90 research outputs found
Natural Cross Chlamydial Infection between Livestock and Free-Living Bird Species
The study of cross-species pathogen transmission is essential to understanding the epizootiology and epidemiology of infectious diseases. Avian chlamydiosis is a zoonotic disease whose effects have been mainly investigated in humans, poultry and pet birds. It has been suggested that wild bird species play an important role as reservoirs for this disease. During a comparative health status survey in common (Falco tinnunculus) and lesser (Falco naumanni) kestrel populations in Spain, acute gammapathies were detected. We investigated whether gammapathies were associated with Chlamydiaceae infections. We recorded the prevalence of different Chlamydiaceae species in nestlings of both kestrel species in three different study areas. Chlamydophila psittaci serovar I (or Chlamydophila abortus), an ovine pathogen causing late-term abortions, was isolated from all the nestlings of both kestrel species in one of the three studied areas, a location with extensive ovine livestock enzootic of this atypical bacteria and where gammapathies were recorded. Serovar and genetic cluster analysis of the kestrel isolates from this area showed serovars A and C and the genetic cluster 1 and were different than those isolated from the other two areas. The serovar I in this area was also isolated from sheep abortions, sheep faeces, sheep stable dust, nest dust of both kestrel species, carrion beetles (Silphidae) and Orthoptera. This fact was not observed in other areas. In addition, we found kestrels to be infected by Chlamydia suis and Chlamydia muridarum, the first time these have been detected in birds. Our study evidences a pathogen transmission from ruminants to birds, highlighting the importance of this potential and unexplored mechanism of infection in an ecological context. On the other hand, it is reported a pathogen transmission from livestock to wildlife, revealing new and scarcely investigated anthropogenic threats for wild and endangered species
Ethnic-Racial Socialization in Early Childhood: The Implications of Color-Consciousness and Colorblindness for Prejudice Development
This chapter outlines how early childhood teachers can bring children into conversations surrounding race and racism by drawing on literature on how parents of color discuss these topics. Although educatorsâ practices surrounding race and racism remain largely unexplored, decades of developmental psychological research indicate that parents of color engage in ethnic-racial socialization practices that are beneficial for children (Hughes et al., 2006). The established dimensions of parental ethnic-racial socialization include (1) cultural socialization, or teaching children about their ethnic heritage and instilling ethnic pride; (2) preparation for bias, or teaching children about racism and preparing them to face discrimination; (3) promotion of mistrust, or warning children about the need to distance themselves from other racial groups; and (4) egalitarianism, or emphasizing the similarities between and equality of all races (Hughes et al. 2006). One consideration to take into account from a developmental perspective is that childrenâs level of cognitive development impacts how they interpret messages about race. This chapter draws a link between parental ethnic-racial socialization and extends this body of work to school settings, with a focus on teachers. The ideologies of colorblindness and color-consciousness are discussed throughout
In Search of the Optimal Surgical Treatment for Velopharyngeal Dysfunction in 22q11.2 Deletion Syndrome: A Systematic Review
<div><h3>Background</h3><p>Patients with the 22q11.2 deletion syndrome (22qDS) and velopharyngeal dysfunction (VPD) tend to have residual VPD following surgery. This systematic review seeks to determine whether a particular surgical procedure results in superior speech outcome or less morbidity.</p> <h3>Methodology/ Principal Findings</h3><p>A combined computerized and hand-search yielded 70 studies, of which 27 were deemed relevant for this review, reporting on a total of 525 patients with 22qDS and VPD undergoing surgery for VPD. All studies were levels 2c or 4 evidence. The methodological quality of these studies was assessed using criteria based on the Cochrane Collaboration's tool for assessing risk of bias. Heterogeneous groups of patients were reported on in the studies. The surgical procedure was often tailored to findings on preoperative imaging. Overall, 50% of patients attained normal resonance, 48% attained normal nasal emissions scores, and 83% had understandable speech postoperatively. However, 5% became hyponasal, 1% had obstructive sleep apnea (OSA), and 17% required further surgery. There were no significant differences in speech outcome between patients who underwent a fat injection, Furlow or intravelar veloplasty, pharyngeal flap pharyngoplasty, Honig pharyngoplasty, or sphincter pharyngoplasty or Hynes procedures. There was a trend that a lower percentage of patients attained normal resonance after a fat injection or palatoplasty than after the more obstructive pharyngoplasties (11â18% versus 44â62%, pâ=â0.08). Only patients who underwent pharyngeal flaps or sphincter pharyngoplasties incurred OSA, yet this was not statistically significantly more often than after other procedures (pâ=â0.25). More patients who underwent a palatoplasty needed further surgery than those who underwent a pharyngoplasty (50% versus 7â13%, pâ=â0.03).</p> <h3>Conclusions/ Significance</h3><p>In the heterogeneous group of patients with 22qDS and VPD, a grade C recommendation can be made to minimize the morbidity of further surgery by choosing to perform a pharyngoplasty directly instead of only a palatoplasty.</p> </div
Experimental Microbial Evolution of Extremophiles
Experimental microbial evolutions (EME) involves studying closely a microbial population after it has been through a large number of generations under controlled conditions (Kussell 2013). Adaptive laboratory evolution (ALE) selects for fitness under experimentally imposed conditions (Bennett and Hughes 2009; Dragosits and Mattanovich 2013). However, experimental evolution studies focusing on the contributions of genetic drift and natural mutation rates to evolution are conducted under non-selective conditions to avoid changes imposed by selection (Hindré et al. 2012).
