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Various Features (various + feature)
Selected AbstractsComparison of human and porcine aortic valvesCLINICAL ANATOMY, Issue 3 2003Eugene K.W. Sim Abstract We compared the anatomy of human and porcine aortic valves. Porcine hearts were collected from the abattoir. Human hearts from patients who had died of non-cardiac causes were examined in the mortuary; only undamaged and anatomically normal hearts were used. Silicon casts were prepared by injecting engineering silicon at 80 mm Hg into the aortic arch. Various features of the aortic valve were measured: circumference, length between the commissural end point and central point of coaptation, surface diameter, and surface area. In total, 12 porcine and 12 human aortic valves were studied. The average circumferences of the human and porcine aortic valves were 8.00 ± 0.2 (SD) cm and 7.90 ± 1.0 cm, respectively. The central point of coaptation in human valves was skewed toward the left coronary cusp, whereas in porcine valves it was skewed toward the non-coronary cusp. In human aortic valves, the non-coronary cusp had the largest surface diameter and surface area with mean measurements of 3.6 ± 0.2 cm and 1.230 ± 0.228 cm2, respectively; the left coronary cusp was smallest for the same variables with measurements of 3.1 ± 0.3 cm and 0.898 ± 0.357 cm2. In porcine valves, the right coronary cusp had the largest surface diameter and surface area with mean measurements of 3.9 ± 0.7 cm and 1.716 ± 0.81 cm2, respectively; the non-coronary cusp was the smallest for the same variables with measurements of 2.9 ± 0.5 cm and 1.023 ± 0.659 cm2. These differences suggest that when using porcine valves as transplant material (e.g., stentless valves), geometric considerations, such as commissural length, may be important. Clin. Anat. 16:193,196, 2003. © 2003 Wiley-Liss, Inc. [source] Nuclear morphometry and texture analysis of B-cell non-Hodgkin lymphoma: Utility in subclassification on cytosmearsDIAGNOSTIC CYTOPATHOLOGY, Issue 2 2010Shilpa Gupta M.D. Abstract Non-Hodgkin lymphoma (NHL) is a heterogeneous group of lymphoid neoplasms and accurate subclassification is an essential prerequisite for proper management of patients. This study was aimed at evaluating the utility of nuclear morphometry and textural features on cytology smears to classify the cases of NHL on aspiration cytology. Fine needle aspiration smears of 50 cases of B-cell NHL were included. Various morphometric and texture parameters were obtained by manually tracing the nuclei on digitized images in each case and discriminant analysis performed using various features taken individually as well as all together. The percentage of cells correctly classified to a particular NHL subtype using the discriminant functions so obtained was noted. Our results show that discriminant analysis done on size parameters could correctly classify a greater number of cells than on shape parameters (36.4% vs. 21.2%, respectively). Texture parameters based on single pixel values (first order texture) were inferior (42.8%) to those based on pair of pixels (58.7%) in subtyping of cells. Discriminant analysis based on color parameters was more effective (61.9%) as compared to rest of the morphometric and textural parameters. Using all the morphometric and textural parameters together, 83.3% of cells could be correctly classified to a particular NHL subtype. The present study, perhaps the first study of detailed morphometric analysis on cytosmears, shows that satisfactory classification of NHL on aspiration cytology is possible using nuclear morphometry and textural parameters considered together. These results are promising for further studies on this subject and development of automated cytodiagnosis. Diagn. Cytopathol. 2010. © 2009 Wiley-Liss, Inc. [source] Geophysical exploration for interlayer slip breccia gold deposits: example from Pengjiakuang gold deposit, Shandong Province, ChinaGEOPHYSICAL PROSPECTING, Issue 2 2004Z. Qingdong ABSTRACT Interlayer slipping breccia-type gold deposit , a new type of gold deposit, defined recently in the northern margin of the Jiaolai Basin, Shandong Province, China , occurs in interlayer slip faults distributed along the basin margin. It has the features of large orebody thickness (ranging from 14 m to 46 m, with an average thickness of 30 m), shallow embedding (0,50 m thickness of cover), low tenor of gold ore (ranging from 3 g/t to 5 g/t), easy mining and ore dressing. This type of gold deposit has promising metallogenic forecasting and potential for economic exploitation. A ground gamma-ray survey in the Pengjiakuang gold-ore district indicates that the potassium/thorium ratio is closely related to the mineralization intensity, i.e. the larger the potassium/thorium ratio, the higher the mineralization. The gold mineralized alteration zone was defined by a potassium/thorium ratio of 0.35. A seismic survey confirms the location of the top and bottom boundaries and images various features within the Pengjiakuang gold mineralization belt. The gold-bearing shovel slipped belt dips to the south at an angle of 50,55° at the surface and 15,20° at depth. The seismic profile is interpreted in terms of a structural band on the seismic section characterized by a three-layered model. The upper layer is represented by weakly discontinuous reflections that represent the overlying conglomerates. A zone of stronger reflections