The impact of resource availability on bacterial resistance to phages in soil

This is the final version of the article. Available from Public Library of Science via the DOI in this recordResource availability can affect the coevolutionary dynamics between host and parasites, shaping communities and hence ecosystem function. A key finding from theoretical and in vitro studies is that host resistance evolves to greater levels with increased resources, but the relevance to natural communities is less clear. We took two complementary approaches to investigate the effect of resource availability on the evolution of bacterial resistance to phages in soil. First, we measured the resistance and infectivity of natural communities of soil bacteria and phage in the presence and absence of nutrient-providing plants. Second, we followed the real-time coevolution between defined bacteria and phage populations with resource availability manipulated by the addition or not of an artificial plant root exudate. Increased resource availability resulted in increases in bacterial resistance to phages, but without a concomitant increase in phage infectivity. These results suggest that phages may have a reduced impact on the control of bacterial densities and community composition in stable, high resource environments.The work was supported by NERC, the AXA research fund, BBSRC, the Royal Society (A.B.), and European Research Council funding under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no. 268504 (K.J.G.)

Optical Modelling and Phylogenetic Analysis Provide Clues to the Likely Function of Corneal Nipple Arrays in Butterflies and Moths.

This is the final version. Available from MDPI via the DOI in this recordThe lenses in compound eyes of butterflies and moths contain an array of nipple-shaped protuberances, or corneal nipples. Previous work has suggested that these nipples increase light transmittance and reduce the eye glare of moths that are inactive during the day. This work builds on but goes further than earlier analyses suggesting a functional role for these structures including, for the first time, an explanation of why moths are attracted to UV light. Using a phylogenetic approach and 3D optical modelling, we show empirically that these arrays have been independently lost from different groups of moths and butterflies and vary within families. We find differences in the shape of nipples between nocturnal and diurnal species, and that anti-glow reflectance levels are different at different wave-lengths, a result thereby contradicting the currently accepted theory of eye glow for predator avoidance. We find that there is reduced reflectance, and hence greater photon absorption, at UV light, which is probably a reason why moths are attracted to UV. We note that the effective refractive index at the end of the nipples is very close to the refractive index of water, allowing almost all the species with nipples to see without distortion when the eye is partially or completely wet and providing the potential to keep eyes dry. These observations provide a functional explanation for these arrays. Of special interest is the finding that their repeated and independent loss across lepidopteran phylogeny is inconsistent with the explanation that they are being lost in the 'higher', more active butterflies

The epidemiology of aerobic physical activity and muscle-strengthening activity guideline adherence among 383,928 U.S. adults

BACKGROUND: The World Health Organization's 'Global Recommendations on Physical Activity for Health' state that adults should engage in regular moderate-to-vigorous intensity aerobic physical activity (MVPA; e.g. walking, running, cycling) and muscle-strengthening activity (MSA; e.g. strength/resistance training). However, assessment of both MVPA and MSA is rare in physical activity surveillance. The aim of this study is to describe the prevalence, correlates and chronic health conditions associated with meeting the combined MVPA-MSA guidelines among a population representative sample of U.S. adults. METHODS: In this cross-sectional study, data were drawn from the U.S. 2015 Behavioral Risk Factor Surveillance System. During telephone interviews, MVPA and MSA were assessed using validated questionnaires. We calculated the proportions meeting both the global MVPA and MSA physical activity guidelines (MVPA >/=150 min/week and MSA >/=2 sessions/week). Poisson regressions with a robust error variance were used to assess: (i) prevalence ratios (PR) for meeting both guidelines across sociodemographic factors (e.g. age, sex, education, income, race/ethnicity); and (ii) PRs of 12 common chronic health conditions (e.g. diabetes, coronary heart disease, hypertension, depression) across different categories of physical activity guideline adherence (met neither [reference]; MSA only; MVPA only; met both). RESULTS: Among 383,928 adults (aged 18-80 years), 23.5% (95% CI: 20.1, 20.6%) met the combined MVPA-MSA guidelines. Those with poorer self-rated health, older adults, women, lower education/income and current smokers were less likely to meet the combined guidelines. After adjustment for covariates (e.g. age, self-rated health, income, smoking) compared with meeting neither guidelines, MSA only and MVPA only, meeting the combined MVPA-MSA guidelines was associated with the lowest PRs for all health conditions (APR range: 0.44-0.76), and the clustering of >/=6 chronic health conditions (APR = 0.33; 95% CI: 0.31-0.35). CONCLUSIONS: Eight out of ten U.S. adults do not meet the global physical activity guidelines. This study supports the need for comprehensive health promotion strategies to increase the uptake and adherence of MVPA-MSA among U.S. adults. Large-scale interventions should target specific population sub-groups including older adults, women, those with poorer health and lower education/income

A descriptive epidemiology of screen-based devices by children and adolescents: a scoping review of 130 surveillance studies since 2000

