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1.
Am J Public Health ; 112(S9): S887-S891, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36265094

RESUMEN

Increasing access to COVID-19 testing in influential, accessible community settings is needed to address COVID-19 disparities among African Americans. We describe COVID-19 testing intervention approaches conducted in Kansas City, Missouri, African American churches via a faith-health-academic partnership. Trained faith leaders promoted COVID-19 testing with church and community members by implementing multilevel interventions using a tailored toolkit and standard education information. The local health department conducted more than 300 COVID-19 tests during or after Sunday church services and outreach ministry activities. (Am J Public Health. 2022;112(S9):S887-S891. https://doi.org/10.2105/AJPH.2022.306981).


Asunto(s)
Negro o Afroamericano , COVID-19 , Humanos , Promoción de la Salud , Prueba de COVID-19 , COVID-19/diagnóstico , Organizaciones
2.
Milbank Q ; 99(3): 648-692, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33904611

RESUMEN

Policy Points Medicaid policymakers have a growing interest in addressing homelessness as a social determinant of health and driver of the potentially avoidable use of expensive medical services. Drawing on extensive document reviews and in-depth interviews in four early-adopter states, we examined the implementation of Medicaid's Section 1115 demonstration waivers to test strategies to finance tenancy support services for persons experiencing or at risk of homelessness. CONTEXT: The Affordable Care Act extended Medicaid eligibility to large numbers of individuals experiencing or at risk of homelessness. This legislative development and the growing recognition of homelessness as a significant social determinant of health have encouraged advocates and policymakers to seek new ways to use Medicaid to provide housing supports. METHODS: We conducted 28 semistructured interviews with 36 stakeholders in four states. The stakeholders were government administrators, health care providers, nonprofit housing staff, and consultants. We supplemented these interviews with extensive reviews of public documents, media accounts, think-tank reports, and published literature. We also conducted a systematic inductive qualitative analysis. FINDINGS: We identified seven challenges to the successful implementation of tenancy support demonstration projects: resolving the housing supply and NIMBY, removing silos between health care and homeless services providers, enrolling and retaining the target populations in Medicaid, contracting with and paying tenancy support providers, recruiting and retaining key workers, ensuring Medicaid's waiver durability, and reducing administrative crowd-out and waiver burden. CONCLUSIONS: Notwithstanding these challenges, three of the four states have made significant progress in launching their initiatives. At this point, the fourth state has delayed its start-up to consider alternatives to a Medicaid demonstration waiver to provide tenancy supports. The experience of the four states suggests lessons for Medicaid officials in other jurisdictions that are interested in pursuing tenancy support initiatives. Nevertheless, the limitations of tenancy support waiver programs suggest that federal policymakers should consider allowing states to more directly subsidize housing costs for those experiencing or at risk of homelessness as an optional Medicaid benefit.


Asunto(s)
Personas con Mala Vivienda , Medicaid/legislación & jurisprudencia , Determinación de la Elegibilidad , Humanos , Entrevistas como Asunto , Determinantes Sociales de la Salud , Estados Unidos
3.
Oecologia ; 195(4): 937-948, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33677683

RESUMEN

Resource selection is a dynamic process driven by habitat valuation and risk avoidance in heterogeneous landscapes. Resource selection and movement decisions of individuals may be sensitive to intrinsic factors, such as body condition, and variation in these choices may have consequences on subsequent survival. We evaluated northern bobwhite (Colinus virginianus) brood resource selection patterns to quantify utility of different cover types during the development period using integrated step-selection analysis in a Bayesian hierarchical modeling framework with three brood stages: flightless broods ≤ 14 days old, dependent broods 15-35 days old, and independent broods over 35 days old. Broods showed strongest selection for native grasslands that were burned and grazed at least once in the previous two years, and agricultural fields. Brood mobility improved with age; broods > 35 days old travelled farther on average and took daily steps > 200 m more frequently than younger broods. Young broods ≤ 14 days old did not select for idle native grasslands, while broods > 35 days old did select for that cover type. Young broods also selected areas farther from trees compared to older broods. We evaluated the survival consequences of resource selection by comparing patterns in choices of broods that succeeded to choices of broods that failed to survive to 35 days. Successful broods chose habitats with more shrub cover and areas farther from trees compared to failed broods. Our results suggest that conservation planning should consider age-specific patterns in habitat use and demographic consequences of habitat choice for greatest effectiveness.


