545 research outputs found
Advance Placement and The Achievement Gap in the 21st Century: A Multiple Linear Regression of Marginalized Populations in AP Enrollment
The analysis of the College Board's Advanced Placement (AP) enrollment focused on marginalized populations' (i.e., African American, Hispanic, and poor students) limited access and the schools' efforts to bridge the gaps. Little research has been done on marginalized populations' AP passage rates. The researchers of this correlational study investigated AP enrollment and passage rates in public and charter high schools in Florida (n = 355) by comparing the enrollment and passage proportions amongst Caucasian, African American, and Hispanic students as well as the proportions of students who received free or reduced lunch. The results showed a weak, positive relationship between proportions of Hispanic, African American, and Caucasian students passing AP exams and the proportion of AP students enrolled. There was a strong, positive relationship amongst the proportions of African-American, Hispanic, and Caucasian students who passed the exam. However, a weak, negative relationship was found between the proportions of students who were enrolled in AP classes and those who received free or reduced lunch. There was also a negative relationship between Hispanic, African American, and Caucasian students passing the AP exam and the percentage of the school's population enrolled in free or reduced lunch. The findings suggest that schools with high poverty rates have a low enrollment rate of students in AP courses. The focus on AP enrollment rates for minority students has led to increased rates of minorities successfully completing advanced coursework, but there is still a need for similar focus on high poverty schools
Song of the Wind
Song of the Wind is an original cantata for contralto soloist, chorus, and chamber orchestra. More similar to Carmina Burana than a cantata such as those written by J. S. Bach, musical influences were drawn from such diverse sources as Greek Orthodox chant, minimalism, and New Age popular music. The story of Song of the Wind is drawn from a number of different texts, mostly Eastern and Mid-Eastern in origin, but European texts are represented as well. These texts span a period of time between 3,000 years before the Common Era and the Renaissance, and also include newly written verse. This spiritual cantata follows the journey of Viatoris (Latin for “female traveler”) who quests for an answer to the eternal question, “What is the meaning of life?” The Wind acts as her spirit guide, speaking surprisingly little, and always in a whisper. Viatoris mainly converses with The Voices, which represent her immediate society and often act as a Greek chorus, commenting on the main action and offering further insight
Domain-specific reasoning for method engineering based on Toulmin's argumentation theory
Methods describe and embody a broad range of relevant knowledge of enterprises. Usually they have to account for requirements stated by a multitude of various stakeholders. These are typically those that are in charge of business related actions and those that are in charge to support such actions with an IT-Infrastructure. The statement of requirements as well as the validation of methods and in particular process models with respect to those requirements relies drastically on natural language. Natural language seems to be a substantial component to explain and to give an understanding about process models or certain aspects of it. This fact requires closing the gap between the natural language and the respective modelling language. This paper proposes argumentative method engineering for purposefully depicting design decisions and convictions for method engineering through arguments. The approach is derived from Toulmin’s Argumentation Model and explicates the process of negotiating with various stakeholders. So, a model, depicting a method, specified by means of argumentative method engineering, not just includes the claims about a certain domain, it further justifies these claims by referring to already established knowledge. While it can’t be ensured that certain requirements are considered in future project, if the reasons for design decisions of method engineering are transcribed in natural language text, but the semi- formalising of arguments regarding these methods allows such an assurance. So the argumentative approach enables the sophisticated management and reuse of knowledge during the development and extension of methods. The approach is evaluated using a case study, in which a software development method was outsourced to contractors
Structural identification of oxidized acyl-phosphatidylcholines that induce platelet activation
