On the construction of hierarchic models

One of the main problems in the field of model-based diagnosis of technical systems today is finding the most useful model or models of the system being diagnosed. Often, a model showing the physical components and the connections between them is all that is available. As systems grow larger and larger, the run-time performance of diagnostic algorithms decreases considerably when using these detailed models. A solution to this problem is using a hierarchic model. This allows us to first diagnose the system using an abstract model, and then use this solution to guide the diagnostic process using a more detailed model. The main problem with this approach is acquiring the hierarchic model. We give a generic hierarchic diagnostic algorithm and show how the use of certain classes of hierarchic models can increase the performance of this algorithm. We then present linear time algorithms for the automatic construction of these hierarchic models, using the detailed model and extra information about cost of probing points and invertibility of components

Mesomorphic flexible chain polymers based on silicon

Poly(dialkylsiloxane)s and poly(dialkylsilane)s form a similar type of columnar mesophase. Although, the polysilanes are stiffer than polysiloxanes, both classes of polymers may be considered to be flexible due to the ability to form chain-folded crystals. Chain flexibility rather than the presence of chain stiffness determines whether the columnar mesophase is formed. A certain amphiphilic character does not appear to be required, as polysiloxanes with short side groups, e.g. polydiethylsiloxane display the same mesophase behaviour as polydialkylsilanes with long side chains and other nonpolar flexible chain molecules. The importance of the entropy gain upon conformational disordering is reflected in the increase in temperature stability with increasing alkyl side group length and the absence of mesophase behaviour in the case of the dimethyl substituted polymers

Salivary Cytokines in Healthy Adolescent Girls: Intercorrelations, Stability, and Associations with Serum Cytokines, Age and Pubertal Stage.

Theoretically, the measurement of cytokines in saliva may have utility for studies of brain, behavior, and immunity in youth. Cytokines in saliva and serum were analyzed across three annual assessments in healthy adolescent girls (N = 114, 11-17 years at enrollment). Samples were assayed for GM-CSF, IFNγ, IL-1β, IL-2, IL-6, IL-8, IL-10, IL-12p70, TNFα, adiponectin, and cotinine. Results revealed: (1) cytokine levels, except IFNγ and IL-10, were detectable in saliva, and salivary levels, except IL-8 and IL-1β, were lower than serum levels; (2) salivary cytokine levels were lower in older girls and positively associated with adiponectin; (3) compared to serum levels, the correlations between salivary cytokines were higher, but salivary cytokines were less stable across years; and (4) except for IL-1β, there were no significant serum-saliva associations. Variation in basal salivary cytokine levels in healthy adolescent girls reflect compartmentalized activity of the oral mucosal immune system, rather than systemic cytokine activity

Cyber security fear appeals:unexpectedly complicated

Cyber security researchers are starting to experiment with fear appeals, with a wide variety of designs and reported efficaciousness. This makes it hard to derive recommendations for designing and deploying these interventions. We thus reviewed the wider fear appeal literature to arrive at a set of guidelines to assist cyber security researchers. Our review revealed a degree of dissent about whether or not fear appeals are indeed helpful and advisable. Our review also revealed a wide range of fear appeal experimental designs, in both cyber and other domains, which confirms the need for some standardized guidelines to inform practice in this respect. We propose a protocol for carrying out fear appeal experiments, and we review a sample of cyber security fear appeal studies, via this lens, to provide a snapshot of the current state of play. We hope the proposed experimental protocol will prove helpful to those who wish to engage in future cyber security fear appeal research

Parenting unraveled : predictors of infant attachment and responses to crying

In dit proefschrift staat ouderschap in de vroege kindertijd centraal, onder andere de reacties van volwassenen op het huilen van baby’s. Voor baby’s is huilen één van de belangrijkste manieren om te communiceren. Zo laten ze weten dat ze ergens behoefte aan hebben of zich niet lekker voelen. Maar niet alle ouders reageren op een sensitieve, liefdevolle manier: voor sommige ouders is het huilen van hun kind zo stressvol dat ze eerder op een hardhandige wijze reageren. In deze studie is onderzocht hoe volwassenen reageren op het huilen van een baby. Daarbij werd een standaard huilfragment van een pasgeboren kind gemanipuleerd en op verschillende hoogten afgespeeld. De toonhoogte van het huilgeluid en de manier waarop volwassenen het huilen interpreteren, bleken belangrijk te zijn. Hoge huilgeluiden vormen een risicofactor voor het stevig willen aanpakken van het kind. Zieke en premature kinderen hebben vaker zulke hoge huiltonen. Ook is onderzocht of verschillen in reactie op huilen erfelijk zijn. Dat is inderdaad het geval, maar niet voor alle aspecten van reageren op huilen. Verschillen in sensitieve reacties waren erfelijk bepaald, maar de neiging om het kind op een hardhandige manier aan te pakken niet.LEI Universiteit LeidenFSW - Gezinsopvoeding - Ou

