Concurrent Visual Feedback, Practice Organization, and Spatial Aiming Accuracy in Rapid Movement Sequences

Int J Exerc Sci 3(2) : 78-91, 2010. While the availability of visual feedback is a well-known factor influencing the accuracy of rapid aiming movements, little is known about how vision might interact with a contextual variable like practice organization. In the current study, the interaction of concurrent visual feedback (CVF) and practice organization on aiming movement accuracy was investigated in the dominant limb of 40 college-aged participants. Participants performed “triplets” of rapid aiming movements with a lightweight lever in the sagittal plane involving short (20°), medium (40°), long (60°) distances and were randomly assigned to one of four groups (n=10) in a 2 (Group: Blocked Practice, Random Practice) x 2 (Vision: CVF, no CVF) factorial design. Participants performed 24 triplets in acquisition and 10 triplets of a novel pattern (15°- 45°-15°) on transfer. Movement time was controlled by a metronome set at 1.43 cycles per second resulting in a cycle time of approximately 700 ms per movement. The constant error and overall error in distance were calculated for each distance and analyzed with separate 2 (Group) x 2 (Vision) x 3 (Movement) ANOVAs with repeated measures on the last factor. When CVF was available, contextual interference effects were shown by better accuracy for the blocked practice groups during acquisition compared to the random practice group. Without CVF, participants tended to overshoot the targets and contextual interference effects were minimized during acquisition and on the first transfer trial. Random practice resulted in better transfer performance compared to blocked practice for both vision conditions when all transfer trials were included in the analysis. The findings contributed to the current literature by demonstrating the importance of practice context and visual feedback to aiming accuracy

Predicting knee osteoarthritis risk in injured populations

Background Individuals who suffered a lower limb injury have an increased risk of developing knee osteoarthritis. Early diagnosis of osteoarthritis and the ability to track its progression is challenging. This study aimed to explore links between self-reported knee osteoarthritis outcome scores and biomechanical gait parameters, whether self-reported outcome scores could predict gait abnormalities characteristic of knee osteoarthritis in injured populations and, whether scores and biomechanical outcomes were related to osteoarthritis severity via Spearman's correlation coefficient. Methods A cross-sectional study was conducted with asymptomatic participants, participants with lower-limb injury and those with medial knee osteoarthritis. Spearman rank determined relationships between knee injury and outcome scores and hip and knee kinetic/kinematic gait parameters. K-Nearest Neighbour algorithm was used to determine which of the evaluated parameters created the strongest classifier model. Findings Differences in outcome scores were evident between groups, with knee quality of life correlated to first and second peak external knee adduction moment (0.47, 0.55). Combining hip and knee kinetics with quality of life outcome produced the strongest classifier (1.00) with the least prediction error (0.02), enabling classification of injured subjects gait as characteristic of either asymptomatic or knee osteoarthritis subjects. When correlating outcome scores and biomechanical outcomes with osteoarthritis severity only maximum external hip and knee abduction moment (0.62, 0.62) in addition to first peak hip adduction moment (0.47) displayed significant correlations. Interpretation The use of predictive models could enable clinicians to identify individuals at risk of knee osteoarthritis and be a cost-effective method for osteoarthritis screening

Hepatitis C virus infection in EU/EEA and United Kingdom prisons: opportunities and challenges for action

Background: Hepatitis C virus (HCV) transmission in the European Union, European Economic Area and United Kingdom is driven by injecting drug use (IDU), which contributes to the high burden of chronic infection among people in prisons. This study aimed to describe the context, epidemiology and response targeting HCV in prisons across the region. Methods: We retrieved and collated HCV-related data from the World Health Organization’s Health in Prisons European Database and the European Centre for Disease Prevention and Control’s hepatitis C prevalence database. Prisons population data were obtained from the Council of Europe Annual Penal Statistics on prison populations (SPACE I). Results: There were 12 to 93,266 people in prisons, with rates of 31·5 to 234·9 per 100,000 population. Median age was between 31 and 40 years, with up to 72% foreign nationals. Average detention time ranged from one to 31 months. Ministries of Health had sole authority over prisons health, budget administration and funding in 27, 31 and 8% of 26 reporting countries, respectively. Seroprevalence of HCV antibodies ranged from 2·3% to 82·6% while viraemic infections ranged from 5·7% to 8·2%, where reported. Up to 25·8 and 44% reported current and ever IDU, respectively. Eight countries routinely offered HCV screening on an opt-out basis. Needle and syringe programmes were available in three countries. Among the nine countries with data, the annual number of those who had completed HCV treatment ranged between one and 1215 people in prisons. Conclusions: HCV burden in prisons remains high, amidst suboptimal levels of interventions. Systematic monitoring at both local and regional levels is warranted, to advance progress towards the elimination of HCV in the region

