Irreversibility is one of the most intriguing concepts in physics. While microscopic physical laws are perfectly reversible, macroscopic average behavior has a preferred direction of time. According ...to the second law of thermodynamics, this arrow of time is associated with a positive mean entropy production. Using a nuclear magnetic resonance setup, we measure the nonequilibrium entropy produced in an isolated spin-1/2 system following fast quenches of an external magnetic field. We experimentally demonstrate that it is equal to the entropic distance, expressed by the Kullback-Leibler divergence, between a microscopic process and its time reversal. Our result addresses the concept of irreversibility from a microscopic quantum standpoint.
Recently, the cities of Yerba Buena and Tucuman in Tucumán Province, Argentina, have been affected by several storm flood events, causing hundreds of people to be evacuated from their homes
. Heavy ...intensity rainfall, new housing developments covering previously permeable grounds, and old drainage systems are the main causes for this situation.
This paper presents a simple approach of urban flood hazard assessment in a region where primary data are scarce. The objectives of this study are to develop a GIS-aided urban flood hazard zoning of the two cities applying multicriteria decision analysis and to evaluate it by means of uncertainty and sensitivity analysis. The research methodology focused on the analysis of those variables that control the water routing when high peak flows exceed the drainage-system capacity. The model incorporates five parameters: distance to the drainage channels, topography (heights and slopes), ground water table depths, and urban land use. A final hazard map for each category is obtained using an algorithm that combines factors in weighted linear combinations. The urban flood hazard map shows that the southeast part of San Miguel de Tucumán has the highest flood hazard over an extended area as a consequence of the conjunction of lowlands with slopes under 0.6% and the presence of urban stream channels with poor maintenance plan. In this area, several neighbourhoods have been flooded. The model was evaluated by the error propagation method and global sensitivity analysis to assess the uncertainty and the relative importance of model input factors. Finally, the influence of criterion weights are analyzed ranging from 25% to 75% of their original values showing a robust behaviour.
This study investigates the possible benefits of radiofrequency ablation (RFA) in patients with non-resectable colorectal liver metastases.
This phase II study, originally started as a phase III ...design, randomly assigned 119 patients with non-resectable colorectal liver metastases between systemic treatment (n = 59) or systemic treatment plus RFA ( ± resection) (n = 60). Primary objective was a 30-month overall survival (OS) rate >38% for the combined treatment group.
The primary end point was met, 30-month OS rate was 61.7% 95% confidence interval (CI) 48.2–73.9 for combined treatment. However, 30-month OS for systemic treatment was 57.6% (95% CI 44.1–70.4), higher than anticipated. Median OS was 45.3 for combined treatment and 40.5 months for systemic treatment (P = 0.22). PFS rate at 3 years for combined treatment was 27.6% compared with 10.6% for systemic treatment only (hazard ratio = 0.63, 95% CI 0.42–0.95, P = 0.025). Median progression-free survival (PFS) was 16.8 months (95% CI 11.7–22.1) and 9.9 months (95% CI 9.3–13.7), respectively.
This is the first randomized study on the efficacy of RFA. The study met the primary end point on 30-month OS; however, the results in the control arm were in the same range. RFA plus systemic treatment resulted in significant longer PFS. At present, the ultimate effect of RFA on OS remains uncertain.
We present spectroscopic redshifts of mJy submillimeter galaxies (SMGs), which have been identified from the ALMA follow-up observations of 870 m detected sources in the Extended Chandra Deep Field ...South (the ALMA-LESS survey). We derive spectroscopic redshifts for 52 SMGs, with a median of z = 2.4 0.1. However, the distribution features a high-redshift tail, with ∼23% of the SMGs at . Spectral diagnostics suggest that the SMGs are young starbursts, and the velocity offsets between the nebular emission and UV ISM absorption lines suggest that many are driving winds, with velocity offsets of up to 2000 km s−1. Using the spectroscopic redshifts and the extensive UV-to-radio photometry in this field, we produce optimized spectral energy distributions (SEDs) using Magphys, and use the SEDs to infer a median stellar mass of = (6 1)× 1010 M for our SMGs with spectroscopic redshift. By combining these stellar masses with the star formation rates (measured from the far-infrared SEDs), we show that SMGs (on average) lie a factor of ∼5 above the so-called "main sequence" at . We provide this library of 52 template fits with robust and uniquely well-sampled SEDs as a resource for future studies of SMGs, and also release the spectroscopic catalog of ∼2000 (mostly infrared-selected) galaxies targeted as part of the spectroscopic campaign.
