Puente carretero Santa Fe-Santo Tomé: análisis del estado luego de 71 años de servicio

En el presente trabajo se realiza una pequeña reseña histórica sobre el Puente Carretero Santa Fe – Santo Tomé que une las ciudades homónimas separadas por el río Salado, formando parte del corredor vial de la Ruta Nacional Nº 11; destacándose que al finalizar su construcción, este puente fue uno de los más importantes del mundo en su género y el mayor de Sud América. Se describen sus características principales y métodos de ejecución utilizados, para poder entender a pleno su funcionamiento y algunas de las patologías que se observaron en la estructura. Se realiza un detalle pormenorizado de sus componentes junto a un análisis de su estado actual dando a conocer las exigencias a las que se encuentra sometido y una caracterización de su entorno natural y antrópico. Para tener una mejor idea de su condición se dan a conocer los resultados de algunos ensayos no destructivos realizados, consistentes en: determinación de la profundidad del frente de carbonatación, determinación de espesores de recubrimientos de armadura, determinaciones del índice de esclerometría y de la calidad del hormigón de recubrimiento, relevamiento de fisuras, desprendimientos y otras patologías. Se comparan los resultados aquí obtenidos con otras estructuras evaluadas en esta zona y con resultados obtenidos en trabajos de investigación, llevados a cabo por el Centro de Investigación y Desarrollo para la Construcción y la Vivienda (CECOVI). Hoy, a 71 años de su inauguración, debemos destacar la calidad de la construcción para el tráfico actual que soporta y para las continuas crecidas del río Salado a las que se ha visto sometido. Su estructura está ejecutada totalmente en hormigón armado y es causa de admiración el buen estado en que se encuentra a pesar de su casi inexistente mantenimiento; esta causa es particularmente una de las responsables de deterioros puntuales que se han relevado

Climate change models predict decreases in the range of a microendemic freshwater fish in Honduras

Despite their incredible diversity, relatively little work has been done to assess impacts of climate change on tropical freshwater organisms. Chortiheros wesseli is a species of Neotropical cichlid (Cichlidae: Cichlinae) restricted to only a few river drainages in the Caribbean-slope of Honduras. Little is known about this species and few specimens had been collected until recently; however, our work with this species in the wild has led to a better understanding of its ecology and habitat preferences making it an excellent model for how freshwater fishes can be affected by climate change. This study assesses the distribution and habitats of Chortiheros wesseli using a combination of field data and species distribution modeling. Results indicate this species is largely limited to its current range, with no realistic suitable habitat nearby. Empirical habitat data show that this species is limited to narrow and shallow flowing waters with rapids and boulders. This habitat type is highly influenced by precipitation, which contributed the greatest influence on the models of present and future habitat suitability. Although several localities are within boundaries of national protected areas, species distribution models all predict a reduction in the range of this freshwater fish based on climate change scenarios. The likelihood of a reduced range for this species will be intensified by adverse changes to its preferred habitats

Low X-Ray Luminosity Galaxy Clusters: Main goals, sample selection, photometric and spectroscopic observations

We present the study of nineteen low X-ray luminosity galaxy clusters (L$_X \sim$ 0.5--45 $\times$ $10^{43}$ erg s$^{-1}$), selected from the ROSAT Position Sensitive Proportional Counters (PSPC) Pointed Observations (Vikhlinin et al. 1998) and the revised version of Mullis et al. (2003) in the redshift range of 0.16 to 0.7. This is the introductory paper of a series presenting the sample selection, photometric and spectroscopic observations and data reduction. Photometric data in different passbands were taken for eight galaxy clusters at Las Campanas Observatory; three clusters at Cerro Tololo Interamerican Observatory; and eight clusters at the Gemini Observatory. Spectroscopic data were collected for only four galaxy clusters using Gemini telescopes. With the photometry, the galaxies were defined based on the star-galaxy separation taking into account photometric parameters. For each galaxy cluster, the catalogues contain the PSF and aperture magnitudes of galaxies within the 90\% completeness limit. They are used together with structural parameters to study the galaxy morphology and to estimate photometric redshifts. With the spectroscopy, the derived galaxy velocity dispersion of our clusters ranged from 507 km~s$^{-1}$ for [VMF98]022 to 775 km~s$^{-1}$ for [VMF98]097 with signs of substructure. Cluster membership has been extensively discussed taking into account spectroscopic and photometric redshift estimates. In this sense, members are the galaxies within a projected radius of 0.75 Mpc from the X-ray mission peak and with cluster centric velocities smaller than the cluster velocity dispersion or 6000 km~s$^{-1}$, respectively. These results will be used in forthcoming papers to study, among the main topics, the red cluster sequence, blue cloud and green populations; the galaxy luminosity function and cluster dynamics.Comment: 13 pages, 6 tables, 9 figures. Uses emulateapj. Accepted for publication in The Astronomical Journal. Some formatting errors fixe

