Pt(IV)-mediated addition of the sulfimide Ph2SNH and the mixed sulfide/sulfimides o- and p-{PhS(NH)}(PhS)C6H4 by the SNH group to the metal-bound nitriles in the platinum(IV) complexes PtCl4(RCN)2 ...proceeds smoothly at room temperature in CH2Cl2 and results in the formation of the heterodiazadiene compounds PtCl4{NHC(R)NSR‘Ph}2 (R‘ = Ph, R = Me, Et, CH2Ph, Ph; R‘ = o- and p-(PhS)C6H4; R = Et). While trans-PtCl4(RCN)2 (R = Et, CH2Ph, Ph) reacting with Ph2SNH leads exclusively to trans-PtCl4{NHC(R)NSPh2}2, cis/trans-PtCl4(MeCN)2 leads to cis/trans mixtures of PtCl4{NHC(Me)NSPh2}2 and the latter have been separated by column chromatography. Theoretical calculations at both HF//HF and MP2//HF levels for the cis and trans isomers of PtCl4{NHC(Me)NSMe2}2 indicate a higher stability for the latter. Compounds trans-PtCl4{E-NHC(R)NSPh2}2 (R = Me, Et) and cis-PtCl4{E-NHC(Me)NSPh2}{Z-NHC(Me)NSPh2} have been characterized by X-ray crystallography. The complexes PtCl4{NHC(R)NSPh2}2 undergo hydrolysis when treated with HCl in nondried CH2Cl2 to achieve the amidines PtCl4{NHC(NH2)R}2 (the compound with R = Et has been structurally characterized) and Ph2SO. The heterodiazadiene ligands, formed upon Pt(IV)-mediated RCN/sulfimide coupling, can be liberated from their platinum(IV) complexes PtCl4{NHC(R)NSR‘Ph}2 by reaction with Ph2PCH2CH2PPh2 (dppe) giving free NHC(R)SR‘Ph and the dppe oxides, which constitutes a novel route for such rare types of heterodiazadienes whose number has also been extended. The hybrid sulfide/sulfimide species o- and p-{PhS(NH)}(PhS)C6H4 also react with the Pt(II) nitrile complex PtCl2(MeCN)2 but the couplingin contrast to the Pt(IV) speciesgives the chelates PtCl2{NHC(Me)NS(Ph)C6H4SPh}. The X-ray crystal structure of PtCl2{NHC(Me)NS(Ph)C6H4SPh-o} reveals the bond parameters within the metallacycle and shows an unusual close interaction of the sulfide sulfur atom with the platinum.
to develop a measure of activities of daily living appropriate for use in assessing the presence of dementia in illiterate rural elderly people in India.
identification of relevant items, pre-testing ...of items and refinement of administrative procedures and scoring in four successive groups of 30 subjects each, pilot testing in a group of 100 subjects comparable to those for whom the measure is intended, administration to a representative sample of 387 people aged 55 and older, and assessment of the reliability of the final measure.
age-stratified random sample of older men and women in rural areas of Ballabgarh, Northern India.
the original pool of 35 items covering mobility, instrumental and personal care activities was reduced to an 11-item unidimensional scale (to which an additional item on mobility was added) with internal consistency (Cronbach's alpha)=0.82, perfect inter- and intra-rater reliability, test-retest reliability (intraclass correlation)=0.82 (any disability) and 0.92 (unable to perform for 'mental' reasons). Women, older subjects, the totally illiterate and subjects with poorer cognitive function performed significantly more poorly (P < or = 0.02 for all). PRODUCT: a brief, reliable and valid activities of daily living measure, with norms, which is appropriate for use in assessing dementia in illiterate rural elderly people in India.
•We investigate nonwetting phase (air and oil) invasion in brine-saturated sandstone.•Snap-off during drainage is observed in all experiments and in simulation results.•Current models of drainage ...which assume connected phase invasion are incomplete.
We study quasi-static drainage displacement experiments in Bentheimer sandstone micro-cores using X-ray computed microtomography. Two nonwetting fluids, air and n-decane, are investigated, under high and low flow rate conditions. Experimental conditions consider viscosity ratios that vary by a factor of 40, and capillary numbers that range five orders of magnitude; but all experiments investigated are conducted under nominally capillary-dominated conditions, indicating that drainage displacements should demonstrate percolation-like invasion patterns. However, we observe significant and prevalent snap-off of nonwetting phase under all experimental conditions, a phenomena not predicted by the conceptual model of percolation invasion. We further observe that the size and persistence of snapped-off ganglia are influenced by the experimental flow rate and the nonwetting phase fluid. The quasi-static experimental observations are supported by lattice-Boltzmann modelling of drainage dynamics. These findings indicate that current conceptual models of drainage are incomplete, with implications for future experimental and modelling studies as well as engineering applications.
