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Swiss Population (swiss + population)

Distribution by Scientific Domains
Life Sciences71%

Selected Abstracts

Migratory connectivity in a declining bird species: using feather isotopes to inform demographic modelling

DIVERSITY AND DISTRIBUTIONS, Issue 4 2010
Thomas S. Reichlin
Abstract Aim, Conservation programmes for endangered migratory species or populations require locating and evaluating breeding, stopover and wintering areas. We used multiple stable isotopes in two endangered European populations of wrynecks, Jynx torquilla L., to locate wintering regions and assess the degree of migratory connectivity between breeding and wintering populations. Location, Switzerland and Germany. Methods, We analysed stable nitrogen (,15N), carbon (,13C) and hydrogen (,D) isotopes from wing feathers from two populations of wrynecks to infer their wintering origins and to assess the strength of migratory connectivity. We tested whether variation in feather isotopic values within the Swiss population was affected by bird age and collection year and then considered differences in isotopic values between the two breeding populations. We used isotopic values of summer- and winter-grown feathers to estimate seasonal distributions. Finally, we calculated a species-specific ,D discrimination factor between feathers and mean annual ,D values to assign winter-grown feathers to origin. Results, Bird age and collection year caused substantial isotopic variation in winter-grown feathers, which may be because of annually variable weather conditions, movements of birds among wintering sites and/or reflect asynchronous moulting or selection pressure. The large isotopic variance in winter-grown feathers nevertheless suggested low migratory connectivity for each breeding population, with partially overlapping wintering regions for the two populations. Main conclusions, Isotopic variance in winter-grown feathers of two breeding populations of wrynecks and their geographical assignment point to defined, albeit overlapping, wintering areas, suggesting both leapfrog migration and low migratory connectivity. On this basis, integrative demographic models can be built looking at seasonal survival patterns with links to local environmental conditions on both breeding and wintering grounds, which may elucidate causes of declines in migratory bird species. [source]

A NEW ROLE FOR CONSUMERS' PREFERENCES IN THE PROVISION OF HEALTHCARE

ECONOMIC AFFAIRS, Issue 3 2006
Harry Telser
In the present allocation of resources in healthcare, preferences of consumers as the ultimate financiers of healthcare services are judged to be of little relevance. This state of affairs is being challenged because the past decade has seen great progress in the measurement of preferences, or more precisely, willingness-to-pay (WTP) as applied to healthcare services. This article reports evidence on WTP of the Swiss population with regard to three hypothetical modifications of the drug benefit to be covered by social health insurance: delaying access to the most recent therapeutic innovations (among them, drugs) by two years in exchange for a reduction of the monthly premium; substituting original preparations by generics, again in return for a lowered premium; and the exclusion of preparations for the treatment of minor complaints from the drug benefit. Using discrete-choice experiments, WTP and its determinants are estimated. Average WTP for avoiding such a delay (which acts across the board) is much higher than for eschewing the exclusive use of generics (which are claimed to be largely equivalent to the original) or the retention of ,unimportant' drugs in the list of benefits , a rating predicted by economic theory. In addition, a great deal of preference heterogeneity between the French-speaking minority and the German-speaking majority was found, pointing to considerable efficiency losses caused by uniformity of social health insurance. [source]

DIFFERENTIAL PERFORMANCE AMONG LDH-B GENOTYPES IN RANA LESSONAE TADPOLES

EVOLUTION, Issue 5 2000
Hansjürg Hotz
Abstract The European pool frog, Rana lessonae, is widely polymorphic for two common alleles (b, e) at the lactate dehydrogenase-B (LDH-B) locus. We compared fitness-related larval life-history traits among LDH-B genotypes, which originated from segregation in heterozygous parents, in an artificial pond experiment where tadpoles of R. lessonae from a Swiss population were raised together with tadpoles of the hemiclonal hybrid R. esculenta at two densities. In R. lessonae, LDH-B e/e homozygotes at each density had a higher proportion of metamorphs among survivors, reached metamorphosis earlier, and were heavier at metamorphosis than b/b homozygotes; b/e heterozygotes had intermediate values. That e/e individuals were superior to b/b in both time to and mass at metamorphosis is surprising because these two life-history traits are thought to reflect a performance trade-off; e/e genotypes apparently compensated for shorter time to metamorphosis by a higher growth rate. The two alleles showed the same performance ranking when combined in hybrids with a R. ridibunda allele: When R. esculenta from Swiss populations reared in the same ponds had received the e allele rather than the b allele from their R. lessonae parent, they reached metamorphosis earlier, but did not differ in mass at metamorphosis. The degree of linkage disequilibrium in the source population of the eight R. lessonae used as parents of the R. lessonae tadpoles is unknown, so we cannot exclude the possibility that the performance differences are caused by some anonymous tightly linked gene, rather than the LDH-B locus, that constitutes the genomically localized target of natural selection. A causal involvement of LDH-B is plausible, nevertheless, because this enzyme takes part in the central energy-metabolizing processes and has been reported to underlie fitness differences in other animals; also, differential performance of LDH-B genotypes has been observed in R. lessonae larvae from another population. The present results suggest strong directional selection for allele e; the sum of available data, including an independent laboratory experiment, suggests that partial environment-dependent overdominance combined with balancing selection favoring e/e homozygotes under some and b/b homozygotes under other conditions may be partially responsible for the broad maintenance of the LDH-B polymorphism in R. lessonae. [source]

Eleven polymorphic microsatellite markers for Oedaleus decorus (Orthoptera, Acrididae), an endangered grasshopper in Central Europe

