Different Levels Of Hierarchy Research Articles

Stiffness gradients in vascular bundles of the palmWashingtonia robusta

Palms can grow at sites exposed to high winds experiencing large dynamic wind and gust loads. Their stems represent a system of stiff fibrous elements embedded in the soft parenchymatous tissue. The proper design of the interface of the stiffening elements and the parenchyma is crucial for the functioning of the stem. The strategy of the palm to compromise between stiff fibre caps and the soft parenchymatous tissue may serve as a model system for avoiding stress discontinuities in inhomogeneous and anisotropic fibre-reinforced composite materials. We investigated the mechanical, structural and biochemical properties of the fibre caps of the palm Washingtonia robusta at different levels of hierarchy with high spatial resolution. A gradual decrease in stiffness across the fibre cap towards the surrounding parenchymatous tissue was observed. Structural adaptations at the tissue level were found in terms of changes in cell cross sections and cell wall thickness. At the cell wall level, gradients across the fibre cap were found in the degree of orientation of the microfibrils and in the lignin level and composition. The impact of these structural variations in the local material stiffness distribution is discussed.

Domain Hierarchy and closed Loops (DHcL): a server for exploring hierarchy of protein domain structure

Domain hierarchy and closed loops (DHcL) (http://sitron.bccs.uib.no/dhcl/) is a web server that delineates energy hierarchy of protein domain structure and detects domains at different levels of this hierarchy. The server also identifies closed loops and van der Waals locks, which constitute a structural basis for the protein domain hierarchy. The DHcL can be a useful tool for an express analysis of protein structures and their alternative domain decompositions. The user submits a PDB identifier(s) or uploads a 3D protein structure in a PDB format. The results of the analysis are the location of domains at different levels of hierarchy, closed loops, van der Waals locks and their interactive visualization. The server maintains a regularly updated database of domains, closed loop and van der Waals locks for all X-ray structures in PDB. DHcL server is available at: http://sitron.bccs.uib.no/dhcl.

Multiple Representations of Belief States and Action Values in Corticobasal Ganglia Loops

Reward-related neural activities have been found in a variety of cortical and subcortical areas by neurophysiological and neuroimaging experiments. Here we present a unified view on how three subloops of the corticobasal ganglia network are involved in reward prediction and action selection using different types of information. The motor/premotor-posterior striatum loop is specialized for action-based value representation and movement selection. The orbitofrontal-ventral striatum loop is specialized for object-based value representation and target selection. The lateral prefrontal-anterior striatum loop is specialized for context-based value representation and context estimation. Furthermore, the medial prefrontal cortex (MPFC) coordinates these multiple value representations and actions at different levels of hierarchy by monitoring the error in predictions.

A functional-structural model for growth of clonal bunchgrasses

Interactions between structural architecture and resource allocation affect the ability of plants to utilise environmental resources. Architecture defines the structural layout and relationships of organs and other structural units at different hierarchical levels in plants. Resource allocation determines how competing structural units are awarded resources at different levels of hierarchy. Functional-structural plant models combine architecture and resource allocation as interacting components of plant growth and functioning. Existing functional-structural plant models concentrate on growth of unitary trees and therefore, lack sufficient structural definition to simulate growth of clonal plants. On the other hand, simulation models designed to consider clonal growth rarely attempt to simulate clonal architecture at a more detailed level than individual ramets. This paper introduces a functional-structural type model, TILLERTREE, which integrates the architectural growth of bunchgrasses with resource capture and allocation of nitrogen and carbohydrate. Resource allocation is implemented using a procedural algorithm based on object hierarchy and priority, and not mechanistically. The model is used to illustrate that growth of bunchgrass clones is regulated by patterns of resource allocation between competing units at low levels of hierarchy, by considering the effect of resource rules controlling secondary tiller recruitment on clonal growth. Simulations are conducted using a chosen model C 4 bunchgrass species Themeda triandra.

