Comments on QED with background electric fields

It is well known that there is a total cancellation of the \emph{factorizable} IR divergences in unitary interacting field theories, such as QED and quantum gravity. In this note we show that such a cancellation does not happen in QED with background electric fields which can produce pairs. There is no factorization of the IR divergences.Comment: 14 pages, 1 figur

Duality Invariant M-theory: Gauged supergravities and Scherk-Schwarz reductions

We consider the reduction of the duality invariant approach to M-theory by a U-duality group valued Scherk-Schwarz twist. The result is to produce potentials for gauged supergravities that are normally associated with non-geometric compactifications. The local symmetry reduces to gauge transformations with the gaugings exactly matching those of the embedding tensor approach to gauged supergravity. Importantly, this approach now includes a nontrivial dependence of the fields on the extra coordinates of the extended space.Comment: 22 pages Latex; v2: typos corrected and references adde

Loss of the sphingolipid desaturase DEGS1 causes hypomyelinating leukodystrophy.

Sphingolipid imbalance is the culprit in a variety of neurological diseases, some affecting the myelin sheath. We have used whole-exome sequencing in patients with undetermined leukoencephalopathies to uncover the endoplasmic reticulum lipid desaturase DEGS1 as the causative gene in 19 patients from 13 unrelated families. Shared features among the cases include severe motor arrest, early nystagmus, dystonia, spasticity, and profound failure to thrive. MRI showed hypomyelination, thinning of the corpus callosum, and progressive thalamic and cerebellar atrophy, suggesting a critical role of DEGS1 in myelin development and maintenance. This enzyme converts dihydroceramide (DhCer) into ceramide (Cer) in the final step of the de novo biosynthesis pathway. We detected a marked increase of the substrate DhCer and DhCer/Cer ratios in patients' fibroblasts and muscle. Further, we used a knockdown approach for disease modeling in Danio rerio, followed by a preclinical test with the first-line treatment for multiple sclerosis, fingolimod (FTY720, Gilenya). The enzymatic inhibition of Cer synthase by fingolimod, 1 step prior to DEGS1 in the pathway, reduced the critical DhCer/Cer imbalance and the severe locomotor disability, increasing the number of myelinating oligodendrocytes in a zebrafish model. These proof-of-concept results pave the way to clinical translation

INTCare: a knowledge discovery based intelligent decision support system for intensive care medicine

This paper introduces the INTCare system, an intelligent information system based on a completely automated Knowledge Discovery process and on the Agents paradigm. The system was designed to work in Hospital Intensive Care Units, supporting the physicians’ decisions by means of prognostic Data Mining models. In particular, these techniques were used to predict organ failure and mortality assessment. The main intention is to change the current reactive behaviour to a pro-active one, enhancing the quality of service. Current applications and experimentations, the functional and structural aspects, and technological options are presented

The 100th anniversary of the Federal Scientific Vegetable Center, the leader of Russian scientific vegetable growing

This year, the staff of the Federal Scientific Vegetable Center (FSVC) celebrates their 100th anniversary. Prof. S. I. Zhegalov was the recognized founder of the institution, which was reorganized from Gribovo Vegetable Experimental Station. Its team started with 14 employees, and the experimental crop area was slightly less than 4 hectares. In a short period of time (1920 to 1927), 74 cultivars of the most popular vegetable crops and a number of flower crop varieties were developed and improved. The second period of the Station’s development (1937 to 1966) was associated with the name of Acad. E. I. Ushakova. During this period, a pleiad of talented scientific plant breeders emerged and thrived: A. V. Alpatyev, S. P. Agapova, E. M. Popova, A. D. Plinka, Yu. A. Kobyakova, and others. In 1971, Gribovo Experimental Station was transformed into the All-Union Scientific Research Institute for Breeding and Seed Production of Vegetable Crops (VNIISSOK). The Institute was headed by Acad. P. F. Sokol. Under his leadership, capacity building and logistic support of the Institute were promoted: new facilities were built, and the experimental production network was expanded. Despite the difficulties associated with the reorganization and the financial and political situation in the country in 1992–2017, the staff achieved significant results during the years of the directorship by Acad. V. F. Pivovarov. New cultivars were developed to meet the demand; they occupied more than 50% of the crop area under vegetables across the country. Each year, the Institute produced 200–300 tons of elite and cultivar seeds. In 2017, the Institute was merged into the Federal Scientific Vege table Center as the keystone element. The Center also incorporated the All-Russian Research Institute of Vegetable Production and seven experiment stations throughout the Russian Federation. The Institute has been successfully cooperating with the N.I. Vavilov Institute of Plant Genetic Resources (VIR) for many years, exchanging germplasm materials and experience, and jointly developing vegetable cultivars

Theoretical Studies of CO Adsorption on Si(100)-2 × 1 Surface

Ab initio molecular orbital and density functional calculations have been carried out to investigate the adsorption of CO on the Si(100)-2 × 1 surface using the Si 9 H 12 and Si 13 H 20 cluster models of the surface. It was found that B3LYP/6-31G(d) is a reasonable level of theory for calculation of the geometries of the clusters and adsorbates, as well as energetics of the adsorbates of the CO/Si(100)-2 × 1 surface. The addition of a doubly contracted polarizarion d-function for the non-hydrogen atoms changes the calculated CO desorption energy by 1 kcal/mol. Increasing the size of the cluster from Si 9 H 12 to Si 13 H 20 , in general, increases the CO desorption energy by 1-2 kcal/mol, while it does not change the Si d -Si d , Si d -Si sub , and Si sub -Si sub bond distances, which suggests that the Si 9 H 12 cluster is a good model for the single-dimer cluster. Interaction of the CO molecule with the surface dramatically changes the Si d -Si d and Si d -Si sub bond distances corresponding to the silicon dimer on the surface and that between the first-and second-layer atoms, respectively. These results suggest that the geometry relaxation of the cluster upon interaction with gas molecules should be taken into account. Different adsorption geometries of CO on the silicon surface dimer have been studied. The adsorbed CO is most stable when bonded perpendicularly to the surface dimer with the C atom attached to one of the Si atoms. The calculated CO desorption energy at the B3LYP/6-311G(2d) level, 10.5 kcal/mol, is in good agreement with the experimental value, 11.4 kcal/mol. Vibrational frequencies of the different CO adsorption isomers have been analyzed. For the OC-normal adsorption process, an extensive search for its transition state failed to locate it; this suggests that the adsorption reaction is a nonactivated process with zero barrier

The effect of seed fractions and nutrition on the physiological changes and productivity of spring barley grown in the south of Uzbekistan

The influence of physiological changes on the grain yield of spring barley sown in optimal fractions and fed with mineral fertilizers in optimal norms in irrigated light gray-meadow soils with unfavorable conditions (subject to wind erosion) of the steppe zones of the Kashkadarya region was studied