Frequency stability measurements of ultra-stable BVA Oscillators

International audienceThe aim of this paper is to present the performances of the instruments developed for the measurement of 5 MHz ultra-stable resonators, before and after being integrated in an oscillator and then measured as an oscillator. The chosen resonator has an estimated stability of several 10-14. Intrinsic noise floor of these benches are about 7 to 8.10-15

The timing of death in patients with tuberculosis who die during anti-tuberculosis treatment in Andhra Pradesh, South India

Background: India has 2.0 million estimated tuberculosis (TB) cases per annum with an estimated 280,000 TBrelated deaths per year. Understanding when in the course of TB treatment patients die is important for determining the type of intervention to be offered and crucially when this intervention should be given. The objectives of the current study were to determine in a large cohort of TB patients in India:- i) treatment outcomes including the number who died while on treatment, ii) the month of death and iii) characteristics associated with “early” death, occurring in the initial 8 weeks of treatment. Methods: This was a retrospective study in 16 selected Designated Microscopy Centres (DMCs) in Hyderabad, Krishna and Adilabad districts of Andhra Pradesh, South India. A review was performed of treatment cards and medical records of all TB patients (adults and children) registered and placed on standardized anti-tuberculosis treatment from January 2005 to September 2009. Results: There were 8,240 TB patients (5183 males) of whom 492 (6%) were known to have died during treatment. Case-fatality was higher in those previously treated (12%) and lower in those with extra-pulmonary TB (2%). There was an even distribution of deaths during anti-tuberculosis treatment, with 28% of all patients dying in the first 8 weeks of treatment. Increasing age and new as compared to recurrent TB disease were significantly associated with “early death”. Conclusion: In this large cohort of TB patients, deaths occurred with an even frequency throughout anti-TB treatment. Reasons may relate to i) the treatment of the disease itself, raising concerns about drug adherence, quality of anti-tuberculosis drugs or the presence of undetected drug resistance and ii) co-morbidities, such as HIV/ AIDS and diabetes mellitus, which are known to influence mortality. More research in this area from prospective and retrospective studies is needed

Electromagnetic Dissociation as a Tool for Nuclear Structure and Astrophysics

Coulomb dissociation is an especially simple and important reaction mechanism. Since the perturbation due to the electric field of the (target) nucleus is exactly known, firm conclusions can be drawn from such measurements. Electromagnetic matrixelements and astrophysical S-factors for radiative capture processes can be extracted from experiments. We describe the basic elements of the theory of nonrelativistic and relativistic electromagnetic excitation with heavy ions. This is contrasted to electromagnetic excitation with leptons (electrons), with their small electric charge and the absence of strong interactions. We discuss various approaches to the study of higher order electromagnetic effects and how these effects depend on the basic parameters of the experiment. The dissociation of neutron halo nuclei is studied in a zero range model using analytical methods. We also review ways how to treat nuclear interactions, show their characteristics and how to avoid them (as far as possible). We review the experimental results from a theoretical point of view. Of special interest for nuclear structure physics is the appearence of low lying electric dipole strength in neutron rich nuclei. Applications of Coulomb dissociation to some selected radiative capture reactions relevant for nuclear astrophysics are discussed. The Coulomb dissociation of 8B is relevant for the solar neutrino problem. The potential of the method especially for future investigations of (medium) heavy exotic nuclei for nuclear structure and astrophysics is explored. We conclude that the Coulomb dissociation mechanism is theoretically well understood, the potential difficulties are identified and can be taken care of. Many interesting experiments have been done in this field and many more are expected in the future.Comment: review article accepted for publication in "Prog. in Part. and Nucl. Physics", 75 pages, 31 figure

Em-‘powering' niche innovations: learning from cycling inequalities

This paper aims to situate power in ‘niche innovations’ through an investigation of cycling inequalities in the city of Birmingham. Much research has focused on the sustainability and innovation potential of cycling. However, debates usually revolve around the power relations between cycling and the dominant automobility regime, thus ignoring the possible inequalities embedded within niches. This paper aims to contribute to such analyses by unfolding the multiple inequalities and relations of exclusion that can be embedded in the practice of cycling. Drawing on Mobilities research for the EPSRC Liveable Cities programme, it focuses on the car-dependent city of Birmingham, in order to explore cycling as a practice with various socio-material, infrastructural, political and economic entanglements that can embed, reproduce or generate new socio-spatial inequalities, processes of gentrification and immobilities. Through such analysis, this paper aims to situate power in examining niche innovations. However, it also aims to underline that understanding and addressing such inequalities are central for not only locating cycling in the centre of developing a more sustainable mobility future, but also enabling a more sustainable future for cycling itself

Marxisme

125p.;20c

Wheat gluten network formation during shear mixing

National audienc

A parametric and microstructural study of the formation of gluten network in mixed flourewater batter

Axe 2 Structuration sous contraintes des agropolymères et réactivité des poudres Contact: fax: +33 (4) 9961 3076. E-mail address: [email protected] audienceThe mechanism of gluten network development is still unclear and remains difficult to study since gluten network formation in bread dough is a rather quick process. In order to better characterize this dynamic event, we slowed down its kinetics by increasing the dough water content. During mixing, performed with a planetary mixer at variable mixing speeds and flour/water ratios, the torque was recorded. Common flours from wheat cultivars Orvantis, Caphorn and Isengrain, similar in composition and Farinograph parameters, were studied. At low flour/water ratios, mixing curves showed a lag phase preceding the increase of torque to the maximum dough resistance peak. Lag phase duration increased with dough water content, whereas increasing the mixing speed decreased time for optimal dough development. For the three flours studied, the time for optimal dough development was found to be related to the instantaneous power delivered to the dough during the lag phase and not to the specific mechanical energy required to get the maximum torque. Besides the effect of this common control parameter, flours exhibited wide variations in response to a given instantaneous power delivery, with dough development times varying by a factor of 6. Orvantis was always faster to develop than Caphorn or Isengrain. Optical microscopy observations of batters, using a protein stain, showed that gluten network development resulted from two successive phenomena. The first one involved the formation of microscopic gluten lumps, and the second one consisted of the development of gluten strands starting, at the end of the lag phase. The very different behaviours observed for the three flours are discussed in relation to the batter structure and to the colloidal properties of Gluten protein