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2.
Case Rep Infect Dis ; 2022: 3348393, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35273815

RESUMO

Hemophagocytic lymphohistiocytosis (HLH) is characterized by a dysregulated activation of the immune system that causes fever, cytopenias, organomegalies, and hemophagocytosis. There are infectious, neoplastic, rheumatologic, and miscellaneous causes. Rickettsioses are a neglected cause of HLH. We report a confirmed case of an immunocompetent woman in Mexico with postpartum HLH secondary to spotted fever. We did a review of the literature for search of similar cases. The association between these two diseases was found in postmortem studies, unrelated to postpartum. This diagnosis should be considered in all patients with HLH without an evident cause in areas of epidemiological risk.

3.
Mar Policy ; 137: 104954, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35035031

RESUMO

Resilience of food systems is key to ensuring food security through crisis. The COVID-19 pandemic presents an unprecedented shock that reveals varying levels of resilience of increasingly interconnected food systems across the globe. We contribute to the ongoing debate about whether increased connectivity reduces or enhances resilience in the context of rural Pacific food systems, while examining how communities have adapted to the global shocks associated with the pandemic to ensure food security. We conducted 609 interviews across 199 coastal villages from May to October 2020 in Federated States of Micronesia, Fiji, Palau, Papua New Guinea, Solomon Islands, Tonga, and Tuvalu to understand community-level impacts and adaptations during the first 5-10 months of the COVID-19 crisis. We found that local food production practices and food sharing conferred resilience, and that imported foods could aid or inhibit resilience. Communities in countries more reliant on imports were almost twice as likely to report food insecurity compared to those least reliant. However, in places dealing with a concurrent cyclone, local food systems were impaired, and imported foods proved critical. Our findings suggest that policy in the Pacific should bolster sustainable local food production and practices. Pacific states should avoid becoming overly reliant on food imports, while having measures in place to support food security after disasters, supplementing locally produced and preserved foods with imported foods when necessary. Developing policies that promote resilient food systems can help prepare communities for future shocks, including those anticipated with climate change.

4.
Mar Pollut Bull ; 173(Pt A): 113016, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34653886

RESUMO

The combustion efficiency of simulated at-sea surface oil burns (in situ burns) was determined in a 63 m3 tank while testing varied boom configurations and air-assist nozzles in the presence and absence of waves. Combustion efficiencies of Alaska North Slope oil based on unburned carbon in the plume emissions ranged from 85% to 93% while values based on oil mass loss ranged from 89% to 99%. A four-fold variation in PM2.5 emission factors was observed from the test conditions. The most effective burns in terms of reduced emissions and post-burn residue concentration of total petroleum hydrocarbons were those that had high length to width boom ratios resulting in higher flame front surface area exposure to ambient air. The amount of oil mass lost was not related to any combustion efficiency parameters measured in the plume, representing a potential tradeoff between unburnt oil and air pollution.


Assuntos
Poluição do Ar , Poluição por Petróleo , Petróleo , Alaska , Hidrocarbonetos , Poluição por Petróleo/análise
5.
PLoS One ; 15(11): e0241146, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33201891

RESUMO

Despite increasing threats to Tonga's coral reefs from stressors that are both local (e.g. overfishing and pollution) and global (e.g. climate change), there is yet to be a systematic assessment of the status of the country's coral reef ecosystem and reef fish fishery stocks. Here, we provide a national ecological assessment of Tonga's coral reefs and reef fish fishery using ecological survey data from 375 sites throughout Tonga's three main island groups (Ha'apai, Tongatapu and Vava'u), represented by seven key metrics of reef health and fish resource status. Boosted regression tree analysis was used to assess and describe the relative importance of 11 socio-environmental variables associated with these key metrics of reef condition. Mean live coral cover across Tonga was 18%, and showed a strong increase from north to south correlated with declining sea surface temperature, as well as with increasing distance from each provincial capital. Tongatapu, the southernmost island group, had 2.5 times greater coral cover than the northernmost group, Vava'u (24.9% and 10.4% respectively). Reef fish species richness and density were comparable throughout Tongatapu and the middle island group, Ha'apai (~35 species/transect and ~2500 fish/km2), but were significantly lower in Vava'u (~24 species/transect and ~1700 fish/km2). Spatial patterns in the reef fish assemblage were primarily influenced by habitat-associated variables (slope, structural complexity, and hard coral cover). The biomass of target reef fish was greatest in Ha'apai (~820 kg/ha) and lowest in Vava'u (~340 kg/ha), and was negatively associated with higher human influence and fishing activity. Overall mean reef fish biomass values suggest that Tonga's reef fish fishery can be classified as moderately to heavily exploited, with 64% of sites having less than 500 kg/ha. This study provides critical baseline ecological information for Tonga's coral reefs that will: (1) facilitate ongoing management and research; and (2) enable accurate reporting on conservation targets locally and internationally.


