Different methods for particle diameter determination of low density and high density lipoproteins-Comparison and evaluation

Predominance of small dense Low Density Lipoprotein (LDL) is associated with a two to threefold increase in risk for Coronary Heart Disease (CVD). Small, dense HDL (High Density Lipoprotein) particles protect small dense LDL from oxidative stress. Technological advancements have introduced an array of techniques for measuring diameters of LDL and HDL as well as estimating overall particle heterogeneity. However, there is lack of comparative studies between these techniques, and, hence, no conclusive evidence to establish the merits of one method relative to others. The primary purpose of this study was to compare Nondenaturing Gradient Gel Electrophoresis (NDGGE) and Dynamic Laser Light Scattering (DLLS) methods in determining LDL and HDL particle diameter. Our comparison entailed: 1) Evaluating the two methods in terms of their reproducibility 2) Correlating the two methods(in future studies method selection would be driven by time and cost considerations if the two methods correlate), and 3) Evaluating the two methods in terms of their ability to identify bi-modal samples. A secondary purpose of this research was to investigate the effect of refrigerated plasma storage on particle diameter. Reproducibility was measured as Coefficient of Variance (CV). Within and between runs, CV for LDL and HDL for NDGGE were <6% and <15%, respectively and for DLLS, CV within runs were <3% and <5.5%, respectively. No correlation was observed between LDL diameter from the two methods. NDGGE showed two bands for 157 HDL samples of which only 24 samples showed bimodal peaks in DLLS. In order to study the effect of storage, three sample sets of LDL and two sample sets of HDL were used. NDGGE showed a significant difference between mean diameter of fresh and stored LDL and HDL sample for all sets, whereas DLLS showed a significant difference in only one LDL sample set and none for HDL sample sets. We conclude that DLLS may be a better method for measuring LDL diameter because NDGGE overestimated LDL diameter. However, NDGGE was able to resolve subpopulation better in an HDL sample than DLLS. Thus, NDGGE may be a better choice for measuring HDL diameter than DLLS

Examining leopard attacks: spatio-temporal clustering of human injuries and deaths in Western Himalayas, India

Shared spaces in Africa and Asia accommodate both humans and big cats. This engenders rare but distinctive cases of human fatalities by lions, tigers, and leopards. Among big cats, leopards have the widest range and occur even among high densities of humans. This increased potential for encounters with humans results in attacks, exemplified most by India where 50% of the states report human injuries and deaths due to leopards. Himachal Pradesh (HP) state reported 30 lethal and 287 non-lethal leopard attacks on humans per year between 2004 – 2015 (N=317). Identifying patterns in big cat attacks on people facilitates targeted interventions for decreasing such fatalities. This study aims to detect if leopards are cluster-causing agents of human injuries and deaths. We identify the patterns of leopard attacks on humans in Himachal Pradesh by examining the following questions: (a) do leopard-attributed attacks on humans cluster in space and time? and among the leopard-attributed attacks (b) do unprovoked attacks on humans cluster spatio-temporally? and (c) what environmental factors are associated with the clustered leopard attacks on humans? We employed a space-time permutation scan statistic commonly used in epidemiology to test for spatio-temporal clustering of leopard attacks. Attacks were spread across 75% (~42,000 km sq.) of HP in 11 out of 12 districts. We found that 23% of attacks clustered into 12 significant spatio-temporal clusters. Nearly 14% of the leopard-attributed attacks (N=317) were unprovoked and attacks displaying “predatory” signs did not form significant clusters. Binomial regression models were run to test association of eight environmental factors with clustered attacks. We found that leopard-attributed attacks farther away from the protected area boundary and closer to the district boundary had higher probability of clustering. The framework developed in this study to identify the outbreak of unprovoked leopard attacks confirms the absence of dedicated “man-eaters” in the study region. This approach can be applied to adaptively manage human-wildlife conflict and it also demonstrates the utility of scan statistic in ecological research

attack_interviews

Details of human attacks by leopards and activity of the person before attacks. NOTE: Geographic coordinates of attack location were removed to protect individual's identity, and because Panthera pardus is a vulnerable species. To obtain these values, please contact Aritra Kshettry <[email protected]

