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1.
Childs Nerv Syst ; 38(9): 1707-1715, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35674829

RESUMO

OBJECT: This study aimed to retrospectively assess dexamethasone utility in pediatric CNS tumor patients over a 10-year period, to better understand dosing variability, and highlight optimal practice. METHODS: All pediatric CNS tumor cases managed operatively for a 10-year period at a single center were reviewed. Information was gathered on demographics, dexamethasone doses, course durations, weaning regimes, PPI co-prescription, adverse events, and route of administration. Comparison within these groups was analyzed through use of statistical testing. RESULTS: One hundred twenty-seven patients received 193 dexamethasone courses. Median age was 7 years, with a median weight of 27.9 kg. Most common tumor type was astrocytoma (24.8%). Median daily dose was 8 mg, with twice-daily dosing most common. Median course duration was 8 days, ranging from 1 to 1103 days. Median weaning duration was 11.5 days. Daily dose was not correlated with patient weight and the median daily dose per kg was 0.2319 mg/kg. Incidence of adverse effects was 14.5% across all course lengths, with weight gain most common. The short-term course duration (<14 days) had the lowest adverse event incidence, with direct correlation between course length and adverse effect incidence. Dexamethasone dose per kg was not significantly different between patients with and without adverse effects. No relationship was noted between adverse effects incidence and administration route (intravenous compared to oral). 64.2% of patients received concurrent PPI with 35.8% receiving no PPI, with 1 gastrointestinal side effect noted in the PPI-receiving population. CONCLUSIONS: Large variation was seen in practice, with prescriptions appearing based on clinician preference and symptom severity rather than patient age or weight. Future guidelines should consider lower dose regimens than are currently presented with less frequent dosing as these may benefit quality of life. Weaning period can be relatively rapid for most patients, taking place in 2-3 days. PPI co-prescription does not seem to add significant benefit. We recommend using a standardized guideline of 0.2 mg/kg/day (max 8 mg/day) given OD or BD, with PPI cover where necessary. For acute presentations, we recommend limiting dexamethasone treatment to <14 days. These recommendations can be adjusted for individual cases to yield optimal results.


Assuntos
Neoplasias , Qualidade de Vida , Criança , Dexametasona/uso terapêutico , Humanos , Prescrições , Estudos Retrospectivos , Centros de Atenção Terciária
2.
Mol Ecol ; 31(10): 2830-2846, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35315161

RESUMO

We investigated the potential mechanisms driving habitat-linked genetic divergence within a bird species endemic to a single 250-km2 island. The island scrub-jay (Aphelocoma insularis) exhibits microgeographic divergence in bill morphology across pine-oak ecotones on Santa Cruz Island, California (USA), similar to adaptive differences described in mainland congeners over much larger geographic scales. To test whether individuals exhibit genetic differentiation related to habitat type and divergence in bill length, we genotyped over 3000 single nucleotide polymorphisms in 123 adult island scrub-jay males from across Santa Cruz Island using restriction site-associated DNA sequencing. Neutral landscape genomic analyses revealed that genome-wide genetic differentiation was primarily related to geographic distance and differences in habitat composition. We also found 168 putatively adaptive loci associated with habitat type using multivariate redundancy analysis while controlling for spatial effects. Finally, two genome-wide association analyses revealed a polygenic basis to variation in bill length with multiple loci detected in or near genes known to affect bill morphology in other birds. Our findings support the hypothesis that divergent selection at microgeographic scales can cause adaptive divergence in the presence of ongoing gene flow.


