The Logarithmic Sobolev Constant of The Lamplighter

We give estimates on the logarithmic Sobolev constant of some finite lamplighter graphs in terms of the spectral gap of the underlying base. Also, we give examples of application

DNA-end capping by the budding yeast transcription factor and subtelomeric binding protein Tbf1

International audienc

Comparison of three devices for the automated detection of estrus in dairy cows

International audienceConsiderable technological advances have been made in the automated detection of estrus in dairy cattle, but few studies have evaluated their relative performance on the same animals or assessed cow-related factors that affect their performance. Our objective was to assess the performance and reliability of three devices commercially available in France for cow estrus detection. The devices were a pedometer (PM; Afitag) and two activity meters (AM1; Heatime-RuminAct, and AM2; HeatPhone). Two algorithms were tested for AM2. We fitted 63 lactating Holstein cows with the three detectors from calving to 90 days after calving. The onset and pattern of cyclicity were monitored from 7 to 90 days postpartum measuring progesterone concentration in milk twice weekly. A total of 211 ovulations were identified. Cyclicity was classified as normal in 60% of cows (38/63). Calculated over the operating period of all the devices (179 periods of estrus), the sensitivities and positive predictive values were, respectively, 71% and 71% for PM, 62% and 84% for AM1, 61% and 67% for the first algorithm of AM2, and 62% and 87% for the second algorithm of AM2. Both activity meters had a lower sensitivity but a higher positive predictive value than the PM (P < 0.05). For all devices, the performance in estrus detection was much poorer at the first postpartum ovulation than at subsequent ovulations (P < 0.05). Lactation rank and milk production affected some devices (P < 0.05). These devices could be used to reinforce visual observations, especially after 50 days postpartum, the minimum recommended delay to insemination. However, their full benefit remains to be verified in different farming systems and taking into account the specific objectives of the dairy farmer

La détection par les éleveurs des chaleurs des vaches : des pratiques et des logiques de décision très diverses

La présente communication basée sur 319 enquêtes propose une analyse des pratiques et des perceptions des éleveurs sur la détection des chaleurs des vaches et la mise à la reproduction. Les observations faites dans quatre zones allaitantes ont été comparées à une zone laitière servant de référence. Les résultats montrent que les pratiques de détection et les processus de décision pour la mise à la reproduction sont complexes et personnels. Les éleveurs se réfèrent en grande majorité à l'acceptation du chevauchement ; les émissions de glaires sont également jugées comme fiables, alors que les signes sexuels secondaires sont moins fréquemment pris en compte par les éleveurs allaitants que par les éleveurs laitiers. De même les pratiques de conseil apparaissent très variables selon les zones

10th Francophone Yeast Meeting 'Levures, Modèles & Outils'

Meeting reportBetween the first and tenth editions of this biannual rendezvous, yeasters were faced with an extraordinary revolution: Saccharomyces cerevisiae was indeed the first eukaryotic genome completely sequenced and released to the community, reviving its enormous potential for understanding life and opening the door to new approaches in biology. This revolution was immediately followed by ambitious programmes for sequencing the genomes of its distant cousins, e.g. the ‘Genolevures’ program held by a consortium of seven French laboratories, with the first aim of deciphering the different mechanisms of eukaryotic genome evolution over long periods of time. Taking advantage of the knowledge of these new genomes, researchers can now tackle much more easily relevant physiological studies in very different and distant yeasts, the diversity of which has once again been attractively represented at this 10th meeting. In addition to S. cerevisiae and Saccharomyces pombe still highly valued by researchers, many oral and written communications attested to the growing interest of our community for these ‘less-conventional’ yeasts. This explains why, in parallel with this genomic revolution, a mutation naturally occurred in the title of this meeting, with the recent emergence of three ‘s’ and subsequent transition from ‘Levure, Mode`le & Outil’ to ‘‘Levures, Mode`les & Outils’. This latest edition of LMO therefore brought together 250 participants from fields that rarely interact in order to discuss the current status of their research interests. This massive participation certified that our community remains very active, but also that it is particularly fond of this appointment. It offers a panoramic view of the extraordinary potential of yeasts, that continue to be driving forces in many fields of biology, from basic research to biotechnological challenges in coming years. Topics therefore ranged from a convincing demonstration of the central role of the mediator complex in RNA-polymerase II-dependent transcription to the engineering of new yeast strains to meet emerging energy problems that humanity will have to face in the near future. This report highlights some of the latest findings presented at this meeting, where two of the sessions were held in memory of renowned French colleagues Barbara Winsor and Pierre Thuriaux, who sadly passed away on the eve of retirement. 1. Beverages and energy: from ancestral use of yeasts to cutting edge biotechnological challenges2. Evolution and the genomics revolution3. Traffic and organelles: focus on mitochondrial ATP synthase4. Let’s travel into the nucleus: from DNA organisation to transcription5. RNA life, from synthesis to translation6. It’s all about control: key elements in cell cycle progression and establishment of cell polarit

