647 research outputs found
Age, Gender, and Socioeconomic Status Differences in Explicit and Implicit Beliefs About Effortlessly Perfect Self-Presentation
Feeling pressure to project an image of effortless perfection -- always appearing to perform with self-confidence and ease --- has been portrayed in the media as an increasingly common mental health vulnerability with potentially serious implications for college women. Despite this, almost no empirical research exists on effortlessly perfect self–presentation (EPSP) or demographic differences in it.
• Some recent research suggests that perfectionism is on the rise among young people (Curran & Hill, 2017), and that it is more associated with mental health problems among students with high rather than low socioeconomic status (Lyman & Luthar, 2014). However, these studies did not focus specifically on EPSP, which differs from more typical perfectionism in that it prohibits apparent effort or anxiety while striving for perfection. Of the two published studies on EPSP, one did not examine demographic differences (Flett et al., 2016) and the other found higher endorsement of EPSP among men than among women (Travers et al., 2016).
• Anonymous interviews we conducted about EPSP in 40 college students (Glazer et al., in prep) yielded very complex, self-contradictory responses suggesting that beliefs about EPSP may be characterized by stigma and ambivalence. For this reason we decided to focus the current study on indirect and implicit measures of EPSP.
• In this study, participants completed three new scales about EPSP, along with the two existing measures of this phenomenon, several mental health measures, and demographics questions. They also rated the perceived social status and self-esteem of two target individuals in a within-person experimental design
Phylogenetic analysis of nodulation and nitrogen fixation genes of a brazilian collection of Bradyrhizobium strains.
The genus Bradyrhizobium encompasses a variety of bacteria that can live in symbiotic and endophytic associations with legumes and non-legumes, and are characterized by physiological and symbiotic versatility and broad geographical distribution. In studies with Bradyrhizobium strains the comparison of phylogenies of nodulation and housekeeping genes has indicated a monophyletic origin of nodulation genes and diffusion by vertical and horizontal gene transfer, the last one probably influenced by the host plants. In previous studies with the strains analyzed in this study we have shown high diversity in the 16S rRNA, ITS rRNA, atpD, glnII, dnaK and recA housekeeping genes (Menna et al., 2006, 2009). However, despite indications of great genetic variability within the Bradyrhizobium genus, little is known about the phylogeny of the nodulation and nitrogen fixation genes. In this study the nodulation genes nodY/K, nodA and nodZ and the nitrogen fixation gene nifH of forty Bradyrhizobium strains were sequenced and analyzed. The great majority of the strains are from tropical regions and were isolated from members of the three subfamilies and nine tribes of the family Leguminosae (=Fabaceae). In all phylogenetic trees a high level of genetic diversity was observed and several clusters were correlated with the subfamilies of the host plants. One example was with the symbionts of Glycine max and Acacia sp., classified in the subfamilies Papilionoideae and Mimosoideae, respectively. In the phylogenetic trees built with nodY/K and nodA the symbionts of Acacia sp. were clustered in an isolated group, and no amplification was obtained for the nodZ gene. A successful amplification of nifH gene was obtained with all strains, and the resulting phylogenetic tree had similar clusters in comparison to the trees build with the nodulation genes (nodY/K, nodA and nodZ). The strains which failed in the amplification for some nodulation genes occupied an isolated position in the nifH tree. The comparison of all trees has shown no correlation between housekeeping and nod and nifH genes. The results pointed out the high diversity of nodulation and nitrogen fixation genes of tropical Bradyrhizobium strains and in several clusters high correlation between nod and nif genes and the host plants was observed. Partially financed by: CNPq (577933/2008-6; 558455/2008-5; 470162/2009-0
Taxonomia e filogenia de estirpes de Bradyrhizobium com base na metodologia de MLSA (Multilocus Sequence Analysis).
