2,684 research outputs found
Relationship Of Block Scheduling To Student Achievement And Learning Activities
Increasingly over the last several decades, school districts turn to their schedules as tools to be leveraged to increase student achievement or to better deliver their educational program. Throughout the late 20th Century and early 21st Century, the exploration of the schedule as a tool for learning quickly turned to action as great movement was made to block scheduling from the traditional schedule. As quickly as action was taken to implement block scheduling, questions arose regarding its impact on student achievement. These questions have attempted to be addressed through a significant body of research conducted over the last twenty-five years. Unfortunately, the research findings are as discrepant today as they have ever been.
This study extends the ongoing research dialogue on this topic to include a focus on the impact of the school schedule on student achievement on the Pennsylvania Keystone Exams and on the level of rigorous learning experiences that students have in the correlating classrooms. Similar to the vast body of studies conducted previously, the goal was to note any significant differences in these two areas between block and traditionally scheduled schools. Achievement data was gathered for the six participating Pennsylvania high schools over three academic years. In addition, data regarding the level of rigor experienced by students in their classrooms was gathered through interviews with the building principals in the participating schools. Schools were paired based on the similarity of their demographics and independent t-tests were conducted for the mean achievement data on each exam type. In addition, data regarding rigor was aggregated by schedule type and then an independent t-test was conducted to compare the mean rigor experienced in block or traditional classrooms as well.
This study concluded that schedule type did not yield a statistically significant difference in mean achievement scores or the level of rigor experienced by students. As a result, the researcher concluded that transformative leaders should continue to leverage the school schedule to best implement the educational program knowing that the schedule alone does not dramatically impact achievement or rigor for students
Diversity and Conservation of Butterflies in the New York City Metropolitan Area
Butterflies are charismatic microfauna that provide opportunities for humans living in urbanized landscapes to directly experience biodiversity. However, very little has been published on which butterfly species currently persist in densely populated urban landscapes, such as the New York City metropolitan area. As a first step towards conservation of butterflies in this heavily populated landscape, we analyzed data on butterfly sightings in the five boroughs of New York City and adjacent counties from January 2001 to November 2009. In total, we compiled 12,732 reported sightings (5822 from within NYC limits) representing 106 butterfly species (87 from within NYC limits) that were observed and reported by 143 observers. Important butterfly locations included large parks such as Ward Pound Ridge in Westchester County (1506 observations), Hook Mountain in Rockland County (878 observations), and Van Cortlandt Park in Bronx County (801 observations). The five most abundant butterfly species were Pieris rapae, Danaus plexippus, Colias eurytheme, Papilio glaucus, and Vanessa virginiensis. Across years, the number of species and observers remained relatively consistent, although certain species were more prevalent in specific years. Some of the species represented by only a few sightings are vagrants while others may be scarce due to the New York City metropolitan area being at the edge of their range. Additional rare butterfly species may be limited by host plant availability and/or specific habitat requirements that might be increased in parks, gardens and other urban green spaces. We provide specific management recommendations for these species and discuss future research needs for conservation of butterflies in the New York City metropolitan area
A chromatin modifying enzyme, SDG8, is involved in morphological, gene expression, and epigenetic responses to mechanical stimulation
Thigmomorphogenesis is viewed as being a response process of acclimation to short repetitive bursts of mechanical stimulation or touch. The underlying molecular mechanisms that coordinate changes in how touch signals lead to long-term morphological changes are enigmatic. Touch responsive gene expression is rapid and transient, and no transcription factor or DNA regulatory motif has been reported that could confer a genome wide mechanical stimulus. We report here on a chromatin modifying enzyme, SDG8/ASHH2, which can regulate the expression of many touch responsive genes identified in Arabidopsis. SDG8 is required for the permissive expression of touch induced genes; and the loss of function of sdg8 perturbs the maximum levels of induction on selected touch gene targets. SDG8 is required to maintain permissive H3K4 trimethylation marks surrounding the Arabidopsis touch-inducible gene TOUCH 3 (TCH3), which encodes a calmodulin-like protein (CML12). The gene neighboring was also slightly down regulated, revealing a new target for SDG8 mediated chromatin modification. Finally, sdg8 mutants show perturbed morphological response to wind-agitated mechanical stimuli, implicating an epigenetic memory-forming process in the acclimation response of thigmomorphogenesis
Upper Atmospheric Monitoring for Ares I-X Ascent Loads and Trajectory Evaluation on the Day-of-Launch
During the launch countdown of the Ares I-X test vehicle, engineers from Langley Research Center will use profiles of atmospheric density and winds in evaluating vehicle ascent loads and controllability. A schedule for the release of balloons to measure atmospheric density and winds has been developed by the Natural Environments Branch at Marshall Space Flight Center to help ensure timely evaluation of the vehicle ascent loads and controllability parameters and support a successful launch of the Ares I-X vehicle
The Metabolism and Transplacental Transfer of Oseltamivir in the Ex Vivo Human Model
Oseltamivir phosphate is extensively metabolized in the ex vivo
human placenta model, and the transplacental passage of the metabolite oseltamivir
carboxylate is incomplete. Objective. To evaluate the metabolism and transplacental transfer of oseltamivir (Tamiflu) in the ex vivo human placental model.
