2,610 research outputs found
Mid-Infrared Galaxy Morphology Along the Hubble Sequence
The mid-infrared emission from 18 nearby galaxies imaged with the IRAC
instrument on Spitzer Space Telescope samples the spatial distributions of the
reddening-free stellar photospheric emission and the warm dust in the ISM.
These two components provide a new framework for galaxy morphological
classification, in which the presence of spiral arms and their emission
strength relative to the starlight can be measured directly and with high
contrast. Four mid-infrared classification methods are explored, three of which
are based on quantitative global parameters (colors, bulge-to-disk ratio)
similar to those used in the past for optical studies; in this limited sample,
all correlate well with traditional B-band classification. We suggest reasons
why infrared classification may be superior to optical classification.Comment: ApJS (in press), Spitzer Space Telescope Special Issue; 13 pages,
LaTeX (or Latex, etc); Figure 1ab is large, color plate; full-resolution
plates in .pdf format available at
http://cfa-www.harvard.edu/irac/publications
Alignment transition in a nematic liquid crystal due to field-induced breaking of anchoring
We report on the alignment transition of a nematic liquid crystal from
initially homeotropic to quasi-planar due to field-induced anchoring breaking.
The initial homeotropic alignment is achieved by Langmuir-Blodgett monolayers.
In this geometry the anchoring strength can be evaluated by the Frederiks
transition technique. Applying an electric field above a certain threshold
provokes turbulent states denoted DSM1 and DSM2. While DSM1 does not affect the
anchoring, DSM2 breaks the coupling between the surface and the liquid crystal:
switching off the field from a DSM2 state does not immediately restore the
homeotropic alignment. Instead, we obtain a quasi-planar metastable alignment.
The cell thickness dependence for the transition is related to theComment: 7 pages, LaTeX2e article, 4 figures, 7 EPS files, added references,
accepted for publication in Europhysics Letter
Possible complex annihilation and B -> K pi direct CP asymmetry
We point out that a sizable strong phase could be generated from the penguin
annihilation in the soft-collinear effective theory for B meson decays. Keeping
a small scale suppressed by O(Lambda/m_b), Lambda being a hadronic scale and
m_b the b quark mass, in the denominators of internal particle propagators
without expansion, the resultant strong phase can accommodate the data of the
B^0 -> K^-+ pi^+- direct CP asymmetry. Our study reconciles the opposite
conclusions on the real or complex penguin annihilation amplitude drawn in the
soft-collinear effective theory and in the perturbative QCD approach based on
k_T factorization theorem.Comment: 8 pages, 1 figure, added reference
Irrational beliefs about COVID-19: A scoping review
Since the emergence of the recent Coronavirus Disease of 2019 (COVID-19) and its spread as a pandemic, there has been a parallel spread of false and misleading information, known as an infodemic. The COVID-19 infodemic has induced distrust in scientific communities, governments, institutions and the population, and a confidence crisis that has led to harmful health behaviours, also impacting on mental health. The aim of this study is to provide a scoping review of the scientific literature about COVID-19-related misinformation and conspiracy theories, focusing on the construction of a conceptual framework which is useful for the interpretation of the conspiracy theory phenomenon surrounding COVID-19, and its consequences. Particular socio-environmental conditions (i.e., low educational level, younger age), psychological processes and attitudes (such as low levels of epistemic trust, the avoidance of uncertainty, extraversion, collective narcissism, and a conspiracy-prone mindset), and contextual factors (e.g., high levels of self-perceived risk and anxiety) seem to underpin the adherence to beliefs that are not solely the domain of paranoids and extremists but a widespread phenomenon that has caused important health, social and political consequences
Preliminary realization of an electric-powered hydraulic pump system for a waste compactor truck and a techno-economic analysis
Most industrial trucks are equipped with hydraulic systems designed for specic operations, for which the required power is supplied by the internal combustion engine (ICE). The largest share of the power consumption is required by the hydraulic system during idling operations, and, consequently, the current literature focuses on energy saving strategies for the hydraulic system rather than making the vehicle traction more efficient. This study presents the preliminary realization of an electric-powered hydraulic pump system (e-HPS) that drives the lifting of the dumpster and the garbage compaction in a waste compactor truck, rather than traditional ICE-driven hydraulic pump systems (ICE-HPSs). The different components of the e-HPS are described and the battery pack was modelled using the kinetic battery model. The end-of-life of the battery pack was determined to assess the economic feasibility of the proposed e-HPS for the truck lifespan, using numerical simulations. The aim was twofold: To provide an implementation method to retrofit the e-HPS to a conventional waste compactor truck and to assess its economic feasibility, investigating fuel savings during the use phase and the consequent reduction of CO2 emissions. Results show that the total lifespan cost saving achieved a value of 65,000. Furthermore, total CO2 emissions for the e-HPS were about 80% lower than those of the ICE-HPS, highlighting that the e-HPS can provide significant environmental benefits in an urban context
Stress induced cardiomyopathy presenting as acute coronary syndrome: Tako-Tsubo in Mercogliano, Southern Italy
