to track purple martins, Progne subis, originating from North American breeding populations, coast-to-coast (n = 95 individuals). We show that breeding populations of the eastern subspecies, P. s. subis, that are separated by ca. 2000 km, nevertheless have almost completely overlapping non-breeding ranges in Brazil. Most (76%) P. s. subis overwintered in northern Brazil near the Amazon River, not in the agricultural landscape of southern Brazil. Individual non-breeding sites had an average of 91 per cent forest and only 4 per cent agricultural ground cover within a 50 km radius, and birds originating from declining northern breeding populations were not more exposed to agricultural landscapes than stable southern breeding populations. Our results show that differences in wintering location and habitat do not explain recent trends in breeding population declines in this species, and instead northern populations may be constrained in their ability to respond to climate change.

Influence of age of males and nutritional condition on short- and long-term reproductive success of elk.

Treesearch

James H. Noyes; Bruce K. Johnson; Brian L. Dick; John G. Kie

2004-01-01

Rocky Mountain elk (Cervus elaphus) populations in some areas of northeastern Oregon have experienced declines in spring calf to cow ratios of nearly 80 percent over the last 40 years. Among the potential causes of these declines, the effects of age of male sires and the nutritional condition of females on conception dates and pregnancy rates have...

Integrated crop pollination: Combining strategies to ensure stable and sustainable yields of pollination-dependent crops

USDA-ARS?s Scientific Manuscript database

Meeting the nutritional needs of our growing human population will be increasingly dependent on bees and other pollinators that provide the essential delivery of pollen to crop flowers during bloom. Honey bees have experienced population declines in some regions, and similar changes are evident for ...

Foothill yellow-legged frog conservation assessment in California

Treesearch

Marc P. Hayes; Clara A. Wheeler; Amy J. Lind; Gregory A. Green; Diane C. Macfarlane

2016-01-01

The foothill yellow-legged frog (Rana boylii) is a stream-breeding amphibian that has experienced significant population declines over a large portion of its historical range. This frog is nearing extirpation in much of the Sierra Nevada region where existing populations are sparse. Water development and diversions are likely to be the primary...

Which native milkweeds are acceptable host plants for larval monarch butterflies (Danaus plexippus) within the Midwestern U.S.

USDA-ARS?s Scientific Manuscript database

Over the past two decades, the population of monarch butterflies east of the Rocky Mountains has experienced a significant decline. Habitat restoration within the summer breeding range is crucial to boost population numbers. Monarch butterfly larvae use milkweeds as their only host plant. However, l...

A look at Asia's changing youth population.

PubMed

Xenos, P; Kabamalan, M; Westley, S B

1999-01-01

This report summarizes findings from a recent East-West Center study on demographic and social changes among young people aged 15-24 years in 17 countries in East, Southeast, and South Asia. Nearly every country in Asia has experienced fertility decline. Decline began in Japan and Singapore during the 1950s, followed by declines in Hong Kong, South Korea, Sri Lanka, the Philippines, Brunei, Taiwan, Malaysia, Thailand, and China during the 1960s. Declines occurred during the 1970s in Indonesia, India, and Myanmar. A "youth bulge" occurred about 20 years later due to declines in infant and child mortality. This bulge varies by country with the timing and magnitude of population growth and subsequent fertility decline. The proportion of youth population rises from 16% to 18% about 20 years after the beginning of fertility decline and declines to a much lower stable level after several decades. The bulge is large in countries with rapid fertility decline, such as China. Governments can minimize the effects of bulge on population growth by raising the legal age at marriage, lengthening the interval between first marriage and first birth, and increasing birth intervals. School enrollments among adolescents are rising. In South Korea, the population aged 15-24 years increased from 3.8 to 8.8 million during 1950-90, a rise of 132% compared to a rise of 653% among school enrollments. It is expected that the number of out-of-school youths will decline from 5.1 to 3.6 million during 1990-2025. Youth employment varies by gender. Policies/programs in family planning and reproductive health will need to address the changing needs of youth population.

The impact of the 2007-2009 recession on workers' health coverage.

PubMed

Fronstin, Paul

2011-04-01

IMPACT OF THE RECESSION: The 2007-2009 recession has taken its toll on the percentage of the population with employment-based health coverage. While, since 2000, there has been a slow erosion in the percentage of individuals under age 65 with employment-based health coverage, 2009 was the first year in which the percentage fell below 60 percent, and marked the largest one-year decline in coverage. FEWER WORKERS WITH COVERAGE: The percentage of workers with coverage through their own job fell from 53.2 percent in 2008 to 52 percent in 2009, a 2.4 percent decline in the likelihood that a worker has coverage through his or her own job. The percentage of workers with coverage as a dependent fell from 17 percent in 2008 to 16.3 percent in 2009, a 4.5 percent drop in the likelihood that a worker has coverage as a dependent. These declines occurred as the unemployment rate increased from an average of 5.8 percent in 2008 to 9.3 percent in 2009 (and reached a high of 10.1 percent during 2009). FIRM SIZE/INDUSTRY: The decline in the percentage of workers with coverage from their own job affected workers in private-sector firms of all sizes. Among public-sector workers, the decline from 73.4 percent to 73 percent was not statistically significant. Workers in all private-sector industries experienced a statistically significant decline in coverage between 2008 and 2009. HOURS WORKED: Full-time workers experienced a decline in coverage that was statistically significant while part-time workers did not. Among full-time workers, those employed full year experienced a statistically significant decline in coverage from their own job. Those employed full time but for only part of the year did not experience a statistically significant change in coverage. Among part-time workers, those employed full year experienced a statistically significant increase in the likelihood of having coverage in their own name, as did part-time workers employed for only part of the year. ANNUAL EARNINGS: The decline in the percentage of workers with coverage through their own job was limited to workers with lower annual earnings. Statistically significant declines were not found among any group of workers with annual earnings of at least $40,000. Workers with a high school education or less experienced a statistically significant decline in the likelihood of having coverage. Neither workers with a college degree nor those with a graduate degree experienced a statistically significant decline in coverage through their own job. Workers of all races experienced statistically significant declines in coverage between 2008 and 2009. Both men and women experienced a statistically significant decline in the percentage with health coverage through their own job. IMPACT OF STRUCTURAL CHANGES TO THE WORK FORCE: The movement of workers from the manufacturing industry to the service sector continued between 2008 and 2009. The percentage of workers employed on a full-time basis decreased while the percentage working part time increased. While there was an overall decline in the percentage of full-time workers, that decline was limited to workers employed full year. The percentage of workers employed on a full-time, part-year basis increased between 2008 and 2009. The distribution of workers by annual earnings shifted from middle-income workers to lower-income workers between 2008 and 2009.

The erosion of employment-based insurance: more working families left uninsured.

PubMed

Gould, Elise

2008-01-01

The number of Americans without health insurance rose from 38.4 million in 2000 to 47.0 million in 2006, primarily due to the precipitous decline in employer-provided health coverage for workers and their families. Nearly 3.9 million fewer Americans under 65 had employer-provided coverage in 2006 than in 2000. The downward trend in the rate of employer-provided insurance continued for the sixth year in a row, falling from 68.3 to 62.9 percent. Individuals among the bottom 20 percent of household income were the least likely to have employer coverage. Jobholders experienced a significant decline in health insurance coverage, from 74.8 percent of workers in 2000 to 70.8 percent in 2006. No category of workers was insulated from loss of coverage. Children experienced declines in employer-provided health insurance coverage (through their parents) in each of the past five years, the rate falling from 65.9 percent of children in 2000 to 59.7 percent in 2006. Public health insurance (Medicaid and the State Children's Health Insurance Program) is no longer offsetting these losses. The decline in employer-provided coverage was felt throughout the country. Between the 2000-2001 and 2005-2006 periods, 38 states experienced significant losses in employment-based coverage for the under-65 population. No state experienced a significant increase in the coverage rate.

Increasingly inbred and fragmented populations of Plasmodium vivax associated with the eastward decline in malaria transmission across the Southwest Pacific

PubMed Central

Waltmann, Andreea; Koepfli, Cristian; Tessier, Natacha; Karl, Stephan; Fola, Abebe; Darcy, Andrew W.; Wini, Lyndes; Harrison, G. L. Abby; Barnadas, Céline; Jennison, Charlie; Karunajeewa, Harin; Boyd, Sarah; Whittaker, Maxine; Kazura, James; Bahlo, Melanie; Mueller, Ivo

2018-01-01

The human malaria parasite Plasmodium vivax is more resistant to malaria control strategies than Plasmodium falciparum, and maintains high genetic diversity even when transmission is low. To investigate whether declining P. vivax transmission leads to increasing population structure that would facilitate elimination, we genotyped samples from across the Southwest Pacific region, which experiences an eastward decline in malaria transmission, as well as samples from two time points at one site (Tetere, Solomon Islands) during intensified malaria control. Analysis of 887 P. vivax microsatellite haplotypes from hyperendemic Papua New Guinea (PNG, n = 443), meso-hyperendemic Solomon Islands (n = 420), and hypoendemic Vanuatu (n = 24) revealed increasing population structure and multilocus linkage disequilibrium yet a modest decline in diversity as transmission decreases over space and time. In Solomon Islands, which has had sustained control efforts for 20 years, and Vanuatu, which has experienced sustained low transmission for many years, significant population structure was observed at different spatial scales. We conclude that control efforts will eventually impact P. vivax population structure and with sustained pressure, populations may eventually fragment into a limited number of clustered foci that could be targeted for elimination. PMID:29373596

Increasingly inbred and fragmented populations of Plasmodium vivax associated with the eastward decline in malaria transmission across the Southwest Pacific.

PubMed

Waltmann, Andreea; Koepfli, Cristian; Tessier, Natacha; Karl, Stephan; Fola, Abebe; Darcy, Andrew W; Wini, Lyndes; Harrison, G L Abby; Barnadas, Céline; Jennison, Charlie; Karunajeewa, Harin; Boyd, Sarah; Whittaker, Maxine; Kazura, James; Bahlo, Melanie; Mueller, Ivo; Barry, Alyssa E

2018-01-01

The human malaria parasite Plasmodium vivax is more resistant to malaria control strategies than Plasmodium falciparum, and maintains high genetic diversity even when transmission is low. To investigate whether declining P. vivax transmission leads to increasing population structure that would facilitate elimination, we genotyped samples from across the Southwest Pacific region, which experiences an eastward decline in malaria transmission, as well as samples from two time points at one site (Tetere, Solomon Islands) during intensified malaria control. Analysis of 887 P. vivax microsatellite haplotypes from hyperendemic Papua New Guinea (PNG, n = 443), meso-hyperendemic Solomon Islands (n = 420), and hypoendemic Vanuatu (n = 24) revealed increasing population structure and multilocus linkage disequilibrium yet a modest decline in diversity as transmission decreases over space and time. In Solomon Islands, which has had sustained control efforts for 20 years, and Vanuatu, which has experienced sustained low transmission for many years, significant population structure was observed at different spatial scales. We conclude that control efforts will eventually impact P. vivax population structure and with sustained pressure, populations may eventually fragment into a limited number of clustered foci that could be targeted for elimination.

Disparities in Age-Associated Cognitive Decline Between African-American and Caucasian Populations: The Roles of Health Literacy and Education.

PubMed

Gupta, Vishal K; Winter, Michael; Cabral, Howard; Henault, Lori; Waite, Katherine; Hanchate, Amresh; Bickmore, Timothy W; Wolf, Michael S; Paasche-Orlow, Michael K

2016-08-01

To examine health literacy as a mediator of racial disparities in cognitive decline as measured by executive function in elderly adults. Prospective cohort study. Secondary analysis of ElderWalk trial in Boston, Massachusetts. English-speaking African-American and Caucasian individuals in a walking intervention for community-dwelling adults aged 65 and older without dementia at baseline who completed baseline and 12-month evaluations (N = 198). Health literacy was measured using the Short Test of Functional Health Literacy in Adults. Fluid and crystallized cognitive functions were measured at baseline and 12 months using the Trail-Making Test Part B minus Part B (TMT B-A) and the Controlled Oral Word Association Test (COWAT). Associations between health literacy and 12-month cognitive decline were modeled using multivariate linear regression. Participants with higher health literacy and education experienced less cognitive decline than those with limited health literacy according to the TMT B-A (P = .01). After adjusting for covariates, Caucasian participants (n = 63) experienced less decline than African-American participants (n = 135) on TMT B-A (P = .001) and COWAT (P = .001). Adjusting for health literacy led to a 25.3% decrease in the point estimate for racial difference in TMT B-A and a 19.5% decrease in COWAT. Although independently related to cognitive decline, educational attainment did not mediate racial differences. Health literacy is a partial mediator of racial disparities in cognitive decline. These results indicate the need to develop interventions to mitigate cognitive decline that individuals with low heath literacy can use and to modify the healthcare environment to better accommodate this population. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

Agroecology for the Shrinking City

EPA Science Inventory

Many cities are experiencing long-term declines in population and economic activity. As a result, frameworks for urban sustainability need to address the unique challenges and opportunities of such shrinking cities. Shrinking, particularly in the U.S., has led to extensive vacant...

Genomic signals of selection predict climate-driven population declines in a migratory bird.

PubMed

Bay, Rachael A; Harrigan, Ryan J; Underwood, Vinh Le; Gibbs, H Lisle; Smith, Thomas B; Ruegg, Kristen

2018-01-05

The ongoing loss of biodiversity caused by rapid climatic shifts requires accurate models for predicting species' responses. Despite evidence that evolutionary adaptation could mitigate climate change impacts, evolution is rarely integrated into predictive models. Integrating population genomics and environmental data, we identified genomic variation associated with climate across the breeding range of the migratory songbird, yellow warbler ( Setophaga petechia ). Populations requiring the greatest shifts in allele frequencies to keep pace with future climate change have experienced the largest population declines, suggesting that failure to adapt may have already negatively affected populations. Broadly, our study suggests that the integration of genomic adaptation can increase the accuracy of future species distribution models and ultimately guide more effective mitigation efforts. Copyright © 2018, American Association for the Advancement of Science.

Status of the amphipod Diporeia Spp. in Lake Superior, 2011

EPA Science Inventory

Amphipods of the genus Diporeia have historically been the dominant benthic macroinvertebrates in deeper waters of the Laurentian Great Lakes. Although Diporeia populations in the lower Great Lakes have experienced severe declines in recent years, densities have remained relativ...

The rise of the mesopredator

USDA-ARS?s Scientific Manuscript database

Apex predators have experienced catastrophic declines throughout the world due to human persecution and habitat loss. These collapses in top predator populations are commonly associated with dramatic increases in the abundance of smaller predators. Known as ‘mesopredator release,’ this trophic inte...

Is Chytridiomycosis Driving Darwin’s Frogs to Extinction?

PubMed Central

Soto-Azat, Claudio; Valenzuela-Sánchez, Andrés; Clarke, Barry T.; Busse, Klaus; Ortiz, Juan Carlos; Barrientos, Carlos; Cunningham, Andrew A.

2013-01-01

Darwin’s frogs (Rhinoderma darwinii and R. rufum) are two species of mouth brooding frogs from Chile and Argentina that have experienced marked population declines. Rhinoderma rufum has not been found in the wild since 1980. We investigated historical and current evidence of Batrachochytrium dendrobatidis (Bd) infection in Rhinoderma spp. to determine whether chytridiomycosis is implicated in the population declines of these species. Archived and live specimens of Rhinoderma spp., sympatric amphibians and amphibians at sites where Rhinoderma sp. had recently gone extinct were examined for Bd infection using quantitative real-time PCR. Six (0.9%) of 662 archived anurans tested positive for Bd (4/289 R. darwinii; 1/266 R. rufum and 1/107 other anurans), all of which had been collected between 1970 and 1978. An overall Bd-infection prevalence of 12.5% was obtained from 797 swabs taken from 369 extant individuals of R. darwinii and 428 individuals representing 18 other species of anurans found at sites with current and recent presence of the two Rhinoderma species. In extant R. darwinii, Bd-infection prevalence (1.9%) was significantly lower than that found in other anurans (7.3%). The prevalence of infection (30%) in other amphibian species was significantly higher in sites where either Rhinoderma spp. had become extinct or was experiencing severe population declines than in sites where there had been no apparent decline (3.0%; x 2 = 106.407, P<0.001). This is the first report of widespread Bd presence in Chile and our results are consistent with Rhinoderma spp. declines being due to Bd infection, although additional field and laboratory investigations are required to investigate this further. PMID:24278196

Presque Isle Peninsula, Frie, Pennsylvania. Volume II. Appendices. Revised.

DTIC Science & Technology

1980-11-01

Population Pyramid 9 c. Employment 9 d. Labor Force 9 .e. Public Facilities and Services 14 1. Transportation 14 2. Health Facilities. 14 3. Communications 14...Distribution of Shoreline Use and Overship, 3 Erie County, PA B2 Population Pyramid of Erie County 13 53 Travel Demand Curve Peak Day Good Weather 38...are also experiencing a decline in total population. 4(5) Population Pyramid B2.13 Figure B2, the population pyramid of Erie County, PA, for the years

Recent fertility declines in China and India: a comparative view.

PubMed

Kulkarni, P M; Rani, S

1995-12-01

This paper compares fertility transitions in China and parts of India. It is argued that China experienced a more rapid and more "impressive" decline than that of India. Socioeconomic conditions in China were more conducive to fertility decline. Kerala State in India experienced a similar decline as China but at a slower pace. The birth control campaign in China is credited with an important role in speeding the transition. It is posited that the political and administrative system and economic conditions in India are not compatible with the Chinese style program strategies. Both countries had similar fertility levels in the immediate post-revolutionary period. The most rapid decline occurred during the 1970s in China. The fertility transition was almost completed by 1981. In India, the total fertility rate (TFR) declined by only 1 point between the 1950s and 1981. In China TFR declined over 3 points during 1970-81. 76.7% of the decline in China during 1970-81 is attributed to a marked decline in marital fertility in all age groups, with the exception of ages 15-19 years. The decline in India is attributed to the decline in marital fertility. Female age at marriage rose in India, but less "impressively." In 1981 the mean age at marriage in India was 18.4 years, but it was 22.8 years in China. Marital fertility among women aged older than 30 years was considerably lower in China. Both countries experienced an increase in literacy, but in China the level of literacy was much greater. Both countries faced food shortages, but China improved food availability and calorie consumption per capita. Health services also improved in both countries, but the Chinese system of "barefoot" doctors brought services with easier reach of rural populations. Political structures differed in their dominance and organization. Family planning programs were introduced earlier in India, but prevalence was 64.4% in China in 1981 and about 22% in India.

The population slide.

PubMed

Mukerjee, M

1998-12-01

The level of total fertility in Bangladesh has fallen from 7 in 1975 to 3 today, the sharpest fertility transition in South Asia. Fertility decline in Bangladesh and Nepal follows such transition occurring first in Sri Lanka, then in India. While in Western countries, levels of fertility began to fall once an advanced stage of development had been reached, these new declines in South Asia are not directly correlated with indicators of development such as increased literacy or the alleviation of poverty. Bangladesh has experienced major fertility decline despite being one of the world's 20 poorest countries. Fertility decline in Bangladesh may be attributed to a combination of an effective government family planning program, a general desire among Bangladesh's population to bear fewer children, reductions in mortality, the availability of microcredit, changes in women's status, and the provision of health and family planning information over the radio 6 hours per day.

Ancient and Contemporary DNA Reveal a Pre-Human Decline but No Population Bottleneck Associated with Recent Human Persecution in the Kea (Nestor notabilis)

PubMed Central

Dussex, Nicolas; Rawlence, Nicolas J.; Robertson, Bruce C.

2015-01-01

The impact of population bottlenecks is an important factor to consider when assessing species survival. Population declines can considerably limit the evolutionary potential of species and make them more susceptible to stochastic events. New Zealand has a well documented history of decline of endemic avifauna related to human colonization. Here, we investigate the genetic effects of a recent population decline in the endangered kea (Nestor notabilis). Kea have undergone a long-lasting persecution between the late 1800s to 1970s where an estimated 150,000 kea were culled under a governmental bounty scheme. Kea now number 1,000–5,000 individuals in the wild and it is likely that the recent population decline may have reduced the genetic diversity of the species. Comparison of contemporary (n = 410), historical (n = 15) and fossil samples (n = 4) showed a loss of mitochondrial diversity since the end of the last glaciation (Otiran Glacial) but no loss of overall genetic diversity associated with the cull. Microsatellite data indicated a recent bottleneck for only one population and a range-wide decline in Ne dating back some 300 – 6,000 years ago, a period predating European arrival in NZ. These results suggest that despite a recent human persecution, kea might have experienced a large population decline before stabilizing in numbers prior to human settlement of New Zealand in response to Holocene changes in habitat distribution. Our study therefore highlights the need to understand the respective effects of climate change and human activities on endangered species dynamics when proposing conservation guidelines. PMID:25719752

Post-1900 mule deer irruptions in the Intermountain West: Principal cause and influences

Treesearch

George E. Gruell

1986-01-01

Tests hypotheses for mule deer population increases between the early 1930's and mid-1960's. Concludes that livestock grazing and absence of fire converted vast areas of grasses and forbs to woody plants favored by mule deer. Mule deer populations, therefore, irrupted between 1930 and 1965 and have since experienced a decline as plant succession moves toward...

Status of the Amphipod Diporeia spp. in Lake Superior, poster presentation

EPA Science Inventory

The amphipod Diporeia has historically been the dominant benthic macroinvertebrate in deeper waters of the Laurentian Great Lakes. Although Diporeia populations in the lower Great Lakes have experienced severe declines in recent years, densities have remained relatively stable i...

Investigating impacts of oil and gas development on greater sage-grouse

USGS Publications Warehouse

Green, Adam; Aldridge, Cameron L.; O'Donnell, Michael

2017-01-01

The sagebrush (Artemisia spp.) ecosystem is one of the largest ecosystems in western North America providing habitat for species found nowhere else. Sagebrush habitats have experienced dramatic declines since the 1950s, mostly due to anthropogenic disturbances. The greater sage-grouse (Centrocercus urophasianus) is a sagebrush-obligate species that has experienced population declines over the last several decades, which are attributed to a variety of disturbances including the more recent threat of oil and gas development. We developed a hierarchical, Bayesian state-space model to investigate the impacts of 2 measures of oil and gas development, and environmental and habitat conditions, on sage-grouse populations in Wyoming, USA using male lek counts from 1984 to 2008. Lek attendance of male sage-grouse declined by approximately 2.5%/year and was negatively related to oil and gas well density. We found little support for the influence of sagebrush cover and precipitation on changes in lek counts. Our results support those of other studies reporting negative impacts of oil and gas development on sage-grouse populations and our modeling approach allowed us to make inference to a longer time scale and larger spatial extent than in previous studies. In addition to sage-grouse, development may also negatively affect other sagebrush-obligate species, and active management of sagebrush habitats may be necessary to maintain some species. 

Pollinator Research at EPA

EPA Science Inventory

Of great concern, honey bee populations have experienced dramatic declines in the US and in many other countries. In response to this issue, the White House instructed the EPA and USDA to lead a Federal Task Force to develop a National Strategy on Pollinator Health which called f...

PHYLOGEOGRAPHY OF RANA YAVAPAIENSIS AND RANA ONCA: PRELIMINARY FINDINGS WITH CONSERVATION IMPLICATIONS

EPA Science Inventory

The closely related aridland frogs Rana onca (Relict Leopard Frog) and Rana yavapaiensis (Lowland Leopard Frog) have both experienced dramatic population declines. Rana onca currently occurs naturally at only 6 disjunct sites in southern Nevada. Rana yavapaiensis is present acros...

Estimation of mussel population response to hydrologic alteration in a southeastern U.S. stream

USGS Publications Warehouse

Peterson, J.T.; Wisniewski, J.M.; Shea, C.P.; Rhett, Jackson C.

2011-01-01

The southeastern United States has experienced severe, recurrent drought, rapid human population growth, and increasing agricultural irrigation during recent decades, resulting in greater demand for the water resources. During the same time period, freshwater mussels (Unioniformes) in the region have experienced substantial population declines. Consequently, there is growing interest in determining how mussel population declines are related to activities associated with water resource development. Determining the causes of mussel population declines requires, in part, an understanding of the factors influencing mussel population dynamics. We developed Pradel reverse-time, tag-recapture models to estimate survival, recruitment, and population growth rates for three federally endangered mussel species in the Apalachicola- Chattahoochee-Flint River Basin, Georgia. The models were parameterized using mussel tag-recapture data collected over five consecutive years from Sawhatchee Creek, located in southwestern Georgia. Model estimates indicated that mussel survival was strongly and negatively related to high flows during the summer, whereas recruitment was strongly and positively related to flows during the spring and summer. Using these models, we simulated mussel population dynamics under historic (1940-1969) and current (1980-2008) flow regimes and under increasing levels of water use to evaluate the relative effectiveness of alternative minimum flow regulations. The simulations indicated that the probability of simulated mussel population extinction was at least 8 times greater under current hydrologic regimes. In addition, simulations of mussel extinction under varying levels of water use indicated that the relative risk of extinction increased with increased water use across a range of minimum flow regulations. The simulation results also indicated that our estimates of the effects of water use on mussel extinction were influenced by the assumptions about the dynamics of the system, highlighting the need for further study of mussel population dynamics. ?? 2011 Springer Science+Business Media, LLC (outside the USA).

Browsing patterns of white-tailed deer following increased timber harvest and a decline in population density

Treesearch

Shawn M. Crimmins; John W. Edwards; W. Mark Ford; Patrick D. Keyser; James M. Crum

2010-01-01

We examined browsing patterns of white-tailed deer (Odocoileus virginianus) on a site in the central Appalachians that experienced a substantial (>50%) reduction in deer population density and an increase in the amount of timber harvest since 2001. We sampled woody browse in and immediately adjacent to 12 clearcuts ranging in age from 0-5 years...

The association between cognitive decline and incident depressive symptoms in a sample of older Puerto Rican adults with diabetes.

PubMed

Bell, Tyler; Dávila, Ana Luisa; Clay, Olivio; Markides, Kyriakos S; Andel, Ross; Crowe, Michael

2017-08-01

Older Puerto Rican adults have particularly high risk of diabetes compared to the general US population. Diabetes is associated with both higher depressive symptoms and cognitive decline, but less is known about the longitudinal relationship between cognitive decline and incident depressive symptoms in those with diabetes. This study investigated the association between cognitive decline and incident depressive symptoms in older Puerto Rican adults with diabetes over a four-year period. Households across Puerto Rico were visited to identify a population-based sample of adults aged 60 years and over for the Puerto Rican Elderly: Health Conditions study (PREHCO); 680 participants with diabetes at baseline and no baseline cognitive impairment were included in analyses. Cognitive decline and depressive symptoms were measured using the Mini-Mental Cabán (MMC) and Geriatric Depression Scale (GDS), respectively. We examined predictors of incident depressive symptoms (GDS ≥ 5 at follow-up but not baseline) and cognitive decline using regression modeling. In a covariate-adjusted logistic regression model, cognitive decline, female gender, and greater diabetes-related complications were each significantly associated with increased odds of incident depressive symptoms (p < 0.05). In a multiple regression model adjusted for covariates, incident depressive symptoms and older age were associated with greater cognitive decline, and higher education was related to less cognitive decline (p < 0.05). Incident depressive symptoms were more common for older Puerto Ricans with diabetes who also experienced cognitive decline. Efforts are needed to optimize diabetes management and monitor for depression and cognitive decline in this population.

Demographic Trends: Impact on Schools

ERIC Educational Resources Information Center

Chong, Sylvia N. Y.; Cheah, Horn Mun

2010-01-01

Background: Singapore is experiencing great demographic change. These demographic trends show fewer young people and declining birth rates, greater longevity for ageing generations and an increase in the number of non-Singaporean residents. Statistics also show that more than half of the total population increase in the last decades was…

A retrospective analysis of pollen host plant use by stable and declining bumble bee species.

PubMed

Kleijn, David; Raemakers, Ivo

2008-07-01

Understanding population declines has been the objective of a wide range of ecological studies. When species have become rare such studies are complicated because particular behavior or life history traits may be the cause but also the result of the decline of a species. We approached this problem by studying species' characteristics on specimens that were collected before the onset of their decline and preserved in natural history museums. In northwestern Europe, some bumble bee species declined dramatically during the 20th century whereas other, ecologically similar, species maintained stable populations. A long-standing debate focuses on whether this is caused by declining species having stricter host plant preferences. We compared the composition of pollen loads of five bumble bee species with stable populations and five with declining populations using museum specimens collected before 1950 in Belgium, England, and The Netherlands. Prior to 1950, the number of plant taxa in pollen loads of declining species was almost one-third lower than that in stable species even though individuals of stable and declining species generally originated from the same areas. There were no systematic differences in the composition of pollen loads between stable and declining species, but the plant taxa preferred by declining species before 1950 had experienced a stronger decline in the 20th century than those preferred by stable species. In 2004 and 2005, we surveyed the areas where bumble bees had been caught in the past and compared the composition of past and present pollen loads of the stable, but not of the by now locally extinct declining species. The number of collected pollen taxa was similar, but the composition differed significantly between the two periods. Differences in composition reflected the major changes in land use in northwestern Europe but also the spread of the invasive plant species Impatiens glandulifera. The main question now is why declining species apparently were not able to switch to less preferred food plants when stable species were. This study shows that natural history collections can play an important role in improving our understanding of the ecological mechanisms driving species population change.

Weather-Related Hazards and Population Change: A Study of Hurricanes and Tropical Storms in the United States, 1980–2012

PubMed Central

FUSSELL, ELIZABETH; CURRAN, SARA R.; DUNBAR, MATTHEW D.; BABB, MICHAEL A.; THOMPSON, LUANNE; MEIJER-IRONS, JACQUELINE

2017-01-01

Environmental determinists predict that people move away from places experiencing frequent weather hazards, yet some of these areas have rapidly growing populations. This analysis examines the relationship between weather events and population change in all U.S. counties that experienced hurricanes and tropical storms between 1980 and 2012. Our database allows for more generalizable conclusions by accounting for heterogeneity in current and past hurricane events and losses and past population trends. We find that hurricanes and tropical storms affect future population growth only in counties with growing, high-density populations, which are only 2 percent of all counties. In those counties, current year hurricane events and related losses suppress future population growth, although cumulative hurricane-related losses actually elevate population growth. Low-density counties and counties with stable or declining populations experience no effect of these weather events. Our analysis provides a methodologically informed explanation for contradictory findings in prior studies. PMID:29326480

Weather-Related Hazards and Population Change: A Study of Hurricanes and Tropical Storms in the United States, 1980-2012.

PubMed

Fussell, Elizabeth; Curran, Sara R; Dunbar, Matthew D; Babb, Michael A; Thompson, Luanne; Meijer-Irons, Jacqueline

2017-01-01

Environmental determinists predict that people move away from places experiencing frequent weather hazards, yet some of these areas have rapidly growing populations. This analysis examines the relationship between weather events and population change in all U.S. counties that experienced hurricanes and tropical storms between 1980 and 2012. Our database allows for more generalizable conclusions by accounting for heterogeneity in current and past hurricane events and losses and past population trends. We find that hurricanes and tropical storms affect future population growth only in counties with growing, high-density populations, which are only 2 percent of all counties. In those counties, current year hurricane events and related losses suppress future population growth, although cumulative hurricane-related losses actually elevate population growth. Low-density counties and counties with stable or declining populations experience no effect of these weather events. Our analysis provides a methodologically informed explanation for contradictory findings in prior studies.

Patterns of Hand Grip Strength and Detection of Strength Loss in Patients Undergoing Bone Marrow Transplantation: A Feasibility Study.

PubMed

Sayre, Cindy A; Belza, Basia; Shannon Dorcy, Kathleen; Phelan, Elizabeth; Whitney, JoAnne D

2017-09-01

To determine the feasibility of measuring hand grip strength (HGS) daily in a population of recipients of bone marrow transplantation (BMT), to describe changes in strength measured by HGS, and to describe relationships between laboratory values (hematocrit, hemoglobin, and absolute neutrophil count) and HGS.
. Prospective, longitudinal, repeated measures, within subject.
. Inpatient units at the University of Washington Medical Center in Seattle.
. 33 patients admitted in preparation for BMT or for complications from BMT.
. HGS measured on admission and daily.
. HGS, absolute neutrophil count, hemoglobin, and hematocrit.
. Participants found HGS testing to be relatively easy. Average time to complete testing was 7.2 minutes (SD = 1.95). Nineteen experienced 20% or greater decline in HGS during hospitalization, with nine experiencing decline during the conditioning phase. Age, gender, and hemoglobin correlated with HGS. Strength loss was more likely in those undergoing allogeneic compared to autologous BMT.
. A majority of patients experienced strength decline during BMT, with a subgroup declining during conditioning. A positive relationship existed between HGS and hemoglobin and hematocrit in participants admitted for conditioning for BMT.
. Weakness increases risk for falls. Patients may experience as much as 50% strength loss during the course of hospitalization for BMT. Strength loss occurs in the conditioning phase for some patients.

Fraser fir stand structure in the Black Mountains of North Carolina

Treesearch

Rachael H. McManamay; Lynn M. Resle; James B. Campbell

2010-01-01

Over the past several decades, naturally occurring populations of Fraser fir (Abies fraseri [Pursh.] Poir) have experienced devastating mortality rates due to attack by the exotic insect, balsam woolly adelgid (BWA) (Adelges piceae Ratz.). The decline in Fraser fir is particularly concerning because its natural geographic...

Public Schools. Cuyahoga County Data Brief

ERIC Educational Resources Information Center

Center on Urban Poverty and Community Development (NJ1), 2010

2010-01-01

Public school enrollment has fallen in most districts in Cuyahoga County, consistent with the overall population loss. The largest decreases of more than 30% have been in Cleveland and East Cleveland districts. Several inner ring suburbs have also experienced large declines, while a few outlying suburbs show increased enrollments. High school…

Milkweed Matters: Monarch butterfly (Lepidoptera: Nymphalidae) survival and development on nine Midwestern milkweed species

USDA-ARS?s Scientific Manuscript database

The population of monarch butterflies east of the Rocky Mountains has experienced a significant decline over the past twenty years. In order to increase monarch numbers in the breeding range, habitat restoration that includes planting milkweed plants is essential. Milkweeds in the genus Asclepias ...

Monarch butterfly oviposition preference supports a diversity of milkweed species on the landscape

USDA-ARS?s Scientific Manuscript database

Over the past two decades, the population of monarch butterflies east of the Rocky Mountains has experienced a significant decline in overwintering numbers. Habitat restoration that includes planting milkweeds is essential to boost monarch numbers within the breeding range. Milkweeds are the only ho...

Genetic diversity of flowering dogwood in the Great Smokey Mountains National Park

USDA-ARS?s Scientific Manuscript database

In the past three decades, flowering dogwood (Cornus florida) populations have experienced severe declines caused by dogwood anthracnose. Mortality has ranged from 48 to 98%, raising the concern that the genetic diversity of this native tree has been reduced significantly. In this study we investiga...

Russia’s Demographic Trend: A Population in Steady Decline

DTIC Science & Technology

2009-03-26

epidemic, but a combination of demographic factors that are irreversible in the short term: birth rates well below replacement level, abnormally high death ... rates , and lowered life expectancies. Exacerbating the trend in the future will be the high rate of HIV/AIDS infection Russia is experiencing. This

Changing Demographics and Needs Assessment for Learning Centers in the 21st Century

ERIC Educational Resources Information Center

Payne, Emily Miller; Hodges, Russ; Hernandez, Elda Patricia

2017-01-01

Students entering postsecondary education embody America's growing diversity. Rapid demographics shifts and changing student attendance patterns pose new challenges for higher education. Enrollment trends vary across states and regions with some areas seeing increased student populations while others are experiencing declining enrollments (Center…

Bird community composition

USGS Publications Warehouse

Antrobus, T.J.; Guilfoyle, M.P.; Barrow, W.C.; Hamel, P.B.; Wakeley, J.S.

2000-01-01

Neotropical migrants are birds that breed in North America and winter primarily in Central and South America. Long-term population studies of birds in the Eastern United States indicated declines of some forest-dwelling birds, many of which winter in the Neotropics (Peterjohn and others 1995). These declines were attributed to loss of wintering and breeding habitat due to deforestation and fragmentation, respectively. Many species of Nearctic migrants--birds that breed in the northern regions of North America and winter in the Southern United States--are also experiencing population declines. Because large areas of undistrubed, older, bottomland hardwood forests oftern contain large numbers of habitat specialists, including forest-interior neotropical migrants and wintering Nearctic migrants, these forests may be critical in maintaining avian diversity. This study had two primary objectivs: (1) to create a baseline data set that can be used as a standard against which other bottomland hardwood forests can be compared, and (2) to establish long-term monitoring stations during both breeding and wintering seasons to discern population trends of avian species using bottomland hardwood forests.

[The demographic potential of Russia].

PubMed

Vishnevskii, A

1998-05-01

This is a general review of current demographic trends in Russia. The author analyzes the decline in population size that is taking place at the end of the twentieth century, and traces its origins as far back as the disturbances associated with World War I, the Communist revolution, and the civil war that followed it. Political repression during the Stalinist period and the tribulations experienced during World War II also contributed to the current demographic crisis. The author discusses the changes in migration patterns and the declining fertility and increasing mortality rates. The decline in life expectancy is also addressed. Some comparisons are made with the demographic situation in other European countries.

The scaling of population persistence with carrying capacity does not asymptote in populations of a fish experiencing extreme climate variability.

PubMed

White, Richard S A; Wintle, Brendan A; McHugh, Peter A; Booker, Douglas J; McIntosh, Angus R

2017-06-14

Despite growing concerns regarding increasing frequency of extreme climate events and declining population sizes, the influence of environmental stochasticity on the relationship between population carrying capacity and time-to-extinction has received little empirical attention. While time-to-extinction increases exponentially with carrying capacity in constant environments, theoretical models suggest increasing environmental stochasticity causes asymptotic scaling, thus making minimum viable carrying capacity vastly uncertain in variable environments. Using empirical estimates of environmental stochasticity in fish metapopulations, we showed that increasing environmental stochasticity resulting from extreme droughts was insufficient to create asymptotic scaling of time-to-extinction with carrying capacity in local populations as predicted by theory. Local time-to-extinction increased with carrying capacity due to declining sensitivity to demographic stochasticity, and the slope of this relationship declined significantly as environmental stochasticity increased. However, recent 1 in 25 yr extreme droughts were insufficient to extirpate populations with large carrying capacity. Consequently, large populations may be more resilient to environmental stochasticity than previously thought. The lack of carrying capacity-related asymptotes in persistence under extreme climate variability reveals how small populations affected by habitat loss or overharvesting, may be disproportionately threatened by increases in extreme climate events with global warming. © 2017 The Author(s).

The legacy of slavery and contemporary declines in heart disease mortality in the U.S. South.

PubMed

Kramer, Michael R; Black, Nyesha C; Matthews, Stephen A; James, Sherman A

2017-12-01

This study aims to characterize the role of county-specific legacy of slavery in patterning temporal (i.e., 1968-2014), and geographic (i.e., Southern counties) declines in heart disease mortality. In this context, the U.S. has witnessed dramatic declines in heart disease mortality since the 1960's, which have benefitted place and race groups unevenly, with slower declines in the South, especially for the Black population. Age-adjusted race- and county-specific mortality rates from 1968-2014 for all diseases of the heart were calculated for all Southern U.S. counties. Candidate confounding and mediating covariates from 1860, 1930, and 1970, were combined with mortality data in multivariable regression models to estimate the ecological association between the concentration of slavery in1860 and declines in heart disease mortality from 1968-2014. Black populations, in counties with a history of highest versus lowest concentration of slavery, experienced a 17% slower decline in heart disease mortality. The association for Black populations varied by region (stronger in Deep South than Upper South states) and was partially explained by intervening socioeconomic factors. In models accounting for spatial autocorrelation, there was no association between slave concentration and heart disease mortality decline for Whites. Nearly 50 years of declining heart disease mortality is a major public health success, but one marked by uneven progress by place and race. At the county level, progress in heart disease mortality reduction among Blacks is associated with place-based historical legacy of slavery. Effective and equitable public health prevention efforts should consider the historical context of place and the social and economic institutions that may play a role in facilitating or impeding diffusion of prevention efforts thereby producing heart healthy places and populations. Graphical abstract.

Influences of water and sediment quality and hydrologic processes on mussels in the Clinch River

USGS Publications Warehouse

Johnson, Gregory C.; Krstolic, Jennifer L.; Ostby, Brett J.K.

2014-01-01

Segments of the Clinch River in Virginia have experienced declining freshwater mussel populations during the past 40 years, while other segments of the river continue to support some of the richest mussel communities in the country. The close proximity of these contrasting reaches provides a study area where differences in climate, hydrology, and historic mussel distribution are minimal. The USGS conducted a study between 2009 and 2011 to evaluate possible causes of the mussel declines. Evaluation of mussel habitat showed no differences in physical habitat quality, leaving water and sediment quality as possible causes for declines. Three years of continuous water-quality data showed higher turbidity and specific conductance in the reaches with low-quality mussel assemblages compared to reaches with high-quality mussel assemblages. Discrete water-quality samples showed higher major ions and metals concentrations in the low-quality reach. Base-flow samples contained high major ion and metal concentrations coincident to low-quality mussel populations. These results support a conceptual model of dilution and augmentation where increased concentrations of major ions and other dissolved constituents from mined tributaries result in reaches with declining mussel populations. Tributaries from unmined basins provide water with low concentrations of dissolved constituents, diluting reaches of the Clinch River where high-quality mussel populations occur.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coddington, Michael; Sciano, Damian; Fuller, Jason

The New York City boroughs of Brooklyn and Queens are undergoing a period of gentrification, infrastructure rebuilding, new construction, and load growth not experienced in decades. Significant numbers of residents are moving in, and structures that had been abandoned or were in disrepair are being refurbished and modernized to accommodate the burgeoning population. Homes, businesses, and industries are reviving areas long in decline, and Brooklyn's growth has made it the nation's fourth most populous city, according to the U.S. Census Bureau.

Reducing impacts of brood parasitism by Brown-headed Cowbirds on riparian-nesting migratory songbirds

Treesearch

Sara H. Schweitzer; Deborah M. Finch; David M. Leslie

1996-01-01

Riparian habitats throughout the Southwest have been altered directly and indirectly by human activities. Many migrant songbird species specific to riparian communities during the breeding season are experiencing population declines. Conversely, the Brown-headed Cowbird (Molothrus ater) benefits from fragmentation of, and livestock grazing in and near riparian habitat...

Using spatial statistics and point pattern simulations to assess the spatial dependency between greater sage-grouse and man-made features

USDA-ARS?s Scientific Manuscript database

The Greater Sage-grouse (Centrocercus urophasianus; hereafter Sage-grouse), a candidate species for listing under the Endangered Species Act, has experienced population declines across its range in the sagebrush (Artemisia spp.) steppe ecosystems of western North America. One factor contributing to...

Using spatial statistics and point-pattern simulations to assess the spatial dependency between greater sage-grouse and anthropogenic features

USDA-ARS?s Scientific Manuscript database

The greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse), a candidate species for listing under the Endangered Species Act, has experienced population declines across its range in the sagebrush (Artemisia spp.) steppe ecosystems of western North America. One factor contributing to...

A Profile of Conditions and Trends in Rural Illinois. Second Printing.

ERIC Educational Resources Information Center

Gruidl, John; Walzer, Norman

Rapid economic and population growth characterized the 1970s in much of rural America. Unfortunately, this "Rural Renaissance" was short-lived. Although some rural areas grew or remained stable during the 1980s, many others experienced stagnation and decline, evidenced by a variety of indicators. This document consists of graphic maps…

Colonies of bumble bees (Bombus impatiens) produce fewer workers, less bee biomass, and have smaller mother queens following fungicide exposure

USDA-ARS?s Scientific Manuscript database

Bees provide vital pollination services to the majority of flowering plants in both natural and agricultural systems. Unfortunately, both native and managed bee populations are experiencing serious declines, threatening the persistence of these plants and crops. Agricultural chemicals are one possib...

Lek ecology of male greater sage-grouse in Carbon County, Wyoming

Treesearch

Aleshia Lynn Fremgen

2014-01-01

Greater sage-grouse (Centrocercus urophasianus, hereafter "sage-grouse") have experienced range-wide population declines for several decades, and as a result they were considered warranted for listing under the Endangered Species Act in 2010. Therefore, wildlife managers need to understand how sage-grouse breeding behavior influences long-term reproductive...

Fine-scale habitat characteristics related to occupancy of the Yosemite Toad, Anaxyrus canorus

Treesearch

Christina T. Liang; Robert L. Grasso; Julie J. Nelson-Paul; Kim E. Vincent; Amy J. Lind

2017-01-01

Fine-scale habitat information can provide insight into species occupancy and persistence that is not apparent at the landscape-scale. Such information is particularly important for rare species that are experiencing population declines, such as the threatened Yosemite Toad (Anaxyrus canorus). Our study examined differences in physical...

Avian community and microhabitat associations of Cerulean Warblers in Alabama

Treesearch

John P. Carpenter; Yong Wang; Callie Schweitzer; Paul B. Hamel

2011-01-01

Cerulean Warblers (Dendroica cerulea) have experienced one of the highest population declines of any neotropical-Nearctic migratory species in North America. We performed point counts and habitat assessments in areas used and unused by Cerulean Warblers in northern Alabama during the 2005 and 2006 breeding seasons to examine their avian associations and identify...

Ecology of the Columbia spotted frog in northeastern Oregon.

Treesearch

Evelyn L. Bull

2005-01-01

The Columbia spotted frog (Rana luteiventris) is one of several amphibians in the Western United States experiencing population declines. The breeding, postbreeding, and overwintering habitat and ecology of this species were investigated in 10 study sites in northeastern Oregon from 1997 through 2004. A variety of habitats with permanent water were...

Managing emerging threats to spotted owls

Treesearch

Ho Yi Wan; Joseph L. Ganey; Christina D. Vojta; Samuel A. Cushman

2018-01-01

The 3 spotted owl (Strix occidentalis) subspecies in North America (i.e., northern spotted owl [S. o. caurina], California spotted owl [S. o. occidentalis], Mexican spotted owl [S. o. lucida]) have all experienced population declines over the past century due to habitat loss and fragmentation from logging. Now, the emerging influences of climate change, high-severity...

Experimental evolution of slowed cognitive aging in Drosophila melanogaster.

PubMed

Zwoinska, Martyna K; Maklakov, Alexei A; Kawecki, Tadeusz J; Hollis, Brian

2017-03-01

Reproductive output and cognitive performance decline in parallel during aging, but it is unknown whether this reflects a shared genetic architecture or merely the declining force of natural selection acting independently on both traits. We used experimental evolution in Drosophila melanogaster to test for the presence of genetic variation for slowed cognitive aging, and assess its independence from that responsible for other traits' decline with age. Replicate experimental populations experienced either joint selection on learning and reproduction at old age (Old + Learning), selection on late-life reproduction alone (Old), or a standard two-week culture regime (Young). Within 20 generations, the Old + Learning populations evolved a slower decline in learning with age than both the Old and Young populations, revealing genetic variation for cognitive aging. We found little evidence for a genetic correlation between cognitive and demographic aging: although the Old + Learning populations tended to show higher late-life fecundity than Old populations, they did not live longer. Likewise, selection for late reproduction alone did not result in improved late-life learning. Our results demonstrate that Drosophila harbor genetic variation for cognitive aging that is largely independent from genetic variation for demographic aging and suggest that these two aspects of aging may not necessarily follow the same trajectories. © 2016 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

In situ effects of pesticides on amphibians in the Sierra Nevada.

PubMed

Sparling, Donald W; Bickham, John; Cowman, Deborah; Fellers, Gary M; Lacher, Thomas; Matson, Cole W; McConnell, Laura

2015-03-01

For more than 20 years, conservationists have agreed that amphibian populations around the world are declining. Results obtained through laboratory or mesocosm studies and measurement of contaminant concentrations in areas experiencing declines have supported a role of contaminants in these declines. The current study examines the effects of contaminant exposure to amphibians in situ in areas actually experiencing declines. Early larval Pseudacris regilla were translocated among Lassen Volcanic, Yosemite and Sequoia National Parks, California, USA and caged in wetlands in 2001 and 2002 until metamorphosis. Twenty contaminants were identified in tadpoles with an average of 1.3-5.9 (maximum = 10) contaminants per animal. Sequoia National Park, which had the greatest variety and concentrations of contaminants in 2001, also had tadpoles that experienced the greatest mortality, slowest developmental rates and lowest cholinesterase activities. Yosemite and Sequoia tadpoles and metamorphs had greater genotoxicity than those in Lassen during 2001, as determined by flow cytometry. In 2001 tadpoles at Yosemite had a significantly higher rate of malformations, characterized as hemimelia (shortened femurs), than those at the other two parks but no significant differences were observed in 2002. Fewer differences in contaminant types and concentrations existed among parks during 2002 compared to 2001. In 2002 Sequoia tadpoles had higher mortality and slower developmental rates but there was no difference among parks in cholinesterase activities. Although concentrations of most contaminants were below known lethal concentrations, simultaneous exposure to multiple chemicals and other stressors may have resulted in lethal and sublethal effects.

Toxicity of two insecticides to California, USA, anurans and its relevance to declining amphibian populations

USGS Publications Warehouse

Sparling, D.W.; Fellers, G.M.

2009-01-01

Contaminants have been associated with population declines of several amphibian species in California (USA). Pesticides from the Central Valley of California are transported by winds into the Sierra Nevada Mountains and precipitate into wet meadows where amphibians breed. The present study examined the chronic toxicity of two of the insecticides most commonly used in the Central Valley and found in the mountains, chlorpyrifos and endosulfan, to larval Pacific treefrogs (Pseudacris regilla) and foothill yellow-legged frogs (Rana boylii) and discusses the implications of this toxicity to declining amphibian populations. Larvae were exposed to the pesticides from Gosner stages 25 to 26 through metamorphosis. The estimated median lethal concentration (LC50) for chlorpyrifos was 365 ??g/L in P. regilla and 66.5 ??g/L for R. boylii. Time to metamorphosis increased with concentration of chlorpyrifos in both species, and cholinesterase activity declined with exposure concentration in metamorphs of both species at Gosner stages 42 to 46. For endosulfan, the estimated LC50 was 15.6 ??g/L for P. regilla and 0.55 ??g/L for R. boylii. All R. boylii exposed to concentrations of greater than 0.8 ??g/L died before they entered metamorphosis. Pseudacris regilla remains relatively abundant and is broadly distributed throughout California. In contrast, R. boylii is among the species experiencing severe population declines. The present study adds to the increasing evidence that pesticides are very harmful to amphibians living in areas that are miles from sources of pesticide application. ?? 2009 SETAC.

Population Size and Decadal Trends of Three Penguin Species Nesting at Signy Island, South Orkney Islands.

PubMed

Dunn, Michael J; Jackson, Jennifer A; Adlard, Stacey; Lynnes, Amanda S; Briggs, Dirk R; Fox, Derren; Waluda, Claire M

2016-01-01

We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua ellsworthii) over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3.5% per annum), chinstrap penguins declined by 68% (-3.6% per annum) and Adélie penguins declined by 42% (-1.5% per annum). The chinstrap population has declined steadily over the last four decades. In contrast, Adélie and gentoo penguins have experienced phases of population increase and decline. Annual surveys of selected chinstrap and Adélie colonies produced similar trends from those revealed by island-wide surveys, allowing total island population trends to be inferred relatively well. However, while the annual colony counts of chinstrap and Adélie penguins showed a trend consistent in direction with the results from all-island surveys, the magnitude of estimated population change was markedly different between colony wide and all island counts. Annual population patterns suggest that pair numbers in the study areas partly reflect immigration and emigration of nesting birds between different parts of the island. Breeding success for all three species remained broadly stable over time in the annually monitored colonies. Breeding success rates in gentoo and chinstrap penguins were strongly correlated, despite the differing trends in population size. This study shows the importance of effective, standardised monitoring to accurately determine long-term population trajectories. Our results indicate significant declines in the Adélie and chinstrap penguin populations at Signy Island over the last five decades, and a gradual increase in gentoo breeding pairs.

Population Size and Decadal Trends of Three Penguin Species Nesting at Signy Island, South Orkney Islands

PubMed Central

Dunn, Michael J.; Jackson, Jennifer A.; Adlard, Stacey; Lynnes, Amanda S.; Briggs, Dirk R.; Fox, Derren; Waluda, Claire M.

2016-01-01

We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua ellsworthii) over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3.5% per annum), chinstrap penguins declined by 68% (-3.6% per annum) and Adélie penguins declined by 42% (-1.5% per annum). The chinstrap population has declined steadily over the last four decades. In contrast, Adélie and gentoo penguins have experienced phases of population increase and decline. Annual surveys of selected chinstrap and Adélie colonies produced similar trends from those revealed by island-wide surveys, allowing total island population trends to be inferred relatively well. However, while the annual colony counts of chinstrap and Adélie penguins showed a trend consistent in direction with the results from all-island surveys, the magnitude of estimated population change was markedly different between colony wide and all island counts. Annual population patterns suggest that pair numbers in the study areas partly reflect immigration and emigration of nesting birds between different parts of the island. Breeding success for all three species remained broadly stable over time in the annually monitored colonies. Breeding success rates in gentoo and chinstrap penguins were strongly correlated, despite the differing trends in population size. This study shows the importance of effective, standardised monitoring to accurately determine long-term population trajectories. Our results indicate significant declines in the Adélie and chinstrap penguin populations at Signy Island over the last five decades, and a gradual increase in gentoo breeding pairs. PMID:27783668

Survival and growth of northern white-cedar and balsam fir seedlings in riparian management zones in northern Minnesota, USA

Treesearch

Brian J. Palik; Brooke K. Haworth; Andrew J. David; Randall K. Kolka

2015-01-01

Northern white-cedar (Thuja occidentalis) and balsam fir (Abies balsamea.) are co-occurring species in riparian forests of the western Great Lakes region. Throughout much of the region, northern white-cedar has been experiencing population declines due to herbivory by white-tailed deer (Odocoileus virginianus)....

Advancing the science of forest hydrology A challenge to agricultural and biological engineers

Treesearch

Devendra Amatya; Wayne Skaggs; Carl Trettin

2009-01-01

For more than a century, agricultural and biological engineers have provided major advances in science, engineering, and technology to increase food and fiber production to meet the demands of a rapidly growing global population. The land base for these technological advances has originated largely from forested lands, which have experienced dramatic declines over the...

Teen Pregnancy Prevention Program Recommendations from Urban and Reservation Northern Plains American Indian Community Members

ERIC Educational Resources Information Center

McMahon, Tracey R.; Hanson, Jessica D.; Griese, Emily R.; Kenyon, DenYelle Baete

2015-01-01

Despite declines over the past few decades, the United States has one of the highest rates of teen pregnancy compared to other industrialized nations. American Indian youth have experienced higher rates of teen pregnancy compared to the overall population for decades. Although it's known that community and cultural adaptation enhance program…

Teachers Need Teachers: An Induction Program for First Year Bilingual Teachers.

ERIC Educational Resources Information Center

Sosa, Alicia Salinas; Gonzales, Frank

A critical shortage of bilingual teachers exists in Texas. While the Hispanic population has grown at a 39% rate, the number of Hispanic teachers has declined. The Teachers Need Teachers program in San Antonio pairs about 75 new bilingual education teachers with experienced bilingual education teachers, who serve as mentors. Its purpose is to…

A Study of Admission Officers' Perceptions of and Attitudes Toward Homeschool Students

ERIC Educational Resources Information Center

Jones, Paul; Gloeckner, Gene

2004-01-01

While the recent growth of homeschooling in America may not be an overall threat to public education in America today, some school districts are reporting that they are experiencing declines in their enrollments, which ultimately means a revenue loss in their school districts (Hetzner, 2000; Vater, 2001). The U.S. homeschool population (K-12) is…

Small Schools in a Big World: Thinking about a Wicked Problem

ERIC Educational Resources Information Center

Corbett, Michael; Tinkham, Jennifer

2014-01-01

The position of small rural schools is precarious in much of rural Canada today. What is to be done about small schools in rural communities which are often experiencing population decline and aging, economic restructuring, and the loss of employment and services? We argue this issue is a classic "wicked" policy problem. Small schools…

Condition varies with habitat choice in postbreeding forest birds

Treesearch

Scott H. Stoleson

2013-01-01

Many birds that are experiencing population declines require extensive tracts of mature forest habitat for breeding. Recent work suggests that at least some may shift their habitat use to early-successional areas after nesting but before migration. I used constant-effort mist netting in regenerating clearcuts (4-8 years postcut) and dense mature-forest understories to...

The Poor Little Rich District: The Effects of Suburbanization on a Rural School and Community

ERIC Educational Resources Information Center

Howley, Aimee; Carnes, Marilyn; Eldridge, Anita; Huber, Donna; Lado, Longun Moses; Kotler, Ruth; Turner, Maryalice

2005-01-01

Contextualized in relationship to other case studies about rural districts that have experienced population growth and decline as well as in relationship to the small sociological literature on "boom towns," this study considered the dynamics that seem to be interfering with one previously rural and now suburbanizing district's ability to address…

Historical and Contemporary DNA Indicate Fisher Decline and Isolation Occurred Prior to the European Settlement of California

PubMed Central

Tucker, Jody M.; Schwartz, Michael K.; Truex, Richard L.; Pilgrim, Kristine L.; Allendorf, Fred W.

2012-01-01

Establishing if species contractions were the result of natural phenomena or human induced landscape changes is essential for managing natural populations. Fishers (Martes pennanti) in California occur in two geographically and genetically isolated populations in the northwestern mountains and southern Sierra Nevada. Their isolation is hypothesized to have resulted from a decline in abundance and distribution associated with European settlement in the 1800s. However, there is little evidence to establish that fisher occupied the area between the two extant populations at that time. We analyzed 10 microsatellite loci from 275 contemporary and 21 historical fisher samples (1880–1920) to evaluate the demographic history of fisher in California. We did not find any evidence of a recent (post-European) bottleneck in the northwestern population. In the southern Sierra Nevada, genetic subdivision within the population strongly influenced bottleneck tests. After accounting for genetic subdivision, we found a bottleneck signal only in the northern and central portions of the southern Sierra Nevada, indicating that the southernmost tip of these mountains may have acted as a refugium for fisher during the anthropogenic changes of the late 19th and early 20th centuries. Using a coalescent-based Bayesian analysis, we detected a 90% decline in effective population size and dated the time of decline to over a thousand years ago. We hypothesize that fisher distribution in California contracted to the two current population areas pre-European settlement, and that portions of the southern Sierra Nevada subsequently experienced another more recent bottleneck post-European settlement. PMID:23300783

Global amphibian declines: perspectives from the United States and beyond

USGS Publications Warehouse

Densmore, Christine L.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

2011-01-01

Over recent decades, amphibians have experienced population declines, extirpations and species-level extinctions at an alarming rate. Numerous potential etiologies for amphibian declines have been postulated including climate and habitat degradation. Other potential anthropogenic causes including overexploitation and the frequent introductions of invasive predatory species have also been blamed for amphibian declines. Still other underlying factors may include infectious diseases caused by the chytrid fungus Batrachochytrium dendrobatidis, pathogenic viruses (Ranavirus), and other agents. It is nearly certain that more than one etiology is to blame for the majority of the global amphibian declines, and that these causal factors include some combination of climatological or physical habitat destabilization and infectious disease, most notably chytridiomycosis. Scientific research efforts are aimed at elucidating these etiologies on local, regional, and global scales that we might better understand and counteract the driving forces behind amphibian declines. Conservation efforts as outlined in the Amphibian Conservation Action Plan of 2005 are also being made to curtail losses and prevent further extinctions wherever possible.

Occupancy patterns of regionally declining grassland sparrow populations in a forested Pennsylvania landscape

USGS Publications Warehouse

Hill, Jason M.; Diefenbach, Duane R.

2014-01-01

Organisms can be affected by processes in the surrounding landscape outside the boundary of habitat areas and by local vegetation characteristics. There is substantial interest in understanding how these processes affect populations of grassland birds, which have experienced substantial population declines. Much of our knowledge regarding patterns of occupancy and density stem from prairie systems, whereas relatively little is known regarding how occurrence and abundance of grassland birds vary in reclaimed surface mine grasslands. Using distance sampling and single-season occupancy models, we investigated how the occupancy probability of Grasshopper (Ammodramus savannarum) and Henslow's Sparrows (A. henslowii) on 61 surface mine grasslands (1591 ha) in Pennsylvania changed from 2002 through 2011 in response to landscape, grassland, and local vegetation characteristics . A subset (n = 23; 784 ha) of those grasslands were surveyed in 2002, and we estimated changes in sparrow density and vegetation across 10 years. Grasshopper and Henslow's Sparrow populations declined 72% and 49%, respectively from 2002 to 2011, whereas overall woody vegetation density increased 2.6 fold. Henslow's Sparrows avoided grasslands with perimeter–area ratios ≥0.141 km/ha and woody shrub densities ≥0.04 shrubs/m2. Both species occupied grasslands ≤13 ha, but occupancy probability declined with increasing grassland perimeter–area ratio and woody shrub density. Grassland size, proximity to nearest neighboring grassland ( = 0.2 km), and surrounding landscape composition at 0.5, 1.5, and 3.0 km were not parsimonious predictors of occupancy probability for either species. Our results suggest that reclaimed surface mine grasslands, without management intervention, are ephemeral habitats for Grasshopper and Henslow's Sparrows. Given the forecasted decline in surface coal production for Pennsylvania, it is likely that both species will continue to decline in our study region for the foreseeable future.

In situ effects of pesticides on amphibians in the Sierra Nevada

USGS Publications Warehouse

Sparling, Donald W.; Bickham, John W.; Cowman, Deborah; Fellers, Gary M.; Lacher, Thomas E.; Matson, Cole W.; McConnell, Laura

2015-01-01

For more than 20 years, conservationists have agreed that amphibian populations around the world are declining. Results obtained through laboratory or mesocosm studies and measurement of contaminant concentrations in areas experiencing declines have supported a role of contaminants in these declines. The current study examines the effects of contaminant exposure to amphibians in situ in areas actually experiencing declines. Early larval Pseudacris regilla were translocated among Lassen Volcanic, Yosemite and Sequoia National Parks, California, USA and caged in wetlands in 2001 and 2002 until metamorphosis. Twenty contaminants were identified in tadpoles with an average of 1.3–5.9 (maximum = 10) contaminants per animal. Sequoia National Park, which had the greatest variety and concentrations of contaminants in 2001, also had tadpoles that experienced the greatest mortality, slowest developmental rates and lowest cholinesterase activities. Yosemite and Sequoia tadpoles and metamorphs had greater genotoxicity than those in Lassen during 2001, as determined by flow cytometry. In 2001 tadpoles at Yosemite had a significantly higher rate of malformations, characterized as hemimelia (shortened femurs), than those at the other two parks but no significant differences were observed in 2002. Fewer differences in contaminant types and concentrations existed among parks during 2002 compared to 2001. In 2002 Sequoia tadpoles had higher mortality and slower developmental rates but there was no difference among parks in cholinesterase activities. Although concentrations of most contaminants were below known lethal concentrations, simultaneous exposure to multiple chemicals and other stressors may have resulted in lethal and sublethal effects.

Six-month outcomes of co-occurring delirium, depression, and dementia in long-term care.

PubMed

McCusker, Jane; Cole, Martin G; Voyer, Philippe; Monette, Johanne; Champoux, Nathalie; Ciampi, Antonio; Vu, Minh; Belzile, Eric

2014-12-01

To describe the 6-month outcomes of co-occurring delirium (full syndrome and subsyndromal symptoms), depression, and dementia in a long-term care (LTC) population. Observational, prospective cohort study with 6-month follow-up conducted from 2005 to 2009. Seven LTC facilities in the province of Quebec, Canada. Newly admitted and long-term residents recruited consecutively from lists of residents aged 65 and older admitted for LTC, with stratification into groups with and without severe cognitive impairment. The study sample comprised 274 residents with complete data at baseline on delirium, dementia, and depression. Outcomes were 6-month mortality, functional decline (10-point decline from baseline on 100-point Barthel scale), and cognitive decline (3-point decline on 30-point Mini-Mental State Examination). Predictors included delirium (full syndrome or subsyndromal symptoms, using the Confusion Assessment Method), depression (Cornell Scale for Depression in Dementia), and dementia (chart diagnosis). The baseline prevalences of delirium, subsyndromal symptoms of delirium (SSD), depression, and dementia were 11%, 44%, 19%, and 66%, respectively. By 6 months, 10% of 274 had died, 19% of 233 had experienced functional decline, and 17% of 246 had experienced cognitive decline. An analysis using multivariable generalized linear models found the following significant interaction effects (P < .15): between depression and dementia for mortality, between delirium and depression for functional decline, and between SSD and dementia for cognitive decline. Co-occurrence of delirium, SSD, depression, and dementia in LTC residents appears to affect some 6-month outcomes. Because of limited statistical power, it was not possible to draw conclusions about the effects of the co-occurrence of some syndromes on poorer outcomes. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

Effective Population Size Dynamics and the Demographic Collapse of Bornean Orang-Utans

PubMed Central

Goossens, Benoit; Nater, Alexander; Morf, Nadja; Salmona, Jordi; Bruford, Michael W.; Van Schaik, Carel P.; Krützen, Michael; Chikhi, Lounès

2012-01-01

Bornean orang-utans experienced a major demographic decline and local extirpations during the Pleistocene and Holocene due to climate change, the arrival of modern humans, of farmers and recent commercially-driven habitat loss and fragmentation. The recent loss of habitat and its dramatic fragmentation has affected the patterns of genetic variability and differentiation among the remaining populations and increased the extinction risk of the most isolated ones. However, the contribution of recent demographic events to such genetic patterns is still not fully clear. Indeed, it can be difficult to separate the effects of recent anthropogenic fragmentation from the genetic signature of prehistoric demographic events. Here, we investigated the genetic structure and population size dynamics of orang-utans from different sites. Altogether 126 individuals were analyzed and a full-likelihood Bayesian approach was applied. All sites exhibited clear signals of population decline. Population structure is known to generate spurious bottleneck signals and we found that it does indeed contribute to the signals observed. However, population structure alone does not easily explain the observed patterns. The dating of the population decline varied across sites but was always within the 200–2000 years period. This suggests that in some sites at least, orang-utan populations were affected by demographic events that started before the recent anthropogenic effects that occurred in Borneo. These results do not mean that the recent forest exploitation did not leave its genetic mark on orang-utans but suggests that the genetic pool of orang-utans is also impacted by more ancient events. While we cannot identify the main cause for this decline, our results suggests that the decline may be related to the arrival of the first farmers or climatic events, and that more theoretical work is needed to understand how multiple demographic events impact the genome of species and how we can assess their relative contributions. PMID:23166666

Ecophysiology of seedling establishment in contrasting spruce-fir forests of southern Appalachian and Rocky Mountain ecotones, USA

Treesearch

William K. Smith; Keith N.C. Reinhardt; Daniel M. Johnson

2010-01-01

Fraser fir (Abies fraseri [Pursh] Poiret) and red spruce (Picea rubens Sarg.) occur as codominant trees in six relic, mountain-top populations that make up the high-elevation forests of the Southern Appalachian Mountains (SA). These two relic species of the former boreal forest have experienced a significant decline over the past...

Evolutionary responses of native plant species to invasive plants: a review.

PubMed

Oduor, Ayub M O

2013-12-01

Strong competition from invasive plant species often leads to declines in abundances and may, in certain cases, cause localized extinctions of native plant species. Nevertheless, studies have shown that certain populations of native plant species can co-exist with invasive plant species,suggesting the possibility of adaptive evolutionary responses of those populations to the invasive plants. Empirical inference of evolutionary responses of the native plant species to invasive plants has involved experiments comparing two conspecific groups of native plants for differences in expression of growth/reproductive traits: populations that have experienced competition from the invasive plant species (i.e. experienced natives) versus populations with no known history of interactions with the invasive plant species (i.e. naıve natives). Here, I employ a meta-analysis to obtain a general pattern of inferred evolutionary responses of native plant species from 53 such studies. In general, the experienced natives had significantly higher growth/reproductive performances than naıve natives, when grown with or without competition from invasive plants.While the current results indicate that certain populations of native plant species could potentially adapt evolutionarily to invasive plant species, the ecological and evolutionary mechanisms that probably underlie such evolutionary responses remain unexplored and should be the focus of future studies.

Regional growth decline of sugar maple (Acer saccharum) and its potential causes

USGS Publications Warehouse

Bishop, Daniel A.; Beier, Colin M.; Pederson, Neil; Lawrence, Gregory B.; Stella, John C; Sullivan, Timothy J.

2015-01-01

Sugar maple (Acer saccharum Marsh) has experienced poor vigor, regeneration failure, and elevated mortality across much of its range, but there has been relatively little attention to its growth rates. Based on a well-replicated dendrochronological network of range-centered populations in the Adirondack Mountains (USA), which encompassed a wide gradient of soil fertility, we observed that the majority of sugar maple trees exhibited negative growth trends in the last several decades, regardless of age, diameter, or soil fertility. Such growth patterns were unexpected, given recent warming and increased moisture availability, as well as reduced acidic deposition, which should have favored growth. Mean basal area increment was greater on base-rich soils, but these stands also experienced sharp reductions in growth. Growth sensitivity of sugar maple to temperature and precipitation was non-stationary during the last century, with overall weaker relationships than expected. Given the favorable competitive status and age structure of the Adirondack sugar maple populations sampled, evidence of widespread growth reductions raises concern over this ecologically and economically important tree. Further study will be needed to establish whether growth declines of sugar maple are occurring more widely across its range.

The disappearing northern leopard frog (Lithobates pipiens): conservation genetics and implications for remnant populations in western Nevada

PubMed Central

Rogers, Serena D; Peacock, Mary M

2012-01-01

Global amphibian declines suggest a major shift in the amount and quality of habitat for these sensitive taxa. Many species that were once widespread are now experiencing declines either in part of or across their historic range. The northern leopard frog (Rana [Lithobates] pipiens] has undergone significant declines particularly in the western United States and Canada. Leopard frog population losses in Nevada are largely due to habitat fragmentation and the introduction of nonnative fish, amphibian, and plant species. Only two populations remain in the Truckee and Carson River watersheds of western Nevada which represents the western boundary of this species range. We used sequence data for an 812 base pair fragment of the mitochondrial NADH dehydrogenase 1 (ND1) gene to support a native origin for western Nevada populations. All frogs had a single haplotype (W07) from the distinct western North America ND1 haplotype clade. Data from seven polymorphic microsatellite loci show that Truckee and Carson River populations are highly differentiated from each other and from leopard frogs collected from eastern Nevada sites. Lack of gene flow among and distinct color morphs among the western Nevada populations likely predates the current geographical isolation. Comparisons with other peripheral L. pipiens populations show western Nevada populations have similar levels of gene diversity despite their contemporary isolation (HE 0.411, 0.482). Restoration of leopard frog populations in these watersheds will be challenging given well-entrenched nonnative bullfrog populations and major changes to the riparian zone over the past century. Declines of once common amphibian species has become a major conservation concern. Contemporary isolation of populations on a species range periphery such as the leopard frog populations in the Truckee and Carson rivers further exacerbate extirpation risk as these populations are likely to have fewer genetic resources to adaptively respond to rapidly changing biotic and abiotic environments. PMID:22957204

Can migration mitigate the effects of ecosystem change? Patterns of dispersal, energy acquisition and allocation in Great Lakes lake whitefish (Coregonus clupeaformis)

USGS Publications Warehouse

Rennie, Michael D.; Ebener, Mark P.; Wagner, Tyler

2012-01-01

Migration can be a behavioural response to poor or declining home range habitat quality and can occur when the costs of migration are overcome by the benefi ts of encountering higher-quality resources elsewhere. Despite dramatic ecosystem-level changes in the benthic food web of the Laurentian Great Lakes since the colonization of dreissenid mussels, coincident changes in condition and growth rates among benthivorous lake whitefi sh populations have been variable. We hypothesized that this variation could be in part mitigated by differences in migratory habits among populations, where increased migration distance can result in an increased probability of encountering high-quality habitat (relative to the home range). Results from four Great Lakes populations support this hypothesis; relative growth rates increased regularly with migration distance. The population with the largest average migration distance also had the least reduction in size-at-age during a period of signifi cant ecosystem change and among the highest estimated consumption and activity rates. In comparison, the population with the greatest declines in size-at-age was among the least mobile, demonstrating only moderate rates of consumption and activity. The least mobile population of lake whitefi sh was supported by a remnant Diporeia population and has experienced only moderate temporal growth declines. Our study provides evidence for the potential role of migration in mitigating the effects of ecosystem change on lake whitefi sh populations.

Reduced population size does not affect the mating strategy of a vulnerable and endemic seabird

NASA Astrophysics Data System (ADS)

Nava, Cristina; Neves, Verónica C.; Andris, Malvina; Dubois, Marie-Pierre; Jarne, Philippe; Bolton, Mark; Bried, Joël

2017-12-01

Bottleneck episodes may occur in small and isolated animal populations, which may result in decreased genetic diversity and increased inbreeding, but also in mating strategy adjustment. This was evaluated in the vulnerable and socially monogamous Monteiro's Storm-petrel Hydrobates monteiroi, a seabird endemic to the Azores archipelago which has suffered a dramatic population decline since the XVth century. To do this, we conducted a genetic study (18 microsatellite markers) in the population from Praia islet, which has been monitored over 16 years. We found no evidence that a genetic bottleneck was associated with this demographic decline. Monteiro's Storm-petrels paired randomly with respect to genetic relatedness and body measurements. Pair fecundity was unrelated to genetic relatedness between partners. We detected only two cases of extra-pair parentage associated with an extra-pair copulation (out of 71 offspring). Unsuccessful pairs were most likely to divorce the next year, but genetic relatedness between pair mates and pair breeding experience did not influence divorce. Divorce enabled individuals to improve their reproductive performances after re-mating only when the new partner was experienced. Re-pairing with an experienced partner occurred more frequently when divorcees changed nest than when they retained their nest. This study shows that even in strongly reduced populations, genetic diversity can be maintained, inbreeding does not necessarily occur, and random pairing is not risky in terms of pair lifetime reproductive success. Given, however, that we found no clear phenotypic mate choice criteria, the part played by non-morphological traits should be assessed more accurately in order to better understand seabird mating strategies.

Marked Campylobacteriosis Decline after Interventions Aimed at Poultry, New Zealand

PubMed Central

Sears, Ann; Wilson, Nick; Marshall, Jonathan; Muellner, Petra; Campbell, Donald M.; Lake, Robin J.; French, Nigel P.