Asunto(s)
Colinus , Animales , Teorema de Bayes , Ecosistema
4.
J Health Polit Policy Law ; 45(4): 633-646, 2020 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-32186339

RESUMEN

Within the American system of shared power among institutions, the executive branch has played an increasingly prominent policy role relative to Congress. The vast administrative discretion wielded by the executive branch has elevated the power of the president. Republican and Democratic presidents alike have employed an arsenal of administrative tools to pursue their policy goals: high-level appointments, administrative rule making, executive orders, proclamations, memoranda, guidance documents, directives, dear colleague letters, signing statements, reorganizations, funding decisions, and more. Presidents Obama and Trump employed most of these tools in an effort to shape the implementation and outcomes of the Affordable Care Act (ACA) during its first decade. This article focuses on the Obama and Trump administrations' use of comprehensive waivers to shape ACA implementation. The Obama administration had mixed success using waivers to convince Republican states to expand Medicaid. Compared to Obama, the Trump administration has found it harder to accomplish its policy goals through waivers, but if the courts support the Trump administration's work requirement and 1332 waiver initiatives, it would enable the president to use waivers to achieve an ever broader set of goals, including program retrenchment.


Asunto(s)
Medicaid/organización & administración , Patient Protection and Affordable Care Act/organización & administración , Política , Gobierno Federal , Política de Salud/legislación & jurisprudencia , Gobierno Estatal , Estados Unidos
5.
J Health Polit Policy Law ; 41(4): 763-80, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27127252

RESUMEN

Medicaid is vastly more important than Medicare or private insurance in funding long-term care (LTC). However, states vary tremendously in their commitment to Medicaid LTC. This article advances knowledge of the origins, nature, and implications of this variation. After examining the degree of variation in state spending on Medicaid LTC, we show how federal policy has over the past fifty years steadily increased state discretion to shape these services. This decentralization largely reflects the potency of the intergovernmental lobby-governors and other state officials-in influencing federal policy. While fueling state variation, the intergovernmental lobby has also provided valuable political support that has helped Medicaid grow and resist retrenchment. After considering policy options that could mitigate Medicaid LTC inequities rooted in state differences, we assess how the catalytic forces that have fueled growth in Medicaid LTC may be insufficient to protect the program from future erosion.


Asunto(s)
Cuidados a Largo Plazo/economía , Medicaid , Humanos , Maniobras Políticas , Medicare , Política , Gobierno Estatal , Estados Unidos
6.
Oecologia ; 178(4): 1251-9, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25842295

RESUMEN

Forecasting the effects of climate change on threatened ecosystems and species will require an understanding of how weather influences processes that drive population dynamics. We have evaluated weather effects on activity patterns of western ratsnakes, a widespread predator of birds and small mammals in eastern North America. From 2010-2013 we radio-tracked 53 ratsnakes in the fragmented region of central Missouri. We relocated each snake 4× per week and used movement frequency as an index of activity. We used generalized linear mixed models within an information-theoretic approach to evaluate temporal and weather variables as potential predictors of snake activity. While snakes were generally sedentary, activity showed a linear response to relative humidity and a quadratic response to air temperature, peaking near 30 °C. Seasonal activity patterns differed between sexes and among years, but snakes were generally least active in mid-summer, regardless of weather. Our findings provide strong evidence that air temperature and relative humidity differentially affect activity patterns of an important predator and are the mechanism explaining increased nest predation rates with warmer temperatures.