Assuntos
Antozoários/fisiologia , Recifes de Corais , Peixes/fisiologia , Animais , Biodiversidade , Biomassa , Biofísica , Conservação dos Recursos Naturais/métodos , Ecossistema , Pesqueiros , Humanos , Temperatura , Tonga
6.
Coluna/Columna ; 17(2): 110-116, Apr.-June 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-952928

RESUMO

ABSTRACT Objective: The objective of this study was to determine the factors associated with the persistence of pain in patients operated on for lumbar stenosis. Method: One hundred and fifty-three patients were studied, divided into two groups: 1) Patients with persistent pain in varying degrees, 2) Patients without pain. Age, sex, affected levels, comorbidities, surgical risk, and type of surgical procedure were evaluated. Results: There were 108 patients in the group with pain and 45 in the group without pain. In the group with pain, there were 28 patients with diabetes mellitus, 31 smokers, and 28 alcohol-dependent patients, with a significant difference of p = 0.001 and an RR = 1.1. A simple widening procedure was performed in 48 patients in the group with pain and 12 patients in the group without pain, with RR = 0.8, and widening plus instrumentation was performed in 7 patients in both the with and without pain groups. Conclusion: The indication of a surgical procedure in patients with spinal stenosis must take many factors into account in addition to clinical factors and the segments affected, since these factors impact patient prognosis. In the multivariate analysis, the variable most closely associated with persistent pain was the procedure performed. Level of Evidence III; Case-control study.g


RESUMO Objetivo: Determinar os fatores associados à persistência da dor em pacientes operados por estenose lombar. Método: 153 pacientes foram estudados em dois grupos: 1) Pacientes com dor persistente em graus variados; 2) Pacientes sem dor. Idade, sexo, níveis afetados, comorbidades, risco cirúrgico e tipo de procedimento cirúrgico foram avaliados. Resultados: 108 pacientes no grupo com dor e 45 no grupo sem dor. Diabetes Mellitus em 28 pacientes no grupo da dor. Grupo com dor positivo em relação ao tabagismo em 31 pacientes, 28 pacientes com alcoolismo, com diferença significativa de p=0,001 e um RR=1,1. Os procedimentos realizados foram: Aumento Simples em 48 pacientes dentro do grupo com dor e em 12 pacientes no grupo sem dor, com RR=0,8, Extensão mais instrumentação em sete pacientes no grupo com dor e em sete pacientes no grupo sem dor. Conclusão: A indicação do procedimento cirúrgico em pacientes com estenose espinhal deve levar em consideração muitos fatores, não apenas os segmentos clínicos ou afetados, uma vez que esses fatores têm um efeito prognóstico no paciente. Na análise multivariada, a condição mais associada à dor persistente foi o procedimento realizado. Nível de Evidência III; Estudo de caso-controle.g


