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1.
J Comp Physiol B ; 194(2): 213-219, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38466418

RESUMEN

Hibernation is a widespread metabolic strategy among mammals for surviving periods of food scarcity. During hibernation, animals naturally alternate between metabolically depressed torpor bouts and energetically expensive arousals without ill effects. As a result, hibernators are promising models for investigating mechanisms that buffer against cellular stress, including telomere protection and restoration. In non-hibernators, telomeres, the protective structural ends of chromosomes, shorten with age and metabolic stress. In temperate hibernators, however, telomere shortening and elongation can occur in response to changing environmental conditions and associated metabolic state. We investigate telomere dynamics in a tropical hibernating primate, the fat-tailed dwarf lemur (Cheirogaleus medius). In captivity, these lemurs can hibernate when maintained under cold temperatures (11-15 °C) with limited food provisioning. We study telomere dynamics in eight fat-tailed dwarf lemurs at the Duke Lemur Center, USA, from samples collected before, during, and after the hibernation season and assayed via qPCR. Contrary to our predictions, we found that telomeres were maintained or even lengthened during hibernation, but shortened immediately thereafter. During hibernation, telomere lengthening was negatively correlated with time in euthermia. Although preliminary in scope, our findings suggest that there may be a preemptive, compensatory mechanism to maintain telomere integrity in dwarf lemurs during hibernation. Nevertheless, telomere shortening immediately afterward may broadly result in similar outcomes across seasons. Future studies could profitably investigate the mechanisms that offset telomere shortening within and outside of the hibernation season and whether those mechanisms are modulated by energy surplus or crises.


Asunto(s)
Cheirogaleidae , Hibernación , Telómero , Animales , Hibernación/fisiología , Cheirogaleidae/fisiología , Cheirogaleidae/genética , Masculino , Femenino , Homeostasis del Telómero/fisiología , Acortamiento del Telómero/fisiología , Estaciones del Año
2.
West Afr J Med ; 40(1): 44-54, 2023 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-36716288

RESUMEN

BACKGROUND/AIM: Malaria is a vector borne disease with high morbidity and mortality in endemic regions. In view to eliminating the disease, integrated vector and environmental hygiene practices have been advocated. There is paucity of studies on the effect of vector control measures on asymptomatic malaria infection which has been observed to be a reflection of malaria transmission. METHODS: Longitudinal community-based intervention study carried out from October to December 2017. Study participants were 477 individuals living in 100 households selected by snow-balling sampling methods. Pre-intervention period included training of all heads of households on vector control methods. During the intervention period, each household received waste bins, two long lasting insecticide bed nets and had wire screen on their doors and windows; every household member was screened for malaria (antigen) using the pf rapid diagnostic test kits. Each household were monitored to ensure they comply with the environmental hygiene practices they were taught. Post-intervention malaria infection was obtained at 8 week being end of the intervention period. RESULTS: Of the 100 households selected, 54.0% were from the lower social class, 45.0% middle class and only 1.0% upper class. Mean age [±] of the heads of the households was 37.1 ± 11.0 (range 16-68) years. There were 477 individuals recruited in the study from the 100 households; 234 (49.0%) females and 243 (51.0%) males; median age was 20.0 (range 1-100) years. Prevalence of malaria infection using mRDT during pre-intervention was 16.8% and an incidence of 1.3% post-intervention. There was 92.0% reduction in asymptomatic malaria infection showing marked reduction in malaria transmission in the study locale. CONCLUSION: Some integrated vector control measures such as use of insecticide-treated net and sanitation were found effective methods for reducing malaria infection and transmission in endemic region.


