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1.
Mol Ecol Resour ; 2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37883295

RESUMO

Landscape genomics can harness environmental and genetic data to inform conservation decisions by providing essential insights into how landscapes shape biodiversity. The massive increase in genetic data afforded by the genomic era provides exceptional resolution for answering critical conservation genetics questions. The accessibility of genomic data for non-model systems has also enabled a shift away from population-based sampling to individual-based sampling, which now provides accurate and robust estimates of genetic variation that can be used to examine the spatial structure of genomic diversity, population connectivity and the nature of environmental adaptation. Nevertheless, the adoption of individual-based sampling in conservation genetics has been slowed due, in large part, to concerns over how to apply methods developed for population-based sampling to individual-based sampling schemes. Here, we discuss the benefits of individual-based sampling for conservation and describe how landscape genomic methods, paired with individual-based sampling, can answer fundamental conservation questions. We have curated key landscape genomic methods into a user-friendly, open-source workflow, which we provide as a new R package, A Landscape Genomics Analysis Toolkit in R (algatr). The algatr package includes novel added functionality for all of the included methods and extensive vignettes designed with the primary goal of making landscape genomic approaches more accessible and explicitly applicable to conservation biology.

2.
Ann Oncol ; 34(7): 589-604, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37121400

RESUMO

BACKGROUND: Prior studies characterized the association of molecular alterations with treatment-specific outcomes in KRAS-mutant (KRASMUT) lung adenocarcinoma (LUAD). Less is known about the prognostic role of molecular alterations and their associations with metastatic disease. PATIENTS AND METHODS: We analyzed clinicogenomic data from 1817 patients with KRASMUT LUAD sequenced at the Dana-Farber Cancer Institute (DFCI) and Memorial Sloan Kettering Cancer Center (MSKCC). Patients with metastatic (M1) and nonmetastatic (M0) disease were compared. Transcriptomic data from The Cancer Genome Atlas (TCGA) were investigated to characterize the biology of differential associations with clinical outcomes. Organ-specific metastasis was associated with overall survival (OS). RESULTS: KEAP1 (DFCI: OR = 2.3, q = 0.04; MSKCC: OR = 2.2, q = 0.00027) and SMARCA4 mutations (DFCI: OR = 2.5, q = 0.06; MSKCC: OR = 2.6, q = 0.0021) were enriched in M1 versus M0 tumors. On integrative modeling, NRF2 activation was the genomic feature most associated with OS. KEAP1 mutations were enriched in M1 versus M0 tumors independent of STK11 status (KEAP1MUT/STK11WT: DFCI OR = 3.0, P = 0.0064; MSKCC OR = 2.0, P = 0.041; KEAP1MUT/STK11MUT: DFCI OR = 2.3, P = 0.0063; MSKCC OR = 2.5, P = 3.6 × 10-05); STK11 mutations without KEAP1 loss were not associated with stage (KEAP1WT/STK11MUT: DFCI OR = 0.97, P = 1.0; MSKCC OR = 1.2, P = 0.33) or outcome. KEAP1/KRAS-mutated tumors with and without STK11 mutations exhibited high functional STK11 loss. The negative effects of KEAP1 were compounded in the presence of bone (HR = 2.3, P = 4.4 × 10-14) and negated in the presence of lymph node metastasis (HR = 1.0, P = 0.91). CONCLUSIONS: Mutations in KEAP1 and SMARCA4, but not STK11, were associated with metastatic disease and poor OS. Functional STK11 loss, however, may contribute to poor outcomes in KEAP1MUT tumors. Integrating molecular data with clinical and metastatic-site annotations can more accurately risk stratify patients.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/patologia , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Fator 2 Relacionado a NF-E2/genética , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Prognóstico , Proteínas Serina-Treonina Quinases/genética , Biomarcadores Tumorais/genética , Mutação , DNA Helicases/genética , Proteínas Nucleares/genética , Fatores de Transcrição/genética
3.
Ecol Evol ; 13(3): e9842, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36911313

