The contribution of patch topology and demographic parameters to PVA predictions: the case of the European tree frog

Population viability analyses (PVA) are increasingly used in metapopulation conservation plans. Two major types of models are commonly used to assess vulnerability and to rank management options: population-based stochastic simulation models (PSM such as RAMAS or VORTEX) and stochastic patch occupancy models (SPOM). While the first set of models relies on explicit intrapatch dynamics and interpatch dispersal to predict population levels in space and time, the latter is based on spatially explicit metapopulation theory where the probability of patch occupation is predicted given the patch area and isolation (patch topology). We applied both approaches to a European tree frog (Hyla arborea) metapopulation in western Switzerland in order to evaluate the concordances of both models and their applications to conservation. Although some quantitative discrepancies appeared in terms of network occupancy and equilibrium population size, the two approaches were largely concordant regarding the ranking of patch values and sensitivities to parameters, which is encouraging given the differences in the underlying paradigms and input data.

Risk assessment of herbicide mixtures in a large European lake

Lake Geneva is one of the largest European lakes with a surface area of 580 km2. Its catchment area covers 7400 km2, of which approximately 20% is arable land. Monitoring campaigns have been carried out in 2004 and 2005 to determine the contamination of the lake by pesticides. The results highlight the widespread presence of herbicides in water, the measured concentrations for most substances remaining constant in 2004 and 2005. However, for some individual herbicides the concentrations increased drastically (e.g., the herbicide foramsulfuron). We assessed the environmental risk of the herbicides detected in the lake using water quality criteria recently determined for the Swiss environmental protection agency. Furthermore, we assessed the risk of herbicide mixtures, grouped based upon their mode of action. Generally, the risk estimated for all single substances is low, except for some sulfonylurea compounds. For these substances, the measured concentrations are higher than the predicted no-effect concentration. Impact on the flora of the lake can therefore not be excluded. When mixtures of pesticides with similar mode of action are taken into account, the risk remains lower than the mixture water quality criteria for all groups, but can reach as high as one third of this quality criteria. A further step would therefore be to assess the risk of the total pesticide mixture, including similar and dissimilar modes of action

Extreme heterochiasmy and nascent sex chromosomes in European tree frogs.

We investigated sex-specific recombination rates in Hyla arborea, a species with nascent sex chromosomes and male heterogamety. Twenty microsatellites were clustered into six linkage groups, all showing suppressed or very low recombination in males. Seven markers were sex linked, none of them showing any sign of recombination in males (r=0.00 versus 0.43 on average in females). This opposes classical models of sex chromosome evolution, which envision an initially small differential segment that progressively expands as structural changes accumulate on the Y chromosome. For autosomes, maps were more than 14 times longer in females than in males, which seems the highest ratio documented so far in vertebrates. These results support the pleiotropic model of Haldane and Huxley, according to which recombination is reduced in the heterogametic sex by general modifiers that affect recombination on the whole genome.

Range-Wide Sex-Chromosome Sequence Similarity Supports Occasional XY Recombination in European Tree Frogs (Hyla arborea).

In contrast with mammals and birds, most poikilothermic vertebrates feature structurally undifferentiated sex chromosomes, which may result either from frequent turnovers, or from occasional events of XY recombination. The latter mechanism was recently suggested to be responsible for sex-chromosome homomorphy in European tree frogs (Hyla arborea). However, no single case of male recombination has been identified in large-scale laboratory crosses, and populations from NW Europe consistently display sex-specific allelic frequencies with male-diagnostic alleles, suggesting the absence of recombination in their recent history. To address this apparent paradox, we extended the phylogeographic scope of investigations, by analyzing the sequences of three sex-linked markers throughout the whole species distribution. Refugial populations (southern Balkans and Adriatic coast) show a mix of X and Y alleles in haplotypic networks, and no more within-individual pairwise nucleotide differences in males than in females, testifying to recurrent XY recombination. In contrast, populations of NW Europe, which originated from a recent postglacial expansion, show a clear pattern of XY differentiation; the X and Y gametologs of the sex-linked gene Med15 present different alleles, likely fixed by drift on the front wave of expansions, and kept differentiated since. Our results support the view that sex-chromosome homomorphy in H. arborea is maintained by occasional or historical events of recombination; whether the frequency of these events indeed differs between populations remains to be clarified.