Asunto(s)
Colubridae/fisiología , Conducta Predatoria/fisiología , Tiempo (Meteorología) , Animales , Cambio Climático , Ecosistema , Femenino , Masculino , Missouri , Dinámica Poblacional , Estaciones del Año , Serpientes/fisiología , Telemetría , Temperatura , Estados Unidos
7.
Health Equity ; 8(1): 147-156, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38505761

RESUMEN

Background: Health inequalities in African American communities have been further exacerbated by COVID-19. Public health departments and other safety-net providers across the United States have partnered with community-based organizations to address barriers to COVID-19 testing in disproportionately impacted communities. This narrative review summarizes lessons learned from published examples of these community-based COVID-19 testing efforts. Methods: We searched online databases for peer-reviewed articles on community-based COVID-19 testing interventions in the United States aimed at increasing COVID-19 testing among African American populations. We abstracted information about each example and synthesized the primary lessons learned and key aspects that contributed to their success. Results: Seven examples of community-based COVID-19 testing aimed at increasing testing among African Americans and other underserved populations were identified and described, across various U.S. locations and involving multiple types of partners (1) St. Paul, MN (faith, health centers, Mayo Clinic); (2) Chicago, IL (university hospital and health centers); (3) NC (health centers, Community Advisory Board); (4) Baltimore, MD (hospitals, community clinic, mobile clinic); (5) Marion County, FL (health department and community partners); (6) New Orleans, LA (health department and health system); and (7) New York City, NY health and hospital system, mobile clinic). Discussion: Several key aspects of the COVID-19 testing models included the following: (1) close proximity of the testing site to affected communities and availability of walk-up and drive-through testing options; (2) partnerships between safety-net providers and broad community networks, which facilitated outreach and trust; (3) increased resources for safety-net providers; and (4) the use of data to identify areas of need and track impact. The merging of resources and relationships among well-equipped, safety-net providers and other health care institutions and culture-rich, community-centered organizations, to jointly address structural and systemic inequities, is key to cultivating health equity in the distribution of COVID-19 testing and other essential public health services.

8.
Inquiry ; 50(1): 71-84, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23720880

RESUMEN

Medicaid insures more than 65 million low-income people, and the Affordable Care Act of 2010 gives states the option to enroll millions more. Historical trends in state Medicaid effort possess important implications for health policy going forward. Nearly all states steadily ratcheted up their Medicaid effort in the period from 1992 to 2009, holding out promise that most will sustain their programs and ultimately participate in the expansion authorized by the Affordable Care Act. But the growth in Medicaid over this period did not appreciably curtail vast geographic disparities in program benefits that threaten to undermine the goals of health reform.


Asunto(s)
Medicaid/economía , Medicaid/estadística & datos numéricos , Patient Protection and Affordable Care Act/economía , Patient Protection and Affordable Care Act/estadística & datos numéricos , Gobierno Estatal , Política de Salud , Humanos , Estados Unidos
9.
Health Econ Policy Law ; : 1-15, 2023 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-37842755

RESUMEN

The Affordable Care Act of 2010 (ACA) was the most significant policy breakthrough to expand health insurance coverage in the USA in 45 years. Culminating a decade-long effort by Republicans to repeal and undermine the ACA, the Trump administration launched a panoply of executive initiatives to sabotage the law. Benefitting from Democratic control of both the House and Senate during its first 2 years, the Biden administration through legislative and executive initiatives made substantial headway in reversing Trump's sabotage and further reinvigorating the ACA. The 2022 elections witnessed a shift in the partisan milieu. Republicans gained control of the House of Representatives; Democrats scored modest gains in state elections. Emphasising two pivotal features of American governance - federalism and the outsized role of the courts - this essay examines the implications of this new partisan context for Biden's efforts to bolster ACA durability prior to the 2024 presidential election.

