Weakly coupled two slow- two fast systems, folded node and mixed mode oscillationsM

We study Mixed Mode Oscillations (MMOs) in systems of two weakly coupled slow/fast oscillators. We focus on the existence and properties of a folded singularity called FSN II that allows the emergence of MMOs in the presence of a suitable global return mechanism. As FSN II corresponds to a transcritical bifurcation for a desingularized reduced system, we prove that, under certain non-degeneracy conditions, such a transcritical bifurcation exists. We then apply this result to the case of two coupled systems of FitzHugh- Nagumo type. This leads to a non trivial condition on the coupling that enables the existence of MMOs

Machine-learning identification of galaxies in the WISExSuperCOSMOS all-sky catalogue

The two currently largest all-sky photometric datasets, WISE and SuperCOSMOS, were cross-matched by Bilicki et al. (2016) (B16) to construct a novel photometric redshift catalogue on 70% of the sky. Galaxies were therein separated from stars and quasars through colour cuts, which may leave imperfections because of mixing different source types which overlap in colour space. The aim of the present work is to identify galaxies in the WISExSuperCOSMOS catalogue through an alternative approach of machine learning. This allows us to define more complex separations in the multi-colour space than possible with simple colour cuts, and should provide more reliable source classification. For the automatised classification we use the support vector machines learning algorithm, employing SDSS spectroscopic sources cross-matched with WISExSuperCOSMOS as the training and verification set. We perform a number of tests to examine the behaviour of the classifier (completeness, purity and accuracy) as a function of source apparent magnitude and Galactic latitude. We then apply the classifier to the full-sky data and analyse the resulting catalogue of candidate galaxies. We also compare thus produced dataset with the one presented in B16. The tests indicate very high accuracy, completeness and purity (>95%) of the classifier at the bright end, deteriorating for the faintest sources, but still retaining acceptable levels of 85%. No significant variation of classification quality with Galactic latitude is observed. Application of the classifier to all-sky WISExSuperCOSMOS data gives 15 million galaxies after masking problematic areas. The resulting sample is purer than the one in B16, at a price of lower completeness over the sky. The automatic classification gives a successful alternative approach to defining a reliable galaxy sample as compared to colour cuts.Comment: 12 pages, 15 figures, accepted for publication in A&A. Obtained catalogue will be included in the public release of the WISExSuperCOSMOS galaxy catalogue available from http://ssa.roe.ac.uk/WISExSCO

Coastal Fortresses: A Cross-Case Analysis of Water, Policy, and Tourism Development in Three Gulf Coast Communities

As a result of development pressures and water resource struggles, once rural, spatially segregated coastal commercial fishing villages along the U.S. portion of the Gulf of Mexico are increasingly tourist frontiers for elites and the emergent businesses that cater to them. Over the course of the twentieth century, water events, from coastal land loss to hurricane destruction to natural disaster, have fast-tracked development projects that have allowed for the expansion of the tourism sector, and relaxed policies to encourage bold new economic development initiatives that often put poor coastal communities and their environment in jeopardy. This outcome is not universal across the northern Gulf Coast, but contingent on a number of local factors overlooked in the literature on coastal tourism and water policy development. This paper investigates the local nuances that have emerged as responses to global and regional development pressures by focusing on the ways in which local values and policy decisions have influenced the spread of coastal urbanization. An intensive analysis will examine the layered effects of changing land-use patterns and tourism growth pressures on three at-risk coastal communities in Louisiana, Mississippi and Florida, in the United States. This paper will test the hypothesis that coastal communities affected by a similar set of development pressures respond to these forces in different ways, depending on complex local and regional variabilities. The paper’s focus is centered on Northern Gulf Coast tourism growth patterns from post-World War II through 2018, and employs a mixed method, multiple-sited case-study design

SALT long-slit spectroscopy of LBQS 2113-4538: variability of the Mg II and Fe II component

The Mg II line is of extreme importance in intermediate redshift quasars since it allows us to measure the black hole mass in these sources and to use these sources as probes of the distribution of dark energy in the Universe, as a complementary tool to SN Ia. Reliable use of Mg II requires a good understanding of all the systematic effects involved in the measurement of the line properties, including the contamination by Fe II UV emission. We performed three spectroscopic observations of a quasar LBQS 2113-4538 (z = 0.956) with the SALT telescope separated in time by several months and we analyze in detail the mean spectrum and the variability in the spectral shape. We show that even in our good-quality spectra the Mg II doublet is well fit by a single Lorentzian shape. We tested several models of the Fe II pseudo-continuum and showed that one of them well represents all the data. The amplitudes of both components vary in time, but the shapes do not change significantly. The measured line width of LBQS 2113-4538 identifies this object as a class A quasar. The upper limit of $3\%$ for the contribution of the Narrow Line Region (NLR) to Mg II may suggest that the separation of the Broad Line Region (BLR) and NLR disappears in this class of objects.Comment: 10 pages, 8 figures, accepted to A&

Orthorexia nervosa and self-attitudinal aspects of body image in female and male university students.

