Risky sexual behaviors and sexually transmitted diseases: a comparison study of cocaine-dependent individuals in treatment versus a community-matched sample

Cocaine users routinely engage in high-risk sexual behaviors that place them at an elevated risk of contracting HIV and other blood-borne infections. The purpose of the present study was to compare trading sex for drugs and/or money, having 10 or more sexual partners in 1 year, and sexually transmitted diseases (STDs) of cocaine-dependent individuals in treatment for their dependence across race and gender and against participants who live in their community. Cocaine-dependent individuals (n = 459) were identified through nine publicly and privately funded inpatient and outpatient chemical dependency treatment centers in the St. Louis area during 2001–2006. Community-based participants (n = 459) were matched to cocaine-dependent participants on age, ethnicity, gender, and zip code of residence. Mean age of the sample was 36 years old, 50% were Caucasians, 50% were African American, and 47% were male. Nearly half of cocaine-dependent participants in treatment had traded sex for drugs and/or money and over one-third had more than 10 sexual partners in 1 year with a risk concentrated among African Americans even after controlling for income and educational attainment. Participants recruited from the community with some exposure to cocaine reported similar rates of high risk sexual behaviors as the cocaine dependent subjects from treatment settings. It is important for clinicians to recognize that once released from treatment, cocaine-dependent individuals may be returning to high-risk environments where sexual risk behaviors are occurring in the context of cocaine use

Evidence for the η_b(1S) Meson in Radiative Υ(2S) Decay

We have performed a search for the η_b(1S) meson in the radiative decay of the Υ(2S) resonance using a sample of 91.6 × 10^6 Υ(2S) events recorded with the BABAR detector at the PEP-II B factory at the SLAC National Accelerator Laboratory. We observe a peak in the photon energy spectrum at E_γ = 609.3^(+4.6)_(-4.5)(stat)±1.9(syst) MeV, corresponding to an η_b(1S) mass of 9394.2^(+4.8)_(-4.9)(stat) ± 2.0(syst) MeV/c^2. The branching fraction for the decay Υ(2S) → γη_b(1S) is determined to be [3.9 ± 1.1(stat)^(+1.1)_(-0.9)(syst)] × 10^(-4). We find the ratio of branching fractions B[Υ(2S) → γη_b(1S)]/B[Υ(3S) → γη_b(1S)]= 0.82 ± 0.24(stat)^(+0.20)_(-0.19)(syst)

Measurement of the quasi-elastic axial vector mass in neutrino-oxygen interactions

The weak nucleon axial-vector form factor for quasi-elastic interactions is determined using neutrino interaction data from the K2K Scintillating Fiber detector in the neutrino beam at KEK. More than 12,000 events are analyzed, of which half are charged-current quasi-elastic interactions nu-mu n to mu- p occurring primarily in oxygen nuclei. We use a relativistic Fermi gas model for oxygen and assume the form factor is approximately a dipole with one parameter, the axial vector mass M_A, and fit to the shape of the distribution of the square of the momentum transfer from the nucleon to the nucleus. Our best fit result for M_A = 1.20 \pm 0.12 GeV. Furthermore, this analysis includes updated vector form factors from recent electron scattering experiments and a discussion of the effects of the nucleon momentum on the shape of the fitted distributions.Comment: 14 pages, 10 figures, 6 table

Cytokinesis in bloodstream stage Trypanosoma brucei requires a family of katanins and spastin

Microtubule severing enzymes regulate microtubule dynamics in a wide range of organisms and are implicated in important cell cycle processes such as mitotic spindle assembly and disassembly, chromosome movement and cytokinesis. Here we explore the function of several microtubule severing enzyme homologues, the katanins (KAT80, KAT60a, KAT60b and KAT60c), spastin (SPA) and fidgetin (FID) in the bloodstream stage of the African trypanosome parasite, Trypanosoma brucei. The trypanosome cytoskeleton is microtubule based and remains assembled throughout the cell cycle, necessitating its remodelling during cytokinesis. Using RNA interference to deplete individual proteins, we show that the trypanosome katanin and spastin homologues are non-redundant and essential for bloodstream form proliferation. Further, cell cycle analysis revealed that these proteins play essential but discrete roles in cytokinesis. The KAT60 proteins each appear to be important during the early stages of cytokinesis, while downregulation of KAT80 specifically inhibited furrow ingression and SPA depletion prevented completion of abscission. In contrast, RNA interference of FID did not result in any discernible effects. We propose that the stable microtubule cytoskeleton of T. brucei necessitates the coordinated action of a family of katanins and spastin to bring about the cytoskeletal remodelling necessary to complete cell divisio

Neutral proteases of human polymorphonuclear granulocytes: putative mediators of pulmonary damage.