10.
J Clin Invest ; 133(24)2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-38099496

RESUMEN

Cell therapies such as tumor-infiltrating lymphocyte (TIL) therapy have shown promise in the treatment of patients with refractory solid tumors, with improvement in response rates and durability of responses nevertheless sought. To identify targets capable of enhancing the antitumor activity of T cell therapies, large-scale in vitro and in vivo clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 screens were performed, with the SOCS1 gene identified as a top T cell-enhancing target. In murine CD8+ T cell-therapy models, SOCS1 served as a critical checkpoint in restraining the accumulation of central memory T cells in lymphoid organs as well as intermediate (Texint) and effector (Texeff) exhausted T cell subsets derived from progenitor exhausted T cells (Texprog) in tumors. A comprehensive CRISPR tiling screen of the SOCS1-coding region identified sgRNAs targeting the SH2 domain of SOCS1 as the most potent, with an sgRNA with minimal off-target cut sites used to manufacture KSQ-001, an engineered TIL therapy with SOCS1 inactivated by CRISPR/Cas9. KSQ-001 possessed increased responsiveness to cytokine signals and enhanced in vivo antitumor function in mouse models. These data demonstrate the use of CRISPR/Cas9 screens in the rational design of T cell therapies.


Asunto(s)
Sistemas CRISPR-Cas , Neoplasias , Humanos , Animales , Ratones , ARN Guía de Sistemas CRISPR-Cas , Linfocitos Infiltrantes de Tumor , Inmunoterapia Adoptiva , Neoplasias/genética , Edición Génica , Proteína 1 Supresora de la Señalización de Citocinas/genética
11.
Can J Gastroenterol ; 26(3): 131-47, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22408764

RESUMEN

Colorectal cancer (CRC) is the second most common cause of cancer deaths in Canadian men and women - accounting for almost 12% of all cancer deaths. In Ontario, it is estimated that 8100 persons were diagnosed with CRC in 2011, and 3250 died from the disease. CRC incidence and mortality rates in Ontario are among the highest in the world. Screening offers the best opportunity to reduce this burden of disease. The present report describes the findings and recommendations of Cancer Care Ontario's Fecal Immunochemical Tests (FIT) Guidelines Expert Panel, which was convened in September 2010 by the Program in Evidence-Based Care. The purpose of the present guideline is to evaluate the existing evidence concerning FIT to inform the decision on how to replace the current guaiac fecal occult blood test with FIT in the Ontario ColonCancerCheck Program. Eleven articles were included in the present guideline, comprising two systematic reviews, five articles reporting on three randomized controlled trials, and reports of four other studies. Additionally, one laboratory study was obtained that reported on several parameters of FIT tests that helped to inform the present recommendation. The performance of FIT is superior to the standard guaiac fecal occult blood test in terms of screening participation rates and the detection of CRC and advanced adenoma. Given greater specimen instability with the use of FIT, a pilot study should be undertaken to determine how to implement the FIT in Ontario.


Asunto(s)
Adenoma/diagnóstico , Neoplasias Colorrectales/diagnóstico , Globinas/análisis , Tamizaje Masivo/métodos , Sangre Oculta , Canadá , Globinas/inmunología , Guayaco , Humanos , Inmunoquímica , Guías de Práctica Clínica como Asunto
12.
Ecol Appl ; 21(6): 2269-82, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21939060