O gênero Bradyrhizobium compreende um grupo diverso de bactérias com capacidade de estabelecer simbiose com plantas da família Leguminosae. Estudos com Bradyrhizobium têm demonstrado diversidade genética elevada, principalmente com estirpes isoladas em regiões tropicais. A análise do gene ribossomal 16S (16S RNAr) tem sido a principal ferramenta utilizada em estudos de diversidade, taxonomia e filogenia bacteriana, mas devido ao alto nível de conservação da sequência nucleotídica deste gene, as informações obtidas podem limitar a determinação de novas espécies, como é o caso do gênero Bradyrhizobium. Desse modo, a metodologia de MLSA (Multilocus Sequence Analysis) tem sido recentemente proposta como uma ferramenta complementar em estudos de filogenia e taxonomia, bem como de diversidade em procariotos. Estudos prévios com as estirpes de Bradyrhizobium utilizadas neste trabalho levantaram a hipótese de existência de novas espécies. Utilizando a metodologia de MLSA, o objetivo do presente trabalho foi elucidar as relações filogenéticas de 12 estirpes de Bradyrhizobium e, assim, determinar com maior precisão sua posição taxonômica. Além do gene 16S RNAr, outros cinco genes housekeeping foram utilizados (atpD, glnII, gyrB, recA e rpoB). A árvore filogenética resultante da análise do MLSA dividiu as estirpes em dois grandes grupos, detectando subgrupos bem definidos e dando maior suporte à descrição de novas espécies. O primeiro grande grupo incluiu as estirpes tipo de B. japonicum, B. liaoningense, B. yuanmingense, B. betae e B. canariense e o segundo grande grupo incluiu a estirpe tipo de B. elkanii USDA 76T. Uma grande diversidade foi observada na árvore filogenética do gene atpD, com a formação de um terceiro grande grupo formado por quatro estirpes e as estirpes tipo de B. betae LMG 21987T e B. liaoningense LMG 18230T. Os resultados obtidos demonstram uma diversidade genética elevada entre as estirpes do gênero Bradyrhizobium utilizadas em inoculantes comerciais para diversas leguminosas no Brasil, confirmando a existência de possíveis novas espécies. A técnica de MLSA também demonstrou ser um método rápido e eficaz em estudos de filogenia e taxonomia de Bradyrhizobium.Resumo, 789-1
Migraine and cluster headache show impaired neurosteroids patterns
Background: Perturbation of neuronal excitability contributes to migraine. Neurosteroids modulate the activity of γ-aminobutyric acid A and N-methyl-d-aspartate receptors, and might be involved in the pathogenesis of migraine. Here, we measured plasma levels of four neurosteroids, i.e., allopregnanolone, epiallopregnanolone, dehydroepiandrosterone and deydroepiandrosterone sulfate, in patients affected by episodic migraine, chronic migraine, or cluster headache. Methods: Nineteen female patients affected by episodic migraine, 51 female patients affected by chronic migraine, and 18 male patients affected by cluster headache were recruited to the study. Sex- and age-matched healthy control subjects (31 females and 16 males) were also recruited. Patients were clinically characterized by using validated questionnaires. Plasma neurosteroid levels were measured by liquid chromatography-tandem mass spectrometry. Results: We found disease-specific changes in neurosteroid levels in our study groups. For example, allopregnanolone levels were significantly increased in episodic migraine and chronic migraine patients than in control subjects, whereas they were reduced in patients affected by cluster headache. Dehydroepiandrosterone and dehydroepiandrosterone sulfate levels were reduced in patients affected by chronic migraine, but did not change in patients affected by cluster headache. Conclusion: We have shown for the first time that large and disease-specific changes in circulating neurosteroid levels are associated with chronic headache disorders, raising the interesting possibility that fluctuations of neurosteroids at their site of action might shape the natural course of migraine and cluster headache. Whether the observed changes in neurosteroids are genetically determined or rather result from exposure to environmental or intrinsic stressors is unknown. This might also be matter for further investigation because stress is a known triggering factor for headache attacks in both migraineurs and cluster headache patients
Transferência horizontal de genes simbióticos de estirpes inoculantes de B. japonicum para estirpes de rizóbios nativas dos solos dos Cerrados.