Tissue proteolytic enzymes are currently believed to be critical to the pathogenesis of panacinar emphysema. Polymorphonuclear leukocytes (Polys) have several enzymes including elastase and cathepsin G in their azurophil granules. They have collagenase in their specific granules. We have found that this collagenase is doubly latent. It has the lysosomal type of latency that depends on the impermeability of the unit membrane that surrounds each specific granule. In addition it has a latency that is converted to activity by proteolytic enzymes. The cathepsin G of the azurophil granule is a potent activator of this latent collagenase once the collagenase is released from its membrane dependent latency. Thus latency of enzymes, the nature of the latency and accessibility of the latent enzymes to activating mechanisms must all be taken into account in any analysis of their contribution to pathogenesis of local lung disease. Equally important is that fact that polys are not a prominent cellular component of normal lung. Polys must be attracted to the lung by chemotactic peptides. These peptides must be released by the interaction of inflammatory stimuli, such as smoke particles, with complement components or they must be provided by other sources. The hypothesis that lung damage in panacinar emphysema is mediated by polys and their proteases is attractive and suggestive evidence supporting this is available. However, more evidence that takes into full account the cell biology of the proteases any poly turnover in the lung are needed to extend the hypothesis and to form a rational basis for therapeutic and prophylactic measures

Measurement of the B+ --> p pbar K+ Branching Fraction and Study of the Decay Dynamics

With a sample of 232x10^6 Upsilon(4S) --> BBbar events collected with the BaBar detector, we study the decay B+ --> p pbar K+ excluding charmonium decays to ppbar. We measure a branching fraction Br(B+ --> p pbar K+)=(6.7+/-0.5+/-0.4)x10^{-6}. An enhancement at low ppbar mass is observed and the Dalitz plot asymmetry suggests dominance of the penguin amplitude in this B decay. We search for a pentaquark candidate Theta*++ decaying into pK+ in the mass range 1.43 to 2.00 GeV/c2 and set limits on Br(B+ --> Theta*++pbar)xBr(Theta*++ --> pK+) at the 10^{-7} level.Comment: 8 pages, 7 postscript figures, submitted to Phys. Rev. D (Rapid Communications

Simulation for training in sinus floor elevation : new surgical bench model

Objectives: to describe a bench model (workshop of abilities) for sinus floor elevation (SFE) training that simulates the surgical environment and to assess its effectiveness in terms of trainees? perception. Study design: thirty-six randomly selected postgraduate students entered this cross-sectional pilot study and asked to fill in an anonymous, self-applied, 12-item questionnaire about a SFE workshop that included a study guide containing the workshop?s details, supervised practice on a simulated surgical environment, and assessment by means of specific check-lists. Results: Thirtiy-six fresh sheep heads were prepared to allow access to the buccal vestible. Using the facial tuber, third premolar and a 3D-CT study as landmarks for trepanation, the sinus membrane was lifted, the space filled with ceramic material and closed with a resorbable membrane. The participants agreed on their ability to perform SFE in a simulated situation (median score= 4.5; range 2-5) and felt capable to teach the technique to other clinicians or to undertake the procedure for a patient under supervision of an expert surgeon (median= 4; range 1-5 ). There were no differences on their perceived ability to undertake the technique on a model or on a real patient under supervision of an expert surgeon (p=0.36). Conclusions: Clinical abilities workshops for SFE teaching are an essential educational tool but supervised clinical practice should always precede autonomous SFE on real patients. Simulation procedures (workshop of abilities) are perceived by the partakers as useful for the surgical practice. However, more studies are needed to validate the procedure and to address cognitive and communication skills, that are clearly integral parts of surgical performance

