710 research outputs found
Initial Metabolic Profiles Are Associated with 7-Day Survival among Infants Born at 22-25 Weeks of Gestation.
OBJECTIVE:To evaluate the association between early metabolic profiles combined with infant characteristics and survival past 7 days of age in infants born at 22-25 weeks of gestation. STUDY DESIGN:This nested case-control consisted of 465 singleton live births in California from 2005 to 2011 at 22-25 weeks of gestation. All infants had newborn metabolic screening data available. Data included linked birth certificate and mother and infant hospital discharge records. Mortality was derived from linked death certificates and death discharge information. Each death within 7 days was matched to 4 surviving controls by gestational age and birth weight z score category, leaving 93 cases and 372 controls. The association between explanatory variables and 7-day survival was modeled via stepwise logistic regression. Infant characteristics, 42 metabolites, and 12 metabolite ratios were considered for model inclusion. Model performance was assessed via area under the curve. RESULTS:The final model included 1 characteristic and 11 metabolites. The model demonstrated a strong association between metabolic patterns and infant survival (area under the curve [AUC] 0.885, 95% CI 0.851-0.920). Furthermore, a model with just the selected metabolites performed better (AUC 0.879, 95% CI 0.841-0.916) than a model with multiple clinical characteristics (AUC 0.685, 95% CI 0.627-0.742). CONCLUSIONS:Use of metabolomics significantly strengthens the association with 7-day survival in infants born extremely premature. Physicians may be able to use metabolic profiles at birth to refine mortality risks and inform postnatal counseling for infants born at <26 weeks of gestation
Ectopic Expression of Zmiz1 Induces Cutaneous Squamous Cell Malignancies in a Mouse Model of Cancer
Cutaneous squamous cell carcinoma (SCC) is the second most common form of cancer in the human population, yet the underlying genetic mechanisms contributing to the disease are not well understood. We recently identified Zmiz1 as a candidate oncogene in nonmelanoma skin cancer through a transposon mutagenesis screen. Here we show that transposon-induced mutations in Zmiz1 drive expression of a truncated transcript that is similar to an alternative endogenous ZMIZ1 transcript found to be overexpressed in human SCCs relative to normal skin. We also describe an original mouse model of invasive keratoacanthoma driven by skin-specific expression of the truncated Zmiz1 transcript. Unlike most mouse models, Zmiz1-induced skin tumors develop rapidly and in the absence of promoting agents such as phorbol esters. In addition, we found that the alternative Zmiz1 isoform has greater protein stability than its full-length counterpart. Finally, we provide evidence that ZMIZ1 is overexpressed in a significant percentage of human breast, ovarian, and colon cancers in addition to human SCCs, suggesting that ZMIZ1 may play a broader role in epithelial cancers
Near-Infrared Variability in Dusty White Dwarfs: Tracing the Accretion of Planetary Material
The inwards scattering of planetesimals towards white dwarfs is expected to be a stochastic process with variability on human time-scales. The planetesimals tidally disrupt at the Roche radius, producing dusty debris detectable as excess infrared emission. When sufficiently close to the white dwarf, this debris sublimates and accretes on to the white dwarf and pollutes its atmosphere. Studying this infrared emission around polluted white dwarfs can reveal how this planetary material arrives in their atmospheres. We report a near-infrared monitoring campaign of 34 white dwarfs with infrared excesses with the aim to search for variability in the dust emission. Time series photometry of these white dwarfs from the United Kingdom Infrared Telescope (Wide Field Camera) in the J, H and K bands were obtained over baselines of up to three years. We find no statistically significant variation in the dust emission in all three near-infrared bands. Specifically, we can rule out variability at ∼ 1.3% for the 13 white dwarfs brighter than 16th mag in K band, and at ∼ 10% for the 32 white dwarfs brighter than 18th mag over time-scales of three years. Although to date two white dwarfs, SDSS J095904.69−020047.6 and WD 1226+110, have shown K band variability, in our sample we see no evidence of new K band variability at these levels. One interpretation is that the tidal disruption events which lead to large variabilities are rare, occur on short time-scales
Near-infrared variability in dusty white dwarfs: tracing the accretion of planetary material
The inwards scattering of planetesimals towards white dwarfs is expected to
be a stochastic process with variability on human time-scales. The
planetesimals tidally disrupt at the Roche radius, producing dusty debris
detectable as excess infrared emission. When sufficiently close to the white
