Kinesthetic Versus Visual Retroactive Inhibition

In this paper an attempt was made to show that forgetting is caused by interfering activities in time and not by time as such. To demonstrate this the many studies concerning the effects of interpolated activities on learning were investigated. These findings were interpreted in terms of an interference theory of forgetting and a perseveration theory of learning. The many studies involving retroactive inhibition seem to support the idea of a perseverating action in the neural tissues of the brain even after the overt learning process has come to an end. When this perseverating activity is allowed to continue without interference, cellular changes occur thereby allowing memory to become permanent. There is evidence presented also which suggests that forgetting is greatest when the interpolated activity and the original learning activity involve the use of the same receptor. Because the use of a specific receptor excites neural activity in a particular area of the brain, it was suggested that forgetting is greatest when a common sense modality is used in the original and interpolated learning, because the neural activity in both cases is concentrated in the same area of the brain. As a result forgetting is increased because of the interference, which prevents the memory trace from becoming established by disrupting the reverberating circuits

Sugar Beet Fertilization

Global sugar beet production spans diverse regions and a wide range of climatic and agroecological regions from rainfed to irrigated production which presents unique management challenges. Sound nutrient management now and into the future must be balanced between production efficiency and managing to have less impact on the environment. N management continues to improve with more precise N rates. Soil testing for N supplying capability plus residual N will need to be increased to enhance productivity and N use efficiency. Newer cultivation techniques, N placement and timing can also fine tune N rates. In irrigated areas, improvements in N management will be coupled with better water management and conversion of furrow irrigation to sprinklers will accelerate improvements. Enhanced efficiency fertilizer products hold promise but require additional research under a range of conditions to determine cost and production effectiveness. Management for secondary and micronutrients seems adequate at this time. Precision agricultural applications for expanded site specific management in sugar beet are just beginning. Work with maize and wheat point to the potential of creating different management zones in fields and by using remote or close sensing to determine N status for N applications. Similar research will be needed to continue efficient sugar beet production

Self-organization of Ce adatoms on Ag(111): a kinetic Monte Carlo study

One of the most fascinating experimental results in fabrication of artificial nanostructures is the creation of the macroscopically ordered superlattice of Ce adatoms on Ag111 F. Silly et al., Phys. Rev. Lett. 92, 016101 2004. Here, performing kinetic Monte Carlo simulations, we study the formation of Ce superlattice at the atomic scale. It is demonstrated that the surface-state mediated long-range interaction between Ce adatoms can lead to their self-assembly into a well ordered structure. The temperature of the substrate and the concentration of Ce adatoms are shown to play a key role in this process

Buffet test in the National Transonic Facility

A buffet test of a commercial transport model was accomplished in the National Transonic Facility at the NASA Langley Research Center. This aeroelastic test was unprecedented for this wind tunnel and posed a high risk for the facility. Presented here are the test results from a structural dynamics and aeroelastic response point of view. The activities required for the safety analysis and risk assessment are described. The test was conducted in the same manner as a flutter test and employed on-board dynamic instrumentation, real time dynamic data monitoring, and automatic and manual tunnel interlock systems for protecting the model

Ab initio study of mirages and magnetic interactions in quantum corrals

The state of the art ab initio calculations of quantum mirages,the spin-polarization of surface-state electrons and the exchange interaction between magnetic adatoms in Cu and Co corrals on Cu(111) are presented. We find that the spin-polarization of the surface-state electrons caused by magnetic adatoms can be projected to a remote location and can be strongly enhanced in corrals compared to an open surface.Our studies give a clear evidence that quantum corrals could permit to tailor the exchange interaction between magnetic adatoms at large separations. The spin-polarization of surface-state electrons at the empty focus in the Co corral used in the experimental setup of Manoharan et al., (Nature 403, 512 (2000)) is revealed.Comment: Submitted to Physical Review Letter

Nitrogen fertility in semiarid dryland wheat production is challenging for beginning organic farmers

Organic farming systems use green and animal manures to supply nitrogen (N) to their fields for crop production. The objective of this study was to evaluate the effect of green manure and composted cattle manure on the subsequent winter wheat (Triticum aestivum L.) crop in a semiarid environment. Dry pea (Pisum sativum L.) was seeded in early April and terminated at first flower in late June. Composted cattle manure was applied at 0, 11.2 or 22.5Mgha−1 just prior to pea termination. Winter wheat was planted in mid September following the green manure or tilled summer fallow. No positive wheat response to green manure or composted cattle manure was observed in any of the 3 years of the study. In 2 of the 3 years, wheat yields and grain test weight were reduced following green manure. Green manure reduced grain yields compared with summer fallow by 220 and 1190 kgha−1 in 2009 and 2010, respectively. This may partially be explained by 40 and 47mm less soil water at wheat planting following peas compared with tilled summer fallow in 2008 and 2009, respectively. Also, in 2008 and 2009, soil nitrate level averaged 45kgha−1 higher for black fallow compared with green manure fallow when no compost was added. Organic growers in the semiarid Central Great Plains will be challenged to supply N fertility to their winter wheat crop in a rapid and consistent manner as a result of the inherently variable precipitation. Growers may need to allow several years to pass before seeing the benefits of fertility practices in their winter wheat cropping systems

G77-361 Using Starter Fertilizers for Corn, Grain Sorghum, and Soybeans

Starter fertilizer may increase early growth of corn and grain sorghum. Grain yield increases from starter nutrients are most likely on low phosphorus soils and some sandy soils. Proper use of a starter fertilizer is an important management tool for crop producers striving for top yields. While the use of a starter fertilizer can be important for crop production on many soils, it is more important for corn production on irrigated sandy soils than on fine textured soils

Magnetic structure of bulk GdMnO₃: Influence of strain

Internal structural distortions are of great interest in the determination of electronic and magnetic properties of the strong correlated rare earth manganites. When combined with external structural modifications like uniaxial or biaxial strains, structural distortions can lead to the emergence of new magnetic ground states. This realization is seemingly more probable with the low-band-width manganite GdMnO3 on the grounds that it is located in the magnetoelectric phase diagram of orthorhombic rare earth manganites between the A-type antiferromagnetic (AFM) order and the cycloidal spin orders. Herein, a thorough analysis of the magnetic structure of GdMnO3 based on the density functional theory connected with a classical Heisenberg model together with Monte Carlo calculations is presented. It is found whether a compressive uniaxial strain along the c direction or biaxial strain on the ab plane favors a ferromagnetic (FM) ground state over the AFM one. On the contrary, a tensile strain also on the ab plane is likely to stabilize the E-type AFM order