Front crawl stroke in swimming: Phase durations and self-similarity.

Human movements, such as walking and running, are able to generate rhythmic motor patterns, with the consequent appearance of hidden time-harmonic structures. Such harmonic structures are represented (at comfortable speed) by the occurrence of the golden ratio as ratio of durations of specific walking and running gait sub-phases. Preliminary experimental evidences suggest that front crawl swimming may behave, under this point of view, like walking and running. This paper aims to demonstrate that a mathematical connection between the golden ratio and the front crawl swimming stroke actually exists, at a pace that plays the role of the comfortable speed in walking and running. Generalized Fibonacci sequences are used to this purpose. They rely on the durations of aggregate phases of the front crawl swimming stroke with a clear physical meaning, while characterizing self-similarity of front crawl strokes in its simple nature and enhanced (stronger) variant. Experimental data on front crawl swimmers illustrate the theoretical derivations, suggesting that the pace playing the role of the comfortable speed in walking and running is the middle/long-distance one, while showing that the self-similarity level increases with the swimming technique and the enhanced self-similarity is associated with the performance of top-level swimmers.

Endothelin-1 circulating levels increase in patients with orthotopic heart transplantation and in chronic therapy with cyclosporine.

BACKGROUND: The aim of the study was to investigate the behaviour of plasma levels of endothelin-1 (ET-1), an endothelial peptide with vasoconstrictive and proliferative actions, in patients with cardiac transplantation and in chronic treatment with cyclosporine A, some of whom became hypertensive after cardiac transplantation. METHODS: We studied: 1) 18 consecutive patients (15 M, 3F; mean age 53 +/- 7 yrs) who underwent cardiac transplantation about six months ago at least (range 6-108 months); 2) 15 patients with essential arterial hypertension (10 M, 5 F; mean age 42 +/- 15 yrs) without organ damage; 3) 21 normal subjects (15 M, 6 F; mean age 31 +/- 12 yrs). Plasma levels of ET-1 (RIA), haemodynamic and functional renal parameters were determined in all groups and plasma levels of cyclosporine were measured in patients with cardiac transplantation. RESULTS: ET-1 was higher in patients with cardiac transplantation than in the other two groups (p < 0.05); instead there was no difference between patients with essential arterial hypertension and controls (p>0.05). A statistical difference was found between circulating ET-1 in hypertensive transplanted patients. In heart transplanted patients a positive and significative correlation was found between plasma levels of ET-1 and systolic (r=0.525; p<0.037) blood pressure.

Parkinsonian syndrome in a patient with a pterional meningioma: case report and review of the literature.

The onset of a Parkinsonism in a patient with intracranial meningioma is definitely rare. The authors described the case of a patient suffering from a Parkinsonian syndrome for 10 years with no evidence of clinical improvement after medical treatment. A CT-scan of the brain evidenced a right pterional intracranial meningioma. The complete surgical removal of the neoplasm succeeded in resolving the Parkinsonian syndrome. The extension of the neoplasm and of the peritumoral edema may play an important role in compressing and consequently impairing perfusion of the basal ganglia region.