140 research outputs found

    Modeling Airline Cost Pass-Through within Regional Aviation Markets

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    Studies assessing the impact of market-based environmental policies in aviation rely on various scenarios of airline cost pass-through, because there is little empirical evidence with respect to the impacts of airline costs on airfares. Instead, the costs effect has been indirectly measured by proxy variables such as distance, fuel price, and aircraft sizes. This paper provides empirical evidence of airline cost pass-through by developing an airfare model that explicitly captures airline operating costs. Using a feasible generalized two-stage least squares (FG2SLS) approach, we obtained coefficients of airline fuel costs per passenger, non-fuel costs per passenger, and non-fuel costs per flight modeling for seven world regions (20 region-pair markets). A comparison of the estimated cost pass-through elasticities conducted across regional markets suggests that airlines may respond to the cost increases differently, depending on the cost types and the markets they operate in. Based on the estimated coefficients, we systematically evaluate the potential impacts of introducing a carbon tax policy within two major regional markets with distinct cost pass-through elasticities

    Pancreatectomy for metastasis to the pancreas from colorectal cancer and reconstruction of superior mesenteric vein: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Tumors of the pancreatic head can infiltrate the superior mesenteric vein. In such cases, the deep veins of the lower limbs can serve as suitable autologous conduits for superior mesenteric vein reconstruction after its resection. Few data exist, however, describing the technique and the immediate patency of such reconstruction.</p> <p>Case report</p> <p>We present the case of a 70-year-old Caucasian man with a metachronous metastasis of colon cancer and infiltration of the uncinate pancreatic process, on the anterior surface of which the tumor was located. <it>En bloc </it>resection of the tumor was performed with resection of the superior mesenteric vein and reconstruction. A 10 cm segment of the superficial femoral vein was harvested for the reconstruction. The superficial femoral vein segment was inter-positioned in an end-to-end fashion. The post-operative conduit patency was documented ultrasonographically immediately post-operatively and after a six-month period. The vein donor limb presented subtle signs of post-operative venous hypertension with edema, which was managed with compression stockings and led to significant improvement after six months.</p> <p>Conclusion</p> <p>In cases of exploratory laparotomies with high clinical suspicion of pancreatic involvement, the potential need for vascular reconstruction dictates the preparation for leg vein harvest in advance. The superficial femoral vein provides a suitable conduit for the reconstruction of the superior mesenteric vein. This report supports the uncomplicated nature of this technique, since few data exist about this type of reconstruction.</p

    Absent cervical spine pedicle and associated congenital spinal abnormalities - a diagnostic trap in a setting of acute trauma: case report

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    BACKGROUND: Congenital spinal abnormalities can easily be misdiagnosed on plain radiographs. Additional imaging is warranted in doubtful cases, especially in a setting of acute trauma. Case Presentation This patient presented at the emergency unit of our university hospital after a motor vehicle accident and was sent to our radiology department for imaging of the cervical spine. Initial clinical examination and plain radiographs of the cervical spine were performed but not conclusive. Additional CT of the neck helped establish the right diagnosis. CONCLUSION: CT as a three-dimensional imaging modality with the possibility of multiplanar reconstructions allows for the exact diagnosis and exclusion of acute traumatic lesions of the cervical spine, especially in cases of doubtful plain radiographs and when congenital spinal abnormalities like absent cervical spine pedicle with associated spina bifida may insinuate severe trauma

    Genome Mining for Radical SAM Protein Determinants Reveals Multiple Sactibiotic-Like Gene Clusters

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    Thuricin CD is a two-component bacteriocin produced by Bacillus thuringiensis that kills a wide range of clinically significant Clostridium difficile. This bacteriocin has recently been characterized and consists of two distinct peptides, Trnβ and Trnα, which both possess 3 intrapeptide sulphur to α-carbon bridges and act synergistically. Indeed, thuricin CD and subtilosin A are the only antimicrobials known to possess these unusual structures and are known as the sactibiotics (sulplur to alpha carbon-containing antibiotics). Analysis of the thuricin CD-associated gene cluster revealed the presence of genes encoding two highly unusual SAM proteins (TrnC and TrnD) which are proposed to be responsible for these unusual post-translational modifications. On the basis of the frequently high conservation among enzymes responsible for the post-translational modification of specific antimicrobials, we performed an in silico screen for novel thuricin CD–like gene clusters using the TrnC and TrnD radical SAM proteins as driver sequences to perform an initial homology search against the complete non-redundant database. Fifteen novel thuricin CD–like gene clusters were identified, based on the presence of TrnC and TrnD homologues in the context of neighbouring genes encoding potential bacteriocin structural peptides. Moreover, metagenomic analysis revealed that TrnC or TrnD homologs are present in a variety of metagenomic environments, suggesting a widespread distribution of thuricin-like operons in a variety of environments. In-silico analysis of radical SAM proteins is sufficient to identify novel putative sactibiotic clusters

    Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

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    Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

    The Highly Virulent 2006 Norwegian EHEC O103:H25 Outbreak Strain Is Related to the 2011 German O104:H4 Outbreak Strain

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    In 2006, a severe foodborne EHEC outbreak occured in Norway. Seventeen cases were recorded and the HUS frequency was 60%. The causative strain, Esherichia coli O103:H25, is considered to be particularly virulent. Sequencing of the outbreak strain revealed resemblance to the 2011 German outbreak strain E. coli O104:H4, both in genome and Shiga toxin 2-encoding (Stx2) phage sequence. The nucleotide identity between the Stx2 phages from the Norwegian and German outbreak strains was 90%. During the 2006 outbreak, stx2-positive O103:H25 E. coli was isolated from two patients. All the other outbreak associated isolates, including all food isolates, were stx-negative, and carried a different phage replacing the Stx2 phage. This phage was of similar size to the Stx2 phage, but had a distinctive early phage region and no stx gene. The sequence of the early region of this phage was not retrieved from the bacterial host genome, and the origin of the phage is unknown. The contaminated food most likely contained a mixture of E. coli O103:H25 cells with either one of the phages

    A randomised controlled trial on hypnotherapy for irritable bowel syndrome: design and methodological challenges (the IMAGINE study)

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    <p>Abstract</p> <p>Background</p> <p>Irritable Bowel Syndrome (IBS) is a common gastro-intestinal disorder in primary and secondary care, characterised by abdominal pain, discomfort, altered bowel habits and/or symptoms of bloating and distension. In general the efficacy of drug therapies is poor. Hypnotherapy as well as Cognitive Behaviour Therapy and short Psychodynamic Therapy appear to be useful options for patients with refractory IBS in secondary care and are cost-effective, but the evidence is still limited. The IMAGINE-study is therefore designed to assess the overall benefit of hypnotherapy in IBS as well as comparing the efficacy of individual versus group hypnotherapy in treating this condition.</p> <p>Methods/Design</p> <p>The design is a randomised placebo-controlled trial. The study group consists of 354 primary care and secondary care patients (aged 18-65) with IBS (Rome-III criteria). Patients will be randomly allocated to either 6 sessions of individual hypnotherapy, 6 sessions of group hypnotherapy or 6 sessions of educational supportive therapy in a group (placebo), with a follow up of 9 months post treatment for all patients. Ten hospitals and four primary care psychological practices in different parts of The Netherlands will collaborate in this study. The primary efficacy parameter is the responder rate for adequate relief of IBS symptoms. Secondary efficacy parameters are changes in the IBS symptom severity, quality of life, cognitions, psychological complaints, self-efficacy as well as direct and indirect costs of the condition. Hypnotherapy is expected to be more effective than the control therapy, and group hypnotherapy is expected not to be inferior to individual hypnotherapy.</p> <p>Discussion</p> <p>If hypnotherapy is effective and if there is no difference in efficacy between individual and group hypnotherapy, this group form of treatment could be offered to more IBS patients, at lower costs.</p> <p>Trial registration number</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN22888906">ISRCTN22888906</a></p

    Is consuming yoghurt associated with weight management outcomes? Results from a systematic review.

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    BACKGROUND: Yoghurt is part of the diet of many people worldwide and is commonly recognised as a 'health food'. Epidemiological studies suggest that yoghurt may be useful as part of weight management programs. In the absence of comprehensive systematic reviews, this systematic review investigated the effect of yoghurt consumption by apparently healthy adults on weight-related outcomes. METHODS: An extensive literature search was undertaken, as part of a wider scoping review, to identify yoghurt studies. A total of 13 631 records were assessed for their relevance to weight-related outcomes. RESULTS: Twenty-two publications were eligible according to the review protocol. Cohort studies (n=6) and cross-sectional studies (n=7) all showed a correlation between yoghurt and lower or improved body weight/composition. Six randomised controlled trials (RCTs) and one controlled trial had various limitations, including small size and short duration. One RCT showed significant effects of yoghurt on weight loss, but was confounded by differences in calcium intake. One trial showed nonsignificant weight gain and the remaining five trials showed nonsignificant weight losses that were greater in yoghurt consumers. CONCLUSIONS: Yoghurt consumption is associated with lower body mass index, lower body weight/weight gain, smaller waist circumference and lower body fat in epidemiological studies. RCTs suggest weight reduction effects, but do not permit determination of a cause-effect relationship. Well-controlled, adequately powered trials in research and community settings appear likely to identify a modest but beneficial effect of yoghurt consumption for prevention of weight gain and management of obesity. The ready availability of yoghurt (a nutrient-dense food) and its ease of introduction to most diets suggests that educating the public to eat yoghurt as part of a balanced and healthy diet may potentially contribute to improved public health. Future carefully designed RCTs could provide proof of principle and large community-based studies could determine the practical impact of yoghurt on body weight/composition
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