128 research outputs found
2D Spectroscopy of Candidate Polar-Ring Galaxies: I. The Pair of Galaxies UGC 5600/09
Observations of the pair of galaxies VV 330 with the SCORPIO multimode
instrument on the 6-m Special Astrophysical Observatory telescope are
presented. Large-scale velocity fields of the ionized gas in H-alfa and
brightness distributions in continuum and H-alfa have been constructed for both
galaxies with the help of a scanning Fabry Perot interferometer. Long-slit
spectroscopy is used to study the stellar kinematics. Analysis of the data
obtained has revealed a complex structure in each of the pair components. Three
kinematic subsystems have been identified in UGC 5600: a stellar disk, an inner
gas ring turned with respect to the disk through ~80degrees, and an outer gas
disk. The stellar and outer gas disks are noncoplanar. Possible scenarios for
the formation of the observed multicomponent kinematic galactic structure are
considered, including the case where the large-scale velocity field of the gas
is represented by the kinematic model of a disk with a warp. The velocity field
in the second galaxy of the pair, UGC 5609, is more regular. A joint analysis
of the data on the photometric structure and the velocity field has shown that
this is probably a late-type spiral galaxy whose shape is distorted by the
gravitational interaction, possibly, with UGC 5600.Comment: 18 pages, 6 figure
Formation of a polar-ring galaxy in a galaxy merger
We numerically investigate stellar and gas dynamics in star-forming and
dissipative galaxy mergers between two disk galaxies with specific orbital
configurations. We find that violent relaxation combined with gaseous
dissipation in galaxy merging transforms two disk galaxies into one S0 galaxy
with polar-rings: Both the central S0-like host and the polar-ring component in
a polar-ring galaxy are originally disk galaxies. We also find that morphology
of the developed polar-rings reflects both the initial orbit configuration of
galaxy merging and the initial mass ratio of the two merger progenitor disk
galaxies. Based upon these results, we discuss the origin of the fundamental
observational properties of polar-ring galaxies, such as the prevalence of S0
galaxies among polar-ring galaxies, the rarity of polar-ring galaxies among S0
galaxies, the dichotomy between narrow polar-rings and annular ones, shapes of
polar-ring warps, and an appreciably larger amount of interstellar gas in the
polar-ring component.Comment: 42 pages, 19 figures, ApJ in pres
Prominent and regressive brain developmental disorders associated with nance-horan syndrome
Nance-Horan syndrome (NHS) is a rare X-linked developmental disorder caused mainly by loss of function variants in the NHS gene. NHS is characterized by congenital cataracts, dental anomalies, and distinctive facial features, and a proportion of the affected individuals also present intellectual disability and congenital cardiopathies. Despite identification of at least 40 distinct hemizygous variants leading to NHS, genotype-phenotype correlations remain largely elusive. In this study, we describe a Sicilian family affected with congenital cataracts and dental anomalies and diagnosed with NHS by whole-exome sequencing (WES). The affected boy from this family presented a late regression of cognitive, motor, language, and adaptive skills, as well as broad behavioral anomalies. Furthermore, brain imaging showed corpus callosum anomalies and periven-tricular leukoencephalopathy. We expand the phenotypic and mutational NHS spectrum and review potential disease mechanisms underlying the central neurological anomalies and the potential neu-rodevelopmental features associated with NHS
Fluorescence spectroscopy for the detection of potentially malignant disorders of the oral cavity: analysis of 30 cases
Oral cancer is a major health problem worldwide and although early diagnosis of potentially malignant and malignant diseases is associated with better treatment results, a large number of cancers are initially misdiagnosed, with unfortunate consequences for long-term survival. Fluorescence spectroscopy is a noninvasive modality of diagnostic approach using induced fluorescence emission in tumors that can improve diagnostic accuracy. The objective of this study was to determine the ability to discriminate between normal oral mucosa and potentially malignant disorders by fluorescence spectroscopy. Fluorescence investigation under 408 and 532 nm excitation wavelengths was performed on 60 subjects, 30 with potentially malignant disorders and 30 volunteers with normal mucosa. Data was analyzed to correlate fluorescence patterns with clinical and histopathological diagnostics. Fluorescence spectroscopy used as a point measurement technique resulted in a great variety of spectral information. In a qualitative analysis of the fluorescence spectral characteristics of each type of injury evaluated, it was possible to discriminate between normal and abnormal oral mucosa. The results show the potential use of fluorescence spectroscopy for an improved discrimination of oral disorders.FAPESP/CePOF-CEPID (07/57126-5)CNPq (477439/2007-1)Instituto Nacional de Ciência e Tecnologia em Oncogenômica (INCITO
