Membership Functions for Spatial Proximity

Formalising nearness has been the subject of extensive work, resulting in many membership functions based on absolute distance metrics, relative distance metrics, and combinations of those. The possible strengths and weaknesses of these functions have been discussed and argued at length, but strangely enough, no experiment seems to have been conducted to assess the merits and shortcomings of competing approaches. Conducting such experiments can be expected not only to provide an objective evaluation of the various measures that have been proposed, but also to suggest new measures that outperform all those being analysed. This paper fulfills these expectations, and gives further evidence that fuzzy logic provides fruitful and powerful methods to formalise qualitative reasoning and capture fundamental qualitative notions. The proposed fuzzy membership functions can be directly used in qualitative reasoning about spatial proximity in Geographic Information Systems, which are becoming more and more important in software development for diverse purposes such as Tourist Information Systems or property development

Chromodomain proteins in development: lessons from CHARGE syndrome

Layman WS, Hurd EA, Martin DM. Chromodomain proteins in development: lessons from CHARGE syndrome.In humans, heterozygous mutations in the adenosine triphosphate-dependent chromatin remodeling gene CHD7 cause CHARGE syndrome, a common cause of deaf–blindness, balance disorders, congenital heart malformations, and olfactory dysfunction with an estimated incidence of approximately 1 in 10,000 newborns. The clinical features of CHARGE in humans and mice are highly variable and incompletely penetrant, and most mutations appear to result in haploinsufficiency of functional CHD7 protein. Mice with heterozygous loss of function mutations in Chd7 are a good model for CHARGE syndrome, and analyses of mouse mutant phenotypes have begun to clarify a role for CHD7 during development and into adulthood. Chd7 heterozygous mutant mice have postnatal delayed growth, inner ear malformations, anosmia/hyposmia, and craniofacial defects, and Chd7 homozygous mutants are embryonic lethal. A central question in developmental biology is how chromodomain proteins like CHD7 regulate important developmental processes, and whether they directly activate or repress downstream gene transcription or act more globally to alter chromatin structure and/or function. CHD7 is expressed in a wide variety of tissues during development, suggesting that it has tissue-specific and developmental stage-specific roles. Here, we review recent and ongoing analyses of CHD7 function in mouse models and cell-based systems. These studies explore tissue-specific effects of CHD7 deficiency, known CHD7 interacting proteins, and downstream target sites for CHD7 binding. CHD7 is emerging as a critical regulator of important developmental processes in organs affected by human CHARGE syndrome.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79089/1/j.1399-0004.2010.01446.x.pd

On high-speed turning of a third-generation gamma titanium aluminide

Gamma titanium aluminides are heat-resistant intermetallic alloys predestined to be employed in components suffering from high mechanical stresses and thermal loads. These materials are regarded as difficult to cut, so this makes process adaptation essential in order to obtain high-quality and defect-free surfaces suitable for aerospace and automotive parts. In this paper, an innovative approach for longitudinal external high-speed turning of a third-generation Ti-45Al-8Nb- 0.2C-0.2B gamma titanium aluminide is presented. The experimental campaign has been executed with different process parameters, tool geometries and lubrication conditions. The results are discussed in terms of surface roughness/integrity, chip morphology, cutting forces and tool wear. Experimental evidence showed that, due to the high cutting speed, the high temperatures reached in the shear zone improve chip formation, so a crack-free surface can be obtained. Furthermore, the use of a cryogenic lubrication system has been identified in order to reduce the huge tool wear, which represents the main drawback when machining gamma titanium aluminides under the chosen process condition

