403 research outputs found
Morale of Educators Amidst a Pandemic: A Heuristic Phenomenological Inquiry
This heuristic phenomenological qualitative research study aimed to understand the educators\u27 perceptions of their lived experience teaching during the COVID-19 pandemic and its effect on teacher morale in the U.S. The theory guiding this study is Narrative Identity Theory, in which Dan McAdams proposed the first full theoretical model. This theory contributed significant awareness to the phenomenon studied when trying to understand the evaluative and emotional meaning expressed through the stories of the teachers. The essence of morale is understood more holistically considering the contribution of Narrative Identity Theory. Data was collected through online interviews on Microsoft Teams and analyzed using NVIVO to create codes and themes
Improving Observation, Assessment, And Management Of Atlantic Coastal Sharks
Coastal sharks represent a group of stocks for which observation, assessment, and management are particularly challenging. Large distributional ranges, complex migratory behavior, low economic value, and relatively few observations in fishery independent surveys hinder relative abundance estimation. Assessing stock status of coastal sharks is encumbered by limited data availability, data quality, and knowledge of life history strategy. Further, coastal sharks are challenging to manage due to their slow intrinsic population growth rates, competing stakeholder interests, history of overexploitation, and in some cases, subjection to international exploitation. This dissertation aimed to improve the capacity to observe relative abundance of coastal sharks. Because a comprehensive survey is unavailable across the full distribution of coastal shark species in the southeast United States, several spatially-limited surveys are conducted, each assumed to represent an independent measure of relative abundance. When compiled, these indices of abundance regularly conflict, obscuring the true trend in stock abundance and potentially biasing estimates of stock status from stock assessments. Using age-structured simulations for Atlantic sharpnose and sandbar sharks, we tested whether dynamic factor analysis (DFA) is an appropriate statistical approach to reconcile conflicting survey indices. The resulting DFA trends were then input into a stock assessment model and results were compared to those generated from inputting conflicting indices into a corresponding assessment model. DFA proved useful in clarifying underlying patterns in stock abundance when the stock abundance exhibited sufficient contrast, and DFA trends were shown to produce more consistent (precise) assessment results. This dissertation serves to improve the capacity to observe patterns in relative abundance over time and likewise expand the toolbox for coastal shark stock assessments. Fishery management procedures (MPs) are pre-agreed upon frameworks designed to manage a stock and typically include information on how the stock is monitored, assessed, how stock status will alter management regulations (‘harvest control rule;’ HCR), and how the management regulations will be applied to the stock. No MP has been developed for coastal sharks in the United States. Consequently, we examined the impact of various HCR parameterizations and stock assessment frequency for the large coastal sandbar shark using a simulation approach termed management strategy evaluation. Notably, sandbar sharks are subjected to unregulated, international removals by Mexico, and the level of future Mexican removals was found to have a significant impact on the ability of the sandbar shark to recover. Trade-offs in management objectives with respect to various parameterizations of the harvest control rule were presented. Further, the frequency of stock assessments had a relatively small impact on the management objectives of the sandbar shark fishery. Through management strategy evaluation, international removals were identified as a potential barrier to sandbar shark recovery. Further, the vast resources required to undergo more numerous stock assessments could be potentially alleviated by reduction of future large coastal shark assessment frequency without compromising management success
Principles to Guide the Office of Legal Counsel
Former members of Office of Legal Counsel ( OLC ) in the Department of Justice offer guidance for their successors. Among the document\u27s recommendations are suggestions that the OLC provide an accurate and honest appraisal of applicable law, even if that advice will constrain the administration’s pursuit of desired policies; and publicly disclose its written legal opinions in a timely manner, absent strong reasons for delay or nondisclosure
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The Spitzer c2d Survey Of Nearby Dense Cores. X. Star Formation In L673 And Cb188