RESUMO

Restriction-site-associated DNA sequencing (RADseq) has become an accessible way to obtain genome-wide data in the form of single-nucleotide polymorphisms (SNPs) for phylogenetic inference. Nonetheless, how differences in RADseq methods influence phylogenetic estimation is poorly understood because most comparisons have largely relied on conceptual predictions rather than empirical tests. We examine how differences in ddRAD and 2bRAD data influence phylogenetic estimation in two non-model frog groups. We compare the impact of method choice on phylogenetic information, missing data, and allelic dropout, considering different sequencing depths. Given that researchers must balance input (funding, time) with output (amount and quality of data), we also provide comparisons of laboratory effort, computational time, monetary costs, and the repeatability of library preparation and sequencing. Both 2bRAD and ddRAD methods estimated well-supported trees, even at low sequencing depths, and had comparable amounts of missing data, patterns of allelic dropout, and phylogenetic signal. Compared to ddRAD, 2bRAD produced more repeatable datasets, had simpler laboratory protocols, and had an overall faster bioinformatics assembly. However, many fewer parsimony-informative sites per SNP were obtained from 2bRAD data when using native pipelines, highlighting a need for further investigation into the effects of each pipeline on resulting datasets. Our study underscores the importance of comparing RADseq methods, such as expected results and theoretical performance using empirical datasets, before undertaking costly experiments.

4.
Mol Ecol Resour ; 23(5): 1124-1141, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36924341

RESUMO

DNA barcoding has greatly facilitated studies of taxonomy, biodiversity, biological conservation, and ecology. Here, we establish a reliable DNA barcoding library for Chinese snakes, unveiling hidden diversity with implications for taxonomy, and provide a standardized tool for conservation management. Our comprehensive study includes 1638 cytochrome c oxidase subunit I (COI) sequences from Chinese snakes that correspond to 17 families, 65 genera, 228 named species (80.6% of named species) and 36 candidate species. A barcode gap analysis reveals gaps, where all nearest neighbour distances exceed maximum intraspecific distances, in 217 named species and all candidate species. Three species-delimitation methods (ABGD, sGMYC, and sPTP) recover 320 operational taxonomic units (OTUs), of which 192 OTUs correspond to named and candidate species. Twenty-eight other named species share OTUs, such as Azemiops feae and A. kharini, Gloydius halys, G. shedaoensis, and G. intermedius, and Bungarus multicinctus and B. candidus, representing inconsistencies most probably caused by imperfect taxonomy, recent and rapid speciation, weak taxonomic signal, introgressive hybridization, and/or inadequate phylogenetic signal. In contrast, 43 species and candidate species assign to two or more OTUs due to having large intraspecific distances. If most OTUs detected in this study reflect valid species, including the 36 candidate species, then 30% more species would exist than are currently recognized. Several OTU divergences associate with known biogeographic barriers, such as the Taiwan Strait. In addition to facilitating future studies, this reliable and relatively comprehensive reference database will play an important role in the future monitoring, conservation, and management of Chinese snakes.


Assuntos
Biodiversidade , Código de Barras de DNA Taxonômico , Humanos , Animais , Filogenia , Código de Barras de DNA Taxonômico/métodos , Serpentes/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética
5.
Syst Biol ; 72(2): 357-371, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35993885

RESUMO

With limited sampling, geographic variation within a single species can be difficult to distinguish from interspecific variation, confounding our ability to draw accurate species boundaries. We argue that thorough sampling and analysis of contact zones between putative taxa can determine if assortative mating or selection against hybrids exists (supporting the presence of two distinct species), or alternatively if mating is random among genotypes and admixture among adjacent populations is gradual and continuous (supporting geographic variation within a single species). Here, we test two alternative hypotheses for two pairs of named taxa at contact zones within the American milksnake (Lampropeltis triangulum) complex. A prior morphological analysis found areas of gradual intergradation among named taxa, and concluded that the taxa represented geographical races of a single polytypic species. In contrast, a subsequent analysis of gene sequence data, but with limited sampling near the contact zones, hypothesized distinct boundaries between species at the contact zones. At the contact zone between proposed species L. triangulum and Lampropeltis gentilis, we examined a $\sim$700 km-wide transect across the states of Kansas and Missouri, with thorough sampling and reduced-representation genomic-level sequencing, to test the two opposing taxonomic hypotheses. Our transect analyses included examinations of population structure, fixed differences, cline-fitting, and an admixture index analysis. These analyses all supported a gradual and continuous geographic cline across a broad intergrade zone between two geographic forms of L. triangulum, thus providing strong support for a single species in this region (and no support for the recognition of L. gentilis as a distinct species). At a second contact zone between proposed species L. triangulum and Lampropeltis elapsoides (but variously treated as species or subspecies by different researchers) in Kentucky and Tennessee, we re-evaluated morphological data. In this case, the contact zone analysis indicated sympatry and reproductive isolation of the two taxa, and thus strongly supported L. triangulum and L. elapsoides as distinct species. We conclude that detailed studies of contact zones, based on either genetic or morphological data, are essential for distinguishing intraspecific from interspecific variation in the case of widely and continuously distributed taxa. [Contact zones; speciation; species concepts; species delimitation; taxonomy.].


