114 research outputs found
VLBI Probes of Jet Physics in Neutrino-Candidate Blazars
In recent years, evidence has accumulated that some high-energy cosmic
neutrinos can be associated with blazars. The strongest evidence for an
individual association was found in the case of the blazar TXS 0506+056 in
2017. In July 2019, another track-like neutrino event (IC190730A) was found
spatially coincident with the well-known bright flat-spectrum radio quasar PKS
1502+106. PKS 1502+106 was not found to be in a particularly elevated gamma-ray
state, but exhibited a remarkably bright radio outburst at the time of the
neutrino detection, similar to TXS 0506+056. We have performed a
multi-frequency VLBI study from 15 GHz up to 86 GHz on TXS 0506+056, PKS
1502+106 and one additional neutrino-candidate blazar (PKS 0215+015) to study
the radio structure of neutrino candidate blazars in response to their neutrino
association. We have obtained target of opportunity observations with the VLBA
for all three sources within 1 month from their associated neutrino
events and are performing multi-epoch studies of the jet kinematics at 15 GHz
as part of the MOJAVE program. Here, we present first results on TXS 0506+056
at 86 GHz and one additional 43 GHz image obtained 27 days after IC170922A,
closer in time to the neutrino event than previously published images. We also
give an overview about our recent work on PKS 1502+106 and PKS 0215+015.Comment: 8 pages, 1 figure, 1 table, Proceedings of 38th International Cosmic
Ray Conference (ICRC2023
Gamow Shell Model Description of Weakly Bound Nuclei and Unbound Nuclear States
We present the study of weakly bound, neutron-rich nuclei using the nuclear
shell model employing the complex Berggren ensemble representing the bound
single-particle states, unbound Gamow states, and the non-resonant continuum.
In the proposed Gamow Shell Model, the Hamiltonian consists of a one-body
finite depth (Woods-Saxon) potential and a residual two-body interaction. We
discuss the basic ingredients of the Gamow Shell Model. The formalism is
illustrated by calculations involving {\it several} valence neutrons outside
the double-magic core: He and O.Comment: 19 pages, 20 encapsulated PostScript figure
TELAMON: Effelsberg monitoring of AGN jets with very-high-energy astroparticle emission -- I. Program description and sample characterization
Aims. We introduce the TELAMON program which is using the Effelsberg 100-m
telescope to monitor the radio spectra of active galactic nuclei (AGN) under
scrutiny in astroparticle physics, specifically TeV blazars and candidate
neutrino-associated AGN. Here, we present and characterize our main sample of
TeV-detected blazars.
Methods. We analyze the data sample from the first ~2.5 years of observations
between August 2020 and February 2023 in the range from 14 GHz to 45 GHz.
During this pilot phase, we have observed all 59 TeV-detected blazars in the
Northern Hemisphere (i.e., Dec. >0{\deg}) known at the time of observation. We
discuss the basic data reduction and calibration procedures used for all
TELAMON data and introduce a sub-band averaging method used to calculate
average light curves for the sources in our sample.