Assuntos
Estudo de Associação Genômica Ampla , Passeriformes , Animais , Ecossistema , Fluxo Gênico , Variação Genética , Genética Populacional , Humanos , Masculino , Passeriformes/genética , Seleção Genética
3.
Conserv Biol ; 36(4): e13898, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35122326

RESUMO

The Judas technique is often used in control or eradication of particular vertebrate pests. The technique exploits the tendency of individuals to form social groups. A radio collar is affixed to an individual and its subsequent monitoring facilitates the detection of other conspecifics. Efficacy of this technique would be improved if managers could estimate the probability that a Judas individual would detect conspecifics. To calculate this probability, we estimated association rates of Judas individuals with other Judas individuals, given the length of time the Judas has been deployed. We developed a simple model of space-use for individual Judas animals and constrained detection probabilities to those specific areas. We then combined estimates for individual Judas animals to infer the probability that a wild individual could be detected in an area of interest via Judas surveillance. We illustrated the method by using data from a feral goat eradication program on Isla Santiago, Galápagos, and a feral pig eradication program on Santa Cruz Island, California. Association probabilities declined as the proximity between individual areas of use of a Judas pair decreased. Unconditional probabilities of detection within individual areas of use averaged 0.09 per month for feral pigs and 0.11 per month for feral goats. Probabilities that eradication had been achieved, given no detections of wild conspecifics, and an uninformative prior probability of eradication were 0.79 (90% CI 0.22-0.99) for feral goats and 0.87 (90% CI 0.44-1.0) for feral pigs. We envisage several additions to the analyses used that could improve estimates of Judas detection probability. Analyses such as these can help managers increase the efficacy of eradication efforts, leading to more effective effects to restore native biodiversity.


La técnica de Judas se usa con frecuencia en el control de ciertas plagas de vertebrados. La técnica se aprovecha de la tendencia a formar grupos sociales que tienen los individuos. Un radio-collar es colocado en uno de los individuos y el monitoreo subsecuente facilita la detección de otros miembros de la misma especie. La eficacia de esta técnica mejoraría si los gestores pudieran estimar la probabilidad que tiene un Judas de detectar a miembros de su especie. Para calcular esta probabilidad, estimamos las tasas de asociación de los Judas con otros Judas, dado el tiempo que el Judas ha sido enviado. Desarrollamos un modelo simple del uso del espacio para animales Judas individuales y limitamos las probabilidades de detección a esas áreas específicas. Después combinamos los estimados de un animal Judas individual para inferir la probabilidad de que un individuo silvestre pudiera ser detectado en un área de interés mediante la vigilancia Judas. Ilustramos el método con los datos de un programa de erradicación de cabras ferales en Isla Santiago, las Galápagos, y uno de cerdos ferales en la Isla de Santa Cruz, California. Las probabilidades de asociación declinaron conforme disminuyó la proximidad entre las áreas individuales de uso de un par de Judas. Las probabilidades incondicionales de detección dentro de las áreas individuales de uso promediaron 0.09 por mes para los cerdos ferales y 0.11 por mes para las cabras ferales. Las probabilidades de que se había logrado la erradicación, dada la ausencia de detecciones de miembros de la misma especie y una mal informada probabilidad previa de erradicación, fueron de 0.79 (90% CI 0.22 - 0.99) para las cabras ferales y 0.87 (90% CI 0.44 - 1.0) para los cerdos ferales. Contemplamos varias adiciones al análisis que usamos que podrían mejorar los estimados de la probabilidad de detección de Judas. Análisis como este pueden ayudar a los gestores a incrementar la efectividad de los esfuerzos de erradicación, lo que resulta en efectos más efectivos para restaurar la biodiversidad nativa.


Assuntos
Animais Selvagens , Conservação dos Recursos Naturais , Animais , Biodiversidade , Conservação dos Recursos Naturais/métodos , Probabilidade , Vertebrados
4.
Mol Ecol ; 31(2): 603-619, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34704295