Avaliação da eficiência na fixação biológica do nitrogênio com a cultura da soja e caracterização genotípica e da diversidade de estirpes de Bradyrhizobium japonicum.
Timing an Accreting Millisecond Pulsar: Measuring the Accretion Torque in IGR J00291+5934
We present here a timing analysis of the fastest accreting millisecond pulsar
IGR J00291+5934 using RXTE data taken during the outburst of December 2004. We
corrected the arrival times of all the events for the orbital (Doppler) effects
and performed a timing analysis of the resulting phase delays. In this way we
find a clear parabolic trend of the pulse phase delays showing that the pulsar
is spinning up as a consequence of accretion torques during the X-ray outburst.
The accretion torque gives us for the first time an independent estimate of the
mass accretion rate onto the neutron star, which can be compared with the
observed X-ray luminosity. We also report a revised value of the spin period of
the pulsar.Comment: Proceedings of the Frascati Workshop 2005: Multifrequency Behaviour
of High Energy Cosmic Sources, Vulcano, May 23-28. 7 pages including 1 figur
Multilocus sequence analysis (MLSA) of Bradyrhizobium strains: revealing high diversity of tropical diazotrophic symbiotic bacteria.
Symbiotic association of several genera of bacteria collectively called as rhizobia and plants belonging to the family Leguminosae (=Fabaceae) results in the process of biological nitrogen fixation, playing a key role in global N cycling, and also bringing relevant contributions to the agriculture. Bradyrhizobium is considered as the ancestral of all nitrogen-fixing rhizobial species, probably originated in the tropics. The genus encompasses a variety of diverse bacteria, but the diversity captured in the analysis of the 16S rRNA is often low. In this study, we analyzed twelve Bradyrhizobium strains selected from previous studies performed by our group for showing high genetic diversity in relation to the described species. In addition to the 16S rRNA, five housekeeping genes (recA, atpD, glnII, gyrB and rpoB) were analyzed in the MLSA (multilocus sequence analysis) approach. Analysis of each gene and of the concatenated housekeeping genes captured a considerably higher level of genetic diversity, with indication of putative new species. The results highlight the high genetic variability associated with Bradyrhizobium microsymbionts of a variety of legumes. In addition, the MLSA approach has proved to represent a rapid and reliable method to be employed in phylogenetic and taxonomic studies, speeding the identification of the still poorly known diversity of nitrogen-fixing rhizobia in the tropics
The near-IR counterpart of IGR J17480-2446 in Terzan 5
Some globular clusters in our Galaxy are noticeably rich in low-mass X-ray
binaries. Terzan 5 has the richest population among globular clusters of X- and
radio-pulsars and low-mass X-ray binaries. The detection and study of
optical/IR counterparts of low-mass X-ray binaries is fundamental to
characterizing both the low-mass donor in the binary system and investigating
the mechanisms of the formation and evolution of this class of objects. We aim
at identifying the near-IR counterpart of the 11 Hz pulsar IGRJ17480-2446
discovered in Terzan 5. Adaptive optics (AO) systems represent the only
possibility for studying the very dense environment of GC cores from the
ground. We carried out observations of the core of Terzan 5 in the near-IR
bands with the ESO-VLT NAOS-CONICA instrument. We present the discovery of the
likely counterpart in the Ks band and discuss its properties both in outburst
and in quiescence. Archival HST observations are used to extend our discussion
to the optical bands. The source is located at the blue edge of the turn-off
area in the color-magnitude diagram of the cluster. Its luminosity increase
from quiescence to outburst, by a factor 2.5, allows us to discuss the nature
of the donor star in the context of the double stellar generation population of
Terzan 5 by using recent stellar evolution models.Comment: 7 pages, 4 figure
Caracterização da estirpe de Sinorhizobium fredii CPAC 402: provável evento de transferência lateral de genes simbióticos em solos dos Cerrados entre gêneros distintos de rizóbios.
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