4,386 research outputs found

    A field study of the wind generation of ocean waves

    Get PDF
    This paper describes a series of field experiments that provide growth curves and wind histories for waves of wave length r 7 m. In each of 29 runs of from 1 to 4 hours, a directional wave recorder with an effective beam width of 20 degrees was towed downwind at the group velocity of these waves starting from a windward shore...

    Identifying wildlife reservoirs of neglected taeniid tapeworms : non-invasive diagnosis of endemic Taenia serialis infection in a wild primate population

    Get PDF
    Despite the global distribution and public health consequences of Taenia tapeworms, the life cycles of taeniids infecting wildlife hosts remain largely undescribed. The larval stage of Taenia serialis commonly parasitizes rodents and lagomorphs, but has been reported in a wide range of hosts that includes geladas (Theropithecus gelada), primates endemic to Ethiopia. Geladas exhibit protuberant larval cysts indicative of advanced T. serialis infection that are associated with high mortality. However, non-protuberant larvae can develop in deep tissue or the abdominal cavity, leading to underestimates of prevalence based solely on observable cysts. We adapted a non-invasive monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) to detect circulating Taenia spp. antigen in dried gelada urine. Analysis revealed that this assay was highly accurate in detecting Taenia antigen, with 98.4% specificity, 98.5% sensitivity, and an area under the curve of 0.99. We used this assay to investigate the prevalence of T. serialis infection in a wild gelada population, finding that infection is substantially more widespread than the occurrence of visible T. serialis cysts (16.4% tested positive at least once, while only 6% of the same population exhibited cysts). We examined whether age or sex predicted T. serialis infection as indicated by external cysts and antigen presence. Contrary to the female-bias observed in many Taenia-host systems, we found no significant sex bias in either cyst presence or antigen presence. Age, on the other hand, predicted cyst presence (older individuals were more likely to show cysts) but not antigen presence. We interpret this finding to indicate that T. serialis may infect individuals early in life but only result in visible disease later in life. This is the first application of an antigen ELISA to the study of larval Taenia infection in wildlife, opening the doors to the identification and description of infection dynamics in reservoir populations

    Institutional Experience with Primary Interventional Radiology Sclerotherapy for Lymphatic Malformation

    Get PDF
    Interventional Radiology Sclerotherapy is effective for treatment of primary and recurrent lymphatic malformationshttps://knowledgeconnection.mainehealth.org/lambrew-retreat-2021/1024/thumbnail.jp

    Can One Measure the Weak Phase of a Penguin Diagram?

    Get PDF
    The b -> d penguin amplitude receives contributions from internal u, c and t-quarks. We show that it is impossible to measure the weak phase of any of these penguin contributions without theoretical input. However, it is possible to obtain the weak phase if one makes a single assumption involving the hadronic parameters. With such an assumption, one can test for the presence of new physics in the b -> d flavour-changing neutral current by comparing the weak phase of B_d^0-{\bar B}_d^0 mixing with that of the t-quark contribution to the b -> d penguin.Comment: 20 pages, no figure

    Report on the May-June 2002 Englebright Lake deep coring campaign

    Get PDF
    This report describes the May-June 2002 Englebright Lake coring project. Englebright Lake is a 14-km-long reservoir on the Yuba River of northern California, impounded by Englebright Dam, which was completed in 1940. The sediments were cored to assess the current conditions in the reservoir as part of the California Bay-Delta Authority’s Upper Yuba River Studies Program. Sediment was collected using both hydraulic-piston and rotational coring equipment mounted on a floating drilling platform. Thirty boreholes were attempted at 7 sites spaced along the longitudinal axis of the reservoir. Complete sedimentary sections were recovered from 20 boreholes at 6 sites. In total, 335 m of sediment was cored, with 86% average recovery. The core sections (each up to 1.5 m long) were processed using a standard set of laboratory techniques, including geophysical logging of physical properties, splitting, visual descriptions, digital photography, and initial subsampling. This report presents the results of these analyses in a series of stratigraphic columns. Using the observed stratigraphy as a guide, several series of subsamples were collected for various sedimentologic, geochemical, and geochronological analyses. The results of laboratory analyses of most of these subsamples will be presented in future reports and articles

    Tantalum versus Titanium Acetabular Shells in Young Active THR Patients: A Radiostereometric Analysis (RSA) Study

    Get PDF
    Introduction: In the active THR (total hip replacement) population, acetabular component stability is crucial for preventing implant failure. Titanium fiber metal coating is the most common material used in cementless THR. Trabecular metal, composed of porous tantalum, is designed to improve tissue infiltration and limit migration. It is unknown if tantalum offers an advantage over titanium in the biologic fixation of porous-coated acetabular shells. Radiostereometric analysis (RSA) provides highly precise measurements of micromotion that are otherwise not detectable by routine radiographs. Methods: In this IRB approved, prospective, randomized, blinded study, 46 patients received a primary THR by a single surgeon. Each patient was randomized to receive a titanium (23) or tantalum (23) uncemented cup. Tantalum RSA markers were implanted around the polyethylene liner and into the patient’s femur and periacetabular bone. Also, patients received either a highly cross-linked (n=25) or a conventional liner (n=21). RSA examinations, Harris Hip, UCLA, WOMAC, SF-12 scores were obtained at 10 days, 6 months, and annually through 5 years. Results: The randomized groups had comparable mean age, preoperative activity, and average BMI. The tantalum shells demonstrated less median translation than the titanium shells at each time-point, but there was no statistical difference between the two shells. At 6 months median translation of tantalum and titanium was -0.01mm and 0.04mm and remained stable with median translation of -0.02mm and 0.04mm at four years. Mean UCLA, WOMAC, Harris Hip, and SF-12 PCS and MCS scores improved similarly in both groups. Conclusions: After THR, both patient cohorts had excellent clinical outcomes with statistically significant improvements in function and pain relief. Although tantalum porous-coated acetabular shells demonstrated less y-translation and y-rotation at all time points, there was no statistically significant difference in shell migration and both shells demonstrated excellent stability with minimal micromotion at four years

