297 research outputs found

    Oscillations and interactions of dark and dark-bright solitons in Bose-Einstein condensates

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    Solitons are among the most distinguishing fundamental excitations in a wide range of non-linear systems such as water in narrow channels, high speed optical communication, molecular biology and astrophysics. Stabilized by a balance between spreading and focusing, solitons are wavepackets, which share some exceptional generic features like form-stability and particle-like properties. Ultra-cold quantum gases represent very pure and well-controlled non-linear systems, therefore offering unique possibilities to study soliton dynamics. Here we report on the first observation of long-lived dark and dark-bright solitons with lifetimes of up to several seconds as well as their dynamics in highly stable optically trapped 87^{87}Rb Bose-Einstein condensates. In particular, our detailed studies of dark and dark-bright soliton oscillations reveal the particle-like nature of these collective excitations for the first time. In addition, we discuss the collision between these two types of solitary excitations in Bose-Einstein condensates.Comment: 9 pages, 4 figure

    Early cancer detection among rural and urban californians

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    BACKGROUND: Since the stage of cancer detection generally predicts future mortality rates, a key cancer control strategy is to increase the proportion of cancers found in the early stage. This study compared stage of detection for members of rural and urban communities to determine whether disparities were present. METHODS: The California Cancer Registry (CCR), a total population based cancer registry, was used to examine the proportion of early stage presentation for patients with breast, melanoma, and colon cancer from 1988 to 2003. Cancer stage at time of detection for these cancers was compared for rural and urban areas. RESULTS: In patients with breast cancer, there were significantly more patients presenting at early stage in 2003 compared to 1988, but no difference in the percentage of patients presenting with early stage disease between rural and urban dwellers. There were no differences in incidence in early stage cancer incidence between these groups for melanoma patients, as well. In colorectal cancer in 1988, significantly more patients presented with early stage disease in the urban areas (42% vs 34%, p < 0.02). However, over time the rural patients were diagnosed with early stage disease with the same frequency in 2003 as 1988. CONCLUSION: This analysis demonstrates that people in rural and urban areas have their breast, melanoma or colorectal cancers diagnosed at similar stages. Health care administrators may take this information into account in future strategic planning

    High frequency of Fredrickson's phenotypes IV and IIb in Brazilians infected by human immunodeficiency virus

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    BACKGROUND: Human immunodeficiency virus (HIV) infection is very prevalent in Brazil. HIV therapy has been recently associated with coronary heart disease (CHD). Dyslipidemia is a major risk factor for CHD that is frequently described in HIV positive patients, but very few studies have been conducted in Brazilian patients evaluating their lipid profiles. METHODS: In the present work, we evaluated the frequency and severity of dyslipidemia in 257 Brazilian HIV positive patients. Two hundred and thirty-eight (93%) were submitted to antiretroviral therapy (224 treated with protease inhibitors plus nucleoside reverse transcriptase inhibitors, 14 treated only with the latter, 12 naive and 7 had no records of treatment). The average time on drug treatment with antiretroviral therapy was 20 months. None of the patients was under lipid lowering drugs. Cholesterol, triglyceride, phospholipid and free fatty acids were determined by enzymatic colorimetric methods. Lipoprotein profile was estimated by the Friedewald formula and Fredrickson's phenotyping was obtained by serum electrophoresis on agarose. Apolipoprotein B and AI and lipoprotein "a" were measured by nephelometry. RESULTS: The Fredrickson phenotypes were: type IIb (51%), IV (41%), IIa (7%). In addition one patient was type III and another type V. Thirty-three percent of all HIV+ patients presented serum cholesterol levels ≥ 200 mg/dL, 61% LDL-cholesterol ≥ 100 mg/dL, 65% HDL-cholesterol below 40 mg/dL, 46% triglycerides ≥ 150 mg/dL and 10% have all these parameters above the limits. Eighty-six percent of patients had cholesterol/HDL-cholesterol ratio ≥ 3.5, 22% increased lipoprotein "a", 79% increased free fatty acids and 9% increased phospholipids. The treatment with protease inhibitors plus nucleoside reverse transcriptase inhibitors increased the levels of cholesterol and triglycerides in these patients when compared with naïve patients. The HDL-cholesterol (p = 0.01) and apolipoprotein A1 (p = 0.02) levels were inversely correlated with the time of protease inhibitor therapy while total cholesterol levels had a trend to correlate with antiretroviral therapy (p = 0.09). CONCLUSION: The highly varied and prevalent types of dyslipidemia found in Brazilian HIV positive patients on antiretroviral therapies indicate the urgent need for their early diagnosis, the identification of the risk factors for CHD and, when needed, the prompt intervention on their lifestyle and/or with drug treatment

