[en] Keloids in black patients frequently recur after surgical excision alone. Surgical excision followed by iridium 192 brachytherapy was used to treat 783 keloids in 502 black patients in Martinique. The surgical and radiation therapy technique is described in detail. The recurrence rate was 21%, in keeping with earlier studies. Factors influencing the risk of recurrence were the size of the keloid before treatment and complications occurring during or immediately after surgical excision. The data reported here suggest that surgical excision followed by brachytherapy is currently the best available method for treating keloids. (authors)

[en] In the course of chlorophyll investigations by vibrational spectroscopy, the magnesium complex Mg(NH₃)₆Cl₂ was studied by infrared and Raman techniques and two porphyrin molecules, by resonance Raman scattering. For the hexa-ammine magnesium chloride, all vibrations predicted by group theory (internal and external vibrations) were observed; ligand orientations gives- the complex ion a D_3d point group symmetry. Five isotopically substituted compounds were studied and a force constant calculation showed that the Mg-N bond has a value higher than most of those calculated for other divalent hexa-ammine metal ions. Two porphyrins were studied: the prophine and the meso-porphyrin IX dimethyl-ester.' Unexpected variations of vibrational bands intensities and depolarization ratios were recorded on changing the excitation wavelength. Three resonance levels were tentatively attributed to the presence of pure electronic transitions in band IV of the absorption spectra of these compounds. (author)

[en] Calcifications of a sub-ependymal giant cell astrocytoma were not recognized by MR. Therefore a CT scan is recommended before stereotaxic needle biopsy in order to avoid intracerebral hemorrhage. (authors)

[en] As required by the energy transition law for green growth, RTE has prepared and published this Annual Electricity Report to provide a general overview of developments affecting the power system over the previous year. The 2015 edition of the Electricity Report shows that the effects of the energy transition are becoming visible in France: After holding at the same level for three years, power demand rose slightly in a more buoyant economic climate. Adjusted for weather impacts, power consumption in mainland France, excluding the energy sector, increased by 0.5% to 476.3 TWh. Growth was stronger in some industrial sectors, like car manufacturing and metallurgy, while others saw declines. Together with improved energy efficiency, this growth was reflected in consumption by households and SMEs. The weather in France was warm on the whole in 2015, though not as mild as in 2014. Gross consumption in mainland France thus rose 2.2% year-on-year. n Renewable generation capacity continued to grow: the country is now home to more than 10 GW of wind capacity and 6 GW of solar capacity. Wind power covered about 4.5% of domestic demand and solar power 1.6%. Taken together with hydropower, which made a moderate contribution over the year, renewable energy sources covered 18.7% of power demand. The six remaining 250 MW coal-fired plants were taken out of service during the year. All in all, nearly 4 GW of coal-fired generation capacity was decommissioned in France between 2013 and 2015. Thanks to the new method for optimising cross-border exchange capacity (flow-based coupling) and the strengthening of the interconnection between France and Spain, France's exchange balance with neighbouring countries reached 61.7 TWh. This is the third time it has risen above 60 TWh in the past ten years. New demand-side flexibility options continue to be developed. Thanks to tenders on the Balancing Mechanism, RTE had up to 1,900 MW of load shedding capacity ready for activation in 2015, up from 1,200 MW in 2014. Lastly, RTE continues to work to ensure that power is available to all parts of France: it is adapting the grid to accommodate renewable energy sources and enable the pooling of energy produced within the new territorial organisation

