293 research outputs found

    Comparative Study in the Embryology of the Turkey

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    It is a well-known fact that the incubation period for the turkey is seven days longer than that of the chicken. A comparative study is being made to ascertain in what respects the embryonic development of the turkey differs from that of the chicken. Observations show that the course of development runs slower in the turkey from the onset of incubation. The turkey embryo lags approximately 24-hours behind the chicken at the stage of closure of the amnion

    Glaucoma Surgery with Fugo Blade

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    Seguridad de JAX-RS frente a ataques por inyección de código

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    Trabajo de InvestigaciónSe implementan tres algoritmos de ataques de inyección de código. Teniendo en cuenta estos algoritmos se definen los requerimientos para diseñar y desarrollar el prototipo, se describe la arquitectura de la aplicación, además del escenario de pruebas donde se encuentran los servicios Web a ser atacados. Por último se indican los niveles de vulnerabilidad encontrados en cada una de las implementaciones seleccionadas y se finaliza con un análisis de los resultados y algunas conclusiones de la investigación.Trabajo de investigaciónINTRODUCCIÓN 1. GENERALIDADES 2. SELECCIÓN DE ALGORITMOS 3. DEFINICIÓN DE REQUISITOS 4. DISEÑO DEL SISTEMA 5. ARQUITECTURA DEL SISTEMA 6. DESARROLLO DEL SISTEMA 7. ESCENARIO DE PRUEBAS 8. EVALUACIÓN DE VULNERABILIDADES 9. CONCLUSIONES REFERENCIASPregradoIngeniero de Sistema

    Adaptáció, koevolúció és stabilitás a gazda-költésparazita kapcsolatokban = Adaptation, coevolution and stability in host-brood parasite relationships

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    A madarak költésparazitizmusa a gazdafaj és a költésparazita közötti koevolúció példái. A közismert kakukk (Cuculus canorus) Magyarországon szokatlanul nagymértékben (41-68%) parazitálja a nádirigót (Acrocephalus arundinaceus), lecsökkentve annak reprodukciós sikerét. A jelen OTKA pályázatban a két faj koevolúciós adaptációit kutattuk, így pl. a gazda tojásdiszkriminációs viselkedését (tojáseltemetés, tojáskidobás és fészekelhagyás). Kimutattuk, hogy a nádirigó fejlett tojásfelismeréssel rendelkezik, s a tojások alapszíne és nem a foltozottság játszik elsődleges szerepet az idegen tojások felsimerésében. Ugyancsak kimutattuk és egy modellel érzékeltettük, hogy a gazdák felismerik saját tojásaikat és memória-sablonnal rendelkeznek róla, s ennek szűk tartományában fogadnak el mimikris kakukktojásokat. A fészekaljon belüli tojások foltozottságnak viszont együttesen van szerepe, azok kis változatossága elősegíti az idegen tojás felismerését, míg azok nagy változatossága gyengíti. Többszörös parazitizmusban a nádirigók kisebb mértékben tudják elutasítani a kakukktojásokat, s így nagyobb lesz a költésparazita reprodukciós sikere. Többek között vizsgáltuk még a kakukkfióka kihordási ösztönének az okát, azaz a tojásból kikelő fióka minden tojást és fiókát kidob a fészekből 3 napon belül. Kísérleteink szerint ennek oka, hogy jobban ki tudja sajátítani a forrásokat ha egyedül van a fészekben, s a gazdákat nagyobb méretű táplálék gyűjtésére ösztönzi. | Cases of avian brood parasitism are examples for coevolution between hosts and brood parasites. In Hungary, the well-known common cuckoos (Cuculus canorus) parasitize great reed warblers (Acrocephalus arundinaceus) at an unusually high rate (41-68%), reducing their reproductive success. We studied coevolutionary adaptations between hosts and brood parasites within the framework of the present OTKA grant, e.g. egg discrimination ability of hosts (egg burial, egg ejection and nest desertion). We showed the well-developed egg discrimination ability of great reed warblers, and the importance of background colour of eggs in respect to spottedness in egg recognition. We also revealed and showed by a model that hosts know their own eggs and have a memory-template of these eggs. They accept mimetic cuckoo eggs if their characteristics fall below the acceptance threshold. We showed that intraclucth variation of eggshell spottedness facilitates foreign egg recognition if intraclucth variation is low, but it was found an opposite effect if it was high. In multiple parasitism hosts showed high tolerance toward cuckoo eggs, resulted in a higher fledging success of the brood parasite. We also revealed that the cuckoo chicks grow up alone in host nests to utilize parental provisioning ability of hosts better than in mixed broods of hosts and cuckoos

