Abstract: INTRODUCTION: The connection between morphologic changes of the spine and the intensity of training has been assessed for a number of sport activities. The influence of horseback riding on the spine has only rarely been evaluated. The aim of our study was to evaluate to what degree horseback riders suffer from back pain and whether there is an association between this parameter and the category i. e. the intensity of horseback riding. Furthermore we wanted to judge whether riding may have a positive effect on pre-existent back pain. METHODS: 508 horseback riders (63.2 % females; 36.8 % males) competing in either dressage, showjumping or vaulting were interviewed using a questionnaire. Apart from biometric data, the intensity with which riding was performed and the localisation and intensity (VAS) of back pain was assessed. Furthermore, in the case of existing back pain, riders were asked whether different riding disciplines and paces changed the intensity of pain. RESULTS: 300 dressage riders (59.1 %), 188 showjumpers (37.0 %) and 20 vaulters (3.9 %) with an average age of 33.5 Jahre (12 – 77 years) were questioned. The incidence of back pain was 72.5 %. A significant correlation between back pain and riding discipline respectively gender or riding level could not be found. Discrepancies in VAS-score for dressage riders (3.95 +/- 0.13), show jumpers (4.10 +/- 0.16) and vaulters (3.76 +/- 0.5) were marginal and not significant (p > 0.05). Overall 58.7 % resp. 15.2 % reported to have pain in the lumbar i.e cervical spine. Despite the fact that a large fraction of dressage riders claimed to have problems in these spine areas with 57.7 % resp. 68.8 %, this finding was not significant compared to the other riding disciplines. While 61.6 % of dressage riders reported an improvement of their back pain when riding, this was only the case in 40.9 % of show jumpers. CONCLUSION: Compared to the general population, a high incidence of back pain is found among riders. A significant correlation between the intensity of riding or the riding discipline and frequency or severity of back pain could not be found. For riders with pre-existent back pain the pace “walk” seems to have a positive influence on pain intensity.

Abstract: Japanese workers have studied social acquisition patterns of new feeding habits in Macaca fuscata which they have termed precultural. The present study investigates the same phenomenon in the chacma baboon and the vervet monkey in their natural habitat. The questions addressed are: (1) How a new feeding habit enters a troop and by which age and sex category, also how it is propagated? (2) When individuals are permitted with a choice between palatable and unpalatable food, can they learn by demonstration only or do they have to pass through a direct learning process? (3) Can the results from the above questions be explained by social parameters such as the social structure of the individual species? It was found that juvenile baboons discover new food and that after the discovery propagation is instantaneous. In vervets discovery is random among the age classes and propagation is slow and takes place through certain 'pivot' individuals. Both species fail to learn about palatability by demonstration but have to go through a direct learning process. This contrasts strongly with the forest baboon Mandrillus sphinx that have been shown to learn by demonstration. Socially, baboon juveniles stay closer to each other than the adults who force them to live at the periphery of the troop. Vervets again forage without precise sub-group formation. The link between social and cultural propagation and social structure is discussed on the basis of these findings.

Abstract: Lipid-lowering fibrate drugs function as agonists for the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha). Sustained activation of PPARalpha leads to the development of liver tumors in rats and mice. However, humans appear to be resistant to the induction of peroxisome proliferation and the development of liver cancer by fibrate drugs. The molecular basis of this species difference is not known. To examine the mechanism determining species differences in peroxisome proliferator response between mice and humans, a PPARalpha-humanized mouse line was generated in which the human PPARalpha was expressed in liver under control of the tetracycline responsive regulatory system. The PPARalpha-humanized and wild-type mice responded to treatment with the potent PPARalpha ligand Wy-14643 as revealed by induction of genes encoding peroxisomal and mitochondrial fatty acid metabolizing enzymes and resultant decrease of serum triglycerides. However, surprisingly, only the wild-type mice and not the PPARalpha-humanized mice exhibited hepatocellular proliferation as revealed by elevation of cell cycle control genes, increased incorporation of 5-bromo-2'-deoxyuridine into hepatocyte nuclei, and hepatomegaly. These studies establish that following ligand activation, the PPARalpha-mediated pathways controlling lipid metabolism are independent from those controlling the cell proliferation pathways. These findings also suggest that structural differences between human and mouse PPARalpha are responsible for the differential susceptibility to the development of hepatocarcinomas observed after treatment with fibrates. The PPARalpha-humanized mice should serve as models for use in drug development and human risk assessment and to determine the mechanism of hepatocarcinogenesis of peroxisome proliferators.

Abstract: Marten and Psarakos have presented some evidence which suggests that objective self-awareness and possibly representations of self may characterize the dolphins' experience of self. Their research demonstrates the possibility of similarities in the sense of self between primate species and dolphins, although whether dolphins have subjective self-awareness, personal memories, and theories of self--all important facets of the sense of self in humans--was not examined. Clearly, even this limited evidence was difficult to achieve; the difficulties in adapting methods and coding behavior are quite apparent in their report. Future progress, however, may depend upon clarification of what are the necessary components for a sense of self and an explication of how these might be reflected in dolphin behavior. We are mindful of the authors' point (pp. 219 and 220) that the dolphin lives more in an acoustic than a visual environment. Thus, while tasks relying upon vision may reveal the presence or absence of the sense of self in primates, it might well be the case that in dolphins self-related experiences might be better revealed in auditory tasks. But then, what is the nature of human self-awareness in terms of audition? While both conceptual and methodological hurdles remain, Marten and Psarakos have demonstrated that important questions can be asked about the minds and phenomenal worlds of nonanthropoid species.

Abstract: Nine yearling horses, stabled in individual stalls, were used in a trial to determine the diurnal pattern of wood chewing and the effects of exercise on this behavior. The trial was a Latin square design conducted over three 2-wk periods during which each horse was exposed to each of the three following treatments: 1) no exercise (NE), 2) exercise after the morning feeding (AM), and 3) exercise in the afternoon (PM). Horses were fed a complete pelleted feed in the morning and both pelleted feed and long-stemmed hay in the afternoon. Exercise consisted of 45 min on a mechanical walker followed by 45 min in a paddock with bare soil. Each stall was equipped with two untreated spruce boards during each period for wood chewing. Wood chewing was evaluated by videotaping each horse for 22 h during each period, determining the weight and volume of the boards before and after each period, and by visual appraisal of the boards. Intake of trace mineralized salt was also measured. Wood chewing occurred primarily between 2200 and 1200. All measures of wood chewing were correlated when totals for the entire 6 wk were analyzed. When analysis was performed on 2-wk values, videotape results were not correlated with volume or weight loss of boards. Horses chewed more when on the NE treatment (511 s/d) than when on AM or PM (57 and 136 s/d, respectively; P less than .05). Salt intake tended to be greater for NE than for the other treatments (P less than .10).(ABSTRACT TRUNCATED AT 250 WORDS)