99 research outputs found

    Head Start Preschool Parent-Teacher Engagement and the Parent’s Transition to Kindergarten

    Get PDF
    This mixed-method study seeks to better understand the relationships that Head Start preschool teachers have with parents and how those relationships impact a parent’s transition to a public school when their child enters kindergarten. Findings revealed that parents have a deep connection to their child’s Head Start teacher, feel informed and empowered to advocate for their child’s needs. Interviews revealed that parents do not feel as connected to their child’s education in the public school. Recommendations for educators include creating more opportunities for parents to connect to the public school during the supportive Head Start school year

    Prevalence of shedding and antibody to Coxiella burnetii in post-partum dairy cows and its association with reproductive tract diseases and performance : a pilot study

    Full text link
    The bacterium Coxiella burnetii has been associated with reproduction disorders in dairy cattle. A cross-sectional study was conducted in Québec, Canada, to estimate the prevalence of C. burnetii in dairy cows from C. burnetii RT-PCR-positive and/or ELISA-positive herds. As a secondary objective, the associations between C. burnetii-positivity and three reproductive outcomes (purulent vaginal discharge, cytological endometritis, and success at first service) were assessed. A total of 202 post-parturient dairy cows from nine herds were sampled at 35 ± 7 days in milk. Vaginal mucus and composite milk were collected from each cow and screened for the presence of C. burnetii by real-time PCR (RT-PCR) and ELISA, respectively. Purulent vaginal discharge and cytological endometritis were evaluated using a Metricheck device and a modified cytobrush, respectively. The first insemination postpartum was done following an ovulation synchronization protocol around 70 days in milk, and success at first service was recorded. Multilevel logistic regressions adjusted for parity were used to model purulent vaginal discharge, cytological endometritis and success at first service according to C. burnetii cow status. All 202 RT-PCR-assayed vaginal samples were C. burnetii-negative. A positive result for anti-C. burnetii antibodies detection in composite milk was obtained in 25/202 samples and a doubtful result in 4/202 samples. After adjustment for sampling weights, the 202 ELISA-assayed composite milk samples gave an estimated overall prevalence of C. burnetii positive cows of 12.9 % (CI = 6.1–19.6 %) and of doubtful cows of 1.4 % (CI = 0.0–3.3 %). The proportion of ELISA-positive cows was lower in first parity (0%) compared to second (17.1 %) or third parity cows (20.0 %). The associations between ELISA positivity and reproductive outcomes were not statistically significant, perhaps due to the limited sample size, but could be used as pilot estimate for large-scale studies investigating the impact of C. burnetii infection on reproduction disorders in dairy cattle

    Epidemiological study of Coxiella burnetii in dairy cattle and small ruminants in Québec, Canada

    Get PDF
    The bacterium Coxiella burnetii (C. burnetii) can infect a wide range of animals, most notably ruminants where it causes mainly asymptomatic infections and, when clinical, it is associated with reproductive disorders such as abortion. It is also the etiological agent of Q fever in humans, a zoonosis of increasingly important public health concern. A cross-sectional study was performed to estimate the apparent prevalence and spatial distribution of C. burnetii positivity in dairy cattle and small ruminant herds of two regions of Québec, Canada, and identify potential risk factors associated with positivity at animal and herd levels. In dairy cattle herds, individual fecal samples and repeated bulk tank milk samples (BTM) were collected. In small ruminant herds, serum and feces were sampled in individual animals. ELISA analyses were performed on serum and BTM samples. Real-time quantitative PCR (qPCR) was done on fecal and BTM samples. An animal was considered C. burnetii-positive when at least one sample was revealed positive by ELISA and/or qPCR, while a herd was considered C. burnetii-positive when at least one animal inside that herd was revealed positive. None of the 155 cows had a qPCR-positive fecal sample, whereas 37.2 % (95 % CI = 25.3–49.1) of the 341 sheep and 49.2 % (95 % CI = 25.6–72.7) of the 75 goats were C. burnetii-positive. The apparent prevalence of C. burnetii-positive herds was 47.3 % (95 % CI = 35.6–59.3) in dairy cattle herds (n = 74), 69.6 % (95 % CI = 47.1–86.8) in sheep flocks (n = 23) and 66.7 % (95 % CI = 22.3–95.7) in goat herds (n = 6). No spatial cluster of positive herds was detected. At the individual level, the only significant association with positivity in multivariable regressions was higher parity number in small ruminants. At the herd level, the use of calving group pen, the distance to the closest positive bovine herd, and small ruminant herd density in a 5 km radius were associated with dairy cattle herd positivity, whereas small ruminant herds with more than 100 animals and with a dog on the farm had greater odds of C. burnetii positivity. Our study shows that the infection is frequent on dairy cattle and small ruminant herds from the two studied regions and that some farm and animal characteristics might influence the transmission dynamics of the C. burnetii infection

