Properties of galaxy dark matter halos from weak lensing

We present the results of a study of weak lensing by galaxies based on 45.5 deg$^2$ of $R_C$ band imaging data from the Red-Sequence Cluster Survey (RCS). We present the first weak lensing detection of the flattening of galaxy dark matter halos. We use a simple model in which the ellipticity of the halo is $f$ times the observed ellipticity of the lens. We find a best fit value of $f=0.77^{+0.18}_{-0.21}$, suggesting that the dark matter halos are somewhat rounder than the light distribution. The fact that we detect a significant flattening implies that the halos are well aligned with the light distribution. Given the average ellipticity of the lenses, this implies a halo ellipticity of $=0.33^{+0.07}_{-0.09}$, in fair agreement with results from numerical simulations of CDM. This result provides strong support for the existence of dark matter, as an isotropic lensing signal is excluded with 99.5% confidence. We also study the average mass profile around the lenses, using a maximum likelihood analysis. We consider two models for the halo mass profile: a truncated isothermal sphere (TIS) and an NFW profile. We adopt observationally motivated scaling relations between the lens luminosity and the velocity dispersion and the extent of the halo. The best fit NFW model yields a mass $M_{200}=(8.4\pm0.7\pm0.4)\times 10^{11} h^{-1} M_\odot$ and a scale radius $r_s=16.2^{+3.6}_{-2.9} h^{-1}$ kpc. This value for the scale radius is in excellent agreement with predictions from numerical simulations for a halo of this mass.Comment: Significantly revised version, accepted for publication in ApJ 11 pages, 6 figure

Promissing cerium-doped barium manganate perovskite for solar thermochemical hydrogen production

Over the past decade, nonstoichiometric oxides have been investigated for solar thermochemical water splitting applications because of their ability to partially reduce and create oxygen vacancies at high temperatures and subsequently reoxidize in steam at lower temperatures, uptaking the oxygen into the lattice and producing hydrogen as a consequence (c.f. Figure 1a). Cerium oxide is currently viewed as the leading candidate for this process because of its fast reoxidation reaction kinetics and considerable H2 yield. However, high temperatures (\u3e1550oC) are required to drive ceria reduction, making the reactor and the solar heat collector design challenging. Furthermore, a low steam oxidation temperature is preferred from a reactor energy balance stand-point. Please click Additional Files below to see the full abstract

Women’s knowledge, attitudes and views of preconception health and intervention delivery methods:a cross-sectional survey

Background: Several preconception exposures have been associated with adverse pregnancy, birth and postpartum outcomes. However, few studies have investigated women’s knowledge of and attitudes towards preconception health, and the acceptability of potential intervention methods. Methods: Seven primary care centres in the West of England posted questionnaires to 4330 female patients aged 18 to 48 years. Without providing examples, we asked women to list maternal preconception exposures that might affect infant and maternal outcomes, and assessed their knowledge of nine literature-derived risk factors. Attitudes towards preconception health (interest, intentions, self-efficacy and perceived awareness and importance) and the acceptability of intervention delivery methods were also assessed. Multivariable multilevel regression examined participant characteristics associated with these outcomes. Results: Of those who received questionnaires, 835 (19.3%) responded. Women were most aware of the preconception risk factors of diet (86.0%) and physical activity (79.2%). Few were aware of weight (40.1%), folic acid (32.9%), abuse (6.3%), advanced age (5.9%) and interpregnancy intervals (0.2%), and none mentioned interpregnancy weight change or excess iron intake. After adjusting for demographic and reproductive covariates, women aged 18–24-years (compared to 40–48-year-olds) and nulligravid women were less aware of the benefit of preconception folic acid supplementation (adjusted odds ratios (aOR) for age: 4.30 [2.10–8.80], gravidity: aOR 2.48 [1.70–3.62]). Younger women were more interested in learning more about preconception health (aOR 0.37 [0.21–0.63]) but nulligravid women were less interested in this (aOR 1.79 [1.30–2.46]). Women with the lowest household incomes (versus the highest) were less aware of preconception weight as a risk factor (aOR: 3.11 [1.65–5.84]) and rated the importance of preconception health lower (aOR 3.38 [1.90–6.00]). The most acceptable information delivery methods were websites/apps (99.5%), printed healthcare materials (98.6%), family/partners (96.3%), schools (94.4%), television (91.9%), pregnancy tests (91.0%) and doctors, midwives and nurses (86.8–97.0%). Dentists (23.9%) and hairdressers/beauticians (18.1%) were the least acceptable. Conclusions: Our findings demonstrate a need to promote awareness of preconception risk factors and motivation for preconception health changes, particularly amongst younger and nulligravid women and women with lower incomes. Interventions to improve preconception health should focus on communication from healthcare professionals, schools, family members, and digital media

