Tangential Center Problem for a Family of Non-generic Hamiltonians

The tangential center problem was solved by Yu. S. Ilyashenko in the generic case Mat Sbornik (New Series), 78, 120, 3,360–373, (1969). With the aim of having well-understood models of non-generic Hamiltonians, we consider here a family of non-generic Hamiltonians, whose Hamiltonian is of the form \(F=\prod f_{j}\), where f _j are real polynomials of degree ≥ 1. For this family, the genericity assumption of transversality at infinity fails and the coincidence of the critical values for different critical points is allowed. We consider some geometric conditions on these polynomials in order to compute the orbit under monodromy of their vanishing cycles. Under those conditions, we provide a solution of the tangential center problem for this family.     

An improved leaded small outline package and equivalent circuit

A leaded plastic package has been developed that significantly improves the insertion and return loss, and pin-to-pin isolation of SO-type packages based on measured data and three-dimensional electromagnetic simulations. In addition, an equivalent circuit has been developed that accurately models the circuit behavior of the improved package to above 8 GHz.     

Butt lengths differ by area deprivation level: a field study to explore intensive smoking.

We collected cigarette butts in a range of residential areas, to assess differences in the length of unburnt tobacco in the butts, and in proportions of roll-your-own (RYO) cigarettes. Two high, two medium, and two low deprivation areas, as classified by deciles of the New Zealand Deprivation Index, were selected for the Wellington region. Collected butts were systematically classified and measured. A mixed model of analysis, treating location clusters nested within deprivation level areas as a random effect, was used to assess differences in mean length of unburnt tobacco in the butts. A total of 6,262 cigarette butts and separate filters were collected, of which 3,509 (56.0%) were measurable manufactured cigarette butts, 1,069 were unmeasurable manufactured butts, 1,450 were RYO butts, and 236 were RYO filters. The RYO butts were not measured because of the extent of their degradation. The unburnt tobacco lengths in manufactured cigarette butts were significantly shorter in the most deprived areas, relative to the least deprived areas (p = .035). Deformed manufactured cigarette butts (i.e., that potentially were stubbed out) showed the same pattern (p = .011 between the most and least deprived areas). We found no significant difference between deprivation areas in the proportion of RYO material found. The shorter mean unburnt tobacco length in the most deprived areas is consistent with more intensive smoking among smokers in those areas. This finding is consistent with other evidence of increased price sensitivity among poorer smokers, and with basic economic theory. Further evidence on observed smoking behavior in the field is necessary to better interpret these preliminary findings.     

Role of museums and botanical gardens in ecosystem services in developing countries: case study and outlook

Unprecedented environmental challenges require new tools. Knowledge based on scientific research is critical for the creation of environmental awareness and education in order to bring about behavioural changes in society at large. Well-structured museums and botanical gardens in developing countries can play significant roles in research, education, and conservation even when governmental institutions are weak and underfunded. The paper offers a case study of the nascent Palestine Institute of Sustainability and Palestine Museum of Natural History with a botanical garden. The related SWOT (strengths, weaknesses, opportunities, and threats) analysis concludes that, despite some limitations and challenges, this is a successful model that should be replicated in other impoverished communities.     

Incidence of hepatitis C virus infection in patients on hemodialysis: A systematic review and meta‐analysis

Hepatitis C virus infection is a perennial concern for hemodialysis units because the prevalence of hepatitis C is significantly higher there than in the general population. Through a systematic review and meta‐analysis, we aim to assess the incidence rate of hepatitis C virus infection in hemodialysis units and explore its potential risk factors. Five electronic databases were used to search articles from 1990 to 2012, including PubMed, Embase, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, and Wanfang. A random‐effects analysis was used to estimate the overall incidence rate of hepatitis C virus infection. A subgroup analysis and meta‐regression analysis were conducted to explore factors associated with heterogeneity between studies. Twenty‐two eligible articles were found, including 23 incidence rate estimates. The overall incidence rate of hepatitis C virus infection was 1.47 per 100 patient‐years (95% confidence interval [CI] 1.14 to 1.80). In the subgroup analysis, the pooled incidence rate was 4.44 (CI 2.65, 6.23) per 100 patient‐years in the developing world and 0.99 (CI 0.66, 1.29) per 100 patient‐years in the developed world. [Correction added on 2 November 2012, after first online publication: Pooled incidence rate in the developed world has been changed.] In addition, in hemodialysis units with higher prevalence, the incidence rate of hepatitis C virus infection also tended to be higher. Meta‐regression analysis showed that the country's development level and initial HCV prevalence combined could explain 67.91% of the observed heterogeneity. The incidence rate of hepatitis C virus infection among patients on hemodialysis was significantly high. Efforts should be taken to control hepatitis C virus infection in hemodialysis units, especially in developing countries.     