RESUMO

Disentangling the effects of neutral and adaptive processes in maintaining phenotypic variation across environmental gradients is challenging in natural populations. Song sparrows (Melospiza melodia) on the California Channel Islands occupy a pronounced east-west climate gradient within a small spatial scale, providing a unique opportunity to examine the interaction of genetic isolation (reduced gene flow) and the environment (selection) in driving variation. We used reduced representation genomic libraries to infer the role of neutral processes (drift and restricted gene flow) and divergent selection in driving variation in thermoregulatory traits with an emphasis on the mechanisms that maintain bill divergence among islands. Analyses of 22,029 neutral SNPs confirm distinct population structure by island with restricted gene flow and relatively large effective population sizes, suggesting bill differences are probably not a product of genetic drift. Instead, we found strong support for local adaptation using 3294 SNPs in differentiation-based and environmental association analyses coupled with genome-wide association tests. Specifically, we identified several putatively adaptive and candidate loci in or near genes involved in bill development pathways (e.g., BMP, CaM, Wnt), confirming the highly complex and polygenic architecture underlying bill morphology. Furthermore, we found divergence in genes associated with other thermoregulatory traits (i.e., feather structure, plumage colour, and physiology). Collectively, these results suggest strong divergent selection across an island archipelago results in genomic changes in a suite of traits associated with climate adaptation over small spatial scales. Future research should move beyond studying univariate traits to better understand multidimensional responses to complex environmental conditions.


Assuntos
Fluxo Gênico , Pardais , Animais , Ilhas Anglo-Normandas , Genética Populacional , Estudo de Associação Genômica Ampla , Seleção Genética , Pardais/genética
5.
Vet Clin North Am Equine Pract ; 37(3): 581-618, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34782097

RESUMO

A healthy foot requires a well-balanced foot capable of shock absorption, traction, and normal proprioception. Radiographs and venograms are helpful in assessing health of the external and internal structures of the foot and in early diagnosis. Other techniques to assess foot mechanics include force plate and inertial sensors. When foot pathology ensues, early recognition and emergency mechanical treatment can improve prognosis and overall outcome. Sheared heels, under-run heels, and clubfeet are common problems that need to be corrected early. Successful management and results require he veterinarians and farriers establishing a professional, collaborative, and respectful relationship.


Assuntos
Doenças do Pé , Casco e Garras , Doenças dos Cavalos , Animais , Fenômenos Biomecânicos , Doenças do Pé/diagnóstico , Doenças do Pé/terapia , Doenças do Pé/veterinária , Marcha , Doenças dos Cavalos/diagnóstico , Cavalos , Masculino , Radiografia
6.
Ann N Y Acad Sci ; 1505(1): 118-141, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34176148

RESUMO

Spatial prioritization is a critical step in conservation planning, a process designed to ensure that limited resources are applied in ways that deliver the highest possible returns for biodiversity and human wellbeing. In practice, many spatial prioritizations fall short of their potential by focusing on places rather than actions, and by using data of snapshots of assets or threats rather than estimated impacts. We introduce spatial action mapping as an approach that overcomes these shortfalls. This approach produces a spatially explicit view of where and how much a given conservation action is likely to contribute to achieving stated conservation goals. Through seven case examples, we demonstrate simple to complex versions of how this method can be applied across local to global scales to inform decisions about a wide range of conservation actions and benefits. Spatial action mapping can support major improvements in efficient use of conservation resources and will reach its full potential as the quality of environmental, social, and economic datasets converge and conservation impact evaluations improve.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/métodos , Ecossistema , Mapeamento Geográfico , Análise Espacial , Conservação dos Recursos Naturais/estatística & dados numéricos , Humanos
8.
Ground Water ; 59(3): 322-333, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33608868

RESUMO

Groundwater is a critical resource not only for human communities but also for many terrestrial, riparian, and aquatic ecosystems and species. Yet groundwater planning and management decisions frequently ignore or inadequately address the needs of these natural systems. As a consequence, ecosystems dependent on groundwater have been threatened, degraded, or eliminated, especially in arid regions. There is growing acknowledgment that governmental protections for these ecological resources are necessary, but current legal, regulatory and voluntary provisions are often inadequate. Groundwater management premised on "safe yield," which aims to balance human withdrawals with natural recharge rates, typically provides little to no consideration for water needed by ecosystems. Alternatively, the "sustainable yield" concept aims to integrate social, economic and environmental needs for groundwater, but the complexity of groundwater systems creates substantial uncertainty about the impact that current or future groundwater withdrawals will have on ecosystems. Regardless of the legal or regulatory framework, guidance is needed to help ensure environmental water needs will be met, especially in the face of pressure to increase human uses of groundwater resources. In this paper, we describe minimum provisions for planning, managing, and monitoring groundwater that collectively can lower the risk of harm to groundwater-dependent ecosystems and species, with a special emphasis on arid systems, where ecosystems and species may be especially reliant upon and sensitive to groundwater dynamics.


