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https://www.readbyqxmd.com/read/28429794/bone-in-culture-array-as-a-platform-to-model-early-stage-bone-metastases-and-discover-anti-metastasis-therapies
#1
Hai Wang, Lin Tian, Amit Goldstein, Jun Liu, Hin-Ching Lo, Kuanwei Sheng, Thomas Welte, Stephen T C Wong, Zbigniew Gugala, Fabio Stossi, Chenghang Zong, Zonghai Li, Michael A Mancini, Xiang H-F Zhang
The majority of breast cancer models for drug discovery are based on orthotopic or subcutaneous tumours. Therapeutic responses of metastases, especially microscopic metastases, are likely to differ from these tumours due to distinct cancer-microenvironment crosstalk in distant organs. Here, to recapitulate such differences, we established an ex vivo bone metastasis model, termed bone-in-culture array or BICA, by fragmenting mouse bones preloaded with breast cancer cells via intra-iliac artery injection. Cancer cells in BICA maintain features of in vivo bone micrometastases regarding the microenvironmental niche, gene expression profile, metastatic growth kinetics and therapeutic responses...
April 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28429157/scenes-as-micro-cultures-examining-heterogeneity-of-hiv-risk-behavior-among-gay-bisexual-and-other-men-who-have-sex-with-men-in-toronto-canada
#2
Syed W Noor, Barry D Adam, David J Brennan, David A Moskowitz, Sandra Gardner, Trevor A Hart
Using latent class analysis (LCA), we examined patterns of participation in multiple scenes, how sexual risk practices vary by scene, and psychosocial factors associated with these patterns among 470 gay, bisexual, and other men who have sex with men (GBM) recruited from Toronto. We calculated posterior probability of being in a class from participation in nine separate scenes. We used Entropy, the Bayesian information criterion and the Lo-Mendel-Rubin likelihood ratio test to identify the best fit model. Fit indices suggested a four-class solution...
April 20, 2017: Archives of Sexual Behavior
https://www.readbyqxmd.com/read/28428866/capture-efficiency-and-trophic-adaptations-of-a-specialist-and-generalist-predator-a-comparison
#3
Ondřej Michálek, Lenka Petráková, Stano Pekár
Specialist true predators are expected to exhibit higher capture efficiencies for the capture of larger and dangerous prey than generalist predators due to their possession of specialized morphological and behavioral adaptations. We used an araneophagous spider (Lampona murina) and a generalist spider (Drassodes lapidosus) as phylogenetically related model species and investigated their realized and fundamental trophic niches and their efficacy with respect to prey capture and prey handling. The trophic niche of both species confirmed that Lampona had a narrow trophic niche with a predominance of spider prey (including conspecifics), while the niche of Drassodes was wide, without any preference...
April 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28428859/species-partitioning-in-a-temperate-mountain-chain-segregation-by-habitat-vs-interspecific-competition
#4
Giulia Bastianelli, Brendan A Wintle, Elizabeth H Martin, Javier Seoane, Paola Laiolo
Disentangling the relative influence of the environment and biotic interactions in determining species coexistence patterns is a major challenge in ecology. The zonation occurring along elevation gradients, or at bioclimatic contact zones, offers a good opportunity to improve such understanding because the small scale at which the partitioning occurs facilitates inference based on experiments and ecological modelling. We studied the influence of abiotic gradients, habitat types, and interspecific competition in determining the spatial turnover between two pipit and two bunting species in NW Spain...
April 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28428850/shortcuts-in-biodiversity-research-what-determines-the-performance-of-higher-taxa-as-surrogates-for-species
#5
Neil Rosser
Biodiversity research is often impeded by the time and resources required to identify species. One possible solution is to use higher taxa to predict species richness and community composition. However, previous studies have shown that the performance of higher taxa as surrogates for species is highly variable, making it difficult to predict whether the method will be reliable for a particular objective. Using 8 independent datasets, I tested whether higher taxa accurately characterize the responses of beetle and ant communities to environmental drivers...