Modeling water states in polyvinyl alcohol-fumed silica nano-composites

We proposed a mathematical model to account for water contents in different states as a function of filler concentration in polymer-filler composites. The water states were characterized in polyvinyl alcohol (PVA) and PVA-fumed silica (FS) composites using low temperature differential scanning calorimetry. This model takes into consideration the inert filler dilution effect, the equilibrium of bound water to free and freezable water states associated with FS nano-particles, and the suppressed hydrogen-bonding ability of hydroxyl groups in polymer chains caused by FS shielding. Predicted results were in excellent agreement with experimental data. This model can yield a great understanding of the distribution of water states into bound and free (and freezable) water states for homogeneous, heterogeneous or micro-phase separated polymers, and especially perfluorosulfonic acid membranes and water-retaining hydrogels.     

Proteomic analysis of whole human saliva detects enhanced expression of interleukin-1 receptor antagonist, thioredoxin and lipocalin-1 in cigarette smokers compared to non-smokers

A gel-based proteomics approach was used to screen for proteins of differential abundance between the saliva of smokers and those who had never smoked. Subjecting precipitated proteins from whole human saliva of healthy non-smokers to two-dimensional electrophoresis (2-DE) generated typical profiles comprising more than 50 proteins. While 35 of the proteins were previously established by other researchers, an additional 22 proteins were detected in the 2-DE saliva protein profiles generated in the present study. When the 2-DE profiles were compared to those obtained from subjects considered to be heavy cigarette smokers, three saliva proteins, including interleukin-1 receptor antagonist, thioredoxin and lipocalin-1, showed significant enhanced expression. The distribution patterns of lipocalin-1 isoforms were also different between cigarette smokers and non-smokers. The three saliva proteins have good potential to be used as biomarkers for the adverse effects of smoking and the risk for inflammatory and chronic diseases that are associated with it.     

Salivary proteins associated with periodontitis in patients with type 2 diabetes mellitus

The objective of this study was to investigate the salivary proteins that are associated with periodontitis in patients with Type 2 diabetes mellitus (T2DM). Volunteers for the study were patients from the Diabetic Unit, University of Malaya Medical Centre, whose periodontal status was determined. The diabetic volunteers were divided into two groups, i.e., patients with periodontitis and those who were periodontally healthy. Saliva samples were collected and treated with 10% TCA/acetone/20 mM DTT to precipitate the proteins, which were then separated using two-dimensional polyacrylamide gel electrophoresis. Gel images were scanned using the GS-800(TM) Calibrated Densitometer. The protein spots were analyzed and expressed in percentage volumes. The percentage volume of each protein spot was subjected to Mann-Whitney statistical analysis using SPSS software and false discovery rate correction. When the expression of the salivary proteins was compared between the T2DM patients with periodontitis with those who were periodontally healthy, seven proteins, including polymeric immunoglobulin receptor, plastin-2, actin related protein 3, leukocyte elastase inhibitor, carbonic anhydrases 6, immunoglobulin J and interleukin-1 receptor antagonist, were found to be differentially expressed (p < 0.01304). This implies that the proteins may have the potential to be used as biomarkers for the prediction of T2DM patients who may be prone to periodontitis.     

Exploring multiple trees through DAG representations

We present a Directed Acyclic Graph visualisation designed to allow interaction with a set of multiple classification trees, specifically to find overlaps and differences between groups of trees and individual trees. The work is motivated by the need to find a representation for multiple trees that has the space-saving property of a general graph representation and the intuitive parent-child direction cues present in individual representation of trees. Using example taxonomic data sets, we describe augmentations to the common barycenter DAG layout method that reveal shared sets of child nodes between common parents in a clearer manner. Other interactions such as displaying the multiple ancestor paths of a node when it occurs in several trees, and revealing intersecting sibling sets within the context of a single DAG representation are also discussed.