On tadpoles and vacuum redefinitions in String Theory

Tadpoles accompany, in one form or another, all attempts to realize supersymmetry breaking in String Theory, making the present constructions at best incomplete. Whereas these tadpoles are typically large, a closer look at the problem from a perturbative viewpoint has the potential of illuminating at least some of its qualitative features in String Theory. A possible scheme to this effect was proposed long ago by Fischler and Susskind, but incorporating background redefinitions in string amplitudes in a systematic fashion has long proved very difficult. In the first part of this paper, drawing from field theory examples, we thus begin to explore what one can learn by working perturbatively in a ``wrong'' vacuum. While unnatural in Field Theory, this procedure presents evident advantages in String Theory, whose definition in curved backgrounds is mostly beyond reach at the present time. At the field theory level, we also identify and characterize some special choices of vacua where tadpole resummations terminate after a few contributions. In the second part we present a notable example where vacuum redefinitions can be dealt with to some extent at the full string level, providing some evidence for a new link between IIB and 0B orientifolds. We finally show that NS-NS tadpoles do not manifest themselves to lowest order in certain classes of string constructions with broken supersymmetry and parallel branes, including brane-antibrane pairs and brane supersymmetry breaking models, that therefore have UV finite threshold corrections at one loop.Comment: 51 pages, LaTeX, 7 eps figures. Typos corrected, refs added. Final version to appear in Nucl. Phys. B. Thanks to W. Mueck for very interesting correspondence. v3 was accidentally in draft forma

Potential Cost Savings from Generic Medicines - Protecting the Prescribed Minimum Benefits

Background: South Africa has followed a pro-generic policy since the introduction of the National Drug Policy in 1996. The selection processes inthe public and private sectors have, however, remained largely disconnected, and at times contradictory. Medicines provided outside of hospitals accounted for 17% of medical aid spend in 2006, up 8.8% from the previous year. Of particular concern to funders has been the expenditure on the 27 chronic conditions listed as Prescribed Minimum Benefits. The Medical Schemes Act (No 131 of 1998) provides for the definition of Prescribed Minimum Benefits, which stipulate a package of services or care a medical scheme must provide for in its benefit design. There is pressure to reconsider these requirements in order to increase the affordability of medical scheme coverage. This study assessed the potential savings that would be achievable by substituting generics for brand name (originator) medicines listed in the chronic disease algorithms set out by the Council for Medical Schemes (CMS).Methods: All medicines listed in the 25 chronic diseases algorithms made available by the CMS were identified. Brand and generic versions wereidentified in the Monthly Index of Medical Specialties (MIMS, May 2006). Single exit prices inclusive of value added tax were obtained from the website of the Pharmaceutical Blue Book and the cost per defined daily dose for one month was then calculated. Cost differentials, where available, were then identified for each medicine listed in the algorithms. Cost differentials for medicines within each algorithm were presented as the median of the difference between brand and generic medicines listed for that algorithm, and also as the median of differences between generic medicines for the same condition.Results: Three of the algorithms (diabetes insipidus, haemophilia and hypothyroidism) list medicines for which no generic equivalent was available at the time of the study. The median cost differential between brand and generic equivalents for the remaining 22 chronic conditions ranged from 19.5% (for type 1 diabetes mellitus) to 97% (for Addison’s disease). Across the entire chronic disease algorithm set, 80 medicines with generic equivalents were listed for 22 conditions. The median cost differential between brand and generic versions of these 80 medicines was 49.9% (interquartile range 32.0 to 78.5%). Of all generic medicines identified, 67.5% were more than 40% cheaper, per defined daily dose (DDD) per month, than the branded version. In 16 medicines the cost differentials between generic versions were 1% or less. Some correlation between the number of generics and the size of the cost differential was apparent (correlation coefficient 0.49). There were examples of high-cost differentials in highly competitive areas of the market.Conclusions: An argument could be made for more closely aligning the process of developing the National Essential Drugs List and the development of the CMS algorithms. By being more specific about which medicines should be covered, needless expenditure on “me-too” agents of doubtful additional benefit could be avoided. Where clinically warranted, appropriate choices could be provided. Finality in respect of the pricing of medicines needs to be achieved. This applies not only to the dispensing fee but also to the proposed benchmarking process and the proposed differential between brand and generic medicines

Structural validation of a realistic wing structure: the RIBES test article

Several experimental test cases are available in literature to study and validate fluid structure interaction methods. They, however, focus the attention mainly on replicating typical cruising aerodynamic conditions forcing the adoption of fully steel made models able to operate with the high loads generated in high speed facilities. This translates in a complete loss of similitude with typical realistic aeronautical wing structures configurations. To reverse this trend, and to better study the aerolastic mechanism from a structural point of view, an aeroelastic measurement campaign was carried within the EU RIBES project. A half wing model for wind tunnel tests was designed and manufactured replicating a typical metallic wing box structure, producing a database of loads, pressure, stress and deformation measurements. In this paper the design, manufacturing and validation activities performed within the RIBES project are described, with a focus on the structural behavior of the test article. All experimental data and numerical models are made freely available to the scientific community