2011-01-01

Beginning in the 1980s, New Zealand experienced rising annual rates of campylobacteriosis that peaked in 2006. We analyzed notification, hospitalization, and other data to explore the 2007–2008 drop in campylobacteriosis incidence. Source attribution techniques based on genotyping of Campylobacter jejuni isolates from patients and environmental sources were also used to examine the decline. In 2008, the annual campylobacteriosis notification rate was 161.5/100,000 population, representing a 54% decline compared with the average annual rate of 353.8/100,000 for 2002–2006. A similar decline was seen for hospitalizations. Source attribution findings demonstrated a 74% (95% credible interval 49%–94%) reduction in the number of cases attributed to poultry. These reductions coincided with the introduction of a range of voluntary and regulatory interventions to reduce Campylobacter spp. contamination of poultry. The apparent success of these interventions may inform approaches other countries could consider to help control foodborne campylobacteriosis. PMID:21749761

Abortion Incidence and Service Availability In the United States, 2014

PubMed Central

Jones, Rachel K.; Jerman, Jenna

2017-01-01

CONTEXT National and state-level information about abortion incidence can help inform policies and programs intended to reduce levels of unintended pregnancy. METHODS In 2015–2016, all U.S. facilities known or expected to have provided abortion services in 2013 or 2014 were surveyed. Data on the number of abortions were combined with population data to estimate national and state-level abortion rates. The number of abortion-providing facilities and changes since a similar 2011 survey were also assessed. The number and type of new abortion restrictions were examined in the states that had experienced the largest proportionate changes in clinics providing abortion services. RESULTS In 2014, an estimated 926,200 abortions were performed in the United States, 12% fewer than in 2011; the 2014 abortion rate was 14.6 abortions per 1,000 women aged 15–44, representing a 14% decline over this period. The number of clinics providing abortions declined 6% between 2011 and 2014, and declines were steepest in the Midwest (22%) and the South (13%). Early medication abortions accounted for 31% of nonhospital abortions, up from 24% in 2011. Most states that experienced the largest proportionate declines in the number of clinics providing abortions had enacted one or more new restrictions during the study period, but reductions were not always associated with declines in abortion incidence. CONCLUSIONS The relationship between abortion access, as measured by the number of clinics, and abortion rates is not straightforward. Further research is needed to understand the decline in abortion incidence. PMID:28094905

Local Ecological Knowledge and Scientific Data Reveal Overexploitation by Multigear Artisanal Fisheries in the Southwestern Atlantic

PubMed Central

Bender, Mariana G.; Machado, Gustavo R.; Silva, Paulo José de Azevedo; Floeter, Sergio R.; Monteiro-Netto, Cassiano; Luiz, Osmar J.; Ferreira, Carlos E. L.

2014-01-01

In the last decades, a number of studies based on historical records revealed the diversity loss in the oceans and human-induced changes to marine ecosystems. These studies have improved our understanding of the human impacts in the oceans. They also drew attention to the shifting baseline syndrome and the importance of assessing appropriate sources of data in order to build the most reliable environmental baseline. Here we amassed information from artisanal fishermen's local ecological knowledge, fisheries landing data and underwater visual census to assess the decline of fish species in Southeastern Brazil. Interviews with 214 fishermen from line, beach seine and spearfishing revealed a sharp decline in abundance of the bluefish Pomatomus saltatrix, the groupers Epinephelus marginatus, Mycteroperca acutirostris, M. bonaci and M. microlepis, and large parrotfishes in the past six decades. Fisheries landing data from a 16-year period support the decline of bluefish as pointed by fishermen's local knowledge, while underwater visual census campaigns show reductions in groupers' abundance and a sharp population decline of the Brazilian endemic parrotfish Scarus trispinosus. Despite the marked decline of these fisheries, younger and less experienced fishermen recognized fewer species as overexploited and fishing sites as depleted than older and more experienced fishermen, indicating the occurrence of the shifting baseline syndrome. Here we show both the decline of multigear fisheries catches – combining anecdotal and scientific data – as well as changes in environmental perceptions over generations of fishermen. Managing ocean resources requires looking into the past, and into traditional knowledge, bringing historical baselines to the present and improving public awareness. PMID:25333661

Local ecological knowledge and scientific data reveal overexploitation by multigear artisanal fisheries in the southwestern Atlantic.

PubMed

Bender, Mariana G; Machado, Gustavo R; Silva, Paulo José de Azevedo; Floeter, Sergio R; Monteiro-Netto, Cassiano; Luiz, Osmar J; Ferreira, Carlos E L

2014-01-01

In the last decades, a number of studies based on historical records revealed the diversity loss in the oceans and human-induced changes to marine ecosystems. These studies have improved our understanding of the human impacts in the oceans. They also drew attention to the shifting baseline syndrome and the importance of assessing appropriate sources of data in order to build the most reliable environmental baseline. Here we amassed information from artisanal fishermen's local ecological knowledge, fisheries landing data and underwater visual census to assess the decline of fish species in Southeastern Brazil. Interviews with 214 fishermen from line, beach seine and spearfishing revealed a sharp decline in abundance of the bluefish Pomatomus saltatrix, the groupers Epinephelus marginatus, Mycteroperca acutirostris, M. bonaci and M. microlepis, and large parrotfishes in the past six decades. Fisheries landing data from a 16-year period support the decline of bluefish as pointed by fishermen's local knowledge, while underwater visual census campaigns show reductions in groupers' abundance and a sharp population decline of the Brazilian endemic parrotfish Scarus trispinosus. Despite the marked decline of these fisheries, younger and less experienced fishermen recognized fewer species as overexploited and fishing sites as depleted than older and more experienced fishermen, indicating the occurrence of the shifting baseline syndrome. Here we show both the decline of multigear fisheries catches - combining anecdotal and scientific data - as well as changes in environmental perceptions over generations of fishermen. Managing ocean resources requires looking into the past, and into traditional knowledge, bringing historical baselines to the present and improving public awareness.

Stressful life events and cognitive decline in late life: moderation by education and age. The Cache County Study.

PubMed

Tschanz, Joann T; Pfister, Roxane; Wanzek, Joseph; Corcoran, Chris; Smith, Ken; Tschanz, Brian T; Steffens, David C; Østbye, Truls; Welsh-Bohmer, Kathleen A; Norton, Maria C

2013-08-01

Stressful life events (SLE) have been associated with increased dementia risk, but their association with cognitive decline has been inconsistent. In a longitudinal population-based study of older individuals, we examined the association between SLE and cognitive decline, and the role of potential effect modifiers. A total of 2665 non-demented participants of the Cache County Memory Study completed an SLE questionnaire at Wave 2 and were revisited 4 and 7 years later. The events were represented via several scores: total number, subjective rating (negative, positive, and unexpected), and a weighted summary based on their impact. Cognition was assessed at each visit with the modified Mini-Mental State Exam. General linear models were used to examine the association between SLE scores and cognition. Effect modification by age, education, and APOE genotype was tested. Years of formal education (p = 0.006) modified the effect of number of SLE, and age (p = 0.009) modified the effect of negative SLE on the rate of cognitive decline. Faster decline was observed among those with fewer years of education experiencing more SLE and also among younger participants experiencing more negative SLE. There was no association between other indicators of SLE and cognitive decline. APOE genotype did not modify any of the aforementioned associations. The effects of SLE on cognition in late life are complex and vary by individual factors such as age and education. These results may explain some of the contradictory findings in the literature. Copyright © 2012 John Wiley & Sons, Ltd.

Projected asymmetric response of Adélie penguins to Antarctic climate change

NASA Astrophysics Data System (ADS)

Cimino, Megan A.; Lynch, Heather J.; Saba, Vincent S.; Oliver, Matthew J.

2016-06-01

The contribution of climate change to shifts in a species’ geographic distribution is a critical and often unresolved ecological question. Climate change in Antarctica is asymmetric, with cooling in parts of the continent and warming along the West Antarctic Peninsula (WAP). The Adélie penguin (Pygoscelis adeliae) is a circumpolar meso-predator exposed to the full range of Antarctic climate and is undergoing dramatic population shifts coincident with climate change. We used true presence-absence data on Adélie penguin breeding colonies to estimate past and future changes in habitat suitability during the chick-rearing period based on historic satellite observations and future climate model projections. During the contemporary period, declining Adélie penguin populations experienced more years with warm sea surface temperature compared to populations that are increasing. Based on this relationship, we project that one-third of current Adélie penguin colonies, representing ~20% of their current population, may be in decline by 2060. However, climate model projections suggest refugia may exist in continental Antarctica beyond 2099, buffering species-wide declines. Climate change impacts on penguins in the Antarctic will likely be highly site specific based on regional climate trends, and a southward contraction in the range of Adélie penguins is likely over the next century.

Has contemporary climate change played a role in population declines of the lizard Ctenophorus decresii from semi-arid Australia?

PubMed

Walker, Samantha; Stuart-Fox, Devi; Kearney, Michael R

2015-12-01

Whilst contemporary climatic changes are small in magnitude compared to those predicted for the coming decades, they have already been linked to species range shifts and local extinctions. Elucidating the drivers behind species' responses to contemporary climate change will better inform management strategies for vulnerable and pest species alike. A recent proposal to explain worldwide local extinctions in lizards is that increasing maximum temperatures have constrained lizard activity time in the breeding season beyond extinction thresholds. Here we document a significant population decline and potential local extinction at the warm (northern) range margin of the tawny dragon, Ctenophorus decresii, a rock-dwelling lizard from the Flinders Ranges in semi-arid Australia. We developed and tested a biophysical model of tawny dragon thermoregulatory behaviour and drove the model with daily weather data for the period 1990-2009 across the Flinders Ranges. Our results indicate that potential annual activity time has likely increased over this period throughout the historic range, with within-season declines only in the summer months at the northern range limit. However, populations that have declined since 2000 have also likely experienced higher active body temperatures and more stringent retreat-site requirements (deeper crevices) than have regions where the species remains common, during a period of declining rainfall. Our laboratory estimates of thermal preference in this species were insensitive to altered nutritional and hydric state. Thus it is possible that recent population declines are linked to desiccation stress driven by higher body temperatures and declining rainfall. Our study illustrates that simple indices of the impact of climate warming on animals, such as activity restriction, may in fact reflect a variety of potential mechanisms whose ultimate outcome will be contingent on other factors such as water and shelter availability. Copyright © 2014 Elsevier Ltd. All rights reserved.

Extinction debt as a driver of amphibian declines: An example with imperiled flatwoods salamanders

USGS Publications Warehouse

Semiltsch, Raymond D; Walls, Susan; Barichivich, William J.; O'Donnell, Katherine

2017-01-01

A comprehensive view of population declines and their underlying causes is necessary to reverse species loss. Historically, in many cases, a narrow view may have allowed species declines to continue, virtually undetected, for long periods of time (perhaps even decades). We suggest that extinction debt is likely responsible for numerous (perhaps most) amphibian declines and that this perspective should be incorporated into the structure of amphibian research and management. Extinction debt, originally proposed to explain changes in species richness following environmental disturbance, also may refer to the proportion of populations of an individual species that is expected to eventually be lost because of habitat change. A conservation framework to address extinction debt focuses research on threats at the individual, population, and metapopulation levels. This approach will help enhance, restore, and protect specific processes and habitats at the proper scale by directing management to the most vulnerable level and stage of a species. We illustrate this approach using Flatwoods Salamanders, Ambystoma cingulatumand Ambystoma bishopi, which occurred historically throughout the Coastal Plain of the southeastern United States but have experienced a greater than 85% loss of populations in recent years. Reversal of these losses is possible only if conservation and recovery efforts encompass individual, population, and metapopulation levels. We illustrate our framework by outlining actions that could be taken at each of these levels to help guide conservation and management of amphibians with complex life cycles and provide options for how to prioritize conservation actions in the face of logistical and budgetary shortfalls.

Pinus albicaulis Engelm. (whitebark pine) in mixed-species stands throughout its US range: Broad-scale indicators of extent and recent decline

Treesearch

Sara A. Goeking; Deborah Kay Izlar

2018-01-01

We used data collected from >1400 plots by a national forest inventory to quantify population-level indicators for a tree species of concern. Whitebark pine (Pinus albicaulis) has recently experienced high mortality throughout its US range, where we assessed the area of land with whitebark pine present, size-class distribution of individual whitebark pine,...

The cerulean warbler in Morgan-Monroe and Yellowwood State Forests, Indiana: pre-treatment data on abundance and spatial characteristics of territories

Treesearch

Kamal Islam; Kyle J. Kaminski; Margaret M. MacNeil; Lila Prichard. Young

2013-01-01

The cerulean warbler (Setophaga cerulea) is a small Neotropical migrant songbird that is currently experiencing population declines. We monitored the number of cerulean warblers, as well as size and spatial attributes of territories, before two methods of silvicultural treatments took place in six of nine study units involved in the Hardwood...

Baby Boomers and Beds: a Demographic Challenge for the Ages.

PubMed

Song, Zirui; Ferris, Timothy G

2018-03-01

The United States is facing a significant demographic transition, with about 10,000 baby boomers turning age 65 each day. At the same time, the nation is experiencing a similarly striking transition in hospital capacity, as the supply of hospital beds has declined in recent decades. The juxtaposition of population aging and hospital capacity portends a potentially widening divergence between supply and demand for hospital care. We provide a closer look at current hospital capacity and a rethinking of the future role of hospital beds in meeting the needs of an aging population.

Detecting warning signs of trouble within population fluctuations: using capture-recapture modeling to uncover changes in population dynamics leading to declines

USGS Publications Warehouse

Spendelow, J.A.; Nichols, J.D.; Kendall, W.L.; Hines, J.E.; Hatfield, J.S.; Nisbet, I.C.T.

2004-01-01

An intensive mark-recapture/resighting program has been carried out on the Roseate Terns nesting at Falkner Island, Connecticut, since the late 1980s as part of a regional study of the metapopulation dynamics and ecology of the endangered Northwest Atlantic breeding population of this species. Substantial losses of tern eggs and chicks to predation at this colony site began in 1996 when at least five Black-crowned Night-Herons started nocturnal raids. This depredation has been a major factor in the reduction of productivity from an average of about 1.0 chicks/pair for the 10 years before night-heron predation began to as low as about 0.2 chicks/pair in 2002. Recent capture-recapture modelling analyses have detected other important impacts on the population dynamics of the Roseate Terns at this site including a reduction by about half in the 'development-of-residency' rates of first-time breeders, and a substantial decline in the local 'survival-and-fidelity' rates of experienced breeders believed due mostly to increased immigration rates to other colony sites.

Bats in the south coast ecoregion: status, conservation issues, and research needs

Treesearch

Karen L. Miner; Drew C. Stokes

2005-01-01

California’s bat fauna is one of the most diverse in the United States. Of the 25 species of bats in the state, 24 have been detected in the south coast ecoregion. Many of these species appear to have experienced population declines in the ecoregion, and 16 are officially recognized as sensitive (including one endangered) by wildlife regulatory agencies. Data from...

Low productivity of Chinook salmon strongly correlates with high summer stream discharge in two Alaskan rivers in the Yukon drainage

USGS Publications Warehouse

Neuswanger, Jason R.; Wipfli, Mark S.; Evenson, Matthew J.; Hughes, Nicholas F.; Rosenberger, Amanda E.

2015-01-01

Yukon River Chinook salmon (Oncorhynchus tshawytscha) populations are declining for unknown reasons, creating hardship for thousands of stakeholders in subsistence and commercial fisheries. An informed response to this crisis requires understanding the major sources of variation in Chinook salmon productivity. However, simple stock–recruitment models leave much of the variation in this system’s productivity unexplained. We tested adding environmental predictors to stock–recruitment models for two Yukon drainage spawning streams in interior Alaska — the Chena and Salcha rivers. Low productivity was strongly associated with high stream discharge during the summer of freshwater residency for young-of-the-year Chinook salmon. This association was more consistent with the hypothesis that sustained high discharge negatively affects foraging conditions than with acute mortality during floods. Productivity may have also been reduced in years when incubating eggs experienced major floods or cold summers and falls. These freshwater effects — especially density dependence and high discharge — helped explain population declines in both rivers. They are plausible as contributors to the decline of Chinook salmon throughout the Yukon River drainage.

Piscivore diet response to a collapse in pelagic prey populations

USGS Publications Warehouse

Zeug, Steven; Feyrer, Frederick; Brodsky, Annie; Melgo, Jenny

2017-01-01

Pelagic fish populations in the upper San Francisco Estuary have experienced significant declines since the turn of the century; a pattern known as the pelagic organism decline (POD). This study investigated food habits of piscivorous fishes over two consecutive fall seasons following the decline of pelagic fish prey. Specifically, this study addressed the contribution of pelagic versus benthic prey to piscivorous fish diets, including the frequency of predation on special-status pelagic species, and the spatial variability in prey consumption. The piscivore community was dominated by Striped Bass and also included small numbers of Sacramento Pikeminnow and Largemouth Bass. Overall, pelagic prey items contributed less than 10% of the diet by weight in both years, whereas pre-POD studies gleaned from the literature found contributions of 39–100%, suggesting a major switch from pelagic to benthic prey resources. Between-year variation in piscivore diets reflected differences in environmental conditions associated with variation in freshwater outflow. No special status fish species were detected in any of the piscivore stomachs examined. The consequences of this pelagic to benthic diet shift warrants further investigation to understand its ecological relevance.

Avian assemblages on altered grasslands

USGS Publications Warehouse

Knopf, Fritz L.

1994-01-01

Grasslands comprise 17% of the North American landscape but provide primary habitat for only 5% of native bird species. On the Great Plains, grasslands include an eastern component of tall grasses and a western component of short grasses, both of which have been regionally altered by removing native grazers, plowing sod, draining wetlands, and encouraging woody vegetation. As a group, populations of endemic bird species of the grasslands have declined more than others (including neotropical migrants) in the last quarter century. Individually, populations of the Upland Sandpiper and McCown’s Longspur have increased; the wetlands-associated Marbled Godwit and Wilson’s Phalarope appear stable; breeding ranges are shifting for the Ferruginous Hawk, Mississippi Kite, Short-eared Owl, Upland Sandpiper, Horned Lark, Vesper, Savannah, and Henslow’s sparrows, and Western Meadowlark; breeding habitats are disappearing locally for Franklin’s Gull, Dickcissel, Henslow’s and Grasshopper sparrows. Lark Bunting, and Eastern Meadowlark; and populations are declining throughout the breeding ranges for Mountain Plover, and Cassin’s and Clay-colored sparrows. Declines of these latter three species, and also the Franklin’s Gull, presumably are due to ecological phenomena on their respective wintering areas. Unlike forest species that winter in the neotropics, most birds that breed in the North American grasslands also winter on the continent and problems driving declines in grassland species are associated almost entirely with North American processes. Contemporary programs and initiatives hold promise for the conservation of breeding habitats for these birds. Ecological ignorance of wintering habits and habitats clouds the future of the endemic birds of grasslands, especially those currently experiencing widespread declines across breeding locales.

Conservation challenges and research needs for Pacific lamprey in the Columbia River Basin

USGS Publications Warehouse

Clemens, Benjamin J.; Beamish, Richard J.; Coates, Kelly C.; Docker, Margaret F.; Dunham, Jason B.; Gray, Ann E.; Hess, Jon E.; Jolley, Jeffrey C.; Lampman, Ralph T.; McIlraith, Brian J.; Moser, Mary L.; Murauskas, Joshua G.; Noakes, David L. G.; Schaller, Howard A.; Schreck, Carl B.; Starcevich, Steven J.; Streif, Bianca; van de Wetering, Stan J.; Wade, Joy; Weitkamp, Laurie A.; Wyss, Lance A.

2017-01-01

The Pacific Lamprey Entosphenus tridentatus, an anadromous fish native to the northern Pacific Ocean and bordering freshwater habitats, has recently experienced steep declines in abundance and range contractions along the West Coast of North America. During the early 1990s, Native American tribes recognized the declining numbers of lamprey and championed their importance. In 2012, 26 entities signed a conservation agreement to coordinate and implement restoration and research for Pacific Lamprey. Regional plans have identified numerous threats, monitoring needs, and strategies to conserve and restore Pacific Lamprey during their freshwater life stages. Prime among these are needs to improve lamprey passage, restore freshwater habitats, educate stakeholders, and implement lamprey-specific research and management protocols. Key unknowns include range-wide trends in status, population dynamics, population delineation, limiting factors, and marine influences. We synthesize these key unknowns, with a focus on the freshwater life stages of lamprey in the Columbia River basin.

HIGHER PARENTAL PERCEPTIONS OF WEALTH ASSOCIATED WITH THE BIRTH OF MORE SONS IN AN AUSTRALIAN POPULATION.

PubMed

Behie, A M; O'Donnell, M H

2017-09-20

Many industrialized nations are currently experiencing a decline in average secondary sex ratio (SSR) resulting in fewer boys being born relative to girls. While many potential factors may explain the decline in the birth of males relative to females, it seems most studies support the idea that male offspring are produced less often when environmental conditions are poor owing to males being more susceptible to loss in harsh environments. This study investigates the maternal factors that are associated with the sex of offspring in a cohort of the Australian population. It found that greater parental perceptions of wealth were significantly associated with an increase in the number of sons produced. These results suggest that male offspring are born at increased numbers to women with higher available resources, which may reflect the fact that male offspring are more vulnerable in poor environments.

Occupancy patterns of regionally declining grassland sparrow populations in a forested Pennsylvania landscape.

PubMed

Hill, Jason M; Diefenbach, Duane R

2014-06-01

Organisms can be affected by processes in the surrounding landscape outside the boundary of habitat areas and by local vegetation characteristics. There is substantial interest in understanding how these processes affect populations of grassland birds, which have experienced substantial population declines. Much of our knowledge regarding patterns of occupancy and density stem from prairie systems, whereas relatively little is known regarding how occurrence and abundance of grassland birds vary in reclaimed surface mine grasslands. Using distance sampling and single-season occupancy models, we investigated how the occupancy probability of Grasshopper (Ammodramus savannarum) and Henslow's Sparrows (A. henslowii) on 61 surface mine grasslands (1591 ha) in Pennsylvania changed from 2002 through 2011 in response to landscape, grassland, and local vegetation characteristics . A subset (n = 23; 784 ha) of those grasslands were surveyed in 2002, and we estimated changes in sparrow density and vegetation across 10 years. Grasshopper and Henslow's Sparrow populations declined 72% and 49%, respectively from 2002 to 2011, whereas overall woody vegetation density increased 2.6 fold. Henslow's Sparrows avoided grasslands with perimeter-area ratios ≥0.141 km/ha and woody shrub densities ≥0.04 shrubs/m(2). Both species occupied grasslands ≤13 ha, but occupancy probability declined with increasing grassland perimeter-area ratio and woody shrub density. Grassland size, proximity to nearest neighboring grassland (x = 0.2 km), and surrounding landscape composition at 0.5, 1.5, and 3.0 km were not parsimonious predictors of occupancy probability for either species. Our results suggest that reclaimed surface mine grasslands, without management intervention, are ephemeral habitats for Grasshopper and Henslow's Sparrows. Given the forecasted decline in surface coal production for Pennsylvania, it is likely that both species will continue to decline in our study region for the foreseeable future. © 2014 Society for Conservation Biology.

Attributing mortality among drivers of population decline in Acropora palmata in the Florida Keys (USA)

NASA Astrophysics Data System (ADS)

Williams, D. E.; Miller, M. W.

2012-06-01

Acropora palmata populations have experienced steep declines over the past 30 years. Although numerous culprits are recognized, their relative contributions to the decline are poorly quantified, making it difficult to prioritize effective conservation measures. In 2004, a demographic monitoring program was implemented in the Florida Keys (USA), aimed at determining the relative importance of various stressors affecting A. palmata. A subset of randomly selected A. palmata colonies within 15 fore-reef plots was tagged and surveyed three to four times per year over 7 years. Colony size, live tissue, prevalence of disease, snail ( Coralliophila abbreviata) predation, physical damage and other conditions were assessed at each survey. The estimated effect of each condition causing recent mortality was ranked, and together, these parameters were used to attribute the population-level tissue loss associated with each condition. In addition, all new colonies in the study plots were counted and assessed annually in order to track trends in total colony count and live tissue abundance. Between 2004 and 2010, the study population has shown more than 50% decline in live area from three main conditions: fragmentation, disease and snail predation. Approximately half of this decline occurred during the catastrophic 2005 hurricane season from which recovery has been minimal. Meanwhile, colony abundance has shown gradual decline throughout the study. Snail predation was the most prevalent condition. However, it ranked third in attributed tissue loss, behind breakage that occurred during the 2005 hurricane season, and disease. Thermal bleaching of A. palmata was not observed during this study. Because mortality continues to outpace recruitment and growth, intervention to ameliorate losses to the more manageable threats including predation and breakage could result in substantial conservation of live tissue, buying time for the abatement of less tractable threats to A. palmata recovery such as climate change and disease.

[Speech by Oscar Julian Bardeci, director of the Centro Latinoamericano de Demografia (CELADE), at the Latinamerican Regional Meeting prior to the International Conference on Population in recognition of the Second Meeting on Population by the Committee of Upper-Level Government Experts (CEGAN), Havana, Cuba, November 16-19, 1983].

PubMed

Bardeci, O J

1983-12-01

This work examines the relationship between population growth and economic development in Latin America and assesses progress in the 10 years since the Bucharest World Population Conference. The Latin American population increased from about 159 million in 1950 to 275 million in 1970 and around 325 million in 1980. The rate of growth reached a maximum of 2.8%/year in the early 1970s and has now declined to about 2.3%/year. The regional growth rate is a product of population dynamics that differ greatly in individual countries. Crude birth rates declined in every country of Latin America between 1975-80, but still exceeded 40/1000 in 1980-85 in Bolivia, Ecuador, El Salvador, Haiti, Honduras, and Nicaragua. Current fertility is the result of the different trajectories of the demographic transition in different countries. While fertility in Argentina, Cuba, and Uruguay underwent a slow but sustained decline that began prior to 1960, other countries including Colombia, Costa Rica, Chile, and Venezuela began an accelerated fertility decline in the 1960s that diffused rapidly through all age and social groups. Other countries have still not entered a definite phase of fertility decline. Mortality rates have declined appreciably in Latin America in the past few decades although they remain high in some countries. After the end of World War II and until the mid-1970s, most countries of the region experienced rapid economic growth coupled with profound changes in the productive structure. The industrial labor force grew in almost all countries along with urbanization, the decline of agricultural employment, and the increase of the tertiary sector. These and other important economic advances through the mid-1970s occurred despite rapid population growth, and the beginning of the fertility decline coincided with slowing economic growth that saw negative rates in 1981-82. Various studies have shown that not all population sectors were incorporated in the process of economic and social development. The proportion of the population in active age groups has increased dramatically, but no corresponding increase in employment opportunities has occurred. The informal sector has absorbed most of the excess growth, a trend reflected in the exclusion of a large segment of the population from the fruits of economic progress. Population growth and increased life expectancy have created demands for more retirement benefits, health and educational services, transportation, recreation, and housing. Nevertheless, it cannot be concluded that rapid population growth necessarily has negative consequences for economic development or social welfare. There are indications that the problem of poverty in Latin America could be solved if the political will to do so existed; obstacles to overcoming poverty are not primarily material or population-related. Urbanization, settlement of marginal areas, and relative decline of agricultural areas are 3 trends in spatial distribution of varying intensity and repercussions in different countries.

Intercolony variation in growth of black brant goslings on the Yukon-Kuskokwim Delta, Alaska

USGS Publications Warehouse

Fondell, T.F.; Flint, Paul L.; Sedinger, J.S.; Nicolai, C.A.; Schamber, J.L.

2011-01-01

Recent declines in black brant (Branta bernicla nigricans) are likely the result of low recruitment. In geese, recruitment is strongly affected by habitat conditions experienced by broods because gosling growth rates are indicative of forage conditions during brood rearing and strongly influence future survival and productivity. In 2006–2008, we studied gosling growth at 3 of the 4 major colonies on the Yukon‐Kuskokwim Delta, Alaska. Estimates of age‐adjusted gosling mass at the 2 southern colonies (approx. 30% of the world population of breeding black brant) was low (gosling mass at 30.5 days ranged 346.7 ± 42.5 g to 627.1 ± 15.9 g) in comparison to a third colony (gosling mass at 30.5 days ranged 640.0 ± 8.3 g to 821.6 ± 13.6 g) and to most previous estimates of age‐adjusted mass of brant goslings. Thus, our results are consistent with the hypothesis that poor gosling growth is negatively influencing the brant population. There are 2 non‐mutually exclusive explanations for the apparent growth rates we observed. First, the population decline may have been caused by density‐independent factors and habitat capacity has declined along with the population as a consequence of the unique foraging feedback between brant and their grazing habitats. Alternatively, a reduction in habitat capacity, as a result of changes to the grazing system, may have negatively influenced gosling growth, which is contributing to the overall long‐term population decline. We found support for both explanations. For colonies over habitat capacity we recommend management to enhance foraging habitat, whereas for colonies below habitat capacity we recommend management to increase nesting productivity.

Regional-Scale Declines in Productivity of Pink and Chum Salmon Stocks in Western North America

PubMed Central

Malick, Michael J.; Cox, Sean P.

2016-01-01

Sockeye salmon (Oncorhynchus nerka) stocks throughout the southern part of their North American range have experienced declines in productivity over the past two decades. In this study, we tested the hypothesis that pink (O. gorbuscha) and chum (O. keta) salmon stocks have also experienced recent declines in productivity by investigating temporal and spatial trends in productivity of 99 wild North American pink and chum salmon stocks. We used a combination of population dynamics and time series models to quantify individual stock trends as well as common temporal trends in pink and chum salmon productivity across local, regional, and continental spatial scales. Our results indicated widespread declines in productivity of wild chum salmon stocks throughout Washington (WA) and British Columbia (BC) with 81% of stocks showing recent declines in productivity, although the exact form of the trends varied among regions. For pink salmon, the majority of stocks in WA and BC (65%) did not have strong temporal trends in productivity; however, all stocks that did have trends in productivity showed declining productivity since at least brood year 1996. We found weaker evidence of widespread declines in productivity for Alaska pink and chum salmon, with some regions and stocks showing declines in productivity (e.g., Kodiak chum salmon stocks) and others showing increases (e.g., Alaska Peninsula pink salmon stocks). We also found strong positive covariation between stock productivity series at the regional spatial scale for both pink and chum salmon, along with evidence that this regional-scale positive covariation has become stronger since the early 1990s in WA and BC. In general, our results suggest that common processes operating at the regional or multi-regional spatial scales drive productivity of pink and chum salmon stocks in western North America and that the effects of these process on productivity may change over time. PMID:26760510

Factors influencing breeding success, ovarian cyclicity, and cub survival in zoo-managed tigers (Panthera tigris).

PubMed

Saunders, Sarah P; Harris, Tara; Traylor-Holzer, Kathy; Beck, Karen Goodrowe

2014-01-10

Understanding factors that influence reproduction and offspring survival in zoo populations is critical for management of threatened and endangered species. Examination of long-term data (1989-2011) compiled from the Association of Zoos and Aquarium's zoo-managed tiger breeding program provides the basis for a more thorough understanding of reproduction and scientifically based decisions for effective population management in this endangered felid. Biological and management-related factors that could influence tiger breeding success and cub survival were evaluated using logistic mixed models. Breeding success improved with female age until approximately age five, then declined thereafter. Experienced female breeders had greater breeding success than inexperienced females. Litter size was most predictive of cub survival, with average-sized litters (3-4 cubs) experiencing the highest proportional survival. Management-related factors, such as whether the breeding institution had a recent tiger litter and whether both animals were already located at the same institution, also influenced breeding success and cub survival. These results highlight the importance of institutional husbandry experience and the need to retain knowledge through staff turnovers to achieve optimal reproductive success. Using fecal estrogen data, frequency of ovarian cyclicity and mean cycle length did not differ by female age or parity; thus, lack of cyclicity and/or increased cycle duration are not likely explanations for declining breeding success with age. These results provide valuable reproductive information that should improve scientific management of zoo-based tiger populations. Copyright © 2013 Elsevier B.V. All rights reserved.

Tufted capuchin monkeys (Sapajus sp) learning how to crack nuts: does variability decline throughout development?

PubMed

Resende, Briseida Dogo; Nagy-Reis, Mariana Baldy; Lacerda, Fernanda Neves; Pagnotta, Murillo; Savalli, Carine

2014-11-01

We investigated the process of nut-cracking acquisition in a semi-free population of tufted capuchin monkeys (Sapajus sp) in São Paulo, Brazil. We analyzed the cracking episodes from monkeys of different ages and found that variability of actions related to cracking declined. Inept movements were more frequent in juveniles, which also showed an improvement on efficient striking. The most effective behavioral sequence for cracking was more frequently used by the most experienced monkeys, which also used non-optimal sequences. Variability in behavior sequences and actions may allow adaptive changes to behavior under changing environmental conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Adverse Childhood and Recent Negative Life Events: Contrasting Associations With Cognitive Decline in Older Persons.

PubMed

Korten, Nicole C M; Penninx, Brenda W J H; Pot, Anne Margriet; Deeg, Dorly J H; Comijs, Hannie C

2014-06-01

To examine whether persons who experienced adverse childhood events or recent negative life events have a worse cognitive performance and faster cognitive decline and the role of depression and apolipoprotein E-∊4 in this relationship. The community-based sample consisted of 10-year follow-up data of 1312 persons participating in the Longitudinal Aging Study Amsterdam (age range 65-85 years). Persons who experienced adverse childhood events showed a faster 10-year decline in processing speed but only when depressive symptoms were experienced. Persons with more recent negative life events showed slower processing speed at baseline but no faster decline. Childhood adversity may cause biological or psychological vulnerability, which is associated with both depressive symptoms and cognitive decline in later life. The accumulation of recent negative life events did not affect cognitive functioning over a longer time period. © The Author(s) 2014.

The use of body condition and haematology to detect widespread threatening processes in sleepy lizards (Tiliqua rugosa) in two agricultural environments.

PubMed

Smyth, Anita K; Smee, Elizabeth; Godfrey, Stephanie S; Crowther, Mathew; Phalen, David

2014-12-01

Agricultural practices, including habitat alteration and application of agricultural chemicals, can impact wildlife resulting in their decline. Determining which of these practices are contributing to declines is essential if the declines are to be reversed. In this study, the health of two geographically separated sleepy lizard (Tiliqua rugosa) populations was compared between a rangeland environment and cropping environment using linear body size index (LBSI) and haematology. Animals in the cropping site were smaller, suggesting genetic differences as the result of geographical isolation. The animals in the cropping site had a lower LBSI and many were experiencing a regenerative anaemia. The anaemia was postulated to be the cause of the low LBSI. The anaemia appeared to be the result of haemolysis and was likely to be caused by exposure to agricultural chemicals applied in the cropping site but not the rangeland site. Elevated white blood cell counts in lizards in the rangeland site suggested that they were experiencing an inflammatory disease of possible ecological significance. Together, these results demonstrate the value of combining physical and haematological parameters when studying the impact of agricultural practices on wildlife. They also show that reptiles may be useful as sentinel species for livestock and humans.

Impacts of golden alga Prymnesium parvum on fish populations in reservoirs of the upper Colorado River and Brazos River basins, Texas

USGS Publications Warehouse

VanLandeghem, Matthew M.; Farooqi, Mukhtar; Farquhar, B.; Patino, Reynaldo

2013-01-01

Several reservoirs in the upper Colorado River and Brazos River basins in Texas have experienced toxic blooms of golden alga Prymnesium parvum and associated fish kills since 2001. There is a paucity of information, however, regarding the population-level effects of such kills in large reservoirs, species-specific resistance to or recovery from kills, or potential differences in the patterns of impacts among basins. We used multiple before-after, control-impact analysis to determine whether repeated golden alga blooms have led to declines in the relative abundance and size structure of fish populations. Sustained declines were noted for 9 of 12 fish species surveyed in the upper Colorado River, whereas only one of eight species was impacted by golden alga in the Brazos River. In the upper Colorado River, White Bass Morone chrysops, White Crappie Pomoxis annularis, Largemouth Bass Micropterus salmoides, Bluegill Lepomis macrochirus, River Carpsucker Carpiodes carpio, Freshwater Drum Aplodinotus grunniens, Channel Catfish Ictalurus punctatus, Flathead Catfish Pylodictis olivaris, and Blue Catfish I. furcatus exhibited sustained declines in relative abundance, size structure, or both; Gizzard Shad Dorosoma cepedianum, Longnose Gar Lepisosteus osseus, and Common Carp Cyprinus carpio did not exhibit those declines. In the Brazos River, only the relative abundance of Blue Catfish was impacted. Overall, toxic golden alga blooms can negatively impact fish populations over the long-term, but the patterns of impact can vary considerably among river basins and species. In the Brazos River, populations of most fish species appear to be healthy, suggesting a positive angling outlook for this basin. In the upper Colorado River, fish populations have been severely impacted, and angling opportunities have been reduced. Basin-specific management plans aimed at improving water quality and quantity will likely reduce bloom intensity and allow recovery of fish populations to the abundances and size structures present before golden alga. Received August 26, 2011; accepted November 25, 2012

Long-term demographic consequences of habitat fragmentation to a tropical understory bird community

USGS Publications Warehouse

Korfanta, N.M.; Newmark, W.D.; Kauffman, M.J.

2012-01-01

Tropical deforestation continues to cause population declines and local extinctions in centers of avian diversity and endemism. Although local species extinctions stem from reductions in demographic rates, little is known about how habitat fragmentation influences survival of tropical bird populations or the relative importance of survival and fecundity in ultimately shaping communities. We analyzed 22 years of mark-recapture data to assess how fragmentation influenced apparent survival, recruitment, and realized population growth rate within 22 forest understory bird species in the Usambara Mountains, Tanzania. This represents the first such effort, in either tropical or temperate systems, to characterize the effect of deforestation on avian survival across such a broad suite of species. Long-term demographic analysis of this suite of species experiencing the same fragmented environment revealed considerable variability in species' responses to fragmentation, in addition to general patterns that emerged from comparison among species. Across the understory bird community as a whole, we found significantly lower apparent survival and realized population growth rate in small fragments relative to large, demonstrating fragmentation effects to demographic rates long after habitat loss. Demographic rates were depressed across five feeding guilds, suggesting that fragmentation sensitivity was not limited to insectivores. Seniority analyses, together with a positive effect of fragmentation on recruitment, indicated that depressed apparent survival was the primary driver of population declines and observed extinctions. We also found a landscape effect, with lower vital rates in one mountain range relative to another, suggesting that fragmentation effects may add to other large-scale drivers of population decline. Overall, realized population growth rate (λ) estimates were < 1 for most species, suggesting that future population persistence even within large forest fragments is uncertain in this biodiversity hotspot.

Isolation and characterization of microsatellite loci for mountain mullet (Agonostomus monticola).

PubMed

Feldheim, Kevin A; Sanchez, Patrick J; Matamoros, Wilfredo A; Schaefer, Jacob F; Kreiser, Brian R

2009-11-01

We report on the isolation of 15 polymorphic microsatellite loci from mountain mullet (Agonostomus monticola). In the two populations sampled, loci exhibited two to 21 alleles and observed heterozygosity values ranged from 0.222 to 1.000. All loci conformed to Hardy-Weinberg equilibrium expectations, and none exhibited linkage disequilibrium. Although A. monticola is an important subsistence fishery in parts of its range, little is known about its ecology and many populations appear to be experiencing declines. These microsatellite loci should prove useful in the study of population structure of A. monticola and aid in other potential conservation efforts such as the management of hatchery broodstock. © 2009 Blackwell Publishing Ltd.

Influence of marital status on testosterone levels-A ten year follow-up of 1113 men.

PubMed

Holmboe, Stine A; Priskorn, Lærke; Jørgensen, Niels; Skakkebaek, Niels E; Linneberg, Allan; Juul, Anders; Andersson, Anna-Maria

2017-06-01

Based on a large population of 1113 men aged 30-60 at baseline (mean: 44.1 years, standard deviation: 10.5), we investigated whether intra-individual changes in testosterone (T) and related reproductive hormones during a ten year period were dependent of marital status at baseline and follow-up. The studied men were part of a health survey in Denmark, conducted between 1982 and 1984 with a follow-up examination approximately ten years later. Data on reproductive hormones, measured in serum, and lifestyle and marital status were obtained at both time points. As expected, an age-related decline in testosterone was observed. However, independent of age and lifestyle, we observed that men who went from unmarried to married (n=81) during the study period experienced an accelerated age-related decline in testosterone (-6.6nmol/L) whereas men who went from married to unmarried (n=67) experienced an attenuated age-related decline (-2.3nmol/L). Men who were either married or unmarried at both time points (n=167, n=798, respectively) had a testosterone decline in between (-3.7nmol/L and -4.6nmol/L, respectively). Changes in T/LH ratio did not differ according to marital status indicating that the lowered T level is not compensated by increasing LH levels. This could suggest a modification of the gonadostat due to an adaptation to changing life circumstances. Copyright © 2017 Elsevier Ltd. All rights reserved.

Labor force participation among persons with musculoskeletal conditions, 1970-1987. National estimates derived from a series of cross-sections.

PubMed

Yelin, E H; Katz, P P

1991-11-01

In the present study, we estimated the labor force participation rate among persons with musculoskeletal conditions in 1987, compared this rate with that experienced by persons with other chronic conditions or with none, and estimated the change in labor force participation rates among persons with musculoskeletal conditions for the period 1970-1987. Rates were estimated from 18 years of National Health Interview Survey data, and the sampling weights from this survey were used to obtain population estimates. To ensure statistically stable estimates, we averaged the rates over 6 years of data. In 1987, 42.9% of all working-age persons with musculoskeletal conditions were out of the labor force, this study's definition of work disability. Overall labor force participation rates among persons with musculoskeletal conditions declined from 71% to 56% between 1976-1981 and 1982-1987, 22% in relative terms. Much of this decline was concentrated among men, especially men 55-64 years of age. However, women 55-64 years of age with musculoskeletal conditions also experienced declining labor force participation rates. Labor force participation patterns among persons with musculoskeletal conditions fit more general labor market trends, with gains among younger women more than offset by declines among older men and women. However, these trends appear to be more accentuated among persons with musculoskeletal conditions, suggesting that enforcement of the employment provisions of the Americans with Disabilities Act of 1990 place special emphasis on labor force participation among such persons.

Embargo on Lion Hunting Trophies from West Africa: An Effective Measure or a Threat to Lion Conservation?

PubMed Central

Bouché, Philippe; Crosmary, William; Kafando, Pierre; Doamba, Benoit; Kidjo, Ferdinand Claude; Vermeulen, Cédric; Chardonnet, Philippe

2016-01-01

The W-Arly-Pendjari (WAP) ecosystem, shared among Benin, Burkina Faso and Niger, represents the last lion stronghold of West Africa. To assess the impact of trophy hunting on lion populations in hunting areas of the WAP, we analyzed trends in harvest rates from 1999 to 2014. We also investigated whether the hunting areas with higher initial hunting intensity experienced steeper declines in lion harvest between 1999 and 2014, and whether lion densities in hunting areas were lower than in national parks. Lion harvest rate remained overall constant in the WAP. At initial hunting intensities below 1.5 lions/1000km2, most hunting areas experienced an increase in lion harvest rate, although that increase was of lower magnitude for hunting areas with higher initial hunting intensity. The proportion of hunting areas that experienced a decline in lion harvest rate increased at initial hunting intensities above 1.5 lions/1000km2. In 2014, the lion population of the WAP was estimated with a spoor count at 418 (230–648) adults and sub-adult individuals, comparable to the 311 (123–498) individuals estimated in the previous 2012 spoor survey. We found no significant lion spoor density differences between national parks and hunting areas. Hunting areas with higher mean harvest rates did not have lower lion densities. The ratio of large adult males, females and sub-adults was similar between the national parks and the hunting areas. These results suggested that the lion population was not significantly affected by hunting in the WAP. We concluded that a quota of 1 lion/1000km2 would be sustainable for the WAP. Based on our results, an import embargo on lion trophies from the WAP would not be justified. It could ruin the incentive of local actors to conserve lions in hunting areas, and lead to a drastic reduction of lion range in West Africa. PMID:27182985

Embargo on Lion Hunting Trophies from West Africa: An Effective Measure or a Threat to Lion Conservation?

PubMed

Bouché, Philippe; Crosmary, William; Kafando, Pierre; Doamba, Benoit; Kidjo, Ferdinand Claude; Vermeulen, Cédric; Chardonnet, Philippe

2016-01-01

The W-Arly-Pendjari (WAP) ecosystem, shared among Benin, Burkina Faso and Niger, represents the last lion stronghold of West Africa. To assess the impact of trophy hunting on lion populations in hunting areas of the WAP, we analyzed trends in harvest rates from 1999 to 2014. We also investigated whether the hunting areas with higher initial hunting intensity experienced steeper declines in lion harvest between 1999 and 2014, and whether lion densities in hunting areas were lower than in national parks. Lion harvest rate remained overall constant in the WAP. At initial hunting intensities below 1.5 lions/1000km2, most hunting areas experienced an increase in lion harvest rate, although that increase was of lower magnitude for hunting areas with higher initial hunting intensity. The proportion of hunting areas that experienced a decline in lion harvest rate increased at initial hunting intensities above 1.5 lions/1000km2. In 2014, the lion population of the WAP was estimated with a spoor count at 418 (230-648) adults and sub-adult individuals, comparable to the 311 (123-498) individuals estimated in the previous 2012 spoor survey. We found no significant lion spoor density differences between national parks and hunting areas. Hunting areas with higher mean harvest rates did not have lower lion densities. The ratio of large adult males, females and sub-adults was similar between the national parks and the hunting areas. These results suggested that the lion population was not significantly affected by hunting in the WAP. We concluded that a quota of 1 lion/1000km2 would be sustainable for the WAP. Based on our results, an import embargo on lion trophies from the WAP would not be justified. It could ruin the incentive of local actors to conserve lions in hunting areas, and lead to a drastic reduction of lion range in West Africa.

Genetic implications of bottleneck effects of differing severities on genetic diversity in naturally recovering populations: An example from Hawaiian coot and Hawaiian gallinule

USGS Publications Warehouse

Sonsthagen, Sarah A.; Wilson, Robert E.; Underwood, Jared G.

2017-01-01

The evolutionary trajectory of populations through time is influenced by the interplay of forces (biological, evolutionary, and anthropogenic) acting on the standing genetic variation. We used microsatellite and mitochondrial loci to examine the influence of population declines, of varying severity, on genetic diversity within two Hawaiian endemic waterbirds, the Hawaiian coot and Hawaiian gallinule, by comparing historical (samples collected in the late 1800s and early 1900s) and modern (collected in 2012–2013) populations. Population declines simultaneously experienced by Hawaiian coots and Hawaiian gallinules differentially shaped the evolutionary trajectory of these two populations. Within Hawaiian coot, large reductions (between −38.4% and −51.4%) in mitochondrial diversity were observed, although minimal differences were observed in the distribution of allelic and haplotypic frequencies between sampled time periods. Conversely, for Hawaiian gallinule, allelic frequencies were strongly differentiated between time periods, signatures of a genetic bottleneck were detected, and biases in means of the effective population size were observed at microsatellite loci. The strength of the decline appears to have had a greater influence on genetic diversity within Hawaiian gallinule than Hawaiian coot, coincident with the reduction in census size. These species exhibit similar life history characteristics and generation times; therefore, we hypothesize that differences in behavior and colonization history are likely playing a large role in how allelic and haplotypic frequencies are being shaped through time. Furthermore, differences in patterns of genetic diversity within Hawaiian coot and Hawaiian gallinule highlight the influence of demographic and evolutionary processes in shaping how species respond genetically to ecological stressors.

Will Elephants Soon Disappear from West African Savannahs?

PubMed Central

Bouché, Philippe; Douglas-Hamilton, Iain; Wittemyer, George; Nianogo, Aimé J.; Doucet, Jean-Louis; Lejeune, Philippe; Vermeulen, Cédric

2011-01-01

Precipitous declines in Africa's native fauna and flora are recognized, but few comprehensive records of these changes have been compiled. Here, we present population trends for African elephants in the 6,213,000 km2 Sudano-Sahelian range of West and Central Africa assessed through the analysis of aerial and ground surveys conducted over the past 4 decades. These surveys are focused on the best protected areas in the region, and therefore represent the best case scenario for the northern savanna elephants. A minimum of 7,745 elephants currently inhabit the entire region, representing a minimum decline of 50% from estimates four decades ago for these protected areas. Most of the historic range is now devoid of elephants and, therefore, was not surveyed. Of the 23 surveyed elephant populations, half are estimated to number less than 200 individuals. Historically, most populations numbering less than 200 individuals in the region were extirpated within a few decades. Declines differed by region, with Central African populations experiencing much higher declines (−76%) than those in West Africa (−33%). As a result, elephants in West Africa now account for 86% of the total surveyed. Range wide, two refuge zones retain elephants, one in West and the other in Central Africa. These zones are separated by a large distance (∼900 km) of high density human land use, suggesting connectivity between the regions is permanently cut. Within each zone, however, sporadic contacts between populations remain. Retaining such connectivity should be a high priority for conservation of elephants in this region. Specific corridors designed to reduce the isolation of the surveyed populations are proposed. The strong commitment of governments, effective law enforcement to control the illegal ivory trade and the involvement of local communities and private partners are all critical to securing the future of elephants inhabiting Africa's northern savannas. PMID:21731620

Microbial community activities during establishment, performance, and decline of bench-scale passive treatment systems for mine drainage.

PubMed

Logan, Miranda V; Reardon, Kenneth F; Figueroa, Linda A; McLain, Jean E T; Ahmann, Dianne M

2005-11-01

Permeable reactive barrier (PRB) technology, in which sulfate-reducing bacteria (SRB) facilitate precipitation of metal sulfides, is a promising approach for remediation of sulfate- and metal-laden mine drainage. While PRBs are easily established, they often decline for reasons not well understood. SRB depend on or compete with multiple dynamic microbial populations within a PRB; as a result, performance depends on the changing PRB chemical composition and on succession and competition within the microbial community. To investigate these interactions, we constructed and monitored eight bench-scale PRBs to define periods of establishment, performance, and decline. We then conducted short-term batch studies, using substrate-supplemented column materials, on Days 0 (pre-establishment), 27 (establishment), 41 (performance), and 99 (decline) to reveal potential activities of cellulolytic bacteria, fermenters + anaerobic respirers, SRB, and methanogens. PRBs showed active sulfate reduction, with sulfate removal rates (SRR) of approximately 1-3 mol/m3/d, as well as effective removal of Zn2+. Potential activities of fermentative + anaerobic respiratory bacteria were initially high but diminished greatly during establishment and dropped further during performance and decline. In contrast, potential SRB activity rose during establishment, peaked during performance, and diminished as performance declined. Potential methanogen activity was low; in addition, SRB-methanogen substrate competition was shown not to limit SRB activity. Cellulolytic bacteria showed no substrate limitation at any time. However, fermenters experienced substrate limitation by Day 0, SRB by Day 27, and methanogens by Day 41, showing the dependence of each group on upstream populations to provide substrates. All potential activities, except methanogenesis, were ultimately limited by cellulose hydrolysis; in addition, all potential activities except methanogenesis declined substantially by Day 99, showing that long-term substrate deprivation strongly diminished the intrinsic capacity of the PRB community to perform.

Urbanization and depopulation in the Alps.

PubMed

Batzing, W; Perlik, M; Dekleva, M

1996-11-01

Demographic developments in the European Alpine region are analyzed over the period 1870-1990. The region is defined as including parts of Germany, France, Italy, Liechtenstein, Austria, Switzerland, and Slovenia. "Studies of growth, stagnation, decline, commune size, and altitude in almost 6,000 communes are presented on three colored maps.... It is apparent that two highly divergent processes are at work and, accordingly, statistical mean values reveal little of importance. Approximately one-half of Alpine Europe is undergoing general economic and demographic growth and has experienced significant increase in population since the end of the agricultural era. This development has taken place primarily in low-lying valleys and basins and in areas bordering the Alps that have good access to transport routes. Tourism is not as widespread as generally assumed and is usually characterized by a punctate pattern. Only in the western part of the Eastern Alps does tourism account for widespread population growth at higher altitudes; elsewhere the Alps have not been affected by modern development and the economy and population are declining, with some areas in danger of becoming completely abandoned. The results challenge the earlier concept of the Alps as a rural region, once populated by peasants, where tourism now plays a major role." (EXCERPT)

Attracting Economics Majors

ERIC Educational Resources Information Center

Okoye, Ifeakandu

2011-01-01

A disturbing concern that has been expressed by academic economists is the low interest in economics as a major, as evidenced by the declining enrollment in most of the economics departments in American colleges and universities. Though some college and university economics departments are experiencing or had experienced a decline in their majors…

Combining Site Occupancy, Breeding Population Sizes and Reproductive Success to Calculate Time-Averaged Reproductive Output of Different Habitat Types: An Application to Tricolored Blackbirds

PubMed Central

Holyoak, Marcel; Meese, Robert J.; Graves, Emily E.

2014-01-01

In metapopulations in which habitat patches vary in quality and occupancy it can be complicated to calculate the net time-averaged contribution to reproduction of particular populations. Surprisingly, few indices have been proposed for this purpose. We combined occupancy, abundance, frequency of occurrence, and reproductive success to determine the net value of different sites through time and applied this method to a bird of conservation concern. The Tricolored Blackbird (Agelaius tricolor) has experienced large population declines, is the most colonial songbird in North America, is largely confined to California, and breeds itinerantly in multiple habitat types. It has had chronically low reproductive success in recent years. Although young produced per nest have previously been compared across habitats, no study has simultaneously considered site occupancy and reproductive success. Combining occupancy, abundance, frequency of occurrence, reproductive success and nest failure rate we found that that large colonies in grain fields fail frequently because of nest destruction due to harvest prior to fledging. Consequently, net time-averaged reproductive output is low compared to colonies in non-native Himalayan blackberry or thistles, and native stinging nettles. Cattail marshes have intermediate reproductive output, but their reproductive output might be improved by active management. Harvest of grain-field colonies necessitates either promoting delay of harvest or creating alternative, more secure nesting habitats. Stinging nettle and marsh colonies offer the main potential sources for restoration or native habitat creation. From 2005–2011 breeding site occupancy declined 3x faster than new breeding colonies were formed, indicating a rapid decline in occupancy. Total abundance showed a similar decline. Causes of variation in the value for reproduction of nesting substrates and factors behind continuing population declines merit urgent investigation. The method we employ should be useful in other metapopulation studies for calculating time-averaged reproductive output for different sites. PMID:24817307

Bat reproduction declines when conditions mimic climate change projections for western North America.

PubMed

Adams, Rick A

2010-08-01

Climate change models predict that much of western North America is becoming significantly warmer and drier, resulting in overall reductions in availability of water for ecosystems. Herein, I demonstrate that significant declines in the reproductive success of female insectivorous bats occur in years when annual environmental conditions mimic the long-term predictions of regional climate change models. Using a data set gathered on bat populations from 1996 through 2008 along the Front Range of Colorado, I compare trends in population numbers and reproductive outcomes of six species of vespertilionid bats with data on mean annual high temperature, precipitation, snow pack, and stream discharge rates. I show that levels of precipitation and flow rates of small streams near maternity colonies is fundamentally tied to successful reproduction in female bats, particularly during the lactation phase. Across years that experienced greater than average mean temperatures with less than average precipitation and stream flow, bat populations responded by slight to profound reductions in reproductive output depending on the severity of drought conditions. In particular, reproductive outputs showed profound declines (32-51%) when discharge rates of the largest stream in the field area dropped below 7 m3/s, indicating a threshold response. Such sensitivity to environmental change portends severe impacts to regional bat populations if current scenarios for climate change in western North America are accurate. In addition, bats act as early-warning indicators of large-scale ecological effects resulting from further regional warming and drying trends currently at play in western North America.

River dolphins can act as population trend indicators in degraded freshwater systems.

PubMed

Turvey, Samuel T; Risley, Claire L; Barrett, Leigh A; Yujiang, Hao; Ding, Wang

2012-01-01

Conservation attention on charismatic large vertebrates such as dolphins is often supported by the suggestion that these species represent surrogates for wider biodiversity, or act as indicators of ecosystem health. However, their capacity to act as indicators of patterns or trends in regional biodiversity has rarely been tested. An extensive new dataset of >300 last-sighting records for the Yangtze River dolphin or baiji and two formerly economically important fishes, the Yangtze paddlefish and Reeves' shad, all of which are probably now extinct in the Yangtze, was collected during an interview survey of fishing communities across the middle-lower Yangtze drainage. Untransformed last-sighting date frequency distributions for these species show similar decline curves over time, and the linear gradients of transformed last-sighting date series are not significantly different from each other, demonstrating that these species experienced correlated population declines in both timing and rate of decline. Whereas species may be expected to respond differently at the population level even in highly degraded ecosystems, highly vulnerable (e.g. migratory) species can therefore display very similar responses to extrinsic threats, even if they represent otherwise very different taxonomic, biological and ecological groupings. Monitoring the status of river dolphins or other megafauna therefore has the potential to provide wider information on the status of other threatened components of sympatric freshwater biotas, and so represents a potentially important monitoring tool for conservation management. We also show that interview surveys can provide robust quantitative data on relative population dynamics of different species.

Age-period-cohort analysis of infectious disease mortality in urban-rural China, 1990-2010.

PubMed

Li, Zhi; Wang, Peigang; Gao, Ge; Xu, Chunling; Chen, Xinguang

2016-03-31

Although a number of studies on infectious disease trends in China exist, these studies have not distinguished the age, period, and cohort effects simultaneously. Here, we analyze infectious disease mortality trends among urban and rural residents in China and distinguish the age, period, and cohort effects simultaneously. Infectious disease mortality rates (1990-2010) of urban and rural residents (5-84 years old) were obtained from the China Health Statistical Yearbook and analyzed with an age-period-cohort (APC) model based on Intrinsic Estimator (IE). Infectious disease mortality is relatively high at age group 5-9, reaches a minimum in adolescence (age group 10-19), then rises with age, with the growth rate gradually slowing down from approximately age 75. From 1990 to 2010, except for a slight rise among urban residents from 2000 to 2005, the mortality of Chinese residents experienced a substantial decline, though at a slower pace from 2005 to 2010. In contrast to the urban residents, rural residents experienced a rapid decline in mortality during 2000 to 2005. The mortality gap between urban and rural residents substantially narrowed during this period. Overall, later birth cohorts experienced lower infectious disease mortality risk. From the 1906-1910 to the 1941-1945 birth cohorts, the decrease of mortality among urban residents was significantly faster than that of subsequent birth cohorts and rural counterparts. With the rapid aging of the Chinese population, the prevention and control of infectious disease in elderly people will present greater challenges. From 1990 to 2010, the infectious disease mortality of Chinese residents and the urban-rural disparity have experienced substantial declines. However, the re-emergence of previously prevalent diseases and the emergence of new infectious diseases created new challenges. It is necessary to further strengthen screening, immunization, and treatment for the elderly and for older cohorts at high risk.

Specialist Individuals, Generalist Populations, and Gentoo Penguin Foraging Ecology Across the Scotia Arc During a Time of Rapid Environmental Change

NASA Astrophysics Data System (ADS)

Herman, R.; Polito, M. J.

2016-02-01

Populations of Gentoo penguins (Pygoscelis papua), have increased in the Scotia arc in the last four decades, while sister species such as Chinstrap (P. antarctics) and Adélie penguins (P. adeliae) have experienced substantial declines in numbers. Previous dietary analyses suggest Gentoo penguins have a generalist foraging niche, which may help buffer them from recent climate-driven declines in key prey species, such as Antarctic krill (Euphausia superba). Ecological theory indicates that generalist populations fall under two different categories: Type A generalist populations exhibit large variation within individuals, and little variation between individuals, where Type B generalist populations are comprised of individual specialists, with large variation between individuals. It is important to identify which type of generalist population Gentoo penguins fall under, as these strategies impart differing ecological and evolutionary ramifications under times of environmental change. We conducted stable isotope analysis using tail feathers from Gentoo penguins at four breeding sites across the Scotia arc, including the Falkland Islands, South Georgia, the South Shetland Islands, and the Western Antarctic Peninsula, to assess individual variation in winter diets and determine the type of generalist strategies that Gentoo penguins utilize. Preliminary analysis indicates the presence of individual specialization within the four geographically distinct breeding colonies, suggesting that individual resilience to further shifts in food availability may vary within Gentoo penguin populations.

Measuring progress towards achieving Millennium Development Goals in small populations: is under-five mortality in Tuvalu declining?

PubMed

Taylor, Richard; Linhart, Christine; Hayes, Geoffrey; Homasi, Steven

2014-08-01

Infant mortality rates (IMR) and under-five mortality rates (U5MR) in Tuvalu (2010 population 11,149) for 1990-2011 were evaluated to determine best estimates of levels and trends. Estimates were graphed over time to identify trends/inconsistencies, and censored for reliability/plausibility. Where possible, 95% confidence intervals (CIs) and tests for linear trend were calculated. Ministry of Health (MoH) data indicates IMR and U5MR (per 1,000 live births) declined over 1990-2008: IMR 62 (95%CI 46-81) for 1991-93 (51 deaths) to 19 (95%CI 10-33) for 2006-08 (12 deaths); U5MR 67 (95%CI 50-87) for 1991-93 (55 deaths) to 19 (95%CI 10-33) for 2006-08 (12 deaths). The 2007 Demographic and Health Survey (DHS) suggests recent trends are increasing: IMR 24 for 1998-2002 to 31 (95%CI 20-42) for 2003-07; U5MR 29 for 1998-2002 to 36 (95%CI 30-43) for 2003-07 (deaths not provided). Tests for linear trend and 95%CIs indicate MoH declines are statistically significant, but recent increased estimates from DHS are not, and could be affected by recall bias. Small populations provide challenges in interpretation of IMR/U5MR trends. To ensure the correct interpretation of rates, CIs (95%) and tests for trend should be calculated. Tuvalu has experienced steady decline in IMR/U5MR over the past 20 years. © 2014 Public Health Association of Australia.

Long and spatially variable Neolithic Demographic Transition in the North American Southwest

PubMed Central

Kohler, Timothy A.; Reese, Kelsey M.

2014-01-01

In many places of the world, a Neolithic Demographic Transition (NDT) is visible as a several-hundred-year period of increased birth rates coupled with stable mortality rates, resulting in dramatic population growth that is eventually curtailed by increased mortality. Similar processes can be reconstructed in particular detail for the North American Southwest, revealing an anomalously long and spatially variable NDT. Irrigation-dependent societies experienced relatively low birth rates but were quick to achieve a high degree of sociopolitical complexity, whereas societies dependent on dry or rainfed farming experienced higher birth rates but less initial sociopolitical complexity. Low birth rates after A.D. 1200 mark the beginning of the decline of the Hohokam. Overall in the Southwest, birth rates increased slowly from 1100 B.C. to A.D. 500, and remained at high levels with some fluctuation until decreasing rapidly beginning A.D. 1300. Life expectancy at 15 increased slowly from 900 B.C. to A.D. 700, and then increased rapidly for 200 y before fluctuating and then declining after A.D. 1400. Life expectancy at birth, on the other hand, generally declined from 1100 B.C. to A.D. 1100/1200, before rebounding. Farmers took two millennia (∼1100 B.C. to ∼A.D. 1000) to reach the carrying capacity of the agricultural niche in the Southwest. PMID:24982134

Tuning stochastic matrix models with hydrologic data to predict the population dynamics of a riverine fish.

PubMed

Sakaris, Peter C; Irwin, Elise R

2010-03-01

We developed stochastic matrix models to evaluate the effects of hydrologic alteration and variable mortality on the population dynamics of a lotic fish in a regulated river system. Models were applied to a representative lotic fish species, the flathead catfish (Pylodictis olivaris), for which two populations were examined: a native population from a regulated reach of the Coosa River (Alabama, USA) and an introduced population from an unregulated section of the Ocmulgee River (Georgia, USA). Size-classified matrix models were constructed for both populations, and residuals from catch-curve regressions were used as indices of year class strength (i.e., recruitment). A multiple regression model indicated that recruitment of flathead catfish in the Coosa River was positively related to the frequency of spring pulses between 283 and 566 m3/s. For the Ocmulgee River population, multiple regression models indicated that year class strength was negatively related to mean March discharge and positively related to June low flow. When the Coosa population was modeled to experience five consecutive years of favorable hydrologic conditions during a 50-year projection period, it exhibited a substantial spike in size and increased at an overall 0.2% annual rate. When modeled to experience five years of unfavorable hydrologic conditions, the Coosa population initially exhibited a decrease in size but later stabilized and increased at a 0.4% annual rate following the decline. When the Ocmulgee River population was modeled to experience five years of favorable conditions, it exhibited a substantial spike in size and increased at an overall 0.4% annual rate. After the Ocmulgee population experienced five years of unfavorable conditions, a sharp decline in population size was predicted. However, the population quickly recovered, with population size increasing at a 0.3% annual rate following the decline. In general, stochastic population growth in the Ocmulgee River was more erratic and variable than population growth in the Coosa River. We encourage ecologists to develop similar models for other lotic species, particularly in regulated river systems. Successful management of fish populations in regulated systems requires that we are able to predict how hydrology affects recruitment and will ultimately influence the population dynamics of fishes.

Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations.

PubMed

Rode, Karyn D; Regehr, Eric V; Douglas, David C; Durner, George; Derocher, Andrew E; Thiemann, Gregory W; Budge, Suzanne M

2014-01-01

Polar bears (Ursus maritimus) have experienced substantial changes in the seasonal availability of sea ice habitat in parts of their range, including the Beaufort, Chukchi, and Bering Seas. In this study, we compared the body size, condition, and recruitment of polar bears captured in the Chukchi and Bering Seas (CS) between two periods (1986-1994 and 2008-2011) when declines in sea ice habitat occurred. In addition, we compared metrics for the CS population 2008-2011 with those of the adjacent southern Beaufort Sea (SB) population where loss in sea ice habitat has been associated with declines in body condition, size, recruitment, and survival. We evaluated how variation in body condition and recruitment were related to feeding ecology. Comparing habitat conditions between populations, there were twice as many reduced ice days over continental shelf waters per year during 2008-2011 in the SB than in the CS. CS polar bears were larger and in better condition, and appeared to have higher reproduction than SB bears. Although SB and CS bears had similar diets, twice as many bears were fasting in spring in the SB than in the CS. Between 1986-1994 and 2008-2011, body size, condition, and recruitment indices in the CS were not reduced despite a 44-day increase in the number of reduced ice days. Bears in the CS exhibited large body size, good body condition, and high indices of recruitment compared to most other populations measured to date. Higher biological productivity and prey availability in the CS relative to the SB, and a shorter recent history of reduced sea ice habitat, may explain the maintenance of condition and recruitment of CS bears. Geographic differences in the response of polar bears to climate change are relevant to range-wide forecasts for this and other ice-dependent species. © 2013 John Wiley & Sons Ltd.

Variation in the response of an Arctic top predator experiencing habitat loss: Feeding and reproductive ecology of two polar bear populations

USGS Publications Warehouse

Rode, Karyn D.; Regehr, Eric V.; Douglas, David C.; Durner, George M.; Derocher, Andrew E.; Thiemann, Gregory W.; Budge, Suzanne M.

2014-01-01

Polar bears (Ursus maritimus) have experienced substantial changes in the seasonal availability of sea ice habitat in parts of their range, including the Beaufort, Chukchi, and Bering Seas. In this study, we compared the body size, condition, and recruitment of polar bears captured in the Chukchi and Bering Seas (CS) between two periods (1986–1994 and 2008–2011) when declines in sea ice habitat occurred. In addition, we compared metrics for the CS population 2008–2011 with those of the adjacent southern Beaufort Sea (SB) population where loss in sea ice habitat has been associated with declines in body condition, size, recruitment, and survival. We evaluated how variation in body condition and recruitment were related to feeding ecology. Comparing habitat conditions between populations, there were twice as many reduced ice days over continental shelf waters per year during 2008–2011 in the SB than in the CS. CS polar bears were larger and in better condition, and appeared to have higher reproduction than SB bears. Although SB and CS bears had similar diets, twice as many bears were fasting in spring in the SB than in the CS. Between 1986–1994 and 2008–2011, body size, condition, and recruitment indices in the CS were not reduced despite a 44-day increase in the number of reduced ice days. Bears in the CS exhibited large body size, good body condition, and high indices of recruitment compared to most other populations measured to date. Higher biological productivity and prey availability in the CS relative to the SB, and a shorter recent history of reduced sea ice habitat, may explain the maintenance of condition and recruitment of CS bears. Geographic differences in the response of polar bears to climate change are relevant to range-wide forecasts for this and other ice-dependent species.

Climate change and the northern elephant seal (Mirounga angustirostris) population in Baja California, Mexico.

PubMed

García-Aguilar, María C; Turrent, Cuauhtémoc; Elorriaga-Verplancken, Fernando R; Arias-Del-Razo, Alejandro; Schramm, Yolanda

2018-01-01

The Earth's climate is warming, especially in the mid- and high latitudes of the Northern Hemisphere. The northern elephant seal (Mirounga angustirostris) breeds and haul-outs on islands and the mainland of Baja California, Mexico, and California, U.S.A. At the beginning of the 21st century, numbers of elephant seals in California are increasing, but the status of Baja California populations is unknown, and some data suggest they may be decreasing. We hypothesize that the elephant seal population of Baja California is experiencing a decline because the animals are not migrating as far south due to warming sea and air temperatures. Here we assessed population trends of the Baja California population, and climate change in the region. The numbers of northern elephant seals in Baja California colonies have been decreasing since the 1990s, and both the surface waters off Baja California and the local air temperatures have warmed during the last three decades. We propose that declining population sizes may be attributable to decreased migration towards the southern portions of the range in response to the observed temperature increases. Further research is needed to confirm our hypothesis; however, if true, it would imply that elephant seal colonies of Baja California and California are not demographically isolated which would pose challenges to environmental and management policies between Mexico and the United States.

Estimation of physician supply by specialty and the distribution impact of increasing female physicians in Japan.

PubMed

Koike, Soichi; Matsumoto, Shinya; Kodama, Tomoko; Ide, Hiroo; Yasunaga, Hideo; Imamura, Tomoaki

2009-10-07

Japan has experienced two large changes which affect the supply and distribution of physicians. They are increases in medical school enrollment capacity and in the proportion of female physicians. The purpose of this study is to estimate the future supply of physicians by specialty and to predict the associated impact of increased female physicians, as well as to discuss the possible policy implications. Based on data from the 2004 and 2006 National Survey of Physicians, Dentists and Pharmacists, we estimated the future supply of physicians by specialty, using multistate life tables. Based on possible scenarios of the future increase in female physicians, we also estimated the supply of physicians by specialty. Even if Japan's current medical school enrollment capacity is maintained in subsequent years, the number of physicians per 1000 population is expected to increase from 2.2 in 2006 to 3.2 in 2036, which is a 46% increase from the current level. The numbers of obstetrician/gynecologists (OB/GYNs) and surgeons are expected to temporarily decline from their current level, whereas the number of OB/GYNs per 1000 births will still increase because of the declining number of births. The number of surgeons per 1000 population, even with the decreasing population, will decline temporarily over the next few years. If the percentage of female physicians continues to increase, the overall number of physicians will not be significantly affected, but in specialties with current very low female physician participation rates, such as surgery, the total number of physicians is expected to decline significantly. At the current medical school enrollment capacity, the number of physicians per population is expected to continue to increase because of the skewed age distribution of physicians and the declining population in Japan. However, with changes in young physicians' choices of medical specialties and as the percentage of female physicians increases, patterns of physician supply will vary between specialties. Specialties less often chosen by young physicians and where males have dominated will face a decline in physician supply. These results highlight the necessity for developing a work environment that attracts female physicians to these types of specialties. This will also lead to improved gender equality in the workforce and more effective use of human resources.

Estimation of physician supply by specialty and the distribution impact of increasing female physicians in Japan

PubMed Central

Koike, Soichi; Matsumoto, Shinya; Kodama, Tomoko; Ide, Hiroo; Yasunaga, Hideo; Imamura, Tomoaki

2009-01-01

Background Japan has experienced two large changes which affect the supply and distribution of physicians. They are increases in medical school enrollment capacity and in the proportion of female physicians. The purpose of this study is to estimate the future supply of physicians by specialty and to predict the associated impact of increased female physicians, as well as to discuss the possible policy implications. Methods Based on data from the 2004 and 2006 National Survey of Physicians, Dentists and Pharmacists, we estimated the future supply of physicians by specialty, using multistate life tables. Based on possible scenarios of the future increase in female physicians, we also estimated the supply of physicians by specialty. Results Even if Japan's current medical school enrollment capacity is maintained in subsequent years, the number of physicians per 1000 population is expected to increase from 2.2 in 2006 to 3.2 in 2036, which is a 46% increase from the current level. The numbers of obstetrician/gynecologists (OB/GYNs) and surgeons are expected to temporarily decline from their current level, whereas the number of OB/GYNs per 1000 births will still increase because of the declining number of births. The number of surgeons per 1000 population, even with the decreasing population, will decline temporarily over the next few years. If the percentage of female physicians continues to increase, the overall number of physicians will not be significantly affected, but in specialties with current very low female physician participation rates, such as surgery, the total number of physicians is expected to decline significantly. Conclusion At the current medical school enrollment capacity, the number of physicians per population is expected to continue to increase because of the skewed age distribution of physicians and the declining population in Japan. However, with changes in young physicians' choices of medical specialties and as the percentage of female physicians increases, patterns of physician supply will vary between specialties. Specialties less often chosen by young physicians and where males have dominated will face a decline in physician supply. These results highlight the necessity for developing a work environment that attracts female physicians to these types of specialties. This will also lead to improved gender equality in the workforce and more effective use of human resources. PMID:19811625

Bighorn sheep (Ovis canadensis) survivorship and habitat studies in Bighorn Canyon National Recreation Area and surrounding lands, Wyoming and Montana, 2000–2003

USGS Publications Warehouse

Schoenecker, Kathryn A.; Singer, Francis J.; Grams, Kayla A.; Roelle, James E.