Continuous belief functions and α-stable distributions

International audienceThe theory of belief functions has been formalized in continuous domain for pattern recognition. Some applications use assumption of Gaussian models. However, this assumption is reductive. Indeed, some data are not symmetric and present property of heavy tails. It is possible to solve these problems by using a class of distributions called α-stable distributions. Consequently, we present in this paper a way to calculate pignistic probabilities with plausibility functions where the knowledge of the sources of information is represented by symmetric α-stable distributions. To validate our approach, we compare our results in special case of Gaussian distributions with existing methods. To illustrate our work, we generate arbitrary distributions which represents speed of planes and take decisions. A comparison with a Bayesian approach is made to show the interest of the theory of belief functions

Plasma Perturbations and Cosmic Microwave Background Anisotropy in the Linearly Expanding Milne-like Universe

We expose the scenarios of primordial baryon-photon plasma evolution within the framework of the Milne-like universe models. Recently, such models find a second wind and promise an inflation-free solution of a lot of cosmological puzzles including the cosmological constant one. Metric tensor perturbations are considered using the five-vectors theory of gravity admitting the Friedmann equation satisfied up to some constant. The Cosmic Microwave Background (CMB) spectrum is calculated qualitatively.Comment: 20 page

Reaching within a dynamic virtual environment

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

The reflective fostering programme: evaluating the intervention co-delivered by social work professionals and foster carers

PURPOSE: There is little evidence regarding how to best support the emotional well-being of children in foster care. This paper aims to present the evaluation of an adaptation of the reflective fostering programme, a group-based programme to support foster carers. This study aimed to explore whether a version of the programme, co-delivered by a social work professional and an experienced foster carer, was acceptable and relevant to foster carers and to gather data on programme effectiveness. DESIGN/METHODOLOGY/APPROACH: In total, 38 foster carers attended the programme and took part in this study. Data was collected regarding carer- and child-focused outcomes at pre-intervention, post-intervention and four-month follow-up. Focus interviews were also conducted to further assess acceptability and relevance for foster carers. FINDINGS: Analysis of quantitative outcome showed statistically significant improvements in all outcomes considered including foster carers stress and carer-defined problems, as well as carer-reported measures of child difficulties. Focus group interviews with foster carers suggested that the programme as co-delivered by a foster carer and a social worker was felt to be relevant and helpful to foster carers. ORIGINALITY/VALUE: These results provide a unique contribution to limited understandings of what works for supporting foster carers and the children in their care. Promising evidence is provided for the acceptability and relevance of the revised version of this novel support programme and its effectiveness in terms of carer- and child-related outcome measures. This work paves the way for further necessary impact evaluation

A random cell motility gradient downstream of FGF controls elongation of amniote embryos

Vertebrate embryos are characterized by an elongated antero-posterior (AP) body axis, which forms by progressive cell deposition from a posterior growth zone in the embryo. Here, we used tissue ablation in the chicken embryo to demonstrate that the caudal presomitic mesoderm (PSM) has a key role in axis elongation. Using time-lapse microscopy, we analysed the movements of fluorescently labelled cells in the PSM during embryo elongation, which revealed a clear posterior-to-anterior gradient of cell motility and directionality in the PSM. We tracked the movement of the PSM extracellular matrix in parallel with the labelled cells and subtracted the extracellular matrix movement from the global motion of cells. After subtraction, cell motility remained graded but lacked directionality, indicating that the posterior cell movements associated with axis elongation in the PSM are not intrinsic but reflect tissue deformation. The gradient of cell motion along the PSM parallels the fibroblast growth factor (FGF)/mitogen-activated protein kinase (MAPK) gradient1, which has been implicated in the control of cell motility in this tissue2. Both FGF signalling gain- and loss-of-function experiments lead to disruption of the motility gradient and a slowing down of axis elongation. Furthermore, embryos treated with cell movement inhibitors (blebbistatin or RhoK inhibitor), but not cell cycle inhibitors, show a slower axis elongation rate. We propose that the gradient of random cell motility downstream of FGF signalling in the PSM controls posterior elongation in the amniote embryo. Our data indicate that tissue elongation is an emergent property that arises from the collective regulation of graded, random cell motion rather than by the regulation of directionality of individual cellular movements