AGPAT2 is mutated in congenital generalized lipodystrophy linked to chromosome 9q34

Congenital generalized lipodystrophy is an autosomal recessive disorder characterized by marked paucity of adipose tissue, extreme insulin resistance, hypertriglyceridemia, hepatic steatosis and early onset of diabetes. We report several different mutations of the gene (AGPAT2) encoding 1-acylglycerol-3-phosphate O-acyltransferase 2 in 20 affected individuals from 11 pedigrees of diverse ethnicities showing linkage to chromosome 9q34. The AGPAT2 enzyme catalyzes the acylation of lysophosphatidic acid to form phosphatidic acid, a key intermediate in the biosynthesis of triacylglycerol and glycerophospholipids. AGPAT2 mRNA is highly expressed in adipose tissue. We conclude that mutations in AGPAT2 may cause congenital generalized lipodystrophy by inhibiting triacylglycerol synthesis and storage in adipocytes.     

Abrupt changes in the Asian southwest monsoon during the Holocene and their links to the North Atlantic Ocean

During the last ice age, the Indian Ocean southwest monsoon exhibited abrupt changes that were closely correlated with millennial-scale climate events in the North Atlantic region, suggesting a mechanistic link. In the Holocene epoch, which had a more stable climate, the amplitude of abrupt changes in North Atlantic climate was much smaller, and it has been unclear whether these changes are related to monsoon variability. Here we present a continuous record of centennial-scale monsoon variability throughout the Holocene from rapidly accumulating and minimally bioturbated sediments in the anoxic Arabian Sea. Our monsoon proxy record reveals several intervals of weak summer monsoon that coincide with cold periods documented in the North Atlantic region--including the most recent climate changes from the Medieval Warm Period to the Little Ice Age and then to the present. We therefore suggest that the link between North Atlantic climate and the Asian monsoon is a persistent aspect of global climate.     

On the contribution of haemolymph to the salivary proteins of the red cotton bug,Dysdercus koenigii F. (Heteroptera,Pyrrhocoridae)

Summary Polyacrylamide gel electrophoresis of haemolymph and the salivary gland of adult maleDysdercus koenigii has been carried out. The presence of common bands in the electropherograms of the salivary gland and haemolymph shows the possible elaboration of haemolymph protein into the salivary glands as also evidenced by leucomethylene blue incorporation into the salivary gland lobules. The results are discussed in the light of our present state of knowledge.I wish to acknowledge the financial support from the C.S.I.R., New Delhi, India. Grateful acknowledgements are made to Prof. P.S. Ramamurty for encouragements, and to Zoology Department, Banaras Hindu University for the working facilities.     

Effect ofβ-Aminoethylisothiuronium-bromide-hydrobromide on the acetate-1-14C incorporation into tissue lipids of irradiated rats

Zusammenfassung Einfluss von Bestrahlung auf die Lipidsynthese, wobei festgestellt wird, dass der Strahlungsschutzstoff AET die Lipidsynthese hemmt.     

Plasma devices to guide and collimate a high density of MeV electrons

The development of ultra-intense lasers has facilitated new studies in laboratory astrophysics and high-density nuclear science, including laser fusion. Such research relies on the efficient generation of enormous numbers of high-energy charged particles. For example, laser-matter interactions at petawatt (10(15) W) power levels can create pulses of MeV electrons with current densities as large as 10(12) A cm(-2). However, the divergence of these particle beams usually reduces the current density to a few times 10(6) A cm(-2) at distances of the order of centimetres from the source. The invention of devices that can direct such intense, pulsed energetic beams will revolutionize their applications. Here we report high-conductivity devices consisting of transient plasmas that increase the energy density of MeV electrons generated in laser-matter interactions by more than one order of magnitude. A plasma fibre created on a hollow-cone target guides and collimates electrons in a manner akin to the control of light by an optical fibre and collimator. Such plasma devices hold promise for applications using high energy-density particles and should trigger growth in charged particle optics.     

Modelling disease outbreaks in realistic urban social networks

Most mathematical models for the spread of disease use differential equations based on uniform mixing assumptions or ad hoc models for the contact process. Here we explore the use of dynamic bipartite graphs to model the physical contact patterns that result from movements of individuals between specific locations. The graphs are generated by large-scale individual-based urban traffic simulations built on actual census, land-use and population-mobility data. We find that the contact network among people is a strongly connected small-world-like graph with a well-defined scale for the degree distribution. However, the locations graph is scale-free, which allows highly efficient outbreak detection by placing sensors in the hubs of the locations network. Within this large-scale simulation framework, we then analyse the relative merits of several proposed mitigation strategies for smallpox spread. Our results suggest that outbreaks can be contained by a strategy of targeted vaccination combined with early detection without resorting to mass vaccination of a population.     

Impedance and ferroelectric properties of Sr2+ modified PZT-PMN ceramics

Sr^2＋ modified polycrystalline PZT-PMN ceramics were synthesized by a semi-wet route. Impedance spectroscopy studies indicate the bulk and grain boundary effects of PZT-PMN material along with the negative temperature coefficient of resistance. The bulk conductiv-ity exhibits an Arrhenius-type thermally activated hopping process which is supported by the AC conductivity behavior as a function of fre-quency and temperature. It is observed that the remnant polarization increases with an increase in the Sr2＋content in PZT-PMN.     

Using Generic Structures in System Dynamics Model Building: Reflection from Modeling for Indian Shrimp Industry

The paper focused on how a system dynamics modeler could reduce model development and testing time by using “Generic Structures” as an interim benchmark between causal loop diagram and stock flow diagram. Using generic structures as a benchmark could prevent the modeler from including redundant structures to the model and getting affected by personal biases that in turn could reduce repetitive amendments to the model during model testing. Indian Shrimp Industry, during 1990–2010, sequentially showed an early growth, a hasty decline, a combative rejuvenation, and an inexorable re-decline behavior in terms of the annual shrimp production and production capacity. Average Yield continuously fluctuated throughout the Industry’s life cycle during 1990–2010. Breaking such progressive behavior into temporal units, we found that the unit behaviors resemble with the behaviors of generic structures like, exponential growth, goal-seeking, S-shaped growth, limits to success, and overshoot-and-collapse. We, using the related generic structures as the interim benchmarks, illustrated a step-by-step modeling exercise for studying the dynamic behavior of Indian Shrimp Industry during 1990–2010. The paper concluded that using generic structures as the benchmark during system dynamics modeling improved the efficiency and the effectiveness of model building due to reduction in model building and testing time.