Distinct behavioral phenotypes in male mice lacking the thyroid hormone receptor alpha1 or beta isoforms

Thyroid hormones influence both neuronal development and anxiety via the thyroid hormone receptors (TRs). The TRs are encoded by two different genes, TRalpha and TRbeta. The loss of TRalpha1 is implicated in increased anxiety in males, possibly via a hippocampal increase in GABAergic activity. We compared both social behaviors and two underlying and related non-social behaviors, state anxiety and responses to acoustic and tactile startle in the gonadally intact TRalpha1 knockout (alpha1KO) and TRbeta (betaKO) male mice to their wild-type counterparts. For the first time, we show an opposing effect of the two TR isoforms, TRalpha1 and TRbeta, in the regulation of state anxiety, with alpha1 knockout animals (alpha1KO) showing higher levels of anxiety and betaKO males showing less anxiety compared to respective wild-type mice. At odds with the increased anxiety in non-social environments, alpha1KO males also show lower levels of responsiveness to acoustic and tactile startle stimuli. Consistent with the data that T4 is inhibitory to lordosis in female mice, we show subtly increased sex behavior in alpha1KO male mice. These behaviors support the idea that TRalpha1 could be inhibitory to ERalpha driven transcription that ultimately impacts ERalpha driven behaviors such as lordosis. The behavioral phenotypes point to novel roles for the TRs, particularly in non-social behaviors such as state anxiety and startle.

The supernova remnant CTB 37B and its associated magnetar CXOU J171405.7-381031: evidence for a magnetar-driven remnant

We discuss the association between the candidate magnetar CXOU J171405.7-381031 and the supernova remnant CTB 37B. The recent detection of the period derivative of the object allowed an estimation of a young characteristic age of only similar to 1000 yr. This value is too small to be compatible even with the minimum radius of the remnant being >= 10 pc, the value corresponding to the lower limit of the estimated distance of 10.2 +/- 3.5 kpc, unless the true distance happens to be even smaller than the lower limit. We argue that a consistent scenario for the remnant`s origin, in which the latter is powered by the energy injected by a young magnetar, is indeed more accurate to explain the young age, and demonstrates its non-standard (i.e. magnetar-driven) nature.

The evolution of the mass-metallicity relation in SDSS galaxies uncovered by astropaleontology

We have obtained the mass-metallicity (M-Z) relation at different lookback times for the same set of galaxies from the Sloan Digital Sky Survey, using the stellar metallicities estimated with our spectral synthesis code STARLIGHT. We have found that this relation steepens and spans a wider range in both mass and metallicity at higher redshifts. We have modelled the time evolution of stellar metallicity with a closed-box chemical evolution model, for galaxies of different types and masses. Our results suggest that the M-Z relation for galaxies with present-day stellar masses down to 10(10) M(circle dot) is mainly driven by the history of star formation and not by inflows or outflows.

Conditional male dimorphism and alternative reproductive tactics in a Neotropical arachnid (Opiliones)

In arthropods, most cases of morphological dimorphism within males are the result of a conditional evolutionarily stable strategy (ESS) with status-dependent tactics. In conditionally male-dimorphic species, the status` distributions of male morphs often overlap, and the environmentally cued threshold model (ET) states that the degree of overlap depends on the genetic variation in the distribution of the switchpoints that determine which morph is expressed in each value of status. Here we describe male dimorphism and alternative mating behaviors in the harvestman Serracutisoma proximum. Majors express elongated second legs and use them in territorial fights; minors possess short second legs and do not fight, but rather sneak into majors` territories and copulate with egg-guarding females. The static allometry of second legs reveals that major phenotype expression depends on body size (status), and that the switchpoint underlying the dimorphism presents a large amount of genetic variation in the population, which probably results from weak selective pressure on this trait. With a mark-recapture study, we show that major phenotype expression does not result in survival costs, which is consistent with our hypothesis that there is weak selection on the switchpoint. Finally, we demonstrate that switchpoint is independent of status distribution. In conclusion, our data support the ET model prediction that the genetic correlation between status and switchpoint is low, allowing the status distribution to evolve or to fluctuate seasonally, without any effect on the position of the mean switchpoint.

