The role of soil biotic processes in the search of quantitative indexes of soil quality

Non-Peer ReviewedMonitoring soil quality involves measurements of soil properties over periods of several years. This article examines the potential role of chemical SOM composition and of soil biotic processes as faster indexes of soil quality. Soil quality was quantified on the basis of individual soil attributes and time. Chemical characterization of soil organic matter by solid 13C-NMR and Py-FIMS showed that a degraded Gleysol cropped to corn during 25 years suffered C losses from all chemical functional groups. Surprisingly, aromatic-C was lost at proportional higher rates than aliphatic-C. These results indicate that chemical composition of SOM determined by quantitative nondestructive methods can be used as quality indexes in agricultural soils. Biotic processes reflect changes in soil quality over shorter periods than total or type of SOM. Microbial specific respiration (qCO2) is a soil attribute that consistently reflected differences in soil quality. It was hypothesized that qCO2 , the microbial adenylate energy charge and anabolic reduction charge may permit to asses soil quality over monitoring periods of weeks to <5y

Natural carbon-13 distribution in forested and cultivated gleysols

Non-Peer ReviewedNatural 13C abundance was measured in two Gleysols, one from a forest and one which had been under continuous corn for more than 25 yr. Delta 13C values increased slightly with depth in the forest soil. In the corn soil, delta 13C values were similar throughout the plow layer but lowest in the deepest layer sampled, 30-50 cm. Between 29 and 3 5% of the carbon in the plow layer of the cultivated soil was derived from corn. The 0-5 cm layer of each soil was separated into particle size fractions; delta 13c values indicated that the sand fraction had the largest proportion of carbon derived from corn whereas the coarse silt had the smallest proportion

Effect of incorporation of wheat straw and nitrogen addition on the flux of soil gases (CH4 and N2O) at two moisture and temperature regimes

Non-Peer ReviewedMethane and nitrous oxide contribute to global warming of the earth's atmosphere. The concentration of CH4 and N2O in the atmosphere is increasing at an alarming rate of 1% and 0.25% yr-1, respectively. Little information is available about the effect of agronomic practices on soil gases emitted from cultivated soils in the prairies. An incubation study was undertaken to understand the effects of agronomic management practices and environmental factors on CH4 and N2O emissions from a cultivated soil. Methane production was preceded by a two week lag phase, and it was emitted only from submerged soils incubated at 25°C. Addition of straw enhanced the emission and N addition reduced the rate of CH4 production. Soil incubated at -30kPa moisture may act as a sink for methane. Emission of N2O was observed within 2 days of submergence and was maximum when nitrogen alone was added to the soil. Addition of wheat straw along with nitrogen decreased the emission of N2O as compared to nitrogen alone. Temperature of 10 °C and moisture at -30kPa limited the emissions of N2O from the soil

The effect of organic structures on the water stability of macro-aggregates.

Non-Peer ReviewedA study was conducted to identify the chemical structures of soil organic matter and examine their effect on the water stability of macro-aggregates (>250 um) in a SiL Brown Chernozem under wheat-fallow (WF) and continuous wheat (CW) . The proportion of water stable macro-aggregates were determined by wet sieving. Chemical structures of soil organic matter were characterized by pyrolysis field ionization mass spectrometry (Py-FIMS), and grouped into seven classes: carbohydrates, phenolic and lignin monomers, lignin dimers, lipids + alkanes and alkenes, sterols, alkyl aromatic and N-compounds. In comparison with CW, there was a reduction in the proportion of macro-aggregates and an increase of micro-aggregates in the WF crop rotation. Sixty-five percent of all the soil organic matter (SOM) was identified by Py-FIMS. The average concentration of each class of compound in whole soil and macro-aggregate samples ranged between 0.1 and 15% of the total identified SOM. Carbohydrates, phenolic, and lignin monomers were the most abundant compounds (>10%). Linear regression models (r2 ~ 0.96, p=0.05) showed that the stability of macro-aggregates was highly correlated with the concentration of the least abundant (<3. 5%) structures of sterols, lipids and lignin dimers. These compounds are metabolic products of plants and soil organisms

Nitrogen fertilization improves quantity and quality of organic matter in a grassland soil

Non-Peer Reviewe

Rough vaccines in animal brucellosis: structural and genetic basis and present status

