Human habitat modification, not apex scavenger decline, drives isotopic niche variation in a carnivore community

Top carnivores can influence the structure of ecological communities, primarily through competition and predation; however, communities are also influenced by bottom-up forces such as anthropogenic habitat disturbance. Top carnivore declines will likely alter competitive dynamics within and amongst sympatric carnivore species. Increasing intraspecific competition is generally predicted to drive niche expansion and/or individual specialisation, while interspecific competition tends to constrain niches. Using stable isotope analysis of whiskers, we studied the effects of Tasmanian devil Sarcophilus harrisii declines upon the population- and individual-level isotopic niches of Tasmanian devils and sympatric spotted-tailed quolls Dasyurus maculatus subsp. maculatus. We investigated whether time since the onset of devil decline (a proxy for severity of decline) and landscape characteristics affected the isotopic niche breadth and overlap of devil and quoll populations. We quantified individual isotopic niche breadth for a subset of Tasmanian devils and spotted-tailed quolls and assessed whether between-site population niche variation was driven by individual-level specialisation. Tasmanian devils and spotted-tailed quolls demonstrated smaller population-level isotopic niche breadths with increasing human-modified habitat, while time since the onset of devil decline had no effect on population-level niche breadth or interspecific niche overlap. Individual isotopic niche breadths of Tasmanian devils and spotted-tailed quolls were narrower in human-modified landscapes, likely driving population isotopic niche contraction, however, the degree of individuals' specialisation relative to one another remained constant. Our results suggest that across varied landscapes, mammalian carnivore niches can be more sensitive to the bottom-up forces of anthropogenic habitat disturbance than to the top-down effects of top carnivore decline.

Intergenomic signatures of coevolution between Tasmanian devils and an infectious cancer

Coevolution is common and frequently governs host-pathogen interaction outcomes. Phenotypes underlying these interactions often manifest as the combined products of the genomes of interacting species, yet traditional quantitative trait mapping approaches ignore these intergenomic interactions. Devil facial tumor disease (DFTD), an infectious cancer afflicting Tasmanian devils (Sarcophilus harrisii), has decimated devil populations due to universal host susceptibility and a fatality rate approaching 100%. Here, we used a recently developed joint genome-wide association study (i.e., co-GWAS) approach, 15 y of mark-recapture data, and 960 genomes to identify intergenomic signatures of coevolution between devils and DFTD. Using a traditional GWA approach, we found that both devil and DFTD genomes explained a substantial proportion of variance in how quickly susceptible devils became infected, although genomic architectures differed across devils and DFTD; the devil genome had fewer loci of large effect whereas the DFTD genome had a more polygenic architecture. Using a co-GWA approach, devil-DFTD intergenomic interactions explained ~3× more variation in how quickly susceptible devils became infected than either genome alone, and the top genotype-by-genotype interactions were significantly enriched for cancer genes and signatures of selection. A devil regulatory mutation was associated with differential expression of a candidate cancer gene and showed putative allele matching effects with two DFTD coding sequence variants. Our results highlight the need to account for intergenomic interactions when investigating host-pathogen (co)evolution and emphasize the importance of such interactions when considering devil management strategies.

The evolution of two transmissible cancers in Tasmanian devils

Tasmanian devils have spawned two transmissible cancer lineages, named devil facial tumor 1 (DFT1) and devil facial tumor 2 (DFT2). We investigated the genetic diversity and evolution of these clones by analyzing 78 DFT1 and 41 DFT2 genomes relative to a newly assembled, chromosome-level reference. Time-resolved phylogenetic trees reveal that DFT1 first emerged in 1986 (1982 to 1989) and DFT2 in 2011 (2009 to 2012). Subclone analysis documents transmission of heterogeneous cell populations. DFT2 has faster mutation rates than DFT1 across all variant classes, including substitutions, indels, rearrangements, transposable element insertions, and copy number alterations, and we identify a hypermutated DFT1 lineage with defective DNA mismatch repair. Several loci show plausible evidence of positive selection in DFT1 or DFT2, including loss of chromosome Y and inactivation of MGA, but none are common to both cancers. This study reveals the parallel long-term evolution of two transmissible cancers inhabiting a common niche in Tasmanian devils.

Seasonal space use and habitat selection of GPS collared snow leopards (Panthera uncia) in the Mongolian Altai range

Although the home range and habitat selection of animal species is among the fundamental pieces of biological information collected by research projects during recent decades, published information on the snow leopard (Panthera uncia) home range is limited. The Altai Mountains of central Asia contain some of the largest and most important remaining conservation landscapes for snow leopards globally, but there is a limited understanding of the species' ecology in this region. First, we used the data from 5 snow leopards equipped with GPS collars at four study sites in the Altai Mountains of Mongolia to broadly characterize patterns of home range use between 2013 and 2019. The data was used to calculate home range size from a 10 month period using three different estimators: minimum convex polygons (MCP), kernel density distributions (KDE), and local convex hulls (LoCoH). Second, ten data sets from 8 individual snow leopards were combined to cover all 12 months of a year and to generate a general additive mixed model of seasonal home range use and seasonal resource use. We found 1) large variation in home ranges between sites during the monitoring period ranging minimally between 26.1 and 395.3km2 (MCP); 2) Local convex hull home ranges were smaller compared to home ranges based on minimum convex polygons and kernels and yielded more biologically appropriate home range estimates; 3) monthly home ranges of males were larger than females; 4) female monthly home ranges decreased in summer, while male monthly range use remained stable throughout the year; and, 5) while both sexes shared similar habitat preference in winter (steep south-western slopes at high elevation), our data suggest different habitat preferences between sexes in summer. Knowledge of the space use of threatened species is crucial for their conservation, and this is especially true for apex predators who often provide benefits for an entire ecosystem. Our study provides a preliminary understanding of the spatial ecology of this important species in an area of critical conservation concern.

