Copper transformation, speciation, and detoxification in anoxic and suboxic freshwater sediments

The complex chemistry of copper (Cu) in freshwater sediments at low concentrations is not well understood. We evaluated the transformation processes of Cu added to freshwater sediments under suboxic and anoxic conditions. Freshwater sediments from three sources in Michigan with different characteristics (Spring Creek, River Raisin, and Maple Lake) were spiked with 30 or 60 mg kg-1 Cu and incubated under a nitrogen atmosphere. After 28-d, each treatment subset was amended with organic matter (OM) to promote anoxic conditions and evaluate its effects on Cu speciation. OM addition triggered a shift from suboxic to anoxic conditions, and sequential extractions showed that Cu accordingly shifted from acid-soluble to oxidizable fractions. Extended X-ray absorption fine-structure (EXAFS) spectroscopy revealed that Cu sulfides dominated all anoxic samples except for Spring Creek 30 mg kgxfffd; 1, where Cu(I) was predominantly complexed to thiol groups of OM. Covellite and chalcopyrite (CuFeS2) were the predominant Cu species in nearly all anoxic samples, as determined by Raman spectroscopy, scanning electron microscopy, and X-ray absorption near-edge structure (XANES) spectroscopy. Copper reduction also occurred under suboxic conditions: for two of three sediments, around 80% had been reduced to Cu(I), while the remaining 20% persisted as Cu(II) complexed to OM. However, in the third coarsest (i.e., Spring Creek), around 50% of the Cu had been reduced, forming Cu(I)-OM complexes, while the remainder was Cu(II)-OM complexes. Toxicity tests showed that survival of H. azteca and D. magna were significantly lower in suboxic treatments. Anoxic sediments triggered a near-complete transformation of Cu to sulfide minerals, reducing its toxicity

Shifting power to people with disability in co-designed research

This paper explores tensions navigated by researchers and project leaders when involving people with disability as experts in co-design and in the core team. Part of an evaluation aiming to improve paid employment of people with intellectual disability is used to consider this work. Assemblage analysis of the data assisted in identifying a range of material and social conditions, flows, and factors that de- and re-territorialise power in the co-design process. The expertise of people with disability informed research design. Structural conditions of funding and institutional support were foundational to the co-design. These included accessible practices, core roles for people with disability and resolving ableist conditions. Power shifts were easily undermined by institutionalised norms that disrespected the co-design contributions. When people in decision-making positions and allies recognised the value of codesigning research, it was key to centring valuable knowledge in articulating key issues, methodology, and analysis. Points of interest It is increasingly expected that people with disability will be involved as researchers and decision-makers in projects. This kind of co-design in research is very popular. When governments or organisations ask researchers to complete research quickly, people with disability are less likely to be involved in designing the research from the start. This reduces how much power they have as members of the research team. Our research found that people with and without disability needed to work together to resist when co-design work was not treated with respect by people or systems. Allies need to work to make co-design positions more secure. For example, people with disability need to be in decision-making positions before research proposals are developed

A High Galactic Latitude HI 21cm-line Absorption Survey using the GMRT: I. Observations and Spectra

We have used the Giant Meterwave Radio Telescope (GMRT) to measure the Galactic HI 21-cm line absorption towards 102 extragalactic radio continuum sources, located at high (|b| >15deg.) Galactic latitudes. The Declination coverage of the present survey is Decl. ~ -45deg.. With a mean rms optical depth of ~0.003, this is the most sensitive Galactic HI 21-cm line absorption survey to date. To supplement the absorption data, we have extracted the HI 21-cm line emission profiles towards these 102 lines of sight from the Leiden Dwingeloo Survey of Galactic neutral hydrogen. We have carried out a Gaussian fitting analysis to identify the discrete absorption and emission components in these profiles. In this paper, we present the spectra and the components. A subsequent paper will discuss the interpretation of these results.Comment: 46 pages, Accepted for publication in Journal of Astrophysics & Astronom

