The Genus Cyclospora (Apicomplexa: Eimeriidae), with a description of Cyclospora schneideri n.sp. in the snake Anilius scytale scytale (Aniliidae) from Amazonian Brazil: a review

A review is made of the recorded species of the coccidian genus Cyclospora and major events leading up to the discovery of C. cayetanensis, which is responsible for serious outbreaks of diarrhoea in man and is one of the aetiological agents of "traveller's diarrhoea". Humans appear to be the specific hosts, with the entire life-cycle in the intestine: to date there is no convincing evidence that the disease is a zoonosis. A description is given of oocysts and endogenous stages of C. schneideri n.sp., in the snake Anilius scytale scytale. Sporulation is exogenous and completed after about one week at 24-26º. Mature oocysts 19.8 × 16.6 (15.1 × 13.8-25.7 × 20.1), shape-index 1.2 (1.0-1.3): no oocyst residuum or polar bodies. Oocyst wall a single colourless, smooth layer with no micropyle: it is rapidly deformed or broken. Sporocysts 13.6 × 9.4 (11.3 × 8.3-15.1 × 9.9), shape-index 1.4 (1.2-1.5) with an inconspicuous Stieda body. Sporozoites 11-13 × 2.5-3. Endogenous stages are intracytoplasmic in the epithelial cells of the small intestine and with the characters of the Eimeriorina.

Angiostrongylus costaricensis: complete redescription of the migratory pathways based on experimental Sigmodon hispidus infection

Angiostrongylus costaricensis lives in the cecal and mesenteric arteries of its vertebrate hosts, and causes an inflammatory disease in humans. To investigate unknown aspects of the abdominal angiostrogyliasis pathogenesis, infected Sigmodon hispidus were sequentially studied in different times of infection. The study revealed that L3 goes alternatively through two migratory courses during its development into an adult worm: lymphatic/venous-arterial and venous portal pathways. The former is considered the principal one, because it is used by most of the larvae. Like other metastrongylides, A. costaricensis passes over the pulmonary circulation to migrate from the lymphatic system to the arterial circulation, where they circulate during some days before reaching their definitive habitat. The oviposition by mature females began on 15th day. Eggs and L1 were detected mainly in the intestine and stomach, surrounded by inflammatory reaction constituted by macrophages, monocytes, and eosinophils. They were also spread to the lungs, mesenteric lymph nodes, pancreas, spleen, and kidneys. The larvae (L1) exhibited the centripetal capacity to invade the lymphatic and venous vessels of the intestine and mesentery. Adult worms that developed in the venous intrahepatic pathway migrated downstream to reach the mesenteric veins and laid eggs that embolized in the portal hepatic vessels.

Creació de taules d'una base de dades relacional a partir del diagrama de classes d'anàlisi d'UML

És ben sabut que les úniques etapes del cicle de vida del programari que necessàriament s'han d'especificar són les de recollida de requisits i l'anàlisi o l'especificació del programari. La resta (disseny, implementació i prova) es pot generar d'una manera més o menys automàtica a partir de l'anàlisi. En aquest PFC hem volgut estudiar la viabilitat de la construcció automàtica de codi SQL a partir de diagrames de classes d'anàlisi UML. S'ha estès l'eina de modelatge UML Poseidon amb un connector, de manera que amb una interfície molt simple es pot obtenir molt ràpidament l'esquema bàsic d'una base de dades, incloent-hi les taules, les seves columnes, claus rimàries i foranes, i també els disparadors (i les claus úniques) necessaris per a garantir les restriccions de cardinalitat de les associacions.