RESUMEN

Selection of a modeling approach is an important step in the conservation planning process, but little guidance is available. We compared two statistical and three theoretical habitat modeling approaches representing those currently being used for avian conservation planning at landscape and regional scales: hierarchical spatial count (HSC), classification and regression tree (CRT), habitat suitability index (HSI), forest structure database (FS), and habitat association database (HA). We focused our comparison on models for five priority forest-breeding species in the Central Hardwoods Bird Conservation Region: Acadian Flycatcher, Cerulean Warbler, Prairie Warbler, Red-headed Woodpecker, and Worm-eating Warbler. Lacking complete knowledge on the distribution and abundance of each species with which we could illuminate differences between approaches and provide strong grounds for recommending one approach over another, we used two approaches to compare models: rank correlations among model outputs and comparison of spatial correspondence. In general, rank correlations were significantly positive among models for each species, indicating general agreement among the models. Worm-eating Warblers had the highest pairwise correlations, all of which were significant (P < 0.05). Red-headed Woodpeckers had the lowest agreement among models, suggesting greater uncertainty in the relative conservation value of areas within the region. We assessed model uncertainty by mapping the spatial congruence in priorities (i.e., top ranks) resulting from each model for each species and calculating the coefficient of variation across model ranks for each location. This allowed identification of areas more likely to be good targets of conservation effort for a species, those areas that were least likely, and those in between where uncertainty is higher and thus conservation action incorporates more risk. Based on our results, models developed independently for the same purpose (conservation planning for a particular species in a particular geography) yield different answers and thus different conservation strategies. We assert that using only one habitat model (even if validated) as the foundation of a conservation plan is risky. Using multiple models (i.e., ensemble prediction) can reduce uncertainty and increase efficacy of conservation action when models corroborate one another and increase understanding of the system when they do not.


Asunto(s)
Aves/fisiología , Conservación de los Recursos Naturales/métodos , Ecosistema , Modelos Biológicos , Modelos Estadísticos , Animales , Estados Unidos
13.
Environ Manage ; 48(6): 1061-5, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22075940

RESUMEN

With 207 million ha of forest covering 22% of its land area, China ranks fifth in the world in forest area. Rapid economic growth, climate change, and forest disturbances pose new, complex challenges for forest research and management. Progress in meeting these challenges is relevant beyond China, because China's forests represent 34% of Asia's forests and 5% of the worlds' forests. To provide a broader understanding of these management challenges and of research and policies that address them, we organized this special issue on contemporary forest research and management issues in China. At the national level, papers review major forest types and the evolution of sustainable forestry, the development of China's forest-certification efforts, the establishment of a forest inventory system, and achievements and challenges in insect pest control in China. Papers focused on Northern China address historical, social, and political factors that have shaped the region's forests; the use of forest landscape models to assess how forest management can achieve multiple objectives; and analysis and modeling of fuels and fire behavior. Papers addressing Central and South China describe the "Grain for Green" program, which converts low productivity cropland to grassland and woodland to address erosion and soil carbon sequestration; the potential effects of climate change on CO(2) efflux and soil respiration; and relationships between climate and net primary productivity. China shares many forest management and research issues with other countries, but in other cases China's capacity to respond to forest management challenges is unique and bears watching by the rest of the world.


Asunto(s)
Ambiente , Agricultura Forestal/tendencias , China , Cambio Climático , Política Ambiental , Geografía
14.
PLoS One ; 16(8): e0255298, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34407114

