Gamma–ray spectroscopy with single–carrier collection in high–resistivity semiconductors

With the standard plane–parallel configuration of semiconductor detectors, good γ–ray spectra can only be obtained when both electrons and holes are completely collected. We show by calculations (and experiments) that with contacts of hemispherical configuration one can obtain γ–ray spectra of adequate resolution and with signal heights of nearly full amplitude even when only one type of carrier is collected. Experiments with CdTe detectors for which the µτ product for electrons is about 10^(3) times that of the holes confirm these calculations. The adoption of hemispherical contacts thus widens the range of high–resistivity semiconductors potentially acceptable for γ–ray detection at room temperature

Composition-Dependent Hydrogen-Bonding Motifs and Dynamics in Brønsted Acid-Base Mixtures

In recent years the interaction of organophosphates and imines, which is at the core of Brønsted acid organocatalysis, has been established to be based on strong ionic hydrogen bonds. Yet, besides the formation of homodimers consisting of two acid molecules and heterodimers consisting of one acid and one base, also multimeric molecular aggregates are formed in solution. These multimeric aggregates consist of one base and several acid molecules. The details of the intermolecular bonding in such aggregates, however, have remained elusive. To characterize compositiondependent bonding and bonding dynamics in these aggregates, we use linear and nonlinear infrared (IR) spectroscopy at varying molar ratios of diphenyl phosphoric acid and quinaldine. We identify the individual aggregate species, giving rise to the structured, strong, and very broad infrared absorptions, which span more than 1000 cm −1. Linear infrared spectra and density functional theory calculations of the proton transfer potential show that doubly ionic intermolecular hydrogen bonds between the acid and the base lead to absorptions which peak at ∼2040 cm −1. The contribution of singly ionic hydrogen bonds between an acid anion and an acid molecule is observed at higher frequencies. As common to such strong hydrogen bonds, ultrafast IR spectroscopy reveals rapid, ∼ 100 fs, dissipation of energy from the proton transfer coordinate. Yet, the full dissipation of the excess energy occurs on a ∼0.8−1.1 ps time scale, which becomes longer when multimers dominate. Our results thus demonstrate the coupling and collectivity of the hydrogen bonds within these complexes, which enable efficient energy transfer

Beyond Improved Retention: Building Value-Added Success on a Broad Foundation

Many have documented the positive benefits of Living and Learning Communities (LLCs), but creating an environment that truly integrates living and learning across campus can be a challenge. In this paper we chronicle an LLC program that was intentionally built upon a broad foundation. By including faculty, staff, and student leader representation from across the campus - from admissions and academic affairs to student engagement, residence life, and enrollment management - Cabrini College has created a program that has gone beyond the numerical targets of increased retention and increased academic success. We believe the program has created transformational experiences for many student participants, and that these experiences are the result of the LLC’s integrated design. After providing a history of the program and its unique institutional structure, and offering suggestions for other institutions designing LLCs, we present both quantitative and qualitative measures of success. Richard D. Gebauer is the Director of the First-Year Experience at Cabrini College in Radnor, Pennsylvania. Nancy L. Watterson is an Associate Professor, Social Justice, at Cabrini College. Eric Malm is an Associate Professor of Economics and Business at Cabrini College. Michelle Filling-Brown is an Assistant Professor of English at Cabrini College. John W. Cordes is an Associate Professor in Communication at Cabrini College

Second-generation antipsychotic use during pregnancy and risk of congenital malformations

Purpose To study if second-generation antipsychotic (S-GA) use during the first trimester of pregnancy is associated with an increased risk of major congenital malformations (MCM). Methods A population-based birth cohort study using national register data extracted from the Drugs and Pregnancy database in Finland, years 1996-2017. The sampling frame included 1,273,987 pregnant women. We included singleton pregnancies ending in live or stillbirth or termination of pregnancy due to severe malformation. Pregnancies with exposure to known teratogens were excluded. Women were categorized into three groups: exposed to S-GAs (n = 3478), exposed to first-generation antipsychotics (F-GAs) (n = 1030), and unexposed (no purchases of S-GAs or F-GAs during pregnancy, n = 22,540). We excluded genetic conditions and compared the prevalence of MCMs in S-GA users to the two comparison groups using multiple logistic regression models. Results Use of S-GAs during early pregnancy was not associated with an increased risk of overall MCMs compared to unexposed (adjusted odds ratio, OR 0.92; 95% CI 0.72-1.19) or to F-GA users (OR 0.82; 95% CI 0.56-1.20). Of individual S-GAs, olanzapine use was associated with an increased risk of overall MCMs (OR 2.12; 95% CI 1.19-3.76), and specifically, an increased risk of musculoskeletal malformations (OR 3.71; 95% CI 1.35-10.1) when compared to unexposed, while comparisons to F-GA users did not show significant results. Conclusions Olanzapine use is associated with an increased risk of major congenital malformations and specifically, musculoskeletal malformations. Use during pregnancy should be restricted to situations where no safer alternatives exist.Peer reviewe

The development and evaluation of exercises for meaningful responses in reading in grade two

Research chapter for this study will be found in Ash, Dorothea: "Development and evaluation of silent reading exercises in grade one" Thesis (M.A.)--Boston Universit

A retrospective study of salmonellosis in Swedish pig herds

Sweden has achieved efficient control of salmonella in the food production sector. Due to this control, red and white meat produced in Sweden can today be claimed to be virtually free from salmonella (I). The different parts of the control programmes have been described in detail elsewhere (2,3). When joining the European Union in 1995, Sweden acquired additional guarantees regarding salmonella when importing live animals and fresh meat, based on the control programme (5)

Humidification Factors from Laboratory Studies of Fresh Smoke from Biomass Fuels

Measurements of smoke aerosol humidification factors were performed in a laboratory for different biomass fuel types and burn conditions. Two nephelometers simultaneously measured dry and humidified light scattering coefficients (bsp(dry) and bsp(RH), respectively), providing the first observations of the temporal evolution of the humidification factor (f(RH) = bsp(RH)/bsp(dry)) for fresh (minutes-old) smoke. Hygroscopic characteristics of the smoke aerosols varied with fuel type and fire conditions, with the mean f(RH) ranging from 1.01 to 1.95 for fresh minutes-old smoke for the relative humidity (RH) range of 70-94%. These f(RH) values exhibited temporal variability, with some fuels alternating from hygroscopic to nonhygroscopic within minutes. Humidograms were also obtained, demonstrating that smoke from different fuels begins to take up water at different RH values. Humidification factors for hour-old smoke ranged from 1.10 to 1.51 for RH \u3e 90%. Finally, light-absorbing carbon mass measured with a multiwavelength aethalometer demonstrated different spectral responses as a function of fuel type. These laboratory experiments demonstrate the complexity of smoke hygroscopicity from young fires and are essential for understanding the radiative effects of biomass burning in the ambient atmosphere

Epidemiology of COVID-19 outbreak in Ghana, 2020

Coronaviruses are RNA viruses that cause respiratory, hepatic and neurological diseases in domestic and wild animals, and humans. Among humans, six species of coronavirus have been identified to cause disease. Among these, Severe Acute Respiratory Syndrome (SARS-CoV) and Middle East Respiratory Syndrome (MERS-CoV) are of zoonotic origin and have been known to cause severe acute respiratory syndrome outbreaks among humans