Nuclear scission and quantum localization.

We examine nuclear scission within a fully quantum-mechanical microscopic framework, focusing on the nonlocal aspects of the theory. Using (240)Pu hot fission as an example, we discuss the identification of the fragments and the calculation of their kinetic, excitation, and interaction energies, through the localization of the orbital wave functions. We show that the disentanglement of the fragment wave functions is essential to the quantum-mechanical definition of scission and the calculation of physical observables. Finally, we discuss the fragments' prescission excitation mechanisms and give a nonadiabatic description of their evolution beyond scission.

[New treatment strategies for hypertension. Which guidelines and how to apply them]. / Nouvelles stratégies thérapeutiques dans l'hypertension artérielle. Quelles recommandations et comment les appliquer?

The diagnosis of hypertension by blood pressure measurements taken in the physician's office has been called into question by several studies. The onset of cardiovascular events appears to correlate better with ambulatory blood pressure measurements than with those taken during consultation (either "white coat" or masked hypertension). While the US, WHO, French and European guidelines diverge as to the specific antihypertensive drug among the seven classes available should be chosen for first-line treatment, there is a consensus for specific choices as a function of the type of hypertension. In any case, most treatment trials show that more than two antihypertensive drugs are often necessary. Treatment can thus begin with two drugs. The optimal target blood pressure is defined by the US JNC7 according to whether the patient also has diabetes or a nephropathy. When hypertension is uncomplicated, the target level is 140/90 mmHg. In the case of diabetes or nephropathy, it is 130/80 mmHg. In all cases, diet and exercise changes are also necessary and it is essential that patients understand them if they are to comply with them. Diastolic blood pressure remains the most important figure for those younger than 50 years, but afterwards, systolic pressure is more relevant. Aortic pressure may be more closely associated with cardiovascular risk than the blood pressure measured at the brachial artery. The concept of comprehensive management is radically modifying our behavior : the hypertensive patient is now above all a patient at high cardiovascular risk and the treatments to consider must not be limited to antihypertensive drugs but must also include treatment of other cardiovascular risk factors (aspirin, statins, smoking cessation, etc.).

[Thermal anomaly in waters of the Gulf of Marseilles during the summer of 1999. A partial explanation of the mortality of certain fixed invertebrates?]. / Anomalie thermique dans les eaux du golfe de Marseille durant l'été 1999. Une explication partielle de la mortalité d'invertébrés fixés?

During summer 1999, a massive mortality of attached benthic invertebrates was reported at several points along the French Mediterranean coast, east of the Rhône River. Such a wide geographical extension suggested the occurrence of a climatic anomaly as a direct or an indirect cause of this phenomenon. The systematic observations of surface water temperature (1 record/30 min) and vertical thermal structure from 0 to 55 m (semi-monthly frequency) performed by the service of observation of centre d'océanologie de Marseille since 1994 in the Gulf of Marseilles (northwestern Mediterranean) compared with historical data obtained for the summer periods (June till October) indicates a thermal anomaly during summer 1999. Although the surface temperatures do not strictly show exceptional values, the stability during long periods of high temperatures (24.1 degrees C +/- 0.5 in September, n = 1,018) and the thermal structure of the water column are remarkable. The vertical temperature profiles of 1999 reflect a general warming of 2-3 degrees C in the water layer overlying the thermocline, accompanied by its deepening (up to 30-40 m). This situation can be explained by the scarcity of NW winds with a marked drop of their relative frequency during July and October 1999 (13-27% versus 42%, mean value calculated from the previous 12 years) and the short duration of these windy periods (between 30 min and 5 h as a mean). Parallel to this, a large number of no wind registrations (125-250 h/month as a mean) were observed during this period. A similar thermal stratification, of lesser amplitude, associated with comparable meteorological conditions was also observed in 1997. The hypothesis that this summer 1999 temperature anomaly could constitute a partial explanation for the recorded massive mortality is discussed.