The RF power coupler development programme at LAL-Orsay and DESY-Hamburg for TESLA and the European X-FEL

In the context of a collaboration between LAL (Orsay) and DESY (Hamburg) a programme of development and tests of proto-type power couplers for superconducting cavities is underway in Orsay. Such couplers need to be developed for linear accelerators which require high gradient superconducting cavities, such as the European X-ray Free Electron Laser or the International Linear Collider (ILC) project. We will describe the technical demands which have to be met to build such couplers and will present pro-type designs which are intended to meet these demands, taking the ILC as an example. A description of the infra-structure necessary for the coupler development will also be given along with first high power tests results on a series of power couplers built in industry

Group A Streptococcus in the Gynecologic Patient

Background: Over the past few decades, physicians have been reminded of the potential for serious complications arising from group A streptococcal (GAS) infections. These infections continue to pose a serious threat, primarily because the pathophysiology of these infections is complex. This article reviews some of the features of GAS infections and presents two case reports of GAS pelvic infections in women

The Role of Uncoupling Protein 3 in Human Physiology

Obesity is simply understood as an imbalance between energy intake and expenditure in favor of weight accretion. However, the human biological interface between food consumption and energy dissipation results in broad individual differences in eating behavior, physical activity, and efficiency of fuel storage and metabolism. In particular, the basal metabolic rate, which accounts for the greatest portion of overall energy expenditure, can vary almost twofold among individuals. Classically, three major biochemical systems are believed to contribute to basal thermogenesis: futile cycles, Na+/K+ATPase activity, and mitochondrial proton leak. The latter is the most important quantitative contributor and can explain up to 50% of the basal metabolic rate (1). The molecular basis of mitochondrial proton leak is unclear, despite its importance in the understanding of energy balance and its potential as a therapeutic target for obesity treatment. The article by Hesselink and colleagues in this issue of the JCI (2) addresses whether uncoupling protein 3 contributes to mitochondrial proton leak in human skeletal muscle

New options for the treatment of obesity and type 2 diabetes mellitus (narrative review)

AbstractModerate weight loss (>5%), which has been associated with improvements in glycemic parameters in patients with dysglycemia, also reduces the presence of other comorbidities, including dyslipidemia and hypertension, culminating in a reduced risk of cardiovascular disease. Lifestyle changes are the recommended preliminary approach to weight loss, with an initial weight-loss goal of 10% of body weight achieved over 6 months at a rate of 1–2 pounds per week selected as an appropriate target to decrease the severity of obesity-related risk factors. Implementing and maintaining the lifestyle changes associated with weight loss can, however, be challenging for many patients. Therefore, additional interventions sometimes may be necessary. Bariatric surgery can also be a highly effective option for weight loss and comorbidity reduction, but surgery carries considerable risks and is still applicable only to selected patients with type 2 diabetes. Thus, attention is turning to the use of weight-loss medications, including 2 recently approved compounds: twice-daily lorcaserin and a once-daily combination of phentermine and topiramate extended-release, both shown to be safe and effective therapies in the management of obesity in patients with type 2 diabetes

Proinflammatory cytokine production and insulin sensitivity regulated by overexpression of resistin in 3T3-L1 adipocytes

Resistin is secreted from adipocytes, and high circulating levels have been associated with obesity and insulin resistance. To investigate whether resistin could exert autocrine effects in adipocytes, we expressed resistin gene in 3T3-L1 fibroblasts using a lentiviral vector, and selected several stably-transduced cell lines under blasticidin selection. We observed that 3T3-L1 adipocytes expressing resistin have a decreased gene expression for related transcriptional factors (CCAAT/enhancer binding protein α(C/EBPα) , peroxisome proliferator-activated receptor gamma (PPARγ), and adipocyte lipid binding protein (ALBP/aP2) which is one of target genes for the PPARγ during adipocyte differentiation,. Overexpression of resistin increased the levels of three proinflammatory cytokines, tumor necrosis factor alpha (TNFα), interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1), which play important roles for insulin resistance, glucose and lipid metabolisms during adipogenesis. Furthermore, overexpressing resistin in adipocytes inhibits glucose transport 4 (GLUT4) activity and its gene expression, reducing insulin's ability for glucose uptake by 30 %. In conclusion, resistin overexpression in stably transduced 3T3-L1 cells resulted in: 1) Attenuation of programmed gene expression responsible for adipogenesis; 2) Increase in expression of proinflammatory cytokines; 3) Decrease in insulin responsiveness of the glucose transport system. These data suggest a new role for resistin as an autocrine/paracrine factor affecting inflammation and insulin sensitivity in adipose tissue

Can Weight Loss Improve the Cardiovascular Outcomes of Patients with Obesity and Obstructive Sleep Apnea?

Cardiovascular events are the primary cause of mortality in patients with obstructive sleep apnea and obesity. The rising prevalence of obstructive sleep apnea in recent decades has been linked to increasing rates of obesity. Obstructive sleep apnea has also been linked with many different cardiovascular diseases including coronary artery disease, stroke, heart failure, hypertension, and atrial fibrillation. Obesity is an increasing health concern globally, in part because obesity complications such as hypertension, diabetes, and obstructive sleep apnea increase the risk of cardiovascular diseases. More than 10% weight loss may be required to prevent or reverse obesity complications. Treatment approaches to obesity include nutritional therapy, exercise therapy, pharmacotherapy, and surgical therapies. This review intends to identify the effects of weight loss on cardiovascular outcomes in patients with obesity and obstructive sleep apnea. Despite the strong association between cardiovascular diseases and obstructive sleep apnea, randomized trials have failed to demonstrate that treatment of obstructive sleep apnea reduces cardiovascular events, even in patients with established cardiovascular diseases. Weight loss in patients with obstructive sleep apnea improves HbA1c, systolic blood pressure, HDL cholesterol, and triglycerides, but thus far no changes in cardiovascular events have been shown. The combination of weight loss with continuous positive airway pressure (CPAP) appears more beneficial than either treatment in isolation. Large well-controlled trials in patients with obstructive sleep apnea to assess the effects of different weight reduction programs on cardiovascular disease are still needed

Probing Nucleon Strangeness with Neutrinos: Nuclear Model Dependences

The extraction of the nucleon's strangeness axial charge, Delta_s, from inclusive, quasielastic neutral current neutrino cross sections is studied within the framework of the plane-wave impulse approximation. We find that the value of Delta_s can depend significantly on the choice of nuclear model used in analyzing the quasielastic cross section. This model-dependence may be reduced by one order of magnitude when Delta_s is extracted from the ratio of total proton to neutron yields. We apply this analysis to the interpretation of low-energy neutrino cross sections and arrive at a nuclear theory uncertainty of plus/minus 0.03 on the value of Delta_s expected to be determined from the ratio of proton and neutron yields measured by the LSND collaboration. This error compares favorably with estimates of the SU(3)-breaking uncertainty in the value of Delta_s extracted from inclusive, polarized deep-inelastic structure function measurements. We also point out several general features of the quasielastic neutral current neutrino cross section and compare them with the analogous features in inclusive, quasielastic electron scattering.Comment: 40 pages (including 11 postscript figures), uses REVTeX and epsfig.st