973 research outputs found

    Negative Skin Friction in Piles and Design Decisions

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    Negative skin friction behavior of pile foundations is described for conditions of pile usage in the USA. Methods of determining downdrag load and pile resistance to downdrag are explained. Other factors entering into design are discussed such as pile load testing and analysis, pile structural strength, factors of safety, pile drivability, and reduction of downdrag loads. Observations from seven unpublished negative skin friction failures are used for illustration

    Internally Electrodynamic Particle Model: Its Experimental Basis and Its Predictions

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    The internally electrodynamic (IED) particle model was derived based on overall experimental observations, with the IED process itself being built directly on three experimental facts, a) electric charges present with all material particles, b) an accelerated charge generates electromagnetic waves according to Maxwell's equations and Planck energy equation and c) source motion produces Doppler effect. A set of well-known basic particle equations and properties become predictable based on first principles solutions for the IED process; several key solutions achieved are outlined, including the de Broglie phase wave, de Broglie relations, Schr\"odinger equation, mass, Einstein mass-energy relation, Newton's law of gravity, single particle self interference, and electromagnetic radiation and absorption; these equations and properties have long been broadly experimentally validated or demonstrated. A specific solution also predicts the Doebner-Goldin equation which emerges to represent a form of long-sought quantum wave equation including gravity. A critical review of the key experiments is given which suggests that the IED process underlies the basic particle equations and properties not just sufficiently but also necessarily.Comment: Presentation at the 27th Int Colloq on Group Theo Meth in Phys, 200

    The Locality Problem in Quantum Measurements

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    The locality problem of quantum measurements is considered in the framework of the algebraic approach. It is shown that contrary to the currently widespread opinion one can reconcile the mathematical formalism of the quantum theory with the assumption of the existence of a local physical reality determining the results of local measurements. The key quantum experiments: double-slit experiment on electron scattering, Wheeler's delayed-choice experiment, the Einstein-Podolsky-Rosen paradox, and quantum teleportation are discussed from the locality-problem point of view. A clear physical interpretation for these experiments, which does not contradict the classical ideas, is given.Comment: Latex, 40 pages, 7 figure

    Full-length human placental sFlt-1-e15a isoform induces distinct maternal phenotypes of preeclampsia in mice

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    <div><p>Objective</p><p>Most anti-angiogenic preeclampsia models in rodents utilized the overexpression of a truncated soluble fms-like tyrosine kinase-1 (sFlt-1) not expressed in any species. Other limitations of mouse preeclampsia models included stressful blood pressure measurements and the lack of postpartum monitoring. We aimed to 1) develop a mouse model of preeclampsia by administering the most abundant human placental sFlt-1 isoform (hsFlt-1-e15a) in preeclampsia; 2) determine blood pressures in non-stressed conditions; and 3) develop a survival surgery that enables the collection of fetuses and placentas and postpartum (PP) monitoring.</p><p>Methods</p><p>Pregnancy status of CD-1 mice was evaluated with high-frequency ultrasound on gestational days (GD) 6 and 7. Telemetry catheters were implanted in the carotid artery on GD7, and their positions were verified by ultrasound on GD13. Mice were injected through tail-vein with adenoviruses expressing hsFlt-1-e15a (n = 11) or green fluorescent protein (GFP; n = 9) on GD8/GD11. Placentas and pups were delivered by cesarean section on GD18 allowing PP monitoring. Urine samples were collected with cystocentesis on GD6/GD7, GD13, GD18, and PPD8, and albumin/creatinine ratios were determined. GFP and hsFlt-1-e15a expression profiles were determined by qRT-PCR. Aortic ring assays were performed to assess the effect of hsFlt-1-e15a on endothelia.</p><p>Results</p><p>Ultrasound predicted pregnancy on GD7 in 97% of cases. Cesarean section survival rate was 100%. Mean arterial blood pressure was higher in hsFlt-1-e15a-treated than in GFP-treated mice (∆MAP = 13.2 mmHg, p = 0.00107; GD18). Focal glomerular changes were found in hsFlt-1-e15a -treated mice, which had higher urine albumin/creatinine ratios than controls (109.3±51.7μg/mg vs. 19.3±5.6μg/mg, p = 4.4x10<sup>-2</sup>; GD18). Aortic ring assays showed a 46% lesser microvessel outgrowth in hsFlt-1-e15a-treated than in GFP-treated mice (p = 1.2x10<sup>-2</sup>). Placental and fetal weights did not differ between the groups. One mouse with liver disease developed early-onset preeclampsia-like symptoms with intrauterine growth restriction (IUGR).</p><p>Conclusions</p><p>A mouse model of late-onset preeclampsia was developed with the overexpression of hsFlt-1-e15a, verifying the <i>in vivo</i> pathologic effects of this primate-specific, predominant placental sFlt-1 isoform. HsFlt-1-e15a induced early-onset preeclampsia-like symptoms associated with IUGR in a mouse with a liver disease. Our findings support that hsFlt-1-e15a is central to the terminal pathway of preeclampsia, and it can induce the full spectrum of symptoms in this obstetrical syndrome.</p></div