representing the interlayer slip fault (gold-bearing mineralized zone) is imaged within the middle of the section, while the strongest reflections are in the lower part of the section and represent metamorphic rocks at depth. At the same time, the seismic reflection survey confirms the existence of a granite body at depth, indicating that ore-forming fluids may be related to the granite. A CSAMT survey showed that the gold-bearing mineralized zone is a conductive layer and contains a low-resistivity anomaly ranging from 2 ,m to 200 ,m. [source] What Do Employees Know About Their Pension Plan?INDUSTRIAL RELATIONS, Issue 4 2000Andrew A. Luchak Original survey data based on 529 respondents in a large organization are used to analyze how much employees know about various features of their occupational pension plan. While the level of understanding was quite low among all employees, it was quite high among those for whom the knowledge matters most in terms of their behavioral decision making. Our results show that rather than being optimal labor contracts that workers enter into with full knowledge at the time of employment, pension contracts are more like contingent claims contracts evolving under conditions of uncertainty and incomplete information. [source] Pattern hunting in climate: a new method for finding trends in gridded climate dataINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 1 2007A. Hannachi Abstract Trends are very important in climate research and are ubiquitous in the climate system. Trends are usually estimated using simple linear regression. Given the complexity of the system, trends are expected to have various features such as global and local characters. It is therefore important to develop methods that permit a systematic decomposition of climate data into different trend patterns and remaining no-trend patterns. Empirical orthogonal functions and closely related methods, widely used in atmospheric science, are unable in general to capture trends because they are not devised for that purpose. The present paper presents a novel method capable of systematically capturing trend patterns from gridded data. The method is based on an eigenanalysis of the covariance/correlation matrix obtained using correlations between time positions of the sorted data, and trends are associated with the leading nondegenerate eigenvalues. Application to simple low-dimensional time series models and reanalyses data are presented and discussed. Copyright © 2006 Royal Meteorological Society. [source] Methods for Generating Longitudinally Correlated Binary DataINTERNATIONAL STATISTICAL REVIEW, Issue 1 2008Patrick J. Farrell Summary The analysis of longitudinally correlated binary data has attracted considerable attention of late. Since the estimation of parameters in models for such data is based on asymptotic theory, it is necessary to investigate the small-sample properties of estimators by simulation. In this paper, we review the mechanisms that have been proposed for generating longitudinally correlated binary data. We compare and contrast these models with regard to various features, including computational efficiency, flexibility and the range restrictions that they impose on the longitudinal association parameters. Some extensions to the data generation mechanism originally suggested by Kanter (1975) are proposed. Résumé L'analyse des données longitudinales corrélées fait récemment l'objet d'un grand intérêt. Comme l'estimation des paramètres des modèles pour de telles données est souvent basée sur des études asymptotiques, il est nécessaire de procéder à des simulations pour explorer les propriétés des estimateurs en petits échantillonages. Dans ce papier, nous présentons une revue des méthodes qui ont été proposées pour générer des données binaires longitudinales corrélées. Nous les comparons sous différents aspects, notamment en termes d'efficience, flexibilité, et des restrictions qu'elles peuvent avoir sur les paramètres dits d'association longitudinale. Quelques extensions, de la méthode suggérée par Kanter (1975) pour générer de telles données, sont aussi proposées. [source] The Nature of the Interaction between Mandatory and Voluntary DisclosuresJOURNAL OF ACCOUNTING RESEARCH, Issue 4 2005ETI EINHORN ABSTRACT This paper demonstrates the crucial role that firms' mandatory disclosures play in determining their voluntary disclosure strategies. It also shows how a firm's propensity for providing voluntary disclosures relates to various features of the mandatory disclosure environment and disclosure regulation. The special case of choosing between aggregated and disaggregated disclosures serves as an illustration of the model's applicability. [source] Resident-oriented care in nursing homes: effects on nursesJOURNAL OF ADVANCED NURSING, Issue 6 2004Afke J.M.B. Berkhout PhD Background., In a resident-oriented care model the assignment of patients to primary nurses takes place. These primary nurses are responsible for the total nursing care of their patients and make use of the nursing process. According to job demand-control models, these enlarged and enriched jobs can be described in terms of autonomy, job demands and social support, and the presence of these work characteristics has a positive influence on workers' psychological and behavioural outcomes. Aims., This paper reports a study to investigate the extent to which the various features of resident-oriented care were