9,515 research outputs found

    Interactions of a hairy vetch-corn rotation and P fertilizer on the NPK balance in an upland red soil of the Yunnan plateau

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    A field experiment was conducted on an infertile red soil under a hairy vetch (Vicia villosa Roth) and corn (Zea mays L.) rotation system in a highland area of Yunnan Province, China. Effects of phosphate (P) fertilization, combined with hairy vetch returned to the soil, on crop yield and soil fertility were studied, and the balances of nitrogen (N), phosphorus (P) and potassium (K) in the rotation system were estimated. As P application increased from 135 to 315 kg ha-1, the dry matter yield of hairy vetch increased by 900.6 to 1283.86 kg DM ha-1, and also promoted P absorption by hairy vetch. When compared with CK, the corn and corn straw yield increased by 16.64 and 33.48%, respectively, from the crop rotation system, while it increased by 18.36 and 34.96% and 32.58 and 66.5%, from the integrated use of green manure and P fertilizer, respectively. Simple crop rotation proceeding could improve soil N content in the 0 to 20 cm soil layer, while the combined P application improved soil P content. After corn harvest, soil Olsen-P content under the different treatments increased by 35.31 and 122.15% and 19.70 and 63.63% in the 0 to 10 and 10 to 20 cm soil layers, respectively. The optimum P fertilizer rate for the hairy vetch-corn rotation system in Yunnan Province was 135 kg P2O5 ha,sup>-1. At this P rate, the nutrient balance surpluses for N, P and K were 84.9, 18.9 and 26.4%, respectively.Keywords: Rotation system, crop yield, green manure, NPK balance, P fertilizer, soil physical and chemical properties

    Red blood cells (RBCs) visualisation in bifurcations and bends

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    Bifurcating networks are commonly found in nature. One example is the microvascular system, composed of blood vessels consecutively branching into daughter vessels, driving the blood into the capillaries, where the red blood cells (RBCs) are responsible for delivering O 2 and up taking cell waste and CO 2 . In this preliminary study, we explore a microfluidic bifurcating geometry inspired by such biological models, for investigating RBC partitioning as well as RBC-plasma separation favored by the consecutive bifurcating channels. A biomimetic design rule [1] based on Murray’s law [2] was used to set the channels’ dimensions along the network, which consists of consecutive bifurcating channels of reducing diameter. The ability to apply differential flow resistances by controlling the flow rates at the end of the network allowed us to monitor the formation of a cell-free layer (CFL) for different flow conditions at haematocrits of 1% and 5%. We have also compared the values of CFL thickness determined directly by the measurement on the projection image created from a stack of images or indirectly by analyzing the intensity profile in the same projection. The results obtained from this study confirm the potential to study RBC partitioning along bifurcating networks, which could be of particular interest for the separation of RBCs from plasma in point-of-care devices.JF would like to thank Professor Graça Minas and her coworkers for providing the laboratory facilities and technical help during the experiments.info:eu-repo/semantics/publishedVersio

    Global Regulation on microRNA in Hepatitis B Virus-Associated Hepatocellular Carcinoma

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    Recent work has revealed the causative links between deregulation of microRNAs (miRNAs) and cancer development. In hepatocellular carcinoma (HCC), aberrant expression of miRNAs has been observed, but the molecular mechanisms that contribute to such changes remains to be elucidated. Here, we reported the analysis of miRNA expression in 94 pairs of tumor and adjacent nontumor tissues from HBV-associated HCC in Chinese patients. We found miRNAs were aberrantly expressed in HCC tissues. To investigate the cause of such deregulation, we detected changes in DNA copy number by measuring locus-specific hybridization intensity, and found changes in expression of several miRNAs are correlated with genomic amplification or deletion. For example, the genomic regions of miR-30d and miR-151 were amplified in ∼50% of HCC tumor tissues, and the expressions of these miRNAs are significantly correlated with DNA copy number. We also employed cDNA microarray data, and provide evidence that key regulators of the miRNA biosynthetic pathway, including DROSHA, DGCR8, AGO1, and AGO2, are frequently overexpressed in HCC. This study provides molecular clues that may contribute to the global changes of miRNA expression in HCC. Copyright © 2011, Mary Ann Liebert, Inc.published_or_final_versio

    Does the weight of basketball shoes affect speed and jumping performance?

