Optical Cherenkov radiation by cascaded nonlinear interaction: an efficient source of few-cycle energetic near- to mid-IR pulses

When ultrafast noncritical cascaded second-harmonic generation of energetic femtosecond pulses occur in a bulk lithium niobate crystal optical Cherenkov waves are formed in the near- to mid-IR. Numerical simulations show that the few-cycle solitons radiate Cherenkov (dispersive) waves in the \lambda=2.2-4.5\mic range when pumping at \lambda_1=1.2-1.8\mic. The exact phase-matching point depends on the soliton wavelength, and we show that a simple longpass filter can separate the Cherenkov waves from the solitons. The Cherenkov waves are born few-cycle with an excellent Gaussian pulse shape, and the conversion efficiency is up to 25%. Thus, optical Cherenkov waves formed with cascaded nonlinearities could become an efficient source of energetic near- to mid-IR few-cycle pulses.Comment: Extended version of Nonlinear Optics 2011 contribution http://www.opticsinfobase.org/abstract.cfm?URI=NLO-2011-NTuA7. Submitted for Optics Express special issue for NLO conferenc

Cystic colon duplication causing intussusception in a 25-year-old man: report of a case and review of the literature

<p>Abstract</p> <p>Background</p> <p>Colonic intussusception is a rare congenital abnormality, mostly manifesting before the age of two with abdominal pain and acute intestinal obstruction with or without bleeding. In adults it may occur idiopathically or due to an intraluminal tumor mass.</p> <p>Case presentation</p> <p>A 25-year-old man presented with an acute abdomen and severe crampy abdominal pain. The clinical picture mimicked acute appendicitis. Transabdominal ultrasound examination revealed a 5 cm circular mass in the right upper abdomen. The ensuing computed tomography suggested an intussusception in the ascending colon. Intraoperatively, no full thickness invagination was detected. Due to a hard, intraluminal tumor a standard right hemicolectomy with ileotransversostomy was performed. The histopathological analysis revealed a cystic colon duplication leading to mucosal invagination and obstruction.</p> <p>Conclusions</p> <p>In adults, colon intussusception is a rare event causing approximately 1% of all acute intestinal obstructions. Unlike its preferentially nonsurgical management in children, a bowel intussusception in adults should be operated because an organic, often malignant lesion is present in most cases.</p

Evaluation of the Effects of Powder Coating Cure Temperatures on the Mechanical Properties of Aluminum Alloy Substrates

The effects of curing temperature, based on new, low-temperature powder coating methods and traditional high-temperature powder coating methods, were studied. Heat-sensitive aluminum alloys (2024-T3, 6061-T6, and 7075-T6) were subjected to two different heat-treatment cycles, which were based on temperatures of 121 and 204 degrees C. Findings indicate that although both cure temperatures achieved powder coatings adhesion and thickness appropriate for industrial uses, the high-temperature cure treatment negatively affected the mechanical properties

Left sided inferior vena cava duplication and venous thromboembolism: case report and review of literature

The etiology of venous thromboembolism in young patients is frequently associated with hereditary coagulation abnormalities, immunologic diseases, and neoplasia. The advent of radiological advances, namely Computed Tomography (CT) scans and venography has identified vena cava malformations as a new etiologic factor worthy of consideration. In this case report, we describe the unusual occurrence of venous thromboembolism in association with a duplicated inferior vena cava. Duplications of the inferior vena cava (IVC) are seen with an incidence of 0.2% to 3.0% in the general population. Embryogenesis of the IVC is a complex process involving the intricate formation and regression of numerous anastomoses, potentially leading to various anomalies. We present a 23-year-old Caucasian woman with IVC duplication who developed a deep venous thrombosis and multiple pulmonary emboli. Anomaly of the IVC is a rare example of a congenital condition that predisposes to thromboembolism, presumably by favoring venous stasis. This diagnosis should be considered in patients under the age of 30 with spontaneous occurrence of blood clots

The Nexus of Political Violence and Economic Deprivation: Pakistani Migrants Disrupt the Refugee / Migrant Dichotomy

There have been discussions about how the labels “forced migrants,” related to political violence, and “voluntary migrants,” associated with economic factors, cannot be understood in categorical ways. However, there has been less focus on the specificities of the asylum-migrant nexus from the perspective of migrants. This essay discusses how such factors intersect as understood by Pakistani migrants residing in Germany. Through enacting a critical view of Pakistan, the migrants demonstrate how aspects of corruption, economic deprivation, and political violence come to intersect so that is becomes impossible to classify asylum seekers in binary/dichotomous ways

