An intensified debate centers on the use of strontium isotopes in surface water run-off as archive for bioavailable signatures in prehistoric provenance studies. Its use has been challenged by a ...recent suggestion that modern agricultural liming of farmlands exerts a serious imprint on the strontium isotope compositions of these waters. We here present results from a soil profile beneath agricultural farmland in the glaciogenic outwash plain of central West Jutland, Denmark, which show that strontium and its isotope composition derived from lime products is efficiently retained near the surface. Pore waters and bioavailable strontium from the acidic zone below the surface soil depict strontium isotope signatures that can best be explained by a mixture of silicate-derived and relic natural (not agriculturally added) carbonate-derived strontium. We therefore argue that agricultural liming does not contaminate groundwaters and groundwater-supported surface waters, rendering reference maps based on them relevant for modern and past provenance studies.
Display omitted
•Agriculturally added strontium is retained in the top soils.•We investigated a soil profile from farmland that experienced long-term liming.•Lime-derived strontium does not penetrate into the vadose zone.•Provenance studies depend on suitable characterization of baselines.•Strontium in surface water is used to characterize baselines for provenance studies.
Cyclization and annulation reactions initiated by ring-opening of small rings, especially cyclopropanes and cyclobutanes are now well-established in synthetic chemistry. Nevertheless, the potential ...of aminocyclopropanes and cyclobutanes, an important subclass for the synthesis of nitrogen-rich building blocks, has remained unexploited for a long time, despite important pioneering results. In the last decade, the situation has changed dramatically and new catalytic methods have emerged both for cyclization and annulation reactions. The purpose of this feature article is to present recent progress in this area, including our own work using donor-acceptor cyclopropanes and cyclobutanes.
Background Clostridium difficile infection (CDI) incidence is a growing concern. This study provides national estimates of CDI over 10 years and identifies trends in mortality and hospital length of ...stay (LOS) among hospitalized adults with CDI. Methods We conducted a retrospective analysis of the US National Hospital Discharge Surveys from 2001-2010. Eligible cases included adults aged ≥18 years discharged from a hospital with an ICD-9-CM diagnosis code for CDI (008.45). Data weights were used to derive national estimates. CDI incidence rates were depicted as CDI discharges per 1,000 total adult discharges. Results These data represent 2.2 million adult hospital discharges for CDI over the study period. CDI incidence increased from 4.5 CDI discharges per 1,000 total adult discharges in 2001 to 8.2 CDI discharges per 1,000 total adult discharges in 2010. The overall in-hospital mortality rate was 7.1% for the study period. Mortality increased slightly over the study period, from 6.6% in 2001 to 7.2% in 2010. Median hospital LOS was 8 days (interquartile range, 4-14 days), and remained stable over the study period. Conclusions The incidence of CDI among hospitalized adults in the United States nearly doubled from 2001-2010. Furthermore, there is little evidence of improvement in patient mortality or hospital LOS.
Drug repurposing, or identifying new uses for existing drugs, has emerged as an alternative to traditional drug discovery processes involving
de novo
synthesis. Drugs that are currently approved or ...under development for non-antibiotic indications may possess antibiotic properties, and therefore may have repurposing potential, either alone or in combination with an antibiotic. They might also serve as “antibiotic adjuvants” to enhance the activity of certain antibiotics.
•High concentrations (up to 120μg/L) of Cr(VI) were locally observed in the groundwaters of Sarigkiol/Kozani area.•Unconfined aquifers are more vulnerable to Cr(VI) pollution from ophiolitic rocks, ...as well as from dispersed fly ash.•Fly ash produced from a power plant burning lignite, was found to contribute to groundwater pollution with Cr(VI).•Positively fractionated δ53Cr values in groundwater and fly ash leachate point to partially anthropogenic origin of Cr(VI).•The natural (geochemical) contribution, regarding Cr (VI) pollution, was found up to 60μg/L.
