Adaptive behaviors of Drosophila larvae on slippery surfaces

Friction is ubiquitous but an essential force for insects during locomotion. Insects use dedicated bio-mechanical systems such as adhesive pads to modulate the intensity of friction, providing a stable grip with touching substrates for locomotion. However, how to uncover behavioral adaptation and regulatory neural circuits of friction modification is still largely understood. In this study, we devised a novel behavior paradigm to investigate adaptive behavioral alternation of Drosophila larvae under low-friction surfaces. We found a tail looseness phenotype similar to slipping behavior in humans, as a primary indicator to assess the degree of slipping. We found a gradual reduction on slipping level in wild-type larvae after successive larval crawling, coupled with incremental tail contraction, displacement, and speed acceleration. Meanwhile, we also found a strong correlation between tail looseness index and length of contraction, suggesting that lengthening tail contraction may contribute to enlarging the contact area with the tube. Moreover, we found a delayed adaptation in rut mutant larvae, inferring that neural plasticity may participate in slipping adaptation. In conclusion, our paradigm can be easily and reliably replicated, providing a feasible pathway to uncover the behavioral principle and neural mechanism of acclimation of Drosophila larvae to low-friction conditions.     

Efficacy of a Community-Based Physical Activity Program KM2H2 for Stroke and Heart Attack Prevention among Senior Hypertensive Patients: A Cluster Randomized Controlled Phase-II Trial

Objective

To evaluate the efficacy of the program Keep Moving toward Healthy Heart and Healthy Brain (KM2H²) in encouraging physical activities for the prevention of heart attack and stroke among hypertensive patients enrolled in the Community-Based Hypertension Control Program (CBHCP).

Design

Cluster randomized controlled trial with three waves of longitudinal assessments at baseline, 3 and 6 months post intervention.

Setting

Community-based and patient-centered self-care for behavioral intervention in urban settings of China.

Participants

A total of 450 participants diagnosed with hypertension from 12 community health centers in Wuhan, China were recruited, and were randomly assigned by center to receive either KM2H² plus standard CBHCP care (6 centers and 232 patients) or the standard care only (6 centers and 218 patients).

Intervention

KM2H² is a behavioral intervention guided by the Transtheoretical Model, the Model of Personalized Medicine and Social Capital Theory. It consists of six intervention sessions and two booster sessions engineered in a progressive manner. The purpose is to motivate and maintain physical activities for the prevention of heart attack and stroke.

Outcome Measures

Heart attack and stroke (clinically diagnosed, primary outcome), blood pressure (measured, secondary outcome), and physical activity (self-report, tertiary outcome) were assessed at the individual level during the baseline, 3- and 6-month post-intervention.

Results

Relative to the standard care, receiving KM2H² was associated with significant reductions in the incidence of heart attack (3.60% vs. 7.03%, p < .05) and stroke (5.11% vs. 9.90%, p<0.05), and moderate reduction in blood pressure (-3.72mmHg in DBP and -2.92 mmHg in DBP) at 6-month post-intervention; and significant increases in physical activity at 3- (d = 0.53, 95% CI: 0.21, 0.85) and 6-month (d = 0.45, 95% CI: 0.04, 0.85) post-intervention, respectively.

Conclusion

The program KM2H² is efficacious to reduce the risk of heart attack and stroke among senior patients who are on anti-hypertensive medication. Findings of this study provide solid data supporting a formal phase-III trial to establish the effectiveness of KM2H² for use in community settings for prevention.

Trial Registration

ISRCTN Register ISRCTN12608966     

一种鉴定过氧化氢酶活性的铁染色法

采用聚丙烯酰胺凝胶电泳(PAGE)技术,建立了一种新的鉴定过氧化氢酶活性的方法──铁染色法．结果表明,细菌过氧化氢酶及牛肝过氧化氢酶显示单一的酶活性带．该方法操作简单、快速、灵敏度高、专一性强.是一种切实可行的鉴定过氧化氢酶活性染色法.     

Doubly penalized buckley-james method for survival data with high-dimensional covariates.

Recent interest in cancer research focuses on predicting patients' survival by investigating gene expression profiles based on microarray analysis. We propose a doubly penalized Buckley-James method for the semiparametric accelerated failure time model to relate high-dimensional genomic data to censored survival outcomes, which uses the elastic-net penalty that is a mixture of L1- and L2-norm penalties. Similar to the elastic-net method for a linear regression model with uncensored data, the proposed method performs automatic gene selection and parameter estimation, where highly correlated genes are able to be selected (or removed) together. The two-dimensional tuning parameter is determined by generalized crossvalidation. The proposed method is evaluated by simulations and applied to the Michigan squamous cell lung carcinoma study.     

Facile synthesis of chain-end functionalized glycopolymers for site-specific bioconjugation

A series of derivatized arylamine initiators were used to generate chain-end functionalized glycopolymers by cyanoxyl-mediated free-radical polymerization. Significant features of this strategy include the capacity to produce polymers of low polydispersity (PDI < 1.5) under aqueous conditions using unprotected monomers bearing a wide range of functional groups. In addition, the presence of a phenyl ring simplifies calculation of polymer saccharide content and molar mass by (1)H NMR. It is particularly noteworthy, however, that derivatized arylamine initiators in conjunction with the presence of a terminal cyanate group provide a convenient approach for synthesizing polymers with a variety of distinct functional groups at alpha and omega chain ends. In the process, the capacity to label glycopolymers or otherwise conjugate them to proteins or other molecules is greatly enhanced.     

A glycopolymer chaperone for fibroblast growth factor-2

Mono- and disaccharide-containing glycopolymers were synthesized by cyanoxyl-mediated polymerization of acrylamide with acrylate-derivatized mono- and disaccharides. We demonstrate that a glycopolymer bearing pendant, fully sulfated lactose units effectively replaces heparin and heparan sulfate as a molecular chaperone for fibroblast growth factor-2 (FGF-2). Specifically, a compound was identified that protects FGF-2 from proteolytic, acid, and heat-induced degradation, while selectively promoting growth factor and receptor dimerization. Significantly, the capacity of this heparin-mimic to promote an FGF-2 specific proliferative cell response was confirmed and suggests potential applications for this compound and related derivatives in areas related to therapeutic angiogenesis.