809 research outputs found
Hysteresis measurement of anomalous microwave surface resistance in superconducting thin films
The anomalous decrease in microwave surface resistance, R_{s}, of
superconducting YBa_{2}Cu_{3}O_{7-d} (YBCO) thin films in the presence of a low
dc magnetic field is studied using a microstrip resonator technique. We have
done a dc field hysteresis measurement of R_{s} to study the effects of vortex
penetration on the anomalous effect. It is shown that the anomaly happens at a
field level far below the low critical field, H_{c1,strip}, of the
superconducting microstrip and vortex (Abrikosov) penetration would eliminate
the anomalous effect observed at low field. This implies that the anomalous
effect is not contributed by vortices.Comment: 2 pages, 1 figure, submitted to Physica C for M2S-HTSC-VI Proceeding
Cultural Perspective on Parenting, Trait Emotional Intelligence and Mental Health in Taiwanese Children
The current study aims to clarify the associations as well as the pathways through which parenting and children's emotional intelligence (EI) may influence children's mental health with a cross-sectional sample of 675 school pupils (fourth grade, mean age = 10.4 years, 310 boy, 356 girls and 9 unidentified) in Taiwan. Hierarchical regression and path analyses were used to examine the relationships between parenting styles, children's trait EI, and their psychological symptoms, with children's psychological symptoms as the dependent variable. The results showed that authoritative parenting was positively associated with children‟s trait EI, which in turn had a negative effect on children‟s psychological symptoms, whereas authoritarian and Chinese-specific parenting styles had direct negative effect on children‟s psychological symptoms. These findings shed light on the pathways of the interrelations between different parenting styles, children's trait EI, and psychological symptoms, providing theoretical as well as practical implications for children's emotional development and mental health
Internet Addiction: A Closer Look at Multidimensional Parenting Practices and Child Mental Health
This study aimed to examine how both psychosocial variables (authoritative, authoritarian, and shaming, and parent-child relationships) and psychological symptoms were associated with Internet addiction, while controlling for the sociodemographic variable (child gender). A national proportionately stratified random sample of 6,233 fourth-grade primary school students in Taiwan participated in the study. Hierarchical regression models were performed to test the research hypotheses. The results show that psychological symptoms, authoritarian parenting, and shaming were positively associated with Internet addiction, whereas authoritative parenting and positive parent-child relationship were negatively associated with Internet addiction. Girls had lower levels of Internet addiction than boys. In conclusion, this study demonstrates the direct effects of child mental health status, multidimensional parenting practices, and family relationship on Internet addiction in children, and the importance of early individual- and family-based prevention and intervention in addressing related public health concerns of Internet addiction in children. The cultural perspectives of parenting and implications of these findings are discussed
Coincident brane nucleation and the neutralization of \Lambda
Nucleation of branes by a four-form field has recently been considered in
string motivated scenarios for the neutralization of the cosmological constant.
An interesting question in this context is whether the nucleation of stacks of
coincident branes is possible, and if so, at what rate does it proceed. Feng et
al. have suggested that, at high ambient de Sitter temperature, the rate may be
strongly enhanced, due to large degeneracy factors associated with the number
of light species living on the worldsheet. This might facilitate the quick
relaxation from a large effective cosmological constant down to the observed
value. Here, we analyse this possibility in some detail. In four dimensions,
and after the moduli are stabilized, branes interact via repulsive long range
forces. Because of that, the Coleman-de Luccia (CdL) instanton for coincident
brane nucleation may not exist, unless there is some short range interaction
which keeps the branes together. If the CdL instanton exists, we find that the
degeneracy factor depends only mildly on the ambient de Sitter temperature, and
does not switch off even in the case of tunneling from flat space. This would
result in catastrophic decay of the present vacuum. If, on the contrary, the
CdL instanton does not exist, coindident brane nucleation may still proceed
through a "static" instanton, representing pair creation of critical bubbles --
a process somewhat analogous to thermal activation in flat space. In that case,
the branes may stick together due to thermal symmetry restoration, and the pair
creation rate depends exponentially on the ambient de Sitter temperature,
switching off sharply as the temperature approaches zero. Such static instanton
may be well suited for the "saltatory" relaxation scenario proposed by Feng et
al.Comment: 38 pages, 6 figures. Replaced with typos correcte
Distributed phase-covariant cloning with atomic ensembles via quantum Zeno dynamics
We propose an interesting scheme for distributed orbital state quantum
cloning with atomic ensembles based on the quantum Zeno dynamics. These atomic
ensembles which consist of identical three-level atoms are trapped in distant
cavities connected by a single-mode integrated optical star coupler. These
qubits can be manipulated through appropriate modulation of the coupling
constants between atomic ensemble and classical field, and the cavity decay can
be largely suppressed as the number of atoms in the ensemble qubits increases.