Muscular collision chess:A qualitative exploration of the role and development of cognition, understanding and knowledge in elite-level decision making
Decision making (DM) is a crucial part of team invasion games. The role of context and how this drives both the initial DM and primes in-action planning and execution, termed contextual priors, has been investigated. Findings suggest a significant role for cognition, which appears to run contrary to some of the suggestions made by an ecological dynamics approach. Wishing to clarify this situation for coaches and psychologists, this research explores the experience of nine top-tier key decision makers in rugby union, using an interview approach. Results showed a wide range of context-based information considered by players during the DM process. Furthermore, this information acted to prime subsequent attention and in-action thinking. Finally, this research sought to understand if, and therefore how, DM could be taught, developed and primed by players and coaches. Our data are supportive of a more cognitively focused approach to developing DM although our data do not dismiss a role for direct perception in optimising performance. Implications for practice are discussed
Coaching Models of School-Based Prevention and Promotion Programmes: A Qualitative Exploration of UK Teachers' Perceptions
There has been increased interest in recent years regarding the utility of imported universal prevention and promotion (P&P) programmes in UK schools, many of which have a coaching model attached. However, there have been relatively few studies exploring the cultural transferability and social validity of these models, even though evidence suggests that these factors are important to the successful implementation of the programmes, and thus the achievement of the intended outcomes. The aim of the current study was to explore the coaching practices that teachers report experiencing, and to further understanding of the perceived benefts of these coaching practices to teachers. The sample consisted of 33 teachers implementing one of two universal, school-based P&P programmes, Good Behavior Game and Promoting Alternative Thinking Strategies as part of large-scale, randomised controlled trials. Qualitative, semi-structured interviews were conducted, and data were analysed thematically utilising a hybrid approach. Teachers typically reported engaging in six distinct practices with their coaches. While the majority of these practices were in line with coaching literature, there were some discrepancies between intended coaching practices and teachers’ reports. The coaching practices were generally perceived to be acceptable to teachers. Two unanticipated practices, validation and motivation, appeared to be of particular value to teachers, although these are not currently a prominent feature in existing coaching models. The fndings provide implications for improving the development of socially valid coaching models for UK schools
Methods to Study Centrosomes and Cilia in Drosophila
The deposited item is a book chapter and is part of the series " Methods in Molecular Biology book series ([MIMB, volume 1454]) published by the publisher Humana Press.The deposited book chapter is a pre-print version and hasn't been submitted to peer reviewing.There is no public supplementary material available for this publication.This publication hasn't any creative commons license associated.Centrioles and cilia are highly conserved eukaryotic organelles. Drosophila melanogaster is a powerful genetic and cell biology model organism, extensively used to discover underlying mechanisms of centrosome and cilia biogenesis and function. Defects in centrosomes and cilia reduce fertility and affect different sensory functions, such as proprioception, olfaction, and hearing. The fly possesses a large diversity of ciliary structures and assembly modes, such as motile, immotile, and intraflagellar transport (IFT)-independent or IFT-dependent assembly. Moreover, all the diverse ciliated cells harbor centrioles at the base of the cilia, called basal bodies, making the fly an attractive model to better understand the biology of this organelle. This chapter describes protocols to visualize centrosomes and cilia by fluorescence and electron microscopy.Fundação Portuguesa para a Ciência e Tecnologia grants: (SFRH/BPD/87479/2012, SFRH/BD/52176/2013); EMBO installation grant; ERC starting grant.info:eu-repo/semantics/publishedVersio
