Spectral properties of the largest asteroids associated with Taurid Complex

We obtained spectra of six of the largest asteroids (2201, 4183, 4486, 5143, 6063, and 269690) associated with Taurid complex. The observations were made with the IRTF telescope equipped with the spectro-imager SpeX. Their taxonomic classification is made using Bus-DeMeo taxonomy. The asteroid spectra are compared with the meteorite spectra from the Relab database. Mineralogical models were applied to determine their surface composition. All the spectral analysis is made in the context of the already published physical data. Five of the objects studied in this paper present spectral characteristics similar to the S taxonomic complex. The spectra of ordinary chondrites (spanning H, L, and LL subtypes) are the best matches for these asteroid spectra. {\bf The asteroid} (269690) 1996 RG3 presents a flat featureless spectrum which could be associated to a primitive C-type object. The increased reflectance above 2.1 microns constrains its geometrical albedo to a value around 0.03. While there is an important dynamical grouping among the Taurid Complex asteroids, the spectral data of the largest objects do not support a common cometary origin. Furthermore, there are significant variations between the spectra acquired until now.Comment: Accepted for publication in A&

Aortic injuries following stents in bariatric surgery: our experience

Background: Due to the large number of laparoscopic sleeve gastrectomy (LSG) performed over the last decade, the management of the leak following LSG has been increasingly reported. The role of covered Self Expandable Metal Stents (cSEMS) for the treatment of the leak is still controversial because of the poor tolerance and high risk of complications. Objectives: The aim of the present study was to analyze the foregut wall perforation and aorta injuries, a very rare but potentially fatal complication, related to the treatment of the leak following LSG using cSEMS. Setting: Private hospital, France. Methods: An audit was conducted in 2 French tertiary bariatric endoscopic centers focusing on aortic injuries after cSEMS use for leak. We examined and classified the initial procedure, leak characteristics, primary endoscopic treatment, and outcome of endoscopic complication for each eligible case. Results: A total of 5 patients were identified with foregut wall perforation and aorta injuries. All stents were deployed for staple line leak following LSG. The recorded mortality in case of esophageal-aortic injuries related to cSEMS use was 80%. Conclusion: cSEMS are potentially effective tools for the management of foregut leaks in bariatric surgery. The biggest challenges with this approach are stent migration and poor quality of life. Caution is required due to the risk of fatal complications such as foregut wall perforation and aortic injury

Near-infrared colors of minor planets recovered from VISTA - VHS survey (MOVIS)

The Sloan Digital Sky Survey (SDSS) and Wide-field Infrared Survey Explorer (WISE) provide information about the surface composition of about 100,000 minor planets. The resulting visible colors and albedos enabled us to group them in several major classes, which are a simplified view of the diversity shown by the few existing spectra. We performed a serendipitous search in VISTA-VHS observations using a pipeline developed to retrieve and process the data that corresponds to solar system objects (SSo). The colors and the magnitudes of the minor planets observed by the VISTA survey are compiled into three catalogs that are available online: the detections catalog (MOVIS-D), the magnitudes catalog (MOVIS-M), and the colors catalog (MOVIS-C). They were built using the third data release of the survey (VISTA VHS-DR3). A total of 39,947 objects were detected, including 52 NEAs, 325 Mars Crossers, 515 Hungaria asteroids, 38,428 main-belt asteroids, 146 Cybele asteroids, 147 Hilda asteroids, 270 Trojans, 13 comets, 12 Kuiper Belt objects and Neptune with its four satellites. The colors found for asteroids with known spectral properties reveal well-defined patterns corresponding to different mineralogies. The distributions of MOVIS-C data in color-color plots shows clusters identified with different taxonomic types. All the diagrams that use (Y-J) color separate the spectral classes more effectively than the (J-H) and (H-Ks) plots used until now: even for large color errors (<0.1), the plots (Y-J) vs (Y-Ks) and (Y-J) vs (J-Ks) provide the separation between S-complex and C-complex. The end members A, D, R, and V-types occupy well-defined regions.Comment: 19 pages, 16 figure

