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The article presents a randomized crossover study on the effects of mouthguards to the oxygen uptake during incremental exercise test. The study examines the hypothesis that mouthguards would not affect ventilation at different exercise intensities. The study used the graded exercise test (GXT) accomplished by the players with or without a mouthguard. The study indicates that there is no observed significant differences on the performance of the athletes during the experimental trials.

Abstract: To study the efficacy of low-intensity pulsed ultrasound (US), or LIPUS, of 85 treated nonunion cases with a minimum fracture age of 8 months, 67 cases met the study criteria. These were: no surgical intervention during 4 months before US treatment and radiographically ceased healing for 3 months before US. In a self-paired control study, the mean fracture age of the 67 patients was 39 ± 6.2 months. After a daily 20-min US treatment at home for an average of 168 days, 85% (57 of 67) of the nonunion cases were clinically and radiographically healed. The study did not include any cases that were malaligned, grossly instable, actively infected or that had extensive bone loss. The results demonstrate that the specific US can effect heal rates similar to those achieved by surgical means, without the associated risks and complications, and to those achieved by electrical bone growth stimulation or by extracorporeal shock-wave therapy. (E-mail: dieter.gebauer@lva-landshut.de) [Copyright &y& Elsevier]

Ophiolites in mainland Greece (Vourinos, Pindos and Othrys) form a NNW–SSE trending belt within the orogen of the Hellenides, extending further north into the Dinarides. Smaller ophiolite outcrops are also found on Aegean islands. A minimum Mid- to Late-Jurassic age has been inferred for these ophiolites, on the basis of paleontological data, as well as radiometric data from the so-called metamorphic soles at the base of the ophiolites. The latter data mark the end of spreading and initiation of intra-oceanic thrusting. U–Pb ion microprobe (SHRIMP) dating of co-magmatic zircon domains from one gabbro and one plagiogranite (Vourinos) yielded weighted mean 206Pb/238U ages at 168.5±2.4 and 172.9±3.1 Ma, respectively, interpreted as the time of crystallization of the rocks. One gabbro from Pindos yielded a crystallization age of 171±3 Ma (1σ). All three ages are identical to within analytical uncertainty. They are also within uncertainty of the radiometric ages reported previously from metamorphic soles. This implies (a) that the time difference between the igneous crystallization of the Vourinos and Pindos ophiolitic rocks dated here and the formation of the metamorphic soles is short, at least not resolvable within the uncertainties of the current geochronological techniques and (b) that the ocean ridge remained active while intra-oceanic thrusting commenced. Our geochronological results and their correlation with existing radiometric data from the metamorphic soles are obviously neither in favor nor against a supra-subduction setting for the formation of the above ophiolites.Zircons from a hornblendite (considered as constituent of the ophiolites) from the island of Crete, close to Kerames area yielded a weighted mean 206Pb/238U age of 162.7±2.8 Ma. This age is in agreement with the oldest of a wide range of K–Ar amphibole ages (166–149 Ma) previously reported for this rock-type. Zircon in the hornblendite is both of an igneous origin, and with recrystallized areas interpreted to have formed immediately after its formation under high-T, in the presence of abundant fluids, both events, or processes, having occurred within the analytical uncertainty time span. The 162.7±2.8 Ma age reflects and its uncertainty encompasses then both the time of igneous crystallization and high-T metamorphism in a high-T shear zone. [Copyright &y& Elsevier]