The present study was designed to investigate orthorexia nervosa, or the phenomenon of being preoccupied with consuming healthy food. Specific aims were to explore relationships between orthorexia features and attitudes towards body image, fitness and health in normal weight female and male university students with high levels of healthy food preoccupation, i.e. orthorexia nervosa. METHODS Participants were 327 female (N = 283) and male (N = 44) students aged 18 to 25 years. All participants completed the Polish adaptation of the 15-item questionnaire assessing orthorexia eating behaviours (the ORTHO-15) and the Multidimensional Body-Self Relations Questionnaire (the MBSRQ). Relationships between scores on the ORTHO-15 and MBSRQ were explored in the 213 students who had high levels of preoccupation with a healthy food intake (68.55% women and 43.18% men, respectively). RESULTS: There were no statistically significant differences in the levels of orthorexia behaviours between females and males. In female students with orthorexia nervosa, preoccupation with consuming healthy food was significantly correlated with the MBSRQ subscale scores for overweight preoccupation, appearance orientation, fitness orientation, health orientation, body areas satisfaction and appearance evaluation. Conversely, in male students with orthorexia nervosa there were no correlations between orthorexic behaviours and the MBSRQ subscales. In female students with orthorexia nervosa multivariable linear regression analysis found high body areas (parts) satisfaction, low fitness orientation, low overweight preoccupation and low appearance orientation were independent predictors of greater fixation on eating healthy food. In male students, we found that aspects of body image were not associated with preoccupation with healthy eating. CONCLUSION: A strong preoccupation with healthy and proper food was not associated with an unhealthy body-self relationship among Polish female student with orthorexia nervosa

The repertoire of protein kinases encoded in the draft version of the human genome: atypical variations and uncommon domain combinations

BACKGROUND: Phosphorylation by protein kinases is central to cellular signal transduction. Abnormal functioning of kinases has been implicated in developmental disorders and malignancies. Their activity is regulated by second messengers and by the binding of associated domains, which are also influential in translocating the catalytic component to their substrate sites, in mediating interaction with other proteins and carrying out their biological roles. RESULT: Using sensitive profile-search methods and manual analysis, the human genome has been surveyed for protein kinases. A set of 448 sequences, which show significant similarity to protein kinases and contain the critical residues essential for kinase function, have been selected for an analysis of domain combinations after classifying the kinase domains into subfamilies. The unusual domain combinations in particular kinases suggest their involvement in ubiquitination pathways and alternative modes of regulation for mitogen-activated protein kinase kinases (MAPKKs) and cyclin-dependent kinase (CDK)-like kinases. Previously unexplored kinases have been implicated in osteoblast differentiation and embryonic development on the basis of homology with kinases of known functions from other organisms. Kinases potentially unique to vertebrates are involved in highly evolved processes such as apoptosis, protein translation and tyrosine kinase signaling. In addition to coevolution with the kinase domain, duplication and recruitment of non-catalytic domains is apparent in signaling domains such as the PH, DAG-PE, SH2 and SH3 domains. CONCLUSIONS: Expansion of the functional repertoire and possible existence of alternative modes of regulation of certain kinases is suggested by their uncommon domain combinations. Experimental verification of the predicted implications of these kinases could enhance our understanding of their biological roles

Tracing dark energy with quasars

The nature of dark energy, driving the accelerated expansion of the Universe, is one of the most important issues in modern astrophysics. In order to understand this phenomenon, we need precise astrophysical probes of the universal expansion spanning wide redshift ranges. Quasars have recently emerged as such a probe, thanks to their high intrinsic luminosities and, most importantly, our ability to measure their luminosity distances independently of redshifts. Here we report our ongoing work on observational reverberation mapping using the time delay of the Mg II line, performed with the South African Large Telescope (SALT).Comment: 3 pages, 2 figures, submitted as PTA proceeding