The proposed numerical design approach investigates both infinite and finite models and includes an experimental validation of elastic wave absorption and vibration suppression for flexural wave band ...gaps in metamaterial plates. The resonant metamaterial is obtained using a 2-dimensional periodic array of resonators (mass-screws) mounted to a thin homogeneous plate. The sensitivity analysis of the band gap frequency range takes into account the uncertainties of all the design parameters of the metamaterial plate. The theoretical approach uses the finite element method (FEM) to compare the predicted band gaps, which are derived from infinite and finite models of the metamaterial. An automatic method is proposed to detect the frequency ranges of band gaps in the finite metamaterial based on the behavior of the corresponding bare plate. Directional plane wave excitation and point force excitation are applied to evaluate the efficiency of the detection method. The results of these analyses are compared with experimental measurements. The frequency ranges of experimental vibration attenuation are in good agreement with the theoretically predicted complete and directional band gaps.
The central region of the Milky Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new ...observations from an unprecedented gamma-ray survey of the Galactic Center (GC) region, i.e., the Inner Galaxy Survey, at very high energies (& GSIM;100 GeV) performed with the H.E.S.S. array of five ground-based Cherenkov telescopes. No significant gamma-ray excess is found in the search region of the 2014-2020 dataset and a profile likelihood ratio analysis is carried out to set exclusion limits on the annihilation cross section (sigma v). Assuming Einasto and Navarro-Frenk-White (NFW) DM density profiles at the GC, these constraints are the strongest obtained so far in the TeV DM mass range. For the Einasto profile, the constraints reach (sigma v) values of 3.7 x 10-26 cm3 s-1 for 1.5 TeV DM mass in the W+W- annihilation channel, and 1.2 x 10-26 cm3 s-1 for 0.7 TeV DM mass in the tau+tau- annihilation channel. With the H.E.S.S. Inner Galaxy Survey, ground-based gamma-ray observations thus probe (sigma v) values expected from thermal-relic annihilating TeV DM particles.
Recurrent novae are repeating thermonuclear explosions in the outer layers of white dwarfs, due to the accretion of fresh material from a binary companion. The shock generated when ejected material ...slams into the companion star's wind can accelerate particles. We report very-high-energy (VHE; Formula: see text) gamma rays from the recurrent nova RS Ophiuchi, up to 1 month after its 2021 outburst, observed using the High Energy Stereoscopic System (H.E.S.S.). The temporal profile of VHE emission is similar to that of lower-energy giga-electron volt emission, indicating a common origin, with a 2-day delay in peak flux. These observations constrain models of time-dependent particle energization, favoring a hadronic emission scenario over the leptonic alternative. Shocks in dense winds provide favorable environments for efficient acceleration of cosmic rays to very high energies.
Introduction
Caregiving negatively affects the psychological and physical health of the caregivers, especially in parents of children with neurological impairement (NI).Furthermore, the behavior and ...demands of the patient make the caregivers encounter increased stress levels and negative thoughtsabout the future that may lead to depression in caregivers.
Objectives
To assess the relationship between caregiver burden and symptoms of depression in parents of children with NI.
Methods
A total of 33 caregivers of children with NI, participated in this cross-sectional, descriptive and analytical study, carried out in Child Neurology Department of the University Hospital in Sfax (Tunisia), between February and April 2021.
The Zarit-Caregiver-Burden-Scale (Zarit-CBS) and the Beck Depression Scale were administered.
Results
The average age of the caregivers (27 mothers and 6 fathers) was 38,33 years ± 6,53 years. Among the parents, 81,81% didn’t exceed the secondary educational level and75,75% of them had an irregular occupation.
The average age of the children (21 boys and 12 girls) was 7,58±4,29 years.Near to the half of them (51,51%) had intellectual disability.Over 54.54% of the children had a functional independence, while 21.21% required help in walking and 24.24% were unable to walk.
The intervention was based on motor rehabilitation (57,57%), adequate equipment (24,24%), ergotherapy (45,45%) and speech therapy (60,6%).After the intervention, 63,63% of children had an improvement and 30,3% had a stationary state.
The mean score of Zarit-CBS was 52,45±14,26. The caregiver burden was noted in 96,96%.
The mean score of Beck was 9,33±5,48. The depression was noted in 78,78%.
The total Zarit-CBS score had positive correlation with Beck scores (p=0.038).
Conclusions
There is a positive relationship between the caregiver burden and depression symptoms. Thus, effort should be made to relieve caregiver burden in parents of children with NI.
