LEOSTAR: A Small Spacecraft for LEO Communication Missions

This paper outlines the major features of LEOSTAR, a small spacecraft able to support two way data message communications and position reporting missions with a multisatellite constellation. LEOSTAR is a three-axis gravity gradient stabilized satellite. A semi-passive control concept is envisaged with an extensible boom providing attitude stabilization together with three orthogonal Magnetic Torquers, an on-board dedicated computer and other devices. Thrusters provide the station keeping and transfer maneuvers according to an optimized strategy. A bipropellant system with monomethyhl hydrazine as propellant and nitrogen tetroxide as oxidizer is adopted. Large autonomy is envisaged through the adoption of an onboard system management processor. The communications\u27 payload power/mass range from 100 W/40 Kg to 200 W/60 Kg. A payload volume of 0.12 m3 and a maximum antenna dimension of 1 m. are allowed. LEOSTAR is designed to be compatible both with SCOUT and PEGASUS launchers in single or double launch configurations. It can also be launched by large vehicles such ARIANE 4 and Delta in cluster and/or piggy back modes

Attention deficits predict phenotypic outcomes in syndrome-specific and domain-specific ways

Attentional difficulties, both at home and in the classroom, are reported across a number of neurodevelopmental disorders. However, exactly how attention influences early socio-cognitive learning remains unclear. We addressed this question both concurrently and longitudinally in a cross-syndrome design, with respect to the communicative domain of vocabulary and to the cognitive domain of early literacy, and then extended the analysis to social behavior. Participants were young children (aged 4–9 years at Time 1) with either Williams syndrome (WS, N = 26) or Down syndrome (DS, N = 26) and typically developing controls (N = 103). Children with WS displayed significantly greater attentional deficits (as indexed by teacher report of behavior typical of attention deficit hyperactivity disorder (ADHD) than children with DS, but both groups had greater attentional problems than the controls. Despite their attention differences, children with DS and those with WS were equivalent in their cognitive abilities of reading single words, both at Time 1 and 12 months later, at Time 2, although they differed in their early communicative abilities in terms of vocabulary. Greater ADHD-like behaviors predicted poorer subsequent literacy for children with DS, but not for children with WS, pointing to syndrome-specific attentional constraints on specific aspects of early development. Overall, our findings highlight the need to investigate more precisely whether and, if so, how, syndrome-specific profiles of behavioral difficulties constrain learning and socio-cognitive outcomes across different domains

Topology of SO(5)-monopoles and three-dimensional, stable Dirac semimetals

The band-touching points of stable, three-dimensional, Kramers-degenerate, Dirac semimetals are singularities of a five-component, unit vector field and non-Abelian, $SO(5)$-Berry's connections, whose topological classification is an important, open problem. We solve this problem by performing second homotopy classification of Berry's connections. Using Abelian projected connections, the generic planes, orthogonal to the direction of nodal separation, and lying between two Dirac points are shown to be higher-order topological insulators, which support quantized, chromo-magnetic flux or relative Chern number, and gapped, edge states. The Dirac points are identified as a pair of unit-strength, $SO(5)$- monopole and anti-monopole, where the relative Chern number jumps by $\pm 1$. Using these bulk invariants, we determine the topological universality class of different types of Dirac semimetals. We also describe a universal recipe for computing quantized, non-Abelian flux for Dirac materials from the windings of spectra of planar Wilson loops, displaying $SO(5)$-gauge invariance. With non-perturbative, analytical solutions of surface-states, we show the absence of helical Fermi arcs, and predict the fermiology and the spin-orbital textures. We also discuss the similarities and important topological distinction between the surface-states Hamiltonian and the generator of Polyakov loop of Berry's connections.Comment: 19 pages, 8 figure

Development of a Modified Cervical Collar to Eliminate Overheating and Dysphagia Side Effects

Currently, thousands of people each year require the use of a rigid cervical collar. The collars are used in situations of emergency, as well as in situations of precaution, when spinal injury is or may be present. There are many different styles and sizes of cervical collars available on the market today; however, common side effects are noticed when wearing the collars that may reduce the effectiveness to the patient. Often patients complain of general discomfort issues or may suffer from more serious side effects such as pressure sores, increased intracranial pressure, dysphagia, and abnormal distraction within the upper spine. A need exists for the modification of current cervical collars to reduce the painful or uncomfortable side effects associated with wearing them which would, in turn, increase the effectiveness of the therapy that the collar provides to the spine. There are two main components of most cervical collar designs: the rigid outer shell and the inner padding. Both of these components have been considered by our design team in the modification design to improve the efficacy of the cervical collar and to reduce side effects from wearing them. The main goals of this project were to reduce the overall discomfort patients experience that is associated with overheating and dysphagia side effects. As a team, we have researched and tested many materials to determine the best fit for our modified cervical collar. The tests included an end user survey that determined the overall comfortability between the available collars, a cold temperature retention test that showed how long the prospective cooling materials would maintain lower temperatures, and an in-collar temperature test that looked at the temperatures of the materials within the lining of a collar As a team, we have designed a rigid cervical collar that utilizes a slightly flexible, but durable 1/16th inch polyethylene outer shell with padded gel inserts. The outer shell is a two piece design that incorporates the favorable concepts of currently manufactured collars. The two pieces were cut using a scroll saw and molded using an application of heat to the desired positions. There are multiple cut outs in the plastic of both pieces that give flexibility when fitting the collar and the pieces can be connected using velcro straps. The inner “cooling system” is composed of two hydrogels: TheraPearl Technology freezable beads and a pressure activated cooling pad marketed by The Green Pet Shop. The cooling materials will then be wrapped together in polyolefin shrink wrap and placed within specified cutout positions in the antimicrobial padding. Finally the components will be covered in a heat resistant cloth material to ensure direct contact with the skin is compatible and comfortable for the patient. The modifications focus on reducing the hot spots on the cheeks, chin, and neck that are commonly associated with discomfort in patients, will address the discomfort of the chin and neck associated with dysphagia, and will also maintain the rigidity and restriction of motion necessary of the collar. Testing on the efficacy of the design concepts brought forth is still in progress, but we believe the modified cervical collar can increase patient comfort levels and reduce overheating

