Immunoglobulin classes in aquatic mammals. Characterization by serologic cross-reactivity, molecular size and binding of human free secretory component.

On the basis of serologic cross-reactivity, three immunoglobulin classes homologous to human IgG, IgM and IgA were identified in two species of acquatic mammal representing the orders Cetacea (dolphin) and Pinnipedea (sea lion). Molecular size was estimated by sucrose density gradient ultracentrifugation and Sephadex G-200 chromatography, indicating a 7S IgG, 19S IgM and heterogeneous serum IgA. Human secretory component was readily bound to the IgM of both species and to an apparently lesser extent to the larger molecular size populations of IgA. No binding was observed with IgG. Several antisera specific for human γ-chains gave a single precipitin line with the sea lion IgG but when made to react with dolphin serum produced two lines, suggesting the presence of two different subclasses of IgG in this species.

Implementació d'un demostrador wireless: network cording i virtualització d'interfícies sense fils

El treball realitzat en aquest projecte es basa en l'implementació d'un demostrador wireless, i més específicament, en l'estudi de les tècniques network coding i virtualització. Network coding és un nou mètode de transmissió de dades que es basa en la codificació de paquets per incrementar el rendiment fins ara obtingut als mètodes de transmissió convencionals. La virtualització és una tècnica que consisteix en compartir de forma més eficient els recursos d'un sistema. En el nostre cas s'utilitzarà la virtualització per dividir una interfície sense fils en diferents usuaris virtuals transmetent i rebent dades simultàniament. L'objectiu del projecte és realitzar un seguit de proves i estudis per veure els avantatges d'aquestes dues tècniques.

Some personal views on the control of schistosomiasis mansoni

Our views are based, on a recent study of a district of Uniao dos Palmares (Alagoas). Although being a very compact community (32 city blocks holding two thousand families), transmission is very uneven, the geometric mean egg counts in the various blocks ranging between extremes of 96 and 1920. (Results do not correlate with the availability of domestic water supply). We thus are led to conclude that: (a) transmission is primarily peridomestic, resulting from pollution of open ditches and other collections of water; (b) control of transmission can be done on a selective basis, requiring quite medest investments. Given the inefficacy of population-based chemotherapy, when used alone, the author insists that this alternative cannot any longer be overlooked. He also regrets the emphasis placed upon vaccine development; allegations that this would, at any rate, prevent severe morbidity can be dismissed, since-whatever the cause-morbidity due to schistosomiasis has been rapidly declining in Northeast Brazil.

The impact of past direct-personal traumatic events on 12-month outcome in first episode psychotic mania: trauma and early psychotic mania.

OBJECTIVE: Past traumatic events have been associated with poorer clinical outcomes in people with bipolar disorder. However, the impact of these events in the early stages of the illness remains unclear. The aim of this study was to investigate whether prior traumatic events were related to poorer outcomes 12 months following a first episode of psychotic mania. METHODS: Traumatic events were retrospectively evaluated from patient files in a sample of 65 participants who had experienced first episode psychotic mania. Participants were aged between 15 and 28 years and were treated at a specialised early psychosis service. Clinical outcomes were measured by a variety of symptomatic and functioning scales at the 12-month time-point. RESULTS: Direct-personal traumatic experiences prior to the onset of psychotic mania were reported by 48% of the sample. Participants with past direct-personal trauma had significantly higher symptoms of mania (p=0.02), depression (p=0.03) and psychopathology (p=0.01) 12 months following their first episode compared to participants without past direct-personal trauma, with medium to large effects observed. After adjusting for baseline scores, differences in global functioning (as measured by the Global Assessment of Functioning scale) were non-significant (p=0.05); however, participants with past direct-personal trauma had significantly poorer social and occupational functioning (p=0.04) at the 12-month assessment with medium effect. CONCLUSIONS: Past direct-personal trauma may predict poorer symptomatic and functional outcomes after first episode psychotic mania. Limitations include that the findings represent individuals treated at a specialist early intervention centre for youth and the retrospective assessment of traumatic events may have been underestimated.