CONTEXTE/OBJECTIF: Le paludisme est une maladie à transmission vectorielle avec une morbidité et une mortalité élevées dans les régions endémiques. En vue d'éliminer la maladie, des pratiques d'hygiène intégrée des vecteurs et de l'environnement ont été préconisées. Il existe peu d'études sur l'effet des mesures de lutte antivectorielle sur l'infection palustre asymptomatique, qui s'est avérée être le reflet de la transmission du paludisme. MÉTHODES: Étude longitudinale d'intervention communautaire réalisée d'octobre à décembre 2017. Les participants à l'étude étaient 477 personnes vivant dans 100 ménages sélectionnés par des méthodes d'échantillonnage en boule de neige. La période de pré-intervention comprenait la formation de tous les chefs de ménage sur les méthodes de lutte antivectorielle. Au cours de la période d'intervention, chaque ménage a reçu des poubelles, deux moustiquaires à insecticide longue durée et avait des grillages sur leurs portes et fenêtres ; chaque membre du ménage a été dépisté pour le paludisme (antigène) à l'aide des kits de test de diagnostic rapide pf. Chaque ménage a été suivi pour s'assurer qu'il respecte les pratiques d'hygiène environnementale qui lui ont été enseignées. L'infection antipaludique post-intervention a été obtenue à 8 semaines, fin de la période d'intervention. RÉSULTATS: Sur les 100 ménages sélectionnés, 54,0% appartenaient à la classe sociale inférieure, 45,0% à la classe moyenne et seulement 1,0% à la classe supérieure. L'âge moyen [±] des chefs de ménage était de 37,1 ± 11,0 (fourchette de 16 à 68) ans. Il y avait 477 personnes recrutées dans l'étude à partir des 100 ménages ; 234 (49,0 %) femmes et 243 (51,0 %) hommes ; l'âge médian était de 20,0 (intervalle de 1 à 100) ans. La prévalence de l'infection du paludisme à l'aide de mRDT pendant la pré-intervention était de 16,8 % et l'incidence de 1,3 % après l'intervention. Il y avait une réduction de 92,0 % de l'infection asymptomatique du paludisme, montrant une réduction marquée de la transmission du paludisme dans le lieu de l'étude. CONCLUSION: Certaines mesures intégrées de lutte antivectorielle telles que l'utilisation de moustiquaires imprégnées d'insecticide et l'assainissement se sont révélées être des méthodes efficaces pour réduire l'infection et la transmission du paludisme dans les régions endémiques. Mots clés: Endémique, Hygiène Environnementale, Ménages, Intervention, Paludisme, Transmission, Vecteur.


Asunto(s)
Mosquiteros Tratados con Insecticida , Insecticidas , Malaria , Masculino , Femenino , Humanos , Lactante , Preescolar , Niño , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Insecticidas/farmacología , Nigeria/epidemiología , Malaria/epidemiología , Malaria/prevención & control , Prevalencia
3.
Clin Oncol (R Coll Radiol) ; 35(2): e215-e226, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36494250

RESUMEN

AIMS: Our understanding of the impact of adjuvant therapy on longitudinal quality of life (QoL) following surgery for patients with uterine cancer is limited. The purpose of this study was to compare QoL in patients who have undergone surgery with or without radiation therapy for uterine cancer. MATERIALS AND METHODS: This was a cross-sectional cohort study that examined women treated for uterine cancer at MD Anderson Cancer Center from 2006 to 2017. Participants included those who underwent hysterectomy/bilateral salphingo-oophorectomy alone, with brachytherapy or external beam radiation therapy (EBRT). A non-cancer cohort of women who underwent a hysterectomy/bilateral salphingo-oophorectomy for benign indications was also identified (non-CA). To compare QoL we used the Functional Assessment of Cancer Therapy - Endometrial survey (FACT-En), a validated survey used to assess QoL. The survey has five subscales: physical, social, emotional, functional and an endometrial cancer-specific subscale. Cohorts were compared using ANOVA tests. RESULTS: In total, 309 women responded to the questionnaire (hysterectomy/bilateral salphingo-oophorectomy 64, brachytherapy 77, EBRT 96, non-CA 72). The median time from surgery to survey completion was 6.7 years. The mean total FACT-En score for the entire cohort was 144 [standard deviation 22]. Overall QoL was different between cohorts, with the EBRT cohort reporting the lowest QoL (mean 139.4 [21.6]) and the brachytherapy cohort the highest (150.6 [18.2], P = 0.006). Among patients who had undergone cancer treatment, the EBRT cohort reported the worst endometrial-specific QoL (53.5 [8.6]), while again the brachytherapy group reported the highest score (57.5 [6.1], P = 0.007). CONCLUSIONS: QoL differences in women who have undergone different treatments for uterine cancer may persist years after treatment. In women with endometrial cancer who require adjuvant therapy, brachytherapy does not appear to have any long-term detriments on QoL.