OUP accepted manuscript

Globally, many wild deer populations are actively studied or managed for conservation, hunting, or damage mitigation purposes. These studies require reliable estimates of population state parameters, such as density or abundance, with a level of precision that is fit for purpose. Such estimates can be difficult to attain for many populations that occur in situations that are poorly suited to common survey methods. We evaluated the utility of combining camera trap survey data, in which a small proportion of the sample is individually recognizable using natural markings, with spatial mark–resight (SMR) models to estimate deer density in a variety of situations. We surveyed 13 deer populations comprising four deer species (Cervus unicolor, C. timorensis, C. elaphus, Dama dama) at nine widely separated sites, and used Bayesian SMR models to estimate population densities and abundances. Twelve surveys provided sufficient data for analysis and seven produced density estimates with coefficients of variation (CVs) ≤ 0.25. Estimated densities ranged from 0.3 to 24.6 deer km⁻². Camera trap surveys and SMR models provided a powerful and flexible approach for estimating deer densities in populations in which many detections were not individually identifiable, and they should provide useful density estimates under a wide range of conditions that are not amenable to more widely used methods. In the absence of specific local information on deer detectability and movement patterns, we recommend that at least 30 cameras be spaced at 500–1,000 m and set for 90 days. This approach could also be applied to large mammals other than deer.

Isotopic niche variation in Tasmanian devils Sarcophilus harrisii with progression of devil facial tumor disease

Devil facial tumor disease (DFTD) is a transmissible cancer affecting Tasmanian devils Sarcophilus harrisii. The disease has caused severe population declines and is associated with demographic and behavioral changes, including earlier breeding, younger age structures, and reduced dispersal and social interactions. Devils are generally solitary, but social encounters are commonplace when feeding upon large carcasses. DFTD tumors can disfigure the jaw and mouth and so diseased individuals might alter their diets to enable ingestion of alternative foods, to avoid conspecific interactions, or to reduce competition. Using stable isotope analysis (δ13C and δ15N) of whiskers, we tested whether DFTD progression, measured as tumor volume, affected the isotope ratios and isotopic niches of 94 infected Tasmanian devils from six sites in Tasmania, comprising four eucalypt plantations, an area of smallholdings and a national park. Then, using tissue from 10 devils sampled before and after detection of tumors and 8 devils where no tumors were detected, we examined whether mean and standard deviation of δ13C and δ15N of the same individuals changed between healthy and diseased states. δ13C and δ15N values were generally not related to tumor volume in infected devils, though at one site, Freycinet National Park, δ15N values increased significantly as tumor volume increased. Infection with DFTD was not associated with significant changes in the mean or standard deviation of δ13C and δ15N values in individual devils sampled before and after detection of tumors. Our analysis suggests that devils tend to maintain their isotopic niche in the face of DFTD infection and progression, except where ecological conditions facilitate a shift in diets and feeding behaviors, demonstrating that ecological context, alongside disease severity, can modulate the behavioral responses of Tasmanian devils to DFTD.

Quantifying 25 years of disease-caused declines in Tasmanian devil populations: host density drives spatial pathogen spread

Infectious diseases are strong drivers of wildlife population dynamics, however, empirical analyses from the early stages of pathogen emergence are rare. Tasmanian devil facial tumour disease (DFTD), discovered in 1996, provides the opportunity to study an epizootic from its inception. We use a pattern-oriented diffusion simulation to model the spatial spread of DFTD across the species' range and quantify population effects by jointly modelling multiple streams of data spanning 35 years. We estimate the wild devil population peaked at 53 000 in 1996, less than half of previous estimates. DFTD spread rapidly through high-density areas, with spread velocity slowing in areas of low host densities. By 2020, DFTD occupied >90% of the species' range, causing 82% declines in local densities and reducing the total population to 16 900. Encouragingly, our model forecasts the population decline should level-off within the next decade, supporting conservation management focused on facilitating evolution of resistance and tolerance.

A transmissible cancer shifts from emergence to endemism in Tasmanian devils

Emerging infectious diseases pose one of the greatest threats to human health and biodiversity. Phylodynamics is often used to infer epidemiological parameters essential for guiding intervention strategies for human viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2). Here, we applied phylodynamics to elucidate the epidemiological dynamics of Tasmanian devil facial tumor disease (DFTD), a fatal, transmissible cancer with a genome thousands of times larger than that of any virus. Despite prior predictions of devil extinction, transmission rates have declined precipitously from ~3.5 secondary infections per infected individual to ~1 at present. Thus, DFTD appears to be transitioning from emergence to endemism, lending hope for the continued survival of the endangered Tasmanian devil. More generally, our study demonstrates a new phylodynamic analytical framework that can be applied to virtually any pathogen.

Evolution and lineage dynamics of a transmissible cancer in Tasmanian devils

Devil facial tumour 1 (DFT1) is a transmissible cancer clone endangering the Tasmanian devil. The expansion of DFT1 across Tasmania has been documented, but little is known of its evolutionary history. We analysed genomes of 648 DFT1 tumours collected throughout the disease range between 2003 and 2018. DFT1 diverged early into five clades, three spreading widely and two failing to persist. One clade has replaced others at several sites, and rates of DFT1 coinfection are high. DFT1 gradually accumulates copy number variants (CNVs), and its telomere lengths are short but constant. Recurrent CNVs reveal genes under positive selection, sites of genome instability, and repeated loss of a small derived chromosome. Cultured DFT1 cell lines have increased CNV frequency and undergo highly reproducible convergent evolution. Overall, DFT1 is a remarkably stable lineage whose genome illustrates how cancer cells adapt to diverse environments and persist in a parasitic niche.

