Degradation mechanisms and consequences for SOC stocks for the world's largest alpine pastoral ecosystem on the Tibetan Plateau

Approximately 1.5 million km² of the Tibetan Plateau are covered with grasslands. Thereof one third is occupied by the world’s largest pastoral alpine ecosystem (Kobresia pastures). Paleo-records indicate the grazing-induced origin of this ecosystem since more than 8000 years or at least since yak domestication since 4000 years. Long-term moderate grazing by yak and sheep increased belowground C allocation of Kobresia pygmaea, caused the development of dense root-mats and finally lead to an accumulation of soil organic carbon (SOC) and nutrients such as nitrogen (N) and phosphorus (P) in the topsoil. These pastures, however, are increasingly affected by large-scale degradation caused by overgrazing of these highly sensitive ecosystems. Loss of the topsoil threatens several ecosystem functions: i.e. SOC and nutrient storage, biodiversity, provision of grazing-ground and supply of clean water for large parts of SE-Asia. Here, we present a conceptual model and results of degradation processes combining anthropogenic and natural amplifications. To evaluate losses of SOC and nutrients we synthesize field observations and surveys in the highlands and validates this with own analyses in the Kobresia core area. We show that drought- and frost-induced polygonal cracking opens the root-mats, already weakened by overgrazing. This initiates a dying of the Kobresia turf, extends the surface cracks, triggers soil erosion and promotes SOC mineralization and leaching losses. Soil erosion caused further high losses of SOC and nutrients from the topsoil (i.e. 0-10 cm: ~5.1 kg C m-2), whereas SOC loss beneath the surface cracks was primary caused by both, decreasing C-input and SOC mineralization (mineralization-derived SOC loss: ~2.5 kg C m-2). The root biomass decreased with intensity of pasture degradation and lower C input constrains the ecosystem recovery. A negative δ13C shift of SOC reflected intensive decomposition and corresponded to a relative enrichment of 13C depleted lignin components. In sum, degradation triggered high SOC loss (up to 70% of intact soil in 0-30 cm: ~7.6 kg C m-2) from this ecosystem with profound consequences for carbon sequestration, atmospheric CO2, water quality and ecosystem stability

Nitrogen Uptake in an Alpine Kobresia Pasture on the Tibetan Plateau: Localization by ¹⁵N Labeling and Implications for a Vulnerable Ecosystem

© 2015, Springer Science+Business Media New York. Grasslands are very important regionally and globally because they store large amounts of carbon (C) and nitrogen (N) and provide food for grazing animals. Intensive degradation of alpine grasslands in recent decades has mainly impacted the upper root-mat/soil horizon, with severe consequences for nutrient uptake in these nutrient-limited ecosystems. We used 15N labeling to identify the role of individual soil layers for N-uptake by Kobresia pygmaea—the dominating plant in the degraded Tibetan pasture ecosystems. We hypothesized a very efficient N-uptake corresponding mainly to the vertical distribution of living roots (topsoil > subsoil). We assume that K. pygmaea develops a very dense root-mat, which has to be maintained by small aboveground biomass, to enable this efficient N-uptake. Consequently, a higher N-investment into roots compared to shoots was hypothesized. The 15N recovery in whole plants (~70%) indicated very efficient N-uptake from the upper injection depths (0–5 cm). The highest 15N amounts were recovered in root biomass, whereby 15N recovery in roots strongly decreased with depth. In contrast, 15N recovery in shoots was generally low (~18%) and independent of the 15N injection depth. This clearly shows that the low N demand of Kobresia shoots can be easily covered by N-uptake from any depth. Less living root biomass in lower versus upper soil was compensated by a higher specific activity of roots for N-uptake. The 15N allocation into roots was on average 1.7 times higher than that into shoots, which agreed well with the very high R/S ratio. Increasing root biomass is an efficient strategy of K. pygmaea to compete for belowground resources at depths and periods with available resources. This implies high C-costs to maintain root biomass (~6.0 kg DM m−2), which must be covered by a very low amount of photosynthetically active shoots (0.3 kg DM m−2). It also suggests that Kobresia grasslands react extremely sensitively toward changes in climate and management that disrupt this above-/belowground trade-off mechanism

Vergleich von Lisinopril und Captopril zur Behandlung der schweren Herzinsuffizienz (NYHA III-IV) bei Hochrisikopatienten. Vorläufige Studienergebnisse (=Comparison of lisinopril and captopril in treatment of severe heart failure (NYHA III-IV) in high risk patients. Preliminary results of the trial)

We present preliminary data of a study comparing captopril, a short acting, with lisinopril, a long acting ACE-inhibitor in 8 of 12 projected patients with severe chronic heart failure (NYHA III-IV) and one additional risk factor (e.g. diabetes mellitus, renal failure). The 8 patients were treated in a cross over design for 12 weeks with either drug. While lisinopril improved NYHA-class in all patients, captopril reached this goal in only 3. Renal function was stable in all patients. Captopril influenced hormones (renin, aldosterone, norepinephrine, epinephrine) and microalbuminuria less than lisinopril. The number of adverse reactions was smaller in lisinopril treated patients. These preliminary data demonstrate at least an equal efficacy of lisinopril compared to captopril in high risk patients with severe chronic heart failure

Maternal mortality: near-miss events in middle-income countries, a systematic review

