Linear and Nonlinear Optical Properties of Mn doped Benzimidazole Thin Films

In the present work, the Mn doped benzimidazole (BMZ) thin films were prepared by simple chemical bath deposition technique. The material was directly deposited as thin film on glass substrates and the metal concentration in the solution was varied in weight percentage in order to investigate the dopant effect on the properties of thin films. Similarly, the Mn doped BMZ films were deposited in different solution temperature to study the effect of deposition temperature on the properties of thin films. The PXRD and FT-IR spectroscopy are used to study the structural and the presence of functional groups in the BMZ medium. Depending upon the solution temperature, thickness of the films varying from 0.6 to 1.2 {\mu}m and the optical transparency of the samples increases with the increasing temperature up to 50 {\deg}C. Second Harmonic Generation (SHG) efficiency of the films is measured for all the films. Third order nonlinear optical properties of the films were analyzed using Z-scan technique. The experimental results show that Mn doped BMZ films exhibits saturation absorption and negative nonlinearity.Comment: This has been presented in DAE 58th Solid State Symposium held at Thapar University, Patiala, Punjab, India. Will be published in AIP conference proceedings soo

Combined information from Raman spectroscopy and optical coherence tomography for enhanced diagnostic accuracy in tissue discrimination

We thank the UK EPSRC for funding, the CR-UK/EPSRC/MRC/DoH (England) imaging programme, the European Union project FAMOS (FP7 ICT, contract no. 317744) and the European Union project IIIOS (FP7/2007-2013, contract no. 238802). We thank Tayside Tissue Bank for providing us with the tissue samples under request number TR000289. K.D. is a Royal Society-Wolfson Merit Award Holder.Optical spectroscopy and imaging methods have proved to have potential to discriminate between normal and abnormal tissue types through minimally invasive procedures. Raman spectroscopy and Optical Coherence Tomography (OCT) provides chemical and morphological information of tissues respectively, which are complementary to each other. When used individually they might not be able to obtain high enough sensitivity and specificity that is clinically relevant. In this study we combined Raman spectroscopy information with information obtained from OCT to enhance the sensitivity and specificity in discriminating between Colonic Adenocarcinoma from Normal Colon. OCT being an imaging technique, the information from this technique is conventionally analyzed qualitatively. To combine with Raman spectroscopy information, it was essential to quantify the morphological information obtained from OCT. Texture analysis was used to extract information from OCT images, which in-turn was combined with the information obtained from Raman spectroscopy. The sensitivity and specificity of the classifier was estimated using leave one out cross validation (LOOCV) method where support vector machine (SVM) was used for binary classification of the tissues. The sensitivity obtained using Raman spectroscopy and OCT individually was 89% and 78% respectively and the specificity was 77% and 74% respectively. Combining the information derived using the two techniques increased both sensitivity and specificity to 94% demonstrating that combining complementary optical information enhances diagnostic accuracy. These results demonstrate that a multimodal approach using Raman-OCT would be able to enhance the diagnostic accuracy for identifying normal and cancerous tissue types.Publisher PD

First record of the occurrence of Pleurotus species on new hosts in Bengaluru, Karnataka, India

Mushrooms have wide geographical distribution, with greatest commercial importance, both in temperate areas and tropical regions of the world. The agarics mycota of tropical eco-regions of Bengaluru, Karnataka was surveyed in different seasons from 2019 to 2020 for collection and identification of fungal samples. Detailed macroscopic and microscopic study of fungal samples was identified as Pleurotus pulmonarius (Fr.) Quél. P. ostreatus (Jack.) P. Kumm. P. populinus O. Hilber & O. K. Mill. For the first time, P. pulmonarius (Fr.) Quél was causing stem decay in Mangifera indica L. was reported from India. New host record of P. populinus O. Hilber & O. K. Mill on Spathodea campanulata was reported from India. Three species of Pleurotus was reported for the first time from the study area of Bengaluru, Karnataka, India

Factors Associated with Tobacco Smoking Among Saudi College Students: A Systematic Review