2004-01-01

In the 1850s, bighorn sheep (Ovis canadensis) were numerous and distributed throughout the Bighorn and Pryor Mountains of Montana and Wyoming. After European settlement, bighorn sheep populations declined, and local extinctions occurred in much of their historic range in the western United States. The current bighorn sheep population of Bighorn Canyon National Recreation Area (BICA) is the product of several reintroductions into BICA and surrounding lands. Following a release in 1973 and growth rates near maximum potential of 19.8% per year, the population grew to an estimated peak population of about 211 animals in 1993 and 1994 (Kissell and others, 1996). Recent counts indicate the bighorn sheep population has declined. Kissell and others (1996) reported that the population began to decline rapidly in 1995 and 1996. He noted low ewe:lamb ratios during the decline phase. Bighorn sheep numbers declined to the lowest minimum viable population size of 100 animals recommended by several bighorn sheep experts (Bailey, 1990; Berger, 1990; Smith and others, 1991). National Park Service (NPS) and Bureau of Land Management (BLM) managers were concerned about the decline and requested a study of its causes. In 2000, the U.S. Geological Survey- Biological Resources Division (USGS-BRD) received funding to start a 3-year study of survivorship, condition, and population growth rate of the BICA bighorn sheep population.Several possibilities exist for the bighorn sheep decline. The herd may have experienced a rapid population expansion, followed by a decline to stability at a lower long-term carrying capacity. This pattern of apparently overshooting carrying capacity following an initial release has been reported for a number of ungulates (Caughley, 1976). Disease may have caused the decline; predation and/or competition with wild horses (Equus caballus) may also have been factors. A spatial model of wild horse carrying capacity (Coughenour, 1999) was developed to assist managers in evaluating wild horse population numbers. Studies of summer consumption rates by wild horses and other ungulates were conducted by James Detling and students from Colorado State University (Peterson and others, 1997; Gerhardt and Detling, 1998; Fahnestock, 1998). Diets and habitat use of wild horses, bighorn sheep and mule deer were studied by Coates and Schemnitz (1989) and Kissell and others (1996). Both Coates and Schemnitz (1989) and Kissell and others (1996) reported a high degree of dietary overlap between wild horses and bighorn sheep. However, Kissell and others (1996) concluded that a high degree of spatial separation between wild horses and bighorn sheep, at least under the study conditions, precluded any significant negative competitive influences. The most important overlap of bighorn sheep and wild horses seems to be on winter range. Competition can be difficult to determine, since current conditions may not reveal competition that has already occurred. Managers remained concerned about the declining bighorn population for the following reasons: Our objectives for the study were to: Evaluate current disease problems and mortality rates, including predation rates, in bighorn sheep through captures and monitoring of bighorn sheep.Determine winter spatial relations of wild horses and bighorn sheep through aerial surveys of winter range.Conduct habitat measurements to determine why bighorn sheep were not using what had been mapped with a GIS-based habitat model as suitable bighorn sheep habitat, and sample winter and summer consumption rates of key forage species to see if there were other factors precluding use of these areas by bighorn sheep.Compare winter lamb recruitment rates and total vegetation consumption rates on bighorn sheep winter use areas, with and without wild horses present.Complete year-round GIS-based distribution maps for wild horses and bighorn sheep in order to identify key areas of species overlap and key areas of species separation for potential habitat improvements.NPS park staff asked USGS to answer the following questions: (a) how large is the population?; (b) how many rams are in the population?; (c) in addition to low lamb recruitment, is mortality or dispersal of adults likely contributing to the decline?; and (d) is trophy hunting of rams contributing to the decline?

Singapore.

PubMed

1982-09-01

Attention in this discussion of Singapore is directed to the following: history of the country's demographic situation; government's overall approach to population problems; population data systems and development planning; institutional arrangements for the integration of population within development planning; government's view of the importance of population policy in achieving development objectives; population size, growth and natural increase; morbidity and mortality; fertility; international migration; and spatial distribution. The Republic of Singapore has experienced high population growth rates for some time, with its population of 1.02 million in 1950 increasing to an estimated 2.39 million in 1980. In recent years the rate has declined significantly, decreasing from nearly 5% per year in the early 1950s to 2.8 in 1960-65 and 1.5 in 1970-75. At the present growth rate of about 1.2% per annum, and anticipating the further declines that have been projected for 1995-2000, the population of Singapore is expected to reach about 2.97 million by the end of this century. The government considers the stabilization of the country's population to be 1 of its important objectives. In 1961 population growth was recognized as a serious problem. Singapore has a long history of census taking, having recently conducted its 11th decennial census. Because of the rapid decline in fertility in recent years, the government perceives the nation's current rates of natural increase and fertility as satisfactory, neither constraining development nor inhibiting economic growth. Yet, the government has established as a social norm a goal of a 2 child family and supports policies that discourage early marriage and childbearing at very young ages. The government maintains that Singapore's current rate of population growth is satisfactory, which is a recent change of position that is based on the rapid decline in fertility in the 1960s and 1970s. The crude death rate declined from about 10.6/1000 in 1950-55 to 7.1 in 1960-65 and to 5.1 in both 1970-75 and 1975-80, according to UN estimates. The average life expectancy at birth for both sexes has been improving. To reduce the need for high cost hospital services, the government has recently given more attention to promotive and preventive medicine. The crude birthrate, which was estimated to be around 44 births/1000 in 1950-55, has declined in the past several decades, decreasing to 17.2/1000 in 1975-80 according to UN estimates. The government regards the current level of fertility as satisfactory and has implemented incentive and disincentive schemes to maintain low rates. The government considers levels and trends of immigration to be not significant and satisfactory. The government regards the spatial distribution of the population to be appropriate and has no policies of intervention concerning either internal migration or the rural and urban configuration of settlement.

Geographic and socioeconomic variation in the onset of decline of coronary heart disease mortality in white women.

PubMed Central

Wing, S; Barnett, E; Casper, M; Tyroler, H A

1992-01-01

BACKGROUND. Regional, metropolitan, and socioeconomic factors related to the onset of decline of coronary heart disease (CHD) mortality among White women are reported. Such studies are important for planning population-level interventions. METHODS. Mortality data for 1962 to 1978 were used, to estimate the year of onset of decline. Ecological analyses of socioeconomic data from the US census were used to emphasize structural and organizational aspects of changes in disease, rather than as a substitute for an individual-level design. RESULTS. Onset of decline of CHD mortality among White women was estimated to have occurred by 1962 in 53% of 507 state economic areas (SEAs), ranging from 79% in the Northeast to 39% in the South. Metropolitan areas experienced earlier onset of decline than did nonmetropolitan areas. Average income, education, and occupational levels were highest in early onset areas and declined across onset categories. CONCLUSIONS. The results provide additional evidence for previously observed geographic and social patterns of CHD decline. Emphasis on structural economic factors determining the shape of the CHD epidemic curve does not detract from the medical importance of risk factors, but underscores the importance of community development to public health improvements. The results are consistent with the idea that the course of the CHD epidemic in the United States has been strongly influenced by socioeconomic development. PMID:1739148

Association Between Cognitive Decline in Older Adults and Utilization of Primary Care Physician Services in Pennsylvania

PubMed Central

Fowler, Nicole R.; Morrow, Lisa A.; Tu, Li-Chuan; Landsittel, Douglas P.; Snitz, Beth E.; Rodriquez, Eric G.; Saxton, Judith A.

2012-01-01

OBJECTIVE To assess the relationship between cognitive decline of older patients (≥65 years) and utilization of primary care physician (PCP) services over 24-months. DESIGN Retrospective analysis of prospectively collected data from a cluster randomized trial that took place from 2006 to 2010 and investigated the relationship between formal neuropsychological evaluation and patient outcomes in primary care. SETTING Twenty-four PCPs in 11 practices in southwestern Pennsylvania. Most practices were suburban and included more than 5 PCPs. PARTICIPANTS A sample of 423 primary care patients 65 years or older. MEASUREMENTS The association between the number of PCP visits and a decline in cognitive status, as determined by multivariable analyses that controlled for patient-level, physician-level, and practice-level factors (e.g., patient age, comorbidities, and symptoms of depression; practice location and size; PCP age and sex) and used a linear mixed model with a random intercept to adjust for clustering. RESULTS Over a two year follow-up, 199 patients (47.0%) experienced a decline in cognitive status. Patients with a cognitive decline had a mean of 0.69 more PCP visits than did patients without a cognitive decline (P<0.05). CONCLUSIONS Early signs of cognitive decline may be an indicator of greater utilization of primary care. Given the demographic trends, more PCPs are likely to be needed to meet the increasing needs of the older population. PMID:22798988

Effects of urban sprawl on obesity.

PubMed

Zhao, Zhenxiang; Kaestner, Robert

2010-12-01

In this paper, we examine the effect of changes in population density-urban sprawl-between 1970 and 2000 on BMI and obesity of residents in metropolitan areas in the U.S. We address the possible endogeneity of population density by using a two-step instrumental variables approach. We exploit the plausibly exogenous variation in population density caused by the expansion of the U.S. Interstate Highway System, which largely followed the original 1947 plan for the Interstate Highway System. We find a negative association between population density and obesity, and estimates are robust across a wide range of specifications. Estimates indicate that if the average metropolitan area had not experienced the decline in the proportion of population living in dense areas over the last 30 years, the rate of obesity would have been reduced by approximately 13%. Copyright © 2010 Elsevier B.V. All rights reserved.

Declining suburbs in Europe and Latin America.

PubMed

Audirac, Ivonne; Cunningham-Sabot, Emmanuèle; Fol, Sylvie; Moraes, Sergio Torres

2012-01-01

Suburban shrinkage, understood as a degenerative urban process stemming from the demise of the Fordist mode of urbanism, is generally manifested in a decline in population, industry and employment. It is also intimately linked to the global restructuring of industrial organization associated with the rise of the post-Fordist mode of urbanism and, more recently, the thrust of Asian industrialization. Framed in the discourse of industrial urbanism, this article examines the first ring of industrial suburbs that developed around large cities in their most rapid Fordist urbanization phase. These industrial suburbs, although they were formed at different times, are today experiencing specific mutations and undergoing profound restructuring on account of their particular spatial position between the central area and the expanding peripheries of the post-Fordist metropolis. This article describes and compares suburban decline in two European cities (Glasgow and Paris) and two Latin American Cities (São Paulo, Brazil and Guadalajara, Mexico), as different instances of places asymmetrically and fragmentarily integrated into the geography of globalization.

Impact of migration on fertility in sub-Saharan Africa.

PubMed

Brockerhoff, M; Yang, X

1994-01-01

Much lower levels of fertility in urban than rural areas throughout sub-Saharan Africa imply that fertility decline in the region may be facilitated by rapid urbanization and rural-to-urban migration. The present study uses data from Demographic and Health Surveys in six countries--Ghana, Kenya, Mali, Senegal, Togo and Uganda--to assess the impact of long-term rural-urban female migration on fertility. Results of logit analyses indicate that in most countries women who leave the countryside represent the higher fertility segment of the rural population in the years before migration. Migrants' risk of conception declines dramatically in all countries around the time of migration and remains lower in the long run among most migrant groups than among rural and urban nonmigrants. Descriptive analyses suggest that the decline in migrant fertility is related to the rapid and pronounced improvement in standard of living experienced by migrants after settling in the urban area and may be due in part to temporary spousal separation.

Trends and Disparities in Heart Disease Mortality Among American Indians/Alaska Natives, 1990–2009

PubMed Central

Ayala, Carma; Schieb, Linda; Dai, Shifan; Henderson, Jeffrey A.; Cho, Pyone

2014-01-01

Objectives. We evaluated heart disease death rates among American Indians and Alaska Natives (AI/ANs) and Whites after improving identification of AI/AN populations. Methods. Indian Health Service (IHS) registration data were linked to the National Death Index for 1990 to 2009 to identify deaths among AI/AN persons aged 35 years and older with heart disease listed as the underlying cause of death (UCOD) or 1 of multiple causes of death (MCOD). We restricted analyses to IHS Contract Health Service Delivery Areas and to non-Hispanic populations. Results. Heart disease death rates were higher among AI/AN persons than Whites from 1999 to 2009 (1.21 times for UCOD, 1.30 times for MCOD). Disparities were highest in younger age groups and in the Northern Plains, but lowest in the East and Southwest. In AI/AN persons, MCOD rates were 84% higher than UCOD rates. From 1990 to 2009, UCOD rates declined among Whites, but only declined significantly among AI/AN persons after 2003. Conclusions. Analysis with improved race identification indicated that AI/AN populations experienced higher heart disease death rates than Whites. Better prevention and more effective care of heart disease is needed for AI/AN populations. PMID:24754556

The present and future disease burden of hepatitis C virus infections with today's treatment paradigm - volume 3.

PubMed

Sibley, A; Han, K H; Abourached, A; Lesmana, L A; Makara, M; Jafri, W; Salupere, R; Assiri, A M; Goldis, A; Abaalkhail, F; Abbas, Z; Abdou, A; Al Braiki, F; Al Hosani, F; Al Jaberi, K; Al Khatry, M; Al Mulla, M A; Al Quraishi, H; Al Rifai, A; Al Serkal, Y; Alam, A; Alavian, S M; Alashgar, H I; Alawadhi, S; Al-Dabal, L; Aldins, P; Alfaleh, F Z; Alghamdi, A S; Al-Hakeem, R; Aljumah, A A; Almessabi, A; Alqutub, A N; Alswat, K A; Altraif, I; Alzaabi, M; Andrea, N; Babatin, M A; Baqir, A; Barakat, M T; Bergmann, O M; Bizri, A R; Blach, S; Chaudhry, A; Choi, M S; Diab, T; Djauzi, S; El Hassan, E S; El Khoury, S; Estes, C; Fakhry, S; Farooqi, J I; Fridjonsdottir, H; Gani, R A; Ghafoor Khan, A; Gheorghe, L; Gottfredsson, M; Gregorcic, S; Gunter, J; Hajarizadeh, B; Hamid, S; Hasan, I; Hashim, A; Horvath, G; Hunyady, B; Husni, R; Jeruma, A; Jonasson, J G; Karlsdottir, B; Kim, D Y; Kim, Y S; Koutoubi, Z; Liakina, V; Lim, Y S; Löve, A; Maimets, M; Malekzadeh, R; Matičič, M; Memon, M S; Merat, S; Mokhbat, J E; Mourad, F H; Muljono, D H; Nawaz, A; Nugrahini, N; Olafsson, S; Priohutomo, S; Qureshi, H; Rassam, P; Razavi, H; Razavi-Shearer, D; Razavi-Shearer, K; Rozentale, B; Sadik, M; Saeed, K; Salamat, A; Sanai, F M; Sanityoso Sulaiman, A; Sayegh, R A; Sharara, A I; Siddiq, M; Siddiqui, A M; Sigmundsdottir, G; Sigurdardottir, B; Speiciene, D; Sulaiman, A; Sultan, M A; Taha, M; Tanaka, J; Tarifi, H; Tayyab, G; Tolmane, I; Ud Din, M; Umar, M; Valantinas, J; Videčnik-Zorman, J; Yaghi, C; Yunihastuti, E; Yusuf, M A; Zuberi, B F; Schmelzer, J D

2015-12-01

The total number, morbidity and mortality attributed to viraemic hepatitis C virus (HCV) infections change over time making it difficult to compare reported estimates from different years. Models were developed for 15 countries to quantify and characterize the viraemic population and forecast the changes in the infected population and the corresponding disease burden from 2014 to 2030. With the exception of Iceland, Iran, Latvia and Pakistan, the total number of viraemic HCV infections is expected to decline from 2014 to 2030, but the associated morbidity and mortality are expected to increase in all countries except for Japan and South Korea. In the latter two countries, mortality due to an ageing population will drive down prevalence, morbidity and mortality. On the other hand, both countries have already experienced a rapid increase in HCV-related mortality and morbidity. HCV-related morbidity and mortality are projected to increase between 2014 and 2030 in all other countries as result of an ageing HCV-infected population. Thus, although the total number of HCV countries is expected to decline in most countries studied, the associated disease burden is expected to increase. The current treatment paradigm is inadequate if large reductions in HCV-related morbidity and mortality are to be achieved. © 2015 John Wiley & Sons Ltd.

Unintended pregnancy and the changing demography of American women, 1987–2008

PubMed Central

Tapales, Athena; Finer, Lawrence

2016-01-01

BACKGROUND In 1987, the U.S. unintended pregnancy rate was 59 per 1,000 women aged 15–44; the rate fell to 54 in 2008. Over this period, American women experienced dramatic demographic shifts, including an aging population that was better educated and more racially and ethnically diverse. OBJECTIVE This study aims to explain trends in unintended pregnancy and understand what factors contributed most strongly to changes in rates over time, focusing on population composition and group-specific changes. METHODS We used the 1988 and 2006–10 waves of the National Survey of Family Growth and employed a decomposition approach, looking jointly at age, relationship status, and educational attainment. RESULTS When we decomposed by the demographic factors together, we found that changes in population composition contributed to an increase in the overall rate, but this was more than offset by group-specific rate declines, which had an impact nearly twice as great in the downward direction. Increases in the share of the population that was cohabiting and the share that was Hispanic were offset by declines in rates among married women. CONCLUSIONS Our findings suggest that a combination of compositional shifts and changes in group-specific rates drove unintended pregnancy, sometimes acting as counterbalancing forces and at other times operating in tandem. PMID:27147904

Changing pattern of premature mortality burden over 6 years of rapid growth of the economy in suburban south-west China: 1998-2003.

PubMed

Cai, Le; Chongsuvivatwong, Virasakdi; Geater, Alan

2008-05-01

This study was conducted in Kunming, the capital of Yunnan, a poor province in south-west China experiencing rapid economic growth. The study examined the short-term trend in premature mortality burden from common causes of death in a suburban region between 1998 and 2003. Years of life lost (YLL) per 1000 population and mortality rate per 100,000 population were calculated from medical death certificates, and broken down by cause of death, sex and year without age weighting but with a discounting rate of 3%. Non-communicable diseases contributed over 80% of all causes of YLL, with a slightly increasing trend. The combined rate for communicable, maternal, prenatal and nutritional deficiencies declined from 4.7 to 2.4 per 1000 population. Remarkably, declining trends in YLL were also seen for chronic obstructive pulmonary disease, drug use and road traffic accidents, whereas increasing trends were seen for ischaemic heart disease (IHD) and liver cancer (males). The YLL rate for stroke, self-inflicted injuries, lung cancer and stomach cancer fluctuated over time. The region should focus on further control of IHD and liver cancer.

Organochlorine residues in six species of estuarine birds, South Carolina, 1971-75

USGS Publications Warehouse

Blus, L.J.; Lamont, T.G.

1979-01-01

In South Carolina between 1971 and 1975, authors evaluated the occurrence of organochlorine residues in the laughing gull (Larus atricilla), white ibis (Eudocimus albus), glossy ibis (Plegadis falcinellus), American oystercatcher (Haematopus palliatus), willet (Catoptrophorus semipalmatus), and ruddy turnstone (Arenaria interpres). Tissues of birds found dead and eggs were analyzed, eggshell thicknesses were measured, and incidental observations were made of reproductive success and population status. Eggshell thickness of the white bis, American oystercatcher, and laughing gull were not significantly different (P less than 0.05) from the pre-1947 norms. DDE and polychlorinated biphenyls (PCBs) were found most frequently and at the highest concentration in eggs. DDE residues declined significantly in oystercatcher eggs, and declined slightly in laughing gull eggs; no change was noted in white ibis eggs. No consistent trends were found for dieldrin and PCBs. Authors found no obvious problems with reproductive success of any species. Populations of the five species breeding in South Carolina appear stable. The white ibis and laughing gull in South Carolina have experienced population explosions over the past 50 years; the glossy ibis has increased substantially since the first documented breeding records in 1947.

Isolation and characterization of microsatellite loci for alligator gar (Atractosteus spatula) and their variability in two other species (Lepisosteus oculatus and L. osseus) of Lepisosteidae

USGS Publications Warehouse

Moyer, G.R.; Sloss, Brian L.; Kreiser, B.R.; Feldheim, K.A.

2009-01-01

We report on the isolation of 17 polymorphic microsatellite loci from alligator gar (Atractosteus spatula), a large-bodied species that has experienced population declines across much of its range. These loci possessed 2-19 alleles and observed heterozygosities of 0-0.974. All loci conformed to Hardy-Weinberg equilibrium expectations, and none exhibited linkage disequilibrium. Nine and eight of these loci were found to be polymorphic in the related species Lepisosteus oculatus and L. osseus, respectively. These microsatellite loci should prove useful in conservation efforts of A. spatula through the study of population structure and hatchery broodstock management. ?? 2009 Blackwell Publishing Ltd.

An extirpated lineage of a threatened frog species resurfaces in southern California

USGS Publications Warehouse

Backlin, Adam R.; Richmond, Jonathan Q.; Gallegos, Elizabeth; Christensen, Clinton K.; Fisher, Robert N.

2017-01-01

Southern California has experienced widespread amphibian declines since the 1960s. One species, the Vulnerable California red-legged frog Rana draytonii, is now considered to be extirpated from most of southern California. In February 2017 a population of R. draytonii was discovered in the southern foothills of the San Bernardino Mountains of Riverside County, California, near the edge of the species’ historical distribution. This population belongs to an mtDNA lineage that was presumed to be extirpated within the USA but is still extant in Baja California, Mexico. This discovery increases the potential for future, evolutionarily informed translocations within the southern portion of this species’ range in California.

Ecophysiology meets conservation: understanding the role of disease in amphibian population declines

PubMed Central

Blaustein, Andrew R.; Gervasi, Stephanie S.; Johnson, Pieter T. J.; Hoverman, Jason T.; Belden, Lisa K.; Bradley, Paul W.; Xie, Gisselle Y.

2012-01-01

Infectious diseases are intimately associated with the dynamics of biodiversity. However, the role that infectious disease plays within ecological communities is complex. The complex effects of infectious disease at the scale of communities and ecosystems are driven by the interaction between host and pathogen. Whether or not a given host–pathogen interaction results in progression from infection to disease is largely dependent on the physiological characteristics of the host within the context of the external environment. Here, we highlight the importance of understanding the outcome of infection and disease in the context of host ecophysiology using amphibians as a model system. Amphibians are ideal for such a discussion because many of their populations are experiencing declines and extinctions, with disease as an important factor implicated in many declines and extinctions. Exposure to pathogens and the host's responses to infection can be influenced by many factors related to physiology such as host life history, immunology, endocrinology, resource acquisition, behaviour and changing climates. In our review, we discuss the relationship between disease and biodiversity. We highlight the dynamics of three amphibian host–pathogen systems that induce different effects on hosts and life stages and illustrate the complexity of amphibian–host–parasite systems. We then review links between environmental stress, endocrine–immune interactions, disease and climate change. PMID:22566676

Decomposing the crude divorce rate in five countries: Singapore, Taiwan, South Korea, the UK, and Australia

PubMed Central

Chen, Mengni

2018-01-01

ABSTRACT Over the past few decades, the level of divorce, measured by the crude divorce rate (CDR), has increased dramatically in both the East and the West, but has recently appeared to fall or level off in some countries. To investigate whether the recent decline or stabilisation of the CDRs reflects the real trends in divorce risk, a decomposition analysis was conducted on the changes in the CDRs over the past 20 years on two western and three East Asian countries, namely, the UK, Australia, Taiwan, South Korea, and Singapore. The following is observed: the decline in the CDRs of the UK and Australia in the 1990s, and of Taiwan and Korea in the 2000s, was mainly due to shrinkage in the proportion of the married population rather than any reduction in divorce risk; only Australia experienced a genuine reduction in divorce risk between 2001 and 2011; and the continuous increase of Singapore’s divorce level between 1990 and 2010 may be is an unintentional effect of the government’s marriage promotion policies. The shift in the population age structure, and more importantly, the drastic decline in marriage, has seriously distorted the CDRs, making them unreliable indicators for monitoring divorce trends. PMID:29930691

Measles, mumps, and rubella antibody patterns of persistence and rate of decline following the second dose of the MMR vaccine.

PubMed

Seagle, Emma E; Bednarczyk, Robert A; Hill, Tenisha; Fiebelkorn, Amy Parker; Hickman, Carole J; Icenogle, Joseph P; Belongia, Edward A; McLean, Huong Q

2018-02-01

Antibodies to measles, mumps, and rubella decline 3% per year on average, and have a high degree of individual variation. Yet, individual variations and differences across antigens are not well understood. To better understand potential implications on individual and population susceptibility, we reanalyzed longitudinal data to identify patterns of seropositivity and persistence. Children vaccinated with the second dose of measles, mumps, rubella vaccine (MMR2) at 4-6 years of age were followed up to 12 years post-vaccination. The rates of antibody decline were assessed using regression models, accounting for differences between and within subjects. Most of the 302 participants were seropositive throughout follow-up (96% measles, 88% mumps, 79% rubella). The rate of antibody decline was associated with MMR2 response and baseline titer for measles and age at first dose of MMR (MMR1) for rubella. No demographic or clinical factors were associated with mumps rate of decline. One month post-MMR2, geometric mean titer (GMT) to measles was high (3892 mIU/mL), but declined on average 9.7% per year among those with the same baseline titer and <2-fold increase post-MMR2. Subjects with ≥2-fold experienced a slower decline (≤7.4%). GMT to rubella was 149 one month post-MMR2, declining 2.6% and 5.9% per year among those who received MMR1 at 12-15 months and >15 months, respectively. GMT to mumps one month post-MMR2 was 151, declining 9.2% per year. Only 14% of subjects had the same persistence trends for all antigens. The rate of antibody decay varied substantially among individuals and the 3 antigen groups. A fast rate of decline coupled with high variation was observed for mumps, yet no predictors were identified. Future research should focus on better understanding waning titers to mumps and its impacts on community protection and individual susceptibility, in light of recent outbreaks in vaccinated populations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Majority Group Members' Negative Reactions to Future Demographic Shifts Depend on the Perceived Legitimacy of Their Status: Findings from the United States and Portugal.

PubMed

Outten, H Robert; Lee, Timothy; Costa-Lopes, Rui; Schmitt, Michael T; Vala, Jorge

2018-01-01

Using concepts from social identity theory (Tajfel and Turner, 1979), we examined whether racial/ethnic majority group members' reactions to future demographic shifts is a function of the degree to which they perceive their ingroup's higher-status in society to be legitimate. In two studies, participants who varied in the degree to which they perceived their group's status to be legitimate were either exposed to real projections for 2060 (i.e., large decline in proportion of population that is the "majority" group), or fake projections for 2060-that resembled current figures (i.e., small decline). In Study 1, White Americans who perceived their status to be highly legitimate expressed greater intergroup threat, and negative feelings (anger and fear) toward minorities after exposure to projections with a large decline in the relative size of the White American population. In contrast, demographic shift condition had no effect on intergroup threat and negative feelings toward minorities among White Americans who perceived their status to be relatively illegitimate; negative feelings and threat remained low across both conditions. Similarly, in Study 2, ethnic Portuguese people in Portugal exposed to projections in which there was a large decline in the relative size of the ethnic Portuguese population experienced more intergroup threat and expressed a greater desire to engage in anti-immigration behaviors. The effect of demographic shift condition on intergroup threat and anti-immigration behaviors was stronger among ethnic Portuguese who perceived their status to be legitimate compared to ethnic Portuguese people who perceived their status to be relatively illegitimate. These results highlight that across different cultural contexts, majority group members' beliefs about the legitimacy of intergroup relations can affect their reactions to the prospect of increased diversity.

Assessing the effects of hybridization and precipitation on invasive weed demography using strength of selection on vital rates.

PubMed

Teitel, Zachary; Klimowski, Agnieszka; Campbell, Lesley G

2016-12-07

As global climate change transforms average temperature and rainfall, species distributions may meet, increasing the potential for hybridization and altering individual fitness and population growth. Altered rainfall specifically may shift the strength and direction of selection, also manipulating population trajectories. Here, we investigated the role of interspecific hybridization and selection imposed by rainfall on the evolution of weedy life-history in non-hybrid (Raphanus raphanistrum) and hybrid (R. raphanistrum x R. sativus) populations using a life table response experiment. In documenting long-term population dynamics, we determined intrinsic (r) and asymptotic (λ) population growth rates and sensitivities, a measure of selection imposed on demographic rates. Hybrid populations experienced 8.7-10.3 times stronger selection than wild populations for increased seedling survival. Whereas crop populations generally exhibit little dormancy and wild populations often exhibit dormancy, non-hybrid populations experienced 10% stronger selection than hybrid populations for exhibiting seed dormancy. Selection on survival-to-flowering in wild, not hybrid, populations declined marginally with increasing soil moisture. Hybrid populations exhibited greater r, but not λ, than wild populations regardless of moisture environment. In general, fecundity contributed most to differences in λ but fecundity only contributed positively to hybrid λ relative to wild λ when precipitation was altered (either higher or lower than control) and not under control watering conditions. Selection on key demographic traits may not change dramatically in response to rainfall, and hybridization may more strongly influence the demography of these weedy species than rainfall. If hybrid populations can respond to selection for increased dormancy, this may make it more difficult to deplete weed seed banks and increase the persistence of crop genes in weed populations.

Impact of Simian Immunodeficiency Virus Infection on Chimpanzee Population Dynamics

PubMed Central

Rudicell, Rebecca S.; Holland Jones, James; Wroblewski, Emily E.; Learn, Gerald H.; Li, Yingying; Robertson, Joel D.; Greengrass, Elizabeth; Grossmann, Falk; Kamenya, Shadrack; Pintea, Lilian; Mjungu, Deus C.; Lonsdorf, Elizabeth V.; Mosser, Anna; Lehman, Clarence; Collins, D. Anthony; Keele, Brandon F.; Goodall, Jane; Hahn, Beatrice H.; Pusey, Anne E.; Wilson, Michael L.

2010-01-01

Like human immunodeficiency virus type 1 (HIV-1), simian immunodeficiency virus of chimpanzees (SIVcpz) can cause CD4+ T cell loss and premature death. Here, we used molecular surveillance tools and mathematical modeling to estimate the impact of SIVcpz infection on chimpanzee population dynamics. Habituated (Mitumba and Kasekela) and non-habituated (Kalande) chimpanzees were studied in Gombe National Park, Tanzania. Ape population sizes were determined from demographic records (Mitumba and Kasekela) or individual sightings and genotyping (Kalande), while SIVcpz prevalence rates were monitored using non-invasive methods. Between 2002–2009, the Mitumba and Kasekela communities experienced mean annual growth rates of 1.9% and 2.4%, respectively, while Kalande chimpanzees suffered a significant decline, with a mean growth rate of −6.5% to −7.4%, depending on population estimates. A rapid decline in Kalande was first noted in the 1990s and originally attributed to poaching and reduced food sources. However, between 2002–2009, we found a mean SIVcpz prevalence in Kalande of 46.1%, which was almost four times higher than the prevalence in Mitumba (12.7%) and Kasekela (12.1%). To explore whether SIVcpz contributed to the Kalande decline, we used empirically determined SIVcpz transmission probabilities as well as chimpanzee mortality, mating and migration data to model the effect of viral pathogenicity on chimpanzee population growth. Deterministic calculations indicated that a prevalence of greater than 3.4% would result in negative growth and eventual population extinction, even using conservative mortality estimates. However, stochastic models revealed that in representative populations, SIVcpz, and not its host species, frequently went extinct. High SIVcpz transmission probability and excess mortality reduced population persistence, while intercommunity migration often rescued infected communities, even when immigrating females had a chance of being SIVcpz infected. Together, these results suggest that the decline of the Kalande community was caused, at least in part, by high levels of SIVcpz infection. However, population extinction is not an inevitable consequence of SIVcpz infection, but depends on additional variables, such as migration, that promote survival. These findings are consistent with the uneven distribution of SIVcpz throughout central Africa and explain how chimpanzees in Gombe and elsewhere can be at equipoise with this pathogen. PMID:20886099

Testing the relationship between human occupancy in the landscape and tadpole developmental stress.

PubMed

Eterovick, Paula C; Bar, Luís F F; Souza, Jorge B; Castro, José F M; Leite, Felipe S F; Alford, Ross A

2015-01-01

Amphibian population declines are widespread; the main causal factors are human related and include habitat fragmentation due to agriculture, mining, fires, and urban development. Brazil is the richest country in species of amphibians, and the Brazilian regions with the greatest amphibian diversity are experiencing relatively high rates of habitat destruction, but there are presently relatively few reports of amphibian declines. It is thus important to develop research methods that will detect deterioration in population health before severe declines occur. We tested the use of measurements of fluctuating asymmetry (FA) taken on amphibian larvae to detect anthropogenic stress. We hypothesized that greater human occupancy in the landscape might result in more stressful conditions for amphibians. We conducted this study at the Espinhaço mountain range in southeastern Brazil, using as a model an endemic species (Bokermannohyla saxicola, Hylidae). We chose two tadpole denticle rows and eye-nostril distance as traits for FA measurement. We measured percent cover of human-altered habitats in the landscape around tadpole sampling points and measured FA levels in sampled tadpoles. We found FA levels to differ among localities but found no relationship between human modification of the landscape and tadpole FA levels. Levels of FA in the traits we examined may not be strongly affected by environmental conditions, or may be affected by local variables that were not captured by our landscape-scale measures. Alternatively, populations may be genetically differentiated, affecting how FA levels respond to stress and obscuring the effects of anthropogenic disturbance.

No evidence of metabolic depression in Western Alaskan juvenile Steller sea lions (Eumetopias jubatus).

PubMed

Hoopes, Lisa A; Rea, Lorrie D; Christ, Aaron; Worthy, Graham A J

2014-01-01

Steller sea lion (Eumetopias jubatus) populations have undergone precipitous declines through their western Alaskan range over the last four decades with the leading hypothesis to explain this decline centering around changing prey quality, quantity, or availability for this species (i.e., nutritional stress hypothesis). Under chronic conditions of reduced food intake sea lions would conserve energy by limiting energy expenditures through lowering of metabolic rate known as metabolic depression. To examine the potential for nutritional stress, resting metabolic rate (RMR) and body composition were measured in free-ranging juvenile Steller sea lions (N = 91) at three distinct geographical locations (Southeast Alaska, Prince William Sound, Central Aleutian Islands) using open-flow respirometry and deuterium isotope dilution, respectively. Average sea lion RMR ranged from 6.7 to 36.2 MJ d(-1) and was influenced by body mass, total body lipid, and to a lesser extent, ambient air temperature and age. Sea lion pups captured in the Aleutian Islands (region of decline) had significantly greater body mass and total body lipid stores when compared to pups from Prince William Sound (region of decline) and Southeast Alaska (stable region). Along with evidence of robust body condition in Aleutian Island pups, no definitive differences were detected in RMR between sea lions sampled between eastern and western populations that could not be accounted for by higher percent total body lipid content, suggesting that that at the time of this study, Steller sea lions were not experiencing metabolic depression in the locations studied.

Stochastic predation events and population persistence in bighorn sheep

PubMed Central

Festa-Bianchet, Marco; Coulson, Tim; Gaillard, Jean-Michel; Hogg, John T; Pelletier, Fanie

2006-01-01

Many studies have reported temporal changes in the relative importance of density-dependence and environmental stochasticity in affecting population growth rates, but they typically assume that the predominant factor limiting growth remains constant over long periods of time. Stochastic switches in limiting factors that persist for multiple time-steps have received little attention, but most wild populations may periodically experience such switches. Here, we consider the dynamics of three populations of individually marked bighorn sheep (Ovis canadensis) monitored for 24–28 years. Each population experienced one or two distinct cougar (Puma concolor) predation events leading to population declines. The onset and duration of predation events were stochastic and consistent with predation by specialist individuals. A realistic Markov chain model confirms that predation by specialist cougars can cause extinction of isolated populations. We suggest that such processes may be common. In such cases, predator–prey equilibria may only occur at large geographical and temporal scales, and are unlikely with increasing habitat fragmentation. PMID:16777749

First and recurrent ischaemic heart disease events continue to decline in New Zealand, 2005-2015.

PubMed

Grey, Corina; Jackson, Rod; Wells, Susan; Wu, Billy; Poppe, Katrina; White, Harvey; Chan, Wing Cheuk; Kerr, Andrew J

2018-01-01

To examine recent trends in first and recurrent ischaemic heart disease (IHD) deaths and hospitalisations. Using anonymous patient-linkage of routinely collected data, all New Zealanders aged 35-84 years who experienced an International Statistical Classification of Diseases and Related Health Problems I(CD)-coded IHD hospitalisation and/or IHD death between 1 January 2005 and 31 December 2015 were identified. A 10-year look-back period was used to differentiate those experiencing first from recurrent events. Age-standardised hospitalisation and mortality rates were calculated for each calendar year and trends compared by sex and age. 160 109 people experienced at least one IHD event (259 678 hospitalisations and 35 548 deaths) over the 11-year study period, and there was a steady decline in numbers (from almost 24 000 in 2005 to just over 16 000 in 2015) and in age-standardised rates each year. With the exception of deaths in younger (35-64 years) women with prior IHD, there was a significant decline in IHD events in men and women of all ages, with and without a history of IHD. The decline in IHD mortality was greater for those experiencing a first rather than recurrent IHD event (3.8%-5.2% vs 0%-3.7% annually on average). In contrast, the decline in IHD hospitalisations was greater for those experiencing a recurrent compared with a first IHD event (5.6%-7.3% vs 3.2%-5.7% annually on average). The substantial decline in IHD hospitalisations and mortality observed in New Zealanders with and without prior IHD between 2005 and 2015 suggests that primary and secondary prevention efforts have been effective in reducing the occurrence of IHD events. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Comparison of respiratory activity and culturability during monochloramine disinfection of binary population biofilms.

PubMed Central

Stewart, P S; Griebe, T; Srinivasan, R; Chen, C I; Yu, F P; deBeer, D; McFeters, G A

1994-01-01

Biofilm bacteria challenged with monochloramine retained significant respiratory activity, even though they could not be cultured on agar plates. Microbial colony counts on agar media declined by approximately 99.9% after 1 h of disinfection, whereas the number of bacteria stained by a fluorescent redox dye experienced a 93% reduction. Integrated measures of biofilm respiratory activity, including net oxygen and glucose utilization rates, showed only a 10 to 15% reduction. In this biofilm system, measures of microbial respiratory activity and culturability yielded widely differing estimates of biocide efficacy. PMID:8017950

Epidemic disease decimates amphibian abundance, species diversity, and evolutionary history in the highlands of central Panama.

PubMed

Crawford, Andrew J; Lips, Karen R; Bermingham, Eldredge

2010-08-03

Amphibian populations around the world are experiencing unprecedented declines attributed to a chytrid fungal pathogen, Batrachochytrium dendrobatidis. Despite the severity of the crisis, quantitative analyses of the effects of the epidemic on amphibian abundance and diversity have been unavailable as a result of the lack of equivalent data collected before and following disease outbreak. We present a community-level assessment combining long-term field surveys and DNA barcode data describing changes in abundance and evolutionary diversity within the amphibian community of El Copé, Panama, following a disease epidemic and mass-mortality event. The epidemic reduced taxonomic, lineage, and phylogenetic diversity similarly. We discovered that 30 species were lost, including five undescribed species, representing 41% of total amphibian lineage diversity in El Copé. These extirpations represented 33% of the evolutionary history of amphibians within the community, and variation in the degree of population loss and decline among species was random with respect to the community phylogeny. Our approach provides a fast, economical, and informative analysis of loss in a community whether measured by species or phylogenetic diversity.

Epidemic disease decimates amphibian abundance, species diversity, and evolutionary history in the highlands of central Panama

PubMed Central

Crawford, Andrew J.; Lips, Karen R.; Bermingham, Eldredge

2010-01-01

Amphibian populations around the world are experiencing unprecedented declines attributed to a chytrid fungal pathogen, Batrachochytrium dendrobatidis. Despite the severity of the crisis, quantitative analyses of the effects of the epidemic on amphibian abundance and diversity have been unavailable as a result of the lack of equivalent data collected before and following disease outbreak. We present a community-level assessment combining long-term field surveys and DNA barcode data describing changes in abundance and evolutionary diversity within the amphibian community of El Copé, Panama, following a disease epidemic and mass-mortality event. The epidemic reduced taxonomic, lineage, and phylogenetic diversity similarly. We discovered that 30 species were lost, including five undescribed species, representing 41% of total amphibian lineage diversity in El Copé. These extirpations represented 33% of the evolutionary history of amphibians within the community, and variation in the degree of population loss and decline among species was random with respect to the community phylogeny. Our approach provides a fast, economical, and informative analysis of loss in a community whether measured by species or phylogenetic diversity. PMID:20643927

Declining physical activity and the socio-cultural context of the geography of industrial restructuring: a novel conceptual framework.

PubMed

Rind, Esther; Jones, Andy

2014-05-01

At the population level, the prevalence of physical activity has declined considerably in many developed countries in recent decades. There is some evidence that areas exhibiting the lowest activity levels are those which have undergone a particularly strong transition away from employment in physically demanding occupations. We propose that processes of deindustrialization may be causally linked to unexplained geographical disparities in levels of physical activity. While the sociocultural correlates of physical activity have been well studied, and prior conceptual frameworks have been developed to explain more general patterns of activity, none have explicitly attempted to identify the components of industrial change that may impact physical activity. In this work we review the current literature on sociocultural correlates of health behaviors before using a case study centered on the United Kingdom to present a novel framework that links industrial change to declining levels of physical activity. We developed a comprehensive model linking sociocultural correlates of physical activity to processes associated with industrial restructuring and discuss implication for policy and practice. A better understanding of sociocultural processes may help to ameliorate adverse health consequences of employment decline in communities that have experienced substantial losses of manual employment.

History of ground-water pumpage and water-level decline in the Black Creek and upper Cape Fear aquifers of the central coastal plain of North Carolina

USGS Publications Warehouse

Winner, M.D.; Lyke, W.L.

1986-01-01

Historical ground-water withdrawals and a general water-level decline in the Black Creek and upper Cape Fear aquifers of the central Coastal Plain of North Carolina are documented. Total municipal and industrial pumpage from these aquifers has increased from approximately 120,000 gal/day (gpd) in 1910 to >21 million gpd in 1980. Major pumpage, > 10,000 gpd, began around 1900. Since that time, per capita water use in the central Coastal Plain area has ranged from 17 to 172 gpd/person. The higher values partially represent the increasing availability and use of modern conveniences since the World War II era. The range of per capita water use can be subdivided according to general water-use and population characteristics for both urban and rural areas. The pumpage of ground water from the Black Creek and upper Cape Fear aquifers has created water-level declines from 0.5 to 4.9 ft/year since 1900. Approximately a third of the study area has experienced a decline > 50 ft up to the period 1979-1981, with 148 ft being the maximum.

Reproductive characteristics and population decline of four species of skate (Rajidae) off the eastern coast of Canada.

PubMed

Mcphie, R P; Campana, S E

2009-07-01

Four of the most common species of skate (Rajidae) were studied off eastern Canada to determine if their reproductive characteristics were linked to their population trajectories. The fecundity of the winter skate Leucoraja ocellata, the little skate Leucoraja erinacea, the thorny skate Amblyraja radiata and the smooth skate Malacoraja senta averaged between 41 and 56 egg cases per year for each species. For all species but L. ocellata, males matured at larger sizes and at later ages than females. Theoretical rates of population increase for non-equilibrium populations of L. ocellata (c. 0.07), M. senta (c. 0.14) and L. erinacea and A. radiata (c. 0.20) were low compared to most fishes, indicating that north-west Atlantic skates are intrinsically unproductive, yet are theoretically capable of supporting low-level fisheries. Nevertheless, the results of 36 years of research surveys indicate that the abundance of mature L. ocellata, A. radiata and M. senta all decreased by >90% since 1970, indicating that past fishing mortality (both directed and undirected) has outstripped the net productivity of the skate populations on the eastern Scotian Shelf. The relationship between maximum age (t(max)) and age of maturity (t(mat)) was a better predictor of population growth rate than was body size, with the species exhibiting the highest ratios of t(mat) :t(max) (L. ocellata = 0.68, M. senta = 0.66) having the lowest predicted population growth rates. L. ocellata appears to have the lowest productivity and has experienced the greatest population decline, thus raising concerns over its future status.

Reproductive behaviour in the 1980s: Europe revisited. Council of Europe: an account of the work of a committee of experts on fertility trends.

PubMed

Deven, F

1985-01-01

This article highlights the findings of a 3-stage analysis conducted in 1982-85 by the Council of Europe Committee of Experts on Fertility Trends: The 1st phase involved a demographic analysis of reproductive behavior in the past decade, the 2nd focused on the background of recent fertility trends, and the 3rd examined possible consequences of these trends. Participating countries included Belgium, France, Federal Republic of Germany, Luxembourg, the Netherlands, Norway, Portugal, Spain, and Switzerland. During the 1970s; most of these countries experienced a continuation of the fertility decline begun in the mid-60s, resulting in the large majority of countries in below-replacement reproduction. In general, the effect of the fertility decline on the birth rate has been partially compensated by the favorable age structure of the reproductive age population. In the 1st half of the 1970s, both nuptiality and reproductive behavior in marriage contributed to the fertility decline; in the 2nd half, marital fertility showed increases. The fertility decline in the 1st half of the 1970s largely reflected the steep decline in fertility among younger age groups, whereas a rise in the fertility in the older age groups was a characteristic of the late 1970s. However, the stabilization or even slight increase in fertility noted in the late 1970s in several European countries reverted to a decline in the early 1980s. In general, small family size appears to be viewed as a good compromise between pyschological and economic costs and benefits. These low fertility trends have had a dramatic effect on household composition and have also facilitated women's personal growth and economic independence. These trends are expected to lead to demographic aging of the population and alleviation of pressures on the labor market. All such changes will require adaptive population policy measures. It is important that such policies do not endanger achievements of modernization such as human rights, fertility regulation, and female employment.

Tuning stochastic matrix models with hydrologic data to predict the population dynamics of a riverine fish

USGS Publications Warehouse

Sakaris, P.C.; Irwin, E.R.

2010-01-01

We developed stochastic matrix models to evaluate the effects of hydrologic alteration and variable mortality on the population dynamics of a lotie fish in a regulated river system. Models were applied to a representative lotic fish species, the flathead catfish (Pylodictis olivaris), for which two populations were examined: a native population from a regulated reach of the Coosa River (Alabama, USA) and an introduced population from an unregulated section of the Ocmulgee River (Georgia, USA). Size-classified matrix models were constructed for both populations, and residuals from catch-curve regressions were used as indices of year class strength (i.e., recruitment). A multiple regression model indicated that recruitment of flathead catfish in the Coosa River was positively related to the frequency of spring pulses between 283 and 566 m3/s. For the Ocmulgee River population, multiple regression models indicated that year class strength was negatively related to mean March discharge and positively related to June low flow. When the Coosa population was modeled to experience five consecutive years of favorable hydrologic conditions during a 50-year projection period, it exhibited a substantial spike in size and increased at an overall 0.2% annual rate. When modeled to experience five years of unfavorable hydrologic conditions, the Coosa population initially exhibited a decrease in size but later stabilized and increased at a 0.4% annual rate following the decline. When the Ocmulgee River population was modeled to experience five years of favorable conditions, it exhibited a substantial spike in size and increased at an overall 0.4% annual rate. After the Ocmulgee population experienced five years of unfavorable conditions, a sharp decline in population size was predicted. However, the population quickly recovered, with population size increasing at a 0.3% annual rate following the decline. In general, stochastic population growth in the Ocmulgee River was more erratic and variable than population growth in the Coosa River. We encourage ecologists to develop similar models for other lotic species, particularly in regulated river systems. Successful management of fish populations in regulated systems requires that we are able to predict how hydrology affects recruitment and will ultimately influence the population dynamics of fishes. ?? 2010 by the Ecological Society of America.

Differential rate in decline in ovarian reserve markers in women with polycystic ovary syndrome compared with control subjects: results of a longitudinal study.

PubMed

Ahmad, Asima K; Kao, Chia-Ning; Quinn, Molly; Lenhart, Nikolaus; Rosen, Mitchell; Cedars, Marcelle I; Huddleston, Heather

2018-03-01

To estimate rates of ovarian aging in polycystic ovary syndrome (PCOS) subjects versus a community control population. Longitudinal. Tertiary academic center. PCOS subjects diagnosed according to the 2004 Rotterdam criteria were systematically enrolled in a PCOS cohort study. The comparison control subjects were from the Ovarian Aging study, a prospective longitudinal study of ovarian aging in healthy women with regular menstrual cycles. Clinical data collection over two study visits. Antral follicle count (AFC), ovarian volume (OV), and antimüllerian hormone level (AMH). PCOS subjects were found to have higher baseline values for all ovarian reserve markers compared with control subjects. Univariate models indicated that, compared with control subjects, PCOS patients experienced significantly faster rates of decline for both AFC and AMH. Change in OV did not differ significantly. To account for potential confounder effects, multiple analysis of covariance models were evaluated for the best fit, considering age, body mass index, and baseline ovarian reserve markers. Adjusted models demonstrated that PCOS patients do not experience a significant difference in AFC decline compared with control subjects, but they do experience a faster rate of decline in AMH (P<.01) and slower rate of decline in OV (P<.01). Ovarian aging in PCOS is characterized by a more rapid decline in AMH and a slower decline in OV compared with control subjects. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Doing good when times are bad: volunteering behaviour in economic hard times.

PubMed

Lim, Chaeyoon; Laurence, James

2015-06-01

This paper examines how the 2008-9 recession has affected volunteering behaviours in the UK. Using a large survey dataset, we assess the recession effects on both formal volunteering and informal helping behaviours. Whilst both formal volunteering and informal helping have been in decline in the UK since 2008, the size of the decline is significantly larger for informal helping than for formal volunteering. The decline is more salient in regions that experienced a higher level of unemployment during the recession and also in socially and economically disadvantaged communities. However, we find that a growing number of people who personally experienced financial insecurity and hardship do not explain the decline. We argue that the decline has more to do with community-level factors such as civic organizational infrastructure and cultural norms of trust and engagement than personal experiences of economic hardship. © London School of Economics and Political Science 2015.

The population genetics of a solitary oligolectic sweat bee, Lasioglossum (Sphecodogastra) oenotherae (Hymenoptera: Halictidae).

PubMed

Zayed, A; Packer, L

2007-10-01

Strong evidence exists for global declines in pollinator populations. Data on the population genetics of solitary bees, especially diet specialists, are generally lacking. We studied the population genetics of the oligolectic bee Lasioglossum oenotherae, a specialist on the pollen of evening primrose (Onagraceae), by genotyping 455 females from 15 populations across the bee's North American range at six hyper-variable microsatellite loci. We found significant levels of genetic differentiation between populations, even at small geographic scales, as well as significant patterns of isolation by distance. However, using multilocus genotype assignment tests, we detected 11 first-generation migrants indicating that L. oenotherae's sub-populations are experiencing ongoing gene flow. Southern populations of L. oenotherae were significantly more likely to deviate from Hardy-Weinberg equilibrium and from genotypic equilibrium, suggesting regional differences in gene flow and/or drift and inbreeding. Short-term N(e) estimated using temporal changes in allele frequencies in several populations ranged from approximately 223 to 960. We discuss our findings in terms of the conservation genetics of specialist pollinators, a group of considerable ecological importance.

The needs of salmon and steelhead in balancing their conservation and use

USGS Publications Warehouse

Burger, Carl V.; Knudsen, E. Eric; Steward, Cleveland R.; MacDonald, Donald D.; Williams, Jack E.; Reiser, Dudley W.

1999-01-01

Over the past 100 years, Pacific salmon Oncorhynchus spp. and steelhead trout O. mykiss populations in the Pacific Northwest have experienced dramatic declines as a result of human population growth and associated development of the region's natural resources. Any strategy to reverse those declines will depend on achieving consensus among a diverse group of stakeholders willing to (1) restore damaged habitats and watersheds; (2) consider the biological needs of salmonid fishes; and (3) understand, conserve, and manage existing levels of biodiversity within an ecosystem context. The objective of this chapter is to review and summarize the needs of Pacific salmon and steelhead trout from perspectives that promote their sustainability and perpetuity, and, within that context, provide a framework, for the development of a sustainable fisheries strategy. Although volumes of information are available on the life histories and habitat requirements of Pacific salmonids, new concepts have begun to address the importance of habitat complexity, genetic diversity among locally adapted populations, and the need for appropriate units of conservation. Habitat variability and complexity are the templates that produce diverse, locally adapted populations of Pacific salmon and steelhead trout. Molded by conditions in the environments they colonized, salmon and steelhead have unique adaptations they may have taken hundred i?? perhaps thousands i?? of years to evolve. Any strategy to reverse the declines of salmon and steelhead must focus on conserving both current levels of genetic diversity as well as restoration and maintenance of habitats compatible with the specific needs of individual populations. An argument can be made that we know enough already about the needs of our salmon and steelhead to allow us to make appropriate decisions. There is strong need to integrate what we know about local salmonid adaptations and habitat needs with conservation and management strategies that address the problems we have created. It may be possible to have healthy, sustainable salmonid populations coastwide if we do not wait too long to make up our minds.

Does habitat fragmentation cause stress in the agile antechinus? A haematological approach.

PubMed

Johnstone, Christopher P; Lill, Alan; Reina, Richard D

2012-01-01

Although the vertebrate stress response is essential for survival, frequent or prolonged stress responses can result in chronic physiological stress, which is associated with a suite of conditions that can impair survivorship and reproductive output. Anthropogenic habitat fragmentation and degradation are potential stressors of free-living vertebrates, and in theory could result in chronic stress. To address this issue, we compared haematological indicators of stress and condition in agile antechinus (Antechinus agilis) populations in 30 forest fragments and 30 undisturbed, continuous forest sites (pseudofragments) in south-eastern Australia over 2 years. In peripheral blood, the total leucocyte count was lower and the neutrophil/lymphocyte ratio and percentage of eosinophils in the total leucocyte population was higher in fragment than pseudofragment populations, indicating that fragment populations were probably experiencing higher levels of stress hormone-mediated and/or parasite infection-related chronic physiological stress. The total erythrocyte count and haematocrit were higher and mean erythrocyte haemoglobin content was lower in fragment than pseudofragment populations. This suggests that fragment populations showed possible signs of regenerative anaemia, a syndrome associated with elevated hypothalamus-pituitary-adrenal axis mediated stress. However, mean erythrocyte volume was also lower in fragments, and red blood cell distribution width did not differ between the study populations, findings which were not consistent with this diagnosis. Whole blood and mean cell haemoglobin concentrations were similar in fragment and pseudofragment populations. We suggest that where anthropogenic activity results in habitat fragmentation and degradation, chronic stress could contribute to a decline in agile antechinus populations. The broader implication is that chronic stress could be both symptomatic of, and contributing to, decline of some vertebrate populations in anthropogenically fragmented and degraded habitats.

Cognitive decline in patients with Alzheimer's disease, vascular dementia and senile dementia of Lewy body type.

PubMed

Ballard, C; Patel, A; Oyebode, F; Wilcock, G

1996-05-01

One hundred and twenty-four patients with DSM-III-R dementia were assessed with a standardized battery which included the Geriatric Mental State Schedule, the History and Aetiology Schedule, the Secondary Dementia Schedule and the CAMCOG. Patients with Alzheimer's disease, vascular dementia and senile dementia of Lewy body type (SDLT) all had a similar degree of cognitive impairment at the time of the baseline interview. Patients with Alzheimer's disease and vascular dementia each experienced a mean decline of 27 points in patients with SDLT. Patients with SDLT had a significantly greater decline of verbal fluency than both the other groups. Women were significantly more impaired than men at the time of the baseline assessment but experienced a similar decline during the year of follow-up.

The consequences of poaching and anthropogenic change for forest elephants.

PubMed

Breuer, Thomas; Maisels, Fiona; Fishlock, Vicki

2016-10-01

Poaching has devastated forest elephant populations (Loxodonta cyclotis), and their habitat is dramatically changing. The long-term effects of poaching and other anthropogenic threats have been well studied in savannah elephants (Loxodonta africana), but the impacts of these changes for Central Africa's forest elephants have not been discussed. We examined potential repercussions of these threats and the related consequences for forest elephants in Central Africa by summarizing the lessons learned from savannah elephants and small forest elephant populations in West Africa. Forest elephant social organization is less known than the social organization of savannah elephants, but the close evolutionary history of these species suggests that they will respond to anthropogenic threats in broadly similar ways. The loss of older, experienced individuals in an elephant population disrupts ecological, social, and population parameters. Severe reduction of elephant abundance within Central Africa's forests can alter plant communities and ecosystem functions. Poaching, habitat alterations, and human population increase are probably compressing forest elephants into protected areas and increasing human-elephant conflict, which negatively affects their conservation. We encourage conservationists to look beyond documenting forest elephant population decline and address the causes of these declines when developing conversation strategies. We suggest assessing the effectiveness of the existing protected-area networks for landscape connectivity in light of current industrial and infrastructure development. Longitudinal assessments of the effects of landscape changes on forest elephant sociality and behavior are also needed. Finally, lessons learned from West African elephant population loss and habitat fragmentation should be used to inform strategies for land-use planning and managing human-elephant interactions. © 2016 Society for Conservation Biology.

Rural-Urban Differences in Cancer Incidence and Trends in the United States.

PubMed

Zahnd, Whitney E; James, Aimee S; Jenkins, Wiley D; Izadi, Sonya R; Fogleman, Amanda J; Steward, David E; Colditz, Graham A; Brard, Laurent

2017-07-27

Cancer incidence and mortality rates in the US are declining, but this decrease may not be observed in rural areas where residents are more likely to live in poverty, smoke, and forego cancer screening. However, there is limited research exploring national rural-urban differences in cancer incidence and trends. We analyzed data from the North American Association of Central Cancer Registries' public use dataset, which includes population-based cancer incidence data from 46 states. We calculated age-adjusted incidence rates, rate ratios, and annual percentage change (APC) for: all cancers combined; selected individual cancers; and cancers associated with tobacco use and human papillomavirus (HPV). Rural-urban comparisons were made by demographic, geographic, and socioeconomic characteristics for 2009 to 2013. Trends were analyzed for 1995 to 2013. Combined cancers incidence rates were generally higher in urban populations, except for the South, though the urban decline in incidence rate was greater than in rural populations (10.2% vs. 4.8%, respectively). Rural cancer disparities included higher rates of tobacco associated, HPV associated, lung and bronchus, cervical , and colorectal cancers across most population groups. Further, HPV-associated cancer incidence rates increased in rural areas (APC=0.724, p<0.05) while temporal trends remained stable in urban areas. Cancer rates associated with modifiable risks - tobacco, HPV, and some preventive screening modalities (e.g. colorectal and cervical cancers) - were higher in rural compared to urban populations. Population-based, clinical, and/or policy strategies and interventions that address these modifiable risk factors could help reduce cancer disparities experienced in rural populations. Copyright ©2017, American Association for Cancer Research.

Connectivity of wood thrush breeding, wintering, and migration sites based on range-wide tracking.

PubMed

Stanley, Calandra Q; McKinnon, Emily A; Fraser, Kevin C; Macpherson, Maggie P; Casbourn, Garth; Friesen, Lyle; Marra, Peter P; Studds, Colin; Ryder, T Brandt; Diggs, Nora E; Stutchbury, Bridget J M

2015-02-01

Many migratory animals are experiencing rapid population declines, but migration data with the geographic scope and resolution to quantify the complex network of movements between breeding and nonbreeding regions are often lacking. Determining the most frequently used migration routes and nonbreeding regions for a species is critical for understanding population dynamics and making effective conservation decisions. We tracked the migration of individual Wood Thrushes (Hylocichla mustelina) (n = 102) from across their range with light-level geolocators and, for the first time, quantified migration routes and wintering regions for distinct breeding populations. We identified regional and species-level migratory connectivity networks for this declining songbird by combining our tracking results with range-wide breeding abundance estimates and forest cover data. More than 50% of the species occupied the eastern wintering range (Honduras to Costa Rica), a region that includes only one-third of all wintering habitat and that is undergoing intensive deforestation. We estimated that half of all Wood Thrushes in North America migrate south through Florida in fall, whereas in spring approximately 73% funnel northward through a narrow span along the central U.S. Gulf Coast (88-93°W). Identifying migratory networks is a critical step for conservation of songbirds and we demonstrated with Wood Thrushes how it can highlight conservation hotspots for regional populations and species as a whole. © 2014 Society for Conservation Biology.

Temporal trends in motor vehicle fatalities in the United States, 1968 to 2010 - a joinpoint regression analysis.

PubMed

Bandi, Priti; Silver, Diana; Mijanovich, Tod; Macinko, James

2015-12-01

In the past 40 years, a variety of factors might have impacted motor vehicle (MV) fatality trends in the US, including public health policies, engineering innovations, trauma care improvements, etc. These factors varied in their timing across states/localities, and many were targeted at particular population subgroups. In order to identify and quantify differential rates of change over time and differences in trend patterns between population subgroups, this study employed a novel analytic method to assess temporal trends in MV fatalities between 1968 and 2010, by age group and sex. Cause-specific MV fatality data from traffic injuries between 1968 and 2010, based on death certificates filed in the 50 states, and DC were obtained from Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research (CDC WONDER). Long-term (1968 to 2010) and short-term (log-linear piecewise segments) trends in fatality rates were compared for males and females overall and in four separate age groups using joinpoint regression. MV fatalities declined on average by 2.4% per year in males and 2.2% per year in females between 1968 and 2010, with significant declines observed in all age groups and in both sexes. In males overall and those 25 to 64 years, sharp declines between 1968 and mid-to-late 1990s were followed by a stalling until the mid-2000s, but rates in females experienced a long-term steady decline of a lesser magnitude than males during this time. Trends in those aged <1 to 14 years and 15 to 24 years were mostly steady over time, but males had a larger decline than females in the latter age group between 1968 and the mid-2000s. In ages 65+, short-term trends were similar between sexes. Despite significant long-term declines in MV fatalities, the application of Joinpoint Regression found that progress in young adult and middle-aged adult males stalled in recent decades and rates in males declined relatively more than in females in certain age groups. Future research is needed to establish the causes of these observed trends, including the potential role of contemporaneous MV-related policies and their repeal. Such research is needed in order to better inform the design and evaluation of future population interventions addressing MV fatalities nationally.

Faith after an Earthquake: A Longitudinal Study of Religion and Perceived Health before and after the 2011 Christchurch New Zealand Earthquake

PubMed Central

Sibley, Chris G.; Bulbulia, Joseph

2012-01-01

On 22 February 2011, Christchurch New Zealand (population 367,700) experienced a devastating earthquake, causing extensive damage and killing one hundred and eighty-five people. The earthquake and aftershocks occurred between the 2009 and 2011 waves of a longitudinal probability sample conducted in New Zealand, enabling us to examine how a natural disaster of this magnitude affected deeply held commitments and global ratings of personal health, depending on earthquake exposure. We first investigated whether the earthquake-affected were more likely to believe in God. Consistent with the Religious Comfort Hypothesis, religious faith increased among the earthquake-affected, despite an overall decline in religious faith elsewhere. This result offers the first population-level demonstration that secular people turn to religion at times of natural crisis. We then examined whether religious affiliation was associated with differences in subjective ratings of personal health. We found no evidence for superior buffering from having religious faith. Among those affected by the earthquake, however, a loss of faith was associated with significant subjective health declines. Those who lost faith elsewhere in the country did not experience similar health declines. Our findings suggest that religious conversion after a natural disaster is unlikely to improve subjective well-being, yet upholding faith might be an important step on the road to recovery. PMID:23227147

Hyperstability masks declines in bumphead parrotfish ( Bolbometopon muricatum) populations

NASA Astrophysics Data System (ADS)

Hamilton, Richard J.; Almany, Glenn R.; Stevens, Don; Bode, Michael; Pita, John; Peterson, Nate A.; Choat, J. Howard

2016-09-01

Bolbometopon muricatum, the largest species of parrotfish, is a functionally important species that is characterised by the formation of aggregations for foraging, reproductive, and sleeping behaviours. Aggregations are restricted to shallow reef habitats, the locations of which are often known to local fishers. Bolbometopon muricatum fisheries are therefore vulnerable to overfishing and are likely to exhibit hyperstability, the maintenance of high catch per unit effort (CPUE) while population abundance declines. In this study, we provide a clear demonstration of hyperstable dynamics in a commercial B. muricatum fishery in Isabel Province, Solomon Islands. Initially, we used participatory mapping to demarcate the Kia fishing grounds into nine zones that had experienced different historic levels of fishing pressure. We then conducted comprehensive underwater visual census (UVC) and CPUE surveys across these zones over a 21-month period in 2012-2013. The individual sites for replicate UVC surveys were selected using a generalised random tessellation stratified variable probability design, while CPUE surveys involved trained provincial fisheries officers and local spearfishers. A comparison of fishery-independent abundance data and fishery-dependent CPUE data indicate extreme hyperstability, with CPUE maintained as B. muricatum abundance declines towards zero. Hyperstability may explain the sudden collapses of many B. muricatum spear fisheries across the Pacific and highlights the limitations of using data-poor fisheries assessment methods to evaluate the status of commercially valuable coral reef fishes that form predicable aggregations.

Demographics and run timing of adult Lost River (Deltistes luxatus) and shortnose (Chasmistes brevirostris) suckers in Upper Klamath Lake, Oregon, 2011

USGS Publications Warehouse

Hewitt, David A.; Janney, Eric C.; Hayes, Brian S.; Harris, Alta C.

2012-01-01

Despite relatively high survival in most years, both species have experienced substantial declines in the abundance of spawning fish because losses from mortality have not been balanced by recruitment of new individuals. Although capture-recapture data indicate substantial recruitment of new individuals into the adult spawning populations for SNS and river spawning LRS in some years, size data do not corroborate these estimates. In fact, fork length data indicate that all populations are largely comprised of fish that were present in the late 1990s and early 2000s. As a result, the status of the endangered sucker populations in Upper Klamath Lake remains worrisome, and the situation is most dire for shortnose suckers. Future investigations should explore the connections between sucker recruitment and survival and various environmental factors, such as water quality and disease. Our monitoring program provides a robust platform for estimating vital population parameters, evaluating the status of the populations, and assessing the effectiveness of conservation and recovery efforts.

No Evidence of Metabolic Depression in Western Alaskan Juvenile Steller Sea Lions (Eumetopias jubatus)

PubMed Central

Hoopes, Lisa A.; Rea, Lorrie D.; Christ, Aaron; Worthy, Graham A. J.

2014-01-01

Steller sea lion (Eumetopias jubatus) populations have undergone precipitous declines through their western Alaskan range over the last four decades with the leading hypothesis to explain this decline centering around changing prey quality, quantity, or availability for this species (i.e., nutritional stress hypothesis). Under chronic conditions of reduced food intake sea lions would conserve energy by limiting energy expenditures through lowering of metabolic rate known as metabolic depression. To examine the potential for nutritional stress, resting metabolic rate (RMR) and body composition were measured in free-ranging juvenile Steller sea lions (N = 91) at three distinct geographical locations (Southeast Alaska, Prince William Sound, Central Aleutian Islands) using open-flow respirometry and deuterium isotope dilution, respectively. Average sea lion RMR ranged from 6.7 to 36.2 MJ d−1 and was influenced by body mass, total body lipid, and to a lesser extent, ambient air temperature and age. Sea lion pups captured in the Aleutian Islands (region of decline) had significantly greater body mass and total body lipid stores when compared to pups from Prince William Sound (region of decline) and Southeast Alaska (stable region). Along with evidence of robust body condition in Aleutian Island pups, no definitive differences were detected in RMR between sea lions sampled between eastern and western populations that could not be accounted for by higher percent total body lipid content, suggesting that that at the time of this study, Steller sea lions were not experiencing metabolic depression in the locations studied. PMID:24416394

A discrete stage-structured model of California newt population dynamics during a period of drought.

PubMed

Jones, Marjorie T; Milligan, William R; Kats, Lee B; Vandergon, Thomas L; Honeycutt, Rodney L; Fisher, Robert N; Davis, Courtney L; Lucas, Timothy A

2017-02-07

We introduce a mathematical model for studying the population dynamics under drought of the California newt (Taricha torosa), a species of special concern in the state of California. Since 2012, California has experienced a record-setting drought, and multiple studies predict drought conditions currently underway will persist and even increase in severity. Recent declines and local extinctions of California newt populations in Santa Monica Mountain streams motivate our study of the impact of drought on newt population sizes. Although newts are terrestrial salamanders, they migrate to streams each spring to breed and lay eggs. Since egg and larval stages occur in water, a precipitation deficit due to drought conditions reduces the space for newt egg-laying and the necessary habitat for larval development. To mathematically forecast newt population dynamics, we develop a nonlinear system of discrete equations that includes demographic parameters such as survival rates for newt life stages and egg production, which depend on habitat availability and rainfall. We estimate these demographic parameters using 15 years of stream survey data collected from Cold Creek in Los Angeles County, California, and our model captures the observed decline of the parameterized Cold Creek newt population. Based upon data analysis, we predict how the number of available newt egg-laying sites varies with annual precipitation. Our model allows us to make predictions about how the length and severity of drought can affect the likelihood of persistence and the time to critical endangerment of a local newt population. We predict that sustained severe drought will critically endanger the newt population but that the newt population can rebound if a drought is sufficiently short. Copyright © 2016 Elsevier Ltd. All rights reserved.

A discrete stage-structured model of California newt population dynamics during a period of drought

USGS Publications Warehouse

Jones, Marjorie T.; Milligan, William R.; Kats, Lee B.; Vandergon, Thomas L.; Honeycutt, Rodney L.; Fisher, Robert N.; Davis, Courtney L.; Lucas, Timothy A.

2017-01-01

We introduce a mathematical model for studying the population dynamics under drought of the California newt (Taricha torosa), a species of special concern in the state of California. Since 2012, California has experienced a record-setting drought, and multiple studies predict drought conditions currently underway will persist and even increase in severity. Recent declines and local extinctions of California newt populations in Santa Monica Mountain streams motivate our study of the impact of drought on newt population sizes. Although newts are terrestrial salamanders, they migrate to streams each spring to breed and lay eggs. Since egg and larval stages occur in water, a precipitation deficit due to drought conditions reduces the space for newt egg-laying and the necessary habitat for larval development. To mathematically forecast newt population dynamics, we develop a nonlinear system of discrete equations that includes demographic parameters such as survival rates for newt life stages and egg production, which depend on habitat availability and rainfall. We estimate these demographic parameters using 15 years of stream survey data collected from Cold Creek in Los Angeles County, California, and our model captures the observed decline of the parameterized Cold Creek newt population. Based upon data analysis, we predict how the number of available newt egg-laying sites varies with annual precipitation. Our model allows us to make predictions about how the length and severity of drought can affect the likelihood of persistence and the time to critical endangerment of a local newt population. We predict that sustained severe drought will critically endanger the newt population but that the newt population can rebound if a drought is sufficiently short.

How many Laysan Teal Anas laysanensis are on Midway Atoll? Methods for monitoring abundance after reintroduction

USGS Publications Warehouse

Reynolds, Michelle H.; Courtot, Karen; Hatfield, Jeffrey

2017-01-01

Wildlife managers often request a simple approach to monitor the status of species of concern. In response to that need, we used eight years of monitoring data to estimate population size and test the validity of an index for monitoring accurately the abundance of reintroduced, endangered Laysan Teal Anas laysanensis. The population was established at Midway Atoll in the Hawaiian archipelago after 42 wild birds were translocated from Laysan Island during 2004–2005. We fitted 587 birds with unique markers during 2004–2015, recorded 21,309 sightings until March 2016, and conducted standardised survey counts during 2007–2015. A modified Lincoln-Petersen mark-resight estimator and ANCOVA models were used to test the relationship between survey counts, seasonal detectability, and population abundance. Differences were found between the breeding and non-breeding seasons in detection and how maximum counts recorded related to population estimates. The results showed strong, positive correlations between the seasonal maximum counts and population estimates. The ANCOVA models supported the use of standardised bi-monthly counts of unmarked birds as a valid index to monitor trends among years within a season at Midway Atoll. The translocated population increased to 661 adult and juvenile birds (95% CI = 608–714) by 2010, then declined by 38% between 2010 and 2012 after the Toˉhoku Japan earthquake-generated tsunami inundated 41% of the atoll and triggered an Avian Botulism type C Clostridium botulinum outbreak. Following another severe botulism outbreak during 2015, the population experienced a 37% decline. Data indicated that the Midway Atoll population, like the founding Laysan Island population, is susceptible to catastrophic population declines. Consistent standardised monitoring using simple counts, in place of mark-recapture and resightings surveys, can be used to evaluate population status over the long-term. We estimate there were 314–435 Laysan Teal (95% CI for population estimate; point estimate = 375 individuals) at Midway Atoll in 2015; c. 50% of the global population. In comparison, the most recent estimate for numbers on Laysan Island was of 339 individuals in 2012 (95% CI = 265–413). We suggest that this approach can be used to validate a survey index for any marked, reintroduced resident wildlife population.

Testing the Relationship between Human Occupancy in the Landscape and Tadpole Developmental Stress

PubMed Central

Eterovick, Paula C.; Bar, Luís F. F.; Souza, Jorge B.; Castro, José F. M.; Leite, Felipe S. F.; Alford, Ross A.

2015-01-01

Amphibian population declines are widespread; the main causal factors are human related and include habitat fragmentation due to agriculture, mining, fires, and urban development. Brazil is the richest country in species of amphibians, and the Brazilian regions with the greatest amphibian diversity are experiencing relatively high rates of habitat destruction, but there are presently relatively few reports of amphibian declines. It is thus important to develop research methods that will detect deterioration in population health before severe declines occur. We tested the use of measurements of fluctuating asymmetry (FA) taken on amphibian larvae to detect anthropogenic stress. We hypothesized that greater human occupancy in the landscape might result in more stressful conditions for amphibians. We conducted this study at the Espinhaço mountain range in southeastern Brazil, using as a model an endemic species (Bokermannohyla saxicola, Hylidae). We chose two tadpole denticle rows and eye-nostril distance as traits for FA measurement. We measured percent cover of human-altered habitats in the landscape around tadpole sampling points and measured FA levels in sampled tadpoles. We found FA levels to differ among localities but found no relationship between human modification of the landscape and tadpole FA levels. Levels of FA in the traits we examined may not be strongly affected by environmental conditions, or may be affected by local variables that were not captured by our landscape-scale measures. Alternatively, populations may be genetically differentiated, affecting how FA levels respond to stress and obscuring the effects of anthropogenic disturbance. PMID:25793699

Effective population size dynamics reveal impacts of historic climatic events and recent anthropogenic pressure in African elephants.

PubMed

Okello, J B A; Wittemyer, G; Rasmussen, H B; Arctander, P; Nyakaana, S; Douglas-Hamilton, I; Siegismund, H R

2008-09-01

Two hundred years of elephant hunting for ivory, peaking in 1970-1980s, caused local extirpations and massive population declines across Africa. The resulting genetic impacts on surviving populations have not been studied, despite the importance of understanding the evolutionary repercussions of such human-mediated events on this keystone species. Using Bayesian coalescent-based genetic methods to evaluate time-specific changes in effective population size, we analysed genetic variation in 20 highly polymorphic microsatellite loci from 400 elephants inhabiting the greater Samburu-Laikipia region of northern Kenya. This area experienced a decline of between 80% and 90% in the last few decades when ivory harvesting was rampant. The most significant change in effective population size, however, occurred approximately 2500 years ago during a mid-Holocene period of climatic drying in tropical Africa. Contrary to expectations, detailed analyses of four contemporary age-based cohorts showed that the peak poaching epidemic in the 1970s caused detectable temporary genetic impacts, with genetic diversity rebounding as juveniles surviving the poaching era became reproductively mature. This study demonstrates the importance of climatic history in shaping the distribution and genetic history of a keystone species and highlights the utility of coalescent-based demographic approaches in unravelling ancestral demographic events despite a lack of ancient samples. Unique insights into the genetic signature of mid-Holocene climatic change in Africa and effects of recent poaching pressure on elephants are discussed.