    Exploring CP Violation with B_d -> D K_s Decays

    Full text link
    We (re)examine CP violation in the decays B_d -> D K_s, where D represents D^0, D(bar), or one of their excited states. The quantity sin2(2β+γ)\sin^2(2\beta + \gamma) can be extracted from the time-dependent rates for Bd(t)>Dˉ0KsB_d(t) -> {\bar D}^{**0} K_s and Bd(t)>D0KsB_d(t) -> D^{**0} K_s, where the D0D^{**0} decays to D()+πD^{(*)+}\pi^-. If one considers a non-CP-eigenstate hadronic final state to which both D(bar) and D^0 can decay (e.g. K+πK^+\pi^-), then one can obtain two of the angles of the unitarity triangle from measurements of the time-dependent rates for Bd(t)>(K+π)DKsB_d(t) -> (K^+\pi^-)_{D K_s} and Bd(t)>(Kπ+)DKsB_d(t) -> (K^-\pi^+)_{D K_s}. There are no penguin contributions to these decays, so all measurements are theoretically clean.Comment: 15 pages, LaTeX, no figure

    Giant Thermoelectric Effect from Transmission Supernodes

    Full text link
    We predict an enormous order-dependent quantum enhancement of thermoelectric effects in the vicinity of a higher-order `supernode' in the transmission spectrum of a nanoscale junction. Single-molecule junctions based on 3,3'-biphenyl and polyphenyl ether (PPE) are investigated in detail. The nonequilibrium thermodynamic efficiency and power output of a thermoelectric heat engine based on a 1,3-benzene junction are calculated using many-body theory, and compared to the predictions of the figure-of-merit ZT.Comment: 5 pages, 6 figure

    B-Decay CP Asymmetries, Discrete Ambiguities and New Physics

    Get PDF
    The first measurements of CP violation in the BB system will likely probe sin2α\sin 2\alpha, sin2β\sin 2\beta and cos2γ\cos 2\gamma. Assuming that the CP angles α\alpha, β\beta and γ\gamma are the interior angles of the unitarity triangle, these measurements determine the angle set (α,β,γ)(\alpha,\beta,\gamma) except for a twofold discrete ambiguity. If one allows for the possibility of new physics, the presence of this discrete ambiguity can make its discovery difficult: if only one of the two candidate solutions is consistent with constraints from other measurements in the BB and KK systems, one is not sure whether new physics is present or not. We review the methods used to resolve the discrete ambiguity and show that, even in the presence of new physics, they can usually be used to uncover this new physics. There are some exceptions, which we describe in detail. We systematically scan the parameter space and present examples of values of (α,β,γ)(\alpha,\beta,\gamma) and the new-physics parameters which correspond to all possibilities. Finally, we show that if one relaxes the assumption that the bag parameters \BBd and \BK are positive, one can no longer definitively establish the presence of new physics.Comment: 29 pages, LaTeX, 1 figures, presentation substantially reworked, physics conclusions unchanged. This version will be published in Phys. Rev.

    New CP observables in B0(t) -> hyperon + antihyperon from parity violation in the sequential decay

    Full text link
    We consider the decay B0(t) -> hyperon + antihyperon, followed by hyperon weak decay. We show that parity violation in the latter allows to reach new CP observables: not only Im(lambda_f) but also Re(lambda_f) can be measured. In the decay B0_d(t) -> Lambda LambdaBar (BR ~ 10-6), Lambda -> p pi- these observables reduce to sin(2alpha) and cos(2alpha) in the small Penguin limit, the latter solving the discrete ambiguity alpha -> pi/2 -alpha. For beta one could consider the Cabibbo suppressed mode B0_d(t) -> Lambda_c Lambda_cBar (BR \~ 10-4), Lambda_c -> Lambda pi+, p K0bar, ... (with BR ~ 10-2). The pure Penguin modes B0_s(t)->Sigma-Sigma-Bar, Xi-Xi-Bar, Omega-Omega-Bar (BR ~ 10-7) can be useful in the search of CP violation beyond the Standard Model. Because of the small total rates, the study of these modes could only be done in future high statistics experiments. Also, in the most interesting case Lambda LambdaBar the time dependence of the asymmetry can be difficult to reconstruct. On the other hand, we show that B_d mesons, being a coherent source of Lambda LambdaBar, is useful to look for CP violation in Lambda decay. We also discuss B0_d(t) -> J/Psi K*0 -> l+ l- K_S pi0 where the secondary decays conserve parity, and angular correlations allow to determine terms of the form cos(delta)cos(2beta), delta being a strong phase. This phase has been measured by CLEO, but we point out that a discrete ambiguity prevents to determine sign(cos(2beta)). However, if one assumes small strong phases, like in factorization and as supported by CLEO data, one could have information on sign(cos(2beta)). Similar remarks can be done for cos(2alpha) in the decay B_d0(t) -> rho rho -> 4pi.Comment: LaTeX, 35 pages, 4 figures in a separate postscript fil
    corecore