New constructions of optimal (r,δ)(r,\delta)-LRCs via good polynomials

Locally repairable codes (LRCs) are a class of erasure codes that are widely used in distributed storage systems, which allow for efficient recovery of data in the case of node failures or data loss. In 2014, Tamo and Barg introduced Reed-Solomon-like (RS-like) Singleton-optimal $(r,\delta)$-LRCs based on polynomial evaluation. These constructions rely on the existence of so-called good polynomial that is constant on each of some pairwise disjoint subsets of $\mathbb{F}_q$. In this paper, we extend the aforementioned constructions of RS-like LRCs and proposed new constructions of $(r,\delta)$-LRCs whose code length can be larger. These new $(r,\delta)$-LRCs are all distance-optimal, namely, they attain an upper bound on the minimum distance, that will be established in this paper. This bound is sharper than the Singleton-type bound in some cases owing to the extra conditions, it coincides with the Singleton-type bound for certain cases. Combing these constructions with known explicit good polynomials of special forms, we can get various explicit Singleton-optimal $(r,\delta)$-LRCs with new parameters, whose code lengths are all larger than that constructed by the RS-like $(r,\delta)$-LRCs introduced by Tamo and Barg. Note that the code length of classical RS codes and RS-like LRCs are both bounded by the field size. We explicitly construct the Singleton-optimal $(r,\delta)$-LRCs with length $n=q-1+\delta$ for any positive integers $r,\delta\geq 2$ and $(r+\delta-1)\mid (q-1)$. When $\delta$ is proportional to $q$, it is asymptotically longer than that constructed via elliptic curves whose length is at most $q+2\sqrt{q}$. Besides, it allows more flexibility on the values of $r$ and $\delta$

Fast Endomorphism for any Genus 2 Hyperelliptic Curve over a Finite Field of Even Characteristic

In EUROCRYPT 2009, Galbraith, Lin and Scott constructed an efficiently computable endomorphism for a large family of elliptic curves defined over finite fields of large characteristic. They demonstrated that the endomorphism can be used to accelerate scalar multiplication in the elliptic curve cryptosystem based on these curves. In this paper we extend the method to any genus 2 hyperelliptic curve defined over a finite field of even characteristic. We propose an efficient algorithm to generate a random genus 2 hyperelliptic curve and its quadratic twist equipped with a fast endomorphism on the Jacobian. The analysis of the operation amount of the scalar multiplication is also given

On the Access Structures of Hyperelliptic Secret Sharing

In this paper we partially determine the access structures of algebraic geometric secret sharing schemes from one point algebraic geometric codes associated with a hyperelliptic curve of any genus. Our result includes the access structures of elliptic secret sharing schemes as a special case

Effect of Core Values of General Practice on Adherence of Patients with Diabetes

BackgroundTreatment adherence is closely related to disease control for patients with diabetes. Primary care is general, and continuous, which may satisfy the general and continuous healthcare needs of diabetic patients. But the association of core values of general practices with adherence of diabetic patients is not yet clear.ObjectiveTo explore the effect of core values of general practice (first contact/first line care, continuity, accessibility, comprehensiveness, coordination and patient-oriented) on the adherence (medication adherence, diet adherence, exercise adherence, self-monitoring adherence and regular hospital visits adherence) of type 2 diabetic patients, providing a reference for improving the adherence of such patients by precisely enhancing the core values of general practices.MethodsA survey was conducted between August and September 2019 with a convenience sample of type 2 diabetics receiving contacted family doctor services from Shayuan Community Health Center of Guangzhou using a questionnaire consisting of three parts〔demographic information, the Chinese version of Primary Care Assessment Survey (ASPC) , and Adherence to Out-of-hospital Treatment of Type 2 Diabetics (AOTTD) 〕. Treatment adherence was compared by various personal factors. Multiple linear regression was used to analyze the association of the core values of general practice with treatment adherence.ResultsAltogether, 224 cases who handed in responsive questionnaires were included for final analysis. The average scores of AOTTD, and ASPC of the respondents were (80.57±11.27) and (72.95±11.40) , respectively. The scores of AOTTD differed significantly by sex and understanding level of type 2 diabetes (P<0.05) . The total score of ASPC and the score of its each domain were associated with the total score of AOTTD, or the domain score of regular hospital visits (P<0.10) . The scores of two domains (accessibility and coordination) of the ASPC were associated with the medication adherence score (P<0.10) . The domain score of coordination was associated with the diet adherence score (P<0.10) . The score of each domain of the ASPC (except for coordination) was associated with the self-monitoring adherence score (P<0.10) .ConclusionFor type 2 diabetics, strengthening each of the core values of general practice could contribute to the increase of their treatment adherence, and regular hospital visits adherence. Improving the accessibility of general practice could enhance their medication adherence. Improving the coordination of general practice could enhance their medication adherence and diet adherence. Improving first contact/first line care, continuity, accessibility, comprehensiveness, coordination and patient-oriented values of general practice could contribute to the increase of their medication adherence. But no association was found between the core values of general practice and patients'exercise adherence, which suggests that providing more exercise resources and environmental support for these patients may be a solution

