Recoil Detection of Threshold Pion Reactions

Supported by the National Science Foundation and Indiana Universit

Head repositioning errors in normal student volunteers: a possible tool to assess the neck's neuromuscular system

BACKGROUND: A challenge for practitioners using spinal manipulation is identifying when an intervention is required. It has been recognized that joint pain can interfere with the ability to position body parts accurately and that the recent history of muscle contraction can play a part in that interference. In this study, we tested whether repositioning errors could be induced in a normal population by contraction or shortening of the neck muscles. METHODS: In the experimental protocol, volunteers free of neck problems first found a comfortable neutral head posture with eyes closed. They deconditioned their cervical muscles by moving their heads 5 times in either flexion/extension or lateral flexion and then attempted to return to the same starting position. Two conditioning sequences were interspersed within the task: hold the head in an extended or laterally flexed position for 10 seconds; or hold a 70% maximum voluntary contraction in the same position for 10 seconds. A computer-interfaced electrogoniometer was used to measure head position while a force transducer coupled to an auditory alarm signaled the force of isometric contraction. The difference between the initial and final head orientation was calculated in 3 orthogonal planes. Analysis of variance (1-way ANOVA) with a blocking factor (participants) was used to detect differences in proprioceptive error among the conditioning sequences while controlling for variation between participants. RESULTS: Forty-eight chiropractic students participated: 36 males and 12 females, aged 28.2 ± 4.8 yrs. During the neck extension test, actively contracting the posterior neck muscles evoked an undershoot of the target position by 2.1° (p <0.001). No differences in repositioning were found during the lateral flexion test. CONCLUSION: The results suggest that the recent history of cervical paraspinal muscle contraction can influence head repositioning in flexion/extension. To our knowledge this is the first time that muscle mechanical history has been shown to influence proprioceptive accuracy in the necks of humans. This finding may be used to elucidate the mechanism behind repositioning errors seen in people with neck pain and could guide development of a clinical test for involvement of paraspinal muscles in cervical pain and dysfunction

Studies of Pi° Production Near Threshold

Supported by the National Science Foundation and Indiana Universit

An international initiative to create a collaborative for pharmacovigilance in hospice and palliative care clinical practice

Background: Medication registration currently requires evidence of safety and efficacy from adequately powered phase 3 studies. Pharmacovigilance (phase 4 studies, postmarketing data, adverse drug reaction reporting) provide data on more widespread and longer term use. Historically, voluntary reporting systems for pharmacovigilance have had low reporting rates, relying on ad hoc reporting and retrospective chart reviews, or prospective registries have often been limited to specific drugs or clinical conditions. Furthermore, these data are often irrelevant in hospice and palliative care due to the timeliness of which such data become available and the unique characteristics of our population and prescribing: compounding comorbidities, progressive organ failure, accumulation of symptom-specific medications, tendency to attribute toxicity to disease progression, use of old, off-patent medications, and incorporation of evolving evidence. There is a need for prospective, systematic pharmacovigilance in hospice and palliative care. Method: Here we describe an international, Web-based, 128-bit secure initiative to collect pharmacovigilance data documenting net clinical benefit and safety of common medications. The intention is for a diverse and large group of clinical units to record data prospectively on a small deidentified consecutive cohort of patients started on the medication of interest. A new medication would be studied every 3 months. Three key time points (different for each medication) will be assessed for each patient, collecting easily codefiable data at baseline, a point at which clinical benefit should be experienced, and a point at which short- to medium-term toxicities may occur. Toxicities can additionally be recorded at any time they occur. Data collection will take a maximum of 10 minutes per patient. Conclusion: The intention is to create an efficient, relevant system to improve hospice and palliative care with maximally generalizable results

Anti-cholinergic load, health care utilization, and survival in people with advanced cancer: a pilot study

Introduction: Anti-cholinergic medications have been associated with increased risks of cognitive impairment, premature mortality and increased risk of hospitalisation. Anti-cholinergic load associated with medication increases as death approaches in those with advanced cancer, yet little is known about associated adverse outcomes in this setting. Methods: A substudy of 112 participants in a randomised control trial who had cancer and an Australia modified Karnofsky Performance Scale (AKPS) score (AKPS) of 60 or above, explored survival and health service utilisation; with anti-cholinergic load calculated using the Clinician Rated Anti-cholinergic Scale (modified version) longitudinally to death. A standardised starting point for prospectively calculating survival was an AKPS of 60 or above. Results: Baseline entry to the sub-study was a mean 62 ± 81 days (median 37, range 1–588) days before death (survival), with mean of 4.8 (median 3, SD 4.18, range 1 – 24) study assessments in this time period. Participants spent 22% of time as an inpatient. There was no significant association between anti-cholinergic score and time spent as an inpatient (adjusted for survival time) (p = 0.94); or survival time. Discussion: No association between anti-cholinergic load and survival or time spent as an inpatient was seen. Future studies need to include cognitively impaired populations where the risks of symptomatic deterioration may be more substantial

Proton Radiative Capture by Deuterium at Medium Energies

This work was supported by the National Science Foundation Grant NSF PHY 81-14339 and by Indiana Universit

Proton Radiative Capture by Deuterium at Medium Energies

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Studies of Proton-Induced Neutral Pion Production Near Threshold

This work was supported by the National Science Foundation Grant NSF PHY 81-14339 and by Indiana Universit

Cross section and analyzing power of pol{p}p -> pn pi+ near threshold

The cross section and analyzing power of the pol{p}p -> pn pi+ reaction near threshold are estimated in terms of data obtained from the pol{p}p -> d pi+ and pp -> pp pi0 reactions. A simple final state interaction theory is developed which depends weakly upon the form of the pion-production operator and includes some Coulomb corrections. Within the uncertainties of the model and the input data, the approach reproduces well the measured energy dependence of the total cross section and the proton analyzing power at a fixed pion c.m. angle of 90deg, from threshold to T_p = 330 MeV. The variation of the differential cross section with pion angle is also very encouraging.Comment: 20 pages, Latex including 4 eps figure

Observation of the Charge Symmetry Breaking d + d -> 4He + pi0 Reaction Near Threshold

We report the first observation of the charge symmetry breaking d + d -> 4He + pi0 reaction near threshold at the Indiana University Cyclotron Facility. Kinematic reconstruction permitted the separation of 4He + pi0 events from double radiative capture 4He + gamma + gamma events. We measured total cross sections for neutron pion production of 12.7 +- 2.2 pb at 228.5 MeV and 15.1 +- 3.1 pb at 231.8 MeV. The uncertainty is dominated by statistical errors.Comment: 7 pages, 2 figures, plain Te