Programas de protección efectivos basados en la comunidad: lo aprendido en la República Democrática del Congo

La labor de Oxfam con las comunidades locales en la República Democrática del Congo ha impulsado que esta organización desarrolle sus propias directrices a seguir por ella misma y por otras que trabajan en situaciones similares

TRPV4 and KCa functionally couple as osmosensors in the PVN

BACKGROUND AND PURPOSE: Transient receptor potential vanilloid type 4 (TRPV4) and calcium-activated potassium channels (KCa ) mediate osmosensing in many tissues. Both TRPV4 and KCa channels are found in the paraventricular nucleus (PVN) of the hypothalamus, an area critical for sympathetic control of cardiovascular and renal function. Here, we have investigated whether TRPV4 channels functionally couple to KCa channels to mediate osmosensing in PVN parvocellular neurones and have characterized, pharmacologically, the subtype of KCa channel involved. EXPERIMENTAL APPROACH: We investigated osmosensing roles for TRPV4 and KCa channels in parvocellular PVN neurones using cell-attached and whole-cell electrophysiology in mouse brain slices and rat isolated PVN neurons. Intracellular Ca(2+) was recorded using Fura-2AM. The system was modelled in the NEURON simulation environment. KEY RESULTS: Hypotonic saline reduced action current frequency in hypothalamic slices; a response mimicked by TRPV4 channel agonists 4αPDD (1 μM) and GSK1016790A (100 nM), and blocked by inhibitors of either TRPV4 channels (RN1734 (5 μM) and HC067047 (300 nM) or the low-conductance calcium-activated potassium (SK) channel (UCL-1684 30 nM); iberiotoxin and TRAM-34 had no effect. Our model was compatible with coupling between TRPV4 and KCa channels, predicting the presence of positive and negative feedback loops. These predictions were verified using isolated PVN neurons. Both hypotonic challenge and 4αPDD increased intracellular Ca(2+) and UCL-1684 reduced the action of hypotonic challenge. CONCLUSIONS AND IMPLICATIONS: There was functional coupling between TRPV4 and SK channels in parvocellular neurones. This mechanism contributes to osmosensing in the PVN and may provide a novel pharmacological target for the cardiovascular or renal systems

Phylogenetic Rate Shifts in Feeding Time During the Evolution of Homo

Unique among animals, humans eat a diet rich in cooked and nonthermally processed food. The ancestors of modern humans who invented food processing (including cooking) gained critical advantages in survival and fitness through increased caloric intake. However, the time and manner in which food processing became biologically significant are uncertain. Here, we assess the inferred evolutionary consequences of food processing in the human lineage by applying a Bayesian phylogenetic outlier test to a comparative dataset of feeding time in humans and nonhuman primates. We find that modern humans spend an order of magnitude less time feeding than predicted by phylogeny and body mass (4.7% vs. predicted 48% of daily activity). This result suggests that a substantial evolutionary rate change in feeding time occurred along the human branch after the human–chimpanzee split. Along this same branch, Homo erectus shows a marked reduction in molar size that is followed by a gradual, although erratic, decline in H. sapiens. We show that reduction in molar size in early Homo (H. habilis and H. rudolfensis) is explicable by phylogeny and body size alone. By contrast, the change in molar size to H. erectus, H. neanderthalensis, and H. sapiens cannot be explained by the rate of craniodental and body size evolution. Together, our results indicate that the behaviorally driven adaptations of food processing (reduced feeding time and molar size) originated after the evolution of Homo but before or concurrent with the evolution of H. erectus, which was around 1.9 Mya.Human Evolutionary BiologyOrganismic and Evolutionary Biolog

Elevated blood pressure, heart rate and body temperature in mice lacking the XL alpha s protein of the Gnas locus is due to increased sympathetic tone

