76 research outputs found

    Reprogrammed Transcriptome in Rhesus-Bovine Interspecies Somatic Cell Nuclear Transfer Embryos

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    Global activation of the embryonic genome (EGA), one of the most critical steps in early mammalian embryo development, is recognized as the time when interspecies somatic cell nuclear transfer (iSCNT) embryos fail to thrive.In this study, we analyzed the EGA-related transcriptome of rhesus-bovine iSCNT 8- to 16-cell embryos and dissected the reprogramming process in terms of embryonic gene activation, somatic gene silencing, and maternal RNA degradation. Compared with fibroblast donor cells, two thousand and seven genes were activated in iSCNT embryos, one quarter of them reaching expression levels comparable to those found in in vitro fertilized (IVF) rhesus embryos. This suggested that EGA in iSCNT embryos had partially recapitulated rhesus embryonic development. Eight hundred and sixty somatic genes were not silenced properly and continued to be expressed in iSCNT embryos, which indicated incomplete nuclear reprogramming. We compared maternal RNA degradation in bovine oocytes between bovine-bovine SCNT and iSCNT embryos. While maternal RNA degradation occurred in both SCNT and iSCNT embryos, we saw more limited overall degradation of maternal RNA in iSCNT embryos than in SCNT embryos. Several important maternal RNAs, like GPF9, were not properly processed in SCNT embryos.Our data suggested that iSCNT embryos are capable of triggering EGA, while a portion of somatic cell-associated genes maintain their expression. Maternal RNA degradation seems to be impaired in iSCNT embryos. Further understanding of the biological roles of these genes, networks, and pathways revealed by iSCNT may expand our knowledge about cell reprogramming, pluripotency, and differentiation

    In Search of the Optimal Surgical Treatment for Velopharyngeal Dysfunction in 22q11.2 Deletion Syndrome: A Systematic Review

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    <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 (11–18% versus 44–62%, p = 0.08). Only patients who underwent pharyngeal flaps or sphincter pharyngoplasties incurred OSA, yet this was not statistically significantly more often than after other procedures (p = 0.25). More patients who underwent a palatoplasty needed further surgery than those who underwent a pharyngoplasty (50% versus 7–13%, p = 0.03).</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

    Interaction of Copper-Based Nanoparticles to Soil, Terrestrial, and Aquatic Systems: Critical Review of the State of the Science and Future Perspectives

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    In the past two decades, increased production and usage of metallic nanoparticles (NPs) has inevitably increased their discharge into the different compartments of the environment, which ultimately paved the way for their uptake and accumulation in various trophic levels of the food chain. Due to these issues, several questions have been raised on the usage of NPs in everyday life and has become a matter of public health concern. Among the metallic NPs, Cu-based NPs have gained popularity due to their cost-effectiveness and multifarious promising uses. Several studies in the past represented the phytotoxicity of Cu-based NPs on plants. However, comprehensive knowledge is still lacking. Additionally, the impact of Cu-based NPs on soil organisms such as agriculturally important microbes, fungi, mycorrhiza, nematode, and earthworms are poorly studied. This review article critically analyses the literature data to achieve a more comprehensive knowledge on the toxicological profile of Cu-based NPs and increase our understanding of the effects of Cu-based NPs on aquatic and terrestrial plants as well as on soil microbial communities. The underlying mechanism of biotransformation of Cu-based NPs and the process of their penetration into plants has also been discussed herein. Overall, this review could provide valuable information to design rules and regulations for the safe disposal of Cu-based NPs into a sustainable environment

    THE ABILITY OF WATER TREATMENT RESIDUALS TO FILTER RHODAMINE-COATED MICROPARTICLES AS PATHOGEN PROXIES AT DIFFERENT IONIC STRENGTH AND PH LEVELS

