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Several Attributes (several + attribute)
Selected AbstractsHAEdb: A novel interactive, locus-specific mutation database for the C1 inhibitor gene,HUMAN MUTATION, Issue 1 2005Lajos Kalmár Abstract Hereditary angioneurotic edema (HAE) is an autosomal dominant disorder characterized by episodic local subcutaneous and submucosal edema and is caused by the deficiency of the activated C1 esterase inhibitor protein (C1-INH or C1INH; approved gene symbol SERPING1). Published C1-INH mutations are represented in large universal databases (e.g., OMIM, HGMD), but these databases update their data rather infrequently, they are not interactive, and they do not allow searches according to different criteria. The HAEdb, a C1-INH gene mutation database (http://hae.biomembrane.hu) was created to contribute to the following expectations: 1) help the comprehensive collection of information on genetic alterations of the C1-INH gene; 2) create a database in which data can be searched and compared according to several flexible criteria; and 3) provide additional help in new mutation identification. The website uses MySQL, an open-source, multithreaded, relational database management system. The user-friendly graphical interface was written in the PHP web programming language. The website consists of two main parts, the freely browsable search function, and the password-protected data deposition function. Mutations of the C1-INH gene are divided in two parts: gross mutations involving DNA fragments >1 kb, and micro mutations encompassing all non-gross mutations. Several attributes (e.g., affected exon, molecular consequence, family history) are collected for each mutation in a standardized form. This database may facilitate future comprehensive analyses of C1-INH mutations and also provide regular help for molecular diagnostic testing of HAE patients in different centers. Hum Mutat 25:1,5, 2005. © 2004 Wiley-Liss, Inc. [source] Algebraic multigrid Laplace solver for the extraction of capacitances of conductors in multi-layer dielectricsINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 5 2007Prasad S. Sumant Abstract This paper describes the development of a robust multigrid, finite element-based, Laplace solver for accurate capacitance extraction of conductors embedded in multi-layer dielectric domains. An algebraic multigrid based on element interpolation is adopted and streamlined for the development of the proposed solver. In particular, a new, node-based agglomeration scheme is proposed to speed up the process of agglomeration. Several attributes of this new method are investigated through the application of the Laplace solver to the calculation of the per-unit-length capacitance of configurations of parallel, uniform conductors embedded in multi-layer dielectric substrates. These two-dimensional configurations are commonly encountered as high-speed interconnect structures for integrated electronic circuits. The proposed method is shown to be particularly robust and accurate for structures with very thin dielectric layers characterized by large variation in their electric permittivities. More specifically, it is demonstrated that for such geometries the proposed node-based agglomeration systematically reduces the problem size and speeds up the iterative solution of the finite element matrix. Copyright © 2007 John Wiley & Sons, Ltd. [source] The impact of elephants on the marula tree Sclerocarya birreaAFRICAN JOURNAL OF ECOLOGY, Issue 4 2002Michelle E. Gadd Abstract This study determined the abundance, density and population structure of the marula tree, Sclerocarya birrea, in three game reserves in South Africa, and assessed patterns and amounts of new and cumulative impact of elephants. Elephant feeding was very patchy so several attributes of individual trees, sampled transects and communities that might influence elephant herbivory were investigated. The incidence and type of elephant impact (bark, branch or stem breakage) were significantly related to tree diameter, but not to fruiting nor proximity to roads. At the transect level, elephant impact was influenced by density of marula trees, but was not influenced by proximity to roads, nor proportion of marula trees bearing fruits in the vicinity. At the community level, elephant impact was higher on reserves with higher total marula densities. Fourfold differences in elephant densities (0.08,0.30 elephants km,2) did not explain marula consumption: the percentage of trees with branch damage was similar across reserves and bark damage was inversely proportional to elephant density. Variation across reserves may reflect local and landscape-level marula tree abundance, differences in alternative food plants and individual feeding habits. The recorded levels of impact appeared to be sustainable because mortality rates were low, affected trees often recovered, and small trees were not preferentially preyed upon. Résumé Cette étude détermine l'abondance, la densité et la structure de la population de l'arbre à Marula, Sclerocarya birrea, dans trois réserves de faune sud-africaines et évalue le schéma et la totalité des impacts nouveaux et successifs des éléphants. Les éléphants se nourrissaient çà et là, de sorte que l'on a étudié divers attributs des arbres pris individuellement, des transects échantillons et des communautés, qui pouvaient influencer le caractère herbivore des éléphants. L'incidence et le type d'impact (écorces, branches ou jeunes pousses) étaient significativement liés au diamètre de l'arbre, mais non à la fructification, ni à la proximité des routes. Au niveau du transect, l'impact des éléphants était influencé par la densité des arbres à Marula, mais pas par la proximité des routes, ni par la proportion d'arbres à Marula en fruits dans le voisinage. Au niveau de la communauté, l'impact des éléphants était plus élevé dans les réserves qui comptaient la plus forte densité totale d'arbres à Marula. Une différence de 1 à 4 dans la densité des éléphants (0.08-0.30/km2) n'explique pas la consommation de marula : le pourcentage d'arbres présentant des branches endommagées était similaire dans toutes les réserves, et les dommages causés aux écorces étaient inversement proportionnels à la densité des éléphants. La variation observée entre les réserves pourrait refléter l'abondance des arbres à Marula tant locale que liée au paysage, des différences dans l'abondance de nourriture végétale alternative et les habitudes alimentaires individuelles. L'importance de l'impact relevé semblait être soutenable parce que le taux de mortalitéétait faible, que les arbres touchés récupéraient souvent et que les petits arbres n'avaient pas souvent la préférence des éléphants. [source] The value of assessing weights in multi-criteria portfolio decision