SciCombinator

Discover the most talked about and latest scientific content & concepts.

893

Objective To investigate the association between active commuting and incident cardiovascular disease (CVD), cancer, and all cause mortality.Design Prospective population based study. Setting UK Biobank.Participants 263 450 participants (106 674 (52%) women; mean age 52.6), recruited from 22 sites across the UK. The exposure variable was the mode of transport used (walking, cycling, mixed mode v non-active (car or public transport)) to commute to and from work on a typical day.Main outcome measures Incident (fatal and non-fatal) CVD and cancer, and deaths from CVD, cancer, or any causes.Results 2430 participants died (496 were related to CVD and 1126 to cancer) over a median of 5.0 years (interquartile range 4.3-5.5) follow-up. There were 3748 cancer and 1110 CVD events. In maximally adjusted models, commuting by cycle and by mixed mode including cycling were associated with lower risk of all cause mortality (cycling hazard ratio 0.59, 95% confidence interval 0.42 to 0.83, P=0.002; mixed mode cycling 0.76, 0.58 to 1.00, P<0.05), cancer incidence (cycling 0.55, 0.44 to 0.69, P<0.001; mixed mode cycling 0.64, 0.45 to 0.91, P=0.01), and cancer mortality (cycling 0.60, 0.40 to 0.90, P=0.01; mixed mode cycling 0.68, 0.57 to 0.81, P<0.001). Commuting by cycling and walking were associated with a lower risk of CVD incidence (cycling 0.54, 0.33 to 0.88, P=0.01; walking 0.73, 0.54 to 0.99, P=0.04) and CVD mortality (cycling 0.48, 0.25 to 0.92, P=0.03; walking 0.64, 0.45 to 0.91, P=0.01). No statistically significant associations were observed for walking commuting and all cause mortality or cancer outcomes. Mixed mode commuting including walking was not noticeably associated with any of the measured outcomes.Conclusions Cycle commuting was associated with a lower risk of CVD, cancer, and all cause mortality. Walking commuting was associated with a lower risk of CVD independent of major measured confounding factors. Initiatives to encourage and support active commuting could reduce risk of death and the burden of important chronic conditions.

Concepts: Epidemiology, Disease, Statistics, Death, Median, Sustainable transport, Bicycle, Commuting

413

Episodes of Palaeolithic cannibalism have frequently been defined as ‘nutritional’ in nature, but with little empirical evidence to assess their dietary significance. This paper presents a nutritional template that offers a proxy calorie value for the human body. When applied to the Palaeolithic record, the template provides a framework for assessing the dietary value of prehistoric cannibalistic episodes compared to the faunal record. Results show that humans have a comparable nutritional value to those faunal species that match our typical body weight, but significantly lower than a range of fauna often found in association with anthropogenically modified hominin remains. This could suggest that the motivations behind hominin anthropophagy may not have been purely nutritionally motivated. It is proposed here that the comparatively low nutritional value of hominin cannibalism episodes support more socially or culturally driven narratives in the interpretation of Palaeolithic cannibalism.

Concepts: Human, Sociology, Science, Anthropology, Human anatomy, Neanderthal, Prehistory, Cannibalism

317

Left ventricular assist devices (LVADs) have been used as an effective therapeutic option in patients with advanced heart failure, either as a bridge to transplantation, as destination therapy, or in some patients, as a bridge to recovery.

Concepts: Cardiology, Ventricular assist device

312

The “wooden-steps” hypothesis [Distel DL, et al. (2000) Nature 403:725-726] proposed that large chemosynthetic mussels found at deep-sea hydrothermal vents descend from much smaller species associated with sunken wood and other organic deposits, and that the endosymbionts of these progenitors made use of hydrogen sulfide from biogenic sources (e.g., decaying wood) rather than from vent fluids. Here, we show that wood has served not only as a stepping stone between habitats but also as a bridge between heterotrophic and chemoautotrophic symbiosis for the giant mud-boring bivalve Kuphus polythalamia This rare and enigmatic species, which achieves the greatest length of any extant bivalve, is the only described member of the wood-boring bivalve family Teredinidae (shipworms) that burrows in marine sediments rather than wood. We show that K. polythalamia harbors sulfur-oxidizing chemoautotrophic (thioautotrophic) bacteria instead of the cellulolytic symbionts that allow other shipworm species to consume wood as food. The characteristics of its symbionts, its phylogenetic position within Teredinidae, the reduction of its digestive system by comparison with other family members, and the loss of morphological features associated with wood digestion indicate that K. polythalamia is a chemoautotrophic bivalve descended from wood-feeding (xylotrophic) ancestors. This is an example in which a chemoautotrophic endosymbiosis arose by displacement of an ancestral heterotrophic symbiosis and a report of pure culture of a thioautotrophic endosymbiont.

Concepts: Algae, Bacteria, Evolution, Symbiosis, Endosymbiont, Hydrothermal vent, Bivalvia, Shipworm

300

Life skills play a key role in promoting educational and occupational success in early life, but their relevance at older ages is uncertain. Here we measured five life skills-conscientiousness, emotional stability, determination, control, and optimism-in 8,119 men and women aged 52 and older (mean 66.7 y). We show that the number of skills is associated with wealth, income, subjective wellbeing, less depression, low social isolation and loneliness, more close relationships, better self-rated health, fewer chronic diseases and impaired activities of daily living, faster walking speed, and favorable objective biomarkers (concentration of high-density lipoprotein cholesterol, vitamin D and C-reactive protein, and less central obesity). Life skills also predicted sustained psychological wellbeing, less loneliness, and a lower incidence of new chronic disease and physical impairment over a 4-y period. These analyses took account of age, sex, parental socioeconomic background, education, and cognitive function. No single life skill was responsible for the associations we observed, nor were they driven by factors such as socioeconomic status or health. Despite the vicissitudes of later life, life skills impact a range of outcomes, and the maintenance of these attributes may benefit the older population.

