Application Of Geophysical And Geochronological Methods To Sedimentologic And Stratigraphic Problems In The Lower Cambrian Monkton Formation: Northwestern Vermont

The Monkton Formation of the western shelf stratigraphic sequence in Vermont (VT) is identified as a Lower Cambrian regressive sandstone unit containing parasequences recording tidal flat progradation. Previous workers identified cycles believed to represent parasequences in a portion of a 1034\u27 deep geothermal well drilled at Champlain College in Burlington, Vermont. For this study, both outcrop and well geophysical surveys were completed to better identify gamma emission curves and relative values for parasequences and select lithologies that are indicators of bathymetry and sea level. After using physical stratigraphic techniques to assemble a composite stratigraphic section for the Monkton Formation, analysis of the gamma emission curve and relative gamma values resulted in the identification and characterization of parasequences and select lithologies within the Monkton. Interpretation of bathymetry-sensitive lithologies along with parasequence architecture and thickness trends reveals three distinctive intervals over the thickness of the Monkton. It is recognized that the succession of these intervals represents an overall decreasing rate in accommodation space generation through Monkton deposition. Previous workers have suggested that biostratigraphic relationships of the Monkton Formation to the Potsdam Group in New York (NY) suggest that that they would be at least partially correlative. To further refine age relationships and constrain and compare the provenance of the Vermont stratigraphy locally and regionally, zircon samples were collected from the Monkton and the overlying Danby Formations and radiometric age determinations were completed by laser ablation–inductively coupled plasma mass spectrometry (LA-ICPMS) at University of Arizona Laserchron Center. Zircon age probability distribution curves show two dominate age peaks between 1.05-1.09 Ga and 1.15-1.18 Ga for the Monkton and Danby suggesting either a continuity of provenance through the Cambrian or the cycling of the Monkton\u27s sand. The 1.05-1.09 Ga age range corresponds to rocks generated during the Ottawan Orogeny while the 1.15-1.18 Ga range is associated with the Shawinigan Orogeny and anorthosite-mangerite-charnockite-granite (AMCG) plutonism. Dominant age peaks in the Vermont samples between 1.15-1.18 Ga are similar to the 1.16 Ga age peak reported by other workers from the Altona and Ausable Formations of the Potsdam Group of New York. The shared dominant age peak and close proximity of the Vermont and New York stratigraphy may suggest a primarily shared provenance

Experimental Photoallergic Contact Dermatitis: A Mouse Model

We have induced photoallergic contact dermatitis in mice to 3,3',4',5 tetrachlorosalicylanilide (TCSA), chlorpromazine and 6-methylcoumarin. These compounds are known to produce photoallergic contact dermatitis in humans. The photoallergic contact dermatitis reaction in the mouse is immunologically specific viz. mice photosensitized to TCSA react, by photochallenge, to that compound and not to chlorpromazine, and conversely. The reaction requires UVA at both sensitization and challenge. It appears to be T-cell medicated in that it can be passively transferred to syngeneic mice by lymph node cells from actively sensitized mice, histology of the reactions resembles that of classic allergic contact dermatitis in mice, challenge reactions are seen at 24 but not at 4hr, and photoallergic contact dermatitis can be induced in B-cell deficient mice. The availability of a mouse model for the study of photo-ACD will facilitate the identification of pertinent control mechanisms and may aid in the management of the disease. It is likely that a bioassay for photoallergens of humans can be based on this mouse model

The Curious Conundrum Regarding Sulfur Abundances In Planetary Nebulae

Sulfur abundances derived from optical emission line measurements and ionization correction factors in planetary nebulae are systematically lower than expected for the objects' metallicities. We have carefully considered a large range of explanations for this "sulfur anomaly", including: (1) correlations between the size of the sulfur deficit and numerous nebular and central star properties; (2) ionization correction factors which under-correct for unobserved ions; (3) effects of dielectronic recombination on the sulfur ionization balance; (4) sequestering of S into dust and/or molecules; and (5) excessive destruction of S or production of O by AGB stars. It appears that all but the second scenario can be ruled out. However, we find evidence that the sulfur deficit is generally reduced but not eliminated when S^+3 abundances determined directly from IR measurements are used in place of the customary sulfur ionization correction factor. We tentatively conclude that the sulfur anomaly is caused by the inability of commonly used ICFs to properly correct for populations of ionization stages higher than S^+2.Comment: 40 pages, 14 figures, 3 tables. Accepted for publication in the Astrophysical Journa

Analytical and Biological Characterization of Supercoiled Plasmids Purified by Various Chromatographic Techniques

This is the publisher's version, also available electronically from http://online.liebertpub.com/doi/abs/10.1089/dna.2005.24.819Supercoiled plasmids are an important component of gene-based delivery vehicles. A number of production methods for clinical applications have been developed, each resulting in very high-quality product with low levels of residual contaminants. There is, however, no consensus on the optimal methods to characterize plasmid quality, and further, to determine if these methods are predictive of either product stability or biological activity. We have produced two plasmids using four production purification methodologies based on PolyFlo® and hydrophobic interaction chromatography (HIC), either alone or in tandem processes. In each case, the product was analyzed using standard molecular biological methods. We also performed a number of biophysical analyses such as dynamic light scattering (DLS), circular dichroism (CD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Minimal differences were detected among the preparations based on the more standard molecular biological methods. Some small differences were detected, however, using biophysical techniques, particularly FTIR and DSC, which may reflect small variations in plasmid tertiary structure and thermal stability. Stability after heat exposure at 60°C, exposure to fetal bovine serum and long-term storage at 4°C varied between plasmids. One plasmid showed no difference in stability depending on the production process, but the other showed significant differences. Evaluation in vivo in models for gene immunization and gene therapy showed significant differences in the response depending on the method of purification. Preparations using a tandem process of PolyFlo used in two separation modes provided higher biological activity compared to a tandem HIC/PolyFlo process or either resin used alone in a single column process. These data indicate that the process by which supercoiled plasmids are made can influence plasmid stability and biological activity and emphasize the need for more rigorous methods to evaluate supercoiled plasmids as gene-delivery vehicles

