Measurement of the Target-Normal Single-Spin Asymmetry in Quasielastic Scattering from the Reaction (3)He(↑)(e,e')

We report the first measurement of the target single-spin asymmetry, A(y), in quasielastic scattering from the inclusive reaction (3)He(↑)(e,e') on a (3)He gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A nonzero A(y) can arise from the interference between the one- and two-photon exchange processes which is sensitive to the details of the substructure of the nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at Q(2)=0.13, 0.46, and 0.97  GeV(2). These measurements demonstrate, for the first time, that the (3)He asymmetry is clearly nonzero and negative at the 4σ-9σ level. Using measured proton-to-(3)He cross-section ratios and the effective polarization approximation, neutron asymmetries of -(1-3)% were obtained. The neutron asymmetry at high Q(2) is related to moments of the generalized parton distributions (GPDs). Our measured neutron asymmetry at Q(2)=0.97  GeV(2) agrees well with a prediction based on two-photon exchange using a GPD model and thus provides a new, independent constraint on these distributions.

Differential risk factors for HIV drug and sex risk-taking among non-treatment-seeking hospitalized injection drug users

Injection drug users (IDUs) are at increased risk of contracting HIV. From a clinical trial assessing an intervention to enhance the linkage of hospitalized patients to opioid treatment after discharge, we conducted multivariate analysis of baseline data from hospitalized IDUs with a history of opioid dependence (n = 104) to identify differences in factors predicting HIV drug and sex risk behaviors. Factors significantly associated with HIV drug risk were being non-Hispanic Caucasian and recent cocaine use. Being female, binge drinking, and poorer mental health were significantly associated with higher sex risk. Because factors predicting HIV sex risk behaviors differ from those predicting HIV drug risk, interventions aimed at specific HIV risks should have different behavioral and substance use targets.

Measurement of double-polarization asymmetries in the quasielastic (3)He[→](e[→],e(')d) process

We present a precise measurement of double-polarization asymmetries in the ^{3}He[over →](e[over →],e^{'}d) reaction. This particular process is a uniquely sensitive probe of hadron dynamics in ^{3}He and the structure of the underlying electromagnetic currents. The measurements have been performed in and around quasielastic kinematics at Q^{2}=0.25(GeV/c)^{2} for missing momenta up to 270  MeV/c. The asymmetries are in fair agreement with the state-of-the-art calculations in terms of their functional dependencies on p_{m} and ω, but are systematically offset. Beyond the region of the quasielastic peak, the discrepancies become even more pronounced. Thus, our measurements have been able to reveal deficiencies in the most sophisticated calculations of the three-body nuclear system, and indicate that further refinement in the treatment of their two-and/or three-body dynamics is required.

The prevalence of abnormal genital findings, vulvovaginitis, enuresis and encopresis in children who present with allegations of sexual abuse

OBJECTIVE

To assess the prevalence of vulvovaginitis, enuresis and encopresis in children who were referred for allegations of sexual abuse.

SUBJECTS

A retrospective chart review of 1280 children presenting for non-acute examination after allegations of sexual abuse during a 15-year time span. Interview documentation, physical examination documentation, urinalysis, urine and vaginal cultures were reviewed.

RESULTS

Of the 1280 children, 73.3% were female and 26.7% male. The ages of the children ranged from 6 months to 18 years (median age was 6 years). Interviews revealed that fondling contact was the most common allegation, followed by oral, vaginal, and anal penetration. Interviews also disclosed lower urinary tract symptoms, UTI, constipation, encopresis and enuresis. Physical examination revealed no abnormal genital findings in 44.7% of cases. Examinations of the vagina noted: erythema (18.1%); hymenal notching (posterior 16.8%, anterior 4.4%); vuvlovaginitis (14.0%); laceration or transection (0.6%); and bruising (0.4%). Examination of the anus noted: anal fissure/tear (14.9%); loss of anal tone (10.6%); reflex anal dilatation (9.2%); venous congestion (3.8%); and proctitis (0.9%). Vulvovaginitis was noted in 14% (131/936) and encopresis in 2.3% (21/936). Enuresis according to age was reported in 13% of 5-9 year olds, 14.7% of 10-16 year olds and 18.2% of 17-18 year olds suspected of being abused.

CONCLUSION

Prevalence of vulvovaginitis and enuresis were increased, and encopresis was decreased in children with allegations of sexual abuse when compared to the general pediatric population. Physicians should continue to be aware of the possibility of the presence of these conditions in children who have been sexually abused, and offer appropriate treatment.

Intraspecific divergence and convergence of floral tube length in specialized pollination interactions

Floral tubes are often thought to be a consequence of adaptive specialization towards pollinator morphology. We explore floral tube length evolution within Tritoniopsis revoluta (Iridaceae), a species with considerable geographical tube length variation. We ask whether tube lengths of T. revoluta populations are associated with pollinator proboscis lengths, whether floral divergence occurs in the presence of different pollinators and whether floral convergence occurs between distantly related populations pollinated by the same pollinator. Finally, we ask whether tube length evolution is directional. Shifts between morphologically different pollinators were always associated with shifts in floral morphology, even when populations were very closely related. Distantly related populations had similar tube lengths when they were pollinated by the same pollinator. Shifts in tube length tended to be from short to long, although reversals were not infrequent. After correcting for the population-level phylogeny, there was a strong positive, linear relationship between floral tube length and pollinator proboscis length, suggesting that plants are functionally specialized on different pollinators at different sites. However, because tube length evolution in this system can be a bidirectional process, specialization to the local pollinator fauna is unlikely to result in evolutionary or ecological dead-ends such as canalization or range limitation.

