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BackgroundNormative student-athlete concussion assessment data may not be appropriate for service academy members (SAMs), particularly rugby players, because of the uniqueness of their academic/military training environment. Having accurate baseline data for this population is important because of their high risk for concussion and frequent lack of assigned sports medicine professional. The primary purpose of this study was to characterise baseline performance on a concussion assessment battery, with secondary purpose to determine effect of sex and concussion history on these measures among SAM rugby players.Methods601 rugby-playing SAMs (19.3±1.5 years, 37.9% female) completed baseline concussion assessments: the Sport Concussion Assessment Tool (SCAT) Symptom and Symptom Severity Checklist, Standard Assessment of Concussion (SAC) and a neuropsychological test (either ImPACT (Immediate Post Concussion Assessment and Cognitive Testing) or ANAM (Automated Neuropsychological Assessment Metrics)). Groups were compared using an independent samples t-test or Mann-Whitney U test. A 2 (sex) × 2 (concussion history) ANOVA was conducted to determine the effects of sex and concussion history on outcomes.ResultsWomen reported greater SCAT total symptoms (3.3 vs 2.8, pConclusionsThese findings provide reference data for SAM rugby players on baseline assessments and to help in clinical decision-making when managing sports-related concussion in absence of baseline data.

Purpose To examine the association between estimated age of first exposure (eAFE) to contact sports and neurocognitive performance and symptom ratings in collegiate U.S. Military Service Academy athletes. We hypothesized that contact-sports participation before the age of 12 would not be associated with worse neuropsychological test performance or greater symptom reporting. Methods Male cadets (N=891) who participated in contact sports [i.e., in lacrosse (n=211), wrestling (n=170), ice hockey (n=81), soccer (n=119), rugby (n=10)], or non-contact sports (n=298), completed the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) test before the season. Generalized linear modeling was used to predict each cognitive domain score and the symptom severity score. Predictor variables were entered in the following order: group (contact vs. non-contact), eAFE (eAFE Results The group-by-eAFE interaction was not significant for any of the ImPACT composite scores (Verbal Memory, Wald Χ2=.073, p=.788; Visual Memory, Wald Χ2=2.71, p=.100; Visual Motor Speed, Wald Χ2=.078, p=.780; Reaction Time, Wald Χ2=.003, p=.955; Symptom Severity, Wald Χ2=2.87, p=.090). Learning accommodation history was associated with lower scores on Visual Motor Speed (Χ2=6.19, p=.013, B=-2.97). Older age was associated with faster reaction time (Χ2=4.40, p=.036, B=-.006) and lesser symptom severity (Χ2=5.55, p=.019, B=-.068). No other parameters were significant. Conclusion We observed no association between eAFE, contact-sport participation, cognitive functioning, or subjectively-experienced symptoms in this cohort. Earlier eAFE to RHI is not related to worse neurocognitive performance or greater subjectively-experienced symptoms in collegiate student-athletes enrolled in military academies.

Flood rhyolites are lavas that have areal extents similar to large ignimbrites. The Davis Mountains volcanic field differs from most other Cenozoic volcanic fields in the southwestern United States in that a major volume of the silicic rocks erupted there are flood rhyolites rather than ignimbrites. A comparative isotopic study was made of a major flood rhyolite unit, the Star Mountain, and mafic to silicic rocks from three other magma systems. The entire range in Nd isotopic compositions found in the volcanic field is relatively small, with ∈ N4 values ranging from about +2 in a basalt to between +1.0 and -1.5 in the silicic rocks including the Star Mountain rhyolite. Pb isotope ratios of the Star Mountain lavas ( 206 Pb/ 204 Pb ≃ 17.9) are considerably higher than those of xenoliths of Proterozoic deep crustal granulites from the region (

The application of the recently developed, versatile and economic technique of microwave assisted catalysis to the reactions of olefinic hydrocarbons, principally ethylene, propylene and 1-pentene is discussed. The reactions are believed to involve free radical intermediates and can result in efficient conversions to selected aliphatic and aromatic hydrocarbons.