Estimating the scale of chronic hepatitis B virus infection among migrants in EU/EEA countries

Background: Chronic hepatitis B (CHB) related morbidity and mortality can be reduced through risk group screening, linkage to care and anti-viral treatment. This study estimates the number of CHB cases among foreign-born (migrants) in the European Union and European Economic Area (EU/EEA) countries in order to identify the most affected migrant populations. Methods: The CHB burden was estimated by combining: demographic data on migrant population size by country of birth in the EU/EEA, extracted from European statistical databases; and CHB prevalence in migrants' countries of birth and in EU/EEA countries, derived from a systematic literature search. The relative contribution of migrants from endemic countries to the total CHB burden in each country was also estimated. The reliability of using country of birth prevalence as a proxy for prevalence among migrants was assessed by comparing it to the prevalence found in studies among migrants in Europe. Results: An estimated 1-1.9 million CHB-infected migrants from endemic countries (prevalence ≥2%) reside in the EU/EEA. Migrants from endemic countries comprise 10.3% of the total EU/EEA population but account for 25% (15%-35%) of all CHB cases. Migrants born in China and Romania contribute the largest number of infections, with over 100,000 estimated CHB cases each, followed by migrants from Turkey, Albania and Russia, in descending order, with over 50,000 estimated CHB cases each. The CHB prevalence reported in studies among migrants in EU/EEA countries was lower than the country of birth prevalence in 9 of 14 studies. Conclusions: Migrants from endemic countries are disproportionately affected by CHB; their contribution however varies between EU/EEA countries. Migrant focused screening strategies would be most effective in countries with a high relative contribution of migrants and a low general population prevalence. In countries with a higher general population prevalence and a lower relative contribution of migrants, screening specific birth cohorts may be a more effective use of scarce resources. Quantifying the number of CHB infections among 50 different migrant groups residing in each of the 31 EU/EEA host countries helps to identify the most affected migrant communities who would benefit from targeted screening and linkage to care

Teenagers’ understandings of and attitudes towards vaccines and vaccine-preventable diseases: a qualitative study

<p>Background: To examine immunisation information needs of teenagers we explored understandings of vaccination and vaccine-preventable diseases, attitudes towards immunisation and experiences of immunisation. Diseases discussed included nine for which vaccines are currently offered in the UK (human papillomavirus, meningitis, tetanus, diphtheria, polio, whooping cough, measles, mumps and rubella), and two not currently included in the routine UK schedule (hepatitis B and chickenpox).</p> <p>Methods Twelve focus groups conducted between November 2010 and March 2011 with 59 teenagers (29 girls and 30 boys) living in various parts of Scotland.</p> <p>Results Teenagers exhibited limited knowledge and experience of the diseases, excluding chickenpox. Measles, mumps and rubella were perceived as severe forms of chickenpox-like illness, and rubella was not associated with foetal damage. Boys commonly believed that human papillomavirus only affects girls, and both genders exhibited confusion about its relationship with cancer. Participants considered two key factors when assessing the threat of diseases: their prevalence in the UK, and their potential to cause fatal or long-term harm. Meningitis was seen as a threat, but primarily to babies. Participants explained their limited knowledge as a result of mass immunisation making once-common diseases rare in the UK, and acknowledged immunisation's role in reducing disease prevalence.</p> <p>Conclusions While it is welcome that fewer teenagers have experienced vaccine-preventable diseases, this presents public health advocates with the challenge of communicating benefits of immunisation when advantages are less visible. The findings are timely in view of the Joint Committee on Vaccination and Immunisation's recommendation that a booster of meningitis C vaccine should be offered to teenagers; that teenagers did not perceive meningitis C as a significant threat should be a key concern of promotional information. While teenagers’ experiences of immunisation in school were not always positive, they seemed enthusiastic at the prospect of introducing more vaccines for their age group.</p&gt