RESUMEN

Resource selection is a key component in understanding the ecological processes underlying population dynamics, particularly for species such as northern bobwhite (Colinus virginianus), which are declining across their range in North America. There is a growing body of literature quantifying breeding season resource selection in bobwhite; however, winter information is particularly sparse despite it being a season of substantial mortality. Information regarding winter resource selection is necessary to quantify the extent to which resource requirements are driving population change. We modeled bobwhite fall and winter resource selection as a function of vegetation structure, composition, and management from traditionally (intensively) managed sites and remnant (extensively managed) grassland sites in southwest Missouri using multinomial logit discrete choice models in a Bayesian framework. We captured 158 bobwhite from 67 unique coveys and attached transmitters to 119 individuals. We created 671 choice sets comprised of 1 used location and 3 available locations. Bobwhite selected for locations which were closer to trees during the winter; the relative probability of selection decreased from 0.45 (85% Credible Interval [CRI]: 0.17-0.74) to 0.00 (85% CRI: 0.00-0.002) as distance to trees ranged from 0-313 m. The relative probability of selection increased from near 0 (85% CRI: 0.00-0.01) to 0.33 (85% CRI: 0.09-0.56) and from near 0 (85% CRI: 0.00-0.00) to 0.51 (85% CRI: 0.36-0.71) as visual obstruction increased from 0 to 100% during fall and winter, respectively. Bobwhite also selected locations with more woody stems; the relative probability of selection increased from near 0.00 (85% CRI: 0.00-0.002) to 0.30 (85% CRI: 0.17-0.46) and near 0.00 (85% CRI: 0.00-0.001) to 0.35 (85% CRI: 0.22-0.55) as stem count ranged from 0 to 1000 stems in fall and winter, respectively. The relative probability of selection also decreased from 0.35 (85% CRI: 0.20-0.54) to nearly 0 (85% CRI: 0.00-0.001) as percent grass varied from 0 to 100% in fall. We suggest that dense shrub cover in close proximity to native grasslands is an important component of fall and winter cover given bobwhite selection of shrub cover and previously reported survival benefits in fall and winter.


Asunto(s)
Colinus , Animales , Teorema de Bayes , Pradera , Estaciones del Año
15.
Ecol Appl ; 20(2): 398-418, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20405795

RESUMEN

Migratory bird needs must be met during four phases of the year: breeding season, fall migration, wintering, and spring migration; thus, management may be needed during all four phases. The bulk of research and management has focused on the breeding season, although several issues remain unsettled, including the spatial extent of habitat influences on fitness and the importance of habitat on the breeding grounds used after breeding. Although detailed investigations have shed light on the ecology and population dynamics of a few avian species, knowledge is sketchy for most species. Replication of comprehensive studies is needed for multiple species across a range of areas, Information deficiencies are even greater during the wintering season, when birds require sites that provide security and food resources needed for survival and developing nutrient reserves for spring migration and, possibly, reproduction. Research is needed on many species simply to identify geographic distributions, wintering sites, habitat use, and basic ecology. Studies are complicated, however, by the mobility of birds and by sexual segregation during winter. Stable-isotope methodology has offered an opportunity to identify linkages between breeding and wintering sites, which facilitates understanding the complete annual cycle of birds. The twice-annual migrations are the poorest-understood events in a bird's life. Migration has always been a risky undertaking, with such anthropogenic features as tall buildings, towers, and wind generators adding to the risk. Species such as woodland specialists migrating through eastern North America have numerous options for pausing during migration to replenish nutrients, but some species depend on limited stopover locations. Research needs for migration include identifying pathways and timetables of migration, quality and distribution of habitats, threats posed by towers and other tall structures, and any bottlenecks for migration. Issues such as human population growth, acid deposition, climate change, and exotic diseases are global concerns with uncertain consequences to migratory birds and even less-certain remedies. Despite enormous gaps in our understanding of these birds, research, much of it occurring in the past 30 years, has provided sufficient information to make intelligent conservation efforts but needs to expand to handle future challenges.


Asunto(s)
Migración Animal/fisiología , Aves/crecimiento & desarrollo , Aves/fisiología , Conservación de los Recursos Naturales/métodos , Animales , Modelos Teóricos , Dinámica Poblacional
16.
Ecology ; 90(6): 1620-30, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19569376

