Métodos de debicagem: desenvolvimento e desempenho produtivo de poedeiras leves e semipesadas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Métodos de debicagem: desenvolvimento e desempenho produtivo de poedeiras leves e semipesadas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Maternal care in the Neotropical harvestman Liogonyleptoides tetracanthus (Opiliones: Gonyleptidae)

We describe post-ovipositional maternal care in Liogonyleptoides tetracanthus Mello-Leitao 1932 (Gonyleptinae) and experimentally evaluate the protective role of this behavior against egg predation under laboratory conditions. Females laid 138.8 eggs on average and remained close to the clutch during the entire day. Eggs hatched after 11-15 days and nymphs dispersed from maternal protection after one to two days. Most of the experimental clutches left unattended were entirely consumed by conspecifics in 2-3 days. There was no reduction in egg number in the clutches protected by females. Although biological data are scarce, there are cases of egg hiding, paternal and maternal care within the subfamily Gonyleptinae. This diversity of forms of parental care is unusual when compared to other gonyleptid subfamilies, and future systematic revisions of the polyphyletic Gonyleptinae should include parental care as a potential source of phylogenetic information.

Embryonic development and larval stages of Steindachneridion parahybae (Siluriformes: Pimelodidae) - implications for the conservation and rearing of this endangered Neotropical species

Steindachneridion parahybae is a freshwater catfish endemic to the Paraiba do Sul River and is classified as an endangered Neotropical species. An increasing number of conservation biologists are incorporating morphological and physiological research data to help conservation managers in rescue these endangered species. This study investigated the embryonic and larval development of S. parahybae in captivity, with emphasis in major events during the ontogeny of S. parahybae. Broodstocks were artificially induced to reproduce, and the extrusion occurred 200-255 degree-hours after hormonal induction at 24 degrees C. Larval ontogeny was evaluated every 10 minutes under microscopic/stereomicroscopic using fresh eggs samples. The main embryogenic development stages were identified: zygote, cleavage, including the morula, blastula, gastrula phase, organogenesis, and hatching. The extruded oocytes showed an average diameter of 1.10 +/- 0.10 mm, and after fertilization and hydration of eggs, the average diameter of eggs increased to about 1.90 +/- 0.60 mm, characterized by a large perivitelline space that persisted up to embryo development, the double chorion, and the poles (animal and vegetative). Cell division started about 2 minutes after fertilization (AF), resulting in 2, 4, 8 (4 x 2 arrangement of cells), 16 (4 x 4), 32 (4 x 8) and 64 (2 x 4 x 8) cells. Furthermore, the blastula and gastrula stages followed after these cells divisions. The closed blastopore occurred at 11 h 20 min AF; following the development, the organogenetic stages were identified and subdivided respectively in: early segmentation phase and late segmentation phase. In the early segmentation phase, there was the establishment of the embryonic axis, and it was possible to distinguish between the cephalic and caudal regions; somites, and the optic vesicles developed about 20 h AF. Total hatching occurred at 54 h AF, and the larvae average length was 4.30 +/- 0.70 mm. Gradual yolk sac reduction was observed during the first two days of larval development. The first feeding occurred at the end of the second day. During the larval phase, cannibalism, heterogeneous larval growth and photophobia were also observed. This information will be important in improving the artificial reproduction protocols of S. parahybae in controlled breeding programs.

Congruências entre posicionamentos estratégicos e redes de negócios: estudo de caso de uma subsidiária brasileira

Na pesquisa exploratória aqui relatada, realizada em 2009 e guiada por uma extensa revisão bibliográfica e pelo emprego do método de estudo de caso, busca-se identificar congruências entre o posicionamento estratégico adotado pela subsidiária brasileira de uma corporação multinacional e o tipo de rede de negócios por ela integrada. Apoiando-se em dois modelos específicos da literatura acadêmica sobre os temas mencionados (posicionamento estratégico e redes), as conclusões dessa investigação sugerem que as Redes Verticais de Demanda e Fornecimento (MOLLER e RAJALA, 2007) são adequadas para operacionalizar o posicionamento definido como Melhor Produto no Modelo Delta (HAX e WILDE II, 1999; 2001).

