Silviculture Methods in Polish Forests Affected by Industrial Pollutants

Data presented by the Headquarters of the State Forests in Poland indicate that about 645,000 ha were threatened by industrial emissions in the mid-1980s. The authors have carried out a complementary study and have come to the conclusion that about 2.8 million ha were threatened in 1988. Due to the future emissions the area under threat is estimated to increase to about 4.2 million ha in the year 2000. This rapid development of decline requires a changed silvicultural management. Guidelines for the changed management of the following order of stands threatened by air pollutants are discussed: (a) stands characterized as being "in the regeneration class"; (b) clear-cut stands; (c) second-order clear-cut stands; (d) seedlings and thickets; (e) stands of medium age classes; and (f) stands with a share of deciduous species exceeding 20%

LOADS ACTING ON THE LOCOMOTIVE SYSTEM OF PROFESSIONAL FEMALEVOLLEYBALL PLAYERS DURING THE LANDING PHASE OF SPIKES AND BLOCKS

The purpose of this study was to identify force and time characteristics of ground reaction forces produced during the landing phase of volleyball technical elements: blocks and spikes. Applying piezoelectric dynamometry and video recording, a series of tests were carried out with the participation of four female volleyball players of the first team of AZS AWF sports club competing in the Female Volleyball League. The recorded force vs time line graphs of ground reaction Rx(t), Ry(t) and Rz(t) were used to calculate the values of kinematic-dynamic parameters that describe the level of dynamic loads. Results show that the majority of loads in these movement tasks is significant and may be traumatogenic

Information-theoretic principle entails orthomodularity of a lattice

Quantum logical axiomatic systems for quantum theory usually include a postulate that a lattice under consideration is orthomodular. We propose a derivation of orthomodularity from an information-theoretic axiom. This provides conceptual clarity and removes a long-standing puzzle about the meaning of orthomodularity.Comment: Version prior to published, with slight modification

Positive auto-sterotyping and self-construal as predictors of national identification

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