205 research outputs found

    Cross Pixel Optical Flow Similarity for Self-Supervised Learning

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    We propose a novel method for learning convolutional neural image representations without manual supervision. We use motion cues in the form of optical flow, to supervise representations of static images. The obvious approach of training a network to predict flow from a single image can be needlessly difficult due to intrinsic ambiguities in this prediction task. We instead propose a much simpler learning goal: embed pixels such that the similarity between their embeddings matches that between their optical flow vectors. At test time, the learned deep network can be used without access to video or flow information and transferred to tasks such as image classification, detection, and segmentation. Our method, which significantly simplifies previous attempts at using motion for self-supervision, achieves state-of-the-art results in self-supervision using motion cues, competitive results for self-supervision in general, and is overall state of the art in self-supervised pretraining for semantic image segmentation, as demonstrated on standard benchmarks

    Prevalence of Campylobacter Species in Adult Crohn's Disease and the Preferential Colonization Sites of Campylobacter Species in the Human Intestine

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    INTRODUCTION: Crohn's disease (CD) and ulcerative colitis (UC) are the two major forms of inflammatory bowel disease (IBD). A high prevalence of Campylobacter concisus was previously detected in paediatric CD and adult UC. Currently, the prevalence of C. concisus in adult CD and the preferential colonization sites of Campylobacter species in the human intestine are unknown. In this study, we examined the prevalence of Campylobacter species in biopsies collected from multiple anatomic sites of adult patients with IBD and controls. METHODS: Three hundred and one biopsies collected from ileum, caecum, descending colon and rectum of 28 patients IBD (15 CD and 13 UC) and 33 controls were studied. Biopsies were used for DNA extraction and detection of Campylobacter species by PCR-sequencing and Campylobacter cultivation. RESULTS: A significantly higher prevalence of C. concisus in colonic biopsies of patients with CD (53%) was detected as compared with the controls (18%). Campylobacter genus-PCR positivity and C. concisus positivity in patients with UC were 85% and 77% respectively, being significantly higher than that in the controls (48% and 36%). C. concisus was more often detected in descending colonic and rectal biopsies from patients with IBD in comparison to the controls. C. concisus was isolated from patients with IBD. CONCLUSION: The high intestinal prevalence of C. concisus in patients with IBD, particularly in the proximal large intestine, suggests that future studies are needed to investigate the possible involvement of C. concisus in a subgroup of human IBD. To our knowledge, this is the first report of the association between adult CD and C. concisus as well as the first study of the preferential colonization sites of C. concisus in the human intestine

    The impact of muscle relaxation techniques on the quality of life of cancer patients, as measured by the FACT-G questionnaire

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    Introduction Patients with cancer frequently suffer from emotional distress, characterized by psychological symptoms such as anxiety or depression. The presence of psychological symptoms combined with the complex nature of oncology processes can negatively impact patients' quality of life. We aimed to determine the impact of a relaxation protocol on improving quality of life in a sample of oncological patients treated in the Spanish National Public Health System. Materials and methods We conducted a multicenter interventional study without a control group. In total, 272 patients with different oncologic pathologies and showing symptoms of anxiety were recruited from 10 Spanish public hospitals. The intervention comprised abbreviated progressive muscle relaxation training, according to Bernstein and Borkovec. This was followed by weekly telephone calls to each patient over a 1-month period. We collected sociodemographic variables related to the disease process, including information about mental health and the intervention. Patients' quality of life was assessed using the Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire. Bivariate and univariate analyses were performed, along with an analysis of multiple correspondences to identify subgroups of patients with similar variations on the FACT-G. Results Patients showed statistically significant improvements on the FACT-G overall score (W = 16806; p<0.001), with an initial mean score of 55.33±10.42 and a final mean score of 64.49±7.70. We also found significant improvements for all subscales: emotional wellbeing (W = 13118; p<0.001), functional wellbeing (W = 16155.5; p<0.001), physical wellbeing (W = 8885.5; p<0.001), and social and family context (W = ?1840; p = 0.037). Conclusions Patients with cancer who learned and practiced abbreviated progressive muscle relaxation experienced improvement in their perceived quality of life as measured by the FACT-G. Our findings support a previous assumption that complementary techniques (including relaxation techniques) are effective in improving the quality of life of patients with cancer

