The Reverse Hölder Inequality for the Solution to p-Harmonic Type System

Some inequalities to A-harmonic equation A(x,du)=d∗v have been proved. The A-harmonic equation is a particular form of p-harmonic type system A(x,a+du)=b+d∗v only when a=0 and b=0. In this paper, we will prove the Poincaré inequality and the reverse Hölder inequality for the solution to the p-harmonic type system

Interaction between CSL students’ motivation and anxiety under different L2 writing tasks: evidence from Vietnamese university students

IntroductionImproving task motivation can reduce anxiety and enhance the efficiency of second language (L2) learning. However, previous research has not determined whether the relationship between task motivation and anxiety is unidirectional facilitation or bidirectional interaction. The reasons for these “relationships” and their impact on L2 learning have not been analysed in depth yet.MethodsThis study investigated the interaction between task motivation and anxiety via qualitative and quantitative research methods with the participation of 229 Vietnamese university students, who were divided into three L2 writing task groups, including the free choice group (FC), the limited choice group (LC), and the no choice group (NC).ResultsThe quantitative results show that the higher individuals’ autonomy levels were, the higher their task motivation levels would be. Besides, the high level of task anxiety reduced task motivation among Vietnamese university students and exited other anxiety factors. The qualitative analysis of semi-structured interviews conducted with 32 Vietnamese university students showed that a small number of negative factors might trigger low levels of task anxiety.DiscussionNevertheless, the results for participants with different levels of Chinese language proficiency were highly variable. Participants with better cognitive and Chinese language levels regarded task anxiety as an opportunity to practice their Chinese language skills. They were motivated to complete the task, while participants with lower Chinese language levels exhibited low confidence and experienced more challenges when completing the task

Genetic Characteristics Of An Ancient Nomadic Group In Northern China

Nomadic populations have played a significant role in the history of not only China but also in many nations worldwide. Because they had no written language, an important aspect in the study of these people is the discovery of their tombs. It has been generally accepted that Xiongnu was the first empire created by nomadic tribe in the 3rd century B.C. However, little population genetic information is available concerning the Donghu, another flourishing nomadic tribe at the same period because of the restriction of materials until Jinggouzi site was excavated. In order to test the genetic characteristics of ancient people in this site and explore the relationship between Jinggouzis and Donghus, two uniparentally inherited markers were analyzed from 42 human remains in this site, which located in northern China, dated approximately 2,500 years ago. With ancient DNA technology, four mtDNA haplogroups (D, G, C and M10) and one Y chromosome haplogroup (C) were identified using mitochondrial DNA and Y-chromosome single nucleotide polymorphisms (Y-SNPs). Those haplogroups are common in North Asia and East Asia. And the Jinggouzi people were genetically closest to the Xianbeis in ancient populations and to the Oroqens among extant populations, who were all pastoralists. This might indicate that ancient Jinggouzi people were nomads. Meanwhile, according to the genetic data and the evidences in archaeology, we inferred that Jinggouzi people were associated with Donghu. It is of much value to trace the history of Donghu tribe and might show some insight into the ancient nomadic societ

Role of the SaeRS two-component regulatory system in Staphylococcus epidermidis autolysis and biofilm formation

<p>Abstract</p> <p>Background</p> <p><it>Staphylococcus epidermidis </it>(SE) has emerged as one of the most important causes of nosocomial infections. The SaeRS two-component signal transduction system (TCS) influences virulence and biofilm formation in <it>Staphylococcus aureus</it>. The deletion of <it>saeR </it>in <it>S. epidermidis </it>results in impaired anaerobic growth and decreased nitrate utilization. However, the regulatory function of SaeRS on biofilm formation and autolysis in <it>S. epidermidis </it>remains unclear.</p> <p>Results</p> <p>The <it>saeRS </it>genes of SE1457 were deleted by homologous recombination. The <it>saeRS </it>deletion mutant, SE1457<it>ΔsaeRS</it>, exhibited increased biofilm formation that was disturbed more severely (a 4-fold reduction) by DNase I treatment compared to SE1457 and the complementation strain SE1457<it>saec</it>. Compared to SE1457 and SE1457<it>saec</it>, SE1457<it>ΔsaeRS </it>showed increased Triton X-100-induced autolysis (approximately 3-fold) and decreased cell viability in planktonic/biofilm states; further, SE1457<it>ΔsaeRS </it>also released more extracellular DNA (eDNA) in the biofilms. Correlated with the increased autolysis phenotype, the transcription of autolysis-related genes, such as <it>atlE </it>and <it>aae</it>, was increased in SE1457<it>ΔsaeRS</it>. Whereas the expression of accumulation-associated protein was up-regulated by 1.8-fold in 1457<it>ΔsaeRS</it>, the expression of an N-acetylglucosaminyl transferase enzyme (encoded by <it>icaA</it>) critical for polysaccharide intercellular adhesin (PIA) synthesis was not affected by the deletion of <it>saeRS.</it></p> <p>Conclusions</p> <p>Deletion of <it>saeRS </it>in <it>S. epidermidis </it>resulted in an increase in biofilm-forming ability, which was associated with increased eDNA release and up-regulated Aap expression. The increased eDNA release from SE1457<it>ΔsaeRS </it>was associated with increased bacterial autolysis and decreased bacterial cell viability in the planktonic/biofilm states.</p

