Associations of changes in public transport use with physical activity and adiposity in older adults

Background: We investigated predictors of two increases in older people’s public transport use: initiating public transport use among non-users; and increasing public transport use amongst users. We also investigated associations of these changes with physical activity, Body Mass Index (BMI) and waist circumference. Methods: Data come from the 2008 and 2012 English Longitudinal Study of Ageing (ELSA). Logistic regression assessed predictors of increases in public transport use among adults aged ≥50 years. Gender-stratified logistic and linear models assessed associations of increases in public transport use with changes in physical activity and adiposity. Results: Those becoming eligible for a free older person’s bus pass were more likely to both initiate and increase public transport use (e.g. for initiating public transport use Adjusted Odds Ratio (AORs) 1.77, 95% Confidence Interval 1.35; 2.33). Retiring from paid work was also associated with both initiating and increasing public transport use e.g. AOR 1.57 (1.29; 1.91) for initiating use. Women who increased public transport use had mean BMI 2.03 kg/m2 lower (− 2.84, − 1.21) at follow up than those who did not, although this was attenuated after adjusting for BMI at baseline (− 0.40 kg/m2, − 0.82, 0.01). After adjustment for baseline physical activity those initiating public transport use were more likely to undertake at least some physical activity in 2012 (e.g. AOR for women 1.67, 1.03; 2.72). Conclusions: Both initiating and increasing public transport use were associated with increased physical activity and may be associated with lower adiposity among women. These findings strengthen the case for considering public transport provision as an effective means of promoting healthier ageing

Associations of public transportation use with cardiometabolic health: a systematic review and meta-analysis

Public transport provides an opportunity to incorporate physical activity into journeys, but potential health impacts have not been systematically examined. Literature searches were carried out up to December 2017 using Medline, Embase, Transport Database, Scopus, Cochrane Library, opengrey.eu and Google. We identified longitudinal studies which examined associations between public transport and cardio-metabolic health including: adiposity, type II diabetes, and cardiovascular disease. We assessed study quality using the Newcastle-Ottawa Scale for cohort studies and performed meta-analyses where possible. Ten studies were identified, seven investigating use of public transport and three examining proximity to public transport. Seven studies used individual level data on changes in BMI with objective outcomes measured in six studies. Study follow-up ranged from one to ten years with three studies adjusting for non-transport physical activity. We found a consistent association between public transport use and lower BMI. Meta-analysis of data from five comparable studies found that switching from car to public transport was associated with lower BMI: −0.30 kg/m2 (−0.47, −0.14). Few studies have investigated associations between public transport use and non-adiposity outcomes. These findings suggest that sustainable urban design which promotes public transport use may produce modest reductions in population BMI

Identification of nonlinear sparse networks using sparse Bayesian learning

© 2017 IEEE. This paper considers a parametric approach to infer sparse networks described by nonlinear ARX models, with linear ARX treated as a special case. The proposed method infers both the Boolean structure and the internal dynamics of the network. It considers classes of nonlinear systems that can be written as weighted (unknown) sums of nonlinear functions chosen from a fixed basis dictionary. Due to the sparse topology, coefficients of most groups are zero. Besides, only a few nonlinear terms in nonzero groups contribute to the internal dynamics. Therefore, the identification problem should estimate both group-and element-sparse parameter vectors. The proposed method combines Sparse Bayesian Learning (SBL) and Group Sparse Bayesian Learning (GSBL) to impose both kinds of sparsity. Simulations indicate that our method outperforms SBL and GSBL when these are applied alone. A linear ring structure network also illustrates that the proposed method has improved performance to the kernel approach

Network Analysis of Host-Virus Communities in Bats and Rodents Reveals Determinants of Cross-Species Transmission

