767 research outputs found
Nitrogen Use Efficiency of Specialized Dairy Farms in Flanders: Evolution and Future Goals
Efficient use of nutrients is one of the major aims of eco-efficient and sustainable agricultural production systems. We determined the nitrogen use efficiency of a representative set of specialised dairy farms in Flanders, between 1989-1990 and 2000-2001 and set achievable eco-efficiency targets for sustainability
Energy Use and Energy Use Efficiency of Specialised Dairy Farms in Flanders
Our highly mechanised agriculture largely depends on ever declining stocks of fossil energy and hence contributes to global warming through the emission of greenhouse gases. Therefore, energy use (efficiency) is an important aspect of eco-efficient and sustainable agricultural production systems. In this study, we estimated direct and indirect energy use on a representative set of specialised dairy farms in Flanders (334 farm datasets in 1989-1990 and 147 farm datasets in 2000-2001) and we calculated their energy use efficiency. We studied the observed evolution between 1989-1990 and 2000-2001
Nonpolar resistance switching of metal/binary-transition-metal oxides/metal sandwiches: homogeneous/inhomogeneous transition of current distribution
Exotic features of a metal/oxide/metal (MOM) sandwich, which will be the
basis for a drastically innovative nonvolatile memory device, is brought to
light from a physical point of view. Here the insulator is one of the
ubiquitous and classic binary-transition-metal oxides (TMO), such as Fe2O3,
NiO, and CoO. The sandwich exhibits a resistance that reversibly switches
between two states: one is a highly resistive off-state and the other is a
conductive on-state. Several distinct features were universally observed in
these binary TMO sandwiches: namely, nonpolar switching, non-volatile threshold
switching, and current--voltage duality. From the systematic sample-size
dependence of the resistance in on- and off-states, we conclude that the
resistance switching is due to the homogeneous/inhomogeneous transition of the
current distribution at the interface.Comment: 7 pages, 5 figures, REVTeX4, submitted to Phys. Rev. B (Feb. 23,
2007). If you can't download a PDF file of this manscript, an alternative one
can be found on the author's website: http://staff.aist.go.jp/i.inoue
Pigeons’ performance in a tracking change-signal procedure is consistent with the independent horse-race mode
This is the author accepted manuscript. The final version is available from the American Psychological Association via the DOI in this record.In many cognitive tasks where humans are thought to rely on executive functioning,
pigeons’ behavior can be explained by associative processes. A key form of executive
functioning is inhibiting prepotent responses, often investigated in humans by means of
“Stop-signal” or “Change-signal” procedures. In these procedures, execution of a wellpractised (“Go”) response to a stimulus is occasionally interrupted by a signal to withhold or
alter the practised response. Performance in such tasks is usually described by the
“independent horse horse-race model” model. This model assumes that the processes that
cause the Go and inhibitory responses occur independently; the process that finishes first
determines the response observed. We further tested this model by training pigeons to
track the circular movement of a colored patch around a touchscreen by pecking it; the spot
occasionally deviated from its normal path (the Change signal). The pigeons had to inhibit
the habitual movement of their heads in order to land a peck on the spot in its unexpected
position. The key predictions of the independent horse-race model were confirmed in the
pigeons’ latency data. Thus, the independent race model can also successfully describe
Stop-change performance of subjects that do not rely on executive control
Does alcohol cue inhibitory control training survive a context shift?
Inhibitory control training (ICT) is a novel psychological intervention that aims to improve inhibitory control in response to alcohol-related cues through associative learning. Laboratory studies have demonstrated reductions in alcohol consumption following ICT compared with control/sham training, but it is unclear if these effects are robust to a change of context. In a preregistered study, we examined whether the effects of ICT would survive a context shift from a neutral context to a seminaturalistic bar setting. In a mixed design, 60 heavy drinkers (40 female) were randomly allocated to receive either ICT or control/sham training in a neutral laboratory over 2 sessions. We developed a novel variation of ICT that used multiple stop signals to establish direct stimulus–stop associations. The effects of ICT/control were measured once in the same context and once following a shift to a novel (alcohol-related) context. Our dependent variables were ad libitum alcohol consumption following training, change in inhibitory control processes, and change in alcohol value. ICT did not reduce alcohol consumption in either context compared with the control group. Furthermore, we demonstrated no effects of ICT on inhibitory control processes or alcohol value. Bayesian analyses demonstrated overall support for the null hypotheses. This study failed to find any effects of ICT on alcohol consumption or candidate psychological mechanisms. These findings illustrate the difficulty in training alcohol-inhibition associations and add to a growing body of literature suggesting that ICT holds little evidential value as a psychological intervention for alcohol use disorders
The inflated mitochondrial genomes of siphonous green algae reflect processes driving expansion of noncoding DNA and proliferation of introns.
Within the siphonous green algal order Bryopsidales, the size and gene arrangement of chloroplast genomes has been examined extensively, while mitochondrial genomes have been mostly overlooked. The recently published mitochondrial genome of Caulerpa lentillifera is large with expanded noncoding DNA, but it remains unclear if this is characteristic of the entire order. Our study aims to evaluate the evolutionary forces shaping organelle genome dynamics in the Bryopsidales based on the C. lentillifera and Ostreobium quekettii mitochondrial genomes. In this study, the mitochondrial genome of O. quekettii was characterised using a combination of long and short read sequencing, and bioinformatic tools for annotation and sequence analyses. We compared the mitochondrial and chloroplast genomes of O. quekettii and C. lentillifera to examine hypotheses related to genome evolution. The O. quekettii mitochondrial genome is the largest green algal mitochondrial genome sequenced (241,739 bp), considerably larger than its chloroplast genome. As with the mtDNA of C. lentillifera, most of this excess size is from the expansion of intergenic DNA and proliferation of introns. Inflated mitochondrial genomes in the Bryopsidales suggest effective population size, recombination and/or mutation rate, influenced by nuclear-encoded proteins, differ between the genomes of mitochondria and chloroplasts, reducing the strength of selection to influence evolution of their mitochondrial genomes
Why decision making may not require awareness
Newell & Shanks (N&S) argue against the idea that any significant role for unconscious influences on decision making has been established by research to date. Inasmuch as this conclusion applies to the idea of an "intelligent cognitive unconscious," we would agree. Our concern is that the article could lead the unwary to conclude that there are no unconscious influences on decision making - and never could be. We give reasons why this may not be the case
Ratchet Effect in Surface Electromigration: Smoothing Surfaces by an ac Field
We demonstrate that for surfaces that have a nonzero Schwoebel barrier the
application of an ac field parallel to the surface induces a net electro-
migration current that points in the descending step direction. The magnitude
of the current is calculated analytically and compared with Monte Carlo
simulations. Since a downhill current smoothes the surface, our results imply
that the application of ac fields can aid the smoothing process during
annealing and can slow or eliminate the Schwoebel-barrier-induced mound
formation during growth.Comment: 4 pages, LaTeX, 4 ps figure
- …