A study of air-to-ground sound propagation using an instrumented meteorological tower

The results of an exploratory NASA study, leading to a better understanding of the effects of meteorological conditions on the propagation of aircraft noise, are reported. The experimental program utilized a known sound source fixed atop an instrumented meteorological tower. The basic experimental scheme consisted of measuring the amplitude of sound radiated toward the ground along a line of microphones fixed to a tower guy wire. Experimental results show the feasibility of this approach in the acquisition of data indicating the variations encountered in the time-averaged and instantaneous amplitudes of propagated sound. The investigation included a consideration of ground reflections, a comparison of measured attenuations with predicted atmospheric absorption losses, and an evaluation of the amplitude fluctuations of recorded sound pressures

Powerful Significance Testing for Unbalanced Clusters

Clustering methods are popular for revealing structure in data, particularly in the high-dimensional setting common to contemporary data science. A central statistical question is, "are the clusters really there?" One pioneering method in statistical cluster validation is SigClust, but it is severely underpowered in the important setting where the candidate clusters have unbalanced sizes, such as in rare subtypes of disease. We show why this is the case, and propose a remedy that is powerful in both the unbalanced and balanced settings, using a novel generalization of k-means clustering. We illustrate the value of our method using a high-dimensional dataset of gene expression in kidney cancer patients. A Python implementation is available at https://github.com/thomaskeefe/sigclust.Comment: 23 pages, 11 figure

Cross-modal orienting of exogenous attention results in visual-cortical facilitation, not suppression

Attention may be oriented exogenously (i.e., involuntarily) to the location of salient stimuli, resulting in improved perception. However, it is unknown whether exogenous attention improves perception by facilitating processing of attended information, suppressing processing of unattended information, or both. To test this question, we measured behavioral performance and cue-elicited neural changes in the electroencephalogram as participants (N = 19) performed a task in which a spatially non-predictive auditory cue preceded a visual target. Critically, this cue was either presented at a peripheral target location or from the center of the screen, allowing us to isolate spatially specific attentional activity. We find that both behavior and attention-mediated changes in visual-cortical activity are enhanced at the location of a cue prior to the onset of a target, but that behavior and neural activity at an unattended target location is equivalent to that following a central cue that does not direct attention (i.e., baseline). These results suggest that exogenous attention operates via facilitation of information at an attended location

Streptavidin-binding peptides and uses thereof

The invention provides peptides with high affinity for streptavidin. These peptides may be expressed as part of fusion proteins to facilitate the detection, quantitation, and purification of proteins of interest

Postpartum Depression Among Low-Income Mothers of Color: A Womanist Perspective

The ideals of “good mothering” are constructed by various social policies and institutions. Many mothers from traditionally oppressed groups may find them difficult to achieve. The intersections of multiple forms of oppression create harsh circumstances for mothers from minority groups that can contribute to postpartum depression (PPD). Left untreated, PPD can have long-lasting negative effects on the mothers’ and their children’s well-being. Despite the growing research on PPD that finds striking disparities in prevalence by race, ethnicity, and socio-economic class, virtually all of the research has focused on mothers from privileged backgrounds and none has used a well-established theory to explain PPD among mothers from minority groups. To address this gap in the literature, this article uses Womanism as a theory to examine PPD among low-income mothers of color as a way to help sociologists and social workers take action to address PPD through theory, research, and practice

Management of Sorafenib-Related Adverse Events: A Clinician’s Perspective

Sorafenib, a tyrosine kinase inhibitor, is approved for the treatment of patients with unresectable hepatocellular carcinoma (HCC) and advanced renal cell carcinoma (RCC). It is being evaluated in phase II and III clinical trials, which include treatment as a single agent (locally advanced/metastatic radioactive iodine-refractory differentiated thyroid cancer [DTC]), as part of multimodality care (HCC), and in combination with chemotherapeutic agents (metastatic breast cancer). Sorafenib-related adverse events (AEs) that commonly occur across these tumor types include hand–foot skin reaction (HSFR), rash, upper and lower gastrointestinal (GI) distress (ie, diarrhea), fatigue, and hypertension. These commonly range from grade 1 to 3, per the Common Terminology Criteria for Adverse Events (CTCAE), and often occur early in treatment. The goal for the management of these AEs is to prevent, treat, and/or minimize their effects, thereby enabling patients to remain on treatment and improve their quality of life. Proactive management, along with ongoing patient education (before and during sorafenib treatment), can help to effectively manage symptoms, often without the need for sorafenib dose modification or drug holidays. Effective management techniques for common sorafenib-related AEs, as well other important disease sequelae not directly related to treatment, are presented. Recommendations and observations are based on physician/author experience and recommendations from published literature

Telomere lengths in human oocytes, cleavage stage embryos and blastocysts

Telomeres are repeated sequences that protect the ends of chromosomes and harbour DNA-repair proteins. Telomeres shorten during each cell division in the absence of telomerase. When telomere length becomes critically short, cell senescence occurs. Telomere length therefore reflects both cellular ageing and capacity for division. We have measured telomere length in human germinal vesicle (GV) oocytes and pre-implantation embryos, by quantitative fluorescence in-situ hybridisation (Q-FISH), providing baseline data towards our hypothesis that telomere length is a marker of embryo quality. The numbers of fluorescent foci suggest that extensive clustering of telomeres occurs in mature GV stage oocytes, and in pre-implantation embryos. When calculating average telomere length by assuming that each signal presents one telomere, the calculated telomere length decreased from the oocyte to the cleavage stages, and increased between the cleavage stages and the blastocyst (11.12 vs 8.43 vs 12.22kb respectively, p<0.001). Other methods of calculation, based upon expected maximum and minimum numbers of telomeres, confirm that telomere length in blastocysts is significantly longer than cleavage stages. Individual blastomeres within an embryo showed substantial variation in calculated average telomere length. This study implies that telomere length changes according to the stage of pre-implantation embryo development