2,876 research outputs found
Infinite Divisibility in Euclidean Quantum Mechanics
In simple -- but selected -- quantum systems, the probability distribution
determined by the ground state wave function is infinitely divisible. Like all
simple quantum systems, the Euclidean temporal extension leads to a system that
involves a stochastic variable and which can be characterized by a probability
distribution on continuous paths. The restriction of the latter distribution to
sharp time expectations recovers the infinitely divisible behavior of the
ground state probability distribution, and the question is raised whether or
not the temporally extended probability distribution retains the property of
being infinitely divisible. A similar question extended to a quantum field
theory relates to whether or not such systems would have nontrivial scattering
behavior.Comment: 17 pages, no figure
Effect of chemical structure on the efficiency of shrinkage reducing admixtures in alkali activated systems
Alkali activated binders, especially those based on alkali activated blast furnace slag (AAS), have the potential to become an alternative construction material to ordinary Portland cement binders. Nevertheless, AAS has some disadvantages which prevent its broader practical applications. An extensive shrinkage is one of the main limiting factors. Therefore, the study of chemical admixtures mitigating especially the drying shrinkage is necessary to be performed. The efficiency of suitable shrinkage reducing admixtures depends on the chemical structure of used surfactants. The study is consequently focused on the molecular architecture of amino alcohol surfactants which are closely associated with their ability to effectively reduce shrinkage. The molecular structure of used chemical compounds is shown in Figure 1. The influence of different substituents bounded to the secondary amine group was studied in terms of their effect on alkali activation, mechanical properties, microstructure arrangement and in particular on the enhancement of drying shrinkage reduction. It was determined that the addition of any tested admixture delayed the CASH gel formation which negatively influenced the flexural as well as compressive strengths in the early stages of hydration process (1 – 7 days). However, only slight decrease in strengths compared to reference sample was measured after 28 days of curing. The deeper insight into the microstructure (Figure 2) confirms previous results. It is obvious that in the case of reference sample the consistent matrix of binding phase is created after 24 hours. On the other hand, only thin layer of hydration products is formed in samples containing the admixture, which increases the porosity of material and tends to the deterioration of mechanical properties. Finally, the study confirms that the reduction of surface tension in pore solution occurs primarily with admixtures containing branched substituents, which further decreases the capillary tension responsible for the shrinkage according to Young-Laplace equation. The presented study highlights the essential role of molecular structure of shrinkage reducing admixtures contributing to the development of a new range of additives designed especially for alkali activated materials.
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Impact of type 2 diabetes on life expectancy and role of kidney disease among inpatients with heart failure in Switzerland: an ambispective cohort study.
BACKGROUND
Type 2 diabetes (T2D) is expected to worsen the prognosis of inpatients with heart failure (HF) but the evidence from observational studies is inconsistent. We aimed to compare mortality outcomes and life expectancy among inpatients with HF with or without T2D and explored whether chronic kidney disease (CKD) influenced these associations.
METHODS
We collected hospital and civil registry records of consecutive inpatients from a tertiary hospital in Switzerland with a diagnosis of HF from the year 2015 to 2019. We evaluated the association of T2D with mortality risk using Cox regression and adjusted for confounders.
RESULTS
Our final cohort consisted of 10,532 patients with HF of whom 27% had T2D. The median age (interquartile range [IQR]) was 75 [68 to 82] and 78 [68 to 86] for the diabetes and non-diabetes groups, respectively. Over a median follow-up [IQR] of 4.5Â years [3.3 to 5.6], 5,347 (51%) of patients died. T2D patients had higher risk of all-cause mortality (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.14 to 1.29). Compared to control (i.e. no T2D nor CKD), average life expectancy (95% CI) among T2D patients, CKD, or both was shorter by 5.4Â months (95% CI 1.1 to 9.7), 9.0Â months (95% CI 8.4 to 9.6), or 14.8Â months (95% CI 12.4 to 17.2), respectively. No difference by sex or ejection fraction category was observed.
