6,212 research outputs found
Focused Deterrence and the Prevention of Violent Gun Injuries: Practice, Theoretical Principles, and Scientific Evidence
Focused deterrence strategies are a relatively new addition to a growing portfolio of evidence-based violent gun injury prevention practices available to policy makers and practitioners. These strategies seek to change offender behavior by understanding the underlying violence-producing dynamics and conditions that sustain recurring violent gun injury problems and by implementing a blended strategy of law enforcement, community mobilization, and social service actions. Consistent with documented public health practice, the focused deterrence approach identifies underlying risk factors and causes of recurring violent gun injury problems, develops tailored responses to these underlying conditions, and measures the impact of implemented interventions. This article reviews the practice, theoretical principles, and evaluation evidence on focused deterrence strategies. Although more rigorous randomized studies are needed, the available empirical evidence suggests that these strategies generate noteworthy gun violence reduction impacts and should be part of a broader portfolio of violence prevention strategies available to policy makers and practitioners
Interplay between s-d exchange interaction and Rashba effect: spin-polarized transport
We investigate the spin-polarized transport properties of a two-dimensional
electron gas in a n-type diluted magnetic narrow gap semiconductor quantum well
subjected to a perpendicular magnetic and electric field. Interesting beating
patterns in the magneto resistance are found which can be tuned significantly
by varying the electric field. A resonant enhancement of spin-polarized current
is found which is induced by the competition between the s-d exchange
interaction and the Rashba effect [Y. A. Bychkov and E. I. Rashba, J. Phys. C
17, 6039 (1984)].Comment: 4 pages, 3 figures, Appl. Phys. Lett. (in press
Chiral Fermions on the Lattice
A recently proposed method for regularizing chiral gauge theories
non-perturbatively is discussed in detail. The result is an effective action
which can be computed from the lattice gauge field, and which is suited for
numerical simulations.Comment: Talk given by G. Schierholz at Yukawa International Seminar on
Non-Perturbative QCD: Structure of the QCD Vacuum (YKIS97), Kyoto, December
1997; typos correcte
'Boom and bust fishery' in a biodiversity hotspot - Is the Western Ghats losing its most celebrated native ornamental fish, Pantius denisond Day?
Refractive Index of Humid Air in the Infrared: Model Fits
The theory of summation of electromagnetic line transitions is used to
tabulate the Taylor expansion of the refractive index of humid air over the
basic independent parameters (temperature, pressure, humidity, wavelength) in
five separate infrared regions from the H to the Q band at a fixed percentage
of Carbon Dioxide. These are least-squares fits to raw, highly resolved spectra
for a set of temperatures from 10 to 25 C, a set of pressures from 500 to 1023
hPa, and a set of relative humidities from 5 to 60%. These choices reflect the
prospective application to characterize ambient air at mountain altitudes of
astronomical telescopes.Comment: Corrected exponents of c0ref, c1ref and c1p in Table
Infection of Myxobolus turpisrotundus sp n. in allogynogenetic gibel carp, Carassius auratus gibelio (Bloch), with revision of Myxobolus rotundus (s. l.) Nemeczek reported from C-auratus auratus (L.)
Infection of a Myxobolus species, previously identified as Myxobolus rotundus, was detected in 182 of 7892 (2.31%) allogynogenetic gibel carp, Carassius auratus gibelio, in a closed pond culture system in China. Morphological and molecular data showed that this myxosporean is a different species from M. rotundus parasitizing Abramis brama in Europe and is thus designated as a new species, Myxobolus turpisrotundus. M. rotundus (s.l.) ex C. auratusauratus is a synonym of M. turpisrotundus. Plasmodia of M. turpisrotundus develop in the subepidermal tissues of the body surface resulting in an unaesthetic appearance and causing severe economic losses. Prevalence of infection with the myxosporean plasmodia varied seasonally, increasing in winter and decreasing in spring. Prevalence was positively correlated to host size, but no host sex-specificity was found. No infection was observed in other fish species (grass carp, bighead carp and yellow catfish) reared in the same pond, suggesting that the parasite has a relatively strict host specificity. Plasmodia grew gradually as the parasite developed, and reached up to a maximum 5.6 mm in diameter. Plasmodia ruptured naturally to release the mature spores and host fish completely recovered with no mortality. Release of spores and regeneration of lesions were not correlated with water temperature. Histology showed that plasmodia developed sub-epidermally, and that the wall of the plasmodia was composed of a multiple complex structure, including layers of fibroblasts, a collagenous membrane, melanophores and a layer of cup-like cells of unknown derivation and function. The cup-like cells are in direct contact with pre-sporogonic stages located in the peripheral parts of the large plasmodia. No severe host inflammatory response was seen
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