671 research outputs found
Theoretical prediction of airplane stability derivatives at subcritical speeds
The theoretical development and application is described of an analysis for predicting the major static and rotary stability derivatives for a complete airplane. The analysis utilizes potential flow theory to compute the surface flow fields and pressures on any configuration that can be synthesized from arbitrary lifting bodies and nonplanar thick lifting panels. The pressures are integrated to obtain section and total configuration loads and moments due side slip, angle of attack, pitching motion, rolling motion, yawing motion, and control surface deflection. Subcritical compressibility is accounted for by means of the Gothert similarity rule
Tuberculosis in Pregnancy
Tuberculosis (TB) during pregnancy and in the perinatal period was once considered to be an
infrequent event in the United States. After a decade of steady decline, however, the disease has
begun a resurgence. According to the CDC, a 20% increase in the number of reported cases
occurred between 1985 and 1992. The factors associated with this increase are the emergence of
human immunodeficiency virus (HIV) infection, the development of drug-resistant organisms,
substance abuse, homelessness, and immigration. Environmental factors promoting transmission
can be found in overcrowded areas such as correctional facilities, nursing homes, hospitals, and
migrant-worker camps. For a large number of medically underserved women, the obstetrician is
the only interface with medical care, as most of these patients do not have primary-care providers.
It is important, therefore, that health-care providers recognize the clinical symptoms of TB and
follow the recognized guidelines for antenatal screening for TB because the omission of these steps
can lead to potentially disastrous sequelae in the fetus and neonate
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Innovative Approaches to Emergency Medical Services Fellowship Challenges
Introduction: Since the development of an Accreditation Council of Graduate Medical Education (ACGME)-accredited emergency medical services (EMS) fellowship, there has been little published literature on effective methods of content delivery or training modalities. Here we explore a variety of innovative approaches to the development and revision of the EMS fellowship curriculum.Methods: Three academic, university-based ACGME-accredited EMS fellowship programs each implemented an innovative change to their existing training curricula. These changes included the following: a novel didactic curriculum delivery modality and evaluation; implementation of a distance education program to improve EMS fellows’ rural EMS experiences; and modification of an existing EMS fellowship curriculum to train a non-emergency medicine physician.Results: Changes made to each of the above EMS fellowship programs addressed unique challenges, demonstrating areas of success and promise for more generalized implementation of these curricula. Obstacles remain in tailoring the described curricula to the needs of each unique institution and system.Conclusion: Three separate curricula and program changes were implemented to overcome specific challenges and achieve educational goals. It is our hope that our shared experiences will enable others in addressing common barriers to teaching the EMS fellowship core content and share similar innovative approaches to educational challenges
High-Performance Interactive Scientific Visualization With Datoviz via the Vulkan Low-Level GPU API
We reported initial work towards a new fast and scalable scientific visualization technology that leverages the Vulkan API to achieve unprecedented performance through GPUs. This technology is implemented in a C/C++ library called Datoviz that offers an intermediate-level API for scientific visualization libraries and software. Datoviz provides a unified graphics stack for 2-D, 3-D, graphical user interfaces, and natively supports efficient interactions between rendering and general-purpose GPU computing. A major direction of development is to investigate the integration of Datoviz as a low-level backend of a future version of VisPy, a popular Python scientific plotting librar
Quantitative characterization of the x-ray imaging capability of rotating modulation collimators with laser light
We developed a method for making quantitative characterizations of bi-grid rotating modulation collimators (RMC ’s) that are used in a Fourier transform x-ray imager. With appropriate choices of the collimator spacings, this technique can be implemented with a beam-expanded He -Ne laser to simulate the plane wave produced by a point source at infinity even though the RMC ’s are diffraction limited at the He -Ne wavelength of 632.8 nm. The expanded beam passes through the grid pairs at a small angle with respect to their axis of rotation, and the modulated transmission through the grids as the RMC ’s rotate is detected with a photomultiplier tube. In addition to providing a quantitative characterization of the RMC ’s, the method also produces a measured point response function and provides an end-to-end check of the imaging system. We applied our method to the RMC ’s on the high-energy imaging device (HEIDI) balloon payload in its preflight configuration. We computed the harmonic ratios of the modulation time profile from the laser measurements and compared them with theoretical calculations, including the diffraction effects on irregular grids. Our results indicate the 25-in. (64-cm) x-ray imaging optics on HEIDI are capable of achieving images near the theoretical limit and are not seriously compromised by imperfections in the grids
Sunplanter
Although the cost of solar technology has been reduced by nearly seventy percent in the last ten years, the cost of implementing solar panels for residential and commercial use has remained stagnant. Due to the lack of affordable, easily installable solar panel systems on residential properties, the goal of our Senior Design Project is to design a stand-alone solar tracking structure. Since the system is stand-alone, it can be easily implemented on a wide range of properties in most areas of California. Our design for the support of the solar tracking system is a two-pole structure, with a wide base under each pole to eliminate the need for a deep foundation. An electric gearmotor system will drive the rotational motion of the solar tracking function, due to its high power output and relatively affordable cost. A hydraulic damping and blocking system was incorporated to precisely control rotational motion. After testing the system for both tracking and static operation, an 11.4% increase power production was observed. Sunplanter solar tracking systems have the potential to provide a financially viable investment opportunity for customers while having a positive impact on the environment
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Black Family Forest Owners in the Southeastern United States: A Case Study in Six Counties
The USDA Forest Service, National Woodland Owner Survey asks family forest owners (FFOs) about their attitudes and intentions regarding their forestland. Historically, the number of responses from Black or African American FFOs has been very low, but it is uncertain whether this is because of nonresponse bias or that there are relatively few Black FFOs. To get a better understanding of these FFOs and to test a method to increase response rates, an intensified survey effort was conducted in three southern states: Alabama, North Carolina, and South Carolina. Analyses indicate that Black FFOs have slightly different objectives, activities, and ownership structure for their forestland than their White counterparts, who have traditionally represented the majority of FFOs.
