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Università della Svizzera italiana

Consensus protocols exploiting network programmability

Dang, Huynh Tu ; Soulé, Robert (Dir.) ; Pedone, Fernando (Codir.)

Thèse de doctorat : Università della Svizzera italiana, 2019 ; 2019INFO003.

Services rely on replication mechanisms to be available at all time. The service demanding high availability is replicated on a set of machines called replicas. To maintain the consistency of replicas, a consensus protocol such as Paxos or Raft is used to synchronize the replicas' state. As a result, failures of a minority of replicas will not affect the service as other non-faulty replicas...

Université de Fribourg

Living long and well: prospects for a personalized approach to the medicine of ageing

Fuellen G. ; Schofield P. ; Flatt Thomas ; Schulz R.-J. ; Boege F. ; Kraft K. ; Rimbach G. ; Ibrahim S. ; Tietz A. ; Schmidt C. ; Köhling R. ; Simm A.

In: Gerontology, 2016, vol. 62, no. 4, p. 409–416

Research into ageing and its underlying molecular basis enables us to develop and implement targeted interventions to ameliorate or cure its consequences. However, the efficacy of interventions often differs widely between individuals, suggesting that populations should be stratified or even individualized. Large-scale cohort studies in humans, similar systematic studies in model organisms as...

Université de Fribourg

Similarities and differences in altitudinal versus latitudinal variation for morphological traits in Drosophila melanogaster

Klepsatel, Peter ; Gáliková, Martina ; Huber, Christian D. ; Flatt, Thomas

In: Evolution, 2014, vol. 68, no. 5, p. 1385–1398

Understanding how natural environments shape phenotypic variation is a major aim in evolutionary biology. Here, we have examined clinal, likely genetically based variation in morphology among 19 populations of the fruit fly (Drosophila melanogaster) from Africa and Europe, spanning a range from sea level to 3000 m altitude and including locations approximating the southern and northern range...

Université de Fribourg

Inference of chromosomal inversion dynamics from Pool-Seq data in natural and laboratory populations of Drosophila melanogaster

Kapun, Martin ; van Schalkwyk, Hester ; McAllister, Bryant ; Flatt, Thomas ; Schlötterer, Christian

In: Molecular Ecology, 2014, vol. 23, no. 7, p. 1813–1827

Sequencing of pools of individuals (Pool‐Seq) represents a reliable and cost‐effective approach for estimating genome‐wide SNP and transposable element insertion frequencies. However, Pool‐Seq does not provide direct information on haplotypes so that, for example, obtaining inversion frequencies has not been possible until now. Here, we have developed a new set of diagnostic marker...

Université de Fribourg

Variation in thermal performance and reaction norms among populations of Drosophila melanogaster

Klepsatel, Peter ; Gáliková, Martina ; De Maio, Nicola ; Huber, Christian D. ; Schlötterer, Christian ; Flatt, Thomas

In: Evolution, 2013, vol. 67, no. 12, p. 3573–3587

The major goal of evolutionary thermal biology is to understand how variation in temperature shapes phenotypic evolution. Comparing thermal reaction norms among populations from different thermal environments allows us to gain insights into the evolutionary mechanisms underlying thermal adaptation. Here, we have examined thermal adaptation in six wild populations of the fruit fly (Drosophila...

Université de Fribourg

The influence of ant-attendance on aphid behaviour investigated with the electrical penetration graph technique

Rauch, Gisep ; Simon, Jean-Christophe ; Chaubet, Bernard ; Haack, Lucie ; Flatt, Thomas ; Weisser, Wolfgang W.

In: Entomologia Experimentalis et Applicata, 2002, no. 102, p. 13-20

For themutualistic interaction between the aphidMetopeurum fuscoviride Stroyan (Homoptera:Aphididae) and the ant Lasius niger L. (Hymenoptera: Formicidae) it has been shown that ant-tended aphids develop faster, reproduce at a higher rate, and live longer than aphids not tended by ants. We used electrical penetration graphs (EPG) to investigate if behavioural patterns differ between ant-tended...

Université de Fribourg

Life-history evolution and the polyphenic regulation of somatic maintenance and survival

Flatt, Thomas ; Amdam, Gro V. ; Kirkwood, Thomas B. L. ; Omholt, Stig W.

In: The Quarterly Review of Biology, 2013, vol. 88, no. 3, p. 185–218

Here we discuss life-history evolution from the perspective of adaptive phenotypic plasticity, with a focus on polyphenisms for somatic maintenance and survival. Polyphenisms are adaptive discrete alternative phenotypes that develop in response to changes in the environment. We suggest that dauer larval diapause and its associated adult phenotypes in the nematode (Caenorhabditis elegans),...

Université de Fribourg

Increased temperature disrupts the biodiversity–ecosystem functioning relationship

Parain, Elodie C. ; Rohr, Rudolf P. ; Gray, Sarah M. ; Bersier, Louis-Félix

In: The American Naturalist, 2018, vol. 193, no. 2, p. 227–239

Gaining knowledge of how ecosystems provide essential services to humans is of primary importance, especially with the current threat of climate change. Yet little is known about how increased temperature will impact the biodiversity–ecosystem functioning (BEF) relationship. We tackled this subject theoretically and experimentally. We developed a BEF theory based on mechanistic population ...

Université de Fribourg

Returns to farm child labor in Tanzania

André, Pierre ; Delesalle, Esther ; Dumas, Christelle

(Working Papers SES ; 502)

In developing countries, the opportunity costs of children’s time can significantly hinder universal education. This paper studies one of these opportunity costs: we estimate the agricultural productivity of children aged 10 to 15 years old using the LSMS-ISA panel survey in Tanzania. Since child labor can be endogenous, we exploit the panel structure of the data and instrument child labor...

Università della Svizzera italiana

High performance selected inversion methods for sparse matrices : direct and stochastic approaches to selected inversion

Verbosio, Fabio ; Schenk, Olaf (Dir.)

Thèse de doctorat : Università della Svizzera italiana, 2019 ; 2019INFO002.

The explicit evaluation of selected entries of the inverse of a given sparse matrix is an important process in various application fields and is gaining visibility in recent years. While a standard inversion process would require the computation of the whole inverse who is, in general, a dense matrix, state-of-the-art solvers perform a selected inversion process instead. Such approach allows...