Bats are natural reservoirs of several important emerging viruses. Cross-species transmission appears to be quite common among bats, which may contribute to their unique reservoir potential. Therefore, understanding the importance of bats as reservoirs requires examining them in a community context rather than concentrating on individual species. Here, we use a network approach to identify ecological and biological correlates of cross-species virus transmission in bats and rodents, another important host group. We show that given our current knowledge the bat viral sharing network is more connected than the rodent network, suggesting viruses may pass more easily between bat species. We identify host traits associated with important reservoir species: gregarious bats are more likely to share more viruses and bats which migrate regionally are important for spreading viruses through the network. We identify multiple communities of viral sharing within bats and rodents and highlight potential species traits that can help guide studies of novel pathogen emergence

A criterion for the fragmentation of bubbly magma based on brittle failure theory

The fragmentation of bubbly magma is a defining point in a volcanic eruption-before fragmentation the magma flows relatively slowly, during fragmentation the bubbles break up to release compressed gas and, afterwards, the eruption becomes a violent gas flow carrying suspended magma particles. Seemingly benign lava flows or domes can suddenly fragment into deadly pyroclastic flows(1-3). Several criteria have been proposed to define the point of magma fragmentation or foam stability(4-7). The criterion of Papale(7) is based on melt relaxation theory and equates magma strain rate with the rate of increase of flow velocity with distance. It ignores, however, the role of bubble pressure in causing fragmentation. Two empirical approaches(4,5) consider the role of high bubble pressure in causing fragmentation but do not address the underlying physics of magma fragmentation. Here I develop a fragmentation criterion for bubbly magma based on brittle failure theory and apply it to the fragmentation of lava domes and flows. On the basis of this theory, a bubbly magma will fragment when the tensile stress at the inner walls of bubbles exceeds the tensile strength of the magma. The fragmentation conditions depend strongly on initial water content, with calculated vesicularity and final water levels coinciding reasonably well with those in observed pumices. This suggests that the proposed criterion captures the essence of the fragmentation process in bubbly magma.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62724/1/402648a0.pd

Arsenic distribution and speciation in the fronds of the hyperaccumulator Pteris vittata

Pteris vittata is the first plant reported to be a hyperaccumulator of arsenic (As), and little is known about the mechanisms of As hyperaccumulation in this plant. Arsenic distribution at the whole plant (fronds) and cellular level was investigated using chemical analyses and energy dispersive X-ray microanalyses (EDXA). Speciation of As in the fronds was determined using X-ray absorption near edge spectroscopy (XANES) analyses. The majority of As was found in the pinnae (96% of total As). The concentration of As in pinnae decreased from the base to the apex of the fronds. Arsenic concentrations in spores and midribs were much lower than in the pinnae. EDXA analyses revealed that As was compartmentalized mainly in the upper and lower epidermal cells, probably in the vacuoles. The distribution pattern of potassium was similar to As, whereas other elements (Ca, Cl, K, Mg, P and S) were distributed differently. XANES analyses showed that approximately 75% of the As in fronds was present in the As(III) oxidation state and the remaining as As(V)

Manipulating vector transmission reveals local processes in bacterial communities of batss

Infectious diseases result from multiple interactions among microbes and hosts, but community ecology approaches are rarely applied. Manipulation of vector populations provides a unique opportunity to test the importance of vectors in infection cycles while also observing changes in pathogen community diversity and species interactions. Yet for many vector-borne infections in wildlife, a biological vector has not been experimentally verified and few manipulative studies have been performed. Using a captive colony of fruit bats in Ghana, we observed changes in the community of Bartonella bacteria over time after the decline and subsequent reintroduction of bat flies. With reduced transmission, community changes were attributed to ecological drift and potential selection through interspecies competition mediated by host immunity. This work demonstrated that forces maintaining diversity in communities of free-living macroorganisms act in similar ways in communities of symbiotic microorganisms, both within and among hosts. Additionally, this study is the first to experimentally test the role of bat flies as vectors of Bartonella species

