Insights into 5-Lipoxygenase Active Site and Catalysis

Leukotrienes are potent immune-modulatory compounds involved in the inflammatory response. 5-Lipoxygenase (5-LOX) is the enzyme that catalyzes the production of Leukotriene A4 (LTA4), which is further metabolized to pro- and anti-inflammatory compounds derived from the substrate Arachidonic Acid (AA), a polyunsaturated fatty acid. The crystal structure of a stabilized form of 5-LOX has been recently reported (Gilbert, Bartlett et al. 2011). However, the structure does not reveal the mode of substrate entry or recognition. The first step in the enzymatic reaction involves the removal of a hydrogen from the central carbon of a pentadiene present in the substrate. It is not known how 5-LOX distinguishes among three such chemically equivalent pentadienes in AA to produce only 5-S-HPETE, which is subsequently transformed to LTA4. The crystal structure suggests a somewhat crescent shaped active site lined with invariant Leucines and Isoleucines, with no clear access port visible for substrate entry. A series of site-directed mutants were produced and the activities of these mutants evaluated. Product analyses of these mutants with AA and substrate analogs suggest entry of the substrate by the opening of the so-called Phenylalanine (F)-Tyrosine(Y) ‘cork’. The data is also consistent with the orientation of AA as carboxyl innermost, as predicted from the stereochemistry of the product and mechanistic models of lipoxygenase function

A constructivist analysis linking norm diffusion to policy networks

Biodiversity encompasses different constructions of ‘nature’, ‘economy’ and ‘livelihood’ that contain tensions between different sets of social and ethical concerns, economic or political preferences, scientific and technological systems, traditions and knowledge. Biodiversity Policy, therefore, is an important space where the competing dynamics of these processes can be observed. Using a constructivist approach, this literature review identifies and analyses particular variables that influence policy formulation in the context of India’s two main biodiversity policies: The Biodiversity Act and the National Biodiversity Strategy Action Plan. The dependant model of the overall analytical framework is to explain participatory policy formulation with regard to biodiversity and the goal achievement of the actors involved. The goal of this paper is to identify the mechanisms of influence that explain a distinct process of policy formulation. These mechanisms of influence are identified first as norm diffusion through regimes - specifically the role of policy entrepreneurs and framing exercises, cultural and institutional structures-, and second, as domestic actors operating within an advocacy coalition. The research is based on expert interviews with key researchers and policy makers. The research attempts to capture the dynamic movement and interpretation of ideas as they move between the international and domestic spheres. This paper is both theoretical and empirical, as it brings in initial results from the field. It elucidates how policy processes have been constructed in certain ways and are influenced both by the international context and ideational components of domestic policy networks

Wetting of PTFE Surface by Mixed Surfactant Solutions in the Presence of Electrolyte

Improving the wettability of hydrophobic surfaces has wide ranges of applications, and mixed surfactant systems are promising to improve the interfacial phenomena including wetting. In this study mixture of cationic (Cetyltrimethyl ammonium bromide, CTAB) and non-ionic (Igepal-630) surfactants have been studied and compared with the pure surfactants.The nonideal behaviour of the mixture indicates the presence of synergism. Another point of attraction for the investigators has been the effect of additives in surfactant solution. Presence of electrolyte enhances the wetting property very effectively, as proved from previous studies. This report mainly focuses on the change in CMC values as well as wetting property of a mixed surfactant system. It is observe the use of electrolyte, further reduce the CMC than the mixed surfactant systems. The main objective of this study is to provide insight on the wetting of hydrophobic surface in the presence of mixed surfactant system + electrolyte