Limulus polyphemus Hemocyanin: 10 Å Cryo-EM Structure, Sequence Analysis, Molecular Modelling and Rigid-body Fitting Reveal the Interfaces Between the Eight Hexamers

The blue copper protein hemocyanin from the horseshoe crab Limulus polyphemus is among the largest respiratory proteins found in nature (3.5 MDa) and exhibits a highly cooperative oxygen binding. Its 48 subunits are arranged as eight hexamers (1×6mers) that form the native 8×6mer in a nested hierarchy of 2×6mers and 4×6mers. This quaternary structure is established by eight subunit types (termed I, IIA, II, IIIA, IIIB, IV, V, and VI), of which only type II has been sequenced. Crystal structures of the 1×6mer are available, but for the 8×6mer only a 40 Å 3D reconstruction exists. Consequently, the structural parameters of the 8×6mer are not firmly established, and the molecular interfaces between the eight hexamers are still to be defined. This, however, is crucial for understanding how allosteric transitions are mediated between the different levels of hierarchy. Here, we show the 10 Å structure (FSC1/2-bit criterion) of the oxygenated 8×6mer from cryo-electron microscopy (cryo-EM) and single-particle analysis. Moreover, we show its molecular model as obtained by DNA sequencing of subunits II, IIIA, IV and VI, and molecular modelling and rigid-body fitting of all subunit types. Remarkably, the latter enabled us to improve the resolution of the cryo-EM structure from 11 Å to the final 10 Å. The 10 Å structure allows firm assessment of various structural parameters of the 8×6mer, the 4×6mer and the 2×6mer, and reveals a total of 46 inter-hexamer bridges. These group as 11 types of interface: four at the 2×6mer level (II–II, II–IV, V–VI, IV–VI), three form the 4×6mer (V–V, V–VI, VI–IIIB/IV/V), and four are required to assemble the 8×6mer (IIIA–IIIA, IIIA–IIIB, II–IV, IV–IV). The molecular model shows the amino acid residues involved, and reveals that several of the interfaces are intriguingly histidine-rich and likely to transfer allosteric signals between the different levels of the nested hierarchy.

Mining Level-Crossing Association Rules from Large Databases

Existing algorithms for mining association rule at multiple concept level, restricted mining strong association among the concept at same level of a hierarchy. However mining level-crossing association rule at multiple concept level may lead to the discovery of mining strong association among at different level of hierarchy. In this study, a top-down progressive deepening method is developed for mining level-crossing association rules in large transaction databases by extension of some existing multiple-level association rule mining techniques. This method is using concept of reduced support and refine the transaction table at each level.

Structure and mechanical properties of carbon fibres: a review of recent microbeam diffraction studies with synchrotron radiation

Hard X-ray beams with beam sizes in the sub-micrometre range are frequently available at third-generation synchrotron radiation sources, enabling new insights into the structure of materials at different levels of hierarchy by applying novel techniques such as scanning microbeam diffraction or scanning small-angle scattering. The high brilliance of the radiation from wiggler and undulator sources allows in situ experiments such as mechanical testing of single fibres to be performed, and even the combination of microbeam scanning with in situ testing is feasible. Three different experiments on single carbon fibres are presented: an in situ tensile test using a 10 microm collimated beam, a scanning experiment applying a 3 microm beam from a tapered glass capillary, and a scanning experiment with simultaneous in situ bending with a 0.1 microm beam provided by a waveguide structure.

Psychophysiological Mechanisms of Choice in High School Students and University Students Specializing in Humanities

Elucidation of behavioral reactions of high school and university students in stochastic and deterministic environments is an important problem. Rapidly changeable and unstable social and information environment makes it urgent to raise the problem of decision-making in all areas of human activity [18]. According to the theory of functional systems suggested by P. K. Anokhin, a behavioral act is considered as an aggregate of many physiological processes selected at the stage of decision-making [1-3]. According to V. B. Shvyrkov [25], a behavioral act should be regarded as a component of a functional system, because interaction of external information with internal processes is mediated by the entire operating complex of the functional system. Although it is beyond doubt that the closed circuit of a functional system is cyclic, principles of central mechanisms are a subject of discussion [23]. In the physiological sense the process of decisionmaking is based on selection of certain executive mechanisms and physiological integration of results of afferent synthesis [2]. A decrease in the degree of freedom of the central nervous system neurons and a decrease in their possible involvement in the functional aggregates are neurophysiological characteristics of the stage of decision-making. Excessive degrees of freedom are easily sorted out by the frontal lobes of the brain. A. R. Luriya considered the frontal lobes of the brain as the main nervous substrate of decision-making in goaloriented spontaneous activity [13]. Psychophysiological aspects of this problem are based on mechanisms of decision-making at different levels of sensorimotor and mental activities [7]. According to the physiological concept suggested by Anokhin, psychophysiological mechanisms of choice can be studied from individual manifestation of different forms of behavioral activity under different experimental settings [18]. Studies of behavior under uncertain conditions are of particular interest [17, 22]. Environmental uncertainty implies the absence of objective and subjective determinancy [10]. According to [5, 21], the main behavioral reaction under uncertain conditions is individual prognosis of the probability of future events. According to A. S. Batuev [4], the process of decision-making includes formation of a dynamic constellation of spatially separated brain structures involved in a behavioral act. Adaptive behavior in a variable environment is based on probabilistic prognosis implemented in associative brain systems. For example, thalamofrontal structures are involved in probabilistic prognosis and goal-oriented behavior. According to the contemporary viewpoint, the rates of decision-making and central information processing are determined by nervous system mobility [24]. Decision-making as an object of psychophysiological research can be studied experimentally, providing thereby the opportunity for testing functional systems of different levels of hierarchy and functional systems involved in various psychophysiological processes. There are objective and subjective factors of learning activity. The psychophysiological state of high school and university students depends on these factors [9, 20], Analytical capacity is an important component of successful learning [8, 9]. It should be noted that agerelated psychophysiological mechanisms of making choice remain virtually obscure [9]. The goal of this work was to elucidate age-related dynamics of certain psychophysiological mechanisms of choice in high school students and university students specializing in humanities.