NEW FINDINGS: What is the central question of this study? Previously, we showed that Gnasxl knock-out mice are lean and hypermetabolic, with increased sympathetic stimulation of adipose tissue. Do these mice also display elevated sympathetic cardiovascular tone? Is the brain glucagon-like peptide-1 system involved? What is the main finding and its importance? Gnasxl knock-outs have increased blood pressure, heart rate and body temperature. Heart rate variability analysis suggests an elevated sympathetic tone. The sympatholytic reserpine had stronger effects on blood pressure, heart rate and heart rate variability in knock-out compared with wild-type mice. Stimulation of the glucagon-like peptide-1 system inhibited parasympathetic tone to a similar extent in both genotypes, with a stronger associated increase in heart rate in knock-outs. Deficiency of Gnasxl increases sympathetic cardiovascular tone. Imbalances of energy homeostasis are often associated with cardiovascular complications. Previous work has shown that Gnasxl-deficient mice have a lean and hypermetabolic phenotype, with increased sympathetic stimulation of adipose tissue. The Gnasxl transcript from the imprinted Gnas locus encodes the trimeric G-protein subunit XLαs, which is expressed in brain regions that regulate energy homeostasis and sympathetic nervous system (SNS) activity. To determine whether Gnasxl knock-out (KO) mice display additional SNS-related phenotypes, we have now investigated the cardiovascular system. The Gnasxl KO mice were ∼20 mmHg hypertensive in comparison to wild-type (WT) littermates (P≤ 0.05) and hypersensitive to the sympatholytic drug reserpine. Using telemetry, we detected an increased waking heart rate in conscious KOs (630 ± 10 versus 584 ± 12 beats min(−1), KO versus WT, P≤ 0.05). Body temperature was also elevated (38.1 ± 0.3 versus 36.9 ± 0.4°C, KO versus WT, P≤ 0.05). To investigate autonomic nervous system influences, we used heart rate variability analyses. We empirically defined frequency power bands using atropine and reserpine and verified high-frequency (HF) power and low-frequency (LF) LF/HF power ratio to be indicators of parasympathetic and sympathetic activity, respectively. The LF/HF power ratio was greater in KOs and more sensitive to reserpine than in WTs, consistent with elevated SNS activity. In contrast, atropine and exendin-4, a centrally acting agonist of the glucagon-like peptide-1 receptor, which influences cardiovascular physiology and metabolism, reduced HF power equally in both genotypes. This was associated with a greater increase in heart rate in KOs. Mild stress had a blunted effect on the LF/HF ratio in KOs consistent with elevated basal sympathetic activity. We conclude that XLαs is required for the inhibition of sympathetic outflow towards cardiovascular and metabolically relevant tissues

A circular economy approach to drinking water treatment residue management in a catchment impacted by historic metal mines

Drinking water treatment residues (DWTR) from mining areas which remove and contain potentially toxic elements (PTE) could still potentially be used as a soil amendment to restore contaminated sites in the same catchment, thus eliminating waste and reducing the chemical and physical mobility of the pollutants. To assess this restorative and regenerative approach to DWTR management, field and pot trials were established with soils from a historic Pb–Zn mine site in the North East of England, amended with either local DWTR or the nearest available municipal green waste compost (GWC). Soils from the mine site were found to have very low levels of nutrients and very high levels of PTE (Pb and Zn > 13, 000 mg/kg). The perennial grass species Phalaris arundinacea, known for many ecosystem service benefits including soil stabilization, was used throughout this study. The application of the BCR sequential extraction to soils amended with the DWTR in the pot trials found a significant decrease in the bioavailability of Pb and Cu (p MIX > DWTR (p < 0.05). Results of the elemental analysis of biomass from the field trial were generally ambiguous and did not reflect the decreased bioavailability noted in the pot trials using the BCR procedure. Pot trials, however, showed increases in plant growth and decreases in concentrations of Cr, Cu, Pb and Zn in above ground biomass following the application of both amendments. Further work should involve the testing of a mixture of DWTR and other soil amendments to enhance plant growth. The success of these trials should provide confidence for those working in drinking water treatment and catchment management to reuse the waste residues in a circular economy and a sustainable way that could improve water quality over time

Chemical and biological tests to assess the viability of amendments and Phalaris arundinacea for the remediation and restoration of historic mine sites

