Controllable switching of vortex chirality in magnetic nanodisks by a field pulse

We propose a way of fast switching the chirality in a magnetic nanodisk by applying a field pulse. To break the symmetry with respect to clockwise or counterclockwise chirality a mask is added by which an inhomogeneous field influences the vortex state of a nanodisk. Using numerical spin--lattice simulations we demonstrate that chirality can be controllably switched by a field pulse, whose intensity is above some critical value. A mathematical definition for the chirality of an arbitrary shaped particle is proposed.Comment: REVTeX, 4 pages, 3 figure

Plant-derived antimicrobials to fight against multi-drug-resistant human pathogens

Antibiotic resistance is becoming a pivotal concern for public health that has accelerated the search for new antimicrobial molecules from nature. Numbers of human pathogens have inevitably evolved to become resistant to various currently available drugs causing considerable mortality and morbidity worldwide. It is apparent that novel antibiotics are urgently warranted to combat these life-threatening pathogens. In recent years, there have been an increasing number of studies to discover new bioactive compounds from plant origin with the hope to control antibiotic-resistant bacteria. This review attempts to focus and record the plant-derived compounds and plant extracts against multi-drug-resistant (MDR) pathogens including methicillin-resistant Staphylococcus aureus (MRSA), MDR-Mycobacterium tuberculosis and malarial parasites Plasmodium spp. reported between 2005 and 2015. During this period, a total of 110 purified compounds and 60 plant extracts were obtained from 112 different plants. The plants reviewed in this study belong to 70 different families reported from 36 countries around the world. The present review also discusses the drug resistance in bacteria and emphasizes the urge for new drugs

Targeting groundwater potential zones using Electrical resistivity and GIS techniques in Kadavanar Sub-basin, South India

Geographical Information System techniques are widely used to determine suitable sites for groundwater recharge through artificial recharge techniques. The present research work is to identify suitable locations for constructing artificial recharge structures in the Kadavanar Sub-basin, South India. People in the Sub-basin mainly depend on the groundwater resources for drinking and irrigation purposes. Groundwater resources are often overexploited in many parts of this Sub-basin to meet the water demand leading to groundwater consumption. A lot of surfaces and sub-surface information and criteria are required for mapping the groundwater recharge zone. This is where the geographic information system [GIS] provides the right impetus besides the groundwater prospective zone to harness multilayered spatial data so that multi-criteria analysis is possible. This analysis integrates historic rainfall data analysis, groundwater level fluctuation, stream network, aquifer thickness, land use/land cover and basin slope. Drainage map, slope map and land use/land cover maps were prepared from satellite imageries. Vertical electrical sounding (VES) geophysical survey with Schlumberger electrode configuration was also conducted in the basin at 50 locations to map the aquifer thickness. Spatial variation maps for groundwater level and aquifer thickness were generated using GIS. Weighted aggregation method was used in this study to obtain groundwater recharge maps. Finally, multi-criteria analysis has been carried out to identify and assess the potential sites for groundwater recharge according to the associated weightages. It is established that GIS is best suited for the mapping of groundwater recharge zones. A similar study can be extended to any other hard-rock region facing water crises

Adopting an ethical approach to migration health policy, practice and research

Migration health is affected by decision making at levels ranging from global to local, both within and beyond the health sector. These decisions impact seeking, entitlements, service delivery, policy making and knowledge production on migration health. It is key that ethical challenges faced by decision makers are recognised and addressed in research and data, clinical practice and policy making on migration health. An ethical approach can provide methods to identify ethical issues, frameworks for systematising information and suggesting ethically acceptable solutions, and guidance on procedural concerns and legitimate decision making processes. By unpacking dilemmas, conflicts of interests and values at stake, an ethical approach is relevant for all who make decisions about migration health policy and practice. Adopting an ethical approach to migration health benefits governments, organisations, policy makers, health workers, data managers, researchers and migrants themselves. First, it highlights the inherent normative questions and trade-offs at stake in migration health. Second, it assists decision makers in deciding what is the ethically justifiable thing to do through an ‘all things considered’ approach. Third, ethical frameworks and technical guidance set normative and practical standards for decision makers facing ethical questions – from ‘bedside rationing’ to collection of big data or in policy making – that can ensure that migrants’ interests are considered. Fourth, there is a need for greater transparency and accountability in decision making, as well as meaningful participation of migrant groups. An ethical approach connects to public health, economic and human rights arguments and highlights the urgent need to mainstream concerns for migrants in global and national health responses