Blood Parasites in Endangered Wildlife-Trypanosomes Discovered During a Survey of Haemoprotozoa from the Tasmanian Devil

The impact of emerging infectious diseases is increasingly recognised as a major threat to wildlife. Wild populations of the endangered Tasmanian devil, Sarcophilus harrisii, are experiencing devastating losses from a novel transmissible cancer, devil facial tumour disease (DFTD); however, despite the rapid decline of this species, there is currently no information on the presence of haemoprotozoan parasites. In the present study, 95 Tasmanian devil blood samples were collected from four populations in Tasmania, Australia, which underwent molecular screening to detect four major groups of haemoprotozoa: (i) trypanosomes, (ii) piroplasms, (iii) Hepatozoon, and (iv) haemosporidia. Sequence results revealed Trypanosoma infections in 32/95 individuals. Trypanosoma copemani was identified in 10 Tasmanian devils from three sites and a second Trypanosoma sp. was identified in 22 individuals that were grouped within the poorly described T. cyclops clade. A single blood sample was positive for Babesia sp., which most closely matched Babesia lohae. No other blood protozoan parasite DNA was detected. This study provides the first insight into haemoprotozoa from the Tasmanian devil and the first identification of Trypanosoma and Babesia in this carnivorous marsupial.

Changes in spatial organization following an acute epizootic: Tasmanian devils and their transmissible cancer

Epidemiological studies commonly monitor host population density but rarely account for how transmission dynamics might be influenced by changes in spatial and social organization that arise from high mortality altering population demography. Devil facial tumour disease (DFTD), a novel transmissible cancer, caused almost 100% mortality of its single host, the Tasmanian devil, and a >90% local population decline since its emergence 20 years ago. We compare size and overlap in home ranges in a devil population before and 15 years after disease outbreak. We used location data collected with VHF tracking collars in 2001 and GPS collars in the same area in 2015 and 2016. Density of adult devils, calculated from live trapping data in the same years, show a strong decrease following the disease outbreak. The decline in density was accompanied by a reduction in female home range size, a trend not observed for males. Both spatially explicit population modelling and animal tracking showed a decrease in female home range overlap following the DFTD outbreak. These changes in spatial organisation of the host population have the potential to alter the local transmission dynamic of the tumours. Our results are consistent with the general theory of sex-biased spatial organization mediated by resource availability and highlight the importance of incorporating spatial ecology into epidemiological studies.

Home range size scales to habitat amount and increasing fragmentation in a mobile woodland specialist

Studies of impacts of fragmentation have focused heavily on measures of species presence or absence in fragments, or species richness in relation to fragmentation, but have often not considered the effects of fragmentation on ranging behavior of individual species. Effective management will benefit from knowledge of the effects of fragmentation on space use by species.We investigated how a woodland specialist, the eastern bettong (Bettongia gaimardi), responded to fragmentation in an agricultural landscape, the Midlands region of Tasmania, Australia. We tested whether individual bettongs could adjust home range size to maintain access to essential habitat across three sites differing in degree of fragmentation.We used GPS tracking to measure the home ranges of individual bettongs. Our models tested the effects of habitat aggregation and habitat amount measured at two radii comparable to a typical core range (250 m) and a typical home range (750 m), and habitat quality and sex on individual home range. We also tested the relationship between fragmentation on woodland used to determine whether individuals could compensate for fragmentation.Depending on the spatial scale of fragmentation measured, bettongs altered their movement to meet their habitat requirements. Our top model suggested that at the core range scale, individuals had smaller ranges when habitat is more aggregated. The second model showed support for habitat amount at the core range, suggesting individuals can occupy larger areas when there is a higher amount of habitat, regardless of configuration.Species that are relatively mobile may be able to compensate for the effects of habitat fragmentation by altering their movement. We highlight that any patch size is of value within a home range and management efforts should focus on maintaining sufficient habitat especially at the core range scale.

Transcriptomics of Tasmanian Devil (Sarcophilus Harrisii) Ear Tissue Reveals Homogeneous Gene Expression Patterns across a Heterogeneous Landscape

In an era of unprecedented global change, exploring patterns of gene expression among wild populations across their geographic range is crucial for characterizing adaptive potential. RNA-sequencing studies have successfully characterized gene expression differences among populations experiencing divergent environmental conditions in a wide variety of taxa. However, few of these studies have identified transcriptomic signatures to multivariate, environmental stimuli among populations in their natural environments. Herein, we aim to identify environmental and sex-driven patterns of gene expression in the Tasmanian devil (Sarcophilus harrisii), a critically endangered species that occupies a heterogeneous environment. We performed RNA-sequencing on ear tissue biopsies from adult male and female devils from three populations at the extremes of their geographic range. There were no transcriptome-wide patterns of differential gene expression that would be suggestive of significant, environmentally-driven transcriptomic responses. The general lack of transcriptome-wide variation in gene expression levels across the devil's geographic range is consistent with previous studies that documented low levels of genetic variation in the species. However, genes previously implicated in local adaptation to abiotic environment in devils were enriched for differentially expressed genes. Additionally, three modules of co-expressed genes were significantly associated with either population of origin or sex.