Efficiency of uniparental male and female care against egg predators in two closely related syntopic harvestmen

Although the benefits of maternal care have been investigated in many species, the caring role of males in species with exclusive paternal care has received less attention. We experimentally quantified the protective role of paternal care in the harvestman Iporangaia pustulosa. Additionally, we compared the effectiveness of paternal care against predation in this species with a syntopic harvestman with maternal care, Acutisoma proximum. We demonstrated that nearly one-third of the unprotected Iporangaia clutches disappeared entirely in 12 days, while the other two-thirds suffered a mean reduction of 55% in egg number. Conversely, 50% of the control clutches did not suffer any reduction, and only one was entirely consumed by predators. We also demonstrated that the mucus coat that covers Iporangaia clutches has an important deterrent role against predation by conspecifics: 58.3% of the clutches without mucus were attacked and three of them were entirely consumed, whereas only three clutches with mucus were attacked, suffering a reduction of up to three eggs. Iporangaia males were as efficient as Acutisoma females in protecting eggs. However, unattended Acutisoma eggs were attacked 20% more frequently than unattended Iporangaia eggs. Unattended Iporangaia eggs are protected by a mucus coat that prevents or decreases predation rate, whereas Acutisoma eggs are more susceptible to predation, probably because they lack this mucus coat. Thus, besides the fact that Iporangaia males efficiently protect the offspring against egg predators, females also contribute to egg protection by providing a mucus coat that deters egg predators. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Nonrecurrent MECP2 duplications mediated by genomic architecture-driven DNA breaks and break-induced replication repair

Recurrent submicroscopic genomic copy number changes are the result of nonallelic homologous recombination (NAHR). Nonrecurrent aberrations, however, can result from different nonexclusive recombination-repair mechanisms. We previously described small microduplications at Xq28 containing MECP2 in four male patients with a severe neurological phenotype. Here, we report on the fine-mapping and breakpoint analysis of 16 unique microduplications. The size of the overlapping copy number changes varies between 0.3 and 2.3 Mb, and FISH analysis on three patients demonstrated a tandem orientation. Although eight of the 32 breakpoint regions coincide with low-copy repeats, none of the duplications are the result of NAHR. Bioinformatics analysis of the breakpoint regions demonstrated a 2.5-fold higher frequency of Alu interspersed repeats as compared with control regions, as well as a very high GC content (53%). Unexpectedly, we obtained the junction in only one patient by long-range PCR, which revealed nonhomologous end joining as the mechanism. Breakpoint analysis in two other patients by inverse PCR and subsequent array comparative genomic hybridization analysis demonstrated the presence of a second duplicated region more telomeric at Xq28, of which one copy was inserted in between the duplicated MECP2 regions. These data suggest a two-step mechanism in which part of Xq28 is first inserted near the MECP2 locus, followed by breakage-induced replication with strand invasion of the normal sister chromatid. Our results indicate that the mechanism by which copy number changes occur in regions with a complex genomic architecture can yield complex rearrangements.

The gynoecium of male Anchietea pyrifolia (Violaceae): Preserved structure with a new function

Structure of inflorescences and flowers and flowering behaviour are reported for the woody liana Anchietea pyrifolia (Violaceae) from Brazil. The specimen studied is grown for some decades now in the greenhouses of Halle Botanical Garden and turned out unisexually male, which adds a further example of dioecism to the family Violaceae, in which this type of sex distribution is rarely encountered. The flowers are exceptional also for the strongly asymmetric anterior petal, which represents a rare case of a species with enantiomorphic flowers pollinated by Lepidoptera. They have a fully developed gynoecium with a complicated architecture comparable to the pistil of bisexual Violaceae flowers, though without ovules. The style head is capable to release viscose liquid on tactile stimulation or pressure, which is known to act as pollen-gathering mechanism in bisexual Violaceae species with usually dry pollen and buzz-pollination. This function has switched in male A. pyrifolia to a mechanism for efficient pollen release mediated by insect pollinators from its short-lived flowers. (C) 2009 Elsevier GmbH. All rights reserved.