    Ancient origin and maternal inheritance of blue cuckoo eggs

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    Maternal inheritance via the female-specific W chromosome was long ago proposed as a potential solution to the evolutionary enigma of co-existing host-specific races (or 'gentes') in avian brood parasites. Here we report the first unambiguous evidence for maternal inheritance of egg colouration in the brood-parasitic common cuckoo Cuculus canorus. Females laying blue eggs belong to an ancient (∼2.6 Myr) maternal lineage, as evidenced by both mitochondrial and W-linked DNA, but are indistinguishable at nuclear DNA from other common cuckoos. Hence, cuckoo host races with blue eggs are distinguished only by maternally inherited components of the genome, which maintain host-specific adaptation despite interbreeding among males and females reared by different hosts. A mitochondrial phylogeny suggests that blue eggs originated in Asia and then expanded westwards as female cuckoos laying blue eggs interbred with the existing European population, introducing an adaptive trait that expanded the range of potential hosts

    Foxp3 Represses Retroviral Transcription by Targeting Both NF-κB and CREB Pathways

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    Forkhead box (Fox)/winged-helix transcription factors regulate multiple aspects of immune responsiveness and Foxp3 is recognized as an essential functional marker of regulatory T cells. Herein we describe downstream signaling pathways targeted by Foxp3 that may negatively impact retroviral pathogenesis. Overexpression of Foxp3 in HEK 293T and purified CD4(+) T cells resulted in a dose-dependent and time-dependent decrease in basal levels of nuclear factor-κB (NF-κB) activation. Deletion of the carboxyl-terminal forkhead (FKH) domain, critical for nuclear localization and DNA-binding activity, abrogated the ability of Foxp3 to suppress NF-κB activity in HEK 293T cells, but not in Jurkat or primary human CD4(+) T cells. We further demonstrate that Foxp3 suppressed the transcription of two human retroviral promoters (HIV-1 and human T cell lymphotropic virus type I [HTLV-I]) utilizing NF-κB-dependent and NF-κB-independent mechanisms. Examination of the latter identified the cAMP-responsive element binding protein (CREB) pathway as a target of Foxp3. Finally, comparison of the percent Foxp3(+)CD4(+)CD25(+) T cells to the HTLV-I proviral load in HTLV-I-infected asymptomatic carriers and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis suggested that high Foxp3 expression is associated with low proviral load and absence of disease. These results suggest an expanded role for Foxp3 in regulating NF-κB- and CREB-dependent cellular and viral gene expression

    IL-6–dependent spontaneous proliferation is required for the induction of colitogenic IL-17–producing CD8+ T cells

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    We propose a novel role for interleukin (IL) 6 in inducing rapid spontaneous proliferation (SP) of naive CD8+ T cells, which is a crucial step in the differentiation of colitogenic CD8+ T cells. Homeostasis of T cells is regulated by two distinct modes of cell proliferation: major histocompatibility complex/antigen–driven rapid SP and IL-7/IL-15–dependent slow homeostatic proliferation. Using our novel model of CD8+ T cell–dependent colitis, we found that SP of naive CD8+ T cells is essential for inducing pathogenic cytokine-producing effector T cells. The rapid SP was predominantly induced in mesenteric lymph nodes (LNs) but not in peripheral LNs under the influence of intestinal flora and IL-6. Indeed, this SP was markedly inhibited by treatment with anti–IL-6 receptor monoclonal antibody (IL-6R mAb) or antibiotic-induced flora depletion, but not by anti–IL-7R mAb and/or in IL-15–deficient conditions. Concomitantly with the inhibition of SP, anti–IL-6R mAb significantly inhibited the induction of CD8+ T cell–dependent autoimmune colitis. Notably, the transfer of naive CD8+ T cells derived from IL-17−/− mice did not induce autoimmune colitis. Thus, we conclude that IL-6 signaling is crucial for SP under lymphopenic conditions, which subsequently caused severe IL-17–producing CD8+ T cell–mediated autoimmune colitis. We suggest that anti–IL-6R mAb may become a promising strategy for the therapy of colitis

    Recurrent Pulmonary Capillary Hemangioma: Dynamic Contrast-Enhanced CT and Histopathologic Findings

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    We report the dynamic contrast-enhanced CT and histopathologic findings of a rare case of recurrent pulmonary capillary hemangiomas. The findings consisted of peripheral nodular enhancement at the early arterial phase and a subsequent "central filling-in" enhancement pattern on the delayed scans, which was identical to the well-known enhancement pattern of hemangiomas of the liver. Although there was no evidence of histological malignancy, pulmonary capillary hemangiomas manifested as multiple nodular lesions and showed postoperative recurrence
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