To understand the application of experimental evolutionary methods to extremophiles it is essential to consider the recent growth in this field over the last decade using model non-extremophilic microorganisms. This growth reflects both a greater appreciation of the power of experimental evolution for testing evolutionary hypotheses and, especially recently, the new power of genomic methods for analyzing changes in experimentally evolved lineages. Since many crucial processes are driven by microorganisms in nature, it is essential to understand and appreciate how microbial communities function, particularly with relevance to selection. However, many theories developed to understand microbial ecological patterns focus on the distribution and the structure of diversity within a microbial population comprised of single species (Prosser et al. 2007). Therefore an understanding of the concept of species is needed. A common definition of species using a genetic concept is a group of interbreeding individuals that is isolated from other such groups by barriers of recombination (Prosser et al. 2007). An alternative ecological species concept defines a species as set of individuals that can be considered identical in all relevant ecological traits (Cohan 2001). This is particularly important because of the abundance and deep phylogenetic complexity of microbial communities. Cohan postulated that âbacteria occupy discrete niches and that periodic selection will purge genetic variation within each niche without preventing divergence between the inhabitants of different nichesâ. The importance of gene exchange mechanisms likely in bacteria and archaea and therefore extremophiles, arises from the fact that their genomes are divided into two distinct parts, the core genome and the accessory genome (Cohan 2001). The core genome consists of genes that are crucial for the functioning of an organism and the accessory genome consists of genes that are capable of adapting to the changing ecosystem through gain and loss of function. Strains that belong to the same species can differ in the composition of accessory genes and therefore their capability to adapt to changing ecosystems (Cohan 2001; Tettelin et al. 2005; Gill et al. 2005). Additional ecological diversity exists in plasmids, transposons and pathogenicity islands as they can be easily shared in a favorable environment but still be absent in the same species found elsewhere (Wertz et al. 2003). This poses a major challenge for studying ALE and community microbial ecology indicating a continued need to develop a fitting theory that connects the fluid nature of microbial communities to their ecology (Wertz et al. 2003; Coleman et al. 2006). Understanding the nature and contribution of different processes that determine the frequencies of genes in any population is the biggest concern in population and evolutionary genetics (Prosser et al. 2007) and it is critical for an understanding of experimental evolution
Delineation of Tumor Habitats based on Dynamic Contrast Enhanced MRI
Tumor heterogeneity can be elucidated by mapping subregions of the lesion with differential imaging characteristics, called habitats. Dynamic Contrast Enhanced (DCE-)MRI can depict the tumor microenvironments by identifying areas with variable perfusion and vascular permeability, since individual tumor habitats vary in the rate and magnitude of the contrast uptake and washout. Of particular interest is identifying areas of hypoxia, characterized by inadequate perfusion and hyper-permeable vasculature. An automatic procedure for delineation of tumor habitats from DCE-MRI was developed as a two-part process involving: (1) statistical testing in order to determine the number of the underlying habitats; and (2) an unsupervised pattern recognition technique to recover the temporal contrast patterns and locations of the associated habitats. The technique is examined on simulated data and DCE-MRI, obtained from prostate and brain pre-clinical cancer models, as well as clinical data from sarcoma and prostate cancer patients. The procedure successfully identified habitats previously associated with well-perfused, hypoxic and/or necrotic tumor compartments. Given the association of tumor hypoxia with more aggressive tumor phenotypes, the obtained in vivo information could impact management of cancer patients considerably
Hepatocellular Carcinomas in Cirrhotic and Noncirrhotic Human Livers Share Angiogenic Characteristics