Using the Social-Local-Mobile App for Smoking Cessation in the SmokeFreeBrain Project: Protocol for a Randomized Controlled Trial

Background: Smoking is considered the main cause of preventable illness and early deaths worldwide. The treatment usually prescribed to people who wish to quit smoking is a multidisciplinary intervention, combining both psychological advice and pharmacological therapy, since the application of both strategies significantly increases the chance of success in a quit attempt. Objective: We present a study protocol of a 12-month randomized open-label parallel-group trial whose primary objective is to analyze the efficacy and efficiency of usual psychopharmacological therapy plus the Social-Local-Mobile app (intervention group) applied to the smoking cessation process compared with usual psychopharmacological therapy alone (control group). Methods: The target population consists of adult smokers (both male and female) attending the Smoking Cessation Unit at Virgen del Rocío University Hospital, Seville, Spain. Social-Local-Mobile is an innovative intervention based on mobile technologies and their capacity to trigger behavioral changes. The app is a complement to pharmacological therapies to quit smoking by providing personalized motivational messages, physical activity monitoring, lifestyle advice, and distractions (minigames) to help overcome cravings. Usual pharmacological therapy consists of bupropion (Zyntabac 150 mg) or varenicline (Champix 0.5 mg or 1 mg). The main outcomes will be (1) the smoking abstinence rate at 1 year measured by means of exhaled carbon monoxide and urinary cotinine tests, and (2) the result of the cost-effectiveness analysis, which will be expressed in terms of an incremental cost-effectiveness ratio. Secondary outcome measures will be (1) analysis of the safety of pharmacological therapy, (2) analysis of the health-related quality of life of patients, and (3) monitoring of healthy lifestyle and physical exercise habits. Results: Of 548 patients identified using the hospital’s electronic records system, we excluded 308 patients: 188 declined to participate and 120 did not meet the inclusion criteria. A total of 240 patients were enrolled: the control group (n=120) will receive usual psychopharmacological therapy, while the intervention group (n=120) will receive usual psychopharmacological therapy plus the So-Lo-Mo app. The project was approved for funding in June 2015. Enrollment started in October 2016 and was completed in October 2017. Data gathering was completed in November 2018, and data analysis is under way. The first results are expected to be submitted for publication in early 2019. Conclusions: Social networks and mobile technologies influence our daily lives and, therefore, may influence our smoking habits as well. As part of the SmokeFreeBrain H2020 European Commission project, this study aims at elucidating the potential role of these technologies when used as an extra aid to quit smoking

Safety and feasibility of percutaneous retrograde coronary sinus delivery of autologous bone marrow mononuclear cell transplantation in patients with chronic refractory angina

<p>Abstract</p> <p>Background</p> <p>Chronic refractory angina is a challenging clinical problem with limited treatment options. The results of early cardiovascular stem cell trials using ABMMC have been promising but have utilized intracoronary or intramyocardial delivery. The goal of the study was to evaluate the safety and early efficacy of autologous bone marrow derived mononuclear cells (ABMMC) delivered via percutaneous retrograde coronary sinus perfusion (PRCSP) to treat chronic refractory angina (CRA).</p> <p>Methods</p> <p>From May 2005 to October 2006, 14 patients, age 68 +/- 20 years old, with CRA and ischemic stress-induced myocardial segments assessed by SPECT received a median 8.19*10⁸± 4.3*10⁸mononuclear and 1.65*10⁷± 1.42*10⁷CD34⁺cells by PRCSP..</p> <p>Results</p> <p>ABMMC delivery was successful in all patients with no arrhythmias, elevated cardiac enzymes or complications related to the delivery. All but one patient improved by at least one Canadian Cardiovascular Society class at 2 year follow-up compared to baseline (p < 0.001). The median baseline area of ischemic myocardium by SPECT of 38.2% was reduced to 26.5% at one year and 23.5% at two years (p = 0.001). The median rest left ventricular ejection fraction by SPECT at baseline was 31.2% and improved to 35.5% at 2 year follow up (p = 0.019).</p> <p>Conclusions</p> <p>PRCSP should be considered as an alternative method of delivery for cell therapy with the ability to safely deliver large number of cells regardless of coronary anatomy, valvular disease or myocardial dysfunction. The clinical improvement in angina, myocardial perfusion and function in this phase 1 study is encouraging and needs to be confirmed in randomized placebo controlled trials.</p

