1,394 research outputs found
Hearing new voices: re-viewing youth justice policy through practitionersâ relationships with young people
The relationship between young people and practitioners is the centrepiece of youth justice provision, yet little research-based knowledge has accumulated on its minutiae. After reviewing reforms affecting professional discretion, the article draws on the concepts of dyadic relationships and praxis to reinvigorate a research agenda aimed at delineating a more nuanced understanding of practice relationships. Drawing on practice wisdom from across related social work fields, we argue that centralizing the practitioner-young person relationship remains the key to successful practice and thus needs greater, more detailed research attention. These claims are supported with a number of pilot interviews with youth justice workers about successful interventions that complement and extend related studies. The article concludes with suggestions for research to enable joint activity between young people and practitioners to ârethinkâ youth justice
A new physical interpretation of optical and infrared variability in quasars
Changing-look quasars are a recently identified class of active galaxies in
which the strong UV continuum and/or broad optical hydrogen emission lines
associated with unobscured quasars either appear or disappear on timescales of
months to years. The physical processes responsible for this behaviour are
still debated, but changes in the black hole accretion rate or accretion disk
structure appear more likely than changes in obscuration. Here we report on
four epochs of spectroscopy of SDSS J110057.70-005304.5, a quasar at a redshift
of whose UV continuum and broad hydrogen emission lines have faded,
and then returned over the past 20 years. The change in this quasar
was initially identified in the infrared, and an archival spectrum from 2010
shows an intermediate phase of the transition during which the flux below
rest-frame 3400\AA\ has decreased by close to an order of magnitude.
This combination is unique compared to previously published examples of
changing-look quasars, and is best explained by dramatic changes in the
innermost regions of the accretion disk. The optical continuum has been rising
since mid-2016, leading to a prediction of a rise in hydrogen emission line
flux in the next year. Increases in the infrared flux are beginning to follow,
delayed by a 3 year observed timescale. If our model is confirmed, the
physics of changing-look quasars are governed by processes at the innermost
stable circular orbit (ISCO) around the black hole, and the structure of the
innermost disk. The easily identifiable and monitored changing-look quasars
would then provide a new probe and laboratory of the nuclear central engine.Comment: 13 pages, 4 figures, 3 tables. Published in MNRAS. All code and data
links on GitHub, https://github.com/d80b2t/WISE_L
Environmental and biological controls on water and energy exchange in Florida scrub oak and pine flatwoods ecosystems
Scrub oak and pine flatwoods are two contrasting ecosystems common to the humid subtropical climate of Florida. Scrub oak forests are short in stature (<2 m) and occur on well-drained sandy soils, and pine flatwoods are much taller and occur in areas with poorly drained soils. Eddy covariance measurements were made from January 2001 to February 2003 over a scrub oak forest and from January 2002 to February 2003 over an adjacent pine flatwoods located on in central Florida, USA, and exposed to similar atmospheric conditions to evaluate how the dynamics of latent heat (lambda E) and sensible heat (H) exchanges are affected by environmental and biological variables. Annual evapotranspiration (Et) for the scrub oak was 737 and 713 mm in 2001 and 2002, respectively. Et was comparatively higher, 812 mm, in 2002 at the pine flatwoods due to higher soil moisture and leaf area. In both ecosystems, springtime increases in lambda E coincided with increasing leaf area and evaporative demand. However, H was the main energy-dissipating component in the spring due to the seasonal decrease in soil water content in the upper soil profile. In the spring, mean weekly Bowen ratio (beta, i.e. H/lambda E) values reached 1.6 and 1.2 in the scrub oak and pine flatwoods, respectively. With the onset of the summertime rainy season, lambda E became the dominant energy flux and beta fells to < 0.4. In both ecosystems, beta was strongly controlled by the interaction between leaf area and soil moisture. The lowest values of the decoupling coefficient (Omega, 0.2 and 0.25 scrub oak and pine flatwoods, respectively) also occurred during the dry springtime period indicating that surface conductance (g(s)) was the mechanism controlling energy partitioning causing high beta in both ecosystems. Et increases in the spring, when water in the upper soil profile was scarce and strongly retained by soil particles, indicated that plants in both ecosystems obtained water from deeper sources. The results from this research elucidate how energy partitioning differs and is regulated in contrasting ecosystems within the Florida landscape, which is important for refining regional hydrological and climate models
