743 research outputs found

    GroundLink: A Dataset Unifying Human Body Movement and Ground Reaction Dynamics

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    The physical plausibility of human motions is vital to various applications in fields including but not limited to graphics, animation, robotics, vision, biomechanics, and sports science. While fully simulating human motions with physics is an extreme challenge, we hypothesize that we can treat this complexity as a black box in a data-driven manner if we focus on the ground contact, and have sufficient observations of physics and human activities in the real world. To prove our hypothesis, we present GroundLink, a unified dataset comprised of captured ground reaction force (GRF) and center of pressure (CoP) synchronized to standard kinematic motion captures. GRF and CoP of GroundLink are not simulated but captured at high temporal resolution using force platforms embedded in the ground for uncompromising measurement accuracy. This dataset contains 368 processed motion trials (~1.59M recorded frames) with 19 different movements including locomotion and weight-shifting actions such as tennis swings to signify the importance of capturing physics paired with kinematics. GroundLinkNet, our benchmark neural network model trained with GroundLink, supports our hypothesis by predicting GRFs and CoPs accurately and plausibly on unseen motions from various sources. The dataset, code, and benchmark models are made public for further research on various downstream tasks leveraging the rich physics information at https://csr.bu.edu/groundlink/

    The impact of child soldiers on rebel groups’ fighting capacities

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    Several rebel groups actively recruit children to serve among their ranks. While this constitutes one of the most egregious violations of children’s rights, it remains unclear what impact recruited children have on the fighting capacities of these armed groups. The existing research suggests that, on the one hand, armed groups drafting children might also be militarily effective, since it is cheaper to provide for children, they are more obedient and aggressive than adults, and easily manipulable. On the other hand, children may negatively affect rebel groups’ fighting capacities as they are less proficient combatants than adults and often difficult to control. We add to this debate by systematically analyzing the quantitative evidence on the impact of child soldiers on rebel groups’ fighting capacities. Based on the analysis of newly compiled data on child recruitment by rebel groups between 1989 and 2010, our analyses show that children may actually increase rebel groups’ fighting capacities. That said, rebels’ ability to procure arms and the access to resources seem to be more important determinants of fighting capacity. The authors discuss these findings in light of policy implications and avenues for future research. </jats:p

    Characteristics of Hospitalized Children with 2009 Pandemic Influenza A (H1N1): A Multicenter Study in Korea

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    The majority of Korean patients with pandemic influenza A (H1N1) during the 2009 epidemic were under 20 yr of age. The limited data on the clinical characteristics of these children led us to conduct a case note-based investigation of children admitted to 6 university hospitals with 2009 H1N1 influenza. A total of 804 children was enrolled. The median age was 5 yr; 63.8% were males; and 22.4% had at least one chronic underlying disease. Ninety-five of the patients (11.8%) were critically ill and they suffered more from shortness of breath, dyspnea and lymphopenia than the other patients. Among all the patients, 98.8% were treated with antivirals and 73% received treatment within 48 hr of illness onset. All the enrolled patients are alive and appear to have had good outcomes, probably due to the early intervention and antiviral treatment. This study deals with hospitalized children whose diagnoses of influenza A (H1N1) were confirmed, and therefore provides important new information about the clinical patterns of children with influenza A (H1N1) in Korea

    Images across Europe: The sending and receiving of sexual images and associations with interpersonal violence in young people's relationships

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    This article explores young people's experiences of sending and receiving sexual images and text messages (sexting) within their interpersonal relationships and the contexts in which this occurs. The article uses data from a recent Daphne funded project ‘Safeguarding teenagers' intimate relationships’ (STIR) involving a survey with 4564 young people aged between 14 and 17 in a number of schools across five countries in Europe. Findings reveal that experiences of sexting vary by country and gender. The study also found that young people who reported victimisation in their relationships were more likely to have sent a sext message than those who had not. The article points to the need for a more nuanced understanding of the varied contexts and experiences around sexting in order to better develop policy, practice and education in this area

    The fragment structure of a putative HsdR subunit of a type I restriction enzyme from Vibrio vulnificus YJ016: implications for DNA restriction and translocation activity

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    Among four types of bacterial restriction enzymes that cleave a foreign DNA depending on its methylation status, type I enzymes composed of three subunits are interesting because of their unique DNA cleavage and translocation mechanisms performed by the restriction subunit (HsdR). The elucidated N-terminal fragment structure of a putative HsdR subunit from Vibrio vulnificus YJ016 reveals three globular domains. The nucleolytic core within an N-terminal nuclease domain (NTD) is composed of one basic and three acidic residues, which include a metal-binding site. An ATP hydrolase (ATPase) site at the interface of two RecA-like domains (RDs) is located close to the probable DNA-binding site for translocation, which is far from the NTD nucleolytic core. Comparison of relative domain arrangements with other functionally related ATP and/or DNA complex structures suggests a possible translocation and restriction mechanism of the HsdR subunit. Furthermore, careful analysis of its sequence and structure implies that a linker helix connecting two RDs and an extended region within the nuclease domain may play a central role in switching the DNA translocation into the restriction activity

