Biodiversity and structure of spider communities along a metal pollution gradient

The objective of the study was to determine whether long-term metal pollution affects communities of epigeal spiders (Aranea), studied at three taxonomic levels: species, genera, and families. Biodiversity was defined by three indices: the Hierarchical Richness Index (HRI), Margalef index (DM) and Pielou evenness index (J). In different ways the indices describe taxa richness and the distribution of individuals among taxa. The dominance pattern of the communities was described with four measures: number of dominant species at a site, percentage of dominant species at a site, average dominant species abundance at a site, and the share of the most numerous species (Alopecosa cuneata) at a site. Spiders were collected along a metal pollution gradient in southern Poland, extending ca. 33 km from zinc and lead smelter to an uncontaminated area. The zinc concentration in soil was used as the pollution index.The study revealed a significant effect of metal pollution on spider biodiversity as described by HRI for species (p = 0.039), genera (p = 0.0041) and families (p = 0.0147), and by DM for genera (p = 0.0259) and families (p = 0.0028). HRI correlated negatively with pollution level, while DM correlated positively. This means that although broadly described HRI diversity decreased with increasing pollution level, species richness increased with increasing contamination. Mesophilic meadows were generally richer. Pielou (J) did not show any significant correlations. There were a few evidences for the intermediate disturbance hypothesis: certain indices reached their highest values at moderate pollution levels rather than at the cleanest or most polluted sites

Measuring underreporting and under-ascertainment in infectious disease datasets: a comparison of methods

Gibbons CL, Mangen M-JJ, Plaß D, et al. Measuring underreporting and under-ascertainment in infectious disease datasets: a comparison of methods. BMC Public Health. 2014;14(1): 147.Background: Efficient and reliable surveillance and notification systems are vital for monitoring public health and disease outbreaks. However, most surveillance and notification systems are affected by a degree of underestimation (UE) and therefore uncertainty surrounds the 'true' incidence of disease affecting morbidity and mortality rates. Surveillance systems fail to capture cases at two distinct levels of the surveillance pyramid: from the community since not all cases seek healthcare (under-ascertainment), and at the healthcare-level, representing a failure to adequately report symptomatic cases that have sought medical advice (underreporting). There are several methods to estimate the extent of under-ascertainment and underreporting. Methods: Within the context of the ECDC-funded Burden of Communicable Diseases in Europe (BCoDE)-project, an extensive literature review was conducted to identify studies that estimate ascertainment or reporting rates for salmonellosis and campylobacteriosis in European Union Member States (MS) plus European Free Trade Area (EFTA) countries Iceland, Norway and Switzerland and four other OECD countries (USA, Canada, Australia and Japan). Multiplication factors (MFs), a measure of the magnitude of underestimation, were taken directly from the literature or derived (where the proportion of underestimated, under-ascertained, or underreported cases was known) and compared for the two pathogens. Results: MFs varied between and within diseases and countries, representing a need to carefully select the most appropriate MFs and methods for calculating them. The most appropriate MFs are often disease-,country-, age-, and sex-specific. Conclusions: When routine data are used to make decisions on resource allocation or to estimate epidemiological parameters in populations, it becomes important to understand when, where and to what extent these data represent the true picture of disease, and in some instances (such as priority setting) it is necessary to adjust for underestimation. MFs can be used to adjust notification and surveillance data to provide more realistic estimates of incidence

Job search information behaviours: An ego-net study of networking amongst young job-seekers

Networking is considered an integral feature of job search, yet its behavioural manifestation has received little attention in the extant literature. Here this is addressed in a study of young job-seekers that adopted an egocentric network approach underpinned by Information Behaviour theory, with specific reference to Wilson's model of information needs and seeking. The analysis of data from semi-structured interviews reveals that job-seekers acquire a broad range of job search information from contacts in their networks, and that the contributions of such contacts extend beyond the sharing of job vacancy alerts. In addition, in cases where social media platforms are accessed by job-seekers, these facilitate crucial ties to industry contacts, and provide valuable informational opportunities to those who adopt them. These findings contribute to a widened understanding of the information behaviours that support the effective mobilisation of contacts within social networks during job search, and are of particula