Seasonal variation in the foraging activity of desert argali (Ovis ammon) in Mongolia

Debate remains whether energy maximization or time minimization strategies best explain foraging in ungulates. It has also been hypothesized that the capacity of an animal to dissipate body heat regulates animal activity. We investigated these hypotheses while measuring the daily activity of desert argali (Ovis ammon (Linnaeus,1758)) for 12 months and relating the activity pattern to environmental seasonality. We found significant seasonal cycles in argali activity, with the greatest proportion of daytime in winter spent foraging and the greatest proportion of daytime in summer spent bedding. Consistent with an energy maximization strategy, argali reduced all behaviors during the winter in favor of foraging, compensating for the increased energy demands of winter at a time of low forage quality. Consistent with a time minimization strategy, argali in summer significantly reduced foraging and spent more time bedding in shaded areas to avoid hyperthermia due to high ambient temperatures. Both optimal foraging and heat dissipation can be used to explain the observed foraging pattern. Foraging behavior in argali is best described by the extent to which the animals schedule their activities to meet their physiological demands, the way these demands are affected by environmental variables, and the time that is available to accomplish them.

Tracing the rise of malignant cell lines: Distribution, epidemiology and evolutionary interactions of two transmissible cancers in Tasmanian devils

Emerging infectious diseases are rising globally and understanding host-pathogen interactions during the initial stages of disease emergence is essential for assessing potential evolutionary dynamics and designing novel management strategies. Tasmanian devils (Sarcophilus harrisii) are endangered due to a transmissible cancer-devil facial tumour disease (DFTD)-that since its emergence in the 1990s, has affected most populations throughout Tasmania. Recent studies suggest that devils are adapting to the DFTD epidemic and that disease-induced extinction is unlikely. However, in 2014, a second and independently evolved transmissible cancer-devil facial tumour 2 (DFT2)-was discovered at the d'Entrecasteaux peninsula, in south-east Tasmania, suggesting that the species is prone to transmissible cancers. To date, there is little information about the distribution, epidemiology and effects of DFT2 and its interaction with DFTD. Here, we use data from monitoring surveys and roadkills found within and adjacent to the d'Entrecasteaux peninsula to determine the distribution of both cancers and to compare their epidemiological patterns. Since 2012, a total of 51 DFTD tumours have been confirmed among 26 individuals inside the peninsula and its surroundings, while 40 DFT2 tumours have been confirmed among 23 individuals, and two individuals co-infected with both tumours. All devils with DFT2 were found within the d'Entrecasteaux peninsula, suggesting that this new transmissible cancer is geographically confined to this area. We found significant differences in tumour bodily location in DFTD and DFT2, with non-facial tumours more commonly found in DFT2. There was a significant sex bias in DFT2, with most cases reported in males, suggesting that since DFT2 originated from a male host, females might be less susceptible to this cancer. We discuss the implications of our results for understanding the epidemiological and evolutionary interactions of these two contemporary transmissible cancers and evaluating the effectiveness of potential management strategies.

Large-effect loci affect survival in Tasmanian devils (Sarcophilus harrisii) infected with a transmissible cancer

Identifying the genetic architecture of complex phenotypes is a central goal of modern biology, particularly for disease-related traits. Genome-wide association methods are a classical approach for identifying the genomic basis of variation in disease phenotypes, but such analyses are particularly challenging in natural populations due to sample size difficulties. Extensive mark-recapture data, strong linkage disequilibrium and a lethal transmissible cancer make the Tasmanian devil (Sarcophilus harrisii) an ideal model for such an association study. We used a RAD-capture approach to genotype 624 devils at ~16,000 loci and then used association analyses to assess the heritability of three cancer-related phenotypes: infection case-control (where cases were infected devils and controls were devils that were never infected), age of first infection and survival following infection. The SNP array explained much of the phenotypic variance for female survival (>80%) and female case-control (>61%). We found that a few large-effect SNPs explained much of the variance for female survival (~5 SNPs explained >61% of the total variance), whereas more SNPs (~56) of smaller effect explained less of the variance for female case-control (~23% of the total variance). By contrast, these same SNPs did not account for a significant proportion of phenotypic variance in males, suggesting that the genetic bases of these traits and/or selection differ across sexes. Loci involved with cell adhesion and cell-cycle regulation underlay trait variation, suggesting that the devil immune system is rapidly evolving to recognize and potentially suppress cancer growth through these pathways. Overall, our study provided necessary data for genomics-based conservation and management in Tasmanian devils.

Fibroblast growth factor 21 and fructose dynamics in humans

Objective

Fructose consumption is a risk factor for metabolic disease. We recently demonstrated that fibroblast growth factor 21 (FGF21), a metabolic hormone involved in lipid and glucose metabolism, is acutely stimulated in humans by 75 g oral fructose, with peak levels occurring 2 h after consumption. This study reports on the dose dependency and reproducibility of the FGF21 response to fructose.

Methods

Lean, healthy adults drank either five different doses of fructose dissolved in water, each separated by 2 weeks, or the same dose on three occasions, each separated by 1 week.

Results

Fibroblast growth factor 21 levels peaked at 2 h in a dose-dependent manner. No significant increase in FGF21 was seen after consumption of 10 g fructose, while robust increases were seen after drinking solutions containing 30, 50 and 75 g. At 2 h, the minimal fold change of FGF21 was highest following a 75 g fructose drink, and all subjects demonstrated at least a doubling of FGF21 levels following consumption of this dose.

Conclusions

The increase in FGF21 following an oral fructose challenge is dose dependent, with levels peaking at 2 h independent of dose. The FGF21 response to 75 g fructose is also highly reproducible within individuals.

Clinical Implications

By demonstrating that the FGF21 response to fructose is dose dependent and reproducible, this study deepens current understanding of FGF21 fructose dynamics and physiology in humans. This is an important area of clinical interest given associations between fructose intake and a wide variety of metabolic derangements.

