Latent Ties: Reconnection of Organizations to Boost Innovation

This paper highlights the temporality dimension of ties. Doing so we respond to recent calls for a more dynamic and processual understanding of networks. We proposed a model in which two antecedents of latent ties, network similarity, and length of the tie, will be tested. Also, our study addresses the relationship between tie latency and innovation. The model tests the impact of the interaction between the number of latent and strong ties on organizations innovative output will be studied. The study highlights the significance of latent ties in coping with the problems of redundancy of dense network and overloading of new weak ties

Methicillin-Resistant Staphylococcus epidermidis in Iran: A Systematic Review and Meta-Analysis

Objective: Methicillin-resistant Staphylococcus epidermidis (MRSE) remains one of the most prevalent drug-resistant bacteria causing health care infections. Limited data are available about how the frequency of MRSE changed in Iran over the past years. The current study aimed at determining the frequency of MRSE in different cities of Iran. Methods: Databases including Web of Sciences, Scopus, Embase, Medline, and Iranian databases were searched to find studies addressing the frequency of MRSE in Iran published from Mar 2006 to Jan 2016. The data were analyzed using comprehensive meta-analysis version 2.2 (Biostat). Of the 139 records identified in the databases, 15 studies met the inclusion criteria. Results: The analyses showed that the frequency of MRSE infections was 73.9% [95% confidence interval (95% CI) 61.4 - 83.4] among culture-positive cases of S. epidermidis in different parts of Iran. The frequency of MRSE was higher in the studies conducted from 2011 to 2015, based on further stratified analyses. Conclusions: The regular surveillance on antimicrobial susceptibility pattern and formulation of definite antibiotic policy may control high rate of MRSE associated infections in Iran. Moreover, rapid and reliable diagnosis of MRSE isolates and regular screening of the personnel and surfaces of hospitals in terms of MRSE are indispensable

Cloning of the Recombinant Cytochrome P450 Cyp141 Protein of Mycobacterium tuberculosis as a Diagnostic Target and Vaccine Candidate

Background: Tuberculosis has been announced as a global emergency by World Health Organization and the second infectious agent of mortality worldwide. The general policy in the development of new vaccines is to develop some vaccines with higher efficiency not only for infants but also for adults compared with the Bacillus Calmette-Guerin vaccine. Recently, cytochrome P450 cyp141 has been introduced as a new target for detecting Mycobacterium tuberculosis from clinical samples. Objectives: The aim of this study was to clone this gene in order to pave the way for more evaluation. Materials and Methods: M. tuberculosis H37Rv DNA was extracted by a standard phenol-chlorophorm protocol. After designing the specific primers, P450 cyp141 gene was replicated by PCR. The purified PCR products were then subcloned into the pTZ57R/T plasmid vector. After extraction, enzyme digestion, and recombinant pTZ57R/T-cyp141 plasmid vector sequencing, the aforementioned products were cloned into a pET-26b plasmid vector. Then, the recombinant pET26b-cyp141 plasmid molecules were transformed to Escherichia coli strain BL21 (DE3) using the transformation method. Next, the recombinant pET26b-cyp141 plasmids were purified and evaluated by the enzyme digestion analysis. Results: The cloning of P450 cyp141 gene was confirmed by the enzyme digestion and sequencing of the recombinant pTZ57R/T-cyp141 and pET26b-cyp141 plasmid vectors. Conclusions: The results of this study demonstrated that the P450 cyp141 gene was successfully cloned into a pET26b plasmid vector as an expression vector. In this paper, for the first time in Iran, this gene was cloned for more purposes, including the expression and purification of the recombinant cytochrome P450 cyp141 protein

Detection of tetracycline resistance genes, aminoglycoside modifying enzymes, and coagulase gene typing of clinical isolates of Staphylococcus aureus in the Southwest of Iran

Objective(s): The aim of the present study was to determine the aminoglycoside modifying enzymes (AMEs) encoded genes, tetracycline resistance genes, and the coa based typing of Staphylococcus aureus isolates in the Southwest of Iran. Materials and Methods: Antimicrobial susceptibility of isolates was carried out by agar disk diffusion methods. Two sets of multiplex PCR mixture were used for detection of AME genes and tet genes.  All of the isolates were typed with the coagulase gene typing method. Of the 121 isolates, 29.75% and 47.93% were resistant to at least one aminoglycosides and tetracyclines, respectively. Results: The aac(6')-Ie-aph(2'') was the most frequent gene (97.22%), and aph (3')-IIIa and ant (4')-Ia genes were detected in 61.11% and 11.11% of aminoglycoside resistant isolates, respectively. The tetK and tetM genes were detected in 82.75% and 56.9% of tetracycline resistant isolates, respectively. Overall 31.4% of isolates were MRSA. Totally 17 distinct coa gene RFLP patterns, numbered C1 to C17, were observed.  The C5 was the most frequent coa type with 31 isolates. Conclusion: The aac(6')-Ie-aph(2'') and aph (3')-IIIa genes were the most important genes contributing to aminoglycosides resistance, while resistance to tetracyclines was mediated by tetK and tetM genes. Interestingly all S. aureus with C5 as the most prevalent coa-type were resistant to at least one of the aminoglycoside antibiotics and tetracycline simultaneously. Moreover, 30 out of 31 isolates with this coa type were MRSA, indicating the importance of the C5 coa-type in MRSA strains and also in isolates that were resistant to aminoglycosides and tetracycline

Emotional Foundations of Individual’s Perception: The Case of Technology Radicalness