The fidelity of each cloned qubit can be obtained with analytic result. The
present scheme provides a new way to construct the quantum communication
network.Comment: 5 pages, 4 figure
Structure of Schlafen13 reveals a new class of tRNA/rRNA- targeting RNase engaged in translational control
Cleavage of transfer (t)RNA and ribosomal (r)RNA are critical and conserved steps of translational control for cells to overcome varied environmental stresses. However, enzymes that are responsible for this event have not been fully identified in high eukaryotes. Here, we report a mammalian tRNA/rRNA-targeting endoribonuclease: SLFN13, a member of the Schlafen family. Structural study reveals a unique pseudo-dimeric U-pillow-shaped architecture of the SLFN13 N'-domain that may clamp base-paired RNAs. SLFN13 is able to digest tRNAs and rRNAs in vitro, and the endonucleolytic cleavage dissevers 11 nucleotides from the 3'-terminus of tRNA at the acceptor stem. The cytoplasmically localised SLFN13 inhibits protein synthesis in 293T cells. Moreover, SLFN13 restricts HIV replication in a nucleolytic activity-dependent manner. According to these observations, we term SLFN13 RNase S13. Our study provides insights into the modulation of translational machinery in high eukaryotes, and sheds light on the functional mechanisms of the Schlafen family
Genomic Islands Confer Heavy Metal Resistance in <i>Mucilaginibacter kameinonensis</i> and <i>Mucilaginibacter rubeus</i> Isolated from a Gold/Copper Mine.
Heavy metals (HMs) are compounds that can be hazardous and impair growth of living organisms. Bacteria have evolved the capability not only to cope with heavy metals but also to detoxify polluted environments. Three heavy metal-resistant strains of <i>Mucilaginibacer rubeus</i> and one of <i>Mucilaginibacter kameinonensis</i> were isolated from the gold/copper Zijin mining site, Longyan, Fujian, China. These strains were shown to exhibit high resistance to heavy metals with minimal inhibitory concentration reaching up to 3.5 mM Cu <sup>(II)</sup> , 21 mM Zn <sup>(II)</sup> , 1.2 mM Cd <sup>(II)</sup> , and 10.0 mM As <sup>(III)</sup> . Genomes of the four strains were sequenced by Illumina. Sequence analyses revealed the presence of a high abundance of heavy metal resistance (HMR) determinants. One of the strain, <i>M. rubeus</i> P2, carried genes encoding 6 putative P <sub>IB-1</sub> -ATPase, 5 putative P <sub>IB-3</sub> -ATPase, 4 putative Zn <sup>(II)</sup> /Cd <sup>(II)</sup> P <sub>IB-4</sub> type ATPase, and 16 putative resistance-nodulation-division (RND)-type metal transporter systems. Moreover, the four genomes contained a high abundance of genes coding for putative metal binding chaperones. Analysis of the close vicinity of these HMR determinants uncovered the presence of clusters of genes potentially associated with mobile genetic elements. These loci included genes coding for tyrosine recombinases (integrases) and subunits of mating pore (type 4 secretion system), respectively allowing integration/excision and conjugative transfer of numerous genomic islands. Further in silico analyses revealed that their genetic organization and gene products resemble the <i>Bacteroides</i> integrative and conjugative element CTnDOT. These results highlight the pivotal role of genomic islands in the acquisition and dissemination of adaptive traits, allowing for rapid adaption of bacteria and colonization of hostile environments
Measurements of the observed cross sections for exclusive light hadrons containing at , 3.650 and 3.6648 GeV
By analyzing the data sets of 17.3, 6.5 and 1.0 pb taken,
respectively, at , 3.650 and 3.6648 GeV with the BES-II
detector at the BEPC collider, we measure the observed cross sections for
, , ,
and at the three energy
points. Based on these cross sections we set the upper limits on the observed
cross sections and the branching fractions for decay into these
final states at 90% C.L..Comment: 7 pages, 2 figure
Partial wave analysis of J/\psi \to \gamma \phi \phi
Using events collected in the BESII detector, the
radiative decay is
studied. The invariant mass distribution exhibits a near-threshold
enhancement that peaks around 2.24 GeV/.
A partial wave analysis shows that the structure is dominated by a
state () with a mass of
GeV/ and a width of GeV/. The
product branching fraction is: .Comment: 11 pages, 4 figures. corrected proof for journa
Direct Measurements of Absolute Branching Fractions for D0 and D+ Inclusive Semimuonic Decays
By analyzing about 33 data sample collected at and around 3.773
GeV with the BES-II detector at the BEPC collider, we directly measure the
branching fractions for the neutral and charged inclusive semimuonic decays
to be and , and determine the ratio of the two branching
fractions to be
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