Asunto(s)
Braquiterapia , Supervivientes de Cáncer , Neoplasias Endometriales , Neoplasias Uterinas , Humanos , Femenino , Calidad de Vida , Estudios Transversales , Radioterapia Adyuvante , Estadificación de Neoplasias , Neoplasias Uterinas/radioterapia , Neoplasias Uterinas/patología , Neoplasias Endometriales/radioterapia , Neoplasias Endometriales/cirugía
4.
BMJ Mil Health ; 168(4): 303-307, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34035158

RESUMEN

INTRODUCTION: Military training is associated with a high incidence of knee pain. Conversion from a rearfoot to non-rearfoot strike during running is effective at reducing knee pain in research environments. The purpose of this report was to demonstrate run retraining as a clinical intervention for service members with knee pain. METHODS: Sixteen service members with running-related chronic knee pain underwent run retraining that converted foot strike from a rearfoot to a non-rearfoot strike using real-time visual feedback. The Lower Extremity Functional Scale (LEFS) and Numerical Pain Rating Scale (NPRS) for knee pain during running were assessed pretraining, at the final training session and at a 1-month follow-up. During running, foot inclination angle and vertical ground reaction force (VGRF) average loading rate were measured pretraining and at 1 month of follow-up. RESULTS: Service members underwent 7.4±1.0 training sessions over the course of 15.8±4.6 days. LEFS improved by 8±6 points immediately after retraining, with an overall improvement of 10±6 points from pretraining to 1-month follow-up (p<0.01). NPRS improved by 2.0±0.4 points immediately after retraining, with an overall improvement of 2.0±0.4 points from pretraining to 1-month follow-up (p<0.01). Conversion to a non-rearfoot strike pattern was apparent at follow-up for all but two patients. VGRF average loading rate decreased by 56%±17% (p<0.01) from pretraining to 1-month follow-up. CONCLUSIONS: Knee pain and function improved as a result of non-rearfoot strike run retraining, which supports the clinical use of this evidence-based intervention.


Asunto(s)
Personal Militar , Carrera , Fenómenos Biomecánicos , Marcha , Humanos , Extremidad Inferior , Dolor
5.
Prospects (Paris) ; 51(1-3): 161-174, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34219813

RESUMEN

Covid-19 has rendered education "remote", opening a chasm in space and time between teachers and students, between how teaching and learning was practiced before and how it is practiced now and for the foreseeable, uncertain future. As many educators find themselves both locked in and locked out, this article seeks to sort through the implications of this remoteness. The article builds on the work of William F. Pinar and George Grant, to argue that technology is an ontology shaping how we encounter who we are and the world in which we live. Caught within the tightening circle of a Covid-19 environment predicated on keeping our distance from one another, while we are connecting technologically, at risk is the complicated conversation, as well as attunement, that lie at the heart of teaching, even as teachers know that it is only through improvisational variations on these that one can hope to chart an ethical course forward.

6.
NPJ Breast Cancer ; 7(1): 87, 2021 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-34226566

RESUMEN

Surgery remains the foundation of curative therapy for non-metastatic breast cancer, but many patients do not undergo surgery. Evidence is limited regarding this population. We sought to assess factors associated with lack of surgery and overall survival (OS) in patients not receiving breast cancer surgery. Retrospective cohort study of patients in the US National Cancer Database treated in 2004-2016. The dataset comprised 2,696,734 patients; excluding patients with unknown surgical status or stage IV, cT0, cTx, or pIS, metastatic or recurrent disease resulted in 1,192,294 patients for analysis. Chi-square and Wilcoxon rank-sum tests were used to assess differences between groups. OS was analyzed using the Kaplan-Meier method with a Cox proportional hazards model performed to assess associated factors. In total 50,626 (4.3%) did not undergo surgery. Black race, age >50 years, lower income, uninsured or public insurance, and lower education were more prevalent in the non-surgical cohort; this group was also more likely to have more comorbidities, higher disease stage, and more aggressive disease biology. Only 3,689 non-surgical patients (7.3%) received radiation therapy (RT). Median OS time for the non-surgical patients was 58 months (3-year and 5-year OS rates 63% and 49%). Median OS times were longer for patients who received chemotherapy (80 vs 50 (no-chemo) months) and RT (85 vs 56 (no-RT) months). On multivariate analysis, age, race, income, insurance status, comorbidity score, disease stage, tumor subtype, treatment facility type and location, and receipt of RT were associated with OS. On subgroup analysis, receipt of chemotherapy improved OS for patients with triple negative (HR 0.66, 95% CI 0.59-0.75, P < 0.001) and HER2+ (HR 0.74, 95% CI 0.65-0.84, P < 0.001) subgroups while RT improved OS for ER+ (HR 0.72, 95% CI 0.64-0.82, P < 0.001) and favorable-disease (ER+, early-stage, age >60) (HR 0.61, 95% CI 0.45-0.83, P = 0.002) subgroups. Approximately 4% of women with breast cancer do not undergo surgery, particularly those with more aggressive disease and lower socioeconomic status. Despite its benefits, RT was underutilized. This study provides a benchmark of survival outcomes for patients who do not undergo surgery and highlights a potential role for use of RT.

