Protection from muscle damage in the absence of changes in muscle mechanical behavior

Introduction: The repeated bout effect characterizes the protective adaptation after a single bout of unaccustomed eccentric exercise that induces muscle damage. Sarcomerogenesis and increased tendon compliance have been suggested as potential mechanisms for the repeated bout effect by preventing muscle fascicles from being stretched onto the descending limb of the length–tension curve (the region where sarcomere damage is thought to occur). In this study, evidence was sought for three possible mechanical changes that would support either the sarcomerogenesis or the increased tendon compliance hypotheses: a sustained rightward shift in the fascicle length–tension relationship, reduced fascicle strain amplitude, and reduced starting fascicle length. Methods: Subjects (n = 10) walked backward downhill (5 km/h, 20% incline) on a treadmill for 30 min on two occasions separated by 7 d. Kinematic data and medial gastrocnemius fascicle lengths (ultrasonography) were recorded at 10-min intervals to compare fascicle strains between bouts. Fascicle length–torque curves from supramaximal tibial nerve stimulation were constructed before, 2 h after, and 2 d after each exercise bout. Results: Maximum torque decrement and elevated muscle soreness were present after the first, but not the second, backward downhill walking bout signifying a protective repeated bout effect. There was no sustained rightward shift in the length–torque relationship between exercise bouts, nor decreases in fascicle strain amplitude or shortening of the starting fascicle length. Conclusions: Protection from a repeated bout of eccentric exercise was conferred without changes in muscle fascicle strain behavior, indicating that sarcomerogenesis and increased tendon compliance were unlikely to be responsible. As fascicle strains are relatively small in humans, we suggest that changes to connective tissue structures, such as extracellular matrix remodeling, are better able to explain the repeated bout effect observed here

Relative contribution of diet and physical activity to increased adiposity among rural to urban migrants in India:A cross-sectional study

BACKGROUND: In common with many other low- and middle-income countries (LMICs), rural to urban migrants in India are at increased risk of obesity, but it is unclear whether this is due to increased energy intake, reduced energy expenditure, or both. Knowing this and the relative contribution of specific dietary and physical activity behaviours to greater adiposity among urban migrants could inform policies for control of the obesity epidemic in India and other urbanising LMICs. In the Indian Migration Study, we previously found that urban migrants had greater prevalence of obesity and diabetes compared with their nonmigrant rural-dwelling siblings. In this study, we investigated the relative contribution of energy intake and expenditure and specific diet and activity behaviours to greater adiposity among urban migrants in India. METHODS AND FINDINGS: The Indian Migration Study was conducted between 2005 and 2007. Factory workers and their spouses from four cities in north, central, and south of India, together with their rural-dwelling siblings, were surveyed. Self-reported data on diet and physical activity was collected using validated questionnaires, and adiposity was estimated from thickness of skinfolds. The association of differences in dietary intake, physical activity, and adiposity between siblings was examined using multivariable linear regression. Data on 2,464 participants (median age 43 years) comprised of 1,232 sibling pairs (urban migrant and their rural-dwelling sibling) of the same sex (31% female) were analysed. Compared with the rural siblings, urban migrants had 18% greater adiposity, 12% (360 calories/day) more energy intake, and 18% (11 kilojoules/kg/day) less energy expenditure (P < 0.001 for all). Energy intake and expenditure were independently associated with increased adiposity of urban siblings, accounting for 4% and 6.5% of adiposity difference between siblings, respectively. Difference in dietary fat/oil (10 g/day), time spent engaged in moderate or vigorous activity (69 minutes/day), and watching television (30 minutes/day) were associated with difference in adiposity between siblings, but no clear association was observed for intake of fruits and vegetables, sugary foods and sweets, cereals, animal and dairy products, and sedentary time. The limitations of this study include a cross-sectional design, systematic differences in premigration characteristics of migrants and nonmigrants, low response rate, and measurement error in estimating diet and activity from questionnaires. CONCLUSIONS: We found that increased energy intake and reduced energy expenditure contributed equally to greater adiposity among urban migrants in India. Policies aimed at controlling the rising prevalence of obesity in India and potentially other urbanising LMICs need to be multicomponent, target both energy intake and expenditure, and focus particularly on behaviours such as dietary fat/oil intake, time spent on watching television, and time spent engaged in moderate or vigorous intensity physical activity

From planetesimals to terrestrial planets: N-body simulations including the effects of nebular gas and giant planets

