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Institution

University of Fribourg

EducationFribourg, Freiburg, Switzerland
About: University of Fribourg is a education organization based out in Fribourg, Freiburg, Switzerland. It is known for research contribution in the topics: Population & Glacier. The organization has 6040 authors who have published 14975 publications receiving 542500 citations. The organization is also known as: UNIFR & Universität Freiburg.


Papers
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Journal ArticleDOI
TL;DR: This is the first experimental study to demonstrate that the production of propagules is highest at intermediate levels of virulence and that parasite genetic variability is available to drive the evolution of virulent in this system.
Abstract: The trade-off hypothesis for the evolution of virulence predicts that parasite transmission stage production and host exploitation are balanced such that lifetime transmission success (LTS) is maximised. However, the experimental evidence for this prediction is weak, mainly because LTS, which indicates parasite fitness, has been difficult to measure. For castrating parasites, this simple model has been modified to take into account that parasites convert host reproductive resources into transmission stages. Parasites that kill the host too early will hardly benefit from these resources, while postponing the killing of the host results in diminished returns. As predicted from optimality models, a parasite inducing castration should therefore castrate early, but show intermediate levels of virulence, where virulence is measured as time to host killing. We studied virulence in an experimental system where a bacterial parasite castrates its host and produces spores that are not released until after host death. This permits estimating the LTS of the parasite, which can then be related to its virulence. We exposed replicate individual Daphnia magna (Crustacea) of one host clone to the same amount of bacterial spores and followed individuals until their death. We found that the parasite shows strong variation in the time to kill its host and that transmission stage production peaks at an intermediate level of virulence. A further experiment tested for the genetic basis of variation in virulence by comparing survival curves of daphniids infected with parasite spores obtained from early killing versus late killing infections. Hosts infected with early killer spores had a significantly higher death rate as compared to those infected with late killers, indicating that variation in time to death was at least in part caused by genetic differences among parasites. We speculate that the clear peak in lifetime reproductive success at intermediate killing times may be caused by the exceptionally strong physiological trade-off between host and parasite reproduction. This is the first experimental study to demonstrate that the production of propagules is highest at intermediate levels of virulence and that parasite genetic variability is available to drive the evolution of virulence in this system.

157 citations

Journal ArticleDOI
TL;DR: The results support the notion that the pathological process in Alzheimer's disease involves specific cellular populations sharing particular morphological and neurochemical characteristics, and suggest that calretinin-immunoreactive neurons, like other calcium-binding protein-containing interneurons, are resistant to degeneration in Alzheimer't disease.

157 citations

Journal ArticleDOI
Georges Aad1, Brad Abbott2, Jalal Abdallah3, S. Abdel Khalek4  +2810 moreInstitutions (209)
TL;DR: In this article, a search for a heavy, CP-odd Higgs boson decaying into a Z boson and a 125 GeV h, with the ATLAS detector at the LHC is presented.

156 citations

Book ChapterDOI
TL;DR: The BIOMET multimodal database for person authentication is described, including face, voice, fingerprint, hand and signature data, and details about the acquisition protocols of each modality are given.
Abstract: Information technology innovations involve a constant evolution of man-machine interaction modes. Automated authentication of people could be used to better adapt the machine to the user. Security can also be enhanced through a better people authentication. Biometrics appears as a promising tool in these two situations. Different modalities can be envisaged, such as: fingerprint, human face images, hand shape, voice, handwritten signature... In order to take advantage of the particularities of each modality, and to improve the performance of a person authentication system, multimodality can be applied. This motivated the recording of BIOMET, a biometric database with five different modalities, including face, voice, fingerprint, hand and signature data. In this paper, the BIOMET multimodal database for person authentication is described. Details about the acquisition protocols of each modality are given. Preliminary monomodal verification results, obtained on a subcorpus of the BIOMET fingerprint data, are also presented.

156 citations

Journal ArticleDOI
TL;DR: In this paper, the 10th International Symposium on Metal-Hydrogen Systems, Fundamentals and Applications, Lahaina, HIGM Res & Dev, Hawaii Hydrogen Carriers LLC; Hy Energy, LLC; Jet Propuls Lab; NIST Ctr Neutron Res; Suzuki Shokan Co, Ltd; Toyota Motor Sales Reference EPFL-ARTICLE-205982

156 citations


Authors

Showing all 6204 results

NameH-indexPapersCitations
Jens Nielsen1491752104005
Sw. Banerjee1461906124364
Hans Peter Beck143113491858
Patrice Nordmann12779067031
Abraham Z. Snyder12532991997
Csaba Szabó12395861791
Robert Edwards12177574552
Laurent Poirel11762153680
Thomas Münzel116105557716
David G. Amaral11230249094
F. Blanc107151458418
Markus Stoffel10262050796
Vincenzo Balzani10147645722
Enrico Bertini9986538167
Sandeep Kumar94156338652
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202367
2022348
20211,110
20201,112
2019966
2018924