Padrões de dominância manual, podálica e performance motora em gêmeos

O método de gêmeos envolve a análise diferencial de gêmeos monozigóticos (MZs) e dizigóticos (DZs) a fim de determinar a proporção de variância em um determinado traço atribuível a fatores genéticos e ambientais. Sendo geneticamente idênticos, os gêmeos MZs tendem a apresentar alto índice de concordância em vários atributos comportamentais, enquanto que, os DZs, compartilham 50 % da carga genética, manifestando um reduzido grau de concordância. Todavia, pesquisadores têm investigado possíveis mecanismos genéticos subjacentes do desenvolvimento cerebral para dominância manual e, não têm encontrado utilidade no método de gêmeos, pois, desde 1924, em todos os estudos de dominância manual em gêmeos, a taxa de discordância para o canhotismo e destrimanismo têm sido similares em MZs e DZs. Além disso, frequentemente gêmeos mostram taxa mais alta de prevalência para o canhotismo que os não gêmeos. O objetivo deste estudo foi investigar as possíveis diferenças entre gêmeos destros e canhotos (MZs e DZs combinados) e não gêmeos em variáveis fenótipicas específicas relacionadas à dominância manual, incluindo dominância podálica (chute de penalty), consistência de dominância manual, canhotismo familiar (CF+), postura manual e medidas de habilidades motoras em três testes : Batidas digitais, Tabuleiro de Annett e Pontilhar Pontinhos. Foram avaliados 286 gêmeos ( 255 destros, 34 canhotos) e, 251 não gêmeos (141 destros e 110 canhotos). A análise dos dados revelou o aumento de canhotismo no sexo masculino em três vezes mais do que no feminino. Além disto, destros e canhotos gêmeos foram mais mistos em suas dominâncias manuais e apontaram alta incidência de CF+ entre parentes de primeiro grau que não gêmeos canhotos e destros. Em concordância com estudos anteriores, a frequência de chute contralateral foi mais alta nos mistos do que nos que apresentaram consistência na dominância manual, especialmente entre os canhotos. No que diz respeito à habilidade manual, não foram encontradas diferenças significativas nos três testes de habilidade manual. Conforme as expectativas, destros e canhotos foram mais proficientes na manipulação do estímulo com suas mãos dominantes. Em todas as três medidas, em contraste com os destros, os canhotos (gêmeos e não gêmeos) apresentaram redução entre as assimetrias manuais. Por extensão, o aumento da prevalência de canhotismo entre gêmeos não poderia ser atribuída a influências patológicas, inversão de assimetria ou ordem de nascimento. É possível, levar em consideração, observando a diferença robusta em dominância manual mista que, o padrão de lateralização neuromotora, pode ser mais difusamente organizado nos hemisférios dos gêmeos que em não gêmeos, mas, esta sugestão requer evidência direta, pelo menos a partir de testes de neuro-imagem.

Comparison of the reliability of multifocal visual evoked cortical potentials generated by pattern reversal and pattern pulse stimulation

This study compared the effectiveness of the multifocal visual evoked cortical potentials (mfVEP) elicited by pattern pulse stimulation with that of pattern reversal in producing reliable responses (signal-to-noise ratio >1.359). Participants were 14 healthy subjects. Visual stimulation was obtained using a 60-sector dartboard display consisting of 6 concentric rings presented in either pulse or reversal mode. Each sector, consisting of 16 checks at 99% Michelson contrast and 80 cd/m2 mean luminance, was controlled by a binary m-sequence in the time domain. The signal-to-noise ratio was generally larger in the pattern reversal than in the pattern pulse mode. The number of reliable responses was similar in the central sectors for the two stimulation modes. At the periphery, pattern reversal showed a larger number of reliable responses. Pattern pulse stimuli performed similarly to pattern reversal stimuli to generate reliable waveforms in R1 and R2. The advantage of using both protocols to study mfVEP responses is their complementarity: in some patients, reliable waveforms in specific sectors may be obtained with only one of the two methods. The joint analysis of pattern reversal and pattern pulse stimuli increased the rate of reliability for central sectors by 7.14% in R1, 5.35% in R2, 4.76% in R3, 3.57% in R4, 2.97% in R5, and 1.78% in R6. From R1 to R4 the reliability to generate mfVEPs was above 70% when using both protocols. Thus, for a very high reliability and thorough examination of visual performance, it is recommended to use both stimulation protocols.