Nonlinear sigma model study of a frustrated spin ladder

A model of two-leg spin-S ladder with two additional frustrating diagonal exchange couplings J_{D}, J_{D}' is studied within the framework of the nonlinear sigma model approach. The phase diagram has a rich structure and contains 2S gapless phase boundaries which split off the boundary to the fully saturated ferromagnetic phase when J_{D} and J_{D}' become different. For the S=1/2 case, the phase boundaries are identified as separating two topologically distinct Haldane-type phases discussed recently by Kim et al. (cond-mat/9910023).Comment: revtex 4 pages, figures embedded (psfig

Quantum and classical criticalities in the frustrated two-leg Heisenberg ladder

This talk was about the frustration-induced criticality in the antiferromagnetic Heisenberg model on the two-leg ladder with exchange interactions along the chains, rungs, and diagonals, and also about the effect of thermal fluctuations on this criticlity. The method used is the bond mean-field theory, which is based on the Jordan-Wigner transformation in dimensions higher than one. In this paper, we will summarize the main results presented in this talk, and report on new results about the couplings and temperature dependences of the spin susceptibility.Comment: 6 pages, 4 figures, talk presented at the Theory Canada 3 conference in 2007, submitted to the Canadian Journal of Physic

Laparoscopic treatment of the hepatic cysts

Sectia Chirugie, Spitalul Municipal de Urgență, Moinesti, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Scop. Prezentarea avantajelor metodei laparoscopice în tratamentul chisturilor hepatice. Material şi metodă. Acest studiu prezintă experienţa noastră în tratamentul laparoscopic pentru 57 de cazuri de chisturi hepatice (42 de cazuri de chisturi seroase şi 15 cazuri de chisturi hidatice selectionate: univezicular, necomplicat, localizat în segmentele hepatice laparoscopice) reprezentând 1,89% din 3010 operații laparoscopice efectuate în perioada “2006-2010”. În 49 de cazuri (85,97%), chistul hepatic a fost unic. Indicația de tratament laparoscopic a fost pusă pe criterii clinice, biologice, imagistice și antecedentele bolnavului. În 45 de cazuri (78,95%), chisturile hepatice au fost localizate în lobul drept, dimensiunile fiind de 6-16 cm. Rezultate. Nu au fost înregistrate cazuri de conversie. Complicaţii postoperatorii au fost la 3 dintre pacienţi (5,26%): supurative - 2 abcese şi o fistula biliara. Durata medie de spitalizare a fost de 4,8 zile, iar perioada postoperatorie a fost fără recidive. La toate cazurile s-a practicat și colecistectomia. Pentru chisturile seroase a fost utilizataă tehnica Lin. Cele 12 cazuri de chisturi hidatice au fost rezolvate prin tehnica Lagrot (după inactivarea cu ser hiperton 20%), iar alte 3 cazuri prin chistectomie ideală. Rezultatele sunt argumente care ne determină să recomandăm această cale de abordare laparoscopică pentru tratamentul chistului hepatic. Pentru cele 15 cazuri profilaxia recidivelor postoperatorii a fost efectuată prin administrare de Albendazol. Concluzie. Chirurgia laparoscopică este o metodă sigură şi eficientă de tratare a pacienților cu chisturi hepatice seroase, iar pentru cazurile selectate de chisturi hidatice este o alternativă la chirurgia clasică. Aceasta respecta principiile chirurgiei deschise, beneficiind de avantajele chirurgiei minim invazive: confort postoperator, dureri minime, spitalizare scurtă, reinsertie socială rapidă.Aim. The evaluation of the advantages of the laparoscopic method in surgery of hepatic cysts. Material and method. This study presents our experience in laparoscopic solution of 57 cases of hepatic cysts (42 cases of serous cysts and 15 selected cases of hydatid cysts: univesicular, uncomplicated, localized in laparoscopic hepatic segments) presenting 1,89 % from one 3010 laparoscopic interventions performed between “2006-2010”. In 49 of cases (85,97%) the hepatic cyst was unique. Laparoscopic treatment of the hepatic cysts was attempted in all patients who had clinical, biological, imaging, and following the patient history. In 45 cases (78,95%) the hepatic cysts were located in the right lobe, with dimensions between 6-16 cm. Results. There weren’t any cases of conversion. In 3 of patients (5,26%) postoperative complications were recorded: suppurative – 2 abscesses and one biliary fistula. The mean hospital stay was 4,8 days, and the postoperative period to a year was without recurrences. In all cases, we performed the cholecystectomy, too. For the serious cysts was used the Lin technique was. In 12 cases of hydatid cysts were performed the Lagrot technique (after inactivation with hypertonic saline 20%), and the other 3 cases were performed by ideal cystectomy. The results are arguments for us to recommend this way of laparoscopic approach for the treatment of hepatic cyst. For the 15 cases, prophylaxis of postoperative recurrence was performed by administration of Albendazole. Conclusions. Laparoscopic surgery is a safe and effective method of treating patients with hepatic serous cysts, and for the selected cases of hydatids cysts, it is an alternative to classic surgery. It respects the principles of open surgery, with all the benefits of laparoscopic surgery: postoperative comfort, minimal pain, short hospital stay, rapid social reintegration