Assuntos
Genética Populacional , Isolamento Reprodutivo , Filogenia , Genótipo , Geografia , Hibridização Genética
6.
Mol Biol Evol ; 39(4)2022 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-35356979

RESUMO

Speciation plays a central role in evolutionary studies, and particularly how reproductive isolation (RI) evolves. The origins and persistence of RI are distinct processes that require separate evaluations. Treating them separately clarifies the drivers of speciation and then it is possible to link the processes to understand large-scale patterns of diversity. Recent genomic studies have focused predominantly on how species or RI originate. However, we know little about how species persist in face of gene flow. Here, we evaluate a contact zone of two closely related toad-headed lizards (Phrynocephalus) using a chromosome-level genome assembly and population genomics. To some extent, recent asymmetric introgression from Phrynocephalus putjatai to P. vlangalii reduces their genomic differences. However, their highly divergent regions (HDRs) have heterogeneous distributions across the genomes. Functional gene annotation indicates that many genes within HDRs are involved in reproduction and RI. Compared with allopatric populations, contact areas exhibit recent divergent selection on the HDRs and a lower population recombination rate. Taken together, this implies that divergent selection and low genetic recombination help maintain RI. This study provides insights into the genomic mechanisms that drive RI and two species persistence in the face of gene flow during the late stage of speciation.


Assuntos
Genética Populacional , Lagartos , Animais , Fluxo Gênico , Especiação Genética , Hibridização Genética , Lagartos/genética , Recombinação Genética , Isolamento Reprodutivo
7.
Mol Phylogenet Evol ; 162: 107194, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33940060

RESUMO

As DNA sequencing technologies and methods for delimiting species with genomic data become more accessible and numerous, researchers have more tools than ever to investigate questions in systematics and phylogeography. However, easy access to sophisticated computational tools is not without its drawbacks. Choosing the right approach for one's question can be challenging when presented with multitudinous options, some of which fail to distinguish between species and intraspecific population structure. Here, we employ a methodology that emphasizes intensive geographic sampling, particularly at contact zones between populations, with a focus on differentiating intraspecific genetic clusters from species in the Pantherophis guttatus complex, a group of North American ratsnakes. Using a mitochondrial marker as well as ddRADseq data, we find evidence of mitonuclear discordance which has contributed to historical confusion about the relationships within this group. Additionally, we identify geographically and genetically structured populations within the species Pantherophis emoryi that are congruent with previously described morphological variation. Importantly, we find that these structured populations within P. emoryi are highly admixed throughout the range of the species and show no evidence of any reproductive isolation. Our data support a revision of the taxonomy of this group, and we recognize two species within the complex and three subspecies within P. emoryi. This study illustrates the importance of thorough sampling of contact zones and consideration of gene flow when delimiting species in widespread complexes containing parapatric lineages.


Assuntos
Núcleo Celular/genética , DNA Mitocondrial/genética , Variação Genética , Genômica , Filogenia , Filogeografia , Serpentes/genética , Animais , Análise de Sequência de DNA
8.
J Neonatal Perinatal Med ; 14(4): 463-473, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33843701

RESUMO

BACKGROUND: Increasing rates of maternal opioid use disorder has led to greater number of opioid exposed newborns (OENs). Maternal enrollment in medication for opioid use disorder (MOUD) program improves short term neonatal outcomes. This study aimed at assessing neurobehavioral outcomes for OENs. METHODS: Retrospective observational cohort study of OENs between Jul 2006 and Dec 2018. Two study groups were identified as initiation of medication for opioid use disorder (MOUD) prior to diagnoses of pregnancy or after. Primary outcome variables were enrollment in and duration of EI services. Secondary outcome variable was diagnoses of a behavioral and/or developmental disorder (BDD) during the study period. RESULTS: Of 242 infants, 113 were enrolled in EI and BDD diagnoses data was available for all infants [age range 6 to 12 years], 82% infants had exposure to maternal MOUD, while 18% were exposed to either maternal prescription non-MOUD opioids or illicit opioids. Maternal MOUD initiation prior to pregnancy was associated with improved short term outcomes for OENs. Almost a third of infants were diagnosed with a BDD with no differences between the two study groups. CONCLUSION: Early initiation of maternal MOUD improved short term outcomes and discharge disposition for OENs. Prolonged in-utero exposure to opioids presents a potential for negative impact on neurodevelopmental and behavioral outcomes. These risks must be considered to increase access and adherence to EI services, as well as to focus on non-opioid based maternal MOUD. Longitudinal studies assessing the safety of MOUD on short and long-term child health outcomes are needed.