We present results from a suite of N-body simulations that follow the accretion history of the terrestrial planets using a new parallel treecode that we have developed. We initially place 2000 equal size planetesimals between 0.5--4.0 AU and the collisional growth is followed until the completion of planetary accretion (> 100 Myr). All the important effect of gas in laminar disks are taken into account: the aerodynamic gas drag, the disk-planet interaction including Type I migration, and the global disk potential which causes inward migration of secular resonances as the gas dissipates. We vary the initial total mass and spatial distribution of the planetesimals, the time scale of dissipation of nebular gas, and orbits of Jupiter and Saturn. We end up with one to five planets in the terrestrial region. In order to maintain sufficient mass in this region in the presence of Type I migration, the time scale of gas dissipation needs to be 1-2 Myr. The final configurations and collisional histories strongly depend on the orbital eccentricity of Jupiter. If today's eccentricity of Jupiter is used, then most of bodies in the asteroidal region are swept up within the terrestrial region owing to the inward migration of the secular resonance, and giant impacts between protoplanets occur most commonly around 10 Myr. If the orbital eccentricity of Jupiter is close to zero, as suggested in the Nice model, the effect of the secular resonance is negligible and a large amount of mass stays for a long period of time in the asteroidal region. With a circular orbit for Jupiter, giant impacts usually occur around 100 Myr, consistent with the accretion time scale indicated from isotope records. However, we inevitably have an Earth size planet at around 2 AU in this case. It is very difficult to obtain spatially concentrated terrestrial planets together with very late giant impacts.Comment: 51 pages, 19 figures, 2 tables, published in Icaru

Using environmental monitoring to complement in-depth qualitative interviews in cold homes research

Cold homes contribute to twenty to forty thousand excess winter deaths each year in the UK and approximately 300,000 hospital admissions. Using fuel poverty as an identifier for those at risk does not always capture everyday exposure to cold homes due to variations in financial trade-offs and behavioural factors. Few fuel poverty studies have combined environmental measurements with qualitative data on lived experiences of fuel poverty and cold homes. This paper looks at the strengths and limitations of using a mixed method, environmental and qualitative interviewing approach. A series of six discreet studies were conducted between 2001 and 2015 using a similar methodology with a mixed methods design where in-depth interviews were conducted alongside temperature and humidity measurements. The research studies found that combining environmental monitoring with qualitative research methods allows both cross validation and triangulation of data in order to provide a richer and more insightful examination into the lives of people living in cold homes. The studies demonstrate how a combined methodological approach can help explain the choices, decisions and behaviour of households experiencing cold homes and fuel poverty. The paper concludes with recommendations for future development and implementation of the research method

The WiggleZ Dark Energy Survey: the selection function and z=0.6 galaxy power spectrum

We report one of the most accurate measurements of the three-dimensional large-scale galaxy power spectrum achieved to date, using 56,159 redshifts of bright emission-line galaxies at effective redshift z=0.6 from the WiggleZ Dark Energy Survey at the Anglo-Australian Telescope. We describe in detail how we construct the survey selection function allowing for the varying target completeness and redshift completeness. We measure the total power with an accuracy of approximately 5% in wavenumber bands of dk=0.01 h/Mpc. A model power spectrum including non-linear corrections, combined with a linear galaxy bias factor and a simple model for redshift-space distortions, provides a good fit to our data for scales k < 0.4 h/Mpc. The large-scale shape of the power spectrum is consistent with the best-fitting matter and baryon densities determined by observations of the Cosmic Microwave Background radiation. By splitting the power spectrum measurement as a function of tangential and radial wavenumbers we delineate the characteristic imprint of peculiar velocities. We use these to determine the growth rate of structure as a function of redshift in the range 0.4 < z < 0.8, including a data point at z=0.78 with an accuracy of 20%. Our growth rate measurements are a close match to the self-consistent prediction of the LCDM model. The WiggleZ Survey data will allow a wide range of investigations into the cosmological model, cosmic expansion and growth history, topology of cosmic structure, and Gaussianity of the initial conditions. Our calculation of the survey selection function will be released at a future date via our website wigglez.swin.edu.au.Comment: 21 pages, 22 figures, accepted for publication in MNRA

Positive emotions: passionate scholarship and student transformation

This paper challenges the practical and conceptual understanding of the role of emotions in higher education from the twin perspectives of transition and transformation. Focusing on the neglected area of positive emotions, exploratory data reveal a rich, low-level milieu of undergraduate emotional awareness in students chiefly attributed to pedagogic actions, primarily extrinsically orientated, and pervasive throughout the learning experience. The data conceive positive affect as oppositional, principally ephemeral and linked to performative pedagogic endeavours of getting, knowing and doing. A cyclical social dynamic of reciprocity, generating positive feedback loops, is highlighted. Finally we inductively construct a tentative 'emotion-transition framework' to assist our understanding of positive emotion as a force for transformational change; our contention is that higher education might proactively craft pedagogic spaces so as to unite the feeling discourse, the thinking discourse (epistemological self) and the wider life-self (ontological) discourse

Collective decision making and social interaction rules in mixed-species flocks of songbirds

