The search for the lepton flavor violating decay
μ
+
→
e
+
γ
will reach an unprecedented level of sensitivity within the next five years thanks to the MEG-II experiment. This experiment will take ...data at the Paul Scherrer Institut where continuous muon beams are delivered at a rate of about
10
8
muons per second. On the same time scale, accelerator upgrades are expected in various facilities, making it feasible to have continuous beams with an intensity of
10
9
or even
10
10
muons per second. We investigate the experimental limiting factors that will define the ultimate performances, and hence the sensitivity, in the search for
μ
+
→
e
+
γ
with a continuous beam at these extremely high rates. We then consider some conceptual detector designs and evaluate the corresponding sensitivity as a function of the beam intensity.
The confining color field in SU(3) gauge theory Baker, M.; Cea, P.; Chelnokov, V. ...
The European physical journal. C, Particles and fields,
06/2020, Letnik:
80, Številka:
6
Journal Article
Recenzirano
Odprti dostop
We extend a previous numerical study of SU(3) Yang–Mills theory in which we measured the spatial distribution of all components of the color fields surrounding a static quark–antiquark pair and ...provided evidence that the simulated gauge invariant chromoelectric field can be separated into a Coulomb-like ‘perturbative’ field and a ‘non-perturbative’ confining field. In this paper we hypothesize that the fluctuating color fields not measured in our simulations do not contribute to the string tension. Under this assumption the string tension is determined by the color fields we measure, which form a field strength tensor pointing in a single direction in color space. We call this the ‘Maxwell picture of confinement’. We provide an additional procedure to isolate the confining field. We then extract the string tension from a stress energy-momentum tensor having the Maxwell form, constructed from the simulated non-perturbative part of the field strength tensor. To test our hypothesis we calculate the string tension for values of the quark–antiquark separation ranging from 0.37 fm to 1.2 fm. We also calculate the spatial distributions of the energy-momentum tensor surrounding static quarks for this range of separations, and we compare with the distributions obtained from direct simulations of the energy-momentum tensor.
Rapidly rotating neutron stars are promising sources of continuous gravitational wave radiation for the LIGO and Virgo interferometers. The majority of neutron stars in our galaxy have not been ...identified with electromagnetic observations. All-sky searches for isolated neutron stars offer the potential to detect gravitational waves from these unidentified sources. The parameter space of these blind all-sky searches, which also cover a large range of frequencies and frequency derivatives, presents a significant computational challenge. Different methods have been designed to perform these searches within acceptable computational limits. Here we describe the first benchmark in a project to compare the search methods currently available for the detection of unknown isolated neutron stars. The five methods compared here are individually referred to as the PowerFlux, sky Hough, frequency Hough, Einstein@Home, and time domain F-statistic methods. We employ a mock data challenge to compare the ability of each search method to recover signals simulated assuming a standard signal model. We find similar performance among the four quick-look search methods, while the more computationally intensive search method, Einstein@Home, achieves up to a factor of two higher sensitivity. We find that the absence of a second derivative frequency in the search parameter space does not degrade search sensitivity for signals with physically plausible second derivative frequencies. We also report on the parameter estimation accuracy of each search method, and the stability of the sensitivity in frequency and frequency derivative and in the presence of detector noise.
We report results of the most sensitive search to date for periodic gravitational waves from Cassiopeia A, Vela Jr., and G347.3 with frequency between 20 and 1500 Hz. The search was made possible by ...the computing power provided by the volunteers of the Einstein@Home project and improves on previous results by a factor of 2 across the entire frequency range for all targets. We find no significant signal candidate and set the most stringent upper limits to date on the amplitude of gravitational wave signals from the target population, corresponding to sensitivity depths between 54 1/Hz and 83 1/Hz, depending on the target and the frequency range. At the frequency of best strain sensitivity, near 172 Hz, we set 90% confidence upper limits on the gravitational wave intrinsic amplitude of h090%≈10−25, probing ellipticity values for Vela Jr. as low as 3×10−8, assuming a distance of 200 pc.
