Fractional forcing number of graphs

The notion of forcing sets for perfect matchings was introduced by Harary, Klein, and \v{Z}ivkovi\'{c}. The application of this problem in chemistry, as well as its interesting theoretical aspects, made this subject very active. In this work, we introduce the notion of the forcing function of fractional perfect matchings which is continuous analogous to forcing sets defined over the perfect matching polytope of graphs. We show that our defined object is a continuous and concave function extension of the integral forcing set. Then, we use our results about this extension to conclude new bounds and results about the integral case of forcing sets for the family of edge and vertex-transitive graphs and in particular, hypercube graphs

Suicide Prevention and Follow-Up Services: A Narrative Review

Previous suicide attempt is the most important predictor of death by suicide. Thus preventive interventions after attempting to suicide is essential to prevent reattempts. This paper attempts to determine whether phone preventive interventions or other vehicles (postal cards, email and case management) are effective in reattempt prevention and health promotion after discharge by providing an overview of studies on suicide reattempts. The research investigated in this review conducted from 1995 to 2014. A total of 26 cases related to the aim of this research were derived from 36 English articles with the aforementioned keywords Research shows that providing comprehensive aids, social support, and follow-up after discharge can significantly prevent suicide reattempts. Several studies showed that follow-up support (phone calls, crisis cards, mails, postal cards.) after discharge can significantly decrease the risk of suicide. More randomized controlled trials (RCT) are required to determine what factors of follow-up are more effective than other methods

Comparing the effects of Merrill & Gagne’s instructional design models on cognitive load, learning and instructional efficiency

Background and Objectives: With the increasing importance of instructional multimedia and the use of their interactive and unique features in the teaching-learning process, we are witnessing the design and production of this technology and its use in teaching courses and different levels of the educational system. Cognitive load theory, as one of the theories related to information processing, is one of the most effective theories in instructional design and an effective guide for designing multimedia and other instructional materials. The basic premise of this theory is that learners have very limited working memory capacity to process when facing with new information. The purpose of this theory is to predict learning outcomes by considering the capabilities and limitations of human cognitive structure. Cognitive load theory is based on the idea that the design of instructional materials should be based on our knowledge of how the human mind works. Based on this assumption, the various processes of acquiring knowledge and understanding are explained based on the load they place on the human cognitive system (which is an active system with limited information processing capacity). Because this theory links the design features of instructional materials to the principles of human cognitive processing, it can be used in a wide range of learning environments.The present study aimed to compare the effects of Merrill and Gagne's instructional design models on students' cognitive load, learning and instructional efficiency in Science lesson. Methods: The study was quasi-experimental with pretest and posttest design with two experimental and one control groups. The statistical population consisted of all male students of the sixth grade elementary school of Qazvin. The sample including three 30 students’ classes were selected through convenience sampling procedure and the classes randomly assigned to experimental and control groups. The materials and instruments included instructional multimedia contents, learning tests, and cognitive load assessment scale. The first experimental group studied the multimedia based on the Merrill model, the second group studied the multimedia based on the Gagne model and the control group studied non-model multimedia. Data were analyzed by using analysis of covariance (ANCOVA). Findings: The results of the study showed that multimedia based on the Merrill instructional design model compared to multimedia based on Gagne instructional design model and non-model multimedia, has led to less cognitive load, more learning and instructional efficiency. Also, multimedia based on Gagne's instructional design model compared to non-model multimedia led to less cognitive load, more learning and instructional efficiency. Conclusion: One of the concerns of educational designers in the process of designing the content of multimedia educational materials and other learning materials has always been focused on the appropriate selection of instructional design models. Since there are different models for instructional design of learning materials, to choose a suitable model, one should rely on theoretical foundations and the results of research conducted in various theoretical areas, including cognitive load theory. According to the findings of this study, it is suggested that in order to reduce the cognitive load and increase students’ learning, Merrill instructional design model would be used in designing instructional multimedia content.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

Alcohol Abuse and Suicide Attempt in Iran: A Case-Crossover Study

Alcohol use and its disorders are associated with increased risk of suicidal behaviors Research has shown that 6-8 of those who use alcohol have a history of suicide attempt. Given the prohibition of alcohol use legally, the increased alcohol consumption, and the lack of strong evidence in favor of its use associated with suicide in Iran, this study was conducted to determine the link between suicide attempt and alcohol abuse. The case-crossover method was used in this research. Out of 305 referrals to the emergency room due to a suicide attempt, 100 reported drinking alcohol up to six hours before their attempt. Paired Matching and Usual Frequency were employed to analyze the data with STATA 12.0. The probability of attempting suicide up to six hours after drinking alcohol appeared increased by 27 times (95 CI: 8.1-60.4). Separate analysis for each of these hours from the first to the sixth hour after alcohol use was also performed. Fifty percent of attempted suicides happened one hour after alcohol use. Relative risk for the first and second hour was 10 and 5 respectively. Alcohol use is a strong proximal risk factor for attempted suicide among Iranian subjects. Prevention of alcohol use should be considered in setting up of the national Suicide attempt prevention program

Radio-frequency dressed lattices for ultracold alkali atoms

Ultracold atomic gases in periodic potentials are powerful platforms for exploring quantum physics in regimes dominated by many-body effects as well as for developing applications that benefit from quantum mechanical effects. Further advances face a range of challenges including the realization of potentials with lattice constants smaller than optical wavelengths as well as creating schemes for effective addressing and manipulation of single sites. In this paper we propose a dressed-based scheme for creating periodic potential landscapes for ultracold alkali atoms with the capability of overcoming such difficulties. The dressed approach has the advantage of operating in a low-frequency regime where decoherence and heating effects due to spontaneous emission do not take place. These results highlight the possibilities of atom-chip technology in the future development of quantum simulations and quantum technologies, and provide a realistic scheme for starting such an exploration

InP/InGaP quantum-dot SESAM mode-locked Alexandrite laser

A semiconductor saturable absorber mirror (SESAM) passively mode-locked Alexandrite laser was demonstrated. Using an InP/InGaP quantum-dot saturable absorber mirror, pulse duration of 420 fs at 774 nm was obtained. The laser was pumped at 532 nm and generated 325 mW of average output power in mode-locked regime with a pump power of 7.12 W. To the best of our knowledge, this is the first report of a passively mode-locked Alexandrite laser using SESAM in general and quantum-dot SESAM in particular

Repetitive transcranial magnetic stimulation in resistant visual hallucinations in a woman with schizophrenia: A case report

A 29-year-old woman with schizophrenia introduced for application of repetitive transcranial magnetic stimulation for refractory visual hallucinations. Following inhibitory rTMS on visual cortex she reported significant reduction in severity and simplification of complexity of hallucinations, which lasted for three months. rTMS can be considered as a possibly potent treatment for visual hallucinations. © 2016, Mazandaran University of Medical Sciences

A Discrete Version of the Inverse Scattering Problem and the J-matrix Method

The problem of the Hamiltonian matrix in the oscillator and Laguerre basis construction from the S-matrix is treated in the context of the algebraic analogue of the Marchenko method.Comment: 11 pages. The Laguerre basis case is adde