Oxidation of low-density lipoprotein (LDL) generates proinflammatory and prothrombotic mediators that may play a crucial role in cardiovascular and inflammatory diseases. In order to study platelet-activating components of oxidized LDL 1-stearoyl-2-arachidonoyl-sn-glycero-3- phosphocholine, a representative of the major phospholipid species in LDL, the 1-acyl-phosphatidylcholines (PC), was oxidized by CuCl2 and H2O2. After separation by high-performance liquid chromatography, three compounds were detected which induced platelet shape change at low micromolar concentrations. Platelet activation by these compounds was distinct from the pathways stimulated by platelet-activating factor, lysophosphatidic acid, lyso-PC and thromboxane A(2), as evidenced by the use of specific receptor antagonists. Further analyses of the oxidized phospholipids by electrospray ionization mass spectrometry structurally identified them as 1-stearoyl-2-azelaoyl-sn-glycero-3-phosphocholine (m/z 694; SAzPC), 1-stearoyl-2-glutaroyl-snglycero-3- phosphocholine (m/z 638; SGPC), and 1-stearoyl-2-( 5-oxovaleroyl)-sn-glycero-3-phosphocholine (m/z 622; SOVPC). These observations demonstrate that novel 1-acyl-PC which had previously been found to stimulate interaction of monocytes with endothelial cells also induce platelet activation, a central step in acute thrombogenic and atherogenic processes. Copyright (C) 2005 S. Karger AG, Basel
Bridging Alone: Religious Conservatism, Marital Homogamy, and Voluntary Association Membership
This study characterizes social insularity of religiously conservative American married couples by examining patterns of voluntary associationmembership. Constructing a dataset of 3938 marital dyads from the second wave of the National Survey of Families and Households, the author investigates whether conservative religious homogamy encourages membership in religious voluntary groups and discourages membership in secular voluntary groups. Results indicate that couples’ shared affiliation with conservative denominations, paired with beliefs in biblical authority and inerrancy, increases the likelihood of religious group membership for husbands and wives and reduces the likelihood of secular group membership for wives, but not for husbands. The social insularity of conservative religious groups appears to be reinforced by homogamy—particularly by wives who share faith with husbands
Lipid Metabolites Enhance Secretion Acting on SNARE Microdomains and Altering the Extent and Kinetics of Single Release Events in Bovine Adrenal Chromaffin Cells
Lipid molecules such as arachidonic acid (AA) and sphingolipid metabolites have been implicated in modulation of neuronal and endocrine secretion. Here we compare the effects of these lipids on secretion from cultured bovine chromaffin cells. First, we demonstrate that exogenous sphingosine and AA interact with the secretory apparatus as confirmed by FRET experiments. Examination of plasma membrane SNARE microdomains and chromaffin granule dynamics using total internal reflection fluorescent microscopy (TIRFM) suggests that sphingosine production promotes granule tethering while arachidonic acid promotes full docking. Our analysis of single granule release kinetics by amperometry demonstrated that both sphingomyelinase and AA treatments enhanced drastically the amount of catecholamines released per individual event by either altering the onset phase of or by prolonging the off phase of single granule catecholamine release kinetics. Together these results demonstrate that the kinetics and extent of the exocytotic fusion pore formation can be modulated by specific signalling lipids through related functional mechanisms
Child Care Time, Parents’ Well-Being, and Gender: Evidence from the American Time Use Survey
This study used data from the ‘Well Being Module’ of the 2010 American Time Use Survey (N = 1699) to analyze how parents experience child care time in terms of meaning and stress levels. Multivariate multilevel regressions showed clear differences by gender and the circumstances of child care activities. Mothers experienced child care time as more stressful than fathers, and fathers as slightly more meaningful. Interactive child care was experienced as more meaningful and less stressful than routine child care, whereas these differences were stronger among fathers than among mothers. Mothers experienced child care with a minor child as highly meaningful, and with an adolescent as particularly stressful. Fathers experienced child care with an infant as highly stressful, and with an offspring in middle childhood as disproportionally meaningful. The spouse’s presence was moderately associated with higher senses of meaning and lower levels of stress during child care, but these differences were modest, and only visible among fathers. Paid work hours increased mothers’ stress levels during child care activities, but reduced fathers’ stress levels. Meanwhile, nonemployed fathers reported child care time as less meaningful than non-employed mothers. Overall, this study has important scientific and practical implications for `understanding the gendered nature of parents’ child care time and well-being
Survey of hormone activities in municipal biosolids and animal manures.
