Endosymbiotic bacteria associated with nematodes, ticks and amoebae.

Endosymbiosis is a mutualistic, parasitic or commensal symbiosis in which one symbiont is living within the body of another organism. Such symbiotic relationship with free-living amoebae and arthropods has been reported with a large biodiversity of microorganisms, encompassing various bacterial clades and to a lesser extent some fungi and viruses. By contrast, current knowledge on symbionts of nematodes is still mainly restricted to Wolbachia and its interaction with filarial worms that lead to increased pathogenicity of the infected nematode. In this review article, we aim to highlight the main characteristics of symbionts in term of their ecology, host cell interactions, parasitism and co-evolution, in order to stimulate future research in a field that remains largely unexplored despite the availability of modern tools.

Physical activity assessment using a pedometer and its comparison with a questionnaire in a large population survey.

The aim of this study was to evaluate the use of the pedometer in epidemiologic research on physical activity. Within the framework of a health examination survey in 1988-1989, physical activity was assessed in a representative population sample of 493 men and women aged 25-74 years who were residents of Switzerland. They wore a pedometer for 1 week at work and during leisure time, and the results, converted into steps per day, were compared with answers to a questionnaire. The average number of steps per day decreased from 11,900 to 6,700 and from 9,300 to 7,300 for men and women, respectively, in the youngest to the oldest age groups. For men, categorized according to type of physical activity at work, there was a highly significant difference in the number of steps (p < 0.001), whereas in women the results were associated with leisure-time physical activity (p = 0.003). For both sexes, practicing sports more than once a week was associated with an important increase in steps per day. Analyzing the number of steps according to the day of the week and occupational category produced an unexpected result: Men with a physically active job engaged in more leisure-time physical activity on the weekend. The pedometer proved to be useful in assessing physical activity in a large, free-living population.

Aprendizagens em contexto de formação inicial: um estudo com futuros professores de ciências em Cabo Verde

O estudo faz parte de um projecto mais amplo, desenvolvido no âmbito do Grupo ESSA (Estudos Sociológicos em Sala de Aula), centrado na formação inicial de professores de ciências. Neste estudo partiu-se do seguinte problema: Que prática(s) pedagógica(s) é(são) implementada(s) na formação inicial de professores de ciências em Cabo Verde e de que forma essa(s) prática(s) se reflecte(m) na aprendizagem e intervenção pedagógica dos formandos? Teoricamente, o estudo baseia-se, em termos sociológicos, no modelo do discurso pedagógico de Bernstein (Bernstein, 2000). Em termos psicológicos, baseia-se nas ideias de Vygotsky (1978) e, na sua vertente epistemológica, na conceptualização de Ziman (1984) sobre a construção da ciência. Metodologicamente, o estudo enquadra-se numa abordagem de investigação mista. Com base numa dialéctica entre o teórico e o empírico, construíram-se instrumentos para caracterizar o contexto de formação inicial e a prática em sala de aula, e um guião de entrevista para apreciar as aprendizagens dos formandos. A investigação envolveu uma formadora e formandos de uma disciplina da área da Metodologia da Biologia de uma Escola Superior de Educação. Os resultados mostraram que o contexto específico de formação se caracterizou, em particular, pela desvalorização do trabalho experimental e da relação entre ciência e metaciência, por um baixo nível de exigência conceptual, por uma fraca articulação entre os conhecimentos e por um grau muito baixo de explicitação do texto a ser adquirido pelos formandos. Revelaram também que a formação pouco contribuiu para a aprendizagem e intervenção pedagógica dos formandos, isto é, para a aquisição da orientação específica de codificação (regras de reconhecimento e de realização) para características relacionadas com o que e com o como do ensino/aprendizagem das ciências. O estudo pretende contribuir com sugestões sobre a inclusão de características pedagógicas da aprendizagem científica na formação inicial de professores de ciências em Cabo Verde e permite reflectir sobre a importância da utilização de instrumentos metodológicos que possibilitem uma análise comparativa entre contextos e textos presentes na formação de professores.

