Spin des niveaux à 0,46 et 0,67 MeV du 34Cl

L'étude de la réaction 32S(3He, pγ) 3Cl a été réalisée à l'aide d'un faisceau 3He++ aux énergies 9, 9,5 et 10 MeV. Les coïncidences pγ ont été effectuées entre protons détectés à 0° et rayonnements γ, conformément à la méthode II de corrélation angulaire de Litherland et Ferguson. L'exploitation des corrélations des groupes de protons menant aux deuxième et troisième niveaux excités du 34CI avec les rayonnements γ correspondants, détermine sans ambiguïté J = 1 pour les niveaux à 0,46 et 0,67 MeV de ce noyau. Ces résultats confirment les prévisions théoriques déduites du modèle en couches avec interaction à deux particules modifiée

Étude d'états excités de 22Ne a l'aide des résonances de capture radiative de particules alpha par 18O entre 1,6 et 5,0 MeV d'énergie incidente

La courbe d'excitation du rayonnement γ de 350 keV issu de la réaction 18O(α, nγ) 21Ne a été mesurée entre 1,6 et 5 MeV. Six nouvelles résonances ont été observées correspondant aux niveaux du 22Ne : Ex = 11,199 MeV (Eα = 1,873 MeV ; Γt = 7 keV) ; 11,271 (1,961 ; 7) ; 11,431 (2,156 ; 47) ; 11,519 (2,263 ; 6) ; 11,577 (2,335 ; 16) ; 11,745 (2,540 ; 41). Nous avons relevé les spectres de désexcitation par rayonnement γ de tous les niveaux mis en évidence et mesuré les distributions angulaires des rayonnements γ de la réaction 18O(α, γ) 22Ne chaque fois que l'intensité de transition le permettait. En fait seules trois résonances déjà observées se trouvaient dans ce cas. Pour le niveau Ex = 11,462 MeV (2,194 ; 9) la distribution angulaire a permis de fixer Jπ = 1 -. Pour les niveaux Ex = 11,682 MeV (2,463 ; 8) et Ex = 11,751 MeV (2,547 ; 8) les valeurs respectives J π = 2+ et Jπ = 1- ont été confirmées. Des rapports d'embranchement (γ0/γ1) ont pu être déterminés pour ces trois niveaux ainsi que les coefficients de mélange de multipolarité des transitions γ1. Des limites supérieures des intensités de transition ωγ pour les transitions γ0 + γ 1 sont données pour les autres niveaux

Exploratory fMRI analysis without spatial normalization

Author Manuscript received 2010 March 11. 21st International Conference, IPMI 2009, Williamsburg, VA, USA, July 5-10, 2009. ProceedingsWe present an exploratory method for simultaneous parcellation of multisubject fMRI data into functionally coherent areas. The method is based on a solely functional representation of the fMRI data and a hierarchical probabilistic model that accounts for both inter-subject and intra-subject forms of variability in fMRI response. We employ a Variational Bayes approximation to fit the model to the data. The resulting algorithm finds a functional parcellation of the individual brains along with a set of population-level clusters, establishing correspondence between these two levels. The model eliminates the need for spatial normalization while still enabling us to fuse data from several subjects. We demonstrate the application of our method on a visual fMRI study.McGovern Institute for Brain Research at MIT. Neurotechnology ProgramNational Science Foundation (U.S.) (CAREER Grant 0642971)National Institutes of Health (U.S.) (NIBIB NAMIC U54-EB005149)National Institutes of Health (U.S.) (NCRR NAC P41-RR13218

Identification and neuromodulation of brain states to promote recovery of consciousness

