Altruism, spite and choosy females

Natural selection favours the genes which are able to introduce replicates of themselves in the next generation with higher certainty than do rival genes (Hamilton 1963). The fitness of an individual, it?s ability to produce future parents, depends on it?s own behaviour as well as on the behaviour of other individuals in the population. For instance, the intensity of competition an individual experience depends on the exploitation of resources by neighbours. The fitness is thus frequency dependent on what neighbours do. Behaviours can be classified according to the costs and benefits they have on the fitness of the behaver and it?s neighbours (Hamilton 1964, Hamilton 1975). According to this classification there exist four distinct social behaviours. (1) A gene confering the ability to use a new ressource is called selfish because it has a positive e_ect on the bearer of the gene but a negative e_ect on neighbours by the concomitant increase in competition. (2) An altruistic behaviour is defined as an action where an individual increases the fitness of a neighbour at the expense of it?s own. The e_ect is deleterious for the actor but positive for the receptor. (3) More surprinsingly, an individual might sacrifice a fraction of it?s ressources to harm another at no direct benefits. This spitefull behaviour incurs a cost for the actor but is also deleterious for the receptor. (4) Finally a cooperative behaviour breeds benefits for both actors and neighbours. In this thesis I will continue on the path traced by numerous evolutionnary biologist which attempt to fine tune our understanding of the evolution of social behaviours since Hamilton?s foundation (1963, 1964). A critical development over the last 40 years has been the realisation that competition between kin can partly or completely cancel out the role of relatedness as an agent favouring altruism (Wilson et al., 1992; Taylor, 1992a,b). Of importance is thus to determine the scale at which competition and altruism occur. One mechanism avoiding the complete dilution of relatedness by competition is the conditionnal expression of the social behaviors. Focus will be given in this thesis at the role played by di_erent recognition mechanism in paving the way to altruism (Komdeur and Hatchwell, 1999) when the population has a spatial structure. Further, the evolution of spite will also be considered in these settings. The thesis is fractionated into two parts. First, di_erent models promoting altruism cooperation and spite will be compared under the same theoretical umbrella. This is a rather informal and more personnal part of my thesis. It also serve as a justification and basis to "Altruism among kin and non-kin individuals" which is an article attempting to clas- sify the mechanisms leading to altruism and cooperation. Second, in the annexe, there are three research papers about kin selection, altruism and dispersal: "Is sociality driven by the costs of dispersal or the benefits of philopatry?: A role for kin-discrimination mechanism", "Altruism, dispersal and phenotype kin recognition" and "Inbreeding avoidance through kin recognition: choosy female boost male dispersal" this last paper incorporates kin recognition as an agent favoring sex-biased dispersal.

Neurophysiologic and proteomic investigations of experience-dependent plasticity in the somatosensory cortex of the adult mouse following chronic whisker stimulation

