197 research outputs found
Students’ Perceptions of the Training Environment: A Study of Race and Gender
This poster presents the results of a study of university students’ perceptions of educational training environments, which is typically limited to course evaluations. Relationships between program organization/structure, students’ perceptions, and cumulative GPA will be examined considering race and gender. Findings will enhance understanding about the impact of program variables. Packets (N = 227) , which included a consent form and a researcher-developed Training Environment Survey, were completed bi-annually by a random sampling of currently enrolled undergraduate (n = 140; 61.7%), graduate (n = 56; 24.7%), and doctoral-level (n = 31; 13.7%) university majors in programs housed within a Department of Human Services in a state institution located in the southern USA , having a total student population of approximately 13,000: Special Education, Deaf and Hard of Hearing, School Psychology, Vision Impairment, Orientation and Mobility, Rehabilitation Services, Counseling, Communication Disorders, and Speech and Language Pathology. The Training Environment Survey (TES) assessed students’ perceptions of: Faculty-Faculty Relationships, Faculty-Student Relationships, Student-Faculty Relationships, Student-Student Relationships and number of student services available (Policies). Twenty-four(23.8%) percent (n = 54) of the participants reported racial/ethnic minority status; 76.2% (n = 173) reported having White or racial/ethnic majority status; 94.2 % (n = 210) were female; and 5.8% (n = 13) were male; 1.8% (n = 4) did not specify; 12.8% (n = 29) identified as African American; 9.3% (n = 21) identified as Latino American; 1.3% (n = 3) identified as Asian American; and .4% (n = 1) identified as International Student status
Measurement report: A comparison of ground-level ice-nucleating-particle abundance and aerosol properties during autumn at contrasting marine and terrestrial locations
Ice-nucleating particles (INPs) are an essential class of aerosols found worldwide that have far-reaching but poorly quantified climate feedback mechanisms through interaction with clouds and impacts on precipitation. These particles can have highly variable physicochemical properties in the atmosphere, and it is crucial to continuously monitor their long-term concentration relative to total ambient aerosol populations at a wide variety of sites to comprehensively understand aerosol–cloud interactions in the atmosphere. Hence, our study applied an in situ forced expansion cooling device to measure ambient INP concentrations and test its automated continuous measurements at atmospheric observatories, where complementary aerosol instruments are heavily equipped. Using collocated aerosol size, number, and composition measurements from these sites, we analyzed the correlation between sources and abundance of INPs in different environments. Toward this aim, we have measured ground-level INP concentrations at two contrasting sites, one in the Southern Great Plains (SGP) region of the United States with a substantial terrestrially influenced aerosol population and one in the Eastern North Atlantic Ocean (ENA) region with a primarily marine-influenced aerosol population. These measurements examined INPs mainly formed through immersion freezing and were performed at a ≤ 12 min resolution and with a wide range of heterogeneous freezing temperatures (Ts above −31 °C) for at least 45 d at each site. The associated INP data analysis was conducted in a consistent manner. We also explored the additional offline characterization of ambient aerosol particle samples from both locations in comparison to in situ data. From our ENA data, on average, INP abundance ranges from ≈ 1 to ≈ 20 L−1 (−30 °C ≤ T ≤ −20 °C) during October–November 2020. Backward air mass trajectories reveal a strong marine influence at ENA with 75.7 % of air masses originating over the Atlantic Ocean and 96.6 % of air masses traveling over open water, but analysis of particle chemistry suggests an additional INP source besides maritime aerosols (e.g., sea spray aerosols) at ENA. In contrast, 90.8 % of air masses at the SGP location originated from the North American continent, and 96.1 % of the time, these air masses traveled over land. As a result, organic-rich SGP aerosols from terrestrial sources exhibited notably high INP abundance from ≈ 1 to ≈ 100 L−1 (−30 °C ≤ T ≤ −15 °C) during October–November 2019. The probability density function of aerosol surface area-scaled immersion freezing efficiency (ice nucleation active surface site density; ns) was assessed for selected freezing temperatures. While the INP concentrations measured at SGP are higher than those of ENA, the ns(T) values of SGP (≈ 105 to ≈ 107 m−2 for −30 °C ≤ T ≤ −15 °C) are reciprocally lower than ENA for approximately 2 orders of magnitude (≈ 107 to ≈ 109 m−2 for −30 °C ≤ T ≤ −15 °C). The observed difference in ns(T) mainly stems from varied available aerosol surface areas, Saer, from two sites (Saer,SGP > Saer,ENA). INP parameterizations were developed as a function of examined freezing temperatures from SGP and ENA for our study periods.</p