Due to the growing importance of enterprise resource planning (ERP) systems, universities and corporate training programs have included such systems into their curricula using novel tools, such as ERP simulation games. To improve our understanding of individuals’ learning patterns, in this study we extend prior cognition based models by incorporating emotions. Moreover, we highlight the role of perceived radicalness, which mediates the relationship between emotions and individual willingness to learn. Our research model draws from the appraisal tendency framework and includes four distinct classes of emotions: challenge, achievement, loss, and deterrence emotions. We conducted a lab experiment to test the model in an ERP simulation game context. The preliminary results indicate that perceived radicalness is an important mechanism via which classes of emotions impact students\u27 learning behaviors. We also found that, in general, negative emotions had more effect on radicalness perceptions compared to positive emotions

How Niche Is Niche? Measuring Individuals’ Perception of Technology Niche

Despite the recent advent and popularity of niche technologies, less is known about the adoption dynamics of such systems. In a quest for understanding and differentiating between mainstream vs. niche technologies, and the way such differences influence individuals’ information systems (IS) behaviors, the study argues that a scale to measure individual’s niche perception in the domain of technology usage is needed. Basing on the main argument of the Optimal Distinctiveness theory, the study introduces a much-needed conceptualization and operationalization of niche technology perceptions in the literature. Across three studies, we test a typology of perceived niche and develop and validate a 4-item scale to measure individuals’ niche perceptions in IS domain. As a result, academic researchers may now rely on the developed scale to investigate the dynamics of users’ IS behaviors by incorporating the potential effect of the perceptions of niche in their future research studies

Understanding the Perception of Information System Niche: Conceptualization, Measurement, and Validation

The number of niche technologies is growing, and they are getting noticed. However, the usage dynamics of such systems have not been explored. This study introduces the “niche” information systems (IS) construct to differentiate between mainstream and niche technologies and to illustrate how such differences potentially influence a person’s IS usage behavior. We posit that niche-ness is perceptual, and a measurement to gauge an individual’s niche perception in the domain of systems usage is desired. Resting on Optimal Distinctiveness theory, the study develops a novel conceptualization and operationalization of niche technology perceptions, focusing on social networking systems. Our main contribution includes the examination of the typology of the perceived niche, which results in the development and validation of an eight-item instrument for perceived technology niche through three studies. In addition, by placing the construct in a nomological network in a fourth study, we demonstrate that the perceived technology niche construct is related to IS continuance intention

Mechanical activation for sulfidic tailings treatment by tailings: Environmental aspects and cement consumption reduction

Sulfidic mine tailings are one of the massive hazardous solid wastes, containing large amounts of toxic heavy metals. Poor management of tailings can lead to the production of acid mine drainage and the heavy metal transfer emissions into the environment. Thus, in this study, mechanical activation was used to reuse a combination of carbonate tailings (TC) and sulfidic tailings (TS) for concrete construction purposes and to effectively immobilize heavy metals. The results showed that after tailings treatment, the heavy metal leaching rate was significantly below the allowed criteria based on the toxicity characteristic leaching procedure (TCLP). The mercury intrusion porosimetry (MIP) test results on the specific surface area and porosity after the activation pointed out increase and reduction, respectively. In the concrete sample containing 20 % cement-replacing activated tailings, the critical pore diameter after 28 curing days was 60 nm, which was less than that of the control sample with a critical pore diameter of 150 nm. According to X-ray diffraction (XRD) and scanning electron microscopy (SEM), ettringite and calcium silicate hydrate gel acted as hosts for heavy metals ions and played an inevitable role in stabilizing metal pollutants. Results revealed that the compressive strength of the sample containing 20 % of the activated tailings after 28 curing days was 31.2 MPa, which was higher than the strength of the control sample (26.99 MPa). Overall, it was concluded that the combined mechanically activated mine tailings can be a viable substitute for cement (up to 40 %) for constructing concrete samples. The utilized combined approach led to diminish adverse effect of sulfide content in concrete samples besides the cement consumption reduction

Simultaneous Removal of Cyanide and Heavy Metals Using Photoelectrocoagulation

One of the new methods used to remove the contaminants from effluent is the electrocoagulation method, which is sometimes combined with other methods to increase the removal efficiency of contaminants. To simultaneously remove nickel, cyanide, zinc, and copper, the combined method of photo-electrocoagulation was used along with an oxidizing agent, namely hydrogen peroxide (Hp). In addition, the effects of factors affecting the removal efficiency were studied, including pH, electrode arrangement, and current intensity. An electric current of 300 mA at a pH of 10 for 60 min, Fe-SS electrodes with a distance between them of 5 cm, and hydrogen peroxide at a rate of 4 mg/L were the ideal conditions needed to accomplish the photo-electrocoagulation-oxidation process. According to these study findings, when the combined method of photocatalyst-electrocoagulation-oxidation (Hp) was used, the highest removal efficiencies of nickel, cyanide, zinc, and copper were 85, 96, 94, and 98%, respectively. The results showed that using the combined photo-electrocoagulation-oxidation method increased the efficiency of simultaneous removal of pollutants by 10% compared to conventional electrocoagulation method. The reason for the increase in removal efficiency is the production of hydroxyl radicals simultaneously with the formation of coagulants produced by electrocoagulation process

Cytochrome CYP141: A new target for direct detection of Mycobacterium tuberculosis from clinical specimens

Cytochrome P450 CYP141 is an intermediary metabolic and respiratory protein that interferes with oxidation reduction in Mycobacterium tuberculosis. This conserved protein has also been debated as a hypothetical target for therapeutics. We used the sequences of CYP141 gene to develop a PCR for rapid detection of Mycobacterium tuberculosis from respiratory specimens. The sensitivity of this PCR for culture positive-smear positive and culture positive-smear negative samples were 92% and 62.5%, respectively. The overall sensitivity and specificity of this PCR was 85.7% and 97.8%. As compared with other studies, it appears that the CYP141 gene is a good target for direct detection of M. tuberculosis from respiratory specimens