Photosynthetic induction in Eucalyptus urograndis seedlings and cuttings measured by an open photoacoustic cell

Photosynthetic induction in leaves of four-month-old Eucalyptus urograndis seedlings and of cuttings obtained from adult trees that were previously dark-adapted was studied by the in vivo and in situ Open Photoacoustic Cell Technique, Results for the gas exchange component of the photoacoustic (PA) signal were interpreted considering that the gas uptake component would have a phase angle nearly opposite to that of the oxygen evolution component. By subtracting the thermal component from the total PA signal, we studied the competition between gas uptake and oxygen evolution during the photosynthetic induction. Seedlings presented a net oxygen evolution prior to cuttings, but cuttings reached a higher steady-state photosynthetic activity. The chlorophyll (Chl) a/b ratio and the Chl fluorescence induction characteristic F-v/F-m were significantly higher for cuttings, while there was no difference between samples in stomata density and leaf thickness. Thus the differences in PA signals of seedlings and cuttings are associated to differences between the photosystem 2 antenna systems of these samples.

International conferences on environmental mutagens in human populations - Opportunities, accomplishments and challenges

A major mission for organizing the series of International Conferences on Environmental Mutagens in Human Populations is to bring science and scientists to the sites where the field of environmental health is in developmental stages and environmental health is a serious concern. The mission has been fulfilled in each of the previous conferences that were held in Egypt, Czech Republic, Thailand and Brazil. These conferences have led to significant enhancement of regional scientific expertise from the acquisition of scientific knowledge and from the generation of sustainable collaborative programs. (C) 2003 Elsevier B.V. All rights reserved.

Actions of angiotensin II and dopamine in the medial preoptic area on prolactin secretion

Dopamine (DA) is known as a primary regulator of prolactin secretion (PRL) and angiotensin II (Ang II) has been recognized as one brain inhibitory factor of this secretion. In this work, estrogen-primed or unprimed ovariectornized rats were submitted to the microinjection of saline or Ang II after previous microinjection of saline or of da antagonist (haloperidol, sulpiride or SCH) both in the medial preoptic area (MPOA). Our study of these interactions has shown that 1) estrogen-induced PRL secretion is mediated by Ang II and da actions in the MPOA, i.e. very high plasma PRL would be prevented by inhibitory action of Ang II, while very low levels would be prevented in part by stimulatory action of da through D-2 receptors, 2) the inhibitory action of Ang II depends on estrogen and is mediated in part by inhibitory action of da through D, receptors and in other part by inhibition of stimulatory action of da through D2 receptors.

Insects on decomposing carcasses of small rodents in a secondary forest in Southeastern Brazil

The decomposition of small carcasses in the open is frequently neglected although it may provide information of forensic importance. This paper describes an experimental study of arthropod species associated with carcasses of mouse, Mus musculus (Linnaeus, 1758) and rat, Rattus norvegicus (Berkenhout, 1769) (Rodentia: Muridae). Four carcasses were left inside iron cages in sunlit and shady areas in a secondary forest in Southeastern Brazil twice a season for four seasons (n = 16 carcasses of each rodent). The carcasses were removed when arthropods ceased to visit them. The visiting and colonizing invertebrates were collected daily and identified. Immatures were also collected and reared in a laboratory for identification. We collected 6,514 arthropods (820 adults and 5,694 juvenile forms) belonging to 53 species from the families Sarcophagidae, Calliphoridae, Muscidae, Fanniidae, Syrphidae, Richardiidae, Sepsidae, Micropezidae, Otitidae, Drosophilidae, Phoridae, Dolichopodidae, Anthomyiidae, Asilidae and Lauxaniidae (Diptera), Formicidae, Ichneumonidae, Encyrtidae and Apidae (Hymenoptera), Staphylinidae (Coleoptera) and Gonyleptidae (Opiliones). Lucilia eximia (Wiedemann, 1819) (Diptera: Calliphoridae) and Peckia (Pattonella) intermutans (Walker, 1861) (Diptera: Sarcophagidae) deserve special attention because both adult and immature forms were collected in all seasons and in both areas. Our results indicate that the frequency of occurrence of these arthropods was positively associated with carcass size (mouse or rat); no marked insect succession on the carcasses occurred; and the diversity of Calliphoridae and Sarcophagidae was high, irrespective of season.