Large emissions from floodplain trees close the Amazon methane budget

Wetlands are the largest global source of atmospheric methane (CH4), a potent greenhouse gas. However, methane emission inventories from the Amazon floodplain, the largest natural geographic source of CH4 in the tropics, consistently underestimate the atmospheric burden of CH4 determined via remote sensing and inversion modelling, pointing to a major gap in our understanding of the contribution of these ecosystems to CH4 emissions. Here we report CH4 fluxes from the stems of 2,357 individual Amazonian floodplain trees from 13 locations across the central Amazon basin. We find that escape of soil gas through wetland trees is the dominant source of regional CH4 emissions. Methane fluxes from Amazon tree stems were up to 200 times larger than emissions reported for temperate wet forests6 and tropical peat swamp forests, representing the largest non-ebullitive wetland fluxes observed. Emissions from trees had an average stable carbon isotope value (δ13C) of −66.2 ± 6.4 per mil, consistent with a soil biogenic origin. We estimate that floodplain trees emit 15.1 ± 1.8 to 21.2 ± 2.5 teragrams of CH4 a year, in addition to the 20.5 ± 5.3 teragrams a year emitted regionally from other sources. Furthermore, we provide a ‘top-down’ regional estimate of CH4 emissions of 42.7 ± 5.6 teragrams of CH4 a year for the Amazon basin, based on regular vertical lower-troposphere CH4 profiles covering the period 2010–2013. We find close agreement between our ‘top-down’ and combined ‘bottom-up’ estimates, indicating that large CH4 emissions from trees adapted to permanent or seasonal inundation can account for the emission source that is required to close the Amazon CH4 budget. Our findings demonstrate the importance of tree stem surfaces in mediating approximately half of all wetland CH4 emissions in the Amazon floodplain, a region that represents up to one-third of the global wetland CH4 source when trees are combined with other emission sources

Can luteal regression be reversed?

The corpus luteum is an endocrine gland whose limited lifespan is hormonally programmed. This debate article summarizes findings of our research group that challenge the principle that the end of function of the corpus luteum or luteal regression, once triggered, cannot be reversed. Overturning luteal regression by pharmacological manipulations may be of critical significance in designing strategies to improve fertility efficacy

Smoothing a rugged protein folding landscape by sequence-based redesign

The rugged folding landscapes of functional proteins puts them at risk of misfolding and aggregation. Serine protease inhibitors, or serpins, are paradigms for this delicate balance between function and misfolding. Serpins exist in a metastable state that undergoes a major conformational change in order to inhibit proteases. However, conformational labiality of the native serpin fold renders them susceptible to misfolding, which underlies misfolding diseases such as $\alpha_1$-antitrypsin deficiency. To investigate how serpins balance function and folding, we used consensus design to create $\textit{conserpin}$, a synthetic serpin that folds reversibly, is functional, thermostable, and polymerization resistant. Characterization of its structure, folding and dynamics suggest that consensus design has remodeled the folding landscape to reconcile competing requirements for stability and function. This approach may offer general benefits for engineering functional proteins that have risky folding landscapes, including the removal of aggregation-prone intermediates, and modifying scaffolds for use as protein therapeutics.BTP is a Medical Research Council Career Development Fellow. AAN and JJH are supported by the Wellcome Trust (grant number WT 095195). SM acknowledges fellowship support from the Australian Research Council (FT100100960). NAB is an Australian Research Council Future Fellow (110100223). GIW is an Australian Research Council Discovery Outstanding Researcher Award Fellow (DP140100087). AMB is a National Health and Medical Research Senior Research Fellow (1022688). JCW is an NHMRC Senior Principal Research fellow and also acknowledges the support of an ARC Federation Fellowship. We thank the Australian Synchrotron for beam-time and technical assistance. This work was supported by the Multi-modal Australian ScienceS Imaging and Visualisation Environment (MASSIVE) (www.massive.org.au). We acknowledge the Monash Protein Production Unit and Monash Macromolecular Crystallization Facilit