Estudos anatômicos e histológicos sôbre a sub-família Triatominae (Heteropterareduviidae): parte XVIII: sistema traqueal do Triatoma infestans

O presente trabalho consta de um estudo sõbre a topografia do sistema traqueal em Triatoma infestans. Com esta finalidade empregaram-se diversas técnicas de coloração por infiltração, além de introduzir-se uma modificação no método de Gäbler. Foram usados vários fixadores e feitas muitas Lâminas histológicas para a comprovação dos resultados. É apresentado, na parte referente a considerações gerais sôbre o sistema, uma citação de alguns autores que mais se dedicaram ao estudo do aparelho respiratório nos insetos. O estudo sôbre a distribuição do sistema traqueal abrange ambos os sexos, porém, é limitado a exemplares adultos. O assunto é abordado em 3 seções: 1) traquéias da região cefálica; 2) traquéias da região torácica; e 3) traquéias da região abdominal. O percurso das traquéias da região cefálica é acompanhado e estudado em todo o trajeto, o mesmo acontecendo com as do tórax e do abdômen. A disposição do sistema em estudo, na região torácica, apresenta-se bem amis complexa e com inúmeras ramificações, que se destinam aos diversos órgãos desta região. É estudada, também, a distribuição dos ramos traqueais nas pernas e nas asas do inseto. É evidenciado um rompimento na continuidade do sistema traqueal, na altura do 1º para o 2º estígmas abdominais. Supõe-se que êste fato esteja ligado ao desaparecimento do 1º esternito e a migração do esclerito contendo o 1º estígma abdominal, para a região dorsal do inseto. Devido a êste fenômeno, o sistema traqueal do Triatoma infestans apresenta-se diferente, funcionando como se fôsse dos sistemas independentes entre si. As diferenças, o número e a disposição das traquéias na região abdominal é abordado amplamente, assim como, realçada a formação e função dos citados sacos traqueais.

Estudos anatômicos e histológicos sôbre a sub-família Triatominae (Heteroptera, Reduviidae): Parte XX: estudo comparado dos estigmas nas espécies mais importantes

É feito um estudo comparado sôbre a estrutura e o mecanismo dos estigmas de Triatoma vitticeps, Triatoma maculata, Triatoma sórdida, Triatoma brasiliensis, Rhodnius prolines e Panstrongyius megistus com os de Triatoma infestans, anteriormente já tratados. É, assim, elaborada uma tabela comparativa sôbre o tamanho e localização, dos espiráculos torácicos e abdominais, nas espécies citadas. Os estigmas mesotorácicos nas espécies do gênero Triatoma apresentam-se com várias modificações morfológicas, porém, não tão significantes como as encontradas em Panstrongyius megistus e Rhodnius prolixus. Seu mecanismo mostra acentuadas diferenças morfológicas. De um modo geral, os estigmas mesotorácicos possuem uma zona dorsal e outra ventral, que se diferenciam nas diferentes espécies e gêneros. A abertura do átrio para o exterior faz-se, perpendicularmente ao eixo maior do corpo do inseto. Nota-se uma região onde a cutícula é mais espêssa e que serve de base para a implantação dos músculos destinados ao seu funcionamento. O côndilo, que varia quanto à forma, nos diversos Triatomíneos, não é evidenciado nos estigmas metatorácicos. Os espiráculos metatorácicos encontram-se ocultos, totalmente, pelos escleritos do mesotórax e metatórax. O aspecto morfológico do mesmo é semelhante ao do mesotorácico, porém, apresenta algumas diferenças. Os espiraculos abdominais são em número de 8 pares. O 1.º par está situado na região látero-dorsal da membrana intersegmental, entre o tórax e o abdômen. Em Rhodnius prolixus o estigma apresenta-se circundado por zonas esclerosadas, em forma de listas. Nos demais Triatomíneos os escleritos estigmatíferos são semelhantes e menos reforçados. A forma e a estrutura e o mecanismo dêstes estigmas variam em todas as espécies citadas, Encontram-se 3 elementos de proteção à traquéia que se limita com o átrio. São eles: 1) rêde protetora que recobre parcialmente a entrada do estigma, semelhante a um peritrema; 2) côndilo interno que comanda a entrada e saída do ar das traquéias; e 3) falsos espinhos, situados no átrio e que variam de tamanho e espessura nos diferentes Triatomíneos. Finalmente, observa-se o VIII par de estigmas abdominais, cuja forma, mecanismo e localização o diferenciam dos demais. Êste par encontra-se citado por alguns autores, porém, na realidade, sua estrutura só é apresentada no presente trabalho.

