199 research outputs found

    Morphometric differences in the grasshopper Cornops aquaticum (Bruner, 1906) from South America and South Africa

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    The semi-aquatic grasshopper Cornops aquaticum is native to South America and inhabits lowlands from southern Mexico to Central Argentina and Uruguay. It is host-specific to aquatic plants in the genera Eichhornia and Pontederia. A quarantine population has existed in South Africa for 10 y, and it is planned to release it there as a biological control agent of water hyacinth, E. crassipes. Various studies of C. aquaticum are coordinated under HICWA (www.mpil-ploen.mpg.de). This paper compares the morphometry of the release population and 11 native populations in South America. We tested four hypotheses: 1) South African and South American populations of C. aquaticum differ in morphology; 2) the South African laboratory population is more similar to other isolated populations in South America than to nonisolated populations; 3) morphology differs across sites; 4) morphology differs with host plant. South African populations differed from continental nonisolated populations, but not from continental isolated ones. Isolated populations presented smaller individuals than nonisolated, but there was also a change in male morphology: while in nonisolated populations male wing length was similar to their body length, in isolated populations, male wings were smaller than body length. Females were larger when on Eicchornia azurea than on E. crassipes, while males presented larger wings than their body on E. azurea, and similar lengths on E. crassipes. These morphological changes may have resulted from phenotypic plasticity, selection for small size, or because of a loss of genetic diversity in quantitative traits.Fil: Adis, Joachim. Institute for Limnology; AlemaniaFil: Sperber, Carlos F. Universidade Federal de Viçosa; BrasilFil: Brede, Edward G. Institute for Limnology; AlemaniaFil: Capello, Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Franceschini, Maria Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Hill, Martin. Rhodes University; SudáfricaFil: Lhano, Marcos G. Universidade Federal de Viçosa; BrasilFil: Marques, Marinê. A;z M.. Universidade Federal de Mato Grosso; BrasilFil: Nunes, Ana L.. Muséu Paraense Emílio Goeldi; BrasilFil: Polar, Perry. CAB International; Trinidad y Tobag

    The Limbic System Conception and Its Historical Evolution

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    Throughout the centuries, scientific observers have endeavoured to extend their knowledge of the interrelationships between the brain and its regulatory control of human emotions and behaviour. Since the time of physicians such as Aristotle and Galen and the more recent observations of clinicians and neuropathologists such as Broca, Papez, and McLean, the field of affective neuroscience has matured to become the province of neuroscientists, neuropsychologists, neurologists, and psychiatrists. It is accepted that the prefrontal cortex, amygdala, anterior cingulate cortex, hippocampus, and insula participate in the majority of emotional processes. New imaging technologies and molecular biology discoveries are expanding further the frontiers of knowledge in this arena. The advancements of knowledge on the interplay between the human brain and emotions came about as the legacy of the pioneers mentioned in this field. The aim of this paper is to describe the historical evolution of the scientific understanding of interconnections between the human brain, behaviour, and emotions

    The limbic system conception and its historical evolution

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    Throughout the centuries, scientific observers have endeavoured to extend their knowledge of the interrelationships between the brain and its regulatory control of human emotions and behaviour. Since the time of physicians such as Aristotle and Galen and the more recent observations of clinicians and neuropathologists such as Broca, Papez, and McLean, the field of affective neuroscience has matured to become the province of neuroscientists, neuropsychologists, neurologists, and psychiatrists. It is accepted that the prefrontal cortex, amygdala, anterior cingulate cortex, hippocampus, and insula participate in the majority of emotional processes. New imaging technologies and molecular biology discoveries are expanding further the frontiers of knowledge in this arena. The advancements of knowledge on the interplay between the human brain and emotions came about as the legacy of the pioneers mentioned in this field. The aim of this paper is to describe the historical evolution of the scientific understanding of interconnections between the human brain, behaviour, and emotions

    Electrodinámica cuántica en guías de onda con emisores distantes

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    La descripción física de la interacción de la luz y la materia ha sido uno de los problemas más importantes desde los inicios de la mecánica cuántica. Debido al gran éxito de la teoría cuántica y de los avances experimentales en los últimos años, hoy en día es posible controlar y manipular una gran variedad de sistemas atómicos y fotónicos con gran precisión. En este trabajo estamos interesados en el estudio de sistemas de dos niveles (qubits) en interacción con fotones que se propagan en un medio unidimensional o guía de onda. En particular,hemos caracterizado la dinámica de un sistema de dos niveles acoplado a una cadena de cavidades estudiando la emisión Markoviana y no Markoviana. Hemos aplicado la teoría de la emisión Markoviana de dos átomos acoplados a una guía al caso de una cadena de cavidades.Hemos analizado el rol de la distancia entre átomos en la emisión espontánea, haciendo énfasis en fenómenos de interacción y decaimiento colectivo. Finalmente, hemos incluído la dinámica de los estados ligados originados por los bordes de banda de la guía y aquellos formados por efectos colectivos y de distancia. <br /