7.
Mol Ecol ; 27(8): 2164-2172, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29427300

RESUMEN

Microbiologists often evaluate microbial community dynamics by formulating functional hypotheses based on ecological processes. Indeed, many of the methods and terms currently used to describe animal microbiomes derive from ecology and evolutionary biology. As our understanding of the composition and functional dynamics of "the microbiome" grows, we increasingly refer to the host as an ecosystem within which microbial processes play out. Even so, an ecosystem service framework that extends to the context of the host has thus far been lacking. Here, we argue that ecosystem services are a useful framework with which to consider the value of microbes to their hosts. We discuss those "microbiome services" in the specific context of the mammalian gut, providing a context from which to develop new hypotheses and to evaluate microbial functions in future studies and novel systems.


Asunto(s)
Evolución Biológica , Ecosistema , Interacciones Microbiota-Huesped/genética , Microbiota/genética , Ecología
8.
J Evol Biol ; 28(2): 481-92, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25611210

RESUMEN

Although numerous studies have attempted to find single unifying mechanisms for generating Madagascar's unique flora and fauna, little consensus has been reached regarding the relative importance of climatic, geologic and ecological processes as catalysts of diversification of the region's unique biota. Rather, recent work has shown that both biological and physical drivers of diversification are best analysed in a case-by-case setting with attention focused on the ecological and life-history requirements of the specific phylogenetic lineage under investigation. Here, we utilize a comprehensive analytical approach to examine evolutionary drivers and elucidate the biogeographic history of Malagasy plated lizards (Zonosaurinae). Data from three genes are combined with fossil information to construct time-calibrated species trees for zonosaurines and their African relatives, which are used to test alternative diversification hypotheses. Methods are utilized for explicitly incorporating phylogenetic uncertainty into downstream analyses. Species distribution models are created for 14 of 19 currently recognized species, which are then used to estimate spatial patterns of species richness and endemicity. Spatially explicit analyses are employed to correlate patterns of diversity with both topographic heterogeneity and climatic stability through geologic time. We then use inferred geographic ranges to estimate the biogeographic history of zonosaurines within each of Madagascar's major biomes. Results suggest constant Neogene and Quaternary speciation with divergence from the African most recent common ancestor ~30 million years ago when oceanic currents and African rivers facilitated dispersal. Spatial patterns of diversity appear concentrated along coastal regions of northern and southern Madagascar. We find no relationship between either topographic heterogeneity or climatic stability and patterns of diversity. Ancestral state reconstructions suggest that western dry forests were important centres of origin with recent invasion into spiny and rain forest. These data highlight the power of combining multilocus phylogenetic and spatially explicit analyses for testing alternative diversification hypotheses within Madagascar's unique biota and more generally, particularly as applied to phylogenetically and biologically constrained systems.


Asunto(s)
Distribución Animal/fisiología , Lagartos/genética , Filogenia , Animales , Ecosistema , Variación Genética , Lagartos/fisiología , Madagascar , Especificidad de la Especie
9.
Mol Ecol Resour ; 14(6): 1198-209, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24890011

RESUMEN

High-throughput sequencing platforms are generating massive amounts of genomic data from nonmodel species, and these data sets are valuable resources that can be mined to advance a number of research areas. An example is the growing amount of transcriptome data that allow for examination of gene expression in nonmodel species. Here, we show how publicly available transcriptome data from nonmodel primates can be used to design novel research focused on immunogenomics. We mined transcriptome data from the world's most endangered group of primates, the lemurs of Madagascar, for sequences corresponding to immunoglobulins. Our results confirmed homology between strepsirrhine and haplorrhine primate immunoglobulins and allowed for high-throughput sequencing of expressed antibodies (Ig-seq) in Coquerel's sifaka (Propithecus coquereli). Using both Pacific Biosciences RS and Ion Torrent PGM sequencing, we performed Ig-seq on two individuals of Coquerel's sifaka. We generated over 150 000 sequences of expressed antibodies, allowing for molecular characterization of the antigen-binding region. Our analyses suggest that similar VDJ expression patterns exist across all primates, with sequences closely related to the human VH 3 immunoglobulin family being heavily represented in sifaka antibodies. Moreover, the antigen-binding region of sifaka antibodies exhibited similar amino acid variation with respect to haplorrhine primates. Our study represents the first attempt to characterize sequence diversity of the expressed antibody repertoire in a species of lemur. We anticipate that methods similar to ours will provide the framework for investigating the adaptive immune response in wild populations of other nonmodel organisms and can be used to advance the burgeoning field of eco-immunology.


