Determination of the

We report the first measurement of the parity-violating elastic electron scattering asymmetry on ^{27}Al. The ^{27}Al elastic asymmetry is A_{PV}=2.16±0.11(stat)±0.16(syst) ppm, and was measured at ⟨Q^{2}⟩=0.02357±0.00010 GeV^{2}, ⟨θ_{lab}⟩=7.61°±0.02°, and ⟨E_{lab}⟩=1.157 GeV with the Q_{weak} apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sophisticated distorted-wave calculations are in good agreement with this result. From this asymmetry the ^{27}Al neutron radius R_{n}=2.89±0.12 fm was determined using a many-models correlation technique. The corresponding neutron skin thickness R_{n}-R_{p}=-0.04±0.12 fm is small, as expected for a light nucleus with a neutron excess of only 1. This result thus serves as a successful benchmark for electroweak determinations of neutron radii on heavier nuclei. A tree-level approach was used to extract the ^{27}Al weak radius R_{w}=3.00±0.15 fm, and the weak skin thickness R_{wk}-R_{ch}=-0.04±0.15 fm. The weak form factor at this Q^{2} is F_{wk}=0.39±0.04.

Precision Measurement of the Beam-Normal Single-Spin Asymmetry in Forward-Angle Elastic Electron-Proton Scattering.

A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of θ_{lab}=7.9° and a mean energy of 1.149 GeV. The asymmetry result is B_{n}=-5.194±0.067(stat)±0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering angles (θ_{lab}→0) where they should be most reliable.

The Ultra-High-Risk for psychosis groups: Evidence to maintain the status quo.

Individuals are considered Ultra-High-Risk (UHR) for psychosis if they meet a set of standardised criteria including presumed genetic vulnerability (Trait), or a recent history of Attenuated Psychotic Symptoms (APS) or Brief Limited Intermittent Psychotic Symptoms (BLIPS). Recent calls to revise these criteria have arisen from evidence that Trait, APS and BLIPS groups may transition to psychosis at different rates. Concurrently, it has become clear that the UHR status confers clinical risk beyond transition to psychosis. Specifically, most UHR individuals will not develop psychosis, but will experience high rates of non-psychotic disorders, persistent APS and poor long-term functional outcomes. Rather than focus on transition, the present study investigated whether UHR groups differ in their broader clinical risk profile by examining baseline clinical characteristics and long-term outcomes other than transition to psychosis. Four UHR groups were defined: Trait-only, APS-only, Trait+APS, and any BLIPS. Participants (N=702) were recruited upon entry to early intervention services and followed-up over a period of up to 13years (mean=4.53, SD=3.84). The groups evidenced similar symptom severity (SANS for negative symptoms, BPRS for positive and depression/anxiety symptoms) and psychosocial functioning (SOFAS, GAF, QLS) at baseline and follow-up as well as similar prevalence of non-psychotic disorders at follow-up. Our findings demonstrate that UHR groups evidence a similar clinical risk profile when we expand this beyond transition to psychosis, and consequently support maintaining the existing UHR criteria.

Cannabis-induced attenuated psychotic symptoms: implications for prognosis in young people at ultra-high risk for psychosis.

BACKGROUND: Cannabis use shows a robust dose-dependent relationship with psychosis risk among the general population. Despite this, it has been difficult to link cannabis use with risk for transitioning to a psychotic disorder among individuals at ultra-high risk (UHR) for psychosis. The present study examined UHR transition risk as a function of cannabis use characteristics which vary substantially between individuals including age of first use, cannabis abuse severity and a history of cannabis-induced attenuated psychotic symptoms (APS). METHOD: Participants were 190 UHR individuals (76 males) recruited at entry to treatment between 2000 and 2006. They completed a comprehensive baseline assessment including a survey of cannabis use characteristics during the period of heaviest use. Outcome was transition to a psychotic disorder, with mean time to follow-up of 5.0 years (range 2.4-8.7 years). RESULTS: A history of cannabis abuse was reported in 58% of the sample. Of these, 26% reported a history of cannabis-induced APS. These individuals were 4.90 (95% confidence interval 1.93-12.44) times more likely to transition to a psychotic disorder (p = 0.001). Greater severity of cannabis abuse also predicted transition to psychosis (p = 0.036). However, this effect was mediated by higher abuse severity among individuals with a history of cannabis-induced APS. CONCLUSIONS: Findings suggest that cannabis use poses risk in a subpopulation of UHR individuals who manifest cannabis-induced APS. Whether this reflects underlying genetic vulnerability requires further study. Nevertheless, findings reveal an important early marker of risk with potentially significant prognostic utility for UHR individuals.

The effect of eliminating implant/abutment rotational misfit on screw joint stability.