Commentary on the need for a research culture in the forensic sciences

Asked to comment on a collective discussion paper by Jennifer L. Mnookin et al., this Commentary identifies difficulties the authors encountered in defining or agreeing on the subject matter "forensic science" and its perceived deficiencies. They conclude that there is a need for a research culture, whereas this Commentary calls for the development of a forensic science culture through the development of forensic science education fed by research dedicated to forensic science issues. It is a call for a change of emphasis and, perhaps, of paradigm.

La enseñanza de la Biblioteconomía y la Documentación en la universidad española a finales de los noventa

Se describe la situación actual de la formación universitaria en Biblioteconomía y Documentación en España y las tendencias a considerar a corto y medio plazo para asegurar que las titulaciones de biblioteconomía y documentación sigan manteniendo una presencia notable en la universidad española. En la primera parte del texto se describe el estado actual de la formación universitaria en todos los ciclos (diplomatura, licenciatura y tercer ciclo), y también la presencia de la biblioteconomía y documentación en otras titulaciones. Se destacan especialmente los problemas relacionados con el descenso del número de matriculaciones. En la segunda parte se hace incidencia las orientaciones que se consideran clave para mantener las titulaciones al máximo nivel: internacionalización, enseñanza a distancia, e integración o convergencia con la archivística. Finalmente, en las conclusiones se destaca la necesidad de planificar adecuadamente la diplomatura y la licenciatura y en la importancia de establecer mecanismos de cooperación interuniversitaria, y también entre las universidades y las asociaciones de profesionales, y las organizaciones públicas y privadas.

Informe del Seminari sobre la convergència europea en els ensenyaments de Biblioteconomia i Documentació (22 de febrer de 2002)

En els dos darrers anys la Universitat de Barcelona ha estat atenta als desenvolupaments que tenen lloc en l'àmbit europeu en el tema de la convergència europea dels ensenyaments universitaris, que té com a punt de partida la Declaració de Bolonya. Des del primer moment, la UB ha estat molt sensible a aquesta convergència i ha liderat una sèrie de reunions i treballs en el si de la universitat espanyola per debatre aquesta qüestió i preparar un futur europeu. El rectorat de la UB també ha tingut informada la seva comunitat de tots aquests desenvolupaments i ha organitzat una sèrie de seminaris i reunions de treball per informar els càrrecs acadèmics i el professorat i sensibilitzar-los de cara a iniciar el treball cap a aquesta convergència europea dels ensenyaments universitaris. D'acord, doncs, amb aquesta línia prioritària de la Universitat de Barcelona, aquest curs 2001-2002 la Facultat de Biblioteconomia i Documentació ha posat en marxa, amb l'ajuda de la Divisió de Ciències de l'Educació, un pla de millora docent on s'emmarquen una sèrie d'actuacions de cara a estudiar la implantació del sistema europeu de crèdits en algunes matèries troncals dels ensenyaments de Biblioteconomia i Documentació. Recentment, la Universitat de Barcelona també ha aprovat que l'ensenyament de Documentació que s'imparteix a la facultat sigui un dels ensenyaments pilot a fer la transició cap al sistema de crèdits europeu.

Els programes de fonts i serveis d'informació a les escoles nord-americanes de biblioteconomia i documentació

S'estableix una relació entre els cursos bàsics de treball de referència, impartits en les escoles de Biblioteconomia i Documentació nord-americanes, i les assignatures Serveis d'informació i Serveis i fonts d'informació presents en els plans d'estudis de la Diplomatura en Biblioteconomia i Documentació de la Universitat de Barcelona durant la dècada dels noranta. Es presenta una revisió de la literatura recent sobre la naturalesa i les tendències del curs bàsic esmentat, i s'analitzen els programes corresponents a aquesta assignatura que s'imparteixen a les millors escoles dels Estats Units d'Amèrica

Los programas de fuentes y servicios de información en las escuelas norteamericanas de biblioteconomía y documentación

Se establece una relación entre los cursos básicos de trabajo de referencia impartidos en las escuelas de Biblioteconomía y Documentación norteamericanas, y las asignaturas Servicios de información y Servicios y fuentes de información presentes en los planes de estudios de la Diplomatura en Biblioteconomía y Documentación de la Universidad de Barcelona durante la década de los noventa. Se ofrece una revisión de la literatura reciente sobre la naturaleza y tendencias del citado curso básico, y se analizan los programas correspondientes a esta asignatura que se imparten en las mejores escuelas de los Estados Unidos de América.

