A Novel Design of Membership Authentication and Group Key Establishment Protocol

A new type of authentication, called group authentication, has been proposed recently which can authenticate all users belonging to the same group at once in a group communication. However, the group authentication can only detect the existence of nonmembers but cannot identify who are the nonmembers. Furthermore, in a group communication, it needs not only to authenticate memberships but also to establish a group key among all members. In this paper, we propose a novel design to provide both membership authentication and group key establishment. Our proposed membership authentication can not only detect nonmembers but also identify who are the nonmembers. We first propose a basic membership authentication and key establishment protocol which can only support one-time group communication. Then, we extend the basic protocol to support multiple group communications. Our design is unique since tokens of users issued by a group manager (GM) during registration are used for both membership authentication and group key establishment

Law as a Sword, Law as a Shield

What does the rule of law mean in the Chinese context? Based on empirical research in Beijing and Hong Kong, this article examines the various ways politically liberal lawyers in China make sense of the rule of law in their discourses and collective action. Although the rule of law is frequently invoked by lawyers as a legitimating discourse against the authoritarian state, its use in practice is primarily for instrumental purposes, as both a sword and a shield. For activist lawyers in Beijing, the pursuit of judicial independence is nothing but a distant dream involving a restructuring of the state, and they therefore focus their mobilisation for rule of law around basic legal freedoms and the growth of civil society. By contrast, Hong Kong lawyers hold the autonomy of their judiciary as a paramount value mainly because it is a powerful defensive weapon against Beijing’s political influence. The rule of law as a shield is only effective where its institutional and normative foundations are solid (as in Hong Kong), and it becomes little more than a blunt sword for lawyers where such foundations are weak or missing (as in mainland China)

On Representable Matroids and Ideal Secret Sharing

In secret sharing, the exact characterization of ideal access structures is a longstanding open problem. Brickell and Davenport (J. of Cryptology, 1991) proved that ideal access structures are induced by matroids. Subsequently, ideal access structures and access structures induced by matroids have attracted a lot of attention. Due to the difficulty of finding general results, the characterization of ideal access structures has been studied for several particular families of access structures. In all these families, all the matroids that are related to access structures in the family are representable and, then, the matroid-related access structures coincide with the ideal ones. In this paper, we study the characterization of representable matroids. By using the well known connection between ideal secret sharing and matroids and, in particular, the recent results on ideal multipartite access structures and the connection between multipartite matroids and discrete polymatroids, we obtain a characterization of a family of representable multipartite matroids, which implies a sufficient condition for an access structure to be ideal. By using this result and further introducing the reduced discrete polymatroids, we provide a complete characterization of quadripartite representable matroids, which was until now an open problem, and hence, all access structures related to quadripartite representable matroids are the ideal ones. By the way, using our results, we give a new and simple proof that all access structures related to unipartite, bipartite and tripartite matroids coincide with the ideal ones

Angelica Sinensis promotes myotube hypertrophy through the PI3K/Akt/mTOR pathway

BACKGROUND: Angelica Sinensis (AS), a folk medicine, has long been used in ergogenic aids for athletes, but there is little scientific evidence supporting its effects. We investigated whether AS induces hypertrophy in myotubes through the phosphatidylinositol 3-kinase (PI3K)/Akt (also termed PKB)/mammalian target of the rapamycin (mTOR) pathway. METHODS: An in vitro experiment investigating the induction of hypertrophy in myotubes was conducted. To investigate whether AS promoted the hypertrophy of myotubes, an established in vitro model of myotube hypertrophy with and without AS was used and examined using microscopic images. The role of the PI3K/Akt/mTOR signaling pathway in AS-induced myotube hypertrophy was evaluated. Two inhibitors, wortmannin (an inhibitor of PI3K) and rapamycin (an inhibitor of mTOR), were used. RESULT: The results revealed that the myotube diameters in the AS-treated group were significantly larger than those in the untreated control group (P < 0.05). Wortmannin and rapamycin inhibited AS-induced hypertrophy. Furthermore, AS increased Akt and mTOR phosphorylation through the PI3K pathway and induced myotube hypertrophy. CONCLUSION: The results confirmed that AS induces hypertrophy in myotubes through the PI3K/Akt/mTOR pathway

MeInfoText 2.0: gene methylation and cancer relation extraction from biomedical literature

