A large topographic feature on the surface of the trans-Neptunian object (307261) 2002 MS4_4 measured from stellar occultations

This work aims at constraining the size, shape, and geometric albedo of the dwarf planet candidate 2002 MS4 through the analysis of nine stellar occultation events. Using multichord detection, we also studied the object's topography by analyzing the obtained limb and the residuals between observed chords and the best-fitted ellipse. We predicted and organized the observational campaigns of nine stellar occultations by 2002 MS4 between 2019 and 2022, resulting in two single-chord events, four double-chord detections, and three events with three to up to sixty-one positive chords. Using 13 selected chords from the 8 August 2020 event, we determined the global elliptical limb of 2002 MS4. The best-fitted ellipse, combined with the object's rotational information from the literature, constrains the object's size, shape, and albedo. Additionally, we developed a new method to characterize topography features on the object's limb. The global limb has a semi-major axis of 412 $\pm$ 10 km, a semi-minor axis of 385 $\pm$ 17 km, and the position angle of the minor axis is 121 $^\circ$ $\pm$ 16$^\circ$. From this instantaneous limb, we obtained 2002 MS4's geometric albedo and the projected area-equivalent diameter. Significant deviations from the fitted ellipse in the northernmost limb are detected from multiple sites highlighting three distinct topographic features: one 11 km depth depression followed by a 25$^{+4}_{-5}$ km height elevation next to a crater-like depression with an extension of 322 $\pm$ 39 km and 45.1 $\pm$ 1.5 km deep. Our results present an object that is $\approx$138 km smaller in diameter than derived from thermal data, possibly indicating the presence of a so-far unknown satellite. However, within the error bars, the geometric albedo in the V-band agrees with the results published in the literature, even with the radiometric-derived albedo

Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

The size, shape, density and ring of the dwarf planet Haumea from a stellar occultation

Haumea—one of the four known trans-Neptunian dwarf planets—is a very elongated and rapidly rotating body1, 2, 3. In contrast to other dwarf planets4, 5, 6, its size, shape, albedo and density are not well constrained. The Centaur Chariklo was the first body other than a giant planet known to have a ring system7, and the Centaur Chiron was later found to possess something similar to Chariklo’s rings8, 9. Here we report observations from multiple Earth-based observatories of Haumea passing in front of a distant star (a multi-chord stellar occultation). Secondary events observed around the main body of Haumea are consistent with the presence of a ring with an opacity of 0.5, width of 70 kilometres and radius of about 2,287 kilometres. The ring is coplanar with both Haumea’s equator and the orbit of its satellite Hi’iaka. The radius of the ring places it close to the 3:1 mean-motion resonance with Haumea’s spin period—that is, Haumea rotates three times on its axis in the time that a ring particle completes one revolution. The occultation by the main body provides an instantaneous elliptical projected shape with axes of about 1,704 kilometres and 1,138 kilometres. Combined with rotational light curves, the occultation constrains the three-dimensional orientation of Haumea and its triaxial shape, which is inconsistent with a homogeneous body in hydrostatic equilibrium. Haumea’s largest axis is at least 2,322 kilometres, larger than previously thought, implying an upper limit for its density of 1,885 kilograms per cubic metre and a geometric albedo of 0.51, both smaller than previous estimates1, 10, 11. In addition, this estimate of the density of Haumea is closer to that of Pluto than are previous estimates, in line with expectations. No global nitrogen- or methane-dominated atmosphere was detected.J.L.O. acknowledges funding from Spanish and Andalusian grants MINECO AYA-2014-56637-C2-1-P and J. A. 2012-FQM1776 as well as FEDER funds. Part of the research leading to these results received funding from the European Union’s Horizon 2020 Research and Innovation Programme, under grant agreement no. 687378. B.S. acknowledges support from the French grants ‘Beyond Neptune’ ANR-08-BLAN-0177 and ‘Beyond Neptune II’ ANR-11-IS56-0002. Part of the research leading to these results has received funding from the European Research Council under the European Community’s H2020 (2014-2020/ERC grant agreement no. 669416 ‘Lucky Star’). A.P. and R.S. have been supported by the grant LP2012-31 of the Hungarian Academy of Sciences. All of the Hungarian contributors acknowledge the partial support from K-125015 grant of the National Research, Development and Innovation Office (NKFIH). G.B.-R., F.B.-R., F.L.R., R.V.-M., J.I.B.C., M.A., A.R.G.-J. and B.E.M. acknowledge support from CAPES, CNPq and FAPERJ. J.C.G. acknowledges funding from AYA2015-63939-C2-2-P and from the Generalitat Valenciana PROMETEOII/2014/057. K.H. and P.P. were supported by the project RVO:67985815. The Astronomical Observatory of the Autonomous Region of the Aosta Valley acknowledges a Shoemaker NEO Grant 2013 from The Planetary Society. We acknowledge funds from a 2016 ‘Research and Education’ grant from Fondazione CRT. We also acknowledge the Slovakian project ITMS no. 26220120029