MOLECULAR ECOLOGY RESOURCES, Issue 6 2008
K. BERTHIER
Abstract We isolated and characterized 11 microsatellite loci in the grasshopper Oedaleus decorus (Orthoptera: Acrididae), an endangered species in Central Europe. Polymorphism was studied from two populations, one out of two populations known from Switzerland (n = 20 individuals) and one site from south of France (n = 20). The number of alleles and the expected heterozygosity ranged from five to 12 and from 0.559 to 0.898, respectively, in the Swiss population, and from 14 to 23 and from 0.895 to 0.974, respectively, in the French population. These microsatellite markers are suitable for further conservation genetic studies of O. decorus. [source]

A de Novo PABPN1 Germline Mutation in a Patient with Oculopharyngeal Muscular Dystrophy,

THE LARYNGOSCOPE, Issue 1 2006
Nicolas Gürtler
Abstract Background: Oculopharyngeal muscular dystrophy (OPMD) is a late-onset autosomal dominantly inherited disorder characterized by dysphagia, ptosis, and proximal limb weakness and is caused by germline mutations (triplet repeat expansions) in the polyadenylate binding protein nuclear 1 (PABPN1) gene. Objective: To describe a 70-year-old female patient with OPMD on the clinical and molecular genetic level and to develop a rapid and efficient molecular genetic screening method to study large patient groups. Methods: Detailed family history and clinical assessment of the OPMD patient were followed by mutation analysis of the PABPN1 gene by direct DNA sequencing and by our newly developed method, fluorescent PABPN1 polymerase chain reaction (PCR) product (flPPP) method. A cohort of 50 healthy Swiss probands was screened using the flPPP to assess the frequency of the (GCG)7 allele in the Swiss population. Cricopharyngeal myotomy was performed as treatment for dysphagia. Results: A heterozygous (GCG)9 triplet repeat expansion in PABPN1 was identified. Since the family history proved to be negative, the mutation is likely to have occurred de novo. The frequency of the (GCG)7 allele among healthy Swiss controls amounted to 1%. The flPPP method showed a sensitivity and specificity of 100%. Two years after cricopharyngeal myotomy, the patient is still relieved of dysphagia. Conclusions: An otolaryngologist should include OPMD in the differential diagnosis of a patient presenting with dysphagia, as this symptom can be the first sign of the disease and family history can be negative. Molecular genetic testing represents a highly accurate and rapid way to confirm the clinical diagnosis of OPMD. Cricopharyngeal myotomy relieves the patient of dysphagia in the majority of cases. [source]

DIFFERENTIAL PERFORMANCE AMONG LDH-B GENOTYPES IN RANA LESSONAE TADPOLES

EVOLUTION, Issue 5 2000
Hansjürg Hotz
Abstract The European pool frog, Rana lessonae, is widely polymorphic for two common alleles (b, e) at the lactate dehydrogenase-B (LDH-B) locus. We compared fitness-related larval life-history traits among LDH-B genotypes, which originated from segregation in heterozygous parents, in an artificial pond experiment where tadpoles of R. lessonae from a Swiss population were raised together with tadpoles of the hemiclonal hybrid R. esculenta at two densities. In R. lessonae, LDH-B e/e homozygotes at each density had a higher proportion of metamorphs among survivors, reached metamorphosis earlier, and were heavier at metamorphosis than b/b homozygotes; b/e heterozygotes had intermediate values. That e/e individuals were superior to b/b in both time to and mass at metamorphosis is surprising because these two life-history traits are thought to reflect a performance trade-off; e/e genotypes apparently compensated for shorter time to metamorphosis by a higher growth rate. The two alleles showed the same performance ranking when combined in hybrids with a R. ridibunda allele: When R. esculenta from Swiss populations reared in the same ponds had received the e allele rather than the b allele from their R. lessonae parent, they reached metamorphosis earlier, but did not differ in mass at metamorphosis. The degree of linkage disequilibrium in the source population of the eight R. lessonae used as parents of the R. lessonae tadpoles is unknown, so we cannot exclude the possibility that the performance differences are caused by some anonymous tightly linked gene, rather than the LDH-B locus, that constitutes the genomically localized target of natural selection. A causal involvement of LDH-B is plausible, nevertheless, because this enzyme takes part in the central energy-metabolizing processes and has been reported to underlie fitness differences in other animals; also, differential performance of LDH-B genotypes has been observed in R. lessonae larvae from another population. The present results suggest strong directional selection for allele e; the sum of available data, including an independent laboratory experiment, suggests that partial environment-dependent overdominance combined with balancing selection favoring e/e homozygotes under some and b/b homozygotes under other conditions may be partially responsible for the broad maintenance of the LDH-B polymorphism in R. lessonae. [source]

New chloroplast primers for intraspecific variation in Dicranum scoparium Hedw. (Dicranaceae) and amplification success in other bryophyte species

MOLECULAR ECOLOGY RESOURCES, Issue 4 2010
A. LANG
Abstract Primers for four loci that amplify cpDNA regions have been designed for population genetic analyses in Dicranum scoparium Hedw. and compared with trnL(UAA)5,exon- trnF. All loci showed intraspecific variation with a number of haplotypes ranging between two and six. trnH- psbADic showed an intercontinental disjunction, but no variability within the four Swiss populations surveyed, whereas the three remaining loci displayed intrapopulation variability in at least one population (rps19- rpl2, rpoB, trnT- rps4). These primers were additionally tested on 22 bryophytes and three fern species. The primers amplified mostly in mosses and liverworts, but less well in ferns, pointing to their evolutionary distance from the bryophytes. [source]