<p>Abstract</p> <p>Background</p> <p>Tako-tsubo syndrome (TTS) in its typical (apical) and atypical (non-apical) forms is being increasingly recognized in the West owing to early systematic coronary angiography in acute coronary syndromes (ACS).</p> <p>Aim of the study</p> <p>To assess the incidence, the clinical characteristics and the outcome of TTS in a single high volume cath lab in Southern Italy over the last 6 years.</p> <p>Methods</p> <p>Among 1674 consecutive patients (pts) referred to our coronary care units in the last 6 years (2001–2006) for ACS we selected 6 (0.5%) pts (6 women; age 57 ± 6 years) who fulfilled the following 4 criteria: 1) transient left ventricular wall motion abnormalities resulting in ballooning at contrast ventricolographic or echocardiographic evaluation; 2) normal coronary artery on coronary angiography performed 5 ± 9 hours from hospitalization; 3) new electrocardiographic ischemic-like abnormalities (either ST-segment elevation or T-wave inversion) and 4) emotional or physical trigger event.</p> <p>Results</p> <p>At admission all pts had presumptive diagnosis of ACS and ECG revealed ST elevation in 3 (50%) and T wave inversion with QT elongation in 3 (50%). In the acute phase cardiogenic shock occurred in 2 (33%) and heart failure in 1(16%). Presenting symptoms were chest pain in 6 (100%), dyspnoea in 2 (33%) and lipotimia in 1 (16%). At echocardiographic-ventricolographic assessment, the mechanical dysfunction (ballooning) was apical in all 6 pts ("classic" TTS). In all patients wall motion abnormalities completely reversed within 4.5 ± 1.5 days. The region of initial recovery was the anterior and lateral wall in 4 cases and the lateral wall in 2 cases. Ejection fraction was 35 ± 8% in the acute phase and increased progressively at discharge (55 ± 6%) and at 41 ± 20 months follow-up (60 ± 4%, p < 0.001 vs. baseline). All patients remained asymptomatic with minimal (aspirin, beta blockers, antihypertensive and antidislipidemic therapy) treatment.</p> <p>Conclusion</p> <p>Classic TTS is a frequent serendipitous diagnosis after coronary angiography showed "surprisingly" normal findings in a clinical setting mimicking an ACS. Despite its long-term good prognosis life threatening complications in the acute phase can occur.</p
A new sustainable and innovative work for paper artworks cleaning process: Gellan hydrogel combined with hydrolytic enzymes
Paper has been used as writing and drawing support for thousands of years. The conservation of paper artworks plays a fundamental role in the field of our cultural heritage. Moreover, restoration of paper artworks is difficult due to their inherent fragility, the presence of many components and their degradation state. Among the factors that may contribute to paper deterioration are the use of glue for the application of different materials (as a lining, mounting or as a repair intervention) on the paper artifact. During a natural ageing process, glue become yellow, acid and less compact, accelerating the degradation processes of the artwork itself. The removal of glues from paper artworks represents, therefore, an important procedure for their preservation. Here we present a sustainable alternative to the common removal systems (e.g. solvents or localized enzymatic packs on the support to be cleaned). For this goal we used a rigid Gellan hydrogel (totally removable in one step) containing hydrolytic enzyme, such as proteinase K. The enzyme works as a selective cleaning agent hydrolyzing animal glues into smaller fragments, soluble into the gel. Our system represents an effective alternative to the traditional techniques because it is easy to be prepared, eco-friendly and efficient
Clustering of red galaxies around the z=1.53 quasar 3C270.1
In the paradigm of hierarchical galaxy formation, luminous radio galaxies
mark mass assembly peaks that should contain clusters of galaxies. Observations
of the z=1.53 quasar 3C270.1 with the Spitzer Space Telescope at 3.6-24 micron
and with the 6.5-m MMT in the z'- and Y-bands allow detection of potential
cluster members via photometric redshifts. Compared with nearby control fields,
there is an excess of 11 extremely red objects (EROs) at 1.33 < z_phot < 1.73,
consistent with a proto-cluster around the quasar. The spectral energy
distributions (SEDs) of 3/4 of the EROs are better fitted with passive
elliptical galaxies than withdust-reddened starbursts, and of four sources
well-detected on an archival HST snapshot image, all have undisturbed
morphologies. However, one ERO, not covered by the HST image, is a double
source with 0.8" separation on the z' image and a marginal (2sigma) 24 micron
detection indicating a dust-enshrouded starburst. The EROs are more luminous
than L* (H = -23.6 AB mag at z=1.5).Comment: 12 pages, 7 figures, accepted by Ap
Blockade and Counterflow Supercurrent in exciton-condensate Josephson junctions
We demonstrate that perfect conversion between charged supercurrents in
superconductors and neutral supercurrents in electron-hole pair condensates is
possible via a new Andreev-like scattering mechanism. As a result, when two
superconducting circuits are coupled through a bilayer exciton condensate, the
superflow in both layers is drastically modified. Depending on the phase biases
the supercurrents can be completely blocked or exhibit perfect drag.Comment: 4 pages, 2 figure
Effects of pesticides on Chelon labrosus (Risso, 1827) evaluated by enzymatic activities along the north eastern Sicilian coastlines (Italy)
Pesticides are frequently applied to agricultural activities to improve harvest, in terms of yield and product quality. Useful tools for ecotoxicological studies of marine ecosystems are based on biomarker application on bioindicator key fish species. The main aim of the present study was to detect the potential presence of pesticides in a polluted coastal marine environment, namely Milazzo Gulf, situated in the north eastern coast of Sicily (Italy), by measuring the enzymatic activities of the ecotoxicological biomarkers acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in brain and blood samples of Chelon labrosus. Also, Marinello Reserve was selected as a reference site. The data showed a significant inhibition in AChE (81%) and BChE (71%) activities in fish from Milazzo Gulf in respect to those from the reference site. The esterase inhibition is primarily due to the presence of organophosphorus insecticides and carbamates that resulted, in Milazzo Gulf, higher in concentration in respect to the reference quality standard decree (D.M. 260, 2010). The results obtained in this study confirm the suspected presence of insecticides in waters and fish from Milazzo Gulf, which may lead to a considerable hazard to humans. This study confirms the relevant advantages of the biomarker approach on fish species in the ecotoxicological evaluation of marine environments
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