130 research outputs found
Positivity and strong ellipticity
We consider second-order partial differential operators in divergence
form on \Ri^d with a positive-semidefinite, symmetric, matrix of real
-coefficients and establish that is strongly elliptic if and only
if the associated semigroup kernel satisfies local lower bounds, or, if and
only if the kernel satisfies Gaussian upper and lower bounds.Comment: 9 page
Second-order operators with degenerate coefficients
We consider properties of second-order operators on \Ri^d with bounded real symmetric
measurable coefficients. We assume that almost
everywhere, but allow for the possibility that is singular. We associate
with a canonical self-adjoint viscosity operator and examine
properties of the viscosity semigroup generated by . The
semigroup extends to a positive contraction semigroup on the -spaces with
. We establish that it conserves probability, satisfies
~off-diagonal bounds and that the wave equation associated with has
finite speed of propagation. Nevertheless is not always strictly
positive because separation of the system can occur even for subelliptic
operators. This demonstrates that subelliptic semigroups are not ergodic in
general and their kernels are neither strictly positive nor H\"older
continuous. In particular one can construct examples for which both upper and
lower Gaussian bounds fail even with coefficients in C^{2-\varepsilon}(\Ri^d)
with .Comment: 44 page
Microarray Analysis of Gene Regulations and Potential Association with Acephate-Resistance and Fitness Cost in Lygus lineolaris
The tarnished plant bug has become increasingly resistant to organophosphates in recent years. To better understand acephate resistance mechanisms, biological, biochemical, and molecular experiments were systematically conducted with susceptible (LLS) and acephate-selected (LLR) strains. Selection of a field population with acephate significantly increased resistance ratio to 5.9-fold, coupled with a significant increase of esterase activities by 2-fold. Microarray analysis of 6,688 genes revealed 329 up- and 333 down-regulated (≥2-fold) genes in LLR. Six esterase, three P450, and one glutathione S-transferase genes were significantly up-regulated, and no such genes were down-regulated in LLR. All vitellogenin and eggshell protein genes were significantly down-regulated in LLR. Thirteen protease genes were significantly down-regulated and only 3 were up-regulated in LLR. More than twice the number of catalysis genes and more than 3.6-fold of metabolic genes were up-regulated, respectively, as compared to those down-regulated with the same molecular and biological functions. The large portion of metabolic or catalysis genes with significant up-regulations indicated a substantial increase of metabolic detoxification in LLR. Significant increase of acephate resistance, increases of esterase activities and gene expressions, and variable esterase sequences between LLS and LLR consistently demonstrated a major esterase-mediated resistance in LLR, which was functionally provable by abolishing the resistance with esterase inhibitors. In addition, significant elevation of P450 gene expression and reduced susceptibility to imidacloprid in LLR indicated a concurrent resistance risk that may impact other classes of insecticides. This study demonstrated the first association of down-regulation of reproductive- and digestive-related genes with resistance to conventional insecticides, suggesting potential fitness costs associated with resistance development. This study shed new light on the understanding of the molecular basis of insecticide resistance, and the information is highly valuable for development of chemical control guidelines and tactics to minimize resistance and cross-resistance risks
A Cross-Sectional Study of Risk Factors for Irritable Bowel Syndrome in Children 8–13 Years of Age in Suzhou, China
To determine the prevalence and risk factors of IBS in children 8–13 years of age in Suzhou city, a cross-sectional study was conducted on children in grades 1 through 6 in public elementary schools in three districts of Suzhou. A multistage stratified random-sampling survey was conducted in a primary investigation using standardized questionnaires. Rome II criteria were used to confirm IBS and their risk factors were analyzed. Of 8,000 questionnaires 7,472 responded satisfactorily for a response rate of 93.4%. IBS was diagnosed in 10.81%. A decrease in the prevalence of IBS was significantly associated with advancing age and grade in school (trend test, P<0.05). The prevalence of IBS in females was higher but not significantly different than males. The significant risk factors for IBS included young age (OR = 0.94), food allergy (OR = 1.53), gastroenteritis during childhood (OR = 1.29), eating fried food (OR = 1.62), anxiety (OR = 1.49), psychological insults in early childhood (OR = 1.47), and parental history of constipation (OR = 1.81; all P<0.05). IBS prevalence of 10.81% in study population warrants preventive measures such as encouraging dietary changes, preventing gastroenteritis and childhood psychological insults
Wavelets, Sobolev Multipliers, and Application to Schrödinger Type Operators with Nonsmooth Potentials
We employ Meyer wavelets to characterize multiplier space Xr,pt(ℝn) without using capacity. Further, we introduce logarithmic Morrey spaces Mr,pt,τ(ℝn) to establish the inclusion relation between Morrey spaces and multiplier spaces. By fractal skills, we construct a counterexample to show that the scope of the index τ of Mr,pt,τ(ℝn) is sharp. As an application, we consider a Schrödinger type operator with potentials in Mr,pt,τ(ℝn)
An Innovative Continuing Nursing Education Program Targeting Key Geriatric Conditions for Hospitalized Older People in China
This article under embargo for 18 months from the date of publication due to publisher copyright restrictions.
