RESUMO
BACKGROUND: African Yam Bean (AYB) is an understudied and underutilized tuberous legume of tropical West and Central African origin. In these geographical regions, both seeds and tubers of AYB are important components of people's diets and a potential target as a nutritional security crop. The understanding of the genetic diversity among AYB accessions is thus an important component for both conservation and potential breeding programs. RESULTS: In this study, 93 AYB accessions were obtained from the International Institute of Tropical Agriculture (IITA) genebank and genotyped using 3722 SNP markers based on Restriction site-Associated DNA sequencing (RAD-Seq). Genetic data was analysed using multiple clustering methods for better understanding the distribution of genetic diversity across the population. Substantial genetic variability was observed in the present set of AYB accessions and different methodologies demonstrated that these accessions are divided into three to four main groups. The accessions were also analysed for important agronomic traits and successfully associated with their genetic clusters where great majority of accessions shared a similar phenotype. CONCLUSIONS: To our knowledge, this is the first study on predicting genotypic-phenotypic diversity relationship analysis in AYB. From a breeding perspective, we were able to identify specific diverse groups with precise phenotype such as seed or both seed and tuber yield purpose accessions. These results provide novel and important insights to support the utilization of this germplasm in AYB breeding programs.
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Produtos Agrícolas/genética , Variação Genética , Genótipo , Técnicas de Genotipagem/métodos , Melhoramento Vegetal/métodos , Sphenostylis/genética , África , FenótipoRESUMO
Salvia limbata is of great importance to the pharmaceutical industry owing to its various biological effects. Therefore, it is important to investigate the main factors that affect its essential oil composition. Although some investigations have been performed with regard to the phytochemistry of S. limbata, this study investigates, for the first time, the effect of growth stage and altitude on the content and chemical composition of essential oil extracted from S. limbata. For this purpose, the essential oil was extracted from 45 air-dried samples by hydrodistillation and analyzed by GC-MS and GC-flame methods. The highest content of essential oil was obtained from aerial parts in the vegetative stage at an altitude of 1500 m (0.86% v/w). Our findings show that the vegetative stage at 1500 m is the optimal harvest time to extract the highest content of oil while the highest content of monoterpenes (including α-pinene and ß-pinene) could be obtained in the same phenological stage at 2000 m. By contrast, the content of sesquiterpenes increased to the highest values in the ripening stage at 1500 and 2500 m. The results of this study help to find the optimal conditions to obtain the highest content of S. limbata essential oil, but additional studies are warranted.
Assuntos
Óleos Voláteis , Salvia , Altitude , Cromatografia Gasosa-Espectrometria de Massas , Monoterpenos/análise , Óleos Voláteis/análise , Óleos Voláteis/química , Salvia/química , Salvia/crescimento & desenvolvimento , Salvia/metabolismoRESUMO
Background: Square knots can be difficult to construct in deep body cavities. The reversing half-hitch alternating post (RHAP) surgical knot has noninferior tensile strength and performance characteristics in deep body cavities. We compared the enterotomy repairs of novice learners in simulated deep body cavities using RHAP versus square knots after proficiency-based training. Methods: Undergraduate students were randomized to RHAP (n = 10) or square knot (n = 10) groups and trained to defined proficiency. They then performed hand-sewn enterotomy repairs of cadaveric porcine small bowels on flat surfaces and in simulated deep body cavities. We recorded time to knot-tying proficiency and to enterotomy repair, and burst pressures for the repair. Results: Mean time-to-proficiency in knot tying was equivalent between the RHAP and square knot groups (23 [standard deviation (SD) 3] v. 21 [SD 2] min, p = 0.33). Mean time for enterotomy repair in deep cavities was shorter for the RHAP group (16 [SD 2] min v. 21 [SD 1] min, p = 0.02). Mean burst pressures for enterotomy repair were equivalent on flat surfaces (128 [SD 41] v. 101 [SD 36] mm Hg, p = 0.31), and were significantly higher for the RHAP group in simulated deep body cavities (32 [SD 13] v. 105 [SD 37] mm Hg, p = 0.05). Conclusion: The RHAP knots appear to have superior performance versus square knots when tied in a deep body cavity by novice learners. Future work should focus on demonstrating the clinical relevance and broad utility of the RHAP knot in abdominal surgery. Both knot types should be taught to novice learners.
