Search

The objective of this work was to evaluate the productivity and extraction of macronutrients by Urochloa brizantha cv. BRS Paiaguás (Syn. Brachiaria brizantha cv. BRS Paiaguás) single and intercropped with pigeon pea (Cajanus cajan cv. BRS Mandarim), subjected to four doses of nitrogen applied in topdressing (0, 80, 160 and 240 kg ha-1). The experiment was carried out in São Luís de Montes Belos, GO, in soil classified as dystrophic red latosol, under Cerrado conditions. Plant height and dry mass of pigeon pea, plant height, number of tillers, dry mass, and macronutrient extraction by Paiaguás palisadegrass were evaluated. Higher mass production was observed in the pasture intercropped with the legume, requiring a lower amount of N. Based on the results exposed, the cultivation of Paiaguás palisadegrass reaches higher productivity when intercropped with a legume such as pigeon pea, in addition to providing greater efficiency in the use of nutrients such as N, P and K. Nitrogen fertilization has a negative influence on the production of dry mass and height of pigeon pea plants.

Soil organic amendments in agricultural production can benefit crop production and a wide range of soil properties, including soil aggregation. Soil aggregate formation is largely driven by microbial activities, and can in-turn influence microbial communities by generating distinct microbial habitats, as well as associated impacts on water and nutrient dynamics. We investigated the long-term effects of two fertilizer management strategies (poultry manure compost vs. mineral fertilizer) and biochar amendment (0 vs. 10 t ha−1 walnut shell biochar, 900 °C pyrolysis temperature, by-product of gasification) on soil aggregation, soil organic C, and microbial community dynamics in water-stable aggregate fractions in corn-tomato rotations. Using wet-sieving, soils (0–15 cm) were divided into four size fractions: large macroaggregates (2000–8000 μm), small macroaggregates (250–2000 μm), microaggregates (53–250 μm) and silt and clay (

Climatic changes are altering precipitation patterns in the Amazon and may influence soil methane (CH4) fluxes due to the differential responses of methanogenic and methanotrophic microorganisms. However, it remains unclear if these climate feedbacks can amplify land-use-related impacts on the CH4 cycle. To better predict the responses of soil CH4-cycling microorganisms and emissions under altered moisture levels in the Eastern Brazilian Amazon, we performed a 30-day microcosm experiment manipulating the moisture content (original moisture; 60%, 80%, and 100% of field capacity - FC) of forest and pasture soils. Gas samples were collected periodically for gas chromatography analysis, and methanogenic archaeal and methanotrophic bacterial communities were assessed using quantitative PCR and metagenomics. Positive and negative daily CH4 fluxes were observed for forest and pasture, indicating that these soils can act as both CH4 sources and sinks. Cumulative emissions and the abundance of methanogenesis-related genes and taxonomic groups were affected by land use, moisture, and their interaction. Pasture soils at 100% FC had the highest abundance of methanogens and CH4 emissions, 22 times higher than forest soils under the same treatment. Higher ratios of methanogens to methanotrophs were found in pasture than in forest soils, even at field capacity conditions. Land use and moisture were significant factors influencing the composition of methanogenic and methanotrophic communities. The diversity and evenness of methanogens did not change throughout the experiment. In contrast, methanotrophs exhibited the highest diversity and evenness in pasture soils at 100% FC. Taken together, our results suggest that increased moisture exacerbates soil CH4 emissions and microbial responses driven by land-use change in the Amazon. This is the first report on the microbial CH4 cycle in Amazonian upland soils that combined one-month gas measurements with advanced molecular methods.

Termites are remarkable for their ability to digest cellulose from wood as their main energy source, but the extremely low nitrogen (N) content of their diet presents a major challenge for N acquisition. Besides the activity of N 2 -fixing bacteria in the gut, the recycling of N from waste products by symbiotic microbes as a complementary N-provisioning mechanism in termites remains poorly understood. In this study, we used a combination of high-throughput amplicon sequencing, quantitative PCR, and cultivation to characterize the microbial community capable of degrading urea, a common waste product, into ammonia in the guts of termites ( Reticulitermes hesperus ) from a wild and laboratory-reared colony. Taxonomic analysis indicated that a majority of the urease ( ureC ) genes in the termite gut (53.0%) matched with a Treponema endosymbiont of gut protists previously found in several other termites, suggesting an important contribution to the nutrition of essential cellulolytic protists. Furthermore, analysis of both the 16S rRNA and ureC amplicons revealed that the laboratory colony had decreased diversity and altered community composition for both prokaryotic and ureolytic microbial communities in the termite gut. Estimation by quantitative PCR showed that microbial ureC genes decreased in abundance in the laboratory-reared colony compared to the wild colony. In addition, most of our cultivated isolates appeared to originate from non-gut environments. Together, our results underscore a more important role for ureolysis by endosymbionts within protists than by free-swimming bacteria in the gut lumen of R. hesperus .