Embryonic development and larval stages of Steindachneridion parahybae (Siluriformes: Pimelodidae): implications for the conservation and rearing of this endangered Neotropical species

Steindachneridion parahybae is a freshwater catfish endemic to the Paraíba do Sul River and is classified as an endangered Neotropical species. An increasing number of conservation biologists are incorporating morphological and physiological research data to help conservation managers in rescue these endangered species. This study investigated the embryonic and larval development of S. parahybae in captivity, with emphasis in major events during the ontogeny of S. parahybae. Broodstocks were artificially induced to reproduce, and the extrusion occurred 200-255 degree-hours after hormonal induction at 24°C. Larval ontogeny was evaluated every 10 minutes under microscopic/stereomicroscopic using fresh eggs samples. The main embryogenic development stages were identified: zygote, cleavage, including the morula, blastula, gastrula phase, organogenesis, and hatching. The extruded oocytes showed an average diameter of 1.10 ± 0.10 mm, and after fertilization and hydration of eggs, the average diameter of eggs increased to about 1.90 ± 0.60 mm, characterized by a large perivitelline space that persisted up to embryo development, the double chorion, and the poles (animal and vegetative). Cell division started about 2 minutes after fertilization (AF), resulting in 2, 4, 8 (4 x 2 arrangement of cells), 16 (4 x 4), 32 (4 x 8) and 64 (2 x 4 x 8) cells. Furthermore, the blastula and gastrula stages followed after these cells divisions. The closed blastopore occurred at 11 h 20 min AF; following the development, the organogenetic stages were identified and subdivided respectively in: early segmentation phase and late segmentation phase. In the early segmentation phase, there was the establishment of the embryonic axis, and it was possible to distinguish between the cephalic and caudal regions; somites, and the optic vesicles developed about 20 h AF. Total hatching occurred at 54 h AF, and the larvae average length was 4.30 ± 0.70 mm. Gradual yolk sac reduction was observed during the first two days of larval development. The first feeding occurred at the end of the second day. During the larval phase, cannibalism, heterogeneous larval growth and photophobia were also observed. This information will be important in improving the artificial reproduction protocols of S. parahybae in controlled breeding programs.

A palavra e as condições da educação escolar

Estudos recentes sobre gestão e resultados escolares apontam a presença do, assim chamado, efeito-professor como um fator associado ao desempenho dos alunos. Desenvolve-se neste texto a premissa de que esses estudos acabam, paradoxalmente, demonstrando a pertinência da reflexão psicanalítica, que aponta para o estatuto da palavra mestre no interior de uma tradição filial professoral como condição necessária à educação escolar.

Low temperatures reduce skin healing in the Jacaré do Pantanal (Caiman yacare, Daudin 1802)

Studies of skin wound healing in crocodilians are necessary given the frequent occurrence of cannibalism in intensive farming systems. Air temperature affects tissue recovery because crocodilians are ectothermic. Therefore, the kinetics of skin wound healing in Caiman yacare were examined at temperatures of 33°C and 23°C. Sixteen caiman were selected and divided into two groups of eight maintained at 23°C or 33°C. The studied individuals' scars were photographed after 1, 2, 3, 7, 15 and 30 days of the experimental conditions, and samples were collected for histological processing after 3, 7, 15 and 30 days. Macroscopically, the blood clot (heterophilic granuloma) noticeably remained in place covering the wound longer for the caiman kept at 23°C. Microscopically, the temperature of 23°C slowed epidermal migration and skin repair. Comparatively, new blood vessels, labeled using von Willebrand factor (vWF) antibody staining, were more frequently found in the scars of the 33°C group. The collagen fibers in the dermis were denser in the 33°C treatment. Considering the delayed healing at 23°C, producers are recommended to keep wounded animals at 33°C, especially when tanks are cold, to enable rapid wound closure and better repair of collagen fibers because such lesions tend to compromise the use of their skin as leather.