Asunto(s)
Perfilación de la Expresión Génica , Inmunoglobulinas/genética , Lemur/genética , Lemur/inmunología , Animales , Madagascar
10.
J Evol Biol ; 27(6): 1229-39, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24797428

RESUMEN

The stochastic process of long-distance dispersal is the exclusive means by which plants colonize oceanic islands. Baker's rule posits that self-incompatible plant lineages are unlikely to successfully colonize oceanic islands because they must achieve a coordinated long-distance dispersal of sufficiently numerous individuals to establish an outcrossing founder population. Here, we show for the first time that Mauritian Coffea species are self-incompatible and thus represent an exception to Baker's rule. The genus Coffea (Rubiaceae) is composed of approximately 124 species with a paleotropical distribution. Phylogenetic evidence strongly supports a single colonization of the oceanic island of Mauritius from either Madagascar or Africa. We employ Bayesian divergence time analyses to show that the colonization of Mauritius was not a recent event. We genotype S-RNase alleles from Mauritian endemic Coffea, and using S-allele gene genealogies, we show that the Mauritian allelic diversity is confined to just seven deeply divergent Coffea S-RNase allelic lineages. Based on these data, we developed an individual-based model and performed a simulation study to estimate the most likely number of founding individuals involved in the colonization of Mauritius. Our simulations show that to explain the observed S-RNase allelic diversity, the founding population was likely composed of fewer than 31 seeds that were likely synchronously dispersed from an ancestral mainland species.


Asunto(s)
Coffea/fisiología , Dispersión de Semillas , Teorema de Bayes , Genes de Plantas , Genotipo , Mauricio , Modelos Genéticos , Filogenia , Dinámica Poblacional , Análisis de Secuencia de ADN
11.
J Agric Saf Health ; 19(3): 175-90, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24400422

RESUMEN

Agriculture has the highest injury and fatality rates when compared with other U.S. industries, and tractor overturns remain the leading cause of agricultural fatalities. Rollover protection structures (ROPS) are the only proven devices to protect a tractor operator in the event of an overturn. These devices are 99% effective when used with a seatbelt. Nearly 49% of tractors in the U.S. are not equipped with a ROPS. Interventions such as social marketing, community awareness campaigns, and financial incentives have been directed at encouraging farmers to install ROPS on their unprotected tractors. The purpose of this study was to conduct similar comparisons of ROPS protection and readiness to retrofit in different segments of the Vermont and Pennsylvania farm communities. A telephone survey was used to collect data on ROPS prevalence, farm demographic characteristics, and farmer's stage of change relative to installing ROPS on farm tractors. Our data provide new and unique information on the prevalence of ROPS-equipped tractors relative to commodity, farm size, and a variety of other demographic variables. Extrapolating from these data, the commodities studied account for roughly 162,072 tractors across the two states. Of these, 85,927 (53%) do not have ROPS. Of these unprotected tractors, 77,203 are in Pennsylvania and 8,724 are in Vermont. Our other two research questions dealt with the farmer's stage of change and possible ways to segment this population. The stage of change portion of our work demonstrates that most Pennsylvania and Vermont farmers are not contemplating ROPS retrofitting in the near future. Since no major differences were found in the stage of change, the number of unprotected tractors was examined for each of the commodity groups. In Pennsylvania, 29% of all unprotected tractors were found on cash crop farms. This trend was even more apparent on smaller farms than large farms. This led to the selection of smaller cash crop farms as the target audience for social marketing messages. In contrast, researchers in Vermont found a bimodal distribution of unprotected tractors. Of all the commodity groups surveyed in Vermont, vegetable and cash crop farmers were least likely to have even one protected tractor to use on the farm. Probably the most encouraging finding from this study is that over 85% of Pennsylvania farms and over 87% of Vermont farms surveyed had at least one tractor available that had ROPS protection. Of those farms, 25.5% of the Pennsylvania farms and 46% of the Vermont farms have ROPS on all of their tractors. Both of these findings were greater than the findings from a 2006 survey of New York State farms, which found that 75% of surveyed New York farms have ROPS on at least one tractor and 18% have ROPS on all tractors. Even with these encouraging data, the goal of 100% of tractors with ROPS is far from being met. There are still an estimated 90,000 unprotected tractors on Pennsylvania and Vermont farms, and these farm owners are currently unmotivated to install ROPS. However as demonstrated in New York State, it may be possible to use social marketing that combines persuasive messages and cost-sharing to persuade these farmers that ROPS are indeed important and accessible.