Brucellosis control and eradication requires serological tests and vaccines. Effective classical vaccines (S19 in cattle and Rev 1 in small ruminants), however, induce antibodies to the O-polysaccharide of the lipopolysaccharide which may be difficult to distinguish from those resulting from infection and may thus complicate diagnosis. Rough attenuated mutants lack the O-polysaccharide and would solve this problem if eliciting protective immunity; the empirically obtained rough mutants 45/20 and RB51 have been used as vaccines. Strain 45/20 is reportedly unstable and it is not presently used. RB51 is increasingly used instead of S19 in some countries but it is rifampicin resistant and its effectiveness is controversial. Some controlled experiments have found good or absolute protection in adult cattle vaccinated orally (full dose) or subcutaneously (reduced dose) and in one field experiment, RB51 was reported to afford absolute protection to calves and to perform better than S19. Controlled experiments in calves, however, have shown reduced doses of RB51 to be ineffective, full doses only partially effective, and RB51 less effective than S19 against severe challenges. Moreover, other observations suggest that RB51 is ineffective when prevalence is high. RB51 is not useful in sheep and evidence in goats is preliminary and contradictory. Rough mutants obtained by molecular biology methods on the knowledge of the genetics and structure of Brucella lipopolysaccharide may offer alternatives. The B. abortus manBcore (rfbK) mutant seems promising in cattle, and analyses in mice suggest that mutations affecting only the O-polysaccharide result in better vaccines than those affecting both core and O-polysaccharide. Possible uses of rough vaccines also include boosting immunity by revaccination but solid evidence on its effectiveness, safety and practicality is not available

Characterization of Brucella abortus O-polysaccharide and core lipopolysaccharide mutants and demonstration that a complete core is required for rough vaccines to be efficient against Brucella abortus and Brucella ovis in the mouse model

Brucella abortus rough lipopolysaccharide (LPS) mutants were obtained by transposon insertion into two wbk genes (wbkA [putative glycosyltransferase; formerly rfbU] and per [perosamine synthetase]), into manB (pmm [phosphomannomutase; formerly rfbK]), and into an unassigned gene. Consistent with gene-predicted roles, electrophoretic analysis, 2-keto-3-manno-D-octulosonate measurements, and immunoblots with monoclonal antibodies to O-polysaccharide, outer and inner core epitopes showed no O-polysaccharide expression and no LPS core defects in the wbk mutants. The rough LPS of manB mutant lacked the outer core epitope and the gene was designated manB(core) to distinguish it from the wbk manB(O-Ag). The fourth gene (provisionally designated wa**) coded for a putative glycosyltransferase involved in inner core synthesis, but the mutant kept the outer core epitope. Differences in phage and polymyxin sensitivity, exposure or expression of outer membrane protein, core and lipid A epitopes, and lipid A acylation demonstrated that small changes in LPS core caused significant differences in B. abortus outer membrane topology. In mice, the mutants showed different degrees of attenuation and induced antibodies to rough LPS and outer membrane proteins. Core-defective mutants and strain RB51 were ineffective vaccines against B. abortus in mice. The mutants per and wbkA induced protection but less than the standard smooth vaccine S19, and controls suggested that anti O-polysaccharide antibodies accounted largely for the difference. Whereas no core-defective mutant was effective against B. ovis, S19, RB51, and the wbkA and per mutants afforded similar levels of protection. These results suggest that rough Brucella vaccines should carry a complete core for maximal effectiveness

Rational use of medicines: prescribing indicators at different levels of health care