implemented and its effects nurses' on work characteristics and on psychological and behavioural outcomes in three Dutch nursing homes. Methods., In a quasi-experimental design, experimental and control groups were followed over 22 months, using a pretest and two post-tests with questionnaires, interviews and qualitative observations. Results., The quantitative data showed significant increases in resident assignment, the two variables measuring the nursing process and, in the psycho-geriatric experimental group, on resident-oriented tasks. The qualitative data showed that a partly task-oriented division of labour was still used and that the planned delegation of coordination tasks to primary nurses was not fully achieved. Effects on work perceptions were limited. After implementation of the new system, the experimental group showed an increase in job autonomy. Conclusions., The intervention appeared to be only partly successful. Most of the expected results regarding work characteristics and psychological and behavioural outcomes did not materialize. Theoretical and methodological reflections are presented in the light of these findings. [source] Approximation algorithms for general one-warehouse multi-retailer systemsNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 7 2009Zuo-Jun Max Shen Abstract Logistical planning problems are complicated in practice because planners have to deal with the challenges of demand planning and supply replenishment, while taking into account the issues of (i) inventory perishability and storage charges, (ii) management of backlog and/or lost sales, and (iii) cost saving opportunities due to economies of scale in order replenishment and transportation. It is therefore not surprising that many logistical planning problems are computationally difficult, and finding a good solution to these problems necessitates the development of many ad hoc algorithmic procedures to address various features of the planning problems. In this article, we identify simple conditions and structural properties associated with these logistical planning problems in which the warehouse is managed as a cross-docking facility. Despite the nonlinear cost structures in the problems, we show that a solution that is within ,-optimality can be obtained by solving a related piece-wise linear concave cost multi-commodity network flow problem. An immediate consequence of this result is that certain classes of logistical planning problems can be approximated by a factor of (1 + ,) in polynomial time. This significantly improves upon the results found in literature for these classes of problems. We also show that the piece-wise linear concave cost network flow problem can be approximated to within a logarithmic factor via a large scale linear programming relaxation. We use polymatroidal constraints to capture the piece-wise concavity feature of the cost functions. This gives rise to a unified and generic LP-based approach for a large class of complicated logistical planning problems. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009 [source] Decentralized control strategies for dynamic routingOPTIMAL CONTROL APPLICATIONS AND METHODS, Issue 6 2002ftar Abstract The routing problem in multi-destination data communication networks is considered. A dynamic model, which can incorporate arbitrary, different, time-varying processing delays at different nodes, is developed to describe the network dynamics. Based on this model, controllers for routing control are proposed. The structures of the proposed controllers are motivated by an optimal control problem. These proposed controllers are completely decentralized in the sense that all necessary on-line computations are done locally at each node. Furthermore, the information needed for these computations is related only to the queue lengths at the present node and the adjacent downstream nodes. Both cases when the controls can be continuously changed and when the controls are updated at discrete time instants are considered. In the latter case the controls at different nodes may be updated at different time instants (i.e. the network is not necessarily synchronous). It is shown that the controllers enjoy many desirable properties; in particular, they clear all the queues of the network in the absence of external message arrivals, in finite time. Furthermore, the controllers do not direct messages around a loop. They also have certain robustness properties. Some simulation results relating to a number of realistic problems are presented to illustrate various features of the controllers. Copyright © 2002 John Wiley & Sons, Ltd. [source] Government,nonprofit relations in comparative perspective: evolution, themes and new directionsPUBLIC ADMINISTRATION & DEVELOPMENT, Issue 1 2002Jennifer M. Brinkerhoff This overview article for the Symposium on Government,Nonprofit Relations in Comparative Perspective summarizes our current understanding of government,nonprofit relations, addresses several themes emerging from the collective papers and Symposium discussions, and discusses new and evolving trends in government,nonprofit relations. The review of government,nonprofit relations encompasses governance models and their incorporation of nonprofits, sector failures and their contribution to government,nonprofit relationships, and cross-sectoral analytic frameworks. Themes addressed include the material and normative benefits sought through