Semiclassical evolution of dissipative Markovian systems

A semiclassical approximation for an evolving density operator, driven by a `closed` Hamiltonian operator and `open` Markovian Lindblad operators, is obtained. The theory is based on the chord function, i.e. the Fourier transform of the Wigner function. It reduces to an exact solution of the Lindblad master equation if the Hamiltonian operator is a quadratic function and the Lindblad operators are linear functions of positions and momenta. Initially, the semiclassical formulae for the case of Hermitian Lindblad operators are reinterpreted in terms of a (real) double phase space, generated by an appropriate classical double Hamiltonian. An extra `open` term is added to the double Hamiltonian by the non-Hermitian part of the Lindblad operators in the general case of dissipative Markovian evolution. The particular case of generic Hamiltonian operators, but linear dissipative Lindblad operators, is studied in more detail. A Liouville-type equivariance still holds for the corresponding classical evolution in double phase space, but the centre subspace, which supports the Wigner function, is compressed, along with expansion of its conjugate subspace, which supports the chord function. Decoherence narrows the relevant region of double phase space to the neighbourhood of a caustic for both the Wigner function and the chord function. This difficulty is avoided by a propagator in a mixed representation, so that a further `small-chord` approximation leads to a simple generalization of the quadratic theory for evolving Wigner functions.

The distribution of male wages in Brazil

This paper examines the evolution of wage inequality in Brazil in the 1980s and 1990s . It tries to investigate the role played by changing economic returns to education and to experience over this period together with the evolution of within-group inequality. It applies a quantile regression approach on grouped data to the Brazilian case. Results using repeated cross-sections of a Brazilian annual household survey indicate that : i) Male wage dispersion remained basically constant overall in the 1980's and 1990' s but has increased substantially within education and age groups. ii) Returns to experience increased significantly over this period, with the rise concentrated on the iliterate/primary school group iii) Returns to college education have risen over time, whereas return to intermediate and high-school education have fallen iv) The apparent rise in within-group inequality seems to be the result of a fall in real wages, since the difference in wage leveIs has dec1ined substantially over the period, especially within the high-educated sample. v) Returns to experience rise with education. vi) Returns to education rise over the life-cycle. vii) Wage inequality increases over the life-cycle. The next step i~ this research will try to conciliate all these stylised facts.

Evolution of the landscape of Madeira Island: long-term vegetation dynamics

The aim of this thesis was to evaluate historical change of the landscape of Madeira Island and to assess spatial and temporal vegetation dynamics. In current research diverse “retrospective techniques”, such as landscape repeat photography, dendrochronology, and research of historical records were used. These, combined with vegetation relevés, aimed to gather information about landscape change, disturbance history, and vegetation successional patterns. It was found that landscape change, throughout 125 years, was higher in the last five decades manly driven by farming abandonment, building growth and exotic vegetation coverage increase. Pristine vegetation was greatly destroyed since early settlement and by the end of the nineteenth century native vegetation was highly devastated due to recurrent antropogenic disturbances. These actions also helped to block plant succession and to modify floristical assemblages, affecting as well as species richness. In places with less hemeroby, although significant growth of vegetation of lower seral stages was detected, the vegetation of most mature stages headed towards unbalance between recovery and loss, being also very vulnerable to exotic species encroachment. Recovery by native vegetation also occurred in areas formerly occupied by exotic plants and agriculture but it was almost negligible. Vegetation recovery followed the successional model currently proposed, attesting the model itself. Yet, succession was slower than espected, due to lack of favourable conditions and to recurrent disturbances. Probable tempus of each seral stage was obtained by growth rates of woody taxa estimated through dendrochronology. The exotic trees which were the dominant trees in the past (Castanea sativa and Pinus pinaster) almost vanished. Eucalyptus globulus, the current main tree of the exotic forest is being replaced by other cover types as Acacia mearnsii. The latter, along with Arundo donax, Cytisus scoparius and Pittosporum undulatum are currently the exotic species with higher invasive behaviour. However, many other exotic species have also proved to be highly pervasive and came together with the ones referred above to prevent native vegetation regeneration, to diminish biological diversity, and to block early successional phases delaying native forest recovery.