Assuntos
Síndrome de Abstinência Neonatal , Transtornos Relacionados ao Uso de Opioides , Analgésicos Opioides/efeitos adversos , Criança , Feminino , Humanos , Lactente , Recém-Nascido , Síndrome de Abstinência Neonatal/tratamento farmacológico , Síndrome de Abstinência Neonatal/epidemiologia , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Transtornos Relacionados ao Uso de Opioides/epidemiologia , Gravidez , Estudos Retrospectivos
9.
Res Involv Engagem ; 7(1): 12, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33648588

RESUMO

Background Continual improvements to health systems, products, and services are necessary for improvements in health. However, many of these improvements are not incorporated into everyday practice. When designing new health systems, products, and services, involving members of the healthcare community and the public with personal healthcare experience can help to make sure that improvements will be useful and relevant to others like them. Methods Together with healthcare workers and family members with healthcare experience, we developed and applied a step-by-step guide to involving those with personal experience in the design of health system improvements. Results Our guide has three phases- 'Pre-Design', 'Co-Design', and 'Post-Design'. This paper describes each of these phases and illustrates how we applied them to our own project, which is to use virtual healthcare methods to improve care for children with chronic healthcare conditions and their families. In our own work, we found that healthcare workers and family members with personal healthcare experiences were able to use their knowledge and creativity to help us imagine how to improve care for children with chronic healthcare conditions and their families. We have created action items from these family member- and healthcare worker-identified needs, which we will use to shape our virtual healthcare system. Conclusions This paper may be useful for those seeking to involve members of the healthcare community and the public in the creation of better healthcare systems, products, and services. Background Challenges with the adoption, scale, and spread of health innovations represent significant gaps in the evidence-to-practice cycle. In the health innovation design process, a lack of attention paid to the needs of end-users, and subsequent tailoring of innovations to meet these needs, is a possible reason for this deficit. In the creative field of health innovation, which includes the design of healthcare products, systems (governance and organization mechanisms), and services (delivery mechanisms), a framework for both soliciting the needs of end-users and translating these needs into the design of health innovations is needed. Methods To address this gap, our team developed and applied a seven-step methodological framework, called A Generative Co-Design Framework for Healthcare Innovation. This framework was developed by an interdisciplinary team that included patient partners. Results This manuscript contributes a framework and applied exemplar for those seeking to engage end-users in the creative process of healthcare innovation. Through the stages of 'Pre-Design', 'Co-Design', and 'Post-Design', we were able to harness the creative insights of end-users, drawing on their experiences to shape a future state of care. Using an expository example of our own work, the DigiComp Kids project, we illustrate the application of each stage of the Framework. Conclusions A Generative Co-Design Framework for Healthcare Innovation provides healthcare innovators, applied health science researchers, clinicians, and quality improvement specialists with a guide to eliciting and incorporating the viewpoints of end-users while distilling practical considerations for healthcare innovation and design.

10.
Astron Astrophys ; 6392020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33173232

RESUMO

CONTEXT: The Orion Molecular Cloud is the nearest massive-star forming region. Massive stars have profound effects on their environment due to their strong radiation fields and stellar winds. Stellar feedback is one of the most crucial cosmological parameters that determine the properties and evolution of the interstellar medium in galaxies. AIMS: We aim to understand the role that feedback by stellar winds and radiation play in the evolution of the interstellar medium. Velocity-resolved observations of the [C II] 158µm fine-structure line allow us to study the kinematics of UV-illuminated gas. Here, we present a square-degree-sized map of [C II] emission from the Orion Nebula complex at a spatial resolution of 16″ and high spectral resolution of 0.2kms-1, covering the entire Orion Nebula (M42) plus M43 and the nebulae NGC 1973, 1975, and 1977 to the north. We compare the stellar characteristics of these three regions with the kinematics of the expanding bubbles surrounding them. METHODS: We use [C II] 158µm line observations over an area of 1.2deg2 in the Orion Nebula complex obtained by the upGREAT instrument onboard SOFIA. RESULTS: The bubble blown by the O7V star θ 1 Ori C in the Orion Nebula expands rapidly, at 13kms-1. Simple analytical models reproduce the characteristics of the hot interior gas and the neutral shell of this wind-blown bubble and give us an estimate of the expansion time of 0.2 Myr. M43 with the B0.5V star NU Ori also exhibits an expanding bubble structure, with an expansion velocity of 6kms-1. Comparison with analytical models for the pressure-driven expansion of H II regions gives an age estimate of 0.02 Myr. The bubble surrounding NGC 1973, 1975, and 1977 with the central B1V star 42 Orionis expands at 1.5kms-1, likely due to the over-pressurized ionized gas as in the case of M43. We derive an age of 0.4 Myr for this structure. CONCLUSIONS: We conclude that the bubble of the Orion Nebula is driven by the mechanical energy input by the strong stellar wind from θ 1 Ori C, while the bubbles associated with M43 and NGC 1977 are caused by the thermal expansion of the gas ionized by their central later-type massive stars.

