2,165 research outputs found
Children facing economic hardships in the United States
This paper helps document significant improvements in the child low-income rate as well as the significant decrease in the proportion of children who relied on public assistance in the United States during the 1990s. Many disadvantaged groups of children were less likely to live in poor or low-income families in the late 1990s than such children a decade earlier. The improvement in the child low-income rates of these disadvantaged groups was accompanied by a substantial increase in parental employment. However, parental employment appears to do less to protect children from economic hardship than it did a decade earlier. This paper shows that working families’ children in many disadvantaged social groups, especially groups in medium risk ranks--children in families with parents between ages 25 to 29, with parents who only had a high-school diploma, and in father-only families--suffered the largest increase in economic hardship. Our results indicate that the increased odds of falling below low-income lines among children in working families facing multiple disadvantaged characteristics and the increased proportion of these children in various subgroups of working families in the 1990s can help explain the increased economic hardship among subgroups in the medium risk ranks listed above. Finally, the paper also notes that the official measure of poverty tends to underestimate low-income rates.bootstrap, child poverty, employment, income, low income, poverty measure, welfare reform
Prevalence and factors associated with low back pain in retired Great Britain’s Olympians:A cross-sectional study
A cross-sectional study of retired Great British Olympians (Berlin 1936 - Sochi 2014):Olympic career injuries, joint health in later life, and reasons for retirement from Olympic sport
The relationship between Olympic career sport injury and the long-term musculoskeletal health of the elite athlete remains unclear. This study describes the lifetime prevalence of medical attention injuries that occurred during training and/or competition as part of the athlete’s Olympic career, reasons for retirement from Olympic sport, and the point prevalence of pain and osteoarthritis (OA) among retired Great Britain’s (GB) Olympians
Expression of The αβ T-Cell Receptor Is Necessary for The Generation of The Thymic Medulla
The architecture of the thymus of mice that congenitally fail to express the αβ T-cell receptor
(TCRαβ) has been examined by immunohistology. In these mice, a defined mutation was
introduced into the TCRc gene by homologous recombination. By using antibodies specific
for cortical or medullary epithelium and for major histocompatibility complex antigens, the
network of cortical epithelium in these mice was shown to be essentially unaltered in
comparison with that of normal mice. In contrast, the thymic medulla was considerably
reduced in size. This analysis shows that expression of the αβ TCR but not the γδ TCR is
obligatory for establishing the thymic medulla and suggests that the growth of medullary
epithelial cells may require contact with TCRαβ-expressing cells
Cholinergic pesticides cause mushroom body neuronal inactivation in honeybees
Pesticides that target cholinergic neurotransmission are highly effective, but their use has been implicated in insect pollinator population decline. Honeybees are exposed to two widely used classes of cholinergic pesticide: neonicotinoids (nicotinic receptor agonists) and orga-nophosphate miticides (acetylcholinesterase inhibitors). Although sublethal levels of neoni-cotinoids are known to disrupt honeybee learning and behaviour, the neurophysiological basis of these effects has not been shown. Here, using recordings from mushroom body Kenyon cells in acutely isolated honeybee brain, we show that the neonicotinoids imidacloprid and clothianidin, and the organophosphate miticide coumaphos oxon, cause a depolarization-block of neuronal firing and inhibit nicotinic responses. These effects are observed at concentrations that are encountered by foraging honeybees and within the hive, and are additive with combined application. Our findings demonstrate a neuronal mechanism that may account for the cognitive impairments caused by neonicotinoids, and predict that exposure to multiple pesticides that target cholinergic signalling will cause enhanced toxicity to pollinators
Bi-directional modulation of AMPA receptor unitary conductance by synaptic activity
BACKGROUND: Knowledge of how synapses alter their efficiency of communication is central to the understanding of learning and memory. The most extensively studied forms of synaptic plasticity are long-term potentiation (LTP) and its counterpart long-term depression (LTD) of AMPA receptor-mediated synaptic transmission. In the CA1 region of the hippocampus, it has been shown that LTP often involves a rapid increase in the unitary conductance of AMPA receptor channels. However, LTP can also occur in the absence of any alteration in AMPA receptor unitary conductance. In the present study we have used whole-cell dendritic recording, failures analysis and non-stationary fluctuation analysis to investigate the mechanism of depotentiation of LTP. RESULTS: We find that when LTP involves an increase in unitary conductance, subsequent depotentiation invariably involves the return of unitary conductance to pre-LTP values. In contrast, when LTP does not involve a change in unitary conductance then depotentiation also occurs in the absence of any change in unitary conductance, indicating a reduction in the number of activated receptors as the most likely mechanism. CONCLUSIONS: These data show that unitary conductance can be bi-directionally modified by synaptic activity. Furthermore, there are at least two distinct mechanisms to restore synaptic strength from a potentiated state, which depend upon the mechanism of the previous potentiation
