81 research outputs found

    Spatially extended and high-velocity dispersion molecular component in spiral galaxies: single-dish vs. interferometric observations

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    Recent studies of the molecular medium in nearby galaxies have provided mounting evidence that the molecular gas can exist in two phases: one that is clumpy and organized as molecular clouds and another one that is more diffuse. This last component has a higher velocity dispersion than the clumpy one. In order to investigate these two molecular components further, we compare the fluxes and line widths of CO in NGC 4736 and NGC 5055, two nearby spiral galaxies for which high-quality interferometric as well as single-dish data sets are available. Our analysis leads to two main results: 1) Employing three different methods, we determine the flux recovery of the interferometer as compared to the single-dish to be within a range of 35-74% for NGC4736 and 81-92% for NGC5055, and 2) when focusing on high (SNR>5) lines of sight, the single-dish line widths are larger by ~(40+-20)% than the ones derived from interferometric data; which is in agreement with stacking all lines of sight. These results point to a molecular gas component that is distributed over spatial scales larger than 30"(~1kpc), and is therefore filtered out by the interferometer. The available observations do not allow us to distinguish between a truly diffuse gas morphology and a uniform distribution of small clouds that are separated by less than the synthesized beam size (~3" or ~100pc), as they would both be invisible for the interferometer. This high velocity dispersion component has a dispersion similar to what is found in the atomic medium, as traced through observations of the HI line.Comment: 12 pages, 5 figures, Accepted to A

    Molecular Gas Velocity Dispersion in Nearby Galaxies

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    Despite the fact that molecular gas in galaxies is the most essential ingredient for the star formation process, its thorough characterization has not yet been accomplished. A common assumption is that molecular gas emission (mostly traced by CO) arises from molecular clouds with observed velocity dispersions of 2-5 km/s. In this thesis, I present the results obtained from investigating the velocity dispersions measured in the molecular gas disks of nearby galaxies. On 0.5 kpc scales (the average spatial resolution), the measured CO velocity dispersions have a mean value of ~12 km/s (1sigma dispersion of 3.9 km/s). These values are higher than previously expected, and are comparable to those measured for neutral atomic gas. To investigate the origin of these large dispersions, a comparison between interferometric and single-dish line width measurements for NGC 4736 and NGC 5055 (at ~0.5 kpc resolution) and for the neighboring Andromeda galaxy, M 31, (at ~100 pc resolution) is presented. Despite the different scales studied, the single-dish line widths are ~50% greater than the corresponding interferometric ones. Additionally, the interferometer recovers only a fraction (50 – 90%) of the flux that is measured by the single-dish. After stacking the high-sensitivity M 31 data, an analysis of the resulting spectral profiles from the two distinct instruments is performed in detail. The results are that single-dish spectra are better described by two components, one narrow (FWHMN !7.5 +- 0.4 km/s) and one broad (FWHMB ~ 14.4+-1.5 km/s); while for the interferometric data, one component suffices (FWHM ~7.1+-0.4 km/s). The overall implication is that molecular gas is present in two distinct phases: one that is clumpy and organized as molecular clouds, and another one that is more diffuse and has larger velocity dispersions

    The radial variation of HI velocity dispersions in dwarfs and spirals

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    Gas velocity dispersions provide important diagnostics of the forces counteracting gravity to prevent collapse of the gas. We use the 21 cm line of neutral atomic hydrogen (HI) to study HI velocity dispersion and HI phases as a function of galaxy morphology in 22 galaxies from The HI Nearby Galaxy Survey (THINGS). We stack individual HI velocity profiles and decompose them into broad and narrow Gaussian components. We study the HI velocity dispersion and the HI surface density, as a function of radius. For spirals, the velocity dispersions of the narrow and broad components decline with radius and their radial profiles are well described by an exponential function. For dwarfs, however, the profiles are much flatter. The single Gaussian dispersion profiles are, in general, flatter than those of the narrow and broad components. In most cases, the dispersion profiles in the outer disks do not drop as fast as the star formation profiles, derived in the literature. This indicates the importance of other energy sources in driving HI velocity dispersion in the outer disks. The radial surface density profiles of spirals and dwarfs are similar. The surface density profiles of the narrow component decline more steeply than those of the broad component, but not as steep as what was found previously for the molecular component. As a consequence, the surface density ratio between the narrow and broad components, an estimate of the mass ratio between cold HI and warm HI, tends to decrease with radius. On average, this ratio is lower in dwarfs than in spirals. This lack of a narrow, cold HI component in dwarfs may explain their low star formation activity.Comment: Accepted for publication in The Astronomical Journal, 13 pages, 10 figures, 4 table

    Genetic Determinants of Financial Risk Taking

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    Individuals vary in their willingness to take financial risks. Here we show that variants of two genes that regulate dopamine and serotonin neurotransmission and have been previously linked to emotional behavior, anxiety and addiction (5-HTTLPR and DRD4) are significant determinants of risk taking in investment decisions. We find that the 5-HTTLPR s/s allele carriers take 28% less risk than those carrying the s/l or l/l alleles of the gene. DRD4 7-repeat allele carriers take 25% more risk than individuals without the 7-repeat allele. These findings contribute to the emerging literature on the genetic determinants of economic behavior