Assuntos
Água Subterrânea , Ecossistema , Humanos , Abastecimento de Água
9.
Teach Teach Educ ; 96: 103149, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32834464

RESUMO

Social media are commonplace in many educators' lives, but their Instagram activities have received no prior attention in the empirical literature. We therefore created and disseminated a survey regarding educators' Instagram use. Analyses of 841 responses suggested participants were generally intensive users of Instagram who engaged in the exchange of both professional knowledge and wisdom, as well as affective support. In addition to identifying benefits to Instagram use, some participants offered critiques of Instagram's professional utility. We discuss the implications of these findings for educators' work in a digital era and the future of research on educators' social media activities.

10.
J Fish Biol ; 97(2): 583-587, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32447755

RESUMO

The upper thermal tolerance of brook trout Salvelinus fontinalis was estimated using critical thermal maxima (CTmax ) experiments on fish acclimated to temperatures that span the species' thermal range (5-25°C). The CTmax increased with acclimation temperature but plateaued in fish acclimated to 20, 23 and 25°C. Plasma lactate was highest, and the hepato-somatic index (IH ) was lowest at 23 and 25°C, which suggests additional metabolic costs at those acclimation temperatures. The results suggest that there is a sub-lethal threshold between 20 and 23°C, beyond which the fish experience reduced physiological performance.


Assuntos
Aclimatação , Temperatura Alta , Truta/fisiologia , Animais , Glicemia , Ácido Láctico/sangue , Truta/sangue
11.
Scott Med J ; 63(2): 39-44, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29514583

RESUMO

Background and aims Novel psychoactive substances are compounds intended to mimic the effects of illicit drugs. They provide a unique challenge to healthcare, as complications of their use and their impact on services are relatively unknown. This study aims to determine nature of presentations, patient demographics and impact on healthcare. Methods Novel psychoactive substances users who presented to a large urban emergency department over 4 weeks were prospectively identified and followed for 1 year. Patients over 13 years old were eligible for inclusion. Information regarding patient demographics and presentations was collected. Results During the study period, 53 patients (39 male), mean age 32.6 ± 8.9 (±standard deviation), presented 148 times with complaints relating to novel psychoactive substances use. Study population characteristics included history of illicit drug use (83.0%), intravenous drug use (64.2%), psychiatric diagnosis or symptoms (56.6%), methadone prescription (52.8%) and having no fixed abode (37.7%). Injection was the most common method of use (72.3%), Burst the most commonly named agent (19.6%) and behavioural change the most common presenting complaint (31.1%). Patients collectively spent 10,620 h in hospital over 1 year. Conclusion This study highlights differences between the young population targeted by government campaigns regarding novel psychoactive substances use and the presenting population to hospital, and the associated burden on the National Health Service.


Assuntos
Overdose de Drogas/terapia , Serviço Hospitalar de Emergência/estatística & dados numéricos , Drogas Ilícitas/efeitos adversos , Psicotrópicos/efeitos adversos , Transtornos Relacionados ao Uso de Substâncias/terapia , Adulto , Overdose de Drogas/epidemiologia , Feminino , Hospitais Urbanos , Humanos , Masculino , Estudos Prospectivos , Transtornos Relacionados ao Uso de Substâncias/epidemiologia
12.
Sci Adv ; 3(8): e1700707, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28845449