Leopard_attacks_victims

Details of all leopard attacks within study area. Month, Year and location of village where attack occurred. NOTE: Geographic coordinates of attack location were removed to protect individual's identity, and because Panthera pardus is a vulnerable species. To obtain these values, please contact Aritra Kshettry <[email protected]

In vitro and in vivo effect of methyl isocyanate on rat liver mitochondrial respiration

Previous work has shown that irrespective of the route of exposure methyl isocyanate (MIC) caused acute lactic acidosis in rats (Jeevaratnam et al., Arch. Environ. Contam. Toxicol. 19, 314�319, 1990) and the hypoxia was of stagnant type due to tissue hypoperfusion resulting from hypovolemic hypotension in rabbits administered MIC subcutaneously (Jeevarathinam et al., Toxicology 51, 223�240, 1988). The present study was designed to investigate whether MIC could induce histotoxic hypoxia through its effects on mitochondrial respiration. Male Wistar rats were used for liver mitochondrial and submitochondrial particle (SMP) preparation. Addition of MIC to tightly coupled mitochondria in vitro resulted in stimulation of state 4 respiration, abolition of respiratory control, decrease in ADP/O ratio, and inhibition of state 3 oxidation. The oxidation of NAD+-linked substrates (glutamate + malate) was more sensitive (fiveto sixfold) to the inhibitory action of MIC than succinate while cytochrome oxidase remained unaffected. MIC induced twofold delay in the onset of anerobiosis, and cytochrome b reduction in SMP with NADH in vitro confirms inhibition of electron transport at complex I region. MIC also stimulated the ATPase activity in tightly coupled mitochondria while lipid peroxidation remained unaffected. As its hydrolysis products, methylamine and N,N?-dimethylurea failed to elicit any change in vitro; these effects reveal that MIC per se acts as an inhibitor of electron transport and a weak uncoupler. Administration of MIC sc at lethal dose caused a similar change only with NAD+-linked substrates, reflecting impairment of mitochondrial respiration at complex I region and thereby induction of histotoxic hypoxia in vivo

Leopard in a tea-cup: A study of leopard habitat-use and human-leopard interactions in north-eastern India

<div><p>There is increasing evidence of the importance of multi-use landscapes for the conservation of large carnivores. However, when carnivore ranges overlap with high density of humans, there are often serious conservation challenges. This is especially true in countries like India where loss of peoples’ lives and property to large wildlife are not uncommon. The leopard (<i>Panthera pardus</i>) is a large felid that is widespread in India, often sharing landscapes with high human densities. In order to understand the ecology of leopards in a human use landscape and the nature of human-leopard interactions, we studied (i) the spatial and temporal distribution and the characteristics of leopard attacks on people, (ii) the spatial variability in the pattern of habitat use by the leopard, and (iii) the spatial relationship between attack locations and habitat use by leopards. The study site, located in northern West Bengal, India, is a densely populated mixed-use landscape of 630 km², comprising of forests, tea plantations, agriculture fields, and human settlements. A total of 171 leopard attacks on humans were reported between January 2009 and March 2016, most of which occurred within the tea-gardens. None of the attacks was fatal. We found significant spatial clustering of locations of leopard attacks on humans. However, most of the attacks were restricted to certain tea estates and occurred mostly between January and May. Analysis of habitat use by leopards showed that the probability of use of areas with more ground vegetation cover was high while that of areas with high density of buildings was low. However, locations of leopard attacks on people did not coincide with areas that showed a higher probability of use by leopards. This indicates that an increased use of an area by leopards, by itself, does not necessarily imply an increase in attacks on people. The spatial and temporal clustering of attack locations allowed us to use this information to prioritize areas to focus mitigation activities in order reduce negative encounters between people and leopards in this landscape which has had a long history of conflict.</p></div

Maps showing (a) Ripley’s K Plots for clustering of attack locations and (b) clusters of location of leopard attack on people between January 2009 and March 2016 in northern West Bengal, India.

<p>K_obs(r): Ripley’s k function of attack locations, K_theo(r): Ripley’s K function for random process.</p

Covariates used in habitat selection models and the expected relationship with site use by leopards.

<p>Covariates used in habitat selection models and the expected relationship with site use by leopards.</p

Map showing location of study area, sampled area, prediction area and land cover types in northern West Bengal, India.

<p>Map showing location of study area, sampled area, prediction area and land cover types in northern West Bengal, India.</p