4,983 research outputs found

    The potential release of phosphorus in floodplains

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    In the Illinois River Watershed, there has been growing concern over elevated phosphorus concentrations in the water column. This study evaluated how much phosphorus is contributed from floodplain soils into surface waters, examining the relationship between the flux of phosphorus released and the amount of phosphorus stored in the soil. This was investigated by artificially inundating soil cores from four sites and determining the soluble reactive phosphorus concentrations of the overlying water and the levels of Water and Mehlich-3 extractable phosphorus in the soil. The flux of phosphorus to the overlying water ranged from 0.43 to 6.61 mg m-2 hr-1 within the short-term (16.5-hr incubation) and 0.06 to 1.26 mg m-2 hr-1 over the long term (282.5-hr incubation). Phosphorus flux to the overlying water was significantly correlated with the amount of phosphorus stored in the soil. This study showed that riparian soils with elevated phosphorus content have the potential to release phosphorus when flooded

    The Common Core State Standards: How did we get here and do we even like it?

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    In 2010, the Common Core State Standards were introduced to the nation as a set of voluntary education standards. Since then, 42 states and the District of Columbia have voluntarily adopted these standards. Scholarship shows that many educational experts, parents, and politicians have voiced their opinions on the Common Core. However, there is little research on the opinions of teachers. As teachers are the ones implementing and teaching the Common Core, my research study focuses on how six educators in Rhode Island have embraced the Common Core in their classrooms. My research has found that teachers generally like the new standards as they encourage critical thinking, allow for collaboration between teachers across the country, and are more rigorous than previous state standards. However, teachers are frustrated by the continual changes to standards, as they have had to re-write curricula to new standards multiple times in the last twenty years, they generally dislike online testing, and are often frustrated by the lack of specialization in the standards for English Language learners and students with disabilities. In this thesis I will explore how we came to adopt these standards, how teachers view them, and how students have faired since the adoption

    Insulin-like growth factor-1 induces hyperproliferation of PKD1 cystic cells via a Ras/Raf dependent signalling pathway

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    Autosomal dominant polycystic kidney disease (ADPKD) largely results from mutations in the PKD1 gene leading to hyperproliferation of renal tubular epithelial cells and consequent cyst formation. Rodent models of PKD suggest that the multifunctional hormone insulin-like growth factor-1 (IGF-1) could play a pathogenic role in renal cyst formation. In order to test this possibility, conditionally immortalized renal epithelial cells were prepared from normal individuals and from ADPKD patients with known germline mutations in PKD1. All patient cell lines had a decreased or absence of polycystin-1 but not polycystin-2. These cells had an increased sensitivity to IGF-1 and to cyclic AMP, which required phosphatidylinositol-3 (PI3)-kinase and the mitogen-activated protein kinase, extracellular signal-regulated protein kinase (ERK) for enhanced growth. Inhibition of Ras or Raf abolished the stimulated cell proliferation. Our results suggest that haploinsufficiency of polycystin-1 lowers the activation threshold of the Ras/Raf signalling system leading to growth factor-induced hyperproliferation. Inhibition of Ras or Raf activity may be a therapeutic option for decreasing tubular cell proliferation in ADPKD

    Analysis of gender and gender-related implicit leadership themes in HR practitioner literature : a comparison of the United States and Brazilian HR practitioner publications.

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    Among the many factors studied in relation to the women and leadership equality gap are gender stereotypes, implicit leadership theories, and the congruity of gender role expectations (Eagly, & Karau, 2002). Multiple studies in the scholarly literature support the finding that men, rather than women, are more likely to be seen as leaders (Bierma, 2016; Eagly, & Schmidt, 2001), and this finding appears to be robust across some cultures (Schein, 2001). While the scholarly research on women and leadership has been burgeoning, few research studies have investigated how human resource (HR) practitioner literature addresses themes related to women and leadership (Hanscome, & Cervero, 2003). Human Resource processes and practitioner decisions relating to selection and promotion, development opportunities, compensation, performance management, and other employment conditions affect women’s and men’s careers. Likewise, investigating practitioner literature in the United States (U.S.), as well as other countries is a worthwhile endeavor to gain an understanding of themes relating to women and leadership cross-culturally. The purpose of this content analysis study is to investigate themes relating to women and leadership in HR practitioner literature found in the U.S. and Brazil, which has the second largest economy in the Western hemisphere. Findings and implications are explored based on scholarly literature on women and leadership and culture, and themes pertaining to implicit leadership theories and gender stereotypes, role congruity, power relations, and intersectionality

    EEG as an Indicator of Cerebral Functioning in Postanoxic Coma.

