New record of grasshopper (Orthoptera: acrididae & romaleidae) defoliators and population dynamics of insects on crops of Heliconia spp. in the Amazon.

Apesar da expansão da ?oricultura, pouco se sabe sobre insetos associados à cultura no norte do Brazil. O objetivo foi identi?car as principais espécies de gafanhotos desfolhadores, associados a cultivos de Heliconia spp. na região Nordeste do Estado do Pará, Brazil, nas cidades de Castanhal, Belém e Benevides de agosto de 2004 a março de 2005. Os representantes com maior abundância desses municípios foram dos herbívoros da ordem Coleoptera, Thysanoptera, Hemiptera e Orthoptera. Os invíduos coletados de Orthoptera foram Cornops frenatum frenatum (Marshall) e Eutropidacris cristata L. (Orthoptera: Acrididae), Prionolopha serrata L. e Chromacris speciosa Thunberg (Orthoptera: Romaleidae), que apresentam potencial de danos ao cultivo de culturas de helicônias no Nordeste do Estado do Pará, Brazil

Tolerance and autoimmunity: novel therapeutic approaches

La función primaria del sistema inmune es resguardar al individuo de los patógenos potencialmente dañinos que invaden el medio ambiente en el cual nos desarrollamos. Este cuenta con dos grandes ramas, la inmunidad innata y la adaptativa, ambas con la propiedad de diferenciar lo peligroso de aquello inofensivo. Estos procesos se hallan regulados por mecanismos homeostáticos que constituyen la tolerancia inmunológica, a los fines de limitar aquellos procesos prolongados y silenciar los potencialmente autoagresivos. Ante la falla de estos mecanismos de control, surgen las enfermedades autoinmunes. Avances en el conocimiento de la fisiopatología de estas entidades, han abierto un nuevo capítulo en el terreno de la inmunofarmacología. Su prometedor potencial actualmente nos ofrece novedosas herramientas terapéuticas para controlar y atenuar el daño causado por este tipo de respuestas. No obstante, debe continuarse la investigación en el campo de los agentes biológicos, ya que ninguno de ellos se encuentra libre de inconvenientes. Seguramente, futuros hallazgos se concretarán en futuros aciertos. Y los aciertos, en Medicina, equivalen a esperanza.The main function of the immune system is to protect the individual against potentially dangerous pathogens. It comprises innate and adaptive cellular and soluble components, both with the capacity to discriminate between harmful and harmless. These processes are regulated by homeostatic mechanisms that constitute the so-called immunological tolerance, which aims to limit the prolonged action of immune mediators and to silence the generation of potentially autoaggressive components. Failure to silence self-reactive T and B cells results in the generation of autoimmune disease. Recent advances in our knowledge of these pathological entities have opened a new chapter in the pharmacology of the immune system. Its promising potential currently offers new therapeutic agents to control and attenuate pathological tissue damage. Nevertheless, further research regarding these biologic agents is required, since they are not free from inconveniences. It is without question that upcoming findings in this field will instill hope into the quest for the “magic bullet”.Fil: Ciliberti, Esteban. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Carambia, Leandro. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; ArgentinaFil: Cavallin, Sebastian. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; ArgentinaFil: Cerda, Osvaldo L.. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Poderoso, Juan J.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Rabinovich, Gabriel Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Trichospilus diatraeae (Hymenoptera: eulophidae): a potential biological control agent of Lepidopteran pests of oil palm in the brazilian Amazon.

A expansão da monocultura da palma do óleo (Elaeis guineensis) pode favorecer pragas como as lagartas Opsiphanes invirae Hübner, Brassolis sophorae L. (Lepidoptera: Nymphalidae) e Eupalamides cyparissias (Fabricius) (Lepidoptera: Castniidae). O objetivo foi avaliar o potencial de Trichospilus diatraeae Cherian & Margabandhu (Hymenoptera: Eulophidae) como parasitóide de pupas de lepidópteras-praga da palma do óleo. Cinquenta fêmeas de T. diatraeae foram mantidas um tubo de ensaio por 48 horas com uma pupa dos seguintes hospedeiros: O. invirae, B. sophorae ou E. cyparissias, com, até, dois dias de idade. Trichospilus diatraeae realizou o parasitismo nas três espécies de Lepidoptera, mas obteve potencial reprodutivo em pupas de O. invirae e B. sophorae. Isto sugere que este parasitoide, de hábito polífago, pode representar uma alternativa para o controle de pragas de lepidópteros da palma de óleo na Amazônia brasileir