Abstract Roux-en-Y gastric bypass (gastric bypass) patients reportedly have changes in perception and consumption of sweet-tasting foods. This study aimed to further investigate alterations in sweet ...food intake in rats and sucrose detection in humans after gastric bypass. Wistar rats were randomized to gastric bypass or sham-operations and preference for sucrose (sweet), sodium chloride (salty), citric acid (sour) and quinine hydrochloride (bitter) was assessed with standard two-bottle intake tests (vs. water). Intestinal T1R2 and T1R3 expression and plasma levels of glucagon-like-peptide 1 (GLP-1) and peptide YY (PYY) were measured. Furthermore, obese patients and normal weight controls were tested for sucrose taste detection thresholds pre- and postoperatively. Visual analogue scales measuring hedonic perception were used to determine the sucrose concentration considered by patients and controls as “just about right” pre- and postoperatively. Gastric bypass reduced the sucrose intake relative to water in rats (p < 0.001). Preoperative sucrose exposure reduced this effect. Preference or aversion for compounds representative of other taste qualities in naïve rats remained unaffected. Intestinal T1R2 and T1R3 expression was significantly decreased in the alimentary limb while plasma levels of GLP-1 and PYY were elevated after bypass in rats (p = 0.01). Bypass patients showed increased taste sensitivity to low sucrose concentrations compared with controls (p < 0.05), but both groups considered the same sucrose concentration as “just about right” postoperatively. In conclusion, gastric bypass reduces sucrose intake relative to water in sucrose-naïve rats, but preoperative sucrose experience attenuates this effect. Changes in sucrose taste detection do not predict hedonic taste ratings of sucrose in bypass patients which remain unchanged. Thus, factors other than the unconditional affective value of the taste may also play a role in determining food preferences after gastric bypass.
To provide evidence for the existence of 6 myofascial meridians proposed by Myers based on anatomic dissection studies.
Relevant articles published between 1900 and December 2014 were searched in ...MEDLINE (PubMed), ScienceDirect, and Google Scholar.
Peer-reviewed human anatomic dissection studies reporting morphologic continuity between the muscular constituents of the examined meridians were included. If no study demonstrating a structural connection between 2 muscles was found, articles on general anatomy of the corresponding body region were targeted.
Continuity between 2 muscles was documented if 2 independent investigators agreed that it was reported clearly. Also, 2 independent investigators rated methodologic quality of included studies by means of a validated assessment tool (Quality Appraisal for Cadaveric Studies).
The literature search identified 6589 articles. Of these, 62 article met the inclusion criteria. The studies reviewed suggest strong evidence for the existence of 3 myofascial meridians: the superficial back line (all 3 transitions verified, based on 14 studies), the back functional line (all 3 transitions verified, based on 8 studies) and the front functional line (both transitions verified, based on 6 studies). Moderate-to-strong evidence is available for parts of the spiral line (5 of 9 verified transitions, based on 21 studies) and the lateral line (2 of 5 verified transitions, based on 10 studies). No evidence exists for the superficial front line (no verified transition, based on 7 studies).
The present systematic review suggests that most skeletal muscles of the human body are directly linked by connective tissue. Examining the functional relevance of these myofascial chains is the most urgent task of future research. Strain transmission along meridians would both open a new frontier for the understanding of referred pain and provide a rationale for the development of more holistic treatment approaches.
