University of Vienna

About: University of Vienna is a education organization based out in Vienna, Austria. It is known for research contribution in the topics: Population & Context (language use). The organization has 44686 authors who have published 95840 publications receiving 2907492 citations.

Quality Control in Crowdsourcing Systems: Issues and Directions

Abstract: As a new distributed computing model, crowdsourcing lets people leverage the crowd's intelligence and wisdom toward solving problems. This article proposes a framework for characterizing various dimensions of quality control in crowdsourcing systems, a critical issue. The authors briefly review existing quality-control approaches, identify open issues, and look to future research directions. In the Web extra, the authors discuss both design-time and runtime approaches in more detail.

Adherence to Mediterranean Diet and Risk of Cancer: An Updated Systematic Review and Meta-Analysis

Abstract: The aim of the present systematic review and meta-analysis was to gain further insight into the effects of adherence to Mediterranean Diet (MedD) on risk of overall cancer mortality, risk of different types of cancer, and cancer mortality and recurrence risk in cancer survivors Literature search was performed using the electronic databases PubMed, and Scopus until 25 August 2017 We included randomized trials (RCTs), cohort (for specific tumors only incidence cases were used) studies, and case-control studies Study-specific risk ratios, hazard ratios, and odds ratios (RR/HR/OR) were pooled using a random effects model Observational studies (cohort and case-control studies), and intervention trials were meta-analyzed separately The updated review process showed 27 studies that were not included in the previous meta-analysis (total number of studies evaluated: 83 studies) An overall population of 2,130,753 subjects was included in the present update The highest adherence score to a MedD was inversely associated with a lower risk of cancer mortality (RRcohort: 086, 95% CI 081 to 091, I2 = 82%; n = 14 studies), colorectal cancer (RRobservational: 082, 95% CI 075 to 088, I2 = 73%; n = 11 studies), breast cancer (RRRCT: 043, 95% CI 021 to 088, n = 1 study) (RRobservational: 092, 95% CI 087 to 096, I2 = 22%, n = 16 studies), gastric cancer (RRobservational: 072, 95% CI 060 to 086, I2 = 55%; n = 4 studies), liver cancer (RRobservational: 058, 95% CI 046 to 073, I2 = 0%; n = 2 studies), head and neck cancer (RRobservational: 049, 95% CI 037 to 066, I2 = 87%; n = 7 studies), and prostate cancer (RRobservational: 096, 95% CI 092 to 100, I2 = 0%; n = 6 studies) Among cancer survivors, the association between the adherence to the highest MedD category and risk of cancer mortality, and cancer recurrence was not statistically significant Pooled analyses of individual components of the MedD revealed that the protective effects appear to be most attributable to fruits, vegetables, and whole grains The updated meta-analysis confirms an important inverse association between adherence to a MedD and cancer mortality and risk of several cancer types, especially colorectal cancer These observed beneficial effects are mainly driven by higher intakes of fruits, vegetables, and whole grains Moreover, we were able to report for the first time a small decrease in breast cancer risk (6%) by pooling seven cohort studies

Ultrasound-guided supraclavicular approach for regional anesthesia of the brachial plexus.

Abstract: We prospectively studied 40 patients (ASA grades I-III) undergoing surgery of the forearm and hand, to investigate the use of ultrasonic cannula guidance for supraclavicular brachial plexus block and its effect on success rate and frequency of complications. Patients were randomized into Group S (supraclavicular paravascular approach; n = 20) and Group A (axillary approach; n = 20). Ultrasonographic study of the plexus sheath was done. After visualization of the anatomy, the plexus sheath was penetrated using a 24-gauge cannula. Plexus block was performed using 30 mL bupivacaine 0.5%. Onset of sensory and motor block of the radial, ulnar, and median nerves was recorded in 10-min intervals for 1 h. Satisfactory surgical anesthesia was attained in 95% of both groups. In Group A, 25% showed an incomplete sensory block of the musculocutaneous nerve, whereas all patients in Group S had a block of this nerve. Complete sensory block of the radial, median, and ulnar nerves was attained after an average of 40 min without a significant difference between the two groups. Because of the direct ultrasonic view of the cervical pleura, we had no cases of pneumothorax. An accidental puncture of subclavian or axillary vessels, as well as neurologic damage, was avoided in all cases. An ultrasonography-guided approach for supraclavicular block combines the safety of axillary block with the larger extent of block of the supraclavicular approach.

Alterations in Nocturnal Serum Melatonin Levels In Humans With Growth and Aging

Abstract: The available data on potential alterations in serum melatonin (MLT) levels during a human lifetime are fragmentary and inconsistent. We, therefore, measured day- and nighttime serum MLT concentrations in 367 subjects (210 males and 157 females), aged 3 days to 90 yr. Blood samples were collected between 0730 and 1000 h and between 2300 and 0100 h. Serum MLT levels were measured by RIA. The mean nighttime serum MLT concentration was low during the first 6 months of life, i.e. 27.3 +/- 5.4 (+/- SE) pg/mL (0.12 +/- 0.02 nmol/L). It then increased to a peak value at 1-3 yr of age [329.5 +/- 42.0 pg/mL; (1.43 +/- 0.18 nmol/L)], and it was considerably lower [62.5 +/- 9.0 pg/mL; (0.27 +/- 0.04 nmol/L)] in individuals aged 15-20 yr. During the following decades serum MLT declined moderately until old age (70-90 yr of age), i.e. 29.2 +/- 6.1 pg/mL (0.13 +/- 0.03 nmol/L). This biphasic MLT decline follows 2 exponential functions with different slopes (from age 1-20 yr: r = -0.56; P less than 0.001; y = 278.7 X e -0.09x; from age 20-90 yr: r = -0.44; P less than 0.001; y = 84.8 X e -0.017x). The decrease in nocturnal serum MLT in children and adolescents (1-20 yr) correlated with the increase in body weight (r = -0.54; P less than 0.001) and body surface area (r = -0.71; P less than 0.001). At a later age (20-90 yr) there was no correlation among these variables. Daytime serum MLT levels were low and no age-related alterations were found. This study revealed major age-related alterations in nocturnal serum MLT levels. The negative correlation between serum MLT and body weight in childhood and adolescence is evidence that expansion of body size is responsible for the huge MLT decrease during that period. The moderate decline at older ages must derive from other factors.