Clinical characteristics in patients with asymmetric idiopathic pulmonary fibrosis.

PubMed

Callahan, Sean J; Xia, Meng; Murray, Susan; Flaherty, Kevin R

2016-10-01

A group of patients with idiopathic pulmonary fibrosis (IPF) presents with disease affecting one lung markedly more than the other. At this time, it is unclear how this population differs from those who present with more symmetric disease. We sought to explain the characteristics of the asymmetric group and how their disease progresses. In this retrospective case-control study we accessed an interstitial lung disease (ILD) database and identified 14 asymmetric IPF cases via high-resolution computed tomography (HRCT) scoring of each lung lobe's disease severity. We identified 28 symmetric IPF controls from the same database using the same methods, and compared the clinical features of each group. Patients with asymmetric disease exhibited similar demographics as those in the general IPF population; they were predominantly male (64%), elderly (69 years old), and used tobacco (57%). We found a trend toward significantly increased all-cause mortality in the case population two years following diagnosis (p = 0.089). Pulmonary function tests were significantly lower in the case group at the time of diagnosis, then both groups experienced gradual decline. We found no statistically significant differences in number of IPF exacerbations (cases 43%, controls 39%, p = 0.824) and gastro-esophageal reflux (both groups 50%). Patients with asymmetric IPF resemble patients in the general IPF population but may have a lower overall survival rate. Further systemic factors may be studied to identify reasons for disease asymmetry and clinical decline in this population. Published by Elsevier Ltd.

Osteoporosis Care in the United States After Declines in Reimbursements for DXA

PubMed Central

Hayes, Burton L.; Curtis, Jeffrey R.; Laster, Andrew; Saag, Kenneth; Tanner, S. Bobo; Liu, Caiqin; Womack, Catherine; Johnson, Karen C.; Khaliq, Fazila; Carbone, Laura D.

2015-01-01

In January 2007, in the United States (US), Medicare initiated a series of cuts to reimbursement for dual-energy X-ray absorptiometry (DXA) services performed in the nonfacility setting that by January 2010 reduced payments for these services by more than 60% compared with 2006 levels. The objectives of this study were to determine if a temporal association exists between Medicare Physician Fee Schedule changes in office-based DXA reimbursement and attendance at educational conferences for osteoporosis, physicians’ perceptions of changes in their medical practices, or national trends in retail prescription medications for osteoporosis in those aged 65 and older. Compared with the 2 yr before the decline in Medicare reimbursement for DXA (2005–2006), attendance at educational meetings for osteoporosis in the US declined in the 2 yr after these cuts (2007–2008) by 6%; declines in attendance were only present in meetings selective for bone densitometry. Survey participants reported changes in DXA services with approximately one-third indicating that they had either decreased the number of DXAs they performed or declined service contracts or hardware/software updates compared with 2005–2006. The number of retail prescriptions for Food and Drug Administratione–approved osteoporosis drugs (excluding estrogen compounds and raloxifene) in the age 65 and older population increased by 5.5% in the time period 2007–2008 compared with 2005–2006. However, in the last year of the study (2008), total retail prescriptions for these drugs experienced for the first time over the interval of the study, a decline (1.4%) compared with the previous year. This occurred despite a 2.6% increase in the US population age 65 and older. In conclusion, there were temporal associations noted between Medicare cuts in DXA payments in attendance at educational conferences for bone densitometry, self-report of office-based provision of DXA services in the US, and retail prescriptions for osteoporosis therapies. PMID:21029972

Flexible risk metrics for identifying and monitoring conservation-priority species

USGS Publications Warehouse

Stanton, Jessica C.; Semmens, Brice X.; McKann, Patrick C.; Will, Tom; Thogmartin, Wayne E.

2016-01-01

Region-specific conservation programs should have objective, reliable metrics for species prioritization and progress evaluation that are customizable to the goals of a program, easy to comprehend and communicate, and standardized across time. Regional programs may have vastly different goals, spatial coverage, or management agendas, and one-size-fits-all schemes may not always be the best approach. We propose a quantitative and objective framework for generating metrics for prioritizing species that is straightforward to implement and update, customizable to different spatial resolutions, and based on readily available time-series data. This framework is also well-suited to handling missing-data and observer error. We demonstrate this approach using North American Breeding Bird Survey (NABBS) data to identify conservation priority species from a list of over 300 landbirds across 33 bird conservation regions (BCRs). To highlight the flexibility of the framework for different management goals and timeframes we calculate two different metrics. The first identifies species that may be inadequately monitored by NABBS protocols in the near future (TMT, time to monitoring threshold), and the other identifies species likely to decline significantly in the near future based on recent trends (TPD, time to percent decline). Within the individual BCRs we found up to 45% (mean 28%) of the species analyzed had overall declining population trajectories, which could result in up to 37 species declining below a minimum NABBS monitoring threshold in at least one currently occupied BCR within the next 50 years. Additionally, up to 26% (mean 8%) of the species analyzed within the individual BCRs may decline by 30% within the next decade. Conservation workers interested in conserving avian diversity and abundance within these BCRs can use these metrics to plan alternative monitoring schemes or highlight the urgency of those populations experiencing the fastest declines. However, this framework is adaptable to many taxa besides birds where abundance time-series data are available.

Habitat availability is a more plausible explanation than insecticide acute toxicity for U.S. grassland bird species declines

USDA-ARS?s Scientific Manuscript database

Grassland bird species have experienced substantial declines in North America. These declines have been largely attributed to habitat loss and degradation, especially from agricultural practices and intensification (the habitat-availability hypothesis). A recent analysis of North American Breeding B...

Molecular insights into the historic demography of bowhead whales: understanding the evolutionary basis of contemporary management practices

PubMed Central

Phillips, C D; Hoffman, J I; George, J C; Suydam, R S; Huebinger, R M; Patton, J C; Bickham, J W

2013-01-01

Patterns of genetic variation observed within species reflect evolutionary histories that include signatures of past demography. Understanding the demographic component of species' history is fundamental to informed management because changes in effective population size affect response to environmental change and evolvability, the strength of genetic drift, and maintenance of genetic variability. Species experiencing anthropogenic population reductions provide valuable case studies for understanding the genetic response to demographic change because historic changes in the census size are often well documented. A classic example is the bowhead whale, Balaena mysticetus, which experienced dramatic population depletion due to commercial whaling in the late 19th and early 20th centuries. Consequently, we analyzed a large multi-marker dataset of bowhead whales using a variety of analytical methods, including extended Bayesian skyline analysis and approximate Bayesian computation, to characterize genetic signatures of both ancient and contemporary demographic histories. No genetic signature of recent population depletion was recovered through any analysis incorporating realistic mutation assumptions, probably due to the combined influences of long generation time, short bottleneck duration, and the magnitude of population depletion. In contrast, a robust signal of population expansion was detected around 70,000 years ago, followed by a population decline around 15,000 years ago. The timing of these events coincides to a historic glacial period and the onset of warming at the end of the last glacial maximum, respectively. By implication, climate driven long-term variation in Arctic Ocean productivity, rather than recent anthropogenic disturbance, appears to have been the primary driver of historic bowhead whale demography. PMID:23403722

New medical risks affecting obstetrics after implementation of the two-child policy in China.

PubMed

Li, Qiang; Deng, Dongrui

2017-12-01

China recently instituted a two-child policy in response to its aging population, declining workforce and demographic dividend, and the need to develop asocial economy. Additionally, women generally delay having a second child because of the overwhelming pressure in their lives. With the improvements in assisted fertility technologies in recent years, the number of elderly women attempting to bear children has increased. The quality of woman's eggs and a man's sperm declined dramatically with increasing age, leading to an increased risk of pregnancy-related complications among older women. Therefore, the types of fertility problems experienced by elderly females must be provided with considerable attention by obstetricians. This commentary article focuses on the medical problems faced by older second-child pregnant women. This work discusses their increased rates of infertility, spontaneous abortion, fetal malformation, gestational diabetes, cesarean section, placenta previa, postpartum hemorrhage, postpartum depression, and hypertensive disorders, which complicate pregnancy.

Bushmeat hunting and extinction risk to the world's mammals

PubMed Central

Abernethy, Katharine; Betts, Matthew G.; Chapron, Guillaume; Dirzo, Rodolfo; Galetti, Mauro; Levi, Taal; Lindsey, Peter A.; Macdonald, David W.; Machovina, Brian; Peres, Carlos A.; Wallach, Arian D.

2016-01-01

Terrestrial mammals are experiencing a massive collapse in their population sizes and geographical ranges around the world, but many of the drivers, patterns and consequences of this decline remain poorly understood. Here we provide an analysis showing that bushmeat hunting for mostly food and medicinal products is driving a global crisis whereby 301 terrestrial mammal species are threatened with extinction. Nearly all of these threatened species occur in developing countries where major coexisting threats include deforestation, agricultural expansion, human encroachment and competition with livestock. The unrelenting decline of mammals suggests many vital ecological and socio-economic services that these species provide will be lost, potentially changing ecosystems irrevocably. We discuss options and current obstacles to achieving effective conservation, alongside consequences of failure to stem such anthropogenic mammalian extirpation. We propose a multi-pronged conservation strategy to help save threatened mammals from immediate extinction and avoid a collapse of food security for hundreds of millions of people. PMID:27853564

Kerala: a unique model of development.

PubMed

Kannan, K P; Thankappan, K R; Ramankutty, V; Aravindan, K P

1991-12-01

This article capsules health in terms of morbidity, mortality, and maternal and child health; sex ratios, and population density in Kerala state in India from a more expanded report. Kerala state is known for its highly literate and female literate, and poor income population, but its well advanced state of demographic transition. There is a declining population growth rate, a high average marriage age, a low fertility rate, and a high degree of population mobility. One of the unique features of Kerala is the high female literacy, and the favorable position of women in decision making and a matrilineal inheritance mode. The rights of the poor and underprivileged have been upheld. The largest part of government revenue is spent on education followed by health. Traditional healing systems such the ayurveda are strong in Kerala, and Christian missionaries have contributed to a caring tradition. Morbidity is high and mortality is low because medical interventions have affected morality only. The reduction of poverty and environmentally related diseases has not been accomplished inspite of land reform, mass schooling, and general egalitarian policies. Mortality declines and a decline in birth rates have lead to a more adult and aged population, which increases the prevalence of chronic degenerative diseases. Historically, the death rate in Kerala was always lower (25/1000 in 1930 and 6.4 in 1986). The gains in mortality were made in reducing infant mortality (27/1000), which is 4 times less than India as a whole and comparable to Korea, Panama, Yugoslavia, Sri Lanka, and Colombia. Lower female mortality occurs in the 0-4 years. Life expectancy which was the same as India's in 1930 is currently 12 years higher than India's. Females have a higher expectation of life. The sex ratio in 1981 was 1032 compared to India's of 935. Kerala had almost replacement level in 1985. The crude birth rate is 21 versus 32 for India. In addition to the decline in death rates of those 5 years, the 45 year population has also experienced a decline. In the 15-24 age group, the most common cause of death is suicides (53/100,000 or 25% of all deaths) and accidents. Further study is needed to examine the determinants. 76% have hospital births. Home deliveries are related to low social class. Pregnancy risk is avoided in higher groups. Child health has been improved by the rise in marriage age, the small family norm, better women's education, greater decision making for women, and health care availability: all socioeconomic factors.

Stochastic environmental fluctuations drive epidemiology in experimental host–parasite metapopulations

PubMed Central

Duncan, Alison B.; Gonzalez, Andrew; Kaltz, Oliver

2013-01-01

Environmental fluctuations are important for parasite spread and persistence. However, the effects of the spatial and temporal structure of environmental fluctuations on host–parasite dynamics are not well understood. Temporal fluctuations can be random but positively autocorrelated, such that the environment is similar to the recent past (red noise), or random and uncorrelated with the past (white noise). We imposed red or white temporal temperature fluctuations on experimental metapopulations of Paramecium caudatum, experiencing an epidemic of the bacterial parasite Holospora undulata. Metapopulations (two subpopulations linked by migration) experienced fluctuations between stressful (5°C) and permissive (23°C) conditions following red or white temporal sequences. Spatial variation in temperature fluctuations was implemented by exposing subpopulations to the same (synchronous temperatures) or different (asynchronous temperatures) temporal sequences. Red noise, compared with white noise, enhanced parasite persistence. Despite this, red noise coupled with asynchronous temperatures allowed infected host populations to maintain sizes equivalent to uninfected populations. It is likely that this occurs because subpopulations in permissive conditions rescue declining subpopulations in stressful conditions. We show how patterns of temporal and spatial environmental fluctuations can impact parasite spread and host population abundance. We conclude that accurate prediction of parasite epidemics may require realistic models of environmental noise. PMID:23966645

Distribution of boreal toad populations in relation to estimated UV-B dose in Glacier National Park, Montana, USA

USGS Publications Warehouse

Hossack, B.R.; Diamond, S.A.; Corn, P.S.

2006-01-01

A recent increase in ultraviolet B radiation is one hypothesis advanced to explain suspected or documented declines of the boreal toad (Bufo boreas Baird and Girard, 1852) across much of the western USA, where some experiments have shown ambient UV-B can reduce embryo survival. We examined B. boreas occupancy relative to daily UV-B dose at 172 potential breeding sites in Glacier National Park, Montana, to assess whether UV-B limits the distribution of toads. Dose estimates were based on ground-level UV-B data and the effects of elevation, local topographic and vegetative features, and attenuation in the water column. We also examined temporal trends in surface UV-B and spring snowpack to determine whether populations are likely to have experienced increased UV-B exposure in recent decades. We found no support for the hypothesis that UV-B limits the distribution of populations in the park, even when we analyzed high-elevation ponds separately. Instead, toads were more likely to breed in water bodies with higher estimated UV-B doses. The lack of a detectable trend in surface UV-B since 1979, combined with earlier snow melt in the region and increasing forest density at high elevations, suggests B. boreas embryos and larvae likely have not experienced increased UV-B.

Applying Thiessen Polygon Catchment Areas and Gridded Population Weights to Estimate Conflict-Driven Population Changes in South Sudan

NASA Astrophysics Data System (ADS)

Jordan, L.

2017-10-01

Recent violence in South Sudan produced significant levels of conflict-driven migration undermining the accuracy and utility of both national and local level population forecasts commonly used in demographic estimates, public health metrics and food security proxies. This article explores the use of Thiessen Polygons and population grids (Gridded Population of the World, WorldPop and LandScan) as weights for estimating the catchment areas for settlement locations that serve large populations of internally displaced persons (IDP), in order to estimate the county-level in- and out-migration attributable to conflict-driven displacement between 2014-2015. Acknowledging IDP totals improves internal population estimates presented by global population databases. Unlike other forecasts, which produce spatially uniform increases in population, accounting for displaced population reveals that 15 percent of counties (n = 12) increased in population over 20 percent, and 30 percent of counties (n = 24) experienced zero or declining population growth, due to internal displacement and refugee out-migration. Adopting Thiessen Polygon catchment zones for internal migration estimation can be applied to other areas with United Nations IDP settlement data, such as Yemen, Somalia, and Nigeria.

Material Resources and Population Health: Disadvantages in Health Care, Housing, and Food Among Adults Over 50 Years of Age

PubMed Central

Soldo, Beth J.; Pagán, José A.; McCabe, John; deBlois, Madeleine; Field, Samuel H.; Asch, David A.; Cannuscio, Carolyn

2009-01-01

Objectives. We examined associations between material resources and late-life declines in health. Methods. We used logistic regression to estimate the odds of declines in self-rated health and incident walking limitations associated with material disadvantages in a prospective panel representative of US adults aged 51 years and older (N = 15 441). Results. Disadvantages in health care (odds ratio [OR] = 1.39; 95% confidence interval [CI] = 1.23, 1.58), food (OR = 1.69; 95% CI = 1.29, 2.22), and housing (OR = 1.20; 95% CI = 1.07, 1.35) were independently associated with declines in self-rated health, whereas only health care (OR = 1.43; 95% CI = 1.29, 1.58) and food (OR = 1.64; 95% CI = 1.31, 2.05) disadvantage predicted incident walking limitations. Participants experiencing multiple material disadvantages were particularly susceptible to worsening health and functional decline. These effects were sustained after we controlled for numerous covariates, including baseline health status and comorbidities. The relations between health declines and non-Hispanic Black race/ethnicity, poverty, marital status, and education were attenuated or eliminated after we controlled for material disadvantage. Conclusions. Material disadvantages, which are highly policy relevant, appear related to health in ways not captured by education and poverty. Policies to improve health should address a range of basic human needs, rather than health care alone. PMID:19890175

Demographic processes underlying subtle patterns of population structure in the scalloped hammerhead shark, Sphyrna lewini.

PubMed

Nance, Holly A; Klimley, Peter; Galván-Magaña, Felipe; Martínez-Ortíz, Jimmy; Marko, Peter B

2011-01-01

Genetic diversity (θ), effective population size (N(e)), and contemporary levels of gene flow are important parameters to estimate for species of conservation concern, such as the globally endangered scalloped hammerhead shark, Sphyrna lewini. Therefore, we have reconstructed the demographic history of S. lewini across its Eastern Pacific (EP) range by applying classical and coalescent population genetic methods to a combination of 15 microsatellite loci and mtDNA control region sequences. In addition to significant population genetic structure and isolation-by-distance among seven coastal sites between central Mexico and Ecuador, the analyses revealed that all populations have experienced a bottleneck and that all current values of θ are at least an order of magnitude smaller than ancestral θ, indicating large decreases in N(e) (θ = 4N(e)μ), where μ is the mutation rate. Application of the isolation-with-migration (IM) model showed modest but significant genetic connectivity between most sampled sites (point estimates of Nm = 0.1-16.7), with divergence times (t) among all populations significantly greater than zero. Using a conservative (i.e., slow) fossil-based taxon-specific phylogenetic calibration for mtDNA mutation rates, posterior probability distributions (PPDs) for the onset of the decline in N(e) predate modern fishing in this region. The cause of decline over the last several thousand years is unknown but is highly atypical as a post-glacial demographic history. Regardless of the cause, our data and analyses suggest that S. lewini was far more abundant throughout the EP in the past than at present.

Demographic Processes Underlying Subtle Patterns of Population Structure in the Scalloped Hammerhead Shark, Sphyrna lewini

PubMed Central

Nance, Holly A.; Klimley, Peter; Galván-Magaña, Felipe; Martínez-Ortíz, Jimmy; Marko, Peter B.

2011-01-01

Genetic diversity (θ), effective population size (Ne), and contemporary levels of gene flow are important parameters to estimate for species of conservation concern, such as the globally endangered scalloped hammerhead shark, Sphyrna lewini. Therefore, we have reconstructed the demographic history of S. lewini across its Eastern Pacific (EP) range by applying classical and coalescent population genetic methods to a combination of 15 microsatellite loci and mtDNA control region sequences. In addition to significant population genetic structure and isolation-by-distance among seven coastal sites between central Mexico and Ecuador, the analyses revealed that all populations have experienced a bottleneck and that all current values of θ are at least an order of magnitude smaller than ancestral θ, indicating large decreases in Ne (θ = 4Neμ), where μ is the mutation rate. Application of the isolation-with-migration (IM) model showed modest but significant genetic connectivity between most sampled sites (point estimates of Nm = 0.1–16.7), with divergence times (t) among all populations significantly greater than zero. Using a conservative (i.e., slow) fossil-based taxon-specific phylogenetic calibration for mtDNA mutation rates, posterior probability distributions (PPDs) for the onset of the decline in Ne predate modern fishing in this region. The cause of decline over the last several thousand years is unknown but is highly atypical as a post-glacial demographic history. Regardless of the cause, our data and analyses suggest that S. lewini was far more abundant throughout the EP in the past than at present. PMID:21789171

Transformation of a cadaver population: Analysis of a South African cadaver program, 1921-2013.

PubMed

Kramer, Beverley; Hutchinson, Erin F

2015-01-01

Anatomy has served as a cornerstone in the training of various allied and clinical disciplines and has traditionally been based on dissection of the human body. Thus, to pursue this method of teaching and learning, access to cadavers is of continuing importance. Over a significant period of time unclaimed cadavers have performed an essential role in the teaching of anatomy in South Africa and in Africa. As recent cadaver numbers were declining at the School of Anatomical Sciences, University of the Witwatersrand, Johannesburg and difficulty in procurement was being experienced, the purpose of this study was to critically evaluate the composition of our cadaver population over time so as to provide possible strategies to arrest the decline. A retrospective, quantitative analysis of cadaver records from the School of Anatomical Sciences between 1921 and 2013 was undertaken. Analysis included a comparison of Poisson counts and Fischer's exact test. A significant decrease in the number of cadavers received during the period 2000-2013 and a slow bequest program over the same period of time has led to concerns about the sustainability of teaching anatomy through dissection. Decreases in the numbers of males and cadavers of the black population group occurred between 1990 and 2013, and of bequests from 2000 to 2013. An influence on the cadaver population from a changing political climate and change in socioeconomic status of part of the population was perceived. Changes in sex and population group of the cadavers may have a long-term effect on teaching and research. © 2014 American Association of Anatomists.

Did the Decline in Social Connections Depress Americans' Happiness?

ERIC Educational Resources Information Center

Bartolini, Stefano; Bilancini, Ennio; Pugno, Maurizio

2013-01-01

During the last 30 years US citizens experienced, on average, a decline in reported happiness, social connections, and confidence in institutions. We show that a remarkable portion of the decrease in happiness is predicted by the decline in social connections and confidence in institutions. We carry out our investigation in three steps. First, we…

Reversing Africa's Decline. Worldwatch Paper 65.

ERIC Educational Resources Information Center

Brown, Lester R.; Wolf, Edward C.

This paper highlights some of the themes that any successful strategy to reverse the decline of Africa must embrace. Africa is a continent experiencing a breakdown in the relationship between people and their natural support systems. Famine and the threat of famine are among the manifestations of this breakdown. This decline can be reversed. To do…

Teachers' Perspectives Regarding the Decline in Boys' Participation in Post-Compulsory Rigorous Mathematics Subjects

ERIC Educational Resources Information Center

Easey, Michael

2013-01-01

This paper explores the decline in boys' participation in post-compulsory rigorous mathematics using the perspectives of eight experienced teachers at an independent, boys' College located in Brisbane, Queensland. This study coincides with concerns regarding the decline in suitably qualified tertiary graduates with requisite mathematical skills…

Racial differences in leading causes of infant death in the United States.

PubMed

Muhuri, Pradip K; MacDorman, Marian F; Ezzati-Rice, Trena M

2004-01-01

We used linked birth/infant death records of over 23 million singletons belonging to six birth cohorts (1989-91 and 1995-97) and examined changes in race differentials in the overall and cause-specific infant mortality risks across time in the United States. Results show that infant mortality declined for all races during the time period, with disproportionately greater declines among non-Hispanic American Indians (AIs). Among the leading causes of infant death, declines in mortality from sudden infant death syndrome (SIDS), respiratory distress syndrome (RDS) and congenital anomalies contributed the most to the overall decline in infant mortality in the 1995-97 cohorts, compared with the 1989-91 cohorts. Disproportionately greater reductions in mortality resulting from SIDS and congenital anomalies led to more rapid mortality declines among non-Hispanic AIs than for other races. There are disturbing findings that infants of almost every race experienced increases in mortality from newborn affected by maternal complications of pregnancy (maternal complications) and that none of the race groups experienced a significant decline in mortality from disorders resulting from short gestation/low birthweight.

Reduced North American terrestrial primary productivity linked to anomalous Arctic warming

DOE PAGES

Kim, Jin-Soo; Kug, Jong-Seong; Jeong, Su-Jong; ...

2017-07-10

Warming temperatures in the Northern Hemisphere have enhanced terrestrial productivity. Despite the warming trend, North America has experienced more frequent and more intense cold weather events during winters and springs. These events have been linked to anomalous Arctic warming since 1990, and may affect terrestrial processes. Here we analyse many observation data sets and numerical model simulations to evaluate links between Arctic temperatures and primary productivity in North America. We find that positive springtime temperature anomalies in the Arctic have led to negative anomalies in gross primary productivity over most of North America during the last three decades, which amountmore » to a net productivity decline of 0.31 PgC yr -1 across the continent. This decline is mainly explained by two factors: severe cold conditions in northern North America and lower precipitation in the South Central United States. In addition, United States crop-yield data reveal that during years experiencing anomalous warming in the Arctic, yields declined by approximately 1 to 4% on average, with individual states experiencing declines of up to 20%. We conclude that the strengthening of Arctic warming anomalies in the past decades has remotely reduced productivity over North America.« less

Reduced North American terrestrial primary productivity linked to anomalous Arctic warming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jin-Soo; Kug, Jong-Seong; Jeong, Su-Jong

Warming temperatures in the Northern Hemisphere have enhanced terrestrial productivity. Despite the warming trend, North America has experienced more frequent and more intense cold weather events during winters and springs. These events have been linked to anomalous Arctic warming since 1990, and may affect terrestrial processes. Here we analyse many observation data sets and numerical model simulations to evaluate links between Arctic temperatures and primary productivity in North America. We find that positive springtime temperature anomalies in the Arctic have led to negative anomalies in gross primary productivity over most of North America during the last three decades, which amountmore » to a net productivity decline of 0.31 PgC yr -1 across the continent. This decline is mainly explained by two factors: severe cold conditions in northern North America and lower precipitation in the South Central United States. In addition, United States crop-yield data reveal that during years experiencing anomalous warming in the Arctic, yields declined by approximately 1 to 4% on average, with individual states experiencing declines of up to 20%. We conclude that the strengthening of Arctic warming anomalies in the past decades has remotely reduced productivity over North America.« less

The Evolution of Dental Materials for Hybrid Prosthesis

PubMed Central

Gonzalez, Jorge

2014-01-01

Since the immemorial, the replacement of missing teeth has been a medical and cosmetic necessity for human kind. Nowadays, middle-aged population groups have experienced improved oral health, as compared to previous generations, and the percentage of edentulous adults can be expected to further decline. However, with the continued increase in the number of older adult population, it is anticipated that the need for some form of full-mouth restoration might increase from 53.8 million in 1991 to 61 million in 2020 [1]. Denture prosthetics has undergone many development stages since the first dentures were fabricated. The introduction of computer-aided design/computer aided manufacturing (CAD/CAM) has resulted in a more accurate manufacturing of prosthetic frameworks, greater accuracy of dental restorations, and in particular, implant supported prosthesis. PMID:24893781

Incidence of End-Stage Renal Disease Attributed to Diabetes Among Persons with Diagnosed Diabetes - United States and Puerto Rico, 2000-2014.

PubMed

Burrows, Nilka Rios; Hora, Israel; Geiss, Linda S; Gregg, Edward W; Albright, Ann

2017-11-03

During 2014, 120,000 persons in the United States and Puerto Rico began treatment for end-stage renal disease (ESRD) (i.e., kidney failure requiring dialysis or transplantation) (1). Among these persons, 44% (approximately 53,000 persons) had diabetes listed as the primary cause of ESRD (ESRD-D) (1). Although the number of persons initiating ESRD-D treatment each year has increased since 1980 (1,2), the ESRD-D incidence rate among persons with diagnosed diabetes has declined since the mid-1990s (2,3). To determine whether ESRD-D incidence has continued to decline in the United States overall and in each state, the District of Columbia (DC), and Puerto Rico, CDC analyzed 2000-2014 data from the U.S. Renal Data System and the Behavioral Risk Factor Surveillance System. During that period, the age-standardized ESRD-D incidence among persons with diagnosed diabetes declined from 260.2 to 173.9 per 100,000 diabetic population (33%), and declined significantly in most states, DC, and Puerto Rico. No state experienced an increase in ESRD-D incidence rates. Continued awareness of risk factors for kidney failure and interventions to improve diabetes care might sustain and improve these trends.

Sexual selection protects against extinction.

PubMed

Lumley, Alyson J; Michalczyk, Łukasz; Kitson, James J N; Spurgin, Lewis G; Morrison, Catriona A; Godwin, Joanne L; Dickinson, Matthew E; Martin, Oliver Y; Emerson, Brent C; Chapman, Tracey; Gage, Matthew J G

2015-06-25

Reproduction through sex carries substantial costs, mainly because only half of sexual adults produce offspring. It has been theorized that these costs could be countered if sex allows sexual selection to clear the universal fitness constraint of mutation load. Under sexual selection, competition between (usually) males and mate choice by (usually) females create important intraspecific filters for reproductive success, so that only a subset of males gains paternity. If reproductive success under sexual selection is dependent on individual condition, which is contingent to mutation load, then sexually selected filtering through 'genic capture' could offset the costs of sex because it provides genetic benefits to populations. Here we test this theory experimentally by comparing whether populations with histories of strong versus weak sexual selection purge mutation load and resist extinction differently. After evolving replicate populations of the flour beetle Tribolium castaneum for 6 to 7 years under conditions that differed solely in the strengths of sexual selection, we revealed mutation load using inbreeding. Lineages from populations that had previously experienced strong sexual selection were resilient to extinction and maintained fitness under inbreeding, with some families continuing to survive after 20 generations of sib × sib mating. By contrast, lineages derived from populations that experienced weak or non-existent sexual selection showed rapid fitness declines under inbreeding, and all were extinct after generation 10. Multiple mutations across the genome with individually small effects can be difficult to clear, yet sum to a significant fitness load; our findings reveal that sexual selection reduces this load, improving population viability in the face of genetic stress.

Abundance, distribution, and population trends of the iconic Hawaiian Honeycreeper, the ʻIʻiwi (Vestiaria coccinea) throughout the Hawaiian Islands

USGS Publications Warehouse

Paxton, Eben H.; Gorresen, P. Marcos; Camp, Richard J.

2013-01-01

Naturalists in the 1800s described the ʻIʻiwi (Vestiaria coccinea) as one of the most abundant forest birds, detected in forested areas from sea level to tree line across all the major Hawaiian Islands. However, in the late 1800s, ʻIʻiwi began to disappear from low elevation forests, and by the mid-1900s, the species was largely absent from low- and mid-elevation areas. Today, ʻIʻiwi are restricted to high-elevation forests on the islands of Hawaiʻi, east Maui, and Kauaʻi, with a few birds apparently persisting on Oʻahu, Molokaʻi, and west Maui. ʻIʻiwi are highly vulnerable to introduced disease, and the prevalence of avian malaria in low and mid-elevations is believed to be the cause of ʻIʻiwi being restricted to high elevations where temperatures are too cold for the development of the disease and its mosquito vector. With global warming, it is feared that the disease will move quickly into the high-elevation forests where the last ʻIʻiwi reside, threatening their viability. The U.S. Fish and Wildlife Service was petitioned to list the ʻIʻiwi as an Endangered Species in 2010, and this report provides a comprehensive review of the abundance, distribution, and trends using historical survey data as well as the most recently available survey information (up to 2012). We estimate the total population size of ‘I‘iwi at 550,972–659,864 (mean = 605,418) individuals. Of these, 90 percent are on the island of Hawaiʻi, followed by east Maui (about 10 percent), with less than 1 percent on Kauaʻi. ʻIʻiwi population trends vary across the islands. ʻIʻiwi population in Kauaʻi has experienced sharp declines, with a projected trend of 92 percent decline over a 25 year period based on the 2000–2012 surveys. On East Maui, the northeastern region has experienced declines (34 percent over a 25 year period), while the southeastern region has been stable to moderately increasing. On the island of Hawaiʻi, population trends are mixed. On the windward side, populations are largely declining, although the northern section (Hakalau Forest) has stable populations. On the leeward side, results suggest a strongly increasing population, with estimates of as much as a 147 percent increase over a 25 year period from the Puʻu Waʻawaʻa region. However, it is unclear how much these results from the leeward side of Hawaiʻi show a population trend contrary to population trends in all other areas or are an artifact of a sparsely sampled area. Trends by elevation suggest a large decrease in numbers of ʻIʻiwi at elevations below 1,200 meters on Kauaʻi and northeast Maui. Low elevation ʻIʻiwi populations also appear to have decreased in other regions, although low-elevation areas are not surveyed as often as other areas because of their lack of native forest birds. An exception to this pattern was the lower portions of the Hakalau Forest National Wildlife Refuge Kona Unit in the central leeward part of the island of Hawaiʻi, where populations appeared stable at the lower elevations. Based on the most recent surveys (up to 2012), approximately 50 percent of ʻIʻiwi live in a narrow, 500-meter band at elevations of 1,200–1,700 meters, suggesting that ʻIʻiwi are vulnerable to future shifts in climate.

Mortality and Morbidity Associated with a New Ciliate Infection of Shrimp that Causes Shrimp Black Gill in the Coastal Southeast USA

NASA Astrophysics Data System (ADS)

Price, A. R.; Fowler, A. E.; Frede, R. L.; Walker, A. N.; Lee, R. F.; Frischer, M. E.

2016-02-01

Penaeid shrimp including Litopenaeus setiferus (white shrimp), Farfantepenaeus aztecus (brown shrimp), and Farfantepenaeus duorarum (pink shrimp) support the most valuable commercial marine fishery in the US Southeast Atlantic. However, since the mid 1990's the fishery has experienced a significant decline in reported harvest. Although decreased fishing effort has contributed to this decline, the decline has been coincident with the emergence of a new ciliate infection causing gill tissue melanization with evidence of tissue necrosis (Black Gill). The identity of the shrimp Black Gill (sBG) ciliate is still uncertain but is uniquely identified molecularly and microscopically. sBG is widely believed by the shrimping industry to have contributed to the decline of shrimp populations in Georgia and South Carolina, USA where prevalence can reach near 100% in the fall white shrimp season and is associated with large catches of dead and deteriorating shrimp along with soft and recently molted shrimp. In this study we report the first observations of mortality and morbidity associated with sBG ciliate infections in L. setiferus. The sBG ciliate is present from approximately May through January with peak infection rates and visibly melanized gills occurring in the late summer through the fall. Molecular and histological studies indicate that the sBG ciliate is absent from shrimp populations during the winter and spring. In laboratory studies, significant direct mortality of shrimp associated with sBG is observed only for a short period of time during the late summer. However, later in the fall symptomatic shrimp exhibit decreased performance response (endurance and respiratory capacity) that likely leads to increased mortality associated with secondary infections and increased predation rates. These studies support the hypothesis that shrimp Black Gill is negatively impacting wild shrimp populations and the fishery.

Changing rates and patterns of drug resistance mutations in antiretroviral-experienced HIV-infected patients.

PubMed

de Mendoza, Carmen; Garrido, Carolina; Corral, Angelica; Ramírez-Olivencia, German; Jiménez-Nacher, Inmaculada; Zahonero, Natalia; Gonzalez-Lahoz, Juan; Soriano, Vincent

2007-07-01

Surveillance of drug resistance mutations in antiretroviral-experienced HIV(+) patients may provide useful information regarding options available for rescue interventions. All resistance tests performed from 1999 to 2005 on antiretroviral-experienced individuals at one reference laboratory in Madrid were examined. Only mutations associated with drug resistance recorded at the September 2006 IAS-USA list were considered. A total of 2137 specimens were analyzed. Overall, 71.1% showed resistance mutations to at least one drug class, 56.1% to at least two, and 21% to all three drug families. Resistance mutations were 65% for NRTI, 44.4% for NNRTI, and 42.5% for PI. Mutations T215Y/F, M184V, and M41L were the most frequent for NRTI. Their rate significantly declined since 1999. K65R significantly increased since 1999 (0.8%) to 2003 (7.3%) but declined up to 3.3% in 2005. For NNRTI, K103N significantly increased from 21.8% in 1999 to 29.5% in 2005 (p < 0.01). The most frequent PI resistance mutations were L90M (24.3%), V82X (19.9%), M46I/L (19.5%), and I54V (17.1%). The presence of five or more was 58.8% in 1999 but declined to 22.2% in 2005. The rate of drug resistance mutations causing NRTI and PI resistance has steadily declined in antiretroviral-experienced patients since 1999. The availability of a large number and/or more convenient NRTI as well as the wide use of ritonavir-boosted PI could explain these observations. However, broad PI cross-resistance was seen in nearly 25% of antiretroviral-experienced patients in 2005. Therefore, there is a still need for new antiretrovirals with different resistance profiles.

Diphtheria in the United States, 1971-81.

PubMed Central

Chen, R T; Broome, C V; Weinstein, R A; Weaver, R; Tsai, T F

1985-01-01

After a decade-long resurgence, including a large cutaneous diphtheria outbreak in Washington State, the diphtheria incidence rate in the United States reached its lowest recorded level ever in 1980--two patients (0.01 case per million). Mortality paralleled the decline in incidence rate. Only 143 of the 3,141 US counties reported noncutaneous diphtheria patients during 1971-81; most were located in the West. The highest attack rates were experienced by children less than 15 years old (0.8 case per million) and by American Indians (22.6 cases per million). Persons immunized with three or more doses of diphtheria toxoid had a lower death-to-case ratio (1.3 per cent) than totally unimmunized persons (13.4 per cent). The reasons for the dramatic decline in diphtheria incidence rates are unclear, although it has been postulated that the gene for producing diphtheria toxin may be lost from organisms in highly immunized populations. Significant proportions of the adult and elderly populations are susceptible to diphtheria. Continuation of primary immunization with increased emphasis on the routine use of tetanus and diphtheria toxoids (Td) boosters in adults should ensure that diphtheria will remain largely a scourge of the past. PMID:4061710

The 1999-2003 Summary of the North American Breeding Bird Survey

USGS Publications Warehouse

Pardieck, K.L.; Sauer, J.R.

2007-01-01

Data from the North American Breeding Bird Survey were used to estimate continental and regional changes in bird populations for the 5-yr period 1999-2003 and the 2-yr period 2002-2003. These short-term changes were placed in the context of population trends estimated over the 1966-2003 interval. During 1999-2003, 41% of all species exhibited positive trends over the entire survey area, while 64% of all species exhibited positive change between 2002-2003. The continental and regional percentages of species with positive trends were also analyzed for 12 species groups having shared life-history traits. Survey-wide for the entire survey period, grassland birds exhibited the lowest percentage of increasing species (14%), with their sharpest declines occurring in the West during 1999-2003 (10% increasing). During 1999-2003, short-distance migrants experienced significant declines in all regions, where numbers of species with increasing trends ranged from 22% - 34%. Most species fared well during the 2002-2003 period, with 64% (P < 0.05) increasing survey-wide. This was primarily a result of increases in the Central and Western BBS regions where 21 of 24 species groups exhibited significant increases in the number of species with positive trends.

Multiple effects of physical activity on molecular and cognitive signs of brain aging: can exercise slow neurodegeneration and delay Alzheimer's disease?

PubMed

Brown, B M; Peiffer, J J; Martins, R N

2013-08-01

Western countries are experiencing aging populations and increased longevity; thus, the incidence of dementia and Alzheimer's disease (AD) in these countries is projected to soar. In the absence of a therapeutic drug, non-pharmacological preventative approaches are being investigated. One of these approaches is regular participation in physical activity or exercise. This paper reviews studies that have explored the relationship between physical activity and cognitive function, cognitive decline, AD/dementia risk and AD-associated biomarkers and processes. There is now strong evidence that links regular physical activity or exercise to higher cognitive function, decreased cognitive decline and reduced risk of AD or dementia. Nevertheless, these associations require further investigation, more specifically with interventional studies that include long follow-up periods. In particular, relatively little is known about the underlying mechanism(s) of the associations between physical activity and AD neuropathology; clearly this is an area in need of further research, particularly in human populations. Although benefits of physical activity or exercise are clearly recognised, there is a need to clarify how much physical activity provides the greatest benefit and also whether people of different genotypes require tailored exercise regimes.

Whole genome resequencing of the human parasite Schistosoma mansoni reveals population history and effects of selection.

PubMed

Crellen, Thomas; Allan, Fiona; David, Sophia; Durrant, Caroline; Huckvale, Thomas; Holroyd, Nancy; Emery, Aidan M; Rollinson, David; Aanensen, David M; Berriman, Matthew; Webster, Joanne P; Cotton, James A

2016-02-16

Schistosoma mansoni is a parasitic fluke that infects millions of people in the developing world. This study presents the first application of population genomics to S. mansoni based on high-coverage resequencing data from 10 global isolates and an isolate of the closely-related Schistosoma rodhaini, which infects rodents. Using population genetic tests, we document genes under directional and balancing selection in S. mansoni that may facilitate adaptation to the human host. Coalescence modeling reveals the speciation of S. mansoni and S. rodhaini as 107.5-147.6KYA, a period which overlaps with the earliest archaeological evidence for fishing in Africa. Our results indicate that S. mansoni originated in East Africa and experienced a decline in effective population size 20-90KYA, before dispersing across the continent during the Holocene. In addition, we find strong evidence that S. mansoni migrated to the New World with the 16-19th Century Atlantic Slave Trade.

Agricultural landscapes: Can they support healthy bird populations as well as farm products?

USGS Publications Warehouse

Peterjohn, B.G.

2003-01-01

At the beginning of the twentieth century, prospects for bird populations occupying farmlands were promising. Agricultural expansion and the resulting deforestation produced wholesale changes to the landscape of eastern North America (Trautman 1977, Zeranski and Baptist 1990, Nicholson 1997). Regional avifaunas were transformed as Horned Larks (Eremophila alpestris), Dickcissels (Spiza americana), and other farmland birds undertook range expansions (Hurley and Franks 1976, Askins 1999). Those farmland birds became conspicuous, frequently in numbers that are hard to imagine today (Trautman 1940).One hundred years later, many of those once plentiful species experienced dramatic population declines (Askins 1993, Peterjohn and Sauer 1999). Those trends were evident for many decades, although pre-1965 trends were largely based on anecdotal accounts and were frequently attributed to changing regional landscapes due to urban expansion, farm abandonment resulting in increased forest cover, and the more intensive use of remaining agricultural fields (Trautman 1940, Herkert 1991, Askins 2000). However, numerous specific factors were implicated in local declines of individual species (Kantrud 1981, Bollinger et al. 1990, Lymn and Temple 1991, Bowen and Kruse 1993, Herkert 1994, Houston and Schmutz 1999, Blackwell and Dolbeer 2001).Understanding factors responsible for population changes can be approached at various geographic scales. Local studies identify specific factors influencing small populations, but the applicability of those results across broad geographic areas is often uncertain. Studies conducted at large geographic scales identify broad patterns of change, but those patterns frequently involve interrelated factors that may be only loosely related to the actual causes of population change. However, correlations between broad patterns of changes in bird populations and land-use characteristics provide a basis for directing future studies conducted at smaller geographic scales.

Changes in management policies for extremely preterm births and neonatal outcomes from 2003 to 2012: two population-based studies in ten European regions.

PubMed

Bonet, M; Cuttini, M; Piedvache, A; Boyle, E M; Jarreau, P H; Kollée, L; Maier, R F; Milligan, Dwa; Van Reempts, P; Weber, T; Barros, H; Gadzinowki, J; Draper, E S; Zeitlin, J

2017-09-01

To investigate changes in maternity and neonatal unit policies towards extremely preterm infants (EPTIs) between 2003 and 2012, and concurrent trends in their mortality and morbidity in ten European regions. Population-based cohort studies in 2003 (MOSAIC study) and 2011/2012 (EPICE study) and questionnaires from hospitals. 70 hospitals in ten European regions. Infants born at <27 weeks of gestational age (GA) in hospitals participating in both the MOSAIC and EPICE studies (1240 in 2003, 1293 in 2011/2012). We used McNemar's Chi 2 test, paired t-tests and conditional logistic regression for comparisons over time. Reported policies, mortality and morbidity of EPTIs. The lowest GA at which maternity units reported performing a caesarean section for acute distress of a singleton non-malformed fetus decreased from an average of 24.7 to 24.1 weeks (P < 0.01) when parents were in favour of active management, and 26.1 to 25.2 weeks (P = 0.01) when parents were against. Units reported that neonatologists were called more often for spontaneous deliveries starting at 22 weeks GA in 2012 and more often made decisions about active resuscitation alone, rather than in multidisciplinary teams. In-hospital mortality after live birth for EPTIs decreased from 50% to 42% (P < 0.01). Units reporting more active management in 2012 than 2003 had higher mortality in 2003 (55% versus 43%; P < 0.01) and experienced larger declines (55 to 44%; P < 0.001) than units where policies stayed the same (43 to 37%; P = 0.1). European hospitals reporting changes in management policies experienced larger survival gains for EPTIs. Changes in reported policies for management of extremely preterm births were related to mortality declines. © 2017 Royal College of Obstetricians and Gynaecologists.

Pragmatic perspective on conservation genetics and demographic history of the last surviving population of Kashmir red deer (Cervus elaphus hanglu) in India.

PubMed

Mukesh; Kumar, Ved P; Sharma, Lalit K; Shukla, Malay; Sathyakumar, Sambandam

2015-01-01

The hangul (Cervus elaphus hanglu) is of great conservation concern because it represents the easternmost and only hope for an Asiatic survivor of the red deer species in the Indian subcontinent. Despite the rigorous conservation efforts of the Department of Wildlife Protection in Jammu & Kashmir, the hangul population has experienced a severe decline in numbers and range contraction in the past few decades. The hangul population once abundant in the past has largely become confined to the Dachigam landscape, with a recent population estimate of 218 individuals. We investigated the genetic variability and demographic history of the hangul population and found that it has shown a relatively low diversity estimates when compared to other red deer populations of the world. Neutrality tests, which are used to evaluate demographic effects, did not support population expansion, and the multimodal pattern of mismatch distribution indicated that the hangul population is under demographic equilibrium. Furthermore, the hangul population did not exhibit any signature of bottleneck footprints in the past, and Coalescent Bayesian Skyline plot analysis revealed that the population had not experienced any dramatic changes in the effective population size over the last several thousand years. We observed a strong evidence of sub-structuring in the population, wherein the majority of individuals were assigned to different clusters in Bayesian cluster analysis. Population viability analysis demonstrated insignificant changes in the mean population size, with a positive growth rate projected for the next hundred years. We discuss the phylogenetic status of hangul for the first time among the other red deer subspecies of the world and strongly recommend to upgrade hangul conservation status under IUCN that should be discrete from the other red deer subspecies of the world to draw more conservation attention from national and international bodies.

Educational Opportunity, Parental Choice and Community: The Case for Reforming Public Education.

ERIC Educational Resources Information Center

Hawkins, Robert B., Jr.

1982-01-01

For the last 10 years, polling data have recorded a consistent decline in the American citizen's support for public education. While public schools experienced an 8 percent decline in enrollment between 1968 and 1978, private school enrollment grew by 12 percent. The decline in quality of public education over the last 50 years appears strongly…

Decline in Kidney Function among Apparently Healthy Young Adults at Risk of Mesoamerican Nephropathy.

PubMed

Gonzalez-Quiroz, Marvin; Smpokou, Evangelia-Theano; Silverwood, Richard J; Camacho, Armando; Faber, Dorien; Garcia, Brenda La Rosa; Oomatia, Amin; Hill, Michael; Glaser, Jason; Le Blond, Jennifer; Wesseling, Catharina; Aragon, Aurora; Smeeth, Liam; Pearce, Neil; Nitsch, Dorothea; Caplin, Ben

2018-06-15

Background Epidemic levels of CKD of undetermined cause, termed Mesoamerican nephropathy in Central America, have been found in low- and middle-income countries. We investigated the natural history of, and factors associated with, loss of kidney function in a population at high risk for this disease. Methods We conducted a 2-year prospective, longitudinal study with follow-up every 6 months in nine rural communities in northwestern Nicaragua and included all men ( n =263) and a random sample of women ( n =87) ages 18-30 years old without self-reported CKD, diabetes, or hypertension. We used growth mixture modeling to identify subgroups of eGFR trajectory and weighted multinomial logistic regression to examine associations with proposed risk factors. Results Among men, we identified three subpopulations of eGFR trajectory (mean baseline eGFR; mean eGFR change over follow-up): 81% remained stable (116 ml/min per 1.73 m 2 ; -0.6 ml/min per 1.73 m 2 per year), 9.5% experienced rapid decline despite normal baseline function (112 ml/min per 1.73 m 2 ; -18.2 ml/min per 1.73 m 2 per year), and 9.5% had baseline dysfunction (58 ml/min per 1.73 m 2 ; -3.8 ml/min per 1.73 m 2 per year). Among women: 96.6% remained stable (121 ml/min per 1.73 m 2 ; -0.6 ml/min per 1.73 m 2 per year), and 3.4% experienced rapid decline (132 ml/min per 1.73 m 2 ; -14.6 ml/min per 1.73 m 2 per year; n =3 women). Among men, outdoor and agricultural work and lack of shade availability during work breaks, reported at baseline, were associated with rapid decline. Conclusions Although Mesoamerican nephropathy is associated with agricultural work, other factors may also contribute to this disease. Copyright © 2018 by the American Society of Nephrology.

The fertility decline in Kenya.

PubMed

Robinson, W C; Harbison, S F

1995-01-01

In Sub-Saharan Africa Kenya is a prime example of a country experiencing a rapid decline in fertility and greater contraceptive prevalence. These changes have occurred since 1980 when fertility was high at 8.0 children per woman. In 1993 the total fertility rate (TFR) was 5.4, and the growth rate declined to about 2.0%. This transition is swifter than any country in contemporary Asia or historical Europe. The likely projection for Kenya is attainment of replacement level fertility during the 2020s and a leveling of population at about 100 million persons. Fertility has declined the most in urban areas and central and eastern regions. Bongaarts' proximate determinants (TFR, total marital fertility rate, total natural marital fertility rate, and total fecundity) are reduced to the proportion of currently married women using contraception, the proportion in lactational nonfecund status, and the proportion currently married. Actual fertility change is accounted for by total fertility change of 3.0 children. Lactational infecundability accounts for 0.5 potential births, and changes in marital fertility account for 1.0 reduced births per woman. About 70% of fertility reduction is accounted for by contraception and abortion. During 1977-78 80% of fertility control was due to lactational nonfecundity, 10% to nonmarriage, and 10% to contraception. In 1993 lactational nonfecundity accounted for 50% of the reduction, nonmarriage for 20%, and abortion about 30%. Future fertility is expected to be dependent on contraceptive prevalence. Kenya has experienced the Coale paradigm of preconditions necessary for demographic transition (willing, ready, and able). High fertility in Africa is not intractable. Creating the change in attitudes that leads to readiness is linked to education, health, and exposure to modernizing media and urban lifestyles. The public sector family planning program in Kenya has created the opportunity for access and availability of contraception. The key features of reform appear to be political stability, public sector programs, and supply of contraception through the health service.

Temporal dynamics of genetic variability in a mountain goat (Oreamnos americanus) population.

PubMed

Ortego, Joaquín; Yannic, Glenn; Shafer, Aaron B A; Mainguy, Julien; Festa-Bianchet, Marco; Coltman, David W; Côté, Steeve D

2011-04-01

The association between population dynamics and genetic variability is of fundamental importance for both evolutionary and conservation biology. We combined long-term population monitoring and molecular genetic data from 123 offspring and their parents at 28 microsatellite loci to investigate changes in genetic diversity over 14 cohorts in a small and relatively isolated population of mountain goats (Oreamnos americanus) during a period of demographic increase. Offspring heterozygosity decreased while parental genetic similarity and inbreeding coefficients (F(IS) ) increased over the study period (1995-2008). Immigrants introduced three novel alleles into the population and matings between residents and immigrants produced more heterozygous offspring than local crosses, suggesting that immigration can increase population genetic variability. The population experienced genetic drift over the study period, reflected by a reduced allelic richness over time and an 'isolation-by-time' pattern of genetic structure. The temporal decline of individual genetic diversity despite increasing population size probably resulted from a combination of genetic drift due to small effective population size, inbreeding and insufficient counterbalancing by immigration. This study highlights the importance of long-term genetic monitoring to understand how demographic processes influence temporal changes of genetic diversity in long-lived organisms. © 2011 Blackwell Publishing Ltd.

Effects of shallow natural gas well structures and associated roads on grassland songbird reproductive success in Alberta, Canada

PubMed Central

Koper, Nicola

2017-01-01

Grassland songbird populations across North America have experienced dramatic population declines due to habitat loss and degradation. In Canada, energy development continues to fragment and disturb prairie habitat, but effects of oil and gas development on reproductive success of songbirds in North American mixed-grass prairies remains largely unknown. From 2010–2012, in southeastern Alberta, Canada, we monitored 257 nests of two ground-nesting grassland songbird species, Savannah sparrow (Passerculus sandwichensis) and chestnut-collared longspur (Calcarius ornatus). Nest locations varied with proximity to and density of conventional shallow gas well structures and associated roads in forty-two 258-ha mixed-grass prairie sites. We estimated the probabilities of nest success and clutch size relative to gas well structures and roads. There was little effect of distance to or density of gas well structure on nest success; however, Savannah sparrow experienced lower nest success near roads. Clutch sizes were lower near gas well structures and cattle water sources. Minimizing habitat disturbance surrounding gas well structures, and reducing abundance of roads and trails, would help minimize impacts on reproductive success for some grassland songbirds. PMID:28355241

Effects of shallow natural gas well structures and associated roads on grassland songbird reproductive success in Alberta, Canada.

PubMed

Yoo, Jenny; Koper, Nicola

2017-01-01

Grassland songbird populations across North America have experienced dramatic population declines due to habitat loss and degradation. In Canada, energy development continues to fragment and disturb prairie habitat, but effects of oil and gas development on reproductive success of songbirds in North American mixed-grass prairies remains largely unknown. From 2010-2012, in southeastern Alberta, Canada, we monitored 257 nests of two ground-nesting grassland songbird species, Savannah sparrow (Passerculus sandwichensis) and chestnut-collared longspur (Calcarius ornatus). Nest locations varied with proximity to and density of conventional shallow gas well structures and associated roads in forty-two 258-ha mixed-grass prairie sites. We estimated the probabilities of nest success and clutch size relative to gas well structures and roads. There was little effect of distance to or density of gas well structure on nest success; however, Savannah sparrow experienced lower nest success near roads. Clutch sizes were lower near gas well structures and cattle water sources. Minimizing habitat disturbance surrounding gas well structures, and reducing abundance of roads and trails, would help minimize impacts on reproductive success for some grassland songbirds.

Could the Health Decline of Prehistoric California Indians be Related to Exposure to Polycyclic Aromatic Hydrocarbons (PAHs) from Natural Bitumen?

PubMed Central

Sholts, Sabrina B.; Erlandson, Jon M.; Gjerdrum, Thor; Westerholm, Roger

2011-01-01

Background: The negative health effects of polycyclic aromatic hydrocarbons (PAHs) are well established for modern human populations but have so far not been studied in prehistoric contexts. PAHs are the main component of fossil bitumen, a naturally occurring material used by past societies such as the Chumash Indians in California as an adhesive, as a waterproofing agent, and for medicinal purposes. The rich archaeological and ethnohistoric record of the coastal Chumash suggests that they were exposed to multiple uptake pathways of bituminous PAHs, including direct contact, fume inhalation, and oral uptake from contaminated water and seafood. Objectives: We investigated the possibility that PAHs from natural bitumen compromised the health of the prehistoric Chumash Indians in California. Conclusions: Exposure of the ancient Chumash Indians to toxic PAHs appears to have gradually increased across a period of 7,500 years because of an increased use of bitumen in the Chumash technology, together with a dietary shift toward PAH-contaminated marine food. Skeletal analysis indicates a concurrent population health decline that may be related to PAH uptake. However, establishing such a connection is virtually impossible without knowing the actual exposure levels experienced by these populations. Future methodological research may provide techniques for determining PAH levels in ancient skeletal material, which would open new avenues for research on the health of prehistoric populations and on the long-term effects of human PAH exposure. PMID:21596651

Population Genetics of the Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) across Multiple Spatial Scales

PubMed Central

Unger, Shem D.; Rhodes, Olin E.; Sutton, Trent M.; Williams, Rod N.

2013-01-01

Conservation genetics is a powerful tool to assess the population structure of species and provides a framework for informing management of freshwater ecosystems. As lotic habitats become fragmented, the need to assess gene flow for species of conservation management becomes a priority. The eastern hellbender (Cryptobranchus alleganiensis alleganiensis) is a large, fully aquatic paedamorphic salamander. Many populations are experiencing declines throughout their geographic range, yet the genetic ramifications of these declines are currently unknown. To this end, we examined levels of genetic variation and genetic structure at both range-wide and drainage (hierarchical) scales. We collected 1,203 individuals from 77 rivers throughout nine states from June 2007 to August 2011. Levels of genetic diversity were relatively high among all sampling locations. We detected significant genetic structure across populations (Fst values ranged from 0.001 between rivers within a single watershed to 0.218 between states). We identified two genetically differentiated groups at the range-wide scale: 1) the Ohio River drainage and 2) the Tennessee River drainage. An analysis of molecular variance (AMOVA) based on landscape-scale sampling of basins within the Tennessee River drainage revealed the majority of genetic variation (∼94–98%) occurs within rivers. Eastern hellbenders show a strong pattern of isolation by stream distance (IBSD) at the drainage level. Understanding levels of genetic variation and differentiation at multiple spatial and biological scales will enable natural resource managers to make more informed decisions and plan effective conservation strategies for cryptic, lotic species. PMID:24204565

The equivalence of numbers: The social value of avoiding health decline: An experimental web-based study

PubMed Central

Schwappach, David LB

2002-01-01

Background Health economic analysis aimed at informing policy makers and supporting resource allocation decisions has to evaluate not only improvements in health but also avoided decline. Little is known however, whether the "direction" in which changes in health are experienced is important for the public in prioritizing among patients. This experimental study investigates the social value people place on avoiding (further) health decline when directly compared to curative treatments in resource allocation decisions. Methods 127 individuals completed an interactive survey that was published in the World Wide Web. They were confronted with a standard gamble (SG) and three person trade-off tasks, either comparing improvements in health (PTO-Up), avoided decline (PTO-Down), or both, contrasting health changes of equal magnitude differing in the direction in which they are experienced (PTO-WAD). Finally, a direct priority ranking of various interventions was obtained. Results Participants strongly prioritized improving patients' health rather than avoiding decline. The mean substitution rate between health improvements and avoided decline (WAD) ranged between 0.47 and 0.64 dependent on the intervention. Weighting PTO values according to the direction in which changes in health are experienced improved their accuracy in predicting a direct prioritization ranking. Health state utilities obtained by the standard gamble method seem not to reflect social values in resource allocation contexts. Conclusion Results suggest that the utility of being cured of a given health state might not be a good approximation for the societal value of avoiding this health state, especially in cases of competition between preventive and curative interventions. PMID:11879529

Change in numbers of resident and migratory shorebirds at the Cabo Rojo Salt Flats, Puerto Rico, USA (1985–2014)

USGS Publications Warehouse

Parks, Morgan A.; Collazo, Jaime A.; Colon, Jose A.; Ramos Alvarez, Katsi R.; Diaz, Oscar

2016-01-01

North American migratory shorebirds have declined markedly since the 1980s, underscoring the importance of population surveys to conduct status and trend assessments. Shorebird surveys were conducted during three multi-year periods between 1985 and 2014 and used to assess changes in numbers and species composition at the Cabo Rojo Salt Flats, Puerto Rico, USA, a site of regional importance in the eastern Caribbean. Eight fewer species (total = 21) were recorded in 2013–2014 as compared to the 29 from 1985–1992; all eight species were Nearctic migrants. Small calidrids had the highest population counts; however, this suite of species and all others experienced a ≥ 70% decline. Combined counts from the salt flats and neighboring wetlands in 2013–2014 were lower than counts only from the Cabo Rojo Salt Flats in two previous multi-year survey periods, which indicated a real change in numbers not just a shift in wetland use. Invertebrate prey density was lower in 2013–2014 than in 1994. Body fat condition of Semipalmated Sandpipers (Calidris pusilla), an index of habitat quality, did not differ between 1985–1992 and 2013–2014. These findings do not exclude the possibility that other species might be affected by lower prey density, or that local declines in numbers reflect changes at hemispheric, not local, scales. The magnitude of change between local and hemispheric scales closely matched for some species. Continued monitoring at the salt flats is warranted to help gauge the status of shorebirds in Puerto Rico and discern the probable cause of declines. Monitoring other sites in the Caribbean is needed for stronger inferences about regional status and trends.

High resting metabolic rate among Amazonian forager-horticulturalists experiencing high pathogen burden

PubMed Central

Gurven, Michael D.; Trumble, Benjamin C.; Stieglitz, Jonathan; Yetish, Gandhi; Cummings, Daniel; Blackwell, Aaron D.; Beheim, Bret; Kaplan, Hillard S.; Pontzer, Herman

2016-01-01

Objectives Resting metabolic rate (RMR) reflects energetic costs of homeostasis and accounts for 60-75% of total energy expenditure (TEE). Lean mass and physical activity account for much RMR variability, but the impact of prolonged immune activation from infection on human RMR is unclear in naturalistic settings. We evaluate the effects of infection on mass-corrected RMR among Bolivian forager-horticulturalists, and assess whether RMR declines more slowly with age than in hygienic sedentary populations, as might be expected if older adults experience high pathogen burden. Materials and Methods RMR was measured by indirect calorimetry (Fitmate MED, Cosmed) in 1,300 adults aged 20-90 and TEE was measured using doubly labeled water (n= 40). Immune biomarkers, clinical diagnoses and anthropometrics were collected by the Tsimane Health and Life History Project. Results Tsimane have higher RMR and TEE than people in sedentary industrialized populations. Tsimane RMR is 18-47% (women) and 22-40% (men) higher than expected using six standard prediction equations. Tsimane mass-corrected TEE is similarly elevated compared to Westerners. Elevated leukocytes and helminths are associated with excess RMR in multivariate regressions, and jointly result in a predicted excess RMR of 10-15%. After age 40, RMR declines by 69 kcal/decade (p<0.0001). Controlling for lean mass and height accounts for 71% of age-related RMR decline, and adding indicators of infection minimally affects the age slope. The residual level of age-related decline from age 40 is 1.2% per decade. Conclusion High pathogen burden may lead to higher metabolic costs, which may be offset by smaller body mass or other energy-sparing mechanisms. PMID:27375044

Socio-economic inequalities in low-birth weight, full-term babies from singleton pregnancies in Taiwan.

PubMed

Li, C Y; Sung, F C

2008-03-01

This study investigated the chronological trend of low-birth weight in full-term babies (TLBW) in Taiwan in the 1980s and 1990s when the nation experienced a rapid economic advancement, and assessed the association between TLBW and parental education and marital status. Data from liveborn singletons from Taiwan's birth registry, born between 1978 and 1997, were used to calculate overall and socio-economic factor-specific rates of TLBW for every 2-year interval in this 20-year period. Logistic regression models were used to assess the trend of TLBW rates, and the interaction between secular time, selected demographic factors and other predictors. Among 6,159,070 full-term, liveborn singletons, 208,729 were TLBW. The average annual rate of TLBW was 3.39% in the study period. The period-specific TLBW declined monotonically from 4.41% in 1978-1979 to 2.49% in 1996-1997, representing a 43% deduction. Multiple logistic regression demonstrated persistent declining trends irrespective of the educational level or marital status of the parents. However, the decline was slower for populations of lower socio-economic status, such as less-educated parents and unmarried mothers, which enhanced the inequalities of TLBW risk across populations. The TLBW risk ratios of the least-educated mothers to the most-educated mothers increased from 1.43 in 1978-1979 to 2.05 in 1996-1997. Unmarried status was an independent predictor of elevated risk of TLBW. The association between socio-economic inequality and the risk of TLBW infants was sustained over the 1980s and 1990s in Taiwan. Interventions are necessary to promote antenatal care and educational attainment, particularly for lower socio-economic and socially deprived populations in Taiwan.

The effects of long-term stress exposure on aging cognition: a behavioral and EEG investigation.

PubMed

Marshall, Amanda C; Cooper, Nicholas R; Segrave, Rebecca; Geeraert, Nicolas

2015-06-01

A large field of research seeks to explore and understand the factors that may cause different rates of age-related cognitive decline within the general population. However, the impact of experienced stress on the human aging process has remained an under-researched possibility. This study explored the association between cumulative stressful experiences and cognitive aging, addressing whether higher levels of experienced stress correlate with impaired performance on 2 working memory tasks. Behavioral performance was paired with electroencephalographic recordings to enable insight into the underlying neural processes impacted on by cumulative stress. Thus, the electroencephalogram was recorded while both young and elderly performed 2 different working memory tasks (a Sternberg and N-back paradigm), and cortical oscillatory activity in the theta, alpha, and gamma bandwidths was measured. Behavioral data indicated that a higher stress score among elderly participants related to impaired performance on both tasks. Electrophysiological findings revealed a reduction in alpha and gamma event-related synchronization among high-stress-group elderly participants, indicating that higher levels of experienced stress may impact on their ability to actively maintain a stimulus in working memory and inhibit extraneous information interfering with successful maintenance. Findings provide evidence that cumulative experienced stress adversely affects cognitive aging. Copyright © 2015 Elsevier Inc. All rights reserved.

Changes in forage fish community indicated by the diet of the Brandt's cormorant (Phalacrocorax penicillatus) in the central California Current

NASA Astrophysics Data System (ADS)

Elliott, Meredith L.; Bradley, Russell W.; Robinette, Dan P.; Jahncke, Jaime

2015-06-01

The population, productivity and diet of two Brandt's cormorant (Phalacrocorax penicillatus) colonies located in the central California Current were compared. The offshore colony on Southeast Farallon Island has experienced a declining population over time and anomalously low productivity in recent years. The nearshore colony near Point Arguello has been increasing and its productivity has remained stable. The diets of cormorants at the two colonies elucidated by analysis of regurgitated pellets, while different, have shown similar decreases in the consumption of northern anchovy (Engraulis mordax) since 2008, followed by increased consumption of rockfish (Sebastes spp.) and flatfish (order Pleuronectiformes). By using the diet results from another seabird nesting in central California, the rhinoceros auklet (Cerorhinca monocerata), and one from which whole fish can be obtained, we found that the rockfish species assemblage has changed with offshore rockfish species decreasing while nearshore ones have increased. This change in the rockfish species has negatively impacted Brandt's cormorants at the offshore colony by forcing them to make longer foraging trips to meet energy needs of themselves and their chicks; this has led to low breeding success and a declining population at this site. On the other hand, the nearshore colony has abundant nearby food resources, and it has prospered. These results underscore the value of using seabird data from multiple colonies to better understand changes occurring in the marine environment.

Do hormone-modulating chemicals impact on reproduction and development of wild amphibians?

PubMed

Orton, Frances; Tyler, Charles R

2015-11-01

Globally, amphibians are undergoing a precipitous decline. At the last estimate in 2004, 32% of the approximately 6000 species were threatened with extinction and 43% were experiencing significant declines. These declines have been linked with a wide range of environmental pressures from habitat loss to climate change, disease and pollution. This review evaluates the evidence that endocrine-disrupting contaminants (EDCs) - pollutants that affect hormone systems - are impacting on wild amphibians and contributing to population declines. The review is limited to anurans (frogs and toads) as data for effects of EDCs on wild urodeles (salamanders, newts) or caecilians (limbless amphibians) are extremely limited. Evidence from laboratory studies has shown that a wide range of chemicals have the ability to alter hormone systems and affect reproductive development and function in anurans, but for the most part only at concentrations exceeding those normally found in natural environments. Exceptions can be found for exposures to the herbicide atrazine and polychlorinated biphenyls in leopard frogs (Rana pipiens) and perchlorate in African clawed frogs (Xenopus laevis). These contaminants induce feminising effects on the male gonads (including 'intersex' - oocytes within testes) at concentrations measured in some aquatic environments. The most extensive data for effects of an EDC in wild amphibian populations are for feminising effects of atrazine on male gonad development in regions across the USA. Even where strong evidence has been provided for feminising effects of EDCs, however, the possible impact of these effects on fertility and breeding outcome has not been established, making inference for effects on populations difficult. Laboratory studies have shown that various chemicals, including perchlorate, polychlorinated biphenyls and bromodiphenylethers, also act as endocrine disrupters through interfering with thyroid-dependent processes that are fundamental for amphibian metamorphosis. Perchlorate has also been shown to induce these effects in wild anuran populations from perchlorate-contaminated environments. Overall, the published data available suggest that some health effects observed in wild anuran populations, most notably intersex, likely have a chemical aetiology; however they derive only from very few anuran species and for a few pesticides at field sites in the USA. To understand better the impacts of EDCs on wild anuran populations, as well as other amphibian groups, assessment of fertility in exposed animals are required. Development of non-destructive biomarkers that are indicative of specific EDC-effect mechanisms are also needed to allow the study of vulnerable populations. This will help to distinguish the effects of EDCs from other environmental and/or genetic influences on development and reproduction. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

Long-term and widespread changes in agricultural practices influence ring-necked pheasant abundance in California

USGS Publications Warehouse

Coates, Peter S.; Brussee, Brianne E.; Howe, Kristy B.; Fleskes, Joseph P.; Dwight, Ian; Connelly, Daniel P.; Meshriy, Matt G.; Gardner, Scott C.

2017-01-01

Declines in bird populations in agricultural regions of North America and Europe have been attributed to agricultural industrialization, increases in use of agrochemical application, and increased predation related to habitat modification. Based on count data compiled from Breeding Bird Survey (BBS) from 1974 to 2012, Christmas Bird Count (CBC) collected from 1914 to 2013, and hunter data from Annual Game Take Survey (AGTS) for years 1948–2010, ring-necked pheasants (Phasianus colchicus) in California have experienced substantial declines in agricultural environments. Using a modeling approach that integrates all three forms of survey data into a joint response abundance index, we found pheasant abundance was related to the amount of harvested and unharvested crop land, types of crops produced, amount of total pesticide applied, minimum temperature, precipitation, and numbers of avian competitors and predators. Specifically, major changes in agricultural practices over the last three decades were associated with declines in pheasant numbers and likely reflected widespread loss of habitat. For example, increases in cropland were associated with increased pheasant abundance during early years of study but this effect decreased through time, such that no association in recent years was evidenced. A post hoc analysis revealed that crops beneficial to pheasant abundance (e.g., barley) have declined substantially in recent decades and were replaced by less advantageous crops (e.g., nut trees). An additional analysis using a restricted data set (1990–2013) indicated recent negative impacts on pheasant numbers associated with land use practices were also associated with relatively high levels of pesticide application. Our results may provide valuable information for management policies aimed at reducing widespread declines in pheasant populations in California and may be applicable to other avian species within agricultural settings. Furthermore, this general analytical approach is not limited to pheasants and could be applied to other taxa for which multiple survey data sources exist.

Impacts of the Brown Tree Snake: Patterns of Decline and Species Persistence in Guam's Avifauna

USGS Publications Warehouse

Wiles, G.J.; Bart, J.; Beck, R.E.; Aguon, C.F.

2003-01-01

Predation by brown tree snakes (Boiga irregularis ) devastated the avifauna of Guam in the Mariana Islands during the last half of the twentieth century, causing the extirpation or serious reduction of most of the island's 25 resident bird species. Past studies have provided qualitative descriptions of the decline of native forest birds but have not considered all species or presented quantitative analyses. We analyzed two sets of survey data gathered in northern Guam between 1976 and 1998 and reviewed unpublished sources to provide a comprehensive account of the impact of brown tree snakes on the island's birds. Our results indicate that 22 species, including 17 of 18 native species, were severely affected by snakes. Twelve species were likely extirpated as breeding residents on the main island, 8 others experienced declines of ≥90% throughout the island or at least in the north, and 2 were kept at reduced population levels during all or much of the study. Declines of ≥90% occurred rapidly, averaging just 8.9 years along three roadside survey routes combined and 1.6 years at a 100-ha forested study site. Declines in northern Guam were also relatively synchronous and occurred from about 1976 to 1986 for most species. The most important factor predisposing a species to coexistence with brown tree snakes was its ability to nest and roost at locations where snakes were uncommon. Large clutch size and large body size were also related to longer persistence times, although large body size appeared to delay, but not prevent, extirpation. Our results draw attention to the enormous detrimental impact that brown tree snakes are likely to have upon invading new areas. Increased containment efforts on Guam are needed to prevent further colonizations, but a variety of additional management efforts would also benefit the island's remaining bird populations.

Molt and aging criteria for four North American grassland passerines

USGS Publications Warehouse

Pyle, Peter; Jones, Stephanie L.; Ruth, Janet M.

2008-01-01

Prairie and grassland habitats in central and western North America have declined substantially since settlement by Europeans (Knopf 1994) and many of the birds and other organisms that inhabit North American grasslands have experienced steep declines (Peterjohn and Sauer 1999; Johnson and Igl 1997; Sauer, Hines, and Fallon 2007). The species addressed here, Sprague’s Pipit (Anthus spragueii), Grasshopper (Ammodramus savannarum) and Baird’s (A. bairdii) sparrows, and Chestnut-collared Longspurs (Calcarius ornatus), are grassland birds that are of special conservation concern throughout their ranges due to declining populations and the loss of the specific grassland habitats required on both their breeding and wintering ranges (Knopf 1994, Davis and Sealy 1998, Davis 2003, Davis 2004, Jones and Dieni 2007). Population-trend data on grassland birds, while clearly showing declines, provides no information on the causes of population declines. Without demographic information (i.e., productivity and survivorship), there are no means to determine when in their life cycle the problems that are creating these declines are occurring, or to determine to what extent population trends are driven by factors that affect birth rates, death rates, or both (DeSante 1995). For migratory birds, population declines may be driven by factors on breeding grounds, during migration, and/or on wintering grounds. Lack of data on productivity and survivorship thus impedes the formulation of effective management and conservation strategies to reverse population declines (DeSante 1992). Furthermore, if deficiencies in survivorship are revealed, management strategies may need to address habitats on both breeding and non-breeding grounds, as well as along migratory pathways. One technique that helps inform management strategies is the biochemical analysis of isotopes and genetic markers, from the sampling of individual feathers from live birds (Smith et al. 2003, Pérez and Hobson 2006; Appendix). Determining demographic parameters and effectively sampling feathers to reveal connectivity between breeding and wintering grounds requires detailed knowledge of molt patterns and age determination criteria for the target species, in the hand. For example, productivity, survivorship, and territory acquisition may all be age-dependent, with first-year birds showing different patterns and responses than older birds. In many cases it may be possible to sample both a feather grown on the breeding grounds and one grown on the wintering grounds from a single individual, but knowledge of age-specific molt patterns, as well as an ability to recognize different feather generations, is needed to accomplish such a task. While some information on molt and aging criteria exists for grassland passerine species (Pyle 1997a), these species have been rarely captured during mark-recapture studies (Jones et al. 2007) and this information thus needs refining. There is a need for additional resources to assist field workers in determining molt patterns and age in captured individuals. Our objective is to describe molt and aging criteria for four grassland passerine species with the aid of digital photographs taken in the field. We hope that this document will be useful for researchers studying grassland species through capture and banding of live individuals on either the breeding or the wintering grounds. We present a general section on molt and aging techniques, followed by specific accounts for the four species treated: Sprague’s Pipits, Grasshopper and Baird sparrows, and Chestnut-collared Longspur. We also provide a brief protocol on collecting feather samples (Appendix).