Redistributive taxation, public expenditure, and size of governent

We introduce a model of redistributive income taxation and public expenditure. This joint treatment permits analyzing the interdependencies between the two policies: one cannot be chosen independently of the other. Empirical evidence reveals that partisan confrontation essentially falls on expenditure policies rather than on income taxation. We examine the case in which the expenditure policy (or the size of government) is chosen by majority voting and income taxation is consistently adjusted. This adjustment consists of designing the income tax schedule that, given the expenditure policy, achieves consensus among the population. The model determines the consensus in- come tax schedule, the composition of public expenditure and the size of government. The main results are that inequality is negatively related to the size of government and to the pro-rich bias in public expenditure, and positively or negatively related to the marginal income tax, depending on substitutability between government supplied and market goods. These implications are validated using OECD data.

Mobile termination, network externalities, and consumer expectations

We re-examine the literature on mobile termination in the presence of network externalities. Externalities arise when firms discriminate between on- and off-net calls or when subscription demand is elastic. This literature predicts that profit decreases and consumer surplus increases in termination charge in a neighborhood of termination cost. This creates a puzzle since in reality we see regulators worldwide pushing termination rates down while being opposed by network operators. We show that this puzzle is resolved when consumers' expectations are assumed passive but required to be fulfilled in equilibrium (as defined by Katz and Shapiro, AER 1985), instead of being rationally responsive to non-equilibrium prices, as assumed until now.

A numerical solver for a nonlinear Fokker-Planck equation representation of neuronal network dynamics

To describe the collective behavior of large ensembles of neurons in neuronal network, a kinetic theory description was developed in [13, 12], where a macroscopic representation of the network dynamics was directly derived from the microscopic dynamics of individual neurons, which are modeled by conductance-based, linear, integrate-and-fire point neurons. A diffusion approximation then led to a nonlinear Fokker-Planck equation for the probability density function of neuronal membrane potentials and synaptic conductances. In this work, we propose a deterministic numerical scheme for a Fokker-Planck model of an excitatory-only network. Our numerical solver allows us to obtain the time evolution of probability distribution functions, and thus, the evolution of all possible macroscopic quantities that are given by suitable moments of the probability density function. We show that this deterministic scheme is capable of capturing the bistability of stationary states observed in Monte Carlo simulations. Moreover, the transient behavior of the firing rates computed from the Fokker-Planck equation is analyzed in this bistable situation, where a bifurcation scenario, of asynchronous convergence towards stationary states, periodic synchronous solutions or damped oscillatory convergence towards stationary states, can be uncovered by increasing the strength of the excitatory coupling. Finally, the computation of moments of the probability distribution allows us to validate the applicability of a moment closure assumption used in [13] to further simplify the kinetic theory.

The multipoint Morisita index for the analysis of spatial patterns

In many fields, the spatial clustering of sampled data points has many consequences. Therefore, several indices have been proposed to assess the level of clustering affecting datasets (e.g. the Morisita index, Ripley's Kfunction and Rényi's generalized entropy). The classical Morisita index measures how many times it is more likely to select two measurement points from the same quadrats (the data set is covered by a regular grid of changing size) than it would be in the case of a random distribution generated from a Poisson process. The multipoint version (k-Morisita) takes into account k points with k >= 2. The present research deals with a new development of the k-Morisita index for (1) monitoring network characterization and for (2) detection of patterns in monitored phenomena. From a theoretical perspective, a connection between the k-Morisita index and multifractality has also been found and highlighted on a mathematical multifractal set.

Level-wise node size distribution of randomly generated regular trees

"Vegeu el resum a l'inici del document del fitxer adjunt."

SYSGENET: a meeting report from a new European network for systems genetics.

The first scientific meeting of the newly established European SYSGENET network took place at the Helmholtz Centre for Infection Research (HZI) in Braunschweig, April 7-9, 2010. About 50 researchers working in the field of systems genetics using mouse genetic reference populations (GRP) participated in the meeting and exchanged their results, phenotyping approaches, and data analysis tools for studying systems genetics. In addition, the future of GRP resources and phenotyping in Europe was discussed.

