12,511 research outputs found
Reliable and robust molecular sexing of the hen harrier (Circus cyaneus) using PCR-RFLP of the CHD1 gene
The hen harrier (Circus cyaneus) is a bird of prey that is persecuted in the United Kingdom, and there is a need for a DNA-based individual identification and sexing system for the use in forensic investigations. This study reports a new set of PCR primers for the chromo-helicase-DNA-binding protein 1 gene, which allows sexing using PCR-RFLP. Instead of exonic primers that amplify across a large intron, this set consists of a primer within the intron, enabling reduction in amplicon sizes from 356 to 212 bp and 565 to 219 bp in W and Z chromosomes. DNA degradation and dilution experiments demonstrate that this set is significantly more robust than one that amplifies across the intron, and sequencing of the intronic primer-binding region across several individuals shows that it is highly conserved. While our objective is to incorporate this primer set into an STR-based individualization kit, it may in the meantime prove useful in forensic or conservation studies
Spectroscopy of Po
Prompt, in-beam rays following the reaction Yb + 142 MeV
Si were measured at the ATLAS facility using 10 Compton-suppressed Ge
detectors and the Fragment Mass Analyzer. Transitions in Po were
identified and placed using -ray singles and coincidence data gated on
the mass of the evaporation residues. A level spectrum up to
J10 was established. The structure of Po is more
collective than that observed in the heavier polonium isotopes and indicates
that the structure has started to evolve towards the more collective nature
expected for deformed nuclei.Comment: 8 pages, revtex 3.0, 4 figs. available upon reques
The International Urban Energy Balance Models Comparison Project: First Results from Phase 1
A large number of urban surface energy balance models now exist with different assumptions about the
important features of the surface and exchange processes that need to be incorporated. To date, no com-
parison of these models has been conducted; in contrast, models for natural surfaces have been compared
extensively as part of the Project for Intercomparison of Land-surface Parameterization Schemes. Here, the
methods and first results from an extensive international comparison of 33 models are presented. The aim of
the comparison overall is to understand the complexity required to model energy and water exchanges in
urban areas. The degree of complexity included in the models is outlined and impacts on model performance
are discussed. During the comparison there have been significant developments in the models with resulting
improvements in performance (root-mean-square error falling by up to two-thirds). Evaluation is based on a
dataset containing net all-wave radiation, sensible heat, and latent heat flux observations for an industrial area in
Vancouver, British Columbia, Canada. The aim of the comparison is twofold: to identify those modeling ap-
proaches that minimize the errors in the simulated fluxes of the urban energy balance and to determine the
degree of model complexity required for accurate simulations. There is evidence that some classes of models
perform better for individual fluxes but no model performs best or worst for all fluxes. In general, the simpler
models perform as well as the more complex models based on all statistical measures. Generally the schemes
have best overall capability to model net all-wave radiation and least capability to model latent heat flux
Nematic liquid crystal alignment on chemical patterns
Patterned Self-Assembled Monolayers (SAMs) promoting both homeotropic and planar degenerate alignment of 6CB and 9CB in their nematic phase, were created using microcontact printing of functionalised organothiols on gold films. The effects of a range of different pattern geometries and sizes were investigated, including stripes, circles and checkerboards. EvanescentWave Ellipsometry was used to study the orientation of the liquid crystal (LC) on these patterned surfaces during the isotropic-nematic phase transition. Pretransitional growth of a homeotropic layer was observed on 1 ¹m homeotropic aligning stripes, followed by a homeotropic mono-domain state prior to the
bulk phase transition. Accompanying Monte-Carlo simulations of LCs aligned on nano-patterned surfaces were also performed. These simulations also showed the presence of the homeotropic mono-domain state prior to the transition.</p
Node-weighted measures for complex networks with spatially embedded, sampled, or differently sized nodes
When network and graph theory are used in the study of complex systems, a
typically finite set of nodes of the network under consideration is frequently
either explicitly or implicitly considered representative of a much larger
finite or infinite region or set of objects of interest. The selection
procedure, e.g., formation of a subset or some kind of discretization or
aggregation, typically results in individual nodes of the studied network
representing quite differently sized parts of the domain of interest. This
heterogeneity may induce substantial bias and artifacts in derived network
statistics. To avoid this bias, we propose an axiomatic scheme based on the
idea of node splitting invariance to derive consistently weighted variants of
various commonly used statistical network measures. The practical relevance and
applicability of our approach is demonstrated for a number of example networks
from different fields of research, and is shown to be of fundamental importance
in particular in the study of spatially embedded functional networks derived
from time series as studied in, e.g., neuroscience and climatology.Comment: 21 pages, 13 figure
Triplet energy differences and the low lying structure of Ga 62
Background: Triplet energy differences (TED) can be studied to yield information on isospin-non-conserving interactions in nuclei.
