116 research outputs found
Exploration of Motivations for Adopting a Four-Day School Week or Year Round Calendars: Evidence from Arkansas
This brief provides an overview of the motivations for Arkansas school districts adopting a four-day school week or year-round calendar. In addition to examining these motivations, this brief provides an overview of the districts adopting non-traditional calendars and policy recommendations for districts and communities considering changing calendars
Exploration of Motivations for Adopting a Four-Day School Week or Year Round Calendars: Evidence from Arkansas
This brief provides an overview of the motivations for Arkansas school districts adopting a four-day school week or year-round calendar. In addition to examining these motivations, this brief provides an overview of the districts adopting non-traditional calendars and policy recommendations for districts and communities considering changing calendars
Correction to: Residual feed intake phenotype and gender affect the expression of key genes of the lipogenesis pathway in subcutaneous adipose tissue of beef cattle
peer-reviewedIn the original publication of this article [1], some errors in Table 4 need to be corrected as below
Residual feed intake phenotype and gender affect the expression of key genes of the lipogenesis pathway in subcutaneous adipose tissue of beef cattle
peer-reviewedBackground
Feed accounts for up to 75% of costs in beef production systems, thus any improvement in feed efficiency (FE) will benefit the profitability of this enterprise. Residual feed intake (RFI) is a measure of FE that is independent of level of production. Adipose tissue (AT) is a major endocrine organ and the primary metabolic energy reservoir. It modulates a variety of processes related to FE such as lipid metabolism and glucose homeostasis and thus measures of inter-animal variation in adiposity are frequently included in the calculation of the RFI index. The aim of this study was to determine the effect of phenotypic RFI status and gender on the expression of key candidate genes related to processes involved in energy metabolism within AT. Dry matter intake (DMI) and average daily gain (ADG) were measured over a period of 70 d for 52 purebred Simmental heifers (n = 24) and bulls (n = 28) with an initial BW±SD of 372±39.6 kg and 387±50.6 kg, respectively. Residual feed intake was calculated and animals were ranked within gender by RFI into high (inefficient; n = 9 heifers and n = 8 bulls) and low (efficient; n = 9 heifers and n = 8 bulls) groups.
Results
Average daily gain ±SD and daily DMI ±SD for heifers and bulls were 1.2±0.4 kg and 9.1±0.5 kg, and 1.8±0.3 kg and 9.5±1 kg respectively. High RFI heifers and bulls consumed 10% and 15% more (P < 0.05) than their low RFI counterparts, respectively. Heifers had a higher expression of all genes measured than bulls (P < 0.05). A gender × RFI interaction was detected for HMGCS2(P < 0.05) in which high RFI bulls tended to have lower expression of HMGCS2 than low RFI bulls (P < 0.1), whereas high RFI heifers had higher expression than low RFI heifers (P < 0.05) and high RFI bulls (P < 0.05). SLC2A4 expression was consistently higher in subcutaneous AT of low RFI animals across gender.
Conclusion
The findings of this study indicate that low RFI cattle exhibit upregulation of the molecular mechanisms governing glucose metabolism in adipose tissue, in particular, glucose clearance. The decreased expression of SLC2A4 in the inefficient cattle may result in less efficient glucose metabolism in these animals. We conclude that SLC2A4 may be a potential biomarker for RFI in cattle
Recombination Hotspots and Population Structure in Plasmodium falciparum
Understanding the influences of population structure, selection, and recombination on polymorphism and linkage disequilibrium (LD) is integral to mapping genes contributing to drug resistance or virulence in Plasmodium falciparum. The parasite's short generation time, coupled with a high cross-over rate, can cause rapid LD break-down. However, observations of low genetic variation have led to suggestions of effective clonality: selfing, population admixture, and selection may preserve LD in populations. Indeed, extensive LD surrounding drug-resistant genes has been observed, indicating that recombination and selection play important roles in shaping recent parasite genome evolution. These studies, however, provide only limited information about haplotype variation at local scales. Here we describe the first (to our knowledge) chromosome-wide SNP haplotype and population recombination maps for a global collection of malaria parasites, including the 3D7 isolate, whose genome has been sequenced previously. The parasites are clustered according to continental origin, but alternative groupings were obtained using SNPs at 37 putative transporter genes that are potentially under selection. Geographic isolation and highly variable multiple infection rates are the major factors affecting haplotype structure. Variation in effective recombination rates is high, both among populations and along the chromosome, with recombination hotspots conserved among populations at chromosome ends. This study supports the feasibility of genome-wide association studies in some parasite populations
Blood immune transcriptome analysis of artificially fed dairy calves and naturally suckled beef calves from birth to 7 days of age
peer-reviewedNeonatal calves possess a very immature and naïve immune system and are reliant on the intake of maternal colostrum for passive transfer of immunoglobulins. Variation in colostrum management of beef and dairy calves is thought to affect early immune development. Therefore, the objective of this study was to examine changes in gene expression and investigate molecular pathways involved in the immune-competence development of neonatal Holstein dairy calves and naturally suckled beef calves using next generation RNA-sequencing during the first week of life. Jugular whole blood samples were collected from Holstein (H) dairy calves (n = 8) artificially fed 5% B.W. colostrum, and from beef calves which were the progenies of Charolais-Limousin (CL; n = 7) and Limousin-Friesian beef suckler cows (LF; n = 7), for subsequent RNA isolation. In dairy calves, there was a surge in pro-inflammatory cytokine gene expression possibly due to the stress of separation from the dam. LF calves exhibited early signs of humoral immune development with observed increases in the expression genes coding for Ig receptors, which was not evident in the other breeds by 7 days of age. Immune and health related DEGs identified as upregulated in beef calves are prospective contender genes for the classification of biomarkers for immune-competence development, and will contribute towards a greater understanding of the development of an immune response in neonatal calves