Disclosure of Interest
None Declared
IntroductionMany neurological, sensory and behavioural deficits, are linked with significant limitations in the overall functioning not only of the child but also his/her closest family, and poses a ...great challenge for the primary parental caregivers.ObjectivesTo assess the caregiver burden in parents of children with neurological impairement (NI), and itsrelated factors.MethodsA total of33 caregivers of children with NI participated in this cross-sectional, descriptive and analytical study, carried out in Child Neurology Department of the University Hospital in Sfax (Tunisia), between February and April 2021.The Zarit-Caregiver-Burden-Scale (Zarit-CBS) was administered.ResultsThe average age of the caregivers (27 mothers and 6 fathers) was 38,33 ± 6,53 years. Among the parents, 17.14% had another disabled child and 30.3% had a mediocre health status. Mother caregivers constitutes the majority of caregiving (82.85%).The average of the number of children in the family was 1.97±1.18 and the average age of the children (21 boys and 12 girls) was 7,58±4,29 years. Near to the half of them (51,51%) had intellectual disability.Over 54.54% of the children had a functional independence, while 21.21% required help in walking and 24.24% were unable to walk. The intervention was based on motor rehabilitation (57,57%), adequate equipment (24,24%), ergotherapy (45,45%) and speech therapy (60,6%).After the intervention, 63,63% of children had an improvement and 30,3% had a stationary state.The mean score of Zarit-CBS was 52,45±14,26. The caregiver burden was noted in 96,96%.The total Zarit-CBS score was associated with the number of children in the family (p=0.047).There was no significant relationship between Zarit-CBS and the severity of impairement (p=0.418).ConclusionsGiven the variety of factors affecting caregiver burden, specific interventions may promote parental caregivers’well-being, and consequently lead to improved quality of care provided to children with NI.Disclosure of InterestNone Declared
The aim of this study is to give a partial answer to the analogue conjecture of Erdős, Joò and Komornik in the field of
p
-adic numbers. We prove that if
β
is a Pisot-Chabauty
p
-adic number, then ...the quantity
l
m
(
β
)
is strictly positive where
l
m
(
β
)
=
inf
{
|
x
|
p
:
x
∈
Λ
m
(
β
)
-
Λ
m
(
β
)
,
x
≠
0
}
and
Λ
m
(
β
)
=
{
∑
i
=
0
n
a
i
β
i
:
a
i
∈
Z
1
p
∩
0
,
1
,
|
a
i
|
p
≤
p
m
}
.
Aims.
The identification of PeVatrons, hadronic particle accelerators reaching the knee of the cosmic ray spectrum (few × 10
15
eV), is crucial to understand the origin of cosmic rays in the ...Galaxy. We provide an update on the unidentified source HESS J1702-420, a promising PeVatron candidate.
Methods.
We present new observations of HESS J1702-420 made with the High Energy Stereoscopic System (H.E.S.S.), and processed using improved analysis techniques. The analysis configuration was optimized to enhance the collection area at the highest energies. We applied a three-dimensional likelihood analysis to model the source region and adjust non thermal radiative spectral models to the
γ
-ray data. We also analyzed archival
Fermi
Large Area Telescope data to constrain the source spectrum at
γ
-ray energies > 10 GeV.
Results.
We report the detection of
γ
-rays up to 100 TeV from a specific region of HESS J1702-420, which is well described by a new source component called HESS J1702-420A that was separated from the bulk of TeV emission at a 5.4
σ
confidence level. The power law
γ
-ray spectrum of HESS J1702-420A extends with an index of Γ = 1.53 ± 0.19
stat
± 0.20
sys
and without curvature up to the energy band 64−113 TeV, in which it was detected by H.E.S.S. at a 4.0
σ
confidence level. This makes HESS J1702-420A a compelling candidate site for the presence of extremely high energy cosmic rays. With a flux above 2 TeV of (2.08 ± 0.49
stat
± 0.62
sys
) × 10
−13
cm
−2
s
−1
and a radius of (0.06 ± 0.02
stat
± 0.03
sys
)°, HESS J1702-420A is outshone – below a few tens of TeV – by the companion HESS J1702-420B. The latter has a steep spectral index of Γ = 2.62 ± 0.10
stat
± 0.20
sys
and an elongated shape, and it accounts for most of the low-energy HESS J1702-420 flux. Simple hadronic and leptonic emission models can be well adjusted to the spectra of both components. Remarkably, in a hadronic scenario, the cut-off energy of the particle distribution powering HESS J1702-420A is found to be higher than 0.5 PeV at a 95% confidence level.
Conclusions.
