480 research outputs found
AIAA Design, Build, Fly: Structures and Controls
For their Santa Clara University Senior Design Project, this team chose to create an unmanned aerial vehicle (UAV) with the intent of participating in the AIAA Design, Build, Fly competition. Divided into two subteams, Aerodynamics and Structures & Controls, the teams worked together to model and construct a working prototype aircraft. The Aerodynamics team focused on selecting adequate airfoil and wing dimensions for the main wing and tail through the use of aircraft design software and CFD simulations. Aiming at a cruise speed of approximately 25 m/s, the team decided that the NACA 4416 airfoil would be the most suitable, with a chord length of 0.3 m and a wingspan of 1.5 m. The Structures & Controls team focused on the integration of the chosen airfoil into a full aircraft assembly, in addition to selection of sub-components for control and propulsion. After considering a balsa wood, carbon sheet, or foam construction, a balsa wood buildup was selected as the ideal manufacturing method to meet the system requirements. Finite element models (FEM) and simulations were preformed to design and analyze the integrity and strength of such a structure under various load cases. For sub-systems a fixed tricycle landing gear set-up was selected to minimize system weight and complexity. For an expected 3.175 kg gross weight with payload, propulsion components were selected based on power requirements established by the Aerodynamics team, consisting of a 2000W 520 Kv brushless DC motor, 22.2 Volt 4,500 mAh LiPo battery, and 15x6E propeller. The control surface actuators chosen were servo motors sized by aerodynamic analysis of the control surfaces. Finally control and transmission components were taken from current inventory including: 2.4 GHz Spektrum DX8 controller and 2.4 GHz X8R receiver. The culmination of this design project resulted in a successful test flight containing a 1 kg payload
A Case of Intramural Coronary Amyloidosis Associated With Hemodialysis
Dialysis-related amyloidosis predominantly occurs in osteo-articular structures and dialysis-related amyloid (DRA) substances also deposit in extra-articular tissues. Clinical manifestations of DRA include odynophagia, gastrointestinal hemorrhage, intestinal obstruction, kidney stones, myocardial dysfunction, and subcutaneous tumors. The pathological characteristics of DRA in the heart of hemodialysis patients have rarely been reported. We report the case of a 73-year-old female with a history of cerebral palsy and end-stage renal disease status post two failed renal transplants who had been on hemodialysis for 30 years. The patient was admitted with the working diagnosis of pneumonia. An echocardiography showed markedly reduced biventricular function manifested by low blood pressure with systolic in the 70s and elevated pulmonary artery pressure of 45 mmHg, which did not respond to therapy. Following her demise, the autopsy revealed bilateral pulmonary edema and pleural effusions. There was cardiac amyloid deposition exclusively in the coronary arteries but not in the perimyocytic interstitium. Amyloids were also found in pulmonary and intrarenal arteries and the colon wall. Previous case reports showed that beta 2-microglobulin amyloid deposits in various visceral organs but less frequently in the atrial and/or the ventricular myocardium. In the present case, amyloids in the heart were present in the intramural coronary arteries causing myocardial ischemia and infarction, which was the immediate cause of death
A case of intramural coronary amyloidosis associated with hemodialysis
Dialysis-related amyloidosis predominantly occurs in osteo-articular structures and dialysis-related amyloid (DRA) substances also deposit in extra-articular tissues. Clinical manifestations of DRA include odynophagia, gastrointestinal hemorrhage, intestinal obstruction, kidney stones, myocardial dysfunction, and subcutaneous tumors. The pathological characteristics of DRA in the heart of hemodialysis patients have rarely been reported. We report the case of a 73-year-old female with a history of cerebral palsy and end-stage renal disease status post two failed renal transplants who had been on hemodialysis for 30 years. The patient was admitted with the working diagnosis of pneumonia. An echocardiography showed markedly reduced biventricular function manifested by low blood pressure with systolic in the 70s and elevated pulmonary artery pressure of 45 mmHg, which did not respond to therapy. Following her demise, the autopsy revealed bilateral pulmonary edema and pleural effusions. There was cardiac amyloid deposition exclusively in the coronary arteries but not in the perimyocytic interstitium. Amyloids were also found in pulmonary and intrarenal arteries and the colon wall. Previous case reports showed that beta 2-microglobulin amyloid deposits in various visceral organs but less frequently in the atrial and/or the ventricular myocardium. In the present case, amyloids in the heart were present in the intramural coronary arteries causing myocardial ischemia and infarction, which was the immediate cause of deat