Contexte: L'exécution de noeuds plats peut être difficile dans les cavités corporelles profondes. Les noeuds de type demi-clé inversée alternée (RHAP, pour reversing halfhitch alternating post) ont une résistance à la traction et un rendement semblables à ceux des noeuds plats dans ces cavités. Nous avons comparé l'efficacité des noeuds plats et des noeuds de type RHAP réalisés par de nouveaux apprenants dans des cavités profondes simulées, après leur avoir enseigné les compétences nécessaires. Méthodes: Les étudiants de premier cycle ont été aléatoirement répartis en 2 groupes, soit le groupe RHAP (n = 10) et le groupe noeud plat (n = 10), et ont reçu une formation pour développer des compétences prédéfinies. Ils ont ensuite suturé à la main un intestin grêle provenant d'un cadavre de porc, sur une surface plane et à l'intérieur d'une cavité profonde simulée. Nous avons mesuré le temps nécessaire à l'exécution du noeud et à la suture complète de l'incision, de même que la pression que pouvait subir cette suture sans se rompre. Résultats: Le temps moyen d'exécution du noeud était semblable entre les groupes RHAP et noeud plat (23 min [écart type (E.T.) 3 min] c. 21 min [E.T. 2 min]; p = 0,33). Le temps moyen nécessaire à la suture de l'incision dans la cavité profonde était plus court dans le groupe RHAP (16 min [E.T. 2 min] c. 21 min [E.T. 1 min]; p = 0,02). La pression moyenne que pouvait subir la suture sans se rompre était comparable pour les sutures effectuées sur une surface plane (128 mm Hg [E.T. 41 mm Hg] c. 101 mm Hg [E.T. 36 mm Hg]; p = 0,31), mais était significativement plus élevée dans le groupe RHAP pour les sutures faites dans la cavité profonde (32 mm Hg [E.T. 13 mm Hg] c. 105 mm Hg [E.T. 37 mm Hg], p = 0,05). Conclusion: Les noeuds de type RHAP semblent avoir un rendement supérieur à celui des noeuds plats lorsqu'ils sont réalisés dans une cavité profonde par de nouveaux apprenants. Des études ultérieures devraient se pencher sur la pertinence clinique et l'utilité générale de ces noeuds en chirurgie abdominale. Les 2 types de noeuds devraient être enseignés aux nouveaux apprenants.
Assuntos
Procedimentos Cirúrgicos do Sistema Digestório/métodos , Treinamento por Simulação , Técnicas de Sutura/educação , Adulto , Animais , Cadáver , Feminino , Humanos , Masculino , Estudos Prospectivos , Método Simples-Cego , SuínosRESUMO
BACKGROUND: Salvia is a large, diverse, and polymorphous genus of the family Lamiaceae, comprising about 900 ornamentals, medicinal species with almost cosmopolitan distribution in the world. The success of Salvia limbata seed germination depends on a numerous ecological factors and stresses. We aimed to analyze Salvia limbata seed germination under four ecological stresses of salinity, drought, temperature and pH, with application of artificial intelligence modeling techniques such as MLR (Multiple Linear Regression), and MLP (Multi-Layer Perceptron). The S.limbata seeds germination was tested in different combinations of abiotic conditions. Five different temperatures of 10, 15, 20, 25 and 30 °C, seven drought treatments of 0, -2, -4, -6, -8, -10 and -12 bars, eight treatments of salinity containing 0, 50, 100.150, 200, 250, 300 and 350 mM of NaCl, and six pH treatments of 4, 5, 6, 7, 8 and 9 were tested. Indeed 228 combinations were tested to determine the percentage of germination for model development. RESULTS: Comparing to the MLR, the MLP model represents the significant value of R2 in training (0.95), validation (0.92) and test data sets (0.93). According to the results of sensitivity analysis, the values of drought, salinity, pH and temperature are respectively known as the most significant variables influencing S. limbata seed germination. Areas with high moisture content and low salinity in the soil have a high potential to seed germination of S. limbata. Also, the temperature of 18.3 °C and pH of 7.7 are proposed for achieving the maximum number of germinated S. limbata seeds. CONCLUSIONS: Multilayer perceptron model helps managers to determine the success of S.limbata seed planting in agricultural or natural ecosystems. The designed graphical user interface is an environmental decision support system tool for agriculture or rangeland managers to predict the success of S.limbata seed germination (percentage) in different ecological constraints of lands.