Study of the Composite Supernova Remnant MSH 11-62

We present the analysis of the X-ray data collected during an observation of the supernova remnant (SNR) MSH 11-62 by the Advanced Satellite for Cosmology and Astrophysics (ASCA). We show that MSH 11-62 is a composite remnant whose X-ray emission comes from two distinct contributions. Nonthermal, synchrotron emission, localized to a region of radius (~~)3' (consistent with a point source) dominates the total flux above 2 keV. A second contribution comes from a thermal component, extended up to a radius of (~~)6' and detected only at energies below 2keV. The spatial and spectral analysis imply the presence of a neutron star losing energy at a rate of about (10**36 - 10**37) ergs/s. No pulsed emission is detected and we set a limit on the pulsed fraction of 10%. This is consistent with the lack of a radio pulsar in the remnant, which may indicate that the pulsed emission from the rapidly rotating compact object that should be powering the synchrotron nebula is beamed and our viewing direction is unfavorable. In either event, the central neutron star deposits much of its spin-down energy into the surrounding synchrotron nebula where, through direct imaging with broadband satellites such as ASCA, it is possible to study the energetics and evolution of the compact remnant.Comment: 30 pages, including 5 figures, Latex. To appear in ApJ (May 20, 1998 issue, Vol. 499.

Effect of spironolactone and potassium canrenoate on cytosolic and nuclear androgen and estrogen receptors of rat liver

Spironolactone and potassium canrenoate are diuretics that are used widely for management of cirrhotic ascites. The administration of spironolactone frequently leads to feminization, which has been noted less frequently with the use of potassium canrenoate, a salt of the active metabolite of spironolactone. The use of these two drugs has been associated with decreases in serum testosterone levels and spironolactone with a reduction in androgen receptor (AR) activity. This decrease in AR has been cited as the cause of the antiandrogen effect of these drugs. We therefore assessed the effect of both drugs on levels of androgen and estrogen receptors (ER) in the liver, a tissue that is responsive to sex steroids. Three groups of male rats (n = 12 rats each) were studied. Group 1 (control) received vehicle only; group 2 received spironolactone (5 mg/day); group 3 received potassium canrenoate (5 mg/day). After 21 days of treatment, the animals of all groups were killed and liver tissue was assayed for nuclear and cytosolic AR and ER, and for male specific estrogen binder (MEB), an androgen-responsive protein. Both drugs drastically decreased the nuclear AR content, as compared with the control group, but only spironolactone decreased cytosolic AR. When the total hepatic content of AR is considered, a highly significant decrease is observed only in rats treated with spironolactone. This reduction in hepatic AR content suggested loss of androgen responsiveness of liver. We confirmed this by assessing levels of MEB, and found that livers from group 2 animals had no detectable MEB activity, whereas livers from both group 1 and 3 had normal MEB activity. No changes were observed in nuclear ER and cytosolic ER of group 3 as compared with group 1. Nuclear estrogen receptor decreased and cytosolic ER increased in group 2, but with no change in total ER content. These results indicate that (a) only spironolactone appears to act as an antiandrogen in liver, resulting in a decrease in both AR and male specific estrogen binder content, and (b) neither drug results in elevated hepatic ER content, although spironolactone-treated animals show an altered subcellular localization. © 1987

Energy Trends: September 2020

Energy Trends and Energy Prices are produced by the Department for Business, Energy and Industrial Strategy (BEIS) on a quarterly basis. Both periodicals are published concurrently in June, September, December and March. The September editions cover the second quarter of the current year

Balance on the Brain: a randomised controlled trial evaluating the effect of a multimodal exercise programme on physical performance, falls, quality of life and cognition for people with mild cognitive impairment—study protocol