April 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28427552/integrating-the-microbiota-of-the-respiratory-tract-with-the-unified-airway-model
#6
REVIEW
Alissa S Hanshew, Marie E Jetté, Sarah P Rosen, Susan L Thibeault
The unified airway model has developed from indications that the upper and lower respiratory tracts share key elements of pathogenesis. These shared traits likely extend to similar niche characteristics that support bacterial communities, and as such, we suspect that similar microbes exist on upper and lower respiratory tract epithelium. Over the past decade and a half there have been significant improvements in microbiological identification and analysis due to the development of new molecular technologies, including next-generation sequencing...
May 2017: Respiratory Medicine
https://www.readbyqxmd.com/read/28426818/alternative-glacial-interglacial-refugia-demographic-hypotheses-tested-on-cephalocereus-columna-trajani-cactaceae-in-the-intertropical-mexican-drylands
#7
Amelia Cornejo-Romero, Carlos Fabián Vargas-Mendoza, Gustavo F Aguilar-Martínez, Javier Medina-Sánchez, Beatriz Rendón-Aguilar, Pedro Luis Valverde, Jose Alejandro Zavala-Hurtado, Alejandra Serrato, Sombra Rivas-Arancibia, Marco Aurelio Pérez-Hernández, Gerardo López-Ortega, Cecilia Jiménez-Sierra
Historic demography changes of plant species adapted to New World arid environments could be consistent with either the Glacial Refugium Hypothesis (GRH), which posits that populations contracted to refuges during the cold-dry glacial and expanded in warm-humid interglacial periods, or with the Interglacial Refugium Hypothesis (IRH), which suggests that populations contracted during interglacials and expanded in glacial times. These contrasting hypotheses are developed in the present study for the giant columnar cactus Cephalocereus columna-trajani in the intertropical Mexican drylands where the effects of Late Quaternary climatic changes on phylogeography of cacti remain largely unknown...
2017: PloS One
https://www.readbyqxmd.com/read/28426754/assessing-environmental-attributes-and-effects-of-climate-change-on-sphagnum-peatland-distributions-in-north-america-using-single-and-multi-species-models
#8
Tobi A Oke, Heather A Hager
The fate of Northern peatlands under climate change is important because of their contribution to global carbon (C) storage. Peatlands are maintained via greater plant productivity (especially of Sphagnum species) than decomposition, and the processes involved are strongly mediated by climate. Although some studies predict that warming will relax constraints on decomposition, leading to decreased C sequestration, others predict increases in productivity and thus increases in C sequestration. We explored the lack of congruence between these predictions using single-species and integrated species distribution models as proxies for understanding the environmental correlates of North American Sphagnum peatland occurrence and how projected changes to the environment might influence these peatlands under climate change...
2017: PloS One
https://www.readbyqxmd.com/read/28426669/a-dynamic-genetic-hormonal-regulatory-network-model-explains-multiple-cellular-behaviors-of-the-root-apical-meristem-of-arabidopsis-thalian
#9
Mónica L García-Gómez, Eugenio Azpeitia, Elena R Álvarez-Buylla
The study of the concerted action of hormones and transcription factors is fundamental to understand cell differentiation and pattern formation during organ development. The root apical meristem of Arabidopsis thaliana is a useful model to address this. It has a stem cell niche near its tip conformed of a quiescent organizer and stem or initial cells around it, then a proliferation domain followed by a transition domain, where cells diminish division rate before transiting to the elongation zone; here, cells grow anisotropically prior to their final differentiation towards the plant base...
April 20, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28426555/creating-artificial-lymphoid-tissues-to-study-immunity-and-hematological-malignancies
#10
Shivem B Shah, Ankur Singh
PURPOSE OF REVIEW: The specialized microenvironments of lymphoid tissue affect immune cell function and progression of disease. However, current animal models are low throughput and a large number of human diseases are difficult to model in animals. Animal models are less amenable to manipulation of tissue niche components, signalling pathways, epigenetics, and genome editing than ex vivo models. On the other hand, conventional 2D cultures lack the physiological relevance to study precise microenvironmental interactions...