Immune modulatory and antioxidant effects of melatonin in experimental periodontitis in rats

PubMed: 23146767Melatonin is an important antioxidant, and through its anti-inflammatory effects it can control immune responses, oxidative stress, and defense cell infiltration. Periodontitis is a disease of the oral cavity and the generation of free radicals is an important consideration in this disease. Therefore, we examined the immune-modulatory and antioxidant roles of melatonin in the treatment of periodontitis. In all, 30 male Wistar rats were randomly divided into three groups: the control group, the periodontitis-induced (PED) group, and the periodontitis+melatonin treatment (MEL+PED) group. The control group received no treatment, whereas periodontitis was induced in both the PED and the MEL+PED groups, with the MEL+PED group being treated with systemic melatonin. For the periodontitis-induced groups, the rats' mandibular first molar teeth were ligatured (3-0 cotton) in a submarginal position for 4 weeks, and then the ligature was removed. After removal of the ligature, melatonin was administered only to the MEL+PED group (an ip dose of 10 mg/kg body wt for 15 days at 11:00 PM each day). In the histological examination, the MEL+PED group, which received the melatonin, showed reduced inflammatory cytokines (IL-1?, from 97.47 to 84.24 pg/ml; TNF-?, from 0.22530 to 0.22519 pg/ml), regulated oxidative stress parameters (MDA, from 41,458 to 30,708 nmol/g; GSH, from 18,166 to 25,858 nmol/mg), and less periodontal tissue destruction (CEJ-PL, lingual, from 244.54 to 140.57 ?m; buccal, from 235.6 to 158.93 ?m; and CEJ-BC, lingual, from 383.65 to 287.76 ?m; buccal, from 391.92 to 296.12 ?m). From these findings we conclude that, even when periodontitis was induced, melatonin reduced the oxidative damage in the rats' periodontal tissue by inhibiting the inflammatory effects and by restoring the antioxidants. © 2012 Elsevier Inc.Atatürk ÜniversitesiThe authors are very grateful to Dr. Bunyami Unal for invaluable scientific advice and support. This study was supported by the Scientific Research Fund of Atatürk University

Temperature changes in superficial and deep tissue layers with respect to time of cold gel pack application in dogs

Despite the widespread clinical use of cryotherapy, there is only limited and inconsistent data on application times. The aim of this study was to determine the changes in tissue temperature and the duration of this effect. In this experimental study, five adult dogs were used. A cold gel pack (10 x 20 cm) was applied transversally over the right leg femoral region

DNA barcoding of twelve shrimp species (Crustacea: Decapoda) from Turkish seas reveals cryptic diversity

DNA barcoding is a useful tool for the identification and potential discovery of new species. In this study, DNA barcoding was employed by sequencing the mitochondrial cytochrome oxidase subunit I gene (COI) to characterize the genetic diversity of 12 shrimp species inhabiting Turkish coastal waters and, when possible, to compare with the genetic data available from different parts of the Mediterranean and eastern Atlantic. This study also comprises the first DNA barcoding study performed in the Turkish Seas using COI. A total of 40 shrimp specimens were collected and analyzed from 9 sites. Generally, the barcoding gap criterion was successful in identifying species; hence, COI appeared to be a good marker of choice for DNA barcoding in this group. Out of the 12 species investigated, five were barcoded for the first time. For six species, two intraspecific clades were retrieved after the analyses. The results suggest the presence of cryptic diversity in a genetically understudied marine area, the Turkish coastal waters, and further investigation of these species using population genetics, taxonomic approaches and nuclear markers is likely to result in designation of new species

Clinical, molecular, radiological investigations in patients with SURF1 mutations and muscle biopsy findings

21st International Congress of the World-Muscle-Society -- OCT 04-08, 2016 -- Granada, SPAINWOS: 000384790100309World Muscle So