dwarf, this debris sublimates and accretes on to the white dwarf and pollutes
its atmosphere. Studying this infrared emission around polluted white dwarfs
can reveal how this planetary material arrives in their atmospheres. We report
a near-infrared monitoring campaign of 34 white dwarfs with infrared excesses
with the aim to search for variability in the dust emission. Time series
photometry of these white dwarfs from the United Kingdom Infrared Telescope
(Wide Field Camera) in the J, H and K bands were obtained over baselines of up
to three years. We find no statistically significant variation in the dust
emission in all three near-infrared bands. Specifically, we can rule out
variability at ~1.3% for the 13 white dwarfs brighter than 16th mag in K band,
and at ~10% for the 32 white dwarfs brighter than 18th mag over time-scales of
three years. Although to date two white dwarfs, SDSS J095904.69-020047.6 and WD
1226+110, have shown K band variability, in our sample we see no evidence of
new K band variability at these levels. One interpretation is that the tidal
disruption events which lead to large variabilities are rare, occur on short
time-scales, and after a few years the white dwarfs return to being stable in
the near-infrared.Comment: 14 pages + supplementary figures, 9 figures, accepted for publication
in MNRA
Calcifying algae maintain settlement cues to larval abalone following algal exposure to extreme ocean acidification
Ocean acidification (OA) increasingly threatens marine systems, and is especially harmful to calcifying organisms. One important question is whether OA will alter species interactions. Crustose coralline algae (CCA) provide space and chemical cues for larval settlement. CCA have shown strongly negative responses to OA in previous studies, including disruption of settlement cues to corals. In California, CCA provide cues for seven species of harvested, threatened, and endangered abalone. We exposed four common CCA genera and a crustose calcifying red algae, Peyssonnelia (collectively CCRA) from California to three pCO levels ranging from 419-2,013 µatm for four months. We then evaluated abalone (Haliotis rufescens) settlement under ambient conditions among the CCRA and non-algal controls that had been previously exposed to the pCO treatments. Abalone settlement and metamorphosis increased from 11% in the absence of CCRA to 45-69% when CCRA were present, with minor variation among CCRA genera. Though all CCRA genera reduced growth during exposure to increased pCO , abalone settlement was unaffected by prior CCRA exposure to increased pCO . Thus, we find no impacts of OA exposure history on CCRA provision of settlement cues. Additionally, there appears to be functional redundancy in genera of CCRA providing cues to abalone, which may further buffer OA effects
Changing the Principal Supervisor Role to Better Support Principals: Evidence from the Principal Supervisor Initiative
The principal supervisor job has traditionally revolved around administration, operations and compliance, but as principals have increasingly been called on in recent years to concentrate on supporting high-quality teaching, the idea of a complementary makeover of the supervisor job has gained attention. In 2014, with funding from The Wallace Foundation, six large school districts around the country embarked on a four-year, $24-million initiative to redesign the supervisor position so it focused primarily on supporting principals in their role as instructional leaders.This report, which looks at the final year and the effects of the Principal Supervisor Initiative, concludes that the effort succeeded in changing the job so that it centered on developing and evaluating principals to help them promote effective teaching and learning in their schools. Over the course of the initiative, principals' ratings of their supervisors' effectiveness rose from 3.88 to 4.10 on a scale of 1-to-5, a statistically significant increase. Principals reported greater frequency of supervisor practices to develop school leadership—such as helping principals with data analysis, providing them with useful feedback and working with them to assess teacher effectiveness
Bottom-up drivers of future fire regimes in western boreal North America