Optimal Content-Based Video Decomposition for Interactive Video Navigation

In this paper, an interactive framework for navigating video sequences is presented using an optimal content-based video decomposition scheme. In particular, each video sequence is analyzed at different content resolution levels, creating a hierarchy from the lowest (coarse) to the highest (fine) resolution. This content hierarchy is represented as a tree structure, each level of which corresponds to a particular content resolution, while the tree nodes indicate the temporal video segments that the sequence content is partitioned at a given resolution. A criterion is introduced to measure the efficiency of the proposed scheme in organizing the video visual content and to compare it with other hierarchical video content representations and navigation schemes. The efficiency is measured as the difficulty for a user to locate a video segment of interest, while moving through different levels of hierarchy. In our case, video is decomposed so that the best efficiency is accomplished. However, the efficiency of a nonlinear video decomposition scheme depends on: 1) the number of paths required for a user to locate a relevant video segment and 2) the number of shot/frame classes (i.e., content representatives) extracted to represent the visual content. Both issues are addressed in this paper. In the first case, the probability of selecting a relevant video segment in the first path is maximized by extracting optimal content representatives through a minimization of a cross-correlation criterion. For the minimization, a genetic algorithm (GA) is adopted, since application of an exhaustive search to obtain the minimum value is too large to be implemented. The cross-correlation criterion is evaluated on the feature domain by extracting appropriate global and object-based descriptors for each video frame so that a better representation of the visual content is achieved. The second aspect (e.g., the number of content representatives) is addressed by minimizing the average transmitted information and simultaneously taking into consideration the temporal video segment complexity. More content representatives are extracted for video segments of high complexity, whereas a low number is required for low-complexity segments. In addition, a degree of interest is assigned to each video shot (or frame) to address the fact that, from the user's perception, the visual content of a set of shots (frames) satisfies his/her information needs. Finally, a computationally efficient algorithm is proposed to regulate the degree of detail (i.e., the number of shot/frames representatives) in case the visual content is not efficiently represented from the user's perceptive view. Experimental results on real-life video sequences indicate the performance of the proposed GA-based video decomposition scheme compared to other hierarchical video organization methods.

Models of Neutrino Masses: Anarchy versus Hierarchy

We present a quantitative study of the ability of models with different levels of hierarchy to reproduce the solar neutrino solutions, in particular the LA solution. As a flexible testing ground we consider models based on SU(5)xU(1)_F. In this context, we have made statistical simulations of models with different patterns from anarchy to various types of hierachy: normal hierarchical models with and without automatic suppression of the 23 (sub)determinant and inverse hierarchy models. We find that, not only for the LOW or VO solutions, but even in the LA case, the hierarchical models have a significantly better success rate than those based on anarchy. The normal hierachy and the inverse hierarchy models have comparable performances in models with see-saw dominance, while the inverse hierarchy models are particularly good in the no see-saw versions. As a possible distinction between these categories of models, the inverse hierarchy models favour a maximal solar mixing angle and their rate of success drops dramatically as the mixing angle decreases, while normal hierarchy models are far more stable in this respect.