Wavelength-Dependent UV Photodesorption of Pure N2N_2 and O2O_2 Ices

Context: Ultraviolet photodesorption of molecules from icy interstellar grains can explain observations of cold gas in regions where thermal desorption is negligible. This non-thermal desorption mechanism should be especially important where UV fluxes are high. Aims: $N_2$ and $O_2$ are expected to play key roles in astrochemical reaction networks, both in the solid state and in the gas phase. Measurements of the wavelength-dependent photodesorption rates of these two infrared-inactive molecules provide astronomical and physical-chemical insights into the conditions required for their photodesorption. Methods: Tunable radiation from the DESIRS beamline at the SOLEIL synchrotron in the astrophysically relevant 7 to 13.6 eV range is used to irradiate pure $N_2$ and $O_2$ thin ice films. Photodesorption of molecules is monitored through quadrupole mass spectrometry. Absolute rates are calculated by using the well-calibrated CO photodesorption rates. Strategic $N_2$ and $O_2$ isotopolog mixtures are used to investigate the importance of dissociation upon irradiation. Results: $N_2$ photodesorption mainly occurs through excitation of the $b^1\sqcap_u$ state and subsequent desorption of surface molecules. The observed vibronic structure in the $N_2$ photodesorption spectrum, together with the absence of $N_3$ formation, supports that the photodesorption mechanism of $N_2$ is similar to CO, i.e., an indirect DIET (Desorption Induced by Electronic Transition) process without dissociation of the desorbing molecule. In contrast, $O_2$ photodesorption in the 7−13.6 eV range occurs through dissociation and presents no vibrational structure. Conclusions: Photodesorption rates of $N_2$ and $O_2$ integrated over the far-UV field from various star-forming environments are lower than for CO. Rates vary between $10^{-3}$ and $10^{-2}$ photodesorbed molecules per incoming photon.Astronom

New Algorithm to Determine True Colocalization in Combination with Image Restoration and Time-Lapse Confocal Microscopy to Map Kinases in Mitochondria

The subcellular localization and physiological functions of biomolecules are closely related and thus it is crucial to precisely determine the distribution of different molecules inside the intracellular structures. This is frequently accomplished by fluorescence microscopy with well-characterized markers and posterior evaluation of the signal colocalization. Rigorous study of colocalization requires statistical analysis of the data, albeit yet no single technique has been established as a standard method. Indeed, the few methods currently available are only accurate in images with particular characteristics. Here, we introduce a new algorithm to automatically obtain the true colocalization between images that is suitable for a wide variety of biological situations. To proceed, the algorithm contemplates the individual contribution of each pixel's fluorescence intensity in a pair of images to the overall Pearsońs correlation and Manders' overlap coefficients. The accuracy and reliability of the algorithm was validated on both simulated and real images that reflected the characteristics of a range of biological samples. We used this algorithm in combination with image restoration by deconvolution and time-lapse confocal microscopy to address the localization of MEK1 in the mitochondria of different cell lines. Appraising the previously described behavior of Akt1 corroborated the reliability of the combined use of these techniques. Together, the present work provides a novel statistical approach to accurately and reliably determine the colocalization in a variety of biological images

Evolutionary connectionism: algorithmic principles underlying the evolution of biological organisation in evo-devo, evo-eco and evolutionary transitions

The mechanisms of variation, selection and inheritance, on which evolution by natural selection depends, are not fixed over evolutionary time. Current evolutionary biology is increasingly focussed on understanding how the evolution of developmental organisations modifies the distribution of phenotypic variation, the evolution of ecological relationships modifies the selective environment, and the evolution of reproductive relationships modifies the heritability of the evolutionary unit. The major transitions in evolution, in particular, involve radical changes in developmental, ecological and reproductive organisations that instantiate variation, selection and inheritance at a higher level of biological organisation. However, current evolutionary theory is poorly equipped to describe how these organisations change over evolutionary time and especially how that results in adaptive complexes at successive scales of organisation (the key problem is that evolution is self-referential, i.e. the products of evolution change the parameters of the evolutionary process). Here we first reinterpret the central open questions in these domains from a perspective that emphasises the common underlying themes. We then synthesise the findings from a developing body of work that is building a new theoretical approach to these questions by converting well-understood theory and results from models of cognitive learning. Specifically, connectionist models of memory and learning demonstrate how simple incremental mechanisms, adjusting the relationships between individually-simple components, can produce organisations that exhibit complex system-level behaviours and improve the adaptive capabilities of the system. We use the term “evolutionary connectionism” to recognise that, by functionally equivalent processes, natural selection acting on the relationships within and between evolutionary entities can result in organisations that produce complex system-level behaviours in evolutionary systems and modify the adaptive capabilities of natural selection over time. We review the evidence supporting the functional equivalences between the domains of learning and of evolution, and discuss the potential for this to resolve conceptual problems in our understanding of the evolution of developmental, ecological and reproductive organisations and, in particular, the major evolutionary transitions