analysisJOURNAL OF MULTI CRITERIA DECISION ANALYSIS, Issue 5-6 2008Jeffrey M. KeislerArticle first published online: 28 SEP 200 Abstract Analytic efforts in support of portfolio decisions can be applied with varying levels of intensity. To gain insight about how to match the effort to the situation, we simulate a portfolio of potential projects and compare portfolio performance under a range of analytic strategies. Each project is scored with respect to several attributes in a linear additive value model. Projects are ranked in order of value per unit cost and funded until the budget is exhausted. Assuming these weights and scores are correct, and the funding decisions made this way are optimal, this process is a gold standard against which to compare other decision processes. In particular, a baseline process would fund projects essentially at random, and we may estimate the value added by various decision processes above this worst case as a percentage of the increase arising from the optimal process. We consider several stylized decision rules and combinations of them: using equal weights, picking one attribute at random, assessing weights from a single randomly selected stakeholder. Simulation results are then used to identify which conditions tend to make which types of analytic strategies valuable, and to identify useful hybrid strategies. Copyright © 2009 John Wiley & Sons, Ltd. [source] Measuring online information seeking context, Part 1: Background and methodJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 13 2006Diane Kelly Context is one of the most important concepts in information seeking and retrieval research. However, the challenges of studying context are great; thus, it is more common for researchers to use context as a post hoc explanatory factor, rather than as a concept that drives inquiry. The purposes of this study were to develop a method for collecting data about information seeking context in natural online environments, and identify which aspects of context should be considered when studying online information seeking. The study is reported in two parts. In this, the first part, the background and method are presented. Results and implications of this research are presented in Part 2 (Kelly, in press). Part 1 discusses previous literature on information seeking context and behavior and situates the current work within this literature. This part further describes the naturalistic, longitudinal research design that was used to examine and measure the online information seeking contexts of users during a 14-week period. In this design, information seeking context was characterized by a user's self-identified tasks and topics, and several attributes of these, such as the length of time the user expected to work on a task and the user's familiarity with a topic. At weekly intervals, users evaluated the usefulness of the documents that they viewed, and classified these documents according to their tasks and topics. At the end of the study, users provided feedback about the study method. [source] Physiological properties of rod photoreceptor electrical coupling in the tiger salamander retinaTHE JOURNAL OF PHYSIOLOGY, Issue 3 2005Jian Zhang Using dual whole-cell voltage and current clamp recording techniques, we investigated the gap junctional conductance and the coupling coefficient between neighbouring rods in live salamander retinal slices. The application of sinusoidal stimuli over a wide range of temporal frequencies allowed us to characterize the band-pass filtering properties of the rod network. We found that the electrical coupling of all neighbouring rods exhibited reciprocal and symmetrical conductivities. On average, the junctional conductance between paired rods was 500 pS and the coupling coefficient (the ratio of voltage responses of the follower cell to those of the driver cell), or K -value, was 0.07. Our experimental results also demonstrated that the rod network behaved like a band-pass filter with a peak frequency of about 2,5 Hz. However, the gap junctions between adjacent rods exhibited linearity and voltage independency within the physiological range of rods. These gap junctions did not contribute to the filtering mechanisms of the rod network. Combined with the computational modelling, our data suggest that the filtering of higher frequency rod signals by the network is largely mediated by the passive resistive and capacitive (RC) properties of rod plasma membranes. Furthermore, we found several attributes of rod electrical coupling resembling the physiological properties of gene-encoded Cx35/36 gap junctions examined in other in vitro studies. This indicates that the previously found Cx35/36 expression in the salamander rod network may be functionally involved in rod,rod electrical coupling. [source] Diversity, abundance, and size structure of bivalve assemblages in the Sipsey River, Alabama,AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 6 2010Wendell R. Haag Abstract 1.Patterns of mussel diversity and assemblage structure in the Sipsey River, Alabama, are described. Qualitative data were used to describe river-wide patterns of diversity. Quantitative data were used to describe the structure of mussel assemblages at several sites based on whole-substrate sampling that ensured all size classes were detected. 2.Major human impacts to the stream are limited to apparent effects of coal mining in the headwaters and the impoundment of the lower 9,km of the river by a dam on the Tombigbee River. These impacts resulted in a sharp decline in mussel diversity in the headwaters, and extirpation or decline of populations of several large-river species in the lower river that were probably dependent on colonization from the Tombigbee River. 3.Despite localized impacts, mussel assemblages throughout much of the river appear to be mostly intact and self-sustaining. These assemblages have several attributes that differ substantially from those in more degraded streams: (1) high retention of historical species richness; (2) gradual, longitudinal increase in species richness from upstream to downstream, resulting in distinctive headwater and downstream assemblages; (3) ubiquity of most species within particular river segments; (4) low dominance and high evenness with large populations of many species; and (5) frequent recruitment for most species resulting in occurrence of individuals in many size classes. 4.Few detailed and demographically unbiased descriptions of relatively intact mussel assemblages exist. We propose that characteristics described in the Sipsey River can be used as a baseline comparison for assessing relative degree of assemblage alteration in other streams and can serve as goals for restoration efforts. Published in 2010 by John Wiley and Sons, Ltd. [source] | ||||||||||