The Diffusion of ICT in Urban Malaysia: How Nature of Job Influencing the Usage of ICT among the Urban Working Population

This paper is based on a questionnaire survey that was conducted on the working population in the service sector in Kuala Lumpur, Malaysia. Our objective is to find out to what extend do the effect of nature of job in contributing to the usage of the Information and Communication Technology (ICT) by the Malaysian urban working population. By using Structural Equation Modeling (SEM), we establish a causal effect relationship focusing on “nature of job”, as well as “income/wealth effect” and “geographical effect” as the factors that will encourage the urban working population to use the ICT services. The result of the analysis confirmed that “nature of job” is the most influential factor for this segment of the population to be networked.However, different level of competency in using ICT is proven from our further analysis (of the collected data) to widen the digital gap among the urban working population across the different level of hierarchy within the organizations. Even though “nature of job” is influencing the urban working population to use the ICT, at the same time it is creating a digital gap that is based on ICT skill among the workforce within/outside the organizations.Finally, we come up with practical recommendations on how to bridge the skill related digital gap among the urban working population in service sector in Kuala Lumpur.

Transcription coupled repair efficiency determines the cell cycle progression and apoptosis after UV exposure in hamster cells

Nucleotide excision repair (NER) is a major pathway for the removal of bulky adducts and helix distorting lesions from the genomic DNA. NER is highly heterogeneous across the genome and operates principally at different levels of hierarchy. Transcription coupled repair (TCR), a special sub-pathway of NER and base excision repair (BER), is critical for cellular resistance after UV irradiation in mammalian cells. In this study, we have investigated the effects of UV-C irradiation on cell cycle progression and apoptosis in G 1 synchronised isogenic hamster cell lines that are deficient in TCR and NER pathways. Our results revealed the existence of two apoptotic modes at low UV (2–4 J/m 2) doses in TCR deficient (UV61) and NER deficient (UV5) cells: one occurring in the first G 1 and the other in the second G 1-phase following the first division. At high UV doses (8–32 J/m 2), UV61 and UV5 cells underwent apoptosis without entry into S-phase after a permanent arrest in the initial G 1. In contrast to repair deficient cells, parental TCR proficient AA8 cells did not show a significant G 1 arrest and apoptosis at doses below 8 J/m 2. UV61 (proficient in repair of 6–4 photoproducts (PPs)) and UV5 (deficient in 6–4 PP repair) cells showed similar patterns of cell cycle progression and apoptosis. Taken together, these results suggest that the persistence of 6–4 PP and the replication inhibition may not be critical for apoptotic response in hamster cells. Instead, the extent of transcription blockage resulting from the TCR deficiency constitutes the major determining factor for G 1 arrest and apoptosis.

A high-level EDA environment for the automatic insertion of HD-BIST structures

This paper presents a High-Level EDA environment based on the Hierarchical Distributed BIST (HD-BIST), a flexible and reusable approach to solve BIST scheduling issues in system-on-chip applications. HD-BIST allows activating and controlling different BISTed blocks at different levels of hierarchy, with a minimum overhead in terms of area and test time. Besides the hardware layer the authors presented the HD-BIST application layer where a simple modeling language, and a prototypical EDA tool demonstrate the effectiveness of the automation of the HD-BIST insertion in the test strategy definition of a complex system-on-chip.

On the Fairness of Death-Penalty Jurors: A Comparison of Bayesian Models with Different Levels of Hierarchy and Various Missing-Data Mechanisms

Jurors who are opposed to the death penalty are excluded from serving on trials in which the defendant may be sentenced to death. The exclusion of such jurors from death-penalty trials raises some concern about the fairness of these juries in deciding the guilt or innocence of a defendant. This article uses data from a survey of behaviors and beliefs of jurors conducted at the conclusion of non–capital offense trials to study this issue. A Bayesian hierarchical model is proposed for the probabilities of voting guilty or not guilty on a particular trial given various death-penalty beliefs. The Gibbs sampler is used to fit the model. The posterior distributions of the log odds of voting guilty for jurors who would be excluded from death-penalty juries versus those who would not be excluded suggest that there may be differences between the decisions of jurors on non–capital offense trials. We believe that they are likely to differ on death-penalty trials as well. The results from fitting the hierarchical model, which includes a jury effect, are compared with a previous analysis by Kadane that took the jurors' responses to be independent. At issue is the comparability of the priors under models with different hierarchical structures. Another issue in the analysis is that some jurors did not respond to the survey concerning their death-penalty beliefs. Because the views of nonrespondents may differ from those of respondents, our analysis includes an investigation of how various assumptions about the missing-data mechanism affect the conclusions.

