4,237 research outputs found
The effect of mark enhancement techniques on the subsequent detection of saliva
There appears to be a limited but growing body of research on the sequential analysis/treatment of multiple types of evidence. The development of an integrated forensic approach is necessary to maximise evidence recovery and to ensure that a particular treatment is not detrimental to other types of evidence. This study aims to assess the effect of latent and blood mark enhancement techniques (e.g. fluorescence, ninhydrin, acid violet 17, black iron-oxide powder suspension) on the subsequent detection of saliva. Saliva detection was performed by means of a presumptive test (Phadebas®) in addition to analysis by a rapid stain identification (RSID) kit test and confirmatory DNA testing. Additional variables included a saliva depletion series and a number of different substrates with varying porosities as well as different ageing periods. Examination and photography under white light and fluorescence was carried out prior to and after chemical enhancement All enhancement techniques (except Bluestar® Forensic Magnum luminol) employed in this study resulted in an improved visualisation of the saliva stains, although the inherent fluorescence of saliva was sometimes blocked after chemical treatment. The use of protein stains was, in general, detrimental to the detection of saliva. Positive results were less pronounced after the use of black iron-oxide powder suspension, cyanoacrylate fuming followed by BY40 and ninhydrin when compared to the respective positive controls. The application of Bluestar® Forensic Magnum luminol and black magnetic powder proved to be the least detrimental, with no significant difference between the test results and the positive controls. The use of non-destructive fluorescence examination provided good visualisation; however, only the first few marks in the depletion were observed. Of the samples selected for DNA analysis only depletion 1 samples contained sufficient DNA quantity for further processing using standard methodology. The 28 day delay between sample deposition and collection resulted in a 5-fold reduction in the amount of useable DNA. When sufficient DNA quantities were recovered, enhancement techniques did not have a detrimental effect on the ability to generate DNA profiles. This study aims to contribute to a strategy for maximising evidence recovery and efficiency for the detection of latent marks and saliva. The results demonstrate that most of the enhancement techniques employed in this study were not detrimental to the subsequent detection of saliva by means of presumptive, confirmative and DNA tests
Southern Infrared Proper Motion Survey I: Discovery of New High Proper Motion Stars From First Full Hemisphere Scan
We present the first results from the Southern Infrared Proper Motion Survey.
Using 2 Micron All Sky Survey data along with that of the SuperCOSMOS sky
survey we have been able to produce the first widefield infrared proper motion
survey. Having targeted the survey to identify nearby M, L and T dwarfs we have
discovered 72 such new objects with proper motions greater than 0.5''/yr with
10 of these having proper motions in excess of 1''/yr. The most interesting of
these objects is SIPS1259-4336 a late M dwarf. We have calculated a
trigonometric parallax for this object of milliarcseconds
yielding a distance of pc. We have also discovered a common proper
motion triple system and an object with a common proper motion with LHS 128.
The survey completeness is limited by the small epoch differences between many
2MASS and UKI observations. Hence we only recover 22% of Luyten objects with
favourable photometry. However the Luyten study is itself unquantifiably
incomplete. We discuss the prospect of enhancing the survey volume by reducing
the lower proper motion limit.Comment: 20 pages, 11 figures, accepted for publication in Astronomy and
Astrophysic
Superlattice Magnetophonon Resonances in Strongly Coupled InAs/GaSb Superlattices
We report an experimental study of miniband magnetoconduction in
semiconducting InAs/GaSb superlattices. For samples with miniband widths below
the longitudinal optical phonon energy we identify a new superlattice
magnetophonon resonance (SLMPR) caused by resonant scattering of electrons
across the mini-Brillouin zone. This new resonant feature arises directly from
the drift velocity characteristics of the superlattice dispersion and total
magnetic quantisation of the superlattice Landau level minibands.Comment: 9 pages, 8 figures, submitted to Phys. Rev.
Inter-band magnetoplasmons in mono- and bi-layer graphene
Collective excitations spectrum of Dirac electrons in mono and bilayer
graphene in the presence of a uniform magnetic field is investigated.