A Search for Extended Ultraviolet Disk (XUV-disk) Galaxies in the Local Universe
We have initiated a search for extended ultraviolet disk (XUV-disk) galaxies
in the local universe. Herein, we compare GALEX UV and visible--NIR images of
189 nearby (D40 Mpc) S0--Sm galaxies included in the GALEX Atlas of Nearby
Galaxies and present the first catalogue of XUV-disk galaxies. We find that
XUV-disk galaxies are surprisingly common but have varied relative (UV/optical)
extent and morphology. Type~1 objects (\ga20% incidence) have structured,
UV-bright/optically-faint emission features in the outer disk, beyond the
traditional star formation threshold. Type~2 XUV-disk galaxies (10%
incidence) exhibit an exceptionally large,
UV-bright/optically-low-surface-brightness (LSB) zone having blue
outside the effective extent of the inner, older stellar population, but not
reaching extreme galactocentric distance. If the activity occuring in XUV-disks
is episodic, a higher fraction of present-day spirals could be influenced by
such outer disk star formation. Type~1 disks are associated with spirals of all
types, whereas Type~2 XUV-disks are predominantly found in late-type spirals.
Type~2 XUV-disks are forming stars quickly enough to double their [presently
low] stellar mass in the next Gyr (assuming a constant SF rate). XUV-disk
galaxies of both types are systematically more gas-rich than the general galaxy
population. Minor external perturbation may stimulate XUV-disk incidence, at
least for Type~1 objects. XUV-disks are the most actively evolving galaxies
growing via inside-out disk formation in the current epoch, and may constitute
a segment of the galaxy population experiencing significant, continued gas
accretion from the intergalactic medium or neighboring objects.Comment: 83 pages, 16 figures, 2 tables. Appearing in the GALEX special issue
of ApJS. (A version with high quality figures and proof corrections can be
found at http://www.journals.uchicago.edu/toc/apjs/173/2
Evolution of the eukaryotic ARP2/3 activators of the WASP family: WASP, WAVE, WASH, and WHAMM, and the proposed new family members WAWH and WAML
<p>Abstract</p> <p>Background</p> <p>WASP family proteins stimulate the actin-nucleating activity of the ARP2/3 complex. They include members of the well-known WASP and WAVE/Scar proteins, and the recently identified WASH and WHAMM proteins. WASP family proteins contain family specific N-terminal domains followed by proline-rich regions and C-terminal VCA domains that harbour the ARP2/3-activating regions.</p> <p>Results</p> <p>To reveal the evolution of ARP2/3 activation by WASP family proteins we performed a "holistic" analysis by manually assembling and annotating all homologs in most of the eukaryotic genomes available. We have identified two new families: the WAML proteins (WASP and MIM like), which combine the membrane-deforming and actin bundling functions of the IMD domains with the ARP2/3-activating VCA regions, and the WAWH protein (WASP without WH1 domain) that have been identified in amoebae, Apusozoa, and the anole lizard. Surprisingly, with one exception we did not identify any alternative splice forms for WASP family proteins, which is in strong contrast to other actin-binding proteins like Ena/VASP, MIM, or NHS proteins that share domains with WASP proteins.</p> <p>Conclusions</p> <p>Our analysis showed that the last common ancestor of the eukaryotes must have contained a homolog of WASP, WAVE, and WASH. Specific families have subsequently been lost in many taxa like the WASPs in plants, algae, Stramenopiles, and Euglenozoa, and the WASH proteins in fungi. The WHAMM proteins are metazoa specific and have most probably been invented by the Eumetazoa. The diversity of WASP family proteins has strongly been increased by many species- and taxon-specific gene duplications and multimerisations. All data is freely accessible via <url>http://www.cymobase.org</url>.</p
The Mechanochemistry of Endocytosis
An integrated theoretical model reveals how the chemical and the mechanical aspects of endocytosis are coordinated coherently in yeast cells, driving progression through the endocytic pathway and ensuring efficient vesicle scission in vivo
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