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Many Features (many + feature)
Selected AbstractsAn evidence-based approach to planning tobacco interventions for Aboriginal peopleDRUG AND ALCOHOL REVIEW, Issue 1 2004ROWENA G. IVERS Abstract Systematic reviews have shown that interventions such as the delivery of cessation advice by heath professionals and the use of nicotine replacement therapy are effective at increasing cessation rates, however little is known about whether such interventions are appropriate and effective for and thus transferable to Aboriginal Australians. The aim of this paper was to assess whether evidence of effectiveness for brief interventions for cessation and nicotine patches from studies conducted in other populations was likely to be transferable to Aboriginal people in the NT. This paper involved assessment of systematic reviews of evidence for the use of brief interventions for smoking cessation and the use of nicotine replacement therapy, when planning two such interventions for delivery to Aboriginal people. Emerging themes are discussed. There were many factors which were likely to mean that these brief advice on cessation and the use of nicotine patches were likely to be less effective when implemented in Aboriginal communities. The planned interventions were delivered in primary care, and were of low intensity. Few studies included in systematic reviews were set in the developing world or in minority populations. Many features of the context for delivery, such as the normality of the use of tobacco among Aboriginal people, the low socio-economic status of this population and cultural issues, may have meant that these interventions were likely to be less effective when delivered in this setting. Further research is required to assess effectiveness of tobacco interventions in this population, as evidence from systematic reviews in other populations may not be directly transferable to Aboriginal people. [source] Thickness of gingiva in association with age, gender and dental arch locationJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 7 2005K. L. Vandana Abstract Background: It has been long known that the clinical appearance of healthy marginal periodontium differs from subject to subject and even among different tooth types. Many features are genetically determined; others seem to be influenced by tooth size, shape and position and biological phenomena such as gender, growth and age. Aim: The purpose of this study was to determine the thickness of facial gingiva among Indians and its association with age, gender and dental arch. Methods: The study group included 16 males and 16 females with an age range of 16,38 years. Gingival thickness was assessed in the maxillary and mandibular anteriors by transgingival probing. Results: It was observed that the younger age group had significantly thicker gingiva than that of the older age group. The gingiva was found to be thinner in females than males and, in the mandibular arch than the maxilla. Conclusion: In the present study, it was concluded that gingival thickness varies according to age, gender and dental arch. [source] Magnetic resonance imaging of entheses using ultrashort TE (UTE) pulse sequencesJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2007Michael Benjamin PhD Abstract The attachment of tendons, ligaments, and joint capsule to bone (entheses) is reviewed and new options for visualizing key components of entheses provided by ultrashort TE (UTE) pulse sequences are described. Many features of entheses are adapted to the dispersion of stress at the boundary between tendons/ligaments and bone. Of particular interest is fibrocartilage, which has mechanical properties different from those of both "pure" tendon/ligament and bone. Features typical of entheses can also be seen at sites where tendons or ligaments are in contact with (but not attached to) bone, and the concept of a "functional enthesis" has been developed to emphasize the similarities. The enthesis concept has also been broadened to include the idea of an "enthesis organ" in which many tissues play a role in dissipating stress concentration. UTE pulse sequences can specifically identify the calcified and uncalcified fibrocartilage tissue components of entheses and differentiate these from fibrous connective tissue and bone. These tissues cannot be separately visualized at entheses with conventional pulse sequences. Entheses are involved in overuse syndromes and seronegative spondyloarthropathies (SpA) and there are important issues related to tissue repair and healing following surgery. J. Magn. Reson. Imaging 2007. © 2007 Wiley-Liss, Inc. [source] Promoting complex systems learning through the use of conceptual representations in hypermediaJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 9 2009Lei Liu Abstract Studying complex systems is increasingly important in many science domains. Many features of complex systems make it difficult for students to develop deep understanding. Our previous research indicated that a function-centered conceptual representation is part of the disciplinary toolbox of biologists, suggesting that it is an appropriate representation to help students develop deep understanding. This article reports on the results of two experiments that investigate how hypermedia using a conceptual representation influences pre-service teachers' and middle school students' learning of a complex biological system, the human respiratory system. We designed two versions of instructional hypermedia based on the structure,behavior-function conceptual representation. One hypermedia was function-centered which emphasized the function and behavior of the system, whereas the other was focused on the structure of the system. We contrasted the instructional effectiveness of these two alternative conceptual representations. The results of both studies indicated that participants using the function-centered hypermedia developed deeper understanding than those using the structure-centered version. This proof-of-concept study suggests that the function-centered conceptual representation is a powerful way to promote complex systems understanding. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 1023,1040, 2009 [source] A Complexity Model and a Polynomial Algorithm for Decision-Tree-Based Feature ConstructionCOMPUTATIONAL INTELLIGENCE, Issue 1 2000Raymond L. Major Using decision trees as a concept description language, we examine the time complexity for learning Boolean functions with polynomial-sized disjunctive normal form expressions when feature construction is performed on an initial decision tree containing only primitive attributes. A shortcoming of several feature-construction algorithms found in the literature is that it is difficult to develop time complexity results for them. We illustrate a way to determine a limit on the number of features to use for building more concise trees within a standard amount of time. We introduce a practical algorithm that forms a finite number of features using a decision tree in a polynomial amount of time. We show empirically that our procedure forms many features that subsequently appear in a tree and the new features aid in producing simpler trees when concepts are being learned from certain problem domains. Expert systems developers can use a method such as this to create a knowledge base of information that contains specific knowledge in the form of If-Then rules. [source] Distributions of estrogen receptors alpha and beta in sympathetic neurons of female rats: Enriched expression by uterine innervationDEVELOPMENTAL NEUROBIOLOGY, Issue 1 2002Elena V. Zoubina Abstract Estrogen modulates many features of the sympathetic nervous system, including cell numbers and ganglion synapses, and can induce uterine sympathetic nerve degeneration. However, distributions of estrogen receptors , and , within sympathetic neurons have not been described, and their regulation by target tissue or estrogen levels has not been explored. We used immunofluorescence and retrograde tracing to define estrogen receptor expression in sympathetic neurons at large in pre- and paravertebral ganglia and in those projecting to the uterine horns. Estrogen receptor , immunoreactivity was present in 29 ± 1%, while estrogen receptor , was expressed by 92 ± 1% of sympathetic neurons at large. The proportions of neurons expressing these receptors were comparable in the superior cervical and thoraco-lumbar paravertebral ganglia from T11 through L5, and in the suprarenal, celiac, and superior mesenteric prevertebral ganglia. Injections of FluoroGold into the uterine horns resulted in labeled neurons, with peak occurrences in T13, L1, and the suprarenal ganglion. Uterine-projecting neurons showed small but significantly greater incidence of estrogen receptor , expression relative to the neuronal population at large, whereas the proportion of uterine-projecting neurons with estrogen receptor ,-immunoreactivity was nearly threefold greater. Numbers of estrogen receptor-expressing neurons were not altered by acute estrogen administration. We conclude that the vast majority of sympathetic neurons express estrogen receptor , immunoreactive protein, whereas a smaller, presumably overlapping subset expresses the estrogen receptor ,. Expression of the latter apparently can be enhanced by target-mediated mechanisms. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 14,23, 2002 [source] Non-alcoholic fatty liver disease, the metabolic syndrome and the risk of cardiovascular disease: the plot thickensDIABETIC MEDICINE, Issue 1 2007G. Targher Abstract Non-alcoholic fatty liver disease (NAFLD) affects a substantial proportion of the general population and is frequently associated with many features of the metabolic syndrome (MetS). Currently, the importance of NAFLD and its relationship with the MetS is being increasingly recognized, and this has stimulated an interest in the possible role of NAFLD in the development of atherosclerosis. Recent studies have reported the association of NAFLD with multiple classical and non-classical risk factors for cardiovascular disease (CVD). Moreover, there is a strong association between the severity of liver histopathology in NAFLD patients and greater carotid artery intima-media thickness and plaque, and lower endothelial flow-mediated vasodilation (as markers of subclinical atherosclerosis) independent of obesity and other MetS components. Finally, it has recently been demonstrated that NAFLD is associated with an increased risk of all-cause death and predicts future CVD events independently of other prognostic factors, including MetS components. Overall, therefore, the evidence from these recent studies strongly emphasizes the importance of assessing the global CVD risk in patients with NAFLD. Moreover, these novel findings suggest a more complex picture and raise the possibility that NAFLD, as a component of the MetS, might not only be a marker but also an early mediator of CVD. [source] Anabolic,androgenic steroid dependence: an emerging disorderADDICTION, Issue 12 2009Gen Kanayama ABSTRACT Aims Anabolic,androgenic steroids (AAS) are widely used illicitly to gain muscle and lose body fat. Here we review the accumulating human and animal evidence showing that AAS may cause a distinct dependence syndrome, often associated with adverse psychiatric and medical effects. Method We present an illustrative case of AAS dependence, followed by a summary of the human and animal literature on this topic, based on publications known to us or obtained by searching the PubMed database. Results About 30% of AAS users appear to develop a dependence syndrome, characterized by chronic AAS use despite adverse effects on physical, psychosocial or occupational functioning. AAS dependence shares many features with classical drug dependence. For example, hamsters will self-administer AAS, even to the point of