Asunto(s)
Accidentes de Trabajo/prevención & control , Agricultura/estadística & datos numéricos , Equipos de Seguridad/estadística & datos numéricos , Humanos , Intención , Motivación , Salud Laboral , Pennsylvania , Vermont
12.
J Agric Saf Health ; 18(2): 103-12, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22655520

RESUMEN

Tractor overturns contribute significantly to the number of work-related deaths that occur every year on U.S. farms. Although the agriculture, forestry, and fishing industries have the highest fatality rates of any industries, researchers predict that the elimination of tractor overturn fatalities could result in a noticeable reduction in the farm fatality rate. Rollover protection structures (ROPS) are 99% effective in preventing overturn fatalities. However, roughly 50% of U.S. tractors do not have a ROPS. In order to identify prominent barriers and motivators to installing ROPS, a phone survey was conducted with a random sample of farmers (n = 327) in Vermont and Pennsylvania, two states interested in developing ROPS installation programs. Results indicated that cost and perceived need were the most frequently highly rated barriers to ROPS installation in both states, while working near hills or ditches and concerns regarding liability were the most frequently highly rated motivators for installing ROPS. Additionally, older farmers identified limited use of a tractor as a highly rated barrier.


Asunto(s)
Agricultura , Traumatismos Ocupacionales/prevención & control , Vehículos a Motor Todoterreno , Equipos de Seguridad/estadística & datos numéricos , Adulto , Anciano , Agricultura/instrumentación , Bases de Datos Factuales , Diseño de Equipo , Seguridad de Equipos/economía , Seguridad de Equipos/métodos , Seguridad de Equipos/estadística & datos numéricos , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , Motivación , Pennsylvania , Equipos de Seguridad/economía , Vermont
13.
Mol Phylogenet Evol ; 54(1): 291-301, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19755165

RESUMEN

Approximately 20 years ago, Avise and colleagues proposed the integration of phylogenetics and population genetics for investigating the connection between micro- and macroevolutionary phenomena. The new field was termed phylogeography. Since the naming of the field, the statistical rigor of phylogeography has increased, in large part due to concurrent advances in coalescent theory which enabled model-based parameter estimation and hypothesis testing. The next phase will involve phylogeography increasingly becoming the integrative and comparative multi-taxon endeavor that it was originally conceived to be. This exciting convergence will likely involve combining spatially-explicit multiple taxon coalescent models, genomic studies of natural selection, ecological niche modeling, studies of ecological speciation, community assembly and functional trait evolution. This ambitious synthesis will allow us to determine the causal links between geography, climate change, ecological interactions and the evolution and composition of taxa across whole communities and assemblages. Although such integration presents analytical and computational challenges that will only be intensified by the growth of genomic data in non-model taxa, the rapid development of "likelihood-free" approximate Bayesian methods should permit parameter estimation and hypotheses testing using complex evolutionary demographic models and genomic phylogeographic data. We first review the conceptual beginnings of phylogeography and its accomplishments and then illustrate how it evolved into a statistically rigorous enterprise with the concurrent rise of coalescent theory. Subsequently, we discuss ways in which model-based phylogeography can interface with various subfields to become one of the most integrative fields in all of ecology and evolutionary biology.


Asunto(s)
Evolución Molecular , Genética de Población , Filogenia , Teorema de Bayes , Cambio Climático , Ecología , Especiación Genética , Genómica , Geografía , Modelos Genéticos , Modelos Estadísticos , Selección Genética
14.
J Agric Saf Health ; 14(3): 333-49, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18788334

RESUMEN

Guidelines in the U.S. Department of Labor's Hazardous Occupations Order in Agriculture (AgHO) regulations state that youth can receive tractor safety certification after participating in a 10-hour course, or receive tractor and machinery safety certification after participating in a 20-hour course. An additional four hours of orientation to on-farm hazards and general safety is required to receive full certification in a 24-hour course. Previous research has shown that traditional safety education certification programs were conducted with non-standardized methods and old curriculum materials. The objective of the National Safe Tractor and Machinery Operation Program (NSTMOP) project was to design an effective, efficient, and accountable youth farm machinery certification program with national uniformity and a single set of economically producible instructional materials with demonstrated content validity. The format for the NSTMOP project was guided by focus groups, a national steering committee, and selected agricultural safety educators. Primary curriculum materials include a task sheet format, and new skills and driving evaluations. Data analysis indicates that the instructional materials, the instructional plan, and the evaluation of student participants satisfactorily met the objectives of the NSTMOP project and the AgHO regulations.