RESUMO

In an era of unprecedented and rapid global change, dynamic conservation strategies that tailor the delivery of habitat to when and where it is most needed can be critical for the persistence of species, especially those with diverse and dispersed habitat requirements. We demonstrate the effectiveness of such a strategy for migratory waterbirds. We analyzed citizen science and satellite data to develop predictive models of bird populations and the availability of wetlands, which we used to determine temporal and spatial gaps in habitat during a vital stage of the annual migration. We then filled those gaps using a reverse auction marketplace to incent qualifying landowners to create temporary wetlands on their properties. This approach is a cost-effective way of adaptively meeting habitat needs for migratory species, optimizes conservation outcomes relative to investment, and can be applied broadly to other conservation challenges.

13.
Trends Ecol Evol ; 32(8): 578-588, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28645487

RESUMO

Historical ecology provides information needed to understand contemporary conditions and make science-based resource management decisions. Gaps in historical records, however, can limit inquiries and inference. Unfortunately, the patchiness of data that poses challenges for today's historical ecologist may be similarly problematic for those in the future seeking to understand what are currently present-day conditions and trends, in part because of societal underinvestment in systematic collection and curation. We therefore highlight the generational imperative that contemporary scientists and managers individually have - especially in this era of tremendous global change - to ensure sufficient documentation of the past and current conditions of the places and resources to which they have access.


Assuntos
Conservação dos Recursos Naturais , Ecologia , Humanos , Pesquisa
14.
Curr Zool ; 63(4): 363-367, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29491996

RESUMO

Scatter hoarding by corvids (crows, jays, magpies, and nutcrackers) provides seed dispersal for many large-seeded plants, including oaks and pines. When hoarding seeds, corvids often choose nonrandom locations throughout the landscape, resulting in differential survival of seeds. In the context of habitat restoration, such disproportional storing of seeds in areas suitable for germination and establishment can accelerate expansion and recovery of large-seeded tree populations and their associated ecosystems. Here, we investigate the spatial preferences of island scrub jays Aphelocoma insularis during scatter hoarding of acorns (Quercus spp.) on Santa Cruz Island. We use a large behavioral data set on the birds' behavior in combination with seedling surveys and spatial analysis to determine whether 1) island scrub jays disproportionally cache seeds in specific habitat types, and 2) whether the preferred habitat type is suitable for oak regeneration. Our results show that the jays nonrandomly cache acorns across the landscape; they use chaparral and coastal sage scrub disproportionally while avoiding open and grassy areas. The areas used most often for caching were also the areas with the highest oak seedling densities. We discuss the potential role of these findings for the recovery of Santa Cruz Island's oak habitat since the 1980s.

15.
Mol Ecol ; 25(10): 2176-94, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26992010

RESUMO

The evolutionary mechanisms generating the tremendous biodiversity of islands have long fascinated evolutionary biologists. Genetic drift and divergent selection are predicted to be strong on islands and both could drive population divergence and speciation. Alternatively, strong genetic drift may preclude adaptation. We conducted a genomic analysis to test the roles of genetic drift and divergent selection in causing genetic differentiation among populations of the island fox (Urocyon littoralis). This species consists of six subspecies, each of which occupies a different California Channel Island. Analysis of 5293 SNP loci generated using Restriction-site Associated DNA (RAD) sequencing found support for genetic drift as the dominant evolutionary mechanism driving population divergence among island fox populations. In particular, populations had exceptionally low genetic variation, small Ne (range = 2.1-89.7; median = 19.4), and significant genetic signatures of bottlenecks. Moreover, islands with the lowest genetic variation (and, by inference, the strongest historical genetic drift) were most genetically differentiated from mainland grey foxes, and vice versa, indicating genetic drift drives genome-wide divergence. Nonetheless, outlier tests identified 3.6-6.6% of loci as high FST outliers, suggesting that despite strong genetic drift, divergent selection contributes to population divergence. Patterns of similarity among populations based on high FST outliers mirrored patterns based on morphology, providing additional evidence that outliers reflect adaptive divergence. Extremely low genetic variation and small Ne in some island fox populations, particularly on San Nicolas Island, suggest that they may be vulnerable to fixation of deleterious alleles, decreased fitness and reduced adaptive potential.