Metastatic Mantle Cell Lymphoma to the Pituitary Gland: Case Report and Literature Review
We present an unusual case of a metastatic mantle cell lymphoma (MCL) to the pituitary gland. The patient had a known history of MCL for which she previously received chemotherapy. She presented with new-onset diplopia and confusion, and reported a history of progressive vision blurriness associated with headache, nausea, and vomiting. MRI of the brain showed an enhancing lesion within the sella turcica involving the cavernous sinuses bilaterally, extending into Meckel\u27s cave on the left, and abutting the optic nerves bilaterally. Following surgical excision, histopathology revealed the tumor to be a MCL. Metastatic pituitary tumors are rare and have been estimated to make up 1% of tumors discovered in the sellar region. The two most common secondary metastatic lesions to the sella are breast and lung carcinoma followed by prostate, renal cell, and gastrointestinal carcinoma. Metastatic lymphoma to the pituitary gland is especially rare and is estimated to constitute 0.5% of all metastatic tumors to the sella turcica. To our knowledge, this is the first reported case of MCL metastasizing to the pituitary gland
RMDO-2, Olig-2 and Synaptophysin Expression Is a Frequent Event in Malignant Melanoma: Diagnostic Pitfalls in Glial Tumor
A case of intramural coronary amyloidosis associated with hemodialysis
Dialysis-related amyloidosis predominantly occurs in osteo-articular structures and dialysis-related amyloid (DRA) substances also deposit in extra-articular tissues. Clinical manifestations of DRA include odynophagia, gastrointestinal hemorrhage, intestinal obstruction, kidney stones, myocardial dysfunction, and subcutaneous tumors. The pathological characteristics of DRA in the heart of hemodialysis patients have rarely been reported. We report the case of a 73-year-old female with a history of cerebral palsy and end-stage renal disease status post two failed renal transplants who had been on hemodialysis for 30 years. The patient was admitted with the working diagnosis of pneumonia. An echocardiography showed markedly reduced biventricular function manifested by low blood pressure with systolic in the 70s and elevated pulmonary artery pressure of 45 mmHg, which did not respond to therapy. Following her demise, the autopsy revealed bilateral pulmonary edema and pleural effusions. There was cardiac amyloid deposition exclusively in the coronary arteries but not in the perimyocytic interstitium. Amyloids were also found in pulmonary and intrarenal arteries and the colon wall. Previous case reports showed that beta 2-microglobulin amyloid deposits in various visceral organs but less frequently in the atrial and/or the ventricular myocardium. In the present case, amyloids in the heart were present in the intramural coronary arteries causing myocardial ischemia and infarction, which was the immediate cause of deat
Personal and Ambient Air Pollution is Associated with Increased Exhaled Nitric Oxide in Children with Asthma
BACKGROUND: Research has shown associations between pediatric asthma outcomes and airborne particulate matter (PM). The importance of particle components remains to be determined. METHODS: We followed a panel of 45 schoolchildren with persistent asthma living in Southern California. Subjects were monitored over 10 days with offline fractional exhaled nitric oxide (Fe(NO)), a biomarker of airway inflammation. Personal active sampler exposures included continuous particulate matter < 2.5 μm in aerodynamic diameter (PM(2.5)), 24-hr PM(2.5) elemental and organic carbon (EC, OC), and 24-hr nitrogen dioxide. Ambient exposures included PM(2.5), PM(2.5) EC and OC, and NO(2). Data were analyzed with mixed models controlling for personal temperature, humidity and 10-day period. RESULTS: The strongest positive associations were between Fe(NO) and 2-day average pollutant concentrations. Per interquartile range pollutant increase, these were: for 24 μg/m(3) personal PM(2.5), 1.1 ppb Fe(NO) [95% confidence interval (CI), 0.1–1.9]; for 0.6 μg/m(3) personal EC, 0.7 ppb Fe(NO) (95% CI, 0.3–1.1); for 17 ppb personal NO(2), 1.6 ppb Fe(NO) (95% CI, 0.4–2.8). Larger associations were found for ambient EC and smaller associations for ambient NO(2). Ambient PM(2.5) and personal and ambient OC were significant only in subjects taking inhaled corticosteroids (ICS) alone. Subjects taking both ICS and antileukotrienes showed no significant associations. Distributed lag models showed personal PM(2.5) in the preceding 5 hr was associated with Fe(NO). In two-pollutant models, the most robust associations were for personal and ambient EC and NO(2), and for personal but not ambient PM(2.5). CONCLUSION: PM associations with airway inflammation in asthmatics may be missed using ambient particle mass, which may not sufficiently represent causal pollutant components from fossil fuel combustion