April 19, 2017: Current Opinion in Hematology
https://www.readbyqxmd.com/read/28424704/draco-stem-an-automatic-tool-to-generate-high-quality-3d-meshes-of-shoot-apical-meristem-tissue-at-cell-resolution
#11
Guillaume Cerutti, Olivier Ali, Christophe Godin
Context: The shoot apical meristem (SAM), origin of all aerial organs of the plant, is a restricted niche of stem cells whose growth is regulated by a complex network of genetic, hormonal and mechanical interactions. Studying the development of this area at cell level using 3D microscopy time-lapse imaging is a newly emerging key to understand the processes controlling plant morphogenesis. Computational models have been proposed to simulate those mechanisms, however their validation on real-life data is an essential step that requires an adequate representation of the growing tissue to be carried out...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28424673/genome-scale-reconstruction-of-the-metabolic-network-in-oenococcus-oeni-to-assess-wine-malolactic-fermentation
#12
Sebastián N Mendoza, Pablo M Cañón, Ángela Contreras, Magdalena Ribbeck, Eduardo Agosín
Oenococcus oeni is the main responsible agent for malolactic fermentation in wine, an unpredictable and erratic process in winemaking. To address this, we have constructed and exhaustively curated the first genome-scale metabolic model of Oenococcus oeni, comprising 660 reactions, 536 metabolites and 454 genes. In silico experiments revealed that nutritional requirements are predicted with an accuracy of 93%, while 14 amino acids were found to be essential for the growth of this bacterial species. When the model was applied to determine the non-growth associated maintenance, results showed that O...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28421279/sporulation-how-to-survive-on-planet-earth-and-beyond
#13
REVIEW
Mingwei Huang, Christina M Hull
Sporulation is a strategy widely utilized by a wide variety of organisms to adapt to changes in their individual environmental niches and survive in time and/or space until they encounter conditions acceptable for vegetative growth. The spores produced by bacteria have been the subjects of extensive studies, and several systems such as Bacillus subtilis have provided ample opportunities to understand the molecular basis of spore biogenesis and germination. In contrast, the spores of other microbes, such as fungi, are relatively poorly understood...
April 18, 2017: Current Genetics
https://www.readbyqxmd.com/read/28421182/tgf-%C3%AE-1-pretreatment-improves-the-function-of-mesenchymal-stem-cells-in-the-wound-bed
#14
Deepraj Ghosh, Daniel J McGrail, Michelle R Dawson
The wound healing process initiates after injury to a tissue and involves a series of orchestrated events to minimize the invasion of foreign matters such as bacteria and efficiently regenerate the damaged tissue. A variety of cells must be recruited to the tissue during wound healing. However, this process is severely disrupted in patients suffering from chronic illness, including diabetes, leading to impaired healing or non-healing wounds. Current avenues of treatment include negative-pressure therapy, wound debridement, growth factor replacement, and cell-based therapies...
2017: Frontiers in Cell and Developmental Biology
https://www.readbyqxmd.com/read/28421003/acellular-gelatinous-material-of-human-umbilical-cord-enhances-wound-healing-a-candidate-remedy-for-deficient-wound-healing
#15
Nazihah Bakhtyar, Marc G Jeschke, Laurence Mainville, Elaine Herer, Saeid Amini-Nik
Impaired wound healing is a severe clinical challenge and research into finding effective wound healing strategies is underway as there is no ideal treatment. Gelatinous material from the umbilical cord called Wharton's jelly is a valuable source of mesenchymal stem cells which have been shown to aid wound healing. While the cellular component of Wharton's jelly has been the subject of extensive research during the last few years, little is known about the de-cellularized jelly material of the umbilical cord...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28415180/reversals-and-collisions-optimize-protein-exchange-in-bacterial-swarms
#16
Aboutaleb Amiri, Cameron Harvey, Amy Buchmann, Scott Christley, Joshua D Shrout, Igor S Aranson, Mark Alber
Swarming groups of bacteria coordinate their behavior by self-organizing as a population to move over surfaces in search of nutrients and optimal niches for colonization. Many open questions remain about the cues used by swarming bacteria to achieve this self-organization. While chemical cue signaling known as quorum sensing is well-described, swarming bacteria often act and coordinate on time scales that could not be achieved via these extracellular quorum sensing cues. Here, cell-cell contact-dependent protein exchange is explored as a mechanism of intercellular signaling for the bacterium Myxococcus xanthus...