death, and both humans and animals exhibit a well-documented AAS withdrawal syndrome, mediated by neuroendocrine and cortical neurotransmitter systems. AAS dependence may particularly involve opioidergic mechanisms. However, AAS differ from classical drugs in that they produce little immediate reward of acute intoxication, but instead a delayed effect of muscle gains. Thus standard diagnostic criteria for substance dependence, usually crafted for acutely intoxicating drugs, must be adapted slightly for cumulatively acting drugs such as AAS. Conclusions AAS dependence is a valid diagnostic entity, and probably a growing public health problem. AAS dependence may share brain mechanisms with other forms of substance dependence, especially opioid dependence. Future studies are needed to characterize AAS dependence more clearly, identify risk factors for this syndrome and develop treatment strategies. [source] Notes on the origins of Epilepsia and the International League Against EpilepsyEPILEPSIA, Issue 3 2009Simon D. Shorvon Summary The recent discovery of archival material has shed interesting light on the origins of Epilepsia and also the International League Against Epilepsy (ILAE). The idea of an international journal devoted to epilepsy seems first to have arisen from talks between Dr. L. J. J. Muskens and Dr. W. Aldren Turner in 1905. A protracted series of subsequent letters between Muskens and a Haarlem publisher show how the idea slowly took shape. The committee of patronage, editorial board, and editorial assistants was probably first approached at the First International Congress of Psychiatry, Neurology, Psychology, and Nursing of the Insane, held in Amsterdam in 1907. At this meeting, the concept of an international organization to fight epilepsy (to become the ILAE) was also first proposed in public, again by Muskens. The concept of the ILAE was clearly modeled on another international organization,the International Commission for the Study of the Causes of Mental Diseases and Their Prophylaxis. This Commission had been first publicly proposed in 1906 by Ludwig Frank, at the Second International Congress for the Care and Treatment of the Insane. The proposed Commission and ILAE shared many features, aims, and personnel. Despite an auspicious start, the International Commission was prevented by personal and political differences from ever actually coming into being. However, the first issue of Epilepsia appeared in March 1909 and the ILAE was inaugurated in August 1909; and both have flourished and celebrate their centenaries this year. [source] Is CEO Pay Really Inefficient?EUROPEAN FINANCIAL MANAGEMENT, Issue 3 2009A Survey of New Optimal Contracting Theories D2; D3; G34; J3 Abstract Bebchuk and Fried (2004) argue that executive compensation is set by CEOs themselves rather than boards on behalf of shareholders, since many features of observed pay packages may appear inconsistent with standard optimal contracting theories. However, it may be that simple models do not capture several complexities of real-life settings. This article surveys recent theories that extend traditional frameworks to incorporate these dimensions, and show that the above features can be fully consistent with efficiency. For example, optimal contracting theories can explain the recent rapid increase in pay, the low level of incentives and their negative scaling with firm size, pay-for-luck, the widespread use of options (as opposed to stock), severance pay and debt compensation, and the insensitivity of incentives to risk. [source] A functional approach to sexual selectionFUNCTIONAL ECOLOGY, Issue 4 2007DUNCAN J. IRSCHICK Summary 1Sexual selection theory is a robust and dynamic field within evolutionary biology, yet despite decades of research, remarkably little is known of the mechanistic bases of mate choice and male competition. 2Because many aspects of sexual selection involve dynamic movements, and are physically challenging, the limits of sexual selection may be defined by key functional and physiological variables (i.e. the ,functional approach'). 3We advocate the functional approach for providing mechanistic resolution on the adaptive basis of sexual structures and signals, the nature of mate choice and how males compete, among other issues. 4An overview of recent work, highlighted in this special issue, shows that many features of sexual selection, including the outcome of male fights, the morphology and design of sexual signals, and the nature of mate choice, all appear to be dictated in large part by functional and physiological parameters. 5We argue that the functional approach provides a potent tool for resolving several unresolved issues in sexual selection theory, particularly the nature of male quality, the handicap and indicator models of sexual selection, and the basis of mate choice. [source] The common fragile site FRA16D and its associated gene WWOX are highly conserved in the mouse at Fra8E1GENES, CHROMOSOMES AND CANCER, Issue 2 2002Kurt A. Krummel Recently, several common fragile sites (CFSs) have been cloned and characterized, including the two most frequently observed in the human population, FRA3B and FRA16D. In addition to their high frequency of breakage, FRA3B and FRA16D colocalize with genes crossing large regions of breakage. At FRA3B, the fragile histidine triad (FHIT) gene spans more than 1 Mb, and at FRA16D, the WWOX gene spans more than 750 kb. It has also been shown that in Mus musculus, a CFS Fra14A2 and the mouse Fhit gene are conserved in the orthologous region of the genome. In this study, we positioned the ortholog to WWOX (Wox1) at chromosome band 8E1 in the mouse genome. To determine whether, like Fra14A2 and Fhit, Fra8E1 and Wox1 colocalized in the mouse, we prepared bacterial and yeast artificial chromosome probes, and we hybridized them to aphidicolin-treated mouse metaphase chromosomes. Our data demonstrate that Wox1 colocalizes with Fra8E1. Furthermore, the sequence