42 research outputs found
The Accumulation of Organic Carbon in Mineral Soils by Afforestation of Abandoned Farmland
The afforestation of abandoned farmland significantly influences soil organic carbon (OC). However, the dynamics between OC inputs after afforestation and the original OC are not well understood. To learn more about soil OC dynamics after afforestation of farmland, we measured the soil OC content in paired forest and farmland plots in Shaanxi Province, China. The forest plots had been established on farmland 18, 24, 48, 100, and 200 yr previously. The natural 13C abundance of soil organic matter was also analyzed to distinguish between crop- and forest-derived C in the afforested soils. We observed a nonlinear accumulation of total OC in the 0–80 cm depth of the mineral soil across time. Total soil OC accumulated more rapidly under forest stands aged 18 to 48 yr than under forest stands aged 100 or 200 yrs. The rate of OC accumulation was also greater in the 0–10 cm depth than in the 10–80 cm depth. Forest-derived OC in afforested soils also accumulated nonlinearly across time, with the greatest increase in the 0–20 cm depth. Forest-derived OC in afforest soils accounted for 52–86% of the total OC in the 0–10 cm depth, 36–61% of the total OC in the 10–20 cm depth, and 11–50% of the total OC in the 20–80 cm depth. Crop-derived OC concentrations in the 0–20 cm depth decreased slightly after afforestation, but there was no change in crop-derived OC concentrations in the 20–80 cm depth. The results of our study support the claim that afforestation of farmland can sequester atmospheric CO2 by increasing soil OC stocks. Changes in the OC stocks of mineral soils after afforestation appear to be influenced mainly by the input of forest-derived C rather than by the loss of original OC
Dramatic pain relief and resolution of bone inflammation following pamidronate in 9 pediatric patients with persistent chronic recurrent multifocal osteomyelitis (CRMO)
<p>Abstract</p> <p>Background</p> <p>Chronic recurrent multifocal osteomyelitis (CRMO) is an inflammatory, non-infectious osteopathy that affects predominantly patients ≤ 18 years of age. There is no uniformly effective treatment. Our objective is to describe clinical, magnetic resonance imaging (MRI), and bone resorption response to intravenous pamidronate in pediatric CRMO.</p> <p>Methods</p> <p>We report our prospectively documented experience with all CRMO patients treated with pamidronate between 2003 and 2008 at a tertiary pediatric centre. Pamidronate was administered as intravenous cycles. The dose of pamidronate varied among subjects but was given as monthly to every 3 monthly cycles depending on the distance the patient lived from the infusion center. Maximum cumulative dose was ≤ 11.5 mg/kg/year. Pamidronate treatment was continued until resolution of MRI documented bone inflammation. Visual analog scale for pain (VAS) and bone resorption marker urine N-telopeptide/urine creatinine (uNTX/uCr) were measured at baseline, preceding each subsequent pamidronate treatment, at final follow-up, and/or at time of MRI confirmed CRMO flare. MRI of the affected site(s) was obtained at baseline, preceding every 2<sup>nd </sup>treatment, and with suspected CRMO recurrence.</p> <p>Results</p> <p>Nine patients (5 F: 4 M) were treated, with a median (range) age at treatment of 12.9 (4.5–16.3) years, and median (range) duration of symptoms of 18 (6–36) months. VAS decreased from 10/10 to 0–3/10 by the end of first 3–day treatment for all patients. The mean (range) time to complete MRI resolution of bone inflammation was 6.0 (2–12) months. The mean (confidence interval (CI)) baseline uNTX/uCr was 738.83 (CI 464.25, 1013.42)nmol/mmol/creatinine and the mean (CI) decrease from baseline to pamidronate discontinuation was 522.17 (CI 299.77, 744.56)nmol/mmol/creatinine. Median (range) of follow-up was 31.4 (24–54) months. Four patients had MRI confirmed CRMO recurrence, which responded to one pamidronate re-treatment. The mean (range) uNTX/uCr change as a monthly rate from the time of pamidronate discontinuation to flare was 9.41 (1.38–19.85)nmol/mmol/creatinine compared to -29.88 (-96.83–2.01)nmol/mmol/creatinine for patients who did not flare by the time of final follow-up.</p> <p>Conclusion</p> <p>Pamidronate resulted in resolution of pain and MRI documented inflammation in all patients. No patient flared while his/her uNTX/uCr remained suppressed. We propose that pamidronate is an effective second-line therapy in persistent CRMO.</p
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Transport of selenium and its modeling through one dimensional saturated soil columns