March 2017: Physical Review. E
https://www.readbyqxmd.com/read/28414791/speciation-in-progress-a-phylogeographic-study-among-populations-of-hemitrichia-serpula-myxomycetes
#17
Nikki Heherson A Dagamac, Carlos Rojas, Yuri K Novozhilov, Gabriel H Moreno, Rabea Schlueter, Martin Schnittler
Myxomycetes (plasmodial slime molds, Amoebozoa) are often perceived as widely distributed, confounding to the "everything is everywhere" hypothesis. To test if gene flow within these spore-dispersed protists is restricted by geographical barriers, we chose the widespread but morphologically unmistakable species Hemitrichia serpula for a phylogeographic study. Partial sequences from nuclear ribosomal RNA genes (SSU) revealed 40 ribotypes among 135 specimens, belonging to three major clades. Each clade is dominated by specimens from a certain region and by one of two morphological varieties which can be differentiated by SEM micrographs...
2017: PloS One
https://www.readbyqxmd.com/read/28412938/broad-and-flexible-stable-isotope-niches-in-invasive-non-native-rattus-spp-in-anthropogenic-and-natural-habitats-of-central-eastern-madagascar
#18
Melanie Dammhahn, Toky M Randriamoria, Steven M Goodman
BACKGROUND: Rodents of the genus Rattus are among the most pervasive and successful invasive species, causing major vicissitudes in native ecological communities. A broad and flexible generalist diet has been suggested as key to the invasion success of Rattus spp. Here, we use an indirect approach to better understand foraging niche width, plasticity, and overlap within and between introduced Rattus spp. in anthropogenic habitats and natural humid forests of Madagascar. RESULTS: Based on stable carbon and nitrogen isotope values measured in hair samples of 589 individual rodents, we found that Rattus rattus had an extremely wide foraging niche, encompassing the isotopic space covered by a complete endemic forest-dwelling Malagasy small mammal community...
April 17, 2017: BMC Ecology
https://www.readbyqxmd.com/read/28410135/custom-built-tools-for-the-study-of-deer-antler-biology
#19
Wenhui Chu, Haiping Zhao, Junde Li, Chunyi Li
Deer antlers can be developed into multiple novel models to study growth and development of tissues for biomedical research. To facilitate this process, we have invented and further refined five custom-built tools through three decades of antler research. These are: 1. Pedicle growth detector to pinpoint the timing when pedicle growth is initiated, thus stimuli for pedicle and first antler formation can be investigated and identified. 2. Thin periosteum slice cutter to thinly slice (0.2mm or 0.7 mm thick) a whole piece of antlerogenic periosteum (AP) or pedicle periosteum (PP), which facilitates gene delivery into cells resident in these tissues, thus making transgenic antlers possible...
June 1, 2017: Frontiers in Bioscience (Landmark Edition)
https://www.readbyqxmd.com/read/28410031/the-ecological-dynamics-of-natural-selection-traits-and-the-coevolution-of-community-structure
#20
Mark A McPeek
Natural selection has both genetic and ecological dynamics. The fitnesses of individuals change with their ecological context, and so the form and strength of selective agents change with abiotic factors and the phenotypes and abundances of interacting species. I use standard models of consumer-resource interactions to explore the ecological dynamics of natural selection and how various trait types influence these dynamics and the resulting structure of a community of coevolving species. Evolutionary optima favored by natural selection depend critically on the abundances of interacting species, and the traits of species can undergo dynamic cycling in limited areas of parameter space...
May 2017: American Naturalist
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