Measurement of Linear Stark Interference in 199Hg

We present measurements of Stark interference in the 6$^1S_0$ $\rightarrow$ 6$^3P_1$ transition in $^{199}$Hg, a process whereby a static electric field $E$ mixes magnetic dipole and electric quadrupole couplings into an electric dipole transition, leading to $E$-linear energy shifts similar to those produced by a permanent atomic electric dipole moment (EDM). The measured interference amplitude, $a_{SI}$ = $(a_{M1} + a_{E2})$ = (5.8 $\pm$ 1.5)$\times 10^{-9}$ (kV/cm)$^{-1}$, agrees with relativistic, many-body predictions and confirms that earlier central-field estimates are a factor of 10 too large. More importantly, this study validates the capability of the $^{199}$Hg EDM search apparatus to resolve non-trivial, controlled, and sub-nHz Larmor frequency shifts with EDM-like characteristics.Comment: 4 pages, 4 figures, 1 table; revised in response to reviewer comment

Improved limit on the permanent electric dipole moment of 199Hg

We report the results of a new experimental search for a permanent electric dipole moment of 199Hg utilizing a stack of four vapor cells. We find d(199Hg) = (0.49 \pm 1.29_stat \pm 0.76_syst) x 10^{-29} e cm, and interpret this as a new upper bound, |d(199Hg)| < 3.1 x 10^{-29} e cm (95% C.L.). This result improves our previous 199Hg limit by a factor of 7, and can be used to set new constraints on CP violation in physics beyond the standard model.Comment: 4 pages, 4 figures. additional reference, minor edits in response to reviewer comment

Ultracold collision properties of metastable alkaline-earth atoms

Ultra-cold collisions of spin-polarized 24Mg,40Ca, and 88Sr in the metastable 3P2 excited state are investigated. We calculate the long-range interaction potentials and estimate the scattering length and the collisional loss rate as a function of magnetic field. The estimates are based on molecular potentials between 3P2 alkaline-earth atoms obtained from ab initio atomic and molecular structure calculations. The scattering lengths show resonance behavior due to the appearance of a molecular bound state in a purely long-range interaction potential and are positive for magnetic fields below 50 mT. A loss-rate model shows that losses should be smallest near zero magnetic field and for fields slightly larger than the resonance field, where the scattering length is also positive.Comment: 4 pages, 4 figure

Metabonomic Investigation of Liver Profiles of Nonpolar Metabolites Obtained from Alcohol-Dosed Rats and Mice Using High Mass Accuracy MSn Analysis

Alcoholism is a complex disorder that, in man, appears to be genetically influenced, although the underlying genes and molecular pathways are not completely known. Here the intragastric alcohol feeding model in rodents was used together with high mass accuracy LC/MS(n) analysis to assess the metabonomic changes in nonpolar metabolite profiles for livers from control and alcohol treated rats and mice. Ion signals with a peak area variance of less than 30% (based on repeat analysis of a pooled quality control sample analysed throughout the batch) were submitted to multivariate statistical analysis (using principal components analysis, PCA). PCA revealed robust differences between profiles from control and alcohol-treated animals from both species. The major metabolites seen to differ between control and alcohol-treated animals were identified using high accuracy MS(n) data and verified using external search engines (http://www.lipidmaps.org; http://www.hmdb.ca; http://www.genome.jp/kegg/) and authentic standards. The main metabolite classes to show major changes in the alcoholic liver-derived samples were fatty acyls, fatty acid ethyl esters, glycerolipids and phosphatidylethanol homologues. Significant metabolites that were up-regulated by alcohol treatment in both rat and mouse livers included fatty acyls, metabolites such as octadecatrienoic acid and eicosapentaenoic acid, a number of fatty acid ethyl esters such as ethyl arachidonate, ethyl docosahexaenoic acid, ethyl linoleate and ethyl oleate and phosphatidylethanol (PEth) homologues (predominantly PEth 18:0/18:2 and PEth 16:0/18:2; PEth homologues are currently considered as potential biomarkers for harmful and prolonged alcohol consumption in man). A number of glycerophospholipids resulted in both up-regulation (m/z 903.7436 [M+H](+) corresponding to a triglyceride) and down-regulation (m/z 667.5296 [M+H](+) corresponding to a diglyceride). Metabolite profiles were broadly similar in both mouse and rat models. However, there were a number of significant differences in the alcohol-treated group particularly in the marked down-regulation of retinol and free cholesterol in the mouse compared to the rat. Unique markers for alcohol treatment included ethyl docosahexaenoic acid. Metabolites were identified with high confidence using predominantly negative ion MS(n) data for the fatty acyl components to match to www.lipidmaps.org MS and MS/MS databases; interpreting positive ion data needed to take into account possible adduct ions which may confound the identification of other lipid classes. The observed changes in lipid profiles were consistent with alcohol induced liver injury in humans