    Treating children traumatized by war and Tsunami: A comparison between exposure therapy and meditation-relaxation in North-East Sri Lanka

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    <p>Abstract</p> <p>Background</p> <p>The North-Eastern part of Sri Lanka had already been affected by civil war when the 2004 Tsunami wave hit the region, leading to high rates of posttraumatic stress disorder (PTSD) in children. In the acute aftermath of the Tsunami we tested the efficacy of two pragmatic short-term interventions when applied by trained local counselors.</p> <p>Methods</p> <p>A randomized treatment comparison was implemented in a refugee camp in a severely affected community. 31 children who presented with a preliminary diagnosis of PTSD were randomly assigned either to six sessions Narrative Exposure Therapy for children (KIDNET) or six sessions of meditation-relaxation (MED-RELAX). Outcome measures included severity of PTSD symptoms, level of functioning and physical health.</p> <p>Results</p> <p>In both treatment conditions, PTSD symptoms and impairment in functioning were significantly reduced at one month post-test and remained stable over time. At 6 months follow-up, recovery rates were 81% for the children in the KIDNET group and 71% for those in the MED-RELAX group. There was no significant difference between the two therapy groups in any outcome measure.</p> <p>Conclusion</p> <p>As recovery rates in the treatment groups exceeded the expected rates of natural recovery, the study provides preliminary evidence for the effectiveness of NET as well as meditation-relaxation techniques when carried out by trained local counselors for the treatment of PTSD in children in the direct aftermath of mass disasters.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Identifier:NCT00820391</p

    Is plant mitochondrial RNA editing a source of phylogenetic incongruence? An answer from in silico and in vivo data sets

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    <p>Abstract</p> <p>Background</p> <p>In plant mitochondria, the post-transcriptional RNA editing process converts C to U at a number of specific sites of the mRNA sequence and usually restores phylogenetically conserved codons and the encoded amino acid residues. Sites undergoing RNA editing evolve at a higher rate than sites not modified by the process. As a result, editing sites strongly affect the evolution of plant mitochondrial genomes, representing an important source of sequence variability and potentially informative characters.</p> <p>To date no clear and convincing evidence has established whether or not editing sites really affect the topology of reconstructed phylogenetic trees. For this reason, we investigated here the effect of RNA editing on the tree building process of twenty different plant mitochondrial gene sequences and by means of computer simulations.</p> <p>Results</p> <p>Based on our simulation study we suggest that the editing ‘noise’ in tree topology inference is mainly manifested at the cDNA level. In particular, editing sites tend to confuse tree topologies when artificial genomic and cDNA sequences are generated shorter than 500 bp and with an editing percentage higher than 5.0%. Similar results have been also obtained with genuine plant mitochondrial genes. In this latter instance, indeed, the topology incongruence increases when the editing percentage goes up from about 3.0 to 14.0%. However, when the average gene length is higher than 1,000 bp (<it>rps3</it>, <it>matR</it> and <it>atp1</it>) no differences in the comparison between inferred genomic and cDNA topologies could be detected.</p> <p>Conclusions</p> <p>Our findings by the here reported <it>in silico</it> and <it>in vivo</it> computer simulation system seem to strongly suggest that editing sites contribute in the generation of misleading phylogenetic trees if the analyzed mitochondrial gene sequence is highly edited (higher than 3.0%) and reduced in length (shorter than 500 bp).</p> <p>In the current lack of direct experimental evidence the results presented here encourage, thus, the use of genomic mitochondrial rather than cDNA sequences for reconstructing phylogenetic events in land plants.</p

    Expression of DDX3 Is Directly Modulated by Hypoxia Inducible Factor-1 Alpha in Breast Epithelial Cells

