167 research outputs found
Perceptions Of Adult-Child Collaboration In Toddler Environments In A Midwestern Montessori School
The purpose of this study was to investigate adult perceptions of adult-child collaboration in two Montessori toddler environments and how it affects language, independence, and social interaction development. The study took place in one Midwestern Montessori school. The study was conducted on perceptions of adult-child collaboration through an electronic survey and intensive interviews. Five Montessori toddler assistants took the survey and two Montessori toddler guides completed intensive interviews. Once data were collected, qualitative theory methods were utilized to code, evaluate, and analyze all data. After data were re-analyzed, new theories and insights emerged surrounding how adult-child collaboration in a Montessori toddler environment affects language, independence, and social interaction development
Echinacea and Preterm Labor: A Natural Remedy
Causally, premature births largely result from inflammation and current treatments are either unsafe or ineffective. Here, our goal was to test whether the use of natural products [Echinacea purpurea (L.) Moench, root extract] with anti-bacterial and -inflammatory activities and a long history of safe use could attenuate induction of inflammation in the cervix (birth canal). Studies using three different complementary models, specifically non-pregnant in vivo, non-pregnant ex vivo and preterm labor models, were conducted. We also sought to decipher mechanisms likely to mediate Echinacea’s anti-inflammatory activities by blocking the activity of heme-oxygenase-1 (HO-1). Tissues were harvested and evaluated using real time-PCR, Western blot and/or histology. Here, we compare the suitability of the three models and show that Echinacea attenuates levels of the activated (phosphorylated) master inflammation transcription factor, nuclear factor kappa B (NF?B), and expression of select pro-inflammatory cytokines associated with inflammation-induced preterm labor. We also show that HO-1 may mediate Echinacea’s anti-inflammatory activities in the cervix. These findings are significant as they provide important data that could potentially lead to the development of natural strategies for modulating infection-induced preterm labor
Peptides encoded by short ORFs control development and define a new eukaryotic gene family
Despite recent advances in developmental biology and in genomics, key questions remain regarding the organisation of cells into embryos. One possibility is that novel types of genes might await discovery and could provide some of the answers. Genome annotation depends strongly on comparison with previously known gene sequences, and so genes having previously uncharacterised structure and function can be missed. Here we present the characterisation of tarsal-less, a new such type of gene. Tarsal-less has two unusual features: first, it contains more than one coding unit, a structure more similar to some bacterial genes. Second, it codes for small peptides rather than proteins, and in fact these peptides represent the smallest gene products known to date. Functional analysis of this gene in the fruitfly Drosophila shows that it has important functions throughout development, including tissue morphogenesis and pattern formation. We identify genes similar to tarsal-less in other species, and thus define a tarsal-less-related gene family. We expect that a combination of bioinformatic and functional methods, such as the ones we use in this study, will identify and characterize more genes of this type. Potentially, thousands of such new genes may exist
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Altered distribution of mucosal NK cells during HIV infection
The human gut mucosa is a major site of HIV infection and infection-associated pathogenesis. Increasing evidence shows that natural killer (NK) cells play an important role in control of HIV infection but the mechanism(s) by which they mediate antiviral activity in the gut is unclear. Here we show two distinct subsets of NK cells exist in the gut, one localized to intraepithelial spaces (IEL) and the other to the lamina propria (LP). The frequency of both subsets of NK cells was reduced in chronic infection, whereas IEL NK cells remained stable in spontaneous controllers with protective KIR/HLA genotypes. Both IEL and LP NK cells were significantly expanded in immunologic non-responsive (INR) patients, who incompletely recovered CD4+ T cells on HAART. These data suggest that both IEL and LP NK cells may expand in the gut in an effort to compensate for compromised CD4+ T cell recovery, but that only IEL NK cells may be involved in providing durable control of HIV in the gut
Protective Antigens Against Glanders Identified by Expression Library Immunization
Burkholderia are highly evolved Gram-negative bacteria that primarily infect solipeds but are transmitted to humans by ingestion and cutaneous or aerosol exposures. Heightened concern over human infections of Burkholderia mallei and the very closely related species B. pseudomallei is due to the pathogens’ proven effectiveness as bioweapons, and to the increased potential for natural opportunistic infections in the growing diabetic and immuno-compromised populations. These Burkholderia species are nearly impervious to antibiotic treatments and no vaccine exists. In this study, the genome of the highly virulent B. mallei ATCC23344 strain was examined by expression library immunization for gene-encoded protective antigens. This protocol for genomic-scale functional screening was customized to accommodate the unusually large complexity of Burkholderia, and yielded 12 new putative vaccine candidates. Five of the candidates were individually tested as protein immunogens and three were found to confer significant partial protection against a lethal pulmonary infection in a murine model of disease. Determinations of peripheral blood cytokine and chemokine profiles following individual protein immunizations show that interleukin-2 (IL-2) and IL-4 are elicited by the three confirmed candidates, but unexpectedly interferon-γ and tumor necrosis factor-α are not. We suggest that these pathogen components, discovered using genetic immunization and confirmed in a conventional protein format, will be useful toward the development of a safe and effective glanders vaccine
Norwalk Virus–specific Binding to Oyster Digestive Tissues
Specific binding of virus to oysters can selectively concentrate a human pathogen