Associations in mixed-species foraging groups are common in animals, yet have rarely been explored in the context of collective behaviour. Despite many investigations into the social and ecological conditions under which individuals should form groups, we still know little about the specific behavioural rules that individuals adopt in these contexts, or whether these can be generalized to heterospecifics. Here, we studied collective behaviour in flocks in a community of five species of woodland passerine birds. We adopted an automated data collection protocol, involving visits by RFID-tagged birds to feeding stations equipped with antennae, over two winters, recording 91 576 feeding events by 1904 individuals. We demonstrated highly synchronized feeding behaviour within patches, with birds moving towards areas of the patch with the largest proportion of the flock. Using a model of collective decision making, we then explored the underlying decision rule birds may be using when foraging in mixed-species flocks. The model tested whether birds used a different decision rule for conspecifics and heterospecifics, and whether the rules used by individuals of different species varied. We found that species differed in their response to the distribution of conspecifics and heterospecifics across foraging patches. However, simulating decisions using the different rules, which reproduced our data well, suggested that the outcome of using different decision rules by each species resulted in qualitatively similar overall patterns of movement. It is possible that the decision rules each species uses may be adjusted to variation in mean species abundance in order for individuals to maintain the same overall flock-level response. This is likely to be important for maintaining coordinated behaviour across species, and to result in quick and adaptive flock responses to food resources that are patchily distributed in space and time

Cancellous bone and theropod dinosaur locomotion. Part I—an examination of cancellous bone architecture in the hindlimb bones of theropods

This paper is the first of a three-part series that investigates the architecture of cancellous (‘spongy’) bone in the main hindlimb bones of theropod dinosaurs, and uses cancellous bone architectural patterns to infer locomotor biomechanics in extinct non-avian species. Cancellous bone is widely known to be highly sensitive to its mechanical environment, and has previously been used to infer locomotor biomechanics in extinct tetrapod vertebrates, especially primates. Despite great promise, cancellous bone architecture has remained little utilized for investigating locomotion in many other extinct vertebrate groups, such as dinosaurs. Documentation and quantification of architectural patterns across a whole bone, and across multiple bones, can provide much information on cancellous bone architectural patterns and variation across species. Additionally, this also lends itself to analysis of the musculoskeletal biomechanical factors involved in a direct, mechanistic fashion. On this premise, computed tomographic and image analysis techniques were used to describe and analyse the three-dimensional architecture of cancellous bone in the main hindlimb bones of theropod dinosaurs for the first time. A comprehensive survey across many extant and extinct species is produced, identifying several patterns of similarity and contrast between groups. For instance, more stemward non-avian theropods (e.g. ceratosaurs and tyrannosaurids) exhibit cancellous bone architectures more comparable to that present in humans, whereas species more closely related to birds (e.g. paravians) exhibit architectural patterns bearing greater similarity to those of extant birds. Many of the observed patterns may be linked to particular aspects of locomotor biomechanics, such as the degree of hip or knee flexion during stance and gait. A further important observation is the abundance of markedly oblique trabeculae in the diaphyses of the femur and tibia of birds, which in large species produces spiralling patterns along the endosteal surface. Not only do these observations provide new insight into theropod anatomy and behaviour, they also provide the foundation for mechanistic testing of locomotor hypotheses via musculoskeletal biomechanical modelling

Herbal medicine as an auspicious therapeutic approach for the eradication of Helicobacter pylori infection: A concise review

Helicobacter pylori (H. pylori) causes gastric mucosa inflammation and gastric cancer mostly via several virulence factors. Induction of proinflammatory pathways plays a crucial role in chronic inflammation, gastric carcinoma, and H. pylori pathogenesis. Herbal medicines (HMs) are nontoxic, inexpensive, and mostly anti-inflammatory reminding meticulous emphasis on the elimination of H. pylori and gastric cancer. Several HM has exerted paramount anti-H. pylori traits. In addition, they exert anti-inflammatory effects through several cellular circuits such as inhibition of 5'-adenosine monophosphate-activated protein kinase, nuclear factor-κB, and activator protein-1 pathway activation leading to the inhibition of proinflammatory cytokines (interleukin 1α [IL-1α], IL-1β, IL-6, IL-8, IL-12, interferon γ, and tumor necrosis factor-α) expression. Furthermore, they inhibit nitrous oxide release and COX-2 and iNOS activity. The apoptosis induction in Th1 and Th17-polarized lymphocytes and M2-macrophagic polarization and STAT6 activation has also been exhibited. Thus, their exact consumable amount has not been revealed, and clinical trials are needed to achieve optimal concentration and their pharmacokinetics. In the aspect of bioavailability, solubility, absorption, and metabolism of herbal compounds, nanocarriers such as poly lactideco-glycolide-based loading and related formulations are helpful. Noticeably, combined therapies accompanied by probiotics can also be examined for better clearance of gastric mucosa. In addition, downregulation of inflammatory microRNAs (miRNAs) by HMs and upregulation of those anti-inflammatory miRNAs is proposed to protect the gastric mucosa. Thus there is anticipation that in near future HM-based formulations and proper delivery systems are possibly applicable against gastric cancer or other ailments because of H. pylori