[en] Two months ago, following North Korea's Unha-3 launch, which put a small satellite into orbit, this publication discussed the possibility of a third North Korean nuclear test. As expected, Pyongyang remained true to its traditional policy of provocation. With carefully calculated timing, it carried out a third nuclear test on 12 February, just hours after Barack Obama's State of the Union address, four days before former leader Kim Jong-il's birthday, and on the eve of the investiture of the new South Korean president on the 25 February. Moreover, the North Korean regime is billing this test as a riposte to the new round of sanctions adopted on by the Security Council on 22 January following the Unha-3 launch in December, as it announced on the 24 January. Yet, aside from the associated posturing, this test confirms, if more confirmation were needed, the North's determination to develop an effective nuclear deterrent. The use of the term miniaturisation is certainly in part a propaganda exercise (can actual miniaturisation be achieved after three nuclear tests, one or two of whose success is highly doubtful?). Nonetheless, North Korea has clearly made progress in developing a nuclear weapon and an intercontinental ballistic missile derived from the Taepodong-2, and has promised to carry out further ballistic launches. Without a doubt, even if the North is a long way from possessing what we would consider an operational nuclear capability, its determination has helped it to make progress, and the country shows no signs of wanting to change course. In light of this fact, what can the international community do beyond existing and future sanctions regimes? Doubtless very little. China, which continues to support the North and which has been known in the past to exert influence on Pyongyang, has expressed its firm displeasure as to the North's activities but appears to have no leverage over Kim Jong-un. The Six-Party talks have little chance of being revived, as North Korean nuclear disarmament is no longer on the table, and the February 2007 agreement has failed to get out of the starting blocks, as has the framework agreed in September 2005 which established the preliminary steps for disarmament and which envisaged, among other elements, the normalisation of diplomatic relations with the United States. Indeed, all the negotiations opened with the North since the mid-1990's have come to nothing, and the United States is in less of a position than ever to undertake a constructive bilateral dialogue that produces tangible results. For its part, the European Union can do no more than adopt further rounds of sanctions. The resilience of the North Korea leadership, heading up a devastated country, in the face of the international community does not cease to amaze. Maintaining China's support is clearly a factor in this respect, since the huge amounts of Chinese aid assures the regime's survival. In the current climate of straining relations between Beijing and Pyongyang, is it not time to change tack with China with regard to North Korea and develop a fresh approach? (author)

[en] The First Committee of the 67. General Assembly of the United Nations closed its discussion on 7 November. It included its traditional dose of disarmament resolutions: fifty-nine were adopted in all, twenty-nine of which required a vote, with the others being passed by consensus. Fifteen of them were specifically about the multiple facets of nuclear disarmament, but contained nothing new on the subject. However, one of these resolutions is particularly worthy of note given its subject and its novelty. This year the Committee adopted a resolution (A/C.1/67/L.19) that decides to convene, on 26 September 2013, a high-level meeting of all States, organised by the president of the General Assembly with the aim of furthering nuclear disarmament. The resolution, sponsored by Indonesia with the support of the Non-Aligned Movement, was passed with 165 votes in favour, none against and 5 abstentions (USA, France, Israel, the UK, and Ukraine). Such a decision is not just a formal exercise, and translates in concrete terms the mounting pressure on the nuclear powers. It establishes a more restrictive diplomatic timetable, whose legitimacy directly derives from the recommendation inscribed in the Millennium Summit Declaration, following the three-day Millennium Summit in September 2000 that brought together heads of State and government. In addition, the resolution is based on another First Committee resolution (A/C.1/67/L.9), which itself is not new, and which deals with the follow-up to the advisory opinion of the International Court of Justice of July 1996 on the legality of the threat or use of nuclear weapons, or, more simply put, on deterrence. Even whilst admitting that the threat or use of nuclear weapons could be legal 'in an extreme circumstance of self-defence, in which the very survival of a State would be at stake', the Court unanimously acknowledged the existence of 'a general obligation of States to pursue in good faith, and bring to a conclusion, negotiations leading to nuclear disarmament in all its aspects under strict and effective international control'. Resolution L.9, passed with 123 votes in favour, 23 against, and 25 abstentions, thus calls on all States to initiate negotiations on the prohibition and elimination of nuclear weapons. Naturally, the meeting on 26 September 2013 will not witness the beginning of such negotiations, which besides do not fall within the General Assembly's mandate. Yet it will be enlightening to see the substance of the debates and the conclusions arising from them, which will not be able to be limited to merely general recommendations. It will also be interesting to observe the concrete repercussions of the meeting in the fields of disarmament and non-proliferation. We may wager that the Conference on Disarmament, paralysed since 1997, but which remains the sole organ of multilateral negotiation in this field, will once again be stigmatised. Will it continue to be the sounding board for differences of opinion of its member States on nuclear and space issues? Or will we one day witness its revival and the exhumation of its 1995 mandate to negotiate a Cut-Off Treaty? If the meeting in September 2013 were to have that kind of effect, it would be most welcome. (author)