    Visuospatial working memory in children and adolescents with 22q11.2 deletion syndrome; an fMRI study

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    22q11.2 deletion syndrome (22q11DS) is a genetic disorder associated with a microdeletion of chromosome 22q11. In addition to high rates of neuropsychiatric disorders such as schizophrenia and attention deficit hyperactivity disorder, children with 22q11DS have a specific neuropsychological profile with particular deficits in visuospatial and working memory. However, the neurobiological substrate underlying these deficits is poorly understood. We investigated brain function during a visuospatial working memory (SWM) task in eight children with 22q11DS and 13 healthy controls, using fMRI. Both groups showed task-related activation in dorsolateral prefrontal cortex (DLPFC) and bilateral parietal association cortices. Controls activated parietal and occipital regions significantly more than those with 22q11DS but there was no significant between-group difference in DLPFC. In addition, while controls had a significant age-related increase in the activation of posterior brain regions and an age-related decrease in anterior regions, the 22q11DS children showed the opposite pattern. Genetically determined differences in the development of specific brain systems may underpin the cognitive deficits in 22q11DS, and may contribute to the later development of neuropsychiatric disorders

    Sex-dependent diversity in ventral tegmental dopaminergic neurons and developmental programing: a molecular, cellular and behavioral analysis

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    The knowledge that diverse populations of dopaminergic neurons within the ventral tegmental area (VTA) can be distinguished in terms of their molecular, electrophysiological and functional properties, as well as their differential projections to cortical and subcortical regions has significance for key brain functions, such as the regulation of motivation, working memory and sensorimotor control. Almost without exception, this understanding has evolved from landmark studies performed in the male sex. However, converging evidence from both clinical and pre-clinical studies illustrates that the structure and functioning of the VTA dopaminergic systems are intrinsically different in males and females. This may be driven by sex differences in the hormonal environment during adulthood ('activational' effects) and development (perinatal and/or pubertal 'organizational' effects), as well as genetic factors, especially the SRY gene on the Y chromosome in males, which is expressed in a sub-population of adult midbrain dopaminergic neurons. Stress and stress hormones, especially glucocorticoids, are important factors which interact with the VTA dopaminergic systems in order to achieve behavioral adaptation and enable the individual to cope with environmental change. Here, also, there is male/female diversity not only during adulthood, but also in early life when neurobiological programing by stress or glucocorticoid exposure differentially impacts dopaminergic developmental trajectories in male and female brains. This may have enduring consequences for individual resilience or susceptibility to pathophysiological change induced by stressors in later life, with potential translational significance for sex bias commonly found in disorders involving dysfunction of the mesocorticolimbic dopaminergic systems. These findings highlight the urgent need for a better understanding of the sexual dimorphism in the VTA if we are to improve strategies for the prevention and treatment of debilitating conditions which differentially affect men and women in their prevalence and nature, including schizophrenia, attention/deficit hyperactivity disorder, autism spectrum disorders, anxiety, depression and addiction

    Staying in the women's guesthouse women victims of violence Life experiences and future plans:Antalya province example

