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Major reductions in abundance of age-0 largemouth bass Micropterus salmoides (76-87%) occurred between May and June (1981) or between June and July (1980, 1982) in Lake Dora, Florida. The severity of this mortality was not consistently related to spawning success, as measured by densities of age-0 fish in spring block-net samples before the periods of heavy mortality. High-mortality periods typically coincided with diet shifts towards piscivory. Age-0 largemouth bass exhibited the least piscivory at the same time that biomass ratios of available fish prey to predators were lowest in the two years (1980, 1981) they were measured. The lowest observed prey: predator ratios also preceded periods of major mortality. This period of density reduction was accompanied by a significant reduction in percentage fat of age-0 fish in 1980 and 1982, but not in 1981. The major reductions in density of age-0 largemouth bass between May and July were believed to represent a survival bottleneck that should be considered in conjunction with stock assessment and management efforts directed at this species. [ABSTRACT FROM AUTHOR]

Home range areas of largemouth bass Micropterus salmoides floridanus in two central Florida lakes varied from 0.01 to 5.16 hectares, and maximum home range dimensions ranged from 50 to 2,364 m, based on 2,047 radio locations of 22 fish from August 1979 to May 1981. Greatest average daily movements occurred during June, May, and February; the smallest were in August. Several largemouth bass migrated during the spawning season as far as 3 km from their home ranges to wave-protected sites within canals. Largemouth bass were often located in small areas of their home range and occupied panic grasses Panicum spp., stands of cattails Typha sp., and spatterdock Nuphar luteum more often than other available vegetation types and open water. A segment of the largemouth bass population remained offshore: 36% of the tagged fish were at least 10 m from shore 25% of the time. Studies such as this should facilitate identification of habitat use by fish, projection of realistic harvest rates, and formulation of predator stocking policies and fishing regulations. [ABSTRACT FROM AUTHOR]

We sampled brown shrimp Penaeus aztecus by small-mesh trawl during 1985 and 1986 in six nursery areas within Pamlico Sound, North Carolina. Size distributions were positively skewed in May through mid-June, and negatively skewed in July through August. Changes in the length-frequency distribution over time appeared to be a result of size-selective emigration; some of the larger brown shrimp apparently began leaving the nursery areas when the upper 10th size percentile reached about 100 mm in total length. [ABSTRACT FROM AUTHOR]

Bone is a remarkable, very strong and flexible structure. Running and jumping, together with muscle work, and lever arms generate ground reaction forces helping to model developing bone. Peak bone mass, strongly determined by genetic factors and exercise, is one of the most important factors in bone health. The amount of bone accrued, especially before the end of the third decade of life, is a major determinant of the risk of fractures in later life. Bones are a living tissue and constantly changing throughout one's lifetime, thus manifold osteopathies are known. The bone itself does not need to be the primary cause of diseases, but rather be affected in combination with other diseases. Besides osteopathies, such as fractures, achondroplasy, Morbus Paget, etc., osteoporosis which is defined as a systematic skeletal disease characterised by low bone mass and micro-architectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture, according to the World Health Organization (WHO), is ranked among the ten prime widespread diseases. Bone mineral density (BMD) is used in diagnosing osteoporosis. Anamnesis and clinical findings, bone densitometry, medical imaging and the basic laboratory are basic diagnostics for osteoporosis. Physical inactivity, medication, sex, age, low body mass index, need to be regarded as risk factors for osteoporosis. Acute and chronic pain caused by osteoporosis restricts activities of daily living and diminishes quality of life. FRAX (a diagnostic tool), disregarding all advantages and disadvantages of the computer based algorithm, calculates the country-specific 10-year-probability of a major hip fracture. Several different bone disorders, especially osteoporosis, are among other reasons linked to a sedentary lifestyle and poor nutrition habits. Preventing osteoporosis is a lifelong task, involving aspects such as nutrition and body weight, physical activity, as well as the abuse of dependence-causing substances. Thus lifestyle modification, calcium, vitamin D3, physical activity, exercise and prevention of falls establish the basic therapy for osteoporosis. Building on this, secondary and tertiary prevention addresses the risk of fracture and repeated fracture prevention via medication. Physical medicine represents not merely an alternative, but rather a complementary and inevitable therapy option in treating bone disorders, especially osteoporosis. Consequently, physical exercise plays a key role in reducing fractures and repeated fractures. The study situation concerning physical activity and osteoporosis is so far not easy to evaluate, because interventions disagree on duration, intensity, specificity, and subject groups. Although there is a vast amount of literature on physical activity (described as one of the best medications against diseases of lifestyle), there is a lack of consensus according to the best dose-response correlation for bone health. In the context of bone health, particular attention is paid to whole body vibration. Whole body vibration may improve muscle strength and power and consequently bones and balance as well. However, the mechanism is not well understood and the exact role is still debated and cannot be uniformly prescribed. As society grows older and lifestyle becomes more and more sedentary, the occurrence of osteoporosis should be held as low as possible and therefore the diagnostic methods need to take action to recognise indications of osteoporosis as soon as possible and be able to determine the most effective treatment options. [ABSTRACT FROM AUTHOR]

Eccentric training is an established training method in competitive sports. It has been used effectively to improve muscle strength during rehabilitation after cruciate ligament reconstruction. However, it is still uncertain whether or not eccentric training contributes to successful rehabilitation after apophysis fractures. A fourteen-year-old soccer player, forward position, presents with an apophysis avulsion located at the right spina iliaca anterior inferior. After completing an early rehabilitation phase and isokinetic concentric strength development, the patient starts an eccentric training programme eight weeks after the injury, including training on an isokinetic dynamometer (Biodex) for four weeks, followed by a four-week eccentric ergometer training (Eccentron). Before and after each eccentric training phase, isokinetic maximum strength tests of the knee extensors and flexors are performed with angular velocities of 60 degrees per second (°/sec.), 180°/sec. and 240°/sec. In response to the eight-week eccentric rehabilitation program, maximum torque increases in all angular velocities in the injured (60°/sec. + 14.4 %; 180°/sec. + 8.8 %; 240°/sec. + 6.3 %) and the uninjured leg (60°/sec. + 15.6 %; 180°/sec. + 1.9 %; 240°/sec. + 8.1 %) between the first and the last test. Furthermore, neuromuscular coordination has improved during the eccentric training sessions. This case study demonstrates that controlled eccentric training in the open and closed kinetic chain increases coordination and strength of the trained muscles and therefore should be regarded as a valuable contribution toward a safe return to sport after apophysis fractures., Competing Interests: Interessenkonflikt: Die Autoren geben an, dass kein Interessenkonflikt besteht., (© Georg Thieme Verlag KG Stuttgart · New York.)