999 resultados para Complex
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Uma lista de novas referências e ocorrências para ácaros tetraniquídeos da mandioca é apresentada.
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n.s. no.47(1988)
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v.73:no.2(1979)
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n.s. no.62(1990)
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We describe the mating behavior of Adelosgryllus rubricephalus Mesa & Zefa, 2004. In trials carried out in laboratory we verified the following mating sequence: (1) sexual recognition by antennation; (2) courtship with male turning his abdomen towards the female, performing mediolateral antennae vibration, jerking its body antero-posteriorly and stridulating intermittently, while receptive female drums on the male's abdomen tip, cerci and hind-tibia with her palpi or foretarsi; the male then stops and stays motionless for some seconds, extrudes the spermatophore and both restart the behavioral sequence described above; (3) copulation: male underneath female; with his tegmina inclined forward, and joins his genitalia to the female's to promote sperm transference ; the female steps off the male, occurring a brief end-to-end position; (4) postcopulation: without guarding behavior; male retains the spermatophore and eats it. We quantified elapsed time of each behavioral sequence and discussed its implications in the observed mating behavior.
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n.s. no.74(1993)
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The condition factor is a parameter which acts as a general indicator of the "well-being" of a species, and it can be obtained through the analysis of width vs. weight relationships. The present work aims to investigate size vs. weight relationship and the condition factor of the crab Goniopsis cruentata (Latreille, 1803). The study area was the Mundaú/Manguaba estuarine complex, Maceió, state of Alagoas, Northeast Brazil. Samplings were monthly accomplished from August 2007 to July 2008. A total of 626 individuals were analyzed, being 309 males and 317 females. Males were larger and heavier than females, what is expected in many brachyuran. The growth was positive allometric to both males (b = 3.42) and females (b = 3.30), not obeying the "cube law". The condition factor of female was higher than that of male crabs, probably due to the gonad weight of females. It also varied seasonally for both sexes, being higher in the autumn and winter in males, and in the autumn and spring in females, and related to the molt and period of spawning intensification.
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Production of desirable outputs is often accompanied by undesirable by products that have damaging effects on the environment, and whose disposal is frequently regulated by public authorities. In this paper, we compute directional technology distance functions under particular assumptions concerning disposability of bads in order to test for the existence of what we call ‘complex situations’, where the biggest producer is not the greatest polluter. Furthermore, we show that how in such situations, environmental regulation could achieve an effective reduction in the aggregate level of bad outputs without reducing the production of good outputs. Finally, we illustrate our methodology with an empirical application to a sample of Spanish tile ceramic producers.
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Economies are open complex adaptive systems far from thermodynamic equilibrium, and neo-classical environmental economics seems not to be the best way to describe the behaviour of such systems. Standard econometric analysis (i.e. time series) takes a deterministic and predictive approach, which encourages the search for predictive policy to ‘correct’ environmental problems. Rather, it seems that, because of the characteristics of economic systems, an ex-post analysis is more appropriate, which describes the emergence of such systems’ properties, and which sees policy as a social steering mechanism. With this background, some of the recent empirical work published in the field of ecological economics that follows the approach defended here is presented. Finally, the conclusion is reached that a predictive use of econometrics (i.e. time series analysis) in ecological economics should be limited to cases in which uncertainty decreases, which is not the normal situation when analysing the evolution of economic systems. However, that does not mean we should not use empirical analysis. On the contrary, this is to be encouraged, but from a structural and ex-post point of view.
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Inductive learning aims at finding general rules that hold true in a database. Targeted learning seeks rules for the predictions of the value of a variable based on the values of others, as in the case of linear or non-parametric regression analysis. Non-targeted learning finds regularities without a specific prediction goal. We model the product of non-targeted learning as rules that state that a certain phenomenon never happens, or that certain conditions necessitate another. For all types of rules, there is a trade-off between the rule's accuracy and its simplicity. Thus rule selection can be viewed as a choice problem, among pairs of degree of accuracy and degree of complexity. However, one cannot in general tell what is the feasible set in the accuracy-complexity space. Formally, we show that finding out whether a point belongs to this set is computationally hard. In particular, in the context of linear regression, finding a small set of variables that obtain a certain value of R2 is computationally hard. Computational complexity may explain why a person is not always aware of rules that, if asked, she would find valid. This, in turn, may explain why one can change other people's minds (opinions, beliefs) without providing new information.
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"Vegeu el resum a l'inici del document del fitxer adjunt."
