The protracted Permo-Triassic crisis and multi-episode extinction around the Permian-Triassic boundary

The Permo-Triassic crisis was a major turning point in geological history. Following the end-Guadalupian extinction phase, the Palaeozoic biota underwent a steady decline through the Lopingian (Late Permian), resulting in their decimation at the level that is adopted as the Permian-Triassic boundary (PTB). This trend coincided with the greatest Phanerozoic regression. The extinction at the end of the Guadalupian and that marking the end of the Permian are therefore related. The subsequent recovery of the biota occupied the whole of the Early Triassic. Several phases of perturbations in [delta]13Ccarb occurred through a similar period, from the late Wuchiapingian to the end of the Early Triassic. Therefore, the Permian-Triassic crisis was protracted, and spanned Late Permian and Early Triassic time. The extinction associated with the PTB occurred in two episodes, the main act with a prelude and the epilogue. The prelude commenced prior to beds 25 and 26 at Meishan and coincided with the end-Permian regression. The main act itself happened in beds 25 and 26 at Meishan. The epilogue occurred in the late Griesbachian and coincided with the second volcanogenic layer (bed 28) at Meishan. The temporal distribution of these episodes constrains the interpretation of mechanisms responsible for the greatest Phanerozoic mass extinction, particularly the significance of a postulated bolide impact that to our view may have occurred about 50,000[no-break space]Myr after the prelude. The prolonged and multi-phase nature of the Permo-Triassic crisis favours the mechanisms of the Earth's intrinsic evolution rather than extraterrestrial catastrophe. The most significant regression in the Phanerozoic, the palaeomagnetic disturbance of the Permo-Triassic Mixed Superchron, widespread extensive volcanism, and other events, may all be related, through deep-seated processes that occurred during the integration of Pangea. These combined processes could be responsible for the profound changes in marine, terrestrial and atmospheric environments that resulted in the end-Permian mass extinction. Bolide impact is possible but is neither an adequate nor a necessary explanation for these changes.

Direct Thy-1/alphaVbeta3 integrin interaction mediates neuron to astrocyte communication.

Thy-1 is an abundant neuronal glycoprotein of poorly defined function. We recently provided evidence indicating that Thy-1 clusters a beta3-containing integrin in astrocytes to induce tyrosine phosphorylation, RhoA activation and the formation of focal adhesions and stress fibers. To date, the alpha subunit partner of beta3 integrin in DI TNC1 astrocytes is unknown. Similarly, the ability of neuronal, membrane-bound Thy-1 to trigger astrocyte signaling via integrin engagement remains speculation. Here, evidence that alphav forms an alphavbeta3 heterodimer in DI TNC1 astrocytes was obtained. In neuron-astrocyte association assays, the presence of either anti-alphav or anti-beta3 integrin antibodies reduced cell-cell interaction demonstrating the requirement of both integrin subunits for this association. Moreover, anti-Thy-1 antibodies blocked stimulation of astrocytes by neurons but not the binding of these two cell types. Thus, neuron-astrocyte association involved binding between molecular components in addition to the Thy-1-integrin; however, the signaling events leading to focal adhesion formation in astrocytes depended exclusively on the latter interaction. Additionally, wild-type (RLD) but not mutated (RLE) Thy-1 was shown to directly interact with alphavbeta3 integrin by Surface Plasmon Resonance analysis. This interaction was promoted by divalent cations and was species-independent. Together, these results demonstrate that the alphavbeta3 integrin heterodimer interacts directly with Thy-1 present on neuronal cells to stimulate astrocytes.

Quand la nourriture se fait parole: Scènes de communication alimentaire dans les récits médiévaux

Depuis les travaux d'Anita Guerreau-Jalabert sur la symbolique des triangles alimentaires dans le roman arthurien, personne ne saurait douter qu'au Moyen Âge la nourriture obéit à des codes. Une scène de table ne se réduit pas à une notation à valeur référentielle, à un éclat de vie aristocratique : intégrée au récit, la notation alimentaire est un élément constitutif du sens de l'oeuvre. Plus particulièrement, un plat peut servir de message adressé par un personnage à un autre. On s'est peu intéressé, si ce n'est pour la légende du coeur mangé, à ces passages où la nourriture vient compléter, voire se substituer à la parole. Des nouvelles de Boccace (traduites par Laurent de Premierfait) aux Cent Nouvelles nouvelles et au Pogge (traduit par Guillaume Tardif), mais aussi dans les romans (Ysaÿe le Triste, Le Cuer d'amours espris, Jehan de Saintré), les exemples ne manquent pas qui, à la fin du Moyen Âge, illustrent la variété des messages alimentaires. Si le plat qu'on sert peut être l'instrument d'une vengeance (le repas cannibale !), il est aussi et surtout utilisé comme moyen de séduction. Parfois, il s'agit d'un avertissement qui, par la transgression des codes, donne voix à la morale ; ailleurs, l'ironie s'en mêle, quand la nourriture traduit une attitude de dérision face au convive. Ce dernier procédé, plus ludique, ne se rencontre pas seulement - comme on pourrait s'y attendre - dans l'univers du fabliau ou de la nouvelle. Il traverse le Moyen Âge et, du XIIe au XVe siècle, prépare l'émergence du cuisinier dont l'art et les « joyeux dits » font un double du poète.

Speaking from the Inside: Challenges Faced by Communication Researchers Investigating Disease-Related Issues in a Hospital Setting.

This commentary came from within the framework of integrating the humanities in medicine and from accompanying research on disease-related issues by teams involving clinicians and researchers in medical humanities. The purpose is to reflect on the challenges faced by researchers when conducting emotionally laden research and on how they impact observations and subsequent research findings. This commentary is furthermore a call to action since it promotes the institutionalization of a supportive context for medical humanities researchers who have not been trained to cope with sensitive medical topics in research. To that end, concrete recommendations regarding training and supervision were formulated.

Communication with terminal cancer patients in palliative care: are there differences between nurses and physicians?

The aim of this study was to find whether there were interprofessional differences in specific elements of communication with terminal cancer patients and decision-making processes that concern such patients. Given that interdisciplinary team work is one of the basic values in palliative care, if there are conflicting views between professions on such important issues it is most important to know about these and to understand them. A questionnaire utilized in an earlier survey of palliative care physicians and addressing their attitudes to and beliefs about specific elements of communication and decision making was sent to a sample of palliative care nurses working in the same regions, i.e. the French-speaking parts of Switzerland, Belgium and France. After a second mailing (reminder), 135 of the 163 questionnaires (83%) were returned. There was general agreement between nurses and physicians on questions dealing with perceptions of patients' knowledge of their diagnosis and stage of disease, patients' need for information, "do not resuscitate" orders and ethical principles in decision-making processes. Statistically significant, but small, differences between professional groups were only observed for a minority of the questions. Interprofessional differences in specific elements of communication with terminal cancer patients and decision-making processes affecting these patients were not so marked that they could be called "conflicting interprofessional views."

Communication skills training in oncology: it works!

While the previous chapter by L. Fallowfield and V. Jenkins focuses on different communication skills training (CST) concepts currently being utilized, this chapter reviews and comments the scientific evidence of the impact of CST on improving communication skills. The aim of this chapter is not to provide a complete review of the evidence-this has already been done in systematic reviews-but to discuss the scientific evidence and reflect on the available results and relevant topics for further investigations.