Cathodoluminescence-controlled radiometric dating (U–Pb SHRIMP) was carried out on zircon domains from metabasic rocks of the Chiavenna unit, a major mafic/ultramafic-bearing unit in the Central Alps. Co-magmatic zircon domains from amphibolites near Chiavenna and Prata areas yielded weighted mean 206Pb/238U ages at 93.0±2.0 and 93.9±1.8 Ma, respectively, interpreted as the age of crystallization of the magmatic protoliths. These ages fit well with the time of late spreading in the Valais Ocean, as suggested by previous paleogeographic reconstructions. Inherited zircon grains and/or core domains (Permo-Triassic, Carboniferous, Proterozoic) are abundant, indicating proximity of the Chiavenna unit to thinned continental crust. This is in line with the origin of this unit from subcontinental mantle sources, as suggested previously on petrological and structural grounds. Metamorphic zircon domains from one amphibolite near Chiavenna yielded a weighted mean 206Pb/238U age at 37.1±0.9 Ma, identical to the 38.5±0.9 Ma SHRIMP age of an amphibolitized eclogite of the Antrona ophiolites (Valais domain, Western Alps). Precise metamorphic ages were difficult to obtain from the composite (poly)metamorphic rim domains of the Prata amphibolite. This is attributed to the location of the Prata area close to the granulite-facies Gruf unit (metamorphosed at ca. 33 Ma) and to the 24–25 Ma old Novate granite, where metamorphic/fluid events probably caused multiple resetting to various degrees. The ca. 93 Ma old magmatism, identified for the first time in the Chiavenna unit, is the youngest basic oceanic magmatism reported in the Alps. The 37.1±0.9 Ma old metamorphism in the Chiavenna unit, attributed to the Valais domain, confirms the model suggesting stepwise younging of metamorphic ages from the south (Adriatic plate) to the north (European plate). It is older than metamorphism in the European margin (ca. 35–31 Ma) lying to the north of the Valais domain and younger than that in the Piemont–Ligurian Ocean (ca. 44–45 Ma) lying to the south of the Valais domain. [ABSTRACT FROM AUTHOR]

Dismembered relics of mafic and ultramafic rock in high-grade basement rocks often record pre-collisional stages of deep lithospheric and/or oceanic mafic magmatism in an orogen. A lens of amphibolites and serpentinites, intercalated between the crystalline Simano and Leventina nappes (lower Penninic nappes, Central Alps, Switzerland) was investigated for the protolith age and chemical and isotopic composition. Despite the polyphase high-grade metamorphic overprinting, primary isotopic and chemical relationships are still preserved and are indicative of an origin in an active margin situation. Trace element geochemistry and Nd isotopes of amphibolites argue for the fractionated gabbros as protoliths, which were formed by the partial melting of the upper mantle. The rocks show a variation of ϵNd values from +7.3 to +4.2 and Nd model ages up to 2 Ga, taken as evidence for the contamination by a geochemically enriched, old lithospheric source. Sr isotopes are heavily disturbed through the percolating crustal fluids after the emplacement into the continental crust. U–Pb age determination of zircon from two amphibolites using both in situ (SHRIMP) and conventional methods converge at an age of 518±11 Ma for the crystallization of the protoliths. The rock association of Loderio–Biasca is a further example from the Alpine basement recording an oceanic domain between Gondwana and the different Gondwana-derived microcontinents in the Cambrian–Ordovician times. Remnants of this ocean were incorporated into the accretionary wedges that formed during the subduction/collision events from Ordovician to Carboniferous, commonly summarized as the Caledonian and Variscan orogeny, and are today spread over the so-called Saxothurigian and Moldanubian domain of the Variscan orogen. These domains consist, thus to large extents, of heterochronous accretionary wedge sequences. [Copyright &y& Elsevier]