Concepts: Cholesterol, Psychology, Osteoporosis, Medicine, Nutrition, Asthma, Chronic, Cognition

294

A new species of tyrannosaurid from the upper Two Medicine Formation of Montana supports the presence of a Laramidian anagenetic (ancestor-descendant) lineage of Late Cretaceous tyrannosaurids. In concert with other anagenetic lineages of dinosaurs from the same time and place, this suggests that anagenesis could have been a widespread mechanism generating species diversity amongst dinosaurs, and perhaps beyond. We studied the excellent fossil record of the tyrannosaurid to test that hypothesis. Phylogenetic analysis places this new taxon as the sister species to Daspletosaurus torosus. However, given their close phylogenetic relationship, geographic proximity, and temporal succession, where D. torosus (~76.7-75.2 Ma) precedes the younger new species (~75.1-74.4 Ma), we argue that the two forms most likely represent a single anagenetic lineage. Daspletosaurus was an important apex predator in the late Campanian dinosaur faunas of Laramidia; its absence from later units indicates it was extinct before Tyrannosaurus rex dispersed into Laramidia from Asia. In addition to its evolutionary implications, the texture of the facial bones of the new taxon, and other derived tyrannosauroids, indicates a scaly integument with high tactile sensitivity. Most significantly, the lower jaw shows evidence for neurovasculature that is also seen in birds.

Concepts: Evolution, Dinosaur, Tyrannosauroidea, Tyrannosaurus, Tyrannosauridae, Alioramus, Daspletosaurus, Gorgosaurus

278

In collaboration with state, tribal, local, and territorial health departments, CDC established the U.S. Zika Pregnancy Registry (USZPR) in early 2016 to monitor pregnant women with laboratory evidence of possible recent Zika virus infection and their infants.

Concepts: Pregnancy, Childbirth, Infant, Fetus, Breastfeeding, Centers for Disease Control and Prevention

256

Persistent episodes of extreme weather in the Northern Hemisphere summer have been shown to be associated with the presence of high-amplitude quasi-stationary atmospheric Rossby waves within a particular wavelength range (zonal wavenumber 6-8). The underlying mechanistic relationship involves the phenomenon of quasi-resonant amplification (QRA) of synoptic-scale waves with that wavenumber range becoming trapped within an effective mid-latitude atmospheric waveguide. Recent work suggests an increase in recent decades in the occurrence of QRA-favorable conditions and associated extreme weather, possibly linked to amplified Arctic warming and thus a climate change influence. Here, we isolate a specific fingerprint in the zonal mean surface temperature profile that is associated with QRA-favorable conditions. State-of-the-art (“CMIP5”) historical climate model simulations subject to anthropogenic forcing display an increase in the projection of this fingerprint that is mirrored in multiple observational surface temperature datasets. Both the models and observations suggest this signal has only recently emerged from the background noise of natural variability.

Concepts: Climate, Weather, Climate change, Wave, Global warming, Waves, Northern Hemisphere, Extreme weather

240

Objective To determine the frequency of prescriptions for short term use of oral corticosteroids, and adverse events (sepsis, venous thromboembolism, fractures) associated with their use.Design Retrospective cohort study and self controlled case series.Setting Nationwide dataset of private insurance claims.Participants Adults aged 18 to 64 years who were continuously enrolled from 2012 to 2014.Main outcome measures Rates of short term use of oral corticosteroids defined as less than 30 days duration. Incidence rates of adverse events in corticosteroid users and non-users. Incidence rate ratios for adverse events within 30 day and 31-90 day risk periods after drug initiation.Results Of 1 548 945 adults, 327 452 (21.1%) received at least one outpatient prescription for short term use of oral corticosteroids over the three year period. Use was more frequent among older patients, women, and white adults, with significant regional variation (all P<0.001). The most common indications for use were upper respiratory tract infections, spinal conditions, and allergies. Prescriptions were provided by a diverse range of specialties. Within 30 days of drug initiation, there was an increase in rates of sepsis (incidence rate ratio 5.30, 95% confidence interval 3.80 to 7.41), venous thromboembolism (3.33, 2.78 to 3.99), and fracture (1.87, 1.69 to 2.07), which diminished over the subsequent 31-90 days. The increased risk persisted at prednisone equivalent doses of less than 20 mg/day (incidence rate ratio 4.02 for sepsis, 3.61 for venous thromboembolism, and 1.83 for fracture; all P<0.001).Conclusion One in five American adults in a commercially insured plan were given prescriptions for short term use of oral corticosteroids during a three year period, with an associated increased risk of adverse events.

Concepts: Time, Epidemiology, Clinical trial, Asthma, Corticosteroid, Respiratory system, Upper respiratory tract, Upper respiratory tract infection

228

Knowledge regarding whether benzodiazepines and similarly acting non-benzodiazepines (Z-drugs) are associated with an increased risk of pneumonia among older adults is lacking. We sought to investigate this association among community-dwelling adults with Alzheimer disease, a condition in which both sedative/hypnotic use and pneumonia are common.

Concepts: Alzheimer's disease, Pneumonia, Benzodiazepine, Zaleplon, Zolpidem