North American Wild Relatives of Grain Crops
The wild-growing relatives of the grain crops are useful for long-term worldwide crop improvement research. There are neglected examples that should be accessioned as living seeds in gene banks. Some of the grain crops, amaranth, barnyard millet, proso millet, quinoa, and foxtail millet, have understudied unique and potentially useful crop wild relatives in North America. Other grain crops, barley, buckwheat, and oats, have fewer relatives in North America that are mostly weeds from other continents with more diverse crop wild relatives. The expanding abilities of genomic science are a reason to accession the wild species since there are improved ways to study evolution within genera and make use of wide gene pools. Rare wild species, especially quinoa relatives in North American, should be acquired by gene banks in cooperation with biologists that already study and conserve at-risk plant populations. Many of the grain crop wild relatives are weeds that have evolved herbicide resistance that could be used in breeding new herbicide-resistant cultivars, so well-documented examples should be accessioned and also vouchered in gene banks
Tight junctions: from simple barriers to multifunctional molecular gates
Epithelia and endothelia separate different tissue compartments and protect multicellular organisms from the outside world. This requires the formation of tight junctions, selective gates that control paracellular diffusion of ions and solutes. Tight junctions also form the border between the apical and basolateral plasma-membrane domains and are linked to the machinery that controls apicobasal polarization. Additionally, signalling networks that guide diverse cell behaviours and functions are connected to tight junctions, transmitting information to and from the cytoskeleton, nucleus and different cell adhesion complexes. Recent advances have broadened our understanding of the molecular architecture and cellular functions of tight junctions
Classifying the evolutionary and ecological features of neoplasms
The consensus conference was supported by Wellcome Genome Campus Advanced Courses and Scientific Conferences. C.C.M. is supported in part by US NIH grants P01 CA91955, R01 CA149566, R01 CA170595, R01 CA185138 and R01 CA140657 as well as CDMRP Breast Cancer Research Program Award BC132057. M.J. is supported by NIH grant K99CA201606. K.S.A. is supported by NCI 5R21 CA196460. K. Polyak is supported by R35 CA197623, U01 CA195469, U54 CA193461, and the Breast Cancer Research Foundation. K.J.P. is supported by NIH grants CA143803, CA163124, CA093900 and CA143055. D.P. is supported by the European Research Council (ERC-617457- PHYLOCANCER), the Spanish Ministry of Economy and Competitiveness (BFU2015-63774-P) and the Education, Culture and University Development Department of the Galician Government. K.S.A. is supported in part by the Breast Cancer Research Foundation and NCI R21CA196460. C.S. is supported by the Royal Society, Cancer Research UK (FC001169), the UK Medical Research Council (FC001169), and the Wellcome Trust (FC001169), NovoNordisk Foundation (ID 16584), the Breast Cancer Research Foundation (BCRF), the European Research Council (THESEUS) and Marie Curie Network PloidyNet. T.A.G. is a Cancer Research UK fellow and a Wellcome Trust funded Investigator. E.S.H. is supported by R01 CA185138-01 and W81XWH-14-1-0473. M.Gerlinger is supported by Cancer Research UK and The Royal Marsden/ICR National Institute of Health Research Biomedical Research Centre. M.Ge., M.Gr., Y.Y., and A.So. were also supported in part by the Wellcome Trust [105104/Z/14/Z]. J.D.S. holds the Edward B. Clark, MD Chair in Pediatric Research, and is supported by the Primary Children's Hospital (PCH) Pediatric Cancer Research Program, funded by the Intermountain Healthcare Foundation and the PCH Foundation. A.S. is supported by the Chris Rokos Fellowship in Evolution and Cancer. Y.Y. is a Cancer Research UK fellow and supported by The Royal Marsden/ICR National Institute of Health Research Biomedical Research Centre. E.S.H. was supported in part by PCORI grants 1505â30497 and 1503â29572, NIH grants R01 CA185138, T32 CA093245, and U10 CA180857, CDMRP Breast Cancer Research Program Award BC132057, a CRUK Grand Challenge grant, and the Breast Cancer Research Foundation. A.R.A.A. was funded in part by NIH grant U01CA151924. A.R.A.A., R.G. and J.S.B. were funded in part by NIH grant U54CA193489
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