Relationship between physical inactivity and adiposity in prepubertal boys.

OBJECTIVE: To study the relationship between the energy expenditure for activity (EEAct), the level of activity and adiposity in a group of 9-year-old boys (n = 28) with different body composition (body weight, 38 +/- 10 kg [range, 23 to 66 kg]; fat mass, 23% +/- 10% [range, 8% to 42%]). METHODS: Total energy expenditure (TEE) was measured by means of the heart-rate monitoring method. EEAct was calculated as TEE-(REE+0.1 TEE), where REE is the postabsorptive resting energy expenditure and 0.1 TEE corresponds to the postprandial thermogenesis (approximately 10% of TEE). RESULTS: TEE, REE, and EEAct were 9388 +/- 1859, 5154 +/- 642, and 3295 +/- 1356 l J/day, respectively. Daily time devoted to sedentary and nonsedentary activities averaged 290 +/- 155 minutes (range, 69 to 621) and 534 +/- 150 minutes (range, 180 to 783), respectively. Time spent on sedentary activities was directly proportional to fat mass percentage (r = 0.46; p < 0.05). It was the only variable, among the free-living physical-activity [EEAct, TEE/(REE+0.1 TEE) ratio, time spent in nonsedentary and sedentary activities] variables, which remained significantly in the multiple step-down regression analysis final equation (r = 0.46; p < 0.05). CONCLUSIONS: The positive relationship between adiposity and time spent on sedentary activities in 9-year-old boys suggests the importance of the role played by muscular activity, at least in the maintenance of obesity in childhood. Prepubertal children should be encouraged to spend less time on sedentary activities to treat and prevent their obesity.

A new accelerometric method to assess the daily walking practice.

OBJECTIVE: To describe a method to obtain a profile of the duration and intensity (speed) of walking periods over 24 hours in women under free-living conditions. DESIGN: A new method based on accelerometry was designed for analyzing walking activity. In order to take into account inter-individual variability of acceleration, an individual calibration process was used. Different experiments were performed to highlight the variability of acceleration vs walking speed relationship, to analyze the speed prediction accuracy of the method, and to test the assessment of walking distance and duration over 24-h. SUBJECTS: Twenty-eight women were studied (mean+/-s.d.) age: 39.3+/-8.9 y; body mass: 79.7+/-11.1 kg; body height: 162.9+/-5.4 cm; and body mass index (BMI) 30.0+/-3.8 kg/m(2). RESULTS: Accelerometer output was significantly correlated with speed during treadmill walking (r=0.95, P<0.01), and short unconstrained walks (r=0.86, P<0.01), although with a large inter-individual variation of the regression parameters. By using individual calibration, it was possible to predict walking speed on a standard urban circuit (predicted vs measured r=0.93, P<0.01, s.e.e.=0.51 km/h). In the free-living experiment, women spent on average 79.9+/-36.0 (range: 31.7-168.2) min/day in displacement activities, from which discontinuous short walking activities represented about 2/3 and continuous ones 1/3. Total walking distance averaged 2.1+/-1.2 (range: 0.4-4.7) km/day. It was performed at an average speed of 5.0+/-0.5 (range: 4.1-6.0) km/h. CONCLUSION: An accelerometer measuring the anteroposterior acceleration of the body can estimate walking speed together with the pattern, intensity and duration of daily walking activity.