Convergence of the mass-transport steepest descent scheme for the sub-critical Patlak-Keller-Segel model

Variational steepest descent approximation schemes for the modified Patlak-Keller-Segel equation with a logarithmic interaction kernel in any dimension are considered. We prove the convergence of the suitably interpolated in time implicit Euler scheme, defined in terms of the Euclidean Wasserstein distance, associated to this equation for sub-critical masses. As a consequence, we recover the recent result about the global in time existence of weak-solutions to the modified Patlak-Keller-Segel equation for the logarithmic interaction kernel in any dimension in the sub-critical case. Moreover, we show how this method performs numerically in one dimension. In this particular case, this numerical scheme corresponds to a standard implicit Euler method for the pseudo-inverse of the cumulative distribution function. We demonstrate its capabilities to reproduce easily without the need of mesh-refinement the blow-up of solutions for super-critical masses.

A relative double commutant theorem for hereditary sub-C*-algebras

We prove a double commutant theorem for hereditary subalgebras of a large class of C*-algebras, partially resolving a problem posed by Pedersen[8]. Double commutant theorems originated with von Neumann, whose seminal result evolved into an entire field now called von Neumann algebra theory. Voiculescu proved a C*-algebraic double commutant theorem for separable subalgebras of the Calkin algebra. We prove a similar result for hereditary subalgebras which holds for arbitrary corona C*-algebras. (It is not clear how generally Voiculescu's double commutant theorem holds.)

The tectonically controlled emplacement of a vertically sheeted gabbro-pyroxenite intrusion: Feeder-zone of an ocean-island volcano (Fuerteventura, Canary Islands)

The Miocene PX1 gabbro-pyroxenite pluton, Fuerteventura, Canary Islands, is a 3.5 x 5.5 km shallow-level intrusion (0.15-0.2 GPa and 1100-1120 degrees C), interpreted as the feeder-zone to an ocean-island volcano. It displays a vertical magmatic banding expressed in five 50 to 100 metre-wide NNE-SSW trending alkaline gabbro sequences alternating with pyroxenites. This emplacement geometry was controlled by brittle to ductile shear zones, generated by a regional E-W extensional tectonic setting that affected Fuerteventura during the Miocene. At a smaller scale, the PX1 gabbro and pyroxenite bands consist of metre-thick differentiation units, which suggest emplacement by periodic injection of magma pulses as vertical dykes that amalgamated, similarly to a sub-volcanic sheeted dyke complex. Individual dykes underwent internal differentiation following a solidification front parallel to the dyke edges. This solidification front may have been favoured by a significant lateral/horizontal thermal gradient, expressed by the vertical banding in the gabbros, the fractionation asymmetry within individual dykes and the migmatisation of the wall rocks. Pyroxenitic layers result from the fractionation and accumulation of clinopyroxene +/- olivine +/- plagioclase crystals from a mildly alkaline basaltic liquid. They are interpreted as truncated differentiation sequences, from which residual melts were extracted at various stages of their chemical evolution by subsequent dyke intrusions, either next to or within the crystallising unit. Compaction and squeezing of the crystal mush is ascribed to the incoming and inflating magma pulses. The expelled interstitial liquid was likely collected and erupted along with the magma flowing through the newly injected dykes. Clinopyroxene mineral orientation - as evidenced by EBSD and micro X-ray tomography investigations - displays a marked pure-shear component, supporting the interpretation of the role of compaction in the generation of the pyroxenites. Conversely, gabbro sequences underwent minor melt extraction and are believed to represent crystallised coalesced magma batches emplaced at lower rates at the end of eruptive cycles. Clinopyroxene orientations in gabbros record a simple shear component suggesting syn-magmatic deformation parallel to observed NNE-SSW trending shear zones induced by the regional tensional stress field. This emplacement model implies a crystallisation time of 1 to 5 years for individual dykes, consistent with PX1 emplacement over less than 0.5 My. A minimum amount of approximately 150 km(3) of magma is needed to generate the pluton, part of it having been erupted through the Central Volcanic Centre of Fuerteventura. If the regional extensional tectonic regime controls the PX1 feeder-zone initiation and overall geometry, rates and volumes of magma depend on other, source-related factors. High injection rates are likely to induce intrusion growth rates larger than could be accommodated by the regional extension. In this case, dyke intrusion by propagation of a weak tip, combined with the inability of magma to circulate through previously emplaced and crystallised dykes could result in an increase of non-lithostatic pressure on previously emplaced mushy dyke walls; thus generating strong pure-shear compaction within the pluton feeder-zone and interstitial melt expulsion. These compaction-dominated processes are recorded by the cumulitic pyroxenite bands. (C) 2010 Elsevier B.V. All rights reserved.