CONCLUSIONS
T2D is associated with a significantly higher risk of all-cause mortality and shorter life expectancy compared to those without among middle-aged and elderly inpatients with HF; presence of CKD may further increase these risks
FATIMA Czech pilot
In FATIMA project, a pilot site in Czechia was established to demonstrate how precision agriculture may serve for optimizing crop yields as well as for protection of water quality, since the pilot is located in Czech largest drinking water reservoir catchment. The pilot site Dehtáře is situated in the south-west Bohemo-Moravian Highland. The site contains tile drainage and is of very heterogeneous soil conditions; from shallow, light and stony Haplic Cambisols to heavy Haplic Gleysols, with profoundly different water regimes. For the field trial (spring barley in 2016), crop yield potential was determined from crop statuses as captured by satellite images) eight years back, assessed by Enhanced Vegetation Index. Based on this, as well as on a detailed soil survey and repeated soil sampling, variable fertilizer application zones (70 – 120%) were delineated and mineral fertilizers distributed accordingly with GPS operated spreader three times from late April to late May. The rest of the site was fertilized uniformly. Soil water regime (soil moisture, soil water potential) was monitored continuously on eight spots and real-time broadcasted by wireless sensor network to WEB GIS interface via SensLog solution, adopted from FOODIE project. In the same spots, soil water was sampled by gravitational soil lysimeters. Precise harvest showed a general agreement with the delineated application zones and yield potential, however, some ambiguities were revealed, most probably due to changeable soil water regime, as documented by the sensors, as well as due to variable soil chemical properties (low soil pH). Nevertheless, precisely applied fertilizer doses in the application zones brought about 10% higher crop yields with simultaneous better N crop efficiency. Soil water quality samples confirmed that heterogeneous doses of fertilizer in correctly delineated zones is a promising approach for improvement of groundwater quality especially in shallow soils with low water and nutrient retention abilit
Reconstruction of three-dimensional porous media using generative adversarial neural networks
To evaluate the variability of multi-phase flow properties of porous media at
the pore scale, it is necessary to acquire a number of representative samples
of the void-solid structure. While modern x-ray computer tomography has made it
possible to extract three-dimensional images of the pore space, assessment of
the variability in the inherent material properties is often experimentally not
feasible. We present a novel method to reconstruct the solid-void structure of
porous media by applying a generative neural network that allows an implicit
description of the probability distribution represented by three-dimensional
image datasets. We show, by using an adversarial learning approach for neural
networks, that this method of unsupervised learning is able to generate
representative samples of porous media that honor their statistics. We
successfully compare measures of pore morphology, such as the Euler
characteristic, two-point statistics and directional single-phase permeability
of synthetic realizations with the calculated properties of a bead pack, Berea
sandstone, and Ketton limestone. Results show that GANs can be used to
reconstruct high-resolution three-dimensional images of porous media at
different scales that are representative of the morphology of the images used
to train the neural network. The fully convolutional nature of the trained
neural network allows the generation of large samples while maintaining
computational efficiency. Compared to classical stochastic methods of image
reconstruction, the implicit representation of the learned data distribution
can be stored and reused to generate multiple realizations of the pore
structure very rapidly.Comment: 21 pages, 20 figure
Ectoplasm with an Edge
The construction of supersymmetric invariant actions on a spacetime manifold
with a boundary is carried out using the "ectoplasm" formalism for the
construction of closed forms in superspace. Non-trivial actions are obtained
from the pull-backs to the bosonic bodies of closed but non-exact forms in
superspace; finding supersymmetric invariants thus becomes a cohomology
problem. For a spacetime with a boundary, the appropriate mathematical language
changes to relative cohomology, which we use to give a general formulation of
off-shell supersymmetric invariants in the presence of boundaries. We also
relate this construction to the superembedding formalism for the construction
of brane actions, and we give examples with bulk spacetimes of dimension 3, 4
and 5. The closed superform in the 5D example needs to be constructed as a
Chern-Simons type of invariant, obtained from a closed 6-form displaying Weil
triviality.Comment: 25 page
Primordial perturbations in a non singular bouncing universe model
We construct a simple non singular cosmological model in which the currently
observed expansion phase was preceded by a contraction. This is achieved, in
the framework of pure general relativity, by means of a radiation fluid and a
free scalar field having negative energy. We calculate the power spectrum of
the scalar perturbations that are produced in such a bouncing model and find
that, under the assumption of initial vacuum state for the quantum field
associated with the hydrodynamical perturbation, this leads to a spectral index
n=-1. The matching conditions applying to this bouncing model are derived and
shown to be different from those in the case of a sharp transition. We find
that if our bounce transition can be smoothly connected to a slowly contracting
phase, then the resulting power spectrum will be scale invariant.Comment: 11 pages, RevTeX 4, 8 figures, submitted to Phys. Rev.
