Incidences of new bad cheque offenders and KLCI performance: 1996 – 2007 analysis

This paper explores the relationship between incidences of new bad cheque offenders (NBCO) and the Kuala Lumpur Composite Index (KLCI) performance in Malaysia for the period 1996 – 2007 using descriptive and correlation analysis. It is perceived that NBCO would increase when KLCI performance falls. The empirical testing results provide a high negative correlation between NBCO and KLCI

The Molecular Basis of Substrate Recognition by the Family of Pellino E3 Ubiquitin Ligases

The four mammalian Pellinos (Pellinos 1, 2, 3a, and 3b) are E3 ubiquitin ligases that have emerging roles in the regulation of Toll-like receptors, interleukin-1 receptor, T-cell receptor, Nod2, and TNF receptor signaling pathways. While each Pellino has a distinct role in facilitating various cellular processes, the underlying mechanisms by which these highly homologous proteins act selectively in these signaling pathways are not clear. In this dissertation, we elucidate the molecular basis of Pellino substrate specificity in order to gain a better understanding of the roles that individual Pellinos play in orchestrating inflammation and cell death. Pellino substrate recognition is mediated by a non-canonical FHA domain, a well-characterized phosphothreonine binding module. We identify a high-affinity Pellino-FHA domain binding motif in the Pellino substrate, interleukin 1 receptor associated kinase 1 (IRAK1). Binding analysis of the different Pellinos to a panel of pT-peptides reveals that each Pellino has a distinct binding specificity. This specificity also manifests in the interaction of Pellinos with a number of known Pellino substrates. These results argue that the non-redundant roles that Pellinos play in immune signaling are in part due to their divergent substrate specificities. In addition to elucidating Pellino substrate binding preferences, we also sought to determine how Pellinos interact with substrates. Through mutational analyses, we have found that the Pellino2 FHA domain β9/β10 loop mediates interactions with IRAK1, but is dispensable for pT-peptide binding. These results show that Pellino substrate binding determinants may require more than a short pT-peptide motif

Divergent Mating Behaviors and the Evolution of Reproductive Isolation

Sexual selection can cause rapid co-divergence of mating traits and mate preferences, generate reproductive barriers among individuals bearing divergent mating traits, and potentially lead to speciation. In my dissertation, I focused on two emerging topics that challenge this traditional speciation-by-mate-choice paradigm. First, sexual selection encompasses both mate preferences and intrasexual competition, yet speciation research disproportionally focused on the role of the former. Second, sexual behaviors are usually assumed to be genetically inherited, but they may often be shaped by learning instead, which can generate very different evolutionary trajectories for traits and preferences. Using studies of the highly polymorphic strawberry poison frogs (Oophaga pumilio), I demonstrated how incorporating (i) male-male competition and (ii) behavioral learning can enhance our understanding of the potential for speciation to be driven by sexual selection. I first characterized behavioral patterns across a natural contact zone between color morphs and showed that coloration (the divergent mating trait) mediates both female choice and male-male competition. Females often prefer males of their own (local) color over a novel color, and males, when defending territories, are more aggressive against their own color morph. I then tested how these color-mediated female preferences and male aggression biases interact to determine mating patterns. I conducted a controlled breeding experiment in which male-male competition and female mate choice act either in same or in opposing directions. In this study, females reproduced more often with the territorial male over the non-territorial male, regardless of the males’ coloration. This challenges the common assumption that knowledge of female preferences for male mating traits is sufficient to predict mating patterns. Finally, I discovered that learning from mothers during the tadpole stage shapes both female mate preferences and male aggression biases in O. pumilio. Based on this finding, I built a population genetic model and used it to demonstrate a simple and elegant mechanism by which sexual selection alone has the potential to initiate speciation. My research highlights the importance of considering interactions between mate choice, intrasexual competition, and behavioral learning, for studies of mating trait evolution and sexual selection’s role in speciation

Single- and multi-photon ionization studies of organosulfur species

Single- and multi-photon ionization techniques were employed for the photoionization and pulsed field ionization (PFI) studies for the following organsulfur species: CH3SH, CH3CH2SH, CH 3CH2S and CS2. Accurate ionization energies were determined for these neutral species using high-resolution lasers and PFI scheme. The uncertainty in the ionization energy is a few wavenumbers. In these studies, the resolution of the PFI spectra by single vacuum ultraviolet photon ionization was higher than that by multi-photon ionization. Information of the energy levels for the neutrals and/or the corresponding cations was retrieved from the experimental results

A Geographic Study on Level of Markets in Meiktila

The study area, Meiktila is situated in the southwestern part of Mandalay Region. Meiktila has good transport system with various regions of Myanmar. There are 9 markets in Meiktila. The main aim is to study the markets which serve as tertiary system in the study area. Normally the tertiary functions are consumer oriented and they need a certain number of consumers or the threshold population for their existence. They, therefore, used to locate in population centers or in areas with high accessibility. In this paper, the distribution of market is determined by using GIS based buffer analysis. As a result, distribution of these markets is a great difference with respect to their tributary area, size of their functions, transportation facilities, accessibility and location of market place. Therefore, it is needed to build better transport system to develop for levels of markets in the study area

Steering between Bloch oscillation and dipole oscillation in parabolic optical waveguide arrays

We study the optical oscillations of supermodes in planar optical waveguide arrays with parabolically graded propagation constant in individual waveguide interacting through nearest neighbor couplings. In these arrays, we have identified a transition between a symmetric dipole oscillation (DO) and a symmetry-breaking Bloch oscillation (BO) under appropriate conditions. There exist obvious correspondences between gradon localization and various optical oscillations. By virtue of an analogue between the oscillation of optical system and that of a plane pendulum, we propose a shift of the graded profile to cause a transition from BO to DO. We confirm the optical transition by means of Hamiltonian optics, as well as by the field evolution of the supermodes. The results offer great potential applications in optical switching, which can be applied to design suitable optical devices.Comment: Submitted to JOSA B for publication