1,831 research outputs found
Denying humanness to victims: How gang members justify violent behavior
The high prevalence of violent offending amongst gang-involved youth has been established in the literature. Yet the underlying psychological mechanisms that enable youth to engage in such acts of violence remain unclear. 189 young people were recruited from areas in London, UK, known for their gang activity. We found that gang members, in comparison to non-gang youth, described the groups they belong to as having recognized leaders, specific rules and codes, initiation rituals, and special clothing. Gang members were also more likely than non-gang youth to engage in violent behavior and endorse moral disengagement strategies (i.e., moral justification, euphemistic language, advantageous comparison, displacement of responsibility, attribution of blame, and dehumanization). Finally, we found that dehumanizing victims partially mediated the relationship between gang membership and violent behavior. These findings highlight the effects of groups at the individual level and an underlying psychological mechanism that explains, in part, how gang members engage in violence
Democratic localism and the implementation of the Community Remedy in England and Wales
This article assesses the development and implementation of the Community Remedy anti-social behaviour policy by Police and Crime Commissioners (PCCs) in England and Wales. The Community Remedy, introduced by the Anti-Social Behaviour, Crime and Policing Act (2014), allows victims of âlow-levelâ anti-social behaviour to select an informal action for their offender from a list designed by their local PCC via consultation with the public. This article reports the results of a benchmarking exercise that investigates how PCCs have translated this policy into practice by examining: public consultation procedures; the contents of the Community Remedy documents; and police usage. The findings indicate an uneven implementation across regions with variable levels of engagement from PCCs, police forces and members of the public. We assess the enactment and adoption of this new power alongside its potential to stimulate democratic localism
Reflection and Transmission in a Neutron-Spin Test of the Quantum Zeno Effect
The dynamics of a quantum system undergoing frequent "measurements", leading
to the so-called quantum Zeno effect, is examined on the basis of a
neutron-spin experiment recently proposed for its demonstration. When the
spatial degrees of freedom are duely taken into account, neutron-reflection
effects become very important and may lead to an evolution which is totally
different from the ideal case.Comment: 26 pages, 6 figure
Seeking safety beyond refuge : the impact of immigration and citizenship policy upon refugees in the UK
Western states are concerned about maintaining and securing national borders. Across Europe, one response has been to implement restrictive asylum regimes that prevent âbogusâ applicants and grant refuge only to the âdeservingâ. Alongside these concerns, states are eager to encourage socially cohesive communities. One recent tool adopted by the UK government has been citizenship policy, including English language/life in the UK tests and citizenship ceremonies. By drawing upon in-depth interviews with refugees in Scotland (UK), this paper explores the impact of the current asylum regime and citizenship policies from the perspective of individual voices that are often absent from wider debates. It explores how temporary refugee status impacts upon individualsâ everyday lives including employment and education, and impacts upon children. The data also question the reasons for refugees deciding to become British citizens (or not) and highlight instrumental reasons alongside less tangible factors such as gaining a sense of security. Taking the discussion forward, the study explores some unintended consequences of immigration and citizenship policies in the UK. The research suggests that not only do restrictive asylum policies negatively impact upon refugees and their integration but also serve to elevate fear and uncertainty, which can unintentionally spur individuals to seek naturalisation
Simple computer model for the quantum Zeno effect
This paper presents a simple model for repeated measurement of a quantum
system: the evolution of a free particle, simulated by discretising the
particle's position. This model is easily simulated by computer and provides a
useful arena to investigate the effects of measurement upon dynamics, in
particular the slowing of evolution due to measurement (the `quantum Zeno
effect'). The results of this simulation are discussed for two rather different
sorts of measurement process, both of which are (simplified forms of)
measurements used in previous simulations of position measurement. A number of
interesting results due to measurement are found, and the investigation casts
some light on previous disagreements about the presence or absence of the Zeno
effect.Comment: REVTeX; 12 pages including 11 figures; figures reformatted to be more
readable; some small changes made to the description of the mode
Active laser frequency stabilization using neutral praseodymium (Pr)
We present a new possibility for the active frequency stabilization of a
laser using transitions in neutral praseodymium. Because of its five outer
electrons, this element shows a high density of energy levels leading to an
extremely line-rich excitation spectrum with more than 25000 known spectral
lines ranging from the UV to the infrared. We demonstrate the active frequency
stabilization of a diode laser on several praseodymium lines between 1105 and
1123 nm. The excitation signals were recorded in a hollow cathode lamp and
observed via laser-induced fluorescence. These signals are strong enough to
lock the diode laser onto most of the lines by using standard laser locking
techniques. In this way, the frequency drifts of the unlocked laser of more
than 30 MHz/h were eliminated and the laser frequency stabilized to within
1.4(1) MHz for averaging times >0.2 s. Frequency quadrupling the stabilized
diode laser can produce frequency-stable UV-light in the range from 276 to 281
nm. In particular, using a strong hyperfine component of the praseodymium
excitation line E = 16 502.616_7/2 cm^-1 -> E' = 25 442.742_9/2 cm^-1 at lambda
= 1118.5397(4) nm makes it possible - after frequency quadruplication - to
produce laser radiation at lambda/4 = 279.6349(1) nm, which can be used to
excite the D2 line in Mg^+.Comment: 10 pages, 14 figure
Computer simulation of Wheeler's delayed choice experiment with photons
We present a computer simulation model of Wheeler's delayed choice experiment
that is a one-to-one copy of an experiment reported recently (V. Jacques {\sl
et al.}, Science 315, 966 (2007)). The model is solely based on experimental
facts, satisfies Einstein's criterion of local causality and does not rely on
any concept of quantum theory. Nevertheless, the simulation model reproduces
the averages as obtained from the quantum theoretical description of Wheeler's
delayed choice experiment. Our results prove that it is possible to give a
particle-only description of Wheeler's delayed choice experiment which
reproduces the averages calculated from quantum theory and which does not defy
common sense.Comment: Europhysics Letters (in press
Randomized Benchmarking of Multi-Qubit Gates
As experimental platforms for quantum information processing continue to
mature, characterization of the quality of unitary gates that can be applied to
their quantum bits (qubits) becomes essential. Eventually, the quality must be
sufficiently high to support arbitrarily long quantum computations. Randomized
benchmarking already provides a platform-independent method for assessing the
quality of one-qubit rotations. Here we describe an extension of this method to
multi-qubit gates. We provide a platform-independent protocol for evaluating
the performance of experimental Clifford unitaries, which form the basis of
fault-tolerant quantum computing. We implemented the benchmarking protocol with
trapped-ion two-qubit phase gates and one-qubit gates and found an error per
random two-qubit Clifford unitary of , thus setting the first
benchmark for such unitaries. By implementing a second set of sequences with an
extra two-qubit phase gate at each step, we extracted an error per phase gate
of . We conducted these experiments with movable,
sympathetically cooled ions in a multi-zone Paul trap - a system that can in
principle be scaled to larger numbers of ions.Comment: Corrected description of parallel single-qubit benchmark experiment.
Results unchange
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