Stem cell therapy for Alzheimer's disease: hype or hope?

Alzheimers disease (AD) is the most common neurodegenerative disease affecting millions of people in the world. Cognitive impairments such as progressive memory loss are devastating manifestations from this disease. Current pharmacological treatment has limited efficacy and only provides symptomatic relief without long-term cure. As a result, cell-replacement therapy using stem cells is an emerging potential treatment to AD. In the last decade, there have been animal trials using stem cells to treat and modulate cognitive impairment in AD models via three different mechanisms - replacing the damaged or dead cholinergic neurons; protecting neurons by reducing toxic amyloid protein aggregates or insoluble tau neurofibrillary tangles and promoting neurogenesis in hippocampus by neurotrophic secretions from stem cells. All of the trials showed promising results and improved our understandings about the mechanism of dementia in AD. With the continued improvement in safety profile of stem cell therapy and the creation of a better animal AD model in which to test them, it is feasible that stem cells could be trialled in humans for AD treatment in the next 5-10 years. © 2013 The Author 2013. Published by Oxford University Press

Modelling the Density of Inflation Using Autoregressive Conditional Heteroscedasticity, Skewness, and Kurtosis Models

The paper aimed at modelling the density of inflation based on time-varying conditional variance, skewness and kurtosis model developed by Leon, Rubio, and Serna (2005) who model higher-order moments as GARCH-type processes by applying a Gram-Charlier series expansion of the normal density function. Additionally, it extended their work by allowing both conditional skewness and kurtosis to have an asymmetry term. The results revealed the significant persistence in conditional variance, skewness and kurtosis which indicate high asymmetry of inflation. Additionally, diagnostic tests reveal that models with nonconstant volatility, skewness and kurtosis are superior to models that keep them invariant.inflation targeting, conditional volatility, skewness and kurtosis, modelling uncertainty of inflation

Statistical Intercell Interference Modeling for Capacity-Coverage Tradeoff Analysis in Downlink Cellular Networks

Interference shapes the interplay between capacity and coverage in cellular networks. However, interference is non-deterministic and depends on various system and channel parameters including user scheduling, frequency reuse, and fading variations. We present an analytical approach for modeling the distribution of intercell interference in the downlink of cellular networks as a function of generic fading channel models and various scheduling schemes. We demonstrate the usefulness of the derived expressions in calculating location-based and average-based data rates in addition to capturing practical tradeoffs between cell capacity and coverage in downlink cellular networks.Comment: 5 pages, 7 figures, conferenc

Parallel eigenanalysis of finite element models in a completely connected architecture

A parallel algorithm is presented for the solution of the generalized eigenproblem in linear elastic finite element analysis, (K)(phi) = (M)(phi)(omega), where (K) and (M) are of order N, and (omega) is order of q. The concurrent solution of the eigenproblem is based on the multifrontal/modified subspace method and is achieved in a completely connected parallel architecture in which each processor is allowed to communicate with all other processors. The algorithm was successfully implemented on a tightly coupled multiple-instruction multiple-data parallel processing machine, Cray X-MP. A finite element model is divided into m domains each of which is assumed to process n elements. Each domain is then assigned to a processor or to a logical processor (task) if the number of domains exceeds the number of physical processors. The macrotasking library routines are used in mapping each domain to a user task. Computational speed-up and efficiency are used to determine the effectiveness of the algorithm. The effect of the number of domains, the number of degrees-of-freedom located along the global fronts and the dimension of the subspace on the performance of the algorithm are investigated. A parallel finite element dynamic analysis program, p-feda, is documented and the performance of its subroutines in parallel environment is analyzed