Nuove tecniche per l'allevamento massale di Ditteri del genere Coenosia Meigen

The species of the genus Coenosia Meigen are polyphagous predators both in the larval and in the adult stage. In Europe five Coenosia species of the ‘tigrina group’ are naturally present in greenhouses, where they can establish for long periods. As their wide preys range includes important pests of protected crops, as Aleyrodidae, Sciaridae and Agromyzidae, Coenosia species are considered promising potential biological control agents. A method for rearing Coenosia species in vivo was developed for the first time in 1993 in Germany, where C. attenuata, C. strigipes and C. humilis were bred on Bradysia paupera (Diptera Sciaridae), reared on Fusarium spp. cultivated on wood fibre. Although this method was partially simplified afterwards, it is still too complex and expensive for a mass production. This research aimed at simplifying this rearing procedure and making it cheaper, in the perspective of an eventual mass production. Studies on potential preys were conducted, to determine their suitability for C. attenuata larvae and adults and to develop rearing methods. Biology and rearing methods of Bradysia paupera Tuomikoski, Scatella stagnalis Fallén and Drosophila melanogaster Meigen (Diptera: Sciaridae, Ephydridae, Drosophilidae) were compared. B. paupera resulted the most suitable prey for rearing C. attenuata in vivo. The Sciarid fly was effectively reared on damp coconut fibre with fresh Agaricus bisporus (J.E. Lange) Pilát, thus simplifying the existing method. After preliminary trials with different potential preys, attempts to rear C. attenuata in vivo on B. paupera and D. melanogaster were made. The best results were obtained with B. paupera, reared on coconut fibre and A. bisporus, but the method needs further improvement. Trials of in vitro rearing of C. attenuata were also made: as no specific diet for Coenosia species is reported in literature, different potentially suitable media were tested. Among these, a specific diet for Diptera Tachinidae resulted a good starting point for further studies and improvements. The biology of C. attenuata adults captured in greenhouses was also studied, by observing both groups and isolated individuals. Data on lifespan, daily number of preys per adult, daily number of laid eggs and hatching rate were recorded, and the effects of different foods on these parameters were analyzed. The following foods were compared: D. melanogaster adults only, as preys for C. attenuata; D. melanogaster adults and a water-honey solution; the water-honey solution only. Honey resulted an effective food integration for C. attenuata, increasing lifespan and the number of egg laying females. It is possible that in greenhouses Coenosia adults complete the preys diet with nectar and/or honeydew. Moreover, the integration with honey reduced the daily preys consumption. This may allow to prevent cannibalism among Coenosia adults in the rearing conditions, where high population densities are required. A survey of the Coenosia species naturally present in Lombardy greenhouses was conducted. The species C. attenuata, C. strigipes, C. tigrina and C. atra were detected. C. attenuata resulted the most common, recorded in most greenhouses and for consecutive years. Besides, the presence of potential preys, weeds and the crops were recorded in each greenhouse. Nevertheless, it is difficult to determine the relation between these parameters and the presence of Coenosia species.

Concentration- and time-dependent effects of the synthetic estrogen, 17alpha-ethinylestradiol, on reproductive capabilities of the zebrafish, Danio rerio

