On the origin of two unidentified radio/X-ray sources discovered with XMM-Newton

We aim at clarifying the nature of the emission of two spatially related unidentified X-ray sources detected with XMM-Newton telescope at intermediate-low Galactic latitude. Observations reveal a point-like source aligned with elongated diffuse emission. The X-ray spectra are best-fitted by absorbed power laws with photon indices ~1.7 for the point-like and ~2.0 for the extended one. Both sources show nonthermal radio-continuum counterparts that might indicate a physical association. From the available data, we did not detect variability on the point-like source in several timescales. Two possible scenarios are analyzed: first, based on HI line absorption, assuming a Galactic origin, we infer a distance upper bound of <2 kpc, which poses a constraint on the height over the Galactic plane of <200 pc and on the linear size of the system of 10^32 erg/s and >7.5 x 10^32 erg/s, for the point-like and extended sources, respectively; second, an extra-Galactic nature is discussed, where the point-like source might be the core of a radio galaxy and the extended source its lobe. In this case, we compare derived fluxes, spectral indices, and spatial correlation with those typical from the radio galaxy population, showing the feasibility of this alternative astrophysical scenario. From the available observational evidence, we suggest that the most promising scenario to explain the nature of these sources is a system consisting of a one-sided radio galaxy, where the point-like source is an active galactic nucleus and the extended source corresponds to the emission from its lobe. Other possibilities include a PSR/PWN origin, where the radio/X-ray emission originates from the synchrotron cooling of relativistic particles in the PSR magnetic field or a casual alignment between two unrelated sources, such as an AGN core and a Galactic X-ray blob.Comment: 6 pages, 2 figures. Accepted for publication in Astronomy and Astrophysics (A&A

Staurosira magallanesica, a replacement name for Staurosira patagonica

Staurosira patagonica M.L.Garcia, Maidana, Ector & E.Morales described a new species found in material of Maar Magallanes, Patagonia, Argentina and other lakes in southern Patagonia. This new species was analysed in detail by light and electron microscopy and a comprehensive description is given in Garcia et al. (2017: 107, 114, figs 2-45). However, this name is a later homonym of Staurosira patagonica Cleve, 1882. If we compare our species to Cleve’s illustration (Cleve 1882: pl. 16: fig. 13), we can easily differentiate the two by their general valve outline and morphometric data. As pointed out by Garcia et al. (2017), re-examination of the type material of members of the Fragilariaceae is needed to confirm identities, establish taxonomic boundaries and to facilitate identification, and this is also the case with Staurosira patagonica Cleve. A new name is, however, required for Staurosira patagonica M.L.Garcia, Maidana, Ector & E.Morales as it is an illegitimate name: Staurosira magallanesica M.L.Garcia, Maidana, Ector & E.Morales nom. nov. Replaced synonym: Staurosira patagonica M.L.Garcia, Maidana, Ector & E.Morales Nova Hedwigia, Beiheft 146: 107, 114, figs 2-45, 2017, nom illeg., non Staurosira patagonica Cleve 1882 Öfversigt af Kongliga Svenska Vetenskaps-Akademiens Förhandlingar 38(10): 13, pl. 16: fig. 13, 1882 ‘1881’. Etymology: we have derived the specific epithet from the name of the paleolake Maar Magallanes where this new species was found for the first time by N.I. Maidana (Maidana & Corbella 1997).Fil: García, María Luján. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Maidana, Nora Irene. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Ector, Luc. Luxembourg Institute of Science and Technology; LuxemburgoFil: Morales, E. A.. Universidade de Évora; Portuga

Weyl law for fat fractals

It has been conjectured that for a class of piecewise linear maps the closure of the set of images of the discontinuity has the structure of a fat fractal, that is, a fractal with positive measure. An example of such maps is the sawtooth map in the elliptic regime. In this work we analyze this problem quantum mechanically in the semiclassical regime. We find that the fraction of states localized on the unstable set satisfies a modified fractal Weyl law, where the exponent is given by the exterior dimension of the fat fractal.Comment: 8 pages, 4 figures, IOP forma

White dwarf evolutionary sequences for low-metallicity progenitors: The impact of third dredge-up

