885 research outputs found
Surgery during holiday periods and prognosis in oesophageal cancer: a population-based nationwide Swedish cohort study
OBJECTIVE: Previous studies indicate an increased short-term and long-term mortality from major cancer surgery performed towards the end of the working week or during the weekend. We hypothesised that the prognosis after major cancer surgery is also negatively influenced by surgery conducted during holiday periods. SETTING: Population-based nationwide Swedish cohort study. PARTICIPANTS: Patients undergoing oesophagectomy for oesophageal cancer between 1987 and 2010. Among 1820 included patients, 206 (11.3%) and 373 (20.5%) patients were operated on during narrow and wide holiday periods, respectively. INTERVENTIONS: Narrow (7 weeks) and wide (14 weeks) Swedish holiday periods. PRIMARY AND SECONDARY OUTCOME MEASURES: 90-day all-cause, 5-year all-cause and 5-year disease-specific mortality. RESULTS: Narrow holiday period did not increase all-cause 90-day (HR=0.84, 95% CI 0.53 to 1.33), all-cause 5-year (HR=1.01, 95% CI 0.85 to 1.21) or disease-specific 5-year mortality (HR=1.04, 95% CI 0.87 to 1.26). Similarly, wide holiday period did not increase the risk of 90-day (HR=0.79, 95% CI 0.55 to 1.13), all-cause 5-year (HR=0.96, 95% CI 0.84 to 1.1) or disease-specific 5-year mortality (HR=1.03, 95% CI 0.89 to 1.19). CONCLUSIONS: No measurable effects of holiday periods on short-term or longer term mortality following surgery for oesophageal cancer were observed in this population-based study, indicating that an adequate surgical experience was maintained during holiday periods
Towards operational remote sensing of forest carbon balance across Northern Europe
Monthly averages of ecosystem respiration (ER), gross primary production (GPP) and net ecosystem exchange (NEE) over Scandinavian forest sites were estimated using regression models driven by air temperature (AT), absorbed photosynthetically active radiation (APAR) and vegetation indices. The models were constructed and evaluated using satellite data from Terra/MODIS and measured data collected at seven flux tower sites in northern Europe. Data used for model construction was excluded from the evaluation. Relationships between ground measured variables and the independent variables were investigated. <br><br> It was found that the enhanced vegetation index (EVI) at 250 m resolution was highly noisy for the coniferous sites, and hence, 1 km EVI was used for the analysis. Linear relationships between EVI and the biophysical variables were found: correlation coefficients between EVI and GPP, NEE, and AT ranged from 0.90 to 0.79 for the deciduous data, and from 0.85 to 0.67 for the coniferous data. Due to saturation, there were no linear relationships between normalized difference vegetation index (NDVI) and the ground measured parameters found at any site. APAR correlated better with the parameters in question than the vegetation indices. Modeled GPP and ER were in good agreement with measured values, with more than 90% of the variation in measured GPP and ER being explained by the coniferous models. The site-specific respiration rate at 10&deg;C (<i>R</i><sub>10</sub>) was needed for describing the ER variation between sites. Even though monthly NEE was modeled with less accuracy than GPP, 61% and 75% (dec. and con., respectively) of the variation in the measured time series was explained by the model. These results are important for moving towards operational remote sensing of forest carbon balance across Northern Europe
Esophageal cancer in a young woman with bulimia nervosa: a case report
Adenocarcinoma of the esophagus has increased dramatically within the United States and continues to have a poor prognosis despite aggressive treatment. Identifying potential risk factors is critical for the early detection and treatment of this disease. The present case report describes a very young woman who developed adenocarcinoma of the esophagus after only a brief history of bulimia. These findings suggest that even in very young patients, bulimia may represent a risk factor for adenocarcinoma of the esophagus
Orbifold projection in supersymmetric QCD at N_f\leq N_c
Supersymmetric orbifold projection of N=1 SQCD with relatively small number
of flavors (not larger than the number of colors) is considered. The purpose is
to check whether orbifolding commutes with the infrared limit. On the one hand,
one considers the orbifold projection of SQCD and obtains the low-energy
description of the resulting theory. On the other hand, one starts with the
low-energy effective theory of the original SQCD, and only then perfoms
orbifolding. It is shown that at finite N_c the two low-energy theories
obtained in these ways are different. However, in the case of stabilized
run-away vacuum these two theories are shown to coincide in the large N_c
limit. In the case of quantum modified moduli space, topological solitons
carrying baryonic charges are present in the orbifolded low-energy theory.
