scholarly journals A multi-chord stellar occultation by the large trans-Neptunian object (174567) Varda

2020 ◽  
Vol 643 ◽  
pp. A125 ◽  
Author(s):  
D. Souami ◽  
F. Braga-Ribas ◽  
B. Sicardy ◽  
B. Morgado ◽  
J. L. Ortiz ◽  
...  

Context. We present results from the first recorded stellar occultation by the large trans-Neptunian object (174567) Varda that was observed on September 10, 2018. Varda belongs to the high-inclination dynamically excited population, and has a satellite, Ilmarë, which is half the size of Varda. Aims. We determine the size and albedo of Varda and constrain its 3D shape and density. Methods. Thirteen different sites in the USA monitored the event, five of which detected an occultation by the main body. A best-fitting ellipse to the occultation chords provides the instantaneous limb of the body, from which the geometric albedo is computed. The size and shape of Varda are evaluated, and its bulk density is constrained using Varda’s mass as is known from previous works. Results. The best-fitting elliptical limb has semi-major (equatorial) axis of (383 ± 3) km and an apparent oblateness of 0.066 ± 0.047, corresponding to an apparent area-equivalent radius R′equiv = (370±7) km and geometric albedo pv = 0.099 ± 0.002 assuming a visual absolute magnitude HV = 3.81 ± 0.01. Using three possible rotational periods for the body (4.76, 5.91, and 7.87 h), we derive corresponding MacLaurin solutions. Furthermore, given the low-amplitude (0.06 ± 0.01) mag of the single-peaked rotational light-curve for the aforementioned periods, we consider the double periods. For the 5.91 h period (the most probable) and its double (11.82 h), we find bulk densities and true oblateness of ρ = (1.78 ± 0.06) g cm−3, ɛ = 0.235 ± 0.050, and ρ = (1.23 ± 0.04) g cm−3, ɛ = 0.080 ± 0.049. However, it must be noted that the other solutions cannot be excluded just yet.

2020 ◽  
Vol 15 (1) ◽  
pp. 107-122
Author(s):  
Boris Siljković ◽  
Nedeljka Dedović ◽  
Mihailo Dedović

Coronavirus crisis from 2020 in USA is a mixture of financial and economic crisis that happened in 1929-33 and 2007-09. The body of work is permeated with attitudes in regards to the coronavirus crisis from 2020 and previous financial crisis from 2007 to 2009 by the world renowned economists and Nobel Prize winners Joseph Stiglitz and Pol Krugman and former presidents of the Federal Reserve Bank Ben Bernanke, Alen Greenspan and others. The US Federal Reserve Bank opted with a relaxed approach to the monetary politics during the coronavirus crisis - a new-old approach that they picked many times before. Current coronavirus crisis measures to the monetary politics in USA on one side will contribute to deflation while on the other side it will grow consumption and production with delay until 2021. Because of the social distancing during the coronavirus crisis, new problems emerged like the economic distancing of the USA economy, enormous debts to FRB on all levels because of emission of securities, bonds, mortgage and other form of securities which caused growth of activity of the top notch monetary institution in USA.


2020 ◽  
Vol 639 ◽  
pp. A134 ◽  
Author(s):  
J. L. Ortiz ◽  
P. Santos-Sanz ◽  
B. Sicardy ◽  
G. Benedetti-Rossi ◽  
R. Duffard ◽  
...  

Context. Deriving physical properties of trans-Neptunian objects is important for the understanding of our Solar System. This requires observational efforts and the development of techniques suitable for these studies. Aims. Our aim is to characterize the large trans-Neptunian object (TNO) 2002 TC302. Methods. Stellar occultations offer unique opportunities to determine key physical properties of TNOs. On 28 January 2018, 2002 TC302 occulted a mv ~ 15.3 star with designation 593-005847 in the UCAC4 stellar catalog, corresponding to Gaia source 130957813463146112. Twelve positive occultation chords were obtained from Italy, France, Slovenia, and Switzerland. Also, four negative detections were obtained near the north and south limbs. This represents the best observed stellar occultation by a TNO other than Pluto in terms of the number of chords published thus far. From the 12 chords, an accurate elliptical fit to the instantaneous projection of the body can be obtained that is compatible with the near misses. Results. The resulting ellipse has major and minor axes of 543 ± 18 km and 460 ± 11 km, respectively, with a position angle of 3 ± 1 degrees for the minor axis. This information, combined with rotational light curves obtained with the 1.5 m telescope at Sierra Nevada Observatory and the 1.23 m telescope at Calar Alto observatory, allows us to derive possible three-dimensional shapes and density estimations for the body based on hydrostatic equilibrium assumptions. The effective diameter in equivalent area is around 84 km smaller than the radiometrically derived diameter using thermal data from Herschel and Spitzer Space Telescopes. This might indicate the existence of an unresolved satellite of up to ~300 km in diameter, which is required to account for all the thermal flux, although the occultation and thermal diameters are compatible within their error bars given the considerable uncertainty of the thermal results. The existence of a potential satellite also appears to be consistent with other ground-based data presented here. From the effective occultation diameter combined with absolute magnitude measurements we derive a geometric albedo of 0.147 ± 0.005, which would be somewhat smaller if 2002 TC302 has a satellite. The best occultation light curves do not show any signs of ring features or any signatures of a global atmosphere.