Forest characteristics, structure, and dynamics within the North American boreal region are heavily influenced by wildfire intensity, severity, and frequency. Increasing temperatures are likely to result in drier conditions and longer fire seasons, potentially leading to more intense and frequent fires. However, an increase in deciduous forest cover is also predicted across the region, potentially decreasing flammability. In this study, we use an individual tree-based forest model to test bottom-up (i.e. fuels) vs top-down (i.e. climate) controls on fire activity and project future forest and wildfire dynamics. The University of Virginia Forest Model Enhanced is an individual tree-based forest model that has been successfully updated and validated within the North American boreal zone. We updated the model to better characterize fire ignition and behavior in relation to litter and fire weather conditions, allowing for further interactions between vegetation, soils, fire, and climate. Model output following updates showed good agreement with combustion observations at individual sites within boreal Alaska and western Canada. We then applied the updated model at sites within interior Alaska and the Northwest Territories to simulate wildfire and forest response to climate change under moderate (RCP 4.5) and extreme (RCP 8.5) scenarios. Results suggest that changing climate will act to decrease biomass and increase deciduous fraction in many regions of boreal North America. These changes are accompanied by decreases in fire probability and average fire intensity, despite fuel drying, indicating a negative feedback of fuel loading on wildfire. These simulations demonstrate the importance of dynamic fuels and dynamic vegetation in predicting future forest and wildfire conditions. The vegetation and wildfire changes predicted here have implications for large-scale changes in vegetation composition, biomass, and wildfire severity across boreal North America, potentially resulting in further feedbacks to regional and even global climate and carbon cycling
Impacts of managerial systems on early educators’ job satisfaction in five countries
The work of early childhood educators is conducted in highly regulated environments in many Western nations. This is due to managerialism, the right arm of neoliberal-inspired policies. To explore educators' work within these contexts, our international study highlights the impacts of these systems on educators and the children they teach. This paper presents findings from five countries, namely, Australia, Canada, Denmark, Georgia and Italy. The results reveal the experiences of educators in these countries, impacted by neoliberal-inspired policies that are manifested in two different ways. They are dealing with increased managerial regulation or with the neglect of the sector in the pursuit of higher profits. Educators' job satisfaction is impacted when they perceive they are not able to adequately educate and support children due to these constraints. Using a critical neoliberal framework, we employed a mixed-method approach. The participants were educators with various roles and qualifications in a variety of service types. To analyse the numerical/closed answer data we used cross tabulation. Thematic analysis was used to analyse the qualitative data. Despite their difficulties, educators provided many ideas on the ways their government can better support their work so that they can focus on supporting children's learning through play. This study will be of interest to researchers, educators, policymakers and teacher educators
Bottom-Up Drivers of Future Fire Regimes in Western Boreal North America
Forest characteristics, structure, and dynamics within the North American boreal region are heavily influenced by wildfire intensity, severity, and frequency. Increasing temperatures are likely to result in drier conditions and longer fire seasons, potentially leading to more intense and frequent fires. However, an increase in deciduous forest cover is also predicted across the region, potentially decreasing flammability. In this study, we use an individual tree-based forest model to test bottom-up (i.e. fuels) vs top-down (i.e. climate) controls on fire activity and project future forest and wildfire dynamics. The University of Virginia Forest Model Enhanced is an individual tree-based forest model that has been successfully updated and validated within the North American boreal zone. We updated the model to better characterize fire ignition and behavior in relation to litter and fire weather conditions, allowing for further interactions between vegetation, soils, fire, and climate. Model output following updates showed good agreement with combustion observations at individual sites within boreal Alaska and western Canada. We then applied the updated model at sites within interior Alaska and the Northwest Territories to simulate wildfire and forest response to climate change under moderate (RCP 4.5) and extreme (RCP 8.5) scenarios. Results suggest that changing climate will act to decrease biomass and increase deciduous fraction in many regions of boreal North America. These changes are accompanied by decreases in fire probability and average fire intensity, despite fuel drying, indicating a negative feedback of fuel loading on wildfire. These simulations demonstrate the importance of dynamic fuels and dynamic vegetation in predicting future forest and wildfire conditions. The vegetation and wildfire changes predicted here have implications for large-scale changes in vegetation composition, biomass, and wildfire severity across boreal North America, potentially resulting in further feedbacks to regional and even global climate and carbon cycling
- …