"This is an Accepted Manuscript of an article published by Taylor & Francis i nEducational Gerontology on 23 May 2013, available online: http://wwww.tandfonline.com/10.1080/03601277.2012.704233."A lack of knowledge in registered nurses about geriatric conditions is one of major
factors that contribute to these conditions being overlooked in hospitalised older people. In
China an innovative geriatric continuing nursing education program aimed at developing
registered nurses’ understanding of the complex care needs of hospitalised older people with
common geriatric conditions were conducted and evaluated. The program consisted of
didactic sessions focused on evidence-based practice and unfolding case study designed to
simulate the care trajectory of an older person with a hip fracture and key geriatric conditions.
Findings from the program evaluations revealed a significant increase in attitudes towards
older people and knowledge concerning common geriatric conditions. The satisfactory rate
ranked by program participants was 90%. The study therefore drew the conclusion that
effective geriatric continuing nursing education should target participants’ learning needs,
support evidence-based practice and engage participants in active learning
Dietary Intake of n-6 Fatty Acids Modulates Effect of Apolipoprotein A5 Gene on Plasma Fasting Triglycerides, Remnant Lipoprotein Concentrations, and Lipoprotein Particle Size
Background— Apolipoprotein A5 gene (APOA5) variation is associated with plasma triglycerides (TGs). However, little is known about whether dietary fat modulates this association. Methods and Results— We investigated the interaction between APOA5 gene variation and dietary fat in determining plasma fasting TGs, remnant-like particle (RLP) concentrations, and lipoprotein particle size in 1001 men and 1147 women who were Framingham Heart Study participants. Polymorphisms –1131T>C and 56C>G, representing 2 independent haplotypes, were analyzed. Significant gene–diet interactions between the –1131T>C polymorphism and polyunsaturated fatty acid (PUFA) intake were found (PG polymorphism. The –1131C allele was associated with higher fasting TGs and RLP concentrations (P6% of total energy). No heterogeneity by sex was found. These interactions showed a dose-response effect when PUFA intake was considered as a continuous variable (P<0.01). Similar interactions were found for the sizes of VLDL and LDL particles. Only in carriers of the –1131C allele did the size of these particles increase (VLDL) or decrease (LDL) as PUFA intake increased (P<0.01). We further analyzed the effects of n-6 and n-3 fatty acids and found that the PUFA–APOA5 interactions were specific for dietary n-6 fatty acids. Conclusions— Higher n-6 (but not n-3) PUFA intake increased fasting TGs, RLP concentrations, and VLDL size and decreased LDL size in APOA5 –1131C carriers, suggesting that n-6 PUFA–rich diets are related to a more atherogenic lipid profile in these subjects.Corella Piquer, Maria Dolores, [email protected]
Federated attention consistent learning models for prostate cancer diagnosis and Gleason grading
Artificial intelligence (AI) holds significant promise in transforming
medical imaging, enhancing diagnostics, and refining treatment strategies.
However, the reliance on extensive multicenter datasets for training AI models
poses challenges due to privacy concerns. Federated learning provides a
solution by facilitating collaborative model training across multiple centers
without sharing raw data. This study introduces a federated
attention-consistent learning (FACL) framework to address challenges associated
with large-scale pathological images and data heterogeneity. FACL enhances
model generalization by maximizing attention consistency between local clients
and the server model. To ensure privacy and validate robustness, we
incorporated differential privacy by introducing noise during parameter
transfer. We assessed the effectiveness of FACL in cancer diagnosis and Gleason
grading tasks using 19,461 whole-slide images of prostate cancer from multiple
centers. In the diagnosis task, FACL achieved an area under the curve (AUC) of
0.9718, outperforming seven centers with an average AUC of 0.9499 when
categories are relatively balanced. For the Gleason grading task, FACL attained
a Kappa score of 0.8463, surpassing the average Kappa score of 0.7379 from six
centers. In conclusion, FACL offers a robust, accurate, and cost-effective AI
training model for prostate cancer pathology while maintaining effective data
safeguards.Comment: 14 page
An emerging recombinant human enterovirus 71 responsible for the 2008 outbreak of Hand Foot and Mouth Disease in Fuyang city of China
Hand, foot and mouth disease (HFMD), a common contagious disease that usually affects children, is normally mild but can have life-threatening manifestations. It can be caused by enteroviruses, particularly Coxsackieviruses and human enterovirus 71 (HEV71) with highly variable clinical manifestations. In the spring of 2008, a large, unprecedented HFMD outbreak in Fuyang city of Anhui province in the central part of southeastern China resulted in a high aggregation of fatal cases. In this study, epidemiologic and clinical investigations, laboratory testing, and genetic analyses were performed to identify the causal pathogen of the outbreak. Of the 6,049 cases reported between 1 March and 9 May of 2008, 3023 (50%) were hospitalized, 353 (5.8%) were severe and 22 (0.36%) were fatal. HEV71 was confirmed as the etiological pathogen of the outbreak. Phylogenetic analyses of entire VP1 capsid protein sequence of 45 Fuyang HEV71 isolates showed that they belong to C4a cluster of the C4 subgenotype. In addition, genetic recombinations were found in the 3D region (RNA-dependent RNA polymerase, a major component of the viral replication complex of the genome) between the Fuyang HEV71 strain and Coxsackievirus A16 (CV-A16), resulting in a recombination virus. In conclusion, an emerging recombinant HEV71 was responsible for the HFMD outbreak in Fuyang City of China, 2008
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