Thermal analysis of space debris for infrared based active debris removal

In space, visual based relative navigation systems suffer from dynamic illumination conditions of the target (Eclipse conditions, solar glare...etc.) where most of these issues are addressed by advanced mission planning techniques. However, such planning would not be always feasible or even if it is, it would not be straightforward for Active Debris Removal (ADR) missions. On the other hand, using an infrared based system would overcome this problem, if a guideline to predict infrared signature of space debris based on the target thermal profile could be provided for algorithm design and testing. Spacecraft thermal design is unique to every platform. This means every ADR target will have a different infrared signature which changes over time not just only due to orbital dynamics but also due to its thermal surface coatings. In order to provide a space debris infrared signature guideline for most of the possible ADR targets, we introduce an innovative grouping system for thermal surface coatings based on their behaviour in Space environment. Through the use of this grouping system, we propose a space debris infrared signature estimation method which was extensively verified by our simulations and experiments. During our verifications, we have also found out very important problem so called ”Signature Ambiguity” that is unique to Infrared Based Active Debris Removal (IR-ADR) systems which we have also discussed in our work

Myristic acid potentiates palmitic acid-induced lipotoxicity and steatohepatitis associated with lipodystrophy by sustaning de novo ceramide synthesis.

Palmitic acid (PA) induces hepatocyte apoptosis and fuels de novo ceramide synthesis in the endoplasmic reticulum (ER). Myristic acid (MA), a free fatty acid highly abundant in copra/palmist oils, is a predictor of nonalcoholic steatohepatitis (NASH) and stimulates ceramide synthesis. Here we investigated the synergism between MA and PA in ceramide synthesis, ER stress, lipotoxicity and NASH. Unlike PA, MA is not lipotoxic but potentiated PA-mediated lipoapoptosis, ER stress, caspase-3 activation and cytochrome c release in primary mouse hepatocytes (PMH). Moreover, MA kinetically sustained PA-induced total ceramide content by stimulating dehydroceramide desaturase and switched the ceramide profile from decreased to increased ceramide 14:0/ceramide16:0, without changing medium and long-chain ceramide species. PMH were more sensitive to equimolar ceramide14:0/ceramide16:0 exposure, which mimics the outcome of PA plus MA treatment on ceramide homeostasis, than to either ceramide alone. Treatment with myriocin to inhibit ceramide synthesis and tauroursodeoxycholic acid to prevent ER stress ameliorated PA plus MA induced apoptosis, similar to the protection afforded by the antioxidant BHA, the pan-caspase inhibitor z-VAD-Fmk and JNK inhibition. Moreover, ruthenium red protected PMH against PA and MA-induced cell death. Recapitulating in vitro findings, mice fed a diet enriched in PA plus MA exhibited lipodystrophy, hepatosplenomegaly, increased liver ceramide content and cholesterol levels, ER stress, liver damage, inflammation and fibrosis compared to mice fed diets enriched in PA or MA alone. The deleterious effects of PA plus MA-enriched diet were largely prevented by in vivo myriocin treatment. These findings indicate a causal link between ceramide synthesis and ER stress in lipotoxicity, and imply that the consumption of diets enriched in MA and PA can cause NASH associated with lipodystrophy

La Formación de Bellmunt (Unidad del Cadí, Pirineo oriental): aportaciones bioestratigráficas de los sistemas lacustres y palustres asociados

The Bellmunt Fm is an alluvial synorogenic unit which was deposited under the influence of the southward displacement of succesive pyrenean nappes. This unit includes, in the boundary between its lower and middle part, many lacustrine and palustrine beds with an abundant fossil fauna and flora. This fossil record allows to recognize thepaleoenviromental andpaleoclimatic scenary. Charophytes and fossil mammals indicate a Middle and Lower Bartonian age for this Formation

Implications of zoonotic and vector-borne parasites to free-roaming cats in central Spain

Cats are definitive hosts and reservoirs for several parasites, some of which are responsible for serious zoonotic diseases. We conducted a case-control study of data from a trap-neuter-return (TNR) programme (years 2014-2017) designed to examine the prevalence of zoonotic parasites in free-roaming cats living in urban areas of central Spain. In the animal population tested (n = 263), we detected a 29.2% prevalence of endoparasites, including high rates of cestodes (12.9%) and Toxocara cati (11.7%). While faecal samples showed no Toxoplasma gondii oocysts, the seroprevalence of T. gondii infection was 24.2%. Antibodies to Leishmania infantum were detected in 4.8% of the animals, though all skin and blood samples analyzed were PCR negative for this parasite. Ectoparasites (ticks and fleas) were found in 4.6% of the cat population, and 10.6% of the cats were detected with Otodectes cynotis. Finally, 6.3% and 7.9% cats tested positive for feline leukaemia virus and feline immunodeficiency virus, respectively. Our study provides useful information for animal-welfare and public-health, as the parasites detected can affect native wild animals through predation, competition and disease transmission. Our detection of zoonotic parasites such as L. infantum, T. gondii, T. cati, Giardia duodenalis and several ectoparasites prompts an urgent need for health control measures in stray cats.S

