Nutrients cause grassland biomass to outpace herbivory.

Human activities are transforming grassland biomass via changing climate, elemental nutrients, and herbivory. Theory predicts that food-limited herbivores will consume any additional biomass stimulated by nutrient inputs ('consumer-controlled'). Alternatively, nutrient supply is predicted to increase biomass where herbivores alter community composition or are limited by factors other than food ('resource-controlled'). Using an experiment replicated in 58 grasslands spanning six continents, we show that nutrient addition and vertebrate herbivore exclusion each caused sustained increases in aboveground live biomass over a decade, but consumer control was weak. However, at sites with high vertebrate grazing intensity or domestic livestock, herbivores consumed the additional fertilization-induced biomass, supporting the consumer-controlled prediction. Herbivores most effectively reduced the additional live biomass at sites with low precipitation or high ambient soil nitrogen. Overall, these experimental results suggest that grassland biomass will outstrip wild herbivore control as human activities increase elemental nutrient supply, with widespread consequences for grazing and fire risk.

The costs of treatment of early and chronic Pseudomonas aeruginosa infection in cystic fibrosis patients.

The aim of cystic fibrosis (CF) care is to improve both the life expectancy and quality of life of patients. However, rising costs and limited resources of health services must be taken into account. There are many different antibiotic strategies for therapy of Pseudomonas aeruginosa infection in CF patients. In this 5-year retrospective study we found that the cost of treatment of initial infection is considerably lower than the cost of treating chronic P. aeruginosa infections. The percentage distribution of costs of antibiotic treatment in relationship to the administration route was considerably different between outpatients and inpatients. We observed an increase in antibiotic costs with the age of the patient and the decrease in FEV(1)values. The implementation of early eradication treatment, in addition to decreasing the prevalence of patients chronically infected by P. aeruginosa, might also bring about a notable decrease in costs.

[Use of quinolones in the treatment of Pseudomonas aeruginosa infections in children with cystic fibrosis]. / Uso di chinolonici nel trattamento di infezioni da Pseudomonas aeruginosa in bambini con fibrosi cistica.

Quinolones, elective drugs for Pseudomonas aeruginosa (P. aeruginosa) pulmonary infections in Cystic Fibrosis (C.F.) patients, are controversially administered in prepuberal age for their arthropathic toxicity. We report the result of retrospective study on the use of quinolones in a group of 43 CF patients. The patients were divided into two groups: below 18 years (22 pts.) and over 18 (21 pts.). All patients were evaluated clinically with the scoring system Shwachman and Kulczyk. Ciprofloxacin and Ofloxacin (15/20 mg/kg/die) were administered. In 11.6% of the patients, all belonging to the second group, side effects, such as urticaria, tongue oedema, foreskin erythema, generalised erythema and itch, were described. No side effect has been reported in the patients below 18 years. Two patients complained knee arthralgias not related to the quinolones administration: in fact in the first case the demineralisation seemed to be responsible of the arthralgia, while in the second case an immunological disorder (ANA+, ICC+) should be involved in the pathogenesis of arthritis. Height velocity evaluation showed the same slowering of the CF untreated patients. In conclusion, our study confirms that quinolones use in indicated in severe and infective complications of CF on the basis of their efficacy, safety and their slight adverse effects similar to those of other potent antibiotic. Moreover our results confirm that no quinolone-induced cartilage toxicity is present in CF patients.