We present new white dwarf evolutionary sequences for low-metallicity progenitors. White dwarf sequences have been derived from full evolutionary calculations that take into account the entire history of progenitor stars, including the thermally-pulsing and the post-asymptotic giant branch phases. We show that for progenitor metallicities in the range 0.00003--0.001, and in the absence of carbon enrichment due to the occurrence of a third dredge-up episode, the resulting H envelope of the low-mass white dwarfs is thick enough to make stable H burning the most important energy source even at low luminosities. This has a significant impact on white dwarf cooling times. This result is independent of the adopted mass-loss rate during the thermally-pulsing and post-AGB phases, and the planetary nebulae stage. We conclude that in the absence of third dredge-up episodes, a significant part of the evolution of low-mass white dwarfs resulting from low-metallicity progenitors is dominated by stable H burning. Our study opens the possibility of using the observed white dwarf luminosity function of low-metallicity globular clusters to constrain the efficiency of third dredge up episodes during the thermally-pulsing AGB phase of low-metallicity progenitors.Comment: To be published in Astronomy and Astrophysics. 12 pages, 11 figure

Role of 5 α -dihydrotestosterone in testicular development of gilthead seabream following finasteride administration

In teleosts, spermatogenesis is regulated by pituitary gonadotropins and sex steroids. 5α-dihydrotestosterone (DHT), derived from testosterone (T) through the action of 5α-reductase, has recently been suggested to play a physiologically important role in some fish species. In this study, gilthead seabream, Sparus aurata L., males received an implant of 1μg T/g body mass (bm) or vehicle alone and, 7 days later, 1 mg finasteride (FIN, an inhibitor of 5α-reductase)/kg bm or vehicle. Serum levels of T, 11-ketotestosterone (11KT), DHT and 17β-estradiol (E2), and the mRNA levels of the main enzymes involved in their synthesis, were analysed. T promoted a transient increase in the serum levels of T, 11KT and E2 but a decrease in those of DHT at day 15 following T injection, in accordance with the up-regulation of mRNA levels of the enzymes involved in T transformation to 11KT (coding genes: cyp11b1 and hsd11b) and the down-regulation of mRNA levels of the enzyme responsible for T transformation to DHT (coding gene:srd5a). Interestingly, a similar effect was observed when FIN was in- jected. However, when fish were injected with T and FIN successively (T + FIN), control levels were not re-covered at the end of the experimental period (28 days). DHT seems to regulate E2 serum levels via the down-regulation of mRNA levels of aromatase (coding gene:cyp19a1a), which is needed for the transformation of T into E2. The testis histology, together with the proliferative rates recorded upon T, FIN or T + FIN treatment, suggests that DHT is involved in the onset of the meiotic phase of spermatogenesis.Versión del edito

De retibus socialibus et legibus momenti

Online Social Networks (OSNs) are a cutting edge topic. Almost everybody --users, marketers, brands, companies, and researchers-- is approaching OSNs to better understand them and take advantage of their benefits. Maybe one of the key concepts underlying OSNs is that of influence which is highly related, although not entirely identical, to those of popularity and centrality. Influence is, according to Merriam-Webster, "the capacity of causing an effect in indirect or intangible ways". Hence, in the context of OSNs, it has been proposed to analyze the clicks received by promoted URLs in order to check for any positive correlation between the number of visits and different "influence" scores. Such an evaluation methodology is used in this paper to compare a number of those techniques with a new method firstly described here. That new method is a simple and rather elegant solution which tackles with influence in OSNs by applying a physical metaphor.Comment: Changes made for third revision: Brief description of the dataset employed added to Introduction. Minor changes to the description of preparation of the bit.ly datasets. Minor changes to the captions of Tables 1 and 3. Brief addition in the Conclusions section (future line of work added). Added references 16 and 18. Some typos and grammar polishe