Model-Driven requirements engineering process aided by ontologies and natural controlled languages

Researches in Requirements Engineering have been growing in the latest few years. Researchers are concerned with a set of open issues such as: communication between several user profiles involved in software engineering; scope definition; volatility and traceability issues. To cope with these issues a set of works are concentrated in (i) defining processes to collect client s specifications in order to solve scope issues; (ii) defining models to represent requirements to address communication and traceability issues; and (iii) working on mechanisms and processes to be applied to requirements modeling in order to facilitate requirements evolution and maintenance, addressing volatility and traceability issues. We propose an iterative Model-Driven process to solve these issues, based on a double layered CIM to communicate requirements related knowledge to a wider amount of stakeholders. We also present a tool to help requirements engineer through the RE process. Finally we present a case study to illustrate the process and tool s benefits and usage

Chromosome evolution in fish: sex chromosome variability in Eigenmannia virescens (Gymnotiformes : Sternopygidae)

New data are presented on the sex chromosomes of the fish species Eigenmannia virescens (Gymnotiformes, Sternopygidae). A new finding, involving the occurrence of ZZ/ ZW sex chromosomes, is described in specimens sampled from the Sao Francisco and Amazon river basins in Brazil. All individuals had a chromosome number of 2n = 38. The homologs of the sex chromosome pair from the Sao Francisco river basin sample differed only in their morphology, while those from the Amazonian sample differed both in morphology and heterochromatin pattern. A possible model for the evolution of the sex chromosomes in E virescens is proposed, including data from populations from the Parana (Brazil) river basin, in which male heterogamety has already been described. The occurrence of different sex chromosome systems in species and populations of the neotropical freshwater fish fauna is discussed. Copyright (C) 2002 S. Karger AG, Basel.

The 5S rDNA family evolves through concerted and birth-and-death evolution in fish genomes: an example from freshwater stingrays

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

Morphological studies on castes of Protopolybia chartergoides (Hymenoptera, Vespidae, Epiponini) observed in colonies during male production stage

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

Strategies of karyotype differentiation in Elateridae (Coleoptera, Polyphaga)

The chromosome study of five species of the family Elateridae, belonging to the subfamilies Agrypninae and Elaterinae, and the analysis of the cytogenetic data previously recorded for this family permitted the establishment of the main strategies of karyotypic differentiation that has occurred in the elaterids. In Agrypninae, the three species studied (Conoderus fuscofasciatus, Conoderus rufidens, and Conoderus sp.) showed the male karyotype 2n = 16 + X0. This karyotypic uniformity detected in these Conoderus species has also been shared with other species of the same genus, differing considerably from chromosomal heterogeneity verified in the subfamily Agrypninae. The use of the C-banding technique in C. fuscofasciatus and Conoderus sp. revealed constitutive heterochromatin in the pericentromeric region of the majority of the chromosomes. In C. fuscofasciatus, additional constitutive heterochromatin were also observed in the long arm terminal region of almost all chromosomes. Among the representatives of Elaterinae, the karyotype 2n = 18 + Xy(p) of Pomachilius sp.2 was similar to that verified in the majority of the Coleoptera species, contrasting with the chromosomal formula 2n = 18 + X0 detected in Cardiorhinus rufilateris, which is most common in the species of Elaterinae. In the majority of the elaterids, the chromosomal differentiation has frequently been driven by reduction of the diploid number; but, among the four cytogenetically examined subfamilies, there are some differences in relation to the trends of karyotypic evolution. (C) 2006 Elsevier Ltd. All rights reserved.