These solitons may restore the correspondence between the two theories provided
that the soliton mass tends to zero in the large N_c limit.Comment: 10 pages; misprint corrected, reference adde
Hormone replacement therapy and risks of oesophageal and gastric adenocarcinomas
Oesophageal and gastric adenocarcinoma share an unexplained male predominance, which would be explained by the hypothesis that oestrogens are protective in this respect. We carried out a nested case–control study of hormone replacement therapy (HRT) among 299 women with oesophageal cancer, 313 with gastric cancer, and 3191 randomly selected control women, frequency matched by age and calendar year in the General Practitioners Research Database in the United Kingdom. Data were adjusted for age, calendar year, tobacco smoking, alcohol consumption, body mass index, hysterectomy, and upper gastrointestinal disorders. Among 1 619 563 person-years of follow-up, more than 50% reduced risk of gastric adenocarcinoma was found among users of HRT compared to nonusers (odds ratio (OR), 0.48, 95% confidence interval (CI) 0.29–0.79). This inverse association appeared to be stronger for gastric noncardia (OR 0.34, 95% CI 0.14–0.78) and weaker for gastric cardia tumours (OR 0.68, 95% CI 0.23–2.01). There was no association between HRT and oesophageal adenocarcinoma (OR 1.17, 95% CI 0.41–3.32)
Fast computation of distance estimators
BACKGROUND: Some distance methods are among the most commonly used methods for reconstructing phylogenetic trees from sequence data. The input to a distance method is a distance matrix, containing estimated pairwise distances between all pairs of taxa. Distance methods themselves are often fast, e.g., the famous and popular Neighbor Joining (NJ) algorithm reconstructs a phylogeny of n taxa in time O(n(3)). Unfortunately, the fastest practical algorithms known for Computing the distance matrix, from n sequences of length l, takes time proportional to l·n(2). Since the sequence length typically is much larger than the number of taxa, the distance estimation is the bottleneck in phylogeny reconstruction. This bottleneck is especially apparent in reconstruction of large phylogenies or in applications where many trees have to be reconstructed, e.g., bootstrapping and genome wide applications. RESULTS: We give an advanced algorithm for Computing the number of mutational events between DNA sequences which is significantly faster than both Phylip and Paup. Moreover, we give a new method for estimating pairwise distances between sequences which contain ambiguity Symbols. This new method is shown to be more accurate as well as faster than earlier methods. CONCLUSION: Our novel algorithm for Computing distance estimators provides a valuable tool in phylogeny reconstruction. Since the running time of our distance estimation algorithm is comparable to that of most distance methods, the previous bottleneck is removed. All distance methods, such as NJ, require a distance matrix as input and, hence, our novel algorithm significantly improves the overall running time of all distance methods. In particular, we show for real world biological applications how the running time of phylogeny reconstruction using NJ is improved from a matter of hours to a matter of seconds
Incidence and survival of oesophageal and gastric cancer in England between 1998 and 2007, a population-based study
BACKGROUND: Major changes in the incidence of oesophageal and gastric cancers have been reported internationally. This study describes recent trends in incidence and survival of subgroups of oesophageal and gastric cancer in England between 1998 and 2007 and considers the implications for cancer services and policy. METHODS: Data on 133,804 English patients diagnosed with oesophageal and gastric cancer between 1998 and 2007 were extracted from the National Cancer Data Repository. Using information on anatomical site and tumour morphology, data were divided into six groups; upper and middle oesophagus, lower oesophagus, oesophagus with an unspecified anatomical site, cardia, non-cardia stomach, and stomach with an unspecified anatomical site. Age-standardised incidence rates (per 100,000 European standard population) were calculated for each group by year of diagnosis and by socioeconomic deprivation. Survival was estimated using the Kaplan-Meier method. RESULTS: The majority of oesophageal cancers were in the lower third of the oesophagus (58%). Stomach with an unspecified anatomical site was the largest gastric cancer group (53%). The incidence of lower oesophageal cancer increased between 1998 and 2002 and remained stable thereafter. The incidence of cancer of the cardia, non-cardia stomach, and stomach with an unspecified anatomical site declined over the 10 year period. Both lower oesophageal and cardia cancers had a much higher incidence in males compared with females (M:F 4:1). The incidence was also higher in the most deprived quintiles for all six cancer groups. Survival was poor in all sub-groups with 1 year survival ranging from 14.8-40.8% and 5 year survival ranging from 3.7-15.6%. CONCLUSIONS: An increased focus on prevention and early diagnosis, especially in deprived areas and in males, is required to improve outcomes for these cancers. Improved recording of tumour site, stage and morphology and the evaluation of focused early diagnosis programmes are also needed. The poor long-term survival reinforces the need for early detection and multidisciplinary care
Computational Cancer Biology: An Evolutionary Perspective
ISSN:1553-734XISSN:1553-735
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