nonprofits; various features of government,nonprofit interactions, including their increasing range and multiple facets, the impact of origins, relationship dynamism, and impacts; and what is public and what is private. The article concludes with the identification of selected new and evolving trends, including the influence of information technology on organizational structures and processes, the rise of supranational spheres of government,nonprofit interaction, the continuing tension between cooperation and identity maintenance, and simultaneous global lesson sharing and an emphasis on local-level problem-solving, where nonprofits are viewed as a means to maintaining continuity and redefining community. The article situates our understanding of government,nonprofit relations in a comparative perspective that accounts for dominant global paradigms, increasing interdependence among actors and nations, and evolving models of governance at all levels. Copyright © 2002 John Wiley & Sons, Ltd. [source] TRADER EXPLOITATION OF ORDER FLOW INFORMATION DURING THE LTCM CRISISTHE JOURNAL OF FINANCIAL RESEARCH, Issue 3 2009Fang Cai Abstract By using a unique data set of audit trail transactions, I examine the trading behavior of market makers in the Treasury-bond futures market during the Long-Term Capital Management (LTCM) crisis in 1998. I find strong evidence that during the crisis market makers in the aggregate engaged in anticipatory trading against customer orders from a particular clearing firm (coded PI7) that closely match various features of LTCM's trades through Bear Stearns. I also show that a significant percentage of market makers made abnormal profits during the crisis. Their aggregate abnormal profits, however, were more than offset by abnormal losses following the recapitalization of LTCM. [source] Memory fragments as components of autobiographical knowledgeAPPLIED COGNITIVE PSYCHOLOGY, Issue 3 2007Darryl Bruce Adults described and dated two kinds of personal remembrances: a fragment,a memory moment that is largely bereft of context,and an episodic, personal event memory,a narrative that consists of a number of related events. In Experiment 1 subjects reported memories from when they were 0,8 years of age and in Experiment 2, from when they were 0,16 years of age. Fragments were judged to be older than event memories, especially in Experiment 2 where the estimated ages of most fragments were from 0 to 8 years and of most episodic memories, from 8 to 16 years. Ratings of various features of the two kinds of memories also differed. We conclude that isolated memory moments possess validity and that although they are most likely to arise when the autobiographical memory system is not fully developed, they can also originate during a time when it is. Copyright © 2006 John Wiley & Sons, Ltd. [source] Xylem heterochrony: an unappreciated key to angiosperm origin and diversificationsBOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009SHERWIN CARLQUIST fls All angiosperms can be arranged along a spectrum from a preponderance of juvenile traits (cambial activity lost) to one of nearly all adult characters (cambium maximally active, mature patterns realized rapidly early in ontogeny). Angiosperms are unique among seed plants in the width of this spectrum. Xylem patterns are considered here to be indicative of contemporary function, not relictual. Nevertheless, most families of early-divergent angiosperms exhibit paedomorphic xylem structure, a circumstance that is most plausibly explained by the concept that early angiosperms had sympodial growth forms featuring limited accumulation of secondary xylem. Sympodial habits have been retained in various ways not only in early-divergent angiosperms, but also among eudicots in Ranunculales. The early angiosperm vessel, relatively marginal in conductive abilities, was improved in various ways, with concurrent redesign of parenchyma and fibre systems to enhance conductive, storage and mechanical capabilities. Flexibility in degree of cambial activity and kinds of juvenile/adult expressions has been basic to diversification in eudicots as a whole. Sympodial growth that lacks cambium, such as in monocots, provides advantages by various features, such as organographic compartmentalization of tracheid and vessel types. Woody monopodial eudicots were able to diversify as a result of production of new solutions to embolism prevention and conductive efficiency, particularly in vessel design, but also in parenchyma histology. Criteria for paedomorphosis in wood include slow decrease in length of fusiform cambial initials, predominance of procumbent ray cells and lesser degrees of cambial activity. Retention of ancestral features in primary xylem (the ,refugium' effect) is, in effect, a sort of inverse evidence of acceleration of adult patterns in later formed xylem. Xylem heterochrony is analysed not only for all key groups of angiosperms (including monocots), but also for different growth forms, such as lianas, annuals, various types of perennials, rosette trees and stem succulents. Xylary phenomena that potentially could be confused with heterochrony are discussed. Heterochronous xylem features seem at least as important as other often cited factors (pollination biology) because various degrees of paedomorphic xylem are found in so many growth forms that relate in xylary terms to ecological sites. Xylem heterochrony can probably be accessed during evolution by relatively simple gene changes in a wide range of angiosperms and thus represents a current as well as a past source of variation upon which diversification was based. Results discussed here are compatible with both current molecular-based phylogenetic analyses and all recent physiological work on conduction in xylem and thus represent an integration of these fields. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161, 26,65. [source] Developmental morphology of Saxicolella amicorum and S. submersa (Podostemaceae: Podostemoideae) from GhanaBOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2002K. GABRIEL AMEKA Saxicolella (six spp.) is a podostemoid genus occurring in tropical west Africa (Cameroon, Ghana, Nigeria). Taxonomically used characters such as root (with holdfasts), pollen (dyads in many Podostemoideae), capsules (with ribs) and seeds are demonstrated and discussed. This paper deals with the structure and development of two species, which are endemic to rivers in southern Ghana: Saxicolella amicorum J.B.Hall and Saxicolella submersa (J.B.Hall) C.D.K.Cook & Rutish. (syn. Polypleurum submersum J.B.Hall).,Saxicolella amicorum has simple, one-flowered stems up to 3 cm long, whereas S. submersa has branched, many-flowered stems up to 25 cm long. Vegetative shoots can reach 12 cm (S. amicorum) and even 50 cm (S. submersa) in length. The latter species was previously placed in the Asian genus Polypleurum because the long floating axis was misinterpreted as a root which would be typical for Polypleurum. The long floating axis of S. submersa develops exogenous leaves and is actually a stem. Both S. amicorum and S. submersa have various features in common: vegetative parts (roots, stems, leaves) are elongate and very thin (diameter less than 1 mm); prostrate roots are narrow ribbons (twice as wide as thick); endogenous shoots in opposite pairs along the root; leaves usually simple and filiform; leaf bases with two attached ear-like stipules; spathella club-shaped to ellipsoidal; erect flowers with a solitary stamen; ovary ellipsoidal to fusiform, bilocular; capsules nearly isolobous, with three prominent ribs per valve (i.e. eight ribs per capsule including sutural ribs). Evolutionary dynamics of the root structures in African Podostemoideae such as Saxicolella include: formation of green prostrate ribbons as a result of dorsoventral root flattening; reduction of root caps; occurrence of adhesive hairs and exogenous holdfasts which are disk- or finger-like. Structural diversity and developmental patterns in the Ghanaian Saxicolella species are compared with other African Podostemoideae. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 2002, 139, 255,273. [source] Sebaceous gland hyperplasia of the foreskinCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 3 2009P. Ena Summary Two men, aged in their 20s, presented with multiple, soft, rounded papules on the prepuce. The lesions were centrally umbilicated, resembling molluscum contagiosum, but clearly distinct from Tyson's glands. Surface microscopy showed well-defined, milky-white, bag-shaped structures, which under histological examination were found to be sebaceous glands with various features of hyperplasia. A lymphocytic T-cell infiltrate, closely associated with progressive degeneration and destruction of the sebocytes, was visible around the glands. In the differential diagnosis of penile papular lesions, this unusual clinical presentation supported by dermatoscopy is consistent with preputial sebaceous gland hyperplasia. As both patients had a prominent T-cell infiltration, it is possible that under inflammatory stimulation, sebaceous glands undergo hypertrophy and gradual central involution. [source] Inspiration-induced vasoconstrictive responses in dominant versus non-dominant handsCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 2 2005Harvey N. Mayrovitz Summary Single rapid and deep inspirations (inspiratory gasps, IG) result in arteriolar vasoconstriction with concomitant transient decreases in skin blood flow that are most prominent in fingers and toes. Vascular responses (inspiratory gasp responses, IGR) are determined as the maximum percentage reduction in blood flow and have been used to assess sympathetic neurovascular function in several conditions. Previous studies have described various features of the response but there has been no reported systematic investigation of the degree of similarity between IGR obtained on dominant and non-dominant hands. This aspect is important in procedures that may use IGR to evaluate suspected unilateral sympathetic dysfunction of a limb-pair or to test the effectiveness of physiological interventions imposed on a single limb of a pair. Thus, the goal of our study was to compare IGR magnitudes that were simultaneously determined in paired-fingers of dominant and non-dominant hands. In 30 healthy seated subjects, skin blood perfusion via laser-Doppler (SBF) was measured on the dorsum of the middle finger of both hands while subjects performed three sequential IG at 3-min intervals. Analysis of variance for repeated measures revealed no significant difference in IGR between dominant (79·3 ± 11·2%) and non-dominant hands (81·9 ± 11·6%, P = 0·965) with an overall IGR of 80·6 ± 11·4%. These results indicate that hand-dominance is not a factor that is likely to significantly effect IGR differentials determined in paired-limbs. [source] | ||||||||||||||||||||||