Estimating the scale of chronic hepatitis C virus infection in the EU/EEA: A focus on migrants from anti-HCV endemic countries

Background: Increasing the proportion diagnosed with and on treatment for chronic hepatitis C (CHC) is key to the elimination of hepatitis C in Europe. This study contributes to secondary prevention planning in the European Union/European Economic Area (EU/EEA) by estimating the number of CHC (anti-HCV positive and viraemic) cases among migrants living in the EU/EEA and born in endemic countries, defining the most affected migrant populations, and assessing whether country of birth prevalence is a reliable proxy for migrant prevalence. Methods: Migrant country of birth and population size extracted from statistical databases and anti-HCV prevalence in countries of birth and in EU/EEA countries derived from a systematic literature search were used to estimate caseload among and most affected migrants. Reliability of country of birth prevalence as a proxy for migrant prevalence was assessed via a systematic literature search. Results: Approximately 11% of the EU/EEA adult population is foreign-born, 79% of whom were born in endemic (anti-HCV prevalence ≥1%) countries. Anti-HCV/CHC prevalence in migrants from endemic countries residing in the EU/EEA is estimated at 2.3%/1.6%, corresponding to ~580,000 CHC infections or 14% of the CHC disease burden in the EU/EEA. The highest number of cases is found among migrants from Romania and Russia (50-60,000 cases each) and migrants from Italy, Morocco, Pakistan, Poland and Ukraine (25-35,000 cases each). Ten studies reporting prevalence in migrants in Europe were identified; in seven of these estimates, prevalence was comparable with the country of birth prevalence and in three estimates it was lower. Discussion: Migrants are disproportionately affected by CHC, account for a considerable number of CHC infections in EU/EEA countries, and are an important population for targeted case finding and treatment. Limited data suggest that country of birth prevalence can be used as a proxy for the prevalence in migrants

Developing and Piloting a Standardized European Protocol for Hepatitis C Prevalence Surveys in the General Population (2016-2019)

Funding Information: This work was funded by the European Center for Disease Prevention and Control (ECDC) through a contract. Publisher Copyright: © Copyright © 2021 Sperle, Nielsen, Bremer, Gassowski, Brummer-Korvenkontio, Bruni, Ciccaglione, Kaneva, Liitsola, Naneva, Perchemlieva, Spada, Toikkanen, Amato-Gauci, Duffell and Zimmermann.Background: A robust estimate of the number of people with chronic hepatitis C virus (HCV) infection is essential for an appropriate public health response and for monitoring progress toward the WHO goal of eliminating viral hepatitis. Existing HCV prevalence studies in the European Union (EU)/European Economic Area (EEA) countries are heterogeneous and often of poor quality due to non-probability based sampling methods, small sample sizes and lack of standardization, leading to poor national representativeness. This project aimed to develop and pilot standardized protocols for undertaking nationally representative HCV prevalence surveys in the general adult population. Methods: From 2016 to 2019 a team from the Robert Koch-Institute contracted by the European Centre for Disease Prevention and Control synthesized evidence on existing HCV prevalence surveys and survey methodology and drafted a protocol. The methodological elements of the protocol were piloted and evaluated in Bulgaria, Finland and Italy, and lessons learnt from the pilots were integrated in the final protocol. An international multidisciplinary expert group was consulted regularly. Results: The protocol includes three alternative study approaches: a stand-alone survey; a "nested" survey within an existing health survey; and a retrospective testing survey approach. A decision algorithm advising which approach to use was developed. The protocol was piloted and finalized covering minimum and gold standards for all steps to be implemented from sampling, data protection and ethical issues, recruitment, specimen collection and laboratory testing options, staff training, data management and analysis and budget considerations. Through piloting, the survey approaches were effectively implemented to produce HCV prevalence estimates and the pilots highlighted the strengths and limitations of each approach and key lessons learnt were used to improve the protocol. Conclusions: An evidence-based protocol for undertaking HCV prevalence serosurveys in the general population reflecting the different needs, resources and epidemiological situations has been developed, effectively implemented and refined through piloting. This technical guidance supports EU/EEA countries in their efforts to estimate their national hepatitis C burden as part of monitoring progress toward the elimination targets.publishersversionPeer reviewe