Exactitud de la punción aspiración con aguja fina en el diagnóstico de cáncer diferenciado de tiroides

La importancia clínica de los nódulos tiroideos (NT) radica en la necesidad de excluircáncer de tiroides (7 al 15% de los casos). En Argentina representa el 2,2% y 0,5% de los cánceres queocurren anualmente en mujeres y hombres respectivamente. La citología por punción aspiración con agujafina (PAAF) de NT estima el riesgo de malignidad y es la prueba confirmatoria de elección para eldiagnóstico, con una especificidad reportada del 94%.OBJETIVO: Determinar la exactitud diagnóstica de los criterios citopatológicos del Sistema Bethesda (SB)obtenidos por PAAF de NT para el diagnóstico de cáncer de tiroides. Establecer la frecuencia de cadacategoría del SB en nuestra población. Calcular el porcentaje de malignidad para cada categoría del SB ennuestra población.PACIENTES Y MÉTODOS: Estudio observacional, retrospectivo, de pruebas diagnósticas. Se incluyeronpacientes adultos con NT sospechosos de malignidad por ecografía y PAAF. Se analizaron las historiasclínicas de pacientes de ambos sexos intervenidos mediante cirugía tiroidea entre el 1 de enero de 2012 yel 31 de diciembre de 2018 en la Clínica Universitaria Reina Fabiola de la Ciudad de Córdoba. Se evaluóla sensibilidad, especificidad, valores predictivos positivo y negativo de los criterios citopatológicos del SBobtenidos por PAAF de NT tomando como estándar de oro el resultado anatomopatológico.RESULTADOS: Se incluyeron 191 pacientes. De ellos el 82,20% eran de sexo femenino y la media deedad fue 43,45 ± 13,29. Presentaron diagnóstico de cáncer de tiroides 89 pacientes, correspondiendo latotalidad a CDT. Las tasas de malignidad para las categorías del SB II, III, IV y V fueron del 18,5; 31,6;62,8 y 90,5%, respectivamente. Al analizar la utilidad del SB como prueba de screening encontramos unasensibilidad para detectar malignidad del 84,6%, con una especificidad del 72,6%, un VPP del 76,7%, unVPN del 81,5% y una exactitud diagnóstica global del 78,8%. Este análisis, en punciones altamentesospechosas, aumentó la exactitud diagnóstica de la prueba hasta el 85,2%, sensibilidad 76,5%,especificidad 93%, VPP 90,7% y VPN 81,5%.CONCLUSIONES: La exactitud diagnóstica de los criterios citopatológicos del Sistema Bethesda (SB)obtenidos por PAAF de nódulos tiroideos para el diagnóstico de cáncer de tiroides es buena, por lo cual esuno de los métodos recomendados en el algoritmo diagnóstico de cáncer de tiroides

Early Stage Biomineralization in the Periostracum of the ‘Living Fossil’ Bivalve Neotrigonia

A detailed investigation of the shell formation of the palaeoheterodont ‘living fossil’ Neotrigonia concentrated on the timing and manufacture of the calcified ‘bosses’ which stud the outside of all trigonioid bivalves (extant and fossil) has been conducted. Electron microscopy and optical microscopy revealed that Neotrigonia spp. have a spiral-shaped periostracal groove. The periostracum itself is secreted by the basal cell, as a thin dark pellicle, becoming progressively transformed into a thin dark layer by additions of secretions from the internal outer mantle fold. Later, intense secretion of the internal surface of the outer mantle fold forms a translucent layer, which becomes transformed by tanning into a dark layer. The initiation of calcified bosses occurred at a very early stage of periostracum formation, deep within the periostracal groove immediately below the initialmost dark layer. At this stage, they consist of a series of polycyclically twinned crystals. The bosses grow as the periostracum traverse through the periostracal groove, in coordination with the thickening of the dark periostracal layer and until, upon reaching the mantle edge, they impinge upon each other and become transformed into large prisms separated by dark periostracal walls. In conclusion, the initial bosses and the external part of the prismatic layer are fully intraperiostracal. With later growth, the prisms transform into fibrous aggregates, although the details of the process are unknown. This reinforces the relationships with other groups that have the ability to form intraperiostracal calcifications, for example the unionoids with which the trigonioids form the clade Paleoheterodonta. The presence of similar structures in anomalodesmatans and other euheterodonts raises the question of whether this indicates a relationship or represents a convergence. The identification of very early calcification within an organic sheet has interesting implications for our understanding of how shells may have evolved.Coordinated Research Projects CGL2010-20748-C02-01 (AGC, EMH) and 02 (CS) (DGI, Spanish MICINN); the Research Group RNM363 (Consejería de Economía, Investigación, Ciencia y Empleo, Junta de Andalucía); and the FP7 COST Action TD0903 of the European Community