from this region, including introns, is highly conserved over at least a 100-kb region. This evolutionary conservation suggests that the two most active CFSs share many features, and that CFSs and their associated genes may be necessary for cell survival. © 2002 Wiley-Liss, Inc. [source] Achieving efficient delivery of morpholino oligos in cultured cellsGENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 3 2001Paul A. Morcos Abstract Summary: One of the many features that make morpholino oligos unique among the antisense structural types is an uncharged backbone. While this feature eliminates the nonspecific interactions of traditional S-oligos, it also renders the morpholino undeliverable via the traditional lipid-based delivery systems. This article describes a highly efficient method of delivering morpholino oligos into adherent and nonadherent cultured cells. In this system, a nonionic morpholino oligo is paired to a complementary DNA "carrier." The DNA is then bound electrostatically to a partially ionized, weakly-basic ethoxylated polyethylenimine (EPEI). This morpholino/DNA/EPEI complex is efficiently endocytosed, and when the pH drops within the endosome, the EPEI more fully ionizes, resulting in permeabilization of the endosomal membrane and release of the morpholino into the cytosol. This article describes optimization of delivery in HeLa cells and provides the basis for delivery in any cultured endocytic cell type. genesis 30:94,102, 2001. © 2001 Wiley-Liss, Inc. [source] The Logic of Action: Indeterminacy, Emotion, and Historical NarrativeHISTORY AND THEORY, Issue 4 2001William M. Reddy Modern social theory, by and large, has aimed at reducing the complexity of action situations to a set of manageable abstractions. But these abstractions, whether functionalist or linguistic, fail to grasp the indeterminacy of action situations. Action proceeds by discovery and combination. The logic of action is serendipitous and combinative. From these characteristics, a number of consequences flow: The whole field of our intentions is engaged in each action situation, and cannot really be understood apart from the situation itself. In action situations we remain aware of the problems of categorization, including the dangers of infinite regress and the difficulties of specifying borders and ranges of categories. In action situations, attention is in permanent danger of being overwhelmed. We must deal with many features of action situations outside of attention; in doing so, we must entertain simultaneously numerous possibilities of action. Emotional expression is a way of talking about the kinds of possibilities we entertain. Expression and action have a rebound effect on attention. "Effort" is required to find appropriate expressions and actions, and rebound effects play a role in such effort, making it either easier or more difficult. Recent theoretical trends have failed to capture these irreducible characteristics of action situations, and have slipped into a number of errors. Language is not rich in meanings or multivocal, except as put to use in action situations. The role of "convention" in action situations is problematic, and therefore one ought not to talk of "culture." Contrary to the assertions of certain theorists, actors do not follow strategies, except when they decide to do so. Actors do not "communicate," in the sense of exchanging information, except in specially arranged situations. More frequently, they intervene in the effortful management of attention of their interlocutors. Dialogue, that is, very commonly becomes a form of cooperative emotional effort. From these considerations, it follows that the proper method for gaining social knowledge is to examine the history of action and of emotional effort, and to report findings in the form of narrative. [source] Functional brain mapping during free viewing of natural scenesHUMAN BRAIN MAPPING, Issue 2 2004Andreas Bartels Abstract Previous imaging studies have used mostly perceptually abstracted, idealized, or static stimuli to show segregation of function in the cerebral cortex. We wanted to learn whether functional segregation is maintained during more natural, complex, and dynamic conditions when many features have to be processed simultaneously, and identify regions whose activity correlates with the perception of specific features. To achieve this, we used functional magnetic resonance imaging (fMRI) to measure brain activity when human observers viewed freely dynamic natural scenes (a James Bond movie). The intensity with which they perceived different features (color, faces, language, and human bodies) was assessed psychometrically in separate sessions. In all subjects different features were perceived with a high degree of independence over time. We found that the perception of each feature correlated with activity in separate, specialized areas whose activity also varied independently. We conclude that even in natural conditions, when many features have to be processed simultaneously, functional specialization is preserved. Our method thus opens a new way of brain mapping, which allows the localization of a multitude of brain areas based on a single experiment using uncontrolled, natural stimuli. Furthermore, our results show that the intensity of activity in a specialized area is linearly correlated with the intensity of its perceptual experience. This leads us to suggest that each specialized area is directly responsible for the creation of a feature-specific conscious percept (a microconsciousness). Hum. Brain Mapp. 21:75,83, 2004. © 2003 Wiley-Liss, Inc. [source] The potential roles of biological soil crusts in dryland hydrologic cyclesHYDROLOGICAL PROCESSES, Issue 15 2006Jayne Belnap Abstract Biological soil crusts (BSCs) are the dominant living cover in many drylands of the world. They possess many features that can influence different aspects of local hydrologic cycles, including soil porosity, absorptivity, roughness, aggregate