617 research outputs found
EFFECT OF POSITIVE RUMINATION-BASED SPORTS PRESCRIPTION ON THE MENTAL HEALTH OF TEENAGERS
Background: Under the pressure of study, relationship, socializing, employment and other aspects, there is an increasing
number of teenagers with psychological problems such as pessimism, anxiety, and depression, seriously affecting their physical and
mental health and comprehensive development. Therefore, it is of vital importance to attach great importance and actively seek
intervention methods to effectively improve their mental health. The aim was to investigate the intervention effect of positive
rumination-based sports prescription on the mental health of teenagers.
Subjects and methods: 497 teenagers living in four communities randomly selected in Guangxi, China community from
February 2021 to August 2021 were included in this study using convenience sampling method. Firstly, Beck Depression Inventory
was adopted for measurement, and 61 volunteers were randomly selected from a population of depressive symptoms to participate in
intervention. There were 29 people the Experimental group, 32 in the control group. The intervention using positive ruminationbased
sports prescription was performed on the Experimental group.
Results: After intervention, the depression score of the control group and the Experimental group was lower than that before
intervention (P<0.001). After intervention, the anxiety score of Experimental group was significantly lower than that of the control
group (P<0.001). There was no significant difference in the scores regarding optimism, hope, self-efficacy, resiliency and
psychological capital (P>0.05), and the scores of the Experimental group regarding optimism, hope, self-efficacy, resiliency and
psychological capital were increased after the intervention, significantly higher than before intervention (P<0.001), and there was
no significant difference in the score of resiliency before and after intervention (P>0.05).
Conclusion: Positive rumination group counseling and the intervention of health Qigong exercise can effectively reduce anxiety
levels of teenagers, improve the levels of optimism, hope, self-efficacy, resiliency and psychological capital, help cultivate teenagers’
positive psychology and alleviate negative psychology
Detection of bottom ferromagnetic electrode oxidation in magnetic tunnel junctions by magnetometry measurements
Surface oxidation of the bottom ferromagnetic (FM) electrode, one of the
major detrimental factors to the performance of a Magnetic Tunnel Junction
(MTJ), is difficult to avoid during the fabrication process of the MTJ's tunnel
barrier. Since Co rich alloys are commonly used for the FM electrodes in MTJs,
over-oxidation of the tunnel barrier results in the formation of a CoO
antiferromagnetic (AF) interface layer which couples with the bottom FM
electrode to form a typical AF/FM exchange bias (EB) system. In this work,
surface oxidation of the CoFe and CoFeB bottom electrodes was detected via
magnetometry measurements of exchange-bias characterizations including the EB
field, training effect, uncompensated spin density, and coercivity. Variations
of these parameters were found to be related to the surface oxidation of the
bottom electrode, among them the change of coercivity is most sensitive.
Annealed samples show evidence for an oxygen migration back to the MgO tunnel
barrier by annealing.Comment: 5 pages, 4 figues, submitted to J. Appl. Phy
High performance implementation of 3D FEM for nonlocal Poisson problem with different ball approximation strategies
Nonlocality brings many challenges to the implementation of finite element
methods (FEM) for nonlocal problems, such as large number of queries and invoke
operations on the meshes. Besides, the interactions are usually limited to
Euclidean balls, so direct numerical integrals often introduce numerical
errors. The issues of interactions between the ball and finite elements have to
be carefully dealt with, such as using ball approximation strategies. In this
paper, an efficient representation and construction methods for approximate
balls are presented based on combinatorial map, and an efficient parallel
algorithm is also designed for assembly of nonlocal linear systems.
Specifically, a new ball approximation method based on Monte Carlo integrals,
i.e., the fullcaps method, is also proposed to compute numerical integrals over
the intersection region of an element with the ball
Advertising strategy for profit-maximization: a novel practice on Tmall's online ads manager platforms
Ads manager platform gains popularity among numerous e-commercial
vendors/advertisers. It helps advertisers to facilitate the process of
displaying their ads to target customers. One of the main challenges faced by
advertisers, especially small and medium-sized enterprises, is to configure
their advertising strategy properly. An ineffective advertising strategy will
bring too many ``just looking'' clicks and, eventually, generate high
advertising expenditure unproportionally to the growth of sales. In this paper,
we present a novel profit-maximization model for online advertising
optimization. The optimization problem is constructed to find optimal set of
features to maximize the probability that target customers buy advertising
products. We further reformulate the optimization problem to a knapsack problem
with changeable parameters, and introduce a self-adjusted algorithm for finding
the solution to the problem. Numerical experiment based on statistical data
from Tmall show that our proposed method can optimize the advertising strategy
given expenditure budget effectively.Comment: Online advertising campaign
Research to Break Oil Shale with High Pressure Water Jet Based on Bionic Nozzle
