Analytical approach to dielectric optical bent slab waveguides

A rigorous classical analytic frequency domain model of con?ned optical wave propagation along 2D bent slab waveguides and curved dielectric interfaces is investigated, based on a piecewise ansatz for bend mode profiles in terms of Bessel and Hankel functions. This approach provides a clear picture of the behaviour of bend modes, concerning their decay for large radial arguments or effects of varying bend radius. Fast and accurate routines are required to evaluate Bessel functions with large complex orders and large arguments. Our implementation enabled detailed studies of bent waveguide properties, including higher order bend modes and whispering gallery modes, their interference patterns, and issues related to bend mode normalization and orthogonality properties

India knows its invasive species problem but this is why nobody can deal with it properly

In 1993, the International Convention on Biological Diversity (CBD) came into legal effect to conserve biological diversity, ensure that biological diversity would be used sustainably and that its benefits would be shared equitably. The Conference of Parties (CoP), the governing body in charge of implementing the CBD’s decisions, is now meeting for the 13th time at Cancun, Mexico. One item on the agenda, during the two-week meeting that started on December 4, is a review of progress on the Strategic Plan for Biodiversity (2011-2020) and the related Aichi Biodiversity Targets. The plan and targets were adopted during the 10th CoP at Nagoya in Japan’s Aichi prefecture, in 2010

The Cutting Edge of Conservation

Mention the word ‘conservation’ and for most people the mental images evoked are of tigers,elephants, giant pandas, marine turtles, or of imposing liana-festooned tropical rain forests. But conservation is as much about these iconic creatures and habitats as it is about other, less photogenic things: the tribal forest-dweller who depends on wild fruits for her livelihood and subsistence; the hill farmer deciding between growing an organic apple orchard or selling his land to a developer wanting to build a mountain-view resort; the decision-makers sitting in far-off cities amending the wildlife protection act, or formulating policies about land use

A study on Nidana and Chikitsa of Mootravaha Sroto Dushti Vikara with Ahara Vidhi of Charaka Samhita

In the present modern life style, we do not take care of our health and the consequences of our eating habits and other styles of life, which are harmful for us. Ahar Vidhi Vidhan described in our classics which are the foundation of dietetics. Which indicates the method of Ahara, these are Ushna, Snigdha, Matravat, is consumed after the digestion of previously ingested food, Virya Avirudha Ahara.[1] Any slight disturbance at the level of Mootravaha Srotas, either structurally or functionally leads to Sammurchana of Dosha and Dushya[2] and as a result disease manifests inside the body. Handling the faulty dietic habits, diseases may be originated and aggravated. To study the effect of Ahara Vidhi in detail with correlation with Mootrvaha Sroto Vikaras in this literary study. Thus properly convincing about the importance of Ahara rules to prevent from diseases is very necessary in present situation of time

Diarrhoeal disease outbreak in a rural area of Karnataka

Background: Acute diarrhoea is the passage of 3 or more loose or watery stools in the past 24 hours with or without dehydration. Owing to WASH strategy (Water, Sanitation and Hygiene) the burden of diarrheal diseases has seen a tremendous decline over the past 2 decades. Cholera is an acute diarrhoeal infection caused by ingestion of food or water contaminated with the bacterium Vibrio Cholerae. Objectives: 1. To document the factors responsible for the outbreak. 2. To provide recommendations for prevention and control of such outbreaks in future. Methods: After receiving verbal information from district office regarding outbreak of diarrhoeal disease (cholera) in a town of Bijapur district, we independently conducted a cross sectional study in the affected area and collected information regarding no. of people affected since the outbreak, their age and sex distribution. A total of 3802 people were interviewed using a predesigned questionnaire on 28th and 29th July, 2012. We also conducted environmental investigation regarding the source of contamination and collected 2 water samples from drinking water source. Results: All the cases were clustered in the five streets, which were consuming water from contaminated two water tanks. A total of 121 cases of diarrhoea were identified affecting 3.18% of the population. Attack rate of cholera was highest (4.5%) in 25-34 years age group followed by 4.22% in 15-24 years age group. Attack rates was higher among females (3.4%) compared to males (2.9%). Laboratory report stated that water samples were unfit for drinking purpose. V. Cholera (Ogawa serotype) was isolated from water sample. Conclusion: Consumption of contaminated water from a newly dug bore-well had led to the diarrhea outbreak. Lack of sanitation and hygiene had worsened the situation

Survey for the Presence of Phytophthora cinnamomi on Reclaimed Mined Lands in Ohio Chosen for Restoration of the American Chestnut

We have been planting blight resistant American chestnut seedlings on reclaimed coal mined areas in Southeastern Ohio, which was once within the natural range of the American chestnut. Towards the goal of restoring the American chestnut, we are testing suitable sites that can aid survival, growth and establishment of planted seedlings pre-inoculated with ectomycorrhizal fungi. Prior to the arrival of the chestnut blight fungus, pathogens of the genus Phytophthora were introduced in the USA that were responsible for the “ink disease” or “root-rot” resulting in wide-spread death of chestnut trees in southern states. Although these pathogens were not observed elsewhere, recent reports indicate their presence in some northern states, including Ohio. We have been testing each location targeted for chestnut plantings for the presence of Phytophthora, specifically P. cinnamomi. The work reported here shows results obtained from seven different sites in southeastern Ohio where reclamation was done 3-20 years ago. Soil was collected at a depth of 4-5” at several locations within each site. A positive control containing ~4 cfu/10 g soil was used in the analysis. We used two different techniques for identifying the pathogen: 1. Direct isolation of the pathogen from the soil using selective media; 2. Using chestnut leaves as a baiting technique followed by selection on plates. In both cases, final identification was done by DNA isolation and sequencing using Phytophthora-specific primers. Our results showed that, at least in the locations we tested, P. cinnamomi was not detected. Because most of these lands were only recently reclaimed, it is possible that the pathogen may not have established there yet. However, samples from locations that were reclaimed more than 2 decades ago also showed absence of this fungus. Results suggest that this pathogen is either not as wide-spread in Ohio as in southern states or mined sites are not favorable for its existence and spread

