Sujita Kumar Kar

Study on Mitigation of Transmission Impairments and Issues and Challenges with PLIA-RWA in Optical WDM Networks

Abstract In all-optical WDM networks, feasibility of a lightpath are determined by physical layer impairment accumulation. Physical layer impairment-aware routing and wavelength assignment (PLIA-RWA) algorithms select a feasible route keeping signal to noise ratio value at the receiver above the threshold limit. This paper reviews the impairments present in optical fiber emphasizing those that result in performance degradation of WDM system. Different types of channel allocation schemes to reduce the number of four wave mixing components generated and performance of the WDM optical network under these channel allocation schemes have also been reviewed. The performance of WDM network due to collective effect of FWM-SRS and FWM-XPM has been discussed. Limitations of amplifier and its optimal location have also been discussed. The article further examines and surveys the role of wavelength converters/regenerators in regard to efficient network design. The paper also presents a survey of different PLIA-RWA algorithms and identifies several open problems for future research.

How Electroconvulsive Therapy Works?: Understanding the Neurobiological Mechanisms

Electroconvulsive therapy (ECT) is a time tested treatment modality for the management of various psychiatric disorders. There have been a lot of modifications in the techniques of delivering ECT over decades. Despite lots of criticisms encountered, ECT has still been used commonly in clinical practice due to its safety and efficacy. Research evidences found multiple neuro-biological mechanisms for the therapeutic effect of ECT. ECT brings about various neuro-physiological as well as neuro-chemical changes in the macro- and micro-environment of the brain. Diverse changes involving expression of genes, functional connectivity, neurochemicals, permeability of blood-brain-barrier, alteration in immune system has been suggested to be responsible for the therapeutic effects of ECT. This article reviews different neurobiological mechanisms responsible for the therapeutic efficacy of ECT.

Neuro-stimulation Techniques for the Management of Anxiety Disorders: An Update.

Neuro-stimulation techniques have gradually evolved over the decades and have emerged potential therapeutic modalities for the treatment of psychiatric disorders, especially treatment refractory cases. The neuro-stimulation techniques involves modalities like electroconvulsive therapy (ECT), repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS), vagus nerve stimulation (VNS) and others. This review discusses the role of neuro-stimulation techniques in the treatment of anxiety disorders. The various modalities of neuro-stimulation techniques are briefly discussed. The evidence base relating to use of these techniques in the treatment of anxiety disorders is discussed further. The review then highlights the challenges in conducting research in relation to the use of neuro-stimulation techniques with reference to patients with anxiety disorders. The review provides the future directions of research and aimed at expanding the evidence base of treatment of anxiety disorders and providing neuro-stimulation techniques as promising effective and acceptable alternative in select cases.

Current understandings about cognition and the neurobiological correlates in schizophrenia.

Schizophrenia is a severe mental disorder. Cognitive deficits are one of the core features of schizophrenia. Multiple domains of cognition (executive function, attention/vigilance, working memory, verbal fluency, visuospatial skills, processing speed, and social cognition) are affected in patients with schizophrenia. Deficits in cognition led to impairment in the real world functioning. Identifying the cognitive deficits and early intervention is required for better functional outcome. This review focuses on conceptual understanding of cognition with its neurobiological correlates in schizophrenia and its different clinical implications.

Effect of chlorine dioxide and sodium hypochlorite on the dissolution of human pulp tissue – An in vitro study

BACKGROUND Organic tissue dissolution is an important property of an irrigant which aids in the success of root canal treatment. Recent studies have advocated the use of Chlorine dioxide as an endodontic irrigant. The aim of this study is to compare the dissolution efficacy of chlorine dioxide and sodium hypochlorite on human pulp tissue. METHODS In this study, 2% Sodium hypochlorite, 5% Chlorine dioxide and isotonic saline solution (control) were used. Thirty human pulp tissue specimens were exposed to three test solutions (n = 10) for 30 min following which the loss of weight was compared from the original weight by using a digital analytical balance. RESULTS Sodium hypochlorite was more efficient in dissolving human pulp tissue when compared to Chlorine dioxide. Isotonic saline solution failed to dissolve any of the specimens. CONCLUSION 5% Chlorine dioxide is capable of dissolving human pulp tissue but sodium hypochlorite was more effective.

Cognitive Deficits in Schizophrenia: Understanding the Biological Correlates and Remediation Strategies

Cognitive deficits are one of the core symptoms of schizophrenia that evolve during the course of schizophrenia, after being originated even before the onset of illness. Existing pharmacological and biological treatment modalities fall short to meet the needs to improve the cognitive symptoms; hence, various cognitive remediation strategies have been adopted to address these deficits. Research evidences suggest that cognitive remediation measures improve the functioning, limit disability bettering the quality of life. The functional outcomes of cognitive remediation in schizophrenia are resultant of neurobiological changes in specific brain areas. Recent years witnessed significant innovations in cognitive remediation strategies in schizophrenia. This comprehensive review highlights the biological correlates of cognitive deficits in schizophrenia and the remedial measures with evidence base.

An empirical review on oxidative stress markers and their relevance in obsessive-compulsive disorder

Oxidative stress results from imbalance in the generation of oxidative free radicals in the body and neutralizing antioxidant mechanisms. It hampers various cellular biochemical processes causing dysfunction of the neurons. Reactive oxygen species and reactive nitrogen species are the two important systems regulating the body′s oxidative stress. Oxidative stress has a role in several psychiatric disorders including obsessive-compulsive disorder (OCD) and other anxiety disorders. Various studies have found elevated levels of malondialdehyde, superoxide dismutase, glutathione peroxidase, and catalase in patients with OCD, which are considered the markers of oxidative stress. This review discusses the relevance of oxidative stress in OCD.

Sources of occupational stress in the police personnel of North India: An exploratory study

Background: Police personnel in India are subjected to several distinct occupational stressors which impact their mental health and their work performance negatively. Aim: The study aimed to explore various sources of stress among police personnel. Method: In this study, 100 constables, 100 inspectors and 100 police officers of Uttar Pradesh, were evaluated using the occupational stress questionnaire. This was subjected to the quantitative as well as the qualitative analysis. Result: Occupational stress was commonly perceived among all police personnel, but the major attributes of stress in various groups were diverse.

Subspecialization in psychiatry: Does it fit with India's need?

Going back to the early 19 century, psychiatry separated from the mainstream of general medicine and now has established its unique identity as a major discipline in developing nations. In India, postgraduate courses in psychiatry started in the 1940s. Like other medical specialties, the development of subpecialization within psychiatry is growing. In recent years some premier institutes in India have initiated subspecialization courses in psychiatry, including geriatric psychiatry, child and adolescent psychiatry and de-addiction psychiatry.

The burning issue of human immunodeficiency virus infection/acquired immune deficiency syndrome in injection drug users: Global scene with a specific focus to India

Intravenous drug use (IDU), initially confined to developed countries, specifically the western countries is no more bound by boundaries. In last few decades, the prevalence has been increased several fold and is a matter of serious concern. IDUs indulge in high-risk activities like sharing of the needle and unprotected sexual activities, which make them more vulnerable to acquired human immunodeficiency virus (HIV) infection (acquired immune deficiency syndrome [AIDS]). They silently spread the infection in the community (other IDUs, spouses and sexual partners). There is an increasing trend of HIV infection/AIDS among intravenous drug abusers across the world including India being no exception. The article highlights the global epidemiological data, specific focus of India.