A Distributed Public Key Caching Scheme in Large Wireless Networks.

When asymmetric cryptography techniques are used in wireless networks, the public keys of the nodes need to be widely available and signed by a Certificate Authority (CA). However, the existence of a single CA in large wireless networks such as mobile ad hoc networks and wireless sensor networks can lead the hotspot problem and become a security weakness. In this work, we propose a distributed technique to cache the public keys on regular nodes. Due to the limited memory size that each node is allowed to dedicate for key caching, only some keys can be cached. In our proposed technique, each node caches the public keys of a mix of local and remote nodes. The local nodes are defined as the nodes within the same neighborhood according to the transmission range, while the remote nodes are the ones outside the range. Access to the public keys of other nodes is possible based on a chain of trust. Multiple copies of public keys from different chains of trusted nodes provide fault tolerance. We explain our technique in detail and investigate its salient features in this work. An interesting observation is the need to balance caching public keys of local nodes and remote nodes. We studied the optimum local/remote public key caching ratios for different networks via investigating the availability of the number of required public key copies. These simulation results showed that by balancing the caching public keys with the optimum ratios, the availability of the required public keys kept increasing and finally became stable. We also did the simulation about studying the number of hops to find the first copies of required public keys. The results showed how local/remote ratios affected the minimum number of hops for reaching the first copies

An experimental and theoretical study of cobalt (II) and nickel (II) complexes with acetonitrile as ligands

Acetonitrile is a weak base and is not frequently used as a ligand in coordination chemistry investigations. Due to the nature of this ligand, it was thought that cobalt(II) and nickel(II) complexes with acetonitrile ligands would be unstable and that the solid state of these complexes probably would not exist. Basolo1 indicated that solid salts separated from solution easiest for combinations of either small-small or large-large cations and anions, preferably with systems having the same but opposite charges on the counter ions. The driving force for the large cation-large anion combination to form solid is the small hydration energy of the ions. When Co (II) and Ni(II) are completely solvated by acetonitrile, they form large cations; these large cations could be effectively stabilized by large anions such as tetrachlorometallates or tetrabromometallates. The purpose of this study is fourfold. The first is to synthesize the complexes by using large anions, BCl4 and BBr4. The second is to compare results with similar systems. The third is to make theoretical investigations of the molecular model assuming distortion and the last is to analyze the complexes experimentally

The Counseling Training Environment Scale (CTES) : development of a self-report measure to assess counseling training environment

Based on Bronfenbrenner's (1979, 1992) ecological framework, the Counseling Training Environment Scale (CTES) was developed as a self-report measure that assesses the learning and training environment of counseling and related mental health training programs as perceived by current students. A two-phase mixed-methods design was used to create and psychometrically evaluate the CTES: (a) item development, and (b) assessment of the outcomes to examine for preliminary evidence of validity and reliability. The results of the item development and content validation process yielded 128 items, of which 34 were used for the final intact version of the CTES. A confirmatory factor analysis (CFA) was conducted on four models of the CTES: (a) 34-item single-factor model, (b) 34-item five-factor model, (c) 26-item modified five-factor model, and (d) 24-item modified single-factor model. Results of the CFA suggest that despite not conforming to the hypothesized model of Bronfenbrenner's (1979, 1992) ecological theory, the data gathered from the modified 24-item single-factor CTES demonstrated the best fit on the following fit indices: NNFI (.95), CFI (.96), SRMR (.04), and RMSEA (.04). The modified 24-item CTES was also found to demonstrate strong reliability and temporal stability as demonstrated through Classical Test Theory analyses (a = .92) and test-retest reliability (r = .90, p< .01, two-tailed)

The Impacts of Shopbots on Online Consumer Search

Online price comparison agents (shopbots) allow consumers to instantaneously receive price and other information from many online retailers. Online consumer clickstream data from ComScore Inc. demonstrate that consumers are increasingly using shopbots to conduct search. This phenomenon raises such questions as "how do shopbots change consumers' search behavior?" and "do they reduce consumers' online search?" Conventional wisdom suggests that consumers are expected to search less because shopbots have displayed prices and other relative information from retailers on the search result page(s). Surprisingly, this study demonstrates the opposite result. That is, consumers are actually visiting more online retailer web sites after using shopbots. This finding suggests that after searching for an item through a shopbot and receiving the price information, consumers will continue to look for detailed information about the online retailers by visiting their web sites. The empirical finding is explained by an analytical model, which shows that on the one hand shopbots reduce the marginal benefit of searching additional online stores; on the other hand they reduce the cost of search. Therefore whether shopbots reduce consumer search depends on the cost of reducing per unit of risk, which is decided by a number of factors, such as marginal search costs, price dispersion and quality differentiation among stores, price and quality correlation, and consumers' relative preference for service quality. The model also gives sufficient and necessary conditions under which shopbots increase consumer surplus