Estrogen Treatment Reverses Prematurity-Induced Disruption in Cortical Interneuron Population
Development of cortical interneurons continues until the end of human pregnancy. Premature birth deprives the newborns from the supply of maternal estrogen and a secure intrauterine environment. Indeed, preterm infants suffer from neurobehavioral disorders. This can result from both preterm birth and associated postnatal complications, which might disrupt recruitment and maturation of cortical interneurons. We hypothesized that interneuron subtypes, including parvalbumin-positive (PV(+)), somatostatin-positive (SST(+)), calretinin-positive (CalR(+)), and neuropeptide Y-positive (NPY(+)) interneurons, were recruited in the upper and lower cortical layers in a distinct manner with advancing gestational age. In addition, preterm birth would disrupt the heterogeneity of cortical interneurons, which might be reversed by estrogen treatment. These hypotheses were tested by analyzing autopsy samples from premature infants and evaluating the effect of estrogen supplementation in prematurely delivered rabbits. The PV(+) and CalR(+) neurons were abundant, whereas SST(+) and NPY(+) neurons were few in cortical layers of preterm human infants. Premature birth of infants reduced the density of PV(+) or GAD67(+) neurons and increased SST(+) interneurons in the upper cortical layers. Importantly, 17 beta-estradiol treatment in preterm rabbits increased the number of PV(+) neurons in the upper cortical layers relative to controls at postnatal day 14 (P14) and P21 and transiently reduced SST population at P14. Moreover, protein and mRNA levels of Arx, a key regulator of cortical interneuron maturation and migration, were higher in estrogen-treated rabbits relative to controls. Therefore, deficits in PV(+) and excess of SST(+) neurons in premature newborns are ameliorated by estrogen replacement, which can be attributed to elevated Arx levels. Estrogen replacement might enhance neurodevelopmental outcomes in extremely preterm infants.SIGNIFICANCE STATEMENT Premature birth often leads to neurodevelopmental delays and behavioral disorders, which may be ascribed to disturbances in the development and maturation of cortical interneurons. Here, we show that preterm birth in humans is associated with reduced population of parvalbumin-positive (PV(+)) neurons and an excess of somatostatin-expressing interneurons in the cerebral cortex. More importantly, 17 beta-estradiol treatment increased the number of PV(+) neurons in preterm-born rabbits, which appears to be mediated by an elevation in the expression of Arx transcription factor. Hence the present study highlights prematurity-induced reduction in PV(+) neurons in human infants and reversal in their population by estrogen replacement in preterm rabbits. Because preterm birth drops plasma estrogen level 100-fold, estrogen replacement in extremely preterm infants might improve their developmental outcome and minimize neurobehavioral disorders
West Nile Virus Infections Projected from Blood Donor Screening Data, United States, 2003
Routine donor nucleic acid amplification testing is a valuable surveillance screening tool
Deweyan tools for inquiry and the epistemological context of critical pedagogy
This article develops the notion of resistance as articulated in the literature of critical pedagogy as being both culturally sponsored and cognitively manifested. To do so, the authors draw upon John Dewey\u27s conception of tools for inquiry. Dewey provides a way to conceptualize student resistance not as a form of willful disputation, but instead as a function of socialization into cultural models of thought that actively truncate inquiry. In other words, resistance can be construed as the cognitive and emotive dimensions of the ongoing failure of institutions to provide ideas that help individuals both recognize social problems and imagine possible solutions. Focusing on Dewey\u27s epistemological framework, specifically tools for inquiry, provides a way to grasp this problem. It also affords some innovative solutions; for instance, it helps conceive of possible links between the regular curriculum and the study of specific social justice issues, a relationship that is often under-examined. The aims of critical pedagogy depend upon students developing dexterity with the conceptual tools they use to make meaning of the evidence they confront; these are background skills that the regular curriculum can be made to serve even outside social justice-focused curricula. Furthermore, the article concludes that because such inquiry involves the exploration and potential revision of students\u27 world-ordering beliefs, developing flexibility in how one thinks may be better achieved within academic subjects and topics that are not so intimately connected to students\u27 current social lives, especially where students may be directly implicated
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