CsCl-type compounds in binary alloys of rare-earth metals with gold and silver

In binary alloys of silver with Sm, Tb, Ho, and Tm, and of gold with Y, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, and Tm, intermediate phases containing stoichiometric proportions of the two metals were found to crystallize into the CsCl (B2)-type structure. The lattice parameters of these phases are reported and a correlation has been found between these lattice parameters and the trivalent ionic radii of the rare-earth metals

The Suberogation Problem for Lei Zhong's Confucian Virtue Theory of Supererogation

A virtue-based theory of right action aims to explain deontic moral principles in terms of virtue and vice. For example, it may maintain the following account of moral obligation: It is morally obligatory for an agent A to ϕ in circumstances C if and only if a fully virtuous and relevantly informed person V would characteristically ϕ in C. However, this account faces the so-called supererogation problem. A supererogatory action is an action that is morally praiseworthy but not morally obligatory. Suppose John risks his own life to save a stranger, which is supererogatory rather than obligatory. However, a fully virtuous..

Hydrogen bonding interactions of benzylidene type Schiff bases studied by vibrational spectroscopic and computational methods

The structural features of four benzylidene type Schiff bases [(E)-benzaldehyde-N-phenyl imine, (A) (E)-2-hydroxybenzaldehyde-N-phenyl imine (B) (E)-benzaldehyde-N-2-hydroxyphenyl imine (C) (E)-2-hydroxybenzaldehyde-N-2-hydroxyphenyl imine (D)] were studied by FT-IR spectroscopy in solution, photoacoustic and Raman spectroscopies in the solid state and quantum chemical calculations. It was found that molecule D dimerised in the solid state with concomitant loss of aromaticity in the benzylidene ring. Beside the intermolecular C=O...HO hydrogen bonds, intramolecular N-H...C=O hydrogen bonds could be found experimentally as well as computationally. Spectra taken in solution and ab initio quantum chemical calculation helped to identify hydrogen bonding interactions occurring for compounds B and C. Intramolecular OH...N hydrogen bond predominated in molecule B, while this interaction, although it existed, was weaker

Role of the protective gene Heme Oxygenase-1 in the control of T cell mediated responses

Tese de doutoramento em Ciências Biomédicas, (Ciências Biopatológicas), apresentada à Universidade de Lisboa através da Faculdade de Medicina, 2008As reacções inflamatórias, geralmente desencadeadas por infeccões e/ou lesões a nível dos tecidos, desempenham um papel fundamental na iniciação de respostas imunes adaptativas e conduzem, em última análise, à eliminação do evento instigador. São vários os mecanismos intrínsecos a esta resposta complexa que asseguram, após a remoção do estímulo nocivo, a correcta reparação quer a nível estrutural quer funcional do tecido afectado, ou seja, o regresso à homeostase. A importância destes mecanismos pode ser comprovada pelo facto de a não resolução das reacções inflamatórias ser uma etapa crítica para o estabelecimento e/ou progressão de um número crescente de patologias. Um dos mecanismos envolvidos na resolução da inflamação consiste na expressão do enzima Heme Oxygenase-1 (HO-1). Em condições inflamatórias, a HO-1 torna-se o enzima limitante no catabolismo dos grupos hémicos livres dando origem a quantidades equimolares de monoxido de carbono (CO), ferro (Fe) e biliverdina (BV). Estes produtos reduzem a reacção inflamatória e evitam o desenvolvimento de doenças inflamatórias. Esta Tese teve como objectivo examinar o papel da HO-1 na regulação do estabelecimento e progressão de condições neuroinflamatórias mediadas por linfócitos T. O trabalho agora apresentado sugere que a HO-1 dita o resultado patológico associado com processos neuroinflamatórios em ratinho, tais como a encefalomielite autoimune experimental (EAE), um modelo de esclerose múltipla (EM), ou a malária cerebral experimental (MCE) resultante da infecção com Plasmodium spp.Inflammatory reactions, elicited in most cases upon infection and/or injury, are critical for the initiation of adaptive immunity and ultimately lead to the removal of the inciting stimuli. Intrinsic to this complex response, there are several mechanisms that operate to ensure that, once the inciting stimulus is dealt with, structural and functional repair of the injured site is attained, i.e. return to homeostasis. However, failure to resolve inflammatory reactions is thought to contribute in a critical manner to the establishment and/or progression of a growing list of pathologic conditions. One of the mechanisms involved in the resolution of inflammation relies in the expression of Heme Oxygenase (HO)-1. Under inflammatory conditions, HO-1 becomes the rate-limiting enzyme in the catabolism of heme, yielding equimolar amounts of carbon monoxide (CO), free iron (Fe) and biliverdin (BV). These heme degradation products dampen inflammation and prevent the development of inflammatory diseases. The focus of this Thesis was to address whether HO-1 regulates the establishment and progression of T cell-mediated neuroinflammatory conditions. The body of work presented herewith suggests that HO-1 can dictate the pathologic outcome of neuroinflammation in mice, as it occurs either during autoimmunity-driven experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis (MS), or during experimental cerebral malaria (ECM) triggered upon infection with Plasmodium spp. Induction of EAE in HO-1-deficient (Hmox-1-/-) mice led to enhanced central nervous system (CNS) demyelination, paralysis and mortality, as compared to wild-type (Hmox-1+/+) mice. Pharmacological induction of HO-1 expression after EAE onset improved the clinical course of the disease, an effect associated with inhibition of T helper (TH) and CD8+ T cell accumulation, proliferation and effector function within the CNS. HO-1 did not act via modulation of the suppressor activity of naturally occurring regulatory T cells (Treg), known to ensure peripheral tolerance to self-antigens and immune homeostasis. Furthermore, under homeostatic conditions Treg development, maintenance and function were found to be independent of HO-1, as assessed in Hmox-1-/- mice. Instead, the mechanism underlying the protective effect of HO-1 is shown to rely on its ability to inhibit major histocompatibility complex (MHC) class II expression by antigen presenting cells, including dendritic cells, microglia and macrophages. Likewise, Hmox-1 deletion or pharmacological inhibition of its activity resulted in increased ECM incidence in otherwise resistant mouse strains whereas pharmacological induction of HO-1 greatly reduced ECM incidence in susceptible mouse strains. The protection afforded by pharmacological induction of HO-1 expression was associated with decreased CD8+ T cell sequestration in the CNS, a critical event in the development of neurological damage associated with ECM. In both pathologies, i.e. EAE and ECM, exogenous CO mimicked these protective effects, suggesting that CO is the main contributor to the protective action of HO-1. Finally, we present evidence of a novel mechanism by which CO counters the development of one of these pathologies, ECM, based on its ability to bind hemoglobin, prevent its oxidation and subsequently the generation of free heme, a central effector molecule in the pathogenesis of ECM. Overall, the findings presented in this Thesis suggest that, during the establishment and/or progression of neuroinflammation, HO-1 and/or CO limit the deleterious effects associated with neuroinflammatory responses, possibly by modulating antigen presenting cells activity, in a manner that prevents the pathologic outcome of these conditions. Further, these results support the notion that pharmacological modulation of HO-1 or CO administration might be potential therapeutic strategies to counter neuroinflammatory diseases