Observation of the anomalous Hall effect in a layered polar semiconductor

Progress in magnetoelectric materials is hindered by apparently contradictory requirements for time-reversal symmetry broken and polar ferroelectric electronic structure in common ferromagnets and antiferromagnets. Alternative routes could be provided by recent discoveries of a time-reversal symmetry breaking anomalous Hall effect in noncollinear magnets and altermagnets, but hitherto reported bulk materials are not polar. Here, we report the observation of a spontaneous anomalous Hall effect in doped AgCrSe$_2$, a layered polar semiconductor with an antiferromagnetic coupling between Cr spins in adjacent layers. The anomalous Hall resistivity 3 $\mu\Omega$ cm is comparable to the largest observed in compensated magnetic systems to date, and is rapidly switched off when the angle of an applied magnetic field is rotated to $\sim 80^{\circ}$ from the crystalline $c$-axis. Our ionic gating experiments show that the anomalous Hall conductivity magnitude can be enhanced by modulating the $p$-type carrier density. We also present theoretical results that suggest the anomalous Hall effect is driven by Berry curvature due to noncollinear antiferromagnetic correlations among Cr spins, which are consistent with the previously suggested magnetic ordering in AgCrSe$_2$. Our results open the possibility to study the interplay of magnetic and ferroelectric-like responses in this fascinating class of materials.Comment: 8 pages, 5 figure

Observation of the anomalous Hall effect in a layered polar semiconductor

Funding: S.-J.K. acknowledged support from the International Max Planck Research School for Chemistry and Physics of Quantum Materials (IMPRS-CPQM). L.Š. acknowledged support from Johannes Gutenberg University Grant TopDyn, and support by the Deutsche Forschungsgemein- schaft (DFG, German Research Foundation) for funding through TRR 288 – 422213477 (projects A09 and B05).Progress in magnetoelectric materials is hindered by apparently contradictory requirements for time‐reversal symmetry broken and polar ferroelectric electronic structure in common ferromagnets and antiferromagnets. Alternative routes can be provided by recent discoveries of a time‐reversal symmetry breaking anomalous Hall effect (AHE) in noncollinear magnets and altermagnets, but hitherto reported bulk materials are not polar. Here, the authors report the observation of a spontaneous AHE in doped AgCrSe2, a layered polar semiconductor with an antiferromagnetic coupling between Cr spins in adjacent layers. The anomalous Hall resistivity 3 μΩcm is comparable to the largest observed in compensated magnetic systems to date, and is rapidly switched off when the angle of an applied magnetic field is rotated to ≈80° from the crystalline c‐axis. The ionic gating experiments show that the anomalous Hall conductivity magnitude can be enhanced by modulating the p‐type carrier density. They also present theoretical results that suggest the AHE is driven by Berry curvature due to noncollinear antiferromagnetic correlations among Cr spins, which are consistent with the previously suggested magnetic ordering in AgCrSe2. The results open the possibility to study the interplay of magnetic and ferroelectric‐like responses in this fascinating class of materials.Publisher PDFPeer reviewe

Factors affecting HPV infection in U.S. and Beijing females: A modeling study

BackgroundHuman papillomavirus (HPV) infection is an important carcinogenic infection highly prevalent among many populations. However, independent influencing factors and predictive models for HPV infection in both U.S. and Beijing females are rarely confirmed. In this study, our first objective was to explore the overlapping HPV infection-related factors in U.S. and Beijing females. Secondly, we aimed to develop an R package for identifying the top-performing prediction models and build the predictive models for HPV infection using this R package.MethodsThis cross-sectional study used data from the 2009–2016 NHANES (a national population-based study) and the 2019 data on Beijing female union workers from various industries. Prevalence, potential influencing factors, and predictive models for HPV infection in both cohorts were explored.ResultsThere were 2,259 (NHANES cohort, age: 20–59 years) and 1,593 (Beijing female cohort, age: 20–70 years) participants included in analyses. The HPV infection rate of U.S. NHANES and Beijing females were, respectively 45.73 and 8.22%. The number of male sex partners, marital status, and history of HPV infection were the predominant factors that influenced HPV infection in both NHANES and Beijing female cohorts. However, condom application was not an independent influencing factor for HPV infection in both cohorts. R package Modelbest was established. The nomogram developed based on Modelbest package showed better performance than the nomogram which only included significant factors in multivariate regression analysis.ConclusionCollectively, despite the widespread availability of HPV vaccines, HPV infection is still prevalent. Compared with condom promotion, avoidance of multiple sexual partners seems to be more effective for preventing HPV infection. Nomograms developed based on Modelbest can provide improved personalized risk assessment for HPV infection. Our R package Modelbest has potential to be a powerful tool for future predictive model studies