The selenium, an essential nutrient and potentially toxic element to human and animal health, is widely used in agriculture and medicine. Soil is the transitional zone through which selenium entered into groundwater. Therefore, the transport of selenium through porous soil is of great environment concern, which is not well understood. The transport of selenite in loessial soil columns was studied using a miscible displacement technique under various flow rates and influent concentrations in this paper. A mathematical model based on one-dimensional convection-dispersion equation was formulated to describe the selenium transport. The breakthrough curves with and without tracers were fitted by using the computer program "studio of analytical models". The results showed that the method without tracer was more accurate than the method with the tracer. Studio of analytical models is a very flexible tool for approximate analysis of one dimensional solute transport problems in soil. The method of parameter estimation using convection-dispersion equation accurately defined the dispersion coefficient and retardation factor from the breakthrough curves and modeled selenite transport through soil. These results suggest that deterministic equilibrium convection-dispersion equation can accurately simulate the breakthrough curves of Se transport in saturated soil and the selection of tracer ions should be cautious when studying the transport of different chemicals
Correction: Ecosystem Carbon and Nitrogen Accumulation after Grazing Exclusion in Semiarid Grassland
I-Cell Disease (Mucolipidosis II) Presenting as Neonatal Fractures: A Case for Continued Monitoring of Serum Parathyroid Hormone Levels
A BROADBAND OUT-OF-PHASE POWER DIVIDER FOR HIGH POWER APPLICATIONS USING THROUGH GROUND VIA (TGV)
Strong flexible polymer/graphene composite films with 3D saw-tooth folding for enhanced and tunable electromagnetic shielding
Strong flexible polymer/graphene composite films with ideal electromagnetic interference (EMI) shielding are fabricated through constructing a sandwich structure consisting of polyester non-woven fabric as reinforcing interlayer and thermoplastic polyurethane (TPU) composite with high graphene loading as conductive coating layer. The engineered sandwich film (defined as TPU/G film) with graphene ;loading of similar to 20 wt% and total coating thickness of similar to 50 mu m not only possesses excellent mechanical flexibility and strong strength, but also exhibits qualified bandwidth of shielding effectiveness (SE) >= 20 dB as wide as similar to 49.1 GHz in a broadband frequency range of 5.4-59.6 GHz. Moreover, saw-tooth folding of the flexible TPU/G films could efficiently enhance the shielding performance, and more conductive folded film with smaller included angle plus longer side would result in much greater SE enhancement along with reduced EM reflection. This finding also realizes the convenient performance regulation of the folded TPU/G films through a simple mechanical deformation, showing promise for tunable EMI shielding. (C) 2016 Elsevier Ltd. All rights reserved
Specific-scale correlations between soil water content and relevant climate forcing factors across two climate zones
Soil water content (SWC) is determined through water exchanges between surface soil and the atmosphere, and changes in SWC will influence both energy conversions and water cycles. Being affected by different climate forcing factors (forcings), SWC is spatially and temporally variable, occurring at various intensities and scales. We compared scale-specific controls on SWC in a sub-humid and a semiarid climate zone based on a multivariate empirical mode decomposition (MEMD) method in conjunction with a multivariate dataset, including SWC (collected separately seven times within five soil layers to a depth of 500 cm) and eight measured climate forcing factors (i.e., precipitation, temperature, normalized differential vegetation index (NDVI), elevation, clay, silt, sand and soil organic carbon (SOC)). We also identified the percent variance of intrinsic mode functions (IMFs) and residuals relative to the original data. Two to three IMFs of SWC were further obtained in the two climate zones. IMFs explained the percent variance of SWC (79.3%), NDVI (77.3%), clay content (76.6%) and SOC (93.9%) to the original data in the sub-humid climate zone, while residuals from all environmental variables (except for SOC) yielded most of the total variance (55.5-93.2%) in the semiarid climate zone. Correlations between the two climate zones exhibited different IMF characteristics (scales) and different climatic conditions. Forcings of the two climate zones also played different roles in controlling SWC. Precipitation and temperature controlled large-scale SWC in both climate zones, namely, NDVI had an inverse effect on SWC between the two climate zones, SOC had a moderate and large-scale effect on SWC in the sub-humid climate zone and clay content had a comparatively critical effect on SWC in the semiarid climate zone. Scale-specific controls of soil properties on SWC were depth dependent in the sub-humid climate zone, while similar characteristics were obtained among the five soil layers in the semiarid climate zone. The specific scale dependence of SWC and relevant forcings were similar regardless of soil water condition (dry or wet). Our results offer insight into relationships between SWC and the main forcings of two different regional climate zones and their scale-dependent controls