Bistability in the Tunnelling Current through a Ring of NN Coupled Quantum Dots

We study bistability in the electron transport through a ring of N coupled quantum dots with two orbitals in each dot. One orbital is localized (called b orbital) and coupling of the b orbitals in any two dots is negligible; the other is delocalized in the plane of the ring (called d orbital), due to coupling of the d orbitals in the neighboring dots, as described by a tight-binding model. The d orbitals thereby form a band with finite width. The b and d orbitals are connected to the source and drain electrodes with a voltage bias V, allowing the electron tunnelling. Tunnelling current is calculated by using a nonequilibrium Green function method recently developed to treat nanostructures with multiple energy levels. We find a bistable effect in the tunnelling current as a function of bias V, when the size N>50; this effect scales with the size N and becomes sizable at N~100. The temperature effect on bistability is also discussed. In comparison, mean-field treatment tends to overestimate the bistable effect.Comment: Published in JPSJ; minor typos correcte

Synthesis of Graphene Nanoribbons on a Kinked Au Surface: Revealing the Frontier Valence Band at the Brillouin Zone Center

Graphene nanoribbons (GNRs) can be synthesized with atomic precision through on-surface chemistry of self-assembled organic precursors on metal surfaces. Here, we examine the growth of seven-armchair GNRs (7-AGNRs) on the Au(16 14 15) vicinal surface, namely, a surface vicinal to Au(111) that features kinked steps. During the thermal activation of the polymerization and cyclodehydrogenation processes that produce the GNRs, the kinked substrate undergoes a strong step-edge reshaping, accompanied by a massive missing-row reconstruction within (111) terraces that aligns GNRs preferentially along two equivalent [11¯ 0] directions. Using angle-resolved photoemission, we are able to detect the occupied frontier band of the 7-AGNR at the center of the first Brillouin zone, as predicted by theoretical calculations. This allows to unambiguously determine the relevant 7-AGNR band properties, namely, energy and effective mass. Copyrigh

Metacognitive scaffolding boosts cognitive and neural benefits following executive attention training in children

Version of Record online: 25 October 2018Interventions including social scaffolding and metacognitive strategies have been used in educational settings to promote cognition. In addition, increasing evidence shows that computerized process-based training enhances cognitive skills. However, no prior studies have examined the effect of combining these two training strategies. The goal of this study was to test the combined effect of metacognitive scaffolding and computer-based training of executive attention in a sample of typically developing preschoolers at the cognitive and brain levels. Compared to children in the regular training protocol and an untrained active control group, children in the metacognitive group showed larger gains on intelligence and significant increases on an electrophysiological index associated with conflict processing. Moreover, changes in the conflict-related brain activity predicted gains in intelligence in the metacognitive scaffolding group. These results suggest that metacognitive scaffolding boosts the influence of process-based training on cognitive efficiency and brain plasticity related to executive attention.Secretaría de Estado de Investigación, Desarrollo e Innovación, Grant/Award Number: PSI2014-55833-

Searching for kagome multi-bands and edge states in a predicted organic topological insulator

This is the final version. Available on open access from the Royal Society of Chemistry via the DOI in this recordRecently, mixed honeycomb-kagome lattices featuring metal-organic networks have been theoretically proposed as topological insulator materials capable of hosting nontrivial edge states. This new family of so-called "organic topological insulators" are purely two-dimensional and combine polyaromatic-flat molecules with metal adatoms. However, their experimental validation is still pending given the generalized absence of edge states. Here, we generate one such proposed network on a Cu(111) substrate and study its morphology and electronic structure with the purpose of confirming its topological properties. The structural techniques reveal a practically flawless network that results in a kagome network multi-band observed by angle-resolved photoemission spectroscopy and scanning tunneling spectroscopy. However, at the network island borders we notice the absence of edge states. Bond-resolved imaging of the network exhibits an unexpected structural symmetry alteration that explains such disappearance. This collective lifting of the network symmetry could be more general than initially expected and provide a simple explanation for the recurrent experimental absence of edge states in predicted organic topological insulators.Spanish Ministry of Economy, Industry and Competitiveness (MINECO)Ministry of Science and Innovation (MICINN)Government of AragonFormación de Personal InvestigadorGovernment of the Basque CountryEuropean Regional Development Fund (ERDF)Royal Societ