Ventricular pacing or dual-chamber pacing for sinus-node dysfunction
BACKGROUND
Dual-chamber (atrioventricular) and single-chamber (ventricular) pacing are alternative treatment approaches for sinus-node dysfunction that causes clinically significant bradycardia. However, it is unknown which type of pacing results in the better outcome. METHODS
We randomly assigned a total of 2010 patients with sinus-node dysfunction to dual-chamber pacing (1014 patients) or ventricular pacing (996 patients) and followed them for a median of 33.1 months. The primary end point was death from any cause or nonfatal stroke. Secondary end points included the composite of death, stroke, or hospitalization for heart failure; atrial fibrillation; heart-failure score; the pacemaker syndrome; and the quality of life. RESULTS
The incidence of the primary end point did not differ significantly between the dual-chamber group (21.5 percent) and the ventricular-paced group (23.0 percent, P=0.48). In patients assigned to dual-chamber pacing, the risk of atrial fibrillation was lower (hazard ratio, 0.79; 95 percent confidence interval, 0.66 to 0.94; P=0.008), and heart-failure scores were better (P CONCLUSIONS
In sinus-node dysfunction, dual-chamber pacing does not improve stroke-free survival, as compared with ventricular pacing. However, dual-chamber pacing reduces the risk of atrial fibrillation, reduces signs and symptoms of heart failure, and slightly improves the quality of life. Overall, dual-chamber pacing offers significant improvement as compared with ventricular pacing
Bias and Evolution of the Mutationally Accessible Phenotypic Space in a Developmental System
Genetic and developmental architecture may bias the mutationally available phenotypic spectrum. Although such asymmetries in the introduction of variation may influence possible evolutionary trajectories, we lack quantitative characterization of biases in mutationally inducible phenotypic variation, their genotype-dependence, and their underlying molecular and developmental causes. Here we quantify the mutationally accessible phenotypic spectrum of the vulval developmental system using mutation accumulation (MA) lines derived from four wild isolates of the nematodes Caenorhabditis elegans and C. briggsae. The results confirm that on average, spontaneous mutations degrade developmental precision, with MA lines showing a low, yet consistently increased, proportion of developmental defects and variants. This result indicates strong purifying selection acting to maintain an invariant vulval phenotype. Both developmental system and genotype significantly bias the spectrum of mutationally inducible phenotypic variants. First, irrespective of genotype, there is a developmental bias, such that certain phenotypic variants are commonly induced by MA, while others are very rarely or never induced. Second, we found that both the degree and spectrum of mutationally accessible phenotypic variation are genotype-dependent. Overall, C. briggsae MA lines exhibited a two-fold higher decline in precision than the C. elegans MA lines. Moreover, the propensity to generate specific developmental variants depended on the genetic background. We show that such genotype-specific developmental biases are likely due to cryptic quantitative variation in activities of underlying molecular cascades. This analysis allowed us to identify the mutationally most sensitive elements of the vulval developmental system, which may indicate axes of potential evolutionary variation. Consistent with this scenario, we found that evolutionary trends in the vulval system concern the phenotypic characters that are most easily affected by mutation. This study provides an empirical assessment of developmental bias and the evolution of mutationally accessible phenotypes and supports the notion that such bias may influence the directions of evolutionary change
Using codes of ethics for disabled children who communicate non-verbally - some challenges and implications for social workers
This is an Accepted Manuscript of an article published by Taylor & Francis in Ethics and Social Welfare on 09/02/2018, available online: http://www.tandfonline.com/doi/full/10.1080/17496535.2018.1430159This article evaluates the use of professional codes of ethics by social workers specialising in work with disabled children who communicate non-verbally. It draws upon phenomenological interviews and other studies to highlight challenges faced by practitioners in a complex role which demands high-levels of skills and knowledge. Supporting other research, codes of ethics were rarely utilised by practitioners who typically maintain a vague appreciation while often compelled to focus upon pragmatic and quick responses to a complex role. Despite this, it is argued that principle-based frameworks embedded within codes of ethics carry important political implications. These include the potential to strengthen existing utilitarian and bioethical discourses embedded in policy or dominant professional narratives, and which can at times marginalise or exclude disabled children
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Order recall in verbal short-term memory: The role of semantic networks
In their recent article, Acheson, MacDonald, and Postle (Journal of Experimental Psychology: Learning, Memory, and Cognition 37:44-59, 2011) made an important but controversial suggestion: They hypothesized that (a) semantic information has an effect on order information in short-term memory (STM) and (b) order recall in STM is based on the level of activation of items within the relevant lexico-semantic long-term memory (LTM) network. However, verbal STM research has typically led to the conclusion that factors such as semantic category have a large effect on the number of correctly recalled items, but little or no impact on order recall (Poirier & Saint-Aubin, Quarterly Journal of Experimental Psychology 48A:384-404, 1995; Saint-Aubin, Ouellette, & Poirier, Psychonomic Bulletin & Review 12:171-177, 2005; Tse, Memory 17:874-891, 2009). Moreover, most formal models of short-term order memory currently suggest a separate mechanism for order coding-that is, one that is separate from item representation and not associated with LTM lexico-semantic networks. Both of the experiments reported here tested the predictions that we derived from Acheson et al. The findings show that, as predicted, manipulations aiming to affect the activation of item representations significantly impacted order memory
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