Background Hypertension was both a mutual cause and the main concern of chronic kidney disease (CKD). Blood pressure control is more problematic in the company of CKD. This study compares the effects of renal sympathetic denervation (RSD) on 24-h ambulatory blood pressure measurements (ABPM) and renal function in individuals with CKD and uncontrolled hypertension by unlike a number of ablated spots using the EnligHTN catheter and the standard irrigated cardiac ablation catheter (SICAC), Flexability. Methods The 112 subjects were randomly divided into two groups according to the catheter that would be used in the procedure EnligHTN ( n = 56) or Flexability ( n = 56). Into each group, we created 5 subgroups according to the number of ablated spots: 4, 8, 12, 16 and 20. All of them were followed for exactly 6 months to assess all the parameters measured in this investigation. Results Comparing the Δ 24-h systolic ABPM according to the number of ablated spots 4 and 20 for EnligHTN vs. Flexability, respectively, the differences were: −3.6 ± 0.9 vs. −6.3 ± 1.4 mmHg ( P vs. −36.3 ± 4.3 mmHg ( P vs. Flexability, respectively, were: +2.7 ± 4.0 vs . +6.0 ± 8.4 mL/min/1.73 m 2 ( P = 0.2287), and +11.9 ± 6.0 vs. +21.4 ± 8.7 mL/min/1.73 m 2 ( P = 0.0222). Conclusion The RSD reduced the mean 24-h ABPM in subjects with CKD and uncontrolled hypertension and improved the renal function in both groups. These effects were more marked and important in subgroups underwent a great number of ablated spots using the SICAC.

We analyzed the microbial community that developed after 4 years of testing different soil-crop management systems in the savannah-forest transition zone of Eastern Ghana where management systems can rapidly alter stored soil carbon as well as soil fertility. The agricultural managements were: (i) the local practice of fallow regrowth of native elephant grass (Pennis e tum purpureum) followed by biomass burning before planting maize in the spring, (ii) the same practice but without burning and the maize receiving mineral nitrogen fertilizer, (iii) a winter crop of a legume, pigeon pea (Cajanus cajan), followed by maize, (iv) vegetation free winter period (bare fallow) followed by maize, and (v) unmanaged elephant grass-shrub vegetation. The mean soil organic carbon (SOC) contents of the soils after 4 years were: 1.29, 1.67, 1.54, 0.80 and 1.34%, respectively, differences that should affect resources for the microbial community.From about 290,000 sequences obtained by pyrosequencing the SSU rRNA gene, canonical correspondence analysis showed that SOC was the most important factor that explained differences in microbial community structure among treatments. This analysis as well as phylogenetic ecological network construction indicated that members of the Acidobacteria GP4 and GP6 were more abundant in soils with relatively high SOC whereas Acidobacteria GP1, GP7, and Actinobacteria were more prevalent in soil with lower SOC. Burning of winter fallow vegetation led to an increase in Bacillales, especially those belonging to spore-forming genera. Of the managements, pigeon-pea cultivation during the winter period promoted a higher microbial diversity and also sequestered more SOC, presumably improving soil structure, fertility, and resiliency. © 2013 Elsevier Ltd.