We present new near-infrared VLTI/GRAVITY interferometric spectra that spatially resolve the broad Br
γ
emission line in the nucleus of the active galaxy IRAS 09149−6206. We use these data to measure ...the size of the broad line region (BLR) and estimate the mass of the central black hole. Using an improved phase calibration method that reduces the differential phase uncertainty to 0.05° per baseline across the spectrum, we detect a differential phase signal that reaches a maximum of ∼0.5° between the line and continuum. This represents an offset of ∼120
μ
as (0.14 pc) between the BLR and the centroid of the hot dust distribution traced by the 2.3
μ
m continuum. The offset is well within the dust sublimation region, which matches the measured ∼0.6 mas (0.7 pc) diameter of the continuum. A clear velocity gradient, almost perpendicular to the offset, is traced by the reconstructed photocentres of the spectral channels of the Br
γ
line. We infer the radius of the BLR to be ∼65
μ
as (0.075 pc), which is consistent with the radius–luminosity relation of nearby active galactic nuclei derived based on the time lag of the H
β
line from reverberation mapping campaigns. Our dynamical modelling indicates the black hole mass is ∼1 × 10
8
M
⊙
, which is a little below, but consistent with, the standard
M
BH
–
σ
*
relation.
The large-scale production of clean energy is one of the major challenges society is currently facing. Molecular hydrogen is envisaged as a key green fuel for the future, but it becomes a sustainable ...alternative for classical fuels only if it is also produced in a clean fashion. Here, we report a supramolecular biomimetic approach to form a catalyst that produces molecular hydrogen using light as the energy source. It is composed of an assembly of chromophores to a bis(thiolate)-bridged diiron (2Fe2S) based hydrogenase catalyst. The supramolecular building block approach introduced in this article enabled the easy formation of a series of complexes, which are all thoroughly characterized, revealing that the photoactivity of the catalyst assembly strongly depends on its nature. The active species, formed from different complexes, appears to be the Fe₂(μ-pdt)(CO)₄{PPh₂(4-py)}₂ (3) with 2 different types of porphyrins (5a and 5b) coordinated to it. The modular supramolecular approach was important in this study as with a limited number of building blocks several different complexes were generated.
We present near-infrared interferometric data on the Seyfert 2 galaxy NGC 1068, obtained with the GRAVITY instrument on the European Southern Observatory Very Large Telescope Interferometer. The ...extensive baseline coverage from 5 to 60
M
λ
allowed us to reconstruct a continuum image of the nucleus with an unrivaled 0.2 pc resolution in the
K
-band. We find a thin ring-like structure of emission with a radius
r
= 0.24 ± 0.03 pc, inclination
i
= 70 ± 5°, position angle PA = −50 ± 4°, and
h
/
r
< 0.14, which we associate with the dust sublimation region. The observed morphology is inconsistent with the expected signatures of a geometrically and optically thick torus. Instead, the infrared emission shows a striking resemblance to the 22 GHz maser disc, which suggests they share a common region of origin. The near-infrared spectral energy distribution indicates a bolometric luminosity of (0.4–4.7) × 10
45
erg s
−1
, behind a large
A
K
≈ 5.5 (
A
V
≈ 90) screen of extinction that also appears to contribute significantly to obscuring the broad line region.
We use VLTI/GRAVITY near-infrared interferometry measurements of eight bright type 1 AGN to study the size and structure of hot dust that is heated by the central engine. We partially resolve each ...source, and report Gaussian full width at half-maximum sizes in the range 0.3−0.8 mas. In all but one object, we find no evidence for significant elongation or asymmetry (closure phases ≲1°). The narrow range of measured angular sizes is expected given the similar optical flux of our targets, and implies an increasing effective physical radius with bolometric luminosity, as found from previous reverberation and interferometry measurements. The measured sizes for Seyfert galaxies are systematically larger than for the two quasars in our sample when measured relative to the previously reported
R
∼
L
1/2
relationship, which is explained by emission at the sublimation radius. This could be evidence of an evolving near-infrared emission region structure as a function of central luminosity.
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