112 research outputs found

    Reciprocal Effects Among Parental Homework Support, Effort, and Achievement? An Empirical Investigation

    Get PDF
    The present study investigates reciprocal influences of parental homework support, effort, and math achievement, using two waves of data from 336 9th-graders. Results revealed that higher prior autonomy-oriented support and homework effort resulted in higher subsequent achievement. Higher prior content-oriented support led to higher subsequent effort, but lower subsequent achievement. Additionally, higher prior effort led to higher subsequent autonomy-oriented support. Furthermore, our results supported the structural path invariance over gender. The current investigation advances extant research, by differentiating two forms of parental homework support (autonomy- and content-oriented support), and by showing their respective influences on subsequent homework effort and math achievement

    Characterization of the Autocrine/Paracrine Function of Vitamin D in Human Gingival Fibroblasts and Periodontal Ligament Cells

    Get PDF
    Background: We previously demonstrated that 25-hydroxyvitamin D-3, the precursor of 1 alpha,25-dihydroxyvitamin D-3, is abundant around periodontal soft tissues. Here we investigate whether 25-hydroxyvitamin D-3 is converted to 1 alpha,25-dihydroxyvitamin D-3 in periodontal soft tissue cells and explore the possibility of an autocrine/paracrine function of 1 alpha,25-dihydroxyvitamin D-3 in periodontal soft tissue cells. Methodology/Principal Findings: We established primary cultures of human gingival fibroblasts and human periodontal ligament cells from 5 individual donors. We demonstrated that 1 alpha-hydroxylase was expressed in human gingival fibroblasts and periodontal ligament cells, as was cubilin. After incubation with the 1 alpha-hydroxylase substrate 25-hydroxyvitamin D-3, human gingival fibroblasts and periodontal ligament cells generated detectable 1 alpha,25-dihydroxyvitamin D-3 that resulted in an up-regulation of CYP24A1 and RANKL mRNA. A specific knockdown of 1 alpha-hydroxylase in human gingival fibroblasts and periodontal ligament cells using siRNA resulted in a significant reduction in both 1 alpha, 25-dihydroxyvitamin D-3 production and mRNA expression of CYP24A1 and RANKL. The classical renal regulators of 1 alpha-hydroxylase (parathyroid hormone, calcium and 1 alpha,25-dihydroxyvitamin D-3) and Porphyromonas gingivalis lipopolysaccharide did not influence 1 alpha-hydroxylase expression significantly, however, interleukin-1 beta and sodium butyrate strongly induced 1 alpha-hydroxylase expression in human gingival fibroblasts and periodontal ligament cells. Conclusions/Significance: In this study, the expression, activity and functionality of 1 alpha-hydroxylase were detected in human gingival fibroblasts and periodontal ligament cells, raising the possibility that vitamin D acts in an autocrine/paracrine manner in these cells.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000305781700070&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Multidisciplinary SciencesSCI(E)PubMed13ARTICLE6e39878

    Student perceptions of homework quality, autonomy support, effort, and math achievement: Testing models of reciprocal effects

    No full text
    This study tests reciprocal influences of perceived homework quality, teacher autonomy support, homework effort, and achievement. Data from 702 8th graders over one school year showed positive reciprocal effects between (a) homework quality and autonomy support, and (b) effort and achievement. Higher prior effort and achievement led to higher homework quality. Autonomy support showed a more positive effect on later achievement when prior effort was high. Meanwhile, autonomy support showed a more positive effect on later effort and homework quality when prior effort was low. These findings hold important implications for teaching practice (i.e. autonomy support to compensate low effort)

    Evaluation of the RF-Based Downscaled SMAP and SMOS Products Using Multi-Source Data over an Alpine Mountains Basin, Northwest China

    No full text
    Passive microwave surface soil moisture (SSM) products tend to have very low resolution, which massively limits their application and validation in regional or local-scale areas. Many climate and hydrological studies are urgently needed to evaluate the suitability of satellite SSM products, especially in alpine mountain areas where soil moisture plays a key role in terrestrial atmospheric exchanges. Aiming to overcome this limitation, a downscaling method based on random forest (RF) was proposed to disaggregate satellite SSM products. We compared the ability of the downscaled soil moisture active passive (SMAP) SSM and soil moisture and ocean salinity satellite (SMOS) SSM products to capture soil moisture information in upstream of the Heihe River Basin by using in situ measurements, the triple collocation (TC) method and temperature vegetation dryness index (TVDI). The results showed that the RF downscaling method has strong applicability in the study area, and the downscaled results of the two products after residual correction have more details, which can better represent the spatial distribution of soil moisture. The validation with the in situ SSM measurements indicates that the correlation between downscaled SMAP and in situ SSM is better than downscaled SMOS at both point and watershed scales in the Babaohe River Basin. From the TC method, the root mean square error (RMSE) of the CLDAS (CMA land data assimilation system), downscaled SMAP and downscaled SMOS were 0.0265, 0.0255 and 0.0317, respectively, indicating that the downscaled SMAP has smaller errors in the study area than others. However, the soil moisture distribution in the study area shown by the SMOS downscaled results is closer than the downscaled SMAP to the degree of drought reflected by TVDI. Overall, this study suggests that the proposed RF-based downscaling method can capture the variation of SSM well, and the downscaled SMAP products perform significantly better than the downscaled SMOS products after the accuracy verification and error analysis of the downscaled results, and it should be helpful to facilitate applications for satellite SSM products at small scales