    The European Large Area ISO Survey IX: the 90 micron luminosity function from the Final Analysis sample

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    We present the 90 micron luminosity function of the Final Analysis of the European Large Area ISO Survey (ELAIS), extending the sample size of our previous analysis (paper IV) by about a factor of 4. Our sample extends to z=1.1, around 50 times the comoving volume of paper IV, and 10^{7.7} < h^{-2}L/Lsun < 10^{12.5}. From our optical spectroscopy campaigns of the northern ELAIS 90 mircon survey (7.4 deg^2 in total, to S(90um)>70mJy), we obtained redshifts for 61% of the sample (151 redshifts) to B<21 identified at 7 microns, 15 microns, 20cm or with bright (B<18.5) optical identifications. The selection function is well-defined, permitting the construction of the 90 micron luminosity function of the Final Analysis catalogue in the ELAIS northern fields, which is in excellent agreement with our Preliminary Analysis luminosity function in the ELAIS S1 field from paper IV. The luminosity function is also in good agreement with the IRAS-based prediction of Serjeant & Harrison (2004), which if correct requires luminosity evolution of (1+z)^{3.4 +/- 1.0} for consistency with the source counts. This implies an evolution in comoving volume averaged star formation rate at z<~1 consistent with that derived from rest-frame optical and ultraviolet surveys.Comment: MNRAS accepted. 7 pages, 5 figures. Uses BoxedEPS (included

    MAMBO 1.2mm observations of luminous starbursts at z~2 in the SWIRE fields

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    We report on--off pointed MAMBO observations at 1.2 mm of 61 Spitzer-selected star-forming galaxies from the SWIRE survey. The sources are selected on the basis of bright 24um fluxes (f_24um>0.4mJy) and of stellar dominated near-infrared spectral energy distributions in order to favor z~2 starburst galaxies. The average 1.2mm flux for the whole sample is 1.5+/-0.2 mJy. Our analysis focuses on 29 sources in the Lockman Hole field where the average 1.2mm flux (1.9+/-0.3 mJy) is higher than in other fields (1.1+/-0.2 mJy). The analysis of the sources multi-wavelength spectral energy distributions indicates that they are starburst galaxies with far-infrared luminosities ~10^12-10^13.3 Lsun, and stellar masses of ~0.2-6 x10^11 M_sun. Compared to sub-millimeter selected galaxies (SMGs), the SWIRE-MAMBO sources are among those with the largest 24um/millimeter flux ratios. The origin of such large ratios is investigated by comparing the average mid-infrared spectra and the stacked far-infrared spectral energy distributions of the SWIRE-MAMBO sources and of SMGs. The mid-infrared spectra exhibit strong PAH features, and a warm dust continuum. The warm dust continuum contributes to ~34% of the mid-infrared emission, and is likely associated with an AGN component. This constribution is consistent with what is found in SMGs. The large 24um/1.2mm flux ratios are thus not due to AGN emission, but rather to enhanced PAH emission compared to SMGs. The analysis of the stacked far-infrared fluxes yields warmer dust temperatures than typically observed in SMGs. Our selection favors warm ultra-luminous infrared sources at high-z, a class of objects that is rarely found in SMG samples. Our sample is the largest Spitzer-selected sample detected at millimeter wavelengths currently available.Comment: Accepted for publication in ApJ (51 pages; 16 figures). The quality of some figures has been degraded for arXiv purposes. Full resolution version available at this http://www.iasf-milano.inaf.it/~polletta/mambo_swire/lonsdale08_ApJ_accepted.pd

    Regeneração térmica de areia fenólica de fundição em leito fluidizado em escala laboratorial