Interdisciplinary studies on stingless bees as alternate managed pollinators

The aim of the work described in this thesis is to improve the preparedness of the horticulture industry for the possible incursion of varroa mite and decline of managed honey bees by developing stingless bees as alternate managed pollinators. In this thesis, we conduct various surveys and experiments that contribute to improving pollination provisioning by native stingless bees. With research predicting ongoing changes in the global environment and resultant fluctuations in pollinator communities , it has become essential to focus on studying alternate and native pollinators. One such pollinator group is the stingless bees, which have a pan-tropical distribution, with a few species in the subtropics and temperate regions. The chapters of my thesis address questions that are yet to be solved regarding adoption of alternate managed pollination, such as the influence of farm management on crop pollination, and documenting the current knowledge among growers and beekeepers regarding managed pollination in India and Australia. In Chapter 2 I study and establish the current nature and status of beekeeping practices in India. Additionally, I study the current knowledge of growers regarding pollinators and pollination service. Overall it was established that growers know very little about pollination and beekeepers predominantly keep the honeybee, Apis mellifera, for honey production rather than for pollination. I then survey the Australian stingless bee industry (Chapter 3), documenting its growth in the past decade and comparing observed patterns to those in two previous decadal surveys. The decadal survey concludes that the stingless bee industry has a higher growth rate than the honey bee industry in Australia. An important step in developing stingless bees as alternate managed pollinators is to look at the effect of farm management on various insect visitors such as pollinators, beneficials and pests. In Chapter 4 I study the effects of farm management practices on insect visitors to conclude that low-spray management practices are an effective method to combat pests while maintaining unmanaged pollinators and beneficials on the orchard. Lastly, I compare various pollination methods – stingless bee pollination, hand pollination and no pollination within a protected cropping system for strawberry production and compare their cost-effectiveness (Chapter 5). The study concludes that strawberry growers will benefit from investing in bee pollination to improve their economic efficiency. Ultimately, these new insights contribute towards our understanding in developing stingless bees as alternated managed pollinators

Using clusters of galaxies as novel and standard probes of dark matter

In this thesis, we apply samples of red-sequence selected galaxy clusters with archival Xray observations as novel and standard probes of dark matter. We detail the construction of samples consisting of clusters in the Sloan Digital Sky Survey and Dark Energy Survey areas selected using the redMaPPer cluster finder, with X-ray confirmation provided by the XMM Cluster Survey (XCS). We apply one of these samples to the investigation of an unmodelled X-ray line at ≃3.5 keV in the spectra of clusters of galaxies. Using the largest cluster sample to date for such a study, we analyse the spectra of 118 galaxy clusters to search for evidence of a flux excess at ≃3.5 keV, which has a suggested origin in the decay of resonantly produced sterile neutrino dark matter with mass ms ≃7 keV. Our results find evidence against a dark matter interpretation of the 3.5 keV feature. We then apply all three samples to calibrating the centering performance of redMaPPer. Central galaxies selected by redMaPPer do not always robustly trace the centre of the cluster’s underlying dark matter distribution, while X-ray emission is seen to be a more reliable tracer of the cluster potential. We therefore model the o↵set between optical and X-ray determinations of the cluster centre using the redMaPPer catalogues and public data from XMM-Newton. The centering performance of the cluster finder is a key component in the accurate measurement of cluster masses and derived estimates of cosmological parameters. Although we find cluster miscentering to be a subdominant source of systematic error in optical datasets (∼2%), it is likely to constitute a more significant contribution to cluster cosmology in future, larger datasets such as LSST

Distributed Service Broker Policy Algorithm for Logistics over Cloud

Logistics information system focuses on flow of information with storage and services of goods supply from the origin point to consumption point of organization. Logistics information system makes this flow more efficient with the help of cloud. Cloud computing manages the logistics information system centrally. The centralized data center keeps the track of information distribution which creates network congestion and overloading on data center when various requests of users from different regions occur at same time. So, the data center needs to be maintained effectively for better performance. This paper presents the distributed service broker policy to implement centralized data center and proposes distributed data center for logistics information system over cloud. This paper also presents the result of distributed service broker policy algorithm to reduce network congestion, higher latency and cost due to large number of demand of particular service in distributed data center for logistics

Confessions And Law In India: A Legal Analysis

The evaluation of the laws pertaining to confession in India brings to the fore the fact that ‘confessions’ has not been defined in any law. This paper is an attempt to examine the embodiment of the provisions pertaining to ‘confession’ under various enactments. The critical discussion encompasses the substantive law as well as the adjective law. Keeping in mind the title of this paper, the provisions have been dealt with in chronological order. The first enactment, which contains provisions pertaining to the confession, is the Indian Penal Code, 1860