Este estudo multicêntrico teve como objetivo investigar o padrão de prescrição de medicamentos para pacientes ambulatoriais atendidos em serviços de saúde vinculados a universidades com diferentes níveis de atenção, em oito cidades do sul e centro-oeste do Brasil. As prescrições coletadas foram submetidas à análise de diversos itens, incluindo os indicadores de prescrição propostos pela OMS. No total, 2.411 prescrições foram analisadas e 469 medicamentos foram identificados. O número de medicamentos prescritos por consulta, a frequência de polifarmácia e a porcentagem de consultas com pelo menos um medicamento injetável ou um antimicrobiano prescrito foram maiores em centros de saúde que ofereciam cuidados de atenção básica, em comparação com aqueles que não dispunham desse tipo de atendimento. A maioria dos medicamentos foi prescrita pelo nome genérico (86,1%). Em unidades com cuidados de atenção básica, a acessibilidade foi maior, a prescrição de medicamentos presentes nas Listas Nacional e Municipais de Medicamentos Essenciais foi mais frequente e instruções foram fornecidas aos pacientes mais comumente. Entretanto, advertências e medidas não farmacológicas foram indicadas com menor frequência. Este estudo revela tendências de prescrição de medicamentos em serviços de saúde ligados a universidades, com diferentes níveis de atenção, e indica possíveis áreas de melhoria na prática da prescrição.This multicenter study aimed to investigate prescribing patterns of drugs at different levels of health care delivery in university-affiliated outpatient clinics located in eight cities in the South and Midwest of Brazil. All prescriptions collected were analyzed for various items, including WHO prescribing indicators. A total of 2,411 prescriptions were analyzed, and 469 drugs were identified. The number of drugs prescribed per encounter, the frequency of polypharmacy, and the percentage of encounters with at least one injection or antibiotic prescribed were higher in centers providing primary health care services, compared to those where this type of care is not provided. Most drugs (86.1%) were prescribed by generic name. In centers with primary health care services, drug availability was higher, drugs included in the National and Municipal Lists of Essential Medicines were more frequently prescribed, and patients were given more instructions. However, warnings and non-pharmacological measures were less frequently recommended. This study reveals trends in drug prescribing at different levels of health care delivery in university-affiliated outpatient clinics and indicates possible areas for improvement in prescribing practices

Extended anticoagulant treatment with full- or reduced-dose apixaban in patients with cancer-associated venous thromboembolism: rationale and design of the API-CAT study

Cancer-associated thrombosis (CT) is associated with a high risk of recurrent venous thromboembolic (VTE) events that require extended anticoagulation in patients with active cancer, putting them at risk of bleeding. The aim of the API-CAT study (NCT03692065) is to assess whether a reduced-dose regimen of apixaban (2.5mg twice daily [bid]) is noninferior to a full-dose regimen of apixaban (5mg bid) for the prevention of recurrent VTE in patients with active cancer who have completed >= 6 months of anticoagulant therapy for a documented index event of proximal deep-vein thrombosis and/or pulmonary embolism. API-CAT is an international, randomized, parallel-group, double-blind, noninferiority trial with blinded adjudication of outcome events. Consecutive patients are randomized to receive apixaban 2.5 or 5mg bid for 12 months. The primary efficacy outcome is a composite of recurrent symptomatic or incidental VTE during the treatment period. The principal safety endpoint is clinically relevant bleeding, defined as a composite of major bleeding or nonmajor clinically relevant bleeding. Assuming a 12-month incidence of the primary outcome of 4% with apixaban and an upper limit of the two-sided 95% confidence interval of the hazard ratio <2.0, 1,722 patients will be randomized, assuming an up to 10% loss in total patient-years (beta=80%; alpha one-sided=0.025). This trial has the potential to demonstrate that a regimen of extended treatment for patients with CT beyond an initial 6 months, with a reduced apixaban dose, has an acceptable risk of recurrent VTE recurrence and decreases the risk of bleeding.Thrombosis and Hemostasi

The ESO Diffuse Interstellar Bands Large Exploration Survey EDIBLES: I. Project description, survey sample and quality assessment

The carriers of the diffuse interstellar bands (DIBs) are largely unidentified molecules ubiquitously present in the interstellar medium (ISM). After decades of study, two strong and possibly three weak near-infrared DIBs have recently been attributed to the C+ 60 fullerene based on observational and laboratory measurements. There is great promise for the identification of the over 400 other known DIBs, as this result could provide chemical hints towards other possible carriers. In an effort to systematically study the properties of the DIB carriers, we have initiated a new large-scale observational survey: the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES). The main objective is to build on and extend existing DIB surveys to make a major step forward in characterising the physical and chemical conditions for a statistically significant sample of interstellar lines-of-sight, with the goal to reverse-engineer key molecular properties of the DIB carriers. EDIBLES is a filler Large Programme using the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope at Paranal, Chile. It is designed to provide an observationally unbiased view of the presence and behaviour of the DIBs towards early-spectraltype stars whose lines-of-sight probe the diffuse-to-translucent ISM. Such a complete dataset will provide a deep census of the atomic and molecular content, physical conditions, chemical abundances and elemental depletion levels for each sightline. Achieving these goals requires a homogeneous set of high-quality data in terms of resolution (R ~ 70 000 – 100 000), sensitivity (S/N up to 1000 per resolution element), and spectral coverage (305–1042 nm), as well as a large sample size (100+ sightlines). In this first paper the goals, objectives and methodology of the EDIBLES programme are described and an initial assessment of the data is provided