Spin-mediated dissipation and frequency shifts of a cantilever at milliKelvin temperatures

We measure the dissipation and frequency shift of a magnetically coupled cantilever in the vicinity of a silicon chip, down to $25$ mK. The dissipation and frequency shift originates from the interaction with the unpaired electrons, associated with the dangling bonds in the native oxide layer of the silicon, which form a two dimensional system of electron spins. We approach the sample with a $3.43$ $\mu$m-diameter magnetic particle attached to an ultrasoft cantilever, and measure the frequency shift and quality factor as a function of temperature and the distance. Using a recent theoretical analysis [J. M. de Voogd et al., arXiv:1508.07972 (2015)] of the dynamics of a system consisting of a spin and a magnetic resonator, we are able to fit the data and extract the relaxation time $T_1=0.39\pm0.08$ ms and spin density $\sigma=0.14\pm0.01$ spins per nm$^2$. Our analysis shows that at temperatures $\leq500$ mK magnetic dissipation is an important source of non-contact friction.Comment: 5 pages, 3 figure

Political Trust as a determinant of Volatile Vote Intentions: Separating Within- from Between-persons effects

This article studies the oft-assumed destabilizing effect of political distrust on party preferences. We argue that there are two mechanisms that relate political trust to electoral volatility: (1) structurally low trust undermines the formation of stable party preferences and thereby stimulates volatility, and (2) declining trust drives voters, particularly supporters of parties in government, to change party preference. These rivaling mechanisms are often conflated. Using the within–between random effects approach on two extensive panel data sets (covering three different governmental periods in The Netherlands between 2006 and 2017) allows us to separate both mechanisms and estimate them simultaneously. We find evidence for both the structural and the dynamic effects of political trust on changing vote intentions

Cerebellar Zones: A Personal History

Cerebellar zones were there, of course, before anyone noticed them. Their history is that of young people, unhindered by preconceived ideas, who followed up their observations with available or new techniques. In the 1960s of the last century, the circumstances were fortunate because three groups, in Leiden, Lund, and Bristol, using different approaches, stumbled on the same zonal pattern in the cerebellum of the cat. In Leiden, the Häggqvist myelin stain divulged the compartments in the cerebellar white matter that channel the afferent and efferent connections of the zones. In Lund, the spino-olivocerebellar pathways activated from individual spinal funiculi revealed the zonal pattern. In Bristol, charting the axon reflex of olivocerebellar climbing fibers on the surface of the cerebellum resulted in a very similar zonal map. The history of the zones is one of accidents and purposeful pursuit. The technicians, librarians, animal caretakers, students, secretaries, and medical illustrators who made it possible remain unnamed, but their contributions certainly should be acknowledged

Targeting Conservation Investments in Heterogeneous Landscapes: A distance function approach and application to watershed management

To achieve a given level of an environmental amenity at least cost, decision-makers must integrate information about spatially variable biophysical and economic conditions. Although the biophysical attributes that contribute to supplying an environmental amenity are often known, the way in which these attributes interact to produce the amenity is often unknown. Given the difficulty in converting multiple attributes into a unidimensional physical measure of an environmental amenity (e.g., habitat quality), analyses in the academic literature tend to use a single biophysical attribute as a proxy for the environmental amenity (e.g., species richness). A narrow focus on a single attribute, however, fails to consider the full range of biophysical attributes that are critical to the supply of an environmental amenity. Drawing on the production efficiency literature, we introduce an alternative conservation targeting approach that relies on distance functions to cost-efficiently allocate conservation funds across a spatially heterogeneous landscape. An approach based on distance functions has the advantage of not requiring a parametric specification of the amenity function (or cost function), but rather only requiring that the decision-maker identify important biophysical and economic attributes. We apply the distance-function approach empirically to an increasingly common, but little studied, conservation initiative: conservation contracting for water quality objectives. The contract portfolios derived from the distance-function application have many desirable properties, including intuitive appeal, robust performance across plausible parametric amenity measures, and the generation of ranking measures that can be easily used by field practitioners in complex decision-making environments that cannot be completely modeled. Working Paper # 2002-01

Discharge of parental authority: considerations regarding the compatibility of the new provision of the Dutch Civil Code with the European Convention on Human Rights.

Coherent privaatrech

Acute toxicity screening of Hanford Site waste grouts using aquatic invertebrates

Waste grouts prepared by mixing a simulated nonradioactive liquid waste with a dry solids blend consisting of cement, fly ash, and clay were screened for their acute toxicity using aquatic invertebrates (D. magna, D. pulex, and C. dubia) as test organisms and a fluorogenic substrate (4-methylumbelliferyl b-d galactoside) as the toxic stress indicator. After one hour of exposing juvenile daphnids to grout extracts of varying concentrations, followed by a 15-minute reaction with the fluorogenic substrate, the degree of in vivo enzymatic inhibition was measured by the number of resulting fluorescent daphnids. The effective concentration at which 50% of the daphnids were adversely affected (EC50) values calculated by probit analysis were 2,877 mg/L, 2,983 mg/L, and 3,174 mg/L for D. pulex, D. magna, and C. dubia, respectively. The results indicated that the grout extracts studied are nonhazardous and not dangerous to daphnids

Metabolic variation in Caribbean giant barrel sponges: influence of age and sea-depth

NWO# 16.161.301Environmental Biolog