Display omitted
Hexavalent chromium constitutes a serious deterioration factor for the groundwater quality of several regions around the world. High concentrations of this contaminant have been also reported in the groundwater of the Sarigkiol hydrological basin (near Kozani city, NW Greece). Specific interest was paid to this particular study area due to the co-existence here of two important factors both expected to contribute to Cr(VI) presence and groundwater pollution; namely the area's exposed ophiolitic rocks and its substantial fly ash deposits originating from the local lignite burning power plant. Accordingly, detailed geochemical, mineralogical, hydro-chemical, geophysical and hydrogeological studies were performed on the rocks, soils, sediments and water resources of this basin. Cr(VI) concentrations varied in the different aquifers, with the highest concentration (up to 120μgL−1) recorded in the groundwater of the unconfined porous aquifer situated near the temporary fly ash disposal site. Recharge of the porous aquifer is related mainly to precipitation infiltration and occasional surface run-off. Nevertheless, a hydraulic connection between the porous and neighboring karst aquifers could not be delineated. Therefore, the presence of Cr(VI) in the groundwater of this area is thought to originate from both the ophiolitic rock weathering products in the soils, and the local leaching of Cr(VI) from the diffused fly ash located in the area surrounding the lignite power plant. This conclusion was corroborated by factor analysis, and the strongly positively fractionated Cr isotopes (δ53Cr up to 0.83‰) recorded in groundwater, an ash leachate, and the bulk fly ash. An anthropogenic source of Cr(VI) that possibly influences groundwater quality is especially apparent in the eastern part of the Sarigkiol basin.
The use of antibiotics is the single most important driver in antibiotic resistance. Nevertheless, antibiotic overuse remains common. Decline in antibiotic prescribing in the United States coincided ...with the launch of national educational campaigns in the 1990s and other interventions, including the introduction of routine infant immunizations with the pneumococcal conjugate vaccine (PCV-7); however, it is unknown if these trends have been sustained through recent measurements.
We performed an analysis of nationally representative data from the Medical Expenditure Panel Surveys from 2000 to 2010. Trends in population-based prescribing were examined for overall antibiotics, broad-spectrum antibiotics, antibiotics for acute respiratory tract infections (ARTIs) and antibiotics prescribed during ARTI visits. Rates were reported for three age groups: children and adolescents (<18 years), adults (18 to 64 years), and older adults (≥65 years).
An estimated 1.4 billion antibiotics were dispensed over the study period. Overall antibiotic prescribing decreased 18% (risk ratio (RR) 0.82, 95% confidence interval (95% CI) 0.72 to 0.94) among children and adolescents, remained unchanged for adults, and increased 30% (1.30, 1.14 to 1.49) among older adults. Rates of broad-spectrum antibiotic prescriptions doubled from 2000 to 2010 (2.11, 1.81 to 2.47). Proportions of broad-spectrum antibiotic prescribing increased across all age groups: 79% (1.79, 1.52 to 2.11) for children and adolescents, 143% (2.43, 2.07 to 2.86) for adults and 68% (1.68, 1.45 to 1.94) for older adults. ARTI antibiotic prescribing decreased 57% (0.43, 0.35 to 0.52) among children and adolescents and 38% (0.62, 0.48 to 0.80) among adults; however, it remained unchanged among older adults. While the number of ARTI visits declined by 19%, patients with ARTI visits were more likely to receive an antibiotic (73% versus 64%; P <0.001) in 2010 than in 2000.
Antibiotic use has decreased among children and adolescents, but has increased for older adults. Broad-spectrum antibiotic prescribing continues to be on the rise. Public policy initiatives to promote the judicious use of antibiotics should continue and programs targeting older adults should be developed.
The dramatic increase in the incidence and severity of allergy and asthma has been proposed to be linked with an altered exposure to, and colonization by, micro‐organisms, particularly early in life. ...However, other lifestyle factors such as diet and physical activity are also thought to be important, and it is likely that multiple environmental factors with currently unrecognized interactions contribute to the atopic state. This review will focus on the potential role of microbial metabolites in immunoregulatory functions and highlights the known molecular mechanisms, which may mediate the interactions between diet, microbiota, and protection from allergy and asthma.