Rhinovirus infections cause wheeze, cough, and bronchial hyperresponsiveness. To investigate the involvement of cysteinyl-leukotrienes and prostanoids in these symptoms, bronchial biopsy specimens ...from 9 normal subjects (nonatopic and with no history of chronic lung disease) were immunostained for 5-lipoxygenase (5-LO) and cyclooxygenase (COX) pathway enzymes 2 weeks before and 4 days after experimental infection with human rhinovirus serotype 16.5-LO-positive cell counts increased 9-fold (from 0.48 to 4.4 cells/mm2; P <.05), and 5- LO-activating protein (FLAP)-positive cell counts increased 3.6-fold (from 1.8 to 6.5 cells/ mm2; P = .09). Levels of leukotriene A4 hydrolase and leukotriene C4 synthase were unchanged. COX-2-positive cell counts increased from 0 to 2.6 cells/mm2 (P = .009), with no change in COX-1 levels. Increases of 3-4-fold were seen in levels of macrophages (P = .02) and mast cells (P = .07) but not of eosinophils (P > .4), and bronchoalveolar lavage fluid cysteinyl-leukotriene levels doubled (from 11.2 to 20.4 pg/mL; P = .13). Cold symptom scores correlated with bronchial immunostaining for FLAP (ρ = 0.93; P = .001). In normal subjects, rhinovirus colds induce bronchial inflammation with markedly enhanced expression of 5-LO pathway proteins and COX-2.
Many species of birds breeding on ocean beaches and in coastal dunes are of global conservation concern. Most of these species rely on invertebrates (e.g. insects, small crustaceans) as an ...irreplaceable food source, foraging primarily around the strandline on the upper beach near the dunes. Sandy beaches are also prime sites for human recreation, which impacts these food resources via negative trampling effects. We quantified acute trampling impacts on assemblages of upper shore invertebrates in a controlled experiment over a range of foot traffic intensities (up to 56 steps per square metre) on a temperate beach in Victoria, Australia. Trampling significantly altered assemblage structure (species composition and density) and was correlated with significant declines in invertebrate abundance and species richness. Trampling effects were strongest for rare species. In heavily trafficked plots the abundance of sand hoppers (Amphipoda), a principal prey item of threatened Hooded Plovers breeding on this beach, was halved. In contrast to the consistently strong effects of trampling, natural habitat attributes (e.g. sediment grain size, compactness) were much less influential predictors. If acute suppression of invertebrates caused by trampling, as demonstrated here, is more widespread on beaches it may constitute a significant threat to endangered vertebrates reliant on these invertebrates. This calls for a re-thinking of conservation actions by considering active management of food resources, possibly through enhancement of wrack or direct augmentation of prey items to breeding territories.
Beach and coastal dune systems are increasingly subjected to a broad range of anthropogenic pressures that on many shorelines require significant conservation and mitigation interventions. But these ...interventions require reliable data on the severity and frequency of adverse ecological impacts. Such evidence is often obtained by measuring the response of ‘indicator species’.
Ghost crabs are the largest invertebrates inhabiting tropical and subtropical sandy shores and are frequently used to assess human impacts on ocean beaches. Here we present the first global meta-analysis of these impacts, and analyse the design properties and metrics of studies using ghost-crabs in their assessment. This was complemented by a gap analysis to identify thematic areas of anthropogenic pressures on sandy beach ecosystems that are under-represented in the published literature.
Our meta-analysis demonstrates a broad geographic reach, encompassing studies on shores of the Pacific, Indian, and Atlantic Oceans, as well as the South China Sea. It also reveals what are, arguably, two major limitations: i) the near-universal use of proxies (i.e. burrow counts to estimate abundance) at the cost of directly measuring biological traits and bio-markers in the organism itself; and ii) descriptive or correlative study designs that rarely extend beyond a simple ‘compare and contrast approach’, and hence fail to identify the mechanistic cause(s) of observed contrasts.