Crimean–Congo haemorrhagic fever (CCHF) is an acute febrile illness, often accompanied by haemorrhagic manifestations, with a high case fatality rate (CFR). The causative agent is CCHF virus (CCHFV), ...and is transmitted to humans mainly through tick bites or exposure to blood or tissues of viraemic patients or livestock. Human-to-human transmission usually occurs in hospital settings, and healthcare workers (HCWs) are mainly affected. A review on nosocomial CCHFV infections was performed to elucidate the routes and circumstances of CCHFV transmission in hospital settings.
From 1953 to 2016, 158 published cases of CCHFV nosocomial infection in 20 countries in Africa, Asia and Europe were found. Almost all cases were symptomatic (92.4%), with an overall CFR of 32.4%. The majority of cases occurred in hospital clinics (92.0%) and 10 cases (8.0%) occurred in laboratories. Most cases occurred among HCWs (86.1%), followed by visitors (12.7%) and hospitalized patients (1.3%). Nursing staff (44.9%) and doctors (32.3%) were the most affected HCWs, followed by laboratory staff (6.3%). The primary transmission route was percutaneous contact (34.3%). Cutaneous contact accounted for 22.2% of cases, followed by exposure to aerosols (proximity) (18.2%), indirect contact (17.2%) and exposure to patient environment (8.1%).
CCHFV can cause nosocomial infections with a high CFR. During the care and treatment of patients with CCHF, standard contact precautions, barrier precautions and airborne preventive measures should be applied. In order to improve patient safety and reduce healthcare-associated CCHFV exposure, there is a need for guidelines and education for HCWs to ensure that CCHF is appropriately included in differential diagnoses; this will enable early diagnosis and implementation of infection prevention measures.
Abstract
We conduct searches for continuous gravitational waves from seven pulsars that have not been targeted in continuous wave searches of Advanced LIGO data before. We target emission at exactly ...twice the rotation frequency of the pulsars and in a small band around such a frequency. The former search assumes that the gravitational-wave quadrupole is changing in a phase-locked manner with the rotation of the pulsar. The latter search over a range of frequencies allows for differential rotation between the component emitting the radio signal and the component emitting the gravitational waves, for example the crust or magnetosphere versus the core. Timing solutions derived from the Arecibo 327 MHz Drift-Scan Pulsar Survey observations are used. No evidence of a signal is found and upper limits are set on the gravitational-wave amplitude. For one of the pulsars we probe gravitational-wave intrinsic amplitudes just a factor of 3.8 higher than the spin-down limit, assuming a canonical moment of inertia of 10
38
kg m
2
. Our tightest ellipticity constraint is 1.5 × 10
−8
, which is a value well within the range of what a neutron star crust could support.
In this paper, we introduce a generalized inexact scalarized proximal point algorithm to find Pareto-Clarke critical points and Pareto efficient solutions of quasiconvex multivalued functions defined ...on Hadamard manifolds considering vectorial and scalar errors to find a critical point of the regularized proximal function in each iteration. Under some assumptions on the problem, we obtain the global convergence of the sequence to a Pareto-Clarke critical point and assuming an extra condition on the proximal parameters we establish convergence to a Pareto efficient solution, approximately linear/superlinear rate of convergence and finite termination of the algorithm. In the convex case, we prove the convergence to a Pareto efficient solution point (more than a weak Pareto efficient solution point). The results of the paper are new even in the Euclidean space.
A very large biomass of intact asexual-stage malaria parasites accumulates in the spleen of asymptomatic human individuals infected with Plasmodium vivax. The mechanisms underlying this intense ...tropism are not clear. We hypothesised that immature reticulocytes, in which P. vivax develops, may display high densities in the spleen, thereby providing a niche for parasite survival.