    Evolutionary Trajectories are Contingent on Mitonuclear Interactions

    Get PDF
    Critical mitochondrial functions, including cellular respiration, rely on frequently interacting components expressed from both the mitochondrial and nuclear genomes. The fitness of eukaryotic organisms depends on a tight collaboration between both genomes. In the face of an elevated rate of evolution in mtDNA, current models predict that the maintenance of mitonuclear compatibility relies on compensatory evolution of the nuclear genome. Mitonuclear interactions would therefore exert an influence on evolutionary trajectories. One prediction from this model is that the same nuclear genome evolving with different mitochondrial haplotypes would follow distinct molecular paths toward higher fitness. To test this prediction, we submitted 1,344 populations derived from 7 mitonuclear genotypes of Saccharomyces cerevisiae to >300 generations of experimental evolution in conditions that either select for a mitochondrial function or do not strictly require respiration for survival. Performing high-throughput phenotyping and whole-genome sequencing on independently evolved individuals, we identified numerous examples of gene-level evolutionary convergence among populations with the same mitonuclear background. Phenotypic and genotypic data on strains derived from this evolution experiment identify the nuclear genome and the environment as the main determinants of evolutionary divergence, but also show a modulating role for the mitochondrial genome exerted both directly and via interactions with the two other components. We finally recapitulated a subset of prominent loss-of-function alleles in the ancestral backgrounds and confirmed a generalized pattern of mitonuclear-specific and highly epistatic fitness effects. Together, these results demonstrate how mitonuclear interactions can dictate evolutionary divergence of populations with identical starting nuclear genotypes

    Correlates of coronary artery calcification prevalence and severity in patients with heterozygous familial hypercholesterolemia