The Paranodal Cytoskeleton Clusters Na+ Channels At Nodes of Ranvier

A high density of Na(+) channels at nodes of Ranvier is necessary for rapid and efficient action potential propagation in myelinated axons. Na+ channel clustering is thought to depend on two axonal cell adhesion molecules that mediate interactions between the axon and myelinating glia at the nodal gap (i.e., NF186) and the paranodal junction (i.e., Caspr). Here we show that while Na(+) channels cluster at nodes in the absence of NF186, they fail to do so in double conditional knockout mice lacking both NF186 and the paranodal cell adhesion molecule Caspr, demonstrating that a paranodal junction-dependent mechanism can cluster Na(+) channels at nodes. Furthermore, we show that paranode-dependent clustering of nodal Na(+) channels requires axonal βII spectrin which is concentrated at paranodes. Our results reveal that the paranodal junction-dependent mechanism of Na(+)channel clustering is mediated by the spectrin-based paranodal axonal cytoskeleton. DOI: http://dx.doi.org/10.7554/eLife.21392.00

Etiological study of esophageal squamous cell carcinoma in an endemic region: a population-based case control study in Huaian, China

BACKGROUND: Continuous exposure to various environmental carcinogens and genetic polymorphisms of xenobiotic-metabolizing enzymes (XME) are associated with many types of human cancers, including esophageal squamous cell carcinoma (ESCC). Huaian, China, is one of the endemic regions of ESCC, but fewer studies have been done in characterizing the risk factors of ESCC in this area. The aims of this study is to evaluate the etiological roles of demographic parameters, environmental and food-borne carcinogens exposure, and XME polymorphisms in formation of ESCC, and to investigate possible gene-gene and gene-environment interactions associated with ESCC in Huaian, China. METHODS: A population based case-control study was conducted in 107 ESCC newly diagnosed cases and 107 residency- age-, and sex-matched controls in 5 townships of Huaian. In addition to regular epidemiological and food frequency questionnaire analyses, genetic polymorphisms of phase I enzymes CYP1A1, CYP1B1, CYP2A6, and CYP2E1, and phase II enzymes GSTM1, GSTT1, GSTP1, and microsomal epoxide hydrolase (EPHX) were assessed from genomic DNA using PCR based techniques. RESULTS: Consuming acrid food, fatty meat, moldy food, salted and pickled vegetables, eating fast, introverted personality, passive smoking, a family history of cancer, esophageal lesion, and infection with Helicobacter pylori were significant risk factors for ESCC (P < 0.05). Regular clean up of food storage utensils, green tea consumption, and alcohol abstinence were protective factors for ESCC (P < 0.01). The frequency of the GSTT1 null genotype was higher in cases (59.4%) compared to controls (47.2%) with an odds ratio (OR) of 1.68 and 95% confidence interval (CI) from 0.96 to 2.97 (P = 0.07), especially in males (OR = 2.78; 95% CI = 1.22–6.25; P = 0.01). No associations were found between polymorphisms of CYP1A1, CYP1B1, CYP2A6, CYP2E1, GSTM1, GSTP1, and EPHX and ESCC (P > 0.05). CONCLUSION: Our results demonstrated that dietary and environmental exposures, some demographic parameters and genetic polymorphism of GSTT1 may play important roles in the development of ESCC in Huaian area, China

Calpain inhibition mediates autophagy-dependent protection against polyglutamine toxicity.

Over recent years, accumulated evidence suggests that autophagy induction is protective in animal models of a number of neurodegenerative diseases. Intense research in the field has elucidated different pathways through which autophagy can be upregulated and it is important to establish how modulation of these pathways impacts upon disease progression in vivo and therefore which, if any, may have further therapeutic relevance. In addition, it is important to understand how alterations in these target pathways may affect normal physiology when constitutively modulated over a long time period, as would be required for treatment of neurodegenerative diseases. Here we evaluate the potential protective effect of downregulation of calpains. We demonstrate, in Drosophila, that calpain knockdown protects against the aggregation and toxicity of proteins, like mutant huntingtin, in an autophagy-dependent fashion. Furthermore, we demonstrate that, overexpression of the calpain inhibitor, calpastatin, increases autophagosome levels and is protective in a mouse model of Huntington's disease, improving motor signs and delaying the onset of tremors. Importantly, long-term inhibition of calpains did not result in any overt deleterious phenotypes in mice. Thus, calpain inhibition, or activation of autophagy pathways downstream of calpains, may be suitable therapeutic targets for diseases like Huntington's disease.This is the published version of the manuscript. It is available online from NPG in Cell Death and Differentiaiton here: http://www.nature.com/cdd/journal/vaop/ncurrent/full/cdd2014151a.html