    First-pass perfusion CMR two days after infarction predicts severity of functional impairment six weeks later in the rat heart

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    <p>Abstract</p> <p>Background</p> <p>In humans, dynamic contrast CMR of the first pass of a bolus infusion of Gadolinium-based contrast agent has become a standard technique to identify under-perfused regions of the heart and can accurately demonstrate the severity of myocardial infarction. Despite the clinical importance of this method, it has rarely been applied in small animal models of cardiac disease. In order to identify perfusion delays in the infarcted rat heart, here we present a method in which a T<sub>1 </sub>weighted MR image has been acquired during each cardiac cycle.</p> <p>Methods and results</p> <p>In isolated perfused rat hearts, contrast agent infusion gave uniform signal enhancement throughout the myocardium. Occlusion of the left anterior descending coronary artery significantly reduced the rate of signal enhancement in anterior regions of the heart, demonstrating that the first-pass method was sensitive to perfusion deficits. <it>In vivo </it>measurements of myocardial morphology, function, perfusion and viability were made at 2 and 8 days after infarction. Morphology and function were further assessed using cine-MRI at 42 days. The perfusion delay was larger in rat hearts that went on to develop greater functional impairment, demonstrating that first-pass CMR can be used as an early indicator of infarct severity. First-pass CMR at 2 and 8 days following infarction better predicted outcome than cardiac ejection fraction, end diastolic volume or end systolic volume.</p> <p>Conclusion</p> <p>First-pass CMR provides a predictive measure of the severity of myocardial impairment caused by infarction in a rodent model of heart failure.</p

    Global profiling of co- and post-translationally N-myristoylated proteomes in human cells

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    Protein N-myristoylation is a ubiquitous co- and post-translational modification that has been implicated in the development and progression of a range of human diseases. Here, we report the global N-myristoylated proteome in human cells determined using quantitative chemical proteomics combined with potent and specific human N-myristoyltransferase (NMT) inhibition. Global quantification of N-myristoylation during normal growth or apoptosis allowed the identification of >100 N-myristoylated proteins, >95% of which are identified for the first time at endogenous levels. Furthermore, quantitative dose response for inhibition of N-myristoylation is determined for >70 substrates simultaneously across the proteome. Small-molecule inhibition through a conserved substrate-binding pocket is also demonstrated by solving the crystal structures of inhibitor-bound NMT1 and NMT2. The presented data substantially expand the known repertoire of co- and post-translational N-myristoylation in addition to validating tools for the pharmacological inhibition of NMT in living cells

    Direct application of plasmid DNA containing type I interferon transgenes to vaginal mucosa inhibits HSV-2 mediated mortality

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    The application of naked DNA containing type I interferon (IFN) transgenes is a promising potential therapeutic approach for controlling chronic viral infections. Herein, we detail the application of this approach that has been extensively used to restrain ocular HSV-1 infection, for antagonizing vaginal HSV-2 infection. We show that application of IFN-α1, -α5, and –β transgenes to vaginal mouse lumen 24 hours prior to HSV-2 infection reduces HSV-2 mediated mortality by 2.5 to 3-fold. However, other type I IFN transgenes (IFN- α4, -α5, -α6, and –α9) are non effectual against HSV-2. We further show that the efficacy of IFN-α1 transgene treatment is independent of CD4+ T lymphocytes. However, in mice depleted of CD8+ T lymphocytes, the ability of IFN-α1 transgene treatment to antagonize HSV-2 was lost

    Clinical effect of continuous corrective force delivery in the non-operative treatment of idiopathic scoliosis: a prospective cohort study of the triac-brace