RESUMEN Objetivo: Determinar los factores asociados a la persistencia del dolor en pacientes operados por estenosis lumbar. Métodos: Se estudiaron 153 pacientes, en dos grupos: 1) Pacientes con persistencia del dolor en grados variables, 2) Pacientes sin dolor. Se evaluó edad, sexo, niveles afectados, comorbilidades, riesgo quirúrgico y tipo de procedimiento quirúrgico. Resultados: Ciento ocho pacientes en el grupo con dolor y 45 en el grupo sin dolor. Diabetes Mellitus en 28 pacientes del grupo con dolor. Grupo positivo tabaquismo con dolor en 31 pacientes, 28 pacientes con alcoholismo, con diferencia significativa de p=0,001 y un RR=1,1. Los procedimientos realizados fueron: aumento simple en 48 pacientes dentro del grupo con dolor y en 12 pacientes en el grupo sin dolor con RR=0,8, extensión más instrumentación en siete pacientes en el grupo con dolor y en siete pacientes en el grupo sin dolor. Conclusiones: La indicación del procedimiento quirúrgico en pacientes con estenosis espinal debe tomar en cuenta numerosos factores, no únicamente los clínicos o los segmentos afectados, ya que esos factores tienen un efecto pronóstico en el paciente. En el análisis multivariado la condición mayormente asociada a la persistencia del dolor fue el procedimiento realizado. Nivel de Evidencia III; Estudio de caso-controlg.


Assuntos
Humanos , Estenose Espinal/cirurgia , Dor Pós-Operatória , Complicações Pós-Operatórias , Coluna Vertebral/cirurgia
7.
Coluna/Columna ; 17(2): 138-142, Apr.-June 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-952915

RESUMO

ABSTRACT Objective: To evaluate the direct costs of transforaminal lumbar interbody fusion (TLIF) and minimally invasive surgery (MIS) or open technique (OPEN). Methods: The present study is descriptive and retrospective. Sixteen patients with degenerative spinal pathology operated on with the TLIF MIS technique and TLIF OPEN were included over a 13-month period. Days of hospital stay, blood loss, surgical time, medical care and costs were compared. Results: The mean number of days of hospital stay was 6.7 ± 4.3 days with TLIF MIS and 11.1 ± 6.5 days with TLIF OPEN. The blood loss was 307 ± 81.6 ml (range 200400 ml) with TLIF MIS and 803 ± 701.3 ml (range 200-1800 ml) with TLIF OPEN. The surgical time was 320 ± 92.6 minutes (range 210-500 minutes) in TLIF MIS and 372 ± 95.2 minutes (280-540 minutes) in TLIF OPEN. Conclusions: The difference in surgical costs and time between the two procedures was not statistically significant. There was less bleeding during the TLIF-MIS surgery, as well as a correlation between shorter days of hospital stay proportional to bleeding and surgical time, which translates into a reduction in the cost of these items. Level of Evidence III; Analysis based on alternatives and limited costs.


RESUMO Objetivo: Garantir benefícios económicos diretos de cada procedimento cirúrgico. Metodologia: apresentar um estudo descritivo e retrospectivo. Dezesseis pacientes com patologia degenerativa de colônias operados com a técnica TLIF MIS e TLIF OPEN foram incluídos durante um período de 13 meses. Foram comparados os dias de internação, perda de sangue, tempo cirúrgico, assistência médica e custo. Resultados: O número de dias hospitalares para 6,7 ± 4,3 dias no TLIF MIS e 11,1 ± 6,5 dias no TLIF OPEN. Quanto à diferença entre a exigência de resultados da imagem e o número de cirurgias. A perda de sangue foi de 307 ± 81,6 ml (intervalo de 200-400 ml) com TLIF MIS e 803 ± 701,3 ml (intervalo de 200 - 1800 ml) com TLIF OPEN. O tempo cirúrgico de 320 ± 92,6 minutos (intervalo 210-500 minutos) em TLIF MIS e 372 ± 95,2 minutos (280-540 minutos) em TLIF OPEN. Conclusões: A diferença entre os procedimentos cirúrgicos e o tempo entre os procedimentos não é estatisticamente significativa. Houve menos sangria durante a cirurgia do TLIF-MIS, assim como uma correlação entre menos dias de internação proporcional ao sangramento e ao tempo cirúrgico, que se traduziu em uma redução dos custos dos itens. Nível de Evidência III; Análise baseada em alternativas e custos limitados.


