8,153 research outputs found
'I just want a job' : what do we really know about young people in jobs without training?
Over recent years, a central concern of policy has been to drive up post-16 participation rates in full-time education and address the needs of young people not in education, employment or training (NEET). As a result, young people who enter work which is classified as 'without training' at 16/17 have largely been ignored. However, the decision to Raise the Participation Age (RPA) for continuing in learning for all 17-year olds from 2013 and for all 18-year olds from 2015 in England, together with a growing unease about the impact of the current recession on youth unemployment rates, have revived interest in the 'jobs without training' (JWT) group. This paper draws on the findings from two studies: first, a qualitative study in two contrasting local labour markets, of young people in JWT, together with their employers and parents; and second, an evaluation of the Learning Agreement Pilots (LAP), which was the first policy initiative in England targeted at the JWT group. Both studies reveal a dearth of understanding about early labour market entrants and a lack of policy intervention and infrastructure to support the needs of the JWT group throughout the UK. From this, it is concluded that questionable assumptions have been made about the composition and the aspirations of young people in JWT, and their employers, on the basis of little or no evidence. As a consequence, a policy 'quick fix' to satisfy the RPA agenda will not easily be achieved. If the decision to raise the participation age is adopted also by the Welsh and Scottish parliaments, similar challenges may have to be faced
Nebular spectroscopy of SN 2014J: Detection of stable nickel in near infrared spectra
We present near infrared (NIR) spectroscopy of the nearby supernova 2014J
obtained 450 d after explosion. We detect the [Ni II] 1.939 m line
in the spectra indicating the presence of stable Ni in the ejecta. The
stable nickel is not centrally concentrated but rather distributed as the iron.
The spectra are dominated by forbidden [Fe II] and [Co II] lines. We use lines,
in the NIR spectra, arising from the same upper energy levels to place
constraints on the extinction from host galaxy dust. We find that that our data
are in agreement with the high and low found in earlier studies
from data near maximum light. Using a Ni mass prior from near maximum
light -ray observations, we find 0.05 M of stable nickel
to be present in the ejecta. We find that the iron group features are
redshifted from the host galaxy rest frame by 600 km s.Comment: 6 pages, 4 figures, submitted to A&
A study of the social and physical environment in catering kitchens and the role of the chef in promoting positive health and safety behaviour
This is the account of a mixed method study of chefs and their kitchens in order to identify the nature of their workplace and how this affects their ability to manage health and safety in the kitchen. It included extended periods of observation, monitoring of physical parameters, analysis of records of reported accidents, and a series of reflexive interviews. The findings were integrated and then fed back in a smaller number of second interviews in order to test whether the findings fitted in with the chefs' understanding of their world. Major factors identified included survival in a market environment, the status of the chef (and the kitchen) within organisations, marked autocracy of chefs, and an increasing tempo building up to service time with commensurate heat, noise, and activity. In particular during the crescendo, a threshold shift in risk tolerance was identified. The factors, their interplay, and their implications for health and safety in the catering kitchen are discussed
A multi-wavelength investigation of the radio-loud supernova PTF11qcj and its circumstellar environment
We present the discovery, classification, and extensive panchromatic (from
radio to X-ray) follow-up observations of PTF11qcj, a supernova discovered by
the Palomar Transient Factory. PTF11qcj is located at a distance of dL ~ 124
Mpc. Our observations with the Karl G. Jansky Very Large Array show that this
event is radio-loud: PTF11qcj reached a radio peak luminosity comparable to
that of the famous gamma-ray-burst-associated supernova 1998bw (L_{5GHz} ~
10^{29} erg/s/Hz). PTF11qcj is also detected in X-rays with the Chandra
observatory, and in the infrared band with Spitzer. Our multi-wavelength
analysis probes the supernova interaction with circumstellar material. The
radio observations suggest a progenitor mass-loss rate of ~10^{-4} Msun/yr x
(v_w/1000 km/s), and a velocity of ~(0.3-0.5)c for the fastest moving ejecta
(at ~10d after explosion). However, these estimates are derived assuming the
simplest model of supernova ejecta interacting with a smooth circumstellar
material characterized by radial power-law density profile, and do not account
for possible inhomogeneities in the medium and asphericity of the explosion.