Inadequate waste disposal practices at historic mining sites around the world have resulted in significant areas impacted by potentially toxic elements (PTE) [1]. Historic mining tailings and spoil are typically too physically, chemically and biologically deficient for spontaneous vegetation, allowing the redistribution of contaminated soils, mobilized through processes such as areolation and the movement water [2]. In-situ biological and chemical stabilisation of sites is increasingly considered the best option when managing the risks associated with historic mining [1]. Studies have shown that the immobilization of PTEs can be achieved through the use of low leaching waste amendments capable of adsorption, precipitation and complexation reactions, resulting in the redistribution of contaminants from solution phase to solid phase, thereby reducing their bioavailability and mobilization potential within the environment [2–4] and promoting plant growth and physical stabilisation. Recent research in the Upper River Derwent, NE England (Lord, pers. com.) has highlighted the contribution of historic mining and mineral processing areas as sources of particulate and dissolved PTEs entering river sediments. Subsequent analysis of mining and mineral processing sites has confirmed the presence of significant Cd, Pb and Zn concentrations in loose spoil, tailings and unvegetated soils. The aim of this study is to evaluate the potential of several organic amendments and a perennial native grass species, Reed Canarygrass (RCG) (Phalaris arundinacea), to immobilize and stabilise contaminated soils [5,6]. This plant was selected for its ability to rapidly colonize and establish on contaminated soils whilst not (usually) accumulating high levels of PTEs or thereby adding to dispersion [5,6]. A combination of biological and chemical approaches will be used to analyse the efficacy of the different amendments throughout this study. These include the use of the modified BCR sequential extraction procedure and single extractants to assess PTE bioavailability, the monitoring of changes in soil properties such as OM, pH and CEC and the measurement of above ground biomass after a 12-week growth period. Although several recent studies have conducted similar pot trials, very few have applied their results to actual field trials, a recommendation commonly made in key literature reviews [1]. The results of our experiments will used to implement a two-year phytoremediation trial at a former mine site beginning in Spring 2019. [1] Bolan N, Kunhikrishnan A, Thangarajan R, Kumpiene J, Park J, Makino T, et al. Journal of Hazardous Materials. (2014) 266:141-166 [2] Rodríguez L, Gómez R, Sánchez V, Alonso-Azcárate J.. Environ Sci Pollut Res. (2016) 23:6046-6054 [3] Alvarenga P, Gonçalves AP, Fernandes RM, de Varennes A, Vallini G, Duarte E, et al.. Sci Total Environ. (2008) 406:43-56 [4] Badmos BK, Sakrabani R, Lord R.. Arch Agron Soil Sci. (2015) 62:865-876 [5] Jensen EF, Casler MD, Farrar K, Finnan JM, Lord R, Palmborg C, et al. 5 –In: Perennial Grasses for Bioenergy and Bioproducts. (2018) 5:153-173 [6] Lord RA. Biomass and Bioenergy. (2015) 78;110-12

The effects of organic waste soil amendments on above ground biomass of Reed Canary Grass (Phalaris arundinacea) grown at a historic Pb-F-Zn mine site

Historic metal mine tailings and spoil are typically too physically, chemically and biologically deficient for spontaneous revegetation. Studies focusing on the Upper River Derwent have highlighted the contribution of historic mining and mineral processing areas as sources of particulate and dissolved potentially toxic elements (PTE) entering river sediments. This study will conduct a two year field trial that aims to evaluate the potential of two organic waste soil amendments and a perennial native grass species, to immobilize PTE and stabilise impacted soils. In-situ biological and chemical stabilisation is increasingly considered the best option when managing the risks associated with historic mining [1]

Chemical and biological tests to assess the viability of amendments and Phalaris arundinacea for the remediation and restoration of historic mine tailings.

Recent research in the Upper River Derwent, NE England highlighted the contribution of historic mining and mineral processing areas as sources of particulate and dissolved potentially toxic elements (PTE) entering river sediments. Subsequent analysis of mining and mineral processing sites has confirmed the presence of significant Cd, Pb and Zn concentrations in loose spoil, tailings and unvegetated soils. The aim of this study is to evaluate the potential of several organic amendments and a perennial native grass species, reed canary grass (Phalaris arundinacea), to immobilize PTEs and stabilise contaminated soils. The plant specie was selected for its ability to rapidly colonize and establish on contaminated soils whilst not (usually) accumulating high levels of PTEs or thereby adding to dispersion. Preliminary pot trials using bulk samples of mine spoil and amendments are currently ongoing following an adapted British Standards (BS/EN 11269-2:2013) method for the effects of PTEs on above ground plant growth. A combination of biological and chemical approaches will be used to analyse the efficacy of the different amendments throughout this study. These include the use of the modified BCR sequential extraction procedure and single extractants to assess PTE bioavailability, the monitoring of changes in soil properties such as OM, pH and CEC and the measurement of above ground biomass after a 12-week growth period. Although several recent studies have conducted similar pot trials, very few have applied their results to actual field trials. The results of these experiments will used to implement a two-year phytoremediation trial at a former mine site beginning in Spring 2019