RESUMEN Objetivo: Evaluar los costos directos de la fusión intersomática lumbar transforaminal (TLIF) de mínima invasión (MIS) o técnica abierta (OPEN). Métodos: El presente estudio es descriptivo y retrospectivo. Se incluyeron 16 pacientes con patología degenerativa de columna intervenidos con la técnica TLIF MIS y TLIF OPEN en un período de 13 meses. Se compararon días de estancia hospitalaria, pérdida sanguínea, tiempo quirúrgico, atención médica y costos. Resultados: La media de días de estancia hospitalaria fue de 6,7 ± 4,3 días con TLIF MIS y de 11,1 ± 6,5 días con TLIF OPEN. La pérdida sanguínea fue de 307 ± 81,6 ml (rango 200-400 ml) con TLIF MIS y de 803 ± 701,3 ml (rango 200-1800 ml) con TLIF OPEN. El tiempo quirúrgico fue de 320 ± 92,6 minutos (rango 210-500 minutos) en TLIF MIS y de 372 ± 95,2 minutos (280-540 minutos) en TLIF OpEN. Conclusiones: La diferencia de costos y tiempo quirúrgico entre ambos procedimientos no fue estadísticamente significativa. Se mostró un menor sangrado durante la cirugía TLIF-MIS, así como una correlación entre menores días de estancia hospitalaria proporcional con el sangrado y tiempo quirúrgico, lo cual traduce una reducción del costo en esos rubros. Nivel de Evidencia III; Análisis basados en alternativas y costos limitados.


Assuntos
Humanos , Procedimentos Cirúrgicos Operatórios/economia , Fusão Vertebral , Coluna Vertebral/cirurgia , Degeneração do Disco Intervertebral
8.
Emerg Med J ; 35(1): 66-68, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29247138

RESUMO

A shortcut review was carried out to establish whether non-steroidal anti-inflammatory drugs (NSAIDs) is safe to prescribe in patients with chicken pox. 66 unique papers were found in CINAHL, Medline, Embase and Cochrane using the reported searches of which 6 presented the best evidence to answer the clinical question. The author, date and country of publication; patient group studied; study type; relevant outcomes; results and study weaknesses of these best papers are tabulated. It is concluded that, pending further research, it is advisable to avoid NSAID use in cases of primary varicella due to the potential increased risk of severe bacterial skin infections. Paracetamol should be given instead.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Varicela/tratamento farmacológico , Segurança/normas , Anti-Inflamatórios não Esteroides/efeitos adversos , Anti-Inflamatórios não Esteroides/uso terapêutico , Pré-Escolar , Feminino , Humanos
9.
Nurs Stand ; 31(32): 28, 2017 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-28378670

RESUMO

The 1% pay increase for nurses is an insult. But nurses are in an abusive relationship.

10.
Acad Radiol ; 21(9): 1195-203, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24998690

RESUMO

RATIONALE AND OBJECTIVES: Breast dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) scanning protocols vary widely. The purpose of this study was to determine the effects of postcontrast timing on delayed-phase lesion kinetics assessment and ability to discriminate malignant from benign lesions. MATERIALS AND METHODS: Following institutional review board approval, we retrospectively reviewed all lesions assessed on magnetic resonance examinations from April 2005 to June 2006. DCE-MRI was performed with 90-second temporal resolution. Delayed-phase kinetic parameters including percentages of persistent, plateau, and washout, and categorizations of predominant and worst curve type were compared between 4.5 and 7.5 minutes postcontrast. Ability to discriminate benign and malignant lesions based on delayed-phase kinetic parameters was compared between postcontrast timings by receiver operating characteristic (ROC) analysis. RESULTS: Two hundred eighty consecutive breast lesions (206 malignant and 74 benign) were evaluated in 228 women. Comparing kinetics assessments at 7.5 versus 4.5 minutes: volume percentage of washout increased in malignancies by a mean of 9.4% (P<.0001) and increased slightly in benign lesions (mean 3.2%, P=.007); predominant curve type categorizations changed significantly only for malignancies (P<.0001); and worst curve categorizations did not change significantly for either benign or malignant lesions (P>.05). There were no significant differences between timings in area under ROC curves for delayed-phase kinetic parameters. CONCLUSIONS: The choice of delayed postcontrast timing more strongly affects the kinetics assessments for malignancies than benign breast lesions, but our results suggest that a shortened breast DCE-MRI protocol may not significantly impact diagnostic accuracy. Furthermore, worst curve type classifications are least affected by postcontrast timing and may provide reliable assessment of delayed-phase kinetics across protocols.


