64 research outputs found
Clinico-Surgical Outcome of Repair of Isolated Atrial Septal Defect At Care Hospital, Banjara Hills-Hyderabad India, 2004-2006
No Abstract
Individual tree and stand-level carbon and nutrient contents across one rotation of loblolly pine plantations on a reclaimed surface mine
While reclaimed loblolly pine (Pinus taeda L.) plantations in east Texas, USA have demonstrated similar aboveground productivity levels relative to unmined forests, there is interest in assessing carbon (C) and nutrients in aboveground components of reclaimed trees. Numerous studies have previously documented aboveground biomass, C, and nutrient contents in loblolly pine plantations; however, similar data have not been collected on mined lands. We investigated C, N, P, K, Ca, and Mg aboveground contents for first-rotation loblolly pine growing on reclaimed mined lands in the Gulf Coastal Plain over a 32-year chronosequence and correlated elemental rates to stand age, stem growth, and similar data for unmined lands. At the individual tree level, we evaluated elemental contents in aboveground biomass components using tree size, age, and site index as predictor variables. At the stand-level, we then scaled individual tree C and nutrients and fit a model to determine the sensitivity of aboveground elemental contents to stand age and site index. Our data suggest that aboveground C and nutrients in loblolly pine on mined lands exceed or follow similar trends to data for unmined pine plantations derived from the literature. Diameter and height were the best predictors of individual tree stem C and nutrient contents (R ≥ 0.9473 and 0.9280, respectively) followed by stand age (R ≥ 0.8660). Foliage produced weaker relationships across all predictor variables compared to stem, though still significant (P ≤ 0.05). The model for estimating stand-level C and nutrients using stand age provided a good fit, indicating that contents aggrade over time predictably. Results of this study show successful modelling of reclaimed loblolly pine aboveground C and nutrients, and suggest elemental cycling is comparable to unmined lands, thus providing applicability of our model to related systems
Yield-scaled mitigation of ammonia emission from N fertilization: the Spanish case
Online supplementary data available from stacks.iop.org/ERL/9/125005/mmedia[EN] Synthetic nitrogen (N) fertilizer and field application of livestock manure are the major sources
of ammonia (NH3) volatilization. This N loss may decrease crop productivity and subsequent
deposition promotes environmental problems associated with soil acidification and
eutrophication. Mitigation measures may have associated side effects such as decreased crop
productivity (e.g. if N fertilizer application is reduced), or the release of other reactive N
compounds (e.g. N2O emissions if manure is incorporated). Here, we present a novel
methodology to provide an integrated assessment of the best strategies to abate NH3 from N
applications to crops. Using scenario analyses, we assessed the potential of 11 mitigation
measures to reduce NH3 volatilization while accounting for their side effects on crop
productivity, N use efficiency (NUE) and N surplus (used as an indicator of potential N losses by
denitrification/nitrification and NO3
− leaching/run-off). Spain, including its 48 provinces, was
selected as a case study as it is the third major producer of agricultural goods in Europe, and also
the European country with the highest increase in NH3 emissions from 1990 to 2011. Mitigation
scenarios comprised of individual measures and combinations of strategies were evaluated at a
country- and regional level. Compared to the reference situation of standard practices for the year
2008, implementation of the most effective region-specific mitigation strategy led to 63% NH3
mitigation at the country level. Implementation of a single strategy for all regions reduced NH3
by 57% at the highest. Strategies that involved combining mitigation measures produced the
largest NH3 abatement in all cases, with an 80% reduction in some regions. Among the strategies
analyzed, only suppression of urea application combined with manure incorporation and
incorporation of N synthetic fertilizers other than urea showed a fully beneficial situation: yieldscaled
NH3 emissions were reduced by 82%, N surplus was reduced by 9%, NUE was increased
by 19% and yield was around 98% that of the reference situation. This study shows that the
adoption of viable measures may provide an opportunity for countries like Spain to meet the