For the first time, H.E.S.S. resolved two components with significantly different morphologies and spectral indices, both detected at > 5
σ
confidence level, whose combined emissions result in the source HESS J1702-420. We detected HESS J1702-420A at a 4.0
σ
confidence level in the energy band 64−113 TeV, which brings evidence for the source emission up to 100 TeV. In a hadronic emission scenario, the hard
γ
-ray spectrum of HESS J1702-420A implies that the source likely harbors PeV protons, thus becoming one of the most solid PeVatron candidates detected so far in H.E.S.S. data. However, a leptonic origin of the observed TeV emission cannot be ruled out either.
Abstract
The High Altitude Water Cherenkov (HAWC) observatory and the High Energy Stereoscopic System (H.E.S.S.) are two leading instruments in the ground-based very-high-energy
γ
-ray domain. HAWC ...employs the water Cherenkov detection (WCD) technique, while H.E.S.S. is an array of Imaging Atmospheric Cherenkov Telescopes (IACTs). The two facilities therefore differ in multiple aspects, including their observation strategy, the size of their field of view, and their angular resolution, leading to different analysis approaches. Until now, it has been unclear if the results of observations by both types of instruments are consistent: several of the recently discovered HAWC sources have been followed up by IACTs, resulting in a confirmed detection only in a minority of cases. With this paper, we go further and try to resolve the tensions between previous results by performing a new analysis of the H.E.S.S. Galactic plane survey data, applying an analysis technique comparable between H.E.S.S. and HAWC. Events above 1 TeV are selected for both data sets, the point-spread function of H.E.S.S. is broadened to approach that of HAWC, and a similar background estimation method is used. This is the first detailed comparison of the Galactic plane observed by both instruments. H.E.S.S. can confirm the
γ
-ray emission of four HAWC sources among seven previously undetected by IACTs, while the three others have measured fluxes below the sensitivity of the H.E.S.S. data set. Remaining differences in the overall
γ
-ray flux can be explained by the systematic uncertainties. Therefore, we confirm a consistent view of the
γ
-ray sky between WCD and IACT techniques.
Abstract
We report on multiwavelength target-of-opportunity observations of the blazar PKS 0735+178, located 2.°2 away from the best-fit position of the IceCube neutrino event IceCube-211208A ...detected on 2021 December 8. The source was in a high-flux state in the optical, ultraviolet, X-ray, and GeV
γ
-ray bands around the time of the neutrino event, exhibiting daily variability in the soft X-ray flux. The X-ray data from Swift-XRT and NuSTAR characterize the transition between the low-energy and high-energy components of the broadband spectral energy distribution (SED), and the
γ
-ray data from Fermi-LAT, VERITAS, and H.E.S.S. require a spectral cutoff near 100 GeV. Both the X-ray and
γ
-ray measurements provide strong constraints on the leptonic and hadronic models. We analytically explore a synchrotron self-Compton model, an external Compton model, and a lepto-hadronic model. Models that are entirely based on internal photon fields face serious difficulties in matching the observed SED. The existence of an external photon field in the source would instead explain the observed
γ
-ray spectral cutoff in both the leptonic and lepto-hadronic models and allow a proton jet power that marginally agrees with the Eddington limit in the lepto-hadronic model. We show a numerical lepto-hadronic model with external target photons that reproduces the observed SED and is reasonably consistent with the neutrino event despite requiring a high jet power.
Abstract
Magnetic fields in galaxies and galaxy clusters are believed to be the result of the amplification of intergalactic seed fields during the formation of large-scale structures in the ...universe. However, the origin, strength, and morphology of this intergalactic magnetic field (IGMF) remain unknown. Lower limits on (or indirect detection of) the IGMF can be obtained from observations of high-energy gamma rays from distant blazars. Gamma rays interact with the extragalactic background light to produce electron−positron pairs, which can subsequently initiate electromagnetic cascades. The gamma-ray signature of the cascade depends on the IGMF since it deflects the pairs. Here we report on a new search for this cascade emission using a combined data set from the Fermi Large Area Telescope and the High Energy Stereoscopic System. Using state-of-the-art Monte Carlo predictions for the cascade signal, our results place a lower limit on the IGMF of
B
> 7.1 × 10
−16
G for a coherence length of 1 Mpc even when blazar duty cycles as short as 10 yr are assumed. This improves on previous lower limits by a factor of 2. For longer duty cycles of 10
4
(10
7
) yr, IGMF strengths below 1.8 × 10
−14
G (3.9 × 10
−14
G) are excluded, which rules out specific models for IGMF generation in the early universe.
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