IN MEMORY OF GAETANO FICHERA

Sono raccolte in questo Volume alcune delle conferenze svolte durante il 3^o Simposio Internazionale Problemi Attuali dell’Analisi e della Fisica Matematica, dedicato alla memoria di Gaetano Fichera, che si è svolto a Taormina dal 29 Giugno al 1 Luglio, 2006. Hanno partecipato al Simposio più di cinquanta studiosi italiani e stranieri (cfr. Elenco dei Partecipanti). Sono state svolte trentasette relazioni.Sono raccolte in questo Volume alcune delle conferenze svolte durante il3o Simposio Internazionale Problemi Attuali dell’Analisi e della Fisica Matematica, dedicato alla memoria di Gaetano Fichera, che si è svolto a Taormina dal 29 Giugno al 1 Luglio, 2006. Hanno partecipato al Simposio più di cinquanta studiosi italiani e stranieri (cfr. Elenco dei Partecipanti). Sono state svolte trentasette relazioni

A comparative analysis of Pancoast tumour resection performed via video-assisted thoracic surgery versus standard open approaches

OBJECTIVES: The aim of the present paper was to conduct a comparative analysis of outcomes after thoracoscopic resection versus standard thoracotomy approach in the treatment of Pancoast tumours. METHODS: All consecutive patients with Pancoast tumours undergoing surgical treatment from March 2000 to November 2012 were enrolled. Patients were divided into 2 groups according to whether a thoracoscopic or standard thoracotomy approach was adopted. In addition to morbidity and mortality, (i) intensity of pain; (ii) respiratory function focusing on the postoperative value and its variation with respect to the predicted value (Delta); (iii) analgesic consumption at different times during the postoperative course; and (iiii) survival rate were recorded in both groups and the inter-group differences were statistically compared. RESULTS: Of the 45 enrolled patients, 34 (75%) were included in the final analysis (18 in the thoracoscopic group and 16 in the standard group). Eleven (25%) patients were excluded because they (i) were unfit for surgery after induction therapy (n = 4); (ii) refused the operation (n = 1) or (iii) had unexpected pleural involvement (n = 6). Compared with the standard group, in the thoracoscopic group we observed less pain (P = 0.01), better recovery of forced vital capacity (P = 0.01) and forced expiratory value in 1 s (P < 0.001), and a reduction in opioid (P = 0.01) and analgesic consumption (P = 0.02). The median survival for all patients was 15 months. Patients with N0/N1 disease had better median survival than N2 patients (47 vs 9 months; P = 0.009). One local recurrence in the standard group was observed 1 year after operation, whereas 2 local recurrences, 1 in the thoracoscopic group and another in the standard group, were registered 2 years after the operation (P = 1.0). Finally, 4 (22%) extrathoracic metastases in the thoracoscopic group and 5 (31%) in the standard group (P = 0.8) were found over the 2 years following the procedure. CONCLUSIONS: In the management of Pancoast tumours, a thoracoscopic approach is safe and may be an effective adjunct to standard surgical resection in selected cases. Such an approach enabled surgeons to explore the pleural cavity and avoid exploratory thoracotomy in cases of unexpected pleural involvement

Responses of four winegrape varieties to managed water stress and partial defoliation in an arid environment

In viticulture, the imposition of managed water deficits is a strategy which has been used to increase both water use efficiency and winemaking quality in arid climates. Partial defoliation early in the season is another innovative practice that may also be used as an aid in regulating yield components and improving fruit quality. The aim of this work was to evaluate the effects of managed water stress and early season partial defoliation on crop yield and quality in two autochthonous (‘Frappato’ and ‘Nero d’Avola’) and two international varieties (‘Syrah’ and ‘Cabernet Sauvignon’) growing in an arid environment. The four treatments were: (i) no leaf removal, un-irrigated, (ii) no leaf removal, irrigated at 30 % of estimated crop evapotranspiration (ETc), (iii) partial leaf removal, un-irrigated, and (iv) partial leaf removal, irrigated at 30 % of estimated ETc. The results confirm the effectiveness of partial defoliation in yield management which leads to smaller clusters. Managed water stress was also an effective strategy for reducing berry size, improving must quality and generally enhancing anthocyanin accumulation.