Distinct Streptococcus pneumoniae cause invasive disease in Papua New Guinea
Streptococcus pneumoniae is a key contributor to childhood morbidity and mortality in Papua New Guinea (PNG). For the first time, whole genome sequencing of 174 isolates has enabled detailed characterisation of diverse S. pneumoniae causing invasive disease in young children in PNG, 1989-2014. This study captures the baseline S. pneumoniae population prior to the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) into the national childhood immunisation programme in 2014. Relationships amongst lineages, serotypes and antimicrobial resistance traits were characterised, and the population was viewed in the context of a global collection of isolates. The analyses highlighted adiverse S. pneumoniae population associated with invasive disease in PNG, with 45 unique Global Pneumococcal Sequence Clusters (GPSCs) observed amongst the 174 isolates reflecting multiple lineages observed in PNG that have not been identified in other geographic locations. The majority of isolates were from children with meningitis, of which 52% (n=72) expressed non-PCV13 serotypes. Over a third of isolates were predicted to be resistant to at least one antimicrobial. PCV13 serotype isolates had 10.1 times the odds of being multidrug-resistant (MDR) compared to non-vaccine serotype isolates, and no isolates with GPSCs unique to PNG were MDR. Serotype 2 was the most commonly identified serotype; we identified a highly clonal cluster of serotype 2 isolates unique to PNG, and a distinct second cluster indicative of long-distance transmission. Ongoing surveillance, including whole-genome sequencing, is needed to ascertain the impact of the national PCV13 programme upon the S. pneumoniae population, including serotype replacement and antimicrobial resistance traits. © 2022 The Authors
Lack of Rbl1/p107 Effects on Cell Proliferation and Maturation in the Inner Ear
Loss of postnatal mammalian auditory hair cells (HCs) is irreversible. Earlier studies have highlighted the importance of the Retinoblastoma family of proteins (pRBs) (i.e., Rb1, Rbl1/p107, and Rbl2/p130) in the auditory cells’ proliferation and emphasized our lack of information on their specific roles in the auditory system. We have previously demonstrated that lack of Rbl2/p130 moderately affects HCs’ and supporting cells’ (SCs) proliferation. Here, we present evidence supporting multiple roles for Rbl1/p107 in the developing and mature mouse organ of Corti (OC). Like other pRBs, Rbl1/p107 is expressed in the OC, particularly in the Hensen’s and Deiters’ cells. Moreover, Rbl1/p107 impacts maturation and postmitotic quiescence of HCs and SCs, as evidenced by enhanced numbers of these cells and the presence of dividing cells in the postnatal Rbl1/p107−/− OC. These findings were further supported by microarray and bioinformatics analyses, suggesting downregulation of several bHLH molecules, as well as activation of the Notch/Hes/Hey signaling pathway in homozygous Rbl1/p107 mutant mice. Physiological assessments and detection of ectopic HC marker expression in postnatal spiral ganglion neurons (SGNs) provided evidence for incomplete cell maturation and differentiation in Rbl1/p107−/− OC. Collectively, the present study highlights an important role for Rbl1/p107 in OC cell differentiation and maturation, which is distinct from other pRBs
Triple return on investment : the cost and impact of 13 interventions that could prevent stillbirths and save the lives of mothers and babies in South Africa
BACKGROUND : The time of labor, birth and the first days of life are the most vulnerable period for mothers and
children. Despite significant global advocacy, there is insufficient understanding of the investment required to save
additional lives. In particular, stillbirths have been neglected. Over 20 000 stillbirths are recorded annually in South
Africa, many of which could be averted. This analysis examines available South Africa specific stillbirth data and
evaluates the impact and cost-effectiveness of 13 interventions acknowledged to prevent stillbirths and maternal
and newborn mortality.
METHODS : Multiple data sources were reviewed to evaluate changes in stillbirth rates since 2000. The intervention
analysis used the Lives Saved tool (LiST) and the Family Planning module (FamPlan) in Spectrum. LiST was used to
determine the number of stillbirths and maternal and neonatal deaths that could be averted by scaling up the
interventions to full coverage (99%) in 2030. The impact of family planning was assessed by increasing FamPlan’s
default 70% coverage of modern contraception to 75% and 80% coverage. Total and incremental costs were
determined in the LiST costing module. Cost-effectiveness measured incremental cost effectiveness ratios per
potential life years gained.
RESULTS: Significant variability exists in national stillbirth data. Using the international stillbirth definition, the SBR
was 17.6 per 1 000 births in 2013. Full coverage of the 13 interventions in 2030 could reduce the SBR by 30% to
12.4 per 1 000 births, leading to an MMR of 132 per 100 000 and an NMR of 7 per 1 000 live births. Increased family
planning coverage reduces the number of deaths significantly. The full intervention package, with 80% family
planning coverage in 2030, would require US7.8 per capita) annually, which is less than baseline
costs of US10.2 per capita). All interventions were highly cost-effective.
CONCLUSION : This is the first analysis in South Africa to assess the impact of scaling up interventions to avert stillbirths.
Improved coverage of 13 interventions that are already recommended could significantly impact the rates of stillbirth
and maternal and neonatal mortality. Family planning should also be prioritized to reduce mortality and overall costs.http://www.biomedcentral.com/bmcpregnancychildbirtham201
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