U–Pb ion microprobe (SHRIMP) dating of zircon domains assisted by cathodoluminescence imaging was carried out on (1) a garnet-rich mafic rock and (2) a cross-cutting pegmatoid from the area of Kimi, East Rhodope. Quartz exsolution lamellae in cpx of the garnet-rich mafic rock point to a precursor supersilicic cpx implying pressures >2.5 GPa. This indicates UHP conditions for the studied geotectonic unit and is in line with the (rare) presence of radial cracks around quartz inclusions in garnet, which suggest the former presence of coesite. Bleb-shaped cpx inclusions in garnet may be interpreted as primary inclusions during garnet growth. However, based on their shape and general orientation, the possibility that they represent exsolutions from a precursor majoritic garnet, in an advanced state of recrystallization (coalescing initial needles) remains open and needs further investigation. If the latter is proven true, it implies minimum pressures of 4 GPa.The oscillatory zoned domains of the zircon crystals from the garnet-rich mafic rock yield a weighted mean age at 117.4±1.9 Ma (Early Cretaceous) for the magmatic crystallization of the protolith. The zircon domains characterized by clearly fainted oscillatory zoning and/or U-rich embayments of the same zircon crystals are interpreted as metamorphic domains. They yield a weighted mean age of metamorphism at 73.5±3.4 Ma (Late Cretaceous). Different degrees of Pb loss resulted in discordant ages scattering between the magmatic and metamorphic age. The euhedral oscillatory zoned zircons of the cross-cutting pegmatoid yield a weighted mean age of 61.9±1.9 Ma for the time of emplacement and crystallization of retrograde metamorphic fluids into the middle-upper crust. Two scenarios are considered as possible for the interpretation of the SHRIMP-results and the petrological observations: (1) the protolith was an ultra high pressure melt (probably a grt±cpx cumulate) crystallizing in the mantle at Early Cretaceous times, partly exhumed into the lithosphere by mantle upwelling, and then transferred to a subduction zone and metamorphosed under eclogite-facies conditions in the Late Cretaceous; (2) the protolith was a cumulate within a gabbroic melt crystallizing at high crustal levels in the Early Cretaceous and subsequently metamorphosed under UHP conditions in the Late Cretaceous. Retrograde stages of metamorphism (ca. 500 °C, 0.5 GPa) occurred at 61.9±1.9 Ma.The petrological findings, which provide evidence for UHP conditions for these rocks of the Kimi Unit, combined with the SHRIMP-results, reveal different conditions of rock formation at different times for the Rhodope zone. The existence of a subduction zone in the Late Cretaceous shows that the Rhodope was not metamorphosed as a single geotectonic element but consists of different terranes subducted and exhumed at different times. [Copyright &y& Elsevier]

Presents information on a study which examined the origin of the zircon domains and the evolutionary history of the rocks at the HP-HT terrane of Rhodope, northern Greece. Overview and geological setting of the HP-terrane of the Rhodope zone; Field relations and petrography of the dated rocks; Analytical procedures; Cathodoluminescence patterns and morphology of zircons; Results of SHRIMP dating and interpretation.

Presents a study which was conducted to better understand the Jurassic opening and the Alpine closure of the Tethys ocean, emphasizing the fundamental importance of the geology of the Zermatt-Saas-Fee ophioligies (ZSFO). Formation of the Alphine chain; What led to the subduction of oceanic and continental crust under the Adriatic margin; Methods which were utilized to conduct the study; Geochronological results of the study.

The Gibeon Kimberlite Province, southern Namibia, comprises numerous, 70–80Ma old kimberlite pipes and dykes commonly containing abundant mantle and crustal xenoliths. We dated by SHRIMP II zircons from a garnet peridotite xenolith (Pipe Hanaus 1). The xenolith consists of garnet, orthopyroxene, clinopyroxene and, almost completely serpentinised, olivine. Crystallisation P–T conditions range between ca. 3.3GPa, 910°C (core composition of minerals) and ca. 3.5GPa, 1000°C (rim composition). Fifteen ca. 150–40μm long and 70–10μm wide zircon crystals show more or less pronounced oscillatory zoning indicating precipitation in a melt or fluid. The SHRIMP results define three age groups: 1013±22Ma, 751±28Ma and 627±24Ma. These ages are clearly correlated with large-scale crustal events in the broad area of Namibia, namely with the granulite-facies metamorphism during the Namaqua collisional event and post-collisional magmatism (ca. 1000–1100Ma), with the intense magmatic activity and initial rifting stages in the Damara belt (ca. 730–770Ma) and with the Early Pan-African orogeny, responsible for the formation of the Damara orogen (ca. 650Ma), respectively. Formation of zircon in the xenoliths is related to the generation and migration of fluids/melts in the mantle via e.g. asthenospheric mantle upwelling or dehydration of subducting lithosphere, associated with crustal large-scale events. [Copyright &y& Elsevier]