stability, texture, pore formation, and water retention. The influence of biological soil crusts on these factors depends on their internal and external structure, which varies with climate, soil, and disturbance history. This paper presents the different types of biological soil crusts, discusses how crust type likely influences various aspects of the hydrologic cycle, and reviews what is known and not known about the influence of biological crusts on sediment production and water infiltration versus runoff in various drylands around the world. Most studies examining the effect of biological soil crusts on local hydrology are done by comparing undisturbed sites with those recently disturbed by the researchers. Unfortunately, this greatly complicates interpretation of the results. Applied disturbances alter many soil features such as soil texture, roughness, aggregate stability, physical crusting, porosity, and bulk density in ways that would not necessarily be the same if crusts were not naturally present. Combined, these studies show little agreement on how biological crusts affect water infiltration or runoff. However, when studies are separated by biological crust type and utilize naturally occurring differences among these types, results indicate that biological crusts in hyperarid regions reduce infiltration and increase runoff, have mixed effects in arid regions, and increase infiltration and reduce runoff in semiarid cool and cold drylands. However, more studies are needed before broad generalizations can be made on how biological crusts affect infiltration and runoff. We especially need studies that control for sub-surface soil features such as bulk density, micro- and macropores, and biological crust structure. Unlike the mixed effects of biological crusts on infiltration and runoff among regions, almost all studies show that biological crusts reduce sediment production, regardless of crust or dryland type.Copyright © 2006 John Wiley & Sons, Ltd. [source] Control of chondrocyte gene expression by actin dynamics: a novel role of cholesterol/Ror-, signalling in endochondral bone growthJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 9b 2009Anita Woods Abstract Elucidating the signalling pathways that regulate chondrocyte differentiation, such as the actin cytoskeleton and Rho GTPases, during development is essential for understanding of pathological conditions of cartilage, such as chondrodysplasias and osteoarthritis. Manipulation of actin dynamics in tibia organ cultures isolated from E15.5 mice results in pronounced enhancement of endochondral bone growth and specific changes in growth plate architecture. Global changes in gene expression were examined of primary chondrocytes isolated from embryonic tibia, treated with the compounds cytochalasin D, jasplakinolide (actin modifiers) and the ROCK inhibitor Y27632. Cytochalasin D elicited the most pronounced response and induced many features of hypertrophic chondrocyte differentiation. Bioinformatics analyses of microarray data and expression validation by real-time PCR and immunohistochemistry resulted in the identification of the nuclear receptor retinoid related orphan receptor-, (Ror-,) as a novel putative regulator of chondrocyte hypertrophy. Expression of Ror-, target genes, (Lpl, fatty acid binding protein 4 [Fabp4], Cd36 and kruppel-like factor 5 [Klf15]) were induced during chondrocyte hypertrophy and by cytochalasin D and are cholesterol dependent. Stimulation of Ror-, by cholesterol results in increased bone growth and enlarged, rounded cells, a phenotype similar to chondrocyte hypertrophy and to the changes induced by cytochalasin D, while inhibition of cholesterol synthesis by lovastatin inhibits cytochalasin D induced bone growth. Additionally, we show that in a mouse model of cartilage specific (Col2-Cre) Rac1, inactivation results in increased Hif-1, (a regulator of Rora gene expression) and Ror-,+ cells within hypertrophic growth plates. We provide evidence that cholesterol signalling through increased Ror-, expression stimulates chondrocyte hypertrophy and partially mediates responses of cartilage to actin dynamics. [source] Some local and systemic immunological features of prepubertal periodontitisJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2001T. Berglundh Abstract Objectives: The aim of the present investigation was to study local (gingival) and systemic host defense characteristics in a sample of children exhibiting local prepubertal periodontitis (LPP). Material and methods: 2 groups of subjects were included in the present study. One group consisted of 11 children (9.5±2.0 years) with signs of periodontal disease (LPP group). A 2nd group comprised 21 adults (48.1±5.8 years) with advanced periodontal disease: adult periodontitis (AP) group. Gingival biopsies and a sample of peripheral blood were obtained in each individual of the AP group and in 7 out of the 11 subjects in the LPP group. The biopsies were prepared for morphometrical and immunohistochemical analysis and the blood samples prepared for immunohistochemical analysis. Results: The cellular infiltrates in the biopsies of the LPP group contained a larger proportion of lymphocytes and, in particular B cells, than was the case in the AP group. The TCR V,/V, gene expression in the lesions in the AP group was dominated by V, 17 and in the LPP group by V, 2. The content in peripheral blood of various lymphocyte sub-populations and TCR V,/V, gene expression in the 2 groups was almost similar. Conclusion: It is suggested that (i) the systemic host response in children with prepubertal periodontitis has many features in common with that seen in adult patients but that (ii) local defense mechanisms in the periodontitis lesion of LPP differ from those in adult periodontitis. [source] Non-pustular palmoplantar psoriasis: is histologic differentiation from eczematous dermatitis possible?JOURNAL OF CUTANEOUS PATHOLOGY, Issue 2 2008Ovgu Aydin