Assuntos
Neoplasias da Mama/diagnóstico , Meios de Contraste , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Mama/patologia , Diagnóstico Diferencial , Feminino , Humanos , Cinética , Pessoa de Meia-Idade , Variações Dependentes do Observador , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
11.
AJR Am J Roentgenol ; 199(3): 703-8, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22915415

RESUMO

OBJECTIVE: The purpose of this study was to compare the differences in kinetic assessments of lesions at breast MRI performed with higher and lower temporal resolution. MATERIALS AND METHODS: All consecutively evaluated BI-RADS category 4, 5, and 6 lesions imaged with breast MRI and pathologically confirmed from October 2005 to August 2009 were identified. Patients underwent MRI with one of two dynamic contrast-enhanced protocols: one with 90-second (October 2005-June 2006) and another with 180-second (July 2006-August 2009) temporal resolution. Studies were processed with a computer-aided evaluation system with initial and delayed contrast-enhanced time points with the k-space centered 90 and 450 seconds after contrast injection. Initial-phase peak enhancement, delayed-phase predominant curve type, and worst curve type were recorded and compared for benign and malignant lesions across protocols. RESULTS: The analysis set comprised 993 lesions: 145 imaged with the 90-second acquisition (17 benign, 28 ductal carcinoma in situ [DCIS], 100 invasive cancer) and 848 imaged with the 180-second acquisition (212 benign, 145 DCIS, 491 invasive cancer). Peak enhancement was significantly higher for both benign lesions (p = 0.01) and invasive cancers (p = 0.0008) with the 180-second protocol. Peak enhancement of DCIS was similar in the two protocols (p = 0.88). Delayed-phase kinetics were similar for the two protocols for both benign and malignant lesions when defined by predominant or worst curve type. CONCLUSION: Although it has lower temporal resolution, a 180-second acquisition may be preferable because it allows higher spatial resolution and captures higher initial-phase peak enhancement without loss of delayed-phase kinetic information.


Assuntos
Neoplasias da Mama/diagnóstico , Aumento da Imagem , Imageamento por Ressonância Magnética , Adulto , Idoso , Idoso de 80 Anos ou mais , Meios de Contraste , Feminino , Gadolínio DTPA , Humanos , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/normas , Pessoa de Meia-Idade , Adulto Jovem
13.
Eukaryot Cell ; 8(6): 852-7, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19363062

RESUMO

Hirano bodies are cytoplasmic inclusions composed mainly of actin and actin-associated proteins. The formation of Hirano bodies during various neurodegenerative disorders, including Alzheimer's disease and amyotrophic lateral sclerosis, has been reported. Although the underlying molecular mechanisms that lead to the formation of these inclusions in the brain are not known, expression of the C-terminal fragment (CT) (amino acids 124 to 295) from the endogenous 34-kDa actin-binding protein of Dictyostelium discoideum leads to the formation of actin inclusions in vivo. In the current study, we report the development of an inducible expression system to study the early phases of Hirano body formation using an inducible promoter system (rnrB). By fusing the CT to a green fluorescent protein (CT-GFP), we monitored protein expression and localization by fluorescence microscopy, flow cytometry, and Western blot analysis. We observed an increase in the number and size of inclusions formed following induction of the CT-GFP vector system. Time-lapse microscopy studies revealed that the CT-GFP foci associated with the cell cortex and fused to form a single large aggregate. Transmission electron microscopy further demonstrates that these inclusions have a highly ordered ultrastructure, a pathological hallmark of Hirano bodies observed in postmortem brain samples from patients with various neurodegenerative disorders. Collectively, this system provides a method to visualize and characterize the events that surround early actin inclusion formation in a eukaryotic model.