The radio light curve shows deviations from such a simple model, as well as a
re-brightening at late times. The X-ray flux from PTF11qcj is compatible with
the high-frequency extrapolation of the radio synchrotron emission (within the
large uncertainties). An IR light echo from pre-existing dust is in agreement
with our infrared data. Our analysis of pre-explosion data from the Palomar
Transient Factory suggests that a precursor eruption of absolute magnitude M_r
~ -13 mag may have occurred ~ 2.5 yr prior to the supernova explosion. Based on
our panchromatic follow-up campaign, we conclude that PTF11qcj fits the
expectations from the explosion of a Wolf-Rayet star. Precursor eruptions may
be a feature characterizing the final pre-explosion evolution of such stars.Comment: 43 pages, 15 figures; this version matches the one published in ApJ
(includes minor changes that address the Referee's comments.
Observations of the GRB afterglow ATLAS17aeu and its possible association with GW170104
We report the discovery and multi-wavelength data analysis of the peculiar
optical transient, ATLAS17aeu. This transient was identified in the skymap of
the LIGO gravitational wave event GW170104 by our ATLAS and Pan-STARRS
coverage. ATLAS17aeu was discovered 23.1hrs after GW170104 and rapidly faded
over the next 3 nights, with a spectrum revealing a blue featureless continuum.
The transient was also detected as a fading x-ray source by Swift and in the
radio at 6 and 15 GHz. A gamma ray burst GRB170105A was detected by 3
satellites 19.04hrs after GW170104 and 4.10hrs before our first optical
detection. We analyse the multi-wavelength fluxes in the context of the known
GRB population and discuss the observed sky rates of GRBs and their afterglows.
We find it statistically likely that ATLAS17aeu is an afterglow associated with
GRB170105A, with a chance coincidence ruled out at the 99\% confidence or
2.6. A long, soft GRB within a redshift range of would be consistent with all the observed multi-wavelength data. The
Poisson probability of a chance occurrence of GW170104 and ATLAS17aeu is
. This is the probability of a chance coincidence in 2D sky location
and in time. These observations indicate that ATLAS17aeu is plausibly a normal
GRB afterglow at significantly higher redshift than the distance constraint for
GW170104 and therefore a chance coincidence. However if a redshift of the faint
host were to place it within the GW170104 distance range, then physical
association with GW170104 should be considered.Comment: 16 pages, 6 figures, accepted to Ap
Sustaining entrepreneurial business: a complexity perspective on processes that produce emergent practice
This article examines the management practices in an entrepreneurial small firm which sustain the business. Using a longitudinal qualitative case study, four general processes are identified (experimentation, reflexivity, organising and sensing), that together provide a mechanism to sustain the enterprise. The analysis draws on concepts from entrepreneurship and complexity science. We suggest that an entrepreneur’s awareness of the role of these parallel processes will facilitate their approaches to sustaining and developing enterprises. We also suggest that these processes operate in parallel at multiple levels, including the self, the business and inter-firm networks. This finding contributes to a general theory of entrepreneurship. A number of areas for further research are discussed arising from this result
ASASSN-15pz: Revealing Significant Photometric Diversity among 2009dc-like, Peculiar SNe Ia
We report comprehensive multi-wavelength observations of a peculiar Type
Ia-like supernova ("SN Ia-pec") ASASSN-15pz. ASASSN-15pz is a spectroscopic
"twin" of SN 2009dc, a so-called "Super-Chandrasekhar-mass" SN, throughout its
evolution, but it has a peak luminosity M_B,peak = -19.69 +/- 0.12 mag that is
\approx 0.6 mag dimmer and comparable to the SN 1991T sub-class of SNe Ia at
the luminous end of the normal width-luminosity relation. The synthesized Ni56
mass of M_Ni56 = 1.13 +/- 0.14 M_sun is also substantially less than that found
for several 2009dc-like SNe. Previous well-studied 2009dc-like SNe have
generally suffered from large and uncertain amounts of host-galaxy extinction,
