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River networks are critically important ecosystems. This interdisciplinary book provides an integrated ecohydrological framework blending laboratory, field, and theoretical evidence that changes our understanding of river networks as ecological corridors. It describes how the physical structure of the river environment impacts biodiversity, species invasions, population dynamics, and the spread of waterborne disease. State-of-the-art research on the ecological roles of the structure of river networks is summarized, including important studies on the spread and control of waterborne diseases, biodiversity loss due to water resource management, and invasions by non-native species. Practical implications of this research are illustrated with numerous examples throughout. This is an invaluable go-to reference for graduate students and researchers interested in river ecology and hydrology, and the links between the two. Describing new related research on spatially-explicit modeling of the spread of waterborne disease, this book will also be of great interest to epidemiologists and public health managers.
We prove the stability with respect to the flux of solutions to initial – boundary value problems for scalar non autonomous conservation laws in one space dimension. Key estimates are obtained through a careful construction of the solutions.
The classification of cultures into a workable number of types for descriptive or interpretative ends has occupied anthropologists since the science was born. Many kinds of data have been selected. Within the last decade Coon's (1948) subdivision of human societies into six levels on the basis of complexity of institutions, and the attempts by Strong (1948), Armillas (1948), Steward (1949), Willey and Phillips (1955) to distinguish developmental periods in the Mesoamerican and Andean archaeological sequences may be cited. Our excuse for attempting yet another formulation is that the current schemes emphasize either ethnographic criteria that are difficult or impossible to detect archaeologically, or unique features of particular cultural configurations rather than general criteria defining more universal patterns. Starting from a point of view different from those heretofore employed, we have tried to develop a classification of cultures that is usable with both ethnographical and archaeological data and that has functional and evolutionary as well as historical and descriptive significance.
Reducing the risk of human immunodeficiency virus type 1 (HIV-1) transmission is still a public health priority. The development of effective control strategies relies on the quantification of the effects of prophylactic and therapeutic measures in disease incidence. Although several assays can be used to estimate HIV incidence, these estimates are limited by the poor performance of these assays in distinguishing recent from long-standing infections. To address such limitation, we have developed an assay to titrate p24-specific IgG3 antibodies as a marker of recent infection. The assay is based on a recombinant p24 protein capable to detect total IgG antibodies in sera using a liquid micro array and enzyme-linked immunosorbent assay. Subsequently, the assay was optimised to detect and titrate anti-p24 IgG3 responses in a panel of sequential specimens from seroconverters over 24 months. The kinetics of p24-specific IgG3 titres revealed a transient peak in the 4 to 5-month period after seroconversion. It was followed by a sharp decline, allowing infections with less than 6 months to be distinguished from older ones. The developed assay exhibited a mean duration of recent infection of 144 days and a false-recent rate of ca. 14%. Our findings show that HIV-1 p24-specific IgG3 titres can be used as a tool to evaluate HIV incidence in serosurveys and to monitor the efficacy of vaccines and other transmission control strategies.
This review aimed to critically analyse data pertaining to the clinical presentation and treatment of neuroendocrine carcinomas of the larynx.
A PubMed search was performed using the term ‘neuroendocrine carcinoma’. English-language articles on neuroendocrine carcinoma of the larynx were reviewed in detail.
Results and conclusion
While many historical classifications have been proposed, in contemporary practice these tumours are sub-classified into four subtypes: carcinoid, atypical carcinoid, small cell neuroendocrine carcinoma and large cell neuroendocrine carcinoma. These tumours exhibit a wide range of biological behaviour, ranging from the extremely aggressive nature of small and large cell neuroendocrine carcinomas, which usually have a fatal prognosis, to the less aggressive course of carcinoid tumours. In small and large cell neuroendocrine carcinomas, a combination of irradiation and chemotherapy is indicated, while carcinoid and atypical carcinoid tumour management entails conservation surgery.
To investigate the nutritional status of North African (NA) immigrant women in Italy, analysing their body size, adiposity and body image perception in comparison to Italian natives and NA residents.
The study utilized a cross-sectional design. Anthropometric traits were directly measured and a few indices were computed as proxy measures of nutritional status and adiposity. Body image perception was assessed using silhouette drawings. ANCOVA, adjusted for age, was used to compare anthropometric traits among different groups of women and the χ2 test to analyse differences in the prevalence of nutritional status.
Italy and North Africa (Tunisia, Morocco).
A sample of 433 women aged 18–60 years old: NA immigrants (n 105); Italians (n 100); Tunisians (n 104); Moroccans (n 124).