Educational Games in Geriatric Medicine Education: A Systematic Review

OBJECTIVE: To systematically review the medical literature to assess the effect of geriatric educational games on the satisfaction, knowledge, beliefs, attitudes and behaviors of health care professionals. METHODS: We conducted a systematic review following the Cochrane Collaboration methodology including an electronic search of 10 electronic databases. We included randomized controlled trials (RCT) and controlled clinical trials (CCT) and excluded single arm studies. Population of interests included members (practitioners or students) of the health care professions. Outcomes of interests were participants' satisfaction, knowledge, beliefs, attitude, and behaviors. RESULTS: We included 8 studies evaluating 5 geriatric role playing games, all conducted in United States. All studies suffered from one or more methodological limitations but the overall quality of evidence was acceptable. None of the studies assessed the effects of the games on beliefs or behaviors. None of the 8 studies reported a statistically significant difference between the 2 groups in terms of change in attitude. One study assessed the impact on knowledge and found non-statistically significant difference between the 2 groups. Two studies found levels of satisfaction among participants to be high. We did not conduct a planned meta-analysis because the included studies either reported no statistical data or reported different summary statistics. CONCLUSION: The available evidence does not support the use of role playing interventions in geriatric medical education with the aim of improving the attitudes towards the elderly.Society of General Internal Medicin

Eigensolution of finite element problems in a completely connected parallel architecture

A parallel algorithm for the solution of the generalized eigenproblem in linear elastic finite element analysis, (K)(phi)=(M)(phi)(omega), where (K) and (M) are of order N, and (omega) is of order q is presented. The parallel algorithm is based on a completely connected parallel architecture in which each processor is allowed to communicate with all other processors. The algorithm has been successfully implemented on a tightly coupled multiple-instruction-multiple-data (MIMD) parallel processing computer, Cray X-MP. A finite element model is divided into m domains each of which is assumed to process n elements. Each domain is then assigned to a processor, or to a logical processor (task) if the number of domains exceeds the number of physical processors. The macro-tasking library routines are used in mapping each domain to a user task. Computational speed-up and efficiency are used to determine the effectiveness of the algorithm. The effect of the number of domains, the number of degrees-of-freedom located along the global fronts and the dimension of the subspace on the performance of the algorithm are investigated. For a 64-element rectangular plate, speed-ups of 1.86, 3.13, 3.18 and 3.61 are achieved on two, four, six and eight processors, respectively

Photo-libération de NO dans les complexes de ruthénium à ligand nitrosyle : nouvelles perspectives en thérapie photo-dynamique par absorption à deux photons

Le monoxyde d'azote NO• a longtemps été considéré uniquement comme un gaz polluant provenant des moteurs de combustion et des centrales électriques. Cependant en 1992, il est cité " Molécule de l'année " par le magazine Science suite à la découverte de ses fonctions physiologiques et de son intervention dans différents processus cellulaires. Il a été reconnu que son effet biologique est dépendant de sa concentration dans le milieu cellulaire. De ce fait, la thérapie photo-dynamique couplée à des systèmes capables de fournir une concentration déterminée de NO• sous irradiation est une voie prometteuse. Les complexes de ruthénium à ligand nitrosyle sont des systèmes potentiellement photo-réactifs. Ces travaux de thèse ont été consacrés au développement des complexes de ruthénium à ligand nitrosyle capable de libérer NO• par excitation à un ou à deux photons. En effet, la photo-libération par un processus bi-photonique permet un traitement sélectif des tumeurs installées dans des couches plus profondes, par excitation dans la fenêtre thérapeutique. Une attention particulière est portée sur les complexes de ruthénium à ligands nitrosyle: les méthodes de synthèse et leurs propriétés. Le premier chapitre de ce mémoire s'intéresse à l'état de l'art dans ce domaine. Le deuxième chapitre présente la synthèse et la caractérisation des complexes de ruthénium à ligand 1,10-phénanthroline. Le troisième chapitre décrit la synthèse et la caractérisation de complexes à ligand 2,2':6',2''-terpyridine substitué [RuII(X-terpy)Cl2(NO)]+. X-terpy désigne le ligand 4'-X-2,2':6',2''-terpyridine avec X = 4-Rphényl et R= Br, OCH3, NO2, N(C2H5)2 ou X=(2-fluorényl). Le quatrième chapitre compare les propriétés physico-chimique de deux isomères cis (Cl,Cl)- et trans (Cl,Cl)- du complexe [RuII(2-fluorényl-terpy)Cl2(NO)](PF6). L'étude de la photolibération de NO par excitation monophotonique ainsi que le rendement quantique (FNO) correspondant sont déterminés. Le cinquième chapitre met en évidence la libération du monoxyde d'azote par excitation biphotonique. Le sixième chapitre est consacré à l'étude toxicologique (cytotoxicité et photocytotoxicité) du complexe trans (Cl,Cl)-[RuII(2-fluorényl-terpy)Cl2(NO)](PF6).Nitric oxide NO• has long been considered only as a pollutant gas from combustion engines. However in 1992, it was named as "Molecule of the Year" by Science review after the discovery of its physiological function and its involvement in different cellular processes. It was recognized that the biological effect is dependent on its concentration in the cell media. Hence the photodynamic therapy combined with systems that provide a fixed concentration of NO• under irradiation is a very challenging topic. The ruthenium complexes based on nitrosyl ligand are potentially photoreactive systems. This thesis was devoted to the development of ruthenium nitrosyl complexes able to release NO• by one or two photons excitation. Indeed, the photo-release by a two-photon process allows selective treatment of tumors installed in deeper layers, for excitement in the therapeutic window. Particular attention is paid to the ruthenium nitrosyl complexes: synthesis methods and properties. The first chapter of this thesis examines the state of the art in this field. The second chapter presents the synthesis and characterization of ruthenium complexes with 1,10-phenanthroline ligand. The third chapter describes the synthesis and characterization of complexes with substituted 4'-X-2,2':6',2''-terpyridine ligand [RuII(X-terpy)Cl2(NO)]+. X-terpy denotes the terpy ligand with X = 4-Rphenyl and R = Br, OCH3, NO2, N(C2H5)2 or X = (2-fluorenyl). The fourth chapter compares the physicochemical properties of two cis isomers (Cl, Cl) - and trans (Cl, Cl) - complex [RuII (2-fluorenyl terpy)Cl2(NO)](PF6). The study of NO photorelease by one photon excitation and the corresponding quantum yield (FNO) are determined. The fifth chapter highlights the release of nitric oxide in trans (Cl, Cl)-[RuII(2-fluorenyl-terpy)Cl2 (NO)](PF6) by two-photon excitation. The sixth chapter is devoted to the toxicological study (cytotoxicity and photocytotoxicity) trans (Cl, Cl) - [RuII(2-fluorenyl-terpy)Cl2(NO)](PF6) complex