    The Anti-Inflammatory and Antibacterial Basis of Human Omental Defense: Selective Expression of Cytokines and Antimicrobial Peptides

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    BACKGROUND: The wound healing properties of the human omentum are well known and have extensively been exploited clinically. However, the underlying mechanisms of these effects are not well understood. We hypothesize that the omentum tissue promotes wound healing via modulation of anti-inflammatory pathways, and because the omentum is rich in adipocytes, the adipocytes may modulate the anti-inflammatory response. Factors released by human omentum may affect healing, inflammation and immune defense. METHODOLOGY: Six human omentum tissues (non obese, free from malignancy, and any other systemic disorder) were obtained during diagnostic laparoscopies having a negative outcome. Healthy oral mucosa (obtained from routine oral biopsies) was used as control. Cultured adipocytes derived from human omentum were exposed to lipopolysaccharide (LPS) (1-50 ng/mL) for 12-72 hours to identify the non-cytotoxic doses. Levels of expression (mRNA and protein) were carried out for genes associated with pro- and anti-inflammatory cytokine responses and antibacterial/antimicrobial activity using qRT-PCR, western blotting, and cell-based ELISA assays. RESULTS: The study shows significant higher levels of expression (mRNA and protein) of several specific cytokines, and antibacterial peptides in the omentum tissues when compared to oral sub-mucosal tissues. In the validation studies, primary cultures of adipocytes, derived from human omentum were exposed to LPS (5 and 10 ng/mL) for 24 and 48 h. The altered expressions were more pronounced in cultured adipocytes cells when exposed to LPS as compared to the omentum tissue. CONCLUSIONS/SIGNIFICANCE: Perhaps, this is the first report that provides evidence of expressional changes in pro- and anti-inflammatory cytokines and antibacterial peptides in the normal human omentum tissue as well as adipocytes cultured from this tissue. The study provides new insights on the molecular and cellular mechanisms of healing and defense by the omentum, and suggests the potential applicability of cultured adipocytes derived from the omentum for future therapeutic applications

    Pulmonary arterial medial smooth muscle thickness in sudden infant death syndrome: an analysis of subsets of 73 cases

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    Previous studies addressing pulmonary artery morphology have compared cases of sudden infant death syndrome (SIDS) to controls but none have compared demographic profiles, exposure to potentially hypoxic risk factors and other pathologic variables in SIDS cases grouped according to pulmonary artery medial smooth muscle thickness. Aims: To compare the relative medial thickness (RMT) in alveolar wall arteries (AW) in SIDS cases with that in age-matched controls and 2. Compare demographic, clinical, and pathologic characteristics among three subsets of SIDS cases based upon alveolar wall (AW) RMT. Retrospective morphometric planimetry of all muscularized arteries in standardized right apical lung sections in 73 SIDS cases divided into three groups based on increasing AW RMT as well as 19 controls age-matched to 19 of the SIDS cases. SIDS and age-matched control cases did not differ with respect to AW RMT or other demographic variables. The SIDS group with the thickest AW RMT had significantly more males and premature birth than the other groups, but the groups did not differ for known clinical risk factors that would potentially expose them to hypoxia. Pathologic variables, including pulmonary inflammation, gastric aspiration, intra-alveolar siderophages, cardiac valve circumferences, and heart and liver weights, were not different between groups. Age was not significantly correlated with RMT of alveolar wall and pre-acinar arteries but was significant at p = .018 for small intra-acinar arteries. The groups were different for RMT of small pre-acinar and intra-acinar arteries, which increased with increasing AW RMT. Statistical differences should not necessarily be equated with clinical importance, however future research incorporating more quantified historical data is recommended

    Association between Physical Activity and Cardiovascular Risk in Chinese Youth Independent of Age and Pubertal Stage

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    <p>Abstract</p> <p>Background</p> <p>Childhood and adolescence are critical periods of habit formation with substantial tracking of lifestyle and cardiovascular risk into adulthood. There are various guidelines on recommended levels of physical activity in youth of school-age. Despite the epidemic of obesity and diabetes in China, there is a paucity of data in this regard in Chinese youth. We examined the association of self-reported level of physical activity and cardiovascular risk in Hong Kong Chinese youth of school-age.</p> <p>Methods</p> <p>This was a cross-sectional study conducted in 2007-8 in a school setting with 2119 Hong Kong Chinese youth aged 6-20 years. Physical activity level was assessed using a validated questionnaire, CUHK-PARCY (The Chinese University of Hong Kong: Physical Activity Rating for Children and Youth). A summary risk score comprising of waist circumference, blood pressure, fasting plasma glucose and lipids was constructed to quantify cardiovascular risk.</p> <p>Results</p> <p>In this cohort, 21.5% reported high level of physical activity with boys being more active than girls (32.1% versus 14.1%, p < 0.001). Regression analysis showed physical activity level, sex and pubertal stage were independently associated with cardiovascular risk score.</p> <p>Conclusion</p> <p>Self-reported level of physical activity is associated with cardiovascular risk factors in Chinese youth after adjusting for sex and pubertal stage.</p
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