Experimental infection of Leishmania (L.) chagasi in a cell line derived from Lutzomyia longipalpis (Diptera:Psychodidae)

The present work describes the in vitro infection of a cell line Lulo, derived from Lutzomyia longipalpis embryonic tissue, by Leishmania chagasi promastigotes. This infection process is compared with a parallel one developed using the J774 cell line. The L. chagasi MH/CO/84/CI-044B strain was used for experimental infection in two cell lines. The cells were seeded on glass coverslips in 24-well plates to reach a final number of 2 x 10(5) cells/well. Parasites were added to the adhered Lulo and J774 cells in a 10:1 ratio and were incubated at 28 and 37ºC respectively. After 2, 4, 6, 8, and 10 days post-infection, the cells were extensively washed with PBS, fixed with methanol, and stained with Giemsa. The number of internalized parasites was determined by counting at least 400 cultured cells on each coverslip. The results showed continuous interaction between L. chagasi promastigotes with the cell lines. Some ultrastructural characteristics of the amastigote forms were observed using transmission electron microscopy. The highest percentage of infection in Lulo cells was registered on day 6 post-infection (29.6%) and on day 4 in the J774 cells (51%). This work shows similarities and differences in the L. chagasi experimental infection process in the two cell lines. However, Lulo cells emerge as a new model to study the life-cycle of this parasite.

Basic biology of Pneumocystis carinii: a mini review

Basic aspects of cell biology of Pneumocystis carinii are reviewed with major emphasis on its life cycle and the structural organization of the trophozoites and cyst forms. Initially considered as a protozoan it is now established that Pneumocystis belongs to the Fungi Kingdom. Its life cycle includes two basic forms: (a) trophozoites, which are haploid cells that divide by binary fission and may conjugate with each other forming an early procyst and (b) cysts where division takes place through a meiotic process with the formation of eight nuclei followed by cytoplasmic delimitation and formation of intracystic bodies which are subsequently released and transformed into trophozoites. Basic aspects of the structure of the two developmental stages of P. carinii are reviewed.

Generació automàtica de codi Java amb ArgoUML

Aquesta memòria presenta un estudi de la generació automàtica de codi Java a partir de diagrames UML amb l'eina ArgoUML. El cicle de vida tradicional del programari presenta alguns problemes com la manca de sincronització entre codi i documentació, poca portabilitat i problemes de interoperabilidad. El paradigma MDA vol solucionar en part aquests problemes fent dels models el centre del desenvolupament del programari i apostant per la generació automàtica de models i codi.

Aplicació per a la sol·licitud de recursos informàtics

L'objectiu d'aquest treball és l'exposició detallada de les etapes d'anàlisi, disseny i prototip del projecte de Sol·licituds de Recursos Informàtics. La finalitat d'aquest projecte és la creació d'una eina colaborativa de workflow (circuit de treball) que permeti gestionar de manera eficaç les peticions de serveis o productes rebudes pel departament de tecnologies d'una empresa mitjana/gran, informant en cada moment del seu cicle de vida les persones involucrades en la mateixa.

Portal de B2C i gestió de comandes per Internet

Aquest treball de final de carrera vol fer un petit projecte informàtic i seguir-ne el cicle de vida, a més d'explorar la tecnologia Java 2 Enterprise Edition, que serà l'escollida per a implementar el projecte.

Esquema criptogràfic per exàmens electrònics segurs

L'objectiu d'aquest projecte és implementar un esquema criptogràfic que permeti fer exàmens electrònics de manera segura. L'esquema presentat en el projecte garanteix, mitjançant protocols i procediments, cadascuna de les etapes que es poden trobar en aquest cicle de vida.

Mètode de gestió de projectes informàtics d'adequació de programari

L'objectiu és triple: establir el cicle de vida d'un projecte i les seves diverses fases; proporcionar la metodologia, la documentació i les eines bàsiques per a gestionar el cicle de vida d'un projecte, i mirar d'extreure el màxim rendiment aprofitant la gestió d'un projecte actualment en execució.