La détection des chaleurs vue par les éleveurs : des pratiques et des logiques de décision très diverses

La présente communication basée sur 319 enquêtes propose une analyse des pratiques et des perceptions des éleveurs sur la détection des chaleurs des vaches et la mise à la reproduction. Les observations faites dans quatre zones allaitantes ont été comparées à une zone laitière servant de référence. Les résultats montrent que les pratiques de détection et les processus de décision pour la mise à la reproduction sont complexes et personnels. Les éleveurs se réfèrent en grande majorité à l’acceptation du chevauchement ; les émissions de glaires sont également jugées comme fiables, alors que les signes sexuels secondaires sont moins fréquemment pris en compte par les éleveurs allaitants que par les éleveurs laitiers. De même les pratiques de conseil apparaissent très variables selon les zones.This study aimed at describing practi ces of heat detection and breeding. A total of 319 breeders were interviewed in 4 beef breed regions and compared with one dairy regi on, used as a reference. The results show that heat detection practices and making AI decisions are comple x and personal. Breeders still trust standing estrus as an estrus sign and observation of mucosal discharge is also widely used. Sexual signs are less taken into account compared to dairy herds. Regarding advice provided by technicians, methods are also highly variable among regions

Métadonnées sur le web : les enjeux autour des techniques d’enrichissement des contenus

Le dossier du numéro 36 s’intéresse aux techniques d’enrichissement des contenus par des méta-informations, réalisé avant ou après leur publication sur le web diversifiant ainsi les modes d’accès à l’information en termes de représentation. Sont ainsi concernés les outils reposant sur l’exploitation des métadonnées combinées à des techniques de filtrage, de classification, de tri, d’infographie, de cartographie. L’élaboration de ces méta-informations ne relève plus exclusivement des professionnels de l’information spécialistes du catalogage et de l’indexation des ressources mais est proposée par de nouveaux acteurs, éditeurs de logiciels ou éditeurs de contenus. Les contributions sélectionnées pour ce dossier indiquent un intérêt continu pour les approches collaboratives et reflètent la diversité des enjeux et la variété des approches méthodologiques allant de la recherche appliquée à la sociologie des usages. Sont notamment abordés : l’extraction d’ontologies pour la sémantique du web, la modélisation des métadonnées pour la documentation collaborative de « petits projets techniques », la redocumentarisation de fonds audiovisuels, la construction d’une veille informationnelle et l’éducation à la « culture » des folksonomies. The focus of issue 36 is the techniques of enriching content with metadata before or after their publication on the Web thus diversifying the means of access to information in terms of representation. Tools based on the exploitation of metadata are also considered combined with filtering techniques, archiving, sorting, computer graphics, and cartography. Use of metadata is no longer the exclusive province of the information professional specialized in archiving and indexing resources, but is also suggested by new actors, software, or content editors. The contributions selected for this issue reveal a continued interest in collaborative approaches and reflect the diversity of issues and variety of methodological approaches stretching from applied research to user experience sociology. Specific topics include the extraction of ontologies for the Semantic Web, metadata modeling for collaborative documentation of “small technical projects,” redocumentation of audiovisual collections, construction of data monitoring procedures, and education on the culture of folksonomies

Compter et mesurer. Réflexions sur Le souci du nombre dans l'évaluation de la production du savoir scientifique.

10 pages.Dans ce texte, nous cherchons à apporter quelques éléments de réflexion sur la bibliométrie et ses conséquences

The Logarithmic Sobolev Constant of The Lamplighter

We give estimates on the logarithmic Sobolev constant of some finite lamplighter graphs in terms of the spectral gap of the underlying base. Also, we give examples of application