Study Design. Perfusion studies were performed in six placentas from term, uncomplicated deliveries. Concentrations of oseltamivir phosphate (OP) that were 5-6 fold, 20–30 fold, and 600–800 fold above the therapeutic peak were tested, as neither OP nor its active metabolite, oseltamivir carboxylate (OC),
could be detected at near-therapeutic concentrations. The transplacental transfer and accumulation of OC were
assessed using the 14C antipyrine reference method.
Results. OP was extensively metabolized to OC. In the 4 placentas with the highest concentration of OP, OC had a mean clearance index of 0.13 ± 0.08, suggesting that transplacental passage occurs at a relatively low rate. Measurable fetal accumulation occurred in the two placentas with the highest initial concentrations.
Conclusions. Oseltamivir phosphate was extensively metabolized in the ex vivo model. Transplacental transfer of the metabolite was incomplete and accumulation was minimal
Discovery of a New Transient Magnetar Candidate: XTE J1810-197
We report the discovery of a new X-ray pulsar, XTE J1810-197. The source was
serendipitously discovered on 2003 July 15 by the Rossi X-ray Timing Explorer
(RXTE) while observing the soft gamma repeater SGR 1806-20. The pulsar has a
5.54 s spin-period and a soft spectrum (photon index ~ 4). We detect the source
in earlier RXTE observations back to 2003 January. These show that a transient
outburst began between 2002 November 17 and 2003 January 23 and that the pulsar
has been spinning down since then, with a high rate Pdot ~ 10^-11 s/s showing
significant timing noise, but no evidence for Doppler shifts due to a binary
companion. The rapid spin-down rate and slow spin-period imply a super-critical
magnetic field B=3x10^14 G and a young characteristic age < 7600 yr. These
properties are strikingly similar to those of anomalous X-ray pulsars and soft
gamma repeaters, making the source a likely new magnetar. A follow-up Chandra
observation provided a 2".5 radius error circle within which the 1.5 m
Russian-Turkish Optical Telescope RTT150 found a limiting magnitude of
R_c=21.5, in accord with other recently reported limits. The source is present
in archival ASCA and ROSAT data as well, at a level 100 times fainter than the
\~ 3 mCrab seen in 2003. This suggests that other X-ray sources that are
currently in a state similar to the inactive phase of XTE J1810-197 may also be
unidentified magnetars awaiting detection via a similar activity.Comment: Submitted to ApJL; 4 pages; 4 figure
Vitamin A and zinc supplementation among pregnant women to prevent placental malaria: a randomized, double-blind, placebo-controlled trial in Tanzania
BACKGROUND: Malaria causes nearly 200 million clinical cases and approximately half a million deaths each year, primarily in sub-Saharan Africa.1 The risk of malaria increases during pregnancy,2 a period during which its prevention is especially important. Not only do pregnant women experience greater severity of illness compared with nonpregnant women,2 but studies have shown strong associations between prenatal malaria and maternal anemia,2 fetal loss, low birthweight, and infant mortality.2 Improving preventive
measures that specifically target malaria in pregnancy is a global health priority.3
METHODS: Study design and participants. This randomized, doubleblind, placebo-controlled trial was implemented at 8 antenatal care clinics in the urban Temeke and Ilala districts of Dar es Salaam, Tanzania. The trial was registered
RESULTS: A total of 2,500 screened participants were enrolled in the trial. The trial profile is shown in Figure 1. It was not possible to collect placentas from 875 participants for the following reasons: miscarriages (fetal loss before 28 weeks of gestation) (N = 234), delivery outside of Dar es Salaam or at a non-study hospital (N = 577), or withdrawal from the study (N = 34). Of the remaining 1,589 women, 1,404 placental
samples were obtained (88%); histology results were available for 1,361 participants. PCR results were available for 1,158 participants, and 1,404 participants had either histology or PCR results available.
