The effect of animals on human health and well-being

Substantial sums of money are invested annually in preventative medicine and therapeutic treatment for people with a wide range of physical and psychological health problems, sometimes to no avail. There is now mounting evidence to suggest that companion animals, such as dogs and cats, can enhance the health of their human owners and may thus contribute significantly to the health expenditure of our country. This paper explores the evidence that pets can contribute to human health and well-being. The article initially concentrates on the value of animals for short- and long-term physical health, before exploring the relationship between animals and psychological health, focusing on the ability of dogs, cats, and other species to aid the disabled and serve as a "therapist" to those in institutional settings. The paper also discusses the evidence for the ability of dogs to facilitate the diagnosis and treatment of specific chronic diseases, notably cancer, epilepsy, and diabetes. Mechanisms underlying the ability of animals to promote human health are discussed within a theoretical framework. Whereas the evidence for a direct causal association between human well-being and companion animals is not conclusive, the literature reviewed is largely supportive of the widely held, and long-standing, belief that "pets are good for us." © 2009 The Society for the Psychological Study of Social Issues.

The bird GPS - long-range navigation in migrants

Nowadays few people consider finding their way in unfamiliar areas a problem as a GPS (Global Positioning System) combined with some simple map software can easily tell you how to get from A to B. Although this opportunity has only become available during the last decade, recent experiments show that long-distance migrating animals had already solved this problem. Even after displacement over thousands of kilometres to previously unknown areas, experienced but not first time migrant birds quickly adjust their course toward their destination, proving the existence of an experience-based GPS in these birds. Determining latitude is a relatively simple task, even for humans, whereas longitude poses much larger problems. Birds and other animals however have found a way to achieve this, although we do not yet know how. Possible ways of determining longitude includes using celestial cues in combination with an internal clock, geomagnetic cues such as magnetic intensity or perhaps even olfactory cues. Presently, there is not enough evidence to rule out any of these, and years of studying birds in a laboratory setting have yielded partly contradictory results. We suggest that a concerted effort, where the study of animals in a natural setting goes hand-in-hand with lab-based study, may be necessary to fully understand the mechanism underlying the long-distance navigation system of birds. As such, researchers must remain receptive to alternative interpretations and bear in mind that animal navigation may not necessarily be similar to the human system, and that we know from many years of investigation of long-distance navigation in birds that at least some birds do have a GPS-but we are uncertain how it works.

PHOTOCATALYTIC DEGRADATION OF 4-CHLOROPHENOL MEDIATED BY TIO2 - A COMPARATIVE-STUDY OF THE ACTIVITY OF LABORATORY MADE AND COMMERCIAL TIO2 SAMPLES

The photocatalytic efficiencies of laboratory made and commercial TiO2 samples were compared using a standard test reaction: the photomineralization of 4-chlorophenol (4-CP) to CO2, H2O and HCl mediated by Degussa P25 TiO2 in a batch reactor. The results show that the rate of photodegradation of 4-CP, sensitized by a sample of TiO2, shows no clear simple dependence on physical characteristics such as the degree of crystallinity, the surface area and the percentage of H2O.

EFFECTIVE LABORATORY MONITORING FOR THE ABUSE OF THE BETA-AGONIST CLENBUTEROL IN CATTLE

The use of the beta-agonist clenbuterol (CBL) as a growth promoter has been outlawed in European meat production. The detection of its illegal use is dependent on CBL residues persisting in animal tissues for longer than the withdrawal times given by abusers. A comparison of urine, bile and liver matrices indicated that analysis of the liver offered the best possibility for CBL detection. However, an experimental study showed that CBL detection following withdrawal could be further extended (up to 56 d) if the retina was used as the target tissue. Analysis of 703 retina and liver samples from cattle suspected of CBL medication revealed that 96 cattle had CBL residues present in their retinas, only 46 of these were liver positive. There were no instances of liver CBL residues being detected without the associated retina also being positive.

RESIDUES OF THE BETA-AGONIST CLENBUTEROL IN TISSUES OF MEDICATED FARM-ANIMALS

Reports of the illegal use of clenbuterol as a growth promotant prompted the development of a competitive enzyme immunoassay for this drug. This procedure was utilized to study the elimination of clenbuterol from tissues in sheep medicated with both therapeutic and growth-promoting doses of the drug. The results indicated that prior to removal of medication clenbuterol was widely distributed throughout the animal tissues. However as the withdrawal periods increased fluid targets such as urine and bile became less effective at detecting clenbuterol usage. At both therapeutic and growth-enhancing concentrations of clenbuterol liver samples remained positive up to the maximum withdrawal time given in this experiment (15 days). Concentrations of clenbuterol likely to cause food poisoning (> 100 ng/g) were only detected in liver samples taken prior to the removal of medication. The highest recorded concentration of clenbuterol in muscle was 22.5 ng/g.