Device-specific Outcomes Following Endovascular Aortic Aneurysm Repair

AbstractObjectiveTo compare aneurysm morphology, initial outcomes and mid-term results in patients receiving Talent or Zenith grafts for elective endovascular aneurysm repair (EVR).MethodsOver a 6-year time period ending in 2007, 286 patients underwent elective EVR of infra-renal abdominal aortic aneurysms using Talent or Zenith devices. Patient demographics, aneurysm morphology and initial outcomes (primary-assisted technical success rates, 30-day limb occlusion, re-intervention and mortality) were compared using chi-squared tests or Student's t-tests. Kaplan–Meier curves were calculated to compare cumulative rates of freedom from type I or III endoleak, re-intervention, endograft patency and overall survival over mid-term follow-up.ResultsAdverse aneurysm morphology was more common in patients receiving Zenith stent grafts, with a greater proportion of shorter neck lengths (<10mm, 12.9% vs 0%; p≤0.001) and severe neck angulation (>60°, 25.0% vs 10.3%; p=0.002). Equivalent primary-assisted technical success rates were achieved with both Talent and Zenith grafts (94.0% vs 96.1%; p=0.41). A significant number of adjunctive procedures were required in both groups to obtain a proximal endograft seal, with relatively more procedures performed in the Talent group (28.6% vs 12.4%; p=0.003). Early outcomes were similar for 30-day re-intervention (5.3% vs 3.9%; p=0.91), 30-day limb occlusion (1.5% vs 2.6%; p=0.51), 30-day morbidity (6.8% vs 11.8%; p=0.15) and 30-day mortality (4.5% vs 3.9%; p=0.80).The cumulative incidence of freedom from re-intervention was 88.3±2.9%, 86.1±3.3% and 84.1±3.9% at 1, 2 and 3 years respectively. There were no significant differences between Talent and Zenith groups for re-intervention, type I or III endoleak or limb occlusion rates over the same time period. Overall patient survival was 88.4±2.85% at 1 year, 83.7±4.0% at 2 years and 78.9±5.5% at 3 years.ConclusionsEquivalent primary-assisted technical success rates can be achieved using either Talent or Zenith endografts for endovascular aneurysm repair, but operating teams should be prepared to perform additional adjunctive procedures to obtain a primary proximal seal with either stent. The Zenith endograft performed well in the context of less favourable pre-operative aneurysm morphology. Both Talent and Zenith endografts appeared equally durable in the medium term

On Quartet Superfluidity of Fermionic Atomic Gas

Possibility of a quartet superfluidity in fermionic systems is studied as a new aspect of atomic gas at ultra low temperatures. The four-fold degeneracy of hyperfine state and moderate coupling is indispensable for the quartet superfluidity to occur. Possible superconductivity with quartet condensation in electron systems is discussed.Comment: 7 pages, 1 figure. J. Phys. Soc. Jpn. vol.74 (2005) No.7, in press; Note added for related previous works; some typographic errors revise

Alcohol-induced retrograde facilitation renders witnesses of crime less suggestible to misinformation

RATIONALE: Research has shown that alcohol can have both detrimental and facilitating effects on memory: intoxication can lead to poor memory for information encoded after alcohol consumption (anterograde amnesia) and may improve memory for information encoded before consumption (retrograde facilitation). This study examined whether alcohol consumed after witnessing a crime can render individuals less vulnerable to misleading post-event information (misinformation). METHOD: Participants watched a simulated crime video. Thereafter, one third of participants expected and received alcohol (alcohol group), one third did not expect but received alcohol (reverse placebo), and one third did not expect nor receive alcohol (control). After alcohol consumption, participants were exposed to misinformation embedded in a written narrative about the crime. The following day, participants completed a cued-recall questionnaire about the event. RESULTS: Control participants were more likely to report misinformation compared to the alcohol and reverse placebo group. CONCLUSION: The findings suggest that we may oversimplify the effect alcohol has on suggestibility and that sometimes alcohol can have beneficial effects on eyewitness memory by protecting against misleading post-event information

