7,474 research outputs found
The double population of Chamaeleon I detected by Gaia DR2
Context. Chamaeleon I represents an ideal laboratory to study the cluster
formation in a low-mass environment. Recently, two sub clusters spatially
located in the northern and southern parts of Chamaeleon I were found with
different ages and radial velocities. Aims. In this letter we report new
insights into the structural properties, age, and distance of Chamaeleon I
based on the astrometric parameters from Gaia data-release 2 (DR2). Methods. We
identified 140 sources with a reliable counterpart in the Gaia DR2 archive. We
determined the median distance of the cluster using Gaia parallaxes and fitted
the distribution of parallaxes and proper motions assuming the presence of two
clusters. We derived the probability of each single source of belonging to the
northern or southern sub-clusters, and compared the HR diagram of the most
probable members to pre-main sequences isochrones. Results. The median distance
of Chamaeleon I is ~190 pc. This is about 20 pc larger than the value commonly
adopted in the literature. From a Kolmogorov-Smirnov test of the parallaxes and
proper-motion distributions we conclude that the northern and southern clusters
do not belong to the same parent population. The northern population has a
distance dN = 192.7+/-0.4 pc, while the southern one dS = 186.5+/-0.7 pc. The
two sub-clusters appear coeval, at variance with literature results, and most
of the sources are younger than 3 Myr. The northern cluster is more elongated
and extends towards the southern direction partially overlapping with the more
compact cluster located in the south. A hint of a relative rotation between the
two sub-clusters is also found.Comment: Letter accepted by A&
Controle de surtos de tristeza parasitária bovina.
No Brasil, os agentes causadores da Tristeza Parasitária Bovina (TPB) são dois protozoários (Babesia bovis e Babesia bigemina) e uma rickettsia (Anaplasma marginale), sendo que a doença pode ser causada por um, dois ou os três agentes juntos.bitstream/item/55746/1/CR26-02.pd
Controle/profilaxia da tristeza parasitária bovina.
O complexo de doenças que inclui a babesiose e a anaplasmose é conhecido, no Brasil, como Tristeza Parasitária Bovina (TPB).bitstream/item/55745/1/ct38-2001.pd
Profilaxia da tristeza parasitária bovina: por quê, quando e como fazer.
A tristeza parasitária bovina - TPB, Ă© um sĂ©rio entrave econĂ´mico na pecuária bovina, pois alĂ©m de apresentar altos Ăndices de mortalidade e morbidade, Ă© motivo de perdas de oportunidade e de mercado tambĂ©m, por parte dos produtores, de desestĂmulo em melhorar a produção.bitstream/item/55691/1/CR28-02.pd
An approach for the modeling of interface-body coupled nonlocal damage
Fiber Reinforced Plastic (FRP) can be used for strengthening concrete or masonry constructions.One of the main problem in the use of FRP is the possible detachment of the reinforcement from the supportmaterial. This paper deals with the modeling of the FRP-concrete or masonry damage interface, accounting forthe coupling occurring between the degradation of the cohesive material and the FRP detachment. To this end,a damage model is considered for the quasi-brittle material. In order to prevent strain localization and strongmesh sensitivity of the solution, an integral-type of nonlocal model based on the weighted spatial averaging of astrain-like quantity is developed. Regarding the interface, the damage is governed by the relative displacementoccurring at bond. A suitable interface model which accounts for the mode I, mode II and mixed mode ofdamage is developed. The coupling between the body damage and the interface damage is performedcomputing the body damage on the bond surface. Numerical examples are presented
Intrapancreatic accessory spleen false positive to 68Ga-Dotatoc: case report and literature review
Background: Intrapancreatic accessory spleen (IPAS) is an uncommon finding of pancreatic mass. Differential diagnosis with pancreatic tumor, especially with non-functional neuroendocrine tumor (NF-NET), may be very hard and sometimes it entails unnecessary surgery. A combination of CT scan, MRI, and nuclear medicine can confirm the diagnosis of IPAS. 68-Ga-Dotatoc PET/CT is the gold standard in NET diagnosis and it can allow to distinguish between IPAS and NET. Case presentation: A 69-year-old man was admitted to our hospital for an incidental nodule in the tail of the pancreas with focal uptake of 68-Ga-dotatate at PET/CT. NET was suspected and open distal splenopancreatectomy was performed. Pathologic examination revealed an IPAS. Conclusion: This is the second IPAS case in which a positive 68Ga-Dotatoc uptake led to a false diagnosis of pancreatic NET. Here is a proposal of a literature review
Age-dependence of electromagnetic power and heat deposition in near-surface tissues in emerging 5G bands
With the development of 5th generation (5G) mobile networks people of different ages will be exposed in the upper part of the microwave spectrum. From the perspective of non-ionizing radiation dosimetry, an accurate analysis of age-dependent electromagnetic power deposition and resulting heating is required. In this study, we evaluate the effect of age on exposure at 26 GHz and 60 GHz. A near-surface tissue model illuminated by a plane wave is used to asses the exposure considering both frequency-independent and frequency-dependent limits. The age-related variation of the skin thickness and tissue electromagnetic properties has been considered. Moreover, the blood flow decrease rate has been taken into account to assess the age-dependent heating. Our results demonstrate that the overall variations of the power density, specific absorption rate (SAR) and heating in the near-surface tissues are limited to about 10–15%. These variations are mainly due to the tissue permittivity and blood flow change with age. In contrast to the transmitted power density that increases with age, the peak SAR decreases at both frequencies. The peak steady-state heating increases from 5 to 70 years old by roughly 11% at 26 GHz and 13% at 60 GHz
An approach for the modeling of interface-body coupled nonlocal damage
Fiber Reinforced Plastic (FRP) can be used for strengthening concrete or masonry constructions. One of the main problem in the use of FRP is the possible detachment of the reinforcement from the support material. This paper deals with the modeling of the FRP-concrete or masonry damage interface, accounting for the coupling occurring between the degradation of the cohesive material and the FRP detachment. To this end, a damage model is considered for the quasi-brittle material. In order to prevent strain localization and strong mesh sensitivity of the solution, an integral-type of nonlocal model based on the weighted spatial averaging of a strain-like quantity is developed. Regarding the interface, the damage is governed by the relative displacement occurring at bond. A suitable interface model which accounts for the mode I, mode II and mixed mode of damage is developed. The coupling between the body damage and the interface damage is performed computing the body damage on the bond surface. Numerical examples are presented
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