Tunneling with dissipation and decoherence for a large spin

We present rigorous solution of problems of tunneling with dissipation and decoherence for a spin of an atom or a molecule in an isotropic solid matrix. Our approach is based upon switching to a rotating coordinate system coupled to the local crystal field. We show that the spin of a molecule can be used in a qubit only if the molecule is strongly coupled with its atomic environment. This condition is a consequence of the conservation of the total angular momentum (spin + matrix), that has been largely ignored in previous studies of spin tunneling.Comment: 4 page

Einstein's quantum theory of the monatomic ideal gas: non-statistical arguments for a new statistics

In this article, we analyze the third of three papers, in which Einstein presented his quantum theory of the ideal gas of 1924-1925. Although it failed to attract the attention of Einstein's contemporaries and although also today very few commentators refer to it, we argue for its significance in the context of Einstein's quantum researches. It contains an attempt to extend and exhaust the characterization of the monatomic ideal gas without appealing to combinatorics. Its ambiguities illustrate Einstein's confusion with his initial success in extending Bose's results and in realizing the consequences of what later became to be called Bose-Einstein statistics. We discuss Einstein's motivation for writing a non-combinatorial paper, partly in response to criticism by his friend Ehrenfest, and we paraphrase its content. Its arguments are based on Einstein's belief in the complete analogy between the thermodynamics of light quanta and of material particles and invoke considerations of adiabatic transformations as well as of dimensional analysis. These techniques were well-known to Einstein from earlier work on Wien's displacement law, Planck's radiation theory, and the specific heat of solids. We also investigate the possible role of Ehrenfest in the gestation of the theory.Comment: 57 pp

Het schrijven van RIKILT rapporten en wetenschappelijke artikelen

Dit rapport is samengesteld door de werkgroep "Herziening rapportindeling RIKILT en herzien door de werkgroep "RIKILT rapporten". Duidelijk ingedeelde rapporten, voorzien van een abstract, verhogen de leesbaarheid en de bekendheid. De aanbevelingen, die hier gegeven worden, zijn gebaseerd op internationale afspraken. Verder zijn er nog aanvullende richtlijnen gegeven voor zover dat nodig was, zodat dit rapport alle informatie bevat voor het schrijven van een RIKILT rapport. Voor het schrijven van wetenschappelijke artikelen is volstaan met het geven van richtlijnen. Doorgaans is het de regel dat ieder tijdschrift en/of iedere uitgever zijn eigen richtlijnen heeft, waaraan de schrijver zich moet houden

Analyseresultaten Zevenlanden-studie

In het kader van de Zevenlandenstudie, een epidemiologische studie naar de relatie tussen voeding en kanker, heeft het RIKILT de gemiddelde voedingspakketten van 16 cohorten onderzocht op het gehalte aan vitamines, spoorelementen en non-nutritieve stoffen als glucosinolaten en flavonoïden. In dit verslag worden de analytisch-chemische aspecten van dit onderzoek nader toegelicht, waarbij aandacht wordt besteed aan de gebruikte analysemethoden, de monstervoorbehandeling, de monsterbewaring en de kwaliteitsbewaking van de analyses

New MMI concepts for situation assessment and decision making in naval command and control

De publikatie geeft een overzicht van de diverse interfacecomponenten opgenomen in de Basic T, een nieuw werkstationconcept ontwikkeld in het kader van de studie 'Toekomstige commandoevoering' in opdracht van de Koninklijke Marine. Voorts worden de eerste resultaten gemeld van een uitgebreide evaluatie met toekomstige gebruikers die er op duiden dat CCO- en LVO-taken met de toegepaste automatiserings- en ondersteuningsconcepten efficienter en effectiever worden uitgevoerd

Adaptive Automation in a Naval Combat Management System

There is a continuing trend of letting fewer people deal with larger amounts of information in more complex situations using highly automated systems. In such circumstances, there is a risk that people are overwhelmed by information during intense periods or, on the other hand, do not build sufficient situational awareness during periods of slack to deal with situations where human intervention becomes necessary. A number of studies show encouraging results in increasing the efficiency of human–machine systems by making the automation adapt itself to the human needs. Current literature shows no examples of adaptive automation in real operational settings, however.We introduce a fine-grained adaptation methodology based on well-established concepts that is easy to comprehend and likely to be accepted by the end user. At the same time, we let the machine operate like a virtual team member in that it continuously builds its own view of the situation independent from the human. Working agreements between human and machine provide lower and upper bounds of automation that are in advance determined by the end user so that unwanted appropriation of responsibility by the machine is avoided. The framework is domain neutral and therefore thought to be applicable across a wide range of complex systems, both military and civilian. It gives researchers an architecture that they can use in their own work to get adaptive automation up and running quickly and easil

Methylation status of CpG islands in the promoter region of genes differentially expressed in colonic mucosa from adenoma patients and controls in response to altered vegetable intake

Vegetables may protect against colorectal cancer (CRC) via changes in gene expression involved in anticarcinogenic mechanisms. There is considerable evidence that aberrant DNA methylation plays an important role in carcinogenesis. Furthermore, DNA methylation can be affected by dietary components. Therefore, in the present study, we investigated the DNA methylation status of CpG dinucleotides within the promoter region of the four genes protein kinase C b 1, ornithine decarboxylase 1, fos proto-oncogene and 5,10-methylenetetrahydrofolate reductase in the colon of female sporadic adenoma patients and healthy controls. These genes were chosen because their expression was modulated in response to altered vegetable intake, they are functionally relevant for CRC; they have CpG islands in their promoter region, and a methylation-specific restriction enzyme is available to permit quantitative assay. No significant differences in extent of methylation in colon DNA were detected for any of the four genes in both adenoma polyp patients and healthy controls after altering vegetable intake. Interestingly, before the intervention, ornithine decarboxylase 1 promoter methylation was lower in the colonic mucosa of the adenoma polyp patients when compared with healthy control subjects, which may explain the increased ornithine decarboxylase 1 activity in CRC reported in the literature. In conclusion, we found no evidence that changes in promoter methylation were responsible for differences in expression of four genes in the human colonic mucosa in response to altered vegetable intake. The mechanism(s) responsible for this altered gene expression and, indeed, potential effects on methylation of other genes remain to be determined