We describe the construction of the complete four-loop four-particle amplitude of N=8 supergravity. The amplitude is ultraviolet finite, not only in four dimensions, but in five dimensions as well. ...The observed extra cancellations provide additional nontrivial evidence that N=8 supergravity in four dimensions may be ultraviolet finite to all orders of perturbation theory.
This article used a CDM three-stage structural model based on data from the Spanish technological innovation panel to analyse the differential impact of technological innovation on labour ...productivity in the three largest Spanish regions and the Spanish economy as a whole. Although a considerable number of studies have used national data to analyse this relationship, very few studies have done so using microdata at the regional level. The results suggest that in Andalusia and Madrid increases in labour productivity were only associated with the increased probability of product innovation, whereas in Catalonia they were only associated with process innovation. These results suggest a lack of convergence in business strategies to improve labour productivity in these regions. Therefore, business investment in R&D and public institution funding decisions on support for technological innovation should be aimed at improving these less effective innovation strategies for increasing labour productivity.
The study of the preparation phase of large earthquakes is essential to understand the physical processes involved, and potentially useful also to develop a future reliable short-term warning system. ...Here we analyse electron density and magnetic field data measured by Swarm three-satellite constellation for 4.7 years, to look for possible in-situ ionospheric precursors of large earthquakes to study the interactions between the lithosphere and the above atmosphere and ionosphere, in what is called the Lithosphere-Atmosphere-Ionosphere Coupling (LAIC). We define these anomalies statistically in the whole space-time interval of interest and use a Worldwide Statistical Correlation (WSC) analysis through a superposed epoch approach to study the possible relation with the earthquakes. We find some clear concentrations of electron density and magnetic anomalies from more than two months to some days before the earthquake occurrences. Such anomaly clustering is, in general, statistically significant with respect to homogeneous random simulations, supporting a LAIC during the preparation phase of earthquakes. By investigating different earthquake magnitude ranges, not only do we confirm the well-known Rikitake empirical law between ionospheric anomaly precursor time and earthquake magnitude, but we also give more reliability to the seismic source origin for many of the identified anomalies.
Background:
Heart failure has high mortality and is linked to substantial burden for patients, carers and health care systems. Patients with chronic heart failure frequently experience recurrent ...hospitalisations peaking at the end of life, but most prefer to avoid hospital. The drivers of hospitalisations are not well understood.
Aim:
We aimed to synthesise the evidence on factors associated with all-cause and heart failure hospitalisations of patients with advanced chronic heart failure.
Design:
Systematic review of studies quantitatively evaluating factors associated with all-cause or heart failure hospitalisations in adult patients with advanced chronic heart failure.
Data sources:
Five electronic databases were searched from inception to September 2020. Additionally, searches for grey literature, citation searching and hand-searching were performed. We assessed the quality of individual studies using the QualSyst tool. Strength of evidence was determined weighing number, quality and consistency of studies. Findings are reported narratively as pooling was not deemed feasible.
Results:
In 54 articles, 68 individual, illness-level, service-level and environmental factors were identified. We found high/moderate strength evidence for specialist palliative or hospice care being associated with reduced risk of all-cause and heart failure hospitalisations, respectively. Based on high strength evidence, we further identified black/non-white ethnicity as a risk factor for all-cause hospitalisations.
Conclusion:
Efforts to integrate hospice and specialist palliative services into care may reduce avoidable hospitalisations in advanced heart failure. Inequalities in end-of-life care in terms of race/ethnicity should be addressed. Further research should investigate the causality of the relationships identified here.
Abstract
We present ultraviolet (UV), optical and infrared photometry and optical spectroscopy of the type Ic superluminous supernova (SLSN) Gaia16apd (=SN 2016eay), covering its evolution from 26 d ...before the g-band peak to 234.1 d after the peak. Gaia16apd was followed as a part of the NOT Unbiased Transient Survey (NUTS). It is one of the closest SLSNe known (z = 0.102 ± 0.001), with detailed optical and UV observations covering the peak. Gaia16apd is a spectroscopically typical type Ic SLSN, exhibiting the characteristic blue early spectra with O ii absorption, and reaches a peak Mg = −21.8 ± 0.1 mag. However, photometrically it exhibits an evolution intermediate between the fast and slowly declining type Ic SLSNe, with an early evolution closer to the fast-declining events. Together with LSQ12dlf, another SLSN with similar properties, it demonstrates a possible continuum between fast and slowly declining events. It is unusually UV-bright even for an SLSN, reaching a non-K-corrected Muvm2 ≃ −23.3 mag, the only other type Ic SLSN with similar UV brightness being SN 2010gx. Assuming that Gaia16apd was powered by magnetar spin-down, we derive a period of P = 1.9 ± 0.2 ms and a magnetic field of B = 1.9 ± 0.2 × 1014 G for the magnetar. The estimated ejecta mass is between 8 and 16 M⊙, and the kinetic energy between 1.3 and 2.5 × 1052 erg, depending on opacity and assuming that the entire ejecta is swept up into a thin shell. Despite the early photometric differences, the spectra at late times are similar to slowly declining type Ic SLSNe, implying that the two subclasses originate from similar progenitors.
