A Brief Survey of Recent Edge-Preserving Smoothers

We introduce recent and very recent smoothing methods and discuss them in the common framework of `energy functions'. Focus is on the preservation of boundaries, spikes and canyons in presence of noise

Estimating the standardized incidence ratio (SIR) with incomplete follow-up data

Background: A standard parameter to compare the disease incidence of a cohort relative to the population is the standardized incidence ratio (SIR). For statistical inference is commonly assumed that the denominator, the expected number of cases, is fixed. If a disease registry is available, incident cases can sometimes be identified by linkage with the registry, however, registries may not contain information on migration or death from other causes. A complete follow-up with a population registry may not be possible. In that case, end-of-follow-up date and therefore, exact person-years of observation are unknown. Methods: We have developed a method to estimate the observation times and to derive the expected number of cases using population data on mortality and migration rates. We investigate the impact of the underlying assumptions with a sensitivity analysis. Results: The method provides a useful estimate of the SIR. We illustrate the method with a numerical example, a simulation study and with a study on standardized cancer incidence ratios in a cohort of migrants relative to the German population. We show that the additional variance induced by the estimation method is small, so that standard methods for inference can be applied. Conclusions: Estimation of the observation time is possible for cohort studies with incomplete follow-up

Risk factors for cardiovascular and cerebrovascular diseases among ethnic Germans from the former Soviet Union: results of a nested case-control study

<p>Abstract</p> <p>Background</p> <p>Diseases of the circulatory system (CVD) are the most common causes of death in developed countries. However, the prevalence of CVD varies between countries; for example, the mortality rate in Russia is about four times higher than in Western Europe. In a recent retrospective cohort study it was unexpectedly found that CVD mortality is lower among "Aussiedler" (ethnic Germans from the former Soviet Union) compared to the German population.</p> <p>Methods</p> <p>This is a case-control study, nested into a recent cohort study of migrants from the former Soviet Union. Relatives of cases and controls themselves were interviewed by telephone using a standardized questionnaire. To estimate relative risks via the odds ratio (OR), a conditional logistic regression procedure was performed.</p> <p>Results</p> <p>Commonly known risk factors for CVD were identified as relevant to Aussiedler. The best multivariate model for CVD includes five risk factors: consumption of alcohol, smoking, diabetes, cholesterol and consumption of sweets. For alcohol consumption and smoking, OR = 3.68 (95% CI, 1.58-8.58) and OR = 3.07 (95% CI, 1.42-6.62), respectively. For diabetes mellitus and high cholesterol values, OR = 3.29 (95% CI, 1.50-7.39) and OR = 2.32 (95% CI, 1.11-4.88), respectively. The almost complete abdication of sweets is associated with a protective effect, OR = 0.34 (95% CI, 0.18-0.64). The prevalence of risk factors is somewhat different to that of the autochthon German population and partly explains the differences in CVD mortality between both groups.</p> <p>Conclusions</p> <p>The reported lower prevalences of known risk factors of CVD such as alcohol consumption, high cholesterol, diabetes and smoking (in women) could contribute to a lower risk of CVD.</p

Tobacco Control Progress in Low and Middle Income Countries in Comparison to High Income Countries

The study aimed to describe worldwide levels and trends of tobacco control policy by comparing low and middle income countries with other income categories from 2007 to 2014 and to analyze the corresponding relation to recent changes in smoking prevalence. Policy measure data representing years 2007 to 2014 were collected from all available World Health Organization (WHO) reports on the global tobacco epidemic. Corresponding policy percentage scores (PS) were calculated based on MPOWER measures. Age-standardized smoking prevalence data for years 2010 and 2015 were collected from the WHO Global Health Observatory Data Repository. Trends of PS were analysed with respect to WHO region and OECD country income category. Scatter plots and regression analysis were used to depict the relationship between tobacco control policy of 2010 and change in smoking prevalence between 2015 and 2010 by sex and income category. Combined PS for all countries increased significantly from 47% in 2007 to 61% by 2014 (p < 0.001). When grouped by income category and region, policies were strengthened in all categories, albeit with varying progression. By 2014, tobacco control policy legislation had reached 45% in the Least Developed Countries (LDCs), 59% in Low Middle Income Countries (LMICs), 66% in Upper Middle Income Countries (UMICs) and 70% in High Income Countries (HICs). Overall, there was a negative relationship between higher policy scores and change in smoking prevalence. Although policy strengthening had been conducted between 2007 and 2014, room for considerable global improvement remains, particularly in LDCs. View Full-Tex

Forced Degradation Testing as Complementary Tool for Biosimilarity Assessment

Oxidation of monoclonal antibodies (mAbs) can impact their efficacy and may therefore represent critical quality attributes (CQA) that require evaluation. To complement classical CQA, bevacizumab and infliximab were subjected to oxidative stress by H2O2 for 24, 48, or 72 h to probe their oxidation susceptibility. For investigation, a middle-up approach was used utilizing liquid chromatography hyphenated with mass spectrometry (LC-QTOF-MS). In both mAbs, the Fc/2 subunit was completely oxidized. Additional oxidations were found in the light chain (LC) and in the Fd’ subunit of infliximab, but not in bevacizumab. By direct comparison of methionine positions, the oxidized residues in infliximab were assigned to M55 in LC and M18 in Fd’. The forced oxidation approach was further exploited for comparison of respective biosimilar products. Both for bevacizumab and infliximab, comparison of posttranslational modification profiles demonstrated high similarity of the unstressed reference product (RP) and the biosimilar (BS). However, for bevacizumab, comparison after forced oxidation revealed a higher susceptibility of the BS compared to the RP. It may thus be considered a useful tool for biopharmaceutical engineering, biosimilarity assessment, as well as for quality control of protein drugs