Big Data in Agriculture – From FOODIE towards data bio
What’s the role of Big Data in the farming ecosystem? Farmers need to measure and understand the impact of a huge amount and variety of data which drive overall quality and yield of their fields. Among those are local weather data, GPS data, ortophotos, satellite imagery, soil specifics, soil conductivity, seed, fertilizer and crop protectant specifications and many more. Being able to leverage this data for running long and short term simulations in response to “events” like changed weather, market need or other parameters is indispensable for farmers in terms of maximizing their profits. IoT (Internet of Technology) including field sensors and machinery monitoring. The experimentation in FarmTelemetry project demonstrates that one average Czech farm (i.e. around 1’000 hectares) could generate daily 20 MegaBytes of data. This could be only for Czech Republic something between 30 and 50 GB per one day. We may easily reach Terabytes of data a day from agricultural basic monitoring by sensors in Europe. Together with satellite data agriculture will need to manage extremely large amount of data. On one side there is growing whole ecosystem with a strong need to secure Big Data from different repositories and heterogeneous sources. In some cases, sharing of data could be common interest, but on other side, there are also different interests and data could help to one part of value chain to take bigger part of profit. From this reason Big data are sensitive topics and trusting of producers about data security is essential. The producers of seeds and chemicals want to maximize their business with farmers. Our team stated implementation of Big Data technologies in frame of European 7FP project FOODIE. This work currently the work continue as part of DataBio project
Closed String Field Theory with Dynamical D-brane
We consider a closed string field theory with an arbitrary matter current as
a source of the closed string field. We find that the source must satisfy a
constraint equation as a consequence of the BRST invariance of the theory. We
see that it corresponds to the covariant conservation law for the matter
current, and the equation of motion together with this constraint equation
determines the classical behavior of both the closed string field and the
matter. We then consider the boundary state (D-brane) as an example of a
source. We see that the ordinary boundary state cannot be a source of the
closed string field when the string coupling g turns on. By perturbative
expansion, we derive a recursion relation which represents the bulk
backreaction and the D-brane recoil. We also make a comment on the rolling
tachyon boundary state.Comment: 30 pages, LaTeX2e, no figures. Typos are correcte
The specificity and patterns of staining in human cells and tissues of p16INK4a antibodies demonstrate variant antigen binding
The validity of the identification and classification of human cancer using antibodies to detect biomarker proteins depends upon antibody specificity. Antibodies that bind to the tumour-suppressor protein p16INK4a are widely used for cancer diagnosis and research. In this study we examined the specificity of four commercially available anti-p16INK4a antibodies in four immunological applications. The antibodies H-156 and JC8 detected the same 16 kDa protein in western blot and immunoprecipitation tests, whereas the antibody F-12 did not detect any protein in western blot analysis or capture a protein that could be recognised by the H-156 antibody. In immunocytochemistry tests, the antibodies JC8 and H-156 detected a predominately cytoplasmic localised antigen, whose signal was depleted in p16INK4a siRNA experiments. F-12, in contrast, detected a predominately nuclear located antigen and there was no noticeable reduction in this signal after siRNA knockdown. Furthermore in immunohistochemistry tests, F-12 generated a different pattern of staining compared to the JC8 and E6H4 antibodies. These results demonstrate that three out of four commercially available p16INK4a antibodies are specific to, and indicate a mainly cytoplasmic localisation for, the p16INK4a protein. The F-12 antibody, which has been widely used in previous studies, gave different results to the other antibodies and did not demonstrate specificity to human p16INK4a. This work emphasizes the importance of the validation of commercial antibodies, aside to the previously reported use, for the full verification of immunoreaction specificity
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