Malaria vaccine efficacy: the difficulty of detecting and diagnosing malaria

New sources of funding have revitalized efforts to control malaria. An effective vaccine would be a tremendous asset in the fight against this devastating disease and increasing financial and scientific resources are being invested to develop one. A few candidates have been tested in Phase I and II clinical trials, and several others are poised to begin trials soon. Some studies have been promising, and others disappointing. It is difficult to compare the results of these clinical trials; even independent trials of the same vaccine give highly discrepant results. One major obstacle in evaluating malaria vaccines is the difficulty of diagnosing clinical malaria. This analysis evaluates the impact of diagnostic error, particularly that introduced by microscopy, on the outcome of efficacy trials of malaria vaccines and make recommendations for improving future trials

Does the inclusion of 'professional development' teaching improve medical students' communication skills?

Background: This study investigated whether the introduction of professional development teaching in the first two years of a medical course improved students' observed communication skills with simulated patients. Students' observed communication skills were related to patient-centred attitudes, confidence in communicating with patients and performance in later clinical examinations.Methods: Eighty-two medical students from two consecutive cohorts at a UK medical school completed two videoed consultations with a simulated patient: one at the beginning of year 1 and one at the end of year 2. Group 1 (n = 35) received a traditional pre-clinical curriculum. Group 2 (n = 47) received a curriculum that included communication skills training integrated into a 'professional development' vertical module. Videoed consultations were rated using the Evans Interview Rating Scale by communication skills tutors. A subset of 27% were double-coded. Inter-rater reliability is reported.Results: Students who had received the professional development teaching achieved higher ratings for use of silence, not interrupting the patient, and keeping the discussion relevant compared to students receiving the traditional curriculum. Patient-centred attitudes were not related to observed communication. Students who were less nervous and felt they knew how to listen were rated as better communicators. Students receiving the traditional curriculum and who had been rated as better communicators when they entered medical school performed less well in the final year clinical examination.Conclusions: Students receiving the professional development training showed significant improvements in certain communication skills, but students in both cohorts improved over time. The lack of a relationship between observed communication skills and patient-centred attitudes may be a reflection of students' inexperience in working with patients, resulting in 'patient-centredness' being an abstract concept. Students in the early years of their medical course may benefit from further opportunities to practise basic communication skills on a one-to-one basis with patients

Measurement of the mass and lifetime of the Ωb−\Omega_b^- baryon

A proton-proton collision data sample, corresponding to an integrated luminosity of 3 fb$^{-1}$ collected by LHCb at $\sqrt{s}=7$ and 8 TeV, is used to reconstruct $63\pm9$ $\Omega_b^-\to\Omega_c^0\pi^-$, $\Omega_c^0\to pK^-K^-\pi^+$ decays. Using the $\Xi_b^-\to\Xi_c^0\pi^-$, $\Xi_c^0\to pK^-K^-\pi^+$ decay mode for calibration, the lifetime ratio and absolute lifetime of the $\Omega_b^-$ baryon are measured to be \begin{align*} \frac{\tau_{\Omega_b^-}}{\tau_{\Xi_b^-}} &= 1.11\pm0.16\pm0.03, \\ \tau_{\Omega_b^-} &= 1.78\pm0.26\pm0.05\pm0.06~{\rm ps}, \end{align*} where the uncertainties are statistical, systematic and from the calibration mode (for $\tau_{\Omega_b^-}$ only). A measurement is also made of the mass difference, $m_{\Omega_b^-}-m_{\Xi_b^-}$, and the corresponding $\Omega_b^-$ mass, which yields \begin{align*} m_{\Omega_b^-}-m_{\Xi_b^-} &= 247.4\pm3.2\pm0.5~{\rm MeV}/c^2, \\ m_{\Omega_b^-} &= 6045.1\pm3.2\pm 0.5\pm0.6~{\rm MeV}/c^2. \end{align*} These results are consistent with previous measurements.Comment: 11 pages, 5 figures, All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-008.htm

Measurement of the Bs0→J/ψηB_{s}^{0} \rightarrow J/\psi \eta lifetime

Using a data set corresponding to an integrated luminosity of $3 fb^{-1}$, collected by the LHCb experiment in $pp$ collisions at centre-of-mass energies of 7 and 8 TeV, the effective lifetime in the $B^0_s \rightarrow J/\psi \eta$ decay mode, $\tau_{\textrm{eff}}$, is measured to be $\tau_{\textrm{eff}} = 1.479 \pm 0.034~\textrm{(stat)} \pm 0.011 ~\textrm{(syst)}$ ps. Assuming $CP$ conservation, $\tau_{\textrm{eff}}$ corresponds to the lifetime of the light $B_s^0$ mass eigenstate. This is the first measurement of the effective lifetime in this decay mode.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-017.htm