international agreements on NH3 mitigation, while maintaining crop yields and increasing NUEThe authors are grateful to the Spanish Ministry of Science and Innovation and the Autonomous Community of Madrid for their economic support through the NEREA project (AGL2012-37815- C05-01, AGL2012-37815-C05-04) and GASPORC (AGL2011-30023-C03) projects. We wish to thank the FIRE (Federation Ile de France de Recherche en Environment, CNRS and UPMC) as well as the Agrisost Project (S2009/AGR-1630). Eduardo Aguilera gratefully acknowledges funding by the 895-2011-1020 project (Canadian Social Sciences and Humanities Research Council). This paper has been produced within the context of the REMEDIA network (http://redremedia.wordpress.com).Sanz-Cobeña, A.; Lassaletta, L.; Estellés, F.; Del Prado, A.; Guardia Guardia, G.; Abalos, D.; Aguilera, E.... (2014). Yield-scaled mitigation of ammonia emission from N fertilization: the Spanish case. Environmental Research Letters. 9(12):1-12. https://doi.org/10.1088/1748-9326/9/12/125005S11291
Variações do carbono orgânico dissolvido e de atributos fÃsicos do solo sob diferentes sistemas de uso da terra na Amazônia central
Qualidade quÃmica do solo e dinâmica de carbono sob monocultivo e consórcio de macaúba e pastagem
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Evaluation of structural chemistry and isotopic signatures of refractory soil organic carbon fraction isolated by wet oxidation methods
Accurate quantification of different soil organic carbon (SOC) fractions is needed to understand their relative importance in the global C cycle. Among the chemical methods of SOC fractionation, oxidative degradation is considered more promising because of its ability to mimic the natural microbial oxidative processes in soil. This study focuses on detailed understanding of changes in structural chemistry and isotopic signatures of SOC upon different oxidative treatments for assessing the ability of these chemicals to selectively isolate a refractory fraction of SOC. Replicated sampling (to similar to 1 m depth) of pedons classified as Typic Fragiudalf was conducted under four land uses (woodlot, grassland, no-till and conventional-till continuous corn [Zea mays L.]) at Wooster, OH. Soil samples (< 2 mm) were treated with three oxidizing agents (hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), disodium peroxodisulfate (Na2S2O8) and sodium hypochlorite (NaOCl)). Oxidation resistant residues and the bulk soil from A1/Ap1 horizons of each land use were further analyzed by solid-state C-13 nuclear magnetic resonance (NMR) spectroscopy and accelerator mass spectrometry to determine structural chemistry and C-14 activity, respectively. Results indicated that, oxidation with NaOCl removed significantly less SOC compared to Na2S2O8 and H<sub>2</sub>O<sub>2</sub>. The NMR spectra revealed that NaOCl oxidation preferentially removed lignin-derived compounds at 56 ppm and at 110-160 ppm. On the other hand, the SOC resistant to Na2S2O8 and H<sub>2</sub>O<sub>2</sub> oxidation were enriched with alkyl C groups, which dominate in recalcitrant macromolecules. This finding was corroborated by the C-14 activity of residual material, which ranged from -542 to -259aEuro degrees for Na2S2O8 resistant SOC and -475 to -182aEuro degrees for H<sub>2</sub>O<sub>2</sub> resistant SOC as compared to relatively greater C-14 activity of NaOCl resistant residues (-47 to 61aEuro degrees). Additionally, H<sub>2</sub>O<sub>2</sub> treatment on soils after light fraction removal was more effective in isolating the oldest (C-14 activity of -725 to -469aEuro degrees) SOC fraction. The Delta C-14 signature of SOC removed by different oxidizing agents, calculated by mass balance, was more or less similar irrespective of the difference in labile SOC removal efficiency. This suggests that SOC isolated by many fractionation methods is still a mixture of much younger and older material and therefore it is very important that the labile SOC should be completely removed before measuring the turnover time of stable and refractory pools of SOC
Kaposi's sarcoma of the lung: a case report.
Pulmonary Kaposi's sarcoma is a rare condition. Its diagnosis may be
tricky due to its similarities in clinical and radiological features
with pulmonary opportunistic infections as well as other lung lesions.
Treatment for Kaposi's sarcoma include radiotherapy, chemotherapy
and/or immunotherapy whereby lung Kaposi's sarcoma respond well to
chemotherapy. An immunocompetent 68-year-old man was admitted with
clinical, radiological and bronchoscopic features of bronchogenic
carcinoma. However, the histological result revealed Kaposi's sarcoma
of the lung. The patient was treated with radiotherapy and recovered
well from his symptoms. Six months later the patient remain
asymptomatic with essentially a normal chest x-ray
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