496 research outputs found
Electronic and Physical Characterization of Hydrothermally Grown Single Crystal ThO\u3csub\u3e2\u3c/sub\u3e
Actinide single crystals are important to the fabrication of next generation electronic devices that could possibly have radiation with the atmosphere and surroundings. Th02 single crystals were obtained previous to this work by hydrothermal synthesis. As these crystals were the first of their kind, the geometric and electric structure of the crystals needed to be extracted. The valence and conduction bands were studied in order to ascertain the band gap using ultraviolet photoemission spectroscopy (UPS) and inverse photoemission spectroscopy (IPES). The unoccupied structure was further characterized using x-ray absorption near edge structure (XANES) and relativistic, real-space Green\u27s functions calculations. The local structure around the Th atoms was investigated using extended x-ray absorption fine structure (EXAFS). A novel Latin hypercube sampling code was developed to extract the local order structure. X-ray photoemission spectroscopy (XPS) was used to measure a surface-to-bulk level shift and extract two new shake-up satellite structures in the 4f region. A temperature dependent XPS study extracted the Debye coefficients
Modification of the Creator recombination system for proteomics applications – improved expression by addition of splice sites
BACKGROUND: Recombinational systems have been developed to rapidly shuttle Open Reading Frames (ORFs) into multiple expression vectors in order to analyze the large number of cDNAs available in the post-genomic era. In the Creator system, an ORF introduced into a donor vector can be transferred with Cre recombinase to a library of acceptor vectors optimized for different applications. Usability of the Creator system is impacted by the ability to easily manipulate DNA, the number of acceptor vectors for downstream applications, and the level of protein expression from Creator vectors. RESULTS: To date, we have developed over 20 novel acceptor vectors that employ a variety of promoters and epitope tags commonly employed for proteomics applications and gene function analysis. We also made several enhancements to the donor vectors including addition of different multiple cloning sites to allow shuttling from pre-existing vectors and introduction of the lacZ alpha reporter gene to allow for selection. Importantly, in order to ameliorate any effects on protein expression of the loxP site between a 5' tag and ORF, we introduced a splicing event into our expression vectors. The message produced from the resulting 'Creator Splice' vector undergoes splicing in mammalian systems to remove the loxP site. Upon analysis of our Creator Splice constructs, we discovered that protein expression levels were also significantly increased. CONCLUSION: The development of new donor and acceptor vectors has increased versatility during the cloning process and made this system compatible with a wider variety of downstream applications. The modifications introduced in our Creator Splice system were designed to remove extraneous sequences due to recombination but also aided in downstream analysis by increasing protein expression levels. As a result, we can now employ epitope tags that are detected less efficiently and reduce our assay scale to allow for higher throughput. The Creator Splice system appears to be an extremely useful tool for proteomics
The Samurai Project: verifying the consistency of black-hole-binary waveforms for gravitational-wave detection
We quantify the consistency of numerical-relativity black-hole-binary
waveforms for use in gravitational-wave (GW) searches with current and planned
ground-based detectors. We compare previously published results for the
mode of the gravitational waves from an equal-mass
nonspinning binary, calculated by five numerical codes. We focus on the 1000M
(about six orbits, or 12 GW cycles) before the peak of the GW amplitude and the
subsequent ringdown. We find that the phase and amplitude agree within each
code's uncertainty estimates. The mismatch between the modes
is better than for binary masses above with respect to
the Enhanced LIGO detector noise curve, and for masses above
with respect to Advanced LIGO, Virgo and Advanced Virgo. Between the waveforms
with the best agreement, the mismatch is below . We find that
the waveforms would be indistinguishable in all ground-based detectors (and for
the masses we consider) if detected with a signal-to-noise ratio of less than
, or less than in the best cases.Comment: 17 pages, 9 figures. Version accepted by PR
Rare Earth Dopant (Nd, Gd, Dy, and Er) Hybridization in Lithium Tetraborate
The four dopants (Nd, Gd, Dy, and Er) substitutionally occupy the Li+ sites in lithium tetraborate (Li2B4O7: RE) glasses as determined by analysis of the extended X-ray absorption fine structure. The dopants are coordinated by 6-8 oxygen at a distance of 2.3 to 2.5 Ã…, depending on the rare earth. The inverse relationship between the RE-O coordination distance and rare earth (RE) atomic number is consistent with the expected lanthanide atomic radial contraction with increased atomic number. Through analysis of the X-ray absorption near edge structure, the rare earth dopants adopt the RE3+ valence state. There are indications of strong rare earth 5d hybridization with the trigonal and tetrahedral formations of BO3 and BO4 based on the determination of the rare earth substitutional Li+ site occupancy from the X-ray absorption near edge structure data. The local oxygen disorder around the RE3+ luminescence centers evident in the structural determination of the various glasses, and the hybridization of the RE3+ dopants with the host may contribute to the asymmetry evident in the luminescence emission spectral lines. The luminescence emission spectra are indeed characteristic of the expected f-to-f transitions; however, there is an observed asymmetry in some emission lines
Breastfeeding Education Support Tool for Baby (BEST4Baby): Feasibility, Acceptability, and Preliminary Impact of an mHealth Supported Breastfeeding Peer Counselor Intervention in rural India
Objective: To evaluate the feasibility of an mHealth-supported breastfeeding peer counselor intervention implemented in rural India and the preliminary impact of the intervention on maternal breastfeeding behaviors, including exclusive breastfeeding (EBF).
