Affine spherical homogeneous spaces with good quotient by a maximal unipotent subgroup

For an affine spherical homogeneous space G/H of a connected semisimple algebraic group G, we consider the factorization morphism by the action on G/H of a maximal unipotent subgroup of G. We prove that this morphism is equidimensional if and only if the weight semigroup of G/H satisfies some simple condition.Comment: v2: title and abstract changed; v3: 16 pages, minor correction

RadioAstron probes the ultra-fine spatial structure in the H2_2O maser emission in the star forming region W49N

H$_2$O maser emission associated with the massive star formation region W49N were observed with the Space-VLBI mission RadioAstron. The procedure for processing of the maser spectral line data obtained in the RadioAstron observations is described. Ultra-fine spatial structures in the maser emission were detected on space-ground baselines of up to 9.6 Earth diameters. The correlated flux densities of these features range from 0.1% to 0.6% of the total flux density. These low values of correlated flux density are probably due to turbulence either in the maser itself or in the interstellar medium.Comment: Accepted for publication in Advances in Space Researc

Endoluminal prolonged endoscopic vacuum-assisted closure therapy in the treatment of patients with perforation of the thoracic segment of the esophagus

Departament Chirurgie №1, Departament Endoscopie, Spitalul Aleksandrovsky, St. Petersburg, Federația Rusă, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Perforația esofagului este un eveniment care pune în pericol viața. Tratamentul chirurgical presupune operații de urgență și acestea adesea sunt asociate cu un risc ridicat de complicații postoperatorii. In cazul asocierii mediastinitei mortalitatea este inalta - 40-80%. Principalele cauze ale letalitatii sunt mediastinita, empiemul pleural, complicatile septice. Căutarea unor metode eficiente de corectare a complicațiilor postoperatorii este o problemă stringentă. Material şi metodă: Sub supravegherea noastră în perioada aprilie-mai 2019, au fost trei pacienți cu perforații al segmentului toracic al esofagului.Tuturor pacientilor a fost aplicat tratamentul endoscopic vacuum-asistat (E-VAC). Pentru crearea presiunii negative intraluminale în zona insuficientii suturilor si la nivelul perforării esofagului, a fost utilizată o constructie constând din sonda nasogastrica cu un burete poliuretanic fixat în portiunea distală. Poziționarea acestei construcții în esofag a fost efectuată sub control endoscopic; pacientul a fost supus unei anestezii intravenoase. Nivelul țintă al presiunii negative a fost de 100-150 mmHg. Buretele este înlocuit la fiecare trei-cinci zile. Rezultate: În urma tratamentul endoscopic vacuum-asistat a avut loc inchidera completa a defectului esofagian, manifestările mediastinitei si empiemului pleural au fost cupate. Durata tratamentului spitalicesc a fost în medie 25 de zile. Concluzii: În cazul insuficientei suturilor esofagului operat sau a perforatilor esofagiene, pentruprevenirea patrunderii in mediastin și cavitatea pleurală a sucurilor digestive și a alimentelor; crearea condiților favorabile pentru stimularea proceselor de reparație în zona afectata tratamentul endoscopic vacuum-asistat poate fi recomandată pentru utilizarea pe scară largă.Introduction: Perforation of the esophagus is a life-threatening situation. Surgical treatment demand immediate surgery and is often accompanied by the high risk of the postoperative complications. Mortality, according to different authors, exceeds 80%. The main causes of death are progressive mediastinitis, empyema and sepsis. The searching of effective ways of correcting postoperative complication are a current problem. Material and methods: Under our supervision from April to May 2019, there were three patients with perforations of the thoracic segment of the esophagus. All patients received endoscopic vacuum-assisted treatment (e-vac). For the creation of negative intraluminal pressure at the level of perforation of the esophagus, a construction consisting of nasogastric probe with a polyurethane sponge was used. The positioning of this construction in the esophagus was carried out under endoscopic control; the patient underwent intravenous anesthesia. The target level of negative pressure was 100-150 mmHg. Spongу is replaced every three to five days. Results: Following the endoscopic vacuum-assisted treatment, the complete closure of the esophageal defect took place; the manifestations of mediastinitis and pleural empyema were cupped. The duration of hospital treatment was on average 25 days. Conclusions: in case of insufficiency of the suture of the operated oesophagus or esophageal perforations, for prevention of penetration into the mediastinum and pleural cavity of digestive juices and food, creating favorable conditions for stimulating the repair processes in the affected area, endoscopic vacuum-assisted treatment can be recommended for widespread use

Renormalization of the Fayet-Iliopoulos Term in Softly Broken SUSY Gauge Theories

It is shown that renormalization of the Fayet-Iliopoulos term in a softly broken SUSY gauge theory, in full analogy with all the other soft terms renormalizations, is completely defined in a rigid or an unbroken theory. However, contrary to the other soft renormalizations, there is no simple differential operator that acts on the renormalization functions of a rigid theory and allows one to get the renormalization of the F-I term. One needs an analysis of the superfield diagrams and some additional diagram calculations in components. The method is illustrated by the four loop calculation of some part of renormalization proportional to the soft scalar masses and the soft triple couplings.Comment: Latex2e, 14 pages, uses axodraw.sty. References adde

FeCr₂S₄ in magnetic fields: possible evidence for a multiferroic ground state.

We report on neutron diffraction, thermal expansion, magnetostriction, dielectric, and specific heat measurements on polycrystalline FeCr2S4 in external magnetic fields. The ferrimagnetic ordering temperatures TC ≈ 170 K and the transition at TOO ≈ 10 K, which has been associated with orbital ordering, are only weakly shifted in magnetic fields up to 9 T. The cubic lattice parameter is found to decrease when entering the state below TOO. The magnetic moments of the Cr- and Fe-ions are reduced from the spin-only values throughout the magnetically ordered regime, but approach the spin-only values for fields >5.5 T. Thermal expansion in magnetic fields and magnetostriction experiments indicate a contraction of the sample below about 60 K. Below TOO this contraction is followed by a moderate expansion of the sample for fields larger than ~4.5 T. The transition at TOO is accompanied by an anomaly in the dielectric constant. The dielectric constant depends on both the strength and orientation of the external magnetic field with respect to the applied electric field for T < TOO. A linear correlation of the magnetic-field-induced change of the dielectric constant and the magnetic-field dependent magnetization is observed. This behaviour is consistent with the existence of a ferroelectric polarization and a multiferroic ground state below 10 K