Le soignant face au patient lombalgique chronique: l'expérience clinique de l'Unité Rachis à l'Hôpital orthopédique [The health professional's approach to chronic lumbago: clinical experience at the Spinal Cord Unit at the orthopedic hospital]

The treatment of back pain patients refers to the biopsychosocial model of care. This model includes illness in patient's personal and relational life. In this context, it is not only the physical symptom of the patient which is focused but also his psychological distress often hidden by algic complain. Clinical interviews conducted with back pain patients have highlighted psychosocial aspects able to influence the relationship between health care user and provider. Taking account of psychosocial aspects implies an interdisciplinary approach that identify and assesses patients' needs through adequate tools. As a result, the different health care providers implied with back pain patients have to collaborate in a structured network.

Personal experience with diagnostic and therapeutic aspects of human Leishmania (Viannia) braziliensis in Três Braços

Diagnostic and therapeutic aspects of human infection with Leishmania (Viannia) braziliensis found in the littoral forest of the state of Bahia are reviewed. There is pressing need for alternative cheap oral drug therapy.

Adult maternal body size matters.

Comment on: Horta BL, Gigante DP, Osmond C, Barros FC, Victora CG. Intergenerational effect of weight gain in childhood on offspring birthweight. Int J Epidemiol. 2009 Jun;38(3):724-32. PMID: 19376883.

Myotonic dystrophy transgenic mice exhibit pathologic abnormalities in diaphragm neuromuscular junctions and phrenic nerves

Myotonic dystrophy Type 1 (DM-1) is caused by abnormal expansion of a (CTG) repeat located in the DM protein kinase gene. Respiratory problems have long been recognized to be a major feature of this disorder. Because respiratory failure can be associated with dysfunction of phrenic nerves and diaphragm muscle, we examined the diaphragm and respiratory neural network in transgenic mice carrying the human genomic DM-1 region with expanded repeats of more than 300 CTG, a valid model of the human disease. Morphologic and morphometric analyses revealed distal denervation of diaphragm neuromuscular junctions in DM-1 transgenic mice indicated by a decrease in the size and shape complexity of end-plates and a reduction in the concentration of acetyl choline receptors on the postsynaptic membrane. More importantly, there was a significant reduction in numbers of unmyelinated, but not of myelinated, fibers in DM-1 phrenic nerves; no morphologic alternations of the nerves or loss of neuronal cells were detected in medullary respiratory centers or cervical phrenic motor neurons. Because neuromuscular junctions are involved in action potential transmission and the afferent phrenic unmyelinated fibers control the inspiratory activity, our results suggest that the respiratory impairment associated with DM-1 may be partially due to pathologic alterations in neuromuscular junctions and phrenic nerves.

Dynamical modeling and analysis of large cellular regulatory networks.

The dynamical analysis of large biological regulatory networks requires the development of scalable methods for mathematical modeling. Following the approach initially introduced by Thomas, we formalize the interactions between the components of a network in terms of discrete variables, functions, and parameters. Model simulations result in directed graphs, called state transition graphs. We are particularly interested in reachability properties and asymptotic behaviors, which correspond to terminal strongly connected components (or "attractors") in the state transition graph. A well-known problem is the exponential increase of the size of state transition graphs with the number of network components, in particular when using the biologically realistic asynchronous updating assumption. To address this problem, we have developed several complementary methods enabling the analysis of the behavior of large and complex logical models: (i) the definition of transition priority classes to simplify the dynamics; (ii) a model reduction method preserving essential dynamical properties, (iii) a novel algorithm to compact state transition graphs and directly generate compressed representations, emphasizing relevant transient and asymptotic dynamical properties. The power of an approach combining these different methods is demonstrated by applying them to a recent multilevel logical model for the network controlling CD4+ T helper cell response to antigen presentation and to a dozen cytokines. This model accounts for the differentiation of canonical Th1 and Th2 lymphocytes, as well as of inflammatory Th17 and regulatory T cells, along with many hybrid subtypes. All these methods have been implemented into the software GINsim, which enables the definition, the analysis, and the simulation of logical regulatory graphs.