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Estudi elaborat a partir d’una estada a la Universitat de Aarhus, Dinamarca, durant juliol 2006. En el present treball s’investiguen, per primer cop, les propietats de absorció bifotòniques del fotosensibilitzador 2,7,12,17-tetrafenilporficè (TPPo) i del seu complex de pal•ladi (II) (PdTPPo). Ambos compostos han rebut molta atenció com a possibles otosensibilitzadors per a Teràpia Fotodinàmica (TFD). S’utilitza la detecció de la fosforescència de l’oxigen singlet, centrada a 1270 nm i produïda per l’absorció de dos fotons, per quantificar la magnitud de la secció d’absorció bifotònica, "delta", dels porficèns estudiats. Els experiments se han dut a terme en el marge espectral 750-850 nm i a l’infraroig proper a 1100nm. Aquestes longituds d’ona corresponen a les zones d’absorció bifotònica en les bandes de Soret i Q. Les propietats bifotòniques obtingudes es comparen i contrasten amb les dades conegudes de la tetrafenilporfirina (TPP), isòmer estructural del tetrafenilporficè però amb més gran simetria, i es troba que en la banda de Soret (que coincideix amb la regió de la pell més transparent) els valors de delta per el TPPo i PdTPPo son aproximadament 2000 GM en el màxim, pràcticament cent vegades més grans que per la TPP. A més a més, aquestos valors son dos ordres de magnitud més grans que els obtinguts a l’irradiar a 1100 nm (bandes Q). Aquestes observacions es poden explicar mitjançant la amplificació per ressonància deguda a la presència de transicions monofotòniques ressonants en la regió de les bandes Q. Els elevats valors de "delta" obtinguts per els tetrafenilporficèns estudiats junt a les principals característiques que aquestos presenten (elevat rendiment de formació d’oxigen singlet, estabilitat química i fotoquímica, absència de citotoxicitat,...) qualifiquen al TPPo y PdTPPo com a possibles fotosensibilitzadors per a Teràpia Fotodinàmica Bifotònica.
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Dissection of 765 sandflies captured in Além Paraíba (the type locality of Leishmania braziliensis) resulted in the isolation, from Psychodopygus hirsuta hirsuta, of a parasite of the Le. braziliensis complex.
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Eukaryotic cells generate energy in the form of ATP, through a network of mitochondrial complexes and electron carriers known as the oxidative phosphorylation system. In mammals, mitochondrial complex I (CI) is the largest component of this system, comprising 45 different subunits encoded by mitochondrial and nuclear DNA. Humans diagnosed with mutations in the gene NDUFS4, encoding a nuclear DNA-encoded subunit of CI (NADH dehydrogenase ubiquinone Fe-S protein 4), typically suffer from Leigh syndrome, a neurodegenerative disease with onset in infancy or early childhood. Mitochondria from NDUFS4 patients usually lack detectable NDUFS4 protein and show a CI stability/assembly defect. Here, we describe a recessive mouse phenotype caused by the insertion of a transposable element into Ndufs4, identified by a novel combined linkage and expression analysis. Designated Ndufs4(fky), the mutation leads to aberrant transcript splicing and absence of NDUFS4 protein in all tissues tested of homozygous mice. Physical and behavioral symptoms displayed by Ndufs4(fky/fky) mice include temporary fur loss, growth retardation, unsteady gait, and abnormal body posture when suspended by the tail. Analysis of CI in Ndufs4(fky/fky) mice using blue native PAGE revealed the presence of a faster migrating crippled complex. This crippled CI was shown to lack subunits of the "N assembly module", which contains the NADH binding site, but contained two assembly factors not present in intact CI. Metabolomic analysis of the blood by tandem mass spectrometry showed increased hydroxyacylcarnitine species, implying that the CI defect leads to an imbalanced NADH/NAD(+) ratio that inhibits mitochondrial fatty acid β-oxidation.
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PURPOSE: To determine the value of applying finger trap distraction during direct MR arthrography of the wrist to assess intrinsic ligament and triangular fibrocartilage complex (TFCC) tears. MATERIALS AND METHODS: Twenty consecutive patients were prospectively investigated by three-compartment wrist MR arthrography. Imaging was performed with 3-T scanners using a three-dimensional isotropic (0.4 mm) T1-weighted gradient-recalled echo sequence, with and without finger trap distraction (4 kg). In a blind and independent fashion, two musculoskeletal radiologists measured the width of the scapholunate (SL), lunotriquetral (LT) and ulna-TFC (UTFC) joint spaces. They evaluated the amount of contrast medium within these spaces using a four-point scale, and assessed SL, LT and TFCC tears, as well as the disruption of Gilula's carpal arcs. RESULTS: With finger trap distraction, both readers found a significant increase in width of the SL space (mean Δ = +0.1mm, p ≤ 0.040), and noticed more contrast medium therein (p ≤ 0.035). In contrast, the differences in width of the LT (mean Δ = +0.1 mm, p ≥ 0.057) and UTFC (mean Δ = 0mm, p ≥ 0.728) spaces, as well as the amount of contrast material within these spaces were not statistically significant (p = 0.607 and ≥ 0.157, respectively). Both readers detected more SL (Δ = +1, p = 0.157) and LT (Δ = +2, p = 0.223) tears, although statistical significance was not reached, and Gilula's carpal arcs were more frequently disrupted during finger trap distraction (Δ = +5, p = 0.025). CONCLUSION: The application of finger trap distraction during direct wrist MR arthrography may enhance both detection and characterisation of SL and LT ligament tears by widening the SL space and increasing the amount of contrast within the SL and LT joint spaces.