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Germinação , Salvia , Inteligência Artificial , Ecossistema , Sementes , TemperaturaRESUMO
BACKGROUND: Cell based therapies, such as bone marrow derived mesenchymal stem cells (BM-MSCs; also known as mesenchymal stromal cells), are currently under investigation for a number of disease applications. The current challenge facing the field is maintaining the consistency and quality of cells especially for cell dose production for pre-clinical testing and clinical trials. Here we determine how BM-donor variability and thus the derived MSCs factor into selection of the optimal primary cell lineage for cell production and testing in a pre-clinical swine model of trauma induced acute respiratory distress syndrome. METHODS: We harvested bone marrow and generated three different primary BM-MSCs from Yorkshire swine. Cells from these three donors were characterized based on (a) phenotype (morphology, differentiation capacity and flow cytometry), (b) in vitro growth kinetics and metabolic activity, and (c) functional analysis based on inhibition of lung endothelial cell permeability. RESULTS: Cells from each swine donor exhibited varied morphology, growth rate, and doubling times. All expressed the same magnitude of standard MSC cell surface markers by flow cytometry and had similar differentiation potential. Metabolic activity and growth potential at each of the passages varied between the three primary cell cultures. More importantly, the functional potency of the MSCs on inhibition of endothelial permeability was also cell donor dependent. CONCLUSION: This study suggests that for production of MSCs for cell-based therapy, it is imperative to examine donor variability and characterize derived MSCs for marker expression, growth and differentiation characteristics and testing potency in application dependent assays prior to selection of the optimal cell lineage for large scale expansion and dose production.
Assuntos
Células da Medula Óssea/citologia , Seleção do Doador , Células-Tronco Mesenquimais/citologia , Animais , Biomarcadores/metabolismo , Células da Medula Óssea/metabolismo , Técnicas de Cultura de Células , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Forma Celular , Meios de Cultivo Condicionados/farmacologia , Impedância Elétrica , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Feminino , Humanos , Imunofenotipagem , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , SuínosRESUMO
Free-energy landscapes govern the behavior of all interactions in the presence of thermal fluctuations in the fields of physical chemistry, materials sciences, and the biological sciences. From the energy landscape, critical information about an interaction, such as the reaction kinetic rates, bond lifetimes, and the presence of intermediate states, can be determined. Despite the importance of energy landscapes to understanding reaction mechanisms, most experiments do not directly measure energy landscapes, particularly for interactions with steep force gradients that lead to premature jump to contact of the probe and insufficient sampling of transition regions. Here we present an atomic force microscopy (AFM) approach for measuring energy landscapes that increases sampling of strongly adhesive interactions by using white-noise excitation to enhance the cantilever's thermal fluctuations. The enhanced fluctuations enable the recording of subtle deviations from a harmonic potential to accurately reconstruct interfacial energy landscapes with steep gradients. Comparing the measured energy landscape with adhesive force measurements reveals the existence of an optimal excitation voltage that enables the cantilever fluctuations to fully sample the shape and depth of the energy surface.
RESUMO
Genomic data are a powerful tool for elucidating the processes involved in the evolution and divergence of species. The speciation and phylogenetic relationships among Chinese Juglans remain unclear. Here, we used results from phylogenomic and population genetic analyses, transcriptomics, Genotyping-By-Sequencing (GBS), and whole chloroplast genomes (Cp genome) data to infer processes of lineage formation among the five native Chinese species of the walnut genus (Juglans, Juglandaceae), a widespread, economically important group. We found that the processes of isolation generated diversity during glaciations, but that the recent range expansion of J. regia, probably from multiple refugia, led to hybrid formation both within and between sections of the genus. In southern China, human dispersal of J. regia brought it into contact with J. sigillata, which we determined to be an ecotype of J. regia that is now maintained as a landrace. In northern China, walnut hybridized with a distinct lineage of J. mandshurica to form J. hopeiensis, a controversial taxon (considered threatened) that our data indicate is a horticultural variety. Comparisons among whole chloroplast genomes and nuclear transcriptome analyses provided conflicting evidence for the timing of the divergence of Chinese Juglans taxa. J. cathayensis and J. mandshurica are poorly differentiated based our genomic data. Reconstruction of Juglans evolutionary history indicate that episodes of climatic variation over the past 4.5 to 33.80 million years, associated with glacial advances and retreats and population isolation, have shaped Chinese walnut demography and evolution, even in the presence of gene flow and introgression.
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Especiação Genética , Genoma de Cloroplastos , Genômica , Hibridização Genética , Juglans/genética , Filogenia , Análise de Sequência de DNA , Transcriptoma/genética , China , Genética Populacional , Técnicas de Genotipagem , Geografia , Haplótipos/genética , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
BACKGROUND: Identifying orthologous genes is an initial step required for phylogenetics, and it is also a common strategy employed in functional genetics to find candidates for functionally equivalent genes across multiple species. At the same time, in silico orthology prediction tools often require large computational resources only available on computing clusters. Here we present OrthoReD, an open-source orthology prediction tool with accuracy comparable to published tools that requires only a desktop computer. The low computational resource requirement of OrthoReD is achieved by repeating orthology searches on one gene of interest at a time, thereby generating a reduced dataset to limit the scope of orthology search for each gene of interest. RESULTS: The output of OrthoReD was highly similar to the outputs of two other published orthology prediction tools, OrthologID and/or OrthoDB, for the three dataset tested, which represented three phyla with different ranges of species diversity and different number of genomes included. Median CPU time for ortholog prediction per gene by OrthoReD executed on a desktop computer was <15 min even for the largest dataset tested, which included all coding sequences of 100 bacterial species. CONCLUSIONS: With high-throughput sequencing, unprecedented numbers of genes from non-model organisms are available with increasing need for clear information about their orthologies and/or functional equivalents in model organisms. OrthoReD is not only fast and accurate as an orthology prediction tool, but also gives researchers flexibility in the number of genes analyzed at a time, without requiring a high-performance computing cluster.
