Kinetics and Mechanistic Studies on Oxidation of Levocarnitine by Bromamine-T in HCl Medium Catalyzed by Ru(III)

A kinetic study on RuCl3-catalysed oxidation of levocarnitine (LC) by sodium N-bromo-p-toluenesulphonamide or bromamine-T (BAT) has been carried out in HCl medium at 303 K. The reaction rate shows a first order dependence on [BAT]0 and fractional order with respect to both [LC]0 and [H+]. Addition of the reaction product, p-toluenesulphonamide, retards the rate. The addition of RuCl3 and chloride ions to the reaction mixture shows an increase in the rate of the reaction. The dielectric effect is positive. The variation of ionic strength of the medium has no significant effect on the rate of the reaction. The reaction fails to initiate polymerization of acrylamide. Michaelis-Menten type of kinetics has been proposed. Thermodynamic parameters have been computed from Arrhenius plot by studying the reaction at different temperatures. The reaction stoichiometry and oxidation products were identified. Based on the experimental observations a suitable mechanism was proposed and rate law deduced

Site substitution in GdMnO3: Effects on structural, electronic, and magnetic properties

We report on detailed structural, electronic, and magnetic studies of GdMn1-xCrxO3 for Cr doping levels; x = 0 <= x <= 1. X-ray diffraction studies suggest that GdMn0.5Cr0.5O3 has a monoclinic P2(1)/b structure with alternate arrangements of Mn and Cr atoms along the [001] direction. In the solid solutions, the Jahn-Teller distortion associated with Mn3+ ions gives rise to major changes in the be-plane sublattice and also an effective orbital ordering in the ab plane, which persist up to compositions x similar to 0.35. These distinct features in the lattice and orbital degrees of freedom are also correlated with be-plane anisotropy of the local Gd environment. A gradual evolution of electronic states with doping is also clearly seen in O K-edge x-ray absorption spectra. Evidence of magnetization reversal in field-cooled-cooling mode for x >= 0.35 coinciding with the Jahn-Teller crossover suggests a close correlation between magnetic interaction and structural distortion. These observations indicate a strong entanglement between lattice, spin, electronic, and orbital degrees of freedom. The nonmonotonic variation of remnant magnetization can be explained by doping-induced modification of magnetic interactions. Density-functional-theory calculations are consistent with layer-by-layer-type arrangements of Cr ions and Mn ions with ferromagnetic (antiferomagnetic) coupling between Mn (Cr) ions for intermediate compounds (x = 0.5). For x = 0.25 compositions, we found alternate layers of Mn and mixed Mn-Cr atoms stacked along the c axis with intralayer ferromagnetic coupling and interlayer antiferromagnetic coupling. For x = 0.75 compositions, there exists strong antiferomagnetic coupling between half-filled t(2g) orbitals of in-plane Cr ions along with a feromagnetic Mn-Cr coupling

Protective effect of intravenous immunoglobulin (IVIG) in an experimental model of pemphigus vulgaris

Uncontrolled studies have found intravenous immunoglobulin (IVIG) to be effective in the treatment of pemphigus vulgaris (PV). The aim of this study was to evaluate the role of IVIG in preventing IgG autoantibodies binding to desmoglein-3 and blister formation using a controlled experimental design. The ability of IVIG to affect the binding of IgG affinity purified from two patients with PV to desmoglein-3 in comparison to IgG from one donor, was conducted by enzyme-linked immunosorbent assay (ELISA). The specificity was confirmed by competition assay. We assessed the effect of IVIG on the induction of experimental-PV in CD1 newborn mice by subcutaneous subjection of IgG affinity purified from two patients with PV. The treatment was conducted by subcutaneous administration of IVIG together with IgG from the pemphigus patients or appropriate control. The skin of the newborns was examined 24–48 h later for blisters, and samples of the affected areas were analysed by immunohistochemistry. IVIG as a whole molecule and its F(ab)(2) portion inhibited the binding of anti-desmoglein-3 antibody to recombinant desmoglein-3 in a dose-dependent manner. The specificity was confirmed by competition assays. In-vivo, IVIG and its F(ab)(2) portion prevented blister formation in the newborn mice. Cutaneous lesions were noted only in the groups of newborn mice who were injected with IgG fractions from the PV patients. Immunopathological evaluation revealed that IVIG prevented the formation of acanthylosis with IgG deposition in the intercellular spaces. These results point to the efficacy of IVIG in the prevention of blister formation in an experimental PV model

From Reef to Table: Social and Ecological Factors Affecting Coral Reef Fisheries, Artisanal Seafood Supply Chains, and Seafood Security

<div><p>Ocean and coastal ecosystems provide critical fisheries, coastal protection, and cultural benefits to communities worldwide, but these services are diminishing due to local and global threats. In response, place-based strategies involve communities and resource users in management have proliferated. Here, we present a transferable community-based approach to assess the social and ecological factors affecting resource sustainability and food security in a small-scale, coral reef fishery. Our results show that this small-scale fishery provides large-scale benefits to communities, including 7,353 ± 1547 kg yr^-1 (mean ± SE) of seafood per year, equating to >30,000 meals with an economic value of $78,432. The vast majority of the catch is used for subsistence, contributing to community food security: 58% is kept, 33.5% is given away, and 8.5% is sold. Our spatial analysis assesses the geographic distribution of community beneficiaries from the fishery (the “food shed” for the fishery), and we document that 20% of seafood procured from the fishery is used for sociocultural events that are important for social cohesion. This approach provides a method for assessing social, economic, and cultural values provided by small-scale food systems, as well as important contributions to food security, with significant implications for conservation and management. This interdisciplinary effort aims to demonstrate a transferable participatory research approach useful for resource-dependent communities as they cope with socioeconomic, cultural, and environmental change.</p></div

A Survey on Farmland Crop Information Acquisition

International audienceThe farmland crop information is the important foundation of developing fine agricultural practice. Crop information acquisition technologies have become the most effective means to increasing crop production and improving crop quality. In this paper, on the basis of introducing the characteristics of farmland crop data, different farmland crop information acquisition methods are surveyed in detail, sections need to be improved of these methods and related core technologies will be discussed. At last, this paper gives a table about crop information acquisition technology and sensing instrument systems applied in different levels (individual level, area level and wide-area level)

Area, number of survey sites, and average biomass for each habitat structure category surveyed in Kīholo Bay.

<p>Sand habitat was not surveyed and not included in this table, though it makes up an additional 0.71 km² of habitat area (28%) in the bay. SE is standard error of the mean for transect biomass values in each category. Average biomass was expanded to the total area of each habitat structure category by trophic group, resulting in an estimate of total standing stock of resource fishes.</p

Kīholo Bay study area, including spatial delineation of sampling area for creel and fish flow surveys (orange outline) and locations of transects for ecological surveys of reef fish.

<p>Background imagery shows the spatial configuration of the bay and the reef complex, and inset shows the location in the Hawaiian Islands.</p

Weight of total reported catch and reported catch with post-landings disposition information, by trophic group, from Kīholo Bay surveys.

<p>Weight of total reported catch and reported catch with post-landings disposition information, by trophic group, from Kīholo Bay surveys.</p