Post-harvest drying kinetics of okra (Abelmoschus Esculentus) under greenhouse drying and heat pump drying

Drying is carried out to prolong the shelf life of food products to reduce post-harvest losses by reducing the moisture content present in it. Thin layer drying kinetics of okra (Abelmoschus esculentus) has been compared with open sun drying, heat pump drying and greenhouse drying with different glazing material such as UV Polyethylene sheet and drip lock sheet under passive and active modes. The experimental results showed that the reduction in moisture content of okra from 87.65 % to 10% was achieved in 16 hours under open sun drying (OSD), 14 hours using UV polyethylene sheet greenhouse dryer under passive mode (UVPM), 13 hours under drip lock sheet greenhouse dryer under passive mode (DLPM) and in UV polyethylene sheet greenhouse dryer under active mode (UVAM), 12 hours to achieve the moisture content of 9.3 % using drip lock sheet greenhouse dryer under active mode (DLAM) and 8 hours in heat pump drying (HPD). The highest dryer efficiency of 38.78% was achieved under HPD and 14.15% was achieved under DLAM greenhouse drying. Higher effective moisture diffusivity value of 2.09 x 10-10 m 2 /s was achieved in HPD compared to other modes and lower effective moisture diffusivity of 1.04 x 10-10 m 2 /s was achieved under open sun drying mode in drying okra. Heat Pump dryer had a higher Specific Moisture Extraction Rate (SMER) value of 2.60 kg/ kWh compared to other methods of drying. It was found that the products dried with minimum drying time in HPD compared to greenhouse drying but still in the economic point of view greenhouse drying has low cost

Post-harvest drying kinetics of okra (Abelmoschus Esculentus) under greenhouse drying and heat pump drying

Drying is carried out to prolong the shelf life of food products to reduce post-harvest losses by reducing the moisture content present in it. Thin layer drying kinetics of okra (Abelmoschus esculentus) has been compared with open sun drying, heat pump drying and greenhouse drying with different glazing material such as UV Polyethylene sheet and drip lock sheet under passive and active modes. The experimental results showed that the reduction in moisture content of okra from 87.65 % to 10% was achieved in 16 hours under open sun drying (OSD), 14 hours using UV polyethylene sheet greenhouse dryer under passive mode (UVPM), 13 hours under drip lock sheet greenhouse dryer under passive mode (DLPM) and in UV polyethylene sheet greenhouse dryer under active mode (UVAM), 12 hours to achieve the moisture content of 9.3 % using drip lock sheet greenhouse dryer under active mode (DLAM) and 8 hours in heat pump drying (HPD). The highest dryer efficiency of 38.78% was achieved under HPD and 14.15% was achieved under DLAM greenhouse drying. Higher effective moisture diffusivity value of 2.09 x 10-10 m 2 /s was achieved in HPD compared to other modes and lower effective moisture diffusivity of 1.04 x 10-10 m 2 /s was achieved under open sun drying mode in drying okra. Heat Pump dryer had a higher Specific Moisture Extraction Rate (SMER) value of 2.60 kg/ kWh compared to other methods of drying. It was found that the products dried with minimum drying time in HPD compared to greenhouse drying but still in the economic point of view greenhouse drying has low cost

Annual Risk of Tuberculosis infection in Chennai City

Aim: To study the proportion of children infected with Mycobacterium Tuberculosis in Chennai city. Methodology: A cluster sampling methodology was adopted to select an estimated sample size of 7000 children from five corporation zones selected systematically from ten zones of the city. A total of 7098 children aged 1-9 years were subjected to Mantoux and test read; 1897 (27%) from slum area and 5201 (73%) from non-slum area. Results: The prevalence of infection among children without BCG scar was estimated to be 10.5 % (ARTI of 2.0%) and was similar to that among children irrespective of scar status. The prevalence of infection was higher among children in slum areas (11.1%; ARTI 2.1%) compared to non-slum areas (8.9%; ARTI 1.7%); but the difference was not statistically different. Conclusion: The tuberculosis situation in Chennai as measured by risk of infection was higher in urban city area than rural areas and comparable to that found in other cities as reported from earlier studies. This information can be used as baseline information for monitoring the epidemiological trends in Chennai city in future