Analytical results for inter-Landau band plasmon spectrum within the
self-consistent-field approach are obtained. SdH type oscillations that are a
monotonic function of the magnetic field are observed in the plasmon spectrum
of both mono- and bi-layer graphene systems. The results presented are also
compared with those obtained in conventional 2DEG. The chiral nature of the
quasiparticles in mono and bilayer graphene system results in the observation
of and Berry's phase in the SdH- type oscillations in the plasmon
spectrum.Comment: 9 pages, 2 figure
The sub-stellar birth rate from UKIDSS
We present a new sample of mid-L to mid-T dwarfs with effective temperatures of 11001700 K selected from the UKIDSS Large Area Survey (LAS) and confirmed with infrared spectra from X-shooter/Very Large Telescope. This effective temperature range is especially sensitive to the formation history of Galactic brown dwarfs and allows us to constrain the form of the sub-stellar birth rate, with sensitivity to differentiate between a flat (stellar like) birth rate and an exponentially declining form. We present the discovery of 63 new L and T dwarfs from the UKIDSS LAS DR7, including the identification of 12 likely unresolved binaries, which form the first complete sub-set from our programme, covering 495 square degrees of sky, complete to J = 18.1. We compare our results for this sub-sample with simulations of differing birth rates for objects of masses 0.10-0.03 M-circle dot and ages 1-10 Gyr. We find that the more extreme birth rates (e. g. a halo type form) can likely be excluded as the true form of the birth rate. In addition, we find that although there is substantial scatter we find a preference for a mass function, with a power-law index a in the range -1 <alpha <0 that is consistent (within the errors) with the studies of late T dwarfs.Peer reviewe
A model of hyphal tip growth involving microtubule-based transport
We propose a simple model for mass transport within a fungal hypha and its
subsequent growth. Inspired by the role of microtubule-transported vesicles, we
embody the internal dynamics of mass inside a hypha with mutually excluding
particles progressing stochastically along a growing one-dimensional lattice.
The connection between long range transport of materials for growth, and the
resulting extension of the hyphal tip has not previously been addressed in the
modelling literature. We derive and analyse mean-field equations for the model
and present a phase diagram of its steady state behaviour, which we compare to
simulations. We discuss our results in the context of the filamentous fungus,
Neurospora crassa.Comment: 5 pages, 5 figure
Gap opening in the zeroth Landau level in gapped graphene: Pseudo-Zeeman splitting in an angular magnetic field
We present a theoretical study of gap opening in the zeroth Landau level in
gapped graphene as a result of pseudo-Zeeman interaction. The applied magnetic
field couples with the valley pseudospin degree of freedom of the charge
carriers leading to the pseudo-Zeeman interaction. To investigate its role in
transport at the Charge Neutrality Point (CNP), we study the integer quantum
Hall effect (QHE) in gapped graphene in an angular magnetic field in the
presence of pseudo-Zeeman interaction. Analytical expressions are derived for
the Hall conductivity using Kubo-Greenwood formula. We also determine the
longitudinal conductivity for elastic impurity scattering in the first Born
approximation. We show that pseudo-Zeeman splitting leads to a minimum in the
collisional conductivity at high magnetic fields and a zero plateau in the Hall
conductivity. Evidence for activated transport at CNP is found from the
temperature dependence of the collisional conductivity.Comment: 20 pages, 4 figures, Accepted in J. Phys. Condensed matte
Evaluation of Unmanned Radar Installations
Several unmanned radar devices were installed on I75 in northern Kentucky in an attempt to reduce speeds. It was assumed that drivers use radar detectors to exceed the speed limit with a resulting variance between their speeds and others in the traffic stream. Therefore, a reduction in overall speeds and variance was expected to reduce the probability of accidents. Historical data indicated an unusually high accident rate for the study area.
Emphasis was placed on collection and analysis of speed-related data. In addition, a survey of radar detector usage was made and accident patterns were documented.
Speed measures analyzed included mean speed, standard deviation in speed, numbers of vehicles exceeding specified speed levels, and 85th percentile speed.
Results indicate that unmanned radar was an effective means of reducing the number of vehicles traveling at excessive speeds. The differences in mean speeds were small and the impact of unmanned radar was less obvious than it was for the percentage of vehicles exceeding speed levels of 65, 70, 75, and 80 mph. The speeds of vehicles with radar detectors decreased significantly as a result of unmanned radar while the speeds of vehicles without detectors were not affected. Radar detector usage was found to be 42 percent in trucks and 11 percent in cars. When comparing accident data three years before and one year after truck diversion and unmanned radar installations, there was a reduction in truck-related and speed-related accidents
One-neutron knockout in the vicinity of the N=32 sub-shell closure: 9Be(57Cr,56Cr+ gamma)X
The one-neutron knockout reaction 9Be(57Cr,56Cr + gamma)X has been measured
in inverse kinematics with an intermediate-energy beam. Cross sections to
individual states in 56Cr were partially untangled through the detection of the
characteristic gamma-ray transitions in coincidence with the reaction residues.
The experimental inclusive longitudinal momentum distribution and the yields to
individual states are compared to calculations that combine spectroscopic
factors from the full fp shell model and nucleon-removal cross sections
computed in a few-body eikonal approach.Comment: PRC, in pres
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