    Phase-Shifted Eccentric Core Fiber Bragg Grating Fabricated by Electric Arc Discharge for Directional Bending Measurement

    No full text
    A phase-shifted eccentric core fiber Bragg grating (PS-ECFBG) fabricated by electric arc discharge (EAD) is presented and demonstrated. It is composed of a fraction of eccentric core fiber fusion spliced in between two pieces of commercial single mode fibers, where a PS-FBG was written. The EAD in this work could flexibly change the amount of phase-shift by changing the discharge number or discharge duration. Because of the offset location of the eccentric core and the ultra-narrow resonant peak of the PS-ECFBG, it has a higher accuracy for measuring the directional bend. The elongation and compression of the eccentric core keep the magnitude of phase shift still unchanged during the bending process. The bending sensitivities of the PS-ECFBG at two opposite most sensitive directions are 57.4 pm/m−1 and −51.5 pm/m−1, respectively. Besides, the PS-ECFBG has the potential to be a tunable narrow bandpass filter, which has a wider bi-directional adjustable range because of the bending responses. The strain and temperature sensitivities of the PS-ECFBG are experimentally measured as well, which are 0.70 pm/με and 8.85 pm/°C, respectively

    Development, structure and evolutionary significance of seed appendages in Salix matsudana (Salicaceae).

    No full text
    The seeds of Salix and Populus (Salicaceae) are characterized by having numerous long hairs which loosely accompanying the seeds and a small annular appendage which surrounding the base of the seed along with tufted hairs. In this study, the complete development and detailed structure of the hairs and annular appendage in Salix matsudana were investigated using standard techniques for plant anatomy and histochemistry. The results show that the hairs originate successively from the single epidermal cells of the placenta (in megaspore mother cell phase) and funiculus (in eight-nucleate phase), and that their development consists of a progressive increase in cell size and an absence of cell division. The annular appendage is initiated from four to five rows of cells at the distal end of the funiculus in octant proembryo phase and its development is characterized by reactivated meristematic activity and a size increase of these cells. The initiation and development of the hairs are irrelevant to ovule development but fertilization and a developed embryo is necessary for the annular appendage to occur. Considering the reliable fossils, we inferred that the feature of seeds surrounded by long hairs is an ancestral character, and that the detachment of hairs from the funiculus and the occurrence of an annular appendage with tufts of hairs may be the more derived states for seed dispersal in Salix and Populus

    VICO: A Framework for Configuring Indoor Visible Light Communication Networks

    No full text
    Abstract—Visible light communications (VLC) are gaining popularity and may provide an alternative means of communications in indoor settings. However, to date, there is very little research on the deployment or higher layer protocol design for VLC. In this paper, we first perform channel measurements using a physical layer testbed in the visible light band to understand its physical layer characteristics. Our measurements suggest that in order to increase data rates with VLC (1) the beam width of a communicating link can be shrunk, and (2) the transmission beam can be tuned to point towards the target recipient. We then perform Matlab simulations to verify that the human eye is able to accommodate the changes brought by shrinking a beam or by tuning the beam direction appropriately. As our main contribution, we then design a configuration framework for a VLC indoor local area network, which we call VICO; we leverage the above features towards achieving the highest throughput while maintaining fairness. VICO first tunes the beamwidths and pointing angles of the transmitters to configurations that provide the highest throughput for each client. It then tries to schedule transmissions while accounting for conflicts and the VLC PHY characteristics. Finally, it opportunistically tunes the idle LEDs to reinforce existing transmissions to increase throughput to the extent possible. We perform extensive simulations to demonstrate the effectiveness of VICO. We find that VICO provides as much as 5-fold increase in throughput compared to a simple scheduler that does not exploit the possible variations in beamwidth or beam-angle. Index Terms—Visible light communication, wireless indoor communication, LED. I

    Systematic Review and Meta-Analysis of Randomized Controlled Trials of Xingnaojing Treatment for Stroke

    No full text
    Objective. Xingnaojing injection (XNJ) is a well-known traditional Chinese patent medicine (TCPM) for stroke. The aim of this study is to assess the efficacy of XNJ for stroke including ischemic stroke, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH). Methods. An extensive search was performed within using eight databases up to November 2013. Randomized controlled trials (RCTs) on XNJ for treatment of stroke were collected. Study selection, data extraction, quality assessment, and meta-analysis were conducted according to the Cochrane standards, and RevMan5.0 was used for meta-analysis. Results. This review included 13 RCTs and a total of 1,514 subjects. The overall methodological quality was poor. The meta-analysis showed that XNJ combined with conventional treatment was more effective for total efficacy, neurological deficit improvement, and reduction of TNF-α levels compared with those of conventional treatment alone. Three trials reported adverse events, of these one trial reported mild impairment of kidney and liver function, whereas the other two studies failed to report specific adverse events. Conclusion. Despite the limitations of this review, we suggest that XNJ in combination with conventional medicines might be beneficial for the treatment of stroke. Currently there are various methodological problems in the studies. Therefore, high-quality, large-scale RCTs are urgently needed
    corecore