The prevalence of simulation technology in athletic training clinical education

Athletic training clinical education is the most integral component in the transition into practice. However, barriers within clinical education exist, which may affect athletic training students' professional preparedness. Simulation technology, within other healthcare professionals' education, has shown promising benefits. However, research regarding simulation technology in athletic training is limited, with current practices relatively unknown. This study assessed the prevalence of simulation technology and explored factors that influence its use in athletic training clinical education. Athletic training program directors or clinical coordinators (n=54) completed an online survey via Qualtrics. The survey examined current simulation technology practices in clinical education. Additionally, participants rated the influence of barriers, challenges, and facilitators on its use. Survey responses indicated that 31 of 54 programs were using some form of simulation technology, with an additional 11 programs stating they were considering using it in the future. Within these programs, high-fidelity simulation (n=22) was the predominant type used. In addition, most of these programs noted improvements in professional competencies (e.g., decision-making, skill development) and clinical experiences (i.e., engaged time, incident variety), 84% and 77%, respectively. Of the 54 programs, 36 rated "high financial cost" as a very influential barrier. "Limited staffing and availability" were also found to be big challenges. On the other hand, 26 of 54 programs rated "additional healthcare programs" very influential, the most among facilitators. The results indicate that simulation technology is currently used within athletic training clinical education, but barriers still influence its use. Future research should continue examining simulation technology's benefits and exploring specific implementation strategies to improve use

Microbial ligand costimulation drives neutrophilic steroid-refractory asthma

Funding: The authors thank the Wellcome Trust (102705) and the Universities of Aberdeen and Cape Town for funding. This research was also supported, in part, by National Institutes of Health GM53522 and GM083016 to DLW. KF and BNL are funded by the Fonds Wetenschappelijk Onderzoek, BNL is the recipient of an European Research Commission consolidator grant and participates in the European Union FP7 programs EUBIOPRED and MedALL. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

RNAseq Analyses Identify Tumor Necrosis Factor-Mediated Inflammation as a Major Abnormality in ALS Spinal Cord

ALS is a rapidly progressive, devastating neurodegenerative illness of adults that produces disabling weakness and spasticity arising from death of lower and upper motor neurons. No meaningful therapies exist to slow ALS progression, and molecular insights into pathogenesis and progression are sorely needed. In that context, we used high-depth, next generation RNA sequencing (RNAseq, Illumina) to define gene network abnormalities in RNA samples depleted of rRNA and isolated from cervical spinal cord sections of 7 ALS and 8 CTL samples. We aligned \u3e50 million 2X150 bp paired-end sequences/sample to the hg19 human genome and applied three different algorithms (Cuffdiff2, DEseq2, EdgeR) for identification of differentially expressed genes (DEG’s). Ingenuity Pathways Analysis (IPA) and Weighted Gene Co-expression Network Analysis (WGCNA) identified inflammatory processes as significantly elevated in our ALS samples, with tumor necrosis factor (TNF) found to be a major pathway regulator (IPA) and TNFα-induced protein 2 (TNFAIP2) as a major network “hub” gene (WGCNA). Using the oPOSSUM algorithm, we analyzed transcription factors (TF) controlling expression of the nine DEG/hub genes in the ALS samples and identified TF’s involved in inflammation (NFkB, REL, NFkB1) and macrophage function (NR1H2::RXRA heterodimer). Transient expression in human iPSC-derived motor neurons of TNFAIP2 (also a DEG identified by all three algorithms) reduced cell viability and induced caspase 3/7 activation. Using high-density RNAseq, multiple algorithms for DEG identification, and an unsupervised gene co-expression network approach, we identified significant elevation of inflammatory processes in ALS spinal cord with TNF as a major regulatory molecule. Overexpression of the DEG TNFAIP2 in human motor neurons, the population most vulnerable to die in ALS, increased cell death and caspase 3/7 activation. We propose that therapies targeted to reduce inflammatory TNFα signaling may be helpful in ALS patients

The role of bisphosphonates in breast cancer: The present and future role of bisphosphonates in the management of patients with breast cancer

At least 25% of patients with breast cancer develop skeletal metastases, with bone the site of disease producing the greatest morbidity. It is apparent that the bisphosphonates present an important component of the treatment strategy. They are now the treatment of choice in tumour-induced hypercalcaemia, and they can reduce bone pain and skeletal complications such as pathological fractures. In addition, bisphosphonates are being increasingly evaluated in the prevention of bone metastases and to prevent and treat cancer therapy-induced osteoporosis. Ongoing research is aimed at trying to define the optimum route, dose, schedule and type of bisphosphonate

Alteration of the serum levels of the epidermal growth factor receptor and its ligands in patients with non-small cell lung cancer and head and neck carcinoma

Serum levels of the soluble epidermal growth factor receptor (sEGFR) and its ligands epidermal growth factor (EGF), transforming growth factor-α (TGF-α) and amphiregulin (AR) were measured in healthy donors and patients with non-small cell lung cancer (NSCLC) and head and neck carcinoma (HNC). In NSCLC, we found sEGFR and EGF levels significantly lowered in patients with respect to healthy donors. In HNC patients, significantly diminished levels were found in the case of sEGFR, EGF and also AR. In both malignancies, no significant association was found between the serum levels of the molecules and the patients' gender, age or smoking habit. Only a significant association was found between the decrease of sEGFR and the absence of distant metastasis in NSCLC and the tumour stage in HNC. The most interesting result was that combining sEGFR and EGF, sensitivities of 88% in NSCLC and 100% in HNC were reached without losing specificity (97.8% in both cases). The use of discriminant analysis and logistic regression improved the sensitivity for NSCLC and the specificity for HNC. These data demonstrate a potentially interesting value of the serum levels of sEGFR and EGF, especially when combined, as markers for NSCLC and HNC