Longer time spent in bed attempting to sleep is associated with rapid renal function decline: the Dongfeng-Tongji cohort study.

PubMed

Li, Yizhun; Yang, Liangle; Wang, Hao; Jiang, Haijing; Qiu, Gaokun; Liu, Yiyi; Xiao, Yang; Yang, Handong; Wu, Tangchun; Zhang, Xiaomin

2018-03-01

Prospective evidence on the relation between time in bed and renal dysfunction remains limited. We aimed to investigate the association of time spent in bed attempting to sleep (TSBS) with renal function decline in a middle-aged and elderly Chinese population. About 16,733 eligible participants with a mean age of 62.3 years at baseline were included. Rapid renal function decline was defined as (baseline eGFR - revisit eGFR)/years of follow-up ≥5 mL/min per 1.73 m 2 /year. A total of 1738 study participants experienced rapid renal function decline after a median 4.6-year follow-up. Logistic regression models were used for multivariate analyses. The adjusted odds ratio (OR) of rapid renal function decline was 1.18 (95% CI: 1.02, 1.37) for TSBS ≥9 h/night compared with TSBS 7 to <8 h/night. This association remained significant (OR = 1.19, 95% CI: 1.03, 1.38) after further adjustment for sleep quality, midday napping and usage of sleeping pills. Particularly, the association appeared to be prominent in individuals with diabetes. Longer TSBS (≥9 h) was independently associated with an increased risk of rapid renal function decline. Our findings emphasized the importance to have optimal TSBS. Key messages Our study firstly investigated the association between time spent in bed attempting to sleep (TSBS) and renal dysfunction in Chinese adults. Compared with individuals TSBS 7 to <8 h, individuals with TSBS ≥9 h had 19% increased risk for rapid renal function decline after adjustment for multivariate confounders. The association appeared to be prominent in individuals with diabetes.

Late Life Leisure Activities and Risk of Cognitive Decline

PubMed Central

2013-01-01

Background. Studies concerning the effect of different types of leisure activities on various cognitive domains are limited. This study tests the hypothesis that mental, physical, and social activities have a domain-specific protection against cognitive decline. Methods. A cohort of a geographically defined population in China was examined in 2003–2005 and followed for an average of 2.4 years. Leisure activities were assessed in 1,463 adults aged 65 years and older without cognitive or physical impairment at baseline, and their cognitive performances were tested at baseline and follow-up examinations. Results. High level of mental activity was related to less decline in global cognition (β = −.23, p < .01), language (β = −.11, p < .05), and executive function (β = −.13, p < .05) in ANCOVA models adjusting for age, gender, education, history of stroke, body mass index, Apolipoprotein E genotype, and baseline cognition. High level of physical activity was related to less decline in episodic memory (β = −.08, p < .05) and language (β = −.15, p < .01). High level of social activity was associated with less decline in global cognition (β = −.11, p < .05). Further, a dose-response pattern was observed: although participants who did not engage in any of the three activities experienced a significant global cognitive decline, those who engaged in any one of the activities maintained their cognition, and those who engaged in two or three activities improved their cognition. The same pattern was observed in men and in women. Conclusions. Leisure activities in old age may protect against cognitive decline for both women and men, and different types of activities seem to benefit different cognitive domains. PMID:22879456

Evaluation of soil saturation, soil chemistry, and early spring soil and air temperatures as risk factors in yellow-cedar decline.

Treesearch

D.V. D' Amore; P.E. Hennon

2006-01-01

Yellow-cedar (Callitropsis nootkatensis (D. Don) Oerst.) is a valuable tree species that is experiencing a widespread decline and mortality in southeast Alaska. This study evaluated the relative importance of several potential risk factors associated with yellow-cedar decline: soil saturation, soil aluminum (Al) toxicity or calcium (Ca) deficiency...

Density dependence, whitebark pine, and vital rates of grizzly bears

USGS Publications Warehouse

van Manen, Frank T.; Haroldson, Mark A.; Bjornlie, Daniel D.; Ebinger, Michael R.; Thompson, Daniel J.; Costello, Cecily M.; White, Gary C.

2016-01-01

Understanding factors influencing changes in population trajectory is important for effective wildlife management, particularly for populations of conservation concern. Annual population growth of the grizzly bear (Ursus arctos) population in the Greater Yellowstone Ecosystem, USA has slowed from 4.2–7.6% during 1983–2001 to 0.3–2.2% during 2002–2011. Substantial changes in availability of a key food source and bear population density have occurred. Whitebark pine (Pinus albicaulis), the seeds of which are a valuable but variable fall food for grizzly bears, has experienced substantial mortality primarily due to a mountain pine beetle (Dendroctonus ponderosae) outbreak that started in the early 2000s. Positive growth rates of grizzly bears have resulted in populations reaching high densities in some areas and have contributed to continued range expansion. We tested research hypotheses to examine if changes in vital rates detected during the past decade were more associated with whitebark pine decline or, alternatively, increasing grizzly bear density. We focused our assessment on known-fate data to estimate survival of cubs-of-the-year (cubs), yearlings, and independent bears (≥2 yrs), and reproductive transition of females from having no offspring to having cubs. We used spatially and temporally explicit indices for grizzly bear density and whitebark pine mortality as individual covariates. Models indicated moderate support for an increase in survival of independent male bears over 1983–2012, whereas independent female survival did not change. Cub survival, yearling survival, and reproductive transition from no offspring to cubs all changed during the 30-year study period, with lower rates evident during the last 10–15 years. Cub survival and reproductive transition were negatively associated with an index of grizzly bear density, indicating greater declines where bear densities were higher. Our analyses did not support a similar relationship for the index of whitebark pine mortality. The results of our study support the interpretation that slowing of population growth during the last decade was associated more with increasing grizzly bear density than the decline in whitebark pine. Grizzly bear density and its potential effect on vital rates and population trajectory warrant consideration for management of the grizzly bear population in the Greater Yellowstone Ecosystem.

Impacts of biodiversity loss on ocean ecosystem services.

PubMed

Worm, Boris; Barbier, Edward B; Beaumont, Nicola; Duffy, J Emmett; Folke, Carl; Halpern, Benjamin S; Jackson, Jeremy B C; Lotze, Heike K; Micheli, Fiorenza; Palumbi, Stephen R; Sala, Enric; Selkoe, Kimberley A; Stachowicz, John J; Watson, Reg

2006-11-03

Human-dominated marine ecosystems are experiencing accelerating loss of populations and species, with largely unknown consequences. We analyzed local experiments, long-term regional time series, and global fisheries data to test how biodiversity loss affects marine ecosystem services across temporal and spatial scales. Overall, rates of resource collapse increased and recovery potential, stability, and water quality decreased exponentially with declining diversity. Restoration of biodiversity, in contrast, increased productivity fourfold and decreased variability by 21%, on average. We conclude that marine biodiversity loss is increasingly impairing the ocean's capacity to provide food, maintain water quality, and recover from perturbations. Yet available data suggest that at this point, these trends are still reversible.

Declining death rates from hyperglycemic crisis among adults with diabetes, U.S., 1985-2002.

PubMed

Wang, Jing; Williams, Desmond E; Narayan, K M Venkat; Geiss, Linda S

2006-09-01

To examine trends in death rates for hyperglycemic crisis (diabetic ketoacidosis or hyperglycemic hyperosmolar state) among adults with diabetes in the U.S. from 1985 to 2002. Deaths with hyperglycemic crisis as the underlying cause were identified from national mortality data. Death rates were calculated using estimates of adults with diabetes from the National Health Interview Survey as the denominator and age adjusted to the 2000 U.S. population. The trends from 1985 to 2002 were tested using joinpoint regression analysis. Deaths due to hyperglycemic crisis dropped from 2,989 in 1985 to 2,459 in 2002. During the time period, age-adjusted death rates decreased from 42.4 to 23.8 per 100,000 adults with diabetes (4.4% decrease per year, P for trend <0.01). Death rates declined in all age-groups, with the greatest decrease occurring among individuals aged > or =65 years. Age-adjusted death rates fell for all race-sex subgroups, with black men experiencing the smallest decline. About one-fifth of deaths occurred at home or on arrival at the hospital, and the death rates for hyperglycemic crisis occurring at these places declined only modestly over time (2.1% decrease per year, P for trend = 0.049). Overall death rates due to hyperglycemic crisis among adults with diabetes have declined in the U.S. However, scope for further improvement remains, especially to further reduce death rates among black men and to prevent deaths occurring at home.

Trends in rates of occupational fatal injuries in the United States (1983-92).

PubMed

Bailer, A J; Stayner, L T; Stout, N A; Reed, L D; Gilbert, S J

1998-07-01

An updated version of a national surveillance system of traumatic occupational fatalities was used to explore adjusted and unadjusted trends in rates of fatal injury. Data from the national traumatic occupational fatalities surveillance system were combined with data on employment from the United States Bureau of Labor Statistics. Poisson regression was then used to examine trends in rates of occupational fatality injuries while controlling for demographic and workplace characteristics. Adjusted annual changes in rates of fatal injuries ranged from a decline of 6.2% for workers in technical and administrative support occupations--for example, health, science, and engineering technicians, pilots, computer programmers--to an increase of 1.6% in machine operators, assemblers, and inspectors. For industries, annual changes ranged from a decline of 5.3% for workers in public administration--for example, justice, public order, and safety workers--to an increase of 2.6% for workers in the wholesale trade. By comparison, the annual decline over all industries and occupations was 3.1%. In many industries and occupations, an effect modification of annual trends by the age of the worker was also found with the oldest workers experiencing either no decline or a significant increase in rates of fatal injuries. This general pattern of decline, adjusted for the effects of demographic characteristics of the worker population, is encouraging; however, increases in rates of fatal injuries found in particular industries and occupations, suggest appropriate targets for increased injury prevention efforts.

Trends in rates of occupational fatal injuries in the United States (1983-92)

PubMed Central

Bailer, A. J.; Stayner, L. T.; Stout, N. A.; Reed, L. D.; Gilbert, S. J.

1998-01-01

OBJECTIVES: An updated version of a national surveillance system of traumatic occupational fatalities was used to explore adjusted and unadjusted trends in rates of fatal injury. METHODS: Data from the national traumatic occupational fatalities surveillance system were combined with data on employment from the United States Bureau of Labor Statistics. Poisson regression was then used to examine trends in rates of occupational fatality injuries while controlling for demographic and workplace characteristics. RESULTS: Adjusted annual changes in rates of fatal injuries ranged from a decline of 6.2% for workers in technical and administrative support occupations--for example, health, science, and engineering technicians, pilots, computer programmers--to an increase of 1.6% in machine operators, assemblers, and inspectors. For industries, annual changes ranged from a decline of 5.3% for workers in public administration--for example, justice, public order, and safety workers--to an increase of 2.6% for workers in the wholesale trade. By comparison, the annual decline over all industries and occupations was 3.1%. In many industries and occupations, an effect modification of annual trends by the age of the worker was also found with the oldest workers experiencing either no decline or a significant increase in rates of fatal injuries. CONCLUSIONS: This general pattern of decline, adjusted for the effects of demographic characteristics of the worker population, is encouraging; however, increases in rates of fatal injuries found in particular industries and occupations, suggest appropriate targets for increased injury prevention efforts.   PMID:9816383

Conceptualizing socio‐hydrological drought processes: The case of the Maya collapse

PubMed Central

Carr, Gemma; Viglione, Alberto; Prskawetz, Alexia; Blöschl, Günter

2016-01-01

Abstract With population growth, increasing water demands and climate change the need to understand the current and future pathways to water security is becoming more pressing. To contribute to addressing this challenge, we examine the link between water stress and society through socio‐hydrological modeling. We conceptualize the interactions between an agricultural society with its environment in a stylized way. We apply the model to the case of the ancient Maya, a population that experienced a peak during the Classic Period (AD 600–830) and then declined during the ninth century. The hypothesis that modest drought periods played a major role in the society's collapse is explored. Simulating plausible feedbacks between water and society we show that a modest reduction in rainfall may lead to an 80% population collapse. Population density and crop sensitivity to droughts, however, may play an equally important role. The simulations indicate that construction of reservoirs results in less frequent drought impacts, but if the reservoirs run dry, drought impact may be more severe and the population drop may be larger. PMID:27840455

Conceptualizing socio-hydrological drought processes: The case of the Maya collapse.

PubMed

Kuil, Linda; Carr, Gemma; Viglione, Alberto; Prskawetz, Alexia; Blöschl, Günter

2016-08-01

With population growth, increasing water demands and climate change the need to understand the current and future pathways to water security is becoming more pressing. To contribute to addressing this challenge, we examine the link between water stress and society through socio-hydrological modeling. We conceptualize the interactions between an agricultural society with its environment in a stylized way. We apply the model to the case of the ancient Maya, a population that experienced a peak during the Classic Period (AD 600-830) and then declined during the ninth century. The hypothesis that modest drought periods played a major role in the society's collapse is explored. Simulating plausible feedbacks between water and society we show that a modest reduction in rainfall may lead to an 80% population collapse. Population density and crop sensitivity to droughts, however, may play an equally important role. The simulations indicate that construction of reservoirs results in less frequent drought impacts, but if the reservoirs run dry, drought impact may be more severe and the population drop may be larger.

Conceptualizing socio-hydrological drought processes: The case of the Maya collapse

NASA Astrophysics Data System (ADS)

Kuil, Linda; Carr, Gemma; Viglione, Alberto; Prskawetz, Alexia; Blöschl, Günter

2016-08-01

With population growth, increasing water demands and climate change the need to understand the current and future pathways to water security is becoming more pressing. To contribute to addressing this challenge, we examine the link between water stress and society through socio-hydrological modeling. We conceptualize the interactions between an agricultural society with its environment in a stylized way. We apply the model to the case of the ancient Maya, a population that experienced a peak during the Classic Period (AD 600-830) and then declined during the ninth century. The hypothesis that modest drought periods played a major role in the society's collapse is explored. Simulating plausible feedbacks between water and society we show that a modest reduction in rainfall may lead to an 80% population collapse. Population density and crop sensitivity to droughts, however, may play an equally important role. The simulations indicate that construction of reservoirs results in less frequent drought impacts, but if the reservoirs run dry, drought impact may be more severe and the population drop may be larger.

The consequences of climate change at an avian influenza 'hotspot'.

PubMed

Brown, V L; Rohani, Pejman

2012-12-23

Avian influenza viruses (AIVs) pose significant danger to human health. A key step in managing this threat is understanding the maintenance of AIVs in wild birds, their natural reservoir. Ruddy turnstones (Arenaria interpres) are an atypical bird species in this regard, annually experiencing high AIV prevalence in only one location-Delaware Bay, USA, during their spring migration. While there, they congregate on beaches, attracted by the super-abundance of horseshoe crab eggs. A relationship between ruddy turnstone and horseshoe crab (Limulus polyphemus) population sizes has been established, with a declining horseshoe crab population linked to a corresponding drop in ruddy turnstone population sizes. The effect of this interaction on AIV prevalence in ruddy turnstones has also been addressed. Here, we employ a transmission model to investigate how the interaction between these two species is likely to be altered by climate change. We explore the consequences of this modified interaction on both ruddy turnstone population size and AIV prevalence and show that, if climate change leads to a large enough mismatch in species phenology, AIV prevalence in ruddy turnstones will increase even as their population size decreases.

Economic crisis and smoking behaviour: prospective cohort study in Iceland

PubMed Central

McClure, Christopher Bruce; Valdimarsdóttir, Unnur A; Hauksdóttir, Arna; Kawachi, Ichiro

2012-01-01

Objective To examine the associations between the 2008 economic collapse in Iceland and smoking behaviour at the national and individual levels. Design A population-based, prospective cohort study based on a mail survey (Health and Wellbeing in Iceland) assessed in 2007 and 2009. Setting National mail survey. Participants Representative cohort (n=3755) of Icelandic adults. Main outcome measure Smoking status. Results A significant reduction in the prevalence of smoking was observed from 2007 (pre-economic collapse) to 2009 (postcollapse) in both males (17.4–14.8%; p 0.01) and females (20.0–17.5%; p 0.01) in the cohort (n=3755). At the individual level of analysis, male former smokers experiencing a reduction in income during the same period were less likely to relapse (OR 0.37; 95% CI 0.16 to 0.85). Female smokers were less likely to quit over time compared to males (OR 0.65; 95% CI 0.45 to 0.93). Among male former smokers who experienced an increase in income between 2007 and 2009, we observed an elevated risk of smoking relapse (OR 4.02; 95% CI 1.15 to 14.00). Conclusions The national prevalence of smoking in Iceland declined following the 2008 economic crisis. This could be due to the procyclical relationship between macro-economic conditions and smoking behaviour (ie, hard times lead to less smoking because of lower affordability), or it may simply reflect a continuation of trends already in place prior to the crisis. In individual-level analysis, we find that former smokers who experienced a decline in income were less likely to relapse; and conversely, an increase in income raises the risk. However, caution is warranted since these findings are based on small numbers. PMID:23048059

Relationship between employment histories and frailty trajectories in later life: evidence from the English Longitudinal Study of Ageing

PubMed Central

Lu, Wentian; Benson, Rebecca; Glaser, Karen; Corna, Laurie M; Worts, Diana; McDonough, Peggy; Price, Debora; Sacker, Amanda

2017-01-01

Background Given the acceleration of population ageing and policy changes to extend working lives, evidence is needed on the ability of older adults to work for longer. To understand more about the health impacts of work, this study examined the relationship between employment histories before retirement and trajectories of frailty thereafter. Methods The sample comprised 2765 women and 1621 men from the English Longitudinal Study of Ageing. We used gendered typologies of life-time employment and a frailty index (FI). Multilevel growth curve models were used to predict frailty trajectories by employment histories. Results Women who had a short break for family care, then did part-time work till 59 years had a lower FI after 60 years than those who undertook full-time work until 59 years. Women who were largely family carers or non-employed throughout adulthood, had higher levels of frailty at 60 years but experienced a slower decline with age. Men who worked full-time but early exited at either 49 or 60 years had a higher FI at 65 years than those who worked full-time up to 65 years. Interaction between employment histories and age indicated that men in full-time work who experienced an early exit at 49 tended to report slower declines. Conclusions For women, experiencing distinct periods throughout the lifecourse of either work or family care may be advantageous for lessening frailty risk in later life. For men, leaving paid employment before 65 years seems to be beneficial for decelerating increases in frailty thereafter. Continuous full-time work until retirement age conferred no long-term health benefits. PMID:27913614

Comparative health assessment of Western Pacific leatherback turtles (Dermochelys coriacea) foraging off the coast of California, 2005-2007.

PubMed

Harris, Heather S; Benson, Scott R; Gilardi, Kirsten V; Poppenga, Robert H; Work, Thierry M; Dutton, Peter H; Mazet, Jonna A K

2011-04-01

Leatherback turtles (Dermochelys coriacea) are critically endangered, primarily threatened by the overharvesting of eggs, fisheries entanglement, and coastal development. The Pacific leatherback population has experienced a catastrophic decline over the past two decades. Leatherbacks foraging off the coast of California are part of a distinct Western Pacific breeding stock that nests on beaches in Indonesia, Papua New Guinea, and the Solomon Islands. Although it has been proposed that the rapid decline of Pacific leatherback turtles is due to increased adult mortality, little is known about the health of this population. Health assessments in leatherbacks have examined females on nesting beaches, which provides valuable biological information, but might have limited applicability to the population as a whole. During September 2005 and 2007, we conducted physical examinations on 19 foraging Pacific leatherback turtles and measured normal physiologic parameters, baseline hematologic and plasma biochemistry values, and exposure to heavy metals (cadmium, lead, and mercury), organochlorine contaminants, and domoic acid. We compared hematologic values of foraging Pacific leatherbacks with their nesting counterparts in Papua New Guinea (n=11) and with other nesting populations in the Eastern Pacific in Costa Rica (n=8) and in the Atlantic in St. Croix (n=12). This study provides the most comprehensive assessment to date of the health status of leatherbacks in the Pacific. We found significant differences in blood values between foraging and nesting leatherbacks, which suggests that health assessment studies conducted only on nesting females might not accurately represent the whole population. The establishment of baseline physiologic data and blood values for healthy foraging leatherback turtles, including males, provides valuable data for long-term health monitoring and comparative studies of this endangered population.

Comparative health assessment of western Pacific leatherback turtles (Dermochelys coriacea) foraging off the coast of California, 2005-2007

USGS Publications Warehouse

Harris, Heather S.; Benson, Scott R.; Gilardi, Kirsten V.; Poppenga, Robert H.; Work, Thierry M.; Dutton, Peter H.; Mazet, Jonna A.K.

2011-01-01

Leatherback turtles (Dermochelys coriacea) are critically endangered, primarily threatened by the overharvesting of eggs, fisheries entanglement, and coastal development. The Pacific leatherback population has experienced a catastrophic decline over the past two decades. Leatherbacks foraging off the coast of California are part of a distinct Western Pacific breeding stock that nests on beaches in Indonesia, Papua New Guinea, and the Solomon Islands. Although it has been proposed that the rapid decline of Pacific leatherback turtles is due to increased adult mortality, little is known about the health of this population. Health assessments in leatherbacks have examined females on nesting beaches, which provides valuable biological information, but might have limited applicability to the population as a whole. During September 2005 and 2007, we conducted physical examinations on 19 foraging Pacific leatherback turtles and measured normal physiologic parameters, baseline hematologic and plasma biochemistry values, and exposure to heavy metals (cadmium, lead, and mercury), organochlorine contaminants, and domoic acid. We compared hematologic values of foraging Pacific leatherbacks with their nesting counterparts in Papua New Guinea (n=11) and with other nesting populations in the Eastern Pacific in Costa Rica (n=8) and in the Atlantic in St. Croix (n=12). This study provides the most comprehensive assessment to date of the health status of leatherbacks in the Pacific. We found significant differences in blood values between foraging and nesting leatherbacks, which suggests that health assessment studies conducted only on nesting females might not accurately represent the whole population. The establishment of baseline physiologic data and blood values for healthy foraging leatherback turtles, including males, provides valuable data for long-term health monitoring and comparative studies of this endangered population.

The Climate-Population Nexus in the East African Horn: Emerging Degradation Trends in Rangeland and Pastoral Livelihood Zones

NASA Astrophysics Data System (ADS)

Pricope, N. G.; Husak, G. J.; Funk, C. C.; Lopez-Carr, D.

2014-12-01

Increasing climate variability and extreme weather conditions along with declining trends in both rainfall and temperature represent major risk factors affecting agricultural production and food security in many regions of the world. We identify regions where significant rainfall decrease from 1979-2011 over the entire continent of Africa couples with significant human population density increase. The rangelands of Ethiopia, Kenya, and Somalia in the East African Horn remain one of the world's most food insecure regions, yet have significantly increasing human populations predominantly dependent on pastoralist and agro-pastoralist livelihoods. Vegetation in this region is characterized by a variable mosaic of land covers, generally dominated by grasslands necessary for agro-pastoralism, interspersed by woody vegetation. Recent assessments indicate that widespread degradation is occurring, adversely impacting fragile ecosystems and human livelihoods. Using two underutilized MODIS products, we observe significant changes in vegetation patterns and productivity over the last decade all across the East African Horn. We observe significant vegetation browning trends in areas experiencing drying precipitation trends in addition to increasing population pressures. We also found that the drying precipitation trends only partially statistically explain the vegetation browning trends, further indicating that other factors such as population pressures and land use changes are responsible for the observed declining vegetation health. Furthermore, we show that the general vegetation browning trends persist even during years with normal rainfall conditions such as 2012, indicating potential long-term degradation of rangelands on which approximately 10 million people depend. These findings have serious implications for current and future regional food security monitoring and forecasting as well as for mitigation and adaptation strategies in a region where population is expected to continue increasing against a backdrop of drying climate trends.

Trends in Otitis Media and Myringotomy With Tube Placement Among American Indian and Alaska Native Children and the US General Population of Children After Introduction of the 13-valent Pneumococcal Conjugate Vaccine.

PubMed

Singleton, Rosalyn; Seeman, Sara; Grinnell, Margaret; Bulkow, Lisa; Kokesh, John; Emmett, Susan; Holve, Stephen; McCollum, Jeffrey; Hennessy, Thomas

2018-01-01

American Indian/Alaska Native (AI/AN) children have experienced higher otitis media (OM) outpatient visit rates than other US children. To understand recent trends, we evaluated AI/AN OM rates before and after 13-valent pneumococcal conjugate vaccine introduction. We analyzed outpatient visits listing OM as a diagnosis among AI/AN children <5 years of age from the Indian Health Service National Patient Information Reporting System for 2010-2013. OM outpatient visits for the general US child population <5 years of age were analyzed using the National Ambulatory Medical Care and National Hospital Ambulatory Care Surveys for 2010-2011. The 2010-2011 OM-associated outpatient visit rate for AI/AN children (63.5 per 100/year) was similar to 2010-2011 rate for same-age children in the general US population (62.8) and decreased from the 2003 to 2005 AI/AN rate (91.4). Further decline in AI/AN OM visit rates was seen for 2010-2011 to 2012-2013 (P < 0.0001). The AI/AN infant OM visit rate (130.5) was 1.6-fold higher than the US infant population. For 2010-2011, the highest AI/AN OM visit rate for <5 year olds was from Alaska (135.0). AI/AN <5-year-old OM visits declined by one third from 2003-2005 to 2010-2011 to a rate similar to the US general population <5 years. However, the AI/AN infant OM rate remained higher than the US infant population. The highest AI/AN <5-year-old OM rate occurred in Alaska.

Drought and cooler temperatures are associated with higher nest survival in Mountain Plovers

USGS Publications Warehouse

Dreitz, V.J.; Conrey, R.Y.; Skagen, S.K.

2012-01-01

Native grasslands have been altered to a greater extent than any other biome in North America. The habitats and resources needed to support breeding performance of grassland birds endemic to prairie ecosystems are currently threatened by land management practices and impending climate change. Climate models for the Great Plains prairie region predict a future of hotter and drier summers with strong multiyear droughts and more frequent and severe precipitation events. We examined how fluctuations in weather conditions in eastern Colorado influenced nest survival of an avian species that has experienced recent population declines, the Mountain Plover (Charadrius montanus). Nest survival averaged 27.2% over a 7-yr period (n = 936 nests) and declined as the breeding season progressed. Nest survival was favored by dry conditions and cooler temperatures. Projected changes in regional precipitation patterns will likely influence nest survival, with positive influences of predicted declines in summer rainfall yet negative effects of more intense rain events. The interplay of climate change and land use practices within prairie ecosystems may result in Mountain Plovers shifting their distribution, changing local abundance, and adjusting fecundity to adapt to their changing environment.

Taxonomic and geographic patterns of decline for threatened and endangered species in the United States.

PubMed

Leidner, Allison K; Neel, Maile C

2011-08-01

Species listed under the U.S. Endangered Species Act (i.e., listed species) have declined to the point that the probability of their extinction is high. The decline of these species, however, may manifest itself in different ways, including reductions in geographic range, number of populations, or overall abundance. Understanding the pattern of decline can help managers assess extinction probability and define recovery objectives. Although quantitative data on changes in geographic range, number of populations, and abundance usually do not exist for listed species, more often qualitative data can be obtained. We used qualitative data in recovery plans for federally listed species to determine whether each listed species declined in range size, number of populations, or abundance relative to historical levels. We calculated the proportion of listed species in each state (or equivalent) that declined in each of those ways. Nearly all listed species declined in abundance, and range size or number of populations declined in approximately 80% of species for which those data were available. Patterns of decline, however, differed taxonomically and geographically. Declines in range were more common among vertebrates than plants, whereas population extirpations were more common among plants. Invertebrates had high incidence of range and population declines. Narrowly distributed plants and invertebrates may be subject to acute threats that may result in population extirpations, whereas vertebrates may be affected by chronic threats that reduce the extent and size of populations. Additionally, in the eastern United States and U.S. coastal areas, where the level of land conversion is high, a greater percentage of species' ranges declined and more populations were extirpated than in other areas. Species in the Southwest, especially plants, had fewer range and population declines than other areas. Such relations may help in the selection of species' recovery criteria. © 2011 Society for Conservation Biology.

Development of 13 microsatellites for Gunnison Sage-grouse (Centrocercus minimus) using next-generation shotgun sequencing and their utility in Greater Sage-grouse (Centrocercus urophasianus)

USGS Publications Warehouse

Fike, Jennifer A.; Oyler-McCance, Sara J.; Zimmerman, Shawna J; Castoe, Todd A.

2015-01-01

Gunnison Sage-grouse are an obligate sagebrush species that has experienced significant population declines and has been proposed for listing under the U.S. Endangered Species Act. In order to examine levels of connectivity among Gunnison Sage-grouse leks, we identified 13 novel microsatellite loci though next-generation shotgun sequencing, and tested them on the closely related Greater Sage-grouse. The number of alleles per locus ranged from 2 to 12. No loci were found to be linked, although 2 loci revealed significant departures from Hardy–Weinberg equilibrium or evidence of null alleles. While these microsatellites were designed for Gunnison Sage-grouse, they also work well for Greater Sage-grouse and could be used for numerous genetic questions including landscape and population genetics.

Is income inequality a determinant of population health? Part 2. U.S. National and regional trends in income inequality and age- and cause-specific mortality.

PubMed

Lynch, John; Smith, George Davey; Harper, Sam; Hillemeier, Marianne

2004-01-01

This article describes U.S. income inequality and 100-year national and 30-year regional trends in age- and cause-specific mortality. There is little congruence between national trends in income inequality and age- or cause-specific mortality except perhaps for suicide and homicide. The variable trends in some causes of mortality may be associated regionally with income inequality. However, between 1978 and 2000 those regions experiencing the largest increases in income inequality had the largest declines in mortality (r= 0.81, p < 0.001). Understanding the social determinants of population health requires appreciating how broad indicators of social and economic conditions are related, at different times and places, to the levels and social distribution of major risk factors for particular health outcomes.

Migrants, healthy worker effect, and mortality trends in the Gulf Cooperation Council countries.

PubMed

Chaabna, Karima; Cheema, Sohaila; Mamtani, Ravinder

2017-01-01

The Gulf Cooperation Council (GCC) countries namely, Bahrain, Kuwait, Oman, Qatar, United Arab Emirates (UAE), and Saudi Arabia, have experienced unique demographic changes. The major population growth contributor in these countries is young migrants, which has led to a shift in the population age pyramid. Migrants constitute the vast proportion of GCC countries' population reaching >80% in Qatar and UAE. Using Global Burden of Disease Study 2015 (GBD 2015) and United Nations data, for the GCC countries, we assessed the association between age-standardized mortality and population size trends with linear and polynomial regressions. In 1990-2015, all-cause age-standardized mortality was inversely proportional to national population size (p-values: 0.0001-0.0457). In Bahrain, Qatar, Oman, and Saudi Arabia, the highest annual decrease in mortality was observed when the annual population growth was the highest. In Qatar, all-cause age-specific mortality was inversely proportional to age-specific population size. This association was statistically significant among the 5-14 and 15-49 age groups, which have the largest population size. Cause-specific age-standardized mortality was also inversely proportional to population size. This association was statistically significant for half of the GBD 2015-defined causes of death such as "cirrhosis and other chronic liver diseases" and "HIV/AIDS and tuberculosis". Remarkably, incoming migrants to Qatar have to be negative for HIV, hepatitis B and C, and tuberculosis. These results show that decline in mortality can be partly attributed to the increase in GCC countries' population suggesting a healthy migrant effect that influences mortality rates. Consequently, benefits of health interventions and healthcare improvement are likely to be exaggerated in such countries hosting a substantial proportion of migrants compared with countries where migration is low. Researchers and policymakers should be cautious to not exclusively attribute decline in mortality within the GCC countries as a result of the positive effects of health interventions or healthcare improvement.

Migrants, healthy worker effect, and mortality trends in the Gulf Cooperation Council countries

PubMed Central

Cheema, Sohaila; Mamtani, Ravinder

2017-01-01

The Gulf Cooperation Council (GCC) countries namely, Bahrain, Kuwait, Oman, Qatar, United Arab Emirates (UAE), and Saudi Arabia, have experienced unique demographic changes. The major population growth contributor in these countries is young migrants, which has led to a shift in the population age pyramid. Migrants constitute the vast proportion of GCC countries’ population reaching >80% in Qatar and UAE. Using Global Burden of Disease Study 2015 (GBD 2015) and United Nations data, for the GCC countries, we assessed the association between age-standardized mortality and population size trends with linear and polynomial regressions. In 1990–2015, all-cause age-standardized mortality was inversely proportional to national population size (p-values: 0.0001–0.0457). In Bahrain, Qatar, Oman, and Saudi Arabia, the highest annual decrease in mortality was observed when the annual population growth was the highest. In Qatar, all-cause age-specific mortality was inversely proportional to age-specific population size. This association was statistically significant among the 5–14 and 15–49 age groups, which have the largest population size. Cause-specific age-standardized mortality was also inversely proportional to population size. This association was statistically significant for half of the GBD 2015-defined causes of death such as “cirrhosis and other chronic liver diseases” and “HIV/AIDS and tuberculosis”. Remarkably, incoming migrants to Qatar have to be negative for HIV, hepatitis B and C, and tuberculosis. These results show that decline in mortality can be partly attributed to the increase in GCC countries’ population suggesting a healthy migrant effect that influences mortality rates. Consequently, benefits of health interventions and healthcare improvement are likely to be exaggerated in such countries hosting a substantial proportion of migrants compared with countries where migration is low. Researchers and policymakers should be cautious to not exclusively attribute decline in mortality within the GCC countries as a result of the positive effects of health interventions or healthcare improvement. PMID:28632794

Future healthy life expectancy among older adults in the US: a forecast based on cohort smoking and obesity history.

PubMed

Cao, Bochen

2016-01-01

In the past three decades, the elderly population in the United States experienced increase in life expectancy (LE) and disability-free life expectancy (LE(ND)), but decrease in life expectancy with disability (LE(D)). Smoking and obesity are two major risk factors that had negative impacts on these trends. While smoking prevalence continues to decline in recent decades, obesity prevalence has been growing and is currently at a high level. This study aims to forecast the healthy life expectancy for older adults aged 55 to 85 in the US from 2011 to 2040, in relation to their smoking and obesity history. First, population-level mortality data from the Human Mortality Database (HMD) and individual-level disability data from the US National Health Interview Survey (NHIS) were used to estimate the transition rates between different health states from 1982 to 2010, using a multi-state life table (MSLT) model. Second, the estimated transition rates were fitted and projected up to 2040, using a modified Lee-Carter model that incorporates cohort smoking and obesity history from NHIS. Mortality and morbidity for both sexes will continue to decline in the next decades. Relative to 2010, men are expected to have 3.2 years gain in LE(ND) and 0.8 years loss in LE(D). For women, there will be 1.8 years gain in LE(ND) and 0.8 years loss in LE(D). By 2040, men and women are expected to spend respectively 80 % and 75 % of their remaining life expectancy between 55 and 85 disability-free. Smoking and obesity have independent negative impacts on both the survival and disability of the US older population in the coming decades, and are responsible for the present and future gender disparity in mortality and morbidity. Overall, the US older population is expected to enjoy sustained health improvements and compression of disability, largely due to decline in smoking.

Response of pigeon guillemots to variable abundance of high-lipid and low-lipid prey

USGS Publications Warehouse

Litzow, Michael A.; Piatt, John F.; Prichard, A.K.; Roby, D.D.

2002-01-01

Populations of the pigeon guillemot (Cepphus columba) and other piscivores have been in decline for several decades in the Gulf of Alaska and Bering Sea, and a decline in abundance of lipid-rich schooling fishes is hypothesized as the major cause. We tested this hypothesis by studying the breeding biology of pigeon guillemots during 1995-1999 while simultaneously measuring prey abundance with beach seines and bottom trawls. Our study area (Kachemak Bay, Alaska) comprises two oceanographically distinct areas. Populations of a lipid-rich schooling fish, Pacific sand lance (Ammodytes hexapterus), were higher in the warmer Inner Bay than in the colder Outer Bay, and sand lance abundance was higher during warm years. Populations of low-lipid content demersal fishes were similar between areas. Chick survival to age 15 days was 47% higher in the Inner Bay (high-lipid diet) than in the Outer Bay (low-lipid diet), and estimated reproductive success (chicks fledged nest-1) was 62% higher in the Inner Bay than in the Outer Bay. Chick provisioning rate (kJ chick-1 h-1) increased with the proportion of sand lance in the diet (r2=0.21), as did growth rate (g day-1) of younger (beta) chicks in two-chick broods (r2=0.14). Pigeon guillemots in the Inner Bay switched to demersal prey during years of below-average sand lance abundance, and these birds reacted to 38-fold interannual changes in sand lance abundance with reductions in beta chick growth rates, with no decline in beta chick survival. In contrast, the proportion of nests experiencing brood reduction in the Outer Bay (demersal diet) increased >300% during years of below-average demersal abundance, although demersal fish abundance varied only 4-fold among years. Our results support the hypothesis that recovery of pigeon guillemot populations from the effects of the Exxon Valdez oil spill is limited by availability of lipid-rich prey.

Changes in land use as a possible factor in Mourning Dove population decline in Central Utah

USGS Publications Warehouse

Ostrand, William D.; Meyers, P.M.; Bissonette, J.A.; Conover, M.R.

1998-01-01

Mourning Dove (Zenaida macroura) population indices for the western United States have declined significantly since 1966. Based on data collected in 1951-1952, in Fillmore, Utah, we examined whether there had been a local decline in the dove population index since the original data were collected. We then determined whether habitat had been altered, identified which foraging habitats doves preferred, and assessed whether changes in land use could be responsible, in part, for a decline in the local population index. We found that dove population indices declined 72% and 82% from 1952-1992 and 1952-1993, respectively. The most dramatic change in habitat was an 82% decline in land devoted to dry land winter wheat production and a decline in livestock feed pens. Doves foraged primarily in harvested wheat fields, feed pens, and weedy patches. We hypothesize that a decrease in wheat availability during the spring and the consolidation of the livestock industry have contributed to a population decline of Mourning Doves in central Utah.

Declining scaup populations: A retrospective analysis of long-term population and harvest survey data

USGS Publications Warehouse

Afton, A.D.; Anderson, M.G.

2001-01-01

We examined long-term databases concerning population status of scaup (lesser [Aythya affinis] and greater scaup [A. marila] combined) and harvest statistics of lesser scaup to identify factors potentially limiting population growth. Specifically, we explored evidence for and against the general hypotheses that scaup populations have declined in association with declining recruitment and/or female survival. We examined geographic heterogeneity in scaup demographic patterns that could yield evidence about potential limiting factors. Several biases exist in survey methodology used to estimate scaup populations and harvest statistics; however, none of these biases likely accounted for our major findings that (1) the continental scaup breeding population has declined over the last 20 years, with widespread and consistent declines within surveyed areas of the Canadian western boreal forest where most lesser scaup breed; (2) sex ratios of lesser scaup in the U.S. harvest have increased (more males now relative to females); and (3) age ratios of lesser scaup in the U.S. harvest have declined (fewer immatures now relative to adults), especially in the midcontinent region. We interpreted these major findings as evidence that (1) recruitment of lesser scaup has declined over the last 20 years, particularly in the Canadian western boreal forest; and (2) survival of female lesser scaup has declined relative to that of males. We found little evidence that harvest was associated with the scaup population decline. Our findings underscore the need for both improvements and changes to population survey procedures and new research to discriminate among various hypotheses explaining the recent scaup population decline.

Constituents' Perceptions in Northen California Conference: Determining What Aspects of Seventh-Day Adventist Education Are Important

ERIC Educational Resources Information Center

von Pohle, Berit

2013-01-01

Schools in the Seventh-day Adventist (SDA) school system have experienced an enrollment decline of more than 25% over the past 30 years. A wide range of anecdotal explanations for this decline are shared by SDA members of the constituency as well as many views about ways to reverse the decline. There is little empirical data, however, to provide…

Estimating the effects of the Balanced Budget act of 1997 on the home health care use of the dually eligible: a natural experiments approach.

PubMed

Williamson, James M

2013-01-01

This research examines the use of home health agency services used by older adults after the implementation of changes to Medicare's payment scheme mandated by the Balanced Budget Act (BBA) of 1997. The objective of this study is to identify differential effects the BBA may have had on home health service use between dually eligible and Medicare-only beneficiaries. The results of this study suggest that although dually eligible and Medicare-only beneficiaries experienced a substantial decline in home health service use, the dually eligible had a relatively larger decline. Following the BBA, the dually eligible had more office-based physician visits but fewer inpatient hospital days, relative to the Medicare-only population. Finally, the author estimates cost savings to Medicare due to the BBA to be $1 billion in the 2 years following the legislation, whereas Medicaid programs shouldered a larger percentage of the home health service bill.

The effects of workplace health promotion on absenteeism and employment costs in a large industrial population.

PubMed Central

Bertera, R L

1990-01-01

We evaluated the impact of a comprehensive workplace health promotion program on absences among full-time employees in a large, multi-location, diversified industrial company. A pretest-posttest control group design was used to study 41 intervention sites and 19 control sites with 29,315 and 14,573 hourly employees, respectively. Blue-collar employees at intervention sites experienced an 14.0 percent decline in disability days over two years versus a 5.8 percent decline at control sites. This resulted in a net difference of 11,726 fewer disability days over two years at program sites compared with non-program sites. Savings due to lower disability costs at intervention sites offset program costs in the first year, and provided a return of $2.05 for every dollar invested in the program by the end of the second year. These results suggest that comprehensive workplace health promotion programs can reduce disability days among blue collar employees and provide a good return on investment. PMID:2382748

Growth, survival, longevity, and population size of the Big Mouth Cave salamander (Gyrinophilus palleucus necturoides) from the type locality in Grundy County, Tennessee, USA

USGS Publications Warehouse

Niemiller, Matthew L.; Glorioso, Brad M.; Fenolio, Dante B.; Reynolds, R. Graham; Taylor, Steven J.; Miller, Brian T.

2016-01-01

Salamander species that live entirely in subterranean habitats have evolved adaptations that allow them to cope with perpetual darkness and limited energy resources. We conducted a 26-month mark–recapture study to better understand the individual growth and demography of a population of the Big Mouth Cave Salamander (Gyrinophilus palleucus necturoides). We employed a growth model to estimate growth rates, age at sexual maturity, and longevity, and an open population model to estimate population size, density, detectability, and survival rates. Furthermore, we examined cover use and evidence of potential predation. Individuals probably reach sexual maturity in 3–5 years and live at least nine years. Survival rates were generally high (>75%) but declined during the study. More than 30% of captured salamanders had regenerating tails or tail damage, which presumably represent predation attempts by conspecifics or crayfishes. Most salamanders (>90%) were found under cover (e.g., rocks, trash, decaying plant material). Based on 11 surveys during the study, population size estimates ranged from 21 to 104 individuals in the ca. 710 m2 study area. Previous surveys indicated that this population experienced a significant decline from the early 1970s through the 1990s, perhaps related to silvicultural and agricultural practices. However, our data suggest that this population has either recovered or stabilized during the past 20 years. Differences in relative abundance between early surveys and our survey could be associated with differences in survey methods or sampling conditions rather than an increase in population size. Regardless, our study demonstrates that this population is larger than previously thought and is in no immediate risk of extirpation, though it does appear to exhibit higher rates of predation than expected for a species believed to be an apex predator of subterranean food webs.

Evaluation of the Volvo intelligent vehicle initiative field operational test, version 1.3

DOT National Transportation Integrated Search

1998-08-01

While all law enforcement agencies seem to be dealing with declining resources and increasing pressures to combat crime, urban police departments seem to be experiencing the greatest difficulty. It is in these agencies where the decline in crash repo...

Increased Mortality Risk in Older Adults with Persistently Low or Declining Feelings of Usefulness to Others

PubMed Central

Gruenewald, Tara L.; Karlamangla, Arun S.; Greendale, Gail A.; Singer, Burton H.; Seeman, Teresa E.

2009-01-01

Objectives To determine if persistently low or declining feelings of usefulness to others in later life predicts increased mortality hazard in older adults. Methods Data on change in perceptions of usefulness, health, behavioral and psychosocial covariate factors, and mortality originate from the MacArthur Study of Successful Aging, a prospective study of 1,189 older adults (age 70–79 years). Results Older adults with persistently low feelings of usefulness or who experienced a decline to low feelings of usefulness over the first 3-years of the study experienced a greater hazard of mortality (sociodemographic adjusted HR = 1.75 (95% CI = 1.22 to 2.51)) over a subsequent 9-year follow-up as compared to older adults with persistently high feelings of usefulness. Discussion Older adults with persistently low perceived usefulness or feelings of usefulness that decline to a low level may be a vulnerable group with increased risk for poor health outcomes in later life. PMID:19104034

Disease introduction is associated with a phase transition in bighorn sheep demographics

PubMed Central

Manlove, Kezia; Cassirer, E. Frances; Cross, Paul Chafee; Plowright, Raina K.; Hudson, Peter J.

2016-01-01

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population-level and 18 years of individual-level monitoring across 12 populations. While populations generally increased (lambda =1.11) prior to disease introduction, most of these same populations experienced an abrupt change in trajectory at the time of disease invasion, usually followed by stagnant-to-declining growth rates (lambda = 0.98) over the next twenty years. Disease-induced juvenile mortality imposed strong constraints on population growth that were not observed prior to disease introduction, even as adult survival returned to pre-invasion levels. Simulations suggested that models including persistent disease-induced mortality in juveniles qualitatively matched observed population trajectories, whereas models that only incorporated all-age disease events did not. We use these results to argue that pathogen persistence may pose a lasting, but under-recognized, threat to host populations, particularly in cases where clinical disease manifests primarily in juveniles. PMID:27859120

Human mining activity across the ages determines the genetic structure of modern brown trout (Salmo trutta L.) populations

PubMed Central

Paris, Josephine R; King, R Andrew; Stevens, Jamie R

2015-01-01

Humans have exploited the earth's metal resources for thousands of years leaving behind a legacy of toxic metal contamination and poor water quality. The southwest of England provides a well-defined example, with a rich history of metal mining dating to the Bronze Age. Mine water washout continues to negatively impact water quality across the region where brown trout (Salmo trutta L.) populations exist in both metal-impacted and relatively clean rivers. We used microsatellites to assess the genetic impact of mining practices on trout populations in this region. Our analyses demonstrated that metal-impacted trout populations have low genetic diversity and have experienced severe population declines. Metal-river trout populations are genetically distinct from clean-river populations, and also from one another, despite being geographically proximate. Using approximate Bayesian computation (ABC), we dated the origins of these genetic patterns to periods of intensive mining activity. The historical split of contemporary metal-impacted populations from clean-river fish dated to the Medieval period. Moreover, we observed two distinct genetic populations of trout within a single catchment and dated their divergence to the Industrial Revolution. Our investigation thus provides an evaluation of contemporary population genetics in showing how human-altered landscapes can change the genetic makeup of a species. PMID:26136823

Disease introduction is associated with a phase transition in bighorn sheep demographics

USGS Publications Warehouse

Manlove, Kezia; Cassirer, E. Frances; Cross, Paul C.; Plowright, Raina K.; Hudson, Peter J.

2016-01-01

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population-level and 18 years of individual-level monitoring across 12 populations. While populations generally increased (λ = 1.11) prior to disease introduction, most of these same populations experienced an abrupt change in trajectory at the time of disease invasion, usually followed by stagnant-to-declining growth rates (λ = 0.98) over the next 20 years. Disease-induced juvenile mortality imposed strong constraints on population growth that were not observed prior to disease introduction, even as adult survival returned to pre-invasion levels. Simulations suggested that models including persistent disease-induced mortality in juveniles qualitatively matched observed population trajectories, whereas models that only incorporated all-age disease events did not. We use these results to argue that pathogen persistence may pose a lasting, but under-recognized, threat to host populations, particularly in cases where clinical disease manifests primarily in juveniles.

Implications of Zostera noltii recolonization on Hydrobia ulvae population structure success.

PubMed

Grilo, T F; Cardoso, P G; Pardal, M A

2012-02-01

Over 1990-1998, the Mondego estuary, Portugal, experienced profound modifications due to eutrophication, culminating in the disappearance and replacement of Zostera noltii by opportunistic macroalgae in the inner most disturbed areas. A decade after restoration measures implementation, Z. noltii started to gradually recolonize the inner parts, following 20 years of absence. This work explores the factors underlying successful Z. noltii recolonization and its subsequent implications on a mud snail Hydrobia ulvae population. During the macroalgal bloom, highest values in H. ulvae abundance, biomass and production were recorded, strongly declining afterwards. Three recovery attempts characterized the post-restoration phase, with considerably increases in H. ulvae abundance, biomass and production since Z. noltii reappearance. The seagrass provided long-term protection and abundant food resources for reproductive adults, contrarily to the ephemeral macroalgae. Through time, large size individuals increased, becoming the population more stable, structured and similar to the one inhabiting the "original"Z. noltii meadows. Copyright © 2011 Elsevier Ltd. All rights reserved.

High fitness costs of climate change-induced camouflage mismatch.

PubMed

Zimova, Marketa; Mills, L Scott; Nowak, J Joshua

2016-03-01

Anthropogenic climate change has created myriad stressors that threaten to cause local extinctions if wild populations fail to adapt to novel conditions. We studied individual and population-level fitness costs of a climate change-induced stressor: camouflage mismatch in seasonally colour molting species confronting decreasing snow cover duration. Based on field measurements of radiocollared snowshoe hares, we found strong selection on coat colour molt phenology, such that animals mismatched with the colour of their background experienced weekly survival decreases up to 7%. In the absence of adaptive response, we show that these mortality costs would result in strong population-level declines by the end of the century. However, natural selection acting on wide individual variation in molt phenology might enable evolutionary adaptation to camouflage mismatch. We conclude that evolutionary rescue will be critical for hares and other colour molting species to keep up with climate change. © 2016 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Democracy in Crisis?

ERIC Educational Resources Information Center

O'Neill, Brenda

2006-01-01

This article discusses the state of Canadian democracy. Although calling Canadian democracy as something to be in a crisis is still debatable, the author expresses worry over the declining turnout levels in recent elections. Canada--along with a number of other liberal democracies--has experienced a significant and consistent decline in election…

Colonies of Bumble Bees (Bombus impatiens) Produce Fewer Workers, Less Bee Biomass, and Have Smaller Mother Queens Following Fungicide Exposure.

PubMed

Bernauer, Olivia M; Gaines-Day, Hannah R; Steffan, Shawn A

2015-06-01

Bees provide vital pollination services to the majority of flowering plants in both natural and agricultural systems. Unfortunately, both native and managed bee populations are experiencing declines, threatening the persistence of these plants and crops. Agricultural chemicals are one possible culprit contributing to bee declines. Even fungicides, generally considered safe for bees, have been shown to disrupt honey bee development and impair bumble bee behavior. Little is known, however, how fungicides may affect bumble bee colony growth. We conducted a controlled cage study to determine the effects of fungicide exposure on colonies of a native bumble bee species (Bombus impatiens). Colonies of B. impatiens were exposed to flowers treated with field-relevant levels of the fungicide chlorothalonil over the course of one month. Colony success was assessed by the number and biomass of larvae, pupae, and adult bumble bees. Bumble bee colonies exposed to fungicide produced fewer workers, lower total bee biomass, and had lighter mother queens than control colonies. Our results suggest that fungicides negatively affect the colony success of a native bumble bee species and that the use of fungicides during bloom has the potential to severely impact the success of native bumble bee populations foraging in agroecosystems.

A reversal of fortunes: climate change ‘winners’ and ‘losers’ in Antarctic Peninsula penguins

PubMed Central

Clucas, Gemma V.; Dunn, Michael J.; Dyke, Gareth; Emslie, Steven D.; Levy, Hila; Naveen, Ron; Polito, Michael J.; Pybus, Oliver G.; Rogers, Alex D.; Hart, Tom

2014-01-01

Climate change is a major threat to global biodiversity. Antarctic ecosystems are no exception. Investigating past species responses to climatic events can distinguish natural from anthropogenic impacts. Climate change produces ‘winners’, species that benefit from these events and ‘losers’, species that decline or become extinct. Using molecular techniques, we assess the demographic history and population structure of Pygoscelis penguins in the Scotia Arc related to climate warming after the Last Glacial Maximum (LGM). All three pygoscelid penguins responded positively to post-LGM warming by expanding from glacial refugia, with those breeding at higher latitudes expanding most. Northern (Pygoscelis papua papua) and Southern (Pygoscelis papua ellsworthii) gentoo sub-species likely diverged during the LGM. Comparing historical responses with the literature on current trends, we see Southern gentoo penguins are responding to current warming as they did during post-LGM warming, expanding their range southwards. Conversely, Adélie and chinstrap penguins are experiencing a ‘reversal of fortunes’ as they are now declining in the Antarctic Peninsula, the opposite of their response to post-LGM warming. This suggests current climate warming has decoupled historic population responses in the Antarctic Peninsula, favoring generalist gentoo penguins as climate change ‘winners’, while Adélie and chinstrap penguins have become climate change ‘losers’. PMID:24865774

A reversal of fortunes: climate change 'winners' and 'losers' in Antarctic Peninsula penguins.

PubMed

Clucas, Gemma V; Dunn, Michael J; Dyke, Gareth; Emslie, Steven D; Naveen, Ron; Polito, Michael J; Pybus, Oliver G; Rogers, Alex D; Hart, Tom

2014-06-12

Climate change is a major threat to global biodiversity. Antarctic ecosystems are no exception. Investigating past species responses to climatic events can distinguish natural from anthropogenic impacts. Climate change produces 'winners', species that benefit from these events and 'losers', species that decline or become extinct. Using molecular techniques, we assess the demographic history and population structure of Pygoscelis penguins in the Scotia Arc related to climate warming after the Last Glacial Maximum (LGM). All three pygoscelid penguins responded positively to post-LGM warming by expanding from glacial refugia, with those breeding at higher latitudes expanding most. Northern (Pygoscelis papua papua) and Southern (Pygoscelis papua ellsworthii) gentoo sub-species likely diverged during the LGM. Comparing historical responses with the literature on current trends, we see Southern gentoo penguins are responding to current warming as they did during post-LGM warming, expanding their range southwards. Conversely, Adélie and chinstrap penguins are experiencing a 'reversal of fortunes' as they are now declining in the Antarctic Peninsula, the opposite of their response to post-LGM warming. This suggests current climate warming has decoupled historic population responses in the Antarctic Peninsula, favoring generalist gentoo penguins as climate change 'winners', while Adélie and chinstrap penguins have become climate change 'losers'.

The role of multiple stressor causes in declining amphibian populations: a wingspread workshop summary

USGS Publications Warehouse

Krest, S.K.; Linder, G.; Sparling, D.W.; Linder, Gregory L.; Krest, Sherry K.; Sparling, Donald W.; Little, Edward E.

2003-01-01

Numerous studies have documented the decline of amphibian populations over the past decade and no single factor has been the linked to these widespread declines. Determining the causes of declining amphibian populations worldwide has proven difficult because of the variety of anthropogenic and natural suspect agents. A Wingspread workshop, convened by The Society of Environmental Toxicology and Chemistry (SETAC), brought together individuals with expertise in the areas of amphibian biology, ecotoxicology, natural resource management, and environmental policy. This workshop had three objectives: 1) create a network for future discussions on multiple stressor causes of declines; 2) characterize and prioritize technical issues critical to the analysis of the decline problem; and 3) identify and develop resource management approaches to promote sustainable and healthy amphibian populations. The workshop proceedings will be summarized in a book entitled, 'Multiple Stressors and Declining Amphibian Populations: Evaluating Cause and Effect.' This paper summarizes the results of the workshop.

The role of multiple stressor causes in declining amphibian populations: A wingspread workshop summary

USGS Publications Warehouse

Krest, S.K.; Linder, G.; Sparling, D.W.; ,

2003-01-01

Numerous studies have documented the decline of amphibian populations over the past decade and no single factor has been the linked to these widespread declines. Determining the causes of declining amphibian populations worldwide has proven difficult because of the variety of anthropogenic and natural suspect agents. A Wingspread workshop, convened by The Society of Environmental Toxicology and Chemistry (SETAC), brought together individuals with expertise in the areas of amphibian biology, ecotoxicology, natural resource management, and environmental policy. This workshop had three objectives: 1) create a network for future discussions on multiple Stressor causes of declines; 2) characterize and prioritize technical issues critical to the analysis of the decline problem; and 3) identify and develop resource management approaches to promote sustainable and healthy amphibian populations. The workshop proceedings will be summarized in a book entitled, "Multiple Stressors and Declining Amphibian Populations: Evaluating Cause and Effect." This paper summarizes the results of the workshop.

Comparative phylogeography highlights the double-edged sword of climate change faced by arctic- and alpine-adapted mammals.

PubMed

Lanier, Hayley C; Gunderson, Aren M; Weksler, Marcelo; Fedorov, Vadim B; Olson, Link E

2015-01-01

Recent studies suggest that alpine and arctic organisms may have distinctly different phylogeographic histories from temperate or tropical taxa, with recent range contraction into interglacial refugia as opposed to post-glacial expansion out of refugia. We use a combination of phylogeographic inference, demographic reconstructions, and hierarchical Approximate Bayesian Computation to test for phylodemographic concordance among five species of alpine-adapted small mammals in eastern Beringia. These species (Collared Pikas, Hoary Marmots, Brown Lemmings, Arctic Ground Squirrels, and Singing Voles) vary in specificity to alpine and boreal-tundra habitat but share commonalities (e.g., cold tolerance and nunatak survival) that might result in concordant responses to Pleistocene glaciations. All five species contain a similar phylogeographic disjunction separating eastern and Beringian lineages, which we show to be the result of simultaneous divergence. Genetic diversity is similar within each haplogroup for each species, and there is no support for a post-Pleistocene population expansion in eastern lineages relative to those from Beringia. Bayesian skyline plots for four of the five species do not support Pleistocene population contraction. Brown Lemmings show evidence of late Quaternary demographic expansion without subsequent population decline. The Wrangell-St. Elias region of eastern Alaska appears to be an important zone of recent secondary contact for nearctic alpine mammals. Despite differences in natural history and ecology, similar phylogeographic histories are supported for all species, suggesting that these, and likely other, alpine- and arctic-adapted taxa are already experiencing population and/or range declines that are likely to synergistically accelerate in the face of rapid climate change. Climate change may therefore be acting as a double-edged sword that erodes genetic diversity within populations but promotes divergence and the generation of biodiversity.

Comparative Phylogeography Highlights the Double-Edged Sword of Climate Change Faced by Arctic- and Alpine-Adapted Mammals

PubMed Central

Lanier, Hayley C.; Gunderson, Aren M.; Weksler, Marcelo; Fedorov, Vadim B.; Olson, Link E.

2015-01-01

Recent studies suggest that alpine and arctic organisms may have distinctly different phylogeographic histories from temperate or tropical taxa, with recent range contraction into interglacial refugia as opposed to post-glacial expansion out of refugia. We use a combination of phylogeographic inference, demographic reconstructions, and hierarchical Approximate Bayesian Computation to test for phylodemographic concordance among five species of alpine-adapted small mammals in eastern Beringia. These species (Collared Pikas, Hoary Marmots, Brown Lemmings, Arctic Ground Squirrels, and Singing Voles) vary in specificity to alpine and boreal-tundra habitat but share commonalities (e.g., cold tolerance and nunatak survival) that might result in concordant responses to Pleistocene glaciations. All five species contain a similar phylogeographic disjunction separating eastern and Beringian lineages, which we show to be the result of simultaneous divergence. Genetic diversity is similar within each haplogroup for each species, and there is no support for a post-Pleistocene population expansion in eastern lineages relative to those from Beringia. Bayesian skyline plots for four of the five species do not support Pleistocene population contraction. Brown Lemmings show evidence of late Quaternary demographic expansion without subsequent population decline. The Wrangell-St. Elias region of eastern Alaska appears to be an important zone of recent secondary contact for nearctic alpine mammals. Despite differences in natural history and ecology, similar phylogeographic histories are supported for all species, suggesting that these, and likely other, alpine- and arctic-adapted taxa are already experiencing population and/or range declines that are likely to synergistically accelerate in the face of rapid climate change. Climate change may therefore be acting as a double-edged sword that erodes genetic diversity within populations but promotes divergence and the generation of biodiversity. PMID:25734275

Future scenarios of land change based on empirical data and demographic trends

USGS Publications Warehouse

Sleeter, Benjamin M.; Wilson, Tamara; Sharygin, Ethan; Sherba, Jason

2017-01-01

Changes in land use and land cover (LULC) have important and fundamental interactions with the global climate system. Top-down global scale projections of land use change have been an important component of climate change research; however, their utility at local to regional scales is often limited. The goal of this study was to develop an approach for projecting changes in LULC based on land use histories and demographic trends. We developed a set of stochastic, empirical-based projections of LULC change for the state of California, for the period 2001–2100. Land use histories and demographic trends were used to project a “business-as-usual” (BAU) scenario and three population growth scenarios. For the BAU scenario, we projected developed lands would more than double by 2100. When combined with cultivated areas, we projected a 28% increase in anthropogenic land use by 2100. As a result, natural lands were projected to decline at a rate of 139 km2 yr−1; grasslands experienced the largest net decline, followed by shrublands and forests. The amount of cultivated land was projected to decline by approximately 10%; however, the relatively modest change masked large shifts between annual and perennial crop types. Under the three population scenarios, developed lands were projected to increase 40–90% by 2100. Our results suggest that when compared to the BAU projection, scenarios based on demographic trends may underestimate future changes in LULC. Furthermore, regardless of scenario, the spatial pattern of LULC change was likely to have the greatest negative impacts on rangeland ecosystems.

Future Scenarios of Land Change Based on Empirical Data and Demographic Trends

NASA Astrophysics Data System (ADS)

Sleeter, Benjamin M.; Wilson, Tamara S.; Sharygin, Ethan; Sherba, Jason T.

2017-11-01

Changes in land use and land cover (LULC) have important and fundamental interactions with the global climate system. Top-down global scale projections of land use change have been an important component of climate change research; however, their utility at local to regional scales is often limited. The goal of this study was to develop an approach for projecting changes in LULC based on land use histories and demographic trends. We developed a set of stochastic, empirical-based projections of LULC change for the state of California, for the period 2001-2100. Land use histories and demographic trends were used to project a "business-as-usual" (BAU) scenario and three population growth scenarios. For the BAU scenario, we projected developed lands would more than double by 2100. When combined with cultivated areas, we projected a 28% increase in anthropogenic land use by 2100. As a result, natural lands were projected to decline at a rate of 139 km2 yr-1; grasslands experienced the largest net decline, followed by shrublands and forests. The amount of cultivated land was projected to decline by approximately 10%; however, the relatively modest change masked large shifts between annual and perennial crop types. Under the three population scenarios, developed lands were projected to increase 40-90% by 2100. Our results suggest that when compared to the BAU projection, scenarios based on demographic trends may underestimate future changes in LULC. Furthermore, regardless of scenario, the spatial pattern of LULC change was likely to have the greatest negative impacts on rangeland ecosystems.

Seasonal changes in physiological performance in wild Clarkia xantiana populations: Implications for the evolution of a compressed life cycle and self-fertilization.

PubMed

Dudley, Leah S; Hove, Alisa A; Emms, Simon K; Verhoeven, Amy S; Mazer, Susan J

2015-06-01

One explanation for the evolution of selfing, the drought escape hypothesis, proposes that self-fertilization may evolve under conditions of intensifying seasonal drought as part of a suite of traits that enable plants to accelerate the completion of their life cycle, thereby escaping late-season drought. Here, we test two fundamental assumptions of this hypothesis in Clarkia xantiana: (1) that a seasonal decline in precipitation causes an increase in drought stress and (2) that this results in changes in physiological performance, reflecting these deteriorating conditions. We examined seasonal and interannual variation in abiotic environmental conditions (estimated by ambient temperature, relative humidity, predawn leaf water potentials, and carbon isotope ratios) and physiological traits (photosynthesis, conductance, transpiration, instantaneous water-use efficiency, ascorbate peroxidase and glutathione reductase activities, quantum yield of photosystem II, PSII potential efficiency) in field populations of C. xantiana in 2009 and 2010. In both years, plants experienced intensifying drought across the growing season. Gas exchange rates decreased over the growing season and were lower in 2009 (a relatively dry year) than in 2010, suggesting that the temporal changes from early to late spring were directly linked to the deteriorating environmental conditions. Seasonal declines in transpiration rate may have increased survival by protecting plants from desiccation. Concomitant declines in photosynthetic rate likely reduced the availability of resources for seed production late in the season. Thus, the physiological patterns observed are consistent with the conditions required for the drought escape hypothesis. © 2015 Botanical Society of America, Inc.

Do observed levels of exploitation from consumption-oriented and trophy-oriented fisheries reduce relative stock densities of Muskellunge below target levels in northern Wisconsin?

USGS Publications Warehouse

Faust, Matthew D.; Hansen, Michael J.

2017-01-01

Muskellunge anglers desire to catch large fish, and release rates by recreational anglers often approach 100% (Isermann et al. 2011). Muskellunge are also a culturally significant fish for Chippewa tribes and support a subsistence spearing fishery in Wisconsin’s Ceded Territory (Erickson 2007). Although Muskellunge populations within the state’s Ceded Territory are exposed to both angling and spearing fishery exploitation, Faust and Hansen (2016) suggested that under certain conditions (e.g., high minimum length limits (MLL) and low spearing exploitation) Muskellunge fisheries with disparate motivations could coexist (i.e., sufficient numbers of large individuals remained despite harvest from consumptive fishery), but noted that larger declines in trophy Muskellunge abundance were predicted at lower MLLs (e.g., 102-cm). Fisheries managers with the Wisconsin Department of Natural Resources (WDNR) wished to further understand how specific relative stock densities (RSD), used by the WDNR to define and monitor trophy Muskellunge fisheries, are reduced at exploitation rates commonly experienced by populations in northern Wisconsin. Similarly, understanding how trophy Muskellunge abundance may have declined under the previous statewide MLL (i.e., 86-cm) at these levels of exploitation was also desired. Thus, our objectives were to 1) determine if observed levels of angling and spearing exploitation reduced predicted RSD indices below thresholds used by the WDNR to define trophy Muskellunge fisheries for three typical Muskellunge growth potentials in northern Wisconsin across a variety of MLLs; and 2) quantify how numbers of trophy Muskellunge declined under an 86-cm MLL at observed levels of exploitation.

Status review of the Marbled Murrelet (Brachyramphus marmoratus) in Alaska and British Columbia

USGS Publications Warehouse

Piatt, John F.; Kuletz, K.J.; Burger, A.E.; Hatch, Shyla A.; Friesen, Vicki L.; Birt, T.P.; Arimitsu, Mayumi L.; Drew, G.S.; Harding, A.M.A.; Bixler, K.S.

2007-01-01

The Marbled Murrelet (Brachyramphus marmoratus) is a small, diving seabird inhabiting inshore waters of the Northeastern Pacific Ocean. This species feeds on small, schooling fishes and zooplankton, and nests primarily on the moss-covered branches of large, old-growth conifers, and also, in some parts of its range, on the ground. We reviewed existing information on this species to evaluate its current status in the northern part of its range-Alaska (U.S.) and British Columbia (Canada). Within the southern part of its range (Washington, Oregon, and California, U.S.), the Marbled Murrelet was listed as a threatened species under the Endangered Species Act (ESA) in 1993, and the U.S. Fish and Wildlife Service (USFWS) needed information on the species throughout its range for ESA deliberations. We compiled published information on the conservation status, population biology, foraging ecology, population genetics, population status and trends, demography, marine and nesting habitat characteristics, threats, and ongoing conservation efforts for Marbled Murrelets in Alaska and British Columbia. We conducted a new genetic study using samples from a segment of the range that had not been included in previous studies (Washington, Oregon) and additional nuclear intron and microsatellite markers. We also analyzed available at-sea survey data from several locations for trend. To understand the reasonableness of the empirical trend data, we developed demographic models incorporating stochasticity to discern what population trends were possible by chance. The genetic studies substantially confirmed previous findings on population structure in the Marbled Murrelet. Our present work finds three populations: (1) one comprising birds in the central and western Aleutian Islands; (2) one comprising birds in central California; and (3) one comprising birds within the center of the range from the eastern Aleutians to northern California. Our knowledge of genetic structure within this central population is limited and it requires additional study. Compiling available abundance information, we estimated that in the recent past, Marbled Murrelets in Alaska numbered on the order of 1 million birds. We were unable to generate a similar estimate for historical population size in British Columbia. Using trend information from at-sea surveys spanning a wide geographic range in Alaska, murrelet numbers declined significantly at five of eight trend sites at annual rates of -5.4 to -12.7 percent since the early 1990s. Applying these rates of decline to the historical population estimate, the current murrelet population in Alaska is projected to be on the order of 270,000 birds. This represents an overall population decline of about 70 percent during the past 25 years. In British Columbia, available trend data indicate that murrelet populations there have experienced similar declines. We updated a recent (2002) population estimate for British Columbia, concluding that there are now between 54,000 and 92,000 murrelets in British Columbia. The rates of decline we observed are within, but at the high end of, a range of rates expected by chance. Given that declines were estimated for sites over essentially the entire northern range of the species, there is cause for concern about the species? status. In their marine habitats, Marbled Murrelets overlap with salmon (Oncorhynchus sp.) gillnetting operations in British Columbia and in Alaska (especially in Prince William Sound and Southeast Alaska), and annual bycatch mortality is likely in the low thousands per year, although bycatch rates are difficult to measure. The species? inshore distribution coincides with high levels of vessel traffic and makes them especially vulnerable to both chronic oil pollution and to catastrophic spills (e.g., the 1989 Exxon Valdez oil spill [EVOS] in south-central Alaska, which is estimated to have killed 12,000 to 15,000 murrelets). In their forested nesting habitats, Marbled Murrelets have lost about 15 percent of their suitable nesting habitat in Southeast Alaska, and 33 to 49 percent in British Columbia, from industrial-scale logging within the past half century. Increased predation also may be a threat to murrelet populations, related to fragmentation and edge effects from logging and development, and recent population increases observed for some important murrelet predators, including Bald Eagles (Haliaeetus leucocephalus), Common Ravens (Corvus corax), and Steller?s Jays (Cyanocitta stelleri). Nesting habitat losses cannot explain the declines observed in areas where industrial logging has not occurred on a large scale (e.g., Prince William Sound) or at all (Glacier Bay). The apparent change in population size and rates of decline reported for the Marbled Murrelet are large, and we therefore considered alternative explanations and precedents for changes of similar magnitude in other marine wildlife populations in the Northeastern Pacific Ocean. The declines are likely real, and related to combined and cumulative effects from climate-related changes in the marine ecosystem (most likely the 1977 regime shift) and human activities (logging, gillnet bycatch, oil pollution). Much uncertainty about the decline could be alleviated by continuing to repeat boat surveys in Prince William Sound and lower Cook Inlet, and by repeating the boat survey of Southeast Alaska that was conducted in 1994. This survey used a statistically sound design and covered the region that has been and likely remains the center of the species? abundance. Important questions remain to be addressed about methods for measuring population status and change, adult mortality (major sources, density dependence, seasonal concordance), and the movements of wintering populations.

Climate variability, human wildlife conflict and population dynamics of lions Panthera leo.

PubMed

Trinkel, Martina

2013-04-01

Large carnivores are threatened by habitat loss, declining prey populations and direct persecution. Pride dynamics of eight lion prides in the centre of the Etosha National Park, Namibia are described during a 16-year study. Since the beginning of the 1980s, the number of adult and subadult lions declined continuously to two third of its initial population size, and reached a new equilibrium in the 1990s. Pride sizes decreased from 6.3 adult females in 1989 to 2.8 lionesses in 1997. While the number of adult females declined continuously, the number of adult males, subadult females and subadult males remained constant over the years. A severe drought period, lasting for more than 20 years, led to declining prey populations inside the lions' territory. Besides declining prey populations, conflict with humans at the border of Etosha puts substantial pressure onto the lion population: 82% of all known lion mortalities were caused by humans, and most of these consisted of adult females (28%) and subadult males (29%). I postulate that the considerable decline in the lion population is a response to declining prey populations, and although the human predator conflict is severe, it does not seem to limit the size of Etosha's lion population.

Climate variability, human wildlife conflict and population dynamics of lions Panthera leo

NASA Astrophysics Data System (ADS)

Trinkel, Martina

2013-04-01

Large carnivores are threatened by habitat loss, declining prey populations and direct persecution. Pride dynamics of eight lion prides in the centre of the Etosha National Park, Namibia are described during a 16-year study. Since the beginning of the 1980s, the number of adult and subadult lions declined continuously to two third of its initial population size, and reached a new equilibrium in the 1990s. Pride sizes decreased from 6.3 adult females in 1989 to 2.8 lionesses in 1997. While the number of adult females declined continuously, the number of adult males, subadult females and subadult males remained constant over the years. A severe drought period, lasting for more than 20 years, led to declining prey populations inside the lions' territory. Besides declining prey populations, conflict with humans at the border of Etosha puts substantial pressure onto the lion population: 82 % of all known lion mortalities were caused by humans, and most of these consisted of adult females (28 %) and subadult males (29 %). I postulate that the considerable decline in the lion population is a response to declining prey populations, and although the human predator conflict is severe, it does not seem to limit the size of Etosha's lion population.

Declining Student Enrollment: A Case Study Exploring How Three Suburban School Districts Crafted Coherence

ERIC Educational Resources Information Center

Dimmitt, Eric J.

2012-01-01

This qualitative multi-site case study's purpose was to prove that the crafting coherence process was evident when three suburban Midwestern school districts implemented schools' goals while experiencing reductions in instructional programming, staffing, and facilities resources along with school closings due to significant declining student…

Rehabilitation Counseling Professional Associations: Membership, Membership Intentions, and Levels of Commitment among Rehabilitation Counseling Professionals

ERIC Educational Resources Information Center

Phillips, Brian N.

2011-01-01

Declining membership is a concerning, yet poorly understood issue affecting professional associations across many disciplines (Bauman, 2008). The discipline of rehabilitation counseling is experiencing membership decline even as the number of certified rehabilitation counselors continues to increase (Leahy, 2009). Little empirical research…

Assessing the association between homocysteine and cognition: reflections on Bradford Hill, meta-analyses, and causality.