Results. The TeV-selected sources in our sample exhibit a median flux density
of 0.12 Jy at 20 mm, 0.20 Jy at 14 mm and 0.60 Jy at 7 mm. The spectrum for
most of the sources is consistent with a flat radio spectrum and we find a
median spectral index () of . Our
results on flux density and spectral index are consistent with previous studies
of TeV-selected blazars. Compared to the GeV-selected F-GAMMA sample, TELAMON
sources are significantly fainter in the radio band. This is consistent with
the double-humped spectrum of blazars being shifted towards higher frequencies
for TeV-emitters (in particular for high-synchrotron peaked BL Lac type
objects), which results in a lower radio flux density. The spectral index
distribution of our TeV-selected blazar sample is not significantly different
from the GeV-selected F-GAMMA sample. Moreover, we present a strategy to track
the light curve evolution of sources in our sample for future variability and
correlation analysis.Comment: 16 pages, 11 figures, 4 tables, accepted for publication in A&
TELAMON: Effelsberg Monitoring of AGN Jets with Very-High-Energy Astroparticle Emissions -- II. Polarization properties
We present recent results of the TELAMON program, which is using the
Effelsberg 100-m telescope to monitor the radio spectra of active galactic
nuclei (AGN) under scrutiny in astroparticle physics, namely TeV blazars and
neutrino-associated AGN. Our sample includes all known Northern TeV-emitting
blazars as well as blazars positionally coincident with IceCube neutrino
alerts. Polarization can give additional insight into the source properties, as
the polarized emission is often found to vary on different timescales and
amplitudes than the total intensity emission. Here, we present an overview of
the polarization properties of the TeV-emitting TELAMON sources at four
frequencies in the 20 mm and 7 mm bands. While at 7 mm roughly of all
observed sources are found to be significantly polarized, for 20 mm the
percentage is . We find that most of the sources exhibit mean
fractional polarizations of , matching the expectations of rather low
polarization levels in these sources from previous studies at lower radio
frequencies. Nevertheless, we demonstrate examples of how the polarized
emission can provide additional information over the total intensity.Comment: 9 pages, 2 figures, Proceedings of the 38th International Cosmic Ray
Conference (ICRC2023
Householders’ Mental Models of Domestic Energy Consumption: Using a Sort-And-Cluster Method to Identify Shared Concepts of Appliance Similarity
If in-home displays and other interventions are to successfully influence people's energy consumption, they need to communicate about energy in terms that make sense to users. Here we explore householders' perceptions of energy consumption, using a novel combination of card-sorting and clustering to reveal shared patterns in the way people think about domestic energy consumption. The data suggest that, when participants were asked to group appliances which they felt naturally 'went together', there are relatively few shared ideas about which appliances are conceptually related. To the extent participants agreed on which appliances belonged together, these groupings were based on activities (e.g., entertainment) and location within the home (e.g., kitchen); energy consumption was not an important factor in people's categorisations. This suggests messages about behaviour change aimed at reducing energy consumption might better be tied to social practices than to consumption itself
Applying behavioural theory to the challenge of sustainable development: using hairdressers as diffusers of more sustainable hair-care practices
The challenges presented by sustainable development are broadly accepted, yet resource use increases unabated. It is increasingly acknowledged that while technical solutions may play a part, a key issue is behaviour change. In response to this there has been a plethora of studies into how behaviour change can be enabled, predominantly from psychological and sociological perspectives. This has resulted in a substantial body of knowledge into the factors that drive behaviour change and how they can be manipulated to achieve desired social goals. In this paper we describe a study that draws on this body of knowledge to design an intervention to drive behaviour change across the hairdressing sector, and by the process of diffusion, across the vast social networks of this occupational group to influence domestic hair-care practices. The intervention was successful: hairdressers indicated positive intentions to adopt more sustainable practices within their salons and pass them onto their customers. The customer survey (N=776) confirms this: customers surveyed after their hairdresser attended the Green-Salon-Makeover intervention were significantly more likely to report that environmental issues had been considered in their salon visit and that they themselves would consider such issues in their hair-care practices at home than customers who were surveyed before the intervention
Antipsychotic withdrawal symptoms: Phenomenology and pathophysiology
The authors review the literature discribing non-dyskinetic antipsychotic withdrawal phenomena. Withdrawal of these agents can cause nausea, emesis, anorexia, diarrhea, rhinorrhea, diaphoresis, myalgia, paresthesia, anxiety, agitation, restlessness, and insomnia. Psychotic relapse is often presaged by increased anxiety, agitation, restlessness and insomnia, but the temporal relationship of these prodromal symptoms to reduction in the dosage or discontinuation of neuroleptics distinguishes them from the effects of abrupt withdrawal.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65190/1/j.1600-0447.1988.tb05116.x.pd
Making a Step Forward Towards Urban Resilience. The Contribution of Digital Innovation
Starting from 'wicked problem' theory as the landmark for framing disaster events in terms of policy issue for city governments, this paper highlights the contribution provided by Big Data analytics and digital innovation in dealing with disaster risks. The research aims at answering the following question: what is the role that 'smart technologies' play in strengthening urban resilience to disaster risks
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