129I, 236U, 239Pu and 240Pu profiles in a peatbog from the Southern Hemisphere

129I, 236U, 239Pu and 240Pu isotopes have been analyzed in the different layers of a peatbog core collected in Madagascar Island (South Hemisphere) and representing at least the last 100 years of atmospheric deposition. The determination of ultra-low levels of these isotopes has been possible by applying the Accelerator Mass Spectrometric Technique (AMS) by using the 1 MV Tandetrom AMS facility located at CNA (Seville, Spain). The elements of interest were extracted and isolated previous to the measurements by applying validated radiochemical procedures. In this contribution, the behavior along the core of the different isotopes under analysis will be discussed, evaluating in particular the magnitude of their post-depositional retention/migration. In this sense, it will be highlighted the great mobility of the 129I with a near uniform profile along the core, in opposition for example with the preservation for the Pu isotopes of the fallout bomb peak. In the case of 236U, the 236U/239Pu atomic ratios determined in a total of eight layers of the core are ranging in the interval 0.02 – 0.29 with an average value of 0.15. As far as we know, these are the first 236U results seeing the light that were obtained in deposits as peatbogs collected in the southern hemisphere.Spanish Ministry MINECO project FIS2015-69673-

Optical Emission Spectroscopy Investigation of a 1-atm DC Glow Discharge With Liquid Anode and Associated Self-Organization Patterns

Optical emission spectroscopy is used to study a 1-atm dc helium glow discharge with a liquid anode to obtain insight into the physical mechanisms underlying observed plasma self-organization at the liquid surface. Plasma column conditions such as gas temperature, electron density, and species composition were determined by means of optical emissions spectroscopy techniques and correlated with the appearance and structure of anode patterns over a broad burning voltage range with fixed flow rate and liquid conductivity. The discharge column was stratified from a species standpoint with the attachment near the liquid surface containing more sodium and water emission, while near the cathode, the predominant emission was from nitrogen and helium. The experiment suggested a complex interplay between the transport of liquid phase species and the actual composition of the plasma, suggesting the importance of processes such as localized boiling and perhaps physical sputtering

Unraveling the Molecular Determinants of Manual Therapy: An Approach to Integrative Therapeutics for the Treatment of Fibromyalgia and Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

Application of protocols without parameter standardization and appropriate controls has led manual therapy (MT) and other physiotherapy-based approaches to controversial outcomes. Thus, there is an urgency to carefully define standard protocols that elevate physiotherapy treatments to rigorous scientific demands. One way in which this can be achieved is by studying gene expression and physiological changes that associate to particular, parameter-controlled, treatments in animal models, and translating this knowledge to properly designed, objective, quantitatively-monitored clinical trials (CTs). Here, we propose a molecular physiotherapy approach (MPTA) requiring multidisciplinary teams, to uncover the scientific reasons behind the numerous reports that historically attribute health benefits to MT-treatments. The review focuses on the identification of MT-induced physiological and molecular responses that could be used for the treatment of fibromyalgia (FM) and chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). The systemic effects associated to mechanical-load responses are considered of particular relevance, as they suggest that defined, low-pain anatomic areas can be selected for MT treatment and yet yield overall benefits, an aspect that might result in it being essential to treat FM. Additionally, MT can provide muscle conditioning to sedentary patients without demanding strenuous physical effort, which is particularly detrimental for CFS/ME patients, placing MT as a real option for integrative medicine programs to improve FM and CFS/ME.This research was funded by the Fundación Universidad Católica de Valencia San Vicente Mártir (UCV) Research Grant Program grant number 2018-121-001.Fisioterapi

Child‐level factors affecting rate of learning to write in first grade

[EN] Background.Written composition requires handwriting, spelling, and text planning skills,all largely learned through school instruction. Students’ rate of learning to compose textin their first months at school will depend, in part, on their literacy-related abilities atschool start. These effects have not previously been explored.Aim.We aimed to establish the effects of various literacy-related abilities on thelearning trajectory of first-grade students as they are taught to write.Sample.179 Spanish first-grade students (94 female, mean age 6.1 years) writing 3,512texts.Method.Students were assessed at start of school for spelling, transcription fluency,letter knowledge, phonological awareness, handwriting accuracy, word reading, and non-verbal reasoning. They were then taught under a curriculum that included researcher-designed instruction in handwriting, spelling, and ideation. Students’ compositionperformance was probed at very regular intervals over their first 13 weeks at school.Results.Controlling for age, overall performance was predicted by spelling, transcrip-tion fluency, handwriting accuracy, word reading, and non-verbal reasoning. Moststudents showed rapid initial improvement, but then much slower learning. Weak spellers(and to a lesser extent less fluent hand-writers) showed weaker initial performance, butthen steady improvement across the study period.SIMinisterio de Economía y Competitivida