PubMed

McCaddon, Andrew; Miller, Joshua W

2015-10-01

Hyperhomocysteinemia is a recognized risk factor for cognitive decline and incident dementia in older adults. Two recent reports addressed the cumulative epidemiological evidence for this association but expressed conflicting opinions. Here, the evidence is reviewed in relation to Sir Austin Bradford Hill's criteria for assessing "causality," and the latest meta-analysis of the effects of homocysteine-lowering on cognitive function is critically examined. The meta-analysis included 11 trials, collectively assessing 22,000 individuals, that examined the effects of B vitamin supplements (folic acid, vitamin B12, vitamin B6) on global or domain-specific cognitive decline. It concluded that homocysteine-lowering with B vitamin supplements has no significant effect on cognitive function. However, careful examination of the trials in the meta-analysis indicates that no conclusion can be made regarding the effects of homocysteine-lowering on cognitive decline, since the trials typically did not include individuals who were experiencing such decline. Further definitive trials in older adults experiencing cognitive decline are still urgently needed. © The Author(s) 2015. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Landscape predictors of pathogen prevalence and range contractions in US bumblebees.

PubMed

McArt, Scott H; Urbanowicz, Christine; McCoshum, Shaun; Irwin, Rebecca E; Adler, Lynn S

2017-11-29

Several species of bumblebees have recently experienced range contractions and possible extinctions. While threats to bees are numerous, few analyses have attempted to understand the relative importance of multiple stressors. Such analyses are critical for prioritizing conservation strategies. Here, we describe a landscape analysis of factors predicted to cause bumblebee declines in the USA. We quantified 24 habitat, land-use and pesticide usage variables across 284 sampling locations, assessing which variables predicted pathogen prevalence and range contractions via machine learning model selection techniques. We found that greater usage of the fungicide chlorothalonil was the best predictor of pathogen ( Nosema bombi ) prevalence in four declining species of bumblebees. Nosema bombi has previously been found in greater prevalence in some declining US bumblebee species compared to stable species. Greater usage of total fungicides was the strongest predictor of range contractions in declining species, with bumblebees in the northern USA experiencing greater likelihood of loss from previously occupied areas. These results extend several recent laboratory and semi-field studies that have found surprising links between fungicide exposure and bee health. Specifically, our data suggest landscape-scale connections between fungicide usage, pathogen prevalence and declines of threatened and endangered bumblebees. © 2017 The Author(s).

Conjuring the ghosts of missing children: a Monte Carlo simulation of reproductive restraint in Tokugawa Japan.

PubMed

Drixler, Fabian F

2015-04-01

This article quantifies the frequency of infanticide and abortion in one region of Japan by comparing observed fertility in a sample of 4.9 million person-years (1660-1872) with a Monte Carlo simulation of how many conceptions and births that population should have experienced. The simulation uses empirical values for the determinants of fertility from Eastern Japan itself as well as the best available studies of comparable populations. This procedure reveals that in several decades of the eighteenth century, at least 40% of pregnancies must have ended in either an induced abortion or an infanticide. In addition, the simulation results imply a rapid decline in the incidence of infanticide and abortion during the nineteenth century, when in a reverse fertility transition, this premodern family-planning regime gave way to a new age of large families.

Comparison of wetlands in different hydrogeological settings under conditions of extreme climate variability

USGS Publications Warehouse

Winter, T.; Rosenberry, D.; Kelly, E.; LaBaugh, J.

2005-01-01

Wetlands in the Cottonwood Lake area in North Dakota, USA, are underlain by poorly permeable till and have little groundwater input. Lakes and wetlands in the Shingobee River headwaters in Minnesota are underlain by permeable sand and have substantial groundwater input. Hydrological, chemical, and biological characteristics of these ecosystems have been monitored since 1977. Both sites experienced the second worst drought of the 20th century followed by the wettest period in more than a century. At Cottonwood Lake, plants that invaded the dry wetlands during the drought were flooded during the wet period and became a food source for animals. This resulted in successive substantial population increases and declines of plankton, invertebrates, amphibians and waterfowl. Substantial groundwater input buffered the lakes and wetlands in the Shingobee area against the changing water conditions. Only subtle changes in water chemistry and plankton populations were observed during the transition from drought to deluge.

Nexus Between Demographic Change and Elderly Care Need in the Gulf Cooperation Council (GCC) Countries: Some Policy Implications.

PubMed

Khan, Hafiz T A; Hussein, Shereen; Deane, John

2017-01-01

Population ageing is a phenomenon affecting the whole world. The countries that make up the Gulf Cooperation Council (GCC) are no exception but transitions in population ageing are still in the early stages of the process. With current demographic dividends experienced by the GCC and the rest of the Middle-East, the pace of population ageing will be faster than that experienced by many European countries. The purpose of this paper is to explore the population ageing experience of different GCC countries while situating this within a context of social policies that still at the very early stages of acknowledging such change. We utilise data from sources such as the United Nations and the World Bank, complemented by policy analysis of current age-related social security measures in the GCC. Given the importance of the family aged care system in the region, we consider the implications of changes in family structures, living conditions, and care needs for the elderly. The findings confirm the declining trend in fertility combined with increased life expectancy in all the six GCC countries. However, they highlight that social policy measures focused on the older generations and their care needs are still relatively at the early stages of each country's policy agenda. The implications of such changes are serious in term of both the demand for and supply of care. Policy-makers need to adapt cohesive social policy strategies that strengthen the complementing relationships between the state, family and wider community as stakeholders in the provision of aged care.

The Great Recession and America’s Geography of Unemployment

PubMed Central

Thiede, Brian C.; Monnat, Shannon M.

2017-01-01

Background The Great Recession of 2007–2009 was the most severe and lengthy economic crisis in the U.S. since the Great Depression. The impacts on the population were multi-dimensional, but operated largely through local labor markets. Objective To examine differences in recession-related changes in county unemployment rates and assess how population and place characteristics shaped these patterns. Methods We calculate and decompose Theil Indexes to describe recession-related changes in the distribution of unemployment rates between counties and states. We use exploratory spatial statistics to identify geographic clusters of counties that experienced similar changes in unemployment. We use spatial regression to evaluate associations between county-level recession impacts on unemployment and demographic composition, industrial structure, and state context. Results The recession was associated with increased inequality between county labor markets within states, but declining between-state differences. Counties that experienced disproportionate recession-related increases in unemployment were spatially clustered and characterized by large shares of historically disadvantaged racial and ethnic minority populations, low educational attainment, and heavy reliance on pro-cyclical industries. Associations between these sources of vulnerability were partially explained by unobserved state-level factors. Conclusions The local consequences of macroeconomic trends are associated with county population characteristics, as well as the structural contexts and policy environments in which they are embedded. The recession placed upward pressure on within-state inequality between local labor market conditions. Contribution To present new estimates of the recession’s impact on local labor markets, quantify how heterogeneous impacts affected the distribution of unemployment prevalence, and identify county characteristics associated with disproportionately large recession-related increases in unemployment. PMID:28663712

Effect of high-dose stereotactic body radiation therapy on liver function in the treatment of primary and metastatic liver malignancies using the Child-Pugh score classification system.

PubMed

Dyk, Pawel; Weiner, Ashley; Badiyan, Shahed; Myerson, Robert; Parikh, Parag; Olsen, Jeffrey

2015-01-01

The purpose of this study was to evaluate liver function after high-dose liver stereotactic body radiation therapy (SBRT) in the treatment of metastatic and primary malignancies of the liver using the Child-Pugh score classification system. This was a retrospective analysis of 46 patients treated with SBRT for metastatic and primary malignancies of the liver. Patient, disease, prior treatment, and SBRT dosimetric factors were analyzed to correlate with decline in Child-Pugh class after liver SBRT. Median follow-up was 11.0 months for patients alive at last follow-up. Twenty-three patients (50%) had primary liver malignancies. Median delivered dose was 55 Gy in 5 fractions (range, 36-60 Gy in 3-6 fractions) to 1 lesion (range, 1-4 lesions) measuring 4.0 cm (range, 1.3-12.4 cm). Forty-one patients (89%) received ≥50 Gy in 3 to 6 fractions. Child-Pugh score classification was A in 42 patients (91%). Seven patients (15%) received adjuvant chemotherapy or targeted therapy. Twenty-nine patients (63%) experienced an intrahepatic recurrence after treatment. Ten patients (22%) experienced a decline in Child-Pugh class at a median of 1.6 months (range, 0.2-6 months). Eighty percent experienced a one-category decline. Only the V20, V25, V30, and V50 were correlated with decline in Child-Pugh class on univariate analysis, with V25 being most significant (P = .027). A V25 >32% was associated with a 42% incidence of Child-Pugh class decline compared with 9% for V25 ≤32 (P = .029). For primary liver malignancies, a V25 >36% was associated with a 4-fold increase in the incidence of Child-Pugh class decline (60% vs 15%, P = .021). Approximately one-quarter of patients experience a decline in Child-Pugh class after high-dose liver SBRT. The V25 may be an important dosimetric parameter predicting decline in liver function after treatment. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Illegal killing for ivory drives global decline in African elephants

PubMed Central

Wittemyer, George; Northrup, Joseph M.; Blanc, Julian; Douglas-Hamilton, Iain; Omondi, Patrick; Burnham, Kenneth P.

2014-01-01

Illegal wildlife trade has reached alarming levels globally, extirpating populations of commercially valuable species. As a driver of biodiversity loss, quantifying illegal harvest is essential for conservation and sociopolitical affairs but notoriously difficult. Here we combine field-based carcass monitoring with fine-scale demographic data from an intensively studied wild African elephant population in Samburu, Kenya, to partition mortality into natural and illegal causes. We then expand our analytical framework to model illegal killing rates and population trends of elephants at regional and continental scales using carcass data collected by a Convention on International Trade in Endangered Species program. At the intensively monitored site, illegal killing increased markedly after 2008 and was correlated strongly with the local black market ivory price and increased seizures of ivory destined for China. More broadly, results from application to continental data indicated illegal killing levels were unsustainable for the species between 2010 and 2012, peaking to ∼8% in 2011 which extrapolates to ∼40,000 elephants illegally killed and a probable species reduction of ∼3% that year. Preliminary data from 2013 indicate overharvesting continued. In contrast to the rest of Africa, our analysis corroborates that Central African forest elephants experienced decline throughout the last decade. These results provide the most comprehensive assessment of illegal ivory harvest to date and confirm that current ivory consumption is not sustainable. Further, our approach provides a powerful basis to determine cryptic mortality and gain understanding of the demography of at-risk species. PMID:25136107

Analysis of the supply chain and conservation status of sharks (Elasmobranchii: Superorder Selachimorpha) based on fisher knowledge.

PubMed

Martins, Ana Paula Barbosa; Feitosa, Leonardo Manir; Lessa, Rosangela Paula; Almeida, Zafira Silva; Heupel, Michelle; Silva, Wagner Macedo; Tchaicka, Ligia; Nunes, Jorge Luiz Silva

2018-01-01

Increasing fishing effort has caused declines in shark populations worldwide. Understanding biological and ecological characteristics of sharks is essential to effectively implement management measures, but to fully understand drivers of fishing pressure social factors must be considered through multidisciplinary and integrated approaches. The present study aimed to use fisher and trader knowledge to describe the shark catch and product supply chain in Northeastern Brazil, and evaluate perceptions regarding the regional conservation status of shark species. Non-systematic observations and structured individual interviews were conducted with experienced fishers and traders. The demand and economic value of shark fins has reportedly decreased over the last 10 years while the shark meat trade has increased slightly, including a small increase in the average price per kilogram of meat. Several threatened shark species were reportedly often captured off shore and traded at local markets. This reported and observed harvest breaches current Brazilian environmental laws. Fishing communities are aware of population declines of several shark species, but rarely take action to avoid capture of sharks. The continuing capture of sharks is mainly due to a lack of knowledge of environmental laws, lack of enforcement by responsible authorities, and difficulties encountered by fishers in finding alternative income streams. National and regional conservation measures are immediately required to reduce overfishing on shark populations in Northeastern Brazil. Social and economic improvements for poor fishing communities must also be implemented to achieve sustainable fisheries.

Illegal killing for ivory drives global decline in African elephants.

PubMed

Wittemyer, George; Northrup, Joseph M; Blanc, Julian; Douglas-Hamilton, Iain; Omondi, Patrick; Burnham, Kenneth P

2014-09-09

Illegal wildlife trade has reached alarming levels globally, extirpating populations of commercially valuable species. As a driver of biodiversity loss, quantifying illegal harvest is essential for conservation and sociopolitical affairs but notoriously difficult. Here we combine field-based carcass monitoring with fine-scale demographic data from an intensively studied wild African elephant population in Samburu, Kenya, to partition mortality into natural and illegal causes. We then expand our analytical framework to model illegal killing rates and population trends of elephants at regional and continental scales using carcass data collected by a Convention on International Trade in Endangered Species program. At the intensively monitored site, illegal killing increased markedly after 2008 and was correlated strongly with the local black market ivory price and increased seizures of ivory destined for China. More broadly, results from application to continental data indicated illegal killing levels were unsustainable for the species between 2010 and 2012, peaking to ∼ 8% in 2011 which extrapolates to ∼ 40,000 elephants illegally killed and a probable species reduction of ∼ 3% that year. Preliminary data from 2013 indicate overharvesting continued. In contrast to the rest of Africa, our analysis corroborates that Central African forest elephants experienced decline throughout the last decade. These results provide the most comprehensive assessment of illegal ivory harvest to date and confirm that current ivory consumption is not sustainable. Further, our approach provides a powerful basis to determine cryptic mortality and gain understanding of the demography of at-risk species.

Analysis of the supply chain and conservation status of sharks (Elasmobranchii: Superorder Selachimorpha) based on fisher knowledge

PubMed Central

Almeida, Zafira Silva; Heupel, Michelle; Silva, Wagner Macedo; Tchaicka, Ligia

2018-01-01

Increasing fishing effort has caused declines in shark populations worldwide. Understanding biological and ecological characteristics of sharks is essential to effectively implement management measures, but to fully understand drivers of fishing pressure social factors must be considered through multidisciplinary and integrated approaches. The present study aimed to use fisher and trader knowledge to describe the shark catch and product supply chain in Northeastern Brazil, and evaluate perceptions regarding the regional conservation status of shark species. Non-systematic observations and structured individual interviews were conducted with experienced fishers and traders. The demand and economic value of shark fins has reportedly decreased over the last 10 years while the shark meat trade has increased slightly, including a small increase in the average price per kilogram of meat. Several threatened shark species were reportedly often captured off shore and traded at local markets. This reported and observed harvest breaches current Brazilian environmental laws. Fishing communities are aware of population declines of several shark species, but rarely take action to avoid capture of sharks. The continuing capture of sharks is mainly due to a lack of knowledge of environmental laws, lack of enforcement by responsible authorities, and difficulties encountered by fishers in finding alternative income streams. National and regional conservation measures are immediately required to reduce overfishing on shark populations in Northeastern Brazil. Social and economic improvements for poor fishing communities must also be implemented to achieve sustainable fisheries. PMID:29534100

Space Cooling in the United States: A Market Deep Dive

DOE PAGES

Baxter, Van D.; Sikes, Karen; Khowailed, Gannate

2016-01-01

The American space cooling market is experiencing stricter efficiency standards, prosperous economic conditions, a steadily recovering housing market, population migration shift to warmer climates, and declining electricity prices. These factors have yielded a climate conducive to growth in air conditioning (AC) and air source heat pump (HP) shipments in the recent past with total AC and HP shipments in 2015 accounting for 6.8 million units, showing a growth of 32 % relative to 2010. In this article, the authors investigate the impact that regulatory changes and economic changes have had on unit shipments and identify future market influencers, including themore » introduction of advanced HVAC technologies and transition to more environmentally friendly refrigerants.« less

Drug and Alcohol Abuse in Booming and Depressed Communities. Services Research Report.

ERIC Educational Resources Information Center

Milkman, Raymond H.; And Others

Boom towns appear to have greater problems of substance abuse associated with economic change indicators than communities suffering from sudden economic declines. A study of 14 communities experiencing sudden economic dislocations revealed a lack of consistent trends, although some depressed communities experienced increases in alcohol abuse. In…

Forest responses to increasing aridity and warmth in the southwestern United States.

PubMed

Williams, A Park; Allen, Craig D; Millar, Constance I; Swetnam, Thomas W; Michaelsen, Joel; Still, Christopher J; Leavitt, Steven W

2010-12-14

In recent decades, intense droughts, insect outbreaks, and wildfires have led to decreasing tree growth and increasing mortality in many temperate forests. We compared annual tree-ring width data from 1,097 populations in the coterminous United States to climate data and evaluated site-specific tree responses to climate variations throughout the 20th century. For each population, we developed a climate-driven growth equation by using climate records to predict annual ring widths. Forests within the southwestern United States appear particularly sensitive to drought and warmth. We input 21st century climate projections to the equations to predict growth responses. Our results suggest that if temperature and aridity rise as they are projected to, southwestern trees will experience substantially reduced growth during this century. As tree growth declines, mortality rates may increase at many sites. Increases in wildfires and bark-beetle outbreaks in the most recent decade are likely related to extreme drought and high temperatures during this period. Using satellite imagery and aerial survey data, we conservatively calculate that ≈ 2.7% of southwestern forest and woodland area experienced substantial mortality due to wildfires from 1984 to 2006, and ≈ 7.6% experienced mortality associated with bark beetles from 1997 to 2008. We estimate that up to ≈ 18% of southwestern forest area (excluding woodlands) experienced mortality due to bark beetles or wildfire during this period. Expected climatic changes will alter future forest productivity, disturbance regimes, and species ranges throughout the Southwest. Emerging knowledge of these impending transitions informs efforts to adaptively manage southwestern forests.

Forest responses to increasing aridity and warmth in the southwestern United States

USGS Publications Warehouse

Williams, A.P.; Allen, Craig D.; Millar, C.I.; Swetnam, T.W.; Michaelsen, J.; Still, C.J.; Leavitt, Steven W.

2010-01-01

In recent decades, intense droughts, insect outbreaks, and wildfires have led to decreasing tree growth and increasing mortality in many temperate forests. We compared annual tree-ring width data from 1,097 populations in the coterminous United States to climate data and evaluated site-specific tree responses to climate variations throughout the 20th century. For each population, we developed a climate-driven growth equation by using climate records to predict annual ring widths. Forests within the southwestern United States appear particularly sensitive to drought and warmth. We input 21st century climate projections to the equations to predict growth responses. Our results suggest that if temperature and aridity rise as they are projected to, southwestern trees will experience substantially reduced growth during this century. As tree growth declines, mortality rates may increase at many sites. Increases in wildfires and bark-beetle outbreaks in the most recent decade are likely related to extreme drought and high temperatures during this period. Using satellite imagery and aerial survey data, we conservatively calculate that ≈2.7% of southwestern forest and woodland area experienced substantial mortality due to wildfires from 1984 to 2006, and ≈7.6% experienced mortality associated with bark beetles from 1997 to 2008. We estimate that up to ≈18% of southwestern forest area (excluding woodlands) experienced mortality due to bark beetles or wildfire during this period. Expected climatic changes will alter future forest productivity, disturbance regimes, and species ranges throughout the Southwest. Emerging knowledge of these impending transitions informs efforts to adaptively manage southwestern forests.

[Economic growth with zero population growth and with declining population].

PubMed

Kurz, R

1982-05-01

The effects of both zero population growth and a declining population on economic growth are considered. Although the neoclassical theory of economic growth leads to optimistic results in such cases, the author suggests that this theory cannot be used as a basis for political action. The need for further research into the economic effects of a stationary or declining population is stressed. (summary in ENG)

Early body composition, but not body mass, is associated with future accelerated decline in muscle quality

PubMed Central

Chiles Shaffer, Nancy; Gonzalez‐Freire, Marta; Shardell, Michelle D.; Zoli, Marco; Studenski, Stephanie A.; Ferrucci, Luigi

2017-01-01

Abstract Background Muscle quality (MQ) or strength‐to‐mass ratio declines with aging, but the rate of MQ change with aging is highly heterogeneous across individuals. The identification of risk factors for accelerated MQ decline may offer clues to identity the underpinning physiological mechanisms and indicate targets for prevention and treatment. Using data from the Baltimore Longitudinal Study of Aging, we tested whether measures of body mass and body composition are associated with differential rates of changes in MQ with aging. Methods Participants included 511 men and women, aged 50 years or older, followed for an average of 4 years (range: 1–8). MQ was operationalized as ratio between knee‐extension isokinetic strength and CT‐thigh muscle cross‐sectional area. Predictors included body mass and body composition measures: weight (kg), body mass index (BMI, kg/m2), dual‐energy x‐ray absorptiometry‐measured total body fat mass (TFM, kg) and lean mass (TLM, kg), and body fatness (TFM/weight). Covariates were baseline age, sex, race, and body height. Results Muscle quality showed a significant linear decline over the time of the follow up (average rate of decline 0.02 Nm/cm2 per year, P < .001). Independent of covariates, neither baseline body weight (P = .756) nor BMI (P = .777) was predictive of longitudinal rate of decline in MQ. Instead, higher TFM and lower TLM at baseline predicted steeper longitudinal decline in MQ (P = .036 and P < .001, respectively). In particular, participants with both high TFM and low TLM at baseline experienced the most dramatic decline compared with those with low TFM and high TLM (about 3% per year vs. 0.5% per year, respectively). Participants in the higher tertile of baseline body fatness presented a significantly faster decline of MQ than the rest of the population (P = .021). Similar results were observed when body mass, TFM, and TLM were modeled as time‐dependent predictors. Conclusions Body composition, but not weight nor BMI, is associated with future MQ decline, suggesting that preventive strategies aimed at maintaining good MQ with aging should specifically target body composition features. PMID:28198113

When can the cause of a population decline be determined?

PubMed

Hefley, Trevor J; Hooten, Mevin B; Drake, John M; Russell, Robin E; Walsh, Daniel P

2016-11-01

Inferring the factors responsible for declines in abundance is a prerequisite to preventing the extinction of wild populations. Many of the policies and programmes intended to prevent extinctions operate on the assumption that the factors driving the decline of a population can be determined. Exogenous factors that cause declines in abundance can be statistically confounded with endogenous factors such as density dependence. To demonstrate the potential for confounding, we used an experiment where replicated populations were driven to extinction by gradually manipulating habitat quality. In many of the replicated populations, habitat quality and density dependence were confounded, which obscured causal inference. Our results show that confounding is likely to occur when the exogenous factors that are driving the decline change gradually over time. Our study has direct implications for wild populations, because many factors that could drive a population to extinction change gradually through time. © 2016 John Wiley & Sons Ltd/CNRS.

When can the cause of a population decline be determined?

USGS Publications Warehouse

Hefley, Trevor J.; Hooten, Mevin B.; Drake, John M.; Russell, Robin E.; Walsh, Daniel P.

2016-01-01

Inferring the factors responsible for declines in abundance is a prerequisite to preventing the extinction of wild populations. Many of the policies and programmes intended to prevent extinctions operate on the assumption that the factors driving the decline of a population can be determined. Exogenous factors that cause declines in abundance can be statistically confounded with endogenous factors such as density dependence. To demonstrate the potential for confounding, we used an experiment where replicated populations were driven to extinction by gradually manipulating habitat quality. In many of the replicated populations, habitat quality and density dependence were confounded, which obscured causal inference. Our results show that confounding is likely to occur when the exogenous factors that are driving the decline change gradually over time. Our study has direct implications for wild populations, because many factors that could drive a population to extinction change gradually through time.

Reproduction, embryonic development, and maternal transfer of contaminants in the amphibian Gastrophryne carolinensis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hopkins, W.A.; DuRant, S.E.; Staub, B.P.

2006-05-15

Although many amphibian populations around the world are declining at alarming rates, the cause of most declines remains unknown. Environmental contamination is one of several factors implicated in declines and may have particularly important effects on sensitive developmental stages. We examined maternal transfer of contaminants in eastern narrow-mouth toads (Gastrophryne carolinensis) collected from a reference site and near a coal-burning power plant. Adult toads inhabiting the industrial area transferred significant quantities of selenium and strontium to their eggs, but Se concentrations were most notable (up to 100 {mu} g/g dry mass). Compared with the reference site, hatching success was reducedmore » by 11% in clutches from the contaminated site. In surviving larvae, the frequency of developmental abnormalities and abnormal swimming was 55-58% higher in the contaminated site relative to the reference site. Craniofacial abnormalities were nearly an order of magnitude more prevalent in hatchlings from the contaminated site. When all developmental criteria were considered collectively, offspring from the contaminated site experienced 19% lower viability. Although there was no statistical relationship between the concentration of Se or Sr transferred to eggs and any measure of offspring viability, our study demonstrates that maternal transfer may be an important route of contaminant exposure in amphibians that has been overlooked.« less

Severe mortality of a population of threatened Agassiz’s desert tortoises: the American badger as a potential predator

USGS Publications Warehouse

Emblidge, Patrick G.; Nussear, Ken E.; Esque, Todd C.; Aiello, Christina M.; Walde, Andrew D.

2015-01-01

In the Mojave Desert of the southwestern United States, adult Agassiz’s desert tortoises Gopherus agassizii typically experience high survival, but population declines associated with anthropogenic impacts led to their listing as a threatened Species under the US Endangered Species Act in 1990. Predation of adult tortoises is not often considered a significant threat as they are adapted to deter most predation attempts. Despite these adaptations, some populations have experienced elevated mortality attributed to predators, suggesting that predation pressure may occasionally increase. During the tortoise activity seasons of 2012 and 2013, we observed unsustainably high mortality in 1 of 4 populations of adult desert tortoises (22 and 84%, respectively) in the western Mojave Desert in the vicinity of Barstow, CA. Photographic evidence from trail cameras and examination of carcass condition suggest that American badgers Taxidea taxus— a sometimes cited but unconfirmed predator of adult tortoises — may have been responsible for some of the mortality observed. We discuss the American badger as a plausible predator of a local tortoise population, but recommend further investigation into these events and the impacts such mortality can have on tortoise persistence.

Monitoring and Evaluation of Supplemented Spring Chinook Salmon and Life Histories of Wild Summer Steelhead in the Grande Ronde Basin, 2007 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boe, Stephen J.; Crump, Carrie A.; Weldert, Rey L.

2009-04-10

This is the ninth annual report for a multi-year project designed to monitor and evaluate supplementation of endemic spring Chinook salmon in Catherine Creek and the upper Grande Ronde River. These two streams historically supported anadromous fish populations that provided significant tribal and non-tribal fisheries, but in recent years, have experienced severe declines in abundance. Conventional and captive broodstock supplementation methods are being used to restore these spring Chinook salmon populations. Spring Chinook salmon populations in Catherine Creek and the upper Grande Ronde River, and other streams in the Snake River Basin have experienced severe declines in abundance over themore » past two decades (Nehlsen et al. 1991). A supplementation program was initiated in Catherine Creek and the upper Grande Ronde River, incorporating the use of both captive and conventional broodstock methods, in order to prevent extinction in the short term and eventually rebuild populations. The captive broodstock component of the program (BPA Project 199801001) uses natural-origin parr collected by seining and reared to maturity at facilities near Seattle, Washington (Manchester Marine Laboratory) and Hood River, Oregon (Bonneville Hatchery). Spawning occurs at Bonneville Hatchery, and resulting progeny are reared in hatcheries. Shortly before outmigration in the spring, juveniles are transferred to acclimation facilities. After an acclimation period of about 2-4 weeks, volitional release begins. Any juveniles remaining after the volitional release period are forced out. The conventional broodstock component uses returning adults collected at traps near the spawning areas, transported to Lookingglass Hatchery near Elgin, Oregon, held, and later spawned. The resulting progeny are reared, acclimated, and released similar to the captive broodstock component. All progeny released receive one or more marks including a fin (adipose) clip, codedwire tag, PIT tag, or visual implant elastomer tag. The numbers of adults used for conventional broodstock are determined by an agreement among comanagers (Zimmerman and Patterson 2002). Activities for this project focus on two life stages of spring Chinook salmon: juveniles during the migration from freshwater to the ocean and adults during prespawning migration through the end of spawning. Life history, production, and genetics are monitored and used to evaluate program effectiveness.« less

Long term cause specific mortality among 34 489 five year survivors of childhood cancer in Great Britain: population based cohort study

PubMed Central

Fidler, Miranda M; Reulen, Raoul C; Winter, David L; Kelly, Julie; Jenkinson, Helen C; Skinner, Rod; Frobisher, Clare

2016-01-01

Objective To determine whether modern treatments for cancer are associated with a net increased or decreased risk of death from neoplastic and non-neoplastic causes among survivors of childhood cancer. Design Population based cohort study. Setting British Childhood Cancer Survivor Study. Participants Nationwide population based cohort of 34 489 five year survivors of childhood cancer with a diagnosis from 1940 to 2006 and followed up until 28 February 2014. Main outcome measures Cause specific standardised mortality ratios and absolute excess risks are reported. Multivariable Poisson regression models were utilised to evaluate the simultaneous effect of risk factors. Likelihood ratio tests were used to test for heterogeneity or trend. Results Overall, 4475 deaths were observed, which was 9.1 (95% confidence interval 8.9 to 9.4) times that expected in the general population, corresponding to 64.2 (95% confidence interval 62.1 to 66.3) excess deaths per 10 000 person years. The number of excess deaths from all causes declined among those treated more recently; those treated during 1990-2006 experienced 30% of the excess number of deaths experienced by those treated before 1970. The corresponding percentages for the decline in excess deaths from recurrence or progression and non-neoplastic causes were 30% and 60%, respectively. Among survivors aged 50-59 years, 41% and 22% of excess deaths were attributable to subsequent primary neoplasms and circulatory conditions, respectively, whereas the corresponding percentages among those aged 60 years or more were 31% and 37%. Conclusions The net effects of changes in cancer treatments, and surveillance and management for late effects, over the period 1940 to 2006 was to reduce the excess number of deaths from both recurrence or progression and non-neoplastic causes among those treated more recently. Among survivors aged 60 years or more, the excess number of deaths from circulatory causes exceeds the excess number of deaths from subsequent primary neoplasms. The important message for the evidence based surveillance aimed at preventing excess mortality and morbidity in survivors aged 60 years or more is that circulatory disease overtakes subsequent primary neoplasms as the leading cause of excess mortality. PMID:27586237

Propagating native milkweeds for restoring monarch butterfly habitat

Treesearch

Thomas D. Landis; R. Kasten Dumroese

2015-01-01

The number of monarch butterflies, charismatic nomads of North America, is rapidly declining. Milkweeds (Asclepias spp.), which are the sole food source for monarch caterpillars, have also experienced a decline throughout the breeding range of this butterfly. Milkweeds can be grown from seeds or vegetatively from root cuttings or rhizomes. Seed germination is often...

Distance Education as Counter to Declining State Appropriations at Public Institutions

ERIC Educational Resources Information Center

Anderson, Theresa

2017-01-01

Universities and colleges have experienced a reduction in state appropriations since the 2008 Great Recession. The purpose of this phenomenological dissertation in practice study was to examine whether distance education would be a viable strategy to compensate for declining state appropriations at four-year public higher education institutions in…

Demographic and fertility characteristics of 4 squatter settlements.

PubMed

Yusof, K; Zulkifli, S N

1985-01-01

The demographic and fertility profiles of 4 squatter areas, 2 with Sang Kancil, a community development project designed specifically for squatter settlements in Kuala Lumpur, are described. Data were taken from a census conducted in 1982. Figure 1 maps out the location of the study areas in the Federal Territory. The squatter household (5.4 members) varied little from the average Malaysian household. The average age of the male head of household was 40 years, i.e., not within the high fertility group; the mean duration of stay was 10 years. Household income/month averaged M$760, falling between estimates for urban and rural mean. Comparing the data on the 2 squatter areas, the non-Sang Kancil head of household was, on average, slightly older and had stayed about 2 years longer than his Sang Kancil counterpart. These differences were statistically significant. Both areas were comparable with regard to household income and size. Ethnically, the Sang Kancil areas were predominantly Malay, comprising 86% of total households. The control areas had a more mixed ethnic structure. From 1978-81, annual increases in total population had been fairly uniform, at around 2%, in non-Sang Kancil Areas. Yet, the Sang Kancil population experienced a growth spurt in 1980, which subsequently declined and appeared to level off. 1982 figures were disregarded in this analysis as they were based on a 1/2 year enumeration only. The age distribution pattern of all squatter areas combined was fairly similar to the national distribution pyramid but for a higher proportion of people in the 15-44 age group than national figures. The proportion of dependents, 0-14 years, was comparable despite having more people in this fertile age group. The proportion of infants (0-11 months) in the control population was constant, but there was a decline down to control values by the end of the surveyed period in the Sang Kancil group. In the toddler group, decreases were evident for both populations. Additionally, the proportion of the population in the 20-39 age group, considered the most fertile, was consistently higher in the Sang Kancil areas throughout the 4.5 years. Thus, for Sang Kancil areas, fertility appeared to have dropped; it has remained fairly steady in non-Sang Kancil controls. In addition to contraceptive practice, 2 others factors most likely have contributed to fertility declines: a progressive decline in those who were married, which is likely to have had a negative effect on fertility rates; and evidence of induced abortion.

Timelines and mechanisms of wildlife population recovery following the Exxon Valdez oil spill

NASA Astrophysics Data System (ADS)

Esler, Daniel; Ballachey, Brenda E.; Matkin, Craig; Cushing, Daniel; Kaler, Robert; Bodkin, James; Monson, Daniel; Esslinger, George; Kloecker, Kim

2018-01-01

Research and monitoring activities over the 28 years since the T/V Exxon Valdez ran aground and spilled oil into Prince William Sound, Alaska have led to an improved understanding of how wildlife populations were damaged, as well as the mechanisms and timelines of recovery. A key finding was that for some species, such as harlequin ducks and sea otters, chronic oil spill effects persisted for at least two decades and were a larger influence on population dynamics over the long term than acute effects of the spill. These data also offer insights into population variation resulting from factors other than the oil spill. For example, while many seabirds experienced direct and indirect effects of the spill, population trajectories of some piscivorous birds, including pigeon guillemots and marbled murrelets, were linked to long-term environmental changes independent of spill effects. Another species, killer whales, suffered population declines due to acute spill effects that have not been resolved despite lack of chronic direct effects, representing a novel pathway of long-term injury. The observed variation in mechanisms and timelines of recovery is linked to species specific life history and natural history traits, and thus may be useful for predicting population recovery for other species following other spills.

Timelines and mechanisms of wildlife population recovery following the Exxon Valdez oil spill

USGS Publications Warehouse

Esler, Daniel N.; Ballachey, Brenda E.; Matkin, Craig O.; Cushing, Daniel; Kaler, Robert; Bodkin, James L.; Monson, Daniel; Esslinger, George G.; Kloecker, Kimberly A.

2018-01-01

Research and monitoring activities over the 28 years since the T/V Exxon Valdez ran aground and spilled oil into Prince William Sound, Alaska have led to an improved understanding of how wildlife populations were damaged, as well as the mechanisms and timelines of recovery. A key finding was that for some species, such as harlequin ducks and sea otters, chronic oil spill effects persisted for at least two decades and were a larger influence on population dynamics over the long term than acute effects of the spill. These data also offer insights into population variation resulting from factors other than the oil spill. For example, while many seabirds experienced direct and indirect effects of the spill, population trajectories of some piscivorous birds, including pigeon guillemots and marbled murrelets, were linked to long-term environmental changes independent of spill effects. Another species, killer whales, suffered population declines due to acute spill effects that have not been resolved despite lack of chronic direct effects, representing a novel pathway of long-term injury. The observed variation in mechanisms and timelines of recovery is linked to species specific life history and natural history traits, and thus may be useful for predicting population recovery for other species following other spills.

Demographic methods to assess food insecurity: a North Korean case study.

PubMed

Robinson, W C; Lee, M K; Hill, K; Hsu, E; Burnham, G

2001-01-01

In complex emergencies, especially those involving famine and/or widespread food insecurity, assessments of malnutrition are critical to understanding the population's health status and to assessing the effectiveness of relief interventions. Although the Democratic People's Republic of Korea (DPRK) has benefited from some of the largest, most sustained appeals in the history of the World Food Program (WFP), the government in Pyongyang has placed restrictions on international efforts to gather data on the health and nutritional status of the affected population. Lacking direct means to assess the nutritional status of the North Korean populace, what other methodologies could be employed to measure the public health impacts of chronic food shortage? The paper begins with a review of methods for assessing nutritional status, particularly in emergencies; a brief history of the North Korean food crisis (1995-2001), and a review of the available nutritional and health data on the DPRK. The main focus of the paper is on the results of a survey of 2,692 North Korean adult migrants in China. Recognizing certain biases and limitations, the study suggests that sample households have experienced an overall decline in food security, as evidenced by both the decline in government rations from an average of 120 grams per person per day to less than 60 grams per day, and by the increase in the percentage of households relying on foraging or bartering of assets as their principal source of food. It also is apparent that the period 1995-1998 has been marked by elevated household mortality, declining fertility, and steadily rising out-migration. Taken together, the signs point toward famine, whether that is defined as a discrete event--that is, as a regional failure in food production or distribution leading to elevated mortality from starvation and associated disease--or as a more complex social process whose sub-states include not only elevated mortality, but declining fertility, eating of alternative 'famine foods', transfer of assets, and the uprooting and separation of families.

Evaluating Ultraviolet Radiation Exposures Determined from TOMS Satellite Data at Sites of Amphibian Declines in Central and South America

NASA Technical Reports Server (NTRS)

Middleton, Elizabeth M.; Smith, David E. (Technical Monitor)

2000-01-01

Many amphibian species have experienced substantial population declines, or have disappeared altogether, during the last several decades at a number of amphibian census sites in Central and South America. This study addresses the use of satellite-derived trends in solar ultraviolet-B (UV-B; 280-320 nm) radiation exposures at these sites over the last two decades, and is intended to demonstrate a role for satellite observations in determining whether UV-B radiation is a contributing factor in amphibian declines. UV-B radiation levels at the Earth's surface were derived from the Total Ozone Mapping Spectrometer (TOMS) satellite data, typically acquired daily since 1979. These data were used to calculate the daily erythemal (sunburning) UV-B, or UV-B(sub ery), exposures at the latitude, longitude, and elevation of each of 20 census sites. The annually averaged UV-B(sub ery) dose, as well as the maximum values, have been increasing in both Central and South America, with higher levels received at the Central American sites. The annually averaged UV-B(sub ery) exposures increased significantly from 1979-1998 at all 11 Central American sites examined (r(exp 2) = 0.60 - 0.79; P<=0.015), with smaller but significant increases at five of the nine South American sites (r(exp 2) = 0.24-0.42; P<=0.05). The contribution of the highest UV-B(sub ery) exposure levels (>= 6750 J/sq m*d) to the annual UV-B(sub ery) total has increased from approx. 5% to approx. 15% in Central America over the 19 year period, but actual daily exposures for each species are unknown. Synergy among UV-B radiation and other factors, especially those associated with alterations of water chemistry (e.g., acidification) in aqueous habitats is discussed. These findings justify further research concerning whether UV-B(sub ery) radiation plays a role in amphibian population declines and extinctions.

Parental decision making around perinatal autopsy: a qualitative investigation.

PubMed

Meaney, Sarah; Gallagher, Stephen; Lutomski, Jennifer E; O'Donoghue, Keelin

2015-12-01

Decades of decline in uptake rates of perinatal autopsies has limited investigation into the causes and risk factors for stillbirth. This study aimed to qualitatively explore perinatal autopsy decision-making processes in parents who experienced antepartum and intrapartum stillbirths. A qualitative semi-structured interview format was utilized. The line of questioning centred on how parents came to decide on consenting or declining to have a perinatal autopsy undertaken. Interpretative phenomenological analysis was employed as the analytic strategy. Purposive sampling was used to recruit 10 parents who either consented or declined autopsy from a large tertiary maternity hospital in Cork Ireland, where there were 30 stillbirths in 2011. Findings revealed four superordinate themes influencing parents' decision-making which varied with type of stillbirth experienced. Those parents who experienced antepartum stillbirths were more likely to consent; thus, knowing that the child was stillborn prior to delivery rather than on the day of delivery was associated with consent. In fact, these parents had more time for meaning-making; those consenting wanted to rule out self-blame and were fearful about future pregnancies. Parents who declined autopsy wanted to protect their infant from further harm. Interestingly, parents' knowledge and understanding of the autopsy itself were acquired primarily from public discourse. Parents' decision-making regarding autopsy is profoundly affected by their emotional response to stillbirth; clinicians and other health professionals may play a key role, especially if they can address parental concerns regarding the invasiveness of the autopsy procedure. © 2014 John Wiley & Sons Ltd.

Disease introduction is associated with a phase transition in bighorn sheep demographics.

PubMed

Manlove, Kezia; Cassirer, E Frances; Cross, Paul C; Plowright, Raina K; Hudson, Peter J

2016-10-01

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population-level and 18 years of individual-level monitoring across 12 populations. While populations generally increased (λ = 1.11) prior to disease introduction, most of these same populations experienced an abrupt change in trajectory at the time of disease invasion, usually followed by stagnant-to-declining growth rates (λ = 0.98) over the next 20 years. Disease-induced juvenile mortality imposed strong constraints on population growth that were not observed prior to disease introduction, even as adult survival returned to pre-invasion levels. Simulations suggested that models including persistent disease-induced mortality in juveniles qualitatively matched observed population trajectories, whereas models that only incorporated all-age disease events did not. We use these results to argue that pathogen persistence may pose a lasting, but under-recognized, threat to host populations, particularly in cases where clinical disease manifests primarily in juveniles. © 2016 by the Ecological Society of America.

Survival and breeding of polar bears in the southern Beaufort Sea in relation to sea ice.

PubMed

Regehr, Eric V; Hunter, Christine M; Caswell, Hal; Amstrup, Steven C; Stirling, Ian

2010-01-01

1. Observed and predicted declines in Arctic sea ice have raised concerns about marine mammals. In May 2008, the US Fish and Wildlife Service listed polar bears (Ursus maritimus) - one of the most ice-dependent marine mammals - as threatened under the US Endangered Species Act. 2. We evaluated the effects of sea ice conditions on vital rates (survival and breeding probabilities) for polar bears in the southern Beaufort Sea. Although sea ice declines in this and other regions of the polar basin have been among the greatest in the Arctic, to date population-level effects of sea ice loss on polar bears have only been identified in western Hudson Bay, near the southern limit of the species' range. 3. We estimated vital rates using multistate capture-recapture models that classified individuals by sex, age and reproductive category. We used multimodel inference to evaluate a range of statistical models, all of which were structurally based on the polar bear life cycle. We estimated parameters by model averaging, and developed a parametric bootstrap procedure to quantify parameter uncertainty. 4. In the most supported models, polar bear survival declined with an increasing number of days per year that waters over the continental shelf were ice free. In 2001-2003, the ice-free period was relatively short (mean 101 days) and adult female survival was high (0.96-0.99, depending on reproductive state). In 2004 and 2005, the ice-free period was longer (mean 135 days) and adult female survival was low (0.73-0.79, depending on reproductive state). Breeding rates and cub litter survival also declined with increasing duration of the ice-free period. Confidence intervals on vital rate estimates were wide. 5. The effects of sea ice loss on polar bears in the southern Beaufort Sea may apply to polar bear populations in other portions of the polar basin that have similar sea ice dynamics and have experienced similar, or more severe, sea ice declines. Our findings therefore are relevant to the extinction risk facing approximately one-third of the world's polar bears.

Survival and breeding of polar bears in the southern Beaufort Sea in relation to sea ice

USGS Publications Warehouse

Regehr, E.V.; Hunter, C.M.; Caswell, H.; Amstrup, Steven C.; Stirling, I.

2010-01-01

1. Observed and predicted declines in Arctic sea ice have raised concerns about marine mammals. In May 2008, the US Fish and Wildlife Service listed polar bears (Ursus maritimus) - one of the most ice-dependent marine mammals - as threatened under the US Endangered Species Act. 2. We evaluated the effects of sea ice conditions on vital rates (survival and breeding probabilities) for polar bears in the southern Beaufort Sea. Although sea ice declines in this and other regions of the polar basin have been among the greatest in the Arctic, to date population-level effects of sea ice loss on polar bears have only been identified in western Hudson Bay, near the southern limit of the species' range. 3. We estimated vital rates using multistate capture-recapture models that classified individuals by sex, age and reproductive category. We used multimodel inference to evaluate a range of statistical models, all of which were structurally based on the polar bear life cycle. We estimated parameters by model averaging, and developed a parametric bootstrap procedure to quantify parameter uncertainty. 4. In the most supported models, polar bear survival declined with an increasing number of days per year that waters over the continental shelf were ice free. In 2001-2003, the ice-free period was relatively short (mean 101 days) and adult female survival was high (0 ∙ 96-0 ∙ 99, depending on reproductive state). In 2004 and 2005, the ice-free period was longer (mean 135 days) and adult female survival was low (0 ∙ 73-0 ∙ 79, depending on reproductive state). Breeding rates and cub litter survival also declined with increasing duration of the ice-free period. Confidence intervals on vital rate estimates were wide. 5. The effects of sea ice loss on polar bears in the southern Beaufort Sea may apply to polar bear populations in other portions of the polar basin that have similar sea ice dynamics and have experienced similar, or more severe, sea ice declines. Our findings therefore are relevant to the extinction risk facing approximately one-third of the world's polar bears. 

The Importance of Non-Native Prey, the Zebra Mussel Dreissena polymorpha, for the Declining Greater Scaup Aythya marila: A Case Study at a Key European Staging and Wintering Site.

PubMed

Marchowski, Dominik; Neubauer, Grzegorz; Ławicki, Łukasz; Woźniczka, Adam; Wysocki, Dariusz; Guentzel, Sebastian; Jarzemski, Maciej

2015-01-01

The European population of Greater Scaup Aythya marila has experienced an alarming, ~60% decline in numbers over the last two decades. The brackish lagoons of the Odra River Estuary (ORE) in the south-western Baltic Sea, represent an important area for the species during the non-breeding season in Europe. The lagoons regularly support over 20 000 Scaup, with peaks exceeding 100 000 (38%-70% of the population wintering in NW Europe and the highest number recorded in April 2011-105 700). In the ORE, Scaup feed almost exclusively on the non-native Zebra Mussel Dreissena polymorpha. This mussel was present in the ORE already in the 19th century and continues to be superabundant. Using the results of 22 Scaup censuses (November to April 2002/2003 to 2013/2014) from the whole ORE (523 km2 of water), we show that Scaup flocks follow areas with the greatest area of occurrence and biomass of the Zebra Mussel, while areas with low mussel densities are ignored. The numbers of Scaup in the ORE are primarily related to the area of Zebra Mussel occurrence on the lagoon's bottom (km2) in a non-linear fashion. Zebra Mussels were absolutely prevalent (97% of biomass) in the digestive tracts of birds unintentionally by-caught in fishing nets (n = 32). We estimate that Scaup alone consume an average of 5 400 tons of Zebra Mussels annually, which represents 5.6% of the total resources of the mussel in the ORE. Our results provide a clear picture of the strong dependence of the declining, migratory duck species on the non-native mussel, its primary food in the ORE. Our findings are particularly important as they can form the basis for the conservation action plan aimed at saving the north-western European populations of Scaup.

The Importance of Non-Native Prey, the Zebra Mussel Dreissena polymorpha, for the Declining Greater Scaup Aythya marila: A Case Study at a Key European Staging and Wintering Site

PubMed Central

Marchowski, Dominik; Neubauer, Grzegorz; Ławicki, Łukasz; Woźniczka, Adam; Wysocki, Dariusz; Guentzel, Sebastian; Jarzemski, Maciej

2015-01-01

The European population of Greater Scaup Aythya marila has experienced an alarming, ~60% decline in numbers over the last two decades. The brackish lagoons of the Odra River Estuary (ORE) in the south-western Baltic Sea, represent an important area for the species during the non-breeding season in Europe. The lagoons regularly support over 20 000 Scaup, with peaks exceeding 100 000 (38%–70% of the population wintering in NW Europe and the highest number recorded in April 2011–105 700). In the ORE, Scaup feed almost exclusively on the non-native Zebra Mussel Dreissena polymorpha. This mussel was present in the ORE already in the 19th century and continues to be superabundant. Using the results of 22 Scaup censuses (November to April 2002/2003 to 2013/2014) from the whole ORE (523 km2 of water), we show that Scaup flocks follow areas with the greatest area of occurrence and biomass of the Zebra Mussel, while areas with low mussel densities are ignored. The numbers of Scaup in the ORE are primarily related to the area of Zebra Mussel occurrence on the lagoon’s bottom (km2) in a non-linear fashion. Zebra Mussels were absolutely prevalent (97% of biomass) in the digestive tracts of birds unintentionally by-caught in fishing nets (n = 32). We estimate that Scaup alone consume an average of 5 400 tons of Zebra Mussels annually, which represents 5.6% of the total resources of the mussel in the ORE. Our results provide a clear picture of the strong dependence of the declining, migratory duck species on the non-native mussel, its primary food in the ORE. Our findings are particularly important as they can form the basis for the conservation action plan aimed at saving the north-western European populations of Scaup. PMID:26709707

Declining amenable mortality: a reflection of health care systems?

PubMed

Gianino, Maria Michela; Lenzi, Jacopo; Fantini, Maria Pia; Ricciardi, Walter; Damiani, Gianfranco

2017-11-15

Some studies have analyzed the association of health care systems variables, such as health service resources or expenditures, with amenable mortality, but the association of types of health care systems with the decline of amenable mortality has yet to be studied. The present study examines whether specific health care system types are associated with different time trend declines in amenable mortality from 2000 to 2014 in 22 European OECD countries. A time trend analysis was performed. Using Nolte and McKee's list, age-standardized amenable mortality rates (SDRs) were calculated as the annual number of deaths over the population aged 0-74 years per 100,000 inhabitants. We classified health care systems according to a deductively generated classification by Böhm. This classification identifies three dimensions that are not entirely independent of each other but follow a clear order: the regulation dimension is first, followed by the financing dimension and finally service provision. We performed a hierarchical semi-log polynomial regression analysis on the annual SDRs to determine whether specific health care systems were associated with different SDR trajectories over time. The results showed a clear decline in SDRs in all 22 health care systems between 2000 and 2014 although at different annual changes (slopes). Regression analysis showed that there was a significant difference among the slopes according to provision dimension. Health care systems with a private provision exhibited a slowdown in the decline of amenable mortality over time. It therefore seems that ownership is the most relevant dimension in determining a different pattern of decline in mortality. All countries experienced decreases in amenable mortality between 2000 and 2014; this decline seems to be partially a reflection of health care systems, especially when affected by the provision dimension. If the private ownership is maintained or promoted by health systems, these findings might be considered when thinking about regulation policies to control factors that might influence health care performance.

Microsatellite Analysis of Museum Specimens Reveals Historical Differences in Genetic Diversity between Declining and More Stable Bombus Species.

PubMed

Maebe, Kevin; Meeus, Ivan; Ganne, Maarten; De Meulemeester, Thibaut; Biesmeijer, Koos; Smagghe, Guy

2015-01-01

Worldwide most pollinators, e.g. bumblebees, are undergoing global declines. Loss of genetic diversity can play an essential role in these observed declines. In this paper, we investigated the level of genetic diversity of seven declining Bombus species and four more stable species with the use of microsatellite loci. Hereto we genotyped a unique collection of museum specimens. Specimens were collected between 1918 and 1926, in 6 provinces of the Netherlands which allowed us to make interspecific comparisons of genetic diversity. For the stable species B. pascuorum, we also selected populations from two additional time periods: 1949-1955 and 1975-1990. The genetic diversity and population structure in B. pascuorum remained constant over the three time periods. However, populations of declining bumblebee species showed a significantly lower genetic diversity than co-occurring stable species before their major declines. This historical difference indicates that the repeatedly observed reduced genetic diversity in recent populations of declining bumblebee species is not caused solely by the decline itself. The historically low genetic diversity in the declined species may be due to the fact that these species were already rare, making them more vulnerable to the major drivers of bumblebee decline.

Population trends from the American woodcock singing-ground survey, 1970-88

USGS Publications Warehouse

Sauer, J.R.; Bortner, J.B.

1991-01-01

Population trend analysis of American woodcook (Scolopax minor) using data from a singing-ground survey indicates population declines throughout the breeding range of the species between 1970 and 1988. In the eastern United States and Canada, this decline has been quite consistent throughout the period, but in the central portion of the continent the population increased during the 1970's and declined during the early 1980's. Observers differ in their ability to hear woodcock, and we document observer differences in the singing-ground survey data and incorporate them into our analyses. Habitat changes have been suggested as the most likely cause of declines in woodcock populations.

Populations at risk: conservation genetics of kangaroo mice (Microdipodops) of the Great Basin Desert.

PubMed

Andersen, John J; Portnoy, David S; Hafner, John C; Light, Jessica E

2013-08-01

The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Dark (Microdipodops megacephalus) and pallid (M. pallidus) kangaroo mice are ecological specialists found within the Great Basin Desert and are potentially ideal organisms for assessing ecosystem health and inferring the biogeographic history of this vulnerable region. Herein, newly acquired nuclear-encoded microsatellite loci were utilized to assess patterns of variation within and among spatially discrete groups of kangaroo mice and to evaluate gene flow, demographic trends, and genetic integrity. Results confirm that there are at least three genetically distinct units within M. megacephalus and two such units within M. pallidus. The three units of M. megacephalus appear to have different demographic histories, with effectively no gene flow among them since their divergence. Similarly, the two units of M. pallidus also appear to have experienced different demographic histories, with effectively no gene exchange. Contemporary effective population sizes of all groups within Microdipodops appear to be low (<500), suggesting that each genetic lineage may have difficulty coping with changing environmental pressures and hence may be at risk of extirpation. Results of this study indicate that each Microdipodops group should be recognized, and therefore managed, as a separate unit in an effort to conserve these highly specialized taxa that contribute to the diversity of the Great Basin Desert ecosystem. The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Herein, newly acquired nuclear-encoded microsatellite loci were utilized to assess patterns of variation within and among spatially discrete groups of the dark (Microdipodops megacephalus) and pallid (M. pallidus) kangaroo mouse, and to evaluate gene flow, demographic trends, and genetic integrity. Results of this study indicate that each Microdipodops group should be recognized, and therefore managed, as a separate unit in an effort to conserve these highly specialized taxa that contribute to the diversity of the Great Basin Desert ecosystem (photo credit J. C. Hafner).

Life Course Trajectories of Systolic Blood Pressure Using Longitudinal Data from Eight UK Cohorts

PubMed Central

Wills, Andrew K.; Lawlor, Debbie A.; Matthews, Fiona E.; Aihie Sayer, Avan; Bakra, Eleni; Ben-Shlomo, Yoav; Benzeval, Michaela; Brunner, Eric; Cooper, Rachel; Kivimaki, Mika; Kuh, Diana; Muniz-Terrera, Graciela; Hardy, Rebecca

2011-01-01

Background Much of our understanding of the age-related progression of systolic blood pressure (SBP) comes from cross-sectional data, which do not directly capture within-individual change. We estimated life course trajectories of SBP using longitudinal data from seven population-based cohorts and one predominantly white collar occupational cohort, each from the United Kingdom and with data covering different but overlapping age periods. Methods and Findings Data are from 30,372 individuals and comprise 102,583 SBP observations spanning from age 7 to 80+y. Multilevel models were fitted to each cohort. Four life course phases were evident in both sexes: a rapid increase in SBP coinciding with peak adolescent growth, a more gentle increase in early adulthood, a midlife acceleration beginning in the fourth decade, and a period of deceleration in late adulthood where increases in SBP slowed and SBP eventually declined. These phases were still present, although at lower levels, after adjusting for increases in body mass index though adulthood. The deceleration and decline in old age was less evident after excluding individuals who had taken antihypertensive medication. Compared to the population-based cohorts, the occupational cohort had a lower mean SBP, a shallower annual increase in midlife, and a later midlife acceleration. The maximum sex difference was found at age 26 (+8.2 mm Hg higher in men, 95% CI: 6.7, 9.8); women then experienced steeper rises and caught up by the seventh decade. Conclusions Our investigation shows a general pattern of SBP progression from childhood in the UK, and suggests possible differences in this pattern during adulthood between a general population and an occupational population. Please see later in the article for the Editors' Summary PMID:21695075

Demographics of an ornate box turtle population experiencing minimal human-induced disturbances

USGS Publications Warehouse

Converse, S.J.; Iverson, J.B.; Savidge, J.A.

2005-01-01

Human-induced disturbances may threaten the viability of many turtle populations, including populations of North American box turtles. Evaluation of the potential impacts of these disturbances can be aided by long-term studies of populations subject to minimal human activity. In such a population of ornate box turtles (Terrapene ornata ornata) in western Nebraska, we examined survival rates and population growth rates from 1981-2000 based on mark-recapture data. The average annual apparent survival rate of adult males was 0.883 (SE = 0.021) and of adult females was 0.932 (SE = 0.014). Minimum winter temperature was the best of five climate variables as a predictor of adult survival. Survival rates were highest in years with low minimum winter temperatures, suggesting that global warming may result in declining survival. We estimated an average adult population growth rate (????) of 1.006 (SE = 0.065), with an estimated temporal process variance (????2) of 0.029 (95% CI = 0.005-0.176). Stochastic simulations suggest that this mean and temporal process variance would result in a 58% probability of a population decrease over a 20-year period. This research provides evidence that, unless unknown density-dependent mechanisms are operating in the adult age class, significant human disturbances, such as commercial harvest or turtle mortality on roads, represent a potential risk to box turtle populations. ?? 2005 by the Ecological Society of America.

Endless urban growth? On the mismatch of population, household and urban land area growth and its effects on the urban debate.

PubMed

Haase, Dagmar; Kabisch, Nadja; Haase, Annegret

2013-01-01

In European cities, the rate of population growth has declined significantly, while the number of households has increased. This increase in the number of households is associated with an increase in space for housing. To date, the effects of both a declining population and decreasing household numbers remain unclear. In this paper, we analyse the relationship between population and household number development in 188 European cities from 1990-2000 and 2000-2006 to the growth of urban land area and per capita living space. Our results support a trend toward decreasing population with simultaneously increasing household number. However, we also found cites facing both a declining population and a decreasing household number. Nevertheless, the urban land area of these "double-declining" cities has continued to spread because the increasing per capita living space counteracts a reduction in land consumption. We conclude that neither a decline in population nor in household number "automatically" solve the global problem of land consumption.

Full Mitogenomes in the Critically Endangered Kākāpō Reveal Major Post-Glacial and Anthropogenic Effects on Neutral Genetic Diversity.

PubMed

Dussex, Nicolas; von Seth, Johanna; Robertson, Bruce C; Dalén, Love

2018-04-19

Understanding how species respond to population declines is a central question in conservation and evolutionary biology. Population declines are often associated with loss of genetic diversity, inbreeding and accumulation of deleterious mutations, which can lead to a reduction in fitness and subsequently contribute to extinction. Using temporal approaches can help us understand the effects of population declines on genetic diversity in real time. Sequencing pre-decline as well as post-decline mitogenomes representing all the remaining mitochondrial diversity, we estimated the loss of genetic diversity in the critically endangered kākāpō ( Strigops habroptilus ). We detected a signal of population expansion coinciding with the end of the Pleistocene last glacial maximum (LGM). Also, we found some evidence for northern and southern lineages, supporting the hypothesis that the species may have been restricted to isolated northern and southern refugia during the LGM. We observed an important loss of neutral genetic diversity associated with European settlement in New Zealand but we could not exclude a population decline associated with Polynesian settlement in New Zealand. However, we did not find evidence for fixation of deleterious mutations. We argue that despite high pre-decline genetic diversity, a rapid and range-wide decline combined with the lek mating system, and life-history traits of kākāpō contributed to a rapid loss of genetic diversity following severe population declines.

The Decline of Teacher Entries into Manitoba: 1970 to 1978.

ERIC Educational Resources Information Center

Thompson, Joy C.

This summary is an examination of teacher inflow into Manitoba from other provinces and other countries. Manitoba has experienced a sharp decline in the total number of teacher entries over the period of 1970 to 1978. The percentage of total provincial staff that are newly recruited from outside Manitoba has shown a corresponding drop. Declines…

Origin and Decline of the First University Radio Web in France

ERIC Educational Resources Information Center

Giorgi, Sebastián Mariano

2017-01-01

"Résonances" was the first university radio web in France. It was founded at the University of Limoges, in 2010. This article is about the origin and decline of this transmedia project. Two strategies are here unfolded: historical the first one, ranging from the conception of the idea, the vicissitudes experienced by the team for…

Physiological condition of bank voles (Myodes glareolus) during the increase and decline phases of the population cycle.

PubMed

Nieminen, Petteri; Huitu, Otso; Henttonen, Heikki; Finnilä, Mikko A J; Voutilainen, Liina; Itämies, Juhani; Kärjä, Vesa; Saarela, Seppo; Halonen, Toivo; Aho, Jari; Mustonen, Anne-Mari

2015-09-01

The dynamics of animal populations are greatly influenced by interactions with their natural enemies and food resources. However, quantifying the relative effects of these factors on demographic rates remains a perpetual challenge for animal population ecology. Food scarcity is assumed to limit the growth and to initiate the decline of cyclic herbivore populations, but this has not been verified with physiological health indices. We hypothesized that individuals in declining populations would exhibit signs of malnutrition-induced deterioration of physiological condition. We evaluated the association of body condition with population cycle phase in bank voles (Myodes glareolus) during the increase and decline phases of a population cycle. The bank voles had lower body masses, condition indices and absolute masses of particular organs during the decline. Simultaneously, they had lower femoral masses, mineral contents and densities. Hemoglobin and hematocrit values and several parameters known to respond to food deprivation were unaffected by the population phase. There were no signs of lymphopenia, eosinophilia, granulocytosis or monocytosis. Erythrocyte counts were higher and plasma total protein levels and tissue proportions of essential polyunsaturated fatty acids lower in the population decline. Ectoparasite load was lower and adrenal gland masses or catecholamine concentrations did not suggest higher stress levels. Food availability seems to limit the size of voles during the decline but they can adapt to the prevailing conditions without clear deleterious health effects. This highlights the importance of quantifying individual health state when evaluating the effects of complex trophic interactions on the dynamics of wild animal populations. Copyright © 2015 Elsevier Inc. All rights reserved.

Demography, Education, and Democracy: global trends and the case of Iran.

PubMed

Lutz, Wolfgang; Cuaresma, Jesús Crespo; Abbasi-Shavazi, Mohammad Jalal

2010-01-01

Reconstructions and projections of populations by age, sex, and educational attainment for 120 countries since 1970 are used to assess the global relationship between improvements in human capital and democracy. Democracy is measured by the Freedom House indicator of political rights. Similar to an earlier study on the effects of improving educational attainment on economic growth, the greater age detail of this new dataset resolves earlier ambiguities about the effect of improving education as assessed using a global set of national time series. The results show consistently strong effects of improving overall levels of educational attainment, of a narrowing gender gap in education, and of fertility declines and the subsequent changes in age structure on improvements in the democracy indicator. This global relationship is then applied to the Islamic Republic of Iran. Over the past two decades Iran has experienced the world's most rapid fertility decline associated with massive increases in female education. The results show that based on the experience of 120 countries since 1970, Iran has a high chance of significant movement toward more democracy over the following two decades.

Batrachochytrium salamandrivorans and the risk of a second amphibian pandemic

USGS Publications Warehouse

Yap, Tiffany A.; Nguyen, Natalie T.; Serr, Megan; Shepak, Alex; Vredenburg, Vance

2017-01-01

Amphibians are experiencing devastating population declines globally. A major driver is chytridiomycosis, an emerging infectious disease caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Bdwas described in 1999 and has been linked with declines since the 1970s, while Bsal is a more recently discovered pathogen that was described in 2013. It is hypothesized that Bsaloriginated in Asia and spread via international trade to Europe, where it has been linked to salamander die-offs. Trade in live amphibians thus represents a significant threat to global biodiversity in amphibians. We review the current state of knowledge regarding Bsal and describe the risk of Bsal spread. We discuss regional responses to Bsal and barriers that impede a rapid, coordinated global effort. The discovery of a second deadly emerging chytrid fungal pathogen in amphibians poses an opportunity for scientists, conservationists, and governments to improve global biosecurity and further protect humans and wildlife from a growing number of emerging infectious diseases.

Unmet need for family planning in Ghana: the shifting contributions of lack of access and attitudinal resistance.

PubMed

Machiyama, Kazuyo; Cleland, John

2014-06-01

In Ghana, despite a 38 percent decline in the total fertility rate from 1988 to 2008, unmet need for family planning among married women exposed to pregnancy risk declined only modestly in this period: from 50 percent to 42 percent. Examining data from the five DHS surveys conducted in Ghana during these years, we find that the relative contribution to unmet need of lack of access to contraceptive methods has diminished, whereas attitudinal resistance has grown. In 2008, 45 percent of women with unmet need experienced no apparent obstacles associated with access or attitude, 32 percent had access but an unfavorable attitude, and 23 percent had no access. Concerns regarding health as a reason for nonuse have been reported in greater numbers over these years and are now the dominant reason, followed by infrequent sex. An enduring resistance to hormonal methods, much of it based on prior experience of side effects, may lead many Ghanaian women, particularly the educated in urban areas, to use periodic abstinence or reduced coital frequency as an alternative to modern contraception. © 2013 The Population Council, Inc.

The effects of declining population growth on the demand for housing.

Treesearch

Thomas C. Marcin

1974-01-01

Declining population growth and unprecedented changes in the age structure of the population in the next several decades will profoundly affect housing demand in the next 50 years. A decline in housing demand and substantial change in the type of housing in demand are likely to occur by 1990.

Sea otter population declines in the Aleutian Archipelago

USGS Publications Warehouse

Doroff, Angela M.; Estes, James A.; Tinker, M. Tim; Burn, Douglas M.; Evans, Thomas J.

2003-01-01

Sea otter (Enhydra lutris) populations were exploited to near extinction and began to recover after the cessation of commercial hunting in 1911. Remnant colonies of sea otters in the Aleutian archipelago were among the first to recover; they continued to increase through the 1980s but declined abruptly during the 1990s. We conducted an aerial survey of the Aleutian archipelago in 2000 and compared results with similar surveys conducted in 1965 and 1992. The number of sea otters counted decreased by 75% between 1965 and 2000; 88% for islands at equilibrial density in 1965. The population decline likely began in the mid-1980s and declined at a rate of 17.5%/year in the 1990s. The minimal population estimate was 8,742 sea otters in 2000. The population declined to a uniformly low density in the archipelago, suggesting a common and geographically widespread cause. These data are in general agreement with the hypothesis of increased predation on sea otters. These data chronicle one of the most widespread and precipitous population declines for a mammalian carnivore in recorded history.

Ecological Energetics of an Abundant Aerial Insectivore, the Purple Martin

PubMed Central

Kelly, Jeffrey F.; Bridge, Eli S.; Frick, Winifred F.; Chilson, Phillip B.

2013-01-01

The atmospheric boundary layer and lower free atmosphere, or aerosphere, is increasingly important for human transportation, communication, environmental monitoring, and energy production. The impacts of anthropogenic encroachment into aerial habitats are not well understood. Insectivorous birds and bats are inherently valuable components of biodiversity and play an integral role in aerial trophic dynamics. Many of these insectivores are experiencing range-wide population declines. As a first step toward gaging the potential impacts of these declines on the aerosphere’s trophic system, estimates of the biomass and energy consumed by aerial insectivores are needed. We developed a suite of energetics models for one of the largest and most common avian aerial insectivores in North America, the Purple Martin ( Progne subis ). The base model estimated that Purple Martins consumed 412 (± 104) billion insects*y-1 with a biomass of 115,860 (± 29,192) metric tonnes*y-1. During the breeding season Purple Martins consume 10.3 (+ 3.0) kg of prey biomass per km3 of aerial habitat, equal to about 36,000 individual insects*km-3. Based on these calculations, the cumulative seasonal consumption of insects*km-3 is greater in North America during the breeding season than during other phases of the annual cycle, however the maximum daily insect consumption*km-3 occurs during fall migration. This analysis provides the first range-wide quantitative estimate of the magnitude of the trophic impact of this large and common aerial insectivore. Future studies could use a similar modeling approach to estimate impacts of the entire guild of aerial insectivores at a variety of temporal and spatial scales. These analyses would inform our understanding of the impact of population declines among aerial insectivores on the aerosphere’s trophic dynamics. PMID:24086755

Predicting impacts of future human population growth and development on occupancy rates of forest-dependent birds

USGS Publications Warehouse

Brown, Michelle L.; Donovan, Therese; Schwenk, W. Scott; Theobald, David M.

2014-01-01

Forest loss and fragmentation are among the largest threats to forest-dwelling wildlife species today, and projected increases in human population growth are expected to increase these threats in the next century. We combined spatially-explicit growth models with wildlife distribution models to predict the effects of human development on 5 forest-dependent bird species in Vermont, New Hampshire, and Massachusetts, USA. We used single-species occupancy models to derive the probability of occupancy for each species across the study area in the years 2000 and 2050. Over half a million new housing units were predicted to be added to the landscape. The maximum change in housing density was nearly 30 houses per hectare; however, 30% of the towns in the study area were projected to add less than 1 housing unit per hectare. In the face of predicted human growth, the overall occupancy of each species decreased by as much as 38% (ranging from 19% to 38% declines in the worst-case scenario) in the year 2050. These declines were greater outside of protected areas than within protected lands. Ninety-seven percent of towns experienced some decline in species occupancy within their borders, highlighting the value of spatially-explicit models. The mean decrease in occupancy probability within towns ranged from 3% for hairy woodpecker to 8% for ovenbird and hermit thrush. Reductions in occupancy probability occurred on the perimeters of cities and towns where exurban development is predicted to increase in the study area. This spatial approach to wildlife planning provides data to evaluate trade-offs between development scenarios and forest-dependent wildlife species.

Meditation and Music Improve Memory and Cognitive Function in Adults with Subjective Cognitive Decline: A Pilot Randomized Controlled Trial.

PubMed

Innes, Kim E; Selfe, Terry Kit; Khalsa, Dharma Singh; Kandati, Sahiti

2017-01-01

While effective therapies for preventing or slowing cognitive decline in at-risk populations remain elusive, evidence suggests mind-body interventions may hold promise. In this study, we assessed the effects of Kirtan Kriya meditation (KK) and music listening (ML) on cognitive outcomes in adults experiencing subjective cognitive decline (SCD), a strong predictor of Alzheimer's disease. Sixty participants with SCD were randomized to a KK or ML program and asked to practice 12 minutes/day for 3 months, then at their discretion for the ensuing 3 months. At baseline, 3 months, and 6 months we measured memory and cognitive functioning [Memory Functioning Questionnaire (MFQ), Trail-making Test (TMT-A/B), and Digit-Symbol Substitution Test (DSST)]. The 6-month study was completed by 53 participants (88%). Participants performed an average of 93% (91% KK, 94% ML) of sessions in the first 3 months, and 71% (68% KK, 74% ML) during the 3-month, practice-optional, follow-up period. Both groups showed marked and significant improvements at 3 months in memory and cognitive performance (MFQ, DSST, TMT-A/B; p's≤0.04). At 6 months, overall gains were maintained or improved (p's≤0.006), with effect sizes ranging from medium (DSST, ML group) to large (DSST, KK group; TMT-A/B, MFQ). Changes were unrelated to treatment expectancies and did not differ by age, gender, baseline cognition scores, or other factors. Findings of this preliminary randomized controlled trial suggest practice of meditation or ML can significantly enhance both subjective memory function and objective cognitive performance in adults with SCD, and may offer promise for improving outcomes in this population.

The rise of digital direct-to-consumer advertising?: Comparison of direct-to-consumer advertising expenditure trends from publicly available data sources and global policy implications.

PubMed

Mackey, Tim K; Cuomo, Raphael E; Liang, Bryan A

2015-06-19

Pharmaceutical marketing is undergoing a major shift in the United States, in part due to new transparency regulations under the healthcare reform act. Changes in pharmaceutical marketing practices include a possible shift from more traditional forms of direct-to-consumer advertising towards emerging use of Internet-based DTCA ("eDTCA") given the growing importance of digital health or "eHealth." Though legally allowed only in the U.S. and New Zealand, eDTCA poses novel regulatory challenges, as it can cross geopolitical boundaries and impact health systems and populations outside of these countries. We wished to assess whether changes in DTCA and eDTCA expenditure trends was occurring using publicly available pharmaceutical marketing data. DTCA data was analyzed to compare trends in aggregate marketing expenditures and to assess if there were statistically significant differences in trends and magnitudes for data sources and DTCA sub-categories (including eDTCA). This was accomplished using regression lines of DTCA trend data and conducting pairwise comparisons of regression coefficients using t-tests. Means testing was utilized for comparing magnitude of DTCA expenditure. Data from multiple data sources indicate that aggregate DTCA expenditures have slightly declined during the period from 2005-2009 and are consistent with results from other studies. For DTCA sub-categories, television remained the most utilized form of DTCA, though experienced trends of declining expenditures (-13.2 %) similar to other traditional media platforms such as radio (-30.7 %) and outdoor ads (-12.1 %). The only DTCA sub-category that experienced substantial increased expenditures was eDTCA (+109.0 %) and it was the only medium that had statistically significant differences in its marketing expenditure trends compared to other DTCA sub-categories. Our study indicates that traditional DTCA marketing may be on the decline. Conversely, the only DTCA sub-category that experienced significant increases was eDTCA. However, to fully understand this possible shift to "digital" DTCA, improvements in publicly available DTCA data sources are necessary to confirm changing trends and validate existing data. Hence, utilizing the newly implemented U.S. physician-payment expenditure transparency requirements, we advocate for the mandatory disclosure of DTCA/eDTCA in order to inform future domestic and international health policy efforts regarding appropriate regulation of pharmaceutical promotion.

Predicting the effects of copper on local population decline of 2 marine organisms, cobia fish and whiteleg shrimp, based on avoidance response.

PubMed

Araújo, Cristiano V M; Cedeño-Macías, Luís A; Vera-Vera, Victoria C; Salvatierra, David; Rodríguez, Elizabeth N V; Zambrano, Ufredo; Kuri, Samir

2016-02-01

The present study focuses on avoidance response to predict population decline of the marine fish Rachycentron canadum (cobia) and larvae of the estuarine shrimp Litopenaeus vannamei (whiteleg shrimp). Avoidance of approximately 60% was recorded for the cobia fry exposed to 1.0 mg Cu/L, 1.60 mg Cu/L, and 1.80 mg Cu/L. For the shrimp larvae, avoidance was approximately 80% for all Cu concentrations. The population decline of cobia fry was conditioned by avoidance in lower concentrations. However, in higher concentrations mortality begins to play an important role. The displacement toward uncontaminated habitats might determine shrimp population decline. A Cu-contaminated environment can determine the habitat selection of both species and, therefore, their local population decline. © 2015 SETAC.

Community differences in the implementation of Strong Communities for Children.