Purpose: The systematic behavior of triplet energy differences (TED) of T=1, J\u3c0=2+ states is examined. The A=62 isobar is identified as having a TED value that deviates significantly from an otherwise very consistent trend. This deviation can be attributed to the tentative assignments of the pertinent states in Ga62 and Ge62.
Methods: An in-beam \u3b3-ray spectroscopy experiment was performed to identify excited states in Ga62 using Gamma-Ray Energy Tracking In-Beam Nuclear Array with the S800 spectrometer at NSCL using a two-nucleon knockout approach. Cross-section calculations for the knockout process and shell-model calculations have been performed to interpret the population and decay properties observed.
Results: Using the systematics as a guide, a candidate for the transition from the T=1, 2+ state is identified. However, previous work has identified similar states with different J\u3c0 assignments. Cross-section calculations indicate that the relevant T=1, 2+ state should be one of the states directly populated in this reaction.
Conclusions: As spins and parities were not measurable, it is concluded that an unambiguous identification of the first T=1, 2+ state is required to reconcile our understanding of TED systematics
Measuring every particle's size from three-dimensional imaging experiments
Often experimentalists study colloidal suspensions that are nominally
monodisperse. In reality these samples have a polydispersity of 4-10%. At the
level of an individual particle, the consequences of this polydispersity are
unknown as it is difficult to measure an individual particle size from
microscopy. We propose a general method to estimate individual particle radii
within a moderately concentrated colloidal suspension observed with confocal
microscopy. We confirm the validity of our method by numerical simulations of
four major systems: random close packing, colloidal gels, nominally
monodisperse dense samples, and nominally binary dense samples. We then apply
our method to experimental data, and demonstrate the utility of this method
with results from four case studies. In the first, we demonstrate that we can
recover the full particle size distribution {\it in situ}. In the second, we
show that accounting for particle size leads to more accurate structural
information in a random close packed sample. In the third, we show that crystal
nucleation occurs in locally monodisperse regions. In the fourth, we show that
particle mobility in a dense sample is correlated to the local volume fraction.Comment: 7 pages, 5 figure
Quasiparticle interfacial level alignment of highly hybridized frontier levels: HO on TiO(110)
Knowledge of the frontier levels' alignment prior to photo-irradiation is
necessary to achieve a complete quantitative description of HO
photocatalysis on TiO(110). Although HO on rutile TiO(110) has been
thoroughly studied both experimentally and theoretically, a quantitative value
for the energy of the highest HO occupied levels is still lacking. For
experiment, this is due to the HO levels being obscured by hybridization
with TiO(110) levels in the difference spectra obtained via ultraviolet
photoemission spectroscopy (UPS). For theory, this is due to inherent
difficulties in properly describing many-body effects at the
HO-TiO(110) interface. Using the projected density of states (DOS) from
state-of-the-art quasiparticle (QP) , we disentangle the adsorbate and
surface contributions to the complex UPS spectra of HO on TiO(110). We
perform this separation as a function of HO coverage and dissociation on
stoichiometric and reduced surfaces. Due to hybridization with the TiO(110)
surface, the HO 3a and 1b levels are broadened into several peaks
between 5 and 1 eV below the TiO(110) valence band maximum (VBM). These
peaks have both intermolecular and interfacial bonding and antibonding
character. We find the highest occupied levels of HO adsorbed intact and
