Nodal domains of the equilateral triangle billiard

We characterize the eigenfunctions of an equilateral triangle billiard in terms of its nodal domains. The number of nodal domains has a quadratic form in terms of the quantum numbers, with a non-trivial number-theoretic factor. The patterns of the eigenfunctions follow a group-theoretic connection in a way that makes them predictable as one goes from one state to another. Extensive numerical investigations bring out the distribution functions of the mode number and signed areas. The statistics of the boundary intersections is also treated analytically. Finally, the distribution functions of the nodal loop count and the nodal counting function are shown to contain information about the classical periodic orbits using the semiclassical trace formula. We believe that the results belong generically to non-separable systems, thus extending the previous works which are concentrated on separable and chaotic systems.

Conformational Analysis of a 20-Membered Cyclic Peptide Disulfide from Conus virgo with a WPW Segment: Evidence for an Aromatic-Proline Sandwich

A novel peptide containing a single disulfide bond, CIWPWC (Vi804), has been isolated and characterised from the venom of the marine cone snail, Conus virgo. A precursor polypeptide sequence derived from complementary DNA, corresponding to the M-superfamily conotoxins, has been identified. The identity of the synthetic and natural peptide sequence has been established. A detailed analysis of the conformation in solution is reported for Vi804 and a synthetic analogue, (CIWPWC)-W-D ((D)W3-Vi804), in order to establish the structure of the novel WPW motif, which occurs in the context of a 20-membered macrocyclic disulfide. Vi804 exists exclusively in the cis W3P4 conformer in water and methanol, whereas (D)W3-Vi804 occurs exclusively as the trans conformer. NMR spectra revealed a W3P4 typeVI turn in Vi804 and a typeII turn in the analogue peptide, (D)W3-Vi804. The extremely high-field chemical shifts of the proline ring protons, together with specific nuclear Overhauser effects, are used to establish a conformation in which the proline ring is sandwiched between the flanking Trp residues, which emphasises a stabilising role for the aromatic-proline interactions, mediated predominantly by dispersion forces.

Inhibition of protein synthesis leading to unfolded protein response is the major event in abrin-mediated apoptosis

Abrin obtained from the plant Abrus precatorius inhibits protein synthesis and also triggers apoptosis in cells. Previous studies from our laboratory suggested a link between these two events. Using an active site mutant of abrin A-chain which exhibits 225-fold lower protein synthesis inhibitory activity than the wild-type abrin A-chain, we demonstrate in this study that inhibition of protein synthesis induced by abrin is the major factor triggering unfolded protein response leading to apoptosis. Since abrin A-chain requires the B-chain for internalization into cells, the wild-type and mutant recombinant abrin A-chains were conjugated to native ricin B-chain to generate hybrid toxins, and the toxic effects of the two conjugates were compared. The rate of inhibition of protein synthesis mediated by the mutant ricin B-rABRA (R167L) conjugate was slower than that of the wild-type ricin B-rABRA conjugate as expected. The mutant conjugate activated p38MAPK and caspase-3 similar to its wild-type counterpart although at later time points. Overall, these results confirm that inhibition of protein synthesis is the major event contributing to abrin-mediated apoptosis.

Estimate of N2O release from pit-toilets

The use of pit-toilets has severely contaminated the groundwater with nitrate ions in Mulbagal town, Karnataka, India. This paper examines the potential of nitrate ions in the pit-toilet effluents to transform to N2O and to escape to atmosphere from 16 wards of Mulbagal town. Anaerobic conditions prevailing in the pit-toilet convert 25 % of the available N to ammonium ions. Only 3-33 % of ammonium ions transform to nitrate ions in the pit-toilet and escape with the effluent. During migration to aquifer, only 4.5 % of available nitrate concentration in the effluent transforms to N-2 and N2O gases in the 1.5-m-thick saturated zone underlying the pit-toilet; 36-55 % of the gases comprise N2O and the remainder of N-2. Further only 18 % of N2O formed escapes to atmosphere, while the remainder is retained in soil solution. Calculations show that 9.88 x 10(13) molecules of N2O/cm(2) would be cumulatively released from 16 wards of Mulbagal town, over an area of 4.9 km(2).

An Evaluation of the Effectiveness of a Charged Bilayered Conducting Fine Mesh as a Dust Filter

Aim: To develop a mesh meant to be mounted on a windowpane that will act as a barrier for dust, while allowing wind to pass freely. Materials and Methods: Two small metal meshes separated at 1 cm, connected to an electrostatic generator and holding opposite charges are used. A videographic analysis has been performed. Results: The charged bilayered mesh was able to prevent a large portion of dust from passing through. Conclusion: The device is a simple, economical, and reliable way of reducing the entry of dust into a room, easing the need for periodic cleaning, and thus creating a healthier environment for the inhabitants of the building. It also has potential space applications.

Towards an exact factorization of the molecular wave function

An exact single-product factorisation of the molecular wave function for the timedependent Schrodinger equation is investigated by using an ansatz involving a phasefactor. By using the Frenkel variational method, we obtain the Schrodinger equations for the electronic and nuclear wave functions. The concept of a potential energy surface (PES) is retained by introducing a modified Hamiltonian as suggested earlier by Cederbaum. The parameter in the phase factor is chosen such that the equations of motion retain the physically appealing Born- Oppenheimer-like form, and is therefore unique.