11.
Syst Biol ; 69(1): 184-193, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31180508

RESUMO

Many recent species delimitation studies rely exclusively on limited analyses of genetic data analyzed under the multispecies coalescent (MSC) model, and results from these studies often are regarded as conclusive support for taxonomic changes. However, most MSC-based species delimitation methods have well-known and often unmet assumptions. Uncritical application of these genetic-based approaches (without due consideration of sampling design, the effects of a priori group designations, isolation by distance, cytoplasmic-nuclear mismatch, and population structure) can lead to over-splitting of species. Here, we argue that in many common biological scenarios, researchers must be particularly cautious regarding these limitations, especially in cases of well-studied, geographically variable, and parapatrically distributed species complexes. We consider these points with respect to a historically controversial species group, the American milksnakes (Lampropeltis triangulum complex), using genetic data from a recent analysis (Ruane et al. 2014). We show that over-reliance on the program Bayesian Phylogenetics and Phylogeography, without adequate consideration of its assumptions and of sampling limitations, resulted in over-splitting of species in this study. Several of the hypothesized species of milksnakes instead appear to represent arbitrary slices of continuous geographic clines. We conclude that the best available evidence supports three, rather than seven, species within this complex. More generally, we recommend that coalescent-based species delimitation studies incorporate thorough analyses of geographic variation and carefully examine putative contact zones among delimited species before making taxonomic changes.


Assuntos
Classificação/métodos , Filogeografia , Animais , Filogenia , Serpentes/classificação , Serpentes/genética
12.
Metabolomics ; 15(5): 72, 2019 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-31049735

RESUMO

INTRODUCTION: Dietary exposure monitoring within populations is reliant on self-reported measures such as Food Frequency Questionnaires and diet diaries. These methods often contain inaccurate information due to participant misreporting, non-compliance and bias. Urinary metabolites derived from individual foods could provide additional objective indicators of dietary exposure. For biomarker approaches to have utility it is essential that they cover a wide-range of commonly consumed foods and the methodology works in a real-world environment. OBJECTIVES: To test that the methodology works in a real-world environment and to consider the impact of the major sources of likely variance; particularly complex meals, different food formulations, processing and cooking methods, as well as the dynamics of biomarker duration in the body. METHODS: We designed and tested a dietary exposure biomarker discovery and validation strategy based on a food intervention study involving free-living individuals preparing meals and collecting urine samples at home. Two experimental periods were built around three consecutive day menu plans where all foods and drinks were provided (n = 15 and n = 36). RESULTS: The experimental design was validated by confirming known consumption biomarkers in urinary samples after the first menu plan. We tested biomarker performance with different food formulations and processing methods involving meat, wholegrain, fruits and vegetables. CONCLUSION: It was demonstrated that spot urine samples, together with robust dietary biomarkers, despite major sources of variance, could be used successfully for dietary exposure monitoring in large epidemiological studies.


Assuntos
Biomarcadores/urina , Dieta , Ingestão de Alimentos , Metabolômica , Bebidas , Estudos Cross-Over , Dieta Saudável/normas , Alimentos , Humanos , Metaboloma , Reino Unido
13.
Food Res Int ; 115: 95-104, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30599987

RESUMO

The sensory properties of coffee are impacted by various factors such as coffee origin, degree of roasting and methods of consumption. This study analyzed impact of consumption temperature on 36 flavor attributes of hot brewed coffee by descriptive sensory analysis. Different coffee samples (2 Arabica, 1 Robusta, and 1 Blended Arabica and Robusta) were consumed at 50 °C, 60 °C and 70 °C. Data were assessed using an Analysis of Variance, mixed effect model with least square means and significance level of α = 0.05. Results showed significant interactions of consumption temperature and coffee samples for attributes such as coffee identity, fidelity, and blendedness. The consumption temperature played a major impact on perceived flavor attributes of coffee and influenced Arabica, Blended and Robusta coffee differently. Coffee identity and fidelity significantly increased with an increase in all temperatures, but most attributes showed significantly higher intensity only for samples consumed at 70 °C regardless of insignificant differences at 60 °C and 50 °C.