Gluon mass generation in the PT-BFM scheme

In this article we study the general structure and special properties of the Schwinger-Dyson equation for the gluon propagator constructed with the pinch technique, together with the question of how to obtain infrared finite solutions, associated with the generation of an effective gluon mass. Exploiting the known all-order correspondence between the pinch technique and the background field method, we demonstrate that, contrary to the standard formulation, the non-perturbative gluon self-energy is transverse order-by-order in the dressed loop expansion, and separately for gluonic and ghost contributions. We next present a comprehensive review of several subtle issues relevant to the search of infrared finite solutions, paying particular attention to the role of the seagull graph in enforcing transversality, the necessity of introducing massless poles in the three-gluon vertex, and the incorporation of the correct renormalization group properties. In addition, we present a method for regulating the seagull-type contributions based on dimensional regularization; its applicability depends crucially on the asymptotic behavior of the solutions in the deep ultraviolet, and in particular on the anomalous dimension of the dynamically generated gluon mass. A linearized version of the truncated Schwinger-Dyson equation is derived, using a vertex that satisfies the required Ward identity and contains massless poles belonging to different Lorentz structures. The resulting integral equation is then solved numerically, the infrared and ultraviolet properties of the obtained solutions are examined in detail, and the allowed range for the effective gluon mass is determined. Various open questions and possible connections with different approaches in the literature are discussed.Comment: 54 pages, 24 figure

Issues in practical model-based diagnosis

The model-based diagnosis project at the University of Twente has been directed at improving the practical usefulness of model-based diagnosis. In cooperation with industrial partners, the research addressed the modeling problem and the efficiency problem in model-based reasoning.Main results of this research are that (1) re-use of electronically available descriptions of systems for diagnostic purposes is possible, and (2) efficient reasoning can be realized using PDE, hierarchic models, and a simple diagnostic strategy. We have built a prototype diagnostic system which shows the technical feasibility of model-based diagnosis in a computer system.The project was concluded in July 1993 by the development of the 'Diagnostic Toolbox'. The Diagnostic Toolbox supports the modeling of technical systems for diagnostic purposes, and it contains several model-based reasoning methods

Dental calculus evidence of Taï Forest Chimpanzee plant consumption and life history transitions

Dental calculus (calcified dental plaque) is a source of multiple types of data on life history. Recent research has targeted the plant microremains preserved in this mineralised deposit as a source of dietary and health information for recent and past populations. However, it is unclear to what extent we can interpret behaviour from microremains. Few studies to date have directly compared the microremain record from dental calculus to dietary records, and none with long-term observation dietary records, thus limiting how we can interpret diet, food acquisition and behaviour. Here we present a high-resolution analysis of calculus microremains from wild chimpanzees (Pan troglodytes verus) of Taï National Park, Côte d"Ivoire. We test microremain assemblages against more tan two decades of field behavioural observations to establish the ability of calculus to capture the composition of diet. Our results show that some microremain classes accumulate as long-lived dietary markers. Phytolith abundance in calculus can reflect the proportions of plants in the diet, yet this pattern is not true for starches. We also report microremains can record information about other dietary behaviours, such as the age of weaning and learned food processing techniques like nutcracking

Induction of epigenetic variation in Arabidopsis by over-expression of DNA METHYLTRANSFERASE1 (MET1)

Epigenetic marks such as DNA methylation and histone modification can vary among plant accessions creating epi-alleles with different levels of expression competence. Mutations in epigenetic pathway functions are powerful tools to induce epigenetic variation. As an alternative approach, we investigated the potential of over-expressing an epigenetic function, using DNA METHYLTRANSFERASE1 (MET1) for proof-of-concept. In Arabidopsis thaliana, MET1 controls maintenance of cytosine methylation at symmetrical CG positions. At some loci, which contain dense DNA methylation in CG- and non-CG context, loss of MET1 causes joint loss of all cytosines methylation marks. We find that over-expression of both catalytically active and inactive versions of MET1 stochastically generates new epi-alleles at loci encoding transposable elements, non-coding RNAs and proteins, which results for most loci in an increase in expression. Individual transformants share some common phenotypes and genes with altered gene expression. Altered expression states can be transmitted to the next generation, which does not require the continuous presence of the MET1 transgene. Long-term stability and epigenetic features differ for individual loci. Our data show that over-expression of MET1, and potentially of other genes encoding epigenetic factors, offers an alternative strategy to identify epigenetic target genes and to create novel epi-alleles

The Effects of Intranasal Oxytocin Administration on Sensitive Caregiving in Mothers with Postnatal Depression

Development Psychopathology in context: famil