Methods: In this quasi-experimental pilot study, participants received either the intervention plus usual care (n = 110) or usual care alone (n = 112). The intervention group received nine in-home visits during and after pregnancy from peer counselors who provided education about and support for EBF and other optimal infant feeding practices and were aided with an mHealth tool. The control group received routine prenatal and postnatal health education. Progress notes and surveys were used to assess feasibility. Logistic regression models were used for between-group comparisons of optimal infant feeding outcomes, including EBF for 6 months.
Results: The intervention was delivered as intended, maintained over the study period, and had high acceptability ratings. There were statistically significant differences in all outcomes between groups. The intervention group had a significantly higher likelihood of EBF at 6 months compared to the control group (adjusted odds ratio 3.57, 95% confidence interval 1.80–7.07).
Conclusion: Integration of mHealth with community-based peer counselors to educate women about EBF is feasible and acceptable in rural India and impacts maternal breastfeeding behaviors
CARMA Survey Toward Infrared-bright Nearby Galaxies (STING): Molecular Gas Star Formation Law in NGC4254
This study explores the effects of different assumptions and systematics on
the determination of the local, spatially resolved star formation law. Using
four star formation rate (SFR) tracers (H\alpha with azimuthally averaged
extinction correction, mid-infrared 24 micron, combined H\alpha and
mid-infrared 24 micron, and combined far-ultraviolet and mid-infrared 24
micron), several fitting procedures, and different sampling strategies we probe
the relation between SFR and molecular gas at various spatial resolutions and
surface densities within the central 6.5 kpc in the disk of NGC4254. We find
that in the high surface brightness regions of NGC4254 the form of the
molecular gas star formation law is robustly determined and approximately
linear and independent of the assumed fraction of diffuse emission and the SFR
tracer employed. When the low surface brightness regions are included, the
slope of the star formation law depends primarily on the assumed fraction of
diffuse emission. In such case, results range from linear when the fraction of
diffuse emission in the SFR tracer is ~30% or less (or when diffuse emission is
removed in both the star formation and the molecular gas tracer), to
super-linear when the diffuse fraction is ~50% and above. We find that the
tightness of the correlation between gas and star formation varies with the
choice of star formation tracer. The 24 micron SFR tracer by itself shows the
tightest correlation with the molecular gas surface density, whereas the
H\alpha corrected for extinction using an azimuthally-averaged correction shows
the highest dispersion. We find that for R<0.5R_25 the local star formation
efficiency is constant and similar to that observed in other large spirals,
with a molecular gas depletion time ~2 Gyr.Comment: accepted for publication in ApJ, vol 729, March 10 2011 issue; 30
pages; 14 figures; revised version includes referee's comments; results
unchange
Influenza epidemiology, vaccine coverage and vaccine effectiveness in sentinel Australian hospitals in 2013: the Influenza Complications Alert Network
The National Influenza Program aims to reduce serious morbidity and mortality from influenza by providing public funding for vaccination to at-risk groups. The Influenza Complications Alert Network (FluCAN) is a sentinel hospital-based surveillance program that operates at 14 sites in all states and territories in Australia. This report summarises the epidemiology of hospitalisations with confirmed influenza, estimates vaccine coverage and influenza vaccine protection against hospitalisation with influenza during the 2013 influenza season. In this observational study, cases were defined as patients admitted to one of the sentinel hospitals, with influenza confirmed by nucleic acid testing. Controls were patients who had acute respiratory illnesses who were test-negative for influenza. Vaccine effectiveness was estimated as 1 minus the odds ratio of vaccination in case patients compared with control patients, after adjusting for known confounders. During the period 5 April to 31 October 2013, 631 patients were admitted with confirmed influenza at the 14 FluCAN sentinel hospitals. Of these, 31% were more than 65 years of age, 9.5% were Indigenous Australians, 4.3% were pregnant and 77% had chronic co-morbidities. Influenza B was detected in 30% of patients. Vaccination coverage was estimated at 81% in patients more than 65 years of age but only 49% in patients aged less than 65 years with chronic comorbidities. Vaccination effectiveness against hospitalisation with influenza was estimated at 50% (95% confidence interval: 33%, 63%,