Mountain ecosystems are particularly susceptible to climate change. Characterizing intraspecific variation of alpine plants along elevational gradients is crucial for estimating their vulnerability ...to predicted changes. Environmental conditions vary with elevation, which might influence plastic responses and affect selection pressures that lead to local adaptation. Thus, local adaptation and phenotypic plasticity among low and high elevation plant populations in response to climate, soil and other factors associated with elevational gradients might underlie different responses of these populations to climate warming. Using a transplant experiment along an elevational gradient, we investigated reproductive phenology, growth and reproduction of the nutrient‐poor grassland species Ranunculus bulbosus, Trifolium montanum and Briza media. Seeds were collected from low and high elevation source populations across the Swiss Alps and grown in nine common gardens at three different elevations with two different soil depths. Despite genetic differentiation in some traits, the results revealed no indication of local adaptation to the elevation of population origin. Reproductive phenology was advanced at lower elevation in low and high elevation populations of all three species. Growth and reproduction of T. montanum and B. media were hardly affected by garden elevation and soil depth. In R. bulbosus, however, growth decreased and reproductive investment increased at higher elevation. Furthermore, soil depth influenced growth and reproduction of low elevation R. bulbosus populations. We found no evidence for local adaptation to elevation of origin and hardly any differences in the responses of low and high elevation populations. However, the consistent advanced reproductive phenology observed in all three species shows that they have the potential to plastically respond to environmental variation. We conclude that populations might not be forced to migrate to higher elevations as a consequence of climate warming, as plasticity will buffer the detrimental effects of climate change in the three investigated nutrient‐poor grassland species.
We thank Khorasani and colleagues for their interest in our recent publication and their thoughtful criticisms.
While we agree that the relative ambivalence about cricoid pressure (CP) among ...anaesthetists may be due to unsatisfactory experiences resulting in part from a lack of proper training and an inattention to details, we would suggest that this reflects real world practice. Any intervention that is to be applied by clinicians should be reflexively able to be performed in a high pace operating theatre with real patients, as well as in a controlled simulation setting.
Prior studies demonstrated marked increases in Clostridium difficile infection (CDI) in the United States (U.S.) in recent years. The objective of this study was to describe the epidemiology of ...initial and recurrent CDI in a national Veterans Health Administration (VHA) cohort over a 12-year period.
This was a retrospective cohort study of all adult VHA beneficiaries with CDI (ICD-9-CM code 008.45) plus a positive CDI stool test between October 1, 2002 and September 30, 2014. Data were obtained from the VA Informatics and Computing Infrastructure. Recurrence was defined as a second ICD-9-CM code plus a new course of CDI therapy following a minimum three-day gap after the initial therapy was completed. CDI incidence and outcomes were presented descriptively and longitudinally.
Overall, 30,326 patients met study inclusion criteria. CDI incidence increased from FY 2003 (1.6 per 10,000) to FY 2013 (5.1 per 10,000). Thereafter, CDI incidence decreased through FY 2014 (4.6 per 10,000). A total of 5,011 patients (17%) experienced a first recurrence and, of those, 1,713 (34%) experienced a second recurrence. Recurrence incidence increased 10-fold over the study period, from (0.1 per 10,000) in FY 2003, to (1.0 per 10,000) in FY 2014. Overall, 30-day mortality and median hospital length of stay (LOS) decreased among initial episodes over the study period. Mortality was higher for initial episodes (21%) compared to first recurrences (11%) and second recurrences (7%). Median hospital LOS was longer for first episodes (13 days) compared to first (9 days) and second recurrences (8 days).
Initial and recurrent CDI episodes increased among veterans over a 12-year period. Outcomes, such as mortality and hospital LOS improved in recent years; both of these outcomes are worse for initial CDI episodes than recurrent episodes.
PDF