Gadolinium decreases inflammation related to myocardial ischemia and reperfusion injury

<p>Abstract</p> <p>Background</p> <p>The lanthanide cation, gadolinium (GdCl₃) protects the myocardium against infarction following ischemia and reperfusion. Neutrophils and macrophages are the main leukocytes responsible for infarct expansion after reperfusion. GdCl₃interferes with macrophage and neutrophil function in the liver by decreasing macrophage secretion of inflammatory cytokines and neutrophil infiltration. We hypothesized that GdCl₃protects against ischemia and reperfusion injury by decreasing inflammation. We determined the impact of GdCl₃treatment for reperfusion injury on 1) circulating monoctye and neutrophil counts, 2) secretion of inflammatory cytokines, and 3) influx of monocytes and neutrophils into the myocardium.</p> <p>Methods</p> <p>Rats (n = 3-6/gp) were treated with saline or GdCl₃(20 μmol/kg) 15 min prior to a 30 min period of regional ischemia and 120 min reperfusion. Sham rats were not subject to ischemia. Blood was collected either after 30 min ischemia or 120 min reperfusion and hearts were harvested at 120 min reperfusion for tissue analysis. Blood was analyzed for leukocytes counts and cytokines. Tissue was analyzed for cytokines and markers of neutrophil and monocyte infiltration by measuring myeloperoxidase (MPO) and α-naphthyl acetate esterase (ANAE).</p> <p>Results</p> <p>GdCl₃did not affect the number of circulating neutrophils prior to ischemia. Two hours reperfusion resulted in a 2- and 3- fold increase in circulating monocytes and neutrophils, respectively. GdCl₃decreased the number of circulating monocytes and neutrophils during reperfusion to levels below those present prior to ischemia. Furthermore, after 120 min of reperfusion, GdCl₃decreased ANAE and MPO activity in the myocardium by 1.9-fold and 6.5-fold respectively. GdCl₃decreased MPO activity to levels below those measured in the Sham group. Serum levels of the major neutrophil chemoattractant cytokine, IL-8 were increased from pre-ischemic levels during ischemia and reperfusion in both control and GdCl₃treated rats. Likewise, IL-8 levels increased throughout the 3 hour time period in the Sham group. There was no difference in IL-8 detected in the myocardium after 120 min reperfusion between groups. In contrast, after 120 min reperfusion GdCl₃decreased the myocardial tissue levels of macrophage secreted cytokines, GM-CSF and IL-1.</p> <p>Conclusion</p> <p>GdCl₃treatment prior to ischemia and reperfusion injury decreased circulating monocytes and neutrophils, macrophage secreted cytokines, and leukocyte infiltration into injured myocardium. These results suggest GdCl₃decreased monoctye and neutrophil migration and activation and may be a novel treatment for inflammation during ischemia and reperfusion.</p

On the Absorption of X-rays in the Interstellar Medium

We present an improved model for the absorption of X-rays in the ISM intended for use with data from future X-ray missions with larger effective areas and increased energy resolution such as Chandra and XMM, in the energy range above 100eV. Compared to previous work, our formalism includes recent updates to the photoionization cross section and revised abundances of the interstellar medium, as well as a treatment of interstellar grains and the H2molecule. We review the theoretical and observational motivations behind these updates and provide a subroutine for the X-ray spectral analysis program XSPEC that incorporates our model.Comment: ApJ, in press, for associated software see http://astro.uni-tuebingen.de/nh

Comparing extrapolations of the coronal magnetic field structure at 2.5 solar radii with multi-viewpoint coronagraphic observations

The magnetic field shapes the structure of the solar corona but we still know little about the interrelationships between the coronal magnetic field configurations and the resulting quasi-stationary structures observed in coronagraphic images (as streamers, plumes, coronal holes). One way to obtain information on the large-scale structure of the coronal magnetic field is to extrapolate it from photospheric data and compare the results with coronagraphic images. Our aim is to verify if this comparison can be a fast method to check systematically the reliability of the many methods available to reconstruct the coronal magnetic field. Coronal fields are usually extrapolated from photospheric measurements typically in a region close to the central meridian on the solar disk and then compared with coronagraphic images at the limbs, acquired at least 7 days before or after to account for solar rotation, implicitly assuming that no significant changes occurred in the corona during that period. In this work, we combine images from three coronagraphs (SOHO/LASCO-C2 and the two STEREO/SECCHI-COR1) observing the Sun from different viewing angles to build Carrington maps covering the entire corona to reduce the effect of temporal evolution to ~ 5 days. We then compare the position of the observed streamers in these Carrington maps with that of the neutral lines obtained from four different magnetic field extrapolations, to evaluate the performances of the latter in the solar corona. Our results show that the location of coronal streamers can provide important indications to discriminate between different magnetic field extrapolations.Comment: Accepted by A&A the 20th of May, 201