Study Implications: By conducting an experiment to increase response rates from Black family forest owners to the National Woodland Owner Survey, we find traditional methodology is not effective. More importantly, we see this group has moderately different responses than their White counterparts. This has wide ranging implications for landowner assistance programs and other initiatives that have been designed on the premise that we are accurately capturing responses from all woodland owners
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Synchronous genitourinary lichen sclerosus signals a distinct urinary microbiome profile in men with urethral stricture disease.
PurposeAlterations in the urinary microbiome have been associated with urological diseases. The microbiome of patients with urethral stricture disease (USD) remains unknown. Our objective is to examine the microbiome of USD with a focus on inflammatory USD caused by lichen sclerosus (LS).MethodsWe collected mid-stream urine samples from men with LS-USD (cases; n = 22) and non-LS USD (controls; n = 76). DNA extraction, PCR amplification of the V4 hypervariable region of the 16S rRNA gene, and sequencing was done on the samples. Operational taxonomic units (OTUs) were defined using a > 97% sequence similarity threshold. Alpha diversity measurements of diversity, including microbiome richness (number of different OTUs) and evenness (distribution of OTUs) were calculated and compared. Microbiome beta diversity (difference between microbial communities) relationships with cases and controls were also assessed.ResultsFifty specimens (13 cases and 37 controls) produced a 16S rRNA amplicon. Mean sample richness was 25.9 vs. 16.8 (p = 0.076) for LS-USD vs. non-LS USD, respectively. LS-USD had a unique profile of bacteria by taxonomic order including Bacillales, Bacteroidales and Pasteurellales enriched urine. The beta variation of observed bacterial communities was best explained by the richness.ConclusionsMen with LS-USD may have a unique microbiologic richness, specifically inclusive of Bacillales, Bacteroidales and Pasteurellales enriched urine compared to those with non-LS USD. Further work will be required to elucidate the clinical relevance of these variations in the urinary microbiome
High throughput mutagenesis for identification of residues regulating human prostacyclin (hIP) receptor
The human prostacyclin receptor (hIP receptor) is a seven-transmembrane G protein-coupled receptor (GPCR) that plays a critical role in vascular smooth muscle relaxation and platelet aggregation. hIP receptor dysfunction has been implicated in numerous cardiovascular abnormalities, including myocardial infarction, hypertension, thrombosis and atherosclerosis. Genomic sequencing has discovered several genetic variations in the PTGIR gene coding for hIP receptor, however, its structure-function relationship has not been sufficiently explored. Here we set out to investigate the applicability of high throughput random mutagenesis to study the structure-function relationship of hIP receptor. While chemical mutagenesis was not suitable to generate a mutagenesis library with sufficient coverage, our data demonstrate error-prone PCR (epPCR) mediated mutagenesis as a valuable method for the unbiased screening of residues regulating hIP receptor function and expression. Here we describe the generation and functional characterization of an epPCR derived mutagenesis library compromising >4000 mutants of the hIP receptor. We introduce next generation sequencing as a useful tool to validate the quality of mutagenesis libraries by providing information about the coverage, mutation rate and mutational bias. We identified 18 mutants of the hIP receptor that were expressed at the cell surface, but demonstrated impaired receptor function. A total of 38 non-synonymous mutations were identified within the coding region of the hIP receptor, mapping to 36 distinct residues, including several mutations previously reported to affect the signaling of the hIP receptor. Thus, our data demonstrates epPCR mediated random mutagenesis as a valuable and practical method to study the structurefunction relationship of GPCRs. © 2014 Bill et al
Reframing human rights: the global network of moral conservative homeschooling activists
In this article, we investigate the composition and actions of a principled issue network within the field of human rights that uses rights-claims to pursue traditionalist goals: the moral conservative pro-homeschooling network. We analyse the rising importance of homeschooling within the global moral conservative movement and examine the transnationalization of pro-homeschooling advocacy. We show that the transnational homeschooling advocacy network, while not successful in court cases, has managed to establish home education as part of a global conservative agenda and has made incursions into redefining the terms of the debate within international organizations. Moral conservative homeschooling advocates use a vocabulary of rights and freedoms, and even of moral pluralism, but in the conservative reading human rights are reframed and used to defend a pro-family agenda that establishes the patriarchal family as the ultimate source of authority and the primary carrier of rights
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