Both palmoplantar psoriasis and eczematous dermatitis of this skin area share similar histologic features. The punch biopsies from 17 patients with psoriasis and 25 with eczematous dermatitis were evaluated, blind to the clinical diagnosis. Vertically situated multiple foci of parakeratosis, alternating with orthokeratosis, were the only statistically significant feature in the differential diagnosis of palmoplantar psoriasis [76.5% (13/17), p = 0.005]. In contrast, multiple foci of parakeratosis [70.6% (12/17)], loss of granular layer at least in focal areas [41.2% (7/17)], presence of neutrophils at the summits of parakeratosis [4% (1/17)], presence of neutrophils and/or plasma in the parakeratotoic foci [94.1% (16/17) and 11.8% (2/17)], psoriasiform epidermal hyperplasia [88.2% (15/17)], spongiosis restricted to the lower parts of the epidermis [47.1% (8/17)], dyskeratotic cells [82.4% (14/17)], thinning of suprapapillary plate [58.8% (10/17)], edema of the papillary dermis [29.4% (5/17)], presence of tortous and dilated capillaries in the papillary dermis [52.9% (9/17) and 76.5% (13/17)] and extravasated erythrocytes [29.4% (5/17)] were found to be more common in palmoplantar psoriasis compared with eczematous dermatitis; but none of them was statistically significant. Interestingly, spongiotic vesicles were seen in most of the patients with psoriasis [76.5% (13/17)]. In conclusion, according to our findings, many features of palmoplantar psoriasis overlapped with those of eczematous dermatitis. However, detection of multiple parakeratotic foci, placed vertically, alternating with orthohyperkeratosis, could be considered in favor of palmoplantar psoriasis. [source] Frequencies of Morphological Characteristics in Two Contemporary Forensic Collections: Implications for Identification,JOURNAL OF FORENSIC SCIENCES, Issue 5 2006Debra Komar Ph.D. ABSTRACT: Positive identification relies on comparison of antemortem and postmortem data. Some identifications are based on morphological features such as fracture, pathological condition, and surgical hardware, despite little literature indicating the frequencies of such traits. This study examines whether such features are sufficiently rare as to be deemed individualizing. Data were collected on two modern North American skeletal collections (N=482 individuals). Presence/absence of features was scored by skeletal element and side. Results indicate that frequencies vary by geographic region (higher frequency of fractures and pathological conditions in New Mexico while individuals in Tennessee were more likely to have surgical interventions), many features such as fractures are remarkably common and that even suites of traits may not be individualizing. Caution is warranted when using written data rather than radiographic comparisons as the primary source of identification. The implications of these findings to missing person databases are also discussed. [source] The life, death, and replacement of oligodendrocytes in the adult CNSJOURNAL OF NEUROCHEMISTRY, Issue 1 2008Dana M. McTigue Abstract Oligodendrocytes (OLs) are mature glial cells that myelinate axons in the brain and spinal cord. As such, they are integral to functional and efficient neuronal signaling. The embryonic lineage and postnatal development of OLs have been well-studied and many features of the process have been described, including the origin, migration, proliferation, and differentiation of precursor cells. Less clear is the extent to which OLs and damaged/dysfunctional myelin are replaced following injury to the adult CNS. OLs and their precursors are very vulnerable to conditions common to CNS injury and disease sites, such as inflammation, oxidative stress, and elevated glutamate levels leading to excitotoxicity. Thus, these cells become dysfunctional or die in multiple pathologies, including Alzheimer's disease, spinal cord injury, Parkinson's disease, ischemia, and hypoxia. However, studies of certain conditions to date have detected spontaneous OL replacement. This review will summarize current information on adult OL progenitors, mechanisms that contribute to OL death, the consequences of their loss and the pathological conditions in which spontaneous oligodendrogenesis from endogenous precursors has been observed in the adult CNS. [source] An evaluation of mathematical models for predicting skin permeabilityJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 1 2008Guoping Lian Abstract A number of mathematical models have been proposed for predicting skin permeability, mostly empirical and very few are deterministic. Early empirical models use simple lipophilicity parameters. The recent trend is to use more complicated molecular structure descriptors. There has been much debate on which models best predict skin permeability. This article evaluates various mathematical models using a comprehensive experimental dataset of skin permeability for 124 chemical compounds compiled from various sources. Of the seven models compared, the deterministic model of Mitragotri gives the best prediction. The simple quantitative structure permeability relationships (QSPR) model of Potts and Guy gives the second best prediction. The two models have many features in common. Both assume the lipid matrix as the pathway of transdermal permeation. Both use octanol,water partition coefficient and molecular size. Even the mathematical formulae are similar. All other empirical QSPR models that use more complicated molecular structure descriptors fail to provide satisfactory prediction. The molecular structure descriptors in the more complicated QSPR models are empirically related to skin permeation. The mechanism on how these descriptors affect transdermal permeation is not clear. Mathematically it is an ill-defined approach to use many colinearly related parameters rather than fewer independent parameters in multi-linear regression. