Recently, the algebraic theory of MV -algebras is intensively studied. In this paper, we extend the concept of derivation of $MV$-algebras and we give someillustrative examples. Moreover, as a generalization of derivations of $MV$ -algebraswe introduce the notion of $f$-derivations and $(f; g)$-derivations of $MV$-algebras.Also, we investigate some properties of them.

Drainage ditches, either seasonally flooded or permanent, are commonly found on intensively managed lowland farmland in the UK. They are potentially important for wetland biodiversity but, despite their ubiquity, information on their biodiversity and management in the wider countryside is scarce. We surveyed 175 ditches for their physical and chemical characteristics, spatial connectivity, plan...

Used were 15 bulls and 15 heifers of the Black-and-White Polish Holstein-Friesian breed, semiintensively fattened, with the aim of evaluating the effect of sex on the selected traits of quality of beef. Bulls were slaughtered at the mean age of 536.2 days and 523.1 kg body weight, and heifers at 528.7 days and 459.7 kg body weight, respectively. After slaughter and post-slaughter treatment, the...

Few studies have investigated the influence of water availability on plant population spatial patterns. We studied changes in the spatial patterns of Caragana stenophylla along a climatic drought gradient within the Inner Mongolian Plateau, China. We examined spatial patterns, seed density, "nurse effects" of shrubs on seedlings, transpiration rates and water use efficiency (WUE) of C. stenophy...

We carried out a one year (2002) study of phosphorus (P) loss from soil to water in three nested grassland catchments with known P input in chemical fertilizer and animal liquid slurry applications. Chemical fertilizer was applied to the grasslands between March and September and animal slurry was applied over the twelve months. The annual chemical P fertilizer applications for the 17 and 211 h...

2009) and estimated to average 89% nationally (Ice et al. in press). Information is needed to successfully address the confluence of technological, biophysical, and environmental issues surrounding intensively managed forests. This overview describes current intensive plantation management practices in the United States and their role in increasing forest productivity. Although a number of plan...

The present work summarizes research related to the definition of nutrient recommendations for feeds used in the intensive production of rabbit's meat. Fibre is the main chemical constituent of rabbit diets that typically contain 320 to 360 and 50 to 90 g/kg of insoluble and soluble fibre, respectively. Instead, the dietary contents of cereal grains (~120 to 160 g/kg), fat (15 to 25 g/kg) and p...