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Introduction: With a Canadian aging population, the prevalence of mild traumatic brain injury (mTBI) among elderly is increasing and the age criterion of the Canadian CT head rule (CCHR) is challenged by many emergency physicians. We evaluated if increasing the age criterion of the CCHR would maintain its validity. Methods: We conducted an historical cohort study using the medical charts of all patients 65 years old or more who consulted at a Level One Trauma Centre emergency department (ED) for a mTBI between 2010 and 2014. The main outcome measures were clinically important brain injury (CIBI) on Computed Tomography (CT) and the presence of the CCHR criteria. The clinical and radiological data collection was standardized. Univariate analysis was performed to measure the predictive capacities of modified age cut-offs at 70 and 75 years old. Results: Out of the 104 confirmed mTBI in this study, 32 (30,8%) had CIBI on CT scan. Sensitivity and specificity [C.I. 95%] of the CCHR were 100% [89.1 - 100] and 0% [0.0 5.0] for an age criterion of 65 years old and above; 100% [89.1 - 100] and 4,2% [0.9 11.7] for a modified criterion of 70 years old; 100% [89.1 - 100] and 13,9% [6.9 24.1] for 75 years old. Furthermore, for an age criterion of 80 and 85 years old, sensitivity was respectively 90,6% [75.0 98.0] and 75,0% [56.6 88.5]. Conclusion: In our cohort, increasing the age criterion of the CCHR for minor head injury to 75 years old would benefit ED by further reducing CT scans without missing CIBI. A larger prospective study is indicated to confirm the proposed modification.

The inclusive Kn, ¶, and {Mathematical expression} production has been studied in a {Mathematical expression} experiment performed in the Mirabelle bubble chamber at an incident beam momentum of 32.1 GeV/c. Total, topological and differential cross sections are presented and compared with those obtained at other energies. The invariant structure functions have been parametrised in the fragmentation region by a power law and are consistent with the expectations based on quark counting rules. © 1981 Springer-Verlag.

Results are presented on the total and differential cross sections for the production of π+, π−, γ,\(\bar K^0 \),K0,K+, andK− in theK−p interactions at 70 GeV/c. The energy dependence of the various production processes shows in paticular a strong rise of the γ cross section and an increase of the average transverse momentum of the charged pion in the fragmentation regions.

The inclusive production ofK *±(890), ρρ(770), ω0(780) andf 0(1,270) mesons is studied in $$\bar pp$$ experiment at 32GeV/c in the MIRABELLE bubble chamber by the analysis of (K 0π±) and (π+π−) invariant mass distributions. The inclusive cross sections are σ(K *±)=2.45±0.30 mb, σ(ρ0)=8.8 ±0.9 mb, σ(ω+)≃6.2 mb, and σ(f 0)=2.2±0.7 mb. The C.M. longitudinal distribution of theK *±(890) is slightly shifted to the primary particles fragmentation regions; the ρ0 is produced more centrally. The studied mesons alone are responsible for 40% of final state poins. The production features of various resonances are compared with quark models predictions.

The inclusive π0 and γ production is studied in a\(\bar PP\) experiment at 32.1 GeV/c performed in the Mirabelle bubble chamber with a sensitivity of ∼2.7 events/μb. Total and topological π0 cross sections are presented. The π0 and γ longitudinal and transverse momentum distributions are obtained and compared with\(\bar PP\) data at 22.4 GeV/c andK ± P data at 32.1 GeV/c. The inclusive π0 distributions are also compared to those obtained for charged pions in the same experiment.

The values of the topological cross-sections for {Mathematical expression} interactions at 32 GeV/c are derived from a sample of ∼74 000 events observed in the Mirabelle bubble chamber. The parameters of the charged-particle multiplicity distribution are compared with similar data at other energies and with those obtained for pp interactions. The difference between the {Mathematical expression} and pp topological cross-sections provides parameters for {Mathematical expression} annihilation. © 1982 Societa Italiana di Fisica.

Longitudinal correlations between pions inclusively produced in the target and beam fragmentation regions are studied in aK−p bubble chamber experiment at 32 GeV/c with a sensitivity of about 6.7 ev/μb. It was found that the\({{\tilde x_2 = x_2 } \mathord{\left/ {\vphantom {{\tilde x_2 = x_2 } {(1 - \left| {x_1 } \right|)}}} \right. \kern-\nulldelimiterspace} {(1 - \left| {x_1 } \right|)}}\) distributions of charged pions with momentum fraction in the proton hemisphere with respect to a charged “trigger” pion with momentum fraction x1 do not show scaling, that those of the associated π1/π2 do not compare toK+p interactions and give indications for quark annihilation. The invariant two- and three pion longitudinal C.M. distributions show significant deviations from the naive quark recombination picture. Distinct long-range correlations observed between π−s from the proton fragmentation region and π+s from theK− fragmentation region could imply contributions from quark exchange or quark annihilation mechanisms inK−p interactions at 32 GeV/c.

Results are presented on the inclusive production of π± mesons and protons in $$\bar p$$ p interactions at an incident antiproton momentum of 32 GeV/c in the MIRABELLE bubble chamber, based on a sample of 55,000 inelastic events. The spectra of π+(π−) andp( $$\bar p$$ ) are separated in the whole kinematically admitted region of phase space by a statistical method. The semi-inclusive and inclusive cross sections and the main average characteristics of π andp production are calculated. The invariant differential cross sections are studied as functions of the Fevnman scaling variablex, the rapidity and the transverse momentum. Thex distribution of π± mesons in the proton fragmentation region does not show any significant contribution from quark exchange or annihilation processes. A possible contribution of hard quark scattering on mesons or baryons is observed for large transverse momenta.

The inclusive production of neutral kaons inK−p interactions at 32 GeV/c is studied in final states with one, two and three strange particles (Kn or Λ). Inclusive and topological cross sections are obtained and their energy dependence discussed by comparison with lower energy data. The invariant differential cross sections of neutral kaons are studied as a function of Feynmanx, the c.m. rapidity and the transverse momentum, and a comparison is made with data at 14.3 GeV/c. Invariantx-distributions are obtained separately for “indirect” neutral kaons from\(\bar K*(890)\) decays and for “prompt” kaons. We also discuss the possibility of connecting quark structure functions with hadron fragmentation spectra at this c.m. energy\(\sqrt s \simeq 8 GeV\).

We present new data on the reaction K−p→Λη from 0.80 to 1.84 GeV/c. An interpretation is attempted in terms of the formation of known hyperon resonances.