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    Şiddet; dil, din, ırk, cinsiyet ayırmaksızın, insanları etkileyen önemli sorulardandır. Şiddetin her türü ve biçimi yıkıcı olmakla beraber, kadına yönelik şiddet, küresel ve ulusal düzeyde devam eden insan hak ihlalleri arasında yer almaktadır. Toplumsal cinsiyet ve ataerkil kalıplar, kadın ve kız çocuklarının ikincilleştirilmesi fırsatlardan eşit ve adil bir şekilde faydalanmamaları yaşam deneyimlerinde savunmasız kalmalarına neden olabilmektedir. Bu araştırmada, Antalya Büyükşehir Belediyesi Kadın Konukevinde kalan şiddet mağduru kadınların yaşam deneyimlerinin ve gelecek planlarının incelenmesi amaçlanmıştır. Niteliksel araştırma yöntemiyle tasarlanan çalışmanın ölçüt örneklemini Antalya Büyükşehir Belediye Kadın Konukevinde kalan şiddet mağduru kadınlar oluşturmaktadır. Yarı yapılandırılmış bir görüşme formu aracılığıyla 31 kadın görüşmeci ile yüz yüze derinlemesine görüşmeler yapılmıştır. Araştırma bulgularına göre; Antalya konukevinde kalan şiddet mağduru kadınların yaşam deneyimlerinin şekillenmesinde, kültürel değerler ve demografik özelliklerden dolayı eğitim imkânına ulaşılamaması, çalışma hayatına katılamaması ile birlikte yoksullaşma sorunu gündeme gelmiş, ekonomik olarak bağımlı olan kadınlar şiddet karşısında savunmasız kalmış, çoğu durumlarda da susmayı tercih etmişlerdir. Gelecek planlarında; ekonomik bağımsızlık, istihdamda yer almak, şiddet ortamından uzakta kendine ait güvenli bir evde yaşamak ilk sırada yerini almaktadır. Araştırma sonucunda; görüşmeci kadınların; uzun süre şiddet ve istismara maruz kalınması sonucu, şiddeti normalleştirerek özsaygı ve benlik duygularını kaybetmelerine neden olduğundan gelecek planlarının bilinçli bir şeklinde kurgulanmasında engel teşkil ettiği görülmüştür. Bundan dolayı konukevi hizmeti sürecinde yapılan güçlendirme çalışmalarında sosyal, hukuki ve bireysel haklarının bilgilendirilerek şiddet tehlikesine karşı kendilerini koruyabilecekleri tespit edilmiştir.Violence; language, religion, race, is one of the important problems affecting people regardless of gender. Although all types and forms of violence are destructive, violence against women is one of the ongoing human rights violations at the global and national level. Gender and patriarchal stereotypes can cause women and girls to be subordinated, not to enjoy equal and fair opportunities, and to be vulnerable in their life experiences. In this study, it is aimed to determine the life experiences and future plans of women who are victims of violence staying in Antalya Metropolitan Municipality Women's Guesthouse. The criterion sample of the study, which was designed with a qualitative research method, consists of women who are victims of violence staying in Antalya Metropolitan Municipality Women's Guest House. in-depth face-to-face interviews were conducted with 31 participants using a semi-structured interview form. According to the research data, in the future plans of the women who are victims of violence staying in the guesthouse; economic independence, participation in employment, living in a safe house of one's own away from violence took place in the first place. Due to cultural values and socio-demographic characteristics, the problem of impoverishment came to the fore because women could not access education and participate in working life, economically dependent women became vulnerable to violence and preferred to remain silent in most cases. As a result of the research; After leaving the guesthouse service, participating women staying in Antalya guesthouse being exposed to violence and abuse for a long time in shaping their future plans, It has been seen that violence causes them to lose their self-respect and sense of self by normalizing it, thus preventing them from consciously constructing their future plans. been determined that they can protect themselves against the danger of violence by informing their social, legal and individual rights in the strengthening works carried out during the guesthouse service process

    CFD study of the rear wing and front cover of a sports car

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    Baltasar is a new car company from Cerdanyola del Vallès (Barcelona, Spain). Its first car, the Baltasar Revolt, is the first track day registrable car (1). It combines the velocity required for the circuit and the versatility of a registrable car. The company itself has considered relevant to make a CFD study of two new different parts of the car to observe how they affect the aerodynamic development of the Revolt. The first one of these two pieces will be the aerodynamic study using CFD of the body part called “front cover” and the comparison with a new redesign. This item is the equivalent of the bonnet of a passenger car. Moreover, this redesigned front cover must be able to accommodate a small cockpit visor for the pilot and co-pilot, which will also be aerodynamically analysed. The second part of the thesis will consist of the aerodynamic study using CFD of a commercial rear wing and conclude if this aerodynamic device could be beneficial to the performance of the car inside a track. Furthermore, it’s going to be an original study because inside the company there isn’t another aerodynamic thesis and the aerodynamic study of the actual car has to be done to correctly make the comparison of these new two pieces. Finally, this thesis and all the deliverables, information and files of various kinds are confidential

    Processing of primary and secondary rewards: a quantitative meta-analysis and review of human functional neuroimaging studies

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    Contains fulltext : 117487pos.pdf (postprint version ) (Open Access)One fundamental question concerning brain reward mechanisms is to determine how reward-related activity is influenced by the nature of rewards. Here, we review the neuroimaging literature and explicitly assess to what extent the representations of primary and secondary rewards overlap in the human brain. To achieve this goal, we performed an activation likelihood estimation (ALE) meta-analysis of 87 studies (1452 subjects) comparing the brain responses to monetary, erotic and food reward outcomes. Those three rewards robustly engaged a common brain network including the ventromedial prefrontal cortex, ventral striatum, amygdala, anterior insula and mediodorsal thalamus, although with some variations in the intensity and location of peak activity. Money-specific responses were further observed in the most anterior portion of the orbitofrontal cortex, supporting the idea that abstract secondary rewards are represented in evolutionary more recent brain regions. In contrast, food and erotic (i.e. primary) rewards were more strongly represented in the anterior insula, while erotic stimuli elicited particularly robust responses in the amygdala. Together, these results indicate that the computation of experienced reward value does not only recruit a core "reward system" but also reward type-dependent brain structures

    Aragón educa : revista del Museo Pedagógico de Aragón

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    Se expone la evolución de los centros de profesores y recursos (CPR) en Aragón desde 1985 hasta 2010. Se hace referencia al proceso que han sufrido desde el nacimiento estos centros, enfocados preferentemente para la formación de profesores de la universidad, hasta convertirse en un centro de recursos y un lugar de encuentro donde se ofrece una formación continuada y desarrollo curricular. Personas vinculadas a estos centros describen el origen, el desarrollo normativo que regula su creación y funcionamiento y los aspectos más destacables desde su puesta en marcha.AragónDirección General de Política Educativa; Avda. Gómez Laguna, 25, planta 2; 50009 Zaragoza; Tel. +34976715416; Fax +34976715496ES
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