Toward 'generalized control theory'

Optimization problems in control theory in terms of criterion function, controller, and information available to controlle

Nuclear pairing and Coriolis effects in proton emitters

We introduce a Hartree-Fock-Bogoliubov mean-field approach to treat the problem of proton emission from a deformed nucleus. By substituting a rigid rotor in a particle-rotor-model with a mean-field we obtain a better description of experimental data in $^{141}$Ho. The approach also elucidates the softening of kinematic coupling between particle and collective rotation, the Coriolis attenuation problem.Comment: 2 pages, 1 figur

Point source models for the gravitational lens B1608+656: Indeterminacy in the prediction of the Hubble constant

We apply elliptical isothermal mass models to reproduce the point source properties, i.e. image positions, flux density ratios and time delay ratios, of the quadruple lens B1608+656. A wide set of suitable solutions is found, showing that models that only fit the properties of point sources are under-constrained and can lead to a large uncertainty in the prediction of Ho. We present two examples of models predicting Ho=100 km/(s Mpc) (chi^2=4) and Ho=69 km/(s Mpc) (chi^2=24).Comment: 2 pages, 1 figure. To appear in "Gravitational Lensing: Recent Progress and Future Goals", Boston University, MA, July 1999, eds. T.G. Brainerd and C.S. Kochane

An enhanced weighted performance-based handover parameter optimization algorithm for LTE networks

This article introduces an enhanced version of previously developed self-optimizing algorithm that controls the handover (HO) parameters of a long-term evolution base station in order to diminish and prevent the negative effects that can be introduced by HO (radio link failures, HO failures and ping-pong HOs) and thus improve the overall network performance. The default algorithm selects the best hysteresis and time-to-trigger combination based on the current network status. The enhancement proposed here aims to maximize the gain provided by the algorithm by improving its convergence time. The effects of this enhancement have been studied in a rural scenario setting and compared to the original algorithm; the results show a clear improvement, faster convergence, and better network performance, because of the enhancement

Factor income taxation and growth with increasing integration of world capital markets

In a closed economy, the infinite-horizon and the overlapping generations (OG) model prescribe diametrically opposite policies on factor taxation: the former argues that the growth-maximizing capital income tax rate should be set to zero, whereas the latter argues that it should be set as high as possible. This note investigates the issue by taking into account global capital market integration. We show that the long-run growth-maximizing capital income tax rate in a small open OG economy is decreasing as the economy's capital market is increasingly integrated with the rest of the world, and will be equal to zero as prescribed in the infinite-horizon model once the degree of integration becomes sufficiently high.Capital mobility, Endogenous growth, Factor income taxation, Overlapping generations, Small open economy