Do Fit FlopsTM increase muscle activity in the lower extremity whilst walking?

Fit FlopTM shoes are widely available commercial products which are advertised with the strap line 'get a work out while you walkTM' (Fit FlopTM, from http://www.fitflop.com/). The basis for this product is the inbuilt Microwobbleboard technologyTM which effectively provides an unstable contact surface with the foot. One of the advertised advantages of Fit FlopsTM is that they increase leg and gluteal muscle activity in comparison to a control shoe. However, to the authors' knowledge there are currently no published independent studies which report these findings. With obesity and sedentary lifestyles on the increase, novel ways of promoting and enhancing 'exercise' levels in the general population are of paramount importance

Thermal analysis of polymers adsorbed on silica and the functionalized mesoporous silica and its application to the adsorption of volatile organic compounds

The thermal behavior of adsorbed poly(vinyl acetate) (PVAc) on silica was determined using temperature-modulated differential scanning calorimetry (TMDSC). PVAc samples with different molecular masses (260, 170 and 100 kDa) were studied. PVAc with high and medium molecular masses, had 0.91±0.31 mg/m2 and 0.66±0.16 mg/m2 amounts of tightly-bound polymer, respectively. The low molecular mass PVAc had a smaller amount of tightly-bound polymer (about 0.53±0.02 mg/m2). The ratios of the heat capacity changes in the glass transition region were consistent with the tightly-bound PVAc in a more restricted environment than the bulk polymer.Functionalized hexagonal mesoporous silica, in powder and pellet forms, was prepared by chemical modification of mesoporous silica with both chlorine-based and alkoxide silylating agents of different chain lengths. The 13C and 29Si NMR and TGA results show that both methods can functionalize the surface of mesoporous silica. Better loading of organic moieties was found when using hexyltrimethoxysilane. A hydrolysis study shows that chlorotrimethylsilane functionalized mesoporous silica can be readily hydrolyzed, but the surfaces generated from the alkoxide silylating agents are more stable. Toluene, nitrobenzene, and naphthalene have been used as adsorbents to probe the difference between pure and functionalized mesoporous silica. Heats of vaporization or sublimation for toluene, nitrobenzene and naphthalene have been measured using an optical absorption method for the pure material and pure and functionalized mesoporous silica. Since, mesoporous silica is a hydrophilic material; nitrobenzene binding energy to the hydroxylated mesoporous silica is higher compared with the functionalized mesoporous silica because of the polarity of nitrobenzene resulting in higher affinity to the hydroxyl groups of mesoporous silica. In contrast, the functionalized mesoporous silica samples exhibit hydrophobic properties. Toluene and naphthalene binding energies to the functionalized mesoporous silica are higher than for the hydroxylated mesoporous silica

Self-serving incentives impair collective decisions by increasing conformity

The average judgment of large numbers of people has been found to be consistently better than the best individual response. But what motivates individuals when they make collective decisions? While it is a popular belief that individual incentives promote out-of-thebox thinking and diverse solutions, the exact role of motivation and reward in collective intelligence remains unclear. Here we examined collective intelligence in an interactive group estimation task where participants were rewarded for their individual or group's performance. In addition to examining individual versus collective incentive structures, we controlled whether participants could see social information about the others' responses. We found that knowledge about others' responses reduced the wisdom of the crowd and, crucially, this effect depended on how people were rewarded. When rewarded for the accuracy of their individual responses, participants converged to the group mean, increasing social conformity, reducing diversity and thereby diminishing their group wisdom. When rewarded for their collective performance, diversity of opinions and the group wisdom increased. We conclude that the intuitive association between individual incentives and individualist opinion needs revising

Intermittent Motion in Desert Locusts: Behavioural Complexity in Simple Environments

10 páginas, 4 figuras.Animals can exhibit complex movement patterns that may be the result of interactions with their environment or may be directly the mechanism by which their behaviour is governed. In order to understand the drivers of these patterns we examine the movement behaviour of individual desert locusts in a homogenous experimental arena with minimal external cues. Locust motion is intermittent and we reveal that as pauses become longer, the probability that a locust changes direction from its previous direction of travel increases. Long pauses (of greater than 100 s) can be considered reorientation bouts, while shorter pauses (of less than 6 s) appear to act as periods of resting between displacements. We observe powerlaw behaviour in the distribution of move and pause lengths of over 1.5 orders of magnitude. While Le´vy features do exist, locusts’ movement patterns are more fully described by considering moves, pauses and turns in combination. Further analysis reveals that these combinations give rise to two behavioural modes that are organized in time: local search behaviour (long exploratory pauses with short moves) and relocation behaviour (long displacement moves with shorter resting pauses). These findings offer a new perspective on how complex animal movement patterns emerge in nature.The authors acknowledge support from the Natural Environment Research Council (S.B.), the Spanish Ministry of Science and Innovation: MICINN-RyC 2009-04133 and BFU2010-22337 (F.B.) Searle Scholars Award 08-SPP-201 (I.D.C.), National Science Foundation Award PHY-0848755 (I.D.C.), Office of Naval Research Award N00014-09-1-1074 (I.D.C.) and a DARPA Grant No. HR0011-09-1-0055 (to Princeton University) and an Army Research Office Grant W911NG-11-1- 0385 (I.D.C.).Peer reviewe