Regionalizing healthcare: a vision for transforming Lebanon into a regional academic hub

<p>Abstract</p> <p>Background</p> <p>Lebanon suffers from a large scale emigration of physicians coupled with an oversaturation of the physician job market. Lebanon is currently witnessing an expansion of its medical education capacity with the establishment of new private medical schools, raising the fears of a worsening market oversaturation.</p> <p>Discussion</p> <p>The neighboring Arabian Gulf countries are suffering from a serious shortage of clinicians and academicians. In spite of their enormous investments in educational, clinical and research collaborative initiatives with some of the most renowned North American medical schools and institutions, their ability to recruit and retain highly qualified clinicians and academicians remains a major challenge. Lebanese universities have the opportunity to establish triangular collaborations with the Gulf regional medical centers and their North American partners. They could achieve this goal by tapping into the globalized and high quality Lebanese physician workforce and consequently regionalize healthcare delivery in the Middle East.</p> <p>Summary</p> <p>By recruiting its globalized and high quality physician workforce to establish collaborations with the Gulf regional, Lebanon could become a regional "academic hub".</p

Morphogenesis and proportionate growth: A finite element investigation of surface growth with coupled diffusion

Modeling the spontaneous evolution of morphology in natural systems and its preservation by proportionate growth remains a major scientific challenge. Yet, it is conceivable that if the basic mechanisms of growth and the coupled kinetic laws that orchestrate their function are accounted for, a minimal theoretical model may exhibit similar growth behaviors. The ubiquity of surface growth, a mechanism by which material is added or removed on the boundaries of the body, has motivated the development of theoretical models, which can capture the diffusion-coupled kinetics that govern it. However, due to their complexity, application of these models has been limited to simplified geometries. In this paper, we tackle these complexities by developing a finite element framework to study the diffusion-coupled growth and morphogenesis of finite bodies formed on uniform and flat substrates. We find that in this simplified growth setting, the evolving body exhibits a sequence of distinct growth stages that are reminiscent of natural systems, and appear spontaneously without any externally imposed regulation or coordination. The computational framework developed in this work can serve as the basis for future models that are able to account for growth in arbitrary geometrical settings, and can shed light on the basic physical laws that orchestrate growth and morphogenesis in the natural world