dissociated on stoichiometric TiO(110) are 1.1 and 0.9 eV below the VBM. We
also find a similar energy of 1.1 eV for the highest occupied levels of HO
when adsorbed dissociatively on a bridging O vacancy of the reduced surface. In
both cases, these energies are significantly higher (by 0.6 to 2.6 eV) than
those estimated from UPS difference spectra, which are inconclusive in this
energy region. Finally, we apply self-consistent QP (scQP1) to obtain
the ionization potential of the HO-TiO(110) interface.Comment: 12 pages, 12 figures, 1 tabl
Stop Atherosclerosis in Native Diabetics Study (SANDS): Baseline Characteristics of the Randomized Cohort
Objectives: To present baseline characteristics of American Indians in the Stop Atherosclerosis in Native Diabetics Study (SANDS) and compare them with population-based data from American Indians and other ethnic groups. Design: 499 people with type 2 diabetes ≥ age 40, without known CVD, were recruited for a randomized 3-year trial to evaluate treatment targets for LDL-C (70 vs. 100 mg/dL) and systolic blood pressure (BP) (115 vs. 130 mmHg). Baseline evaluations included physical exam, collection of blood and urine samples, and carotid ultrasound and echocardiographic measures. Results: Mean age was 56 years; 66% were female. Average BMI was 33 kg/m2. Average duration of both hypertension and diabetes was 10 years, average A1c was 8.0 %, and mean LDL-C was 104 mg/dL. Participants in the conventional treatment group had slightly higher systolic BPs than participants in the aggressive treatment group (133 mm Hg vs. 128 mm Hg, p \u3c 0.002). Compared with the population-based cohorts of the Strong Heart Study (SHS), NHANES, and the TRIAD registry, SANDS participants had similar values for lipids, BP, and CRP, as well as degree of obesity, smoking rates, and renal function as indicated by estimated glomerular filtration rate. Conclusions: The baseline characteristics of the SANDS cohort are similar to those of a population-based sample of American Indian diabetic men and women and closely resemble diabetic men and women of other ethnic groups. Results from this study can be used to identify appropriate targets for LDL-C and BP lowering in diabetic American Indians and diabetic patients in other ethnic groups
OGLE-2017-BLG-0329L: A Microlensing Binary Characterized with Dramatically Enhanced Precision Using Data from Space-based Observations
Mass measurements of gravitational microlenses require one to determine the microlens parallax π E, but precise π E measurement, in many cases, is hampered due to the subtlety of the microlens-parallax signal combined with the difficulty of distinguishing the signal from those induced by other higher-order effects. In this work, we present the analysis of the binary-lens event OGLE-2017-BLG-0329, for which π E is measured with a dramatically improved precision using additional data from space-based Spitzer observations. We find that while the parallax model based on the ground-based data cannot be distinguished from a zero-π E model at the 2σ level, the addition of the Spitzer data enables us to identify two classes of solutions, each composed of a pair of solutions according to the well-known ecliptic degeneracy. It is found that the space-based data reduce the measurement uncertainties of the north and east components of the microlens-parallax vector π E by factors ~18 and ~4, respectively. With the measured microlens parallax combined with the angular Einstein radius measured from the resolved caustic crossings, we find that the lens is composed of a binary with component masses of either (M1, M2) ~ (1.1, 0.8) M⊙ or ~(0.4, 0.3) M⊙ according to the two solution classes. The first solution is significantly favored but the second cannot be securely ruled out based on the microlensing data alone. However, the degeneracy can be resolved from adaptive optics observations taken ~10 years after the event
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