Factors influencing the local scale colonisation and change in density of a widespread invasive plant species, Lantana camara, in South India

Identifying factors that underlie invasive species colonisation and change in density could provide valuable insights into the mechanisms of biological invasions and for invasive species management. We examined a suite of factors potentially influencing the landscape-level invasion of Lantana camara L., one of the most ubiquitous invasive species in South Asia. These factors included disturbance factors like forest fires, historical habitat modification, and edge effects, in addition to factors like propagule pressure and habitat suitability. We examined the relative importance of these factors on the colonisation and change in density of L. camara in the Biligiri Rangaswamy Temple Tiger Reserve, Western Ghats, India. We used extensive (1997–2008) datasets tracking the presence and abundance of L. camara and combined these with corresponding data on disturbances, propagule pressure, and habitat suitability. We used an information-theoretic model selection approach to determine the relative importance of each factor on the colonisation and change in density of L. camara. Colonisation was mainly a function of proximity to already established populations (i.e. propagule pressure), whereas increase in L. camara density appeared to be constrained by high fire frequency. Research and management efforts need to recognize the multi dimensional nature of mechanisms underlying L. camara’s success during different invasion phases when strategizing interventions to mitigate its effects

Seismology of the Sun : Inference of Thermal, Dynamic and Magnetic Field Structures of the Interior

Recent overwhelming evidences show that the sun strongly influences the Earth's climate and environment. Moreover existence of life on this Earth mainly depends upon the sun's energy. Hence, understanding of physics of the sun, especially the thermal, dynamic and magnetic field structures of its interior, is very important. Recently, from the ground and space based observations, it is discovered that sun oscillates near 5 min periodicity in millions of modes. This discovery heralded a new era in solar physics and a separate branch called helioseismology or seismology of the sun has started. Before the advent of helioseismology, sun's thermal structure of the interior was understood from the evolutionary solution of stellar structure equations that mimicked the present age, mass and radius of the sun. Whereas solution of MHD equations yielded internal dynamics and magnetic field structure of the sun's interior. In this presentation, I review the thermal, dynamic and magnetic field structures of the sun's interior as inferred by the helioseismology.Comment: To be published in the proceedings of the meeting "3rd International Conference on Current Developments in Atomic, Molecular, Optical and Nano Physics with Applications", December 14-16, 2011, New Delhi, Indi

Radial-Distance Based Shape Descriptor for Image Retrieval

Shape analysis is used in many application fields including emerging virtual environments or 3D model market, security applications, medical imaging and many more. A Shape descriptor (or Signature) is the simplified representation of images. These shape descriptors carry important image information to store and makes easy the comparing of different shapes. The proposed shape descriptor is based on radial-distances. The type of shape descriptor used here is contour-based shape descriptor. Distance from center of bounding box encompassing the edge image to farthest point on the edge is calculated. A circle is drawn using the distance mentioned above as radius. The ratio of Euclidean distances of an edge pixel and the radius is considered as a feature. A set of such ratios for all the edge pixels forms a shape descriptor. The descriptor is divided into segments so as to avoid global distribution. A rotational matching scheme ensures invariance to rotation. As the computation of feature set is compact, implementation of this method results in quick retrieval of images invariant to scaling, translation and rotation

A Comparison of Solar Cycle Variations in the Equatorial Rotation Rates of the Sun's Subsurface, Surface, Corona, and Sunspot Groups

Using the Solar Optical Observing Network (SOON) sunspot-group data for the period 1985-2010, the variations in the annual mean equatorial-rotation rates of the sunspot groups are determined and compared with the known variations in the solar equatorial-rotation rates determined from the following data: i) the plasma rotation rates at 0.94Rsun, 0.95Rsun,...,1.0Rsun measured by Global Oscillation Network Group (GONG) during the period 1995-2010, ii) the data on the soft X-ray corona determined from Yohkoh/SXT full disk images for the years 1992-2001, iii) the data on small bright coronal structures (SBCS) which were traced in Solar and Heliospheric Observatory (SOHO)/EIT images during the period 1998-2006, and iv) the Mount Wilson Doppler-velocity measurements during the period 1986-2007. A large portion (up to approximate 30 deg latitude) of the mean differential-rotation profile of the sunspot groups lies between those of the internal differential-rotation rates at 0.94Rsun and 0.98Rsun.The variation in the yearly mean equatorial-rotation rate of the sunspot groups seems to be lagging that of the equatorial-rotation rate determined from the GONG measurements by one to two years.The amplitude of the latter is very small.The solar-cycle variation in the equatorial-rotation rate of the solar corona closely matches that determined from the sunspot-group data.The variation in the equatorial-rotation rate determined from the Mount Wilson Doppler-velocity data closely resembles the corresponding variation in the equatorial-rotation rate determined from the sunspot-group data that included the values of the abnormal angular motions (> 3 deg per day) of the sunspot groups. Implications of these results are pointed out.Comment: 22 pages, 10 figures, accepted by Solar Physic