Environmental and biological controls on water and energy exchange in Florida scrub oak and pine flatwoods ecosystems
Scrub oak and pine flatwoods are two contrasting ecosystems common to the humid subtropical climate of Florida. Scrub oak forests are short in stature (\u3c2 \u3em) and occur on well-drained sandy soils, and pine flatwoods are much taller and occur in areas with poorly drained soils. Eddy covariance measurements were made from January 2001 to February 2003 over a scrub oak forest and from January 2002 to February 2003 over an adjacent pine flatwoods located on in central Florida, USA, and exposed to similar atmospheric conditions to evaluate how the dynamics of latent heat (lambda E) and sensible heat (H) exchanges are affected by environmental and biological variables. Annual evapotranspiration (Et) for the scrub oak was 737 and 713 mm in 2001 and 2002, respectively. Et was comparatively higher, 812 mm, in 2002 at the pine flatwoods due to higher soil moisture and leaf area. In both ecosystems, springtime increases in lambda E coincided with increasing leaf area and evaporative demand. However, H was the main energy-dissipating component in the spring due to the seasonal decrease in soil water content in the upper soil profile. In the spring, mean weekly Bowen ratio (beta, i.e. H/lambda E) values reached 1.6 and 1.2 in the scrub oak and pine flatwoods, respectively. With the onset of the summertime rainy season, lambda E became the dominant energy flux and beta fells to \u3c 0.4. In both ecosystems, beta was strongly controlled by the interaction between leaf area and soil moisture. The lowest values of the decoupling coefficient (Omega, 0.2 and 0.25 scrub oak and pine flatwoods, respectively) also occurred during the dry springtime period indicating that surface conductance (g(s)) was the mechanism controlling energy partitioning causing high beta in both ecosystems. Et increases in the spring, when water in the upper soil profile was scarce and strongly retained by soil particles, indicated that plants in both ecosystems obtained water from deeper sources. The results from this research elucidate how energy partitioning differs and is regulated in contrasting ecosystems within the Florida landscape, which is important for refining regional hydrological and climate models
X-ray enabled MOCASSIN: a 3D code for photoionized media
We present a new version of the fully 3D photoionization and dust radiative
transfer code, MOCASSIN, that uses a Monte Carlo approach for the transfer of
radiation. The X-ray enabled MOCASSIN allows a fully geometry independent
description of low-density gaseous environments strongly photoionized by a
radiation field extending from radio to gamma rays. The code has been
thoroughly benchmarked against other established codes routinely used in the
literature, using simple plane parallel models designed to test performance
under standard conditions. We show the results of our benchmarking exercise and
discuss applicability and limitations of the new code, which should be of
guidance for future astrophysical studies with MOCASSIN.Comment: Accepted for publication in ApJS 9 pages, 5 figure
Thomson scattering from a shock front
We have obtained a Thomson scattering spectrum in the collective regime by scattering a probe beam from a shock front, in an experiment conducted at the Omega laser at the Laboratory for Laser Energetics. The probe beam was created by frequency converting a beamline at Omega to a 2âns2ns pulse of 0.263âÎŒm0.263ÎŒm light, focused with a dedicated optical focusing system. The diagnostic system included collecting optics, spectrometer, and streak camera, with a scattering angle of 101°. The target included a primary shock tube, a 20-ÎŒm20-ÎŒm-thick beryllium drive disk, 0.3-ÎŒm0.3-ÎŒm-thick polyimide windows mounted on a secondary tube, and a gas fill tube. Detected acoustic waves propagated parallel to the target axis. Ten laser beams irradiated the beryllium disk with 0.351âÎŒm0.351ÎŒm light at 5Ă1014âW/cm25Ă1014Wâcm2 for 1âns1ns starting at toto, driving a strong shock through argon gas at Ïo = 1âmg/ccÏo=1mgâcc. The 200âJ200J probe beam fired at t = 19ânst=19ns for 2âns2ns, and at t = 20.1ânst=20.1ns a 0.3âns0.3ns signal was detected. We attribute this signal to scattering from the shocked argon, before the density increased above critical due to radiative collapse.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87893/2/10E504_1.pd
