Off-axis short GRBs from structured jets as counterparts to GW events

Binary neutron star mergers are considered to be the most favorable sources that produce electromagnetic (EM) signals associated with gravitational waves (GWs). These mergers are the likely progenitors of short duration gamma-ray bursts (GRBs). The brief gamma-ray emission (the "prompt GRB" emission) is produced by ultra-relativistic jets, as a result, this emission is strongly beamed over a small solid angle along the jet. It is estimated to be a decade or more before a short GRB jet within the LIGO volume points along our line of sight. For this reason, the study of the prompt signal as an EM counterpart to GW events has been sparse. We argue that for a realistic jet model, one whose luminosity and Lorentz factor vary smoothly with angle, the prompt signal can be detected for a significantly broader range of viewing angles. This can lead to a new type of EM counterpart, an "off-axis" short GRB. Our estimates and simulations show that it is feasible to detect these signals with the aid of the temporal coincidence from a LIGO trigger, even if the observer is substantially misaligned with respect to the jet.Comment: 6 pages, 4 figures, accepted to MNRAS Letter

Alternative Learning Approaches for Enhanced Students’ Engagement in Engineering Courses

In the context of globalization and explosion of knowledge, engineering practices have to make a shift from mere problem solving towards more innovative solutions embedded in an array of social, economic, cultural and ethical issues.  Innovation is a key differentiator in an increasingly global economy.  The role of our engineering schools in providing human capital, necessary to meet future national needs, new orientation. Today’s learners perceive learning as a “plug and play” experience.  They want to plunge in and learn through participation and experimentation. Traditional approaches emphasize the presentation of information and consider learning as mere absorption of information.  In contrast an effective student centered learning requires different perspectives from students and the teachers.  The lecture dominated system encourages a passive learning environment, a highly compartmentalized curriculum and instills neither motivation nor skills for lifelong learning.  It leaves no time for critical thinking, creative thinking and association with reality.  Students today are active learners.  The need of the hour is knowledge construction that can be achieved through active learning strategies like discussions, role play, group work, problem based learning, and project based learning.  Students’ engagement is seen as a successful indicator of classroom instruction. It depends on the level of academic challenge, active and collaborative learning, student-faculty interaction, enriching educational experiences and a supportive learning environment.  This paper reports the various faculty training programmes organized in a university environment on the use of alternative learning approaches like discussions, role play and group work and its impact on students’ engagement. Keywords: Critical thinking; Creative thinking; Active learning; Students’ engagement; Alternative learning approache

Influence of High Impact Teaching Skills on the Teaching - Learning Process in Engineering Education

Teaching in higher education institutions is becoming more and more critical and intricate with each new generation of students entering the portals of higher education. Academic Staff College at VIT University, from time to time, has been organizing a range of training programmes and faculty empowerment workshops for its faculty, newly recruited and faculty who are already serving. During the training sessions, it has been observed that there are some specific soft skills desired to be possessed by engineering teachers, in addition to their disciplinary knowledge and subject matter expertise. These skills are: creating a positive impression, simplifying complex information, use of analogies, communicating with greater impact, responding to difficult class room situations and inspiring peers and students to embrace change. In addition, generic communication skills such as use of appropriate body language and gestures, confidence, presentation of information in a logical and methodical manner, showing empathy and concern and listening skills are also required for engineering teachers. The authors have designed and implemented a model in a training environment to impart these soft skills and training in a comprehensive manner. The training methodology adopted, analysis of the observations made, the key learnings and the challenges that lie ahead for the successful development of soft skills amongst the engineering educators and teacher trainers are presented in this paper. Keywords: engineering education, training, soft skills, communication skills, using analogies, class room situations, inspiring to embrace change

Analysis Of Question Papers In Engineering Courses With Respect To Hots (Higher Order Thinking Skills)

It is generally perceived that a substantial number of engineering faculty are still unaware of alternative educational methods, and many who are aware of them choose not to incorporate them into their approach to teaching. There are several likely reasons for this inertia, aside from the inevitable human resistance to change. The primary focus of imparting information is restricted to fulfilling the course requirements and, the upcoming term end examination. It is imperative to adopt a change from teaching to learning paradigm engaging the students in Higher Order Thinking Skills. Knowledge and technological advancements are changing the role of engineering and engineering faculty in the society. Engineering Education reforms need to focus on inductive teaching and stimulated learning. Students should be taught critical thinking skills and creative thinking skills to keep pace with the rapidly changing engineering profession. This paper reports the study done to test and explore the faculty awareness of Bloom’s Taxonomy of Educational Objectives in the cognitive domain and Higher Order Thinking Skills (HOTS) and to evaluate question papers set by engineering faculty with respect to HOTS as proposed by Bloom’s Taxonomy. Various active learning strategies to enhance critical thinking skills and creative thinking skills of the students are recommended for use by the faculty in their interactions with the students.