Author(s):  
Sunandar Macpal ◽  
Fathianabilla Azhar

The aims of this paper is to explain the use of high heels as an agency for a woman's body. Agency context refers to pain in the body but pain is perceived as something positive. In this paper, the method used is a literature review by reviewing writings related to the use of high heels. The findings in this paper that women experience body image disturbance or anxiety because they feel themselves are not beautiful or not attractive. The use of high heels, makes women more attractive and more confident, on the other hand the use of high heels actually makes women feel pain and discomfort. However, for the achievement of beauty standards, women voluntarily allow their bodies to experience pain. However, the agency's willingness to beauty standards here is meaningless without filtering and directly accepted. Instead women keep negotiating with themselves so as to make a decision why use high heels.


2018 ◽  
Vol 8 (4) ◽  
pp. 28-33
Author(s):  
Mao Nguyen Van ◽  
Thao Le Thi Thu

Background: In practice it was difficult or impossible to have a correct diagnosis for the lymphoid proliferation lesions based on only H.E standard histopathology. In addition to histopathology, the application of immunohistochemistry was indispensable for the definitive diagnosis of the malignant or benign tumours and the origin of the tumour cells as well. Objectives: 1. To describe the gross and microscopic features of the suspected lesions of lymphoma; 2. To asses the expression of some immunologic markers for the diagnosis and classification of the suspected lesions of lymphoma. Materials and Method: Cross-sectional research on 81 patients diagnosed by histopathology as lymphomas or suspected lesions of lymphoma, following with immunohistopathology staining of 6 main markers including LCA, CD3, CD20, Bcl2, CD30 and AE1/3. Results: The most site was lymph node 58.1% which appeared at cervical region 72.3%, then the stomach 14.9% and small intestine 12.4%. The other sites in the body were met with lower frequency. Histopathologically, the most type of the lesions was atypical hyperplasia of the lymphoid tissue suspecting the lymphomas 49.4%, lymphomas 34.5%, the other diagnoses were lower including inflammation, poor differentiation carcinoam not excluding the lymphomas, lymphomas differentiating with poor differentiation carcinomas. Immunohistochemistry showed that, LCA, CD3, CD20, Bcl2, CD30 and AE1/3 were all positive depending on such type of tumours. The real lymphomas were 48/81 cases (59.3%), benign ones 35.8% and poor differentiated carcinomas 4.9%. Conclusion: Immunohistochemistry with 6 markers could help to diagnose correctly as benign or malignant lesions, classify and determine the origin of the tumour cells as lymphocytes or epithelial cells diagnosed by histopathology as lymphomas or suspected lesions of lymphomas. Key words: histopathology, immunohistochemistry, lymphomas, poor differentiated carcinomas, hyperplasia, atypicality


Author(s):  
Zoran Vrucinic

The future of medicine belongs to immunology and alergology. I tried to not be too wide in description, but on the other hand to mention the most important concepts of alergology to make access to these diseases more understandable, logical and more useful for our patients, that without complex pathophysiology and mechanism of immune reaction,we gain some basic insight into immunological principles. The name allergy to medicine was introduced by Pirquet in 1906, and is of Greek origin (allos-other + ergon-act; different reaction), essentially representing the reaction of an organism to a substance that has already been in contact with it, and manifested as a specific response thatmanifests as either a heightened reaction, a hypersensitivity, or as a reduced reaction immunity. Synonyms for hypersensitivity are: altered reactivity, reaction, hypersensitivity. The word sensitization comes from the Latin (sensibilitas, atis, f.), which means sensibility,sensitivity, and has retained that meaning in medical vocabulary, while in immunology and allergology this term implies the creation of hypersensitivity to an antigen. Antigen comes from the Greek words, anti-anti + genos-genus, the opposite, anti-substance substance that causes the body to produce antibodies.


Author(s):  
Stefan Bittmann

Since the outbreak near a fish market in Wuhan, China, in December 2019, researchers have been searching for an effective therapy to control the spreading of the new coronavirus SARS-CoV-2 and inhibit COVID-19 infection. Many countries like Italy, Spain, and the USA were ambushed by this viral agent. To date, more than 2.5 million people were infected with SARS-CoV-2. There is no clear answer, why SARS-CoV-2 infects so many people so fast. To date of April 2020, no effective drug has been found to treat this new severe viral infection. There are many therapy options under review and clinical trials were initiated to get clearer information, what kind of drug can help in this devastating and serious situation. The world has no time.


Author(s):  
Oscar Gutiérrez-Bolívar ◽  
Oscar Gutiérrez-Bolívar ◽  
Pedro Fernández Carrasco ◽  
Pedro Fernández Carrasco

The opening of relationships between United States and Cuba could be a drive for a huge increase in the affluence of tourism to Cuba and especially to the coast areas. Cuba has been for many years an important tourist destination for people from many countries, but almost forbidden for US citizens. The proximity of the USA, its amount of population as well as their great acquisition power will increase in a very substantial way the demand for accommodation and other uses in the proximity of the coasts. There will be a need to implement a package of measures that reduce the impact of such sudden increase in the coastal line. On the other hand that augment in tourism could be an opportunity to improve the standard of life of Cubans. The consideration of different possibilities of such development, the analysis of the damages that each one could cause as well as the measures that could avoid, ameliorate or compensate such effects are the goals that are going to be presented in this paper.


Author(s):  
Isabella Image

This chapter discusses Hilary’s dichotomous body–soul anthropology. Although past scholars have tried to categorize Hilary as ‘Platonic’ or ‘Stoic’, these categories do not fully summarize fourth-century thought, not least because two-way as well as three-way expressions of the human person are also found in Scripture. The influence of Origen is demonstrated with particular reference to the commentary on Ps. 118.73, informed by parallels in Ambrose and the Palestinian Catena. As a result, it is possible to ascribe differences between Hilary’s commentaries to the fact that one is more reliant on Origen than the other. Nevertheless, Hilary’s position always seems to be that the body and soul should be at harmony until the body takes on the spiritual nature of the soul.


Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.


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