On the Fairness of Death-Penalty Jurors: A Comparison of Bayesian Models with Different Levels of Hierarchy and Various Missing-Data Mechanisms

Abstract Jurors who are opposed to the death penalty are excluded from serving on trials in which the defendant may be sentenced to death. The exclusion of such jurors from death-penalty trials raises some concern about the fairness of these juries in deciding the guilt or innocence of a defendant. This article uses data from a survey of behaviors and beliefs of jurors conducted at the conclusion of non–capital offense trials to study this issue. A Bayesian hierarchical model is proposed for the probabilities of voting guilty or not guilty on a particular trial given various death-penalty beliefs. The Gibbs sampler is used to fit the model. The posterior distributions of the log odds of voting guilty for jurors who would be excluded from death-penalty juries versus those who would not be excluded suggest that there may be differences between the decisions of jurors on non–capital offense trials. We believe that they are likely to differ on death-penalty trials as well. The results from fitting the hierarchical model, which includes a jury effect, are compared with a previous analysis by Kadane that took the jurors' responses to be independent. At issue is the comparability of the priors under models with different hierarchical structures. Another issue in the analysis is that some jurors did not respond to the survey concerning their death-penalty beliefs. Because the views of nonrespondents may differ from those of respondents, our analysis includes an investigation of how various assumptions about the missing-data mechanism affect the conclusions.

Feasibility and performance region modeling of analog and digital circuits

Hierarchy plays a significant role in the design of digital and analog circuits. At each level of the hierarchy it becomes essential to evaluate if a sub-block design is feasible and if so which design style is the best candidate for the particular problem. This paper proposes a general methodology for evaluating the feasibility and the performance of sub-blocks at all levels of the hierarchy. A vertical binary search technique is used to generate the feasibility macromodel and a layered volume-slicing methodology with radial basis functions is used to generate the performance macromodel. Macromodels have been developed and verified for both analog and digital blocks. Analog macromodels have been developed at three different levels of hierarchy (current mirror, opamp, and A/D converter). The impact of different fabrication processes on the performance of analog circuits have also been explored. Though the modeling technique has been fine tuned to handle analog circuits the approach is general and is applicable to both analog and digital circuits. This feature makes it particularly suitable for mixed-signal designs.

Identifying objects at different levels of hierarchy: A positron emission tomography study

AbstractSubjects decided whether names were appropriate for accompanying pictures while their local cerebral blood flow was monitored using positron emission tomography (PET); in one condition, the names were at the “entry” level (i.e., the level spontaneously named, as in “bird” for a robin), in another condition they were at a superordinate level (e.g., “animal”), and in another they were at a subordinate level (e.g., “robin”). The results indicated that different processes are used to evaluate terms at the different levels of analysis. Specifically, there was evidence that memory search is used to evaluate superordinates, but one must collect additional perceptual information to evaluate subordinates. In addition, in another condition the subjects saw written words that named the entry‐level term and decided whether the object could be named by superordinate terms. Similar, but not identical, activation was observed as was found when subjects evaluated superordinate terms for pictures. © 1995 Wiley‐Liss, Inc.

Quantitative stromatolitology

All aspects of stromatolites can be quantified, encompassing morphologic, dimensional, material, and positional attributes. Numerical data obtained by electronic image analysis or otherwise can facilitate taxonomy, classification, and studies of evolutionary tendencies in stromatolites, and bridge the language barriers as well. Consensus on basic attributes for recognizing taxa at different levels of hierarchy still needs to be developed; quantitative data can promote reduction or elimination of disagreements.

Co-ordination processes: modelling and taxonomy

The hierarchy of information units and interactions in manag­ ing of Organizational Systems is ruther complicated. Interactions between de­ partments of different levels of hierarchy are named (Mesarovic, Mako, Takahara, 1970). This paper deals with the coordination as the verti­ cal informational interfaces between the units called elementary management cycles which compose the structure of managing process. The taxonomy of co-ordination processes presented in this paper is based on the decomposition of information processing at managing in so called the Space of Processes (Gudas, 1991).

Extended hypercube: a hierarchical interconnection network of hypercubes

A new interconnection topology-the extended hypercube-consisting of an interconnection network of k-cubes is discussed. The extended hypercube is a hierarchical, expansive, recursive structure with a constant predefined building block. The extended hypercube retains the positive features of the k-cube at different levels of hierarchy and at the same time has some additional advantages like reduced diameter and constant degree of a node. The paper presents an introduction to the topology of the extended hypercube and analyzes its architectural potential in terms of message routing and executing a class of highly parallel algorithms. Topological properties and performance studies of the extended hypercube are presented. >