We examined spleen tissue in 22 mostly untreated individuals naturally exposed to P. vivax and Plasmodium falciparum undergoing splenectomy for any clinical indication in malaria-endemic Papua, Indonesia (2015 to 2017). Infection, parasite and immature reticulocyte density, and splenic distribution were analysed by optical microscopy, flow cytometry, and molecular assays. Nine non-endemic control spleens from individuals undergoing spleno-pancreatectomy in France (2017 to 2020) were also examined for reticulocyte densities. There were no exclusion criteria or sample size considerations in both patient cohorts for this demanding approach. In Indonesia, 95.5% (21/22) of splenectomy patients had asymptomatic splenic Plasmodium infection (7 P. vivax, 13 P. falciparum, and 1 mixed infection). Significant splenic accumulation of immature CD71 intermediate- and high-expressing reticulocytes was seen, with concentrations 11 times greater than in peripheral blood. Accordingly, in France, reticulocyte concentrations in the splenic effluent were higher than in peripheral blood. Greater rigidity of reticulocytes in splenic than in peripheral blood, and their higher densities in splenic cords both suggest a mechanical retention process. Asexual-stage P. vivax-infected erythrocytes of all developmental stages accumulated in the spleen, with non-phagocytosed parasite densities 3,590 times (IQR: 2,600 to 4,130) higher than in circulating blood, and median total splenic parasite loads 81 (IQR: 14 to 205) times greater, accounting for 98.7% (IQR: 95.1% to 98.9%) of the estimated total-body P. vivax biomass. More reticulocytes were in contact with sinus lumen endothelial cells in P. vivax- than in P. falciparum-infected spleens. Histological analyses revealed 96% of P. vivax rings/trophozoites and 46% of schizonts colocalised with 92% of immature reticulocytes in the cords and sinus lumens of the red pulp. Larger splenic cohort studies and similar investigations in untreated symptomatic malaria are warranted.
Immature CD71+ reticulocytes and splenic P. vivax-infected erythrocytes of all asexual stages accumulate in the same splenic compartments, suggesting the existence of a cryptic endosplenic lifecycle in chronic P. vivax infection. Findings provide insight into P. vivax-specific adaptions that have evolved to maximise survival and replication in the spleen.
The promyelocytic leukemia protein (PML) is a tumor suppressor identified in acute PML and implicated in the pathogenesis of a variety of tumors. PML is essential for the proper assembly of a nuclear ...macromolecular structure called the PML nuclear body (PML-NB). PML and PML-NBs are functionally promiscuous and have been associated with the regulation of several cellular functions. Above all these is the control of apoptosis, a function of PML whose physiological relevance is emphasized by in vivo studies that demonstrate that mice and cells lacking Pml are resistant to a vast variety of apoptotic stimuli. The function of PML in regulating apoptosis is not confined to a linear pathway; rather, PML works within a regulatory network that finely tunes various apoptotic pathways, depending on the cellular context and the apoptotic stimulus. Here, we will summarize earlier and recent advances on the molecular mechanisms by which PML regulates apoptosis and the implication of these findings for cancer pathogenesis.
Reconfiguration of subspace partitions Akman, Fusun; Sissokho, Papa A.
Journal of combinatorial designs,
January 2022, Letnik:
30, Številka:
1
Journal Article
Recenzirano
Let
q be a fixed prime power and let
V
(
n
,
q
) denote a vector space of dimension
n over the Galois field with
q elements. A subspace partition (also called “vector space partition”) of
V
(
n
,
q
) ...is a collection of subspaces of
V
(
n
,
q
) with the property that every nonzero element of
V
(
n
,
q
) appears in exactly one of these subspaces. Given positive integers
a
,
b
,
n such that
1
≤
a
<
b
<
n, we say a subspace partition of
V
(
n
,
q
) has type
a
x
b
y if it is composed of
x subspaces of dimension
a and
y subspaces of dimension
b. Let
c
=
gcd
(
a
,
b
). In this paper, we prove that if
b divides
n, then one can (algebraically) construct every possible subspace partition of
V
(
n
,
q
) of type
a
x
b
y whenever
y
≥
(
q
e
−
1
)
∕
(
q
b
−
1
), where
0
≤
e
<
a
b
∕
c and
n
≡
e
(
mod
a
b
∕
c
). Our construction allows us to sequentially reconfigure batches of
(
q
a
−
1
)
∕
(
q
c
−
1
) subspaces of dimension
b into batches of
(
q
b
−
1
)
∕
(
q
c
−
1
) subspaces of dimension
a. In particular, this accounts for all numerically allowed subspace partition types
a
x
b
y of
V
(
n
,
q
) under some additional conditions, for example, when
e
=
b.
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