CONCLUSION: This study is the first to examine the impact of vitamin A and zinc supplementation starting in early pregnancy on placental malaria. We observed that supplementation with 25 mg zinc per day from the first trimester until delivery was associated with a 36% (95% CI = 9–56%) reduced risk of histopathology-positive placental infection, but not PCRpositive infection. Vitamin A supplementation had no impact on placental malaria, but was associated with an increased risk for severe anemia
Factors affecting the local distribution of <i>Polystigma rubrum</i> stromata on <i>Prunus spinosa</i>
Background and aims – Polystigma rubrum forms orange-red stromata on the surface of living leaves of Prunus spinosa and P. domestica. Records suggests that this fungus now has a much more limited distribution in Britain than recorded in the 19th and early 20th century. Methods – We studied the local distribution of the fungus in the Burren Hills of western Ireland where it remains very common. Key results – Assessment of the local distribution of the fungus over two years found stromata to occur more frequently on P. spinosa leaves in hedgerows than woodlands. On individual trees in areas of open limestone pavement, the frequency of stromata was ten times higher in 2016 than 2015, possibly related to interannual rainfall differences. On hedgerow trees subjected to winter flooding, stromata were much less abundant, whereas stromata were more abundant on leaves also infected by the gall mite Eriophyes prunispinosae. The identity of Po. rubrum was confirmed by ITS sequencing.Conclusion – At a field location where Po. rubrum stromata are present in unusually high abundance, the distribution of stromata on trees in different habitats showed high levels of variation linked to both habitat and the presence of gall mites. Further work is required to determine whether variation in leaf surface and soil moisture are the key determinants of the observed distribution. Such investigations may reveal why Po. rubrum, once common in northern Europe is now restricted mainly to westerly, coastal locations
Public interest in hyaluronic acid injections for knee osteoarthritis in the United States and Europe: An international Google Trends analysis
BACKGROUND: Hyaluronic acid injections remain a common nonsurgical alternative for the treatment of knee osteoarthritis despite limited clinical evidence and varying global recommendations regarding its use. We used the Google Trends tool to provide a quantitative analysis of public interest in hyaluronic acid injections for knee osteoarthritis in the United States and Europe.
METHODS: We customized Google Trends parameters to obtain search data from January 2009 to December 2019 in both the United States and Europe. Combinations of arthritis , osteoarthritis , hyaluronic acid , knee arthritis , knee osteoarthritis , and knee injection were entered into the Google Trends tool, and trend analyses were performed.
RESULTS: The models generated to describe public interest in hyaluronic acid for knee injections in both the United States and Europe showed increased Google queries as time progressed (
CONCLUSIONS: Our results indicate a significant increase in Google queries related to hyaluronic acid injections for knee osteoarthritis since 2009 in both the United States and Europe. Our models suggest that despite mixed evidence supporting its use, orthopedic surgeons should expect continued public interest in hyaluronic acid for knee osteoarthritis. The results of our study may help to prepare surgeons for patient inquiries, inform the creation of evidence-based shared decision-making tools, and direct future research
Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference, Carlsbad, California, 2015
The third International Exercise-Associated Hyponatremia (EAH) Consensus Development Conference convened in Carlsbad, California in February 2015 with a panel of 17 international experts. The delegates represented 4 countries and 9 medical and scientific sub-specialties pertaining to athletic training, exercise physiology, sports medicine, water/sodium metabolism, and body fluid homeostasis. The primary goal of the panel was to review the existing data on EAH and update the 2008 Consensus Statement.1 This document serves to replace the second International EAH Consensus Development Conference Statement and launch an educational campaign designed to address the morbidity and mortality associated with a preventable and treatable fluid imbalance.
The following statement is a summary of the data synthesized by the 2015 EAH Consensus Panel and represents an evolution of the most current knowledge on EAH. This document will summarize the most current information on the prevalence, etiology, diagnosis, treatment and prevention of EAH for medical personnel, athletes, athletic trainers, and the greater public. The EAH Consensus Panel strove to clearly articulate what we agreed upon, did not agree upon, and did not know, including minority viewpoints that were supported by clinical experience and experimental data. Further updates will be necessary to both: (1) remain current with our understanding and (2) critically assess the effectiveness of our present recommendations. Suggestions for future research and educational strategies to reduce the incidence and prevalence of EAH are provided at the end of the document as well as areas of controversy that remain in this topic. [excerpt
- …