The role of lipid composition on the interaction between a tryptophan-rich protein and model bacterial membranes

The interaction between tryptophan-rich puroindoline proteins and model bacterial membranes at the air-liquid interface has been investigated by FTIR spectroscopy, surface pressure measurements and Brewster angle microscopy. The role of different lipid constituents on the interactions between lipid membrane and protein was studied using wild type (Pin-b) and mutant (Trp44 to Arg44 mutant, Pin-bs) puroindoline proteins. The results show differences in the lipid selectivity of the two proteins in terms of preferential binding to specific lipid head groups in mixed lipid systems. Pin-b wild type was able to penetrate mixed layers of phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) head groups more deeply compared to the mutant Pin-bs. Increasing saturation of the lipid tails increased penetration and adsorption of Pin-b wild type, but again the response of the mutant form differed. The results provide insight as to the role of membrane architecture, lipid composition and fluidity, on antimicrobial activity of proteins. Data show distinct differences in the lipid binding behavior of Pin-b as a result of a single residue mutation, highlighting the importance of hydrophobic and charged amino acids in antimicrobial protein and peptide activity

Preconception exposures and adverse pregnancy, birth and postpartum outcomes:Umbrella review of systematic reviews

Background Preconception exposures have been associated with adverse pregnancy, birth and postpartum outcomes. However, the reports, statements and guidelines of national and international health organisations vary in what they recommend individuals should monitor, avoid, reduce or practise in the preconception period. Objectives To synthesise and evaluate the evidence across systematic reviews for associations between exposures before conception and adverse pregnancy, birth and postpartum outcomes. Data sources MEDLINE, Embase, Epistemonikos (to May 2020) and reference lists of included reviews, without language or date restrictions. Study selection, data extraction and synthesis Systematic literature reviews of observational and/or interventional studies reporting associations between preconception exposures in women and/or men of reproductive age and pregnancy, birth or postpartum health outcomes were included. The methodological quality of reviews and the certainty of the evidence underlying each exposure-outcome association were assessed using AMSTAR 2 and the GRADE approach. Results We identified 53 eligible reviews reporting 205 unique exposure-outcome associations. Methodological quality was generally low with only two reviews rated as ‘high’ quality and two as ‘moderate’. We found high-certainty, randomised trial evidence that maternal folate supplementation reduces the risk of neural tube defects and anomaly-related terminations. Moderate-certainty, observational evidence was found that maternal physical activity is associated with reduced risk of pre-eclampsia and gestational diabetes, and that paternal age of ≥40 years and maternal body mass index (BMI) and interpregnancy weight gain are associated with increased risk of various adverse pregnancy and birth outcomes. Low- and very low-certainty evidence was found for other associations. Conclusions Clinicians and policymakers can be confident that maternal folate supplementation should be encouraged during the preconception period. There is moderate certainty in the evidence base that maternal physical activity, BMI and interpregnancy weight gain and advanced paternal age are important preconception considerations. High-quality research is required to better understand other exposure-outcome associations

Extinction risk of the world's freshwater mammals

The continued loss of freshwater habitats poses a significant threat to global biodiversity. We reviewed the extinction risk of 166 freshwater aquatic and semiaquatic mammals—a group rarely documented as a collective. We used the International Union for the Conservation of Nature Red List of Threatened Species categories as of December 2021 to determine extinction risk. Extinction risk was then compared among taxonomic groups, geographic areas, and biological traits. Thirty percent of all freshwater mammals were listed as threatened. Decreasing population trends were common (44.0%), including a greater rate of decline (3.6% in 20 years) than for mammals or freshwater species as a whole. Aquatic freshwater mammals were at a greater risk of extinction than semiaquatic freshwater mammals (95% CI –7.20 to –1.11). Twenty-nine species were data deficient or not evaluated. Large species (95% CI 0.01 to 0.03) with large dispersal distances (95% CI 0.03 to 0.15) had a higher risk of extinction than small species with small dispersal distances. The number of threatening processes associated with a species compounded their risk of extinction (95% CI 0.28 to 0.77). Hunting, land clearing for logging and agriculture, pollution, residential development, and habitat modification or destruction from dams and water management posed the greatest threats to these species. The basic life-history traits of many species were poorly known, highlighting the need for more research. Conservation of freshwater mammals requires a host of management actions centered around increased protection of riparian areas and more conscientious water management to aid the recovery of threatened species