Ant diversity (Hymenoptera: Formicidae) and predation by ants on the different stages of the sugarcane borer life cycle Diatraea saccharalis (Lepidoptera: Crambidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A study of meiosis and spermiogenesis in the testicular lobes of Antiteuchus tripterus (Heteroptera : Pentatomidae)

An analysis of testicular morphology and spermatogenesis in the Heteroptera species Antileuchus tripterus (Pentatomidae) revealed that these traits differ from that recorded for other species of the same family. The testes of A. tripterus have only six lobes, while other species of the same family typically have seven lobes, including a compound lobe, i.e., a lobe containing another in its lumen. A study of meiosis and sperm structure in the different lobes of A. tripterus revealed a conventional meiosis in the lobes numbered one to three. In lobe four, however, prophase I spermatocytes exhibit the morphological characteristics of the so called diffuse stage and are larger than those in lobes 1-3 in this and the remaining phases of meiosis. Thus, the resulting spermatids are not only larger but also their head is morphologically different. Lobe 5 exhibits characteristies known from other Pentatomidae species such as an uneven distribution of chromatin to the daughter cells, which give rise to cells of different sizes. This lobe forms spermatozoa of different sizes. Lobe 6, contained within lobe 5, differs from it by having larger cells at a stage similar to the so called diffuse and spermatid tails with cross divisions, which are not found in other lobes and unreported in the literature.

Comparative analysis of the testes and spermatogenesis in species of the family Pentatomidae (Heteroptera)

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

T-duality in affine NA Toda models

The construction of non-Abelian affine Toda models is discussed in terms of its underlying Lie algebraic structure. It is shown that a subclass of such non-conformal two-dimensional integrable models naturally leads to the construction of a pair of actions, which share the same spectra and are related by canonical transformations.

Integrable field theories with defects

The structure of integrable field theories in the presence of defects is discussed in terms of boundary functions under the Lagrangian formalism. Explicit examples of bosonic and fermionic theories are considered. In particular, the boundary functions for the super sinh-Gordon model is constructed and shown to generate the Backlund transformations for its soliton solutions.

Análise cinemática tridimensional do movimento de eqüinos em esteira rolante

Adaptou-se uma metodologia utilizada no estudo do movimento humano para analisar o movimento de eqüinos em esteira rolante de alto desempenho, construindo-se um sistema de calibração utilizando-se um teodolito eletrônico de alta precisão e calibradores que demarcavam o espaço ocupado pelo animal. Dessa forma, foram obtidas as coordenadas espaciais dos marcadores presentes nos calibradores, compondo o arquivo de calibração. Duas câmeras de vídeo (60Hz) foram posicionadas em vista lateral esquerda, distantes 5m da manta de rolagem da esteira a 1,8m de altura. As imagens foram enquadradas utilizando-se um monitor de vídeo. Para a validação do método, um membro da equipe movimentou, no espaço calibrado, uma haste rígida com marcadores fixados nas suas extremidades, distantes um do outro 43,8cm. Para a análise das imagens, utilizou-se o programa Dvideow, desenvolvido pelo Laboratório de Instrumentação para Biomecânica - UNICAMP. Após a reconstrução tridimensional das imagens utilizou-se um programa matemático para o cálculo do valor médio da distância entre os marcadores. Obteve-se, após a mensuração em 100 quadros, o valor médio de 43,7cm com coeficiente de variação de 0,8%. Estes resultados mostram que a metodologia desenvolvida é precisa e adequada para o estudo da locomoção de eqüinos.

Immunomodulatory activities associated with beta-glucan derived from Saccharomyces cerevisiae

In this study we investigated the effect of beta-glucan derived from Saccharomyces cerevisiae on fungicidal activity, cytokine production and natural killer activity. Spleen and peritoneal cells from female C57BL/6 mice, previously injected (24 or 48 h) with 20 or 100 mu g of glucan by i.p. route, were assayed. In vivo mu-glucan administration primed spleen cells for a higher production of IL-12 and TNF-alpha when S. aureus was used as a stimulus. In addition, beta-glucan increased NK spleen cells activity against YAC target cells. Some immunomodulatory activities not yet described for beta-glucan were observed in this work.

Gas exchange in lisianthus plants (Eustoma grandiflorum) submitted to different doses of nitrogen

The effect of different doses of nitrogen (N) on gas exchange, relative chlorophyll (Chl) amount, and the content of N in the aerial biomass of lisianthus was evaluated. The treatments consisted of six different concentrations of N (50, 100, 150, 200, 250, and 300 g m(-3) noted as N-50, N-100, N-150, N-200, N-250, and N-300, respectively), applied through the fertirrigation technique. N-250 and N-300 induced increase in the contents of foliar Chl and N in the aerial biomass, that in turn contributed to an increase of photosynthetic activity in lisianthus.

Determining the season of death from the family composition of insects infesting carrion

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