A real-time coherent dedispersion pipeline for the giant metrewave radio telescope

A fully real-time coherent dedispersion system has been developed for the pulsar back-end at the Giant Metrewave Radio Telescope (GMRT). The dedispersion pipeline uses the single phased array voltage beam produced by the existing GMRT software back-end (GSB) to produce coherently dedispersed intensity output in real time, for the currently operational bandwidths of 16 MHz and 32 MHz. Provision has also been made to coherently dedisperse voltage beam data from observations recorded on disk. We discuss the design and implementation of the real-time coherent dedispersion system, describing the steps carried out to optimise the performance of the pipeline. Presently functioning on an Intel Xeon X5550 CPU equipped with a NVIDIA Tesla C2075 GPU, the pipeline allows dispersion free, high time resolution data to be obtained in real-time. We illustrate the significant improvements over the existing incoherent dedispersion system at the GMRT, and present some preliminary results obtained from studies of pulsars using this system, demonstrating its potential as a useful tool for low frequency pulsar observations. We describe the salient features of our implementation, comparing it with other recently developed real-time coherent dedispersion systems. This implementation of a real-time coherent dedispersion pipeline for a large, low frequency array instrument like the GMRT, will enable long-term observing programs using coherent dedispersion to be carried out routinely at the observatory. We also outline the possible improvements for such a pipeline, including prospects for the upgraded GMRT which will have bandwidths about ten times larger than at present.

Stable p-type conductivity in B and N co-doped ZnO epitaxial thin film

We report on the observation of stable p-type conductivity in B and N co-doped epitaxial ZnO thin films grown by pulsed laser deposition. Films grown at higher oxygen partial pressure (similar to 10(-1) Torr) shows p-type conductivity with a carrier concentration of similar to 3 x 10(16) cm(-3). This p-type conductivity is associated with the significant decrease in defect emission peaks due to the vacancy oxygen (V-O) and Schottky type-I native defects compared to films grown at low oxygen partial pressure (similar to 10(-5) Torr). The p-type conductivity is explained with the help of density functional theory (DFT) calculation considering off-stoichiometric BN1+x in the ZnO lattice. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Role of self-efficacy in predicting outcomes from a programme for controlled drinking

Predicted the outcomes of 40 men and 20 women who attended a controlled drinking program in a general hospital. Measures included a behavioral interview, the Alcohol Dependence Scale (ADS), the Severity of Alcohol Dependence Questionnaire (SADQ) described by T. Stockwell et al (1979), and a problem drinking self-efficacy scale (PDSES). Substantial reductions in drinking appeared after the program and appeared to be sustained over a 6-mo follow-up. Intake dropped from 11.3 drinks per day to 2.2 drinks during follow-up. Drinking history and alcohol dependence (as measured by the SADQ, but not the ADS) were significant predictors of alcohol consumption during follow-up. Predictive utility of the PDSES was confirmed. PDSES administered at the end of the program significantly predicted alcohol consumption over the next 6 mo.

Building resilience to prevent mental health problems in young people : The resourceful adolescent programme (RAP)

This chapter describes an evidence-based programme called the Resourceful Adolescent Program (RAP), which has been successful in building resilience in young people to prevent depressive symptoms developing.The programme adopts a strengths-focused approach. It aims to build a range of coping resources that foster teenagers’ abilities to maintain a positive sense of self and regulate emotions in the face of the vicissitudes of everyday struggles and difficult life events.This groupbased programme can be implemented routinely in schools or by counselling professionals as an early intervention or prevention programme. While there is no universal definition, ‘resilience’ generally means the process of avoiding the negative trajectories associated with exposure to risk factors (Fergus and Zimmerman, 2005). Current models of resilience are also very clear that there ‘are many pathways to resilience’ (Bonanno, 2004) and there is no

The key lessons learnt from producing the ABC programme Talking Heads a talk show/documentary hybrid in a fast turnaround environment

The following exegesis will detail the key advantages and disadvantages of combining a traditional talk show genre with a linear documentary format using a small production team and a limited budget in a fast turnaround weekly environment. It will deal with the Australian Broadcasting Corporation series Talking Heads, broadcast weekly in the early evening schedule for the network at 18.30 with the presenter Peter Thompson. As Executive Producer for the programme at its inception I was responsible for setting it up for the ABC in Brisbane, a role that included selecting most of the team to work on the series and commissioning the music, titles and all other aspects required to bring the show to the screen. What emerged when producing this generic hybrid will be examined at length, including: „h The talk show/documentary hybrid format needs longer than 26¡¦30¡¨ to be entirely successful. „h The type of presenter ideally suited to the talk show/documentary format requires someone who is genuinely interested in their guests and flexible enough to maintain the format against tangential odds. „h The use of illustrative footage shot in a documentary style narrative improves the talk show format. iv „h The fast turnaround of the talk show/documentary hybrid puts tremendous pressure on the time frames for archive research and copyright clearance and therefore needs to be well-resourced. „h In a fast turnaround talk show/documentary format the field components are advantageous but require very low shooting ratios to be sustainable. „h An intimate set works best for a talk show hybrid like this. Also submitted are two DVDs of recordings of programmes I produced and directed from the first and third series. These are for consideration in the practical component of this project and reflect the changes that I made to the series.