Assuntos
Evolução Molecular , Raposas/genética , Deriva Genética , Genética Populacional , Animais , California , Variação Genética , Técnicas de Genotipagem , Ilhas , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA
16.
J Anim Ecol ; 85(3): 798-805, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26876417

RESUMO

Corvids (crows, jays, magpies and nutcrackers) are important dispersers of large-seeded plants. Studies on captive or supplemented birds suggest that they flexibly adjust their scatter-hoarding behaviour to the context of social dynamics and relative seed availability. Because many corvid-dispersed trees show high annual variation in seed production, context-dependent foraging can have strong effects on natural corvid scatter-hoarding behaviour. We investigated how seed availability and social dynamics affected scatter-hoarding in the island scrub jays (Aphelocoma insularis). We quantified rates of scatter-hoarding behaviour and territorial defence of 26 colour-marked birds over a three-year period with variable acorn crops. We tested whether caching parameters were correlated with variation in annual seed production of oaks as predicted by the predator dispersal hypothesis, which states that caching rates and distances should vary with seed abundance in ways that benefit tree fitness. We also tested whether antagonistic interactions with conspecifics would affect scatter-hoarding adversely, as found in experimental studies. Caching behaviour varied with acorn availability. Caching distances correlated positively with annual acorn crop size, increasing by as much as 40% between years. Caching rates declined over time in years with small acorn crops, but increased when crops were large. Acorn foraging and caching rates were also negatively correlated with rates of territorial aggression. Overall foraging rates, however, were not associated with aggression, suggesting that reduced dispersal rates were not simply due to time constraints. Our field results support laboratory findings that caching rates and distances by scatter-hoarding corvids are context-dependent. Furthermore, our results are consistent with predictions of the predator dispersal hypothesis and suggest that large seed crops and social interactions among scatter-hoarders affect dispersal benefits for oaks and other masting tree species.


Assuntos
Comportamento Alimentar , Passeriformes/fisiologia , Dispersão de Sementes , Animais , Comportamento Apetitivo , Quercus/fisiologia , Sementes , Territorialidade
17.
J Mammal ; 97(3): 823-838, 2016 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-29899578