Partial or full life-cycle tests are needed to assess the potential of endocrine-disrupting compounds (EDCs) to adversely affect development and reproduction of fish. Small fish species such as zebrafish, Danio rerio, are under consideration as model organisms for appropriate test protocols. The present study examines how reproductive effects resulting from exposure of zebrafish to the synthetic estrogen 17alpha-ethinylestradiol (EE2) vary with concentration (0.05 to 10 ng EE2 L(-1), nominal), and with timing/duration of exposure (partial life-cycle, full life-cycle, and two-generation exposure). Partial life-cycle exposure of the parental (F1) generation until completion of gonad differentiation (0-75 d postfertilization, dpf) impaired juvenile growth, time to sexual maturity, adult fecundity (egg production/female/day), and adult fertilization success at 1.1 ng EE2 L(-1) and higher. Lifelong exposure of the F1 generation until 177 dpf resulted in lowest observed effect concentrations (LOECs) for time to sexual maturity, fecundity, and fertilization success identical to those of the developmental test (0-75 dpf), but the slope of the concentration-response curve was steeper. Reproduction of zebrafish was completely inhibited at 9.3 ng EE2 L(-1), and this was essentially irreversible as a 3-mo depuration restored fertilization success to only a very low rate. Accordingly, elevated endogenous vitellogenin (VTG) synthesis and degenerative changes in gonad morphology persisted in depurated zebrafish. Full life-cycle exposure of the filial (F2) generation until 162 dpf impaired growth, delayed onset of spawning and reduced fecundity and fertilization success at 2.0 ng EE2 L(-1). In conclusion, results show that the impact of estrogenic agents on zebrafish sexual development and reproductive functions as well as the reversibility of effects, varies with exposure concentration (reversibility at < or = 1.1 ng EE2 L(-1) and irreversibility at 9.3 ng EE2 L(-1)), and between partial and full life-cycle exposure (exposure to 10 ng EE2 L(-1) during critical period exerted no permanent effect on sexual differentiation, but life-cycle exposure did).

Investigation of potential causes for the development of porcine ear necrosis: different study designs--comparable results?

During the last years two studies for the investigation of the etiology of porcine ear necrosis were carried out at the Clinic for Swine of the University of Veterinary Medicine Vienna. In study 1, parameters, which are discussed in this context, were collected by veterinary practitioners by completing specially designed questionnaires in farms with symptoms of the porcine ear necrosis syndrome. In study 2, samples of piglets and feed were collected for laboratory analysis of the most important infectious agents as well as mycotoxins. In the present manuscript, the results of both projects were compared. Even if the selection criteria of both studies differed, the affected age class was comparable (5.5 to ten weeks of life in study 1 and six to ten weeks of life in study 2). The herd-specific prevalence of the porcine ear necrosis syndrome varied considerably with percentages between 2 and 10, respectively, to 100%. The evaluation of questionnaires in study 1 showed that 51% of the farms had problems with cannibalism. Particles of plant material, which were frequently seen on the histologic slides of study 2, could have got into the tissue by chewing the ears of the pen mates or cannibalism. Whereas in study 1 the negative effect of parameters as high pig density, suboptimal climate, missing enrichment material and bad quality of feed and water were considered, in study 2 all these factors were checked at sample collection and ruled out as precursor for cannibalism. In both studies bacterial agents proved to be a crucial co-factor for the expansion of the necroses to deeper tissue layers, whereas viral pathogens were classified less important. In both projects it was not possible to estimate the direct impact of infectious agents and mycotoxins as direct trigger of the necroses as well as their participation as co-factors or precursor in the sense of an immunosuppression or previous damage of blood vessels or tissue.

Functional studies of insulin-like growth factor binding protein 2 pathway in glioma progression

