Influence of the Nature of Calcium Salts on Serum Calcium, Phosphorus, Calcitonin, Growth Hormone, and Somatomedin C

peer reviewedTwenty healthy males were randomly divided into three groups. Each subject received either 405 mg elemental calcium (Ca) as a salt linked to an amino acid precursor, 405 mg CaC12 or 1000 mg Ca as Ca gluconolactate and carbonate. In all three cases, Ca intake led to an increase of serum Ca and TCT production and a decrease of PTH liberation. However, when Ca is linked to the amino acid precursor, an elective stimulation of growth hormone (GH) and somatomedin C (SmC) occurs. Due to the nature of its amino acid precursor, this salt seems to stimulate GH and SmC liberation through hypophysis. This could be a major pathway in decoupling of the sequence resorption-formation and therapy of metabolic bone diseases

Ice caves as an indicator of winter climate evolution: a case study from the Jura Mountains

Subsurface ice fillings were first described in the Jura Mountains at the end of the sixteenth century. In order to assess the impact of climate change on low-altitude cave ice a detailed inventory has been drawn up and more than 50 objects have been identified. Comparisons between older cave maps, photographic documents and present-day observations outline a negative trend in ice mass balances, a trend that increased at the end of the 1980s. As most of these ice caves act as cold air traps, this negative mass balance is mainly attributed to higher winter temperatures and to reduced snow precipitation at low altitudes. The equilibrium line altitude of ice caves is believed to have increased several hundred metres between AD 1978 and 2004. Photographic comparisons and proxy records in some of the caves studied provide evidence of a rapid mass turnover. Ice ages range between less than a few decades and a millennium. Climatic records in these ice fillings will therefore present only short time series compared with other cave sediments. However, indications of former ice fillings have been found in different caves of the Jura Mountains and outline their potential role as palaeoclimatic markers