Sympathovagal Imbalance in Prehypertensive Offspring of Two Parents versus One Parent Hypertensive

Objective. Though prehypertension has strong familial predisposition, difference in pathophysiological mechanisms in its genesis in offspring of both parents and single parent hypertensive have not been elucidated. Methods. Body mass index (BMI), waist-hip ratio (WHR), basal heart rate (BHR), blood pressure (BP), HR and BP response to standing, deep breathing difference, BP response to handgrip and spectral indices of heart rate variability (HRV) were analyzed in normotensive offspring of two parents hypertensive (Group I), normotensive offspring of one parent hypertensive (Group II), prehypertensive offspring of two parents hypertensive (Group III) and prehypertensive offspring of one parent hypertensive (Group IV). Results. Sympathovagal imbalance (SVI) in prehypertensive offspring was observed due to increased sympathetic and decreased vagal activity. In group III, SVI was more prominent with greater contribution by vagal withdrawal. LF-HF ratio, the marker of SVI was correlated more with diastolic pressure, 30 : 15 ratio and E : I ratio in prehypertensives and the degree of correlation was more in group III prehypertensives. Conclusion. Vagal withdrawal plays a critical role in development of SVI in prehypertensive offspring of hypertensive parents. The intensity of SVI was more in offspring of two parents hypertensive compared to single parent hypertensive

Effect of vitamin D on vascular health in hypertensive patients with vitamin D deficiency

Background: Many observational studies have shown association of cardiovascular disease and vitamin D deficiency. However, there is a need for prospective studies to show causal effect of vitamin D and cardiovascular diseases in India. Hence the present study was designed to study the effect of vitamin D on markers of vascular health in hypertensive patients with vitamin D deficiency. The objective of the study was to assess the effect of vitamin D supplementation on markers of vascular health in hypertensive patients with vitamin D deficiency.Methods: Hypertensive patients were screened for vitamin D deficiency defined as 25 OH vitamin D less than 20 ng/mL after written informed consent. Hypertensives deficient with 25 OH vitamin D were recruited for the study to receive cholecalciferol 60000 IU/ week for 8 weeks. The vascular parameters such as blood pressure, pulse wave velocity, arterial stiffness index, malondialdehyde and total antioxidant status were assessed at baseline and after 8 weeks of cholecalciferol. The results were analysed using paired‘t’ test.Results: A total of 119 hypertensive patients were screened for vitamin D status. Among them 57 patients were found to be vitamin D deficient (48.7%). Thirty two patients completed the study. The baseline serum 25 OH vitamin D3 was 12.55 ± 5.7 ng/mL and it increased to 40.06 ± 10.53 ng /mL after 8 weeks.Conclusions: The vascular parameters didn’t show any statistically significant difference between baseline and at 8 weeks. However trend for decline was observed for malondialdehyde, right brachial pulse wave velocity

An Investigation of Process Variables Influencing Fatigue Properties of Components Produced by Direct Metal Laser Sintering

Direct Metal Laser Sintering (DMLS) is one of the methods in layered manufacturing technologies by which metal powder can be directly used to produce both prototype and production tools. Fatigue strength is one of the important mechanical properties for the functional application of DMLS parts. This study was carried out to determine the optimum process parameters influencing the fatigue cycles to failure of DMLS components. Sintering speed, scan spacing, post-contouring speed, infiltration and hatch type are the process parameters taken up for the study. Statistical design of experiments using Taguchi’s orthogonal array was employed for this study. Experimental data obtained were analysed using analysis of variance (ANOVA). From the results, it is found that one of the process parameters, sintering speed affects the fatigue properties of parts produced by this technology to a significant exten