Echinococcus multilocularis management by fox culling: An inappropriate paradigm

With the ongoing spread of Echinococcus multilocularis in Europe, sanitary authorities are looking for the most efficient ways of reducing the risk for human populations. Fox culling is one particular tool that has recently shifted from predation control to population health management. Our study aims to assess the effectiveness of this tool in limiting E. multilocularis prevalence in fox populations in France. During four years, a culling protocol by night shooting from cars was implemented around the city of Nancy (eastern France) representing ∼1700h of night work and ∼15,000km driven. The 776 foxes killed represented an overall increase of 35% of the pressure on the fox population over 693km². Despite this consequent effort of culling, not only did night shooting of foxes fail to decrease the fox population, but it resulted in an increase in E. multilocularis prevalence from 40% to 55% while remaining stable in an adjacent control area (585km²). Though no significant change in age structure could be described, an increase in immigration and local recruitment is the best hypothesis for population resilience. The increase in prevalence is therefore considered to be linked to a higher rate of juvenile movement within the culled area shedding highly contaminated faeces. We therefore advocate managers to consider alternative methods such as anthelmintic baiting, which has been proven to be efficient elsewhere, to fight against alveolar echinococcosis.

Recovery of molybdenum, nickel and cobalt by precipitation from the acidic leachate of a mineral sludge

The objective of this study was to investigate the recovery potential of molybdenum (Mo), nickel (Ni) and cobalt (Co) from synthetic and real acidic leachate of a mineral sludge from a metal recycling plant by sulfide precipitation. The operational parameters (metal sulfide (M/S) ratio 0.1-1, agitation speed 0-100 rpm, contact time 15-120 min and pH 1-5) were optimized in batch conditions on synthetic metal leachate (0.5 M HNO3, Mo = 101.6 mg L(-1), Ni = 70.8 mg L(-1), Co = 27.1 mg L(-1)) with a 0.1 M Na2S solution. Additionally, recovery of the target metals was theoretically simulated with a chemical equilibrium model (Visual MINTEQ 3.0). The optimized Na2S precipitation of metals from the synthetic leachate resulted in the potential selective recovery of Mo at pH 1 (98% by modeling, 95% experimental), after simultaneous precipitation of Ni and Co as sulfide at pH 4 (100% by modeling, 98% experimental). Metal precipitation from the real leachate (18 M H2SO4, Mo = 10,160 mg L(-1), Ni = 7,080 mg L(-1), Co = 2,710 mg L(-1)) was performed with 1 M Na2S, and resulted in a maximal Mo recovery at pH 2 (50%), while maximal recoveries of Ni and Co were observed at pH 4 (56% and 60%, respectively). Real leachate gave a lower metals recovery efficiency compared with synthetic leachate, which can be attributed to changes in the pH, nature of leachant, co-precipitation of Zn and competition for S(2-) ions.

Acid extraction of molybdenum, nickel and cobalt from mineral sludge generated by rainfall water at a metal recycling plant

This study investigated the leaching yields of Mo, Ni and Co from a mineral sludge of a metal recycling plant generated by rainfalls. The investigated mineral sludge had a complex heterogeneous composition, consisting of particles of settled soil combined with metal-bearing particles (produced by catalysts, metallic oxides and battery recycling). The leaching potential of different leaching reagents (stand-alone strong acids (HNO3 (68%), H2SO4 (98%) and HCl (36%)) and acid mixtures (aqua regia (nitric + hydrochloric (1:3)), nitric + sulphuric (1:1) and nitric + sulphuric + hydrochloric (2:1:1)) was investigated at changing operational parameters (solid-liquid (S/L) ratio, leaching time and temperature), in order to select the leaching reagent which achieves the highest metal leaching yields. Sulphuric acid (98% H2SO4) was found to be the leachant with the highest metal leaching potential. The optimal leaching conditions were a three-stage successive leaching at 80 °C with a leaching time of 2 h and S/L ratio of 0.25 g L(-1). Under these conditions, the achieved mineral sludge sample leaching yields were 85.5%, 40.5% and 93.8% for Mo, Ni and Co, respectively. The higher metal leaching potential of H2SO4 in comparison with the other strong acids/acid mixtures is attributed to the fact that H2SO4 is a diacidic compound, thus it has more H(+) ions, resulting in its stronger oxidizing power and corrosiveness.

Fox baiting against Echinococcus multilocularis: contrasted achievements among two medium size cities

In Europe, most cities are currently colonized by red foxes (Vulpes vulpes), which are considered to be the main definitive host of the zoonotic cestode Echinococcus multilocularis. The risk of transmission to humans is of particular concern where high fox populations overlap with high human populations. The distribution of baits containing praziquantel has successfully reduced the infection pressure in rural areas and in small plots within large cities. The purpose of this study was to assess its efficiency in two medium size cities (less than 100,000 inhabitants) in areas of high human alveolar echinococcosis incidence. From August 2006 to March 2009, 14 baiting campaigns of praziquantel treatment were run in Annemasse and Pontarlier (Eastern France), each of which encompassed 33 km(2), with a density of 40 baits/km(2). The bait consumption appeared to be lower in strictly urban context compared to suburban areas (78.9% vs. 93.4%) and lower in Annemasse than in Pontarlier (82.2% vs. 89.5%). During our study, the prevalence of E. multilocularis, as assessed by EM-ELISA on fox faeces collected in the field in Annemasse, was lower within the treated area than in the rural control area. A "before/during" treatment comparison revealed a significant decrease of spring prevalence from 13.3% to 2.2%. No significant change in prevalence was detected in Pontarlier (stable prevalence: 9.1%) where the contamination of the treated area followed the temporal trend observed in the control area. There, a greater resilience of the parasite's life cycle, probably due to a strong pressure of recontamination from outside the treated area, may have counteracted the prophylaxis treatment. These contrasted outcomes suggest that the frequency of fox anthelmintic treatment should be adapted to the local situation.