Oviposition preference assessment of Diabrotica speciosa (Coleoptera: Chrysomelidae) for different soybean genotypes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Feeding preference of Nezara viridula (Hemiptera: Pentatomidae) and attractiveness of soybean genotypes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Stress Abolishes the Effect of Previous Chronic Ethanol Consumption on Drug Place Preference and on the Mesocorticolimbic Brain Pathway

BackgroundConditioned place preference (CPP) to ethanol (EtOH) is an important addiction-related alteration thought to be mediated by changed neurotransmission in the mesocorticolimbic brain pathway. Stress is a factor of major importance for the initiation, maintenance, and reinstatement of drug abuse and modulates the neurochemical outcomes of drugs. Thus, the aim of this study was to investigate the effects of concomitant exposure to chronic EtOH and stress on CPP to this drug and alterations of dopaminergic and serotonergic neurotransmission in mice.MethodsMale Swiss mice were chronically treated with EtOH via a liquid diet and were exposed to forced swimming stress. After treatment, animals were evaluated for conditioning, extinction, and reinstatement of CPP to EtOH. Also, mice exposed to the same treatment protocol had their prefrontal cortex (PFC), nucleus accumbens (NAc), and amygdala dissected for the quantitation of dopamine, serotonin, and their metabolites content.ResultsData showed that previous chronic exposure to EtOH potentiated EtOH conditioning and increased dopaminergic turnover in PFC. Exposure to stress potentiated EtOH conditioning and decreased dopaminergic turnover in the NAc. However, animals exposed to both chronic EtOH and stress did not display alterations of CPP and showed an elevated content of dopamine in amygdala. No treatment yielded serotonergic changes.ConclusionsThe present study indicates that previous EtOH consumption as well as stress exposure induces increased EtOH conditioning, which can be related to dopaminergic alterations in the PFC or NAc. Interestingly, concomitant exposure to both stimuli abolished each other's effect on conditioning and PFC or NAc alterations. This protective outcome can be related to the dopaminergic increase in the amygdala.

Excitonic instabilities and spontaneous time-reversal symmetry breaking on the honeycomb lattice

We elucidate the close relationship between spontaneous time-reversal symmetry breaking and the physics of excitonic instabilities in strongly correlated multiband systems. The underlying mechanism responsible for the spontaneous breaking of time-reversal symmetry in a many-body system is closely related to the Cooper-like pairing instability of interband particle-hole pairs involving higher-order symmetries. Studies of such pairing instabilities have, however, mainly focused on the mean-field aspects of the virtual exciton condensate, which ignores the presence of the underlying collective Fermi-liquid excitations. We show that this relationship can be exploited to systematically derive the coupling of the condensate order parameter to the intraband Fermi-liquid particle-hole excitations. Surprisingly, we find that the static susceptibility is negative in the ordered phase when the coupling to the Fermi-liquid collective excitations are included, suggesting that a uniform condensate of virtual excitons, with or without time-reversal breaking, is an unstable phase at T = 0.