AbstractOil shale is a sedimentary rock, it is increasingly attracting widespread attention as petroleum supplement energy. Using borehole hydraulic mining techniques to mine oil shale seams at a certain depth in the underground, first and foremost is the use of high pressure water jet to make the overall oil shale ore broken into small pieces and peel them off parent rock. Based on the bionic theories, to design the bionic nozzles are adding several bionic units in the internal flow channel surface of the nozzle, it makes the original smooth flow channel inside the nozzle has become bionic non-smooth surface structure, to some extent, effectively improved the hydraulic characteristics of the nozzle internal flow channel, and reduced the flow resistance of the water. Based on CFD simulation and analysis, the reasons for upgrading effect of the crushed oil shale by the bionic nozzle high pressure water jet are analyzed. Experiments show that, in the same working conditions, bionic nozzle compared with the normal nozzle of the same structure parameters, the diameter of the erosion and crushing pit on oil shale samples expanded 4mm, and the crushing pit depth deepened 3.8mm using bionic nozzle
Optimization of Pinocembrin Biosynthesis in Saccharomyces cerevisiae
The flavonoid pinocembrin and its derivatives have gained increasing interest for their benefits on human health. While pinocembrin and its derivatives can be produced in engineered Saccharomyces cerevisiae, yields remain low. Here, we describe novel strategies for improved de novo biosynthesis of pinocembrin from glucose based on overcoming existing limitations in S. cerevisiae. First, we identified cinnamic acid as an inhibitor of pinocembrin synthesis. Second, by screening for more efficient enzymes and optimizing the expression of downstream genes, we reduced cinnamic acid accumulation. Third, we addressed other limiting factors by boosting the availability of the precursor malonyl-CoA, while eliminating the undesired byproduct 2′,4′,6′-trihydroxy dihydrochalcone. After optimizing cultivation conditions, 80 mg/L pinocembrin was obtained in a shake flask, the highest yield reported for S. cerevisiae. Finally, we demonstrated that pinocembrin-producing strains could be further engineered to generate 25 mg/L chrysin, another interesting flavone. The strains generated in this study will facilitate the production of flavonoids through the pinocembrin biosynthetic pathway
TCP over geo-routing for high mobility: vehicle grids and airborne swarms
Ad hoc wireless networks have become the architecture of choice for peer to peer communications in areas where the telecommunications infrastructure is inadequate or has failed. A major challenge is the reliable delivery of data when nodes move. The reliable Internet protocol is TCP. However, TCP performs poorly in mobile ad hoc networks, mainly because of route breakage. To overcome this problem, a robust routing protocol must be used. To this effect, Geo-routing has recently received attention in large scale, mobile systems as it does not require end- to-end path establishment and pre-computed packet forwarding routing structure at nodes. These properties make Geo-routing robust to highly dynamic route changes.
For best performance, however, several parameters must be carefully tuned.
In this paper we study the joint optimization of TCP and Geo-routing parame- ters to handle high speeds. We first introduce two highly mobile ad hoc scenarios that require reliable delivery, namely the vehicle urban grid and the airborne swarms.
Then, we study the impact of critical system parameters (e.g., hello message ex- change rate, delay timer in TCP for out-of-order delivery, etc) on the performance of both UDP and TCP. We improve hello message effciency in Geo-routing by using an adaptive hello exchange scheme. Then, we fix the out-of-order problem in TCP by using a receiver-side out-of-order detection and delayed ack strategy. We show that these parameter adjustments are critical for effcient TCP over Geo-routing in highly mobile applications. With these enhancements our TCP with Geo-routing solution easily outperforms TCP over traditional ad hoc routing schemes, such as AODV.1st IFIP International Conference on Ad-Hoc NetWorkingRed de Universidades con Carreras en Informática (RedUNCI
The Effect of Isostatic Pressing on the Dielectric Properties of Screen Printed Ba\u3csub\u3e0.5\u3c/sub\u3eSr\u3csub\u3e0.5\u3c/sub\u3eTiO\u3csub\u3e3\u3c/sub\u3e Thick Films
Ba0.5Sr0.5TiO3 thick films with B2O3–Li2O glass sintering aid were prepared by the screen printing method on Al2O3 substrates. A 200 MPa isostatic pressure was applied to the films before sintering. After being sintered at 950∘C, lower porosity and denser microstructure was obtained compared with the films without isostatic pressing. The dielectric constant and dielectric loss were 238 and 0.0028, respectively. A tunability of 61.7% was obtained for the isostatic pressed films, a 27.8% enhancement compared to unpressurized films. These results suggest that isostatic pressing is an effective way to prepare dielectric thick films with dense microstructure, low dielectric loss, and high tunability
Yeast optimizes metal utilization based on metabolic network and enzyme kinetics
Metal ions are vital to metabolism, as they can act as cofactors on enzymes and thus modulate individual enzymatic reactions. Although many enzymes have been reported to interact with metal ions, the quantitative relationships between metal ions and metabolism are lacking. Here, we reconstructed a genome-scale metabolic model of the yeast Saccharomyces cerevisiae to account for proteome constraints and enzyme cofactors such as metal ions, named CofactorYeast. The model is able to estimate abundances of metal ions binding on enzymes in cells under various conditions, which are comparable to measured metal ion contents in biomass. In addition, the model predicts distinct metabolic flux distributions in response to reduced levels of various metal ions in the medium. Specifically, the model reproduces changes upon iron deficiency in metabolic and gene expression levels, which could be interpreted by optimization principles (i.e., yeast optimizes iron utilization based on metabolic network and enzyme kinetics rather than preferentially targeting iron to specific enzymes or pathways). At last, we show the potential of using the model for understanding cell factories that harbor heterologous iron-containing enzymes to synthesize high-value compounds such as p-coumaric acid. Overall, the model demonstrates the dependence of enzymes on metal ions and links metal ions to metabolism on a genome scale
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