PubMed

McLeigh, Jill D; McDonell, James R; Melton, Gary B

2015-03-01

In 1993, the U.S. Advisory Board on Child Abuse and Neglect recommended a neighborhood-based strategy to prevent child abuse and neglect. The Board further recommended the development of Prevention Zones to allow for testing of the effectiveness of community-wide child protection efforts in neighborhoods of differing population density, ethnic and cultural composition, and social and economic resources. Following the Board's recommendation, this article presents the results of a trial of the effectiveness of a neighborhood-based strategy in low- and high-resource communities. Using management, survey, and administrative data, the research showed that both community types experienced declines in founded cases of and injuries suggesting child maltreatment for children under age 5. Low-resource communities experienced greater levels of mobilization, as measured by community and institutional engagement, and a greater number of positive outcomes related to changes in the quality of life for families and community norms relative to child and family well-being. In particular, the low-resource communities experienced the largest increases in receiving help from neighbors, neighboring, perceived household safety for neighborhood children, and observed positive parenting. High-resource communities experienced greater increases in intermediate outcomes related to self-reported parenting practices. The findings suggest that, ultimately, community mobilization can occur and be an effective means of preventing child maltreatment across community types. It appears, however, that community mobilization may play a more significant role in low-resource communities. Copyright © 2014 Elsevier Ltd. All rights reserved.

Non-stationary recruitment dynamics of rainbow smelt: the influence of environmental variables and variation in size structure and length-at-maturation

USGS Publications Warehouse

Feiner, Zachary S.; Bunnell, David B.; Hook, Tomas O.; Madenjian, Charles P.; Warner, David M.; Collingsworth, Paris D.

2015-01-01

Fish stock-recruitment dynamics may be difficult to elucidate because of nonstationary relationships resulting from shifting environmental conditions and fluctuations in important vital rates such as individual growth or maturation. The Great Lakes have experienced environmental stressors that may have changed population demographics and stock-recruitment relationships while causing the declines of several prey fish species, including rainbow smelt (Osmerus mordax). We investigated changes in the size and maturation of rainbow smelt in Lake Michigan and Lake Huron and recruitment dynamics of the Lake Michigan stock over the past four decades. Mean lengths and length-at-maturation of rainbow smelt generally declined over time in both lakes. To evaluate recruitment, we used both a Ricker model and a Kalman filter-random walk (KF-RW) model which incorporated nonstationarity in stock productivity by allowing the productivity term to vary over time. The KF-RW model explained nearly four times more variation in recruitment than the Ricker model, indicating the productivity of the Lake Michigan stock has increased. By accounting for this nonstationarity, we were able identify significant variations in stock productivity, evaluate its importance to rainbow smelt recruitment, and speculate on potential environmental causes for the shift. Our results suggest that investigating mechanisms driving nonstationary shifts in stock-recruit relationships can provide valuable insights into temporal variation in fish population dynamics.

Vulnerability of shortgrass prairie bird assemblages to climate change

USGS Publications Warehouse

Skagen, Susan K.; Dreitz, Victoria; Conrey, Reesa Y.; Yackel, Amy; Panjabi, Arvind O.; Knuffman, Lekha

2016-01-01

The habitats and resources needed to support grassland birds endemic to North American prairie ecosystems are seriously threatened by impending climate change. To assess the vulnerability of grassland birds to climate change, we consider various components of vulnerability, including sensitivity, exposure, and adaptive capacity (Glick et al. 2011). Sensitivity encompasses the innate characteristics of a species and, in this context, is related to a species’ tolerance to changes in weather patterns. Groundnesting birds, including prairie birds, are particularly responsive to heat waves combined with drought conditions, as revealed by abundance and distribution patterns (Albright et al. 2010). To further assess sensitivity, we estimated reproductive parameters of nearly 3000 breeding attempts of a suite of prairie birds relative to prevailing weather. Fluctuations in weather conditions in eastern Colorado, 1997-2014, influenced breeding performance of a suite of avian species endemic to the shortgrass prairie, many of which have experienced recent population declines. High summer temperatures and intense rain events corresponded with lower nest survival for most species. Although dry conditions favored nest survival of Burrowing Owls and Mountain Plovers (Conrey 2010, Dreitz et al. 2012), drought resulted in smaller clutch sizes and lower nest survival for passerines (Skagen and Yackel Adams 2012, Conrey et al. in review). Declining summer precipitation may reduce the likelihood that some passerine species can maintain stable breeding populations in this region of the shortgrass prairie.

Habitat availability is a more plausible explanation than insecticide acute toxicity for U.S. grassland bird species declines

USGS Publications Warehouse

Hill, Jason M.; Egan, J. Franklin; Stauffer, Glenn E.; Diefenbach, Duane R.

2014-01-01

Grassland bird species have experienced substantial declines in North America. These declines have been largely attributed to habitat loss and degradation, especially from agricultural practices and intensification (the habitat-availability hypothesis). A recent analysis of North American Breeding Bird Survey (BBS) “grassland breeding” bird trends reported the surprising conclusion that insecticide acute toxicity was a better correlate of grassland bird declines in North America from 1980–2003 (the insecticide-acute-toxicity hypothesis) than was habitat loss through agricultural intensification. In this paper we reached the opposite conclusion. We used an alternative statistical approach with additional habitat covariates to analyze the same grassland bird trends over the same time frame. Grassland bird trends were positively associated with increases in area of Conservation Reserve Program (CRP) lands and cropland used as pasture, whereas the effect of insecticide acute toxicity on bird trends was uncertain. Our models suggested that acute insecticide risk potentially has a detrimental effect on grassland bird trends, but models representing the habitat-availability hypothesis were 1.3–21.0 times better supported than models representing the insecticide-acute-toxicity hypothesis. Based on point estimates of effect sizes, CRP area and agricultural intensification had approximately 3.6 and 1.6 times more effect on grassland bird trends than lethal insecticide risk, respectively. Our findings suggest that preserving remaining grasslands is crucial to conserving grassland bird populations. The amount of grassland that has been lost in North America since 1980 is well documented, continuing, and staggering whereas insecticide use greatly declined prior to the 1990s. Grassland birds will likely benefit from the de-intensification of agricultural practices and the interspersion of pastures, Conservation Reserve Program lands, rangelands and other grassland habitats into existing agricultural landscapes.

Multiple Imputation of Cognitive Performance as a Repeatedly Measured Outcome

PubMed Central

Rawlings, Andreea M.; Sang, Yingying; Sharrett, A. Richey; Coresh, Josef; Griswold, Michael; Kucharska-Newton, Anna M.; Palta, Priya; Wruck, Lisa M.; Gross, Alden L.; Deal, Jennifer A.; Power, Melinda C.; Bandeen-Roche, Karen

2016-01-01

Background Longitudinal studies of cognitive performance are sensitive to dropout, as participants experiencing cognitive deficits are less likely to attend study visits, which may bias estimated associations between exposures of interest and cognitive decline. Multiple imputation is a powerful tool for handling missing data, however its use for missing cognitive outcome measures in longitudinal analyses remains limited. Methods We use multiple imputation by chained equations (MICE) to impute cognitive performance scores of participants who did not attend the 2011-2013 exam of the Atherosclerosis Risk in Communities Study. We examined the validity of imputed scores using observed and simulated data under varying assumptions. We examined differences in the estimated association between diabetes at baseline and 20-year cognitive decline with and without imputed values. Lastly, we discuss how different analytic methods (mixed models and models fit using generalized estimate equations) and choice of for whom to impute result in different estimands. Results Validation using observed data showed MICE produced unbiased imputations. Simulations showed a substantial reduction in the bias of the 20-year association between diabetes and cognitive decline comparing MICE (3-4% bias) to analyses of available data only (16-23% bias) in a construct where missingness was strongly informative but realistic. Associations between diabetes and 20-year cognitive decline were substantially stronger with MICE than in available-case analyses. Conclusions Our study suggests when informative data are available for non-examined participants, MICE can be an effective tool for imputing cognitive performance and improving assessment of cognitive decline, though careful thought should be given to target imputation population and analytic model chosen, as they may yield different estimands. PMID:27619926

Biodiversity Loss following the Introduction of Exotic Competitors: Does Intraguild Predation Explain the Decline of Native Lady Beetles?

PubMed Central

Smith, Chelsea A.; Gardiner, Mary M.

2013-01-01

Exotic species are widely accepted as a leading cause of biodiversity decline. Lady beetles (Coccinellidae) provide an important model to study how competitor introductions impact native communities since several native coccinellids have experienced declines that coincide with the establishment and spread of exotic coccinellids. This study tested the central hypothesis that intraguild predation by exotic species has caused these declines. Using sentinel egg experiments, we quantified the extent of predation on previously-common (Hippodamia convergens) and common (Coleomegilla maculata) native coccinellid eggs versus exotic coccinellid (Harmonia axyridis) eggs in three habitats: semi-natural grassland, alfalfa, and soybean. Following the experiments quantifying egg predation, we used video surveillance to determine the composition of the predator community attacking the eggs. The extent of predation varied across habitats, and egg species. Native coccinellids often sustained greater egg predation than H. axyridis. We found no evidence that exotic coccinellids consumed coccinellid eggs in the field. Harvestmen and slugs were responsible for the greatest proportion of attacks. This research challenges the widely-accepted hypothesis that intraguild predation by exotic competitors explains the loss of native coccinellids. Although exotic coccinellids may not be a direct competitor, reduced egg predation could indirectly confer a competitive advantage to these species. A lower proportion of H. axyridis eggs removed by predators may have aided its expansion and population increase and could indirectly affect native species via exploitative or apparent competition. These results do not support the intraguild predation hypothesis for native coccinellid decline, but do bring to light the existence of complex interactions between coccinellids and the guild of generalist predators in coccinellid foraging habitats. PMID:24386383

Habitat availability is a more plausible explanation than insecticide acute toxicity for U.S. grassland bird species declines.

PubMed

Hill, Jason M; Egan, J Franklin; Stauffer, Glenn E; Diefenbach, Duane R

2014-01-01

Grassland bird species have experienced substantial declines in North America. These declines have been largely attributed to habitat loss and degradation, especially from agricultural practices and intensification (the habitat-availability hypothesis). A recent analysis of North American Breeding Bird Survey (BBS) "grassland breeding" bird trends reported the surprising conclusion that insecticide acute toxicity was a better correlate of grassland bird declines in North America from 1980-2003 (the insecticide-acute-toxicity hypothesis) than was habitat loss through agricultural intensification. In this paper we reached the opposite conclusion. We used an alternative statistical approach with additional habitat covariates to analyze the same grassland bird trends over the same time frame. Grassland bird trends were positively associated with increases in area of Conservation Reserve Program (CRP) lands and cropland used as pasture, whereas the effect of insecticide acute toxicity on bird trends was uncertain. Our models suggested that acute insecticide risk potentially has a detrimental effect on grassland bird trends, but models representing the habitat-availability hypothesis were 1.3-21.0 times better supported than models representing the insecticide-acute-toxicity hypothesis. Based on point estimates of effect sizes, CRP area and agricultural intensification had approximately 3.6 and 1.6 times more effect on grassland bird trends than lethal insecticide risk, respectively. Our findings suggest that preserving remaining grasslands is crucial to conserving grassland bird populations. The amount of grassland that has been lost in North America since 1980 is well documented, continuing, and staggering whereas insecticide use greatly declined prior to the 1990s. Grassland birds will likely benefit from the de-intensification of agricultural practices and the interspersion of pastures, Conservation Reserve Program lands, rangelands and other grassland habitats into existing agricultural landscapes.

Declining average daily census. Part 1: Implications and options.

PubMed

Weil, T P

1985-12-01

A national trend toward declining average daily (inpatient) census (ADC) started in late 1982 even before the Medicare prospective payment system began. The decrease in total days will continue despite an increasing number of aged persons in the U.S. population. This decline could have been predicted from trends during 1978 to 1983, such as increasing available beds but decreasing occupancy, 100 percent increases in hospital expenses, and declining lengths of stay. Assuming that health care costs will remain as a relatively fixed part of the gross national product and no major medical advances will occur in the next five years, certain implications and options exist for facilities experiencing a declining ADC. This article discusses several considerations: Attempts to improve market share; Reduction of full-time equivalent employees; Impact of greater acuity of illness among remaining inpatients; Implications of increasing the number of physicians on medical staffs; Option of a closed medical staff by clinical specialty; Unbundling with not-for-profit and profit-making corporations; Review of mergers, consolidations, and multihospital systems to decide when this option is most appropriate; Sale of a not-for-profit hospital to an investor-owned chain, with implications facing Catholic hospitals choosing this option; Impact and difficulty of developing meaningful alternative health care systems with the hospital's medical staff; Special problems of teaching hospitals; The social issue of the hospital shifting from the community's health center to a cost center; Increased turnover of hospital CEOs; With these in mind, institutions can then focus on solutions that can sometimes be used in tandem to resolve this problem's impact. The second part of this article will discuss some of them.

Body and diet composition of sympatric black and grizzly bears in the Greater Yellowstone Ecosystem

USGS Publications Warehouse

Schwartz, Charles C.; Fortin, Jennifer K.; Teisberg, Justin E.; Haroldson, Mark A.; Servheen, Christopher; Robbins, Charles T.; van Manen, Frank T.

2013-01-01

The Greater Yellowstone Ecosystem (GYE) has experienced changes in the distribution and availability of grizzly bear (Ursus arctos) food resources in recent decades. The decline of ungulates, fish, and whitebark pine seeds (Pinus albicaulis) has prompted questions regarding their ability to adapt. We examined body composition and diet of grizzly bears using bioelectrical impedance and stable isotopes to determine if 1) we can detect a change in diet quality associated with the decline in either ungulates or whitebark pine, and 2) the combined decline in ungulates, fish, and pine seeds resulted in a change in grizzly bear carrying capacity in the GYE. We contrasted body fat and mass in grizzly bears with a potential competitor, the American black bear (Ursus americanus), to address these questions. Grizzly bears assimilated more meat into their diet and were in better body condition than black bears throughout the study period, indicating the decline in ungulate resources did not affect grizzly bears more than black bears. We also found no difference in autumn fat levels in grizzly bears in years of good or poor pine seed production, and stable isotope analyses revealed this was primarily a function of switching to meat resources during poor seed-producing years. This dietary plasticity was consistent over the course of our study. We did not detect an overall downward trend in either body mass or the fraction of meat assimilated into the diet by grizzly bears over the past decade, but we did detect a downward trend in percent body fat in adult female grizzly bears after 2006. Whether this decline is an artifact of small sample size or due to the population reaching the ecological carrying capacity of the Yellowstone ecosystem warrants further investigation.

Falls and cognitive decline in Mexican Americans 75 years and older

PubMed Central

Padubidri, Anokha; Al Snih, Soham; Samper-Ternent, Rafael; Markides, Kyriakos S; Ottenbacher, Kenneth J; Raji, Mukaila A

2014-01-01

Background Little is known about long-term emotional and cognitive consequences of falls. We examined the association between falls and subsequent cognitive decline, and tested the hypothesis that depression would mediate any falls–cognition association among cognitively intact Hispanic Elders. Methods We used data from the Hispanic Established Population for the Epidemiological Study of the Elderly to examine change in Mini Mental State Examination (MMSE) scores over the 6-year period according to number of falls. All participants (N=1,119) had MMSE scores ≥21 and complete data on Center for Epidemiologic Studies of Depression Scale, social and demographic factors, medical conditions (diabetes, heart attack, stroke, and hypertension), and hand grip muscle strength. Results At baseline, participants’ mean age was 80.8 years (range, 74–109), mean education was 6.3 years (range, 0–17), and mean MMSE was 25.2 (range, 21–30). Of the 1,119 participants, 15.8% experienced one fall and 14.4% had two or more falls. In mixed model analyses, having two or more falls was associated with greater decline in MMSE score (estimate =−0.81, standard error =0.19, P<0.0001) compared to having no fall, after adjusting for age, sex, marital status, and education. The magnitude of the association decreased (estimate =−0.65, standard error =0.19, P=0.0007) when adjustment was made for high depressive symptoms, suggesting a possible mediating effect of depression on the falls–cognition association. Female sex, high level of education, and high performance in hand grip muscle strength were associated with a slower decline in MMSE scores. Conclusion Having two or more falls was independently associated with steeper decline in cognition over 6 years, with a possible mediating effect of depression on the falls–cognition association. PMID:24790424

Habitat Availability Is a More Plausible Explanation than Insecticide Acute Toxicity for U.S. Grassland Bird Species Declines

PubMed Central

Hill, Jason M.; Egan, J. Franklin; Stauffer, Glenn E.; Diefenbach, Duane R.

2014-01-01

Grassland bird species have experienced substantial declines in North America. These declines have been largely attributed to habitat loss and degradation, especially from agricultural practices and intensification (the habitat-availability hypothesis). A recent analysis of North American Breeding Bird Survey (BBS) “grassland breeding” bird trends reported the surprising conclusion that insecticide acute toxicity was a better correlate of grassland bird declines in North America from 1980–2003 (the insecticide-acute-toxicity hypothesis) than was habitat loss through agricultural intensification. In this paper we reached the opposite conclusion. We used an alternative statistical approach with additional habitat covariates to analyze the same grassland bird trends over the same time frame. Grassland bird trends were positively associated with increases in area of Conservation Reserve Program (CRP) lands and cropland used as pasture, whereas the effect of insecticide acute toxicity on bird trends was uncertain. Our models suggested that acute insecticide risk potentially has a detrimental effect on grassland bird trends, but models representing the habitat-availability hypothesis were 1.3–21.0 times better supported than models representing the insecticide-acute-toxicity hypothesis. Based on point estimates of effect sizes, CRP area and agricultural intensification had approximately 3.6 and 1.6 times more effect on grassland bird trends than lethal insecticide risk, respectively. Our findings suggest that preserving remaining grasslands is crucial to conserving grassland bird populations. The amount of grassland that has been lost in North America since 1980 is well documented, continuing, and staggering whereas insecticide use greatly declined prior to the 1990s. Grassland birds will likely benefit from the de-intensification of agricultural practices and the interspersion of pastures, Conservation Reserve Program lands, rangelands and other grassland habitats into existing agricultural landscapes. PMID:24846309

Worldwide status of burbot and conservation measures

USGS Publications Warehouse

Stapanian, Martin A.; Paragamian, Vaughn L.; Madenjian, Charles P.; Jackson, James R.; Lappalainen, Jyrki; Evenson, Matthew J.; Neufeld, Matthew D.

2010-01-01

Although burbot (Lota lota Gadidae) are widespread and abundant throughout much of their natural range, there are many populations that have been extirpated, endangered or are in serious decline. Due in part to the species’ lack of popularity as a game and commercial fish, few regions consider burbot in management plans. We review the worldwide population status of burbot and synthesize reasons why some burbot populations are endangered or declining, some burbot populations have recovered and some burbot populations do not recover despite management measures. Burbot have been extirpated in much of Western Europe and the United Kingdom and are threatened or endangered in much of North America and Eurasia. Pollution and habitat change, particularly the effects of dams, appear to be the main causes for declines in riverine burbot populations. Pollution and the adverse effects of invasive species appear to be the main reasons for declines in lacustrine populations. Warmer water temperatures, due either to discharge from dams or climate change, have been noted in declining burbot populations at the southern extent of their range. Currently, fishing pressure does not appear to be limiting burbot populations world-wide. We suggest mitigation measures for burbot population recovery, particularly those impacted by dams and invasive species.

Relationship between employment histories and frailty trajectories in later life: evidence from the English Longitudinal Study of Ageing.

PubMed

Lu, Wentian; Benson, Rebecca; Glaser, Karen; Platts, Loretta G; Corna, Laurie M; Worts, Diana; McDonough, Peggy; Di Gessa, Giorgio; Price, Debora; Sacker, Amanda

2017-05-01

Given the acceleration of population ageing and policy changes to extend working lives, evidence is needed on the ability of older adults to work for longer. To understand more about the health impacts of work, this study examined the relationship between employment histories before retirement and trajectories of frailty thereafter. The sample comprised 2765 women and 1621 men from the English Longitudinal Study of Ageing. We used gendered typologies of life-time employment and a frailty index (FI). Multilevel growth curve models were used to predict frailty trajectories by employment histories. Women who had a short break for family care, then did part-time work till 59 years had a lower FI after 60 years than those who undertook full-time work until 59 years. Women who were largely family carers or non-employed throughout adulthood, had higher levels of frailty at 60 years but experienced a slower decline with age. Men who worked full-time but early exited at either 49 or 60 years had a higher FI at 65 years than those who worked full-time up to 65 years. Interaction between employment histories and age indicated that men in full-time work who experienced an early exit at 49 tended to report slower declines. For women, experiencing distinct periods throughout the lifecourse of either work or family care may be advantageous for lessening frailty risk in later life. For men, leaving paid employment before 65 years seems to be beneficial for decelerating increases in frailty thereafter. Continuous full-time work until retirement age conferred no long-term health benefits. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

[Rural depopulation: 1954-1990].

PubMed

Chauvel, L

1994-10-01

"The purpose of this paper is to present evidence for a long term link between employment and population [in rural France]. A model is built in order to describe the interaction between employment, migration and natural population increase over 1962-1990. This shows how declining departments are bound within a vicious mechanism: while the decline of local employment leads to population outflow, the population decline contributes to a further employment fall." (SUMMARY IN ENG) excerpt

Vicarious stress: patterns of disturbance and use of mental health services by those indirectly affected by the Oklahoma City bombing.

PubMed

Sprang, G

2001-10-01

This study explored the intermediate psychological effects of terrorism on adults not directly affected by the Oklahoma City bombing by examining the course of PTSD and subthreshold PTSD symptoms over time and whether treatment affected this course. The respondents were interviewed at 3-mo. intervals for 18 mo. following an initial 6-mo. survey. Analysis suggested avoidance, re-experiencing, and increased arousal symptoms in this population were limited over time, declining with or without treatment between 6 and 9 mo. Conversely, victimization symptoms remained high without mental health intervention for the first year after the disaster. The study also examined the nature and occurrence of comorbidity in groups seeking and not seeking treatment.

Home-grown slaves: women, reproduction, and the abolition of the slave trade, Jamaica 1788-1807.

PubMed

Turner, Sasha

2011-01-01

Once the British transatlantic slave trade came under abolitionists' scrutiny in 1788, West Indian slaveholders had to consider alternative methods of obtaining well-needed laborers. This article examines changes in enslaved women's working lives as planters sought to increase birth rates to replenish declining laboring populations. By focusing more on variances in work assignment and degrees of punishment rather than their absence, this article establishes that enslaved women in Jamaica experienced a considerable shift in their work responsibilities and their subjection to discipline as slaveholders sought to capitalize on their abilities to reproduce. Enslaved women's reproductive capabilities were pivotal for slavery and the plantation economy's survival once legal supplies from Africa were discontinued.

Decline in physical performance among women with a recent transient ischemic attack or ischemic stroke: opportunities for functional preservation a report of the Women's Estrogen Stroke Trial.

PubMed

Kernan, Walter N; Viscoli, Catherine M; Brass, Lawrence M; Gill, Thomas M; Sarrel, Philip M; Horwitz, Ralph I

2005-03-01

Physical performance for walking, reaching, turning, and other common tasks is a major determinant of functional independence after stroke. Current strategies to preserve physical performance focus on prevention of recurrent stroke. Loss of physical performance, however, may occur in the absence of recurrence. To examine this possibility, we measured change in physical performance, independent of subsequent stroke, among women with a recent ischemic stroke or transient ischemic attack (TIA). Among 664 postmenopausal women who participated in a clinical trial of estrogen therapy after stroke or TIA, we administered the Physical Performance Test (PPT) at baseline (mean 58 days from the cerebrovascular event) and annually. Women who died or had a stroke during follow-up were censored. Decline or improvement in physical performance was defined as a change in the PPT score from baseline of at least 3 points. Sustained decline or improvement was defined as 2 consecutive years during which the score had declined or improved, respectively, relative to the baseline score. With each year of follow-up, a smaller proportion of the cohort demonstrated improvement (16% in year 1, 6% in year 5) and a larger proportion demonstrated decline (15% in year 1, 35% in year 5). In an analysis restricted to 259 women with 3 years of follow-up, 46 (18%) experienced a nonsustained decline in physical performance, and 39 (15%) experienced a sustained decline. Decline in physical performance is common after an ischemic stroke or TIA even in the absence of a recurrent neurological event. Our findings suggest that specific interventions to maintain and improve physical performance may be important for reducing long-term disability.

An analysis of social consequences of rapid fertility decline in China.

PubMed

Liu, Z; Liu, L

1988-12-01

Rapid fertility decline in China has brought about 2 direct effects: 1) the natural increase of the population has slowed down, and 2) the age structure has changed from the young to the adult type. These 2 effects have caused a series of economic and social consequences. Rapid fertility decline increases the gross national product per capita and accelerates the improvement of people's lives. Rapid fertility decline slows population growth and speeds up the accumulation of capital and the development of the economy. Since 1981, accumulation growth has exceeded consumption growth. Fertility decline alleviates the enrollment pressure on primary and secondary schools, raises the efficiency of education funds, and promotes the popularization of education. The family planning program strengthens the maternal and child health care and the medical care systems. As the result of economic development, the people's nutritional levels are improving. The physical quality of teenagers has improved steadily. The change in the age structure will alleviate the tension of rapid population growth and benefit population control in the next century. Fertility decline forces the traditional attitude toward childbearing from "more children, more happiness" to improved quality of children. The rapid fertility decline has caused a great deal of concern both inside and outside China about the aging of the population. The labor force, however, will continue to grow for the next 60 years. At present, China's population problems are still those of population growth.

Beyond the disease: Is Toxoplasma gondii infection causing population declines in the eastern quoll (Dasyurus viverrinus)?

PubMed Central

Fancourt, Bronwyn A.; Nicol, Stewart C.; Hawkins, Clare E.; Jones, Menna E.; Johnson, Chris N.

2014-01-01

Disease is often considered a key threat to species of conservation significance. For some, it has resulted in localised extinctions and declines in range and abundance. However, for some species, the assertion that a disease poses a significant threat of extinction is based solely on correlative or anecdotal evidence, often inferred from individual clinical case reports. While a species’ susceptibility to a disease may be demonstrated in a number of individuals, investigations rarely extend to measuring the impact of disease at the population level and its contribution, if any, to population declines. The eastern quoll (Dasyurus viverrinus) is a medium-sized Australian marsupial carnivore that is undergoing severe and rapid decline in Tasmania, its last refuge. Reasons for the decline are currently not understood. Feral cats (Felis catus) may be undergoing competitive release following the ongoing decline of the Tasmanian devil (Sarcophilus harrisii), with cats suppressing eastern quolls through increased predation, competition, exclusion or exposure to diseases such as toxoplasmosis. To investigate the effects of Toxoplasma gondii infection, eastern quoll populations at four sites were regularly screened for the seroprevalence of T. gondii-specific IgG antibodies. Seroprevalence was approximately five times higher at sites with declining quoll populations, and there was a negative association between seroprevalence and quoll abundance. However, T. gondii infection did not reduce quoll survival or reproduction. Despite a high susceptibility to T. gondii infection, eastern quoll populations do not appear to be limited by the parasite or its resultant disease. Significantly higher seroprevalence is a signal of greater exposure to feral cats at sites where eastern quolls are declining, suggesting that increased predation, competition or exclusion by feral cats may be precipitating population declines. PMID:25161908

Episodic death across species of desert shrubs.

PubMed

Miriti, Maria N; Rodríguez-Buriticá, Susana; Wright, S Joseph; Howe, Henry F

2007-01-01

Extreme events shape population and community trajectories. We report episodic mortality across common species of thousands of long-lived perennials individually tagged and monitored for 20 years in the Colorado Desert of California following severe regional drought. Demographic records from 1984 to 2004 show 15 years of virtual stasis in populations of adult shrubs and cacti, punctuated by a 55-100% die-off of six of the seven most common perennial species. In this episode, adults that experienced reduced growth in a lesser drought during 1984-1989 failed to survive the drought of 2002. The significance of this event is potentially profound because population dynamics of long-lived plants can be far more strongly affected by deaths of adults, which in deserts potentially live for centuries, than by seedling births or deaths. Differential mortality and rates of recovery during and after extreme climatic events quite likely determine the species composition of plant and associated animal communities for at least decades. The die-off recorded in this closely monitored community provides a unique window into the mechanics of this process of species decline and replacement.

Presence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in threatened corroboree frog populations in the Australian Alps.

PubMed

Hunter, David A; Speare, Rick; Marantelli, Gerry; Mendez, Diana; Pietsch, Rod; Osborne, Will

2010-11-01

Since the early 1980s, the southern corroboree frog Pseudophryne corroboree and northern corroboree frog P. pengilleyi have been in a state of decline from their sub-alpine and high montane bog environments on the southern tablelands of New South Wales, Australia. To date, there has been no adequate explanation as to what is causing the decline of these species. We investigated the possibility that a pathogen associated with other recent frog declines in Australia, the amphibian chytrid fungus Batrachochytrium dendrobatidis, may have been implicated in the decline of the corroboree frogs. We used histology of toe material and real-time PCR of skin swabs to investigate the presence and infection rates with B. dendrobatidis in historic and extant populations of both corroboree frog species. Using histology, we did not detect any B. dendrobatidis infections in corroboree frog populations prior to their decline. However, using the same technique, high rates of infection were observed in populations of both species after the onset of substantial population declines. The real-time PCR screening of skin swabs identified high overall infection rates in extant populations of P. corroboree (between 44 and 59%), while significantly lower rates of infection were observed in low-altitude P. pengilleyi populations (14%). These results suggest that the initial and continued decline of the corroboree frogs may well be attributed to the emergence of B. dendrobatidis in populations of these species.

Demographic and clinical characteristics related to cognitive decline in Alzheimer disease in China: A multicenter survey from 2011 to 2014.

PubMed

Peng, Dantao; Shi, Zhihong; Xu, Jun; Shen, Lu; Xiao, Shifu; Zhang, Nan; Li, Yi; Jiao, Jinsong; Wang, Yan-Jiang; Liu, Shuai; Zhang, Meilin; Wang, Meng; Liu, Shuling; Zhou, Yuying; Zhang, Xiao; Gu, Xiao-Hua; Yang, Ce-Ce; Wang, Yu; Jiao, Bin; Tang, Beisha; Wang, Jinhuan; Yu, Tao; Ji, Yong

2016-06-01

Alzheimer disease (AD) is the most frequent cause of dementia. AD diagnosis, progression, and treatment have not been analyzed nationwide in China. The primary aim of this study was to analyze demographic and clinical characteristics related to cognitive decline in AD patients treated at outpatient clinics in China.We performed a retrospective study of 1993 AD patients at 10 cognitive centers across 8 cities in China from March 2011 to October 2014. Of these, 891 patients were followed for more than 1 year.The mean age at diagnosis was 72.0 ± 10.0 years (range 38-96 years), and the mean age at onset of AD was 69.8 ± 9.5 years. Most patients (65.1%) had moderate to severe symptoms at the time of diagnosis, and mean Mini-Mental State Examination at diagnosis was 15.7 ± 7.7. AD patients showed significant cognitive decline at 12 months after diagnosis. Having more than 9 years of formal education was an independent risk factor related to rapid cognitive decline [odds ratio (OR) = 1.80; 95% confidence interval (95% CI): 1.11-2.91]. Early-onset AD patients experienced more rapid cognitive decline than late-onset patients (OR = 1.83; 95% CI: 1.09-3.06).Most AD patients in China had moderate to severe symptoms at the time of diagnosis and experienced significant cognitive decline within 1 year. Rapid cognitive decline in AD was related to having a higher educational level and younger age of onset.

Relating Climate and Enviornmental Stress to Conflict... or Cooperation?

NASA Astrophysics Data System (ADS)

Kelley, C. P.

2016-12-01

There are many factors which contribute to social unrest, including governance, economy, access to resources and others. As global climate change progresses, many regions and nations, particularly those that are most vulnerable and least resilient, will face increasing challenges with respect to water and food scarcity. Increasing population and demand for water, combined with declining access to groundwater, will greatly increase exisiting vulnerability. Syria, Yemen and other countries serve as examples of nations that have experienced increasing both environmental stress and conflict. The Syria case in particular has had clear global repercussions, most notably contributing to a global refugee crisis. However, there are also examples of nations that have experienced increasing environmental stress that instead demonstrated transboundary water cooperation rather than conflict. An important and emerging body of work is that which seeks to better understand and characterize real-time resilience and vulnerability in order to better mitigate the consequences of future regional climate change. Prediction of potential conflict is a formidable challenge, one that is highly complex and multivariate, operating on many different temporal and spatial scales.

Health Assimilation among Hispanic Immigrants in the United States: The Impact of Ignoring Arrival-cohort Effects.

PubMed

Hamilton, Tod G; Palermo, Tia; Green, Tiffany L

2015-12-01

A large literature has documented that Hispanic immigrants have a health advantage over their U.S.-born counterparts upon arrival in the United States. Few studies, however, have disentangled the effects of immigrants' arrival cohort from their tenure of U.S. residence, an omission that could produce imprecise estimates of the degree of health decline experienced by Hispanic immigrants as their U.S. tenure increases. Using data from the 1996-to-2014 waves of the March Current Population Survey, we show that the health (i.e., self-rated health) of Hispanic immigrants varies by both arrival cohort and U.S. tenure for immigrants hailing from most of the primary sending countries/regions of Hispanic immigrants. We also find evidence that acculturation plays an important role in determining the health trajectories of Hispanic immigrants. With respect to self-rated health, however, our findings demonstrate that omitting arrival-cohort measures from health assimilation models may result in overestimates of the degree of downward health assimilation experienced by Hispanic immigrants. © American Sociological Association 2015.

Migratory stopover timing is predicted by breeding latitude, not habitat quality, in a long-distance migratory songbird

DOE PAGES

Loon, A. Van; Ray, J. D.; Savage, A.; ...

2017-02-06

The timing of migration can have important survival impacts, as birds must synchronize their movements with favourable environmental conditions to reach their destination. The timing of arrival at and duration of migratory stopover may be largely governed by environmental conditions experienced en route as well as by endogenous factors, but our understanding of these processes is limited. We used light-level geolocators to collect start-to-finish spatio-temporal migration data for a declining aerial insectivore, the Purple Martin ( Progne subis), that travels seasonally between North and South America. Using data obtained for birds originating from range-wide breeding populations, our objectives were tomore » test intrinsic and extrinsic hypotheses for migration stopover duration as well as to identify important stopover regions during fall migration. We examined whether breeding latitude, fall migration timing, age, sex or habitat quality at stopover sites (measured using Normalized Difference Vegetation Index) influenced the duration of stopovers. We found that most individuals rely on the eastern coast of the Yucatan Peninsula, Honduras, and Nicaragua for stopovers during fall migration, where duration ranged from 1 to 36 days (average 6.8 ± 8.2). Stopovers in these regions were later and of longer duration for more northern breeding populations. Only breeding latitude predicted stopover duration, and not habitat quality at stopovers, lending support to the hypothesis that duration is prescribed by endogenous factors. Lastly, the important core stopover regions we documented could be targeted for conservation efforts, particularly for steeply-declining, more northern breeding populations that have greater stopover duration in these areas.« less

Migratory stopover timing is predicted by breeding latitude, not habitat quality, in a long-distance migratory songbird

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loon, A. Van; Ray, J. D.; Savage, A.

The timing of migration can have important survival impacts, as birds must synchronize their movements with favourable environmental conditions to reach their destination. The timing of arrival at and duration of migratory stopover may be largely governed by environmental conditions experienced en route as well as by endogenous factors, but our understanding of these processes is limited. We used light-level geolocators to collect start-to-finish spatio-temporal migration data for a declining aerial insectivore, the Purple Martin ( Progne subis), that travels seasonally between North and South America. Using data obtained for birds originating from range-wide breeding populations, our objectives were tomore » test intrinsic and extrinsic hypotheses for migration stopover duration as well as to identify important stopover regions during fall migration. We examined whether breeding latitude, fall migration timing, age, sex or habitat quality at stopover sites (measured using Normalized Difference Vegetation Index) influenced the duration of stopovers. We found that most individuals rely on the eastern coast of the Yucatan Peninsula, Honduras, and Nicaragua for stopovers during fall migration, where duration ranged from 1 to 36 days (average 6.8 ± 8.2). Stopovers in these regions were later and of longer duration for more northern breeding populations. Only breeding latitude predicted stopover duration, and not habitat quality at stopovers, lending support to the hypothesis that duration is prescribed by endogenous factors. Lastly, the important core stopover regions we documented could be targeted for conservation efforts, particularly for steeply-declining, more northern breeding populations that have greater stopover duration in these areas.« less

Microsatellite Analysis of Museum Specimens Reveals Historical Differences in Genetic Diversity between Declining and More Stable Bombus Species

PubMed Central

Maebe, Kevin; Meeus, Ivan; Ganne, Maarten; De Meulemeester, Thibaut; Biesmeijer, Koos; Smagghe, Guy

2015-01-01

Worldwide most pollinators, e.g. bumblebees, are undergoing global declines. Loss of genetic diversity can play an essential role in these observed declines. In this paper, we investigated the level of genetic diversity of seven declining Bombus species and four more stable species with the use of microsatellite loci. Hereto we genotyped a unique collection of museum specimens. Specimens were collected between 1918 and 1926, in 6 provinces of the Netherlands which allowed us to make interspecific comparisons of genetic diversity. For the stable species B. pascuorum, we also selected populations from two additional time periods: 1949–1955 and 1975–1990. The genetic diversity and population structure in B. pascuorum remained constant over the three time periods. However, populations of declining bumblebee species showed a significantly lower genetic diversity than co-occurring stable species before their major declines. This historical difference indicates that the repeatedly observed reduced genetic diversity in recent populations of declining bumblebee species is not caused solely by the decline itself. The historically low genetic diversity in the declined species may be due to the fact that these species were already rare, making them more vulnerable to the major drivers of bumblebee decline. PMID:26061732

Baseline projections for Latin America: base-year assumptions, key drivers and greenhouse emissions

DOE PAGES

van Ruijven, Bas J.; Daenzer, Katie; Fisher-Vanden, Karen; ...

2016-02-14

This article provides an overview of the base-year assumptions and core baseline projections for the set of models participating in the LAMP and CLIMACAP projects. Here we present the range in core baseline projections for Latin America, and identify key differences between model projections including how these projections compare to historic trends. We find relatively large differences across models in base year assumptions related to population, GDP, energy and CO 2 emissions due to the use of different data sources, but also conclude that this does not influence the range of projections. We find that population and GDP projections acrossmore » models span a broad range, comparable to the range represented by the set of Shared Socioeconomic Pathways (SSPs). Kaya-factor decomposition indicates that the set of core baseline scenarios mirrors trends experienced over the past decades. Emissions in Latin America are projected to rise as result of GDP and population growth and a minor shift in the energy mix toward fossil fuels. Most scenarios assume a somewhat higher GDP growth than historically observed and continued decline of population growth. Minor changes in energy intensity or energy mix are projected over the next few decades.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

van Ruijven, Bas J.; Daenzer, Katie; Fisher-Vanden, Karen

This article provides an overview of the base-year assumptions and core baseline projections for the set of models participating in the LAMP and CLIMACAP projects. Here we present the range in core baseline projections for Latin America, and identify key differences between model projections including how these projections compare to historic trends. We find relatively large differences across models in base year assumptions related to population, GDP, energy and CO 2 emissions due to the use of different data sources, but also conclude that this does not influence the range of projections. We find that population and GDP projections acrossmore » models span a broad range, comparable to the range represented by the set of Shared Socioeconomic Pathways (SSPs). Kaya-factor decomposition indicates that the set of core baseline scenarios mirrors trends experienced over the past decades. Emissions in Latin America are projected to rise as result of GDP and population growth and a minor shift in the energy mix toward fossil fuels. Most scenarios assume a somewhat higher GDP growth than historically observed and continued decline of population growth. Minor changes in energy intensity or energy mix are projected over the next few decades.« less

Social activity, cognitive decline and dementia risk: a 20-year prospective cohort study.

PubMed

Marioni, Riccardo E; Proust-Lima, Cecile; Amieva, Helene; Brayne, Carol; Matthews, Fiona E; Dartigues, Jean-Francois; Jacqmin-Gadda, Helene

2015-10-24

Identifying modifiable lifestyle correlates of cognitive decline and risk of dementia is complex, particularly as few population-based longitudinal studies jointly model these interlinked processes. Recent methodological developments allow us to examine statistically defined sub-populations with separate cognitive trajectories and dementia risks. Engagement in social, physical, or intellectual pursuits, social network size, self-perception of feeling well understood, and degree of satisfaction with social relationships were assessed in 2854 participants from the Paquid cohort (mean baseline age 77 years) and related to incident dementia and cognitive change over 20-years of follow-up. Multivariate repeated cognitive information was exploited by defining the global cognitive functioning as the latent common factor underlying the tests. In addition, three latent homogeneous sub-populations of cognitive change and dementia were identified and contrasted according to social environment variables. In the whole population, we found associations between increased engagement in social, physical, or intellectual pursuits and increased cognitive ability (but not decline) and decreased risk of incident dementia, and between feeling understood and slower cognitive decline. There was evidence for three sub-populations of cognitive aging: fast, medium, and no cognitive decline. The social-environment measures at baseline did not help explain the heterogeneity of cognitive decline and incident dementia diagnosis between these sub-populations. We observed a complex series of relationships between social-environment variables and cognitive decline and dementia. In the whole population, factors such as increased engagement in social, physical, or intellectual pursuits were related to a decreased risk of dementia. However, in a sub-population analysis, the social-environment variables were not linked to the heterogeneous patterns of cognitive decline and dementia risk that defined the sub-groups.

Acute Respiratory Distress Syndrome, Sepsis, and Cognitive Decline: A Review and Case Study

PubMed Central

Jackson, James C.; Hopkins, Ramona O.; Miller, Russell R.; Gordon, Sharon M.; Wheeler, Arthur P.; Ely, E. Wesley

2013-01-01

The objective of this investigation is to review existing research pertaining to cognitive impairment and decline following critical illness and describe a case involving a 49-year-old female with sepsis and acute respiratory distress syndrome (ARDS) with no prior neurologic history who, compared to baseline neuropsychological test data, experienced dramatic cognitive decline and brain atrophy following treatment in the medical intensive care unit (ICU) at Vanderbilt University Medical Center. The patient participated in detailed clinical interviews and underwent comprehensive neuropsychological testing and neurological magnetic resonance imaging (MRI) at approximately 8 months and 3.5 years after ICU discharge. Compared to pre-ICU baseline test data, her intellectual function declined approximately 2 standard deviations from 139 to 106 (from the 99th to the 61st percentile) on a standardized intelligence test 8 months post-discharge, with little subsequent improvement. Initial diffusion tensor brain magnetic resonance imaging (DT-MRI) at the end of ICU hospitalization showed diffuse abnormal hyperintense areas involving predominately white matter in both hemispheres and the left cerebellum. A brain MRI nearly 4 years after ICU discharge demonstrated interval development of profound and generalized atrophy with sulcal widening and ventricular enlargement. The magnitude of cognitive decline experienced by ICU survivors is difficult to quantify due to the unavailability of pre-morbid neuropsychological data. The current case, conducted on a patient with baseline neuropsychological data, illustrates the trajectory of decline occurring after critical illness and ICU-associated brain injury with marked atrophy and concomitant cognitive impairments. PMID:19864995

Dealing with China's future population decline: a proposal for replacing low birth rates with sustainable rates.

PubMed

Cao, Shixiong; Wang, Xiuqing

2009-09-01

Decreasing population levels due to declining birth rates are becoming a potentially serious social problem in developed and rapidly developing countries. China urgently needed to reduce birth rates so that its population would decline to a sustainable level, and the family planning policy designed to achieve this goal has largely succeeded. However, continuing to pursue this policy is leading to serious, unanticipated problems such as a shift in the country's population distribution towards the elderly and increasing difficulty supporting that elderly population. Social and political changes that promoted low birth rates and the lack of effective policies to encourage higher birth rates suggest that mitigating the consequences of the predicted population decline will depend on a revised approach based on achieving sustainable birth rates.

Progression of the epidemiological transition in a rural South African setting: findings from population surveillance in Agincourt, 1993-2013.

PubMed

Kabudula, Chodziwadziwa W; Houle, Brian; Collinson, Mark A; Kahn, Kathleen; Gómez-Olivé, Francesc Xavier; Clark, Samuel J; Tollman, Stephen

2017-05-10

Virtually all low- and middle-income countries are undergoing an epidemiological transition whose progression is more varied than experienced in high-income countries. Observed changes in mortality and disease patterns reveal that the transition in most low- and middle-income countries is characterized by reversals, partial changes and the simultaneous occurrence of different types of diseases of varying magnitude. Localized characterization of this shifting burden, frequently lacking, is essential to guide decentralised health and social systems on the effective targeting of limited resources. Based on a rigorous compilation of mortality data over two decades, this paper provides a comprehensive assessment of the epidemiological transition in a rural South African population. We estimate overall and cause-specific hazards of death as functions of sex, age and time period from mortality data from the Agincourt Health and socio-Demographic Surveillance System and conduct statistical tests of changes and differentials to assess the progression of the epidemiological transition over the period 1993-2013. From the early 1990s until 2007 the population experienced a reversal in its epidemiological transition, driven mostly by increased HIV/AIDS and TB related mortality. In recent years, the transition is following a positive trajectory as a result of declining HIV/AIDS and TB related mortality. However, in most age groups the cause of death distribution is yet to reach the levels it occupied in the early 1990s. The transition is also characterized by persistent gender differences with more rapid positive progression in females than males. This typical rural South African population is experiencing a protracted epidemiological transition. The intersection and interaction of HIV/AIDS and antiretroviral treatment, non-communicable disease risk factors and complex social and behavioral changes will impact on continued progress in reducing preventable mortality and improving health across the life course. Integrated healthcare planning and program delivery is required to improve access and adherence for HIV and non-communicable disease treatment. These findings from a local, rural setting over an extended period contribute to the evidence needed to inform further refinement and advancement of epidemiological transition theory.

Scaling rules for the final decline to extinction

PubMed Central

Griffen, Blaine D.; Drake, John M.

2009-01-01

Space–time scaling rules are ubiquitous in ecological phenomena. Current theory postulates three scaling rules that describe the duration of a population's final decline to extinction, although these predictions have not previously been empirically confirmed. We examine these scaling rules across a broader set of conditions, including a wide range of density-dependent patterns in the underlying population dynamics. We then report on tests of these predictions from experiments using the cladoceran Daphnia magna as a model. Our results support two predictions that: (i) the duration of population persistence is much greater than the duration of the final decline to extinction and (ii) the duration of the final decline to extinction increases with the logarithm of the population's estimated carrying capacity. However, our results do not support a third prediction that the duration of the final decline scales inversely with population growth rate. These findings not only support the current standard theory of population extinction but also introduce new empirical anomalies awaiting a theoretical explanation. PMID:19141422

Evaluating key landscape features of a climate- induced forest decline (Project WC-EM-07-01)

Treesearch

Paul Hennon; Dustin Wittwer

2013-01-01

Yellow-cedar is a culturally, economically, and ecologically important tree in coastal Alaska that has been experiencing a widespread mortality known as yellow-cedar decline for about 100 years. Mapping during annual aerial detection surveys has identified nearly the entire geographical distribution of the problem, which totals over 500,000 acres in Alaska (Lamb and...

Economic Growth, Productivity, and Public Education Funding: Is South Carolina a Death Spiral State?

ERIC Educational Resources Information Center

Driscoll, Lisa G.; Knoeppel, Robert C.; Della Sala, Matthew R.; Watson, Jim R.

2014-01-01

As a result of the Great Recession of 2007-2009, most states experienced declines in employment, consumer spending, and economic productivity (Alm, Buschman, and Sjoquist 2011). In turn, these events led to historic declines in state tax revenues (Mikesell and Mullins 2010; Boyd and Dadayan 2009), resulting in major cuts in public spending. Local…

Student Perspectives on Enrolling in Undergraduate Forestry Degree Programs in the United States

ERIC Educational Resources Information Center

Sharik, Terry L.; Frisk, Stacey L.

2011-01-01

Undergraduate U.S. forestry degree programs experienced a steady decline in enrollments over a decade beginning in the mid-1990s. This decline prompted a survey of students enrolled in these programs to determine what factors led to their decisions to matriculate there and conversely, what may have made them hesitant to do so. The sample…

Effects of illegal harvest of eggs on the population decline of leatherback turtles in Las Baulas Marine National Park, Costa Rica.

PubMed

Tomillo, Pilar Santidrián; Saba, Vincent S; Piedra, Rotney; Paladino, Frank V; Spotila, James R

2008-10-01

Within 19 years the nesting population of leatherback turtles (Dermochelys coriacea) at Parque Nacional Marino Las Baulas declined from 1500 turtles nesting per year to about 100. We analyzed the effects of fishery bycatch and illegal harvesting (poaching) of eggs on this population. We modeled the population response to different levels of egg harvest (90, 75, 50, and 25%) and the effect of eradicating poaching at different times during the population decline. We compared effects of 90% poaching with those of 20% adult mortality because both of these processes were present in the population at Las Baulas. There was a stepwise decline in number of nesting turtles at all levels of egg harvest. Extirpation times for different levels of poaching ranged from 45 to 282 years. The nesting population declined more slowly and survived longer with 20% adult mortality (146 years) than it did with 90% poaching (45 years). Time that elapsed until poaching stopped determined the average population size at which the population stabilized, ranging from 90 to 420 nesting turtles. Our model predicted that saving clutches lost naturally would restore the population when adult mortality rates were low and would contribute more to population recovery when there were short remigration intervals between nesting seasons and a large proportion of natural loss of clutches. Because the model indicated that poaching was the most important cause of the leatherback decline at Las Baulas, protecting nests on the beach and protecting the beach from development are critical for survival of this population. Nevertheless, the model predicted that current high mortality rates of adults will prevent population recovery. Therefore, protection of the beach habitat and nests must be continued and fishery bycatch must be reduced to save this population.

Explaining trends in alcohol-related harms in Scotland, 1991-2011 (I): the role of incomes, effects of socio-economic and political adversity and demographic change.

PubMed

McCartney, G; Bouttell, J; Craig, N; Craig, P; Graham, L; Lakha, F; Lewsey, J; McAdams, R; MacPherson, M; Minton, J; Parkinson, J; Robinson, M; Shipton, D; Taulbut, M; Walsh, D; Beeston, C

2016-03-01

This paper tests the extent to which differing trends in income, demographic change and the consequences of an earlier period of social, economic and political change might explain differences in the magnitude and trends in alcohol-related mortality between 1991 and 2011 in Scotland compared to England & Wales (E&W). Comparative time trend analyses and arithmetic modelling. Three approaches were utilised to compare Scotland with E&W: 1. We modelled the impact of changes in income on alcohol-related deaths between 1991-2001 and 2001-2011 by applying plausible assumptions of the effect size through an arithmetic model. 2. We used contour plots, graphical exploration of age-period-cohort interactions and calculation of Intrinsic Estimator coefficients to investigate the effect of earlier exposure to social, economic and political adversity on alcohol-related mortality. 3. We recalculated the trends in alcohol-related deaths using the white population only to make a crude approximation of the maximal impact of changes in ethnic diversity. Real incomes increased during the 1990s but declined from around 2004 in the poorest 30% of the population of Great Britain. The decline in incomes for the poorest decile, the proportion of the population in the most deprived decile, and the inequality in alcohol-related deaths, were all greater in Scotland than in E&W. The model predicted less of the observed rise in Scotland (18% of the rise in men and 29% of the rise in women) than that in E&W (where 60% and 68% of the rise in men and women respectively was explained). One-third of the decline observed in alcohol-related mortality in Scottish men between 2001 and 2011 was predicted by the model, and the model was broadly consistent with the observed trends in E&W and amongst women in Scotland. An age-period interaction in alcohol-related mortality was evident for men and women during the 1990s and 2000s who were aged 40-70 years and who experienced rapidly increasing alcohol-related mortality rates. Ethnicity is unlikely to be important in explaining the trends or differences between Scotland and E&W. The decline in alcohol-related mortality in Scotland since the early 2000s and the differing trend to E&W were partly described by a model predicting the impact of declining incomes. Lagged effects from historical social, economic and political change remain plausible from the available data. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Using demographic characteristics of populations to detect spatial fragmentation following suspected ebola outbreaks in great apes.

PubMed

Genton, Céline; Cristescu, Romane; Gatti, Sylvain; Levréro, Florence; Bigot, Elodie; Motsch, Peggy; Le Gouar, Pascaline; Pierre, Jean-Sébastien; Ménard, Nelly

2017-09-01

Demographic crashes due to emerging diseases can contribute to population fragmentation and increase extinction risk of small populations. Ebola outbreaks in 2002-2004 are suspected to have caused a decline of more than 80% in some Western lowland gorilla (Gorilla gorilla gorilla) populations. We investigated whether demographic indicators of this event allowed for the detection of spatial fragmentation in gorilla populations. We collected demographic data from two neighbouring populations: the Lokoué population, suspected to have been affected by an Ebola outbreak (followed from 2001 to 2014), and the Romani population, of unknown demographic status before Ebola outbreaks (followed from 2005 to 2014). Ten years after the outbreak, the Lokoué population is slowly recovering and the short-term demographic indicators of a population crash were no longer detectable. The Lokoué population has not experienced any additional demographic perturbation over the past decade. The Romani population did not show any of the demographic indicators of a population crash over the past decade. Its demographic structure remained similar to that of unaffected populations. Our results highlighted that the Ebola disease could contribute to fragmentation of gorilla populations due to the spatially heterogeneous impact of its outbreaks. The demographic structure of populations (i.e., age-sex and group structure) can be useful indicators of a possible occurrence of recent Ebola outbreaks in populations without known history, and may be more broadly used in other emerging disease/species systems. Longitudinal data are critical to our understanding of the impact of emerging diseases on wild populations and their conservation. © 2017 Wiley Periodicals, Inc.

Pre-adoptive Factors Predicting Lesbian, Gay, and Heterosexual Couples’ Relationship Quality Across the Transition to Adoptive Parenthood

PubMed Central

Goldberg, Abbie E.; Smith, JuliAnna Z.; Kashy, Deborah A.

2010-01-01

The current study examined pre-adoptive factors as predictors of relationship quality (love, ambivalence, and conflict) among 125 couples (44 lesbian couples, 30 gay couples, and 51 heterosexual couples) across the first year of adoptive parenthood. On average, all new parents experienced declines in their relationship quality across the first year of parenthood, regardless of sexual orientation, with women experiencing steeper declines in love. Parents who, pre-adoption, reported higher levels of depression, greater use of avoidant coping, lower levels of relationship maintenance behaviors, and less satisfaction with their adoption agencies reported lower relationship quality at the time of the adoption. The effect of avoidant coping on relationship quality varied by gender. Parents who, pre-adoption, reported higher levels of depression, greater use of confrontative coping, and higher levels of relationship maintenance behaviors reported greater declines in relationship quality. These findings have implications for professionals who work with adoptive parents both pre- and post-adoption. PMID:20545395

Illicit drug use and marital satisfaction.

PubMed

Homish, Gregory G; Leonard, Kenneth E; Cornelius, Jack R

2008-02-01

With the acquisition of adult social roles such as marriage, more deviant or socially disapproved behaviors such as drug use often decrease. The objective of this work was to examine patterns of illicit drug use in a community sample of adults during the transition and early years of marriage. Additionally, this work examined if couples who were discrepant in their drug use (i.e., one individual reported past year drug use and the partner reported no use) experience sharper declines in marital satisfaction compared to other couples. Multilevel regression models explored these issues over the first four years of marriage (N=634 couples). Although rates of illicit drug use decline over the first four years of marriage, a significant number of husbands and wives continued to use illicit drugs (21% and 16%, respectively). At the transition to marriage, both husbands and wives who had discrepant drug use behaviors experienced lower levels of marital satisfaction compared to other couples. Over the first four years of marriage, couples in each group experienced significant declines in marital satisfaction.

Illicit Drug Use and Marital Satisfaction

PubMed Central

Leonard, Kenneth E.; Cornelius, Jack R.

2008-01-01

With the acquisition of adult social roles such as marriage, more deviant or socially disapproved behaviors such as drug use often decrease. The objective of this work was to examine patterns of illicit drug use in a community sample of adults during the transition and early years of marriage. Additionally, this work examined if couples who were discrepant in their drug use (i.e., one individual reported past year drug use and the partner reported no use) experience sharper declines in marital satisfaction compared to other couples. Multilevel regression models explored these issues over the first four years of marriage (N= 634 couples). Although rates of illicit drug use decline over the first four years of marriage, a significant number of husbands and wives continued to use illicit drugs (21% and 16%, respectively). At the transition to marriage, both husbands and wives who had discrepant drug use behaviors experienced lower levels of marital satisfaction compared to other couples. Over the first four years of marriage, couples in each group experienced significant declines in marital satisfaction. PMID:17945436

Risk factors for financial hardship in patients receiving adjuvant chemotherapy for colon cancer: a population-based exploratory analysis.

PubMed

Shankaran, Veena; Jolly, Sanjay; Blough, David; Ramsey, Scott D

2012-05-10

Characteristics that predispose patients to financial hardship during cancer treatment are poorly understood. We therefore conducted a population-based exploratory analysis of potential factors associated with financial hardship and treatment nonadherence during and following adjuvant chemotherapy for colon cancer. Patients diagnosed with stage III colon cancer between 2008 and 2010 were identified from a population-based cancer registry representing 13 counties in Washington state. Patients were asked to complete a comprehensive survey on treatment-related costs. Patients were considered to have experienced financial hardship if they accrued debt, sold or refinanced their home, borrowed money from friends or family, or experienced a 20% or greater decline in their annual income as a result of treatment-related expenses. Logistic regression analysis was used to investigate factors associated with financial hardship and treatment nonadherence. A total of 284 responses were obtained from 555 eligible patients (response rate, 51.2%). Nearly all patients in the final sample were insured during treatment. In this sample, 38% of patients reported one or more financial hardships as a result of treatment. The factors most closely associated with treatment-related financial hardship were younger age and lower annual household income. Younger age, lower income, and unemployment or disability (which occurred in most instances following diagnosis) were most closely associated with treatment nonadherence. A significant proportion of patients undergoing adjuvant chemotherapy for stage III colon cancer may experience financial hardship, despite having health insurance coverage. Interventions to help at-risk patients early on during therapy may prevent long-term financial adverse effects.

Causes of mortality in California sea otters during periods of population growth and decline

USGS Publications Warehouse

Estes, J.A.; Hatfield, B.B.; Ralls, K.; Ames, J.

2003-01-01

Elevated mortality appears to be the main reason for both sluggish growth and periods of decline in the threatened California sea otter population. We assessed causes of mortality from salvage records of 3,105 beach-cast carcasses recovered from 1968 through 1999, contrasting two periods of growth with two periods of decline. Overall, an estimated 40%-60% of the deaths were not recovered and 70% of the recovered carcasses died from unknown causes. Nonetheless, several common patterns were evident in the salvage records during the periods of population decline. These included greater percentages of (1) prime age animals (3-10 yr), (2) carcasses killed by great white shark attacks, (3) carcasses recovered in spring and summer, and (4) carcasses for which the cause of death was unknown. Neither sex composition nor the proportion of carcasses dying of infectious disease varied consistently between periods of population increase and decline. The population decline from 1976 to 1984 was likely due to incidental mortality in a set-net fishery, and the decline from 1995 to 1999 may be related to a developing live-fish fishery. Long-term trends unrelated to periods of growth and decline included a decrease in per capita pup production and mass/length ratios of adult carcasses over the 31-yr study. The generally high proportion of deaths from infectious disease suggests that this factor has contributed to the chronically sluggish growth rate of the California sea otter population.

Sweden Faces Zero Population Growth. Population Bulletin, Vol. 35, No. 2, June, 1980.

ERIC Educational Resources Information Center

Gendell, Murray

This bulletin examines the causes of the fertility decline in Sweden and the concerns and ambivalence of Swedes about zero population growth (ZPG). The fertility decline is attributed to many causes. In recent years there has been a drop in marriage rates and a sharp increase in non-marital cohabitation. The decline is also related to the…

Physical Frailty Is Associated with Longitudinal Decline in Global Cognitive Function in Non-Demented Older Adults: A Prospective Study.

PubMed

Chen, S; Honda, T; Narazaki, K; Chen, T; Kishimoto, H; Haeuchi, Y; Kumagai, S

2018-01-01

To assess the relationship between physical frailty and subsequent decline in global cognitive function in the non-demented elderly. A prospective population-based study in a west Japanese suburban town, with two-year follow-up. Community-dwellers aged 65 and older without placement in long-term care, and not having a history of dementia, Parkinson's disease and depression at baseline, who participated in the cohort of the Sasaguri Genkimon Study and underwent follow-up assessments two years later (N = 1,045). Global cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). Physical frailty was identified according to the following five components: weight loss, low grip strength, exhaustion, slow gait speed and low physical activities. Linear regression models were used to examine associations between baseline frailty status and the MoCA scores at follow-up. Logistic regression models were used to estimate the risk of cognitive decline (defined as at least two points decrease of MoCA score) according to baseline frailty status. Seven hundred and eight non-demented older adults were included in the final analyses (mean age: 72.6 ± 5.5 years, male 40.3%); 5.8% were frail, and 40.8% were prefrail at baseline. One hundred and fifty nine (22.5%) participants experienced cognitive decline over two years. After adjustment for baseline MoCA scores and all confounders, being frail at baseline was significantly associated with a decline of 1.48 points (95% confidence interval [CI], -2.37 to -0.59) in MoCA scores, as compared with non-frailty. Frail persons were over two times more likely to experience cognitive decline (adjusted odds ratio 2.28; 95% CI, 1.02 to 5.08), compared to non-frail persons. Physical frailty is associated with longitudinal decline in global cognitive function in the non-demented older adults over a period of two years. Physically frail older community-dwellers should be closely monitored for cognitive decline that can be sensitively captured by using the MoCA.

Decline of disjunct green salamander (Aneides aeneus) populations in the southern appalachians

USGS Publications Warehouse

Corser, J.D.

2001-01-01

Coincident with other amphibians around the world Aneides aeneus, a terrestrial plethodontid salamander, suffered a population collapse in a disjunct portion of its range in the mid-late 1970s. Long-term monitoring of seven historical green salamander populations throughout the 1990s showed a 98% decline in relative abundance since 1970. Three out of six populations first discovered in 1991 also crashed in 1996-1997. The synchronized suddenness of the declines, their region-wide impact, and effects on both small and larger populations, suggest the role of a novel agent of mortality beginning in the mid-late 1970s. Acting alone, but more likely in concert, habitat loss, overcollecting, epidemic disease and climate change could account for this region-wide decline.

Five decades on: Use of historical weaning size data reveals that a decrease in maternal foraging success underpins the long-term decline in population of southern elephant seals (Mirounga leonina).

PubMed

Clausius, Ella; McMahon, Clive R; Hindell, Mark A

2017-01-01

The population of Southern elephant seals (Mirounga leonina) at Macquarie Island has declined since the 1960s, and is thought to be due to changing oceanic conditions leading to reductions in the foraging success of Macquarie Island breeding females. To test this hypothesis, we used a 55-year-old data set on weaning size of southern elephant seals to quantify a decrease in weaning size from a period of population stability in 1950s to its present state of on-going decline. Being capital breeders, the size of elephant seal pups at weaning is a direct consequence of maternal foraging success in the preceding year. During the 1940-1950s, the mean of female pups at weaning was similar between the Heard and Macquarie Island populations, while the snout-tail-length length of male weaners from Heard Island were longer than their conspecifics at Macquarie Island. Additionally, the snout-tail-length of pups at weaning decreased by 3cm between the 1950s and 1990s in the Macquarie Island population, concurrent with the observed population decline. Given the importance of weaning size in determining first-year survival and recruitment rates, the decline in the size at weaning suggests that the decline in the Macquarie Island population has, to some extent, been driven by reduced maternal foraging success, consequent declines in the size of pups at weaning, leading to reduced first-year survival rates and recruitment of breeding females into the population 3 to 4 years later.

Changes in Tennessee's secondary hardwood processing and sawmill industries from 2005 to 2009

Treesearch

William G. Luppold; Delton Alderman; Doug. Schnabel

2012-01-01

Tennessee is in the center of the Eastern hardwood region and has experienced large declines in employment by primary and secondary hardwood processors since 2005 in a pattern similar to the one these processors have experienced nationally. The objective of this article is to examine changes in national hardwood processing industries between 2005 and 2009 and compare...

Republic of Austria. Country profile.

PubMed

Newcomb, L C

1985-07-01

A summary description of Austria's demographic situation, economic conditions, labor force characteristics, housing conditions, household characteristics, and marriage patterns is provided. Austria, the former center of the Hapsburg Empire, covers 32,375 square miles and is divided into 9 provinces, including Vienna, the federal capital. Austria's population increased from 6.9 million in 1950 to 7.6 million in 1980. Since 1980 it declined slightly and in 1985 it was estimated to be 7,487,000. Between 1961-81, the industrial, western region of the country grew more rapidly than the predominantly rural eastern section of the country. Vienna, the largest city in the country, experienced a decline in population size from 1.9 million to 1.5 million since 1923. Part of the decline was due to the annihilation of the city's Jewish population in 1938. Austria has a lower urban population (56%) than most other industrialized countries. This low rate reflects the availability of tourist related jobs in the rural areas. 98% of the population is Austrian, the official language is German, and most of the inhabitants are Roman Catholic. Due to the homogeneity of the population, the country has few religious and racial problems; however, a recent study indicated that about 1/2 of the population has anti-Semetic attitudes. Life expectancy is 69 years for men and 76 years for women. Austria's population is aging. Currently, 18% of the population is under 15 years of age, and 14% is 65 years of age or older. Births are expected to increase slightly until the end of the 1900s and then decline slightly. Austrians place a high value on children and family life. Between 1978-82 the marriage rate increased from 4.5/1000 to 4.8/1000, and the median age at marriage increased from 22.4-23.0 years for women and from 25.6-25.8 years for men. The number of divorces/year increased from 11,168-14.298 between 1976-82. Currently, there are 2,767,000 households, and the average household size is 2.6 persons. The proportion of single family member households increased in recent years. Most urban dwellers live in apartments, and 20% of the dwelling in Vienna are owned by the government. Education is stressed and students take their education seriously. 41% of all students in higher education in 1980 were female. Austria's labor force is well educated, and 30% are engaged in manufacturing; 20%, in commercial, social, and personal services, 175, in commerce and hotel services; and 10%, in the primary sector. Labor disputes are generally resolved by an unofficial coalition of representatives from industry, labor unions, and the government. Strikes rarely occur. Average earning are US$850/month. Imported labor was used to supplement a deficiency in the supply of labor in the 1960s and 1970s. Currently, few imported laborers are used, and the country has some unemployment. Austria was not seriously affected by the recent economic recession. In 1985 the gross domestic product is expected to increase by 3.0%, the country has a favorable trade balance, and the economic outlook for the country is good.

Effects of an invasive plant on population dynamics in toads.

PubMed

Greenberg, Daniel A; Green, David M

2013-10-01

When populations decline in response to unfavorable environmental change, the dynamics of their population growth shift. In populations that normally exhibit high levels of variation in recruitment and abundance, as do many amphibians, declines may be difficult to identify from natural fluctuations in abundance. However, the onset of declines may be evident from changes in population growth rate in sufficiently long time series of population data. With data from 23 years of study of a population of Fowler's toad (Anaxyrus [ = Bufo] fowleri) at Long Point, Ontario (1989-2011), we sought to identify such a shift in dynamics. We tested for trends in abundance to detect a change point in population dynamics and then tested among competing population models to identify associated intrinsic and extrinsic factors. The most informative models of population growth included terms for toad abundance and the extent of an invasive marsh plant, the common reed (Phragmites australis), throughout the toads' marshland breeding areas. Our results showed density-dependent growth in the toad population from 1989 through 2002. After 2002, however, we found progressive population decline in the toads associated with the spread of common reeds and consequent loss of toad breeding habitat. This resulted in reduced recruitment and population growth despite the lack of significant loss of adult habitat. Our results underscore the value of using long-term time series to identify shifts in population dynamics coincident with the advent of population decline. © 2013 Society for Conservation Biology.

Exploring Agro-Climatic Trends in Ethiopia Using CHIRPS

NASA Astrophysics Data System (ADS)

Pedreros, D. H.; Funk, C. C.; Brown, M. E.; Korecha, D.; Seid, Y. M.

2015-12-01

The Famine Early Warning Systems Network (FEWS NET) uses the Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) to monitor agricultural food production in different regions of the world. CHIRPS is a 1981-present, 5 day, approximately 5km resolution, rainfall product based on a combination of geostationary satellite observations, a high resolution climatology and in situ station observations. Furthermore, FEWS NET has developed a gridded implementation of the Water Requirement Satisfaction Index (WRSI), a water balance measurement indicator of crop performance. This study takes advantage of the CHIRPS' long term period of record and high spatial and temporal resolution to examine agro-climatic trends in Ethiopia. We use the CHIRPS rainfall dataset to calculate the WRSI for the boreal spring and summer crop seasons, as well as for spring-summer rangelands conditions. We find substantial long term rainfall declines in the spring and summer seasons across southeastern and northeastern Ethiopia. Crop Model results indicate that rainfall declines in the cropped regions have been associated with water deficits during the critical grain filling periods in well populated and/or highly vulnerable parts of eastern Ethiopia. WRSI results in the pastoral areas indicate substantial reductions in rangeland health during the later part of the growing seasons. These health declines correspond to the regions of Somaliland and Afar that have experienced chronic severe food insecurity since 2010. Key words: CHIRPS, satellite estimated rainfall, agricultural production

Demographics and run timing of adult Lost River (Deltistes luxatus) and short nose (Chasmistes brevirostris) suckers in Upper Klamath Lake, Oregon, 2009

USGS Publications Warehouse

Hewitt, David A.; Hayes, Brian S.; Janney, Eric C.; Harris, Alta C.; Koller, Justin P.; Johnson, Mark A.

2011-01-01

Data from a long-term capture-recapture program were used to assess the status and dynamics of populations of two long-lived, federally endangered catostomids in Upper Klamath Lake, Oregon. Lost River suckers (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) have been captured and tagged with passive integrated transponder (PIT) tags during their spawning migrations in each year since 1995. In addition, beginning in 2005, individuals that had been previously PIT-tagged were reencountered on remote underwater antennas deployed throughout the spawning areas. Captures and remote encounters during spring 2009 were used to describe the spawning migrations in that year and also were incorporated into capture-recapture analyses of population dynamics over the last decade. Cormack-Jolly-Seber (CJS) open population capture-recapture models were used to estimate annual survival probabilities, and a reverse-time analog of the CJS model was used to estimate recruitment of new individuals into the spawning populations. In addition, data on the size composition of captured fish was examined for any additional evidence of recruitment. Survival and recruitment estimates were combined to estimate changes in population size over time and to determine the status of the populations through 2007. Separate analyses were conducted for each species and also for each subpopulation of Lost River suckers (LRS). One subpopulation of LRS migrates into tributaries to spawn, similar to shortnose suckers (SNS), whereas the other subpopulation spawns at upwelling areas along the eastern shoreline of the lake. In 2009, we captured and tagged 781 LRS at four shoreline areas and recaptured an additional 638 individuals that had been tagged in previous years. Across all four areas, the remote antennas detected 6,056 individual LRS during the spawning season. Spawning activity peaked in April and most individuals were encountered at Sucker Springs and Cinder Flats. In the Williamson River, we captured and tagged 3,008 LRS and 287 SNS, and recaptured 271 LRS and 81 SNS that had been tagged in previous years. Remote antennas that spanned the river downstream of the tributary spawning areas detected a total of 12,509 LRS and 5,023 SNS. Most LRS passed upstream in mid-April when water temperatures were rising and near or greater than 10°C. In contrast, peaks in upstream passage of SNS occurred in late April and early May when water temperatures were rising and near or greater than 12°C. Finally, an additional 1,569 LRS and 1,794 SNS were captured in trammel net sampling at prespawn staging areas in the northeastern portion of the lake. Of these, 209 of the LRS and 452 of the SNS had been PIT-tagged in previous years. For LRS, encounter histories showed that nearly all of the fish captured at the staging areas were members of the subpopulation that spawns in the tributaries.Capture-recapture analyses for the LRS subpopulation that spawns at the shoreline areas included encounter histories for more than 9,000 individuals, and analyses for the subpopulation that spawns in the tributaries included more than 14,000 encounter histories. With a few exceptions, the survival of males and females in both subpopulations was high (>0.9) between 1999 and 2007. Notably lower survival occurred for both sexes from the tributaries in 2000, for males from the shoreline areas in 2002, and for males from the tributaries in 2006. Recruitment of new individuals into either spawning population was trivial in all years between 2002 and 2007. Over that period, the abundance of males in the lakeshore spawning subpopulation declined by 44–53 percent and the abundance of females declined by 25–38 percent. Similarly, the abundance of males in the tributary spawning subpopulation declined by as much as 39 percent and the abundance of females declined by as much as 33 percent. Capture-recapture analyses for SNS included encounter histories for more than 12,000 individuals. The majority of annual survival estimates between 2001 and 2007 were high (>0.8), but SNS experienced more years of low survival than either LRS subpopulation. The survival of both sexes was particularly low in both 2001 and 2004, and male survival also was somewhat low in 2002 and 2006. Similar to LRS, recruitment of new individuals into the spawning population was trivial in all years between 2001 and 2007. Over that period, the abundance of male SNS declined by 58–80 percent and the abundance of females declined by 52–73 percent. Despite relatively high survival in most years, both species have experienced substantial declines in the abundance of spawning fish because losses from mortality have not been balanced by recruitment of new individuals. Indeed, all populations appear to be largely comprised of fish that were present in the late 1990s and early 2000s. As a result, the status of the endangered sucker populations in Upper Klamath Lake remains worrisome, and the situation is most dire for shortnose suckers. Survival analyses show that the two species do not necessarily experience poor survival in the same years and that poor survival on an annual scale is not predictable from fish die-offs observed in the summer and fall. Future analyses will explore the connections between annual sucker survival and environmental factors of interest, such as water quality and disease. Our monitoring program provides a robust platform for estimating vital population parameters, evaluating the status of the populations, and assessing the effectiveness of conservation and recovery efforts.

Teenage childbearing in the United States, 1960-1997.

PubMed

Ventura, S J; Freedman, M A

2000-07-01

Teenage childbearing in the United States has declined significantly in the 1990s. Still the U.S. teen birth rate is higher than in other developed countries; in 1997 it was 52.3 births per 1000 women aged 15 to 19. A steep rise in teen birth rates in the late 1980s generated a great deal of public concern and a variety of initiatives targeted to reducing teen births. Data from the National Center for Health Statistics' National Vital Statistics System are used to review and describe trends and variations in births and birth rates for teenagers for the period 1960-1997. Teen birth rates were much higher in the early 1960s than at present; in fact, rates for 18- to 19-year-olds were double what they are currently. In the 1990s, birth rates for teenagers dropped for younger and older teenagers, with greater declines recorded for younger teens. While rates have fallen in all population groups, the greatest declines have been experienced by black teenagers, whose rates have dropped 24% on average. %Trends in teen births and birth rates since 1960 have been affected by a variety of factors. These include wide swings in the number of female teenagers, substantial declines in marriage among older teens, falling birth rates for married teens concurrent with rapidly rising birth rates for unmarried teens, and sharp increases in sexual activity among teens that have abated only recently, according to the National Center for Health Statistics' National Survey of Family Growth. This review article also tracks changes in contraceptive practice and abortion rates.