Transcatheter stent-valve implantation in a stenotic pulmonary conduit via a sub-xyphoidian access

Patients who develop a severe stenosis in biological pulmonary conduits previously implanted for pulmonary outflow trunk reconstructions are treated either by surgical re-replacement, or by transcatheter stent-valve implantation through a femoral vein access. A catheter-based sub-xyphoidian access through the right ventricle for stent-valve positioning in a pulmonary conduit has rarely been proposed. We describe the case of a 20-year-old man who underwent a pulmonary trunk reconstruction for a congenital pulmonary valve dysplasia and a few years later developed a stenosis in the pulmonary conduit. He was successfully treated with a 23 mm Edwards Sapien stent-valve implantation in pulmonary position, through an unusual right ventricular, sub-xyphoidian access and without contrast medium injections and pleura opening.

Public Governance, Health and Foreign Direct Investment in Sub-Saharan Africa

In this paper we diverge from the existing empirical literature on FDI determinants in two ways. First, we decompose the sources of the foreign direct investment (FDI) gap between Sub-Saharan Africa (SSA) and other developing regions. Once market size has been accounted for, we nd that SSA's FDI de cit is mostly explained by insufficient provision of public goods: low human capital accumulation, especially health, in SSA explains 100-140% of the inter-regional FDI gaps. Second, we estimate the indirect effect of infectious diseases on FDI through their direct impact on health. We find that a 1% point rise in HIV prevalence in the adult population is associated with a decrease in net FDI inflows of 3.5%, while a country in which 100% of the population is at risk of contracting deadly malaria receives about 16% less FDI than a similar country located in a malaria-free region.

Native-like, long synthetic peptides as components of sub-unit vaccines: practical and theoretical considerations for their use in humans.

Vaccines have been used as a successful tool in medicine by way of controlling many major diseases. In spite of this, vaccines today represent only a handful of all infectious diseases. Therefore, there is a pressing demand for improvements of existing vaccines with particular reference to higher efficacy and undisputed safety profiles. To this effect, as an alternative to available vaccine technologies, there has been a drive to develop vaccine candidate polypeptides by chemical synthesis. In our laboratory, we have recently developed a technology to manufacture long synthetic peptides of up to 130 residues, which are correctly folded and biologically active. This paper discusses the advantages of the molecularly defined, long synthetic peptide approach in the context of vaccine design, development and use in human vaccination.

Gas emission during laparoscopic colorectal surgery using a bipolar vessel sealing device: A pilot study on four patients.