<p>Abstract</p> <p>Background</p> <p>DNA methylation is regarded as a potential biomarker in the diagnosis and treatment of cancer. The relations between aberrant gene methylation and cancer development have been identified by a number of recent scientific studies. In a previous work, we used co-occurrences to mine those associations and compiled the MeInfoText 1.0 database. To reduce the amount of manual curation and improve the accuracy of relation extraction, we have now developed MeInfoText 2.0, which uses a machine learning-based approach to extract gene methylation-cancer relations.</p> <p>Description</p> <p>Two maximum entropy models are trained to predict if aberrant gene methylation is related to any type of cancer mentioned in the literature. After evaluation based on 10-fold cross-validation, the average precision/recall rates of the two models are 94.7/90.1 and 91.8/90% respectively. MeInfoText 2.0 provides the gene methylation profiles of different types of human cancer. The extracted relations with maximum probability, evidence sentences, and specific gene information are also retrievable. The database is available at <url>http://bws.iis.sinica.edu.tw:8081/MeInfoText2/</url>.</p> <p>Conclusion</p> <p>The previous version, MeInfoText, was developed by using association rules, whereas MeInfoText 2.0 is based on a new framework that combines machine learning, dictionary lookup and pattern matching for epigenetics information extraction. The results of experiments show that MeInfoText 2.0 outperforms existing tools in many respects. To the best of our knowledge, this is the first study that uses a hybrid approach to extract gene methylation-cancer relations. It is also the first attempt to develop a gene methylation and cancer relation corpus.</p

Understanding the Role of Knowledge Co-Production between Users and Developers in ISD Project: An Intellectual Capital Perspective

Information system development (ISD) has long been treated as that process that system developers craft an artifact to support business operation based on their special expertise. However, a significant portion of projects still have failed because the developed outcome cannot fit users’ needs. An emerging internal service concept indicates that, by treating ISD as one type of service, the requirement definition can be viewed as a co-production process in which users and developers integrate their own knowledge. By incorporating this concept into research design and taking intellectual capital perspective into account, this study proposed a model to examine the antecedents and consequences of knowledge co-production between users and developers. Data collected from 267 developers confirmed our hypotheses that knowledge co-production can benefit ISD outcomes, and common knowledge, relational capital and participative decision-making between these two parties increase the effectiveness of knowledge co-production effectively. Lastly, the implications toward academic and practitioner are also provided

How to Share Secret Efficiently over Networks

In a secret-sharing scheme, the secret is shared among a set of shareholders, and it can be reconstructed if a quorum of these shareholders work together by releasing their secret shares. However, in many applications, it is undesirable for nonshareholders to learn the secret. In these cases, pairwise secure channels are needed among shareholders to exchange the shares. In other words, a shared key needs to be established between every pair of shareholders. But employing an additional key establishment protocol may make the secret-sharing schemes significantly more complicated. To solve this problem, we introduce a new type of secret-sharing, called protected secret-sharing (PSS), in which the shares possessed by shareholders not only can be used to reconstruct the original secret but also can be used to establish the shared keys between every pair of shareholders. Therefore, in the secret reconstruction phase, the recovered secret is only available to shareholders but not to nonshareholders. In this paper, an information theoretically secure PSS scheme is proposed, its security properties are analyzed, and its computational complexity is evaluated. Moreover, our proposed PSS scheme also can be applied to threshold cryptosystems to prevent nonshareholders from learning the output of the protocols

Genetic copy number variants in myocardial infarction patients with hyperlipidemia

<p>Abstract</p> <p>Background</p> <p>Cardiovascular disease is the chief cause of death in Taiwan and many countries, of which myocardial infarction (MI) is the most serious condition. Hyperlipidemia appears to be a significant cause of myocardial infarction, because it causes atherosclerosis directly. In recent years, copy number variation (CNV) has been analyzed in genomewide association studies of complex diseases. In this study, CNV was analyzed in blood samples and SNP arrays from 31 myocardial infarction patients with hyperlipidemia.</p> <p>Results</p> <p>We identified seven CNV regions that were associated significantly with hyperlipidemia and myocardial infarction in our patients through multistage analysis (P<0.001), at 1p21.3, 1q31.2 (<it>CDC73</it>), 1q42.2 (<it>DISC1</it>), 3p21.31 (<it>CDCP1</it>), 10q11.21 (<it>RET</it>) 12p12.3 (<it>PIK3C2G</it>) and 16q23.3 (<it>CDH13</it>), respectively. In particular, the CNV region at 10q11.21 was examined by quantitative real-time PCR, the results of which were consistent with microarray findings.</p> <p>Conclusions</p> <p>Our preliminary results constitute an alternative method of evaluating the relationship between CNV regions and cardiovascular disease. These susceptibility CNV regions may be used as biomarkers for early-stage diagnosis of hyperlipidemia and myocardial infarction, rendering them valuable for further research and discussion.</p