Assuntos
Software , Actinobacteria/genética , Actinobacteria/metabolismo , Animais , Bases de Dados Factuais , Drosophila/genética , Drosophila/metabolismo , Genética , Genoma , Sequenciamento de Nucleotídeos em Larga Escala , Magnoliopsida/genética , Magnoliopsida/metabolismo , TranscriptomaRESUMO
Intravenous administration of bone marrow derived mesenchymal stem cells (MSCs) has been shown to reduce blood brain barrier compromise and improve neurocognition following traumatic brain injury (TBI). These effects occur in the absence of engraftment and differentiation of these cells in the injured brain. Recent studies have shown that soluble factors produced by MSCs mediate a number of the therapeutic effects. In this study, we sought to determine if intravenous administration of MSCs (IV-MSCs) could enhance hippocampal neurogenesis following TBI. Our results demonstrate that IV-MSC treatment attenuates loss of neural stem cells and promotes hippocampal neurogenesis in TBI injured mice. As Wnt signaling has been implicated in neurogenesis, we measured circulating Wnt3a levels in serum following IV-MSC administration and found a significant increase in Wnt3a. Concurrent with this increase, we detected increased activation of the Wnt/ß-catenin signaling pathway in hippocampal neurons. Furthermore, IV recombinant Wnt3a treatment provided neuroprotection, promoted neurogenesis, and improved neurocognitive function in TBI injured mice. Taken together, our results demonstrate a role for Wnt3a in the therapeutic potential of MSCs and identify Wnt3a as a potential stand-alone therapy or as part of a combination therapeutic strategy for the treatment of TBI. Stem Cells 2016;34:1263-1272.
Assuntos
Lesões Encefálicas Traumáticas/tratamento farmacológico , Cognição , Células-Tronco Mesenquimais/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Recuperação de Função Fisiológica , Proteína Wnt3A/metabolismo , Proteína Wnt3A/uso terapêutico , Administração Intravenosa , Animais , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/fisiopatologia , Sobrevivência Celular/efeitos dos fármacos , Cognição/efeitos dos fármacos , Hipocampo/patologia , Hipocampo/fisiopatologia , Humanos , Pulmão/metabolismo , Transplante de Células-Tronco Mesenquimais , Camundongos Endogâmicos C57BL , Modelos Biológicos , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Neurogênese/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Recuperação de Função Fisiológica/efeitos dos fármacos , Resultado do Tratamento , Via de Sinalização Wnt/efeitos dos fármacos , Proteína Wnt3A/sangue , Proteína Wnt3A/farmacologiaRESUMO
Mesenchymal stem cells (MSCs) have been shown to have potent therapeutic effects in a number of disorders including traumatic brain injury (TBI). However, the molecular mechanism(s) underlying these protective effects are largely unknown. Herein we demonstrate that tissue inhibitor of matrix metalloproteinase-3 (TIMP3), a soluble protein released by MSCs, is neuroprotective and enhances neuronal survival and neurite outgrowth in vitro. In vivo in a murine model of TBI, intravenous recombinant TIMP3 enhances dendritic outgrowth and abrogates loss of hippocampal neural stem cells and mature neurons. Mechanistically we demonstrate in vitro and in vivo that TIMP3-mediated neuroprotection is critically dependent on activation of the Akt-mTORC1 pathway. In support of the neuroprotective effect of TIMP3, we find that intravenous delivery of recombinant TIMP3 attenuates deficits in hippocampal-dependent neurocognition. Taken together, our data strongly suggest that TIMP3 has direct neuroprotective effects that can mitigate the deleterious effects associated with TBI, an area with few if any therapeutic options.