Cyclic Behaviour of Beam-Column Dowel Connection in Precast Elements

Disruption of structural continuity due to the inherent nature of the connections poses a challenge in seismic design of precast concrete structures. Seismic behaviour of portal frame systems typically used for industrial halls, is greatly influenced by the beam-column connections. Capacity design dictates that these connections should have an elastic behaviour under seismic horizontal actions to allow for the dissipation mechanisms to develop in the desired area, in this case the base of the columns. If this connection fails, the entire structure is compromised and may lead to a premature, partial, or even total collapse. Efforts are currently underway for a better understanding of the seismic response of precast structures (e.g. SAFECAST project). In this study, the test setups tried to replicate as closely as possible the behaviour of a commonly used beam-column assembly connected by steel dowels. The test specimens were designed as full scale precast concrete elements. This experimental campaign aimed to determine the failure mechanisms of the assemblies and to check if capacity design requirements were satisfied. Three setups have been tested according to the experimental protocol described in the SAFECAST report. The first test specimen was subjected to a unidirectional monotonic loading protocol with the aim of observing the maximum failure force and deformation. The resulted maximum displacement was used to determine the displacement step increment for the cyclic loading protocol of the following two specimens. In all the cases, failure has occurred in the region of the dowel connection. The failure mechanism was either because of dowel yielding, concrete spalling around the dowel, or a combination of both, consistent with results obtained by other researchers. The results have showed that the column was far from reaching its failure capacity and a premature failure has occurred in the connection area, which should be avoided in common practice. Marius G.L. Moldovan, Mihai Nedelcu and Zsolt Kovac

Ultimate performance of Quantum Well Infrared Photodetectors in the tunneling regime

Thanks to their wavelength diversity and to their excellent uniformity, Quantum Well Infrared Photodetectors (QWIP) emerge as potential candidates for astronomical or defense applications in the very long wavelength infrared (VLWIR) spectral domain. However, these applications deal with very low backgrounds and are very stringent on dark current requirements. In this paper, we present the full electro-optical characterization of a 15 micrometer QWIP, with emphasis on the dark current measurements. Data exhibit striking features, such as a plateau regime in the IV curves at low temperature (4 to 25 K). We show that present theories fail to describe this phenomenon and establish the need for a fully microscopic approach

Apparent close approaches between near-Earth asteroids and quasars. Precise astrometry and frame linking

Reproduced with permission. Copyright ESO. Article published by EDP Sciences and available at www.aanda.org.International audienceAims. We investigate the link between the International Celestial Reference Frame (ICRF) and the dynamical reference frame realized by the ephemerides of the Solar System bodies. Methods. We propose a procedure that implies a selection of events for asteroids with accurately determined orbits crossing the CCD field containing selected quasars. Using a Bulirsch-Stoer numerical integrator, we constructed 8-years (2010-2018) ephemerides for a set of 836 numbered near-Earth asteroids (NEAs). We searched for close encounters (within a typical field of view of groundbased telescopes) between our selected set of asteroids and quasars with high-accuracy astrometric positions extracted from the Large Quasars Astrometric Catalog (LQAC). Results. In the designated period (2010-2018), we found a number of 2924, 14 257, and 6972 close approaches (within 10') between asteroids with a minimum solar elongation value of 60◦and quasars from the ICRF-Ext2, the Very Large Baseline Array Calibrator Survey (VLBA-CS), and the Very Large Array (VLA), respectively. This large number of close encounters provides the observational basis needed to investigate the link between the dynamical reference frame and the ICRF