The metabasites from the KTB pilot and main drill holes can be divided into two major associations. The first is the metagabbro-amphibolite suite which is composed principally of metagabbros, basalts, and basaltic andesites with tholeiitic P-MORB affinities. The second is the amphibolite-gneiss suite that is characterized by alternating layers of metabasites which intimately interfinger with metasedimentary rocks. Metabasites from the amphibolite-gneiss suite are alkaline, and they include metamorphosed basanites, basalts, basaltic andesites, and trachy-andesites. A distinctive subgroup of the amphibolite-gneiss suite are basanitic metabasites which are interlayered with marble. With regard to trace elements, the alkaline rocks are distinguished from the tholeiites by steeper slopes of their spidergrams and REE patterns, and distinctively higher Nb concentrations (20–50 vs 3–20 ppm). Oxygen isotope studies establish that the most primitive metabasites of both series have mantle like δ18O values between 5 and 7‰. More differentiated samples have δ18O values reaching 8‰, and some alkaline metabasites have values as high as 10.5‰ indicating extensive interaction with sedimentary material. In general, ɛNd values decrease with differentiation. Gabbroic samples from the tholeiitic suite have highest ɛNd(0) values at approximately +5, whereas andesitic samples have values as low as –5. At least three components are needed to explain the trace element and isotope trends found in the metabasites: (a) an enriched asthenospheric MORB-type mantle; (b) a within-plate plume source; and (c) continental detritus with the composition of paragneiss. Melts from the two mantle sources mixed extensively, and the andesitic rocks are those with the highest contribution from the sedimentary component. Most probably all ZEV rocks were deposited in an oceanic basin close to an active continental margin where magmas were alternately derived from a tholeiitic mantle source as well as highly enriched within-plate magma source.

Granulite facies metamorphic rocks and ultramafic nodules, of lower crustal and upper mantle origin, respectively, occur as xenoliths in a host alkali basalt at the La Olivina peridot mine, approximately 150 km southeast of Ciudad Chihuahua. The La Olivina ultramafic xenoliths are of three compositional groups that are distinguished by clinopyroxene chemistry: a high magnesian (Mg/Mg+Fe = 0.90), high Cr 2 O 3 group (Group I); a moderately-magnesian (Mg/Mg+Fe = 0.76), high A1 2 0 3 , high TiO 2 group (Group II); and a group compositionally intermediate between these two (Transitional Group). Analyses of primary minerals show that these xenoliths are similar to ones from San Carlos, Arizona (USA), from Xalapasco de La Joya, San Luis Potosi (Mexico), and from Kilbourne Hole, New Mexico (USA). The La Olivina mantle xenoliths are of three textural groups: allotriomorphic granular (igneous?), porphyroclastic (metamorphic?), and granoblastic (metamorphic?). All Group I xenoliths are granoblastic, and most nodules of Group II and the Transitional Group are allotriomorphic granular. Porphyroclastic texture is less common than the other textures in the rocks studied, but it is found in some Transitional Group rocks. The La Olivina lower crust xenoliths are predominantly pelitic gneisses and pyroxene granulites. The pelitic gneisses are uniform in mineral assemblage with garnet + quartz + plagioclase + sanidine + sillimanite + rutile + graphite. Most of the pyroxene granulites are plagioclase-bearing, but some contain scapolite in place of plagioclase. These lower crustal samples are identical in mineral assemblage and very similar in mineral chemistry to xenoliths described from Kilbourne Hole. The granulites and pelitic gneisses have model Nd ages of 1.1 to 1.2 b.y. using a chondritic initial ratio, or 1.6 b.y. using a depleted source model. The latter age is in excellent agreement with those from Kilbourne Hole. Thus it appears that Precambrian craton, similar in age, metamorphic history, and protolith composition to that which underlies Kilbourne Hole, extends into Mexico at least as far southeast as La Olivina.

Las rocas volcánicas del Cenozoico al Reciente en la parte continental de México están confinadas principalmente en tres provincias geológicas: la Sierra Madre Occidental (SMO), el Cinturón Volcánico Mexicano (CVM) y la provincia alcalina oriental. Las dos primeras provincias están dominadas por series de rocas calci-alcalinas, pero también se encuentran rocas alcalinas contemporáneas. La tercera provincia está compuesta en su mayor parte por rocas volcánicas alcalinas.La comparación entre las dos provincias calci-alcalinas revela que cada una tiene características diferentes. Las rocas volcánicas del Terciario Medio de la SMO están constituidas principalmente por ignimbritas riolíticas, mientras que el CVM se caracteriza por centros neovolcánicos prominentes cuya composición es primordialmente andesítica. Las andesitas calci-alcalinas del oeste del CVM (Ceboruco) tienen características químicas distintas de las andesitas del CVM central (Colima, Paricutín, Orizaba, Jorullo, Popocatépetl, Toluca). Las andesitas del Ceboruco tienen contenidos más altos de Na2O+ K20, K2O, Na2O, TiO2, P205, Ba, La y (Ce/Yb)N, y más bajos de CaO, MgO, Cr y Ba/La que las andesitas del CVM central. Las andesitas del norte de la SMO (área de Batopilas y de la parte central del CVM tienen álcalis totales similares, K2O, Na2O, CaO, Sr, Zr y (Ce/Yb)N. Las andesitas de la SMO tienen también contenidos más bajos de MgO y K/Rb, y más altos de FeO* TiO2, Rb, Th, La y Y que las rocas calci-alcalinas de la parte central del CVM. Las proporciones isotópicas iniciales de Sr de las rocas volcánicas del CVM composicionalmente intermedias están restringidas al rango 0.7035 - 0.7047, mientras que los contenidos de SrI de las rocas volcánicas félsicas intermedias de la SMO fluctúan entre 0.7033 y 0.7614. Tales proporciones indican interacción significativa de magmas primarios con la corteza radiogénica anterior para las rocas volcánicas de la SMO, pero relativamente menor interacción, si acaso hubo alguna, con magmas primarios de las rocas volcánicas del CVM. Los pocos datos isotópicos de Nd disponibles para las rocas volcánicas calci-alcalinas del CVM (Colima, Los Humeros, Paricutín y La Primavera) generalmente tienen εNd mayores que la tierra total (hasta +5 y +6). Las rocas volcánicas del norte de la SMO (área de Batopilas) y el sureste de Chihuahua tienen εNd hasta ± 2.5 unidades de Tierra total.La evolución de las secuencias rocosas en centros eruptivos individuales parece haber estado determinada principalmente por fraccionación cristalina. Otros procesos simultáneamente operativos pueden incluir mezcla de magmas y asimilación por la corteza (la última, especialmente en la SMO). La naturaleza de las regiones de procedencia para los magmas primarios de las rocas volcánicas tanto en el CVM como en las áreas de la SMO y la provincia oriental no ha sido todavía tratada en forma global.