[en] Heat transport in a plasma with a magnetic perturbation of amplitude b and a transverse diffusion of typical scale δ is investigated. On Tore Supra, such a perturbation is induced at the edge by the Ergodic Divertor. Classically, the heat transport is expected to be diffusive, but the experimental evidence does not support such a model. The main experimental features are temperature modulations and a transport barrier which allows no loss of confinement in the core plasma. An analysis of both temperature filed nd magnetic perturbation indicates clearly delimited regions of strong and weak transport that are related to the loss of memory on a filed line due to the transverse diffusion. Furthermore, the perturbation is strongly space-dependent. This implies non local transport and a region (separatrix) in which the Chirikov parameter is less that one. This analysis leads to a 1D analytical model which recovers modulations. A transport barrier is also expected, assuming a dissymmetrical transport process around the separatrix. A mapping transport code has also been developed which takes the basic features of the ergodic divertor into account. Both experimental results, modulations, and a transport barrier are recovered. The latter depends on the ratio b/δ, but occurs without any assumption of dissymmetrical transport. For the same ratio b/δ as Tore Supra, the core confinement, as with the experiment, is not affected. A lower ratio leads to a loss of confinement, while a larger value produces improved confinement. The barrier can be attributed to non diffusive transport out of islands located around the separatrix. The trapping mechanisms in these islands, combined with some small level of transverse transport, reduce the probability for particles to flow back to the perturbed region. A dissymmetrical process then appears and allows for a transport barrier. (author)

[en] The density profile of fusion plasmas can be investigated by the reflectometry diagnostic. The measurement principle is based on the radar techniques which calculate the phase shift of a millimeter wave propagating into the plasma and reflected at a cut-off layer. We have tried to describe the density fluctuation effects upon detected signal to understand the disturbing mechanisms which prevent, sometime, the measurement of the phase. First, we have tried to understand the mechanisms and the origin of the turbulence which is responsible for phase disturbance. We point out the role of collisionality ν^* and plasma radiation (with the Hugill normalised parameter H) which control the instability. We also demonstrate that the phase delay of the probing wave is very sensitive to the plasma MHD phenomena and is less affected by the micro-turbulence. The second part of this work is the development and the use of a new heterodyne reflectometer. This new diagnostic uses O-mode beam polarisation and works on the 26-36 GHz frequency range. It launches simultaneously into the plasma two frequencies separated by 320 MHz and we can study them separately or with the amplitude modulation technique. It possesses a better sensitivity than the previous homodyne reflectometer and a higher frequency agility. Its heterodyne detection allows us to separate phase and amplitude informations from the detected signal. (author)

[en] The reducing coupling reactions of ketones in diols and olefins are generally carried out with titanium or samarium compounds. In this work uranium complexes have been used. They have allowed to study the chemical reaction mechanism. This thesis is divided into three parts: 1) the reduction mechanism of uranium tetrachloride by cyclic voltametry has been studied at first. It has been shown that this reduction is followed by a transfer reaction of chlorides between the reduced specie of the higher electronic density and UCl . 2) In the second part is described: the synthesis, the crystal structure, the reactivity of the chemical agents, the stereochemistry of diols and alkenes formation and the pinacolisation reaction catalysis. 3) In the last part, the limits of the McMurry reaction are given by the study of the aromatic ketones pinacolisation reaction by-products. The obtained results show that the complexes of the metals which present a high reducing and oxo-philic (Ti, Sm, U..) character react in a similar way with the carbonyl compounds. If the uranium compounds are less used than those of the titanium in the field of the organic synthesis applications, they are precious auxiliaries and excellent models for reactions mechanisms study and for the synthesis methods optimization. (O.M.)

[en] The aim of this work is to propose a new frame to study turbulent transport in plasmas. In order to avoid the restraint of scale separability the forcing by flux is used. A critical one-dimension self-organized cellular model is developed. In keeping with experience the average transport can be described by means of diffusion and convection terms whereas the local transport could not. The instability due to interchanging process is thoroughly studied and some simplified equations are derived. The proposed model agrees with the following experimental results: the relative fluctuations of density are maximized on the edge, the profile shows an exponential behaviour and the amplitude of density fluctuations depends on ionization source strongly. (A.C.)