Unshielded spin-valve sensors were fabricated with trackwidth W varying from 25 to 2 micron and height h ranging from 7 to 1 micron. Magnetoresistance signals range from 7.5% to 3%. We find that heads with a geometry W/h/spl ges/4 are Barkhausen noise free. The effect of current density on sensor heating and output linearization is described. The pinned NiFe layer is exchange-biased to a 120 /spl Aring/ thick TbCo layer, where the exchange field can be tuned by changing the TbCo thickness. >

Co-Cu-NiFe-Cu weakly coupled multilayers, were patterned into stripes with dimensions from 1×6μm2 to 2×20μm2. After proper biasing using a DC field created by an adjacent bias conductor, these structures show large linear field spans (±1500e), with MR values up to 6%. These can be used for current or position sensor applications. Sensor response to AC fields was studied up to 1Mhz, using the bias conductors as sources of the AC field. We find that the signal output is reduced above 10 to 100kHz. For comparison, sensors were also fabricated out Co-Cu AF-coupled multilayer (3×100μm2 structures) needed for field detection up to several kOe.

Text: The Nutrition Care Process (NCP) provides a standardized yet individualized approach to nutritional care of patients. When the decision was made to implement the NCP into the electronic documentation system at Harbor-UCLA Medical Center, dietitians (RDs) raised two primary concerns: would the briefer method of documentation meet regulatory requirements and would formation of the Nutrition Diagnosis (ND) statement take significantly longer to develop during the initial transition, resulting in decreased productivity? RDs were trained in the NCP over a six month period and the Clinical Nutrition Manager (CNM) worked with Information Systems (IS) to ensure all ND and Nutrition Intervention terminology was included in the Affinity Patient Charting system. The NCP was formally implemented in October, 2007. RD productivity pre-NCP ranged from 1.39 1.81 (average 1.63) inpatients seen per hour. Since implementation of the NCP, productivity has averaged 1.58 (range 1.53 1.67). A minimum of 5 chart reviews are conducted on each RD quarterly to ensure compliance with regulatory requirements as well as assess competency. Chart audit scores prior to NCP implementation ranged from 90.98% to 97.54%. Post-implementation, initial chart audit scores were 95%, increasing to 98.32% the following quarter. In summary, use of the NCP has not resulted in a decreased productivity level, even during the initial learning phase, and chart audit scores have improved to an annual high during the recent quarter. As the staff become more accustomed to the NCP, data will continued to be tracked for further improvement in productivity, competency, and regulatory compliance.

We describe the bias mechanism and MR output of a properly biased unshielded spin-valve sensor with trackwidth W of 12 μm, height h of 3 μm, and total stripe length L of 15 μm. For a smaller device ( L = 6 μm, W = 2 μm, and h = 1.5 μm) we could no longer keep the NiFe pinned layer at 90° with respect to the free layer, since the shape anisotropy became dominant, when compared with the exchange or uniaxial anisotropy field.

Sulphate ions have been known for some years to enhance the activity of hepatic glycogen phosphorylase b in vitro. Here we report that intravenous injections of 4.92 mmol of Na2SO4/kg body wt. to rats induced marked hepatic glycogenolysis in vivo, accompanied by polyuria, glycosuria and a mild hyperglycaemia. These effects were observed both in normal (Wistar) rats and in gsd/gsd rats that lacked hepatic phosphorylase kinase. In both rat strains the activity of glycogen phosphorylase in liver extracts was enhanced by pretreatment of the animals with Na2SO4, but in phosphorylase kinase-deficient livers the enhancement was solely in phosphorylase b activity, whereas both the a and b forms of the enzyme were activated in normal livers. Hepatic glycogenolysis was also induced by perfusing rat livers, both normal and gsd/gsd, with 25 mM-Na2SO4. Under these conditions both the rat strains showed only enhanced activities of glycogen phosphorylase b. This suggested that the increased activity of phosphorylase a in the extracts of normal livers after Na2SO4 administration in vivo was due to a hormonally mediated conversion of the b form into the a form. The activation of glycogen phosphorylase b was stable to dilution and appeared to be due to a long-lasting structural change in the enzyme or very tight binding of an activator.

Unshielded spin-valve sensors were fabricated and annealed to study the effect of high temperature processing on the transfer curves. A micromagnetic simulation program was developed to analyze the changes observed on the transfer curves upon annealing. Analysis of experimental data versus the micromagnetic simulations indicates two causes responsible for the progressive loss of the MR signal upon annealing above the blocking temperature: a rotation of the pinned layer magnetization from the transverse to the longitudinal direction (along the sensor trackwidth) and an increase of the free layer anisotropy. Rotation of the free layer easy axis can also be observed. Cool down in a magnetic field can prevent this MR loss by pinning the magnetization direction during the high temperature stage.