Identifying the science and technology dimensions of emerging public policy issues through horizon scanning
Public policy requires public support, which in turn implies a need to enable the public not just to understand policy but also to be engaged in its development. Where complex science and technology issues are involved in policy making, this takes time, so it is important to identify emerging issues of this type and prepare engagement plans. In our horizon scanning exercise, we used a modified Delphi technique [1]. A wide group of people with interests in the science and policy interface (drawn from policy makers, policy adviser, practitioners, the private sector and academics) elicited a long list of emergent policy issues in which science and technology would feature strongly and which would also necessitate public engagement as policies are developed. This was then refined to a short list of top priorities for policy makers. Thirty issues were identified within broad areas of business and technology; energy and environment; government, politics and education; health, healthcare, population and aging; information, communication, infrastructure and transport; and public safety and national security.Public policy requires public support, which in turn implies a need to enable the public not just to understand policy but also to be engaged in its development. Where complex science and technology issues are involved in policy making, this takes time, so it is important to identify emerging issues of this type and prepare engagement plans. In our horizon scanning exercise, we used a modified Delphi technique [1]. A wide group of people with interests in the science and policy interface (drawn from policy makers, policy adviser, practitioners, the private sector and academics) elicited a long list of emergent policy issues in which science and technology would feature strongly and which would also necessitate public engagement as policies are developed. This was then refined to a short list of top priorities for policy makers. Thirty issues were identified within broad areas of business and technology; energy and environment; government, politics and education; health, healthcare, population and aging; information, communication, infrastructure and transport; and public safety and national security
Toll-like receptor signaling adapter proteins govern spread of neuropathic pain and recovery following nerve injury in male mice.
BackgroundSpinal Toll-like receptors (TLRs) and signaling intermediaries have been implicated in persistent pain states. We examined the roles of two major TLR signaling pathways and selected TLRs in a mononeuropathic allodynia.MethodsL5 spinal nerve ligation (SNL) was performed in wild type (WT, C57BL/6) male and female mice and in male Tlr2-/-Tlr3-/-, Tlr4-/-, Tlr5-/-, Myd88-/-, Triflps2, Myd88/Triflps2, Tnf-/-, and Ifnar1-/- mice. We also examined L5 ligation in Tlr4-/- female mice. We examined tactile allodynia using von Frey hairs. Iba-1 (microglia) and GFAP (astrocytes) were assessed in spinal cords by immunostaining. Tactile thresholds were analyzed by 1- and 2-way ANOVA and the Bonferroni post hoc test was used.ResultsIn WT male and female mice, SNL lesions resulted in a persistent and robust ipsilateral, tactile allodynia. In males with TLR2, 3, 4, or 5 deficiencies, tactile allodynia was significantly, but incompletely, reversed (approximately 50%) as compared to WT. This effect was not seen in female Tlr4-/- mice. Increases in ipsilateral lumbar Iba-1 and GFAP were seen in mutant and WT mice. Mice deficient in MyD88, or MyD88 and TRIF, showed an approximately 50% reduction in withdrawal thresholds and reduced ipsilateral Iba-1. In contrast, TRIF and interferon receptor null mice developed a profound ipsilateral and contralateral tactile allodynia. In lumbar sections of the spinal cords, we observed a greater increase in Iba-1 immunoreactivity in the TRIF-signaling deficient mice as compared to WT, but no significant increase in GFAP. Removing MyD88 abrogated the contralateral allodynia in the TRIF signaling-deficient mice. Conversely, IFNβ, released downstream to TRIF signaling, administered intrathecally, temporarily reversed the tactile allodynia.ConclusionsThese observations suggest a critical role for the MyD88 pathway in initiating neuropathic pain, but a distinct role for the TRIF pathway and interferon in regulating neuropathic pain phenotypes in male mice
- …