Assuntos
Coffea/química , Café/química , Paladar , Temperatura , Análise de Variância , Manipulação de Alimentos/métodos , Temperatura Alta , Fenômenos Fisiológicos , Extratos Vegetais/análise
14.
Nature ; 565(7741): 618-621, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30617315

RESUMO

Massive stars inject mechanical and radiative energy into the surrounding environment, which stirs it up, heats the gas, produces cloud and intercloud phases in the interstellar medium, and disrupts molecular clouds (the birth sites of new stars1,2). Stellar winds, supernova explosions and ionization by ultraviolet photons control the lifetimes of molecular clouds3-7. Theoretical studies predict that momentum injection by radiation should dominate that by stellar winds8, but this has been difficult to assess observationally. Velocity-resolved large-scale images in the fine-structure line of ionized carbon ([C II]) provide an observational diagnostic for the radiative energy input and the dynamics of the interstellar medium around massive stars. Here we report observations of a one-square-degree region (about 7 parsecs in diameter) of Orion molecular core 1-the region nearest to Earth that exhibits massive-star formation-at a resolution of 16 arcseconds (0.03 parsecs) in the [C II] line at 1.9 terahertz (158 micrometres). The results reveal that the stellar wind originating from the massive star θ1 Orionis C has swept up the surrounding material to create a 'bubble' roughly four parsecs in diameter with a 2,600-solar-mass shell, which is expanding at 13 kilometres per second. This finding demonstrates that the mechanical energy from the stellar wind is converted very efficiently into kinetic energy of the shell and causes more disruption of the Orion molecular core 1 than do photo-ionization and evaporation or future supernova explosions.

15.
Clin Exp Allergy ; 48(1): 13-22, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29130617

RESUMO

BACKGROUND: Subsets of patients with severe asthma remain symptomatic despite prolonged, high-dose glucocorticoid therapy. We hypothesized that the clinical glucocorticoid sensitivity of these asthmatics is reflected in differences in peripheral blood dendritic cell subsets. OBJECTIVE: To compare peripheral blood leucocyte populations using flow cytometry at baseline and after 2 weeks of systemic glucocorticoid (steroid) treatment to identify immunological differences between steroid-sensitive (SS) and steroid-resistant (SR) asthmatics. METHODS: Adult severe asthmatics (SS n = 12; SR n = 23) were assessed for their response to 2 weeks of therapy with oral prednisolone. Peripheral blood was obtained before and after therapy and stained for lymphocyte (CD3, CD19, CD4, CD8 and Foxp3) and dendritic cell markers (Lineage negative [CD3, CD14, CD16, CD19, CD20, CD56], HLA-DR+, CD304, CD11c, ILT3 and CD86). RESULTS: A higher median frequency of myeloid DCs (mDCs) but not plasmacytoid DCs (pDCs) was observed in the blood of SR as compared to SS asthmatics (P = .03). Glucocorticoid therapy significantly increased median B cell, but not T cell numbers in both cohorts, with a trend for increased numbers of Foxp3+ Tregs in SS (P = .07), but not SR subjects. Oral prednisolone therapy significantly reduced the median numbers and frequencies of total DCs and pDCs in both SS and SR asthmatics. Interestingly, the expression of HLA-DR and ILT3 was also reduced on pDCs in all patients. In contrast, therapy increased the median frequency of mDCs in SS, but reduced it in SR asthmatics. CONCLUSIONS: Myeloid DC frequency is elevated in SR compared with SS asthmatics, and mDC shows a differential response to oral prednisolone therapy.


Assuntos
Antígenos CD/imunologia , Células Dendríticas/imunologia , Glucocorticoides/administração & dosagem , Prednisolona/administração & dosagem , Linfócitos T/imunologia , Administração Oral , Adulto , Asma/tratamento farmacológico , Asma/imunologia , Asma/patologia , Células Dendríticas/patologia , Feminino , Citometria de Fluxo , Humanos , Masculino , Linfócitos T/patologia
16.
Aliment Pharmacol Ther ; 44(7): 662-72, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27464984