Biosorption properties of extracellular polymeric substances (EPS) towards Cd, Cu and Pb for different pH values

The aim of this study was to assess the influence of pH on the metal biosorption of extracellular polymeric substances (EPS) extracted from two different activated sludges called A and B. The composition and physico-chemical characteristics of EPS were determined. The biosorption capacities of the EPS were examined at pH 4, 6, 7 and 8 successively with three metals Cu, Pb and Cd using differential pulse polarography (DPP) as an investigation tool and Ruzic's model was used to produce polarographic titration curves. Two apparent pKa were obtained, the first were 6.6 (EPS A) and 5.7 (EPS B), attributed to carboxylic and phosphoric groups whereas the second was 8.7 for EPS A and 9.4 for B and these were attributed to phenolic and amino functional groups. Whatever the EPS and the metal considered, the conditional binding constant did not show significant differences in the strength of complex formed between the EPS and metals. But for all metals, the number of EPS binding sites was significantly lowered by a decrease in the pH of the medium. At pH 4, the metal biosorption capacity of EPS is very low. At pH 6, the number of EPS binding sites increased in the following order: Pb>Cu>Cd whereas at pH 7 and 8, this order changed and was: Cu>Pb>>Cd. Simulations of the speciation states of Cu, Pb and Cd at the different pH values in ultra-pure water (25 degrees C, ionic strength 0.045 M) were performed with MINEQL 4.5 software and indicated the presence of hydroxylated forms and sometimes solid forms for Pb and Cu. But the polarographic titration curves revealed precipitation of Cu only at the end of the experiments at pH 8.

[Epidemiology and costs of lung cancer in France]

There were 21,850 cases of newly diagnosed lung cancers in France in 1995. This figure corresponds to an incidence rate (standardized to the population of Europe) of 66.5 per 100,000 men and 8.9 per 100,000 women. The incidence is age-related and reaches a peak between 70 and 74 years of age for men and between 75 and 79 years of age for women. The incidence also varies by region and the highest rates were observed in east of France. Non-small-cell lung cancers represent 80% of all lung cancers. Between 1985 and 1995, as a result of changes in tobacco consumption, the incidence rates increased by 56% in women and by 5% in men under the age of 65. The incidence rates in France are close to the average rates observed in Europe. In 1995, lung cancers led to 23,900 deaths in France (mortality rate standardized to Europe: 36.6 per 100,000). 85% of deaths due to lung cancer occurred among men. Prognosis of lung cancer remains poor and has not improved appreciably over the last two decades. 58% of all patients died during the first year and 82% during the three years following lung cancer diagnosis. Survival rates appear to be better for patients with non small cell lung cancer than for patients with small cell lung cancer. Few studies have addressed the economics of lung cancer in France. Cost-of-illness studies of lung cancer were published mainly in Canada, the Netherlands and Australia. These analyses have included descriptive works as well as economic models based on theoretical diagnostic and treatment algorithms.

International validation of the CLAU-S quality-of-life questionnaire for use in patients with intermittent claudication

BACKGROUND

Intermittent claudication (IC) occurs in patients with peripheral occlusive arterial disease and results in leg pain after walking a certain distance - the claudication distance. Until recently, no specific questionnaire has been available to measure quality of life in patients with IC.

OBJECTIVES

To validate the Claudication Scale (CLAU-S) questionnaire in patients in France, the UK, Germany and Belgium.

METHODS

Patients completed the CLAU-S questionnaire and provided demographic and clinical data. Pooled data were examined for psychometric and structural validity and test-retest reliability. Structural equation modelling (SEM) was used to confirm that the questionnaire was measuring the causal relationships involved in IC in each of the language groups studied.

RESULTS

Cross-sectional and factor analysis confirmed the validity of the questionnaire in the pooled patient population. Item convergent and discriminant coefficients and internal consistency reliability coefficients met or exceeded standard criteria. Principal component analysis confirmed the factorial structure. The underlying causal relationships in IC were identified using SEM and were consistent in all language groups studied.

CONCLUSIONS

The CLAU-S questionnaire has undergone validation in English, French, German and Flemish and has a very satisfactory validity in these languages.

The long-term cost-effectiveness of improving alcohol abstinence with adjuvant acamprosate

A computer model was developed with decision analysis software to explore the long-term clinical and economic outcomes of alcohol abstinence maintenance with either standard counselling therapy or standard therapy plus 48 weeks of adjuvant acamprosate in detoxified alcoholic patients. Important complications of alcoholism were modelled using Markov processes, and included relapse (return to drinking), alcohol-related hepatic disease, acute and chronic pancreatitis, acute and chronic gastritis, oropharyngeal carcinoma, oesophageal carcinoma, alcoholic cardiomyopathy, alcohol-related peripheral neuropathy, alcoholic psychosis, accidental death, and suicide. Probabilities of developing complications were dependent on whether the patients within the cohort remained abstinent or had relapsed. Relapse rates, probabilities, and costs for acamprosate therapy and treatment of complications were taken from published literature. The analysis was performed from the German health insurance perspective. Life expectancy and total lifetime costs (costs of initial abstinence maintenance therapy plus costs of complications) were calculated for a typical male cohort with average age of 41 years, 80% with fatty liver, 15% with cirrhosis, 22% with chronic pancreatitis, and 1% with alcoholic cardiomyopathy at baseline. Life expectancy with and without acamprosate therapy was 15.90 and 14.70 years respectively, and discounted (5% per annum) average total lifetime costs per patient were DEM 46 448 and DEM 49 549 respectively. We conclude that, despite the acquisition costs of DEM 2177, adjuvant acamprosate therapy was both clinically and economically attractive under conservative assumptions.

