891 research outputs found
Public injecting and public amenity in an inner-city suburb of Melbourne, Australia
Background: Public drug markets and injecting impose significant burden on individuals and the community. This study aimed to document public injecting and amenity in North Richmond, an inner-city suburb of Melbourne, Australia. Methods: A rapid assessment methodology was employed. Data comprised: secondary data on drug use indicators, structured observations and interviews with key stakeholders. Primary data were collected from May to October 2012. Quantitative data are summarised using descriptive statistics. Basic content analysis was performed on interview transcripts. Results: An average of 1843 needle–syringes (NS) were collected per month from syringe disposal bins and street-sweeps in the period January–December 2012. Discarded NS and other injecting paraphernalia were observed in a variety of locations. Stakeholder interviews indicated substantial concerns over the presence of NS and witnessing injecting and overdose. Discussion: Public injecting is widespread, frequent, and highly visible in North Richmond and has a substantial negative effect on public amenity. The research identified two main priorities: (1) enhance access to harm reduction services and materials; and (2) improve public amenity. Among other responses, the study findings support the introduction of a supervised injecting facility (SIF) as a viable component of a comprehensive harm reduction response to illicit drug use in this area
Atom-molecule Rabi oscillations in a Mott insulator
We observe large-amplitude Rabi oscillations between an atomic and a
molecular state near a Feshbach resonance. The experiment uses 87Rb in an
optical lattice and a Feshbach resonance near 414 G. The frequency and
amplitude of the oscillations depend on magnetic field in a way that is well
described by a two-level model. The observed density dependence of the
oscillation frequency agrees with the theoretical expectation. We confirmed
that the state produced after a half-cycle contains exactly one molecule at
each lattice site. In addition, we show that for energies in a gap of the
lattice band structure, the molecules cannot dissociate
Improved Fast Neutron Spectroscopy via Detector Segmentation
Organic scintillators are widely used for fast neutron detection and
spectroscopy. Several effects complicate the interpretation of results from
detectors based upon these materials. First, fast neutrons will often leave a
detector before depositing all of their energy within it. Second, fast neutrons
will typically scatter several times within a detector, and there is a
non-proportional relationship between the energy of, and the scintillation
light produced by, each individual scatter; therefore, there is not a
deterministic relationship between the scintillation light observed and the
neutron energy deposited. Here we demonstrate a hardware technique for reducing
both of these effects. Use of a segmented detector allows for the
event-by-event correction of the light yield non-proportionality and for the
preferential selection of events with near-complete energy deposition, since
these will typically have high segment multiplicities.Comment: Accepted for publication in Nuclear Instruments and Methods in
Physics Research Section
CEP-stable Tunable THz-Emission Originating from Laser-Waveform-Controlled Sub-Cycle Plasma-Electron Bursts
We study THz-emission from a plasma driven by an incommensurate-frequency
two-colour laser field. A semi-classical transient electron current model is
derived from a fully quantum-mechanical description of the emission process in
terms of sub-cycle field-ionization followed by continuum-continuum electron
transitions. For the experiment, a CEP-locked laser and a near-degenerate
optical parametric amplifier are used to produce two-colour pulses that consist
of the fundamental and its near-half frequency. By choosing two incommensurate
frequencies, the frequency of the CEP-stable THz-emission can be continuously
tuned into the mid-IR range. This measured frequency dependence of the
THz-emission is found to be consistent with the semi-classical transient
electron current model, similar to the Brunel mechanism of harmonic generation
The use of ceramic drills on a zirconium oxide basis in bone preparation
The favourable mechanical properties and high biocompatibility of the newly
developed mixed ceramics composed of zirconium oxide and aluminium oxide
have continuously extended the scope of their application. Rotating instruments
on a zirconium oxide basis are regarded as superior to metal burs in dentoalveolar
surgery in terms of favourable temperature effects on the surrounding bone
tissue and the economic advantage that they wear slowly, enabling them to be
used repeatedly. In this study ten round burs made of zirconium oxide and
aluminium oxide mixed ceramics were used for typical dental-alveolar preparation
types on an explanted pig jaw. Prior to the first and following the tenth application
a scanning electron microscopic (SEM) analysis of possible wear signs was conducted.
However, this revealed no evidence of wear or resulting loss of sharpness
Results for the response function determination of the Compact Neutron Spectrometer
The Compact Neutron Spectrometer (CNS) is a Joint European Torus (JET)
Enhancement Project, designed for fusion diagnostics in different plasma
scenarios. The CNS is based on a liquid scintillator (BC501A) which allows good
discrimination between neutron and gamma radiation. Neutron spectrometry with a
BC501A spectrometer requires the use of a reliable, fully characterized
detector. The determination of the response matrix was carried out at the Ion
Accelerator Facility (PIAF) of the Physikalisch-Technische Bundesanstalt (PTB).
This facility provides several monoenergetic beams (2.5, 8, 10, 12 and 14 MeV)
and a 'white field'(Emax ~17 MeV), which allows for a full characterization of
the spectrometer in the region of interest (from ~1.5 MeV to ~17 MeV. The
energy of the incoming neutrons was determined by the time of flight method
(TOF), with time resolution in the order of 1 ns. To check the response matrix,
the measured pulse height spectra were unfolded with the code MAXED and the
resulting energy distributions were compared with those obtained from TOF. The
CNS project required modification of the PTB BC501A spectrometer design, to
replace an analog data acquisition system (NIM modules) with a digital system
developed by the 'Ente per le Nuove tecnologie, l'Energia e l'Ambiente' (ENEA).
Results for the new digital system were evaluated using new software developed
specifically for this project.Comment: Proceedings of FNDA 201
Declining drinking among adolescents: are we seeing a denormalisation of drinking and a normalisation of non-drinking?
Background
In the early 2000s, alcohol use among young people began to decline in many western countries, especially among adolescents (aged between 12-17 years old). These declines have continued steadily over the past two decades, against the backdrop of much smaller declines among the general population.
Argument
Hypotheses examining individual factors fail adequately to provide the necessary ‘big picture’ thinking needed to understand declines in adolescent drinking. We use the normalisation thesis to argue that there is strong international evidence for both processes of denormalisation of drinking and normalisation of non-drinking occurring for adolescents in many western countries.
Conclusions
Research on declining adolescent drinking provides evidence of both denormalisation of alcohol consumption and normalisation of non-drinking. This has implications for enabling policy environments more amenable to regulation and increasing the acceptability of non-drinking in social contexts. Normalisation theory (and its various interpretations) provides a useful multi-dimensional tool for understanding declines in adolescent drinking
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