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    DEAD box protein, DDX3, is aberrantly expressed in breast cancer cells ranging from weakly invasive to aggressive phenotypes and functions as an important regulator of cancer cell growth and survival. Here, we demonstrate that hypoxia inducible factor-1α is a transcriptional activator of DDX3 in breast cancer cells. Within the promoter region of the human DDX3 gene, we identified three putative hypoxia inducible factor-1 responsive elements. By luciferase reporter assays in combination with mutated hypoxia inducible factor-1 responsive elements, we determined that the hypoxia inducible factor-1 responsive element at position -153 relative to the translation start site is essential for transcriptional activation of DDX3 under hypoxic conditions. We also demonstrated that hypoxia inducible factor-1 binds to the DDX3 promoter and that the binding is specific, as revealed by siRNA against hypoxia inducible factor-1 and chromatin immunoprecipitation assays. Thus, the activation of DDX3 expression during hypoxia is due to the direct binding of hypoxia inducible factor-1 to hypoxia responsive elements in the DDX3 promoter. In addition, we observed a significant overlap in the protein expression pattern of hypoxia inducible factor-1α and DDX3 in MDA-MB-231 xenograft tumors. Taken together, our results demonstrate, for the first time, the role of DDX3 as a hypoxia-inducible gene that exhibits enhanced expression through the interaction of hypoxia inducible factor-1 with hypoxia inducible factor-1 responsive elements in its promoter region

    A monodisperse transmembrane α-helical peptide barrel

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    The fabrication of monodisperse transmembrane barrels formed from short synthetic peptides has not been demonstrated previously. This is in part because of the complexity of the interactions between peptides and lipids within the hydrophobic environment of a membrane. Here we report the formation of a transmembrane pore through the self-assembly of 35 amino acid α-helical peptides. The design of the peptides is based on the C-terminal D4 domain of the Escherichia coli polysaccharide transporter Wza. By using single-channel current recording, we define discrete assembly intermediates and show that the pore is most probably a helix barrel that contains eight D4 peptides arranged in parallel. We also show that the peptide pore is functional and capable of conducting ions and binding blockers. Such α-helix barrels engineered from peptides could find applications in nanopore technologies such as single-molecule sensing and nucleic-acid sequencing

    Anti-infectives in Drug Delivery-Overcoming the Gram-Negative Bacterial Cell Envelope.

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    Infectious diseases are becoming a major menace to the state of health worldwide, with difficulties in effective treatment especially of nosocomial infections caused by Gram-negative bacteria being increasingly reported. Inadequate permeation of anti-infectives into or across the Gram-negative bacterial cell envelope, due to its intrinsic barrier function as well as barrier enhancement mediated by resistance mechanisms, can be identified as one of the major reasons for insufficient therapeutic effects. Several in vitro, in silico, and in cellulo models are currently employed to increase the knowledge of anti-infective transport processes into or across the bacterial cell envelope; however, all such models exhibit drawbacks or have limitations with respect to the information they are able to provide. Thus, new approaches which allow for more comprehensive characterization of anti-infective permeation processes (and as such, would be usable as screening methods in early drug discovery and development) are desperately needed. Furthermore, delivery methods or technologies capable of enhancing anti-infective permeation into or across the bacterial cell envelope are required. In this respect, particle-based carrier systems have already been shown to provide the opportunity to overcome compound-related difficulties and allow for targeted delivery. In addition, formulations combining efflux pump inhibitors or antimicrobial peptides with anti-infectives show promise in the restoration of antibiotic activity in resistant bacterial strains. Despite considerable progress in this field however, the design of carriers to specifically enhance transport across the bacterial envelope or to target difficult-to-treat (e.g., intracellular) infections remains an urgently needed area of improvement. What follows is a summary and evaluation of the state of the art of both bacterial permeation models and advanced anti-infective formulation strategies, together with an outlook for future directions in these fields

    Quality of dietary fat and genetic risk of type 2 diabetes: individual participant data meta-analysis.