As teorias freudianas na perspectiva da gestão de pessoas: uma análise crítica

As relações de trabalho, as organizações em si, sofreram ao longo do tempo grandes transformações. A mais importante foi a percepção de que o capital humano é o grande “bem” de uma organização, contudo para lidarmos com pessoas temos que entender de pessoas. Para falarmos de questões emocionais e entender um pouco como funciona o indivíduo, e este no seu ambiente de trabalho será utilizada a ajuda da Psicanálise. O sujeito psicanalítico é um ser desejoso e o que constitui o desejo, é a falta. Sendo assim a busca de satisfação perdura uma vida inteira. Segundo FREUD (BRENNER, 1987), erramos quando pensamos que somos donos de nossa mente, pois na verdade somos dirigidos e dominados por processos inconscientes, desejos, medos, conflitos e fantasias. “Sabemos que tudo o que fazemos ou pensamos, está moldado, em parte, pelas forças do id, isto é, pelo legado dos desejos da infância, em parte pelas defesas contra esses desejos (o ego), e em parte pelas exigências morais (o superego), e em parte pelas exigências impostas por nossas circunstâncias externas. ” (BRENNER, 1987) O ser humano trabalhador, quando inserido numa organização, querendo ou não, está á mercê de suas regras. Sendo assim o sujeito é obrigado a reprimir seus desejos, pois existem regras, e também a pressão do trabalho. Hoje, quem não tiver um diferencial, estará fora do mercado de trabalho e na correria da vida, a tensão e a satisfação parecem lutar entre si para se fazer presente, e este jogo inconsciente temos a questão profissional que fica lado a lado com as questões inconscientes. O sujeito quando entra na empresa, tem seus valores, condutas, regras e que podem divergir das da empresa e isso acaba tornando um dos pontos para as diversidades, conflitos e problemas profissionais, pois entram em cena aspectos emocionais deste integrante que não são deixados de fora quando entram no ambiente de trabalho

Consumption responses to a large shock to financial wealth: evidence from Italy

We estimate marginal propensities to consume from wealth shocks for Italian households early in the Great Recession. Large asset-price shocks in 2007-2008 underpin instrumental variables. A euro fall in risky financial wealth resulted in cuts in annual total (non-durable) consumption of 8.5-9 (5.5-5.7) cents. We find small effects on food spending. Counterfactuals indicate financial-wealth effects were relatively important for consumption falls in Italy in 2007/08. The estimated effects are consistent with a simulated lifecycle model that captures the wealth shock. Also consistent with the model are findings of stronger wealth effects for agents who were pessimistic about stock returns

Electronic properties of bulk and thin film SrRuO3_3: a search for the metal-insulator transition

We calculate the properties of the 4$d$ ferromagnet SrRuO$_3$ in bulk and thin film form with the aim of understanding the experimentally observed metal to insulator transition at reduced thickness. Although the spatial extent of the 4$d$ orbitals is quite large, many experimental results have suggested that electron-electron correlations play an important role in determining this material's electronic structure. In order to investigate the importance of correlation, we use two approaches which go beyond the conventional local density approximation to density functional theory (DFT): the local spin density approximation + Hubbard $U$ (LSDA+$U$) and the pseudopotential self-interaction correction (pseudo-SIC) methods. We find that the details of the electronic structure predicted with the LSDA do not agree with the experimental spectroscopic data for bulk and thin film SrRuO$_3$. Improvement is found by including electron-electron correlations, and we suggest that bulk orthorhombic SrRuO$_3$ is a {\it weakly strongly-correlated} ferromagnet whose electronic structure is best described by a 0.6 eV on-site Hubbard term, or equivalently with corrections for the self-interaction error. We also perform {\it ab initio} transport calculations that confirm that SrRuO$_3$ has a negative spin polarization at the Fermi level, due to the position of the minority Ru 4$d$ band center. Even with correlations included in our calculations we are unable to reproduce the experimentally observed metal-insulator transition, suggesting that the electronic behavior of SrRuO$_3$ ultra-thin films might be dominated by extrinsic factors such as surface disorder and defects.Comment: 15 pages, 12 figures, 3 table