Resolving the Circumstellar Disk Around the Massive Protostar Driving the HH 80-81 Jet

We present new high-angular resolution observations toward the driving source of the HH 80-81 jet (IRAS 18162-2048). Continuum emission was observed with the Very Large Array at 7 mm and 1.3 cm, and with the Submillimeter Array at 860 microns, with angular resolutions of ~0"1 and ~0"8 respectively. Submillimeter observations of the sulfur oxide (SO) molecule are reported as well. At 1.3 cm the emission traces the well-known radio jet, while at 7 mm the continuum morphology is quadrupolar and seems to be produced by a combination of free-free and dust emission. An elongated structure perpendicular to the jet remains in the 7 mm image after subtraction of the free-free contribution. This structure is interpreted as a compact accretion disk of ~200 AU radius. Our interpretation is favored by the presence of rotation in our SO observations observed at larger scales. The observations presented here add to the small list of cases where the hundred-AU scale emission from a circumstellar disk around a massive protostar has been resolved.Comment: Accepted for publication in ApJ Letter

A 1.3 mm SMA Survey of 29 Variable Young Stellar Objects

© 2018 ESO. Reproduced with permission from Astronomy & Astrophysics.Context. Young stellar objects (YSOs) may undergo periods of active accretion (outbursts), during which the protostellar accretion rate is temporarily enhanced by a few orders of magnitude. Whether or not these accretion outburst YSOs possess similar dust and gas reservoirs to each other, and whether or not their dust and gas reservoirs are similar as quiescent YSOs, are issues yet to be clarified.Aims. The aim of this work is to characterize the millimeter thermal dust emission properties of a statistically significant sample of long and short duration accretion outburst YSOs (i.e., FUors and EXors) and the spectroscopically identified candidates of accretion outbursting YSOs (i.e., FUor-like objects). Methods. We have carried out extensive Submillimeter Array (SMA) observations mostly at ~225 GHz (1.33 mm) and ~272 GHz (1.10 mm), from 2008 to 2017. We covered accretion outburst YSOs located at 3σ significance. Detected sources except for the two cases of V883 Ori and NGC 2071 MM3 were observed with ~1″ angular resolution. Overall our observed targets show a systematically higher millimeter luminosity distribution than those of the M ∗ > 0.3 MClass II YSOs in the nearby (400 pc) low-mass star-forming molecular clouds (e.g., Taurus, Lupus, Upp Scorpio, and Chameleon I). In addition, at 1 mm our observed confirmed binaries or triple-system sources are systematically fainter than the rest of the sources even though their 1 mm fluxes are broadly distributed. We may have detected ∼30-60% millimeter flux variability from V2494 Cyg and V2495 Cyg, from the observations separated by approximately one year.Peer reviewe

Biochemical and structural characterization of a novel arginine kinase from the spider <i>Polybetes pythagoricus</i>

Energy buffering systems are key for homeostasis during variations in energy supply. Spiders are the most important predators for insects and therefore key in terrestrial ecosystems. From biomedical interest, spiders are important for their venoms and as a source of potent allergens, such as arginine kinase (AK, EC 2.7.3.3). AK is an enzyme crucial for energy metabolism, keeping the pool of phosphagens in invertebrates, and also an allergen for humans. In this work, we studied AK from the Argentininan spider Polybetes pythagoricus (PpAK), from its complementary DNA to the crystal structure. The PpAK cDNA from muscle was cloned, and it is comprised of 1068 nucleotides that encode a 384-amino acids protein, similar to other invertebrate AKs. The apparent Michaelis-Menten kinetic constant (Km) was 1.7 mM with a kcat of 75 s-1. Two crystal structures are presented, the apoPvAK and PpAK bound to arginine, both in the open conformation with the active site lid (residues 310-320) completely disordered. The guanidino group binding site in the apo structure appears to be organized to accept the arginine substrate. Finally, these results contribute to knowledge of mechanistic details of the function of arginine kinase.Instituto de Investigaciones Bioquímicas de La Plat