On the use of scaling relations for the Tolman test

The use of relations between structural parameters of early type galaxies to perform the Tolman test is reconsidered. Scaling relations such as the FP or the Kormendy relation, require the transformation from angular to metric sizes, to compare the relation at different z values. This transformation depends on the assumed world model: galaxies of a given angular size, at a given z, are larger (in kpc) in a non-expanding universe than in an expanding one. Furthermore, the luminosities of galaxies are expected to evolve with z in an expanding model. These effects are shown to conspire to reduce the difference between the predicted SB change with redshift in the expanding and non expanding cases. We find that the predictions for the visible photometric bands of the expanding models with passive luminosity evolution are very similar to those of the static model till z about 1, and therefore, the test cannot distinguish between the two world models. Recent good quality data are consistent with the predictions from both models. In the K-band, where the expected (model) luminosity evolutionary corrections are smaller, the differences between the xpanding and static models amount to about 0.4 (0.8) magnitudes at z = 0.4 (1). It is shown that, due to that small difference between the predictions in the covered z-range, and to the paucity and uncertainties of the relevant SB photometry, the existing K-band data is not adequate to distinguish between the different world metrics, and cannot be yet used to discard the static case. It is pointed out that the scaling relations could still be used to rule out the non-evolving case if it could be shown that the coefficients change with the redshift.Comment: Latex, 15 pages with 2 figures. To be published in ApJ Letter

Clinical use of Heliox in Asthma and COPD

Heliox is a low density gas mixture of helium and oxygen commonly used in deep diving (> 6 ATM). This mixture has been also used for clinical purposes, particularly in the critical care setting. Due to of its physical proprieties, Heliox breathing reduces air flow resistances within the bronchial tree; in patients with obstructive lung diseases Heliox may also reduce the work of breathing and improve pulmonary gas exchange efficiency. Beneficial effects have been documented in severe asthma attacks and in patients with chronic obstructive pulmonary disease. A reduction in WOB during mechanical ventilation and an increase in exercise endurance capacity have also been described in COPD. Heliox has been also used in the treatment of upper airways obstruction, bronchiolitis and bronchopulmonary dysplasia. Despite the encouraging results, Heliox use in routine practice remains controversial because of technical implications and high costs

The prognostic importance of chronic end-stage diseases in geriatric patients admitted to 163 Italian ICUs

BACKGROUND: The number of elderly patients undergoing major surgical interventions and then needing admission to intensive care unit (ICU) grows steadily. We investigated this issue in a cohort of 232,278 patients admitted in five years (2011-2015) to 163 Italian general ICUs. METHODS: Surgical patients older than 75 registered in the GiViTI MargheritaPROSAFE project were analyzed. The impact on hospital mortality of important chronic conditions (severe COPD, NYHA class IV, dementia, end-stage renal disease, cirrhosis with portal hypertension) was investigated with two prognostic models developed yearly on patients staying in the ICU less or more than 24 hours. RESULTS: 44,551 elderly patients (19.2%) underwent emergency (47.3%) or elective surgery (52.7%). At least one severe comorbidity was present in 14.6% of them, yielding a higher hospital mortality (32.4%, vs. 21.1% without severe comorbidity). In the models for patients staying in the ICU 24 hours or more, cirrhosis, NYHA class IV, and severe COPD were constant independent predictors of death (adjusted odds ratios [ORs] range 1.67-1.97, 1.54-1.91, and 1.34-1.50, respectively), while dementia was statistically significant in four out of five models (adjusted ORs 1.23-1.28). End-stage renal disease, instead, never resulted to be an independent prognostic factor. For patients staying in the ICU less than 24 hours, chronic comorbidities were only occasionally independent predictors of death. CONCLUSIONS: Our study confirms that elderly surgical patients represent a relevant part of all ICUs admissions. About one of seven bear at least one severe chronic comorbidity, that, excluding end-stage renal disease, are all strong independent predictors of hospital death