Towards Integrated Governance of Landscape Development : The Swiss Model of Regional Nature Parks

Coherent regulation of landscape as a resource is a major challenge. How can the development interests of some actors (eg cable car operators and property developers) be reconciled with those of others (agriculture, forestry) and with conservation of biodiversity and scenic value? To help understand how the newly introduced Regional Nature Parks (RNPs) can improve the coherence of the regulation regime in Switzerland, we highlight current direct mechanisms for regulation of landscape as a resource (bans, inventories, subsidies) as well as indirect mechanisms (taking place through the regulation of the physical basis of landscapes, eg forest, land, and water planning policies). We show that RNPs are fundamentally innovative because they make it possible to manage and coordinate indirect strategies for appropriate regulation of resources at a landscape scale. In other words, RNPs enable organization of governance of landscape as a resource in a perimeter that is not necessarily restricted to administrative boundaries.

Audit report on America's Agricultural Industrial Heritage Landscape Inc., D/B/A Silos and Smokestacks National Heritage Area, Independent Auditor's Reports, Financial Statements and Supplementary Information, Schedule of Findings and Questioned Costs, December 31, 2004 & 2005

Other Audit Reports - 28E Organizations

Appropriateness of early management of newly diagnosed Crohn's disease in a European population-based cohort.

OBJECTIVE: The European Panel on the Appropriateness of Crohn's disease Therapy (EPACT) has developed appropriateness criteria. We have applied these criteria retrospectively to the population-based inception cohort of Crohn's disease (CD) patients of the European Collaborative Study Group on Inflammatory Bowel Disease (EC-IBD). MATERIAL AND METHODS: A total of 426 diagnosed CD patients from 13 European centers were enrolled at the time of diagnosis (first flare, naive patients). We used the EPACT definitions to identify 247 patients with active luminal CD. We then assessed the appropriateness of the initial drug prescription according to the EPACT criteria. RESULTS: Among the cohort patients 163 suffered from mild-to-moderate CD and 84 from severe CD. Among the mild-to-moderate disease group, 96 patients (59%) received an appropriate treatment, whereas for 66 patients (40%) the treatment was uncertain and in one case (1%) inappropriate. Among the severe disease group, 86% were treated medically and 14% required surgery. 59 (70%) were appropriately treated, whereas for one patient (1%) the procedure was considered uncertain and for 24 patients (29%) inappropriate. CONCLUSION: Initial treatment was appropriate in the majority of cases for non-complicated luminal CD. Inappropriate or uncertain treatment was given in a significant minority of patients, with an increased potential risk of adverse events.

Blood pressure changes after renal denervation at 10 European expert centers.

We did a subject-level meta-analysis of the changes (Δ) in blood pressure (BP) observed 3 and 6 months after renal denervation (RDN) at 10 European centers. Recruited patients (n=109; 46.8% women; mean age 58.2 years) had essential hypertension confirmed by ambulatory BP. From baseline to 6 months, treatment score declined slightly from 4.7 to 4.4 drugs per day. Systolic/diastolic BP fell by 17.6/7.1 mm Hg for office BP, and by 5.9/3.5, 6.2/3.4, and 4.4/2.5 mm Hg for 24-h, daytime and nighttime BP (P0.03 for all). In 47 patients with 3- and 6-month ambulatory measurements, systolic BP did not change between these two time points (P0.08). Normalization was a systolic BP of <140 mm Hg on office measurement or <130 mm Hg on 24-h monitoring and improvement was a fall of 10 mm Hg, irrespective of measurement technique. For office BP, at 6 months, normalization, improvement or no decrease occurred in 22.9, 59.6 and 22.9% of patients, respectively; for 24-h BP, these proportions were 14.7, 31.2 and 34.9%, respectively. Higher baseline BP predicted greater BP fall at follow-up; higher baseline serum creatinine was associated with lower probability of improvement of 24-h BP (odds ratio for 20-μmol l(-1) increase, 0.60; P=0.05) and higher probability of experiencing no BP decrease (OR, 1.66; P=0.01). In conclusion, BP responses to RDN include regression-to-the-mean and remain to be consolidated in randomized trials based on ambulatory BP monitoring. For now, RDN should remain the last resort in patients in whom all other ways to control BP failed, and it must be cautiously used in patients with renal impairment.

Décret de la Convention nationale, du 31 janvier 1793... relatif à la réparation des prisons de l'Abbaye, à l'exécution des loix concernant les maisons de justice, d'arrêt et de correction, et au jugement de ceux qui sont prévenus de délits militaires

[Acte. 1793-01-31]