[Intermittent claudication and quality of life. Psychometric validation of the French version of the CLAU-S questionnaire]

CLAU-S is a disease-specific quality of life (QoL) scale for patients with intermittent claudication due to peripheral arterial disease of the lower limbs. Initially developed in Germany, the scale has been translated into French according to classical forward/backward methodology. The objective of this study was to test the validity of the French version of CLAU-S. In its current format, the CLAU-S scale evaluates 5 dimensions: "Daily Living"; "Pain"; "Social Life"; "Disease-specific anxiety"; and "Mood", for a total of 47 items. The QoL scores and clinical findings in 157 patients with intermittent claudication were analysed. Validation of the convergence and discriminatory power of the scale were confirmed. Analysis of structural validity showed grouping of items in accordance with initial scale construction and a clear separation between the different dimensions. Analysis of the internal reliability of the questionnaire confirmed the good internal coherence of these dimensions. Reproducibility of the scores over time was confirmed by test-retest analysis. In addition to the actual validation of CLAU-S, a new, innovative mathematical technique called Structural Modelling Equations was used on this QoL instrument. It related the causal structure of the QoL components in peripheral arterial disease of the lower limbs (stage 2). An indisputable causal relationship was demonstrated between clinical parameters, particularly walking distance, and the QoL components. The classical symptom-deficit-disability causal structure of disease- specific QoL questionnaires was also studied. In particular, we found an essential relationship between the Daily Living dimension and, to a lesser extent, the Social Life activities and Disease- specific anxiety dimension, and QoL. The Pain dimension proved to be an explanatory variable of the other QoL components without being directly related to QoL. Finally, the Mood dimension was a resultant variable of QoL and not an explanatory variable of QoL. This study therefore enabled validation of the psychometric properties of the French version of CLAU-S and also demonstrated the complementary roles of walking distance and QoL in the management of patients with intermittent claudication.

[Consequences of obliterating arteriopathy of the legs on the professional activity of patients and external assistance]

Peripheral arterial occlusive disease of the lower limbs results in increased risks of cardiovascular and cerebrovascular morbidity and mortality. However, peripheral arterial disease also has an incapacitating effect upon patients' daily lives, and indeed can have considerable consequences upon their quality of life as well as upon their professional activities. The purpose of this study was to describe patients in terms of their professional activities, the consequences of the disease upon such activities, need for external assistance, and the effects of treatment over a six-month treatment follow-up period. This was a prospective, randomised, double-blind, multicentre study comparing naftidrofuryl (three 200-mg tablets per day) versus placebo in patients presenting with stage-II peripheral arterial disease. Four study visits were scheduled for each patient: an initial selection visit, followed by a 30-day placebo wash-out period, an inclusion visit (to allow verification of inclusion and non-inclusion criteria), and follow-up visits after 3 and 6 months of treatment. 234 patients were included in the study in intention to treat (117 patients in the naftidrofuryl group and 117 patients in the placebo group). These two groups were entirely comparable for all criteria (sociodemographic criteria, risk factors, cardiovascular history, duration of disease) except for obesity and dyslipidaemia, for which prevalence was higher in the naftidrofuryl group. 12.4% of the study population were professionally active at the time of the survey (mean age: 65.9 years). However, 42.3% of patients had in fact been active at the time when arterial disease became manifest. Of these patients, 45.4% (45 patients) stated that arterial disease had affected their professional activity: 28.9% (13 patients) reported a change in their activity, 26.7% (12 patients) reported partial suspension of their activity, and 44.4% (20 patients) stated that all professional activities had ceased. Changes in professional activity comprised invalidity (36.2%), prolonged sick leave (25.5%), premature retirement (14.9%), sick leave (17%), unemployment (6.4%), reduction in long-distance travel (4.3%), change of job (8.5%) or salary reduction (2.1%). During the 6-month follow-up period, only 4 patients were on sick leave (3 in the placebo group and 1 in the naftidrofuryl group). Furthermore, less than 10% of the study population required external assistance as a result of the disease. This analysis thus highlights the repercussions of this disease upon the patients' daily and professional activities.

Glycemic control and cardiovascular disease in type 2 diabetes: a review

Cardiovascular disease is the major cause of morbidity and mortality in people with Type 2 diabetes, and risk of atherosclerotic disease is markedly increased in people with diabetes compared to people with normal glucose tolerance. The excess risk can not be completely explained by increased prevalence of other cardiovascular disease risk factors such as hypertension and hyperlipidaemia in people with diabetes. This review examines the role of hyperglycemia and glycemic control in cardiovascular disease in people with Type 2 diabetes. The results of prospective observational studies and randomized controlled trials are summarized. We conclude that control of hypertension and hyperlipidemia are important to reduce risk of cardiovascular disease in people with diabetes and may be more easily achieved than tight glycemic control.

[Changes in prescription patterns for peripheral and cerebral vasoactive drugs before and after establishing prescription standards in France]

OBJECTIVES

Assess changes in the number of prescriptions for peripheral and cerebral vasoactive drugs for the treatment of lower limb arteritis and cerebrovascular disease since the promulgation in 1995 of prescription standards for the treatment of lower limb arteritis. Assess compliance to prescription standards with a detailed analysis of patient features, prescriptions written for lower limb arteritis, cerebrovascular disease and concomitant diseases and evaluate changes in treatment costs for lower limb arteritis and cerebrovascular disease as well as cost of the full prescription, including treatments for associated diseases.