Fundamental mode operation of a ribbon fiber laser by way of volume Bragg gratings

Selection of the fundamental mode of an active large mode area "ribbon" fiber laser with core dimensions of 107.8 μm by 8.3 μm was produced by a transmitting Bragg grating (TBG) in a free-space resonator. The multimode performance of the original laser was characterized to have an M2 of 11.3 with an absorbed power slope efficiency of 76%. With the TBG aligned to provide maximum diffraction efficiency for the fundamental mode, the M2 improved to 1.45 at an absorbed power slope efficiency of 54% and enhanced the brightness by 5.1 times.

Enumeration of bacteriophage particles: Comparative analysis of the traditional plaque assay and real-time QPCR- and nanosight-based assays

Bacteriophages are increasingly being utilized and considered for various practical applications, ranging from decontaminating foods and inanimate surfaces to human therapy; therefore, it is important to determine their concentrations quickly and reliably. Traditional plaque assay (PA) is the current "gold standard" for quantitating phage titers. However, it requires at least 18 h before results are obtained, and they may be significantly influenced by various factors. Therefore, two alternative assays based on the quantitative real-time polymerase chain reaction (QPCR) and NanoSight Limited (NS) technologies were recently proposed for enumerating phage particles. The present study compared the three approaches' abilities to quantitate Listeria monocytogenes-, Escherichia coli O157:H7- and Yersinia pestis-specific lytic phages quickly and reproducibly. The average coefficient of variation (CVS) of the PA method including all three phages was 0.15. The reproducibility of the PA method decreased dramatically when multiple investigators performed the assays, and mean differences of as much as 0.33 log were observed. The QPC R method required costly equipment and the synthesis of phage-specific oligonucleotide primers, but it determined phage concentrations faster (within about 4 h) and more precisely than did PA (CVS = 0.13). NS technology required costly equipment, was less precise (CVS = 0.28) than the PA and QPCR methods, and only worked when the phages were suspended in clear medium. However, it provided results within 5 min. After the overall correlation is established with the PA method, either of the two assays may be useful for quickly and reproducibly determining phage concentrations.

Buprenorphine treatment for hospitalized, opioid-dependent patients: a randomized clinical trial

IMPORTANCE

Buprenorphine opioid agonist treatment (OAT) has established efficacy for treating opioid dependency among persons seeking addiction treatment. However, effectiveness for out-of-treatment, hospitalized patients is not known.

OBJECTIVE

To determine whether buprenorphine administration during medical hospitalization and linkage to office-based buprenorphine OAT after discharge increase entry into office-based OAT, increase sustained engagement in OAT, and decrease illicit opioid use at 6 months after hospitalization.

DESIGN, SETTING, AND PARTICIPANTS

From August 1, 2009, through October 31, 2012, a total of 663 hospitalized, opioid-dependent patients in a general medical hospital were identified. Of these, 369 did not meet eligibility criteria. A total of 145 eligible patients consented to participation in the randomized clinical trial. Of these, 139 completed the baseline interview and were assigned to the detoxification (n = 67) or linkage (n = 72) group.

INTERVENTIONS

Five-day buprenorphine detoxification protocol or buprenorphine induction, intrahospital dose stabilization, and postdischarge transition to maintenance buprenorphine OAT affiliated with the hospital's primary care clinic (linkage).

MAIN OUTCOMES AND MEASURES

Entry and sustained engagement with buprenorphine OAT at 1, 3, and 6 months (medical record verified) and prior 30-day use of illicit opioids (self-report).

RESULTS

During follow-up, linkage participants were more likely to enter buprenorphine OAT than those in the detoxification group (52 [72.2%] vs 8 [11.9%], P < .001). At 6 months, 12 linkage participants (16.7%) and 2 detoxification participants (3.0%) were receiving buprenorphine OAT (P = .007). Compared with those in the detoxification group, participants randomized to the linkage group reported less illicit opioid use in the 30 days before the 6-month interview (incidence rate ratio, 0.60; 95% CI, 0.46-0.73; P < .01) in an intent-to-treat analysis.

CONCLUSIONS AND RELEVANCE

Compared with an inpatient detoxification protocol, initiation of and linkage to buprenorphine treatment is an effective means for engaging medically hospitalized patients who are not seeking addiction treatment and reduces illicit opioid use 6 months after hospitalization. However, maintaining engagement in treatment remains a challenge.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00987961.

Probing the repulsive core of the nucleon-nucleon interaction via the (4)He(e,e'pN) triple-coincidence reaction

We studied simultaneously the (4)He(e,e'p), (4)He(e,e'pp), and (4)He(e,e'pn) reactions at Q(2)=2(GeV/c)(2) and x(B)>1, for an (e,e'p) missing-momentum range of 400 to 830  MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum, in a region where the nucleon-nucleon (NN) force is expected to change from predominantly tensor to repulsive. The abundance of neutron-proton pairs is reduced as the nucleon momentum increases beyond ∼500  MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum. Our data are compared with calculations of two-nucleon momentum distributions in (4)He and discussed in the context of probing the elusive repulsive component of the NN force.