External hexagonal implants of known dimensions were assembled with premachined cast abutments and rebroached cast abutments. The abutment screws were tightened to 20 Ncm and 30 Ncm, and the samples were loaded off axis with 133.3 N. Load application was at 1,150 cycles per minute with a sample counterclockwise rotation of 28 cycles per minute. The premachined cast abutments tightened to 20 Ncm failed with a mean of 357,162 cycles (SD = 77,981 cycles). The rebroached cast abutments were cycled to 1 million cycles without failure. At 30 Ncm, the premachined cast abutments failed at a mean of 5.0 million cycles (SD = 2.2 X 10(6) cycles). Two of five rebroached cast abutments failed at 4.3 million and 9.5 million cycles, but the remaining samples showed no evidence of screw loosening after 10 million cycles, at which time the test was terminated. The results indicate a direct correlation between rotational misfit and screw loosening. Screw joints can be made more resistive to screw loosening by the elimination of rotational misfit.

Research in pediatric residency programs.

BACKGROUND AND OBJECTIVES: We have required residents in pediatrics at the Cleveland Clinic Foundation to give research presentations since 1989; this article reviews our experience with this program. Additionally, we sought to determine how many other accredited pediatric programs in the United States also require this. METHODS: Retrospective review of the Cleveland Clinic program; descriptive statistics of other United States residency programs, obtained by questionnaire. RESULTS: Pediatric residents at the Cleveland Clinic have given 108 research presentations since 1989, and have developed 33 (30.5%) of them into manuscripts or abstracts. We mailed questionnaires to 215 pediatric residency program directors and received responses from 177 (82%). Of these, 48 (27%) indicated their programs had a research requirement; residents could present their findings in departmental meetings or submit an abstract or manuscript to a professional society or journal. Respondents cited several barriers to research: residents are too busy, there are too few faculty members to mentor them, financial resources are limited, and there is no residency review committee requirement. CONCLUSIONS: Even though only approximately one fourth of the pediatric residency programs in the United States require research, we feel it is worthwhile experience. Despite barriers, residents can and do perform research and publish their findings.

Extracorporeal endotoxin removal in a canine model of septic shock.

The authors induced endotoxic shock in an animal model and attempted to treat this state by direct hemoperfusion over a modified anion sorbent column. It has been shown that the reversal of septic shock correlates with the efficiency of extracorporeal endotoxin removal. In this experiment, there were five control animals (sham) and five test animals (hemoperfusion over sorbent column). The efficacy of treatment was evaluated by survival at 24 hr, changes in mean arterial pressure, blood-acid base balance, and plasma endotoxin levels. There was 0% survival in the control group and 100% survival in the test group. The control dogs never recovered from shock or metabolic acidosis, but the test animals were at their initial values for these parameters by 6 hr. The endotoxin levels measured at 6 hr were higher in the control group (265 +/- 88 ng/ml) as compared with the test group (7.0 +/- 6.2 ng/ml). Direct hemoperfusion over a modified sorbent column effectively removed endotoxin and reversed the course of fatal septic shock.

Postpartum myocardial infarction: a rehabilitation challenge.

Myocardial infarction in pregnancy or the puerperium is an uncommon occurrence. Thus, when young pregnant women sustain a myocardial infarction, they present a complex challenge to cardiovascular nurses. Issues such as female gender, young age, and child-bonding must be considered in addition to assisting the recovery from the myocardial infarction itself. This case study describes the rehabilitative nursing care of a young woman who sustained a postpartum myocardial infarction.

The abuse of volatile substances.

Volatile substances have been used to alter consciousness since ancient times. Societal trends have brought forth one inhalant fad after another. It would be reasonable to expect this pattern to change as certain of the inhalants come under greater control or become less available (e.g., leaded gasoline). Experimentation with these agents among younger adolescents probably will continue, and for this reason, pediatric practitioners should be aware of the use of these agents and their potential toxicities.

Intensive care aspects of organ transplantation in children.

Children will benefit from the increasing availability of transplantation techniques as treatment for end-stage kidney and liver disease. Support of these services will involve the intensivist to as great degree as these children will frequently require invasive monitoring. Hypovolemia in the postoperative period can be devastating to later graft function and must be avoided. The drugs used to induce graft tolerance have significant effects and potential major toxicities. Their use places these children at risk of serious and life-threatening bacterial, viral, fungal, and protozoan infections. A team effort is essential to the successful care of these children. The demands are great, but the goal of a return of these gravely ill children to a normal and happy life is well worth the effort.

Safety and efficacy of jet anesthesia for bone marrow aspirations.

Aspirations or Jamshidi needle biopsies (n = 287) of bone marrow were performed on children and adolescents with acute leukemia or other malignant disease following the use of a spring-loaded instrument that delivered local anesthetic in a jet spray; 89% of the patients were receiving chemotherapy, 12% were thrombocytopenic, and 23% of the 269 patients who were afebrile at the time of the procedure were severely neutropenic. None of these patients had an infection or a hemorrhage as a complication of the procedure. We conclude that not only is this procedure safe, but it is also much less painful than the traditional method of local anesthetic infiltration using a syringe and needle.