Asunto(s)
Agricultura , Examen de Aptitud para la Conducción de Vehículos/legislación & jurisprudencia , Certificación , Vehículos a Motor Todoterreno/legislación & jurisprudencia , Accidentes de Trabajo/prevención & control , Adolescente , Adulto , Factores de Edad , Agricultura/instrumentación , Agricultura/legislación & jurisprudencia , Agricultura/normas , Diseño de Equipo , Seguridad de Equipos , Femenino , Humanos , Masculino , Vehículos a Motor Todoterreno/normas , Factores de Riesgo , Seguridad , Estados Unidos , Heridas y Lesiones/prevención & control
15.
Mol Ecol ; 16(4): 839-51, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17284215

RESUMEN

New applications of genetic data to questions of historical biogeography have revolutionized our understanding of how organisms have come to occupy their present distributions. Phylogenetic methods in combination with divergence time estimation can reveal biogeographical centres of origin, differentiate between hypotheses of vicariance and dispersal, and reveal the directionality of dispersal events. Despite their power, however, phylogenetic methods can sometimes yield patterns that are compatible with multiple, equally well-supported biogeographical hypotheses. In such cases, additional approaches must be integrated to differentiate among conflicting dispersal hypotheses. Here, we use a synthetic approach that draws upon the analytical strengths of coalescent and population genetic methods to augment phylogenetic analyses in order to assess the biogeographical history of Madagascar's Triaenops bats (Chiroptera: Hipposideridae). Phylogenetic analyses of mitochondrial DNA sequence data for Malagasy and east African Triaenops reveal a pattern that equally supports two competing hypotheses. While the phylogeny cannot determine whether Africa or Madagascar was the centre of origin for the species investigated, it serves as the essential backbone for the application of coalescent and population genetic methods. From the application of these methods, we conclude that a hypothesis of two independent but unidirectional dispersal events from Africa to Madagascar is best supported by the data.


Asunto(s)
Quirópteros/genética , Demografía , Evolución Molecular , Genética de Población , Filogenia , Animales , Secuencia de Bases , Teorema de Bayes , Cartilla de ADN , Geografía , Madagascar , Modelos Genéticos , Datos de Secuencia Molecular , Dinámica Poblacional , Análisis de Secuencia de ADN
16.
J Agric Saf Health ; 11(1): 61-74, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15782889

RESUMEN

This article reports on the use of expert panels by Purdue University's Agricultural Safety and Health Program staff to address three separate research questions related to: (1) developing strategies for the prevention of flowing grain engulfments, (2) evaluation of commercial lifts used by operators with restricted mobility to gain access to agricultural tractors and equipment, and (3) identifying essential competencies for youth enrolled in federally mandated tractor and machinery certification programs. Advantages and disadvantages associated with the use of expert panels are addressed, and specific examples of outcomes are presented. Recommendations for using expert panels during research projects are also included.


Asunto(s)
Accidentes de Trabajo/prevención & control , Enfermedades de los Trabajadores Agrícolas/prevención & control , Seguridad de Equipos , Testimonio de Experto/estadística & datos numéricos , Seguridad , Prevención de Accidentes , Agricultura/instrumentación , Guías como Asunto , Humanos , Indiana , Evaluación de Programas y Proyectos de Salud , Investigación/normas , Universidades
17.
J Vet Pharmacol Ther ; 25(3): 189-93, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12081614

RESUMEN

The antithyroid drug methimazole is widely used for the medical management of feline hyperthyroidism. Recently, custom veterinary pharmacies have offered methimazole in a transdermal gel containing pluronic and lecithin (PLO), with anecdotal evidence of efficacy. The purpose of this study was to determine the bioavailability, relative to i.v. and oral routes of administration, of transdermal methimazole in a PLO gel in cats. Six healthy adult cats were assigned to receive 5 mg of methimazole by the i.v., oral, or transdermal routes, in a randomized triple crossover protocol with 1 week washout between doses. Blood samples were taken for high performance liquid chromatography (HPLC) determination of serum methimazole, at 0, 5, 15, 30, 60 min, and 2, 4, 6, 12 and 24 h after dosing. Methimazole absorption following transdermal administration was poor and variable, with only two of six cats achieving detectable serum methimazole concentrations at any time point following transdermal administration. Area under the concentration-time curve (AUC), maximum concentration (Cmax), and absolute bioavailability were all significantly lower for the transdermal route (0.39 +/- 0.63 microg h/mL, 0.05 +/- 0.09 microg/mL, and 11.4 +/- 18.7%, respectively) than for either i.v. (7.96 +/- 4.38 microg h/mL, 3.34 +/- 2.00 microg/mL, 100%) or oral routes (2.94 +/- 1.24 microg h/mL, 0.51 +/- 0.15 microg/mL, 40.4 +/- 8.1%). The results of this study indicate generally low to undetectable bioavailability of methimazole in a lecithin/pluronic gel given as a single transdermal dose to healthy cats, although one individual cat did achieve nearly 100% transdermal bioavailability relative to the oral route.