RESUME Les follicules des vibrisses des rongeurs sont représentés sous la forme d'une carte topographique dans le cortex à tonneaux. Lorsque un groupe de vibrisses est coupé pendant plusieurs jours chez un rongeur adulte, en laissant les autres vibrisses intactes, le champ réceptif des neurones du cortex à tonneaux est modifié, ce qui démontre que les cartes corticales sont plastiques. Dans notre étude, une expérience sensorielle a été induite chez une souris adulte se comportant librement en stimulant chroniquement une de ses vibrisses pendant 24h. Par une analyse des potentiels de champ locaux, nous démontrons que les caractéristiques spatiotemporelles du flux d'excitation évoqué par la vibrisse principale (VP) dans la colonne corticale correspondante à la vibrisse stimulée n'est pas altéré. Par contre, l'enregistrement des potentiels d'actions d'un total de 1041 neurones à travers le cortex à tonneaux révèlent plusieurs modifications de l'activité neuronale. L'activité spontanée ainsi que la réponse évoquée par la VP sont déprimées dans la colonne corticale stimulée (nombre moyen de potentiels d'action évoqués par la VP diminue de 25 % et 36% dans la couche IV et les couches II&III). La réponse des neurones à la vibrisse stimulée diminue également dans les colonnes corticales adjacentes, «non-stimulées». La dépression de l'activité spontanée et de la réponse à la VP est localisée à la colonne corticale stimulée. Dans le tonneau stimulé, la première partie de la réponse à la VP n'est pas affaiblie, démontrant que la dépression de la réponse n'est pas due à un phénomène de plasticité sous-corticale ou thalamocorticale. La stimulation chronique d'une vibrisse entraîne une augmentation du nombre de synapses GABAergiques dans la couche IV du tonneau correspondant (Knott et al, 2002). Dès lors, nos résultats suggèrent qu'une augmentation de l'inhibition dans le tonneau stimulé serait à l'origine de la diminution des potentiels d'action évoqués par la vibrisse stimulée et en conséquence de l'amplitude du flux d'excitation vers les couches II&III puis vers les colonnes corticales adjacentes. Toutes les réponses des neurones du tonneau stimulé ne sont pas déprimées. Les réponses des neurones à la vibrisse voisine caudale à VP diminuent dans la couche IV (42%) et dans les couches II&III (52%) mais pas les réponses aux 7 autres vibrisses voisines. Les entrées synaptiques en provenance de la vibrisse caudale pourraient avoir été spécifiquement déprimées en raison d'une décorrélation prolongée entre l'activité évoquée dans les chemins sensoriels relatifs à la vibrisse stimulée et à la vibrisse caudale, spécificité qui découlerait du fait que, parmi les vibrisses voisines à la VP, la vibrisse caudale génère les réponses les plus fortes dans la colonne corticale. Quatre jours après l'arrêt de la stimulation, l'activité neuronale n'est plus déprimée; au contraire, nous observons une potentiation des réponses à la VP dans la couche IV de la colonne corticale stimulée. De plus, nous montrons que l'expression des protéines GLT-1 et GLAST, deux transporteurs astrocytaires du glutamate, est augmentée de ~2.5 fois dans la colonne corticale stimulée, indiquant l'existence d'une «plasticité gliale» et suggérant que les cellules gliales participent activement à l'adaptation du cerveau à l'expérience. ABSTRACT In the barrel cortex, mystacial whisker follicles are represented in the form of a topographie map. The selective removal of a set of whiskers while sparing others for several days in an adult rodent alters receptive field of barrel cortex neurons, demonstrating experience-dependent plasticity of cortical maps. Here sensory experience was altered by chronic stimulation of a whisker for a 24h period in a freely behaving adult mouse. By means of an evoked local field potential analysis, we show that chronic stimulation does not alter the flow of excitation evoked by the principal whisker (PW) in the stimulated barrel column. However, the recording of neuronal firing from a total of 1041 single units throughout the barrel cortex reveals several changes in neuronal activity. Immediately after chronic stimulation, spontaneous activity as well as PW-responses are depressed in the stimulated barrel column (mean number of spikes per PW-deflection decreases by 25% and 36% in layer IV and layers II&III, respectively). Neuronal responses towards the chronically stimulated whisker are also significantly depressed in layers II&III of the adjacent "non-stimulated" barrel' columns. The depression of both spontaneous activity and PW-responses are restricted to the stimulated ban-el column. The earliest time epoch of the PW-response in the stimulated barrel is not depressed, demonstrating that the decrease of cortical responses is not due to subcortical or thalamocortical plasticity. The depression of PW-response in the stimulated barrel correlates with an increase in the number of GABAergic synapses in layer IV (Knott et al., 2002). Therefore, our results suggest that an increase in inhibition within the stimulated barrel may reduce its excitatory output and accordingly the flow of excitation towards layers and the subsequent horizontal spread into adjacent barrel columns. Not all responses of neurons in the stimulated barrel are depressed. Neuronal responses towards the caudal in-row whisker decrease by 42% in layer IV and 52% in layers MM but responses to the other 7 immediate surround whiskers (SWs) are not affected. The synaptic inputs from the SW that elicit the strongest responses in the stimulated barrel may have been specifically depressed following a prolonged period of diminished coherence between neuronal activity evoked in the pathways from the chronically stimulated whisker and from its surrounding in-row whisker. Four days after the cessation of the stimulation, depression of neuronal activity is no longer present; on the contrary, we observe a small but significant potentiation of PW-responses in layer IV of the stimulated barrel column. Moreover we show that the expression of astrocytic glutamate transporters GLT-1 and GLAST proteins were both upregulated by ~2.5 fold in the stimulated barrel column, which indicates that glial cells exhibit experience-dependent functional changes and could actively take part in the adaptation of the cerebral cortex to experience.

Open Labware: 3-D printing your own lab equipment.

The introduction of affordable, consumer-oriented 3-D printers is a milestone in the current "maker movement," which has been heralded as the next industrial revolution. Combined with free and open sharing of detailed design blueprints and accessible development tools, rapid prototypes of complex products can now be assembled in one's own garage--a game-changer reminiscent of the early days of personal computing. At the same time, 3-D printing has also allowed the scientific and engineering community to build the "little things" that help a lab get up and running much faster and easier than ever before.

The importance of sonographer experience and machine quality with regards to the role of musculoskeletal ultrasound in routine care of rheumatoid arthritis patients.