METHODS

This study was based on data recorded during the Permanent Study of Medical Prescriptions conducted from March 1994 to February 1995 and from March 1995 to February 1996 by the IMS. Prescription costs were established from the National Description Files of the IMS. Treatment costs were expressed as public price (FF) tax included. Prescriptions meeting the following criteria were selected for each period: prescriptions written by general practitioners for drugs with peripheral and cerebral vasoactivity (excepting calcium antagonists with a cerebral target) belonging to the Anatomic Therapeutic Classes C4A1 of the European Pharmaceutical Marketing Research Association, Bromly 1996; prescriptions for diagnoses 447.6 (arteritis) and 437.9 (cerebrovascular disease) according to the 9th WHO classification. A random sample of 500 prescriptions was selected to calculate costs.

RESULTS

Since the advent of the prescription standards in 1995, prescriptions have dropped off by 6.3% for lower limb arteritis and by 14.8% for cerebrovascular disease. There was a 3.7 point decline in the percentage of multiple prescriptions of vasoactive drugs for lower limb arteritis (21.7% prior to March 1995 versus 18% after promulgation of the prescription standards, p > 0.1) and a 1.8 increase in the percentage of multiple prescriptions for cerebrovascular disease (14% prior to March 1995 and 15.8% after promulgation of the prescription standards, p > 0.1). For the treatment of lower limb arteritis, prescription costs fell by a mean 9% per prescription and for the treatment of cerebrovascular disease they rose by a mean 7% per prescription. The price rise, due to multiple prescriptions of vasoactive drugs was 190 FF per prescription for lower limb arteritis and 104 FF per prescription for cerebrovascular disease.

CONCLUSION

Despite the retrospective nature of this study where confounding factors could not be controlled, our findings are in agreement with those reported earlier suggesting that cost containment policy implemented by the prescription standards has had little efficacy. In patients with arterial disease of the lower limbs, the percentage of prescriptions not complying with the recommended standards decreased by one-third to one-half over a 2-year period since the prescription standards were first announced in 1994.

Peripheral arterial obliterative disease. Cost of illness in France

The main purpose of this study, carried out in 1995, was to determine, using available sources, the cost of peripheral arterial obliterative disease (PAOD) in France over a 1-year period. This cost-of-illness study was based on a retrospective analysis of the available literature and databases. It involved a description of epidemiological data and a cost estimate of the different medical resources consumed over 1 year. For this latter purpose, a payer perspective was chosen. Data were extracted from national representative surveys and databases with respect to morbidity and mortality [from the National Institute of Health and Medical Research (Institut National de la Santé et de la Recherche Médicale; INSERM) and the National Sickness Insurance Fund for Salaried People (Caisse Nationale d'Assurance Maladie des Travailleurs Salariés; CNAMTS)], consultations, examination tests and drug prescriptions [from the French Medical Audit conducted by Intercontinental Medical Statistics (IMS)], hospitalisations [from the Statistical Unit of the Department of Health-Service des Statistiques, des Etudes et des Systemes d'Information (SESI) and the National Public Research Centre in Health Economics (Centre de Recherche d'Etude et de Documentation en Economie de la Santé; CREDES)] and related health expenditure from CNAMTS. In France, the prevalence of stage II PAOD (Leriche and Fontaine classification) in 1992 was estimated to be 675,000; 53% of these patients had undergone vascular or bypass surgery. The total annual cost of healthcare (including consultations, drugs, laboratory tests, hospitalisation and hydrotherapy) for the management of patients with PAOD ranged from 3.9 billion French francs (F) to F4.6 billion (1995 values), depending on the type of hospital considered. 50% of this cost was related to hospitalisations and 75% was covered by the CNAMTS. Although this study was only a partial evaluation and did not take into account indirect costs or nonmedical direct costs, such as transport and care by healthcare assistants and paramedics, these results may help to establish public health priorities and modify clinical practice to favour an earlier diagnosis of PAOD.

[Prediction and prognosis of diabetes incidence in treated hypertensive patients]

The study is based on a clinical population of 1962 hypertensive men and women consecutively examined as in- or out-patients in our clinic from Jan. 1967 to Dec. 1976. Those having a diabetes (treated for diabetes, or fasting glycemia greater than or equal to 7.75 USI) at initial exam were excluded. In february 1977, all were contacted by mail. 89 p. 100 of the subjects still living at the same address answered. 74 "cases" had developed a diabetes (clinical diagnosis, or fasting glycemia greater than or equal to 9.5 USI); they were matched with "controls" according to sex, age (+/- 2), and date of entry (+/- 4 months); all the controls had answered that they were not diabetic in Feb. 1977. At initial exam, the following abnormalities were significantly more pronounced in cases than in controls (by decreasing level of significance): glycemia 1 h. after glucose load, weight index (W/H2), fasting glycemia (p less than 0.001); ECG abnormalities of T (Minnesota code 5.1-3), and J-ST (4.1-3) (p less than 0.01); angina (p less than 0.05). Incidence of diabetes was studied in the basal population, by life table method, according to two abnormalities: relative weight greater than or equal to 115 p. 100, glycemia after load greater than or equal to 8.33. At five years, the estimations were: 0 p. 100 in both sexes, when both abnormalities were absent; 20 p. 100 in men and 31 p. 100 in women when both abnormalities were simultaneously present; 4 p. 100 in men and 2 p. 100 in women in other cases.(ABSTRACT TRUNCATED AT 250 WORDS)