Thermogenesis, vocalization, and temperature preference of 1-day-old chicken hatchlings after cold-exposure in late embryogenesis

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

Actions of oestradiol and progesterone on the prostate in female gerbils: reversal of the histological effects of castration

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

Preference and infestation level of Anastrepha fraterculus (Wiedemann, 1830) on fruits of some Psidium guajava L. cultivars and relation to their physicochemical parameters

This study aimed to verify the preference and infestation level of Anastrepha fraterculus (Diptera: Tephritidae) [South American fruit fly] in fruits of guava cultivars and to correlate them to variables such as peel coloration, soluble solids and pH of fruit cultivars. The following cultivars were used: Pedro Sato, Paluma, Casco and S,culo XXI. The infestation was evaluated in cages, considering two scenarios: no-choice and multiple choice. In both tests, evaluations of the fruit attraction to insects were conducted for a period of 1', 3', 5', 10', 20', 30', 1 h, 2 h, 6 h, 12 h and 24 h. The visit of A. fraterculus on the assayed cultivars in relation to the time was studied by logistic regression. After 10 days, the number of larvae in each fruit was recorded. In the multiple choice test, the visit proportions were significantly higher in the fruits of cvs. S,culo XXI and Pedro Sato than in those of cvs. Paluma and Casco. In the no-choice test, the visit proportions were significantly lower in the Paluma fruits. In both tests, the rate of fruit infestation by A. fraterculus did not differ among cvs. Pedro Sato, Paluma and Casco, whereas the fruits of cv. S,culo XXI were more infested. The indexes of pH did not interfere with the infestation of A. fraterculus, whereas a high rate of soluble solids and low color angle appear to be crucial for discriminating the fruits of the most susceptible cultivars. Infestation rate of S,culo XXI fruits displayed significant correlations with: A degrees Brix (r= 0.7078) and color angle (h) (r= -0.9499) of guava fruits under the multiple choice conditions.

Foraging Activity and Seasonal Food Preference of Linepithema micans (Hymenoptera: Formicidae), a Species Associated With the Spread of Eurhizococcus brasiliensis (Hemiptera: Margarodidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Non-preference for oviposition and antibiosis in bean cultivars to Bemisia tabaci biotype B (Hemiptera: Aleyrodidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Glycaspis brimblecombei Moore, 1964 (Hemiptera: Psyllidae) on eucalyptus: oviposition non-preference and antibiosis

Forest plantations with Eucalyptus spp. (L'H,r) in Brazil are highly yielding. However, this activity is more and more threatened due to interactions with phytophagous insects, especially by exotic species, such as the red gum lerp psyllid Glycaspis brimblecombei Moore (Hemiptera: Psyllidae). This study aimed to evaluate the resistance in eucalyptus against the psyllid in oviposition and biological development assays, attempting to identify potential genotypes resistant to the pest for forest plantations. In addition, we tested the hypothesis of that concentration of total phenolics and lignin, and amount of epicuticular wax were associated with the expression of resistance. Results showed that there was variation in the levels of resistance among the genotypes assessed. Oviposition non-preference was observed on Eucalyptus citriodora (Hook) in free-choice and no-choice tests, and Clone FP10 was least preferred in the no-choice test. The genotypes E. citriodora and Clone FP6 provided 100 % nymphal mortality, and Clones FP7 and FP9 also affected negatively the G. brimblecombei development by lengthening the duration of the nymphal stage and reducing adult emergence. Clone FP6 had higher concentration of total phenolics and larger contact angle formed between the water droplet and leaf surface, which may be associated with thicker layer of epicuticular wax on the leaves, and one of the causes of high nymphal mortality. Thus, the use of the resistant genotypes of eucalyptus screened against G. brimblecombei is a promising and viable alternative for forest plantations infested with this pest.

Temperature-induced spontaneous time-reversal symmetry breaking on the honeycomb lattice

Phase transitions involving spontaneous time-reversal symmetry breaking are studied on the honeycomb lattice at finite hole doping with next-nearest-neighbor repulsion. We derive an exact expression for the mean-field equation of state in closed form, valid at temperatures much less than the Fermi energy. Contrary to standard expectations, we find that thermally induced intraband particle-hole excitations can create and stabilize a uniform metallic phase with broken time-reversal symmetry as the temperature is raised in a region where the ground state is a trivial metal.

Estimation of a preference map of new consumers for spatial load forecasting simulation methods using a spatial analysis of points

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)