Levy statistical fluctuations from a Random Amplifying Medium

We report the studies of emission from a novel random amplifying medium that we term a ``Levy Laser'' due to the non-Gaussian statistical nature of its emission over the ensemble of random realizations. It is observed that the amplification is dominated by certain improbable events that are ``larger than rare'', which give the intensity statistics a Levy like ``fat tail''. This, to the best of our knowledge, provides the first experimental realization of Levy flight in optics in a random amplifying medium.Comment: 22 pages, 14 figures (postscript format

Characteristics of Self-managed Weight Loss in Australian Adults: An Exploratory Study

The capacity of health care services to address obesity in Australia is inadequate given the enormity of the issue. There are many people that self-manage their weight loss, without accessing support from the health system (or commercial services) but this group have not been extensively researched. Knowing more about those that self-manage can provide valuable insights for obesity management strategies. This thesis focussed on understanding the characteristics of self-managed weight losers, their weight loss journeys, and outcomes. Methodological questions about what data should be collected and how best to recruit participants were important to consider. Quantitative and qualitative techniques were used to examine different aspects of self-managed weight loss. Most participants were completely unassisted in their weight loss journey. A third of the participants were successful at achieving modest weight loss, and a tenth achieved clinically significant weight loss despite the disruptions brought on by the COVID-19 pandemic. The short-term results achieved, the strategies that were used, the characteristics associated with success, as well as the barriers faced were comparable to those reported in clinical or research settings. The strengths of this thesis were the uniqueness of the population studied and the breadth of data collected on the features of self-managed weight loss. The methodology was well informed by preliminary research and a large pilot study. The limitations were the small sample size achieved and the occurrence of the Covid-19 pandemic in the midst of the longitudinal study. Given the scale of the issue in Australia, and the limited existing health care resources this thesis recommends that self-managed weight loss be recognised as a legitimate weight management strategy that individuals can pursue. This approach should be encouraged and supported unless contraindicated

Light scattering from a magnetically tunable dense random medium with weak dissipation : ferrofluid

We present a semi-phenomenological treatment of light transmission through and its reflection from a ferrofluid, which we regard as a magnetically tunable system of dense random dielectric scatterers with weak dissipation. Partial spatial ordering is introduced by the application of a transverse magnetic field that superimposes a periodic modulation on the dielectric randomess. This introduces Bragg scattering which effectively enhances the scattering due to disorder alone, and thus reduces the elastic mean free path towards Anderson localization. Our theoretical treatment, based on invariant imbedding, gives a simultaneous decrease of transmission and reflection without change of incident linear polarisation as the spatial order is tuned magnetically to the Bragg condition, namely the light wave vector being equal to half the Bragg vector (Q). Our experimental observations are in qualitative agreement with these results. We have also given expressions for the transit (sojourn) time of light and for the light energy stored in the random medium under steady illumination. The ferrofluid thus provides an interesting physical realization of effectively a "Lossy Anderson-Bragg" (LAB) cavity with which to study the effect of the interplay of spatial disorder, partial order and weak dissipation on light transport. Given the current interest in propagation, optical limiting and storage of light in ferrofluids, the present work seems topical

Thianthrene is a novel inhibitor of Leishmania donovani pteridine reductase 1 (PTR1)

Pteridine reductase 1 (PTR1) from Leishmania donovani is a short chain reductase that catalyses the NADPH-dependent reduction of folates and pterins. It has gained attention as a therapeutic target because it acts as a metabolic bypass for dihydrofolate reductase (DHFR) targeting drugs and is thought to be responsible for the failure of conventional therapies against the trypanosomatids. In the present study, we report the identification of thianthrene as a potent inhibitor of L. donovani PTR1 (LdPTR1) based on both structure-based virtual screening and experimental verification. Thianthrene displayed uncompetitive mixed type inhibition in a recombinant enzyme inhibition assay. In addition, cell based assays and flow cytometry showed that the intracellular amastigotes were inhibited by thianthrene in vitro. The results of our study could be considered for the development of novel therapeutics based on PTR1 inhibition

Health service approaches to providing care for people who seek treatment for obesity : identifying challenges and ways forward

OBJECTIVE: This paper aims to identify challenges in current health service approaches to providing optimal care for people who seek treatment for obesity. Type of program or service: Health service management of obesity in Australia Methods: Drawing on lived experience, clinical and academic perspectives, and available evidence, we reflect on the current state of the healthcare system to support people seeking treatment for obesity. We suggest actions to enable effective, acceptable and equitable care for this group of people. RESULTS: Identified challenges include the complexity of care required to adequately manage obesity, existing service capability and capacity, and high out-of-pocket patient costs. LESSONS LEARNT: To address these challenges, a comprehensive response is required at all levels of the healthcare system. As a starting point, we propose eight areas of action: partner with people living with obesity; eliminate weight stigma; increase healthcare professional education, guidelines and resources; establish clear referral pathways and working partnerships; scale services to meet demand; ensure flexible and accessible service delivery; implement changes to the Medicare Benefits Schedule to increase service provision and pursue opportunities for subsidised medicines

Mycobacterium tuberculosis NAD(+)-dependent DNA ligase is selectively inhibited by glycosylamines compared with human DNA ligase I