RESUMEN

Migration presents a trade-off for individuals between the potential fitness benefits of reaching high-quality habitat vs. the potential costs of migration. Within an information-theoretic framework, we examined the costs of migration for adult wood frogs (Rana sylvatica) in response to timber harvest and annual weather conditions using Cox proportional-hazard estimates of survival. In 2004 prior to timber harvest, survival did not differ between the inside (0.75, SE = 0.078) and outside (0.73, SE = 0.235) of the circular timber harvest arrays (each 164 m radius). Following timber harvest, survival inside arrays in both 2005 and 2006 (0.22, SE = 0.065; 0.42, SE = 0.139) was lower than survival outside of the arrays and prior to harvest. Sources of mortality included predation in all years and desiccation in the drought year of 2005. The most-supported models for explaining both predation and desiccation risks reflected behaviors as opposed to timber harvest or weather conditions. Both predation and desiccation risks increased when frogs made frequent movements or were located near breeding ponds. Optimal behaviors for reducing predation and desiccation risks were the same before and after timber harvest; however, the survival consequences for not adopting these behaviors were more severe following harvest. Our results provide empirical evidence for (1) the ecological pressures that influence migratory behavior and (2) differential survival in relation to migratory behavior which reveals why frogs move relatively long distances away from breeding sites.


Asunto(s)
Migración Animal/fisiología , Sequías , Agricultura Forestal , Ranidae/fisiología , Animales , Cruzamiento , Deshidratación , Femenino , Masculino , Dinámica Poblacional , Reproducción/fisiología
17.
Sci Total Environ ; 634: 1214-1221, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-29710627

RESUMEN

Demographic processes (fecundity, dispersal, colonization, growth, and mortality) and their interactions with environmental changes are not well represented in current climate-distribution models (e.g., niche and biophysical process models) and constitute a large uncertainty in projections of future tree species distribution shifts. We investigate how species biological traits and environmental heterogeneity affect species distribution shifts. We used a species-specific, spatially explicit forest dynamic model LANDIS PRO, which incorporates site-scale tree species demography and competition, landscape-scale dispersal and disturbances, and regional-scale abiotic controls, to simulate the distribution shifts of four representative tree species with distinct biological traits in the central hardwood forest region of United States. Our results suggested that biological traits (e.g., dispersal capacity, maturation age) were important for determining tree species distribution shifts. Environmental heterogeneity, on average, reduced shift rates by 8% compared to perfect environmental conditions. The average distribution shift rates ranged from 24 to 200myear-1 under climate change scenarios, implying that many tree species may not able to keep up with climate change because of limited dispersal capacity, long generation time, and environmental heterogeneity. We suggest that climate-distribution models should include species demographic processes (e.g., fecundity, dispersal, colonization), biological traits (e.g., dispersal capacity, maturation age), and environmental heterogeneity (e.g., habitat fragmentation) to improve future predictions of species distribution shifts in response to changing climates.


Asunto(s)
Cambio Climático , Monitoreo del Ambiente , Bosques , Árboles/fisiología , Dispersión de las Plantas
18.
Ecology ; 88(7): 1803-12, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17645026

RESUMEN

Climate change is thought to promote the poleward movement of geographic ranges; however, the spatial dynamics, mechanisms, and regional anthropogenic drivers associated with these trends have not been fully explored. We estimated changes in latitude of northern range boundaries, center of occurrence, and center of abundance for 254 species of winter avifauna in North America from 1975 to 2004. After accounting for the effect of range size and the location of the northern boundary, positive latitudinal trends were evident for the northern boundary (1.48 km/yr), center of occurrence (0.45 km/yr), and center of abundance (1.03 km/yr). The northern boundary, when examined across individual species, had the most variable trends (SD = 7.46 km/yr) relative to the center of occurrence (SD = 2.36 km/yr) and center of abundance (SD = 5.57 km/yr). Trends did not differ based on migratory status, but there was evidence that trends differed for species with ranges centered in the southern vs. northern portion of the study area. Species occurred more sporadically over time at northern range boundaries, and northern boundaries were associated with a concentration of colonization and extirpation events, with a greater prevalence of colonization events likely promoting poleward trends. Regional anthropogenic drivers explained approximately 8% of the trend for the northern boundary, 14% for the center of occurrence, and 18% for the center of abundance; however, these effects were localized in the northern portion of species' ranges and were associated with distributional changes within ranges, primarily abundance, producing patterns that mimicked poleward movements. We conclude that poleward distributional shifts represent the interaction between climate change and regional factors whose outcome is determined by the scale of the analysis and the biotic and abiotic features in the region, and how anthropogenic activities have impacted these features.