Biology of three species of the Meccus phyllosomus complex (Hemiptera: Reduviidae: Triatominae) fed on blood of hens and rabbits

Aspects related to hatching, life time, number of blood meals to molt, mortality, feeding time and postfeed defecation delay for each instar of Meccus phyllosomus, M. mazzottii, and M. bassolsae, life-cycle were evaluated and compared in two cohorts of each of those three species, fed on hens or rabbits. No significant (p > 0.05) differences were recorded among cohorts fed on hens respect to cohorts fed on rabbits in M. phyllosomus and M. mazzottii and the average time of hatching was 21.5 days for cohorts fed on hens and 22.5 for cohorts fed on rabbits. Average egg-to-adult development times were no significant (p > 0.05) different between both cohorts of M. phyllosomus and M. mazzotti, independent of the blood meal source. The average span in days for each instar fed on hens was not significantly different to the average span for each instar fed on rabbits, when comparisons were made by species. The number of blood meals at each nymphal instar varied from 1 to 6 in both cohorts of each species. The mortality rates were higher on older nymphs, in both cohorts of M. phyllosomus and M. bassolsae, whereas they were higher on first instar nymphs on M. mazzottii. Mean feeding time was no significant (p > 0.05) different in triatomines fed on hens or fed on rabbits, when each species were compared separately. A similar number of nymphs of each cohort, completed the cycle. Defecation delay was no significant (p > 0.05) different when cohorts fed on hens and fed on rabbits were compared by species. Most of the studied parameters showed no significant (p > 0.05) differences among those cohorts fed on hens and for fed on rabbits, which could mean a high degree of association of those species with birds as much as mammals, under wild conditions, increasing their capacity to colonize human dwellings.

Characterization of the gene expression related to the process of DNA damage tolerance in Schistosoma mansoni

In the course of its complex life cycle, the parasite Schistosoma mansoni need to adapt to distinct environments, and consequently is exposed to various DNA damaging agents. The Schistosoma genome sequencing initiative has uncovered sequences from genes and transcripts related to the process of DNA damage tolerance as the enzymes UBC13, MMS2, and RAD6. In the present work, we evaluate the importance of this process in different stages of the life cycle of this parasite. The importance is evidenced by expression and phylogenetic profiles, which show the conservation of this pathway from protozoa to mammalians on evolution.

The spread of incompatibility-inducing parasites in sub-divided host populations.

BACKGROUND:Maternally transmitted symbionts have evolved a variety of ways to promote their spread through host populations. One strategy is to hamper the reproduction of uninfected females by a mechanism called cytoplasmic incompatibility (CI). CI occurs in crosses between infected males and uninfected females and leads to partial to near-complete infertility. CI-infections are under positive frequency-dependent selection and require genetic drift to overcome the range of low frequencies where they are counter-selected. Given the importance of drift, population sub-division would be expected to facilitate the spread of CI. Nevertheless, a previous model concluded that variance in infection between competing groups of breeding individuals impedes the spread of CI.RESULTS:In this paper we derive a model on the spread of CI-infections in populations composed of demes linked by restricted migration. Our model shows that population sub-division facilitates the invasion of CI. While host philopatry (low migration) favours the spread of infection, deme size has a non-monotonous effect, with CI-invasion being most likely at intermediate deme size. Individual-based simulations confirm these predictions and show that high levels of local drift speed up invasion but prevent high levels of prevalence across the entire population. Additional simulations with sex-specific migration rates further show that low migration rates of both sexes are required to facilitate the spread of CI.CONCLUSION:Our analyses show that population structure facilitates the invasion of CI-infections. Since some level of sub-division is likely to occur in most natural populations, our results help to explain the high incidence of CI-infections across species of arthropods. Furthermore, our work has important implications for the use of CI-systems in order to genetically modify natural populations of disease vectors.

Impairment of cell division of Trypanosoma cruzi epimastigotes

The mechanisms that facilitate the adaptation of Trypanosoma cruzi to two distinct hosts, insect and vertebrate, are poorly understood, in part due to the limited ability to perform gene disruption studies by homologous recombination. This report describes a developmentally-defective phenotype that resulted from integration of a drug marker adjacent to the GAPDH gene in T. cruzi.

Early Cretaceous trypanosomatids associated with fossil sand fly larvae in Burmese amber

Early Cretaceous flagellates with characters typical of trypanosomatids were found in the gut of sand fly larvae, as well as in surrounding debris, in Burmese amber. This discovery supports a hypothesis in which free-living trypanosomatids could have been acquired by sand fly larvae in their feeding environment and then carried transtadially into the adult stage. At some point in time, specific genera were introduced into vertebrates, thus establishing a dixenous life cycle.