Discusses the use of individual and group journals as a way to develop students' abilities to critically analyze reading materials in a college level sociology course. Describes the process by which ...the journals are written and evaluated. Contends that the learning strategy improved students' analytical abilities and writing skills. (CFR)
The Qweak experiment has measured the parity-violating asymmetry in polarized e-p elastic scattering at Q^2 = 0.025(GeV/c)^2, employing 145 microamps of 89% longitudinally polarized electrons on a ...34.4cm long liquid hydrogen target at Jefferson Lab. The results of the experiment's commissioning run are reported here, constituting approximately 4% of the data collected in the experiment. From these initial results the measured asymmetry is Aep = -279 +- 35 (statistics) +- 31 (systematics) ppb, which is the smallest and most precise asymmetry ever measured in polarized e-p scattering. The small Q^2 of this experiment has made possible the first determination of the weak charge of the proton, QpW, by incorporating earlier parity-violating electron scattering (PVES) data at higher Q^2 to constrain hadronic corrections. The value of QpW obtained in this way is QpW(PVES) = 0.064 +- 0.012, in good agreement with the Standard Model prediction of QpW(SM) = 0.0710 +- 0.0007. When this result is further combined with the Cs atomic parity violation (APV) measurement, significant constraints on the weak charges of the up and down quarks can also be extracted. That PVES+APV analysis reveals the neutron's weak charge to be QnW(PVES+APV) = -0.975 +- 0.010.
Examination of the archaeological evidence for the expression of identity in later European prehistory provides a new and promising approach to understanding change in this period. New views of the ...role of material culture in the communication of meanings, of the nature of identity, and of agency in the past provide a useful framework for approaching the evidence. Analysis of patterns of sameness and difference in style and decoration of manufactured objects indicates how people used their material culture to structure and to communicate their identities—on the level of the individual, of groups such as families and residential communities, and of larger entities commonly referred to as ethnic groups. This approach offers insights that complement social and economic models of change in later prehistory.
This article presents the rationale and evidence for the treatment of lower-extremity deep venous thrombosis (DVT) with thrombolytic agents. DVT is a common condition that has both acute and chronic ...complications. Standard treatment including anticoagulation therapy and compression stockings may not be entirely adequate, because a significant proportion of patients eventually develop severe post-thrombotic syndrome (PTS). Thrombolytic agents offer a potential advantage because they may reduce residual vein stenosis and valve damage. The authors performed a systematic review of published randomized trials evaluating thrombolytic agents for DVT. The authors determined that thrombolysis therapy results in greater lysis and complication rates than does anticoagulation alone. The authors also found that PTS incidence is lower in patients treated with thrombolytics. However, several methodological flaws limit the conclusions with respect to reduction in PTS. Therefore, the authors conclude that although the lysis rate is greater for thrombolytic agents, they cannot be recommended routinely for DVT treatment.
In the December 2000 issue of the Journal of Abnormal Child Psychology, we published a set of papers presenting secondary analyses of the Multimodal Treatment Study of ADHD (MTA), and R. A. Barkley ...(2000) provided a commentary. A critique of the design of the study (MTA Cooperative Group, 1999) was presented based on a theoretical perspective of a "behavioral inhibition" deficit that has been hypothesized as the core deficit of ADHD (R. A. Barkley, 1997). The commentary questioned the design and analysis of the MTA in terms of (1) the empirical criteria for selection of components of behavioral (Beh) intervention, (2) the effectiveness of the Beh intervention, (3) the methods for analyses at the group and individual level, (4) implications of the MTA findings for clinical practice, (5) the role of genetics in response to treatment, and (6) the lack of a nontreatment control group. In this response, we relate the content of the papers to the commentary, (1) by reviewing the selection criteria for the Beh treatment, as outlined by K. C. Wells, W. E. Pelham, et al. (2000), (2) by addressing the myth that the MTA Beh treatment was ineffective (Pelham, 1999), (3) by describing the use of analyses at the level of the individual participant, as presented by J. S. March et al. (2000) and W. E. Pelham et al. (2000) as well as elsewhere by J. M. Swanson et al. (2001) and C. K. Conners et al. (2001), (4) by relating some of the suggestions from the secondary analyses about clinically relevant factors such as comorbidity (as presented by J. S. March et al., 2000) and family and parental characteristics (as presented by B. Hoza et al., 2000, S. P. Hinshaw et al., 2000, and K. C. Wells, J. N. Epstein, et al., 2000), (5) by discussing the statistical concept of heritability and the lack of a significant difference in the presence of ADHD symptoms in parents of the MTA families compared to parents in the classmate-control families (as presented by J. N. Epstein, et al., 2000), and (6) by acknowledging that an ethically necessary weakness of the MTA design is that it did not include a no-treatment control group. We discuss the use of secondary analyses to suggest how, when, and for what subgroups effectiveness of the Beh treatment may have been manifested. Finally, we invite others to use the large and rich data set that will soon be available in the public domain, to perform secondary analyses to mine the meaning of the MTA and to evaluate theories of ADHD and response to treatments.