Objective To describe the incidence and main causes of maternal near-miss events in middle-income countries using the World Health Organization's (WHO) maternal near-miss tool and to evaluate its applicability in these settings. Methods We did a systematic review of studies on maternal near misses in middle-income countries published over 2009-2020. We extracted data on number of live births, number of maternal near misses, major causes of maternal near miss and most frequent organ dysfunction. We extracted, or calculated, the maternal near-miss ratio, maternal mortality ratio and mortality index. We also noted descriptions of researchers'experiences and modifications of the WHO tool for local use. Findings We included 69 studies from 26 countries (12 lower-middle- and 14 upper-middle-income countries). Studies reported a total of 50 552 maternal near misses out of 10 450 482 live births. Median number of cases of maternal near miss per 1000 live births was 15.9 (interquartile range, IQR: 8.9-34.7) in lower-middle- and 7.8 (IQR: 5.0-9.6) in upper-middle-income countries, with considerable variation between and within countries. The most frequent causes of near miss were obstetric haemorrhage in 19/40 studies in lower-middleincome countries and hypertensive disorders in 15/29 studies in upper-middle-income countries. Around half the studies recommended adaptations to the laboratory and management criteria to avoid underestimation of cases of near miss, as well as clearer guidance to avoid different interpretations of the tool. Conclusion In several countries, adaptations of the WHO near-miss tool to the local context were suggested, possibly hampering international comparisons, but facilitating locally relevant audits to learn lessons.Research into fetal development and medicin

POTENTIAL ENHANCEMENTS TO NATURAL ATTENUATION: LINES OF INQUIRY SUPPORTING ENHANCED PASSIVE REMEDIATION OF CHLORINATED SOLVENTS

The Department of Energy (DOE) is sponsoring an initiative to facilitate efficient, effective and responsible use of Monitored Natural Attenuation (MNA) and Enhanced Passive Remediation (EPR) for chlorinated solvents. This Office of Environmental Management (EM) ''Alternative Project,'' focuses on providing scientific and policy support for MNA/EPR. A broadly representative working group of scientists supports the project along with partnerships with regulatory organizations such as the Interstate Technology and Regulatory Council and the U.S. Environmental Protection Agency (EPA). The initial product of the technical working group was a summary report that articulated the conceptual approach and central scientific tenants of the project, and that identified a prioritized listing of technical targets for field research. This report documented the process in which: (1) scientific ground rules were developed, (2) lines of inquiry were identified and then critically evaluated, (3) promising applied research topics were highlighted in the various lines of inquiry, and (4) these were discussed and prioritized. The summary report will serve as a resource to guide management and decision-making throughout the period of the subject MNA/EPR Alternative Project. To support and more fully document the information presented in the summary report, we are publishing a series of supplemental documents that present the full texts from the technical analyses within the various lines of inquiry (see listing). The following report - documenting our evaluation of the state of the science of the characterization and monitoring process and tools-- is one of those supplemental documents

Great saves or near misses? Severe maternal outcome in Metro East, South Africa: a region-wide population-based case-control study

Objective To assess the incidence of severe maternal outcome (SMO), comprising maternal mortality (MM) and maternal near miss (MNM), in Metro East health district, Western Cape Province, South Africa between November 2014 and November 2015 and to identify associated determinants leading to SMO with the aim to improve maternity care.Methods Region-wide population-based case-control study. Women were included in the study, if they were maternal deaths or met MNM criteria, both as defined by WHO. Characteristics of women with SMO were compared with those of a sample of women without SMO, matched for age and parity, taken from midwifery-led obstetrical units from two residential areas in Metro East, using multivariate regression analysis.Results Incidence of SMO was 9.1 per 1000 live births, and incidence of MNM was 8.6 per 1000 live births. Main causes of SMO were obstetrical hemorrhage and hypertensive disorders. Factors associated with SMO were HIV (adjusted odds ratio [aOR] 24.8; 95% confidence interval [CI] 10.0-61.6), pre-eclampsia (aOR 17.5; 95% CI 7.9-38.7), birth by cesarean section (aOR 8.4; 95% CI 5.8-12.3), and chronic hypertension (aOR 2.4; 95% CI 1.1-5.1).Conclusion Evaluation of SMO incidence and associated determinants supports optimizing tailored guidelines in Metro-East health district to improve maternal health.Research into fetal development and medicin

Polycyclic Aromatic Hydrocarbon-degrading Bacteria from Aviation Fuel Spill Site at Ibeno, Nigeria

Polycyclic aromatic hydrocarbon (PAH)–degrading bacteria were isolated from aviation fuel contaminated soil at Inua Eyet Ikot in Ibeno, Nigeria. PAH-degrading bacteria in the contaminated soil were isolated by enrichment culture technique. Isolates with high PAH degrading potential characterized by their extensive growth on PAH-supplemented minimal salt medium were screened for their naphthalene, phenanthrene and chrysene degradability. The screening medium which contained selected PAHs as the sole source of carbon and energy showed that Micrococcus varians AFS-2, Pseudomonas putida AFS-3 and Alcaligenes faecalis AFS-5 exhibited a concentration–dependent growth in all the PAH–compounds tested. There were visible changes in the color of growth medium suggesting the production of different metabolites. Their acclimation to different PAH substrates was also evident as A. faecalis AFS-5 isolated from chrysene grew well on other less complex aromatic compounds. The isolate exhibited best growth (0.44 OD600) when exposed to 10 ppm of chrysene for 5 days and could utilize up to 90 ppm of chrysene. This isolate and others with strong PAH-degrading potentials are recommended for bioremediation of PAHs in aviation fuel-contaminated sites in the tropics