Plumage ornaments, bacterial colonisation and signalling in european starling, "Sturnus vulgaris"

Abstract Animal behaviours or structures are used by senders as signals to try to increase their fitness by altering the behaviour of receivers. A large fraction of studies on sexual selection have focussed on male ornaments and have demonstrated that these ornaments signal the quality of their owner and are used by female for mate choice. Although females can also exhibit conspicuous traits, studies on female ornaments are markedly lacking. In chapter 1, we show that female starlings are showier on chest whiteness than males and that females' whiteness may potentially indicate female condition at the start of breeding and provide fitness advantages to breeding birds. Furthermore we point out that feather density and abrasion are important factors shaping the expression of chest whiteness. This suggests that further understanding of the evolution of chest whiteness in Starlings requires to examine the environmental and physiological factors that shape feather condition. Plumage may suffer from damage through abrasion and bacterial activity. In chapter 2, we focus on factors that influence feather-degrading bacterial communities. Within the hypothesis that parental care can be trade-off against the demands of self-maintenance, we show that a brood size manipulation modifies the structure of feather-degrading bacterial communities and the density of free- living bacteria. Thus we have pointed out a potentially poorly known cost of reproduction. In the same context of a trade-off between reproductive activities and individual self-maintenance, chapter 3 shows that at a proximate level in females but not in males, the individual variation in time and/or energy allocated in reproductive activities is associated with prolactin hormone levels. Our study provides evidence for the existence of a sex related difference in the relationship between brood size and prolactin levels. Birds have evolved sanitation behaviours and preen gland secretions to preserve the condition of their plumage. In chapter 4, we describe a method that allows to measure preen gland in situ. Then we use this method to characterize a number of phenotypic and ecological factors that explain variation in preen gland size in free-living individuals. In parent-offspring interactions, parents use offspring signals to provision their brood. In chapter 5, we demonstrate that nestling flanges and body skin reflect in the ultra-violet (UV) wavelengths ant that parents use this UV reflectance in food allocation decisions. Résumé Certains comportements et structures chez les animaux agissent, pour ceux qui les émettent, comme des signaux permettant d'augmenter leur fitness en altérant les comportements de ceux qui les perçoivent. Une grande partie des études sur la sélection sexuelle s'est focalisée sur les ornements mâles. Ces études ont démontré que ces ornements pouvaient signaler la qualité de celui qui les porte et influencer le choix des femelles. Bien que les femelles puissent aussi présenter des traits voyants, les études sur leurs ornements font défaut. Dans le chapitre 1 de ce travail, nous montrons que les étourneaux femelles sont plus voyantes que les mâles sur la base de la blancheur de la poitrine. De plus la blancheur des femelles peut signaler leur condition au début de la saison de reproduction et ainsi être corrélée avec leur fitness. Nous mettons aussi en évidence que la densité et l'abrasion des plumes sont des facteurs importants, contrôlant l'expression de la blancheur de la poitrine. Ceci suggère que des études futures pourraient examiner le rôle des facteurs environnementaux et physiologiques qui influencent la condition des plumes pour mieux comprendre l'évolution de la blancheur chez les étourneaux. Le plumage subit des dommages à travers l'abrasion et probablement aussi par l'activité de dégradation de bactéries. Dans le chapitre 2 de ce travail, nous nous intéressons aux facteurs qui influencent les communautés de bactéries dégradant les plumes. Nous basant sur l'hypothèse selon laquelle il existe un compromis entre les soins parentaux et la maintenance corporelle, nous montrons qu'une manipulation de la taille de nichée modifie la structure des communautés de bactéries dégradant les plumes ainsi que les densités de bactéries libres présentes sur le plumage. Ainsi nous mettons en évidence un coût encore peu connu des activités de reproduction. Dans le même contexte, nous montrons, dans le chapitre 3, que des variations individuelles dans l'énergie et/ou le temps alloué dans les activités de reproduction sont associés, chez les femelles, à un niveau proximal à l'hormone prolactine. Cette relation n'est pas présente chez les mâles. Cette étude montre que la relation entre la taille de nichée et les niveaux de prolactine diffère avec le sexe des individus. Les oiseaux utilisent des comportements de nettoyage associés aux sécrétions de la glande uropygiale afin de préserver la condition de leurs plumes. Dans le chapitre 4 de ce travail, nous décrivons une méthode qui permet de mesurer la taille de la glande in situ. Puis nous caractérisons certains facteurs écologiques et physiologiques qui expliquent les variations de la taille de la glande chez des individus capturés dans leur environnement. Les parents nourrissent leur progéniture en réponse à des signaux émis par ceux-ci. Dans le chapitre 5 de ce travail, nous démontrons que les commissures et la peau sur le corps des oisillons reflètent la lumière dans l'ultraviolet. Nous montrons que les parents utilisent cette réflexion dans l'ultraviolet lors de l'allocation de nourriture pour leurs jeunes.