OBJECTIVES: Regarding recent progress, musculoskeletal ultrasound (US) will probably soon be integrated in standard care of patient with rheumatoid arthritis (RA). However, in daily care, quality of US machines and level of experience of sonographers are varied. We conducted a study to assess reproducibility and feasibility of an US scoring for RA, including US devices of different quality and rheumatologist with various levels of expertise in US as it would be in daily care. METHODS: The Swiss Sonography in Arthritis and Rheumatism (SONAR) group has developed a semi-quantitative score using OMERACT criteria for synovitis and erosion in RA. The score was taught to 108 rheumatologists trained in US. One year after the last workshop, 19 rheumatologists participated in the study. Scans were performed on 6 US machines ranging from low to high quality, each with a different patient. Weighted kappa was calculated for each pair of readers. RESULTS: Overall, the agreement was fair to moderate. Quality of device, experience of the sonographers and practice of the score before the study improved substantially the agreement. Agreement assessed on higher quality machine, among sonographers with good experience in US increased to substantial (median kappa for B-mode and Doppler: 0.64 and 0.41 for erosion). CONCLUSIONS: This study demonstrated feasibility and reproducibility of the Swiss US SONAR score for RA. Our results confirmed importance of the quality of US machine and the training of sonographers for the implementation of US scoring in the routine daily care of RA.

Medical physicists' implication in radiological diagnostic procedures: results after 1 y of experience.

Since January 2008-de facto 2012-medical physics experts (MPEs) are, by law, to be involved in the optimisation process of radiological diagnostic procedures in Switzerland. Computed tomography, fluoroscopy and nuclear medicine imaging units have been assessed for patient exposure and image quality. Large spreads in clinical practice have been observed. For example, the number of scans per abdominal CT examination went from 1 to 9. Fluoroscopy units showed, for the same device settings, dose rate variations up to a factor of 3 to 7. Quantitative image quality for positron emission tomography (PET)/CT examinations varied significantly depending on the local image reconstruction algorithms. Future work will be focused on promoting team cooperation between MPEs, radiologists and radiographers and on implementing task-oriented objective image quality indicators.

Longitudinal study of informed consent in innovative therapy research: experience and provisional recommendations from a multicenter trial of intracerebral grafting.

BACKGROUND: There is an urgent need to assess and improve the consent process in clinical trials of innovative therapies for neurodegenerative disorders. METHODS: We performed a longitudinal study of the consent of Huntington's disease patients during the Multicenter Fetal Cell Intracerebral Grafting Trial in Huntington's Disease (MIG-HD) in France and Belgium. Patients and their proxies completed a consent questionnaire at inclusion, before signing the consent form and after one year of follow-up, before randomization and transplantation. The questionnaire explored understanding of the protocol, satisfaction with the information delivered, reasons for participating in the trial and expectations regarding the transplant. Forty-six Huntington's disease patients and 27 proxies completed the questionnaire at inclusion, and 27 Huntington's disease patients and 16 proxies one year later. RESULTS: The comprehension score was high and similar for Huntington's disease patients and proxies at inclusion (72.6% vs 77.8%; P > 0.1) but only decreased in HD patients after one year. The information satisfaction score was high (73.5% vs 66.5%; P > 0.1) and correlated with understanding in both patients and proxies. The motivation and expectation profiles were similar in patients and proxies and remained unchanged after one year. CONCLUSIONS: Cognitively impaired patients with Huntington's disease were capable of consenting to participation in this trial. This consent procedure has presumably strengthened their understanding and should be proposed before signing the consent form in future gene or cell therapy trials for neurodegenerative disorders. Because of the potential cognitive decline, proxies should be designated as provisional surrogate decision-makers, even in competent patients.

Partial cricotracheal resection for paediatric subglottic stenosis: update of the Lausanne experience with 129 cases.

OBJECTIVES: Partial cricotracheal resection (PCTR) is widely accepted for treating severe paediatric laryngotracheal stenosis (LTS). However, it remains limited to a few experienced centres. Here we report an update of the Lausanne experience in paediatric PCTR performed or supervised by a senior surgeon (Philippe Monnier). METHODS: An ongoing database of 129 paediatric patients who underwent PCTR for benign LTS between March 1978 and July 2012 at our hospital was retrospectively reviewed. Demographic characteristics and information on preoperative status, stenosis and surgery were collected. Primary outcomes were measured as overall and operation-specific decannulation rates (ODR and OSDR, respectively), and secondary outcomes as morbidity, mortality and postoperative functional results. RESULTS: A total of 129 paediatric patients [79 males and 50 females; mean age, 4.1 years (1 month-16 years, median age of 2 years old)] underwent PCTR during the study period. ODR and OSDR were 90 and 81%, respectively. The decannulation rates were significantly superior for single-stage PCTR compared with double-stage PCTR in both ODR and OSDR. Eight patients died postoperatively for reasons unrelated to surgery. Partial anastomotic dehiscence was seen in 13 patients, 9 of whom were successfully treated by revision surgery. Respiratory, voice and swallowing functions were near normal or only minimally impaired in 86, 65 and 81% of patients, respectively. CONCLUSIONS: PCTR is effective and feasible with good ODR and OSDR for highgrade / severe LTS. Glottic involvement and the presence of comorbidities were negative predictive factors of decannulation. Early detection and reintervention of postoperative incipient dehiscence contribute to avoiding the progress to late restenosis; however, voice improvement remains a challenge.