Association of extent of cannabis use and psychotic like intoxication experiences in a multi-national sample of first episode psychosis patients and controls

BackgroundFirst episode psychosis (FEP) patients who use cannabis experience more frequent psychotic and euphoric intoxication experiences compared to controls. It is not clear whether this is consequent to patients being more vulnerable to the effects of cannabis use or to their heavier pattern of use. We aimed to determine whether extent of use predicted psychotic-like and euphoric intoxication experiences in patients and controls and whether this differs between groups.MethodsWe analysed data on patients who had ever used cannabis (n = 655) and controls who had ever used cannabis (n = 654) across 15 sites from six countries in the EU-GEI study (2010-2015). We used multiple regression to model predictors of cannabis-induced experiences and to determine if there was an interaction between caseness and extent of use.ResultsCaseness, frequency of cannabis use and money spent on cannabis predicted psychotic-like and euphoric experiences (p ≤ 0.001). For psychotic-like experiences (PEs) there was a significant interaction for caseness × frequency of use (p &lt; 0.001) and caseness × money spent on cannabis (p = 0.001) such that FEP patients had increased experiences at increased levels of use compared to controls. There was no significant interaction for euphoric experiences (p &gt; 0.5).ConclusionsFEP patients are particularly sensitive to increased psychotic-like, but not euphoric experiences, at higher levels of cannabis use compared to controls. This suggests a specific psychotomimetic response in FEP patients related to heavy cannabis use. Clinicians should enquire regarding cannabis related PEs and advise that lower levels of cannabis use are associated with less frequent PEs

Carbon sequestration potential of the South Wales Coalfield

This paper presents a preliminary evaluation of the carbon dioxide (CO2) storage capacity of the unmined coal resources in the South Wales Coalfield, UK. Although a significant amount of the remaining coal may be mineable through traditional techniques, the prospects for opening new mines appear poor. Also, many of the South Wales coal seams are lying unused since they are too deep to be mined economically using conventional methods. There is instead a growing worldwide interest in the potential for releasing the energy value of such coal reserves through alternative technologies – for example through carbon dioxide sequestration with enhanced coal bed methane recovery. In this study, geographical information systems and three-dimensional interpolation are used to obtain the total unmined coal resource below 500 m deep, where the candidate seams for carbon dioxide sequestration are found. The ‘proved’, ‘probable’ and ‘possible’ carbon dioxide storage capacities of the South Wales Coalfield are then obtained using an established methodology. Input parameters are based on statistical distributions, considering a combination of laboratory coal characterisation results and literature review. The results are a proved capacity of 70·1 Mt carbon dioxide, a probable capacity of 104·9 Mt carbon dioxide and a possible capacity of 152·0 Mt carbon dioxide

The contribution of cannabis use to the increased psychosis risk among minority ethnic groups in Europe

Background: We examined whether cannabis use contributes to the increased risk of psychotic disorder for non-western minorities in Europe. Methods: We used data from the EU-GEI study (collected at sites in Spain, Italy, France, the United Kingdom, and the Netherlands) on 825 first-episode patients and 1026 controls. We estimated the odds ratio (OR) of psychotic disorder for several groups of migrants compared with the local reference population, without and with adjustment for measures of cannabis use. Results: The OR of psychotic disorder for non-western minorities, adjusted for age, sex, and recruitment area, was 1.80 (95% CI 1.39-2.33). Further adjustment of this OR for frequency of cannabis use had a minimal effect: OR = 1.81 (95% CI 1.38-2.37). The same applied to adjustment for frequency of use of high-potency cannabis. Likewise, adjustments of ORs for most sub-groups of non-western countries had a minimal effect. There were two exceptions. For the Black Caribbean group in London, after adjustment for frequency of use of high-potency cannabis the OR decreased from 2.45 (95% CI 1.25-4.79) to 1.61 (95% CI 0.74-3.51). Similarly, the OR for Surinamese and Dutch Antillean individuals in Amsterdam decreased after adjustment for daily use: from 2.57 (95% CI 1.07-6.15) to 1.67 (95% CI 0.62-4.53). Conclusions: The contribution of cannabis use to the excess risk of psychotic disorder for non-western minorities was small. However, some evidence of an effect was found for people of Black Caribbean heritage in London and for those of Surinamese and Dutch Antillean heritage in Amsterdam

Design of an optimized nested-mirror neutron reflector for a NNBAR experiment

The NNBAR experiment for the European Spallation Source will search for free neutrons converting to antineutrons with an expected sensitivity improvement of three orders of magnitude compared to the last such search. This paper describes both the simulations of a key component for the experiment, the neutron optical reflector and the expected gains in sensitivity