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    Purpose: The objective of this study was to analyze the effect of different weights of basketball shoes on speed and jumping performance in male basketball players. Material: 20 male basketball players in two groups, as eyes open (n:10) and eyes closed (n:10) participated in the study. The two groups performed vertical jump (VJ) and 10m sprint tests with three different weights of shoes (light, 352g; medium, 510g; heavy, 637g). The data were analyzed with Friedman repeated measurements variance analysis. Results: In Vertical Jump test, jumping performance of the eyes open group (EOG) with light shoes was found to be statistically higher as 1.8% and 2.1%, respectively when compared with medium and heavy shoes (p0.005). In 10 meter (m) sprint test, 10 m sprint time of the eyes open group was found to be statistically better as 0.5% and 1.6%, respectively when compared with medium and heavy shoe performance (p<0.001). Medium weight shoe was found to be 1.2% statistically better than heavy shoes (p<0.001). In eyes closed group, light shoes affected 10m sprint performance statistically better with 1% when compared with heavy shoes (p<0.001). Conclusions: Wearing light shoes in basketball has 2.1% and 1.6% positive effect on jumping and sprint performance, respectively. It can increase basketball players' performance. Choosing light shoes will help provide both psychological and physical advantages

    Modeling Changes in Cellular Micro-Environment in Mild to Moderate Head Trauma

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    Our work aims to connect and model multiple small, inter-related tissue injuries as a consequence of mild traumatic brain injuries (mTBI). It has been shown that frontal and temporal lobes are vulnerable regions for brain traumatic injury. A brain injury from a blow or high-speed impact can cause undersurface of the frontal and temporal lobes to deform against the anterior and cranial fossae. This deformation can often trigger damage to the cerebral vasculature, which is ill-understood and can result in chronic damage to larger vessels over time. These physiological injuries can be manifested psychologically; such as patients’ sleep-wake disturbances. The connection between mTBI and the cause of sleep-issues is found to be associated with vascular epithelial injuries to the pineal gland that lies directly at the anterior to the tentorial ridge. In this research, we are modeling brain trauma with two injuries tissue gliding between temporal, frontal and parietal lobes. The frontal lobe may explain the psychological problem and parietal may explain the large venous injury, while the midbrain including pineal and hypothalamus injury may explain sleep issues. Although white matter connectivity is disturbed, the literature is not enough for us to include that within our cell injury model. Learning from these devastating symptoms of mTBI, it is critical to push for more scientific researches to understand the mTBI and offer psychosocial as well as neurobiological interventions

    Hydrogen is neuroprotective against surgically induced brain injury

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    <p>Abstract</p> <p>Background</p> <p>Neurosurgical operations cause unavoidable damage to healthy brain tissues. Direct surgical injury as well as surgically induced oxidative stress contributes to the subsequent formation of brain edema. Therefore, we tested the neuroprotective effects of hydrogen (H<sub>2</sub>) in an established surgical brain injury (SBI) model in rats.</p> <p>Materials and methods</p> <p>Adult male Sprague - Dawley rats (weight 300-350g) were divided into three groups to serve as sham operated, SBI without treatment, and SBI treated with H<sub>2 </sub>(2.9%). Brain water content, myeloperoxidase (MPO) assay, lipid peroxidation (LPO), and neurological function were measured at 24 hrs after SBI.</p> <p>Results</p> <p>SBI resulted in localized brain edema (p = < 0.001). Hydrogen (2.9%) administered concurrently with surgery significantly decreased the formation of cerebral edema (p = 0.028) and improved neurobehavioral score (p = 0.022). However, hydrogen treatment failed to reduce oxidative stress (LPO assay) or inflammation (MPO assay) in brain tissues.</p> <p>Conclusions</p> <p>Hydrogen appears to be promising as an effective, yet inexpensive way to reduce cerebral edema caused by surgical procedures. Hydrogen has the potential to improve clinical outcome, decrease hospital stay, and reduce overall cost to patients and the health care system.</p