L673 and CB188 are two low-mass clouds isolated from large star-forming regions that were observed as part of the Spitzer Legacy Project "From Molecular Clouds to Planet Forming disks" (c2d). We identified and characterized all the young stellar objects (YSOs) of these two regions and modeled their spectral energy distributions (SEDs) to examine whether their physical properties are consistent with values predicted from the theoretical models and with the YSO properties in the c2d survey of larger clouds. Overall, 30 YSO candidates were identified by the c2d photometric criteria, 27 in L673 and 3 in CB188. We confirm the YSO nature of 29 of them and remove a false Class III candidate in L673. We further present the discovery of two new YSO candidates, one Class 0 and another possible Class I candidate in L673, therefore bringing the total number of YSO candidates to 31. Multiple sites of star formation are present within L673, closely resembling other well-studied c2d clouds containing small groups such as B59 and L1251B, whereas CB188 seems to consist of only one isolated globule-like core. We measure a star formation efficiency (SFE) of 4.6%, which resembles the SFE of the larger c2d clouds. From the SED modeling of our YSO sample we obtain envelope masses for Class I and Flat spectrum sources of 0.01-1.0 M-circle dot. The majority of Class II YSOs show disk accretion rates from 3.3 x 10(-10) to 3 x 10(-8) M-circle dot yr(-1) and disk masses that peak at 10(-4) to 10(-3) M-circle dot. Finally, we examined the possibility of thermal fragmentation in L673 as the main star-forming process. We find that the mean density of the regions where significant YSO clustering occurs is of the order of similar to 10(5) cm(-3) using 850 mu m observations and measure a Jeans Length that is greater than the near-neighbor YSO separations by approximately a factor of 3-4. We therefore suggest that other processes, such as turbulence and shock waves, may have had a significant effect on the cloud's filamentary structure and YSO clustering.University of SouthamptonNASA 1279198, 1288806, 1365763Jet Propulsion Laboratory, California Institute of TechnologyAstronom
A First Look at the Auriga-California Giant Molecular Cloud With Herschel and the CSO: Census of the Young Stellar Objects and the Dense Gas
We have mapped the Auriga/California molecular cloud with the Herschel PACS
and SPIRE cameras and the Bolocam 1.1 mm camera on the Caltech Submillimeter
Observatory (CSO) with the eventual goal of quantifying the star formation and
cloud structure in this Giant Molecular Cloud (GMC) that is comparable in size
and mass to the Orion GMC, but which appears to be forming far fewer stars. We
have tabulated 60 compact 70/160um sources that are likely pre-main-sequence
objects and correlated those with Spitzer and WISE mid-IR sources. At 1.1 mm we
find 18 cold, compact sources and discuss their properties. The most important
result from this part of our study is that we find a modest number of
additional compact young objects beyond those identified at shorter wavelengths
with Spitzer. We also describe the dust column density and temperature
structure derived from our photometric maps. The column density peaks at a few
x 10^22 cm^-2 (N_H2) and is distributed in a clear filamentary structure along
which nearly all the pre-main-sequence objects are found. We compare the YSO
surface density to the gas column density and find a strong non-linear
correlation between them. The dust temperature in the densest parts of the
filaments drops to ~10K from values ~ 14--15K in the low density parts of the
cloud. We also derive the cumulative mass fraction and probability density
function of material in the cloud which we compare with similar data on other
star-forming clouds.Comment: in press Astrophysical Journal, 201
Generation of orthotopic patient-derived xenografts from gastrointestinal stromal tumor.
BackgroundGastrointestinal stromal tumor (GIST) is the most common sarcoma and its treatment with imatinib has served as the paradigm for developing targeted anti-cancer therapies. Despite this success, imatinib-resistance has emerged as a major problem and therefore, the clinical efficacy of other drugs has been investigated. Unfortunately, most clinical trials have failed to identify efficacious drugs despite promising in vitro data and pathological responses in subcutaneous xenografts. We hypothesized that it was feasible to develop orthotopic patient-derived xenografts (PDXs) from resected GIST that could recapitulate the genetic heterogeneity and biology of the human disease.MethodsFresh tumor tissue from three patients with pathologically confirmed GISTs was obtained immediately following tumor resection. Tumor fragments (4.2-mm3) were surgically xenografted into the liver, gastric wall, renal capsule, and pancreas of immunodeficient mice. Tumor growth was serially assessed with ultrasonography (US) every 3-4 weeks. Tumors were also evaluated with positron emission tomography (PET). Animals were sacrificed when they became moribund or their tumors reached a threshold size of 2500-mm3. Tumors were subsequently passaged, as well as immunohistochemically and histologically analyzed.ResultsHerein, we describe the first model for generating orthotopic GIST PDXs. We have successfully xenografted three unique KIT-mutated tumors into a total of 25 mice with an overall success rate of 84% (21/25). We serially followed tumor growth with US to describe the natural history of PDX growth. Successful PDXs resulted in 12 primary xenografts in NOD-scid gamma or NOD-scid mice while subsequent successful passages resulted in 9 tumors. At a median of 7.9 weeks (range 2.9-33.1 weeks), tumor size averaged 473 ± 695-mm³ (median 199-mm3, range 12.6-2682.5-mm³) by US. Furthermore, tumor size on US within 14 days of death correlated with gross tumor size on necropsy. We also demonstrated that these tumors are FDG-avid on PET imaging, while immunohistochemically and histologically the PDXs resembled the primary tumors.ConclusionsWe report the first orthotopic model of human GIST using patient-derived tumor tissue. This novel, reproducible in vivo model of human GIST may enhance the study of GIST biology, biomarkers, personalized cancer treatments, and provide a preclinical platform to evaluate new therapeutic agents for GIST
Relationship of national institutes of health stroke scale to 30-day mortality in medicare beneficiaries with acute ischemic stroke.