Assuntos
Doença de Alzheimer/metabolismo , Dictyostelium/metabolismo , Expressão Gênica , Corpos de Inclusão/metabolismo , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Proteínas de Protozoários/metabolismo , Actinas/genética , Actinas/metabolismo , Doença de Alzheimer/genética , Motivos de Aminoácidos , Animais , Dictyostelium/química , Dictyostelium/genética , Humanos , Corpos de Inclusão/química , Corpos de Inclusão/genética , Proteínas dos Microfilamentos/química , Modelos Biológicos , Ligação Proteica , Proteínas de Protozoários/química , Proteínas de Protozoários/genética
14.
J Appl Behav Anal ; 42(3): 541-9, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20190917

RESUMO

The effectiveness of a behavioral skills training (BST) package to teach the implementation of the first three phases of the picture exchange communication system (PECS) was evaluated with 3 adults who had no history teaching any functional communication system. A multiple baseline design across participants was used to evaluate the effectiveness of the training package, which consisted of a video, written and verbal instructions, modeling, rehearsal, and feedback. Results showed significant improvements relative to baseline in a short amount of training time and that skills generalized to a learner with a severe developmental disability. Skills were maintained at 1 month follow-up for 1 participant.


Assuntos
Comportamento/fisiologia , Capacitação em Serviço , Comunicação não Verbal , Ensino/métodos , Adulto , Lista de Checagem , Feminino , Humanos , Masculino , Avaliação de Programas e Projetos de Saúde
15.
Am J Physiol Endocrinol Metab ; 294(2): E444-50, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18056794

RESUMO

Recent studies have suggested that abnormal regulation of protein phosphatase 2A (PP2A) is associated with Type 2 diabetes in rodent and human tissues. Results with cultured mouse myotubes support a mechanism for palmitate activation of PP2A, leading to activation of glycogen synthase kinase 3. Phosphorylation and inactivation of glycogen synthase by glycogen synthase kinase 3 could be the mechanism for long-chain fatty acid inhibition of insulin-mediated carbohydrate storage in insulin-resistant subjects. Here, we test the effects of palmitic acid on cultured muscle glycogen synthase and PP2A activities. Palmitate inhibition of glycogen synthase fractional activity is increased in subjects with high body mass index compared with subjects with lower body mass index (r = -0.43, P = 0.03). Palmitate action on PP2A varies from inhibition in subjects with decreased 2-h plasma glucose concentration to activation in subjects with increased 2-h plasma glucose concentration (r = 0.45, P < 0.03) during oral glucose tolerance tests. The results do not show an association between palmitate effects on PP2A and glycogen synthase fractional activity. We conclude that subjects at risk for Type 2 diabetes have intrinsic differences in palmitate regulation of at least two enzymes (PP2A and glycogen synthase), contributing to abnormal insulin regulation of glucose metabolism.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Inibidores Enzimáticos/farmacologia , Glicogênio Sintase/antagonistas & inibidores , Ácido Palmítico/farmacologia , Proteína Fosfatase 2/metabolismo , Adolescente , Adulto , Glicemia/metabolismo , Índice de Massa Corporal , Feminino , Teste de Tolerância a Glucose , Humanos , Insulina/sangue , Masculino , Mioblastos/efeitos dos fármacos , Fatores de Risco
16.
Perm J ; 10(3): 41-2, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-21519470
17.
Mol Ecol ; 12(1): 89-103, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12492880

RESUMO

American marten (Martes americana) have a close association with mature temperate forests, a habitat that expanded throughout the Pacific Northwest as glaciers receded at the end of the Pleistocene. Similar to several other forest-associated mammals in North America (e.g. black bear), genetic analysis of the marten shows a deep phylogeographical subdivision that reflects populations with distinctive evolutionary histories. Using a suite of 14 microsatellite markers, we explored the genetic structure of marten populations in two reciprocally monophyletic clades in the Pacific Northwest identified previously as M. caurina and M. americana by mitochondrial haplotypes and morphology. Microsatellite phylogeographical patterns were congruent with mitochondrial analyses. These independent data sets shed light upon hybridization patterns, population structure and evolutionary histories. Hybridization between M. caurina and M. americana individuals was documented in two regions of sympatry (Kuiu Island in southeastern Alaska and southern Montana). Northern insular populations of M. caurina exhibited higher differentiation and lower variability relative to northern populations of M. americana. Greater divergence among M. caurina populations may reflect longer isolation and persistence in coastal forest habitat that was fragmented by rising sea level in the early Holocene. Lower differentiation among northern M. americana populations and close relationship to other continental M. americana populations may reflect more recent expansion into the Pacific Northwest and/or continued gene flow among populations. Differentiation among M. caurina populations was attributed to habitat fragmentation (i.e. rising sea level), as opposed to isolation-by-distance; oceanic straits pose significant barriers to gene flow among M. caurina populations and between populations of M. caurina and M. americana.


