Soil N2O emissions from three corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] systems in central Iowa were measured from the spring of 2003 through February 2005. The three managements systems evaluated were full-width tillage (fall chisel plow, spring disk), no-till, and no-till with a rye (Secale cereale L. 'Rymin') winter cover crop. Four replicate plots of each treatment were establishe...

Arable land weed seed banks are dynamic and reflect cropping history, current management, and environment. Changes in crop rotation and tillage system can alter weed seed density and species composition. In the semi-arid region of the Pacific Northwest, USA, no-till spring cropping is being studied as an alternative to the traditional winter wheat (Triticum aestivum L.)/dust-mulch fallow (WWF) ...

The balance between applied and harvested nitrogen (yield removed nitrogen, YRN %) is a recognized indicator of the risk of N leaching. In this study we monitored the genetic improvements and environmental variability as well as differences among crop species (spring cereals and rapeseed) in YRN in order to characterize changes that have occurred and environmental constraints associated with re...

The optimization of nitrogen application for root crops such as radish is important not only for yield and product quality (sponginess and hollowness) but also for the environment. Therefore, we evaluated the effect of four levels of N application (0, 150, 300 and 450 mg l-1 N) on three radish cultivars (Saxa, Red Fuoko and White Ghiaccio) grown in pots in autumn/winter (from mid-October to mid...

Context The winter feed gap is a common problem for livestock grazing systems worldwide, and changes to climate have made these deficits more unpredictable extreme. Dual-purpose crops are an important tool in many southern Australian mixed crop–livestock help fill the gap. Providing reliable over can remove constraints allow earlier lambing autumn with potential whole-farm system benefits. Aims...

Commercially available prosthetic hands are simple grippers with one or two degrees of freedom; these pinch type devices have two rigid fingers in opposition to a rigid thumb. This paper focuses on an innovative approach for the design of a myoelectric prosthetic hand. The new prosthesis features underactuated mechanisms in order to achieve a natural grasping behavior and a good distribution of...

This report makes a case for the need to examine the methodological foundations of AI. Many aspects of AI have not yet developed to a point of general agreement. The goals of AI work, the methods for acheiving these goals, the presentation of results, and the assessment of claims are all highly contentious issues. All aspects of AI methodology are subject to debate The Workshop on the Foundatio...

Problem 1. Infinite Products and Coproducts in Ab. We have seen that finite products and coproducts agree in Ab. However, the same is not true for infinite products and coproducts. Let I be a set and let {Ai}i∈I be a family of abelian groups, each equal to some fixed group A. (a) Show that the set AI := HomSet(I, A) is an abelian group. Furthermore, show that we can think of this group as the i...

introduction saffron as a winter active plant with low water requirement is the most strategic medicinal plant in arid and semi-arid parts of iran. this slow-growing plant has narrow leaves and no aerial stem, hence weeds can be overcome it. moreover, because of its root and canopy structure an important part of different resources is not used by this low input crop. therefore, the use of assoc...