Evidence for a historically narrow range of assessed pressures (i.e., chiefly urbanisation, vehicles, beach nourishment, and recreation) is juxtaposed with rich opportunities for the broader integration of ghost crabs as a model taxon in studies of disturbance and impact assessments on ocean beaches. Tangible advances will most likely occur where ghost crabs provide foci for experiments that test specific hypotheses associated with effects of chemical, light and acoustic pollution, as well as the consequences of climate change (e.g. species range shifts).
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•Mitigating threats to sandy beaches requires accurate assessments of condition.•Ghost crabs are widely used as indicator species in ecological beach assessments.•Human impacts detected with ghost crabs are globally evident for sandy shores.•Applied conservation needs experiments that yield defensible cause–effect evidence.•Priority areas are acoustic and light pollution, debris, climate change effects.
Observations of chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) provide valuable comparative data for understanding the significance of conspecific killing. Two kinds of hypothesis have been ...proposed. Lethal violence is sometimes concluded to be the result of adaptive strategies, such that killers ultimately gain fitness benefits by increasing their access to resources such as food or mates. Alternatively, it could be a non-adaptive result of human impacts, such as habitat change or food provisioning. To discriminate between these hypotheses we compiled information from 18 chimpanzee communities and 4 bonobo communities studied over five decades. Our data include 152 killings (n = 58 observed, 41 inferred, and 53 suspected killings) by chimpanzees in 15 communities and one suspected killing by bonobos. We found that males were the most frequent attackers (92% of participants) and victims (73%); most killings (66%) involved intercommunity attacks; and attackers greatly outnumbered their victims (median 8:1 ratio). Variation in killing rates was unrelated to measures of human impacts. Our results are compatible with previously proposed adaptive explanations for killing by chimpanzees, whereas the human impact hypothesis is not supported.
Natural ecosystems in estuaries are modified by the effects of runoff from disturbed watersheds and are frequently replaced by armoured estuarine shorelines. Whilst the effects of these 2 stressors ...are widely recognised, they are typically studied in isolation, and it is not clear how these contrasting types of urbanisation interact to shape faunal assemblages. In this study, fish assemblages were surveyed with underwater videos arranged in a 200 m grid throughout the lower reaches of 3 estuaries in eastern Australia (resulting in ≥63 sites per estuary and 277 sites in total) which differed in their extent of shoreline and watershed urbanisation. Overall, the least urbanised estuary supported more than twice the number of fish species and a significantly greater abundance of fish. The spatial patterns of fish diversity and abundance within estuaries were related to the proximity of urbanised shorelines, with most fish groups aggregating near armoured shorelines. These effects of distance from urbanised shorelines were, however, modified by the degree to which the entire estuary had been modified. We show that the ecological effects of urbanisation can extend across estuaries and suggest that coastal landscapes should therefore be managed as interlinked mosaics of both natural and artificial habitats.
Summary
Background
Inhibition of gastric acid removes a defence against ingested bacteria and spores, increasing the risk of some forms of gastroenteritis. Previous studies investigating a possible ...link between acid suppression therapy and Clostridium difficile‐associated diarrhoea have reported conflicting results.
Aim
To investigate whether acid suppression therapy is associated with an increased risk of C. difficile‐associated diarrhoea.
Methods
Prospective case–control study of 155 consecutive in‐patients with C. difficile‐associated diarrhoea.
Results
Antibiotics had been received by 143 (92%) of the C. difficile‐associated diarrhoea group and 76 (50%) of the controls during the preceding 3 months. Among those receiving antibiotics, 59 (41%) of the C. difficile‐associated diarrhoea group had also received acid suppression, compared with 21 (28%) of controls (OR 1.84, CI 1.01, 3.36, χ2 = 4.0, P = 0.046). Among the entire C. difficile‐associated diarrhoea group 64 (41%) had received acid suppression compared with 40 (26%) of controls (OR 1.99, CI 1.19, 3.31, χ2 = 7.9, P = 0.005). Logistic regression analyses found that C. difficile‐associated diarrhoea was independently associated with: antibiotic use (OR 13.1, 95% CI: 6.6, 26.1); acid suppression therapy (OR 1.90, 95% CI: 1.10, 3.29); and female sex (OR 1.79, 95% CI: 1.06, 3.04).
Conclusions
The risk of C. difficile‐associated diarrhoea in hospitalized patients receiving antibiotics may be compounded by exposure to proton pump inhibitor therapy.