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Lesões Encefálicas/tratamento farmacológico , Transtornos Cognitivos/tratamento farmacológico , Hipocampo/metabolismo , Células-Tronco Neurais/metabolismo , Neurônios/metabolismo , Inibidor Tecidual de Metaloproteinase-3/farmacologia , Animais , Lesões Encefálicas/metabolismo , Lesões Encefálicas/patologia , Lesões Encefálicas/fisiopatologia , Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/patologia , Hipocampo/patologia , Camundongos , Células-Tronco Neurais/patologia , Neurônios/patologiaRESUMO
BACKGROUND: In current blood banking practices, platelets (PLTs) are stored in plasma at 22°C, with gentle agitation for up to 5 days. To date, the effects of storage and donor variability on PLT regulation of vascular integrity are not known. STUDY DESIGN AND METHODS: In this study, we examined the donor variability of leukoreduced fresh (Day 1) or stored (Day 5) PLTs on vascular endothelial barrier function in vitro and in vivo. In vitro, PLT effects on endothelial cell (EC) monolayer permeability were assessed by analyzing transendothelial electrical resistances (TEER). PLT aggregation, a measure of hemostatic potential, was analyzed by impedance aggregometry. In vivo, PLTs were investigated in a vascular endothelial growth factor A (VEGF-A)-induced vascular permeability model in NSG mice, and PLT circulation was measured by flow cytometry. RESULTS: Treatment of endothelial monolayers with fresh Day 1 PLTs resulted in an increase in EC barrier resistance and decreased permeability in a dose-dependent manner. Subsequent treatment of EC monolayers with Day 5 PLTs demonstrated diminished vasculoprotective effects. Donor variability was noted in all measures of PLT function. Day 1 PLT donors were more variable in their effects on TEER than Day 5 PLTs. In mice, while all PLTs regardless of storage time demonstrated significant protection against VEGF-A-induced vascular leakage, Day 5 PLTs exhibited reduced protection when compared to Day 1 PLTs. Day 1 PLTs demonstrated significant donor variability against VEGF-A-challenged vascular leakage in vivo. Systemic circulating levels of Day 1 PLTs were higher than those of Day 5 PLTs CONCLUSIONS: In vitro and in vivo, Day 1 PLTs are protective in measures of vascular endothelial permeability. Donor variability is most prominent in Day 1 PLTs. A decrease in the protective effects is found with storage of the PLT units between Day 1 and Day 5 at 22°C, thereby suggesting that Day 5 PLTs are diminished in their ability to attenuate vascular endothelial permeability.
Assuntos
Doadores de Sangue , Plaquetas/metabolismo , Preservação de Sangue , Células Endoteliais da Veia Umbilical Humana/metabolismo , Plaquetoferese , Animais , Humanos , Camundongos , Camundongos Endogâmicos NOD , Fatores de TempoRESUMO
BACKGROUND: Although a majority of the studies conducted to date on platelet (PLT) storage have been focused on PLT hemostatic function, the effects of 4°C PLTs on regulation of endothelial barrier permeability are still not known. In this study, we compared the effects of room temperature (22°C) stored and (4°C) stored PLTs on the regulation of vascular endothelial cell (EC) permeability in vitro and in vivo. STUDY DESIGN AND METHODS: Day 1, Day 5, and Day 7 leukoreduced apheresis PLTs stored at 4 or 22°C were studied in vitro and in vivo. In vitro, PLT effects on EC permeability and barrier function, adhesion, and impedance aggregometry were investigated. In vivo, using a mouse model of vascular leak, attenuation of vascular leak and circulating PLT numbers were measured. RESULTS: Treatment of EC monolayers with Day 5 or Day 7 PLTs, stored at both 22°C and 4°C, resulted in similar decreases in EC permeability on average. However, analysis of individual samples revealed significant variation that was donor dependent. Additional in vitro measurements revealed a decrease in inflammatory mediators, nonspecific PLT-endothelial aggregation and attenuated loss of aggregation over time to TRAP, ASPI, ADP, and collagen with 4°C storage. In mice, while 22°C and 4°C PLTs both demonstrated significant protection against vascular endothelial growth factor A (VEGF-A)-induced vascular leak 22°C PLTs exhibited increased protection compared to 4°C PLTs. Systemic circulating levels of 4°C PLTs were decreased compared to 22°C PLTs. CONCLUSIONS: In vitro, 4°C-stored PLTs exhibit a greater capacity to inhibit EC permeability than 22°C-stored PLTs. In vivo, 22°C PLTs provide superior control of vascular leak induced by VEGF-A. This discrepancy may be due to increased clearance of 4°C PLTs from the systemic circulation.