Excessive use of screen-based devices can be detrimental for child and adolescent health. While epidemiological reviews have been focusing on traditional screen-based activities (e.g., television, computer use), the availability of newer screen-based devices (e.g., mobile phones, tablets) has increased considerably in recent years. However, there is limited understanding of the descriptive epidemiology of these newer devices and their contribution towards health-related screen time guidelines (≤2 h/day). This systematic scoping review synthesizes the descriptive epidemiology of screen-based devices, incorporating newer forms of screens, among 5–18-year-olds. Medline, Web of Science, PsycINFO, SPORTDiscus, ERIC, Science Direct, and Scopus databases were searched for articles published in English since year 2000. Search terms included terms that related to screen time and target population. Data were extracted from 130 population-based surveillance studies (minimum sample size N = ≥5000). Screening and data extraction (study characteristics, estimates of prevalence rates and screen time-use point-estimates) were performed in duplicate for accuracy. Television viewing (64.3%) was the most common measure of screen time, whilst fewer reported on newer screen-based devices (mobile phones: 4.6%, active gaming consoles: <1%). On average, 52.3% of participants (k = 19 studies) exceeded 2 h/day of screen time and total screen time was 3.6 h/day (1.3–7.9 h/day). Findings can inform and facilitate future research and policy designed to limit overall screen time among children and adolescents for health gains where appropriate. Moreover, policy makers can use this information to track and monitor screen time among children and adolescents

Total and domain-specific sitting time among employees in desk-based work settings in Australia

Objective: To describe the total and domain-specific daily sitting time among a sample of Australian office-based employees. Methods: In April 2010, paper-based surveys were provided to desk-based employees (n=801) in Victoria, Australia. Total daily and domain-specific (work, leisure-time and transport-related) sitting time (minutes/day) were assessed by validated questionnaires. Differences in sitting time were examined across socio-demographic (age, sex, occupational status) and lifestyle characteristics (physical activity levels, body mass index [BMI]) using multiple linear regression analyses. Results: The median (95% confidence interval [CI]) of total daily sitting time was 540 (531-557) minutes/day. Insufficiently active adults (median=578 minutes/day, [95%CI: 564-602]), younger adults aged 18-29 years (median=561 minutes/day, [95%CI: 540-577]) reported the highest total daily sitting times. Occupational sitting time accounted for almost 60% of total daily sitting time. In multivariate analyses, total daily sitting time was negatively associated with age (unstandardised regression coefficient [B]=-1.58, p&lt;0.001) and overall physical activity (minutes/week) (B=-0.03, p&lt;0.001) and positively associated with BMI (B=1.53, p=0.038). Conclusions: Desk-based employees reported that more than half of their total daily sitting time was accrued in the work setting. Implications: Given the high contribution of occupational sitting to total daily sitting time among desk-based employees, interventions should focus on the work setting

Colour remote sensing of the impact of artificial light at night (I): the potential of the International Space Station and other DSLR-based platforms

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Sensors on remote sensing satellites have provided useful tools for evaluation of the environmental impacts of nighttime artificial light pollution. However, due to their panchromatic nature, the data available from these sensors (VI-IRS/DNB and DMSP/OLS) has a limited capacity accurately to assess this impact. Moreover, in some cases, recorded variations can be misleading. Until new satellite platforms and sensors are available, only nighttime images taken with DSLR cameras from the International Space Station (ISS), airplanes, balloons or other such platforms can provide the required information. Here we describe a theoretical approach using colour-colour diagrams to analyse images taken by astronauts on the ISS to estimate spatial and temporal variation in the spectrum of artificial lighting emissions. We then evaluate how this information can be used to determine effects on some key environmental indices: photopic vision, the Melatonin Suppression Index, the Star Light Index, the Induced Photosynthesis Index, production of NO2-NO radicals, energy efficiency and CO2 emissions, and Correlated Colour Temperature. Finally, we use the city of Milan as a worked example of the approach.Natural Environment Research Council (NERC

Light pollution is associated with earlier tree budburst across the United Kingdom

ArticleThe ecological impact of night-time lighting is of concern because of its well-demonstrated effects on animal behaviour. However, the potential of light pollution to change plant phenology and its corresponding knock-on effects on associated herbivores are less clear. Here, we test if artificial lighting can advance the timing of budburst in trees. We took a UK-wide 13 year dataset of spatially referenced budburst data from four deciduous tree species and matched it with both satellite imagery of night-time lighting and average spring temperature. We find that budburst occurs up to 7.5 days earlier in brighter areas, with the relationship being more pronounced for later-budding species. Excluding large urban areas from the analysis showed an even more pronounced advance of budburst, confirming that the urban ‘heat-island’ effect is not the sole cause of earlier urban budburst. Similarly, the advance in budburst across all sites is too large to be explained by increases in temperature alone. This dramatic advance of budburst illustrates the need for further experimental investigation into the impact of artificial night-time lighting on plant phenology and subsequent species interactions. As light pollution is a growing global phenomenon, the findings of this study are likely to be applicable to a wide range of species interactions across the world.R.S.-Y. was supported by a GWR-ESF Studentship awarded by the University of Exeter to R.H.f.-C. The study was also founded by a BBSRC grant to R.H.f-C