Long-term effects of high doses of nicotine on feeding behavior and brain nitric oxide synthase activity in female mice.

We studied the long-term effects of repeated doses of nicotine, causing dependence, 120 days after its withdrawal on feeding behavior and on brain nitric oxide (NO) formation in female mice. Nicotine dependence was induced by subcutaneous (s.c.) nicotine injection (2 mg/kg, four injections daily) for 14 days. Daily food intake was evaluated for the entire observational period (120 days). Moreover, 30, 60, and 120 days after nicotine withdrawal, we evaluated food intake, nitrite/nitrate levels, and nitric oxide synthase (NOS) activity and expression in the hypothalamus after food deprivation (24 h). In animals in which nicotine dependence was induced (NM), daily food intake was similar to that of controls (M). However, following food deprivation, NM mice showed i) a significant increase in food intake, ii) changes in weight gain and in hypothalamic nitrite/nitrate levels, and iii) enhancement of hypothalamic neuronal NOS (nNOS) activity. Results indicate that high doses of nicotine producing dependence induce long-term changes in feeding behavior consequent to food deprivation associated to alterations in the brain nitrergic system. Keywords:: food intake, nicotine, nitric oxide, weight gain, food deprivatio

Soil physical-mechanical properties evaluation in different tillage systems

In environments characterized by steep slopes or arranged in terraces, among the shallow tillage systems, rototilling is extensively used. However, the effect of the repeated use of ro-totilling has a considerable influence on soil characteristics; it appears finely powdered, soft and without structure. In order to limit these inconveniences, an innovative self-propelled machine equipped with working tools as a spade, to be used in steep slopes or arranged in terraces areas, was designed by the Mechanics Section of the Department of Agricultural and Forest Sciences, University of Palermo, in cooperation with Agrotec company, Padua, Italy. The aim of this study is to compare the effects of three machines for shallow tillage: a chisel plough (CP), a rototilling (RT) and a spading machine (SM) on penetration resistance in semi-arid environments of the Mediterranean basin. No tillage was also included. Penetration resistance (PR) was surveyed for all the treatments to a depth of 300 mm with an electronic dynamometer. The study was carried out in 2011-201. The treatments consisted in the exe-cution of a shallow tillage to a depth of 150 mm. SP treatment allowed us to obtain PR lower values throughout the tillage profile than RT, CP and NT. It follows that the type of machine used influences soil PR, and then the soil water storage capacity, key factor for the agricultural productions in semi-arid environments as in Sicily