The status of sea ducks in the North Pacific Rim: Toward their conservation and management

USGS Publications Warehouse

Goudie, R. Ian; Brault, Solange; Conant, Bruce; Kondratyev, Alexander V.; Petersen, Margaret R.; Vermeer, Kees; McCabe, Richard E.; Wadsworth, Kelly G.

1994-01-01

Sea ducks (tribe Mergini after Johnsgard 1960) are the most northerly distributed ducks, and species diversity is greatest in the North Pacific. They exploit a diversity of inshore and offshore marine habitats during the non-breeding season, and their use of habitat during breeding varies from coastal through freshwater wetlands of the tundra and taiga (Figure 1, Appendix 1). Non-breeding cohorts frequent marine habitats most of the year. Sea ducks thus are important indicators of the quality of freshwater and marine ecosystems of northern biomes.Of the 17 species discussed in this manuscript, at least 3 are reported to be declining (Appendix 2). However, the basis for many of those assessments is equivocal because there has been little effort to monitor populations. The efforts to more precisely assess their status point to catastrophic declines (Kertell 1991, Stehn et a 1993). Conservation problems related to sea ducks have a long history throughout the Holarctic. For example, the Labrador duck (Camptorhynchus labradorius) became extinct in 1875. (Phillips 1925); common eiders (Somateria mollissima) declined seriously throughout the northern hemisphere (Townsend 1914, Phillips 1925, Doughty 1979); harlequin ducks (Histrionicus histrionicus) experienced declines in Iceland and Greenland (Gudmundsson1971, Salomonson 1950), and more recently have been designated endangered in eastern Canada (Committee On the Status of Endangered Wildlife in Canada 1990). In Russia, all species of eider and harlequin ducks have been closed to sport hunting since 1981, and the Chinese mergansers (Mergus squamatus) presently are extremely rare and fully protected, i.e. category one of the red book (Solomonov 1987).

Self-reported sleep duration and time in bed as predictors of physical function decline: results from the InCHIANTI study.

PubMed

Stenholm, Sari; Kronholm, Erkki; Bandinelli, Stefania; Guralnik, Jack M; Ferrucci, Luigi

2011-11-01

To characterize elderly persons into sleep/rest groups based on their self-reported habitual total sleeping time (TST) and habitual time in bed (TIB) and to examine the prospective association between sleep/rest behavior on physical function decline. Population-based InCHIANTI study with 6 years follow-up (Tuscany, Italy). Community. Men and women aged ≥ 65 years (n = 751). At baseline, participants were categorized into 5 sleep/rest behavior groups according to their self-reported TST and TIB, computed from bedtime and wake-up time. Physical function was assessed at baseline and at 3- and 6-year follow-ups as walking speed, the Short Physical Performance Battery (SPPB), and self-reported mobility disability (ability to walk 400 m or climb one flight of stairs). Both long (≥ 9 h) TST and long TIB predicted accelerated decline in objectively measured physical performance and greater incidence in subjectively assessed mobility disability, but short (≤ 6 h) TST did not. After combining TST and TIB, long sleepers (TST and TIB ≥ 9 h) experienced the greatest decline in physical performance and had the highest risk for incident mobility disability in comparison to mid-range sleepers with 7-8 h TST and TIB. Subjective short sleepers reporting short (≤ 6 h) TST but long (≥ 9 h) TIB showed a greater decline in SPPB score and had a higher risk of incident mobility disability than true short sleepers with short (≤ 6 h) TST and TIB ≤ 8 hours. Extended time in bed as well as long total sleeping time is associated with greater physical function decline than mid-range or short sleep. TIB offers important additive information to the self-reported sleep duration when evaluating the consequences of sleep duration on health and functional status.

Fishing, fast growth and climate variability increase the risk of collapse

PubMed Central

Pinsky, Malin L.; Byler, David

2015-01-01

Species around the world have suffered collapses, and a key question is why some populations are more vulnerable than others. Traditional conservation biology and evidence from terrestrial species suggest that slow-growing populations are most at risk, but interactions between climate variability and harvest dynamics may alter or even reverse this pattern. Here, we test this hypothesis globally. We use boosted regression trees to analyse the influences of harvesting, species traits and climate variability on the risk of collapse (decline below a fixed threshold) across 154 marine fish populations around the world. The most important factor explaining collapses was the magnitude of overfishing, while the duration of overfishing best explained long-term depletion. However, fast growth was the next most important risk factor. Fast-growing populations and those in variable environments were especially sensitive to overfishing, and the risk of collapse was more than tripled for fast-growing when compared with slow-growing species that experienced overfishing. We found little evidence that, in the absence of overfishing, climate variability or fast growth rates alone drove population collapse over the last six decades. Expanding efforts to rapidly adjust harvest pressure to account for climate-driven lows in productivity could help to avoid future collapses, particularly among fast-growing species. PMID:26246548

Fishing, fast growth and climate variability increase the risk of collapse.

PubMed

Pinsky, Malin L; Byler, David

2015-08-22

Species around the world have suffered collapses, and a key question is why some populations are more vulnerable than others. Traditional conservation biology and evidence from terrestrial species suggest that slow-growing populations are most at risk, but interactions between climate variability and harvest dynamics may alter or even reverse this pattern. Here, we test this hypothesis globally. We use boosted regression trees to analyse the influences of harvesting, species traits and climate variability on the risk of collapse (decline below a fixed threshold) across 154 marine fish populations around the world. The most important factor explaining collapses was the magnitude of overfishing, while the duration of overfishing best explained long-term depletion. However, fast growth was the next most important risk factor. Fast-growing populations and those in variable environments were especially sensitive to overfishing, and the risk of collapse was more than tripled for fast-growing when compared with slow-growing species that experienced overfishing. We found little evidence that, in the absence of overfishing, climate variability or fast growth rates alone drove population collapse over the last six decades. Expanding efforts to rapidly adjust harvest pressure to account for climate-driven lows in productivity could help to avoid future collapses, particularly among fast-growing species. © 2015 The Author(s).

Policy implications of the next world demographic transition.

PubMed

Harbison, Sarah F; Robinson, Warren C

2002-03-01

Although the world demographic transition from high to low fertility appears to be nearing its completion, observed in perspective, this is the latest in a series of such transitions stretching back into prehistory. A stable new equilibrium is far from inevitable; indeed, it is unlikely. Many countries are experiencing below-replacement-level fertility, and this trend is spreading. Couples are now able to choose their family size, free of the traditional pressures to bear children that was characteristic of most traditional societies. In fact, most societal pressures for the last generation have been distinctly antinatalist, in response to the enormous attention paid by the media to the "population bomb" agenda. This antinatalist attitude is changing, however, and what seems more likely than either a stationary or declining world population is a new growth cycle reflecting a resurgence of fertility as a response to growing material affluence and potential technological mastery of environmental challenges. Societal pressures and policies will play a role in this transition as they did in earlier ones.

College students' use of cocaine.

PubMed

Williams, Jenny; Pacula, Rosalie Liccardo; Chaloupka, Frank J; Wechsler, Henry

2006-01-01

After experiencing a period of rapid decline between 1986 and 1994, cocaine use is once again on the rise in the United States. The increased prevalence of use among college students is particularly troubling because of its potential impact on human capital acquisition and long-term labor market success. Merging information on the price of cocaine and marijuana from the U.S. Drug Enforcement Agency with data on cocaine use from the College Alcohol Study, we investigate the demand for cocaine in the college population. We find evidence that participation in cocaine use by college students is responsive to changes in the price of cocaine and marijuana and that cocaine and marijuana are economic complements for this population. Further investigation revealed significant differences in the demand for cocaine by those less than age 21 and those at least age 21, years, with the younger age group being more responsive to changes in the price of cocaine. No difference is found, however, in the demand for cocaine across gender.

Teen Pregnancy Prevention Program Recommendations from Urban and Reservation Northern Plains American Indian Community Members.

PubMed

McMahon, Tracey R; Hanson, Jessica D; Griese, Emily R; Kenyon, DenYelle Baete

2015-07-03

Despite declines over the past few decades, the United States has one of the highest rates of teen pregnancy compared to other industrialized nations. American Indian youth have experienced higher rates of teen pregnancy compared to the overall population for decades. Although it's known that community and cultural adaptation enhance program effectiveness, few teen pregnancy prevention programs have published on recommendations for adapting these programs to address the specific needs of Northern Plains American Indian youth. We employed a mixed-methods analysis of 24 focus groups and 20 interviews with a combined total of 185 urban and reservation-based American Indian youth and elders, local health care providers, and local school personnel to detail recommendations for the cultural adaptation, content, and implementation of a teen pregnancy prevention program specific to this population. Gender differences and urban /reservation site differences in the types of recommendations offered and the potential reasons for these differences are discussed.

AMPHIBIAN DECLINE, ULTRAVIOLET RADIATION AND LOCAL POPULATION ADAPTATION

EPA Science Inventory

Amphibian population declines have been noted on both local and global scales. Causes for these declines are unknown although many hypotheses have been offered. In areas adjacent to human development, loss of habitat is a fairly well accepted cause. However in isolated, seemingl...

Amphibian and reptile declines over 35 years at La Selva, Costa Rica.

PubMed

Whitfield, Steven M; Bell, Kristen E; Philippi, Thomas; Sasa, Mahmood; Bolaños, Federico; Chaves, Gerardo; Savage, Jay M; Donnelly, Maureen A

2007-05-15

Amphibians stand at the forefront of a global biodiversity crisis. More than one-third of amphibian species are globally threatened, and over 120 species have likely suffered global extinction since 1980. Most alarmingly, many rapid declines and extinctions are occurring in pristine sites lacking obvious adverse effects of human activities. The causes of these "enigmatic" declines remain highly contested. Still, lack of long-term data on amphibian populations severely limits our understanding of the distribution of amphibian declines, and therefore the ultimate causes of these declines. Here, we identify a systematic community-wide decline in populations of terrestrial amphibians at La Selva Biological Station, a protected old-growth lowland rainforest in lower Central America. We use data collected over 35 years to show that population density of all species of terrestrial amphibians has declined by approximately 75% since 1970, and we show identical trends for all species of common reptiles. The trends we identify are neither consistent with recent emergence of chytridiomycosis nor the climate-linked epidemic hypothesis, two leading putative causes of enigmatic amphibian declines. Instead, our data suggest that declines are due to climate-driven reductions in the quantity of standing leaf litter, a critical microhabitat for amphibians and reptiles in this assemblage. Our results raise further concerns about the global persistence of amphibian populations by identifying widespread declines in species and habitats that are not currently recognized as susceptible to such risks.

Tobacco smoking trends in Samoa over four decades: can continued globalization rectify that which it has wrought?

PubMed

Linhart, Christine; Naseri, Take; Lin, Sophia; Taylor, Richard; Morrell, Stephen; McGarvey, Stephen T; Magliano, Dianna J; Zimmet, Paul

2017-06-12

The island country of Samoa (population 188,000 in 2011) forms part of Polynesia in the South Pacific. Over the past several decades Samoa has experienced exceptional modernization and globalization of many sectors of society, with noncommunicable diseases (NCD) now the leading cause of morbidity and mortality. The evolution of risk factor prevalence underpinning the increase in NCDs, however, has not been well described, including tobacco smoking which is related to cardiovascular disease, lung cancer, and chronic obstructive pulmonary disease. The present study examines tobacco smoking in relation to different forms and effects of globalization in Samoa using 7 population-based surveys (n = 9223) over 1978-2013. The prevalence of daily tobacco smoking steadily decreased over 1978-2013 from 76% to 36% in men, and from 27% to 15% in women (p < 0.0001 both sexes). During 1991-2013, current tobacco smoking also steadily decreased from 64% to 40% in men (p < 0.0001), and from 21% to 17% in women (p < 0.05). Declines were similar in younger (25-44 years) and older (45-64 years) men and women. Colonial globalization facilitated the introduction and prolific spread of tobacco trade and consumption in the Pacific Islands from the sixteenth century, with many populations inexorably pulled into trade relations and links to the global economy. It has also been a different globalization which may have led to the decline in smoking prevalence in Samoa in recent decades, through global dissemination since the 1950s of information on the harmful effects of tobacco smoking derived from research studies in the USA and Europe. Over the past 35 years tobacco smoking has steadily declined among Samoan adults; the only NCD risk factor to demonstrate marked declines during this period. By 2013 tobacco smoking in women had decreased to levels similar to Australia and New Zealand (ANZ), however in men smoking prevalence remained more than three times higher than ANZ. The impact on smoking prevalence of the variety of tobacco control interventions that have been implemented so far in Samoa need to be evaluated in order to determine the most effective initiatives that should be prioritized and strengthened.

Can selective migration explain why health is worse in regions with population decline?: A study on migration and self-rated health in the Netherlands.

PubMed

Dijkstra, Aletta; Kibele, Eva U B; Verweij, Antonia; van der Lucht, Fons; Janssen, Fanny

2015-12-01

Health disparities between population declining and non-declining areas have received little attention, even though population decline is an established phenomenon in Europe. Selective migration, in which healthier people move out of deprived areas, can possibly explain worse health in declining regions. We assessed whether selective migration can explain the observed worse average health in declining regions as compared with non-declining regions in the Netherlands. Combining data from the Dutch Housing and Living Survey held in 2002 and 2006 with Dutch registry data, we studied the relation between health status and migration in a 5-year period at the individual level by applying logistic regression. In our sample of 130,600 participants, we compared health status, demographic and socioeconomic factors of movers and stayers from declining and non-declining regions. People in the Netherlands who migrated are healthier than those staying behind [odds ratio (OR): 1.80]. This effect is larger for persons moving out of declining regions (OR: 1.76) than those moving into declining regions (OR: 1.47). When controlled for demographic and socioeconomic characteristics, these effects are not significant. Moreover, only a small part of the population migrates out of (0.29%) or into (0.25%) declining regions in the course of 5 years. Despite the relation between health and migration, the effect of selective migration on health differences between declining and non-declining regions in the Netherlands is small. Both health and migration are complexly linked with socioeconomic and demographic factors. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Are snake populations in widespread decline?

PubMed Central

Reading, C. J.; Luiselli, L. M.; Akani, G. C.; Bonnet, X.; Amori, G.; Ballouard, J. M.; Filippi, E.; Naulleau, G.; Pearson, D.; Rugiero, L.

2010-01-01

Long-term studies have revealed population declines in fishes, amphibians, reptiles, birds and mammals. In birds, and particularly amphibians, these declines are a global phenomenon whose causes are often unclear. Among reptiles, snakes are top predators and therefore a decline in their numbers may have serious consequences for the functioning of many ecosystems. Our results show that, of 17 snake populations (eight species) from the UK, France, Italy, Nigeria and Australia, 11 have declined sharply over the same relatively short period of time with five remaining stable and one showing signs of a marginal increase. Although the causes of these declines are currently unknown, we suspect that they are multi-faceted (such as habitat quality deterioration, prey availability), and with a common cause, e.g. global climate change, at their root. PMID:20534600

Increases in residential and energy development are associated with reductions in recruitment for a large ungulate.

PubMed

Johnson, Heather E; Sushinsky, Jessica R; Holland, Andrew; Bergman, Eric J; Balzer, Trevor; Garner, James; Reed, Sarah E

2017-02-01

Land-use change due to anthropogenic development is pervasive across the globe and commonly associated with negative consequences for biodiversity. While land-use change has been linked to shifts in the behavior and habitat-use patterns of wildlife species, little is known about its influence on animal population dynamics, despite the relevance of such information for conservation. We conducted the first broad-scale investigation correlating temporal patterns of land-use change with the demographic rates of mule deer, an iconic species in the western United States experiencing wide-scale population declines. We employed a unique combination of long-term (1980-2010) data on residential and energy development across western Colorado, in conjunction with congruent data on deer recruitment, to quantify annual changes in land-use and correlate those changes with annual indices of demographic performance. We also examined annual variation in weather conditions, which are well recognized to influence ungulate productivity, and provided a basis for comparing the relative strength of different covariates in their association with deer recruitment. Using linear mixed models, we found that increasing residential and energy development within deer habitat were correlated with declining recruitment rates, particularly within seasonal winter ranges. Residential housing had two times the magnitude of effect of any other factor we investigated, and energy development had an effect size similar to key weather variables known to be important to ungulate dynamics. This analysis is the first to correlate a demographic response in mule deer with residential and energy development at large spatial extents relevant to population performance, suggesting that further increases in these development types on deer ranges are not compatible with the goal of maintaining highly productive deer populations. Our results underscore the significance of expanding residential development on mule deer populations, a factor that has received little research attention in recent years, despite its rapidly increasing footprint across the landscape. © 2016 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Condition index monitoring supports conservation priorities for the protection of threatened grass-finch populations

PubMed Central

French, Kristine; Legge, Sarah; Astheimer, Lee; Garnett, Stephen

2015-01-01

Abstract Conservation agencies are often faced with the difficult task of prioritizing what recovery actions receive support. With the number of species under threat of decline growing globally, research that informs conservation priorities is greatly needed. The relative vulnerability of cryptic or nomadic species is often uncertain, because populations are difficult to monitor and local populations often seem stable in the short term. This uncertainty can lead to inaction when populations are in need of protection. We tested the feasibility of using differences in condition indices as an indication of population vulnerability to decline for related threatened Australian finch sub-species. The Gouldian finch represents a relatively well-studied endangered species, which has a seasonal and site-specific pattern of condition index variation that differs from the closely related non-declining long-tailed finch. We used Gouldian and long-tailed finch condition variation as a model to compare with lesser studied, threatened star and black-throated finches. We compared body condition (fat and muscle scores), haematocrit and stress levels (corticosterone) among populations, seasons and years to determine whether lesser studied finch populations matched the model of an endangered species or a non-declining species. While vulnerable finch populations often had lower muscle and higher fat and corticosterone concentrations during moult (seasonal pattern similar to Gouldian finches), haematocrit values did not differ among populations in a predictable way. Star and black-throated finch populations, which were predicted to be vulnerable to decline, showed evidence of poor condition during moult, supporting their status as vulnerable. Our findings highlight how measures of condition can provide insight into the relative vulnerability of animal and plant populations to decline and will allow the prioritization of efforts towards the populations most likely to be in jeopardy of extinction. PMID:27293710

Condition index monitoring supports conservation priorities for the protection of threatened grass-finch populations.

PubMed

Maute, Kimberly; French, Kristine; Legge, Sarah; Astheimer, Lee; Garnett, Stephen

2015-01-01

Conservation agencies are often faced with the difficult task of prioritizing what recovery actions receive support. With the number of species under threat of decline growing globally, research that informs conservation priorities is greatly needed. The relative vulnerability of cryptic or nomadic species is often uncertain, because populations are difficult to monitor and local populations often seem stable in the short term. This uncertainty can lead to inaction when populations are in need of protection. We tested the feasibility of using differences in condition indices as an indication of population vulnerability to decline for related threatened Australian finch sub-species. The Gouldian finch represents a relatively well-studied endangered species, which has a seasonal and site-specific pattern of condition index variation that differs from the closely related non-declining long-tailed finch. We used Gouldian and long-tailed finch condition variation as a model to compare with lesser studied, threatened star and black-throated finches. We compared body condition (fat and muscle scores), haematocrit and stress levels (corticosterone) among populations, seasons and years to determine whether lesser studied finch populations matched the model of an endangered species or a non-declining species. While vulnerable finch populations often had lower muscle and higher fat and corticosterone concentrations during moult (seasonal pattern similar to Gouldian finches), haematocrit values did not differ among populations in a predictable way. Star and black-throated finch populations, which were predicted to be vulnerable to decline, showed evidence of poor condition during moult, supporting their status as vulnerable. Our findings highlight how measures of condition can provide insight into the relative vulnerability of animal and plant populations to decline and will allow the prioritization of efforts towards the populations most likely to be in jeopardy of extinction.

An epidemiologic perspective on a case management program.

PubMed

Kahler, Deborah; Salber, Patricia; Wilson, Thomas

2010-01-01

to improve a case management (CM) program using the principles and tools of epidemiology. Specifically, to use epidemiology to describe the population being managed, to analyze factors influencing outcomes, to assess the degree to which the CM process (or intervention) is related to those outcomes, to utilize the findings in order to make recommendations (to take action) for both better evaluation and improved and more efficient CM process, to provide an estimate of the impact of the CM program based on the comparison of pre-CM and post-CM interventions, and finally to discuss the caveat that pre-CM period probably does not provide a prediction of patterns to be expected in the post-CM period had CM not been present (an ideal, but difficult-to-find referent population for this kind of effectiveness analysis). a Medicare Advantage health plan. there were a total of 12,185 individuals who met the continuous enrollment requirement of 6 months (28 days) prior to initial contact with the CM department and 6 months after the contact date: 53% were female; the average age was 73.9 (standard deviation = ± 9.5). There was a linear relationship between the average "dose" of CM-as measured by the number of times a case manager had contact with a case-and the risk profile of the case-as measured by a standard risk assessment tool provided by the Centers for Medicare & Medicaid Services. The month-to-month costs for the study population prior to CM showed a sharp rise in the month prior to the initial contact with CM and a sharp decline beginning before the contact. This pattern was consistent across different risk profiles and our operational definition of CM "dose."The average costs 6 months prior to CM were higher than the average costs 6 months after the CM. The difference in cost varied by "dose" category. When coupled with the number of cases per dosage category, the greatest value for the CM program was in the management of moderate risk cases called two to four times.However, some of the overall decline that begins prior to the initial CM contact is likely attributed to "regression to the mean" (i.e., costs may have shown a decline in spite of CM) but not all. Subsequent studies will be designed to assess the degree to which this is the case by including an equivalent referent; ideally, one that has not experienced CM or, in the absence of that, one that experienced a different kind of CM so that a valid "comparative effectiveness" study can be conducted. the "dose" of CM to its cases was in synch with an independent assessment of risk of the cases. This implies that case managers were directing their resources to those in need. However, case managers and CM processes are a limited resource and it is of interest for management to allocate those CM resources in the most efficient way possible. Methods of assessment based on individual experiences of case managers can be improved with structured, population-based assessment. These population-based tools, according to the principles of epidemiology, will be used to better allocate CM resources for optimized impact on patient populations in the future.

Genomic Consequences of Population Decline in the Endangered Florida Scrub-Jay.

PubMed

Chen, Nancy; Cosgrove, Elissa J; Bowman, Reed; Fitzpatrick, John W; Clark, Andrew G

2016-11-07

Understanding the population genetic consequences of declining population size is important for conserving the many species worldwide facing severe decline [1]. Thorough empirical studies on the impacts of population reduction at a genome-wide scale in the wild are scarce because they demand huge field and laboratory investments [1, 2]. Previous studies have demonstrated the importance of gene flow in introducing genetic variation to small populations [3], but few have documented both genetic and fitness consequences of decreased immigration through time in a natural population [4-6]. Here we assess temporal variation in gene flow, inbreeding, and fitness using longitudinal genomic, demographic, and phenotypic data from a long-studied population of federally Threatened Florida scrub-jays (Aphelocoma coerulescens). We exhaustively sampled and genotyped the study population over two decades, providing one of the most detailed longitudinal investigations of genetics in a wild animal population to date. Immigrants were less heterozygous than residents but still introduced genetic variation into our study population. Owing to regional population declines, immigration into the study population declined from 1995-2013, resulting in increased levels of inbreeding and reduced fitness via inbreeding depression, even as the population remained demographically stable. Our results show that, contrary to conventional wisdom, small peripheral populations that already have undergone a genetic bottleneck may play a vital role in preserving genetic diversity of larger and seemingly stable populations. These findings underscore the importance of investing in the persistence of small populations and maintaining population connectivity in conservation of fragmented species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of two years of nitrogen deposition on shoot growth and phenology of Engelmann spruce seedlings

Treesearch

A. W. Schoettle

2000-01-01

As a result of anthropogenic combustion processes, ecosystems in the eastern and western United States and Europe have experienced elevated atmospheric deposition of nitrogen for most of this century and have begun to show symptoms of decline. If there is a cause and effect relationship between nitrogen deposition and ecosystem decline, one would expect that the...

Impacts of land use change and climate variations on annual inflow into the Miyun Reservoir, Beijing, China

Treesearch

Jiangkun Zheng; Ge Sun; Wenhong Li; Xinxiao Yu; Chi Zhang; Yuanbo Gong; Lihua Tu

2016-01-01

The Miyun Reservoir, the only surface water source for Beijing city, has experienced water supply decline in recent decades. Previous studies suggest that both land use change and climate contribute to the changes of water supply in this critical watershed. However, the specific causes of the decline in the Miyun Reservoir are debatable under a non-stationary climate...

Employment changes in U.S. hardwood lumber consuming industries during economic expansions and contractions since 1991

Treesearch

William G. Luppold; Matt Bumgardner

2016-01-01

Understanding employment trends is important for discerning the economic vitality of U.S. hardwood lumber users. After a period of growth in the 1990s, employment in industries consuming hardwood lumber has declined in the 21st century. The wood household furniture industry has experienced the greatest decline, with North Carolina, Virginia, and California being the...

Relaxation of risk-sensitive behaviour of prey following disease-induced decline of an apex predator, the Tasmanian devil

PubMed Central

Hollings, Tracey; McCallum, Hamish; Kreger, Kaely; Mooney, Nick; Jones, Menna

2015-01-01

Apex predators structure ecosystems through lethal and non-lethal interactions with prey, and their global decline is causing loss of ecological function. Behavioural changes of prey are some of the most rapid responses to predator decline and may act as an early indicator of cascading effects. The Tasmanian devil (Sarcophilus harrisii), an apex predator, is undergoing progressive and extensive population decline, of more than 90% in long-diseased areas, caused by a novel disease. Time since local disease outbreak correlates with devil population declines and thus predation risk. We used hair traps and giving-up densities (GUDs) in food patches to test whether a major prey species of devils, the arboreal common brushtail possum (Trichosurus vulpecula), is responsive to the changing risk of predation when they forage on the ground. Possums spend more time on the ground, discover food patches faster and forage more to a lower GUD with increasing years since disease outbreak and greater devil population decline. Loss of top–down effects of devils with respect to predation risk was evident at 90% devil population decline, with possum behaviour indistinguishable from a devil-free island. Alternative predators may help to maintain risk-sensitive anti-predator behaviours in possums while devil populations remain low. PMID:26085584

Replacement Migration: Is It a Solution to Declining and Ageing Populations?

ERIC Educational Resources Information Center

United Nations, New York, NY. Dept. of Economic and Social Affairs.

The United Nations (UN) Population Division monitors fertility, mortality, and migration trends for all countries as a basis for producing the official UN population estimates and projections. Among recent demographic trends, two are prominent: (1) population decline and (2) population aging. Focusing on these two critical trends, a study…

Loss of sagebrush ecosystems and declining bird populations in the Intermountain West: Priority research issues and information needs

USGS Publications Warehouse

,

2002-01-01

Sagebrush lands in the Intermountain West are declining rapidly in quality and extent. Consequently, populations of many bird species dependent on these ecosystems also are declining. The greater sage-grouse has been petitioned for listing as a threatened and endangered species, and other species of sagebrush-obligate birds have special conservation status in most states. We identified the primary issues and information needs during a multi-agency workshop, conducted in response to concerns by management agencies related to declining bird population trends in sagebrush habitats. Priority needs were to (1) obtain a better understanding of bird response to habitat and landscape features, (2) develop monitoring designs to sample habitats and bird populations, (3) determine the effects of land use on sagebrush habitats and dependent bird species, and (4) identify linkages between breeding and wintering ranges. This agenda will identify causes and mechanisms of population declines in birds dependent on sagebrush ecosystems and will lead to better management of the ecosystems upon which they depend.

Differential patterns of Batrachochytrium dendrobatidis infection in relict amphibian populations following severe disease-associated declines.

PubMed

Whitfield, Steven M; Alvarado, Gilbert; Abarca, Juan; Zumbado, Hector; Zuñiga, Ibrahim; Wainwright, Mark; Kerby, Jacob

2017-09-20

Global amphibian biodiversity has declined dramatically in the past 4 decades, and many amphibian species have declined to near extinction as a result of emergence of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd). However, persistent or recovering populations of several amphibian species have recently been rediscovered, and such populations may illustrate how amphibian species that are highly susceptible to chytridiomycosis may survive in the presence of Bd. We conducted field surveys for Bd infection in 7 species of Costa Rican amphibians (all species that have declined to near extinction but for which isolated populations persist) to characterize infection profiles in highly Bd-susceptible amphibians post-decline. We found highly variable patterns in infection, with some species showing low prevalence (~10%) and low infection intensity and others showing high infection prevalence (>80%) and either low or high infection intensity. Across sites, infection rates were negatively associated with mean annual precipitation, and infection intensity across sites was negatively associated with mean average temperatures. Our results illustrate that even the most Bd-susceptible amphibians can persist in Bd-enzootic ecosystems, and that multiple ecological or evolutionary mechanisms likely exist for host-pathogen co-existence between Bd and the most Bd-susceptible amphibian species. Continued monitoring of these populations is necessary to evaluate population trends (continuing decline, stability, or population growth). These results should inform efforts to mitigate impacts of Bd on amphibians in the field.

Latent population responses of summer birds to a catastrophic, climatological event

USGS Publications Warehouse

Knopf, Fritz L.; Sedgwick, James A.

1987-01-01

Catastrophic events can create ecological crunches for avian populations. Ornithologists generally assume that such events elicit immediate, dramatic declines in populations followed by rapid recolonization of a site with habitat recovery. Despite total inundation of habitats within the South Platte floodplain of eastern Colorado during the 1983 breeding season, populations of Brown Thrashers (Toxostoma rufum) and Rufoussided Towhees (Pipilo erythrophthalmus) did not decline significantly from 1982 densities. However, populations of both species declined significantly in 1984 and towhee populations remained low in 1985. These observations support speculations from recent studies of shrubsteppe bird populations that site tenacity may play a stronger role in determining annual densities of breeding birds than previously realized.

Demographic and genetic status of an isolated population of bog turtles (Glyptemys muhlenbergii): Implications for managing small populations of long-lived animals

USGS Publications Warehouse

Pittman, Shannon E.; King, T.L.; Faurby, S.; Dorcas, M.E.

2011-01-01

In this study, we sought to determine the population stability and genetic diversity of one isolated population of the federally-threatened bog turtle (Glyptemys muhlenbergii) in North Carolina. Using capture-recapture data, we estimated adult survival and population growth rate from 1992 to 2007. We found that the population decreased from an estimated 36 adult turtles in 1994 to approximately 11 adult turtles in 2007. We found a constant adult survival of 0. 893 (SE = 0. 018, 95% confidence interval, 0. 853-0. 924) between 1992 and 2007. Using 18 microsatellite markers, we compared the genetic status of this population with five other bog turtle populations. The target population displayed allelic richness (4. 8 ?? 0. 5) and observed heterozygosity (0. 619 ?? 0. 064) within the range of the other bog turtle populations. Coalescent analysis of population growth rate, effective population size, and timing of population structuring event also indicated the genetics of the target population were comparable to the other populations studied. Estimates of effective population size were a proportion of the census size in all populations except the target population, in which the effective population size was larger than the census size (30 turtles vs. 11 turtles). We attribute the high genetic diversity in the target population to the presence of multiple generations of old turtles. This study illustrates that the demographic status of populations of long-lived species may not be reflected genetically if a decline occurred recently. Consequently, the genetic integrity of populations of long-lived animals experiencing rapid demographic bottlenecks may be preserved through conservation efforts effective in addressing demographic problems. ?? 2011 Springer Science+Business Media B.V.

What we know and don't know about amphibian declines in the West

USGS Publications Warehouse

Corn, Paul Stephen

1994-01-01

The problem of declining amphibian species is thought to be particularly acute in western North America, but there are many gaps in our knowledge. Although several declines have been well-documented, other declines are anecdotal or hypothesized. Most documented declines are of ranid frogs or toads (Bufo). Species from montane habitats and those occurring in California have been best studied. Status of many desert species is unknown. Habitat destruction and introduced predators are the most common threats to amphibian populations. Some declines may represent natural variation in population size. Causes have not been determined for several cases where common species have declined over large areas. There are important considerations for ecosystem management, whether changes in amphibian populations are natural or caused by human activities. Causes for declines must be known so that management can be prescribed (or proscribed) to eliminate or minimize these causes. The natural variability of amphibian population numbers and the complexity of metapopulation structure emphasize the necessity of considering multiple temporal and spatial scales in ecosystem management. The decline of amphibian species throughout the world has received considerable recent attention (e.g., Blaustein and Wake 1990, Griffiths and Beebee 1992, Yoffe 1992). Much of this attention derives from a workshop held in February, 1990 on declining amphibians sponsored by the National Research Council Board (NRC) on Biology in Irvine, California (Barinaga 1990, Borchelt 1990). Because of media attention in the aftermath of this conference, it is a popular perception that amphibian declines are a new phenomenon that herpetologists have been slow to recognize (Griffiths and Beebee 1992, Quammen 1993). However, concern about amphibian populations in the United States dates back over 20 years. Beginning in the 1960s, a large, well-documented decline of northern leopard frogs (Rana pipiens) occurred in the upper Midwest (Gibbs et al. 1971, Hine, 1981, Rittshof 1975).

Productivity, mortality, and population trends of wolves in northeastern Minnesota

USGS Publications Warehouse

Mech, L.D.

1977-01-01

Population parameters, mortality causes, and mechanisms of a population decline were studied in wolves (Canis lupus lycaon) from 1968 to 1976 in the Superior National Forest. The main method was aerial radio-tracking of 129 wolves and their packmates. Due to a decline in white-tailed deer (Odocoileus virginianus), the wolf population decreased during most of the study. Average annual productivity varied from 1.5 to 3.3 pups per litter, and annual mortality rates from 7 to 65 percent. Malnutrition and intraspecific strife accounted equally for 58 percent of the mortality; human causes accounted for the remainder. As wolf numbers began to decline, pup starvation became apparent, followed by lower pup production, and then by increased intraspecific strife. At higher densities, adult pack wolves were the most secure members of the population, but as the population declined, they became the least secure because of intraspecific strife.

Millennial-scale faunal record reveals differential resilience of European large mammals to human impacts across the Holocene.

PubMed

Crees, Jennifer J; Carbone, Chris; Sommer, Robert S; Benecke, Norbert; Turvey, Samuel T

2016-03-30

The use of short-term indicators for understanding patterns and processes of biodiversity loss can mask longer-term faunal responses to human pressures. We use an extensive database of approximately 18,700 mammalian zooarchaeological records for the last 11,700 years across Europe to reconstruct spatio-temporal dynamics of Holocene range change for 15 large-bodied mammal species. European mammals experienced protracted, non-congruent range losses, with significant declines starting in some species approximately 3000 years ago and continuing to the present, and with the timing, duration and magnitude of declines varying individually between species. Some European mammals became globally extinct during the Holocene, whereas others experienced limited or no significant range change. These findings demonstrate the relatively early onset of prehistoric human impacts on postglacial biodiversity, and mirror species-specific patterns of mammalian extinction during the Late Pleistocene. Herbivores experienced significantly greater declines than carnivores, revealing an important historical extinction filter that informs our understanding of relative resilience and vulnerability to human pressures for different taxa. We highlight the importance of large-scale, long-term datasets for understanding complex protracted extinction processes, although the dynamic pattern of progressive faunal depletion of European mammal assemblages across the Holocene challenges easy identification of 'static' past baselines to inform current-day environmental management and restoration. © 2016 The Author(s).

Projected response of an endangered marine turtle population to climate change

NASA Astrophysics Data System (ADS)

Saba, Vincent S.; Stock, Charles A.; Spotila, James R.; Paladino, Frank V.; Tomillo, Pilar Santidrián

2012-11-01

Assessing the potential impacts of climate change on individual species and populations is essential for the stewardship of ecosystems and biodiversity. Critically endangered leatherback turtles in the eastern Pacific Ocean are excellent candidates for such an assessment because their sensitivity to contemporary climate variability has been substantially studied. If incidental fisheries mortality is eliminated, this population still faces the challenge of recovery in a rapidly changing climate. Here we combined an Earth system model, climate model projections assessed by the Intergovernmental Panel on Climate Change and a population dynamics model to estimate a 7% per decade decline in the Costa Rica nesting population over the twenty-first century. Whereas changes in ocean conditions had a small effect on the population, the ~2.5°C warming of the nesting beach was the primary driver of the decline through reduced hatching success and hatchling emergence rate. Hatchling sex ratio did not substantially change. Adjusting nesting phenology or changing nesting sites may not entirely prevent the decline, but could offset the decline rate. However, if future observations show a long-term decline in hatching success and emergence rate, anthropogenic climate mitigation of nests (for example, shading, irrigation) may be able to preserve the nesting population.

[Fertility change in Mexico and the politics of population].

PubMed

Zavala De Cosio, M E

1993-01-01

This introduction to a detailed study of fertility change in Mexico assesses the available fertility data and describes the sources used, traces the beginning and course of the demographic transition in Mexico, and describes the work. Mexico's demographic transition began around 1930 with the acceleration of mortality decline. The considerable time lag between the mortality decline and the beginning of the fertility decline resulted in a period of very rapid growth. Between 1955 and 1975, the growth rate exceeded 3% annually. The start of the fertility decline dated to about 1970, the time of a major reform of population policy and creation of institutions to reduce growth. But the fertility decline was not solely the result of population programs. An incipient fertility decline could be observed in the metropolitan and more educated population sectors beginning in the early 1960s. The onset of the mortality decline in the 1930s resulted from the sustained social and economic progress made possible after the conclusion of the Mexican Revolution. Between 1930 and 1980, the adult illiteracy rate declined from 61.2% to 17%, while life expectancy increased from 33 years to 63.2 years. In Mexico as in other Latin American countries, the mortality decline, which disturbed the traditional balance between high mortality and high fertility, was the force setting off the demographic transition and the necessary precursor to fertility decline. The first of two main sections of the book focuses on examination of fertility variations in Mexico since around 1900 using cross-sectional and longitudinal methods of analysis. The second part describes the origins, history, and institutions involved in Mexico's population policies and the demographic programs and their principal results. The influence of population policies in demographic change is assessed, especially in the case of fertility changes induced by family planning programs. Both the first and second parts sought to place Mexican fertility trends in the context of the demographic transition and to observe the functioning and effects of demographic programs.

Patterns of Senescence in Human Cardiovascular Fitness: VO2max in Subsistence and Industrialized Populations

PubMed Central

Pisor, Anne C.; Gurven, Michael; Blackwell, Aaron D.; Kaplan, Hillard; Yetish, Gandhi

2014-01-01

Objectives This study explores whether cardiovascular fitness levels and senescent decline are similar in the Tsimane of Bolivia and Canadians, as well as other subsistence and industrialized populations. Among Tsimane, we examine whether morbidity predicts lower levels and faster decline of cardiovascular fitness, or whether their lifestyle (e.g., high physical activity) promotes high levels and slow decline. Alternatively, high activity levels and morbidity might counterbalance such that Tsimane fitness levels and decline are similar to those in industrialized populations. Methods Maximal oxygen uptake (VO2max) was estimated using a step test heart rate method for 701 participants. We compared these estimates to the Canadian Health Measures Survey and previous studies in industrialized and subsistence populations. We evaluated whether health indicators and proxies for market integration were associated with VO2max levels and rate of decline for the Tsimane. Results The Tsimane have significantly higher levels of VO2max and slower rates of decline than Canadians; initial evidence suggests differences in VO2max levels between other subsistence and industrialized populations. Low hemoglobin predicts low VO2max for Tsimane women while helminth infection predicts high VO2max for Tsimane men, though results might be specific to the VO2max scaling parameter used. No variables tested interact with age to moderate decline. Conclusions The Tsimane demonstrate higher levels of cardiovascular fitness than industrialized populations, but levels similar to other subsistence populations. The high VO2max of Tsimane is consistent with their high physical activity and few indicators of cardiovascular disease, measured in previous studies. PMID:24022886

Advances in development reverse fertility declines.

PubMed

Myrskylä, Mikko; Kohler, Hans-Peter; Billari, Francesco C

2009-08-06

During the twentieth century, the global population has gone through unprecedented increases in economic and social development that coincided with substantial declines in human fertility and population growth rates. The negative association of fertility with economic and social development has therefore become one of the most solidly established and generally accepted empirical regularities in the social sciences. As a result of this close connection between development and fertility decline, more than half of the global population now lives in regions with below-replacement fertility (less than 2.1 children per woman). In many highly developed countries, the trend towards low fertility has also been deemed irreversible. Rapid population ageing, and in some cases the prospect of significant population decline, have therefore become a central socioeconomic concern and policy challenge. Here we show, using new cross-sectional and longitudinal analyses of the total fertility rate and the human development index (HDI), a fundamental change in the well-established negative relationship between fertility and development as the global population entered the twenty-first century. Although development continues to promote fertility decline at low and medium HDI levels, our analyses show that at advanced HDI levels, further development can reverse the declining trend in fertility. The previously negative development-fertility relationship has become J-shaped, with the HDI being positively associated with fertility among highly developed countries. This reversal of fertility decline as a result of continued economic and social development has the potential to slow the rates of population ageing, thereby ameliorating the social and economic problems that have been associated with the emergence and persistence of very low fertility.

Conservation genetics of extremely isolated urban populations of the northern dusky salamander (Desmognathus fuscus) in New York City

PubMed Central

Zak, Yana; Pehek, Ellen

2013-01-01

Urbanization is a major cause of amphibian decline. Stream-dwelling plethodontid salamanders are particularly susceptible to urbanization due to declining water quality and hydrological changes, but few studies have examined these taxa in cities. The northern dusky salamander (Desmognathus fuscus) was once common in the New York City metropolitan area, but has substantially declined throughout the region in recent decades. We used five tetranucleotide microsatellite loci to examine population differentiation, genetic variation, and bottlenecks among five remnant urban populations of dusky salamanders in NYC. These genetic measures provide information on isolation, prevalence of inbreeding, long-term prospects for population persistence, and potential for evolutionary responses to future environmental change. All populations were genetically differentiated from each other, and the most isolated populations in Manhattan have maintained very little genetic variation (i.e. <20% heterozygosity). A majority of the populations also exhibited evidence of genetic bottlenecks. These findings contrast with published estimates of high genetic variation within and lack of structure between populations of other desmognathine salamanders sampled over similar or larger spatial scales. Declines in genetic variation likely resulted from population extirpations and the degradation of stream and terrestrial paths for dispersal in NYC. Loss of genetic variability in populations isolated by human development may be an underappreciated cause and/or consequence of the decline of this species in urbanized areas of the northeast USA. PMID:23646283

Yangtze River, an insignificant genetic boundary in tufted deer (Elaphodus cephalophus): the evidence from a first population genetics study.

PubMed

Sun, Zhonglou; Pan, Tao; Wang, Hui; Pang, Mujia; Zhang, Baowei

2016-01-01

Great rivers were generally looked at as the geographical barrier to gene flow for many taxonomic groups. The Yangtze River is the third largest river in the world, and flows across South China and into the East China Sea. Up until now, few studies have been carried out to evaluate its effect as a geographical barrier. In this study, we attempted to determine the barrier effect of the Yangtze River on the tufted deer ( Elaphodus cephalophus ) using the molecular ecology approach. Using mitochondrial DNA control region (CR) sequences and 13 nuclear microsatellite loci, we explored the genetic structure and gene flow in two adjacent tufted deer populations (Dabashan and Wulingshan populations), which are separated by the Yangtze River. Results indicated that there are high genetic diversity levels in the two populations, but no distinguishable haplotype group or potential genetic cluster was detected which corresponded to specific geographical population. At the same time, high gene flow was observed between Wulingshan and Dabashan populations. The tufted deer populations experienced population decrease from 0.3 to 0.09 Ma BP, then followed by a distinct population increase. A strong signal of recent population decline ( T = 4,396 years) was detected in the Wulingshan population by a Markov-Switching Vector Autoregressions(MSVAR) process population demography analysis. The results indicated that the Yangtze River may not act as an effective barrier to gene flow in the tufted deer. Finally, we surmised that the population demography of the tufted deer was likely affected by Pleistocene climate fluctuations and ancient human activities.

Population status of Kittlitz's and Marbled Murrelets and surveys for other marine bird and mammal species in the Kenai Fjords area, Alaska

USGS Publications Warehouse

van Pelt, Thomas I.; Piatt, John F.

2003-01-01

The Kittlitz's murrelet (Brachyramphus brevirostris) is a rare seabird that nests in alpine terrain and generally forages near tidewater glaciers during the breeding season. More than 95% of the global population breeds in Alaska, with the remainder occurring in the Russian Far East. A global population estimate using best-available data in the early 1990s was 20,000 individuals. However, survey data from two core areas (Prince William Sound and Glacier Bay) suggest that populations have declined by 80-90% during the past 10-20 years. In response to these declines, a coalition of environmental groups petitioned the USFWS in May of 2001 to list the Kittlitz’s murrelet under the Endangered Species Act. In 2002, we began a three-year project to examine population status and trend of Kittlitz’s Murrelets in areas where distribution and abundance are poorly known. Here we report on the first field season, focused on the south coast of the Kenai Peninsula. We re-surveyed selected historical transects to evaluate trends, and surveyed new transects for improved population estimation during early July 2002. From a total of 66 Kittlitz’s Murrelets seen on transects, we estimate a total population of 509 Kittlitz’s Murrelets along the south coast of the Kenai Peninsula. Comparisons with past surveys suggest a decline of 83% since 1976, with an average rate of decline calculated as–6.9 % per annum. This decline is in agreement with population declines observed elsewhere in the species’ core glaciated range, indicating that steep population declines observed to date are likely to be a range-wide phenomenon. While the focus of the study was Kittlitz’s Murrelets, other species of marine birds and mammals were also surveyed. Populations of the closely related Marbled Murrelet appear to have increased during the same time period. The abundance and distribution of other species are presented in appendices.

Child Odors and Parenting: A Survey Examination of the Role of Odor in Child-Rearing.

PubMed

Okamoto, Masako; Shirasu, Mika; Fujita, Rei; Hirasawa, Yukei; Touhara, Kazushige

2016-01-01

Parental caregiving is critical for the survival of our young and continuation of our species. In humans, visual and auditory signals from offspring have been shown to be potent facilitators of parenting. However, whether odors emitted by our young also influence human parenting remains unclear. To explore this, we conducted a series of questionnaire surveys targeting parents with children under 6 years old. First, we collected episodes on experiencing odors/sniffing various parts of a child's body (n = 507). The prevalence of experiencing events described in those episodes was examined in a separate survey (n = 384). Based on those results, the Child Odor in Parenting scale (COPs) was developed, and subsequently used in the main survey (n = 888). We found COPs to have adequate content validity, concurrent validity, and reliability. Responses to the COPs demonstrated that parents, especially mothers with infants, are aware of odors from their offspring, and actively seek them in daily child-rearing. The factor structure and content of the COPs items indicated that child odors have both affective and instrumental roles. Affective experiences induce loving feeling and affectionate sniffing, while instrumental experiences pertain to specific hygienic needs. The head was the most frequent source of affective experiences, and the child's bottom of instrumental. Each was experienced by more than 90% of the mothers with a child below 1 year of age. Affective experiences significantly declined as the child grew older, possibly associated with the decline of physical proximity between parents and child. This age-related decline was not prominent for instrumental experiences, except for the bottom, which significantly declined after 3 years of age. The present findings suggest that child odors play roles in human parenting, and that their nature and significance change during the course of a child's development.

Predicting Metapopulation Responses to Conservation in Human-Dominated Landscapes

Treesearch

Zachary S. Ladin; Vincent D' Amico; Jan M. Baetens; Roland R. Roth; W. Gregory Shriver

2016-01-01

Loss of habitat to urbanization is a primary cause of population declines as human-dominated landscapes expand at increasing rates. Understanding how the relative effects of different conservation strategies is important to slow population declines for species in urban landscapes. We studied the wood thrush Hylocichla mustelina, a declining forest-...

Amphibian and reptile declines over 35 years at La Selva, Costa Rica

PubMed Central

Whitfield, Steven M.; Bell, Kristen E.; Philippi, Thomas; Sasa, Mahmood; Bolaños, Federico; Chaves, Gerardo; Savage, Jay M.; Donnelly, Maureen A.

2007-01-01

Amphibians stand at the forefront of a global biodiversity crisis. More than one-third of amphibian species are globally threatened, and over 120 species have likely suffered global extinction since 1980. Most alarmingly, many rapid declines and extinctions are occurring in pristine sites lacking obvious adverse effects of human activities. The causes of these “enigmatic” declines remain highly contested. Still, lack of long-term data on amphibian populations severely limits our understanding of the distribution of amphibian declines, and therefore the ultimate causes of these declines. Here, we identify a systematic community-wide decline in populations of terrestrial amphibians at La Selva Biological Station, a protected old-growth lowland rainforest in lower Central America. We use data collected over 35 years to show that population density of all species of terrestrial amphibians has declined by ≈75% since 1970, and we show identical trends for all species of common reptiles. The trends we identify are neither consistent with recent emergence of chytridiomycosis nor the climate-linked epidemic hypothesis, two leading putative causes of enigmatic amphibian declines. Instead, our data suggest that declines are due to climate-driven reductions in the quantity of standing leaf litter, a critical microhabitat for amphibians and reptiles in this assemblage. Our results raise further concerns about the global persistence of amphibian populations by identifying widespread declines in species and habitats that are not currently recognized as susceptible to such risks. PMID:17449638

Survival rates of female white-tailed deer on an industrial forest following a decline in population density

Treesearch

Shawn M. Crimmins; John W. Edwards; Patrick D. Keyser; James M. Crum; W. Mark Ford; Brad F. Miller; Tyler A. Campbell; Karl V. Miller

2013-01-01

With white-tailed deer (Odocoileus virginianus) populations at historically high levels throughout many North American forests, many current management activities are aimed at reducing deer populations. However, very little information exists on the ecology of low-density white-tailed deer populations or populations that have declined in density. We...

Monarch butterfly population decline in North America: identifying the threatening processes

USGS Publications Warehouse

Thogmartin, Wayne E.; Wiederholt, Ruscena; Oberhauser, Karen; Drum, Ryan G.; Diffendorfer, Jay E.; Altizer, Sonia; Taylor, Orley R.; Pleasants, John M.; Semmens, Darius J.; Semmens, Brice X.; Erickson, Richard A.; Libby, Kaitlin; Lopez-Hoffman, Laura

2017-01-01

The monarch butterfly (Danaus plexippus) population in North America has sharply declined over the last two decades. Despite rising concern over the monarch butterfly's status, no comprehensive study of the factors driving this decline has been conducted. Using partial least-squares regressions and time-series analysis, we investigated climatic and habitat-related factors influencing monarch population size from 1993 to 2014. Potential threats included climatic factors, habitat loss (milkweed and overwinter forest), disease and agricultural insecticide use (neonicotinoids). While climatic factors, principally breeding season temperature, were important determinants of annual variation in abundance, our results indicated strong negative relationships between population size and habitat loss variables, principally glyphosate use, but also weaker negative effects from the loss of overwinter forest and breeding season use of neonicotinoids. Further declines in population size because of glyphosate application are not expected. Thus, if remaining threats to habitat are mitigated we expect climate-induced stochastic variation of the eastern migratory population of monarch butterfly around a relatively stationary population size.

Diet overlap of top-level predators in recent sympatry: bull trout and nonnative lake trout

USGS Publications Warehouse

Guy, Christopher S.; McMahon, Thomas E.; Fredenberg, Wade A.; Smith, Clinton J.; Garfield, David W.; Cox, Benjamin S.

2011-01-01

The establishment of nonnative lake trout Salvelinus namaycush in lakes containing lacustrine–adfluvial bull trout Salvelinus confluentus often results in a precipitous decline in bull trout abundance. The exact mechanism for the decline is unknown, but one hypothesis is related to competitive exclusion for prey resources. We had the rare opportunity to study the diets of bull trout and nonnative lake trout in Swan Lake, Montana during a concomitant study. The presence of nonnative lake trout in Swan Lake is relatively recent and the population is experiencing rapid population growth. The objective of this study was to evaluate the diets of bull trout and lake trout during the early expansion of this nonnative predator. Diets were sampled from 142 bull trout and 327 lake trout during the autumn in 2007 and 2008. Bull trout and lake trout had similar diets, both consumed Mysis diluviana as the primary invertebrate, especially at juvenile stages, and kokanee Oncorhynchus nerka as the primary vertebrate prey, as adults. A diet shift from primarily M. diluviana to fish occurred at similar lengths for both species, 506 mm (476–545 mm, 95% CI) for bull trout and 495 mm (470–518 mm CI) for lake trout. These data indicate high diet overlap between these two morphologically similar top-level predators. Competitive exclusion may be a possible mechanism if the observed overlap remains similar at varying prey densities and availability.

Future Estimation of Convenience Living Facilities Withdrawal due to Population Decline all Over Japan from 2010 TO 2040 - Focus on Supermarkets, Convenience Stores and Drugstores

NASA Astrophysics Data System (ADS)

Nishimoto, Yuka; Akiyama, Yuki; Shibasaki, Ryosuke

2016-06-01

Population explosion is considered to be one of the most crucial problems in the world. However, in Japan, the opposite problem: population decline has become serious now. Japanese population is estimated to decrease by twenty millions in 2040. This negative situation will cause to increase areas where many residents cannot make a daily living all over Japan because many convenience living facilities such as supermarkets, convenience stores and drugstores will be difficult to maintain their market area population due to future population decline. In our research, we used point data of convenience living facilities developed by address geocoding of digital telephone directory and point data of future population projection developed by distribution of Japanese official population projection data proportionally among the building volume of digital residential map, which can monitor building volumes all over Japan. In conclusion, we estimated that various convenience living facilities in Japan will shrink and close by population decline in near future. In particular, it is cleared that approximately 14.7% of supermarkets will be possible to withdraw all over Japan by 2040. In addition, it is cleared that over 40% of supermarkets in some countryside prefectures will be possible to withdraw by 2040. Thus, we estimated future distributions of convenience living facilities that cannot maintain their market area population due to future population decline. Moreover, we estimated the number of people that they will become inconvenience in buying fresh foods.

Evidence for a trophic cascade on rocky reefs following sea star mass mortality in British Columbia

PubMed Central

Cloutier, Ryan N.; Côté, Isabelle M.

2016-01-01

Echinoderm population collapses, driven by disease outbreaks and climatic events, may be important drivers of population dynamics, ecological shifts and biodiversity. The northeast Pacific recently experienced a mass mortality of sea stars. In Howe Sound, British Columbia, the sunflower star Pycnopodia helianthoides—a previously abundant predator of bottom-dwelling invertebrates—began to show signs of a wasting syndrome in early September 2013, and dense aggregations disappeared from many sites in a matter of weeks. Here, we assess changes in subtidal community composition by comparing the abundance of fish, invertebrates and macroalgae at 20 sites in Howe Sound before and after the 2013 sea star mortality to evaluate evidence for a trophic cascade. We observed changes in the abundance of several species after the sea star mortality, most notably a four-fold increase in the number of green sea urchins, Strongylocentrotus droebachiensis, and a significant decline in kelp cover, which are together consistent with a trophic cascade. Qualitative data on the abundance of sunflower stars and green urchins from a citizen science database show that the patterns of echinoderm abundance detected at our study sites reflected wider local trends. The trophic cascade evident at the scale of Howe Sound was observed at half of the study sites. It remains unclear whether the urchin response was triggered directly, via a reduction in urchin mortality, or indirectly, via a shift in urchin distribution into areas previously occupied by the predatory sea stars. Understanding the ecological implications of sudden and extreme population declines may further elucidate the role of echinoderms in temperate seas, and provide insight into the resilience of marine ecosystems to biological disturbances. PMID:27168988

A multicenter study on the health-related quality of life of cataract patients: baseline data.

PubMed

Yamada, Masakazu; Mizuno, Yoshinobu; Miyake, Yozo

2009-09-01

This study examines the impact of cataracts on health-related quality of life (HR-QOL) and health events in the older population. The study population consisted of 439 unoperated cataract patients aged 60 years or older who visited any of the facilities affiliated with the Cataract Survey Group of the National Hospital Organization of Japan, which has been conducting a prospective multicenter cohort study on cataract patients. HR-QOL of the patients was assessed using the Japanese version of Visual Function Questionnaire-25 (VFQ-25) and the 8-Item Short-Form Health Survey (SF-8). The health condition and health events of the patients were also investigated. The average age of the 439 patients enrolled (126 men and 313 women) was 73.0 +/- 7.1 years. There were 323 patients with comorbidities (73.6%), 81 of whom (23.7%) felt it was hard to visit the hospital owing to their visual impairment. In the previous year, 74 patients (16.9%) had experienced a fall and 14 (3.2%) had been in a traffic accident. Of those, 43.2% and 8.3% respectively answered that the falls and the accident could have been triggered by their visual impairment. When the patients were classified according to visual acuity, most of the VFQ-25 subscale scores declined significantly with decreasing visual acuity, whereas the SF-8 scores showed no significant change. The participants of this study were patients with unoperated cataract, and thus the decline of HR-QOL was modest. The survey of health events, however, revealed that the visual constraint has a certain impact on the daily lives of the older population.

The short-term impacts of development-induced displacement on wealth and subjective well-being in the Brazilian Amazon

PubMed Central

RANDELL, HEATHER

2017-01-01

Summary Displacement due to development projects such as dams, mines, and urban infrastructure often leads to livelihood decline among affected communities. The challenge, therefore, lies in implementing projects that achieve national or regional development goals while also generating positive social and economic outcomes for displaced populations. This paper uses a longitudinal, mixed-methods design to understand the short-term changes in wealth and subjective well-being of households displaced due to construction of the Belo Monte Dam in the Brazilian Amazon. The households were compensated by either cash or credit for their lost land and assets, and were then responsible for finding and purchasing new property. Using pre- and post-displacement household survey and semi-structured interview data, as well as data from a small comparison group, I find that wealth increased for the majority of the study population and that socioeconomic inequality decreased, as poorer households experienced greater improvements in housing conditions, assets, and property ownership. In addition, subjective well-being improved for most households, particularly among those who did not own land at baseline, those who gained assets such as vehicles, those who remained closer to the original study area, and those who remained in close proximity to other households from the study population. Moving to an urban destination was strongly associated with declines in well-being, as was moving far from family or friends. These results suggest that investing sufficient resources in a compensation-based resettlement program can benefit households displaced by large infrastructure projects in the short term, but additional data collection is needed after the completion of dam construction to determine whether these benefits are sustained over the longer term. PMID:28316364

Investigation of the decline in reported smoking-caused wildfires in the USA from 2000 to 2011

Treesearch

David T. Butry; Jeffrey P. Prestemon; Douglas S. Thomas

2014-01-01

The number of smoking-caused wildfires has been falling nationwide. In national forests in 2011, smoking-caused wildfires represented only 10% of their 1980 level. No other cause of wildfire has experienced this level of decline. For 12 states, we evaluate the rate of smoking-caused wildfires and find it is a function of weather, other ignitions, the number of adult...

Cowbird parasitism in grassland and cropland in the northern Great Plains: Chapter 27

USGS Publications Warehouse

Koford, Rolf R.; Bowen, B.S.; Lokemoen, John T.; Kruse, Arnold D.; Smith, James N.M.; Cook, T.L.; Rothstein, S. IU.; Robinson, S.K.; Sealy, S.G.

2000-01-01

The landscape of the Great Plains has been greatly altered by human activities in the past century, and several grassland passerines have experienced significant population declines in recent decades. We explore here whether brood parasitism by Brown-headed Cowbirds, which are abundant in the Great Plains, has contributed to these declines. We measured the frequency of cowbird parasitism of passerine species in seeded grassland, natural grassland, and cropland in studies conducted in North Dakota during 1981-1993. The proportions of parasitized nests were 25%, 34%, and 39% in seeded grassland, natural grassland, and cropland, respectively. We speculate that much of the variation in parasitism rate among these habitats is related to the local abundance of cowbirds, to nest visibility, and to the presence of suitable perches for female cowbirds. Local abundance of cowbirds may be high in areas with cattle pastures. Nests and nesting behavior are probably more visible to female cowbirds in cropland than in grassland. Female cowbirds may use shrubs as perches while searching for host nests, and shrubs are more common in natural grasslands than in the other habitats we examined. Experimental work on the determinants of cowbird abundance in grasslands is needed.

Economic effect of restaurant smoking restrictions on restaurant business in Massachusetts, 1992 to 1998.

PubMed

Bartosch, William J; Pope, G C

2002-06-01

To determine if restaurant business declines or improves after the implementation of restrictive restaurant smoking policies. Analysis used a pre/post-quasi-experimental design that compared town meals tax receipts before and after the imposition of highly restrictive restaurant smoking policies in adopting versus non-adopting communities. The effect of restaurant smoking policies was estimated using a fixed effects regression model, entering a panel of 84 months of data for the 239 towns in the study. A separate model estimated the effect of restaurant smoking policies on establishments that served alcohol. Change in the trend in meals tax revenue (adjusted for population) following the implementation of highly restrictive restaurant smoking policies. The local adoption of restrictive restaurant smoking policies did not lead to a measurable deviation from the strong positive trend in revenue between 1992 and 1998 that restaurants in Massachusetts experienced. Controlling for other less restrictive restaurant smoking policies did not change this finding. Similar results were found for only those establishments that served alcoholic beverages. Highly restrictive restaurant smoking policies do not have a significant effect on a community's level of meal receipts, indicating that claims of community wide restaurant business decline under such policies are unwarranted.

Neotropical Amphibian Declines Affect Stream Ecosystem Properties

NASA Astrophysics Data System (ADS)

Connelly, S.; Pringle, C. M.; Bixby, R. J.; Whiles, M. R.; Lips, K. R.; Brenes, R.; Colon-Gaud, J. C.; Kilham, S.; Hunte-Brown, M.

2005-05-01

Global declines of amphibians are well documented, yet effects of these dramatic losses on ecosystem structure and function are poorly understood. As part of a larger collaborative project, we compared two upland Panamanian streams. Both streams are biologically and geologically similar; however, one stream (Fortuna) has recently experienced almost complete extirpation of stream-dwelling frogs, while the other (Cope) still has intact populations. We experimentally excluded tadpoles from localized areas in each stream. We then compared chlorophyll a, algal community composition, ash-free dry mass (AFDM), inorganic matter, and insect assemblages in control and exclusion areas. Additionally, we sampled the natural substrate of both streams monthly for chlorophyll a, algal community composition, AFDM, and inorganic matter. At Cope, chlorophyll a, AFDM, and inorganic matter were greater in areas where tadpoles were excluded than in their presence. Numbers of dominant algal species (e.g., Nupela praecipua and Eunotia siolii) were greater in the exclusion versus control treatments. Monthly sampling of natural substrate indicated higher chlorophyll a and AFDM at Cope compared to Fortuna. Our data suggest that stream-dwelling anuran larvae have significant impacts on algal communities. These results also have implications for predicting the relevance of short-term experimental manipulations to long-term, whole-stream processes.

Competition amplifies drought stress in forests across broad climatic and compositional gradients

USGS Publications Warehouse

Gleason, Kelly; Bradford, John B.; Bottero, Alessandra; D'Amato, Tony; Fraver, Shawn; Palik, Brian J.; Battaglia, Michael; Iverson, Louis R.; Kenefic, Laura; Kern, Christel C.

2017-01-01

Forests around the world are experiencing increasingly severe droughts and elevated competitive intensity due to increased tree density. However, the influence of interactions between drought and competition on forest growth remains poorly understood. Using a unique dataset of stand-scale dendrochronology sampled from 6405 trees, we quantified how annual growth of entire tree populations responds to drought and competition in eight, long-term (multi-decadal), experiments with replicated levels of density (e.g., competitive intensity) arrayed across a broad climatic and compositional gradient. Forest growth (cumulative individual tree growth within a stand) declined during drought, especially during more severe drought in drier climates. Forest growth declines were exacerbated by high density at all sites but one, particularly during periods of more severe drought. Surprisingly, the influence of forest density was persistent overall, but these density impacts were greater in the humid sites than in more arid sites. Significant density impacts occurred during periods of more extreme drought, and during warmer temperatures in the semi-arid sites but during periods of cooler temperatures in the humid sites. Because competition has a consistent influence over growth response to drought, maintaining forests at lower density may enhance resilience to drought in all climates.

Status and Conservation of the Bobolink (Dolichonyx oryzivorus) in Argentina

Treesearch

Adrian S. Di Giacomo; Alejandro G. Di Giacomo; Julio R. Contreras

2005-01-01

It is clear that grassland bird populations have declined significantly during the last 30 years. Declines are widespread in North America, making grassland birds a continental conservation priority. In New England and New York steep population declines for many species warranted listing in many states. Habitat loss through farm abandonment and the subsequent...

Effects of white-nose syndrome on regional population patterns of 3 hibernating bat species.

PubMed

Ingersoll, Thomas E; Sewall, Brent J; Amelon, Sybill K

2016-10-01

Hibernating bats have undergone severe recent declines across the eastern United States, but the cause of these regional-scale declines has not been systematically evaluated. We assessed the influence of white-nose syndrome (an emerging bat disease caused by the fungus Pseudogymnoascus destructans, formerly Geomyces destructans) on large-scale, long-term population patterns in the little brown myotis (Myotis lucifugus), the northern myotis (Myotis septentrionalis), and the tricolored bat (Perimyotis subflavus). We modeled population trajectories for each species on the basis of an extensive data set of winter hibernacula counts of more than 1 million individual bats from a 4-state region over 13 years and with data on locations of hibernacula and first detections of white-nose syndrome at each hibernaculum. We used generalized additive mixed models to determine population change relative to expectations, that is, how population trajectories differed with a colony's infection status, how trajectories differed with distance from the point of introduction of white-nose syndrome, and whether declines were concordant with first local observation of the disease. Population trajectories in all species met at least one of the 3 expectations, but none met all 3. Our results suggest, therefore, that white-nose syndrome has affected regional populations differently than was previously understood and has not been the sole cause of declines. Specifically, our results suggest that in some areas and species, threats other than white-nose syndrome are also contributing to population declines, declines linked to white-nose syndrome have spread across large geographic areas with unexpected speed, and the disease or other threats led to declines in bat populations for years prior to disease detection. Effective conservation will require further research to mitigate impacts of white-nose syndrome, renewed attention to other threats to bats, and improved surveillance efforts to ensure early detection of white-nose syndrome. © 2016 Society for Conservation Biology.

Population ecology of insect invasions and their management

Treesearch

Andrew M. Liebhold; Patrick C. Tobin

2008-01-01

During the establishment phase of a biological invasion, population dynamics are strongly influenced by Allee effects and stochastic dynamics, both of which may lead to extinction of low-density populations. Allee effects refer to a decline in population growth rate with a decline in abundance and can arise from various mechanisms. Strategies to eradicate newly...

The leaky pipeline: factors associated with early decline in interest in premedical studies among underrepresented minority undergraduate students.

PubMed

Barr, Donald A; Gonzalez, Maria Elena; Wanat, Stanley F

2008-05-01

To determine the causes among underrepresented racial and ethnic minority groups (URM) of a decline in interest during the undergraduate years in pursuing a career in medicine. From fall 2002 through 2007, the authors conducted a longitudinal study of 362 incoming Stanford freshmen (23% URM) who indicated on a freshman survey that they hoped to become physicians. Using a 10-point scale of interest, the authors measured the change in students' levels of interest in continuing premedical studies between the beginning of freshman year and the end of sophomore year. Follow-up interviews were conducted with 68 participants, approximately half of whom had experienced decreases in interest in continuing as premeds, and half of whom who had experienced increases in interest. URM students showed a larger decline in interest than did non-URM students; women showed a larger decline than did men, independent of race or ethnicity. The authors found no association between scholastic ability as measured by SAT scores and changes in level of interest. The principal reason given by students for their loss of interest in continuing as premeds was a negative experience in one or more chemistry courses. Students also identified problems in the university's undergraduate advising system as a contributor. Largely because of negative experiences with chemistry classes, URM students and women show a disproportionate decline in interest in continuing in premedical studies, with the result that fewer apply to medical school.

Pesticides and amphibian population declines in California, USA

USGS Publications Warehouse

Sparling, Donald W.; Fellers, Gary M.; McConnell, Laura L.

2001-01-01

Several species of anuran amphibians have undergone drastic population declines in the western United States over the last 10 to 15 years. In California, the most severe declines are in the Sierra Mountains east of the Central Valley and downwind of the intensely agricultural San Joaquin Valley. In contrast, coastal and more northern populations across from the less agrarian Sacramento Valley are stable or declining less precipitously. In this article, we provide evidence that pesticides are instrumental in declines of these species. Using Hyla regilla as a sentinel species, we found that cholinesterase (ChE) activity in tadpoles was depressed in mountainous areas east of the Central Valley compared with sites along the coast or north of the Valley. Cholinesterase was also lower in areas where ranid population status was poor or moderate compared with areas with good ranid status. Up to 50% of the sampled population in areas with reduced ChE had detectable organophosphorus residues, with concentrations as high as 190 ppb wet weight. In addition, up to 86% of some populations had measurable endosulfan concentrations and 40% had detectable 4,4'- dichlorodiphenyldichloroethylene, 4,4'-DDT, and 2,4'-DDT residues.

Water Transfers, Air Quality, Ecosystems and Population Growth at the US-Mexico Border: An Integrated Model of the Mexicali and Imperial Valleys

NASA Astrophysics Data System (ADS)

Forster, C. B.; Gonzalez, T.; Peach, J.; Kjelland, M.; Collins, K.; Grant, W. E.

2006-12-01

Borderland communities in the Imperial-Mexicali Valleys (IMVs) of California (U.S.A.) and Mexicali (Mexico) are experiencing socioeconomic and environmental changes driven by policy makers and environmental conditions both within and outside the IMVs. The Colorado River Quantification Settlement Agreement (QSA) of 2003 will transfer 30 million acre-feet of Colorado River water from Imperial Valley (IV) agricultural users to Southern California urban users over a 75-year period. Because the water level of the Salton Sea is supported by agricultural runoff, reduced water flows to the sea raise concerns that: 1) air quality will be degraded as dust is generated by the drying Sea-bed, and 2) declining fish populations due to increasing salinity will no longer support birds migrating along a key avian flyway. Rapid population growth in the Mexican border-city of Mexicali, combined with new power plants and plans for water reuse, raises concerns that: 1) the quantity and quality of water supplied to the Salton Sea will decline, and 2) increased vehicle use and electrical power generation will lead to declining air quality in the binational air basin. Each concern may be affected by climate change. As environmental factors change, so too may the agricultural economy of the Imperial Valley that, in turn, depends on the availability of both water and manual labor. The economy of Mexicali is dominated by the maquiladora (manufacturing) industry that depends upon the availability of power, labor and water. A system dynamics model, with annual time step, simulates this complex binational system. The model was developed by an academic team with input from local experts/decision-makers from both Mexico and the US. We are preparing to engage community stakeholders and decision-makers in exploring the model. Insights gained from model results yield better understanding of the consequences of alternative future scenarios that include: QSA water transfers and land fallowing plans, socioeconomic change, climate-related variations in future Colorado River flows, plans for Salton Sea restoration, and changing wastewater discharge from Mexicali.

Glasgow marathons 1982-1987. A review of medical problems.

PubMed

Ridley, S A; Rogers, P N; Wright, I H

1990-02-01

The race statistics, whether conditions and incidence of medical problems for the six consecutive years of the Glasgow Marathon are reviewed. The results suggest that the popularity of marathon running is declining but that the competitors are becoming more experienced, seeking medical assistance earlier and, as a result, experiencing fewer and less serious problems at the finish. The effect of weather conditions on the runners' performance is discussed.

Effects of pesticides on owls in North America

USGS Publications Warehouse

Blus, L.J.

1996-01-01

A literature review of the effects of pesticides on owls in North America showed that relatively few studies have been undertaken. Owls used in experiments seem as sensitive to organochlorine pesticides (OCs) as other birds of prey, but wild owls experienced few serious problems, primarily because they were exposed to lower residues in their predominately mammalian or invertebrate prey. For example, the great horned owl ( Bubo virginianus ) and the common barn-owl ( Tyto alba ) neither experienced marked changes in mortality or recruitment rates nor was there any evidence of population decreases even during the maximum period of OC pesticide use. Also, eggshell thinning was not a widespread problem. There were adverse effects on individual owls including verified records of 74 owls of six species that died from secondary or tertiary poisoning related to strychnine, organochlorines, anticholinesterases (antiChEs) and anticoagulants in 16 states within the U.S. and one province in Canada. Most of the pesticide-related deaths occurred during the 1980s, although this probably does not represent a true temporal distribution. Verified mortalities of owls probably represent a small fraction of the actual number that died from pesticides. Incidence of mortality seems biased geographically toward areas such as New York that have active ecotoxicological programs. Burrowing owl ( Speotyto cunicularia ) populations currently are decreasing throughout much of the range in the U.S. and Canada. Studies in Canada indicate that antiChE pesticides, particularly carbofuran, were responsible for the declines there.

Simulated global change: contrasting short and medium term growth and reproductive responses of a common alpine/Arctic cushion plant to experimental warming and nutrient enhancement.

PubMed

Alatalo, Juha M; Little, Chelsea J

2014-01-01

Cushion plants are important components of alpine and Arctic plant communities around the world. They fulfill important roles as facilitators, nurse plants and foundation species across trophic levels for vascular plants, arthropods and soil microorganisms, the importance of these functions increasing with the relative severity of the environment. Here we report results from one of the few experimental studies simulating global change impacts on cushion plants; a factorial experiment with warming and nutrient enhancement that was applied to an alpine population of the common nurse plant, Silene acaulis, in sub-arctic Sweden. Experimental perturbations had significant short-term impacts on both stem elongation and leaf length. S. acaulis responded quickly by increasing stem elongation and (to a lesser extent) leaf length in the warming, nutrient, and the combined warming and nutrient enhancements. Cover and biomass also initially increased in response to the perturbations. However, after the initial positive short-term responses, S. acaulis cover declined in the manipulations, with the nutrient and combined warming and nutrient treatments having largest negative impact. No clear patterns were found for fruit production. Our results show that S. acaulis living in harsh environments has potential to react quickly when experiencing years with favorable conditions, and is more responsive to nutrient enhancement than to warming in terms of vegetative growth. While these conditions have an initial positive impact, populations experiencing longer-term increased nutrient levels will likely be negatively affected.