Assuntos
Carnívoros/genética , Meio Ambiente , Grupos de População Animal , Animais , Canadá , Carnívoros/classificação , Frequência do Gene , Genética Populacional , Repetições de Microssatélites , Filogenia , Estados Unidos
18.
Mol Ecol ; 11(10): 2049-63, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12296948

RESUMO

Phylogeographic patterns were used to assess intraspecific diversification of American martens (Martes americana). Within martens, two morphological groups (americana and caurina) have been recognized, though the level of distinction between them has been debated. We examined mitochondrial cytochrome b gene haplotypes from 680 martens to explore the colonization history of the Pacific Northwest and found two clades that correspond to the morphological groups. The widespread americana clade extends from interior Alaska south to Montana and eastward to Newfoundland and New England (i.e. northwestern, north-central and northeastern North America). The caurina clade occurs in western North America, minimally extending from Admiralty Island (southeastern Alaska) south to Oregon and Wyoming. Our data indicated two colonization events for the Pacific Northwest (one by members of each clade) and were consistent with the persistence of populations throughout past glacial periods in eastern and western refugia. Due to vegetational and geological history following the past deglaciation, we hypothesize that martens of the caurina clade spread along the North Pacific Coast, and into southeastern Alaska, earlier than martens of the americana clade. Mismatch distributions for the americana clade were indicative of populations that recently experienced demographic expansion, while mismatch distributions for the caurina clade suggested that populations were at equilibrium. These clades are reciprocally monophyletic and distinctive (interclade divergence ranged from 2.5 to 3.0% (uncorrected p), whereas, intraclade divergence was < 0.7%), and two regions of sympatry have been identified. Genetic signatures of past admixture in hybrid zones may have been extinguished during subsequent glacial periods when ranges contracted. This recurrent pattern of relatively restricted western, or Pacific coastal, lineages and more widespread eastern, or interior continental, lineages exists across broad taxonomic groups and suggests a shared biogeographical history.


Assuntos
Carnívoros/fisiologia , DNA Mitocondrial/genética , Filogenia , Árvores , Animais , Sequência de Bases , Carnívoros/classificação , Carnívoros/genética , Grupo dos Citocromos b/genética , Ecossistema , Genética Populacional , Haplótipos , Dados de Sequência Molecular , Noroeste dos Estados Unidos , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA
19.
Mol Phylogenet Evol ; 24(2): 169-79, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12144754

RESUMO

The Bering Land Bridge has served as a major corridor of interchange between the northern continents for many organisms. We investigated the phylogeny of all extant species of Martes (except for Martes gwatkinsi from India) to infer evolutionary relationships and characterize the extent of trans-Beringian movements. Analyses of complete sequences of the mitochondrial cytochrome b gene and partial sequences of the nuclear aldolase C gene (241bp) suggested that the genus Martes may be paraphyletic with respect to Gulo gulo. These data supported the fossil record's indication that early radiations gave rise to two subgenera (Pekania and Charronia) and that a more recent, possibly rapid, radiation gave rise to species of the third subgenus (Martes). Two colonizations of North America are evident, one by members of the subgenus Pekania and another by member of the subgenus Martes. Contrary to hypotheses based on morphological evidence, the "americana" and "caurina" subspecies groups of Martes americana are not the result of independent colonizations of North America. The phylogenetic analyses of cytochrome b data were consistent with the recognition of these subspecies groups as monophyletic clades; however, variation in the aldolase C sequences indicated that these generally parapatric groups may interbreed in a region of limited geographic overlap.


Assuntos
Carnívoros/fisiologia , Evolução Molecular , Filogenia , Animais , Ásia , Núcleo Celular/genética , Grupo dos Citocromos b/genética , DNA Mitocondrial , Europa (Continente) , Frutose-Bifosfato Aldolase/genética , Variação Genética , América do Norte
20.
Evolution ; 53(6): 2008-2012, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28565444
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