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Plaquetas , Preservação de Sangue , Permeabilidade Capilar , Temperatura Baixa , Endotélio Vascular/metabolismo , Temperatura Alta , Células Endoteliais da Veia Umbilical Humana/metabolismo , Animais , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Fatores de TempoRESUMO
Invasive species have great ecological and economic impacts and are difficult to control once established, making the ability to understand and predict invasive behavior highly desirable. Preemptive measures to prevent potential invasive species from reaching new habitats are the most economically and environmentally efficient form of management. Darwin's naturalization hypothesis predicts that invaders less related to native flora are more likely to be successful than those that are closely related to natives. Here we test this hypothesis, using the weed-rich thistle tribe, Cardueae, in the California Floristic Province, a biodiversity hotspot, as our study system. An exhaustive molecular phylogenetic approach was used, generating and examining more than 100,000 likely phylogenies of the tribe based on nuclear and chloroplast DNA markers, representing the most in-depth reconstruction of the clade to date. Branch lengths separating invasive and noninvasive introduced taxa from native California taxa were used to represent phylogenetic distances between these groups and were compared at multiple biogeographical scales to ascertain whether invasive thistles are more or less closely related to natives than noninvasive introduced thistles are. Patterns within this highly supported clade show that not only are introduced thistles more closely related to natives more likely to be invasive, but these invasive species are also evolutionarily closer to native flora than by chance. This suggests that preadaptive traits are important in determining an invader's success. Such rigorous molecular phylogenetic analyses may prove a fruitful means for furthering our understanding of biological invasions and developing predictive frameworks for screening potential invasive taxa.
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Adaptação Biológica/fisiologia , Asteraceae/genética , Evolução Biológica , Espécies Introduzidas , Modelos Biológicos , Filogenia , Asteraceae/fisiologia , Sequência de Bases , Teorema de Bayes , California , Funções Verossimilhança , Modelos Genéticos , Dados de Sequência Molecular , Filogeografia , Análise de Sequência de DNARESUMO
The mechanisms that trigger initiation of arteriogenesis in response to pathogenic obstruction of arterial flow are not fully understood. Our objective is to determine whether glycocalyx mediated mechanotransduction of fluid shear stress to the endothelial layer is an essential first step in inducing arteriogenesis. Mice were implanted with an osmotic minipump containing saline or hyaluronan synthase inhibitor 4-methylesculetin (4ME) 2 wk before femoral artery ligation. 4ME was effective in modifying the endothelial glycocalyx as measured by dextran exclusion and perfused boundary region changes. Glycocalyx modification resulted in a 52% (P = 0.002) reduction in perfusion restoration through the 21-day follow-up [area under the curve, 4.9 ± 1.1 (n = 11) vs. 10.2 ± 3.2 (n = 10), 4ME vs. control (Ctrl)]. Upon femoral artery ligation, no change in collateral vessel diameter in 4ME treated mice (49.8 ± 26.3 vs. 47.1 ± 14.0 µm, ligated vs unligated) was observed (Ctrl, 88.5 ± 18.8 vs. 35.1 ± 3.0 µm, ligated vs unligated, P < 0.05). This impaired arteriogenic process was accompanied by lack of local induction of both endothelial and smooth muscle cell activation (Ki67, endothelial nitric oxide synthase, and ICAM-1), as well as a failure to recruit CD11b-positive cells in 4ME-treated collateral vessels (0.012 ± 0.003 vs. 0.010 ± 0.003 cells/µm vessel perimeter, ligated vs. unligated), whereas in Ctrls, the number of CD11b cells was increased (0.024 ± 0.002 vs. 0.010 ± 0.004 cells/µm vessel perimeter, P < 0.05). Modification of the glycocalyx by inhibition of hyaluronan synthesis renders the endothelium unresponsive to altered hemodynamic conditions resulting from femoral artery ligation, which results in a hampered restoration of distal perfusion.
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Endotélio Vascular/metabolismo , Glicocálix/metabolismo , Mecanotransdução Celular , Neovascularização Fisiológica , Animais , Endotélio Vascular/fisiologia , Glucuronosiltransferase/antagonistas & inibidores , Glicocálix/efeitos dos fármacos , Hialuronan Sintases , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Umbeliferonas/farmacologiaRESUMO
The number of exotic plant species that have been introduced into the United States far exceeds that of other groups of organisms, and many of these have become invasive. As in many regions of the globe, invasive members of the thistle tribe, Cardueae, are highly problematic in the California Floristic Province, an established biodiversity hotspot. While Darwin's naturalization hypothesis posits that plant invaders closely related to native species would be at a disadvantage, evidence has been found that introduced thistles more closely related to native species are more likely to become invasive. To elucidate the mechanisms behind this pattern, we modelled the ecological niches of thistle species present in the province and compared niche similarity between taxa and their evolutionary relatedness, using fossil-calibrated molecular phylogenies of the tribe. The predicted niches of invasive species were found to have higher degrees of overlap with native species than noninvasive introduced species do, and pairwise niche distance was significantly correlated with phylogenetic distance, suggesting phylogenetic niche conservatism. Invasive thistles also displayed superior dispersal capabilities compared to noninvasive introduced species, and these capabilities exhibited a phylogenetic signal. By analysing the modelled ecological niches and dispersal capabilities of over a hundred thistle species, we demonstrate that exapted preferences to the invaded environment may explain why close exotic relatives may make bad neighbours in the thistle tribe.