Asunto(s)
Antitiroideos/farmacocinética , Gatos/metabolismo , Metimazol/farmacocinética , Administración Cutánea , Administración Oral , Animales , Antitiroideos/administración & dosificación , Antitiroideos/sangre , Área Bajo la Curva , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión , Estudios Cruzados , Femenino , Inyecciones Intravenosas/veterinaria , Masculino , Metimazol/administración & dosificación , Metimazol/sangre , Fosfatidilcolinas , Valores de Referencia
19.
Syst Biol ; 50(3): 408-24, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12116583

RESUMEN

Tests for incongruence as an indicator of among-data partition conflict have played an important role in conditional data combination. When such tests reveal significant incongruence, this has been interpreted as a rationale for not combining data into a single phylogenetic analysis. In this study of lorisiform phylogeny, we use the incongruence length difference (ILD) test to assess conflict among three independent data sets. A large morphological data set and two unlinked molecular data sets--the mitochondrial cytochrome b gene and the nuclear interphotoreceptor retinoid binding protein (exon 1)--are analyzed with various optimality criteria and weighting mechanisms to determine the phylogenetic relationships among slow lorises (Primates, Loridae). When analyzed separately, the morphological data show impressive statistical support for a monophyletic Loridae. Both molecular data sets resolve the Loridae as paraphyletic, though with different branching orders depending on the optimality criterion or character weighting used. When the three data partitions are analyzed in various combinations, an inverse relationship between congruence and phylogenetic accuracy is observed. Nearly all combined analyses that recover monophyly indicate strong data partition incongruence (P = 0.00005 in the most extreme case), whereas all analyses that recover paraphyly indicate lack of significant incongruence. Numerous lines of evidence verify that monophyly is the accurate phylogenetic result. Therefore, this study contributes to a growing body of information affirming that measures of incongruence should not be used as indicators of data set combinability.


Asunto(s)
Proteínas del Ojo , Lorisidae/clasificación , Lorisidae/genética , Filogenia , Animales , Secuencia de Bases , Biometría , Grupo Citocromo b/genética , ADN/genética , ADN Mitocondrial/genética , Modelos Genéticos , Proteínas de Unión al Retinol/genética
20.
Genetics ; 156(3): 1323-37, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11063705

RESUMEN

Indole-3-butyric acid (IBA) is widely used in agriculture because it induces rooting. To better understand the in vivo role of this endogenous auxin, we have identified 14 Arabidopsis mutants that are resistant to the inhibitory effects of IBA on root elongation, but that remain sensitive to the more abundant auxin indole-3-acetic acid (IAA). These mutants have defects in various IBA-mediated responses, which allowed us to group them into four phenotypic classes. Developmental defects in the absence of exogenous sucrose suggest that some of these mutants are impaired in peroxisomal fatty acid chain shortening, implying that the conversion of IBA to IAA is also disrupted. Other mutants appear to have normal peroxisomal function; some of these may be defective in IBA transport, signaling, or response. Recombination mapping indicates that these mutants represent at least nine novel loci in Arabidopsis. The gene defective in one of the mutants was identified using a positional approach and encodes PEX5, which acts in the import of most peroxisomal matrix proteins. These results indicate that in Arabidopsis thaliana, IBA acts, at least in part, via its conversion to IAA.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Indoles/farmacología , Mutagénesis , Receptores Citoplasmáticos y Nucleares/genética , Secuencia de Aminoácidos , Arabidopsis/efectos de los fármacos , Proteínas de Arabidopsis/metabolismo , Clonación Molecular , Cartilla de ADN , Metanosulfonato de Etilo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/fisiología , Ácidos Indolacéticos/farmacología , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Receptor de la Señal 1 de Direccionamiento al Peroxisoma , Reguladores del Crecimiento de las Plantas/farmacología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/fisiología , Reacción en Cadena de la Polimerasa , Receptores Citoplasmáticos y Nucleares/química , Receptores Citoplasmáticos y Nucleares/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido
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