Measles transmission from an anthroposophic community to the general population, Germany 2008

<p>Abstract</p> <p>Background</p> <p>In Germany, measles vaccination coverage with two doses is not yet sufficient to prevent regional outbreaks. Among the 16 German federal states, vaccination coverage was lowest in Bavaria with 85% in 2008. From March to mid-April 2008, four neighbouring Bavarian counties reported 55 measles-cases mostly linked to an ongoing measles outbreak in an anthroposophic school in Austria. We investigated this outbreak to guide future public health action.</p> <p>Methods</p> <p>We applied the German national case-definition for measles and collected data using the national surveillance system and a questionnaire. Measles cases with disease onset a maximum of 18 days apart and spatial contact (e.g. same household, same school) were summed up in clusters. Two different interventions, which were implemented in schools and kindergartens in Bavaria, were compared by their impact on the size and duration of measles clusters. Susceptible persons were excluded from schools or kindergartens either with the first (intervention A) or second (intervention B) measles case occurring in the respective institution.</p> <p>Results</p> <p>Among the 217 Bavarian measles cases identified from March-July 2008, 28 (13%) cases were attendees of the anthroposophic school in Austria. In total, vaccination status was known in 161 (74%) cases and 156 (97%) of them were not vaccinated. The main factor for non-vaccination was "fear of vaccine-related adverse events" (33%). Twenty-nine (18%) of 161 cases suffered complications. Exclusively genotype D5 was detected. Overall, 184 cases could be epidemiologically grouped into 59 clusters. Of those, 41 clusters could be linked to households and 13 to schools or kindergartens. The effect of intervention A and B was analysed in 10 school or kindergarten clusters. Depending on the respective intervention A or B, the median number of cases per cluster was 3 versus 13 (p = 0.05), and the median duration of a cluster was 3 versus 26 days (p = 0.13).</p> <p>Conclusions</p> <p>Introduction of measles virus into a pocket of susceptible persons (e.g. vaccination opponents or sceptics) may lead to large outbreaks in the general population, if the general population's vaccination coverage is below the WHO recommended level. Education on the safety of measles vaccine needs to be strengthened to increase measles vaccination coverage. Early intervention may limit spread in schools or kindergartens. Suspected measles has to be reported immediately to the local health authorities in order to allow intervention as early as possible.</p

Planetary population synthesis

In stellar astrophysics, the technique of population synthesis has been successfully used for several decades. For planets, it is in contrast still a young method which only became important in recent years because of the rapid increase of the number of known extrasolar planets, and the associated growth of statistical observational constraints. With planetary population synthesis, the theory of planet formation and evolution can be put to the test against these constraints. In this review of planetary population synthesis, we first briefly list key observational constraints. Then, the work flow in the method and its two main components are presented, namely global end-to-end models that predict planetary system properties directly from protoplanetary disk properties and probability distributions for these initial conditions. An overview of various population synthesis models in the literature is given. The sub-models for the physical processes considered in global models are described: the evolution of the protoplanetary disk, the planets' accretion of solids and gas, orbital migration, and N-body interactions among concurrently growing protoplanets. Next, typical population synthesis results are illustrated in the form of new syntheses obtained with the latest generation of the Bern model. Planetary formation tracks, the distribution of planets in the mass-distance and radius-distance plane, the planetary mass function, and the distributions of planetary radii, semimajor axes, and luminosities are shown, linked to underlying physical processes, and compared with their observational counterparts. We finish by highlighting the most important predictions made by population synthesis models and discuss the lessons learned from these predictions - both those later observationally confirmed and those rejected.Comment: 47 pages, 12 figures. Invited review accepted for publication in the 'Handbook of Exoplanets', planet formation section, section editor: Ralph Pudritz, Springer reference works, Juan Antonio Belmonte and Hans Deeg, Ed