Selected wheat seed defense proteins exhibit competitive binding to model microbial lipid interfaces

Puroindolines (Pins) and purothionins (Pths) are basic, amphiphilic, cysteine-rich wheat proteins that play a role in plant defense against microbial pathogens. We have examined the co-adsorption and sequential addition of Pins (Pin-a, Pin-b and a mutant form of Pin-b with Trp-44 to Arg-44 substitution) and β-purothionin (β-Pth) model anionic lipid layers, using a combination of surface pressure measurements, external reflection FTIR spectroscopy and neutron reflectometry. Results highlighted differences in the protein binding mechanisms, and in the competitive binding and penetration of lipid layers between respective Pins and β-Pth. Pin-a formed a blanket-like layer of protein below the lipid surface that resulted in the reduction or inhibition of β-Pth penetration of the lipid layer. Wild-type Pin-b participated in co-operative binding with β-Pth, whereas the mutant Pin-b did not bind to the lipid layer in the presence of β-Pth. The results provide further insight into the role of hydrophobic and cationic amino acid residues in antimicrobial activity

Search for a Solution of the Pioneer Anomaly

In 1972 and 1973 the Pioneer 10 and 11 missions were launched. They were the first to explore the outer solar system and achieved stunning breakthroughs in deep-space exploration. But beginning in about 1980 an unmodeled force of \sim 8 \times 10^{-8} cm/s^2, directed approximately towards the Sun, appeared in the tracking data. It later was unambiguously verified as being in the data and not an artifact. The cause remains unknown (although radiant heat remains a likely origin). With time more and more effort has gone into understanding this anomaly (and also possibly related effects). We review the situation and describe ongoing programs to resolve the issue.Comment: 24 pages 8 figure

A Pleistocene Clone of Palmer's Oak Persisting in Southern California

BACKGROUND: The distribution of Palmer's oak (Quercus palmeri Engelm.) includes numerous isolated populations that are presumably relicts of a formerly larger range that has contracted due to spreading aridity following the end of the Pleistocene. PRINCIPAL FINDINGS: We investigated a recently discovered disjunct population of Palmer's oak in the Jurupa Mountains of Riverside County, California. Patterns of allozyme polymorphism, morphological homogeneity, widespread fruit abortion, and evidence of fire resprouting all strongly support the hypothesis that the population is a single clone. The size of the clone and estimates of annual growth from multiple populations lead us to conclude that the clone is in excess of 13,000 years old. CONCLUSIONS: The ancient age of the clone implies it originated during the Pleistocene and is a relict of a vanished vegetation community. Range contraction after climate change best explains the modern disjunct distribution of Q. palmeri and perhaps other plants in California

HST/WFC3 Observations of an Off-Nuclear Superbubble in Arp 220

We present a high spatial resolution optical and infrared study of the circumnuclear region in Arp 220, a late-stage galaxy merger. Narrowband imaging using HST/WFC3 has resolved the previously observed peak in H$\alpha$+[NII] emission into a bubble-shaped feature. This feature measures 1.6" in diameter, or 600 pc, and is only 1" northwest of the western nucleus. The bubble is aligned with the western nucleus and the large-scale outflow axis seen in X-rays. We explore several possibilities for the bubble origin, including a jet or outflow from a hidden active galactic nucleus (AGN), outflows from high levels of star formation within the few hundred pc nuclear gas disk, or an ultraluminous X-ray source. An obscured AGN or high levels of star formation within the inner $\sim$100 pc of the nuclei are favored based on the alignment of the bubble and energetics arguments.Comment: Accepted for publication in ApJ. 12 pages, 10 figure