Overweight/obesity prevalence was very high in immigrants (79·8 %). Immigrants had the highest BMI value, the greatest hip circumference and mid upper-arm circumference. Their triceps skinfold thickness was significantly higher than that of Italians, but lower than that of NA residents.
NA immigrant women in Italy showed a higher incidence of overweight compared with Italians and NA residents. All groups showed a preference for a thinner body in comparison to their actual bodies and the immigrants are the most dissatisfied. Immigrants remain a high-risk group for obesity. Assessment of their body composition and health risk profile should be improved by using specific anthropometric measures that are easy to collect even in the case of large migration flows.
Presence of Vibrio cholerae serogroups O1 and O139 in the waters of the rural area of Matlab, Bangladesh, was investigated with quantitative measurements performed with a portable flow cytometer. The relevance of this work relates to the testing of a field-adapted measurement protocol that might prove useful for cholera epidemic surveillance and for validation of mathematical models. Water samples were collected from different water bodies that constitute the hydrological system of the region, a well-known endemic area for cholera. Water was retrieved from ponds, river waters, and irrigation canals during an inter-epidemic time period. Each sample was filtered and analysed with a flow cytometer for a fast determination of V. cholerae cells contained in those environments. More specifically, samples were treated with O1- and O139-specific antibodies, which allowed precise flow-cytometry-based concentration measurements. Both serogroups were present in the environmental waters with a consistent dominance of V. cholerae O1. These results extend earlier studies where V. cholerae O1 and O139 were mostly detected during times of cholera epidemics using standard culturing techniques. Furthermore, our results confirm that an important fraction of the ponds’ host populations of V. cholerae are able to self-sustain even when cholera cases are scarce. Those contaminated ponds may constitute a natural reservoir for cholera endemicity in the Matlab region. Correlations of V. cholerae concentrations with environmental factors and the spatial distribution of V. cholerae populations are also discussed.
At present, bovine neosporosis is an important worldwide concern because of its wide geographic distribution and economic impact. Abortion is the main clinical sign of bovine neosporosis in both dairy and beef cattle. Ruminant challenge models are critical to evaluate potential vaccine candidates to help tackle bovine neosporosis and to study pathogenesis and host responses to infection. Several research groups have developed ruminant models of Neospora caninum infection independently of others, resulting in a high degree of variability due to the use of different species of animals, breeds, strains/isolates of N. caninum, doses, routes and times of inoculation. Standardization is greatly needed to advance research in a more collaborative, timely and efficient manner. In the absence of widely accepted international guidelines, this manuscript serves to summarize and discuss the different models and parameters currently in use. Parameters essential for the development of non-pregnant and pregnant ruminant models are outlined and the main knowledge gaps are identified. This information could act as the basis to develop a consensus for international standard guidelines for ruminant models of neosporosis that would be helpful for researchers in this field worldwide.
The gametogenic cycle and life history of Nicolea uspiana (Nogueira, 2003) (Polychaeta: Terebellidae) was studied by taking monthly samples over a 13 month period. Each month, 10 females were sorted; 50 oocytes were removed from the coelom of each specimen, and the maximum diameter was determined. Additionally, 10 males were sorted and 100 gametes were randomly selected from each specimen to evaluate their shape and maturation stage. This species is gonochoric and exhibits slight external sexual dimorphism (in the shape of the nephridial papillae). The sex-ratio of N. uspiana was 2.4 male for each female. The initial gametic stages of both sexes are produced in special structures called nephromixia. Oogenesis is extra-ovarian, and the germ cells are clumped and surrounded by follicle cells. These cells are ovulated into the coelomic fluid, and yolk synthesis occurs in this cavity. The maximum diameter of oocytes measured, 225 µm, showed that these eggs fall into the size-range for lecithotrophy. Furthermore, N. uspiana is an iteroparous species, as the mature individuals can breed several times during their lifetime. Male gonads release germ cells early in development, and sperm maturation also occurs in the coelomic fluid. The male gametes consist of flattened plaques of germ cells attached on their anterior part by a cytophore assuming a rosette-like appearance. Following maturation of the male cells, the spermatids produce arrays of stiffly vibratile tails, assuming a morula shape. The reproductive patterns and life history of the terebellids are also discussed.
In late 2008, Indonesia's parliament passed a law against pornography. The debate was short, because the bill had already been thoroughly discussed and revised in committees and a majority of legislators had agreed to support it. Prior to the vote, however, nearly a hundred legislators opposed to the bill stormed out of parliament in protest. The ratification of the legislation Rancangan Undang-Undang Pornografi, or RUU Pornografi as it is commonly known, marks the end of one of the many bitter public controversies that have preoccupied Indonesians since the collapse of the authoritarian Soeharto regime in 1998.