Experimental and clinical studies of consciousness identify brain states (i.e., transient, relevant features of the brain associated with the state of consciousness) in a non-systematic manner and largely independent from the research into the induction of state changes. In this narrative review with a focus on patients with a disorder of consciousness (DoC), we synthesize advances on the identification of brain states associated with consciousness in animal models and physiological (sleep), pharmacological (anesthesia) and pathological (DoC) states of altered consciousness in human. We show that in reduced consciousness the frequencies in which the brain operates are slowed down and that the pattern of functional communication in the brain is sparser, less efficient, and less complex. The results also highlight damaged resting state networks, in particular the default mode network, decreased connectivity in long-range connections and in the thalamocortical loops. Next, we show that therapeutic approaches to treat DoC, through pharmacology (e.g., amantadine, zolpidem), and (non-)invasive brain stimulation (e.g., transcranial current stimulation, deep brain stimulation) have shown some effectiveness to promote consciousness recovery. It seems that these deteriorated features of conscious brain states may improve in response to these neuromodulation approaches, yet, targeting often remains non-specific and does not always lead to (behavioral) improvements. Furthermore, in silico model-based approaches allow the development of personalized assessment of the effect of treatment on brain-wide dynamics. Although still in infancy, the fields of brain state identification and neuromodulation of brain states in relation to consciousness are showing fascinating developments that, when united, might propel the development of new and better targeted techniques for DoC. For example, brain states could be identified in a predictive setting, and the theoretical and empirical testing (i.e., in animals, under anesthesia and patients with a DoC) of neuromodulation techniques to promote consciousness could be investigated. This review further helps to identify where challenges and opportunities lay for the maturation of brain state research in the context of states of consciousness. Finally, it aids in recognizing possibilities and obstacles for the clinical translation of these diagnostic techniques and neuromodulation treatment options across both the multi-modal and multi-species approaches outlined throughout the review. This paper presents interactive figures, supported by the Live Paper initiative of the Human Brain Project, enabling the interaction with data and figures illustrating the concepts in the paper through EBRAINS (go to https://wiki.ebrains.eu/bin/view/Collabs/live-paper-states-altered-consciousness and get started with an EBRAINS account).NA is research fellow, OG is Research Associate, and SL is research director at FRS-FNRS. JA is postdoctoral fellow at the FWO. The study was further supported by the University and University Hospital of Liège, the BIAL Foundation, the Belgian National Funds for Scientific Research (FRS-FNRS), the European Union's Horizon 2020 Framework Programme for Research and Innovation under the Specific Grant Agreement No. 945539 (Human Brain Project SGA3), the FNRS PDR project (T.0134.21), the ERA-Net FLAG-ERA JTC2021 project ModelDXConsciousness (Human Brain Project Partnering Project), the fund Generet, the King Baudouin Foundation, the Télévie Foundation, the European Space Agency (ESA) and the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Programme, the Public Utility Foundation 'Université Européenne du Travail', "Fondazione Europea di Ricerca Biomedica", the BIAL Foundation, the Mind Science Foundation, the European Commission, the Fondation Leon Fredericq, the Mind-Care foundation, the DOCMA project (EU-H2020-MSCA–RISE–778234), the National Natural Science Foundation of China (Joint Research Project 81471100) and the European Foundation of Biomedical Research FERB Onlus

Diverse aging rates in ectothermic tetrapods provide insights for the evolution of aging and longevity

Comparative studies of mortality in the wild are necessary to understand the evolution of aging; yet, ectothermic tetrapods are underrepresented in this comparative landscape, despite their suitability for testing evolutionary hypotheses. We present a study of aging rates and longevity across wild tetrapod ectotherms, using data from 107 populations (77 species) of nonavian reptiles and amphibians. We test hypotheses of how thermoregulatory mode, environmental temperature, protective phenotypes, and pace of life history contribute to demographic aging. Controlling for phylogeny and body size, ectotherms display a higher diversity of aging rates compared with endotherms and include phylogenetically widespread evidence of negligible aging. Protective phenotypes and life-history strategies further explain macroevolutionary patterns of aging. Analyzing ectothermic tetrapods in a comparative context enhances our understanding of the evolution of aging.Animal science