BackgroundThe National Institutes of Health Stroke Scale (NIHSS), a well-validated tool for assessing initial stroke severity, has previously been shown to be associated with mortality in acute ischemic stroke. However, the relationship, optimal categorization, and risk discrimination with the NIHSS for predicting 30-day mortality among Medicare beneficiaries with acute ischemic stroke has not been well studied.Methods and resultsWe analyzed data from 33102 fee-for-service Medicare beneficiaries treated at 404 Get With The Guidelines-Stroke hospitals between April 2003 and December 2006 with NIHSS documented. The 30-day mortality rate by NIHSS as a continuous variable and by risk-tree determined or prespecified categories were analyzed, with discrimination of risk quantified by the c-statistic. In this cohort, mean age was 79.0 years and 58% were female. The median NIHSS score was 5 (25th to 75th percentile 2 to 12). There were 4496 deaths in the first 30 days (13.6%). There was a strong graded relation between increasing NIHSS score and higher 30-day mortality. The 30-day mortality rates for acute ischemic stroke by NIHSS categories were as follows: 0 to 7, 4.2%; 8 to 13, 13.9%; 14 to 21, 31.6%; 22 to 42, 53.5%. A model with NIHSS alone provided excellent discrimination whether included as a continuous variable (c-statistic 0.82 [0.81 to 0.83]), 4 categories (c-statistic 0.80 [0.79 to 0.80]), or 3 categories (c-statistic 0.79 [0.78 to 0.79]).ConclusionsThe NIHSS provides substantial prognostic information regarding 30-day mortality risk in Medicare beneficiaries with acute ischemic stroke. This index of stroke severity is a very strong discriminator of mortality risk, even in the absence of other clinical information, whether used as a continuous or categorical risk determinant. (J Am Heart Assoc. 2012;1:42-50.)
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A microRNA cluster in the Fragile-X region expressed during spermatogenesis targets FMR1.
Testis-expressed X-linked genes typically evolve rapidly. Here, we report on a testis-expressed X-linked microRNA (miRNA) cluster that despite rapid alterations in sequence has retained its position in the Fragile-X region of the X chromosome in placental mammals. Surprisingly, the miRNAs encoded by this cluster (Fx-mir) have a predilection for targeting the immediately adjacent gene, Fmr1, an unexpected finding given that miRNAs usually act in trans, not in cis Robust repression of Fmr1 is conferred by combinations of Fx-mir miRNAs induced in Sertoli cells (SCs) during postnatal development when they terminate proliferation. Physiological significance is suggested by the finding that FMRP, the protein product of Fmr1, is downregulated when Fx-mir miRNAs are induced, and that FMRP loss causes SC hyperproliferation and spermatogenic defects. Fx-mir miRNAs not only regulate the expression of FMRP, but also regulate the expression of eIF4E and CYFIP1, which together with FMRP form a translational regulatory complex. Our results support a model in which Fx-mir family members act cooperatively to regulate the translation of batteries of mRNAs in a developmentally regulated manner in SCs
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Phase identifications in crud from commercial boiling-water reactors at the Idaho National Laboratory by transmission electron microscopy
Summarizes results of two studies of "crud" at the INL. All data is from INL/EXT-06-11742 and INL/JOU-06-11507 and has been previously released for publication
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Design of the PACIFIC study: A randomized controlled trial evaluating a novel treatment for adults with overweight and obesity.
The majority of adults in the United States have overweight or obesity which is associated with significant health and psychological consequences. Behavioral Weight Loss (BWL) is the current gold-standard weight-loss program for adults but recidivism rates continue to be disturbingly high. Given the health consequences of excess weight and the lack of long-term effectiveness of BWL, it is important to identify novel weight-loss programs. We developed the ROC (Regulation of Cues) program to reduce overeating through improvement in sensitivity to appetitive cues and decreased responsivity to external food cues. This study is a 4-arm randomized control trial designed to evaluate the efficacy of ROC, ROC combined with BWL, BWL alone and an active comparator over 24 months. Study recruitment completed in November 2017. Two hundred and seventy-one participants were randomized (mean age = 46.97 years; 82% female, mean BMI = 34.59; 20% Hispanic) and assessments were conducted at baseline, mid-treatment (6 months) and post-treatment (12 months). At this time, participants are completing 6- (18 months) and 12-month (24 months) follow-ups. Targeting novel mechanisms is critically important to improve weight-loss programs. Through this trial, we hope to identify treatments for adults with overweight and obesity to facilitate long-term weight loss and improved health
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