High-precision satellite positioning system as a new tool to study the biomechanics of human locomotion.

New Global Positioning System (GPS) receivers allow now to measure a location on earth at high frequency (5Hz) with a centimetric precision using phase differential positioning method. We studied whether such technique was accurate enough to retrieve basic parameters of human locomotion. Eight subjects walked on an athletics track at four different imposed step frequencies (70-130steps/min) plus a run at free pace. Differential carrier phase localization between a fixed base station and the mobile antenna mounted on the walking person was calculated. In parallel, a triaxial accelerometer, attached to the low back, recorded body accelerations. The different parameters were averaged for 150 consecutive steps of each run for each subject (total of 6000 steps analyzed). We observed a perfect correlation between average step duration measured by accelerometer and by GPS (r=0.9998, N=40). Two important parameters for the calculation of the external work of walking were also analyzed, namely the vertical lift of the trunk and the velocity variation per step. For an average walking speed of 4.0km/h, average vertical lift and velocity variation were, respectively, 4.8cm and 0.60km/h. The average intra-individual step-to-step variability at a constant speed, which includes GPS errors and the biological gait style variation, were found to be 24. 5% (coefficient of variation) for vertical lift and 44.5% for velocity variation. It is concluded that GPS technique can provide useful biomechanical parameters for the analysis of an unlimited number of strides in an unconstrained free-living environment.

Role of superoxide, nitric oxide, and peroxynitrite in doxorubicin-induced cell death in vivo and in vitro.

Doxorubicin (DOX) is a potent available antitumor agent; however, its clinical use is limited because of its cardiotoxicity. Cell death is a key component in DOX-induced cardiotoxicity, but its mechanisms are elusive. Here, we explore the role of superoxide, nitric oxide (NO), and peroxynitrite in DOX-induced cell death using both in vivo and in vitro models of cardiotoxicity. Western blot analysis, real-time PCR, immunohistochemistry, flow cytometry, fluorescent microscopy, and biochemical assays were used to determine the markers of apoptosis/necrosis and sources of NO and superoxide and their production. Left ventricular function was measured by a pressure-volume system. We demonstrated increases in myocardial apoptosis (caspase-3 cleavage/activity, cytochrome c release, and TUNEL), inducible NO synthase (iNOS) expression, mitochondrial superoxide generation, 3-nitrotyrosine (NT) formation, matrix metalloproteinase (MMP)-2/MMP-9 gene expression, poly(ADP-ribose) polymerase activation [without major changes in NAD(P)H oxidase isoform 1, NAD(P)H oxidase isoform 2, p22(phox), p40(phox), p47(phox), p67(phox), xanthine oxidase, endothelial NOS, and neuronal NOS expression] and decreases in myocardial contractility, catalase, and glutathione peroxidase activities 5 days after DOX treatment to mice. All these effects of DOX were markedly attenuated by peroxynitrite scavengers. Doxorubicin dose dependently increased mitochondrial superoxide and NT generation and apoptosis/necrosis in cardiac-derived H9c2 cells. DOX- or peroxynitrite-induced apoptosis/necrosis positively correlated with intracellular NT formation and could be abolished by peroxynitrite scavengers. DOX-induced cell death and NT formation were also attenuated by selective iNOS inhibitors or in iNOS knockout mice. Various NO donors when coadministered with DOX but not alone dramatically enhanced DOX-induced cell death with concomitant increased NT formation. DOX-induced cell death was also attenuated by cell-permeable SOD but not by cell-permeable catalase, the xanthine oxidase inhibitor allopurinol, or the NADPH oxidase inhibitors apocynine or diphenylene iodonium. Thus, peroxynitrite is a major trigger of DOX-induced cell death both in vivo and in vivo, and the modulation of the pathways leading to its generation or its effective neutralization can be of significant therapeutic benefit.