Thigh muscles' responses caused by a single combined aerobic and resistance training session in healthy young men.

The aim of this study was to understand the amplitude and localization of neuromuscular response induced by a training session combining an aerobic and a resistance component. Ten healthy men completed a single session of combined (aerobic and resistance) and aerobic only training, in a randomized order. Surface electromyographic activity and torque obtained during maximal voluntary and electrically evoked contractions of the knee extensor muscles were analyzed to distinguish peripheral from central adaptations. The isometric torque developed by the knee extensor muscles during maximal voluntary contraction decreased significantly following a single session of both combined (-9.2%, p=0.043) and aerobic (-9.6%, p=0.005) training. This was accompanied by a decrease in central activation of the knee extensor muscles after each training session (respectively 2.9, p=0.005 and 1.8% p=0.040) as indicated by twitch interpolation technique. After the combined training protocol, the peak torque of the twitch significantly increased by 6.8% (p=0.046), whereas it decreased by 17.3% (p=0.016) after the aerobic training protocol. The present study demonstrates that the decrease in torque production is similar after a single combined training session or after an aerobic training session of the same duration. Both central and peripheral mechanisms could explain the decrease of torque.

[Isolated depressed fracture of the cheek bone in alpine rapid-river canoeing]. / Die isolierte Impressionsfraktur des Jochbogens beim alpinen Wildwasserkanusport.

Whitewater kayaking is a rapidly growing form of extreme sport with a high risk potential for upper-body injuries, mainly concerning the head and torso. Direct impact traumata, such as a creek bone fracture, require an operation. The follow up treatment is aimed to prevent any loading from taking place. If necessary, a special facemask can be made to avoid injuries resulting from direct contact with hard surfaces. A suitable helmet for kayaking should include facial protection, which is not very common.

Spatial complexity in children's language.

The purpose of this research was to explore the properties of locative scenes which influence the sequence of the acquisition of spatial prepositions in English. Children ranging in age from about 2;8 to 5;6 were tested with a comprehension test involving a sentence-picture matching task. The comprehension test contained six kinds of spatial contrasts which were judged to vary in the geometric complexity of the scene. The order of acquisition was as follows: (1) into/out of & onto/off of, (2) in/on, (3) into/onto & out of/off of and through/over (around), (4) between X & Y/Y & Z, and (5) across/along. Complexity depends on a number of factors such as the number of referent objects and the nature of the relationship between the object to be located and the critical feature of the referent object. Prepositions which involve a more complex spatial geometry are more difficult for young children to comprehend. It was argued that the sequence of acquisition is partially determined by the course of conceptual development.

The interaction of language and thought in children's language acquisition: a crosslinguistic study.

The purpose of this research was to investigate the potential interaction of conceptual representations and linguistic systems in the process of language acquisition. Language-thought interactions were studied in 80 American, 48 Finnish and 48 Polish preschool children. The research focused on the conceptual and linguistic development of space and time. The spatial and temporal conceptual tasks were designed to measure the transition from experimental to inferential knowledge of space/time representations. In the linguistic domain, comprehension and production tests were used to evaluate the children's capacity to understand mono- and bi-referential location in space and time, where mono-referential location involves a single referent object/event with intrinsic properties (e.g. in/on or past/non-past), and bi-referential location requires two or more referent objects/events and relative perspective (e.g. deictic front/back or before/after). The conceptual and linguistic tests revealed significant changes during the period from two to five years of age, and measures of conceptual development were correlated with measures of linguistic development. As spatial and temporal representations became more structured, children were able to move from mono- to bi-referential location. In a comprehension test, we discovered an interaction of language by dimension. Finnish children found spatial distinctions relatively easy and Polish children found temporal distinctions relatively easy. This interaction was expected on the basis of the relative complexity of the morpho-syntactic coding in the spatial and temporal systems of the two languages. However, the argument relating the timing of acquisition to the transparency versus opacity of the linguistic systems was not supported by the English language comparison. Finally, the Finnish children were relatively better able to accomplish the spatial conceptual tasks as compared to the Polish children. This finding is consistent with a developmental concept of linguistic relativity. In general, the research indicates that spatial and temporal linguistic systems and representational knowledge interact during development with the influence occurring in both directions.

Spatial and temporal locations in child Jordanian Arabic.

The purpose of this research was to evaluate the influence of cognitive development on the acquisition of the spatial and temporal systems in Jordanian Arabic. 60 Jordanian children 2 to 6 years old received a comprehension test based on a 1991 sentence-picture matching task of Weist, wherein each problem contained a minimal morphological contrast. These contrasts were either spatial, e.g., 'in/on', or temporal, e.g., past/future tense. Further, the contrasts required either a single referent object or event, e.g., 'in/on' and past/future tense, or they required two or more referent objects or events, e.g., 'between' and 'before/after'. Firstly, significant change across age groups was noted. Secondly, problems which required two referent objects or events were more difficult than those requiring one referent object or event. Finally, spatial contrasts were easier than temporal ones. The findings were related to the general issue of the interaction of language and thought during the acquisition of language.

A cross-linguistic perspective on the development of temporal systems.

The purpose of this research was to evaluate the development of temporal location within a cross-linguistic experimental design. The research focused on the transition from a temporal system based on absolute temporal relation involving speech time and event time to a more complex system involving relative temporal relationships and reference time. A comprehension test was constructed with problems which were diagnostic of two salient distinctions within each of three temporal systems. The procedure was based on a two-choice sentence-picture matching task. The children who participated were from Poland, the USA and Finland, and there were 12 children at each of the following age levels: 2;6, 3;6, 4;6, 5;6, and 6;6. The Polish and American children solved problems requiring absolute temporal location at 2;6, and the older children eventually solved most of the problems requiring relative location. The Finnish children followed a different pattern taking longer to comprehend both types of problems. A second experiment confirmed the Finnish pattern of development. The results of the comprehension test were compared to observations of conversational and narrative discourse which were the product of two elicitation procedures. The research demonstrates the way in which conceptual development places a universal constraint on the developmental process and how the specific properties of individual languages also have an effect.

Shallow and deep phases of comprehension of discourse by children.

Children listened to stories which contained two kinds of anomalies. One type of anomaly was produced by violating semantic restrictions (violation of sentence), and the other anomaly was based on conflicting propositions at two points in a story (violation of discourse). The capacity to detect violations of relations within sentences developed more rapidly than the capacity to detect violations of relations within discourse. The research gives an estimate of the child's developing capacity to integrate and store the structure of stories.

Parent and sibling comprehension of children's speech.

In this research, the capacity of parents and siblings to understand the speech of children in early phases of language development was investigated. The utterances of young children were video tape recorded and presented to family members and nonparent and nonsibling controls. Family members showed a comprehension advantage over the appropriate control groups.