BACKGROUND: Dissection during laparoscopic surgery produces smoke containing potentially toxic substances. The aim of the present study was to analyze smoke samples produced during laparoscopic colon surgery using a bipolar vessel sealing device (LigaSuretrade mark). METHODS: Four consecutive patients undergoing left-sided colectomy were enrolled in this pilot study. Smoke was produced by the use of LigaSuretrade mark. Samples (5,5l) were evacuated from the pneumoperitoneum in a closed system into a reservoir. Analysis was performed with CO2-laser-based photoacoustic spectroscopy and confirmed by a Fourier-transform infrared spectrum. The detected spectra were compared to the available spectra of known toxins. RESULTS: Samples from four laparoscopic sigmoid resections were analyzed. No relevant differences were noted regarding patient and operation characteristics. The gas samples were stable over time proven by congruent control measurements as late as 24 h after sampling. The absorption spectra differed considerably between the patients. One broad absorption line at 100 ppm indicating H2O and several unknown molecules were detected. With a sensitivity of alpha min ca 10-5 cm-1 no known toxic substances like phenol or indole were identified. CONCLUSION: The use of a vessel sealing device during laparoscopic surgery does not produce known toxic substances in relevant quantity. Further studies are needed to identify unknown molecules and to analyze gas emission under various conditions.

Quality of web-based information on bipolar disorder

Rapport de synthèse : Introduction : Internet est une source importante d'information sur la santé mentale. Le trouble bipolaire est communément associé à un handicap, des comorbidités, un faible taux d'introspection et une mauvaise compliance au traitement. Le fardeau de la maladie, de par les épisodes dépressifs et maniaques, peut conduire les personnes (dont le diagnostic de trouble bipolaire a été déjà posé ou non), ainsi que leur famille à rechercher des informations sur Internet. De ce fait, il est important que les sites Web traitant du sujet contiennent de l'information de haute qualité, basée sur les évidences scientifiques. Objectif.: évaluer la qualité des informations consultables sur Internat au sujet du trouble bipolaire et identifier des indicateurs de qualité. Méthode: deux mots-clés : « bipolar disorder » et « manic depressive illness » ont été introduits dans les moteurs de recherche les plus souvent utilisés sur Internet. Les sites Internet ont été évalués avec un formulaire standard conçu pour noter les sites sur la base de l'auteur (privé, université, entreprise,...), la présentation, l'interactivité, la lisibilité et la qualité du contenu. Le label de qualité « Health On the Net» (HON), et l'outil DISCERN ont été utilisés pour vérifier leur efficacité comme indicateurs de la qualité. Résultats: sur les 80 sites identifiés, 34 ont été inclus. Sur la base de la mesure des résultats, la qualité du contenu des sites s'est avérée être bonne. La qualité du contenu des sites Web qui traitent du trouble bipolaire est expliquée de manière significative par la lisibilité, la responsabilité et l'interactivité aussi bien que par un score global. Conclusions: dans l'ensemble, la qualité du contenu de l'étude des sites Web traitant du trouble bipolaire est de bonne qualité.

La crisi sub-prime i el crack de 1929: Comparació d'episodis d'eufòria financera

Treball de recerca realitzat per un alumne d'ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l'any 2009. La present investigació té per objecte d’estudi la relació, atès el període de turbulències econòmiques que travessa el món globalitzat, entre els episodis d’eufòria financera i les crisi financeres i econòmiques, i la periodicitat amb les que aquestes es produeixen. Aquesta pretén confrontar-se des d’una aproximació històric-econòmica, mitjançant l’anàlisi i la comparació de dos successos -el crack borsari de 1929 i la crisi sub-prime- per tal de demostrar la existència de comuns denominadors, i, a la llum dels resultats, apreciar les conclusions que aporta la Història. Serà, doncs, aquesta periodicitat i les seves implicacions la qual s'ambicionarà contrastar amb la realitat mitjançant l'aplicació i l'anàlisi pràctica de dos episodis rellevants i paradigmàtics, amb el recolzament i l'autoritat del model comparatiu establerts per l'economista John Kenneth Galbraith al seu llibre ''Breve historia de la euforia financiera''.