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Asteraceae/genética , Evolução Biológica , Ecossistema , Filogenia , California , Ecologia/métodos , Espécies Introduzidas , Modelos BiológicosRESUMO
Reconstructing the phylogeny of Pyrus has been difficult due to the wide distribution of the genus and lack of informative data. In this study, we collected 110 accessions representing 25 Pyrus species and constructed both phylogenetic trees and phylogenetic networks based on multiple DNA sequence datasets. Phylogenetic trees based on both cpDNA and nuclear LFY2int2-N (LN) data resulted in poor resolution, especially, only five primary species were monophyletic in the LN tree. A phylogenetic network of LN suggested that reticulation caused by hybridization is one of the major evolutionary processes for Pyrus species. Polytomies of the gene trees and star-like structure of cpDNA networks suggested rapid radiation is another major evolutionary process, especially for the occidental species. Pyrus calleryana and P. regelii were the earliest diverged Pyrus species. Two North African species, P. cordata, P. spinosa and P. betulaefolia were descendent of primitive stock Pyrus species and still share some common molecular characters. Southwestern China, where a large number of P. pashia populations are found, is probably the most important diversification center of Pyrus. More accessions and nuclear genes are needed for further understanding the evolutionary histories of Pyrus.
Assuntos
Evolução Biológica , Filogenia , Pyrus/classificação , Teorema de Bayes , China , DNA de Cloroplastos/genética , DNA de Plantas/genética , Haplótipos , Hibridização Genética , Pyrus/genética , Análise de Sequência de DNARESUMO
BACKGROUND: Flow cytometric sorting can be used to separate sperm based on sex chromosome content. Differential fluorescence emitted by stained X- vs. Y-chromosome-bearing sperm enables sorting and collection of samples enriched in either X- or Y-bearing sperm for use to influence the likelihood that the offspring will be a particular sex. Herein we report the effectiveness of flow cytometric sorting of human sperm and its use in human ART procedures. METHODS: This prospective, observational cohort study of the series of subjects treated with flow cytometrically sorted human sperm was conducted at investigational sites at two private reproductive centers. After meeting inclusion criteria, married couples (n = 4993) enrolled to reduce the likelihood of sex-linked or sex-limited disease in future children (n = 383) or to balance the sex ratio of their children (n = 4610). Fresh or frozen-thawed semen was processed and recovered sperm were stained with Hoechst 33342 and sorted by flow cytometry (n = 7718) to increase the percentage of X-bearing sperm (n = 5635) or Y-bearing sperm (n = 2083) in the sorted specimen. Sorted sperm were used for IUI (n = 4448) and IVF/ICSI (n = 2957). Measures of effectiveness were the percentage of X- and Y-bearing sperm in sorted samples, determined by fluorescence in situ hybridization, sex of babies born, IVF/ICSI fertilization- and cleavage rates, and IUI, IVF/ICSI, FET pregnancy rates and miscarriage rates. RESULTS: Sorted specimens averaged 87.7 ± 5.0% X-bearing sperm after sorting for X and 74.3 ± 7.0% Y-bearing sperm after sorting for Y. Seventy-three percent of sorts were for girls. For babies born, 93.5% were females and 85.3% were males after sorting for X- and Y-bearing sperm, respectively. IUI, IVF/ICSI, and FET clinical pregnancy rates were 14.7%, 30.8%, and 32.1%, respectively; clinical miscarriage rates were 15.5%, 10.2%, and 12.7%. CONCLUSIONS: Flow cytometric sorting of human sperm shifted the X:Y sperm ratio. IUI, IVF/ICSI and FET outcomes were consistent with unimpaired sperm function. Results provide evidence supporting the effectiveness of flow cytometric sorting of human sperm for use as a preconception method of influencing a baby's sex. TRIAL REGISTRATION: NCT00865735 (ClinicalTrials.gov).