At a time when Indonesia is still in the process of political and social flux, the recent debates over issues such as pornography entail competing ideas about how Islam should be incorporated into the nation-state. Arguments about the pornography bill, for example, revolved around whether the state should regulate the media to prevent it from disseminating images that offend Islamic norms of modesty. In this way, the debate over the role of the state in regulating images or behaviour was also a debate about the extent to which the state's actions should be guided by religious, in this case Islamic, ideologies. These controversies are moral debates, in that they involve arguments about individual or collective rights vis-à-vis the state, as well as struggles over what constitutes an ideal society, which are often informed by religion.
Gender ideologies are a profound, but often underappreciated aspect of moral debates. The Indonesian debates about pornography not only involve competing ideas about rights and freedoms, but also about how bodies, particularly those of women, should be seen in public. Feminist scholars have argued that moral debates such as the one over pornography reflect attempts to define collective identities and to shape the gender structure of society (Yuval-Davis 1997). And in the case of Indonesia, such debates are also part of a continuing process of struggle over the relationship between religion and public life (Brenner 2011; Rinaldo 2011).
Quasispecies theory predicts that there is a critical mutation probability above which a viral population will go extinct. Above this threshold the virus loses the ability to replicate the best-adapted genotype, leading to a population composed of low replicating mutants that is eventually doomed. We propose a new branching model that shows that this is not necessarily so. That is, a population composed of ever changing mutants may survive.
Several realistic situations in vehicular traffic that
give rise to queues can be modeled through conservation laws with
boundary and unilateral constraints on the flux. This paper provides
a rigorous analytical framework for these descriptions, comprising
stability with respect to the initial data, to the boundary inflow
and to the constraint. We present a framework to rigorously state
optimal management problems and prove the existence of the
corresponding optimal controls. Specific cases are dealt with in
detail through ad hoc numerical integrations. These are here
obtained implementing the wave front tracking algorithm, which
appears to be very precise in computing, for instance, the exit
The capability of hydrogen to passivate nitrogen in dilute nitrides is exploited to in-plane engineer the electronic properties of Ga(AsN)/GaAs heterostructures. Two methods are presented: i) by deposition of hydrogen-opaque metallic masks on Ga(AsN) and subsequent hydrogen irradiation, we artificially create zones of the crystal having the band gap of untreated Ga(AsN) surrounded by GaAs-like barriers; ii) by employing an intense (∼100 nA) and narrow (∼100 nm) beam of electrons, we dissociate the complexes formed by N and H in a spatially delimited part of a hydrogenated Ga(AsN) sample. As a consequence, in the spatial regions irradiated by the electron beam, hydrogenated Ga(AsN) recovers the smaller energy gap it had before hydrogen implantation.
This paper focuses on the analytical properties of the
solutions to the continuity equation with non local flow. Our
driving examples are a supply chain model and an equation for the
description of pedestrian flows. To this aim, we prove the well
posedness of weak entropy solutions in a class of equations
comprising these models. Then, under further regularity conditions,
we prove the differentiability of solutions with respect to the
initial datum and characterize this derivative. A necessary
condition for the optimality of suitable integral functionals then
Statistical models with latent structure have a history going back to the 1950s and have seen widespread use in the social sciences and, more recently, in computational biology and in machine learning. Here we study the basic latent class model proposed originally by the sociologist Paul F. Lazarfeld for categorical variables, and we explain its geometric structure. We draw parallels between the statistical and geometric properties of latent class models and we illustrate geometrically the causes of many problems associated with maximum likelihood estimation and related statistical inference. In particular, we focus on issues of non-identifiability and determination of the model dimension, of maximisation of the likelihood function and on the effect of symmetric data. We illustrate these phenomena with a variety of synthetic and real-life tables, of different dimension and complexity. Much of the motivation for this work stems from the ‘100 Swiss Francs’ problem, which we introduce and describe in detail.
Latent class (LC) or latent structure analysis models were introduced in the 1950s in the social science literature to model the distribution of dichotomous attributes based on a survey sample from a populations of individuals organised into distinct homogeneous classes on the basis of an unobservable attitudinal feature. See (Anderson 1954, Gibson 1955, Madansky 1960) and, in particular, (Henry and Lazarfeld 1968). These models were later generalised in (Goodman 1974, Haberman 1974, Clogg and Goodman 1984) as models for the joint marginal distribution of a set of manifest categorical variables, assumed to be conditionally independent given an unobservable or latent categorical variable, building upon the then recently developed literature on log-linear models for contingency tables.