De Sitter Vacua in No-Scale Supergravity

No-scale supergravity is the appropriate general framework for low-energy effective field theories derived from string theory. The simplest no-scale K\"ahler potential with a single chiral field corresponds to a compactification to flat Minkowski space with a single volume modulus, but generalizations to single-field no-scale models with de Sitter vacua are also known. In this paper we generalize these de Sitter constructions to two- and multi-field models of the types occurring in string compactifications with more than one relevant modulus. We discuss the conditions for stability of the de Sitter solutions and holomorphy of the superpotential, and give examples whose superpotential contains only integer powers of the chiral fields.Comment: 22 pages, 7 figure

Pre- and post-processing for Cosmic/NASTRAN on personal computers and mainframes

An interface between Cosmic/NASTRAN and GIFTS has recently been released, combining the powerful pre- and post-processing capabilities of GIFTS with Cosmic/NASTRAN's analysis capabilities. The interface operates on a wide range of computers, even linking Cosmic/NASTRAN and GIFTS when the two are on different computers. GIFTS offers a wide range of elements for use in model construction, each translated by the interface into the nearest Cosmic/NASTRAN equivalent; and the options of automatic or interactive modelling and loading in GIFTS make pre-processing easy and effective. The interface itself includes the programs GFTCOS, which creates the Cosmic/NASTRAN input deck (and, if desired, control deck) from the GIFTS Unified Data Base, COSGFT, which translates the displacements from the Cosmic/NASTRAN analysis back into GIFTS; and HOSTR, which handles stress computations for a few higher-order elements available in the interface, but not supported by the GIFTS processor STRESS. Finally, the versatile display options in GIFTS post-processing allow the user to examine the analysis results through an especially wide range of capabilities, including such possibilities as creating composite loading cases, plotting in color and animating the analysis

Breaking an Epigenetic Chromatin Switch: Curious Features of Hysteresis in Saccharomyces cerevisiae Telomeric Silencing

In addition to gene network switches, local epigenetic modifications to DNA and histones play an important role in all-or-none cellular decision-making. Here, we study the dynamical design of a well-characterized epigenetic chromatin switch: the yeast SIR system, in order to understand the origin of the stability of epigenetic states. We study hysteresis in this system by perturbing it with a histone deacetylase inhibitor. We find that SIR silencing has many characteristics of a non-linear bistable system, as observed in conventional genetic switches, which are based on activities of a few promoters affecting each other through the abundance of their gene products. Quite remarkably, our experiments in yeast telomeric silencing show a very distinctive pattern when it comes to the transition from bistability to monostability. In particular, the loss of the stable silenced state, upon increasing the inhibitor concentration, does not seem to show the expected saddle node behavior, instead looking like a supercritical pitchfork bifurcation. In other words, the 'off' state merges with the 'on' state at a threshold concentration leading to a single state, as opposed to the two states remaining distinct up to the threshold and exhibiting a discontinuous jump from the 'off' to the 'on' state. We argue that this is an inevitable consequence of silenced and active regions coexisting with dynamic domain boundaries. The experimental observations in our study therefore have broad implications for the understanding of chromatin silencing in yeast and beyond

Characterisation and comparison of bacterial communities on reverse osmosis membranes of a full-scale desalination plant by bacterial 16S rRNA gene metabarcoding

Microbiomes of full-scale seawater reverse osmosis membranes are complex and subject to variation within and between membrane units. The pre-existing bacterial communities of unused membranes before operation have been largely ignored in biofouling studies. This study is novel as unused membranes were used as a critical benchmark for comparison. Fouled seawater reverse osmosis membrane biofilm communities from an array of autopsied membrane samples, following a 7-year operational life-span in a full-scale desalination plant in Western Australia, were characterised by 16S rRNA gene metabarcoding using the bacterial primers 515F and 806R. Communities were then compared based on fouling severity and sampling location. Microbiomes of proteobacterial predominance were detected on control unused membranes. However, fouled membrane communities differed significantly from those on unused membranes, reflecting that operational conditions select specific bacteria on the membrane surface. On fouled membranes, Proteobacteria were also predominant but families differed from those on unused membranes, followed by Bacteriodetes and Firmicutes. Betaproteobacteria correlated with stable, mature and thick biofilms such as those in severely fouled membranes or samples from the feed end of the membrane unit, while Alpha and Gammaproteobacteria were predominantly found in biofilms on fouled but visually clean, and moderately fouled samples or those from reject ends of membrane units. Gammaproteobacteria predominated the thin, compact biofilms at the mid-feed end of membrane units. The study also supported the importance of Caulobacterales and glycosphingolipid-producing bacteria, namely Sphingomonadales, Rhizobiales and Sphingobacteriia, in primary attachment and biofilm recalcitrance. Nitrate-and-nitrite-reducing bacteria such as Rhizobiales, Burkholderiales and some Pseudomonadales were also prevalent across all fouled membranes and appeared to be critical for ecological balance and biofilm maturation