Mathematical description of bacterial traveling pulses

The Keller-Segel system has been widely proposed as a model for bacterial waves driven by chemotactic processes. Current experiments on E. coli have shown precise structure of traveling pulses. We present here an alternative mathematical description of traveling pulses at a macroscopic scale. This modeling task is complemented with numerical simulations in accordance with the experimental observations. Our model is derived from an accurate kinetic description of the mesoscopic run-and-tumble process performed by bacteria. This model can account for recent experimental observations with E. coli. Qualitative agreements include the asymmetry of the pulse and transition in the collective behaviour (clustered motion versus dispersion). In addition we can capture quantitatively the main characteristics of the pulse such as the speed and the relative size of tails. This work opens several experimental and theoretical perspectives. Coefficients at the macroscopic level are derived from considerations at the cellular scale. For instance the stiffness of the signal integration process turns out to have a strong effect on collective motion. Furthermore the bottom-up scaling allows to perform preliminary mathematical analysis and write efficient numerical schemes. This model is intended as a predictive tool for the investigation of bacterial collective motion.

Suicidal expression among school-attending adolescents in a middle-income sub-Saharan country.

We investigated correlates for suicidal expression among adolescents in the Seychelles. Data on 1,432 students (52% females) were derived from the Global School-based Health Survey. Participants were divided into three groups: those with no suicidal behavior (N = 1,199); those with suicide ideation/SI (N = 89); and those reporting SI with a plan to carry out a suicide attempt/SISP (N = 139), each within a 12-month recall period. Using multinomial logistic regression, we examined the strength of associations with social, behavioral and economic indicators while adjusting for covariates. Sixteen percent of school-attending adolescents reported a suicidal expression (10% with a plan/6.2% without). Those reporting SI were younger (relative risk ratio RRR = 0.81; CI = 0.68-0.96), indicated signs of depression (RRR = 1.69; CI = 1.05-2.72) and loneliness (RRR=3.36; CI =1.93-5.84). Tobacco use (RRR = 2.34; CI = 1.32-4.12) and not having close friends (RRR = 3.32; CI = 1.54-7.15) were significantly associated with SI. Those with SISP were more likely to be female (RRR = 0.47; 0.30-0.74), anxious (RRR = 3.04; CI = 1.89-4.88) and lonely (RRR = 1.74; CI = 1.07-2.84). Having no close friends (RRR = 2.98; 1.56-5.69) and using tobacco (RRR = 2.41; 1.48-3.91) were also strongly associated. Having parents who were understanding was protective (RRR = 0.50; CI = 0.31-0.82). Our results suggest that school health promotion programs may benefit from targeting multiple factors associated with suicidal expression. More research, particularly multilevel designs are needed to identify peer and family influences which may modify associations with suicidality.

Use of High Doses of Quetiapine in Bipolar Disorder Episodes are not Linked to High Activity of Cytochrome P4503A4 and/or Cytochrome P4502D6.

The use of quetiapine for treatment of bipolar disorders at a higher dosage than the licensed range is not unusual in clinical practice. Quetiapine is predominantly metabolised by cytochrome P450 3A4 (CYP3A4) and to a lesser extent by CYP2D6. The large interindividual variability of those isozyme activities could contribute to the variability observed in quetiapine dosage. The aim of the present study is to evaluate if the use of high dosages of quetiapine in some patients, as compared to patients treated with a dosage in the licensed range (up to 800 mg/day), could be explained by a high activity of CYP3A4 and/or of CYP2D6. CYP3A4 activities were determined using the midazolam metabolic ratio in 21 bipolar and schizoaffective bipolar patients genotyped for CYP2D6. 9 patients were treated with a high quetiapine dosage (mean ± SD, median; range: 1467 ± 625, 1200; 1000-3000 mg/day) and 11 with a normal quetiapine dosage (433 ± 274, 350; 100-800 mg/day). One patient in the high dose and one patient in the normal dose groups were genotyped as CYP2D6 ultrarapid metabolizers. CYP3A4 activities were not significantly different between the two groups (midazolam metabolic ratio: 9.4 ± 8.2; 6.2; 1.7-26.8 vs 3.9 ± 2.3; 3.8; 1.5-7.6, in the normal dose group as compared to the high dose group, respectively, NS). The use of high quetiapine dosage for the patients included in the present study cannot be explained by variations in pharmacokinetics parameters such as a high activity of CYP3A4 and/or of CYP2D6.