Collecting core data in severely injured patients using a consensus trauma template: an international multicentre study
Introduction: No worldwide, standardised definitions exist for documenting, reporting and comparing data from severely injured trauma patients. This study evaluated the feasibility of collecting the data variables of the international consensus-derived Utstein Trauma Template. Methods: Trauma centres from three different continents were invited to submit Utstein Trauma Template core data during a defined period, for up to 50 consecutive trauma patients. Directly admitted patients with a New Injury Severity Score (NISS) equal to or above 16 were included. Main outcome variables were data completeness, data differences and data collection difficulty. Results: Centres from Europe (n = 20), North America (n = 3) and Australia (n = 1) submitted data on 965 patients, of whom 783 were included. Median age was 41 years (interquartile range (IQR) 24 to 60), and 73.1% were male. Median NISS was 27 (IQR 20 to 38), and blunt trauma predominated (91.1%). Of the 36 Utstein variables, 13 (36%) were collected by all participating centres. Eleven (46%) centres applied definitions of the survival outcome variable that were different from those of the template. Seventeen (71%) centres used the recommended version of the Abbreviated Injury Scale (AIS). Three variables (age, gender and AIS) were documented in all patients. Completeness > 80% was achieved for 28 variables, and 20 variables were > 90% complete. Conclusions: The Utstein Template was feasible across international trauma centres for the majority of its data variables, with the exception of certain physiological and time variables. Major differences were found in the definition of survival and in AIS coding. The current results give a clear indication of the attainability of information and may serve as a stepping-stone towards creation of a European trauma registry
A Near-Infrared Stellar Census of the Blue Compact Dwarf Galaxy VII~Zw~403
We present near-infrared single-star photometry for the low-metallicity Blue
Compact Dwarf galaxy VII~Zw~403. We achieve limiting magnitudes of
F110W~~25.5 and F160W~~24.5 using one of the NICMOS cameras
with the HST equivalents of the ground-based J and H filters. The data have a
high photometric precision (0.1 mag) and are % complete down to magnitudes
of about 23, far deeper than previous ground-based studies in the near-IR. The
color-magnitude diagram contains about 1000 point sources. We provide a
preliminary transformation of the near-IR photometry into the ground system...Comment: Accepted for publication by the AJ, preprint has 49 pages, 2 tables,
and 16 figure
Foundations for Self-Determination in Early Childhood: Preliminary Preschool Study
Foundations for self-determination begin in early childhood for children with disabilities with the onset of self-regulation and engagement in activities at home, school, and in the community. This article describes the development and preliminary results of an intervention model that encourages collaborative practices for parents and teachers around short-term goal setting to adjust environments for young children with special needs or at risk for delay. The Foundations Intervention was used with 48 children in authentic early childhood settings and involved parents, teachers, and a facilitator to enhance children’s self-regulation and engagement at home and school. Results showed feasibility of the intervention; positive child outcomes in goal attainment, self-regulation, and engagement measures were also evident. When parents and teachers communicated about a child’s strengths and needs within routines at home and school, this appeared to strengthen parent and teacher connections and helped children become more engaged or regulated in daily activities.U.S. Department of Education Grant R324A09026
High slope efficiency and high refractive index change in direct-written Yb-doped waveguide lasers with depressed claddings
We report the first Yb:ZBLAN and Yb:IOG10 waveguide lasers fabricated by the fs-laser direct-writing technique. Pulses from a Titanium-Sapphire laser oscillator with 5.1 MHz repetition rate were utilized to generate negative refractive index modifications in both glasses. Multiple modifications were aligned in a depressed cladding geometry to create a waveguide. For Yb:ZBLAN we demonstrate high laser slope efficiency of 84% with a maximum output power of 170 mW. By using Yb:IOG10 a laser performance of 25% slope efficiency and 72 mW output power was achieved and we measured a remarkably high refractive index change exceeding Δn = 2.3 × 10(-2).Guido Palmer, Simon Gross, Alexander Fuerbach, David G. Lancaster and Michael J. Withfor
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