RESUMO

BACKGROUND: Short-chain fatty acids (SCFA) produced through fermentation of nondigestible carbohydrates by the gut microbiota are associated with positive metabolic effects. However, well-controlled trials are limited in humans. AIMS: To develop a methodology to deliver SCFA directly to the colon, and to optimise colonic propionate delivery in humans, to determine its role in appetite regulation and food intake. METHODS: Inulin SCFA esters were developed and tested as site-specific delivery vehicles for SCFA to the proximal colon. Inulin propionate esters containing 0-61 wt% (IPE-0-IPE-61) propionate were assessed in vitro using batch faecal fermentations. In a randomised, controlled, crossover study, with inulin as control, ad libitum food intake (kcal) was compared after 7 days on IPE-27 or IPE-54 (10 g/day all treatments). Propionate release was determined using (13) C-labelled IPE variants. RESULTS: In vitro, IPE-27-IPE-54 wt% propionate resulted in a sevenfold increase in propionate production compared with inulin (P < 0.05). In vivo, IPE-27 led to greater (13) C recovery in breath CO2 than IPE-54 (64.9 vs. 24.9%, P = 0.001). IPE-27 also led to a reduction in energy intake during the ad libitum test meal compared with both inulin (439.5 vs. 703.9 kcal, P = 0.025) and IPE-54 (439.5 vs. 659.3 kcal, P = 0.025), whereas IPE-54 was not significantly different from inulin control. CONCLUSIONS: IPE-27 significantly reduced food intake suggesting colonic propionate plays a role in appetite regulation. Inulin short-chain fatty acid esters provide a novel tool for probing the diet-gut microbiome-host metabolism axis in humans.


Assuntos
Colo/metabolismo , Ácidos Graxos Voláteis/administração & dosagem , Inulina/administração & dosagem , Adulto , Estudos Cross-Over , Ingestão de Alimentos , Ingestão de Energia , Ésteres/química , Ácidos Graxos Voláteis/metabolismo , Fezes , Fermentação , Humanos , Masculino , Pessoa de Meia-Idade , Propionatos
17.
Med Vet Entomol ; 30(3): 247-52, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27352139

RESUMO

The impact of deltamethrin-impregnated cloth targets on Stegomyia polynesiensis (= Aedes polynesiensis) (Marks) (Diptera: Culicidae) was assessed under laboratory and semi-field settings in French Polynesia. Stegomyia polynesiensis females were released into small laboratory cages and large field cages containing either a deltamethrin-treated or an untreated navy blue cloth, and mosquito knock-down and mortality were assessed. The 24-h mortality rate in mosquitoes exposed to the insecticide-treated target in small cages was 98.0%. These mosquitoes also demonstrated significantly higher levels of knock-down than those exposed to the untreated target. Mortality in field cages was assessed at 24 and 48 h. The 24-h mortality rate in mosquitoes exposed to the control target was 31.2%, whereas that in those exposed to the deltamethrin-treated target was 54.3%. The 48-h mortality rate was also elevated in mosquitoes exposed to the deltamethrin-treated target, but this result did not differ significantly from that observed in mosquitoes exposed to the control target. The significant suppression of female S. polynesiensis by deltamethrin-treated resting targets in this study indicates that these targets could play a role in the control of an important disease vector in the South Pacific region.


Assuntos
Aedes , Controle de Insetos/normas , Inseticidas , Nitrilas , Piretrinas , Animais , Feminino , Polinésia , Análise de Sobrevida
18.
PLoS One ; 11(4): e0154363, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27116180

RESUMO

BACKGROUND: High rates of species discovery and loss have led to the urgent need for more rapid assessment of species diversity in the herpetofauna. DNA barcoding allows for the preliminary identification of species based on sequence divergence. Prior DNA barcoding work on reptiles and amphibians has revealed higher biodiversity counts than previously estimated due to cases of cryptic and undiscovered species. Past studies have provided DNA barcodes for just 14% of the North American herpetofauna, revealing the need for expanded coverage. METHODOLOGY/PRINCIPAL FINDINGS: This study extends the DNA barcode reference library for North American herpetofauna, assesses the utility of this approach in aiding species delimitation, and examines the correspondence between current species boundaries and sequence clusters designated by the BIN system. Sequences were obtained from 730 specimens, representing 274 species (43%) from the North American herpetofauna. Mean intraspecific divergences were 1% and 3%, while average congeneric sequence divergences were 16% and 14% in amphibians and reptiles, respectively. BIN assignments corresponded with current species boundaries in 79% of amphibians, 100% of turtles, and 60% of squamates. Deep divergences (>2%) were noted in 35% of squamate and 16% of amphibian species, and low divergences (<2%) occurred in 12% of reptiles and 23% of amphibians, patterns reflected in BIN assignments. Sequence recovery declined with specimen age, and variation in recovery success was noted among collections. Within collections, barcodes effectively flagged seven mislabeled tissues, and barcode fragments were recovered from five formalin-fixed specimens. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that DNA barcodes can effectively flag errors in museum collections, while BIN splits and merges reveal taxa belonging to deeply diverged or hybridizing lineages. This study is the first effort to compile a reference library of DNA barcodes for herpetofauna on a continental scale.