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:584,598, 2008 [source] Principles of pharmacodynamics and their applications in veterinary pharmacologyJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2004P. LEES Pharmacodynamics (PDs) is the science of drug action on the body or on microorganisms and other parasites within or on the body. It may be studied at many organizational levels , sub-molecular, molecular, cellular, tissue/organ and whole body , using in vivo, ex vivo and in vitro methods and utilizing a wide range of techniques. A few drugs owe their PD properties to some physico-chemical property or action and, in such cases, detailed molecular drug structure plays little or no role in the response elicited. For the great majority of drugs, however, action on the body is crucially dependent on chemical structure, so that a very small change, e.g. substitution of a proton by a methyl group, can markedly alter the potency of the drug, even to the point of loss of activity. In the late 19th century and first half of the 20th century recognition of these facts by Langley, Ehrlich, Dale, Clarke and others provided the foundation for the receptor site hypothesis of drug action. According to these early ideas the drug, in order to elicit its effect, had to first combine with a specific ,target molecule' on either the cell surface or an intracellular organelle. It was soon realized that the ,right' chemical structure was required for drug,target site interaction (and the subsequent pharmacological response). In addition, from this requirement, for specificity of chemical structure requirement, developed not only the modern science of pharmacology but also that of toxicology. In relation to drug actions on microbes and parasites, for example, the early work of Ehrlich led to the introduction of molecules selectively toxic for them and relatively safe for the animal host. In the whole animal drugs may act on many target molecules in many tissues. These actions may lead to primary responses which, in turn, may induce secondary responses, that may either enhance or diminish the primary response. Therefore, it is common to investigate drug pharmacodynamics (PDs) in the first instance at molecular, cellular and tissue levels in vitro, so that the primary effects can be better understood without interference from the complexities involved in whole animal studies. When a drug, hormone or neurotransmitter combines with a target molecule, it is described as a ligand. Ligands are classified into two groups, agonists (which initiate a chain of reactions leading, usually via the release or formation of secondary messengers, to the response) and antagonists (which fail to initiate the transduction pathways but nevertheless compete with agonists for occupancy of receptor sites and thereby inhibit their actions). The parameters which characterize drug receptor interaction are affinity, efficacy, potency and sensitivity, each of which can be elucidated quantitatively for a particular drug acting on a particular receptor in a particular tissue. The most fundamental objective of PDs is to use the derived numerical values for these parameters to classify and sub-classify receptors and to compare and classify drugs on the basis of their affinity, efficacy, potency and sensitivity. This review introduces and summarizes the principles of PDs and illustrates them with examples drawn from both basic and veterinary pharmacology. Drugs acting on adrenoceptors and cardiovascular, non-steroidal anti-inflammatory and antimicrobial drugs are considered briefly to provide a foundation for subsequent reviews in this issue which deal with pharmacokinetic (PK),PD modelling and integration of these drug classes. Drug action on receptors has many features in common with enzyme kinetics and gas adsorption onto surfaces, as defined by Michaelis,Menten and Langmuir absorption equations, respectively. These and other derived equations are outlined in this review. There is, however, no single theory which adequately explains all aspects of drug,receptor interaction. The early ,occupation' and ,rate' theories each explain some, but not all, experimental observations. From these basic theories the operational model and the two-state theory have been developed. For a discussion of more advanced theories see Kenakin (1997). [source] Issues and opportunities in accelerator mass spectrometry for stable isotopesMASS SPECTROMETRY REVIEWS, Issue 5 2008Sam Matteson Abstract Accelerator mass spectrometry (AMS) has developed in the last 30 years many notable applications to the spectrometry of radioisotopes, particularly in radiocarbon dating. The instrumentation science of trace element AMS (TEAMS) that analyzes stable isotopes, also called Accelerator SIMS or MegaSIMS, while unique in many features, has also shared in many of these significant advances and has pushed TEAMS sensitivity to concentration levels surpassing many competing mass spectroscopic technologies. This review examines recent instrumentation developments, the capabilities of the new instrumentation and discernable trends for future development. © 2008 Wiley Periodicals, Inc., Mass Spec Rev 27: 470,484, 2008 [source] The Fountain Hills unique CB chondrite: Insights into thermal processes on the CB parent bodyMETEORITICS & PLANETARY SCIENCE, Issue 6 2009Dante S. LAURETTA This meteorite is closely related to the CBa class. Mineral compositions and O-isotopic ratios are indistinguishable from other members of this group. However, many features of Fountain Hills are distinct from the other CB chondrites. Fountain Hills contains 23 volume percent metal, significantly lower than other members of this class. In addition, Fountain Hills contains porphyritic chondrules, which are extremely rare in other CBa chondrites. Fountain Hills does not appear to have experienced the extensive shock seen in other CB chondrites. The chondrule textures and lack of fine-grained matrix suggests that Fountain Hills formed in a dust-poor region of the early solar