1,355 research outputs found
The Closing of the Gates The Politics of Xenophobia in Immigrant Nations
The following study seeks to explain the reason for increasing immigration restriction in countries with strong histories of immigration. The main country of focus is the United States, with Argentina and Canada analyzed in comparison. After exploring the conventional answers of: right-wing populism, economic explanations, and security concerns, the study makes the argument that a history of deep-rooted xenophobia is the best explanation for increasing immigration restriction in all three countries of analysis
Hybrid adiabatic quantum computing for tomographic image reconstruction -- opportunities and limitations
Our goal is to reconstruct tomographic images with few measurements and a low
signal-to-noise ratio. In clinical imaging, this helps to improve patient
comfort and reduce radiation exposure. As quantum computing advances, we
propose to use an adiabatic quantum computer and associated hybrid methods to
solve the reconstruction problem. Tomographic reconstruction is an ill-posed
inverse problem. We test our reconstruction technique for image size, noise
content, and underdetermination of the measured projection data. We then
present the reconstructed binary and integer-valued images of up to 32 by 32
pixels. The demonstrated method competes with traditional reconstruction
algorithms and is superior in terms of robustness to noise and reconstructions
from few projections. We postulate that hybrid quantum computing will soon
reach maturity for real applications in tomographic reconstruction. Finally, we
point out the current limitations regarding the problem size and
interpretability of the algorithm
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One-fifth-scale and full-scale fuel element rocking tests. [HTGR]
Using /sup 1///sub 5/-scale and /sup 1///sub 1/-scale (prototype H451) fuel elements, one, two, or three stacked elements on a clamped base element were rocked from an initial release position. Relative displacement, rock-down loads, and dowel pin shear forces were measured. A scaled comparison between /sup 1///sub 5/-scale and /sup 1///sub 1/-scale results was made to evaluate the model scaling laws, and an error analysis was performed to assess the accuracy and usefulness of the test data
Dietary supplementation with lactose or artificial sweetener enhances swine gut Lactobacillus population abundance
The commensal bacteria Lactobacillus are widely used as probiotic organisms conferring a heath benefit on the host. They have been implicated in promoting gut health via the stimulation of host immunity and anti-inflammatory responses, as well as protecting the intestinalmucosa against pathogen invasion. Lactobacilli grow by fermenting sugars and starches and produce lactic acid as their primary metabolic product. For efficient utilisation of varied carbohydrates, lactobacilli have evolved diverse sugar transport and metabolic systems, which are specifically induced by their own substrates. Many bacteria are also capable of sensing and responding to changes in their environment. These sensory responses are often independent of transport or metabolism and are mediated through membrane-spanning receptor proteins. We employed DNA-based pyrosequencing technology to investigate the changes in the intestinal microbiota of piglets weaned to a diet supplemented with either a natural sugar, lactose or an artificial sweetener (SUCRAM®, consisting of saccharin and neohesperidin dihydrochalcone (NHDC); Pancosma SA). The addition of either lactose or saccharin/NHDC to the piglets' feed dramatically increased the caecal population abundance of Lactobacillus, with concomitant increases in intraluminal lactic acid concentrations. This is the first report of the prebiotic-like effects of saccharin/NHDC, an artificial sweetener, being able to influence the commensal gut microbiota. The identification of the underlying mechanism(s) will assist in designing nutritional strategies for enhancing gut immunity and maintaining gut healt
Laparoscopic Distal Pancreatectomy with Splenic Conservation: An Operation without Increased Morbidity
Objectives. The advent of minimally invasive techniques was marked by a paradigm shift towards the use of laparoscopy for benign distal pancreatic masses. Herein we describe one center's experience with laparoscopic distal pancreatectomy. Methods. A retrospective chart review was performed for all distal pancreatectomies completed laparoscopically from 1999 to 2009. Outcomes from those cases completed with a concurrent splenectomy were compared to the spleen-preserving procedures. Results. Twenty-four patients underwent laparoscopic distal pancreatectomy. Seven had spleen-conserving operations. There was no difference in the mean estimated blood loss (316 versus 285 mL, P = .5) or operative time (179 versus 170 minutes, P = .9). The mean tumor size was not significantly different (3.1 versus 2.2 cm, P = .9). There was no difference in the average hospital stay (7.1 versus 7.0 days, P = .7). Complications in the spleen-preserving group included one iatrogenic colon injury, two pancreatic fistulas, and two cases of iatrogenic diabetes. In the splenectomy group, two developed respiratory failure, three acquired iatrogenic diabetes, and two suffered pancreatic fistulas (71% versus 41%, P = .4). Conclusions. The laparoscopic distal pancreatectomy is a safe operation with a low morbidity. Splenic conservation does not significantly increase the morbidity of the procedure
Исследование влияния технологического процесса изготовления обмоток на дефектность корпусной изоляции асинхронных двигателей
В работе проведено исследование влияния колебаний режимов работы статорообмоточных станков WST-660 и пазоизолировочных станков ИПС-3 на дефектность корпусной изоляции. Получены математические модели дефектообразования в корпусной изоляции обмотки с учетом режимов работы технологического оборудования и качества материала корпусной изоляции в состоянии поставки. Установлено, что изменением режимов работы технологического оборудования можно добиться требуемого качества корпусной изоляции при максимальной производительности оборудования
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Default perception of high-speed motion
When human observers are exposed to even slight motion signals followed by brief visual transients—stimuli containing no detectable coherent motion signals—they perceive large and salient illusory jumps. This novel effect, which we call “high phi”, challenges well-entrenched assumptions about the perception of motion, namely the minimal-motion principle and the breakdown of coherent motion perception with steps above an upper limit. Our experiments with transients such as texture randomization or contrast reversal show that the magnitude of the jump depends on spatial frequency and transient duration, but not on the speed of the inducing motion signals, and the direction of the jump depends on the duration of the inducer. Jump magnitude is robust across jump directions and different types of transient. In addition, when a texture is actually displaced by a large step beyond dmax, a breakdown of coherent motion perception is expected, but in the presence of an inducer observers again perceive coherent displacements at or just above dmax. In sum, across a large variety of stimuli, we find that when incoherent motion noise is preceded by a small bias, instead of perceiving little or no motion, as suggested by the minimal-motion principle, observers perceive jumps whose amplitude closely follows their own dmax limits
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