Introduction: There has been an increase in tobacco smoking among Saudi college students in recent years. However, no study has examined, with a systematic approach, the extent to which specific factors are associated with tobacco smoking among this population. Methods: PubMed, ProQuest, CINAHL, and Web of Science were utilized to retrieve studies addressing risk factors associated with tobacco smoking among Saudi college students between 2010 and 2019. After confirming their eligibility criteria, studies were imported to the NVivo software for data collection and synthesis. All included articles were critically appraised, based on a modified STROBE. Results: Twenty-one out of 300 studies met the eligibility requirements for inclusion. Riyadh, health-related science, and male were the location, field of study, and gender of the population of most of those included in the studies, respectively. Only one study used a longitudinal design based on a theoretical framework; the rest were cross-sectional and lacked theoretical utilization. Four individual and two social factors were established to have a significant relationship with tobacco smoking behavior among college students in four or more studies. Environmental factors were found to be associated with a change in smoking behavior among Saudi college students based on two studies. Conclusions: There is a dearth of research in utilizing theoretical frameworks to guide the research in order to propose an intervention program among Saudi college students. Future research should aim to recruit participants from different institutions in the KSA, apply other methodological approaches, test other measurements of tobacco smoking, and utilize a theoretical framework.https://digitalcommons.odu.edu/gradposters2020_healthsciences/1000/thumbnail.jp

Concept-modulated model-based offline reinforcement learning for rapid generalization

The robustness of any machine learning solution is fundamentally bound by the data it was trained on. One way to generalize beyond the original training is through human-informed augmentation of the original dataset; however, it is impossible to specify all possible failure cases that can occur during deployment. To address this limitation we combine model-based reinforcement learning and model-interpretability methods to propose a solution that self-generates simulated scenarios constrained by environmental concepts and dynamics learned in an unsupervised manner. In particular, an internal model of the agent's environment is conditioned on low-dimensional concept representations of the input space that are sensitive to the agent's actions. We demonstrate this method within a standard realistic driving simulator in a simple point-to-point navigation task, where we show dramatic improvements in one-shot generalization to different instances of specified failure cases as well as zero-shot generalization to similar variations compared to model-based and model-free approaches

Factors Associated With Tobacco Smoking Among Saudi College Students: A Systematic Review

INTRODUCTION There has been an increase in tobacco smoking among Saudi college students in recent years. However, no study has examined, with a systematic approach, the extent to which specific factors are associated with tobacco smoking among this population. METHODS PubMed, ProQuest, CINAHL, and Web of Science were utilized to retrieve studies addressing risk factors associated with tobacco smoking among Saudi college students between 2010 and 2019. After confirming their eligibility criteria, studies were imported to the NVivo software for data collection and synthesis. All included articles were critically appraised, based on a modified STROBE. RESULTS Twenty-one out of 300 studies met the eligibility requirements for inclusion. Riyadh was the location, health-related science was the field of study, and male the gender of the population of most of the included studies. Only one study used a longitudinal design based on a theoretical framework, the rest were cross-sectional and lacked theoretical utilization. Four individual and two social factors were established to have a significant relationship with tobacco smoking behavior among college students in four or more studies. Environmental factors were found to be associated with a change in smoking behavior among Saudi college students based on two studies. CONCLUSIONS There is a dearth of research in utilizing theoretical frameworks to guide the research in order to propose an intervention program among Saudi college students. Future research should aim to recruit participants from different institutions in the Kingdom of Saudi Arabia (KSA), apply other methodological approaches, test other measurements of tobacco smoking, and utilize a theoretical framework

Anisotropic Topological Hall Effect with Real and Momentum Space Berry Curvature in the Antiskrymion Hosting Heusler Compound Mn1.4_{1.4}PtSn

The topological Hall effect (THE) is one of the key signatures of topologically non-trivial magnetic spin textures, wherein electrons feel an additional transverse voltage to the applied current. The magnitude of THE is often small compared to the anomalous Hall effect. Here, we find a large THE of 0.9 $\mu\Omega$cm that is of the same order of the anomalous Hall effect in the single crystalline antiskyrmion hosting Heusler compound Mn$_{1.4}$PtSn, a non-centrosymmetric tetragonal compound. The THE is highly anisotropic and survives in the whole temperature range where the spin structure is noncoplanar (<170 K). The THE is zero above the spin reorientation transition temperature of 170 K, where the magnetization will have a collinear and ferromagnetic alignment. The large value of the THE entails a significant contribution from the momentum space Berry curvature along with real space Berry curvature, which has never been observed earlier