    Get PDF
    Background Determinants of coronary artery calcification (CAC) prevalence and severity in heterozygous familial hypercholesterolemia (HeFH) remain understudied. The objective of this cross-sectional study was to investigate correlates of CAC in patients with HeFH. Methods A CAC score was calculated by a noncontrast computed tomography scan in women (n = 68) and men (n = 78) with genetically defined HeFH. We classified CAC prevalence and severity using 3 categories: CAC score = 0 Agatston Unit (AU), CAC score = 1-100 AU, and CAC score > 100 AU. Information on potential correlates of CAC including familial and personal health history, cardiovascular risk factors, lipid-lowering medication, and lifestyle habits was collected. Results A total of 95 patients had prevalent CAC. Independent correlates of CAC prevalence and severity included age (odds ratio [OR] per 10 years: 5.06, 95% confidence interval [CI]: 3.19, 7.93, P < 0.0001), family history of premature cardiovascular disease (OR: 3.88, 95% CI: 1.71, 8.81, P = 0.001), male sex (OR: 3.40, 95% CI: 1.49, 7.78, P = 0.004), statin use (OR: 15.5, 95% CI: 1.89, 126, P = 0.01), diet quality assessed with the Alternative Healthy Eating Index score (OR per 1 standard deviation: 0.59, 95% CI: 0.39, 0.90, P = 0.01), ever smoking (OR: 3.06, 95% CI: 1.20, 7.81, P = 0.02), receptor-negative genotype (OR: 3.17, 95% CI: 1.16, 8.66, P = 0.02), lipoprotein(a) year-score (OR per 1 standard deviation of log-transformed year-score: 1.53, 95% CI: 0.99, 2.36, P = 0.05). Conclusions In individuals with HeFH, age, family history of premature cardiovascular disease, sex, statin use, diet quality, smoking status, the LDLR genotype, and lipoprotein(a) concentrations were independently associated with CAC prevalence and severity.Contexte Les déterminants de la prévalence et de la sévérité de la calcification des artères coronaires (CAC) dans l'hypercholestérolémie familiale hétérozygote (HFHe) demeurent peu étudiés. L’objectif de cette étude transversale était d'identifier les corrélats de la CAC chez des patients atteints d’HFHe. Méthodologie Un score calcique coronarien (SCC) a été calculé par un examen de tomodensitométrie sans contraste chez des femmes (n = 68) et des hommes (n = 78) avec HFHe génétiquement définie. Nous avons classé la prévalence et la gravité de la CAC en trois catégories : SCC = 0 unité d’Agatston (UA), SCC = 1 à 100 UA et SCC > 100 UA. Des renseignements ont été recueillis sur des corrélats potentiels de la CAC, dont les antécédents médicaux familiaux et personnels, les facteurs de risque cardiovasculaire, les médicaments hypolipidémiants et les habitudes de vie. Résultats Au total, 95 patients présentaient une CAC. Les corrélats indépendants de la prévalence et de la gravité de la CAC comprenaient l’âge (rapport de cotes [RC] par tranche de 10 ans : 5,06; intervalle de confiance [IC] à 95 % : 3,19 à 7,93; p < 0,0001), des antécédents familiaux de maladie cardiovasculaire précoce (RC : 3,88; IC à 95 % : 1,71 à 8,81; p = 0,001), le sexe masculin (RC : 3,40; IC à 95 % : 1,49 à 7,78; p = 0,004), l’emploi de statines (RC : 15,5; IC à 95 % : 1,89 à 126; p = 0,01), la qualité du régime alimentaire évaluée selon le score AHEI (Alternative Healthy Eating Index) (RC par écart-type : 0,59; IC à 95 % : 0,39 à 0,90; p = 0,01), le tabagisme (RC : 3,06; IC à 95 % : 1,20 à 7,81; p = 0,02), le génotype récepteur-négatif (RC : 3,17; IC à 95 % : 1,16 à 8,66; p = 0,02) et le score lipoprotéine(a)-année (RC par écart-type du score-année transformé en logarithme : 1,53; IC à 95 % : 0,99 à 2,36; p = 0,05). Conclusions Chez les personnes atteintes d’HFHe, l’âge, les antécédents familiaux de maladie cardiovasculaire précoce, le sexe, l’emploi de statines, la qualité du régime alimentaire, le statut de tabagisme, le génotype du LDLR et les concentrations de lipoprotéine(a) ont été associés de façon indépendante à la prévalence et à la gravité de la CAC

    Prevalence of Coxiella burnetii seropositivity and shedding in farm, pet and feral cats and associated risk factors in farm cats in Quebec, Canada

    Get PDF
    Cats represent a potential source of Coxiella burnetii, the aetiological agent of Q fever in humans. The prevalence and risk factors of C. burnetii infection in farm, pet and feral cats were studied in Quebec, Canada, using a cross-sectional study. Serum samples were tested using a specific enzyme-linked immunosorbent assay (ELISA) for the presence of antibodies against C. burnetii, whereas rectal swabs were assayed using real-time quantitative polymerase chain reaction (qPCR) for the molecular detection of the bacteria. Potential risk factors for farm cats were investigated using clinical examinations, questionnaires and results from a concurrent study on C. burnetii farm status. A total of 184 cats were tested: 59 from ruminant farms, 73 pets and 52 feral cats. Among farm cats, 2/59 (3.4%) were ELISA-positive, 3/59 (5.1%) were ELISA-doubtful and 1/59 (1.7%) was qPCR-positive. All pets and feral cats were negative to C. burnetii ELISA and qPCR. Farm cat positivity was associated with a positive C. burnetii status on the ruminant farm (prevalence ratio = 7.6, P = 0.03). Our results suggest that although pet and feral cats do not seem to pose a great C. burnetii risk to public health, more active care should be taken when in contact with cats from ruminant farms

    The Fungal Cell Wall : Structure, Biosynthesis, and Function

    Get PDF
    N.G. is funded by the Wellcome Trust via a senior investigator award and a strategic award and by the MRC Centre for Medical Mycology. C.M. acknowledges the support of the Wellcome Trust and the MRC. N.G. and C.M. are part of the MRC Centre for Medical Mycology. J.P.L. acknowledges support from ANR, Aviesan, and FRM.Peer reviewedPublisher PD

    The glycosylphosphatidylinositol-linked aspartyl protease Yps1 is transcriptionally regulated by the calcineurin-Crz1 and Slt2 MAPK pathways in Candida glabrata.

