46 research outputs found
Novel photon detectors
The paper reviews recent progress in photodetectors, discussing vacuum-based
detectors, semiconductor sensors, and gas-based detectors. The emphasis in this
review is on the detection of low light levels, enhanced timing resolution, and
spectral range of photon detectors, as well as the development of photosensors
for extreme conditions, for operation in cryogenic and high radiation-level
environments
The Belle II Upgrade Program
The Belle II detector at the SuperKEKB accelerator complex is covering a wide
range of exciting physics topics. To achieve the project's research goals, a
substantial increase of the data sample to 50~ab is needed, and for
that, the luminosity has to reach the ambitious goal of
cm s. The progress towards the design luminosity is accompanied
by research and development of the accelerator, detector components, operation
methods, as well as their upgrades. In the present contribution, we will
discuss the status and plans of the project, timescales for upgrades, their
motivations, and opportunities, an overview of upgrade options, and finish with
an outlook and perspectives
Uropathogenic Escherichia coli Induces Serum Amyloid A in Mice following Urinary Tract and Systemic Inoculation
Serum amyloid A (SAA) is an acute phase protein involved in the homeostasis of inflammatory responses and appears to be a vital host defense component with protective anti-infective properties. SAA expression remains poorly defined in many tissues, including the urinary tract which often faces bacterial challenge. Urinary tract infections (UTIs) are usually caused by strains of uropathogenic Escherichia coli (UPEC) and frequently occur among otherwise healthy individuals, many of whom experience bouts of recurrent and relapsing infections despite the use of antibiotics. To date, whether SAA is present in the infected urothelium and whether or not the induction of SAA can protect the host against UPEC is unclear. Here we show, using mouse models coupled with immunofluorescence microscopy and quantitative RT-PCR, that delivery of UPEC either directly into the urinary tract via catheterization or systemically via intraperitoneal injection triggers the expression of SAA. As measured by ELISA, serum levels of SAA1/2 were also transiently elevated in response to UTI, but circulating SAA3 levels were only up-regulated substantially following intraperitoneal inoculation of UPEC. In in vitro assays, physiological relevant levels of SAA1/2 did not affect the growth or viability of UPEC, but were able to block biofilm formation by the uropathogens. We suggest that SAA functions as a critical host defense against UTIs, preventing the formation of biofilms both upon and within the urothelium and possibly providing clinicians with a sensitive serological marker for UTI
Evidence of and search for double-charmonium production in and decays
Using data samples of and
events collected with the Belle detector, a first experimental
search has been made for double-charmonium production in the exclusive decays
, where , , , , and . No significant signal is
observed in the spectra of the mass recoiling against the reconstructed
or except for the evidence of production with a
significance of for . The
measured branching fraction \BR(\Upsilon(1S)\rightarrow J/\psi+\chi_{c1}) is
. The
confidence level upper limits on the branching fractions of the other modes
having a significance of less than are determined. These results are
consistent with theoretical calculations using the nonrelativistic QCD
factorization approach.Comment: 12 pages, 4 figures, 1 table. The fit range was extended to include
X(4160) signal according to referee's suggestions. Other results unchanged.
Paper was accepted for publication as a regular article in Physical Review
Relativistic Brownian Motion
Stimulated by experimental progress in high energy physics and astrophysics,
the unification of relativistic and stochastic concepts has re-attracted
considerable interest during the past decade. Focusing on the framework of
special relativity, we review, here, recent progress in the phenomenological
description of relativistic diffusion processes. After a brief historical
overview, we will summarize basic concepts from the Langevin theory of
nonrelativistic Brownian motions and discuss relevant aspects of relativistic
equilibrium thermostatistics. The introductory parts are followed by a detailed
discussion of relativistic Langevin equations in phase space. We address the
choice of time parameters, discretization rules, relativistic
fluctuation-dissipation theorems, and Lorentz transformations of stochastic
differential equations. The general theory is illustrated through analytical
and numerical results for the diffusion of free relativistic Brownian
particles. Subsequently, we discuss how Langevin-type equations can be obtained
as approximations to microscopic models. The final part of the article is
dedicated to relativistic diffusion processes in Minkowski spacetime. Due to
the finiteness of velocities in relativity, nontrivial relativistic Markov
processes in spacetime do not exist; i.e., relativistic generalizations of the
nonrelativistic diffusion equation and its Gaussian solutions must necessarily
be non-Markovian. We compare different proposals that were made in the
literature and discuss their respective benefits and drawbacks. The review
concludes with a summary of open questions, which may serve as a starting point
for future investigations and extensions of the theory.Comment: review article, 159 pages, references updated, misprints corrected,
App. A.4. correcte
The QCD transition temperature: results with physical masses in the continuum limit II.
We extend our previous study [Phys. Lett. B643 (2006) 46] of the cross-over
temperatures (T_c) of QCD. We improve our zero temperature analysis by using
physical quark masses and finer lattices. In addition to the kaon decay
constant used for scale setting we determine four quantities (masses of the
\Omega baryon, K^*(892) and \phi(1020) mesons and the pion decay constant)
which are found to agree with experiment. This implies that --independently of
which of these quantities is used to set the overall scale-- the same results
are obtained within a few percent. At finite temperature we use finer lattices
down to a <= 0.1 fm (N_t=12 and N_t=16 at one point). Our new results confirm
completely our previous findings. We compare the results with those of the
'hotQCD' collaboration.Comment: 19 pages, 8 figures, 3 table
Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults
Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We
estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from
1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.
Methods We used data from 3663 population-based studies with 222 million participants that measured height and
weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate
trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children
and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the
individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference)
and obesity (BMI >2 SD above the median).
Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in
11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed
changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and
140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of
underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and
countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior
probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse
was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of
thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a
posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%)
with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and
obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for
both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such
as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged
children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls
in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and
42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents,
the increases in double burden were driven by increases in obesity, and decreases in double burden by declining
underweight or thinness.
Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an
increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy
nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of
underweight while curbing and reversing the increase in obesit
The Densification Process of Wood Waste
This book examines the very current issue of wood waste treatment to a solid biofuel for energy recovery. The book is dedicated to research in the densification processes of wood waste and its mathematical description for uniaxial densification into compact biofuels – briquettes.This monograph, derived from an experimental research of densification process in laboratory conditions and also in real technologies in practice, provides a thorough understanding of the influencing parameters impact during densification of wood waste into solid biofuel. The book shows the experimental strategy to determine the effects of individual parameters and specifies their impact on the resulting density of the briquettes. The publication also defines the level of importance of the results in terms of optimization of the densification machine’s pressing chamber. Using a designed mathematical model, which was a result of experimental research and which can serve to predict the density of briquettes for some predefined densification conditions and can aid in the design of densification machines, the author has made this topic accessible beyond his discipline, biofuels producers and the academic community