Bringing Molecular Biology to Bear on Adhesion Prevention: Postsurgical Adhesion Reduction Using Intraperitoneal Inoculation of Hyaluronic Acid–Inducing Adenoviral Vector in a Murine Model

Objective: Seprafilm (Genzyme, Cambridge, MA) an absorbable adhesion barrier incorporating hyaluronic acid (HA), a high molecular mass glycosaminoglycan and important component of the extracellular matrix, has been shown to prevent adhesions in both experimental models and human subjects. Yet, the application of HA as a sheet at the time of surgery has several important logistic limitations. Recently, our laboratory has identified and cloned the genes encoding murine hyaluronic acid synthase 2 (mHAS2) and 3 (mHAS3) and engineered adenoviruses incorporating these genes, which, on intraperitoneal injection, significantly increases HA in peritoneal fluid. We hypothesized that intraperitoneal gene therapy with mHAS2 or mHAS3 via an adenoviral vector prior to a standardized cecal abrasion surgery would lead to a reduction in postoperative adhesion severity. Methods: Mice were assigned to one of four groups: (1) intraperitoneal inoculation with adenovirus encoding mHAS2; (2) mHAS3; (3) a control reporter adenovirus (RV) encoding GFP; or (4) intraoperative placement of a commercially available and murine-validated hyaluronic acid adhesion barrier (Seprafilm, SF). An a priori sample size calculation was performed. Mice in groups 1, 2, and 3 underwent injection of 2 x 107 viral particles in 1 ml of fluid on day -1. Sham injection was performed on group 4 SF mice. On day 0, laparotomy was performed in random sequence by surgeon blinded to the experimental group. On day 7, adhesion scores (0-3) were assigned independently by two blinded investigators. Results: Mean adhesion scores (n = 247) were 0.68 (mHAS2), 0.91 (mHAS3), 1.28 (RV), and 0.47 (SF). Pairwise comparisons using Wilcoxon rank-sum test revealed significant reduction in severity of adhesions between mHAS2, mHAS3, and SF compared to RV (p = 0.0004, 0.039, and 0.0001, respectively). Significance persisted despite correction for multiple comparisons (p = 0.0002, Kruskal-Wallis). There was a direct relationship between intraperitoneal HA concentration and adhesion reduction. Only one death (RV) was secondary to adhesive disease; differential risk of death between groups was statistically significant (p = 0.008) (highest in mHAS2 group). Conclusions: In a dose-response relationship, an intraperitoneal gene therapy approach to adhesion prevention in a murine model was successful, with adenoviruses most productive of HA resulting in the most significant reduction in adhesion scores compared to empty virus (RV). Although SF best reduced postoperative adhesions, the adenoviral gene delivery approach may prove to be more effective in clinical use when peritoneal injury is less localized or at laparoscopy where the application of SF is not possible. Further studies to elucidate the reason for the differential death rates (time bias may have played a role) and to validate results are in progress

Creation of ultracold molecules from a Fermi gas of atoms

Since the realization of Bose-Einstein condensates (BEC) in atomic gases an experimental challenge has been the production of molecular gases in the quantum regime. A promising approach is to create the molecular gas directly from an ultracold atomic gas; for example, atoms in a BEC have been coupled to electronic ground-state molecules through photoassociation as well as through a magnetic-field Feshbach resonance. The availability of atomic Fermi gases provides the exciting prospect of coupling fermionic atoms to bosonic molecules, and thus altering the quantum statistics of the system. This Fermi-Bose coupling is closely related to the pairing mechanism for a novel fermionic superfluid proposed to occur near a Feshbach resonance. Here we report the creation and quantitative characterization of exotic, ultracold $^{40}$K$_2$ molecules. Starting with a quantum degenerate Fermi gas of atoms at T < 150 nanoKelvin we scan over a Feshbach resonance to adiabatically create over a quarter million trapped molecules, which we can convert back to atoms by reversing the scan. The small binding energy of the molecules is controlled by detuning from the Feshbach resonance and can be varied over a wide range. We directly detect these weakly bound molecules through rf photodissociation spectra that probe the molecular wavefunction and yield binding energies that are consistent with theory