    Get PDF
    In the pathogenic fungus Candida glabrata, the YPS1 gene, which encodes a glycosylphosphatidylinositol-linked aspartyl protease, is required for cell wall integrity and virulence. Although the expression of YPS1 has been studied in Saccharomyces cerevisiae, the transcriptional regulation of this gene in C. glabrata is not well understood. Here, we report that C. glabrata Yps1 is required for cell growth at elevated temperatures, and that the heat-induced expression of YPS1 is regulated predominantly by the calcineurin-Crz1 pathway and partially by the Slt2 MAPK pathway. Although a total of 11 YPS genes are present in the C. glabrata genome, the loss of transcriptional induction in a calcineurin mutant was observed only for YPS1. The results of a YPS1 promoter-lacZ reporter assay using a series of constructs with mutated promoter elements indicated that the transcription factor Crz1 binds to multiple sites in the promoter region of YPS1. To date, as none of the putative Crz1 targets in C. glabrata have been characterized using a Δcrz1 mutant, monitoring the expression of YPS1 represents an effective method for measuring the activity of the calcineurin-Crz1 signaling pathway in this fungus

    The genetic interaction network of CCW12, a Saccharomyces cerevisiae gene required for cell wall integrity during budding and formation of mating projections

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Mannoproteins construct the outer cover of the fungal cell wall. The covalently linked cell wall protein Ccw12p is an abundant mannoprotein. It is considered as crucial structural cell wall component since in baker's yeast the lack of <it>CCW12 </it>results in severe cell wall damage and reduced mating efficiency.</p> <p>Results</p> <p>In order to explore the function of <it>CCW12</it>, we performed a Synthetic Genetic Analysis (SGA) and identified genes that are essential in the absence of <it>CCW12</it>. The resulting interaction network identified 21 genes involved in cell wall integrity, chitin synthesis, cell polarity, vesicular transport and endocytosis. Among those are <it>PFD1</it>, <it>WHI3</it>, <it>SRN2</it>, <it>PAC10</it>, <it>FEN1 </it>and <it>YDR417C</it>, which have not been related to cell wall integrity before. We correlated our results with genetic interaction networks of genes involved in glucan and chitin synthesis. A core of genes essential to maintain cell integrity in response to cell wall stress was identified. In addition, we performed a large-scale transcriptional analysis and compared the transcriptional changes observed in mutant <it>ccw12</it>Δ with transcriptomes from studies investigating responses to constitutive or acute cell wall damage. We identified a set of genes that are highly induced in the majority of the mutants/conditions and are directly related to the cell wall integrity pathway and cell wall compensatory responses. Among those are <it>BCK1</it>, <it>CHS3</it>, <it>EDE1</it>, <it>PFD1</it>, <it>SLT2 </it>and <it>SLA1 </it>that were also identified in the SGA. In contrast, a specific feature of mutant <it>ccw12</it>Δ is the transcriptional repression of genes involved in mating. Physiological experiments substantiate this finding. Further, we demonstrate that Ccw12p is present at the cell periphery and highly concentrated at the presumptive budding site, around the bud, at the septum and at the tip of the mating projection.</p> <p>Conclusions</p> <p>The combination of high throughput screenings, phenotypic analyses and localization studies provides new insight into the function of Ccw12p. A compensatory response, culminating in cell wall remodelling and transport/recycling pathways is required to buffer the loss of <it>CCW12</it>. Moreover, the enrichment of Ccw12p in bud, septum and mating projection is consistent with a role of Ccw12p in preserving cell wall integrity at sites of active growth.</p> <p>The microarray data produced in this analysis have been submitted to NCBI GEO database and GSE22649 record was assigned.</p

    Detection and elimination of cellular bottlenecks in protein-producing yeasts

    Get PDF
    Yeasts are efficient cell factories and are commonly used for the production of recombinant proteins for biopharmaceutical and industrial purposes. For such products high levels of correctly folded proteins are needed, which sometimes requires improvement and engineering of the expression system. The article summarizes major breakthroughs that led to the efficient use of yeasts as production platforms and reviews bottlenecks occurring during protein production. Special focus is given to the metabolic impact of protein production. Furthermore, strategies that were shown to enhance secretion of recombinant proteins in different yeast species are presented
    corecore