RESUMO

Fossil data are ambiguous regarding the evolutionary origin of contemporary desert bighorn sheep ( Ovis canadensis subspecies). To address this uncertainty, we conducted phylogeographic and population genetic analyses on bighorn sheep subspecies found in southwestern North America. We analyzed 515 base pairs of mtDNA control region sequence and 39 microsatellites in 804 individuals from 58 locations. Phylogenetic analyses revealed 2 highly divergent clades concordant with Sierra Nevada ( O. c. sierrae ) and Rocky Mountain ( O. c. canadensis ) bighorn and showed that these 2 subspecies both diverged from desert bighorn prior to or during the Illinoian glaciation (~315-94 thousand years ago [kya]). Desert bighorn comprised several more recently diverged haplogroups concordant with the putative Nelson ( O. c. nelsoni ), Mexican ( O. c. mexicana ), and Peninsular ( O. c. cremnobates ) subspecies. Corresponding estimates of effective splitting times (~17-3 kya), and haplogroup ages (~85-72 kya) placed the most likely timeframe for divergence among desert bighorn subspecies somewhere within the last glacial maximum. Median-joining haplotype network and Bayesian skyline analyses both indicated that desert bighorn collectively comprised a historically large and haplotype-diverse population, which subsequently lost much of its diversity through demographic decline. Using microsatellite data, discriminant analysis of principle components (DAPC) and Bayesian clustering analyses both indicated genetic structure concordant with the geographic distribution of 3 desert subspecies. Likewise, microsatellite and mitochondrial-based FST comparisons revealed significant fixation indices among the desert bighorn genetic clusters. We conclude these desert subspecies represent ancient lineages likely descended from separate Pleistocene refugial populations and should therefore be managed as distinct taxa to preserve maximal biodiversity. Los datos de fósiles sobre el origen evolutivo de las ovejas del desierto ( Ovis canadensis subespecies) contemporáneas son ambiguos. Para dilucidar esta incertidumbre, llevamos a cabo análisis filogeográficos y de genética de poblaciones entre cinco subespecies de ovejas del suroccidente de Norteamérica. Analizamos 515 pb de secuencia de la región control del ADN mitocondrial y 39 microsatélites en 804 ovejas de 58 localidades. Los análisis filogenéticos revelaron 2 clados altamente divergentes concordantes con ovejas de la Sierra Nevada ( O. c. sierrae ) y de las Montañas Rocosas ( O. c. canadensis ), y demostraron que estas dos subespecies divergieron antes o durante la glaciación de Illinois (315,000-94,000 años). Las ovejas del desierto formaron varios haplogrupos recientemente derivados concordantes con las subespecies de Nelson ( O. c. nelsoni ), México ( O. c. mexicana ) y peninsular ( O. c. cremnobates ). Las estimaciones correspondientes al tiempo de separación efectiva (17,000-3,000 años) y edades de haplogrupos (85,000-72,000 años) son los plazos más probables para las divergencias entre subespecies de ovejas del desierto dentro de la última glaciación máxima. Análisis de redes de haplotipos de unión de medias y análisis bayesianos de líneas de horizonte indicaron que las ovejas del desierto formaron una población históricamente grande y diversa en términos de haplotipos, que luego perdieron gran parte de su diversidad a través de un descenso demográfico. Utilizando datos de microsatélites los análisis DAPC y TESS indicaron agrupamiento genético concordante con la distribución geográfica actual de las tres subespecies. Asimismo, comparaciones de FST con datos de microsatélites y mitocondriales revelaron índices de fijación significativos entre los grupos genéticos de ovejas del desierto. Concluimos que estas subespecies de ovejas del desierto representan linajes antiguos que probablemente descienden de poblaciones de distintos refugios del Pleistoceno, y que por lo tanto deben ser manejadas como taxones distintos para preservar su biodiversidad máxima.

18.
Top Spinal Cord Inj Rehabil ; 21(2): 93-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26364278

RESUMO

BACKGROUND: Loss of legged mobility due to spinal cord injury (SCI) is associated with multiple physiological and psychological impacts. Powered exoskeletons offer the possibility of regained mobility and reversal or prevention of the secondary effects associated with immobility. OBJECTIVE: This study was conducted to evaluate mobility outcomes for individuals with SCI after 5 gait-training sessions with a powered exoskeleton, with a primary goal of characterizing the ease of learning and usability of the system. METHODS: Sixteen subjects with SCI were enrolled in a pilot clinical trial at Shepherd Center, Atlanta, Georgia, with injury levels ranging from C5 complete to L1 incomplete. An investigational Indego exoskeleton research kit was evaluated for ease of use and efficacy in providing legged mobility. Outcome measures of the study included the 10-meter walk test (10 MWT) and the 6-minute walk test (6 MWT) as well as measures of independence including donning and doffing times and the ability to walk on various surfaces. RESULTS: At the end of 5 sessions (1.5 hours per session), average walking speed was 0.22 m/s for persons with C5-6 motor complete tetraplegia, 0.26 m/s for T1-8 motor complete paraplegia, and 0.45 m/s for T9-L1 paraplegia. Distances covered in 6 minutes averaged 64 meters for those with C5-6, 74 meters for T1-8, and 121 meters for T9-L1. Additionally, all participants were able to walk on both indoor and outdoor surfaces. CONCLUSIONS: Results after only 5 sessions suggest that persons with tetraplegia and paraplegia learn to use the Indego exoskeleton quickly and can manage a variety of surfaces. Walking speeds and distances achieved also indicate that some individuals with paraplegia can quickly become limited community ambulators using this system.