Absence of antiretroviral therapy and other risk factors for morbidity and mortality in Malaysian compulsory drug detention and rehabilitation centers

Background: Throughout Asia, people who use drugs are confined in facilities referred to as compulsory drug detention and rehabilitation centers. The limited transparency and accessibility of these centers has posed a significant challenge to evaluating detainees and detention conditions directly.Despite HIV being highly prevalent in this type of confined setting, direct evaluation of detainees with HIV and their access to medical care has yet to be reported in the literature. Methods: We evaluated the health status of 100 adult male detainees with HIV and their access to medical care in the two largest Malaysian compulsory drug detention and rehabilitation centers holding HIV-infected individuals.Results: Approximately 80% of all detainees with HIV were surveyed in each detention center. Most participants reported multiple untreated medical conditions. None reported being able to access antiretroviral therapy during detention and only 9% reported receiving any HIV-related clinical assessment or care. Nearly a quarter screened positive for symptoms indicative of active tuberculosis, yet none reported having been evaluated for tuberculosis.Although 95% of participants met criteria for opioid dependence prior to detention, none reported being able to access opioid substitution therapy during detention, with 86% reporting current cravings for opioids and 87% anticipating relapsing to drug use after release.Fourteen percent of participants reported suicidal ideation over the previous two weeks.Conclusion: We identified a lack of access to antiretroviral therapy in two of the six compulsory drug detention and rehabilitation centers in Malaysia designated to hold HIV-infected individuals and found significant, unmet health needs among detainees with HIV. Individuals confined under such conditions are placed at considerably high risk for morbidity and mortality.Our findings underscore the urgent need for evidence-based drug policies that respect the rights of people who use drugs and seek to improve, rather than undermine, their health

The Social Context of Cannibalism in Migratory Bands of the Mormon Cricket

Cannibalism has been shown to be important to the collective motion of mass migratory bands of insects, such as locusts and Mormon crickets. These mobile groups consist of millions of individuals and are highly destructive to vegetation. Individuals move in response to attacks from approaching conspecifics and bite those ahead, resulting in further movement and encounters with others. Despite the importance of cannibalism, the way in which individuals make attack decisions and how the social context affects these cannibalistic interactions is unknown. This can be understood by examining the decisions made by individuals in response to others. We performed a field investigation which shows that adult Mormon crickets were more likely to approach and attack a stationary cricket that was side-on to the flow than either head- or abdomen-on, suggesting that individuals could reduce their risk of an attack by aligning with neighbours. We found strong social effects on cannibalistic behaviour: encounters lasted longer, were more likely to result in an attack, and attacks were more likely to be successful if other individuals were present around a stationary individual. This local aggregation appears to be driven by positive feedback whereby the presence of individuals attracts others, which can lead to further crowding. This work improves our understanding of the local social dynamics driving migratory band formation, maintenance and movement at the population level

Prevalence and Correlates of HIV and Hepatitis C Virus Infections and Risk Behaviors among Malaysian Fishermen

Fishermen in Southeast Asia have been found to be highly vulnerable to HIV, with research evidence highlighting the role of sexual risk behaviors. This study aims to estimate the rate of HIV as well as hepatitis C virus (HCV) infections among Malaysian fishermen, and the risky sexual and injection drug use behaviors that may contribute to these infections. The study also includes an assessment of socio-demographic, occupational and behavioral correlates of testing positive for HIV or HCV, and socio-demographic and occupational correlates of risk behaviors. The study had a cross-sectional design and recruited 406 fishermen through respondent-driven sampling (RDS). Participants self-completed a questionnaire and provided biological specimens for HIV and HCV testing. We conducted and compared results of analyses of both unweighted data and data weighted with the Respondent-Driven Sampling Analysis Tool (RDSAT). Of the participating fishermen, 12.4% were HIV positive and 48.6% had HCV infection. Contrary to expectations and findings from previous research, most fishermen (77.1%) were not sexually active. More than a third had a history of injection drug use, which often occurred during fishing trips on commercial vessels and during longer stays at sea. Of the fishermen who injected drugs, 42.5% reported unsafe injection practices in the past month. Reporting a history of injection drug use increased the odds of testing HIV positive by more than 6 times (AOR = 6.22, 95% CIs [2.74, 14.13]). Most fishermen who injected drugs tested positive for HCV. HCV infection was significantly associated with injection drug use, being older than 25 years, working on a commercial vessel and spending four or more days at sea per fishing trip. There is an urgent need to strengthen current harm reduction and drug treatment programs for Malaysian fishermen who inject drugs, especially among fishermen who work on commercial vessels and engage in deep-sea fishing