The role of long waves in the stability of the plane wake

This work is directed towards investigating the fate of three-dimensional long perturbation waves in a plane incompressible wake. The analysis is posed as an initial-value problem in space. More specifically, input is made at an initial location in the downstream direction and then tracing the resulting behavior further downstream subject to the restriction of finite kinetic energy. This presentation follows the outline given by Criminale and Drazin [Stud. in Applied Math. \textbf{83}, 123 (1990)] that describes the system in terms of perturbation vorticity and velocity. The analysis is based on large scale waves and expansions using multi scales and multi times for the partial differential equations. The multiscaling is based on an approach where the small parameter is linked to the perturbation property independently from the flow control parameter. Solutions of the perturbative equations are determined numerically after the introduction of a regular perturbation scheme analytically deduced up to the second order. Numerically, the complete linear system is also integrated. Since the results relevant to the complete problem are in very good agreement with the results of the first order analysis, the numerical solution at the second order was deemed not necessary. The use for an arbitrary initial-value problem will be shown to contain a wealth of information for the different transient behaviors associated to the symmetry, angle of obliquity and spatial decay of the long waves. The amplification factor of transversal perturbations never presents the trend - a growth followed by a long damping - usually seen in waves with wavenumber of order one or less. Asymptotical instability is always observed.Comment: accepted Physical Review E, March 201

The Evolution of Dust Opacity in Galaxies

(Abridged) We investigate the evolution of the opacity of galaxies as a function of redshift, using simple assumptions about the metal and dust enrichment of the gas and the distribution of dust in galaxies. We use an iterative procedure to reconstruct the intrinsic Star Formation Rate (SFR) density of galaxies with redshift, by applying dust obscuration corrections to the observed UV emission. The iterative procedure converges to multiple solutions for the intrinsic SFR density, divided into two basic classes. The first class of solutions predicts relatively large UV attenuation at high redshift, with A(1500 A)=1.9 mag at z~3, and smaller attenuations at z<1, with A(2800 A)=1.25 mag. The SFR density of this set of solutions is constant for z>~1.2 and declines for z<1.2; it resembles in shape the ``monolithic collapse'' scenario for star formation. The second class of solutions predicts relatively low UV attenuations at high redshift, with A(1500 A)=0.75 mag at z~3, and larger attenuations at z<1, with A(2800 A)=1.50 mag. The SFR density in this case has a peak at z~1.2. The advantages and shortcomings of both classes are analyzed in the light of available observational constraints, including the opacity of galaxies at 0<z<1 and the intensity and spectral energy distribution of the cosmic infrared background from the COBE DIRBE and FIRAS data. We conclude that both classes of models are acceptable within the current uncertainties, but the ``monolithic collapse'' class matches the available observations better than the other one. We also investigate the dependence of our solutions on the different model assumptions.Comment: 54 pages, includes 1 embedded postscript Table and 22 embedded postscript Figures, Latex, uses AAS Latex macro. Accepted for publication in the Astrophysical Journa

Surface induced selective delamination of amphiphilic ABA block copolymer thin films

This is the result of an ongoing collaboration with Dr. N. Sommerdijk’s Biomaterials group at the University of Eindhoven (the Netherlands) and illustrates the close collaboration that exists in pursuing the design and application of novel polymeric materials between the two groups. This details work on a physical phenomenon (selective delamination) and key materials (amphiphilic block copolymers) that have subsequently been applied in the design of novel biomaterials. These results have appeared in a larger body of work including Advanced Materials, Angewandtie Chemie International Edition and the Journal of Materials Chemistry

Synthesis and evaluation of an azo dye for the chromogenic detection of metal cations

"This article belongs to the Proceedings of The 26th International Electronic Conference on Synthetic Organic Chemistry"A carboxylic acid azo dye, Dabcyl, was synthesized and evaluated as a colorimetric chemosensor for metal cations with biological and environmental importance. The dye was prepared in high yield and characterized by 1H and 13C NMR and UV-vis absorption spectroscopies. A preliminary chemosensing study showed that Dabcyl displayed a marked color change, from light yellow to pink, for Hg2+, Fe2+, Pd2+, Sn2+ and Al3+ in acetonitrile solution. Consequently, spectrophotometric titrations were carried out for this dye with selected cations, which clearly indicated that Dabcyl has potential application as a chromogenic probe for the cations under study with remarkable sensitivity and a marked color change.This research was funded by the Foundation for Science and Technology (FCT) for financial support to CQ/UM (UID/QUI/00686/2020), project PTDC/QUI-COL/28052/2017 and a PhD grant to C. D. F. Martins (SFRH/BD/05277/2020). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Pro-gram for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT

IRAC Observations of M81

IRAC images of M81 show three distinct morphological constituents: a smooth distribution of evolved stars with bulge, disk, and spiral arm components; a clumpy distribution of dust emission tracing the spiral arms; and a pointlike nuclear source. The bulge stellar colors are consistent with M-type giants, and the disk colors are consistent with a slightly younger population. The dust emission generally follows the blue and ultraviolet emission, but there are large areas that have dust emission without ultraviolet and smaller areas with ultraviolet but little dust emission. The former are presumably caused by extinction, and the latter may be due to cavities in the gas and dust created by supernova explosions. The nucleus appears fainter at 8 um than expected from ground-based 10 um observations made four years ago.Comment: ApJS in press (Spitzer special issue); 15 pages, 3 figures. Changes: unused references removed, numbers and labels in Table 1 change

Development of a Simple and Cost-Effective Bead-Milling Method for DNA Extraction from Fish Muscles

In the fish food sector, due to a growing globalization of the market, where intentional and unintentional frauds reach alarming levels, the molecular analysis is increasingly used by both official agencies, to enforce the law on traceability, and private companies, to verify the quality of goods. DNA extraction represents a necessary and critical step for all types of DNA analysis. Among the drawbacks associated with this procedure, there are handling of toxic materials, low DNA yield, and low throughput, due to time-consuming manual procedures. In this work, to overcome some of these problems, we developed an alternative method based on a bead-milling procedure without proteinase K digestion. The new method was then compared with both a salting-out protocol, developed in a previous work, and a commercial kit. Yield, spectrophotometric purity, electrophoretic degradation pattern, and amplificability of the extracted DNA were assessed. In particular, DNA amplificability was evaluated by comparing the band intensity on the gel, after amplification of the 16S rRNA and cytochrome oxidase I genes with a conventional PCR, and the take-off cycles, after amplification of the 16S rRNA gene with a real-time PCR. The results showed that the bead-based method allowed to obtain acceptable amounts of DNA, with good purity and good characteristics of amplificability. Although the salting-out method remains the most effective protocol in terms of pure performances, the bead-milling procedure can be considered a valid alternative, in the light of its lower demand in terms of labor and costs

Propuesta integradora para un estudio del uso de plantas con propiedades psicoactivas en pipas del período alfarero temprano y sus implicancias sociales

Th is is a new comprehensive approximation to the study of the act of smoking, incorporating the investigation of the social aspects of smoking and the selection of plants through the collection of direct and indirect information. Ethnohistoric and ethnographic documents were consulted, and we obtained direct evidence through the application of recovery techniques and the analysis of microfossils contained in the residues found in pipes from archaeological sites in the northern semi-arid, central and southern Chile. Furthermore, the social operational chain involved in the action of smoking is an important part of this study, as is reaching wider conclusions, reason for which a new approach has been proposed with the object of understanding the defi nition of Smoking Complex.The preliminary results support this study, with the observation of the differential depositation in the chambers and pipes/mouthpieces (cultural depositation) and sediment (natural depositation). In turn, the study differentiates various categories of microfossils and highlights the presence of starches with characteristics that may be attributed to Nicotiana spp. As a part of this proposal, the sequence of social contents linked to the act of smoking is explained and graphically shownas an operational model.Diccionario    Este trabajo es una nueva aproximación integral al estudio de pipas prehispánicas, incorporando la indagación de los aspectos sociales involucrados en el acto de fumar, y la selección de plantas utilizadas para esa finalidad, a través de la recopilación de información indirecta y directa. Se consultaron fuentes etnohistóricas y etnográfi cas que aportan al tema, y se aplicaron técnicas de recuperación y análisis de microfósiles contenidos en residuos adheridos de pipas procedentes de sitios arqueológicos del norte semiárido, zona central y sur de Chile. La cadena social operativa que se desarrolla en los diversos procesos que confluyen en la acción de fumar, es parte importante de este estudio, así como lo es llegar a conclusiones más amplias al proponer un nuevo enfoque para entender la definición de Complejos Fumatorios.Los primeros resultados obtenidos avalan la dirección positiva del estudio realizado, con la observación de residuos diferenciales en los hornillos y los tubos/boquillas (depositación cultural) y los sedimentos (depositación natural). A su vez se discriminan diversas categorías de microfósiles, y se destaca la presencia de almidones cuyas características pueden atribuirse a Nicotiana spp. Como parte de la propuesta, la secuencia de contenidos sociales vinculados a la acción de fumar, es explicada y graficada en un modelo operacional.