DNA ligases are important enzymes which catalyze the joining of nicks between adjacent bases of double-stranded DNA. NAD(+)-dependent DNA ligases (LigA) are essential in bacteria and are absent in humans. They have therefore been identified as novel, validated and attractive drug targets. Using virtual screening against an in-house database of compounds and our recently determined crystal structure of the NAD(+) binding domain of the Mycobacterium tuberculosis LigA, we have identified N(1), N(n)-bis-(5-deoxy-α-d-xylofuranosylated) diamines as a novel class of inhibitors for this enzyme. Assays involving M.tuberculosis LigA, T4 ligase and human DNA ligase I show that these compounds specifically inhibit LigA from M.tuberculosis. In vitro kinetic and inhibition assays demonstrate that the compounds compete with NAD(+) for binding and inhibit enzyme activity with IC(50) values in the µM range. Docking studies rationalize the observed specificities and show that among several glycofuranosylated diamines, bis xylofuranosylated diamines with aminoalkyl and 1, 3-phenylene carbamoyl spacers mimic the binding modes of NAD(+) with the enzyme. Assays involving LigA-deficient bacterial strains show that in vivo inhibition of ligase by the compounds causes the observed antibacterial activities. They also demonstrate that the compounds exhibit in vivo specificity for LigA over ATP-dependent ligase. This class of inhibitors holds out the promise of rational development of new anti-tubercular agents

Powder microscopic, physicochemical and chromatographic approach for the quality control of anti-hypertensive drug Rattha Piththathirku Kudinir Chooranam

The present work aims to study powder microscopy, physicochemical and high-performance thin-layer chromatography photo documentation and fingerprint profiles of a Siddha drug, Rattha Piththathirku Kudinir Chooranam (RPK). The raw drugs were collected, authenticated and the RPK was prepared. Then the drug was investigated for powder microscopic characters, physicochemical parameters, Thin Layer Chromatographic photo documentation (TLC), High-Performance Thin-Layer Chromatographic (HPTLC) fingerprint profiles of successive n-hexane, successive chloroform, successive ethanol and hydro alcohol (1:1) extracts. The successive and hydro alcohol extracts of the drug displayed distinct TLC spots and HPTLC peaks which are distinct to this drug

Assessment of Population Exposure to Coarse and Fine Particulate Matter in the Urban Areas of Chennai, India

Research outcomes from the epidemiological studies have found that the course (PM 10 ) and the fine particulate matter (PM 2.5 ) are mainly responsible for various respiratory health effects for humans. The population-weighted exposure assessment is used as a vital decision-making tool to analyze the vulnerable areas where the population is exposed to critical concentrations of pollutants. Systemic sampling was carried out at strategic locations of Chennai to estimate the various concentration levels of particulate pollution during November 2013-January 2014. The concentration of the pollutants was classified based on the World Health Organization interim target (IT) guidelines. Using geospatial information systems the pollution and the high-resolution population data were interpolated to study the extent of the pollutants at the urban scale. The results show that approximately 28% of the population resides in vulnerable locations where the coarse particulate matter exceeds the prescribed standards. Alarmingly, the results of the analysis of fine particulates show that about 94% of the inhabitants live in critical areas where the concentration of the fine particulates exceeds the IT guidelines. Results based on human exposure analysis show the vulnerability is more towards the zones which are surrounded by prominent sources of pollution

Highly enhanced electrochemical performance of novel based electrode materials for supercapacitor applications: an overview.

The research and recent progress of electrochemical energy storage devices applied to various applications during the past two decayed are reviewed. Different electrode materials (carbon-based materials, metal oxides, conducting polymers, metal nanoparticles and nanocomposites), can be used as the most important features for supercapacitors. Recently, research efforts of supercapacitor electrodes have been used to increase the specific capacitance and its cyclic stability. In this review designate current efforts energy storage preparation methods, materials and different morphological structure for electrochemical capacitor applications. The principle of design, extended surface area, improve the capacitance properties and long-durability of the electrochemical capacitor are discussed

Knock-out of vasotocin reduces reproductive success in female zebrafish, Danio rerio

The vertebrate nonapeptide vasotocin/vasopressin is evolutionarily highly conserved and acts as neuromodulator and endocrine/paracrine signaling molecule. Circumstantial and mechanistic evidence from pharmacological manipulations of the vasotocin system in several teleost fishes suggest sex- and species-specific reproductive roles of vasotocin. While effects of vasotocin on teleost reproductive physiology involve both courtship behaviors and the regulation of the hypothalamic-pituitary-gonadal (HPG) axes, comprehensive studies investigating behavioral and physiological reproductive consequences of genetic ablation of vasotocin in a genetically tractable fish model, such as the zebrafish, are currently lacking. Here, we report the generation of homozygous CRISPR/Cas9-based vasotocin gene knock-out zebrafish. Breeding pairs of vasotocin knock-out fish produce significantly fewer fertilized eggs per clutch compared to wildtype fish, an effect coincident with reduced female quivering courtship behavior. Crossbreeding experiments reveal that this reproductive phenotype is entirely female-dependent, as vasotocin-deficient males reproduce normally when paired with female wild-type fish. Histological analyses of vasotocin knock-out ovaries revealed an overall reduction in oocytes and differential distribution of oocyte maturation stages, demonstrating that the reproductive phenotype is linked to oocyte maturation and release. Ovarian hormone quantification and gene expression analysis in mutant fish indicated reduced synthesis of Prostaglandin F2α, a hormone involved in ovarian maturation, egg release and regulation of female courtship behavior in some cyprinids. However, acute injection of vasotocin did not rescue the female mutant reproductive phenotype, suggesting a contribution of organizational effects of vasotocin. Together, this study provides further support for emerging roles of vasotocin in female teleost reproduction in an important teleost model species