Assuntos
Exoesqueleto Energizado , Traumatismos da Medula Espinal/reabilitação , Caminhada , Adolescente , Adulto , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Paraplegia/reabilitação , Projetos Piloto , Quadriplegia/reabilitação , Resultado do Tratamento , Adulto Jovem
19.
PLoS One ; 10(7): e0131490, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26177290

RESUMO

Wide-ranging large carnivores pose myriad challenges for conservation, especially in highly fragmented landscapes. Over a 13-year period, we combined monitoring of radio collared pumas (Puma concolor) with complementary multi-generational genetic analyses to inform puma conservation in southern California, USA. Our goals were to generate survivorship estimates, determine causes of mortality, identify barriers to movement, and determine the genetic and demographic challenges to puma persistence among >20,000,000 people and extensive urban, suburban, and exurban development. Despite protection from hunting, annual survival for radio collared pumas was surprisingly low (55.8%), and humans caused the majority of puma deaths. The most common sources of mortality were vehicle collisions (28% of deaths), and mortalities resulting from depredation permits issued after pumas killed domestic animals (17% of deaths). Other human-caused mortalities included illegal shootings, public safety removals, and human-caused wildfire. An interstate highway (I-15) bisecting this study area, and associated development, have created a nearly impermeable barrier to puma movements, resulting in severe genetic restriction and demographic isolation of the small puma population (n ~ 17-27 adults) in the Santa Ana Mountains west of I-15. Highways that bisect habitat or divide remaining "conserved" habitat, and associated ongoing development, threaten to further subdivide this already fragmented puma population and increase threats to survival. This study highlights the importance of combining demographic and genetic analyses, and illustrates that in the absence of effective measures to reduce mortality and enhance safe movement across highways, translocation of pumas, such as was done with the endangered Florida panther (P. c. coryi), may ultimately be necessary to prevent further genetic decline and ensure persistence of the Santa Ana Mountains population.


Assuntos
Puma , Distribuição Animal , Animais , California , Ecossistema , Feminino , Humanos , Masculino , Mortalidade , Dinâmica Populacional , Modelos de Riscos Proporcionais , Urbanização
20.
PLoS One ; 10(7): e0130710, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26147215

RESUMO

The ranges and abundances of species that depend on freshwater habitats are declining worldwide. Efforts to counteract those trends are often hampered by a lack of information about species distribution and conservation status and are often strongly biased toward a few well-studied groups. We identified the 3,906 vascular plants, macroinvertebrates, and vertebrates native to California, USA, that depend on fresh water for at least one stage of their life history. We evaluated the conservation status for these taxa using existing government and non-governmental organization assessments (e.g., endangered species act, NatureServe), created a spatial database of locality observations or distribution information from ~400 data sources, and mapped patterns of richness, endemism, and vulnerability. Although nearly half of all taxa with conservation status (n = 1,939) are vulnerable to extinction, only 114 (6%) of those vulnerable taxa have a legal mandate for protection in the form of formal inclusion on a state or federal endangered species list. Endemic taxa are at greater risk than non-endemics, with 90% of the 927 endemic taxa vulnerable to extinction. Records with spatial data were available for a total of 2,276 species (61%). The patterns of species richness differ depending on the taxonomic group analyzed, but are similar across taxonomic level. No particular taxonomic group represents an umbrella for all species, but hotspots of high richness for listed species cover 40% of the hotspots for all other species and 58% of the hotspots for vulnerable freshwater species. By mapping freshwater species hotspots we show locations that represent the top priority for conservation action in the state. This study identifies opportunities to fill gaps in the evaluation of conservation status for freshwater taxa in California, to address the lack of occurrence information for nearly 40% of freshwater taxa and nearly 40% of watersheds in the state, and to implement adequate protections for freshwater taxa where they are currently lacking.


Assuntos
Biodiversidade , Água Doce , Animais , California , Conservação dos Recursos Naturais , Invertebrados/classificação , Plantas/classificação , Vertebrados/classificação
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