Comparison of gene expressing profiles between gliomas with different grades revealed frequent overexpression of insulin-like growth factor binding protein 2 (IGFBP2) in glioblastomas (GBM), in which uncontrolled cell proliferation, angiogenesis, invasion and anti-apoptosis are hallmarks. Using the glia-specific gene transfer transgenic mouse and the stable LN229(BP2) GBM cell lines, we found that IGFBP2 by itself cannot transform cells in vitro and in vivo. IGFBP2 had growth inhibitory effects on mouse primary neural progenitors, but overexpression of IGFBP2 had no effect on GBM cells. ^ Although IGFBP2 does not initiate gliomagenesis, using tissue array technology, we observed strong correlation between IGFBP2 overexpression and VEGF up-regulation in human diffuse gliomas. Furthermore, overexpression of IGFBP2 in GBM cells not only enhanced VEGF expression but also increased the malignant potential of U87 MG cells in our angiogenesis xenograft animal model. ^ In parallel to these studies, using established stable SNB19 GBM cells that overexpress IGFBP2, we found that IGFBP2 significantly increased invasion by induction of matrix metalloproteinase-2 (MMP-2) as well as other invasion related genes, providing evidence that IGFBP2 contributes to glioma progression in part by enhancing MMP-2 gene transcription and in turn tumor cell invasion. ^ Finally, we found that primary filial cells infected with an anti-sense IGFBP2 construct have markedly increased sensitivity to γ irradiation and reduced Akt activation. On the other hand, SNB19(BP2) stable lines have consistently increased levels of Akt and NFkB activation, suggesting that one possible mechanism for anti-apoptosic function of IGFBP2 is through the activation of Akt and NFkB. Beside this, what is especially interesting is the finding that Akt protein was cleaved and inactivated during apoptosis by caspases, and IGFBP2 can prevent Akt cleavage, revealing another possible mechanism through it IGFBP2 exhibit strong antiapoptotic effects. Our data showed that IGFBP2 is a specific substrate for caspase-3, raising the possibility that IGFBP2 may inhibit apoptosis by a suicide mechanism. ^ In summary, using cellular, genomics, and molecular approaches, this thesis documented the potential roles of IGFBP2 in glioma progression. Our findings shed light on an important biological aspect of glioma progression and may provide new insights useful for the design of novel mechanism-based therapies for GBM. ^

Colonización, inmigración y etnicidad en la provincia de Misiones, Argentina. Etapa II. Cartografia etnografica de la plurietnicidad en Misiones. Argentina. 16H237

La provincia de Misiones constituye un área particularmente relevante para el estudio de los procesos migratorios. En un espacio que abarca 30.719 km2, cuyos límites de frontera alcanzan un 90% entre los países de Paraguay y Brasil, se asentaron pobladores de más de veinte nacionalidades diferentes, fenómeno que se constituye en un paisaje étnico particular y diverso para el estudio del poblamiento de la provincia. Poblamiento que se ha constituido desde fines del siglo XIX con población de la zona -paraguayos, correntinos, aborígenes- a los que se suman las colonizaciones que se dividen en oficiales y privadas, así como por el poblamiento espontáneo. A partir del análisis de lo antedicho, observamos que la influencia de las migraciones y asentamiento de población extranjera en Misiones prefigura particularidades vinculadas a: la organización del espacio geográfico, la gestación de la historia regional, los procesos de interculturización, la constitución de identidades culturales y las relaciones interétnicas e intraétnicas. Tan es así que entre las caracterizaciones de la Provincia, la mayoría de las publicaciones existentes, destacan esta particularidad desde la denominación de “Misiones crisol de razas” u otros como “provincia pluriétnica”. Frente a esta caracterización de Misiones, la elaboración de una “cartografía etnográfica” de los habitantes y de las colectividades ubicadas en la provincia será de gran utilidad para el conocimiento de: lugares de procedencia, periodización de los movimientos migratorios, lugares de asentamiento, relaciones (de trabajo, de parentesco, religiosas, etc.) establecidas entre los diferentes grupos étnicos, la población de origen y de fronteras de la zona. De la misma manera, conociendo la inserción en el medio de “los que llegaron” y la “descendencia” filial de los mismos, podremos reconstruir un mapa poblacional en cuanto a sus ascendencias y descendencias, hecho que sin dudas se convierte en un diacrítico interesante al momento de su caracterización. 7

Cuerpos invadidos : cuerpo y corporalidad en algunos relatos de Antonio Di Benedetto