ABSTRACT: The potential exists for natural or synthetic hormonal chemicals present in agricultural fertilizers to be transferred to adjacent aquatic environments in order to alter endocrine function in exposed wildlife. Recombinant yeast and mammalian cell line (BG1Luc4E 2 ) assays were used to screen crude organic extracts of municipal biosolids and animal manures for estrogen-, androgen-, and progesterone receptor gene transcription activities. Of the biosolid extracts, those samples that had undergone aerobic digestion had no or minimal estrogen-and no androgen receptor gene transcription activities. In contrast, those biosolid samples that had undergone anaerobic digestion had much higher estrogen-and, for all but one site, androgen receptor gene transcription activities. Extracts prepared from animal manure samples had variable levels of androgen-and estrogen receptor gene transcription activities, which may be related to the type, sex, age, and reproductive status of the animals. The diet and treatment of animals with hormone implants also appeared to be factors influencing hormone activity in animal manure. Progesterone receptor gene transcription activity was observed for only one chicken litter sample. Overall, results of this study suggest that in vitro bioassays can be used to survey and detect hormone activity in municipal biosolids and animal manures. Furthermore, results of these assays can be used to develop 216 practices that will minimize the potential environmental endocrine-disrupting effects of these substances
The ALFAM2 database on ammonia emission from field-applied manure: Description and illustrative analysis
peer-reviewedAmmonia (NH3) emission from animal manure contributes to air pollution and ecosystem degradation, and the loss of reactive nitrogen (N) from agricultural systems. Estimates of NH3 emission are necessary for national inventories and nutrient management, and NH3 emission from field-applied manure has been measured in many studies over the past few decades. In this work, we facilitate the use of these data by collecting and organizing them in the ALFAM2 database. In this paper we describe the development of the database and summarise its contents, quantify effects of application methods and other variables on emission using a data subset, and discuss challenges for data analysis and model development. The database contains measurements of emission, manure and soil properties, weather, application technique, and other variables for 1895 plots from 22 research institutes in 12 countries. Data on five manure types (cattle, pig, mink, poultry, mixed, as well as sludge and “other”) applied to three types of crops (grass, small grains, maize, as well as stubble and bare soil) are included. Application methods represented in the database include broadcast, trailing hose, trailing shoe (narrow band application), and open slot injection. Cattle manure application to grassland was the most common combination, and analysis of this subset (with dry matter (DM) limited to <15%) was carried out using mixed- and fixed-effects models in order to quantify effects of management and environment on ammonia emission, and to highlight challenges for use of the database. Measured emission in this subset ranged from <1% to 130% of applied ammonia after 48 h. Results showed clear, albeit variable, reductions in NH3 emission due to trailing hose, trailing shoe, and open slot injection of slurry compared to broadcast application. There was evidence of positive effects of air temperature and wind speed on NH3 emission, and limited evidence of effects of slurry DM. However, random-effects coefficients for differences among research institutes were among the largest model coefficients, and showed a deviation from the mean response by more than 100% in some cases. The source of these institute differences could not be determined with certainty, but there is some evidence that they are related to differences in soils, or differences in application or measurement methods. The ALFAM2 database should be useful for development and evaluation of both emission factors and emission models, but users need to recognize the limitations caused by confounding variables, imbalance in the dataset, and dependence among observations from the same institute. Variation among measurements and in reported variables highlights the importance of international agreement on how NH3 emission should be measured, along with necessary types of supporting data and standard protocols for their measurement. Both are needed in order to produce more accurate and useful ammonia emission measurements. Expansion of the ALFAM2 database will continue, and readers are invited to contact the corresponding author for information on data submission. The latest version of the database is available at http://www.alfam.dk
Alkaline air: changing perspectives on nitrogen and air pollution in an ammonia-rich world
Ammonia and ammonium have received less attention than other forms of air pollution, with limited progress in controlling emissions at UK, European and global scales. By contrast, these compounds have been of significant past interest to science and society, the recollection of which can inform future strategies. Sal ammoniac (nūshādir, nao sha) is found to have been extremely valuable in long-distance trade (ca AD 600–1150) from Egypt and China, where 6–8 kg N could purchase a human life, while air pollution associated with nūshādir collection was attributed to this nitrogen form. Ammonia was one of the keys to alchemy—seen as an early experimental mesocosm to understand the world—and later became of interest as ‘alkaline air’ within the eighteenth century development of pneumatic chemistry. The same economic, chemical and environmental properties are found to make ammonia and ammonium of huge relevance today. Successful control of acidifying SO2 and NOx emissions leaves atmospheric NH3 in excess in many areas, contributing to particulate matter (PM2.5) formation, while leading to a new significance of alkaline air, with adverse impacts on natural ecosystems. Investigations of epiphytic lichens and bog ecosystems show how the alkalinity effect of NH3 may explain its having three to five times the adverse effect of ammonium and nitrate, respectively. It is concluded that future air pollution policy should no longer neglect ammonia. Progress is likely to be mobilized by emphasizing the lost economic value of global N emissions ($200 billion yr−1), as part of developing the circular economy for sustainable nitrogen management
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