Assuntos
Anfíbios/classificação , Código de Barras de DNA Taxonômico/métodos , DNA Mitocondrial/genética , Répteis/classificação , Animais , Biodiversidade , Biblioteca Gênica , História Natural , América do Norte , Especificidade da Espécie
19.
Int J Sports Med ; 37(8): 607-13, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27116342

RESUMO

The maximal capacity to oxidize fat during exercise (MFO) is associated with 24-h fat balance and insulin sensitivity. Understanding factors that influence MFO could have implications for metabolic health. We investigated relationships between selected plasma metabolites, hormones and overnight-fasted resting fat oxidation rates (Resting), with MFO. Resting fat oxidation and MFO was measured in 57 men with blood collected at rest and during exercise. Plasma glycerol (R=0.39, P=0.033), non-esterified fatty acids (NEFA: R=0.27, P=0.030) and insulin (R=- 0.36, P=0.007) measured at MFO correlated with MFO; only glycerol remained correlated when controlled for resting concentrations (R=0.36, P=0.008). The change in glycerol from rest to MFO correlated with exercise-induced fat oxidation (R=0.32, P=0.012). V˙O 2max correlated with resting fat oxidation (R=0.44, P=0.001) and MFO (R=0.52, P<0.001). Resting fat oxidation correlated with MFO (R=0.55, P<0.001); this remained when controlled for V˙O 2max (R=0.41, P=0.001). This study reports weak-to-moderate, albeit significant, relationships between plasma lipolytic markers, insulin and resting overnight-fasted fat oxidation with MFO and shows the plasma glycerol response to uniquely reflect exercise-induced fat oxidation. V˙O 2max correlates with fat oxidation but the relationship can be dissociated. Interventions to increase fat oxidation for optimal metabolic health would benefit from, but are not reliant on, increases in V˙O 2max.


Assuntos
Tecido Adiposo/metabolismo , Exercício Físico/fisiologia , Metabolismo dos Lipídeos , Adolescente , Adulto , Biomarcadores/sangue , Estudos Transversais , Teste de Esforço , Ácidos Graxos não Esterificados/sangue , Glicerol/sangue , Humanos , Insulina/sangue , Resistência à Insulina , Ácido Láctico/sangue , Masculino , Oxirredução , Consumo de Oxigênio/fisiologia , Descanso , Adulto Jovem
20.
Diabetes Obes Metab ; 18(1): 72-81, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26434748

RESUMO

AIMS: To investigate, for a given energy expenditure (EE) rise, the differential effects of glucagon infusion and cold exposure on brown adipose tissue (BAT) activation in humans. METHODS: Indirect calorimetry and supraclavicular thermography was performed in 11 healthy male volunteers before and after: cold exposure; glucagon infusion (at 23 °C); and vehicle infusion (at 23 °C). All volunteers underwent (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/CT scanning with cold exposure. Subjects with cold-induced BAT activation on (18)F-FDG PET/CT (n = 8) underwent a randomly allocated second (18)F-FDG PET/CT scan (at 23 °C), either with glucagon infusion (n = 4) or vehicle infusion (n = 4). RESULTS: We observed that EE increased by 14% after cold exposure and by 15% after glucagon infusion (50 ng/kg/min; p < 0.05 vs control for both). Cold exposure produced an increase in neck temperature (+0.44 °C; p < 0.001 vs control), but glucagon infusion did not alter neck temperature. In subjects with a cold-induced increase in the metabolic activity of supraclavicular BAT on (18)F-FDG PET/CT, a significant rise in the metabolic activity of BAT after glucagon infusion was not detected. Cold exposure increased sympathetic activation, as measured by circulating norepinephrine levels, but glucagon infusion did not. CONCLUSIONS: Glucagon increases EE by a similar magnitude compared with cold activation, but independently of BAT thermogenesis. This finding is of importance for the development of safe treatments for obesity through upregulation of EE.


Assuntos
Tecido Adiposo Marrom/metabolismo , Metabolismo Energético/efeitos dos fármacos , Glucagon/farmacocinética , Adulto , Temperatura Baixa , Estudos Controlados Antes e Depois , Fluordesoxiglucose F18 , Voluntários Saudáveis , Humanos , Masculino , Tomografia por Emissão de Pósitrons/métodos , Distribuição Aleatória , Termogênese/efeitos dos fármacos , Tomografia Computadorizada por Raios X , Adulto Jovem
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