which is negligible for ASASSN-15pz. Based on the color of ASASSN-15pz, we
estimate a host extinction for SN 2009dc of E(B-V)_host=0.12 mag and confirm
its high luminosity (M_B, peak[2009dc] \approx -20.3 mag). The 2009dc-like SN
population, which represents ~1% of SNe Ia, exhibits a range of peak
luminosities, and do not fit onto the tight width-luminosity relation. Their
optical light curves also show significant diversity of late-time (>~ 50 days)
decline rates. The nebular-phase spectra provide powerful diagnostics to
identify the 2009dc-like events as a distinct class of SNe Ia. We suggest
referring to these sources using the phenomenology-based "2009dc-like SN
Ia-pec" instead of "Super-Chandrasekhar SN Ia," which is based on an uncertain
theoretical interpretation.Comment: 21 pages, 16 figures, accepted for publication in Ap
Light curves of hydrogen-poor Superluminous Supernovae from the Palomar Transient Factory
We investigate the light-curve properties of a sample of 26 spectroscopically
confirmed hydrogen-poor superluminous supernovae (SLSNe-I) in the Palomar
Transient Factory (PTF) survey. These events are brighter than SNe Ib/c and SNe
Ic-BL, on average, by about 4 and 2~mag, respectively. The peak absolute
magnitudes of SLSNe-I in rest-frame band span ~mag, and these peaks are not powered by radioactive Ni,
unless strong asymmetries are at play. The rise timescales are longer for SLSNe
than for normal SNe Ib/c, by roughly 10 days, for events with similar decay
times. Thus, SLSNe-I can be considered as a separate population based on
photometric properties. After peak, SLSNe-I decay with a wide range of slopes,
with no obvious gap between rapidly declining and slowly declining events. The
latter events show more irregularities (bumps) in the light curves at all
times. At late times, the SLSN-I light curves slow down and cluster around the
Co radioactive decay rate. Powering the late-time light curves with
radioactive decay would require between 1 and 10 of Ni masses.
Alternatively, a simple magnetar model can reasonably fit the majority of
SLSNe-I light curves, with four exceptions, and can mimic the radioactive decay
of Co, up to days from explosion. The resulting spin values do
not correlate with the host-galaxy metallicities. Finally, the analysis of our
sample cannot strengthen the case for using SLSNe-I for cosmology.Comment: 120 pages, 48 figures, 78 tables. ApJ in pres
Monte Carlo radiative transfer for the nebular phase of Type Ia supernovae
We extend the range of validity of the ARTIS 3D radiative transfer code up to hundreds of days after explosion, when Type Ia supernovae (SNe Ia) are in their nebular phase. To achieve this, we add a non-local thermodynamic equilibrium population and ionization solver, a new multifrequency radiation field model, and a new atomic data set with forbidden transitions. We treat collisions with non-thermal leptons resulting from nuclear decays to account for their contribution to excitation, ionization, and heating. We validate our method with a variety of tests including comparing our synthetic nebular spectra for the well-known one-dimensional W7 model with the results of other studies. As an illustrative application of the code, we present synthetic nebular spectra for the detonation of a sub-Chandrasekhar white dwarf (WD) in which the possible effects of gravitational settling of 22Ne prior to explosion have been explored. Specifically, we compare synthetic nebular spectra for a 1.06 M☉ WD model obtained when 5.5 Gyr of very efficient settling is assumed to a similar model without settling. We find that this degree of 22Ne settling has only a modest effect on the resulting nebular spectra due to increased 58Ni abundance. Due to the high ionization in sub-Chandrasekhar models, the nebular [Ni II] emission remains negligible, while the [Ni III] line strengths are increased and the overall ionization balance is slightly lowered in the model with 22Ne settling. In common with previous studies of sub-Chandrasekhar models at nebular epochs, these models overproduce [Fe III] emission relative to [Fe II] in comparison to observations of normal SNe Ia
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