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    OBJECTIVE: To investigate whether the genetic burden of type 2 diabetes modifies the association between the quality of dietary fat and the incidence of type 2 diabetes. DESIGN: Individual participant data meta-analysis. DATA SOURCES: Eligible prospective cohort studies were systematically sourced from studies published between January 1970 and February 2017 through electronic searches in major medical databases (Medline, Embase, and Scopus) and discussion with investigators. REVIEW METHODS: Data from cohort studies or multicohort consortia with available genome-wide genetic data and information about the quality of dietary fat and the incidence of type 2 diabetes in participants of European descent was sought. Prospective cohorts that had accrued five or more years of follow-up were included. The type 2 diabetes genetic risk profile was characterized by a 68-variant polygenic risk score weighted by published effect sizes. Diet was recorded by using validated cohort-specific dietary assessment tools. Outcome measures were summary adjusted hazard ratios of incident type 2 diabetes for polygenic risk score, isocaloric replacement of carbohydrate (refined starch and sugars) with types of fat, and the interaction of types of fat with polygenic risk score. RESULTS: Of 102 305 participants from 15 prospective cohort studies, 20 015 type 2 diabetes cases were documented after a median follow-up of 12 years (interquartile range 9.4-14.2). The hazard ratio of type 2 diabetes per increment of 10 risk alleles in the polygenic risk score was 1.64 (95% confidence interval 1.54 to 1.75, I2=7.1%, τ2=0.003). The increase of polyunsaturated fat and total omega 6 polyunsaturated fat intake in place of carbohydrate was associated with a lower risk of type 2 diabetes, with hazard ratios of 0.90 (0.82 to 0.98, I2=18.0%, τ2=0.006; per 5% of energy) and 0.99 (0.97 to 1.00, I2=58.8%, τ2=0.001; per increment of 1 g/d), respectively. Increasing monounsaturated fat in place of carbohydrate was associated with a higher risk of type 2 diabetes (hazard ratio 1.10, 95% confidence interval 1.01 to 1.19, I2=25.9%, τ2=0.006; per 5% of energy). Evidence of small study effects was detected for the overall association of polyunsaturated fat with the risk of type 2 diabetes, but not for the omega 6 polyunsaturated fat and monounsaturated fat associations. Significant interactions between dietary fat and polygenic risk score on the risk of type 2 diabetes (P>0.05 for interaction) were not observed. CONCLUSIONS: These data indicate that genetic burden and the quality of dietary fat are each associated with the incidence of type 2 diabetes. The findings do not support tailoring recommendations on the quality of dietary fat to individual type 2 diabetes genetic risk profiles for the primary prevention of type 2 diabetes, and suggest that dietary fat is associated with the risk of type 2 diabetes across the spectrum of type 2 diabetes genetic risk.The EPIC-InterAct study received funding from the European Union (Integrated Project LSHM-CT-2006-037197 in the Framework Programme 6 of the European Community). We thank all EPIC participants and staff for their contribution to the study. We thank Nicola Kerrison (MRC Epidemiology Unit, University of Cambridge, Cambridge, UK) for managing the data for the InterAct Project. In addition, InterAct investigators acknowledge funding from the following agencies: MT: Health Research Fund (FIS) of the Spanish Ministry of Health; the CIBER en Epidemiología y Salud Pública (CIBERESP), Spain; Murcia Regional Government (N° 6236); JS: JS was supported by a Heisenberg-Professorship (SP716/2-1), a Clinical Research Group (KFO218/1) and a research group (Molecular Nutrition to JS) of the Bundesministerium für Bildung und Forschung (BMBF); YTvdS, JWJB, PHP, IS: Verification of diabetes cases was additionally funded by NL Agency grant IGE05012 and an Incentive Grant from the Board of the UMC Utrecht; HBBdM: Dutch Ministry of Public Health, Welfare and Sports (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds, Dutch ZON (Zorg Onderzoek Nederland), World Cancer Research Fund (WCRF), Statistics Netherlands (The Netherlands); MDCL: Health Research Fund (FIS) of the Spanish Ministry of Health; Murcia Regional Government (N° 6236); FLC: Cancer Research UK; PD: Wellcome Trust; LG: Swedish Research Council; GH: The county of Västerbotten; RK: Deutsche Krebshilfe; TJK: Cancer Research UK; KK: Medical Research Council UK, Cancer Research UK; AK: Medical Research Council (Cambridge Lipidomics Biomarker Research Initiative); CN: Health Research Fund (FIS) of the Spanish Ministry of Health; Murcia Regional Government (N° 6236); KO: Danish Cancer Society; OP: Faculty of Health Science, 47 University of Aarhus, Denmark; JRQ: Asturias Regional Government; LRS: Asturias Regional Government; AT: Danish Cancer Society; RT: AIRE-ONLUS Ragusa, AVIS-Ragusa, Sicilian Regional Government; DLvdA, WMMV: Dutch Ministry of Public Health, Welfare and Sports (VWS), Netherlands Cancer Registry (NKR), LK Research Funds, Dutch Prevention Funds, Dutch ZON (Zorg Onderzoek Nederland), World Cancer Research Fund (WCRF), Statistics Netherlands (The Netherlands); MMC: Wellcome Trust (083270/Z/07/Z), MRC (G0601261)
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