    Spectral anisotropy of Elsässer variables in two-dimensional wave-vector space as observed in the fast solar wind turbulence

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    Intensive studies have been conducted to understand the anisotropy of solar wind turbulence. However, the anisotropy of Elsässer variables Z± in 2D wave-vector space has yet to be investigated. Here we first verify the transformation based on the projection-slice theorem between the power spectral density PSD2D(k∥,k⊥) and the spatial correlation function CF2D(r∥,r⊥) Based on the application of the transformation to the magnetic field and the particle measurements from the WIND spacecraft, we investigate the spectral anisotropy of Elsässer variables (Z±), and the distribution of residual energy ER, Alfvén ratio R∧, and Elsässer ratio RE in the (k∥,k⊥) space. The spectra PSD2D(k∥,k⊥) of B, V, and Zmajor (the larger of Z±) show a similar pattern that PSD2D(k∥,k⊥) is mainly distributed along a ridge inclined toward the k⊥ axis. This is probably the signature of the oblique Alfvénic fluctuations propagating outwardly. Unlike those of B, V, and Zmajorm the spectrum PSD2D(k∥,k⊥) of Zminor is distributed mainly along the k⊥ axis. Close to the k⊥ axis, |ER| becomes larger while R∧ becomes smaller, suggesting that the dominance of magnetic energy over kinetic energy becomes more significant at small k∥. RE is larger at small k∥, implying that PSD2D(k∥,k⊥) of Zminor is more concentrated along the k⊥ direction as compared to that of Z major. The residual energy condensate at small k∥ is consistent with simulation results in which ER is spontaneously generated by Alfvén wave interaction

    Cross-linguistic Sharing of Morphological Awareness in Biliteracy Development: A Systematic Review and Meta-analysis of Correlation Coefficients

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    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordThis study examined the cross-linguistic sharing of morphological awareness (MA) in biliteracy development. The analysis included 34 correlational studies with 40 independent samples (N = 4,056). Correlational coefficients were meta-analyzed, yielding four main findings: (1) the correlation between first language (L1) and second language (L2) MA was small (r = 0.30). (2) The interlingual correlations between L1 MA and L2 word decoding and between L1 MA and L2 reading comprehension were both small (respective r = 0.35, 0.39). (3) The intralingual correlations between L2 MA and L2 word decoding and between L2 MA and L2 reading comprehension were both moderate (r = 0.45, 0.52). (4) MA measurement type and age were significant moderators. Our review suggested that there is a need for future research to align the definition and measurement of MA as a multifaceted construct, and pay equal attention to its contributions to both word decoding and reading comprehension

    ABCD transfer matrix model of Gaussian beam propagation in Fabry-Perot etalons

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    A numerical model of Gaussian beam propagation in planar Fabry-Perot (FP) etalons is presented. The model is based on the ABCD transfer matrix method. This method is easy to use and interpret, and readily connects models of lenses, mirrors, fibres and other optics to aid simulating complex multi-component etalon systems. To validate the etalon model, its predictions were verified using a previously validated model based on Fourier optics. To demonstrate its utility, three different etalon systems were simulated. The results suggest the model is valid and versatile and could aid in designing and understanding a range of systems containing planar FP etalons. The method could be extended to model higher order beams, other FP type devices such as plano-concave resonators, and more complex etalon systems such as those involving tilted components

    Microscopic Polarization in Bilayer Graphene

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    Bilayer graphene has drawn significant attention due to the opening of a band gap in its low energy electronic spectrum, which offers a promising route to electronic applications. The gap can be either tunable through an external electric field or spontaneously formed through an interaction-induced symmetry breaking. Our scanning tunneling measurements reveal the microscopic nature of the bilayer gap to be very different from what is observed in previous macroscopic measurements or expected from current theoretical models. The potential difference between the layers, which is proportional to charge imbalance and determines the gap value, shows strong dependence on the disorder potential, varying spatially in both magnitude and sign on a microscopic level. Furthermore, the gap does not vanish at small charge densities. Additional interaction-induced effects are observed in a magnetic field with the opening of a subgap when the zero orbital Landau level is placed at the Fermi energy
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