Mutants of Pseudomonas aeruginosa PAC1R (serotype O:3) which were resistant to bacteriophage D were isolated and shown to react with O:5d, O:9 and O:13 antisera as well as O:3. Antisera to the parent ...strain and to the three polyagglutinating (PA) mutants also showed cross-reactions. The mutants differed from the parent strain in their lipopolysaccharide (LPS) composition. The LPS from two of the three mutants yielded high molecular weight polysaccharide fractions. Although the high molecular weight fraction from one of the mutants contained the amino sugars and other components characteristic of the O:3 serotype strains, its mobility on Sephadex G75 was different from that of the parent strain. The high molecular weight material from the second mutant lacked the O-antigenic determinants but these were present in a semi-rough LPS fraction. The third mutant appeared rough and completely lacked the O-antigenic components. These three mutants were compared with the parent strain and with a non-agglutinating LPS-defective mutant which lacked both O-antigenic side chains and all neutral sugars in the outer core. Agglutination with absorbed sera and haemagglutination using purified LPS and ELISA detection suggested that wall components other than LPS were responsible for some of the cross-reactions observed. The components responsible were detected after SDS-PAGE of crude outer membrane fractions by a combination of Coomassie blue and silver-staining and antigenic components were detected by immunoelectrophoresis and ELISA-linked immunoblotting of the gels. The main antigenic determinants detected by antiserum to the parent strain were in the high molecular weight O-polysaccharide fractions and in the semirough fractions of the LPS, with some activity due to the H protein of the outer membrane. O:5d antisera reacted with unidentified high molecular weight polysaccharide fractions. Cross-reactions with the O:9 antiserum appeared to be due mainly to the F porin and, to a lesser extent, to the G and E proteins of the outer membrane. O:13 antiserum reacted with high molecular weight polysaccharide fractions but also with the rough core and F and H protein. Cross-reactivity of the other three mutant antisera could largely be interpreted in terms of the outer membrane components exposed in each strain. One reacted strongly with the F porin and the rough core, while the others reacted with a number of protein and LPS-derived fractions.
The parity-violating asymmetry arising from inelastic electron-nucleon scattering at backward angle (~95 degrees) near the Delta(1232) resonance has been measured using a hydrogen target. From this ...asymmetry, we extracted the axial transition form factor G^A_{N\Delta}, a function of the axial Adler form factors C^A_i. Though G^A_{N\Delta} has been previously studied using charged current reactions, this is the first measurement of the weak neutral current excitation of the Delta using a proton target. For Q^2 = 0.34 (GeV/c)^2 and W = 1.18 GeV, the asymmetry was measured to be -33.4 \pm (5.3)_{stat} \pm (5.1)_{sys} ppm. The value of G^A_{N\Delta} determined from the hydrogen asymmetry was -0.05 \pm (0.35)_{stat} \pm (0.34)_{sys} \pm (0.06)_{theory}. These findings agree within errors with theoretical predictions for both the total asymmetry and the form factor. In addition to the hydrogen measurement, the asymmetry was measured at the same kinematics using a deuterium target. The asymmetry for deuterium was determined to be -43.6 \pm (14.6)_{stat} \pm (6.2)_{sys} ppm.
A subset of results from the recently completed Jefferson Lab Qweak experiment are reported. This experiment, sensitive to physics beyond the Standard Model, exploits the small parity-violating ...asymmetry in elastic e→p$\vec e{\rm{p}}$ scattering to provide the first determination of the proton’s weak charge Qwp$Q_w^p$. The experiment employed a 180 μA longitudinally polarized 1.16 GeV electron beam on a 35 cm long liquid hydrogen target. Scattered electrons in the angular range 6° < θ < 12° corresponding to Q2 = 0.025 GeV2 were detected in eight Cerenkov detectors arrayed symmetrically around the beam axis. The goals of the experiment were to provide a measure of e→p$\vec e{\rm{p}}$ to 4.2% (combined statisstatistical and systematic error), which implies a measure of sin2(θw) at the level of 0.3%, and to help constrain the vector weak quark charges C1u and C1d. The experimental method is described, with particular focus on the challenges associated with the world’s highest power LH2 target. The new constraints on C1u and C1d provided by the subset of the experiment’s data analyzed to date will also be shown, together with the extracted weak charge of the neutron.
There is limited information on longer-term outcomes of pulmonary homograft monocusp (PHM) reconstruction of the right ventricular outflow tract (RVOT).
A retrospective review of 131 consecutive ...patients undergoing RVOT reconstruction with PHM was completed.
Median age was 7.6 months (range, 1 day to 14 years) and weight was 7.3 kg (range, 2 to 65 kg). Most patients (108 of 131; 82%) underwent repair for Tetralogy. After PHM, median duration of mechanical ventilation was 1 day (range, 0 to 89) and hospital stay was 6.5 days (range, 2 to 137). Hospital mortality was 2% (3 of 131) with 1 patient undergoing early replacement of PHM. Echocardiogram at hospital discharge demonstrated peak RVOT gradient of 16 mm Hg (range, 4 to 64 mm Hg); and pulmonary insufficiency was absent/trivial in 40%, mild in 42%, moderate in 16%, and severe in 2%. Follow-up is completed in 91% of hospital survivors at a median of 5 years (range, 1 to 12). There were 5 late deaths, with an actuarial survival of 96% +/- 3.7%, 94% +/- 4.6%, and 89% +/- 9.2% at 1 year, 5 years, and 10 years, respectively. There were 24 reinterventions, including 10 pulmonary valve replacements. Median time to valve replacement was 1.9 years (range, 0.4 to 4.6). Actuarial freedom from pulmonary valve replacement was 97% +/- 3.0%, 90% +/- 6.1%, and 85% +/- 10.3% at 1 year, 5 years, and 10 years, respectively. Echocardiogram at last follow-up demonstrated no increase in RVOT gradient compared with hospital discharge (16 mm Hg), but there was significant increase in pulmonary insufficiency (mild 27%, moderate 39%, severe 34%).
Pulmonary homograft monocusp reconstruction is an alternative strategy for RVOT reconstruction and provides early but gradually diminishing protection against pulmonary insufficiency without a risk of stenosis. As expected, PHM function decreases over time as the RVOT grows and the homograft tissue undergoes structural deterioration.
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