The KMOS Redshift One Spectroscopic Survey (KROSS): the Tully–Fisher relation at z ∼ 1

We present the stellar mass (M*), and K-corrected K-band absolute magnitude (MK) Tully–Fisher relations (TFRs) for subsamples of the 584 galaxies spatially resolved in H α emission by the KMOS Redshift One Spectroscopic Survey (KROSS). We model the velocity field of each of the KROSS galaxies and extract a rotation velocity, V80 at a radius equal to the major axis of an ellipse containing 80 per cent of the total integrated H α flux. The large sample size of KROSS allowed us to select 210 galaxies with well-measured rotation speeds. We extract from this sample a further 56 galaxies that are rotationally supported, using the stringent criterion V80/σ > 3, where σ is the flux weighted average velocity dispersion. We find the MK and M* TFRs for this subsample to be MK/mag=(−7.3±0.9)×[(log(V80/km s−1)−2.25]−23.4±0.2MK/mag=(−7.3±0.9)×[(log⁡(V80/km s−1)−2.25]−23.4±0.2, and log(M∗/M⊙)=(4.7±0.4)×[(log(V80/km s−1)−2.25]+10.0±0.3log⁡(M∗/M⊙)=(4.7±0.4)×[(log⁡(V80/km s−1)−2.25]+10.0±0.3, respectively. We find an evolution of the M* TFR zero-point of −0.41 ± 0.08 dex over the last ∼8 billion years. However, we measure no evolution in the MK TFR zero-point over the same period. We conclude that rotationally supported galaxies of a given dynamical mass had less stellar mass at z ∼ 1 than the present day, yet emitted the same amounts of K-band light. The ability of KROSS to differentiate, using integral field spectroscopy with KMOS, between those galaxies that are rotationally supported and those that are not explains why our findings are at odds with previous studies without the same capabilities

Medial-lateral centre of mass displacement and base of support are equally good predictors of metabolic cost in amputee walking

Amputees are known to walk with greater metabolic cost than able-bodied individuals and establishing predictors of metabolic cost from kinematic measures, such as centre of mass (CoM) motion, during walking are important from a rehabilitative perspective, as they can provide quantifiable measures to target during gait rehabilitation in amputees. While it is known that vertical CoM motion poorly predicts metabolic cost, CoM motion in the medial-lateral (ML) and anterior-posterior directions have not been investigated in the context of gait efficiency in the amputee population. Therefore, the aims of this study were to investigate the relationship between CoM motion in all three directions of motion, base of support and walking speed, and the metabolic cost of walking in both able-bodied individuals and different levels of lower limb amputee. 37 individuals were recruited to form groups of controls, unilateral above- and below-knee, and bilateral above-knee amputees respectively. Full-body optical motion and oxygen consumption data were collected during walking at a self-selected speed. CoM position was taken as the mass-weighted average of all body segments and compared to each individual’s net non-dimensional metabolic cost. Base of support and ML CoM displacement were the strongest correlates to metabolic cost and the positive correlations suggest increased ML CoM displacement or Base of support will reduce walking efficiency. Rehabilitation protocols which indirectly reduce these indicators, rather than vertical CoM displacement will likely show improvements in amputee walking efficiency

MIGHTEE : total intensity radio continuum imaging and the COSMOS/XMM-LSS Early Science fields

Please read abstract in the article.The UK Science and Technology Facilities Council; the South African Radio Astronomy Observatory; the Leverhulme Trust through an Early Career Research Fellowship; the South African Research Chairs Initiative of the Department of Science and Technology; the National Research Foundation; the Science and Technology Foundation (FCT, Portugal); the UK STFC ; the South African Research Chairs Initiative of the Department of Science and Innovation; the Bundesministerium für Bildung und Forschung (BMBF); the Italian Ministry of Foreign Affairs and International Cooperation; the South African Department of Science and Technology’s National Research Foundation (DST-NRF).https://academic.oup.com/mnrashj2022Physic

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: A systematic analysis for the Global Burden of Disease Study 2015

Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods: We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings: Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation: Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding: Bill & Melinda Gates Foundation

The KMOS Redshift One Spectroscopic Survey (KROSS): rotational velocities and angular momentum of z ≈ 0.9 galaxies

We present dynamical measurements for 586 Hα detected star-forming galaxies from the KMOS (K-band Multi-Object Spectrograph) Redshift One Spectroscopic Survey (KROSS). The sample represents typical star-forming galaxies at this redshift (z = 0.6–1.0), with a median star formation rate of ≈7 M⊙ yr−1 and a stellar mass range of log (M⋆[M⊙])≈9–11. We find that the rotation velocity-stellar mass relationship (the inverse of the Tully-Fisher relationship) for our rotationally-dominated sources (VC/σ0 > 1) has a consistent slope and normalisation as that observed for z = 0 disks. In contrast, the specific angular momentum (j⋆; angular momentum divided by stellar mass), is ≈0.2–0.3 dex lower on average compared to z = 0 disks. The specific angular momentum scales as j s ∝M 0.6±0.2 ⋆ js∝M⋆0.6±0.2 , consistent with that expected for dark matter (i.e., j DM ∝M 2/3 DM jDM∝MDM2/3 ). We find that z ≈ 0.9 star-forming galaxies have decreasing specific angular momentum with increasing Sérsic index. Visually, the sources with the highest specific angular momentum, for a given mass, have the most disk-dominated morphologies. This implies that an angular momentum–mass–morphology relationship, similar to that observed in local massive galaxies, is already in place by z ≈ 1

The energetics of starburst-driven outflows at z ∼ 1 from KMOS

We present an analysis of the gas outflow energetics from KMOS observations of 529 main-sequence star-forming galaxies at z 1 using broad, underlying Hα and forbid- den lines of [Nii] and [Sii]. Based on the stacked spectra for a sample with median star- formation rates and stellar masses of SFR=7M⊙ / yr and M⋆ =(1.0±0.1)×1010M⊙ respectively, we derive a typical mass outflow rate of ˙Mwind =1–4M⊙ yr−1 and a mass loading of ˙Mwind / SFR=0.2–0.4. By comparing the kinetic energy in the wind with the energy released by supernovae, we estimate a coupling efficiency between the star formation and wind energetics of ǫ 0.03. The mass loading of the wind does not show a strong trend with star-formation rate over the range 2–20M⊙ yr−1, although we identify a trend with stellar mass such that dM/ dt / SFR/M0.26±0.07 ⋆ . Finally, the line width of the broad Hα increases with disk circular velocity with a sub-linear scal- ing relation FWHMbroad /v0.21±0.05. As a result of this behavior, in the lowest mass galaxies (M⋆ ∼ 1010M⊙) most of the gas will be retained, flowing back on to the galaxy disk at later times