Introduction: Exercise and physical activity have been shown to improve cognition for people living with mild cognitive impairment (MCI). There is strong evidence for the benefits of aerobic exercise and medium evidence for participating in regular strength training for people with MCI. However, people living with MCI fall two times as often as those without cognitive impairment and the evidence is currently unknown as to whether balance training for people with MCI is beneficial, as has been demonstrated for older people without cognitive impairment. The aim of this study is to determine whether a balance-focused multimodal exercise intervention improves balance and reduces falls for people with MCI, compared with a control group receiving usual care. Methods and analysis: This single blind randomised controlled trial (Balance on the Brain) will be offered to 396 people with MCI living in the community. The multimodal exercise intervention consists of two balance programmes and a walking programme to be delivered by physiotherapists over a 6-month intervention period. All participants will be followed up over 12 months (for the intervention group, this involves 6-month intervention and 6-month maintenance). The primary outcomes are (1) balance performance and (2) rate of falls. Physical performance, levels of physical activity and sedentary behaviour, quality of life and cognition are secondary outcomes. A health economic analysis will be undertaken to evaluate the cost-effectiveness of the intervention compared with usual care. Ethics and dissemination: Ethics approval has been received from the South Metropolitan Health Service Human Research Ethics Committee (HREC), Curtin University HREC and the Western Australia Department of Health HREC; and approval has been received to obtain data for health costings from Services Australia. The results will be disseminated through peer-review publications, conference presentations and online platforms

Will fire danger be reduced by using Solar Radiation Management to limit global warming to 1.5°C compared to 2.0°C

This is the author accepted manuscript. The final version is available from American Geophysical Union (AGU) via the DOI in this record.The commitment to limit warming to 1.5°C as set out in the Paris Agreement is widely regarded as ambitious and challenging. It has been proposed that reaching this target may require a number of actions, which could include some form of carbon removal or Solar Radiation Management in addition to strong emission reductions. Here we assess one theoretical solution using Solar Radiation Management to limit global mean warming to 1.5°C above pre‐industrial temperatures, and use the McArthur fire danger index to evaluate the change in fire danger. The results show that globally fire danger is reduced in most areas when temperatures are limited to 1.5°C compared to 2.0°C. The number of days where fire danger is ‘high’ or above is reduced by up to 30 days per year on average, although there are regional variations. In certain regions, fire danger is increased, experiencing 31 more days above ‘high’ fire danger.This work was supported by the European Commission‟s 7th Framework Programme (EU/FP7) under Grant Agreement 603864 (HELIX), and the Joint UK BEIS/Defra Met Office Hadley Centre Climate Programme (GA01101)

Control of human endometrial stromal cell motility by PDGF-BB, HB-EGF and trophoblast-secreted factors

Human implantation involves extensive tissue remodeling at the fetal-maternal interface. It is becoming increasingly evident that not only trophoblast, but also decidualizing endometrial stromal cells are inherently motile and invasive, and likely contribute to the highly dynamic processes at the implantation site. The present study was undertaken to further characterize the mechanisms involved in the regulation of endometrial stromal cell motility and to identify trophoblast-derived factors that modulate migration. Among local growth factors known to be present at the time of implantation, heparin-binding epidermal growth factor-like growth factor (HB-EGF) triggered chemotaxis (directed locomotion), whereas platelet-derived growth factor (PDGF)-BB elicited both chemotaxis and chemokinesis (non-directed locomotion) of endometrial stromal cells. Supernatants of the trophoblast cell line AC-1M88 and of first trimester villous explant cultures stimulated chemotaxis but not chemokinesis. Proteome profiling for cytokines and angiogenesis factors revealed neither PDGF-BB nor HB-EGF in conditioned media from trophoblast cells or villous explants, while placental growth factor, vascular endothelial growth factor and PDGF-AA were identified as prominent secretory products. Among these, only PDGF-AA triggered endometrial stromal cell chemotaxis. Neutralization of PDGF-AA in trophoblast conditioned media, however, did not diminish chemoattractant activity, suggesting the presence of additional trophoblast-derived chemotactic factors. Pathway inhibitor studies revealed ERK1/2, PI3 kinase/Akt and p38 signaling as relevant for chemotactic motility, whereas chemokinesis depended primarily on PI3 kinase/Akt activation. Both chemotaxis and chemokinesis were stimulated upon inhibition of Rho-associated, coiled-coil containing protein kinase. The chemotactic response to trophoblast secretions was not blunted by inhibition of isolated signaling cascades, indicating activation of overlapping pathways in trophoblast-endometrial communication. In conclusion, trophoblast signals attract endometrial stromal cells, while PDGF-BB and HB-EGF, although not identified as trophoblast-derived, are local growth factors that may serve to fine-tune directed and non-directed migration at the implantation site