Assuntos
Separação Celular/métodos , Citometria de Fluxo/métodos , Pré-Seleção do Sexo/métodos , Espermatozoides/citologia , Cromossomos Humanos X/genética , Cromossomos Humanos Y/genética , Feminino , Fertilização in vitro , Humanos , Hibridização in Situ Fluorescente , Recém-Nascido , Inseminação Artificial , Masculino , Gravidez , Resultado da Gravidez , Taxa de Gravidez , Estudos Prospectivos , Reprodutibilidade dos Testes , Razão de Masculinidade , Injeções de Esperma Intracitoplásmicas , Espermatozoides/metabolismoRESUMO
Many turf managers prefer to control foliage- and root-feeding pests with the same application, so-called multiple-targeting, using a single broad-spectrum insecticide or a premix product containing two or more active ingredients. We compared the impact of a neonicotinoid (clothianidin), a premix (clothianidin + bifenthrin), and an anthranilic diamide (chlorantraniliprole), the main insecticide classes used for multiple targeting, on four species of beneficial insects: Harpalus pennsylvanicus, an omnivorous ground beetle, Tiphia vernalis, an ectoparasitoid of scarab grubs, Copidosoma bakeri, a polyembryonic endoparasitoid of black cutworms, and Bombus impatiens, a native bumble bee. Ground beetles that ingested food treated with clothianidin or the premix suffered high mortality, as did C. bakeri wasps exposed to dry residues of those insecticides. Exposure to those insecticides on potted turf cores reduced parasitism by T. vernalis. Bumble bee colonies confined to forage on white clover (Trifolium repens L.) in weedy turf that had been treated with clothianidin or the premix had reduced numbers of workers, honey pots, and immature bees. Premix residues incapacitated H. pennsylvanicus and C. bakeri slightly faster than clothianidin alone, but otherwise we detected no synergistic or additive effects. Chlorantraniliprole had no apparent adverse effects on any of the beneficial species. Implications for controlling turf pests with least disruption of non-target invertebrates are discussed.
Assuntos
Abelhas/efeitos dos fármacos , Diamida/toxicidade , Inseticidas/toxicidade , Animais , Besouros/efeitos dos fármacos , Guanidinas/toxicidade , Himenópteros/efeitos dos fármacos , Isoxazóis , Neonicotinoides , Plantas Daninhas/efeitos dos fármacos , Piretrinas/toxicidade , Tiazóis/toxicidade , ortoaminobenzoatos/toxicidadeRESUMO
With >80 million United States households engaged in lawn and gardening activities, increasing sustainability of lawn care is important. Mowing height is an easily manipulated aspect of lawn management. We tested the hypothesis that elevated mowing of tall fescue lawn grass promotes a larger, more diverse community of arthropod natural enemies which in turn provides stronger biological control services, and the corollary hypothesis that doing so also renders the turf itself less suitable for growth of insect pests. Turf-type tall fescue was mowed low (6.4 cm) or high (10.2 cm) for two growing seasons, natural enemy populations were assessed by vacuum sampling, pitfall traps, and ant baits, and predation and parasitism were evaluated with sentinel prey caterpillars, grubs, and eggs. In addition, foliage-feeding caterpillars and root-feeding scarab grubs were confined in the turf to evaluate their performance. Although some predatory groups (e.g., rove beetles and spiders) were more abundant in high-mowed grass, predation rates were uniformly high because ants, the dominant predators, were similarly abundant regardless of mowing height. Lower canopy temperatures in high-mowed grass were associated with slower growth of grass-feeding caterpillars. Higher lawn mowing reduces fuel consumption and yard waste, and promotes a deep, robust root system that reduces need for water and chemical inputs. Although in this study elevated mowing height did not measurably increase the already-high levels of predation, it did suggest additional ways through which bottom-up effects on insect pest growth might interact with natural enemies to facilitate conservation biological control.
Assuntos
Artrópodes/fisiologia , Ecossistema , Jardinagem/métodos , Controle Biológico de Vetores/métodos , Poaceae/crescimento & desenvolvimento , Análise de Variância , Animais , Conservação dos Recursos Naturais , Herbivoria/fisiologia , Kentucky , Densidade Demográfica , Comportamento Predatório/fisiologiaRESUMO
The Japanese beetle Popillia japonica is a pest insect that feeds on hundreds of species of wild and cultivated plants including important fruit, vegetable, and field crops. Native to Japan, the pest has invaded large areas of the USA, Canada, the Azores (Portugal), Italy, and Ticino (Switzerland), and it is considered a priority for control in the European Union. We determined the complete mitochondrial genome sequence in 86 individuals covering the entire distribution of the species. Phylogenetic analysis supports a major division between South Japan and Central/North Japan, with invasive samples coming from the latter. The origin of invasive USA samples is incompatible, in terms of the timing of the event, with a single introduction, with multiple Japanese lineages having been introduced and one accounting for most of the population expansion locally. The origin of the two invasive European populations is compatible with two different invasions followed by minimal differentiation locally. Population analyses provide the possibility to estimate the rate of sequence change from the data and to date major invasion events. Demographic analysis identifies a population expansion followed by a period of contraction prior to the invasion. The present study adds a time and demographic dimension to available reconstructions.