Asunto(s)
Migración Animal , Aves/fisiología , Geografía , Estaciones del Año , Animales , Efecto Invernadero , América del Norte , Dinámica Poblacional
19.
PLoS One ; 12(6): e0179524, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28614414

RESUMEN

Habitat selection is a fundamental component of community ecology, population ecology, and evolutionary biology and can be especially important to species with complex annual habitat requirements, such as migratory birds. Resource preferences on the breeding grounds may change during the postfledging period for migrant songbirds, however, the degree to which selection changes, timing of change, and whether all or only a few species alter their resource use is unclear. We compared resource selection for nest sites and resource selection by postfledging juvenile ovenbirds (Seiurus aurocapilla) and Acadian flycatchers (Empidonax virescens) followed with radio telemetry in Missouri mature forest fragments from 2012-2015. We used Bayesian discrete choice modeling to evaluate support for local vegetation characteristics on the probability of selection for nest sites and locations utilized by different ages of postfledging juveniles. Patterns of resource selection variation were species-specific. Resource selection models indicated that Acadian flycatcher habitat selection criteria were similar for nesting and dependent postfledging juveniles and selection criteria diverged when juveniles became independent from adults. After independence, flycatcher resource selection was more associated with understory foliage density. Ovenbirds differed in selection criteria between the nesting and postfledging periods. Fledgling ovenbirds selected areas with higher densities of understory structure compared to nest sites, and the effect of foliage density on selection increased as juveniles aged and gained independence. The differences observed between two sympatric forest nesting species, in both the timing and degree of change in resource selection criteria over the course of the breeding season, illustrates the importance of considering species-specific traits and postfledging requirements when developing conservation efforts, especially when foraging guilds or prey bases differ. We recommend that postfledging habitat selection be considered in future conservation efforts dealing with Neotropical migrants and other forest breeding songbirds.


Asunto(s)
Migración Animal/fisiología , Conducta Alimentaria/fisiología , Vuelo Animal/fisiología , Bosques , Comportamiento de Nidificación/fisiología , Pájaros Cantores/fisiología , Animales , Teorema de Bayes , Cruzamiento , Ecosistema , Femenino , Masculino , Missouri , Estaciones del Año , Pájaros Cantores/clasificación , Especificidad de la Especie , Árboles/clasificación , Árboles/crecimiento & desarrollo
20.
Ecol Evol ; 7(22): 9557-9566, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-29187989

RESUMEN

Predicting the effects of global climate change on species interactions has remained difficult because there is a spatiotemporal mismatch between regional climate models and microclimates experienced by organisms. We evaluated resource selection in a predominant ectothermic predator using a modeling approach that permitted us to assess the importance of habitat structure and local real-time air temperatures within the same modeling framework. We radio-tracked 53 western ratsnakes (Pantherophis obsoletus) from 2010 to 2013 in central Missouri, USA, at study sites where this species has previously been linked to prey population demographics. We used Bayesian discrete choice models within an information theoretic framework to evaluate the seasonal effects of fine-scale vegetation structure and thermal conditions on ratsnake resource selection. Ratsnake resource selection was influenced most by canopy cover, canopy cover heterogeneity, understory cover, and air temperature heterogeneity. Ratsnakes generally preferred habitats with greater canopy heterogeneity early in the active season, and greater temperature heterogeneity later in the season. This seasonal shift potentially reflects differences in resource requirements and thermoregulation behavior. Predicted patterns of space use indicate that ratsnakes preferentially selected open habitats in spring and early summer and forest-field edges throughout the active season. Our results show that downscaled temperature models can be used to enhance our understanding of animal resource selection at scales that can be addressed by managers. We suggest that conservation of snakes or their prey in a changing climate will require consideration of fine-scale interactions between local air temperatures and habitat structure.

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