Right Hemisphere Partial Complex Seizures: Mania, Hallucinations, and Speech Disturbances During Ictal Events
A patient with right hemisphere complex partial seizures exhibited extreme emotional lability resembling mania, neologisms resembling those found in fluent aphasia, and hallucinations during ictal periods. The electroencephalographic and clinical findings in this case suggest that cortical and subcortical structures of the right hemisphere may play a role in mediating the expression of language content. RĂSUMĂ Chez un patient prĂsentant des crises partielles complexes de l'hĂmisphĂre droit, nous avons observĂ pendant les crises une labilitĂĂmotionnelle Ăvoquant le diagnostic de manie. des nĂologismes ressemblant Ă ceux de l'aphasie de Wernicke et des hallucinations. Nos constatation EEG et cliniques suggĂrent que les structures corticales et sous-corticales de l'hĂmisphĂre droit peuvent jouer un rĂle dans la mĂdiation de l'expression du contenu linguistique. RESUMEN Un paciente con ataques parciales complejos originados en el hemisferio derecho mostrĂ una labilidad emocional extrema semejante a la mania, neologismos comparables a los que se encuentran en la afasia fluida y alucinaciones durante los perĂodos ictales. Los hallazgos clĂnicos y del EEG en este caso sugieren que estructuras corticales y subcorticales del hemisferio derecho pueden jugar un papel en la funciĂn del contenido del lenguaje expresivo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66016/1/j.1528-1157.1988.tb05093.x.pd
Development of an Interpretive Simulation Tool for the Proton Radiography Technique
Proton radiography is a useful diagnostic of high energy density (HED)
plasmas under active theoretical and experimental development. In this paper we
describe a new simulation tool that interacts realistic laser-driven point-like
proton sources with three dimensional electromagnetic fields of arbitrary
strength and structure and synthesizes the associated high resolution proton
radiograph. The present tool's numerical approach captures all relevant physics
effects, including effects related to the formation of caustics.
Electromagnetic fields can be imported from PIC or hydrodynamic codes in a
streamlined fashion, and a library of electromagnetic field `primitives' is
also provided. This latter capability allows users to add a primitive, modify
the field strength, rotate a primitive, and so on, while quickly generating a
high resolution radiograph at each step. In this way, our tool enables the user
to deconstruct features in a radiograph and interpret them in connection to
specific underlying electromagnetic field elements. We show an example
application of the tool in connection to experimental observations of the
Weibel instability in counterstreaming plasmas, using particles
generated from a realistic laser-driven point-like proton source, imaging
fields which cover volumes of mm. Insights derived from this
application show that the tool can support understanding of HED plasmas.Comment: Figures and tables related to the Appendix are included in the
published journal articl
Prison Life, Sociology of: Recent Perspectives from the United Kingdom
Prison life both fascinates and repels. As with many aspects of punishment it attracts the interest of both academics and the general public. In this short and accessible account the principal issues of prison life are presented in a historical context that traces the emergence of focussed academic study of the way people live, and die, in prison. The most influential theoretical perspectives are clearly set out alongside a discussion of their influence on research and analysis in the UK and beyond. Questions of womenâs experience and that of black and minority ethnic prisoners are explored before a consideration of post-colonial prison studies is introduced. These studies of prison life beyond the axis of Europe and north America challenge some of the accumulated academic wisdom of Anglo-phone and European studies of prison life, indicating the potential of novel developments to come in an era which, nfortunately, shows no signs of declining to produce more and more prisons
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