Hipertofična kardiomiopatija u 12 pasa (2004. - 2008.): prvi opis u Indiji.

A total of 1276 dogs of various breeds and both sexes were presented to the Teaching Veterinary Clinical Complex, Bhoiguda, College of Veterinary Science, Hyderabad with a history and signs of cardio-pulmonary disorders, from 2004 to 2008. Based on physical, electrocardiographic, radiographic and echocardiographic examinations, 12 dogs were diagnosed with Hypertrophic Cardiomyopathy (HCM). No abnormalities were detected from the Complete Blood Count and blood biochemistry, except elevated levels of Creatine Kinase MB and Lactate Dehydrogenase. All the HCM dogs revealed common manifestations such as: exercise intolerance, poor appetite, lethargy, cough, seizures (8 dogs) and syncope (6 dogs) for more than a couple of weeks. The HCM dogs were under treatment for more than a month with diuretics and Angiotensin Converting Enzyme (ACE)-inhibitors but without any improvement. After supplementation of diltiazem along with ramipril and fursemide, improvement in clinical manifestations were noticed over 3-5 days and complete clinical recovery after 30-60 days. Hence, from the present findings it may be concluded that echocardiography is the most sensitive mode of diagnosis and the role of diltiazem in successful treatment of HCM in dogs is clear.Hypertrophic cardiomyopathy in 12 dogs (2004-2008): first report in Indi

Dielectric properties of liquid crystalline dimer mixtures exhibiting the nematic and twist-bend nematic phases

A detailed investigation of the thermal and dielectric properties of a series of binary mixtures exhibiting the nematic ( N ) and twist-bend nematic ( N TB ) liquid crystal phases is presented. The mixtures consist of an achiral, dimeric liquid crystal CB7CB, which forms the nematic and twist-bend nematic phases, and a calamitic liquid crystal 5CB, which shows the nematic phase. As the concentration of the calamitic liquid crystal is increased, the transition temperatures decrease linearly, and the width of the nematic phase increases. The enthalpies of phase transitions obtained from DSC measurements show that on increasing the concentration of 5CB in the binary mixtures, the enthalpy associated with the N − N TB phase transitions reduces considerably compared to a clear first-order N − N TB transition in pure CB7CB. The real and imaginary parts of the dielectric permittivity are measured as a function of frequency from 100 Hz to 2 MHz in the nematic and twist-bend nematic phases in planar and homeotropic devices. A significant decrease in the average dielectric permittivity as a function of temperature for mixtures forming the N TB phase is observed. Measurements of the imaginary part of the dielectric permittivity show a relaxation peak in the measured frequency window for all of the mixtures exhibiting the N TB phase. The activation energy associated with this relaxation process is calculated and is shown to remain constant irrespective of the composition of the mixtures

Performance of Indian Manufacturing in the Post Reform Period

Many emerging countries in recent decades have relied on a development strategy that focused primarily on promoting the manufacturing sector and the exports of manufactured goods. However, an acceleration of growth of output and employment in manufacturing has eluded India. This is despite the fact that the central focus of the reforms in the 1980s and 1990s was to unshackle the manufacturing sector. Instead it is the services sector which has grown rapidly, contributing about two-third of GDP growth in recent years. This paper discusses the reasons behind the modest performance of the manufacturing sector in India post reforms. It argues that there are many factors that have inhibited the growth of industrial sector in India. One major factor is the rigid and strict labor laws which have affected the industrial performance in a number of ways, by keeping the size of the establishments small, by not encouraging the production of labor intensive goods, by pushing activities to the unorganized sector, and by keeping the Indian industry uncompetitive. Besides the labor laws other factors that are responsible for the modest performance of the manufacturing sector include difficulty in the acquisition of land for industrial use, inadequate financing and infrastructure, and cumbersome business climate. The paper presents arguments and evidence which shows the importance of these factors