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    A prospective cohort study of skeletally immature idiopathic scoliotic patients treated with the TriaC brace. To determine if the TriaC brace is effective in preventing curve progression in immature adolescent idiopathic scoliotic patients with a very high risk of curve progression based on reported natural history data. The aim of the newly introduced TriaC brace is to reverse the pathologic transverse force pattern by externally applied and continuously present orthotic forces. In the frontal plane the force system used in the TriaC brace is similar to the force system of the conventional braces. However, in the sagittal plane the force system acts only on the thoracic region. In addition, the brace allows upper trunk flexibility without affecting the corrective forces during body motion. In a preliminary study it is demonstrated that the brace prevents further progression of both the Cobb angle and axial rotation in idiopathic scoliosis. Skeletally immature patients with idiopathic scoliosis with curves between 20 and 40° were studied prospectively. Skeletally immature was defined as a Risser sign 0 or 1 for both boys and girls, or pre-menarche or less than 1-year post-menarche for girls. Curves of less than 30° had to have documented progression before entry. The mean age of the patients at the start of treatment was 11.3 ± 3.1 years. All measurements were collected by a single observer, and all patients were followed up to skeletal maturity. Treatment was complete for all participants when they had reached Risser sign 4 and did not show any further growth at length measurements. This was at a mean age of 15.6 ± 1.1 years, with a mean follow-up of 1.6 years post bracing. In our study a successful outcome was obtained in 76% of patients treated with the TriaC brace. Comparing our data to literature data on natural history of a similar cohort shows that the TriaC brace significantly alters the predicted natural history. The current study demonstrates that treatment with the TriaC brace reduces the scoliosis, and that the achieved correction is maintained in some degree after skeletal maturity is reached and bracing is discontinued. It also prevents further progression of the Cobb angle in idiopathic scoliosis. The new brace does not differ from the conventional braces as far as maintaining the deformity is concerned

    Sport and transgender people: a systematic review of the literature relating to sport participation and competitive sport policies

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    Background Whether transgender people should be able to compete in sport in accordance with their gender identity is a widely contested question within the literature and among sport organisations, fellow competitors and spectators. Owing to concerns surrounding transgender people (especially transgender female individuals) having an athletic advantage, several sport organisations place restrictions on transgender competitors (e.g. must have undergone gender-confirming surgery). In addition, some transgender people who engage in sport, both competitively and for leisure, report discrimination and victimisation. Objective To the authors’ knowledge, there has been no systematic review of the literature pertaining to sport participation or competitive sport policies in transgender people. Therefore, this review aimed to address this gap in the literature. Method Eight research articles and 31 sport policies were reviewed. Results In relation to sport-related physical activity, this review found the lack of inclusive and comfortable environments to be the primary barrier to participation for transgender people. This review also found transgender people had a mostly negative experience in competitive sports because of the restrictions the sport’s policy placed on them. The majority of transgender competitive sport policies that were reviewed were not evidence based. Conclusion Currently, there is no direct or consistent research suggesting transgender female individuals (or male individuals) have an athletic advantage at any stage of their transition (e.g. cross-sex hormones, gender-confirming surgery) and, therefore, competitive sport policies that place restrictions on transgender people need to be considered and potentially revised

    Identification of Novel Single Nucleotide Polymorphisms (SNPs) in Deer (Odocoileus spp.) Using the BovineSNP50 BeadChip

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    Single nucleotide polymorphisms (SNPs) are growing in popularity as a genetic marker for investigating evolutionary processes. A panel of SNPs is often developed by comparing large quantities of DNA sequence data across multiple individuals to identify polymorphic sites. For non-model species, this is particularly difficult, as performing the necessary large-scale genomic sequencing often exceeds the resources available for the project. In this study, we trial the Bovine SNP50 BeadChip developed in cattle (Bos taurus) for identifying polymorphic SNPs in cervids Odocoileus hemionus (mule deer and black-tailed deer) and O. virginianus (white-tailed deer) in the Pacific Northwest. We found that 38.7% of loci could be genotyped, of which 5% (n = 1068) were polymorphic. Of these 1068 polymorphic SNPs, a mixture of putatively neutral loci (n = 878) and loci under selection (n = 190) were identified with the FST-outlier method. A range of population genetic analyses were implemented using these SNPs and a panel of 10 microsatellite loci. The three types of deer could readily be distinguished with both the SNP and microsatellite datasets. This study demonstrates that commercially developed SNP chips are a viable means of SNP discovery for non-model organisms, even when used between very distantly related species (the Bovidae and Cervidae families diverged some 25.1−30.1 million years before present)
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