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    Postanoxic coma after cardiac arrest is one of the most serious acute cerebral conditions and a frequent cause of admission to critical care units. Given substantial improvement of outcome over the recent years, a reliable and timely assessment of clinical evolution and prognosis is essential in this context, but may be challenging. In addition to the classic neurologic examination, EEG is increasingly emerging as an important tool to assess cerebral functions noninvasively. Although targeted temperature management and related sedation may delay clinical assessment, EEG provides accurate prognostic information in the early phase of coma. Here, the most frequently encountered EEG patterns in postanoxic coma are summarized and their relations with outcome prediction are discussed. This article also addresses the influence of targeted temperature management on brain signals and the implication of the evolution of EEG patterns over time. Finally, the article ends with a view of the future prospects for EEG in postanoxic management and prognostication

    A textbook example of ram-pressure stripping in the Hydra A/A780 cluster

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    In the current epoch, one of the main mechanisms driving the growth of galaxy clusters is the continuous accretion of group-scale halos. In this process, the ram pressure applied by the hot intracluster medium on the gas content of the infalling group is responsible for stripping the gas from its dark-matter halo, which gradually leads to the virialization of the infalling gas in the potential well of the main cluster. Using deep wide-field observations of the poor cluster Hydra A/A780 with XMM-Newton and Suzaku, we report the discovery of an infalling galaxy group 1.1 Mpc south of the cluster core. The presence of a substructure is confirmed by a dynamical study of the galaxies in this region. A wake of stripped gas is trailing behind the group over a projected scale of 760 kpc. The temperature of the gas along the wake is constant at kT ~ 1.3 keV, which is about a factor of two less than the temperature of the surrounding plasma. We observe a cold front pointing westwards compared to the peak of the group, which indicates that the group is currently not moving in the direction of the main cluster, but is moving along an almost circular orbit. The overall morphology of the group bears remarkable similarities with high-resolution numerical simulations of such structures, which greatly strengthens our understanding of the ram-pressure stripping process

    The XMM Cluster Outskirts Project (X-COP): Physical conditions to the virial radius of Abell 2142

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    Context. Galaxy clusters are continuously growing through the accretion of matter in their outskirts. This process induces inhomogeneities in the gas density distribution (clumping) which need to be taken into account to recover the physical properties of the intracluster medium (ICM) at large radii. Aims. We studied the thermodynamic properties in the outskirts (R > R500) of the massive galaxy cluster Abell 2142 by combining the Sunyaev Zel'dovich (SZ) effect with the X-ray signal. Methods. We combined the SZ pressure profile measured by Planck with the XMM-Newton gas density profile to recover radial profiles of temperature, entropy and hydrostatic mass out to 2R500. We used a method that is insensitive to clumping to recover the gas density, and we compared the results with traditional X-ray measurement techniques. Results. When taking clumping into account, our joint SZ/X-ray entropy profile is consistent with the predictions from pure gravitational collapse, whereas a significant entropy flattening is found when the effect of clumping is neglected. The hydrostatic mass profile recovered using joint X-ray/SZ data agrees with that obtained from spectroscopic X-ray measurements and with mass reconstructions obtained through weak lensing and galaxy kinematics. Conclusions. We found that clumping can explain the entropy flattening observed by Suzaku in the outskirts of several clusters. When using a method insensitive to clumping for the reconstruction of the gas density, the thermodynamic properties of Abell 2142 are compatible with the assumption that the thermal gas pressure sustains gravity and that the entropy is injected at accretion shocks, with no need to evoke more exotic physics. Our results highlight the need for X-ray observations with sufficient spatial resolution, and large collecting area, to understand the processes at work in cluster outer regions.Comment: 22 pages, 32 figures, accepted in the journal A&

    Different protein source (soybean or faba bean) in postweaning diets for Apennine and Sopravissana (Italian Merino) light lamb: slaughtering performances

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    While Apennine is an autochthonous medium-large size Italian meat sheep breed well placed in Central Italy, Italian Merino (Sopravissana) is an ancient endangered sheep breed once raised all over Central Italy and now interesting a marginal sheep farming. Due to economical problems in fattening lamb at high weights for Italian farmers (Sanudo et al., 2000; Sarti, 1992), light lamb is one of the main products in Italian meat sheep farming

    Study of the deactivation of a commercial catalyst for ethylbenzene dehydrogenation to styrene

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    The catalytic performance and characteristics of an industrial catalyst, fresh and spent, i.e. downloaded from an industrial reactor after a normal lifetime cycle, were compared. Some different causes of catalyst deactivation, such as loss or redistribution of promoters, active phase modification, Fe 3+ reduction, coke deposition on catalyst surface and physical modifications, were evidenced by means of several techniques. All the mentioned causes of deactivation showed strictly interconnected and concurred to the decrease of conversion. However, the key factors leading to irreversible deactivation showed potassium migration towards the inner part of the extrudate particle, its agglomeration into concentrated spots and its volatilisation from the surface, together with the progressive Fe3+ reduction to Fe 2+. These modifications led to the enhancement of coking activity and to the loss of mechanical properties, so making deactivation irreversible

    An agent-based approach to assess drivers’ interaction with pre-trip information systems.

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    This article reports on the practical use of a multi-agent microsimulation framework to address the issue of assessing drivers’ responses to pretrip information systems. The population of drivers is represented as a community of autonomous agents, and travel demand results from the decision-making deliberation performed by each individual of the population as regards route and departure time. A simple simulation scenario was devised, where pretrip information was made available to users on an individual basis so that its effects at the aggregate level could be observed. The simulation results show that the overall performance of the system is very likely affected by exogenous information, and these results are ascribed to demand formation and network topology. The expressiveness offered by cognitive approaches based on predicate logics, such as the one used in this research, appears to be a promising approximation to fostering more complex behavior modelling, allowing us to represent many of the mental aspects involved in the deliberation process
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