Clinical outcomes of all‐ceramic single crowns and fixed dental prostheses supported by ceramic implants: A systematic review and meta‐analyses

Objective: To analyze the clinical outcomes of all-ceramic single crowns (SCs) and fixed dental prostheses (FDPs) supported by ceramic implants. Materials and methods: Based on a focused question and customized PICO framework, electronic (Medline/EMBASE/Cochrane) and manual searches for studies reporting the clinical outcomes of all-ceramic SCs and FDPs supported by ceramic implants ≥12 months were performed. The primary outcomes were reconstruction survival and the chipping proportion. The secondary outcomes were implant survival, technical complications, and patient-related outcome measurements. Meta-analyses were performed after 1, 2, and 5 years using random-effect meta-analyses. Results: Eight of the 1,403 initially screened titles and 55 full texts were included. Five reported on monolithic lithium disilicate (LS2) SCs, one on veneered zirconia SCs, and two on veneered zirconia SCs and FDPs, which reported all on cement-retained reconstructions (mean observation: 12.0-61.0 months). Meta-analyses estimated a 5-year survival rate of 94% (95% confidence interval [CI]: 82%-100%) for overall implant survival. Reconstruction survival proportions after 5 years were: monolithic LS2, 100% (95%CI: 95%-100%); veneered zirconia SCs, 89% (95%CI: 62%-100%); and veneered zirconia FDPs 94% (95%CI: 81%-100%). The chipping proportion after 5 years was: monolithic LS2, 2% (95%CI: 0%-11%); veneered zirconia SCs, 38% (95%CI: 24%-54%); and veneered zirconia FDPs, 57% (95%CI: 38%-76%). Further outcomes were summarized descriptively. Conclusions: Due to the limited data available, only tendencies could be identified. All-ceramic reconstructions supported by ceramic implants demonstrated promising survival rates after mid-term observation. However, high chipping proportions of veneered zirconia SCs and, particularly, FDPs diminished the overall outcome. Monolithic LS2 demonstrated fewer clinical complications. Monolithic reconstructions could be a valid treatment option for ceramic implants. Keywords: ceramics; dental implants; implant-supported dental prosthesis; meta-analysis; survival analysis; systematic review; treatment outcome; zirconia

A mathematical and computational review of Hartree-Fock SCF methods in Quantum Chemistry

We present here a review of the fundamental topics of Hartree-Fock theory in Quantum Chemistry. From the molecular Hamiltonian, using and discussing the Born-Oppenheimer approximation, we arrive to the Hartree and Hartree-Fock equations for the electronic problem. Special emphasis is placed in the most relevant mathematical aspects of the theoretical derivation of the final equations, as well as in the results regarding the existence and uniqueness of their solutions. All Hartree-Fock versions with different spin restrictions are systematically extracted from the general case, thus providing a unifying framework. Then, the discretization of the one-electron orbitals space is reviewed and the Roothaan-Hall formalism introduced. This leads to a exposition of the basic underlying concepts related to the construction and selection of Gaussian basis sets, focusing in algorithmic efficiency issues. Finally, we close the review with a section in which the most relevant modern developments (specially those related to the design of linear-scaling methods) are commented and linked to the issues discussed. The whole work is intentionally introductory and rather self-contained, so that it may be useful for non experts that aim to use quantum chemical methods in interdisciplinary applications. Moreover, much material that is found scattered in the literature has been put together here to facilitate comprehension and to serve as a handy reference.Comment: 64 pages, 3 figures, tMPH2e.cls style file, doublesp, mathbbol and subeqn package

Search for rare quark-annihilation decays, B --> Ds(*) Phi

We report on searches for B- --> Ds- Phi and B- --> Ds*- Phi. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and u-bar quarks in the B- meson. Our results are based on 234 million Upsilon(4S) --> B Bbar decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limits on the branching fractions BF(B- --> Ds- Phi) Ds*- Phi)<1.2x10^(-5). These results are consistent with Standard Model expectations.Comment: 8 pages, 3 postscript figues, submitted to Phys. Rev. D (Rapid Communications