Thermodynamics of a Higher Order Phase Transition: Scaling Exponents and Scaling Laws

The well known scaling laws relating critical exponents in a second order phase transition have been generalized to the case of an arbitrarily higher order phase transition. In a higher order transition, such as one suggested for the superconducting transition in Ba$_{0.6}$K$_{0.4}$BiO$_3$ and in Bi$_2$Sr$_2$CaCu$_2$O$_8$, there are singularities in higher order derivatives of the free energy. A relation between exponents of different observables has been found, regardless of whether the exponents are classical (mean-field theory, no fluctuations, integer order of a transition) or not (fluctuation effects included). We also comment on the phase transition in a thin film.Comment: 10 pages, no figure

‘Retournement’ of the aedeagus in Curculionidae (Coleoptera, Curculionoidea)

Retournement or turning of the aedeagus about its longitudinal axis through about 180o during development is known in Chrysomeloidea (Coleoptera). This change in the orientation of the organ may be observed during the postembryonic development. This change produces certain morphological effects. By observing these morphological features in the imago the retournement may be inferred. Such morphological features in Curculionidae (Coleoptera) are here recorded. From this it has been inferred not only that retournement of the aedeagus is included in the ontogeny of curculionids, but also that the change of orientation of the organ occurs by the same mechanism as in Chrysomeloidea. These inferences attest the notion of a close phyletic relationship between the superfamilies Curculionoidea and Chrysomeloidea

Fish-diversity in relation to physico-chemical characteristics of river Devaha, District Pilibhit (U.P.), India

In the present study, the fish diversity was examined in relation to physico-chemical parameters of river Devaha, District Pilibhit, U.P., INDIA. The samples of water and fish species were collected in summer, rainy and winter seasons from site I (Doony dam), site II (premerger site of river Khakra) and site III (post merger point of river Khakra) from June 2010 to December 2012. Fish species belonging to 15 families and 26 genera were collected in the laboratory and identified. Cyprinids formed the most dominant group and were represented by 13 species belonging to 7 genera, followed by Bagridae (3 species). The distribution of fish showed interesting patterns about the species which were common to all the three sites. The Shannon-Weiner diversity index, ranged from 1.82 to 3.06 (lowest in May and highest in October), during the study period. The study showed that out of 34 species recorded 16 could be identified as at lower risk, 12 as vulnerable and 06 as endangered. The study showed that the river supports considerable diversity of fish fauna, about 52.94% fish being either vulnerable or endangered and are important for conservation. The river supports considerable percentage of food fish (86.5%), ornamental fish (4.92%) and sport fish (5.9%) and remaining of unidentified characteristics. The pollution potential of river was investigated by various physico-chemical parameters viz., water temperature (0C), turbidity (NTU), conductivity (μmhocm-1), pH, TDS (mg/L), DO (mg/L), BOD (mg/L) and COD (mg/L).&nbsp

Virulence System of <i>Salmonella</i> with Special Reference to <i>Salmonella enterica</i>

Virulence system of Salmonella is very complex as many genes are involved in contributing the virulence of Salmonella. Some of the genes are involved in enhancing the invasion of organism in host defense system; some are playing their role in survival and replication of organism inside the host, while some genes are involved in the production of molecules that produce the clinical symptoms of the disease. Broadly, we can classify virulence genes into two categories: genes that are located on the virulence contributing plasmid like spvc gene and genes that are chromosomal in nature like stn. On chromosome, virulence genes are located in various clusters, which are known as Salmonella pathogenicity islands and till today seventeen pathogenicity islands have been identified. The genes located on these pathogenicity islands produce several effector molecules, which assist in invasion, replication and survival of Salmonella inside the host. The role of plasmid is still not very clear, but it is presumed that the genes located on virulence plasmids affect the intracellular growth of Salmonella in macrophages. Though lot of research work has been carried out to understand the virulence regulation system of Salmonella, still many questions are to be answered to decode the virulence regulation of Salmonella