Mundo Animal (1953) es una colección de cuentos que inicia la carrera literaria del narrador mendocino, Antonio Di Benedetto. Libro de difícil ubicación genérica, tiene una marcada intencionalidad ética que el mismo autor señala de modo explícito. Es además, evidente la filiación kafkianas de muchas de estas historias. Esta relación se observa, especialmente, en el clima fuertemente onírico y opresivo tanto para los personajes como para los lectores, en el escaso interés por la realidad circundante y en la presencia de un espacio de tipo esquemático, fuertemente simbólico. Este trabajo se propone, precisamente, detenerse en el análisis de los grietas de este espacio que, si bien no refleja la realidad circundante o referencial, ahonda en torno a otras realidades de profunda relevancia para el hombre contemporáneo. Entre estos espacios esquemáticos, pero de gran valor metafórico, llama la atención la fuerte presencia del cuerpo que, en varios relatos, es presentado como un espacio dentro del cual se desarrolla la acción, o bien que involucra fuertemente dicha acción. En primer lugar estudiaremos la noción de cuerpo y corporalidad presente en el horizonte cultural de Di Benedetto para centrarnos luego en el análisis específico de los cuentos que textualizan el espacio corporal.

Modalidades actuales de la diversidad en la familia y transmisión intergeneracional

Temática principal: El presente trabajo, forma parte de la Mesa temática autoconvocada 'Familias, Parejas y Diversidad. Avances de investigación' y se enmarca en la investigación en curso 'Modalidades de la diversidad en el ejercicio de la parentalidad y la pareja' (Facultad de Psicología. UNLP). Se propone reflexionar y articular los efectos que las actuales modalidades del vínculo familiar producen en la función de transmisión intergeneracional y transgeneracional. Objetivos: Frente a las transformaciones en la organización y la configuración de losvínculos familiares y los modos actuales de pensarse el envejecimiento, nuestro objetivo es interrogarnos sobre las perspectivas teóricas, las múltiples funciones y formas en que puede pensarse las relaciones inter ytransgeneracionales en las nuevas configuraciones familiares desde la diversidad. A la par, indagar sobre el lugar y función de los representantes de las familias de origen (ancestros) frente a la diversidad, en familias con parejas homosexuales, o familias monoparentales. Metodología: se implementa una metodología cualitativa, centrada en la diversidad como postura epistemológica. Se selecciona un muestreo intencional: organizaciones familiares no tradicionales (uniparentales, ensambladas, entre otras); parejas del mismo sexo con y sin hijos; parejas de diferente sexo sin hijos, por elección e informantes clave. Se implementan entrevistas en profundidad, individuales y vinculares con madres y/o padres y parejas, realizadas por dos investigadores formados en abordajes vinculares. Resultados: La interpretación de los hallazgos y conclusiones, por partir de los primeros datos relevados en el trabajo de campo, son provisorios y parciales. En lasprimeras entrevistas se exploran los modos en que se significan el lugar de los ancestros y su función, la resignificación por los orígenes, y las nuevas formas en las que se busca una continuidad histórica familiar que asigne un lugar de pertenencia y de producción de sentido. En esta línea nos encontramos con investigaciones preexistentes que apuntan a teorizar sobre las nuevas formas que adquiere la transmisión intergeneracional en las modalidades de la diversidad del vínculo filial. Aportes que permiten pensar la metabolización que los sujetos realizan para hallar un lugar en los nuevos vínculos. Conclusiones: estamos en un tiempo de la investigación de relevamiento y recolección de los datos empíricos. Aún no podríamos sacar conclusiones definitivas, pero sí nos permite encontrar, del material obtenido hasta el momento, nuevos efectos de sentido que nos permitan arrimarnos a conocer cómo los sujetos pueden ir realizando la metabolización y construyendo su propia subjetivación con relación a procesos de cambio. La realidad actual nos encuentra con un escenario familiar y social con transformaciones profundas acerca de las funciones a cumplir. Nos preguntamos qué espera hoy la cultura acerca de la función de transmisión?; qué esperan los integrantes de las nuevas modalidades del vinculo filial de la función que auspicie la continuidad histórica y el sostén identificatorio?, interrogantes que cuestionan los modelos anteriores y otorgan cierta fragilidad a los modelos identificatorios familiares, dando sustento y legitimidad al grupo social que acompaña y ampara decisiones novedosas del vinculo