    Scale-Up of the Nitridation and Sintering of Silicon Preforms Using Microwave Heating

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    AbstractScale-up studies were performed in which microwave heating was used to fabricate reactionbonded silicon nitride and sintered reaction-bonded silicon nitride (SRBSN). Tests were performed in both a 2.45 GHz, 500 liter and a 2.45 GHz, 4000 liter multimode cavities. A variety of sizes, shapes, and compositions of silicon preforms were processed in the studies, including bucket tappets and clevis pins for diesel engines. Up to 230 samples were processed in a single microwave furnace run. Data were collected which included weight gains for nitridation experiments, and final densities for nitridation and sintering experiments. For comparison, nitridation and sintering studies were performed using a conventional resistance-heated furnace.</jats:p

    Nutritional care is a human right: Translating principles to clinical practice

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    We have previously advocated that nutritional care be raised to the level of a human right, in close relationship to two well-recognized fundamental rights: the right to food and the right to health. This article aims to analyze the implication of nutritional care as a human right for healthcare practitioners. We will focus on the impact of the Human Rights Basic Approach (HRBA) on healthcare professionals (HCPs), namely how they can translate HRBA into routine clinical practice. Ethics and human rights are guiding values for clinical nutrition practitioners. Together they ensure a patient-centered approach, in which the needs and rights of the patients are of the most significant importance. Human rights are based on the powerful idea of equal dignity for all people while expressing a set of core values, including fairness, respect, equality, dignity, and autonomy (FREDA). Through the analysis of FREDA principles, we have provided the elements to understand human rights and how an HRBA can support clinicians in the decision-making process. Clinical practice guidelines in clinical nutrition should incorporate disease-specific ethical issues and the HRBA. The HRBA should contribute to building conditions for HCPs to provide optimal and timely nutritional care. Nutritional care must be exercised by HCPs with due respect for several fundamental ethical values: attentiveness, responsibility competence, responsiveness, and solidarity

    A Spontaneous Mutation in Contactin 1 in the Mouse

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    Mutations in the gene encoding the immunoglobulin-superfamily member cell adhesion molecule contactin1 (CNTN1) cause lethal congenital myopathy in human patients and neurodevelopmental phenotypes in knockout mice. Whether the mutant mice provide an accurate model of the human disease is unclear; resolving this will require additional functional tests of the neuromuscular system and examination of Cntn1 mutations on different genetic backgrounds that may influence the phenotype. Toward these ends, we have analyzed a new, spontaneous mutation in the mouse Cntn1 gene that arose in a BALB/c genetic background. The overt phenotype is very similar to the knockout of Cntn1, with affected animals having reduced body weight, a failure to thrive, locomotor abnormalities, and a lifespan of 2–3 weeks. Mice homozygous for the new allele have CNTN1 protein undetectable by western blotting, suggesting that it is a null or very severe hypomorph. In an analysis of neuromuscular function, neuromuscular junctions had normal morphology, consistent with previous studies in knockout mice, and the muscles were able to generate appropriate force when normalized for their reduced size in late stage animals. Therefore, the Cntn1 mutant mice do not show evidence for a myopathy, but instead the phenotype is likely to be caused by dysfunction in the nervous system. Given the similarity of CNTN1 to other Ig-superfamily proteins such as DSCAMs, we also characterized the expression and localization of Cntn1 in the retinas of mutant mice for developmental defects. Despite widespread expression, no anomalies in retinal anatomy were detected histologically or using a battery of cell-type specific antibodies. We therefore conclude that the phenotype of the Cntn1 mice arises from dysfunction in the brain, spinal cord or peripheral nervous system, and is similar in either a BALB/c or B6;129;Black Swiss background, raising a possible discordance between the mouse and human phenotypes resulting from Cntn1 mutations

    Nutritional care is a human right: Translating principles to clinical practice

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    We have previously advocated that nutritional care be raised to the level of a human right in a close relationship to two well recognized fundamental rights: the right to food and the right to health. This paper aims to analyze the implication of nutritional care as a human right for healthcare practitioners. We will focus on the impact of the Human Rights Basic Approach (HRBA) on health care professionals (HCPs), namely how they can translate HRBA into routine clinical practice. Ethics and human rights are guiding values for clinical nutrition practitioners. Together they ensure a patient-centered approach, where the needs and rights of the patients are of the most significant importance. Human rights are based on the powerful idea of equal dignity for all people while expressing a set of core values, including fairness, respect, equality, dignity, and autonomy (FREDA). Through the analysis of FREDA principles, we have provided the elements to understand human rights and how a HRBA can support clinicians in the decision-making process. Clinical practice guidelines in clinical nutrition should incorporate disease-specific ethical issues and the HRBA. The HRBA should contribute to build conditions for HCPs to provide optimal and timely nutritional care. Nutritional care must be exercised by HCPs with due respect for several fundamental ethical values: attentiveness, responsibility competence, responsiveness, and solidarity
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