Noise Reduction in Images: Some Recent Edge-Preserving Methods

We introduce some recent and very recent smoothing methods which focus on the preservation of boundaries, spikes and canyons in presence of noise. We try to point out basic principles they have in common; the most important one is the robustness aspect. It is reflected by the use of `cup functions' in the statistical loss functions instead of squares; such cup functions were introduced early in robust statistics to down weight outliers. Basically, they are variants of truncated squares. We discuss all the methods in the common framework of `energy functions', i.e we associate to (most of) the algorithms a `loss function' in such a fashion that the output of the algorithm or the `estimate' is a global or local minimum of this loss function. The third aspect we pursue is the correspondence between loss functions and their local minima and nonlinear filters. We shall argue that the nonlinear filters can be interpreted as variants of gradient descent on the loss functions. This way we can show that some (robust) M-estimators and some nonlinear filters produce almost the same result

Stage of cancer diagnoses among migrants from the former Soviet Union in comparison to the German population – are diagnoses among migrants delayed?

Background: In this study, we compared stage at diagnosis, standardized incidence ratio (SIR) and standardized mortality ratio (SMR) of most frequent cancer diagnoses between re-settlers (Aussiedler) from the former Soviet Union and the general population in the Saarland in Germany to assess possible delays in diagnosis of cancer among this migrant group. Methods: Lung cancer, colorectal cancer, breast cancer, prostate cancer, malignant melanoma of the skin and stomach cancer diagnoses among a cohort of 18,619 re-settlers living in the Saarland between 1990 and 2009 were identified by the federal state’s cancer registry. Vital status was available for the respective time-period and used to calculate SIR and SMR in comparison to the autochthonous population. Tumor stages were condensed into local and advanced stages. Odds ratios (OR) for an advanced tumor stage were modeled in dependence of re-settler-status and relevant covariates by logistic regression. Missing values were addressed in a sensitivity analysis. The influence of duration of stay in Germany on advanced stage diagnosis was analyzed among re-settlers. Results: SIR and SMR of lung and breast cancer were lower among female re-settlers, while SIR and SMR of colorectal and prostate cancer were lower among male re-settlers. SIR and SMR of stomach cancer were elevated among both sexes. Female re-settlers showed an elevated OR for being diagnosed with advanced stage breast cancer. Both male and female re-settlers showed an elevated OR when observing all six sites combined (OR among males 1.47, p = 0.04; OR among females 1.37, p = 0.05). The result of elevated ORs was supported in the sensitivity analysis. Finally, male re-settlers showed a weak association between duration of stay in Germany and reduced risk for advanced stage diagnosis. Conclusion: Re-settlers were more likely to be diagnosed at an advanced tumor stage. These findings are in line with previous research having shown unfavorable health care utilization of re-settlers. Overall, low mortality rates despite an increased risk of advanced stage at diagnosis argue for a sufficient follow-up care, comparable to the autochthonous population

Environmental methods for dengue vector control - A systematic review and meta-analysis

Background Vector control remains the primary method to prevent dengue infections. Environmental interventions represent sustainable and safe methods as there are limited risks of environmental contamination and toxicity. The objective of this study is to perform a systematic review and meta-analysis of the effectiveness of the following environmental methods for dengue vector control. Methodology/Principal findings Following the PRISMA guidelines, a systematic literature search was conducted using the databases PubMed, EMBASE, LILACS, the Cochrane Library and Google Scholar. Quality assessment was done using the CONSORT 2010 checklist. For the meta-analysis the difference-in-differences (DID) and the difference-of-endlines (DOE) were calculated according to the Schmidt-Hunter method for the Breteau index (BI) and the pupae per person index (PPI). Nineteen studies were eligible for the systematic review, sixteen contributed data to the meta-analysis. The following methods were evaluated: (a) container covers with and without insecticides, (b) waste management and clean-up campaigns, and (c) elimination of breeding sites by rendering potential mosquito breeding sites unusable or by eliminating them. Study quality was highest for container covers with insecticides, followed by waste management without direct garbage collection and elimination of breeding places. Both, systematic review and meta-analysis, showed a weak effect of the interventions on larval populations, with no obvious differences between the results of each individual method. For the meta-analysis, both, container covers without insecticides (BI: DID -7.9, DOE -5) and waste management with direct garbage collection (BI: DID -8.83, DOE -6.2) achieved the strongest reductions for the BI, whereas for the PPI results were almost opposite, with container covers with insecticides (PPI: DID -0.83, DOE 0.09) and elimination of breeding places (PPI: DID -0.95, DOE -0.83) showing the strongest effects. Conclusions Each of the investigated environmental methods showed some effectiveness in reducing larval and pupal densities of Aedes sp. mosquitoes. However, there is a need for more comparable high-quality studies at an adequate standard to strengthen this evidence. Author summary Dengue is an emerging mosquito-borne viral disease, which is transmitted through the bite of Aedes sp. mosquitoes. The dengue virus causes 390 million infections and 96 million cases every year, and represents a major public health problem in the tropics and subtropics. Although a dengue vaccine was licensed in late 2015, it does not represent a general solution due to significant imperfections. Vector control remains still the primary method to prevent dengue infections. Environmental interventions to control dengue vectors represent sustainable and safe methods as there are limited risks of environmental contamination and toxicity. We provide a systematic review and meta-analysis of the effectiveness of the following environmental methods for dengue vector control: container covers with and without insecticides, waste management with and without direct garbage collection, elimination of breeding places. Both, systematic review and meta-analysis, showed a weak effect of the interventions on larval Aedes sp. populations, with no obvious differences between the results of each individual method. However, there is a need for more comparable high-quality studies at an adequate standard to strengthen this evidence