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      A disposição inadequada de areia de processos de moldagem após vazamento do metal fundido aumenta os custos de logística e impacto ambiental por causa da presença da resina fenólica na sua composição. O pro-cesso de regeneração de resíduos areia fenólica de fundição (RAFF) objetiva a reciclagem deste material. Como os métodos de regeneração mecânica não são eficientes para garantir 100% de limpeza dos grãos de areia e sua utilização novamente no processo de moldagem, este trabalho investigou a eficiência de um mé-todo de regeneração térmica deste tipo de resíduo que pode operar de forma complementar. Um reator de leito fluidizado em escala de laboratório foi projetado e construído para regenerar RAFF que foi tratada ante-riormente por um método mecânico. A metodologia utilizada para projetar e construir o protótipo de leito fluidizado é descrita, assim como a caracterização do resíduo, da areia limpa padrão e da areia regenerada. Os resultados da regeneração térmica no leito fluidizado foram muito satisfatórios no que concerne a eficiência de regeneração. Para as nove condições de processos testadas, os valores de perda ao fogo foram reduzidos quando comparados a areia limpa padrão. Este estudo apresenta as vantagens de uma combinação de dois processos, regeneração mecânica e térmica, que permite reduzir o tempo e eventualmente a temperatura de remoção da resina, devido à remoção parcial da camada de resina ou seu enfraquecimento durante o processo de regeneração mecânica. Das nove condições de processo testadas, seis tiveram perda em valores de ignição abaixo da CSS. Desta forma, a regeneração térmica nos resultados do leito fluidizado foi bastante satisfatória em relação à eficiência de regeneração.Palavras-chave: regeneração térmica, areia usada de fundição, resina fenólica, reciclagem

    Micronutrient supplementation adherence and influence on the prevalences of anemia and iron, zinc and vitamin A deficiencies in preemies with a corrected age of six months

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    OBJECTIVE: To analyze adherence to the recommended iron, zinc and multivitamin supplementation guidelines for preemies, the factors associated with this adherence, and the influence of adherence on the occurrence of anemia and iron, zinc and vitamin A deficiencies. METHODS: This prospective cohort study followed 58 preemies born in 2014 until they reached six months corrected age. The preemies were followed at a referral secondary health service and represented 63.7% of the preterm infants born that year. Outcomes of interest included high or low adherence to iron, zinc and multivitamin supplementation guidelines; prevalence of anemia; and prevalences of iron, zinc, and vitamin A deficiencies. The prevalence ratios were calculated by Poisson regression. RESULTS: Thirty-eight (65.5%) preemies presented high adherence to micronutrient supplementation guidelines. At six months of corrected age, no preemie had vitamin A deficiency. The prevalences of anemia, iron deficiency and zinc deficiency were higher in the low-adherence group but also concerning in the high-adherence group. Preemies with low adherence to micronutrient supplementation guidelines were 2.5 times more likely to develop anemia and 3.1 times more likely to develop zinc deficiency. Low maternal education level increased the likelihood of nonadherence to all three supplements by 2.2 times. CONCLUSIONS: Low maternal education level was independently associated with low adherence to iron, zinc and vitamin A supplementation guidelines in preemies, which impacted the prevalences of anemia and iron and zinc deficiencies at six months of corrected age

    Resulting alterations at the level of testes and semen in dogs submitted to vincristine sulphate administra tion

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    Foram estudados 14 animais da espécie canina, sem raça definida, machos, adultos, com o objetivo de analisar, laboratorialmente, o sêmen e os aspectos histológicos dos testículos antes e após a administração do sulfato de vincristina. Para tanto, os animais foram divididos em 2 grupos. No grupo I (8 animais), submeteu-se os animais à orquiectomia unilateral e um fragmento do testículo e epidídimo foram analisados histologicamente. Ao término das aplicações, os animais sofreram a orquiectomia do testículo remanescente e foram avaliados histologicamente. No grupo II (6 animais), inicialmente, condicionou-se os animais para colheita de sêmen. Após obtenção do material fecundante, este foi analisado laboratorialmente. No grupo I, todos os animais apresentaram degeneração testicular em grau leve ou moderada. No grupo II, observaram-se alterações espermáticas, principalmente ao nível de peça intermediária e cauda. Entretanto, considerando que em termos de média, as características físicas e morfológicas do sêmen de cães sofreram alterações que são reversíveis à utilização do sulfato de vincristina, como recurso terapêutico, pode ser instituído nesta espécie animal.Sperm analysis and testicular histological studies were performed before and after vincristine sulphate treatment, in fourteen male dogs. In group I (n = 8), unilateral orchiectomy was carried out before and after mitostatic treatment, and testicular and epididymal biopsies were examined histologically. All histological examinations showed a slight to moderate degeneration of testicular tissue. In group II (n = 6) semen was collected and was submitted to laboratorial analysis. After vincristine treatment, middle piece and tail abnormalities were found. However, as physical and morphological abnormalities showed to be reversible, vincristine sulphate therapy may be used in such species
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