Influence of preferential adsorption of mobile phase on effectiveness of enantioseparation of amino acids on chirobiotic stationary phase

Enatioselective chromatography on chiral stationary phase has become integral part of drug research, development and production on the industrial scale. Development of new highly selective stationary phases and effective techniques of chromatographic separation such as SMB or Varicol processes resulted in increasing interest in chromatographic process as an effective separation method. Due to high cost of chiral stationary phases chromatographic separation should be conducted under conditions guaranteeing the highest process performance. An important operating variable is composition of the mobile phase, which has crucial influence on the selectivity of separation. Hence, type and concentration of active components of the mobile phase should be properly selected and their effect on the process performance should be quantified. In this work adsorption of the mobile phase has been investigated on Chirobiotic-T stationary phase. Binary mixtures of polar solvents allowing enantioseparation of amino acid, D and L threonine, have been considered. Absorption equilibria of three different systems of binary water-alcohol mixtures have been examined: water mixed with methanol, ethanol or propan-2-ol. The excess adsorption of the alcohols have been measured and isotherm equations have been quantified. Strongly nonideal behavior of solvents in both the mobile and the stationary phases has been identified and accounted for by the activity coefficients. The Margules or van-Laar equations for water-alcohol mixtures reported in literature have been exploited to quantify nonideality of the mobile phase. Activity coefficients in the adsorbed phase have been determined by fitting the simulations to the experimental data of the excess adsorption. In the next stage adsorption equilibria of isomers of threonine have been determined at different alcohol contents in the mobile phase. The heterogeneous mechanism of adsorption has been identified and was approximated by bi-Langmuir isotherms. The results obtained for all three systems have been compared. Strong influence of adsorption of alcohols on the retention behavior of the solutes have been evidenced and analyzed. The results obtained will be presented and discussed

Influenza and the rates of hospitalization for respiratory disease among infants and young children

Background: Young children may be at increased risk for serious complications from influenzavirus infection. However, in population-based studies it has been difficult to separate the effects of influenzavirus from those of respiratory syncytial virus. Respiratory syncytial virus often circulates with influenzaviruses and is the most frequent cause of hospitalization for lower respiratory tract infections in infants and young children. We studied the rates of hospitalization for acute respiratory disease among infants and children during periods when the circulation of influenzaviruses predominated over the circulation of respiratory syncytial virus. Methods: For each season from October to May during the period from 1992 to 1997, we used local viral surveillance data to define periods in Washington State and northern California when the circulation of influenzaviruses predominated over that of respiratory syncytial virus. We calculated the rates of hospitalization for acute respiratory disease, excess rates attributable to influenzavirus, and incidence-rate ratios for all infants and children younger than 18 years of age who were enrolled in either the Kaiser Permanente Medical Care Program of Northern California or the Group Health Cooperative of Puget Sound. Results: The rates of hospitalization for acute respiratory disease among children who did not have conditions that put them at high risk for complications of influenza (e.g., asthma, cardiovascular diseases, or premature birth) and who were younger than two years of age were 231 per 100,000 person-months at Northern California Kaiser sites (from 1993 to 1997) and 193 per 100,000 person-months at Group Health Cooperative sites (from 1992 to 1997). These rates were approximately 12 times as high as the rates among children without high-risk conditions who were 6 to 17 years of age (19 per 100,000 person-months at Northern California Kaiser sites and 16 per 100,000 person-months at Group Health Cooperative sites) and approached the rates among children with chronic health conditions who were 6 to 17 years of age (386 per 100,000 person-months and 216 per 100,000 person-months, respectively). Conclusions: Infants and young children without chronic or serious medical conditions are at increased risk for hospitalization during influenza seasons. Routine influenza vaccination should be considered in these children.Link_to_subscribed_fulltex