Las ignimbritas riolíticas de la región de Batopilas, del norte de la Sierra Madre Occidental, están interestratificadas con un número menor de lavas andesiticas y daciticas. Varias líneas de evidencia indican que esta serie andesita - dacita - riolitica es co-magmática. Por ejemplo, esta serie es distinta químicamente de rocas ígneas más jóvenes y más viejas de la misma región; no se observan variaciones sistemáticas en composición isotrópica, y las variaciones en elementos-traza en la serie pueden ser modeladas por cálculos de fracción Rayleigh. Las variaciones en las concentraciones de Sr no concuerdan con un origen de fusión parcial para la serie y las riolitas parecen ser el producto de un sistema cerrado de cristalización fraccionada de magmas de una fuente subcortial. Los resultados adicionales publicados sobre reiolitas terciarias de otras cuatro áreas de la Sierra Madre Occidental establecen que estas rocas son heterogéneas isotópicamente, al comprarlas con las de Batopilas y que algunas de ellas contienen una componente cortical. La fuente sub-cortical debajo de la Sierra Madre Occidental tiene cocientes de 87Sr/86Sr entre 0.7042 y 0.7050 y €Nd cercaos a cero. La mayoría de las riolitas analizadas tienen razones iniciales de Sr menores de 0.7070 y sus composiciones isotrópicas pueden explicarse por un modelo de asimilación y cristalización fraccionada que abarca menos del 25% de componente cortical. La extrusión de la secuencia Volcánica Superior y el emplazamiento del batolito marcaron un evento mayor de formación de corteza en el occidente de México.

A total of 139 breccia and crystalline rock fragments in the size range 2–4 mm from four Apollo 15 soil samples have been examined. Two of the sample stations are on the mare surface (4 and 9A) and two are on the Apennine Front (2 and 6). Approximately 90% of the fragments from the Apennine Front are brown-glass “soil” breccias, but those from the mare surface are 60%–70% basalt. Several textural varieties of mare basalt have been recognized, but within experimental error there is no difference in their40Ar-39Ar ages. The major non-mare (Pre-Imbrian) crystalline rock types in the Apennine Front regolith are KREEP basalt, anorthositic rocks, recrystallized norite (including anorthositic norite) and recrystallized polymict breccias; however, such crystalline rocks are rare in the samples examined. Apparently, the near surface Imbrium ejecta below the regolith has not been thermally recrystallized, and probably there are no outcrops of crystalline rocks upslope from the sample stations.

Only fine-grained rocks are present in the Luna 20 samples, and coarser-grained rocks are represented by fragments of single crystals. A petrologic study has been made of 47 fine-grained crystalline rocks, microbreccias, and glassy aggregates. In addition, a total of 33 single crystals of pyroxene, plagioclase, olivine, and spinel, in the size range from 125 to 500 microns, have been examined using electron microprobe and single-crystal X-ray diffraction techniques. The most abundant fine-grained crystalline rocks in the samples examined are recrystallized anorthositic norite and anorthositic troctolite. Gabbroic rocks, anorthosite, and KREEP basalt are present but not common. Most of the single crystals of pyroxene and plagioclase could have been derived from coarser-grained noritic, troctolitic, and anorthositic rocks. However, three of the 14 pyroxene crystals, and two of the five olivine crystals have Fe/(Fe + Mg) contents greater than 0.45 and are believed to have been derived from mare basalts or related rocks.