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    Contamination of water by pathogens such as bacteria, viruses, and protozoa is a worldwide problem and the most common source of these contaminants is point sources from cattle enterprises. Water treatment residuals (WTRs), a byproduct of surface water treatment for drinking, were studied for their ability to filter contaminants through column flow experiments. WTRs are good candidates for filtration devices due to their high clay content, and resulting high numbers of sorption sites. The WTR used in this study are composed primarily of kaolinite clay. Quartz sand is widely used as a filtration medium, and was used as a control in this study. Sand and WTRs were filtered at size-60 mesh to remove fine particles. Rhodamine-coated microparticles (RMPs) were sent through column flow experiments as proxies for pathogens such as large bacteria such as Salmonella enterica and small protozoa such as Cryptosporidium because they are of similar size, and can be easily measured with through fluorimetry. WTRs filter RMPs primarily through sorption and/or straining. Column flow experiments are being run to test WTR filtering ability under varying solution chemistry at two different pH levels (5 and 7.6) and two different ionic strengths (3 mM and 15 mM) representative of environmental conditions found in Georgia. The pH and ionic strength changes alter the surface charge environment and potentially sorption of RMPs onto WTRs and quartz sand. A conservative chlorine tracer was used for comparison. Preliminary data shows WTRs had a small retardant effect on the RMP compared to the normal flow of water through the column, but also had created preferential flow and moved RMPs through the column more quickly. The different combinations of pH and ionic strength have not yet appeared to have any significant difference on the retardation of the RMP

    Cytological studies of recombination in rhesus males

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    An immunofluorescence approach was used to directly examine meiotic recombination events in 483 pachytene spermatocytes from 11 male rhesus monkeys. Specifically, we examined the nuclear localization patterns of the DNA mismatch repair protein MLH1, known from analyses of other mammalian species to be a useful marker of meiotic cross-overs. Our results indicated that rhesus pachytene spermatocytes contain approximately 40 cross-overs per cell, corresponding to about one cross-over per chromosome. The chromosomal distribution of these exchanges was consistent with data from human and mouse males but, surprisingly, the overall number of foci was lower, and the number of ‘exchangeless’ bivalents higher, than reported for either humans or mice

    National Board Certified Teachers andTheir Students' Achievement

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    Contemporary research on teaching indicates that teachers are powerful contributors to students’ academic achievement, though the set and interrelationships of characteristics that make for high-quality and effective teaching have yet to be satisfactorily determined. Nevertheless, on the basis of the extant research and a vision of exemplary teaching, the National Board for Professional Teaching Standards stipulated a definition of a superior teacher. The Board did this without empirical evidence to support their claim that teachers’ who meet the standards set by the Board were superior in promoting academic achievement to those who did not meet those standards. In the 17 years since the founding of the National Board, only a few empirical studies have addressed this important issue. In this study we compare the academic performance of students in the elementary classrooms of 35 National Board Certified teachers and their non-certified peers, in 14 Arizona school districts. Board Certified teachers and their principals provide additional information about these teachers and their schools. Four years of results from the Stanford Achievement Tests in reading, mathematics and language arts, in grades three through six, were analyzed. In the 48 comparisons (four grades, four years of data, three measures of academic performance), using gain scores adjusted for students’ entering ability, the students in the classes of National Board Certified Teachers surpassed students in the classrooms of non-Board certified teachers in almost threequarters of the comparisons. Almost one-third of these differences were statistically significant. In the cases where the students of non-Board certified teachers gained more in an academic year, none of the differences found were statistically significant. Effect size, translated into grade equivalents, informs us that the gains made by students of Board Certified teachers were over one month greater than the gains made by the students of non-Board certified peer teachers. Teachers identified through the assessments of the National Board for Professional Teaching Standards are, on average, more effective teachers in terms of academic achievement, one of the many outcomes of education for which teachers are responsible. This study does not address whether other, cheaper, or better alternatives to the National Boards exist, as some critics suggest. On the other hand, the results of this study provide support for the policies in many states that honor and provide extra remuneration for National Board Certified Teachers
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