Telomere attrition rates are associated with weather conditions and predict productive lifespan in dairy cattle
Standardization of surface electromyography utilized to evaluate patients with dysphagia
<p>Abstract</p> <p>Backgorund</p> <p>Patients suspected of having swallowing disorders, could highly benefit from simple diagnostic screening before being referred to specialist evaluations. We introduce surface electromyography (sEMG) to carry out rapid assessment of such patients and propose suggestions for standardizing sEMGs in order to identify abnormal deglutition.</p> <p>Methods</p> <p>Specifics steps for establishing standards for applying the technique for screening purposes (e.g., evaluation of specific muscles), the requirements for diagnostic sEMG equipment, the sEMG technique itself, and defining the tests suitable for assessing deglutition (e.g., saliva, normal, and excessive swallows and uninterrupted drinking of water) are presented in detail. A previously described normative database for single swallowing and drinking and standard approach to analysis was compared to data on the duration and electric activity of muscles involved in deglutition and with sEMG recordings in order to estimate stages of a swallow.</p> <p>Conclusion</p> <p>SEMG of swallowing is a simple and reliable method for screening and preliminary differentiation among dysphagia and odynophagia of various origins. This noninvasive radiation-free examination has a low level of discomfort, and is simple, timesaving and inexpensive to perform. With standardization of the technique and an established normative database, sEMG can serve as a reliable screening method for optimal patient management.</p
No evidence for parental age effects on offspring leukocyte telomere length in free-living Soay sheep
Abstract In humans, the effect of paternal age at conception (PAC) on offspring leukocyte telomere length (LTL) is well established, with older fathers thought to pass on longer telomeres to their offspring in their sperm. Few studies have looked for PAC effects in other species, but it has been hypothesised that the effect will be exacerbated in polygamous species with higher levels of sperm competition and production. We test for maternal (MAC) and paternal age at conception effects on offspring LTL in Soay sheep, a primitive breed experiencing strong sperm competition. We use qPCR to measure relative telomere length in 389 blood samples (n = 318 individuals) collected from an unmanaged population of sheep on St Kilda, where individual age and parentage are known. We find no evidence that either MAC or PAC are associated with LTL in offspring across the age range, or when considering only young lambs (n = 164). This is the first study to test for parental age effects on offspring LTL in a wild mammal population, and the results contrast with the findings of numerous human studies that find a PAC effect, as well as predictions of a stronger PAC effect in polygamous species
Production of ice-nucleating particles (INPs) by fast-growing phytoplankton
Sea spray aerosol contains ice-nucleating particles (INPs), which affect the formation and properties of clouds. Here, we show that aerosols emitted from fast-growing marine phytoplankton produce effective immersion INPs, which nucleate at temperatures significantly warmer than the atmospheric homogeneous freezing (−38.0 ∘C) of pure water. Aerosol sampled over phytoplankton cultures grown in a Marine Aerosol Reference Tank (MART) induced nucleation and freezing at temperatures as high as −15.0 ∘C during exponential phytoplankton growth. This was observed in monospecific cultures representative of two major groups of phytoplankton, namely a cyanobacterium (Synechococcus elongatus) and a diatom (Thalassiosira weissflogii). Ice nucleation occurred at colder temperatures (−28.5 ∘C and below), which were not different from the freezing temperatures of procedural blanks, when the cultures were in the stationary or death phases of growth. Ice nucleation at warmer temperatures was associated with relatively high values of the maximum quantum yield of photosystem II (ΦPSII), an indicator of the physiological status of phytoplankton. High values of ΦPSII indicate the presence of cells with efficient photochemistry and greater potential for photosynthesis. For comparison, field measurements in the North Atlantic Ocean showed that high net growth rates of natural phytoplankton assemblages were associated with marine aerosol that acted as effective immersion INPs at relatively warm temperatures. Data were collected over 4 d at a sampling station maintained in the same water mass as the water column stabilized after deep mixing by a storm. Phytoplankton biomass and net phytoplankton growth rate (0.56 d−1) were greatest over the 24 h preceding the warmest mean ice nucleation temperature (−25.5 ∘C). Collectively, our laboratory and field observations indicate that phytoplankton physiological status is a useful predictor of effective INPs and more reliable than biomass or taxonomic affiliation. Ocean regions associated with fast phytoplankton growth, such as the North Atlantic during the annual spring bloom, may be significant sources of atmospheric INPs.</p
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