Analysis of genetic polymorphism is a powerful tool for epidemiological surveillance and research. Powerful inference from pathogen genetic variation, however, is often restrained by limited access ...to representative target DNA, especially in the study of obligate parasitic species for which ex vivo culture is resource-intensive or bias-prone. Modern sequence capture methods enable pathogen genetic variation to be analyzed directly from host/vector material but are often too complex and expensive for resource-poor settings where infectious diseases prevail. This study proposes a simple, cost-effective 'genome-wide locus sequence typing' (GLST) tool based on massive parallel amplification of information hotspots throughout the target pathogen genome. The multiplexed polymerase chain reaction amplifies hundreds of different, user-defined genetic targets in a single reaction tube, and subsequent agarose gel-based clean-up and barcoding completes library preparation at under 4 USD per sample. Our study generates a flexible GLST primer panel design workflow for Trypanosoma cruzi, the parasitic agent of Chagas disease. We successfully apply our 203-target GLST panel to direct, culture-free metagenomic extracts from triatomine vectors containing a minimum of 3.69 pg/μl T. cruzi DNA and further elaborate on method performance by sequencing GLST libraries from T. cruzi reference clones representing discrete typing units (DTUs) TcI, TcIII, TcIV, TcV and TcVI. The 780 SNP sites we identify in the sample set repeatably distinguish parasites infecting sympatric vectors and detect correlations between genetic and geographic distances at regional (< 150 km) as well as continental scales. The markers also clearly separate TcI, TcIII, TcIV and TcV + TcVI and appear to distinguish multiclonal infections within TcI. We discuss the advantages, limitations and prospects of our method across a spectrum of epidemiological research.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary
Vascular malformations classification may pose a diagnostic challenge for physicians. In the early stages, they are diagnosed clinically mainly by visual inspection. For a deeper analysis, ...Doppler ultrasonography is the preferred technique to determine the haemodynamic behaviour of the anomaly. However, this imaging method is not always available and it requires trained operators to acquire and interpret the images. There is a lack of portable and user‐friendly systems that may help physicians in the assessment of vascular malformations. We propose a new diagnostic procedure, more affordable and easier to use, based on a portable thermal camera. This technique provides information about temperature, which has been found to be correlated with the flow rate of the lesion. In our study, > 60 vascular malformations of previously diagnosed patients were analysed with a thermal camera to classify them into low‐flow and high‐flow malformations. The value was 1 for both sensitivity and specificity of this technique.
Context.
The full third
Gaia
data release will provide, for the first time, the calibrated spectra obtained with the blue and red
Gaia
slitless spectrophotometers (BP and RP, respectively).
Gaia
is a ...very complex mission and cannot be considered as a single instrument, but rather as many instruments. The two lines of sight with wide fields of view introduce strong variations of the observations across the large focal plane with more than one hundred different detectors. The main challenge when facing
Gaia
spectral calibration is that no lamp spectra or flat fields are available during the mission. Also, the significant size of the line spread function with respect to the dispersion of the prisms produces alien photons contaminating neighbouring positions of the spectra. This makes the calibration special and different from standard approaches.
Aims.
This work gives a detailed description of the internal calibration model for the spectrophotometric data used to obtain the content of the
Gaia
catalogue. The main purpose of the internal calibration is to bring all the epoch spectra onto a common flux and pixel (pseudo-wavelength) scale, taking into account variations over the focal plane and with time, producing a mean spectrum from all the observations of the same source.
Methods.
In order to describe all observations on a common mean flux and pseudo-wavelength scale, we constructed a suitable representation of the internally calibrated mean spectra via basis functions, and we described the transformation between non-calibrated epoch spectra and calibrated mean spectra via a discrete convolution, parametrising the convolution kernel to recover the relevant coefficients.
Results.
The model proposed here for the internal calibration of the
Gaia
spectrophotometric observations is able to combine all observations into a mean instrument to allow the comparison of different sources and observations obtained with different instrumental conditions along the mission and the generation of mean spectra from a number of observations of the same source. We derived a calibration model that can handle the self-calibrating nature of the problem. The output of this model provides the internal mean spectra, not as a sampled function (flux and wavelength), but as a linear combination of basis functions, although sampled spectra can easily be derived from them.
•Mechanical performance and durability of OPC/flax nonwovens composites for façade pieces is explored.•The effect of two pozzolanic additions combined with nonwoven treatment is ...evaluated.•Significant improvements in the durability using treated nonwovens.
This experimental research analyzes the mechanical performance and durability of façade pieces based on Portland cement matrix and flax nonwovens as reinforcement. Two types of pozzolanic additions (silica fume and metakaolin) combined with nonwovens subjected to different treatments to decrease their water absorption are analyzed as potential materials for fiber-cement sheets for building envelopes with high strength and durability. For this purpose, on the one hand, the mechanical performance and chemical composition of various ternary compositions were studied. On the other hand, various treatments were performed on the nonwovens and the nonwoven–matrix adherence was also analyzed. Finally, composites were prepared from some selected treated nonwovens and matrix mixtures, and their mechanical properties and durability were evaluated under four-point bending tests after 28days of curing in a humidity chamber and after accelerated aging. The composites developed with the treated nonwovens presented very high performance combined with enough durability to be potential candidates for the development of sustainable materials for building envelopes.
Gaia Data Release 2 Evans, D. W.; Riello, M.; De Angeli, F. ...
Astronomy and astrophysics (Berlin),
08/2018, Letnik:
616
Journal Article
Recenzirano
Odprti dostop
Aims.
We describe the photometric content of the second data release of the
Gaia
project (
Gaia
DR2) and its validation along with the quality of the data.
Methods.
The validation was mainly carried ...out using an internal analysis of the photometry. External comparisons were also made, but were limited by the precision and systematics that may be present in the external catalogues used.
Results.
In addition to the photometric quality assessment, we present the best estimates of the three photometric passbands. Various colour-colour transformations are also derived to enable the users to convert between the
Gaia
and commonly used passbands.
Conclusions.
The internal analysis of the data shows that the photometric calibrations can reach a precision as low as 2 mmag on individual CCD measurements. Other tests show that systematic effects are present in the data at the 10 mmag level.
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