Ex-ante evaluation of tightening environmental policy: the case of mineral use in Dutch agriculture

Non-point source pollution is notoriously difficult to asses. A relevant example is mineral emissions in the Netherlands. Since the mid 1980s the Dutch government has sought to reduce emissions through a wide variety of measures, the effect of which in turn is monitored using modeling techniques. This paper presents the current generation of mineral emission models from agriculture based on microsimulation of farms in combination with a spatial equilibrium model for the dispersion of manure from excess regions with high livestock intensities within the country to areas with low livestock intensities. The micro-simulation approach retains the richness in the heterogeneity of farm household decision making that are the core cause of the difficulty of assessing non-point source pollution, while using the best available data to track corresponding pollution. Using scenario analysis we are able to assess the possible effects of further tightening of agro-environmental policy.micro-simulation, spatial-equilibrium model, non-point source pollution, Environmental Economics and Policy,

Producing translationally cold, ground-state CO molecules

Carbon monoxide molecules in their electronic, vibrational, and rotational ground state are highly attractive for trapping experiments. The optical or ac electric traps that can be envisioned for these molecules will be very shallow, however, with depths in the sub-milliKelvin range. Here we outline that the required samples of translationally cold CO (X$^1\Sigma^+$, $v"$=0, $N"$=0) molecules can be produced after Stark deceleration of a beam of laser-prepared metastable CO (a$^3\Pi_1$) molecules followed by optical transfer of the metastable species to the ground state \emph{via} perturbed levels in the A$^1\Pi$ state. The optical transfer scheme is experimentally demonstrated and the radiative lifetimes and the electric dipole moments of the intermediate levels are determined

Instrumentarium monitoring mestmarkt en enkele analyses

Het nieuwe mestbeleid met daarin een stelsel van gebruiksnormen en de bijbehorende normen grijpen naar verwachting fors in op de mestmarkt. Dit rapport beschrijft onderdelen van het instrumentarium voor de monitoring van de mestmarkt. De onderdelen zijn analyses van derogatiebedrijven (1), van de acceptatie van dierlijke mest op kleiakkerbouwbedrijven (2) en van het gedrag van melkveehouders op het nieuwe mestbeleid (3). Daarnaast beschrijft het rapport de opzet voor een systeem voor monitoring van mestprijzen (4) en de opzet voor interviews met mestdistributeurs (5)

Visual signals and children's communication: negative effects on task outcome

Previous research has found that young children fail to adapt to audio-only interaction (e.g. Doherty-Sneddon & Kent, 1996), and perform difficult communication tasks better face-to-face. In this new study, children aged 6- and 10 year-olds were compared in face-to-face and audio-only interaction. A problem-solving communication task involving description of abstract stimuli was employed. When describing the abstract stimuli both groups of children showed evidence of face-to-face interference rather than facilitation. It is concluded that, contrary to previous research, for some communication tasks access to visual signals (such as facial expression and eye gaze) may hinder rather than help children’s communication

Non-locality and Medium Effects in the Exclusive Photoproduction of Eta Mesons on Nuclei

A relativistic model for the quasifree exclusive photoproduction of $\eta$ mesons on nuclei is extended to include both non-local and medium effects. The reaction is assumed to proceed via the dominant contribution of the S$_{11}$(1535) resonance. The complicated integrals resulting from the non-locality are simplified using a modified version of a method given by Cooper and Maxwell. The non-locality effects are found to affect the magnitude of the cross section. Some possibilities reflecting the effects of the medium on the propagation and properties of the intermediate S$_{11}$ resonance are studied. The effects of allowing the S$_{11}$ to interact with the medium via mean field scalar and vector potentials are considered. Both broadening of width and reduction in mass of the resonance lead to a suppression of the calculated cross sections.Comment: 19 pages, 7 figure

Simplified screening approach of anabolic steroid esters using a compact atmospheric solid analysis probe mass spectrometric system

Due to the absence of chromatographic separation, ambient ionization mass spectrometry had the potential to improve the throughput of control laboratories in the last decades and will soon be an excellent approach for on-site use as well. In this study, an atmospheric solids analysis probe (ASAP) with a single quadrupole mass analyzer has been evaluated to identify anabolic steroid esters rapidly. Sample introduction, applied scan time, and probe temperature were optimized for sensitivity. The in-source fragmentations of seventeen selected steroid esters, commonly found in illicit samples, were determined by applying different cone voltages (12, 20, 30, and 40 V). A spectral library was created for these steroid esters based on the four stages of in-source fragmentation spectra. The applicability of this method was demonstrated for the rapid identification of steroid esters in oily injection solutions, providing test results in less than 2 min

Methods to create a stringent selection system for mammalian cell lines

The efficient establishment of high protein producing recombinant mammalian cell lines is facilitated by the use of a stringent selection system. Here, we describe two methods to create a stringent selection system based on the Zeocin resistance marker. First, we cloned increasingly longer stretches of DNA, encoding a range of 8–131 amino acids immediately upstream of the Zeocin selection marker gene. The DNA stretches were separated from the open reading frame of the selection marker gene by a stopcodon. The idea behind this was that the translation machinery will first translate the small peptide, stop and then restart at the AUG of the Zeocin marker. This process, however, will become less efficient with increasingly longer stretches of DNA upstream of the Zeocin marker that has to be translated first. This would result in lower levels of the Zeocin selection marker protein and thus a higher selection stringency of the system. Secondly, we performed a genetic screen to identify PCR induced mutations in the Zeocin selection protein that functionally impair the selection marker protein. Both the insertion of increasingly longer peptides and several Zeocin selection protein mutants resulted in a decreasing number of stably transfected colonies that concomitantly displayed higher protein expression levels. When the Zeocin mutants were combined with very short small peptides (8–14 amino acids long), this created a flexible, high stringency selection system. The system allows the rapid establishment of few, but high protein producing mammalian cell lines