system by melting of solid precursors. Refractory siderophiles and lithophile elements are present in near-CI abundances (within a factor of two, related to the enhancement of metal). Moderately volatile and highly volatile elements are significantly depleted in Fountain Hills. The abundances of refractory siderophile trace elements in metal grains are consistent with condensation from a gas that is reduced relative to solar composition and at relatively high pressures (10,3bars). Fountain Hills experienced significant thermal metamorphism on its parent asteroid. Combining results from the chemical gradients in an isolated spinel grain with olivine-spinel geothermometry suggests a peak temperature of metamorphism between 535 °C and 878 °C, similar to type-4 ordinary chondrites. [source] An explanation for the soft X-ray excess in active galactic nucleiMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2006J. Crummy ABSTRACT We present a large sample of type 1 active galactic nuclei (AGN) spectra taken with XMM,Newton, and fit them with both the conventional model (a power law and blackbody) and the relativistically blurred photoionized disc reflection model of Ross & Fabian. We find that the disc reflection model is a better fit. The disc reflection model successfully reproduces the continuum shape, including the soft excess, of all the sources. The model also reproduces many features that would conventionally be interpreted as absorption edges. We are able to use the model to infer the properties of the sources, specifically that the majority of black holes in the sample are strongly rotating, and that there is a deficit in sources with an inclination >70°. We conclude that the disc reflection model is an important tool in the study of AGN X-ray spectra. [source] Enterochromaffin cell hyperplasia and decreased serotonin transporter in a mouse model of postinfectious bowel dysfunctionNEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2005J. Wheatcroft Abstract, Patients with postinfective irritable bowel syndrome and Trichinella spiralis -infected mice share many features including visceral hypersensitivity and disordered motility. We assessed enterochromaffin (EC) numbers and serotonin transporter (SERT) using National Institute of Health (NIH) female mice studied for up to 56 days post- T. spiralis infection. The effects of steroid treatment and the T-cell dependence of the observed responses were assessed by infection of hydrocortisone-treated or T-cell receptor knock out [TCR (,×,) KO] animals. Enterochromaffin cell density in uninfected animals increased from duodenum 10.0 cells mm,2 (5.9,41.0) to colon 61.8. (46.3,162) cells mm,2P < 0.0001. Infection increased duodenal and jejunal counts which rose to 37.3 (22,57.7) cells mm,2 and 50.6 (7,110.8) cells mm,2, respectively, at day 14. Infection significantly reduced jejunal SERT expression, with luminance values falling from 61.0 (45.1,98.3) to a nadir of 11.6 (0,36.0) units at day 9, P < 0.001. Specific deficiencies in all T cells reduced EC hyperplasia and abrogated infection-induced mastocytosis. Thus infection induced inflammation increases EC numbers, as has been reported in PI-IBS, and reduces SERT. This may increase mucosal 5HT availability and contribute to the clinical presentation of PI-IBS. [source] Political Economy of Economic System Change in the Age of Neoliberalism: A Comparative Study of Germany and KoreaPACIFIC FOCUS, Issue 2 2003Young-Tae Jung This paper explores the plausibility of the neoliberal convergence theory, by exploring recent developments in the German and Korean economies. These two countries are the focus of this paper largely because their original economic systems had many features which contrasted with and were distinctive from the Anglo-American economic system; however, it appears that they have now moved toward the Anglo-American system. It will be argued that the neoliberal convergence theory is too simplistic and, therefore, misleading for both theoretical and empirical reasons. Rather, the reality is that different countries and institutions undergo different degrees of change toward the neoliberal model of political economic organization largely due to distinctive characteristics of prior established institutions-more precisely, due to different configurations of socio-political forces. It will be suggested that there may be two alternative development strategies open to the two countries in question for the future. One is that they may have to transform their underlying cultural factors and their ,superstructures'- i.e., political institutions and practices-if an Anglo-American economic system is really recognized as the best for them. The other is that they may have to modify the Anglo-American system to make it more suitable for their societies if the latter is not really the best, but just one of many best, economic systems. [source] High-resolution extracted ion chromatography, a new tool for metabolomics and lipidomics using a second-generation orbitrap mass spectrometerRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 10 2009Albert Koulman Most analytical methods in metabolomics are based on one of two strategies. The first strategy is aimed at specifically analysing a limited number of known metabolites or compound classes. Alternatively, an unbiased approach can be used for profiling as many features as possible in a given metabolome without prior knowledge of the identity of these features. Using high-resolution mass spectrometry with instruments capable of measuring m/z ratios with sufficiently low mass measurement uncertainties and simultaneous high scan speeds, it is possible to combine these two strategies, allowing unbiased profiling of biological samples and targeted analysis of specific compounds at the same time without compromises. Such high mass accuracy and mass resolving power reduces the number of candidate metabolites occupying the same retention time and m/z ratio space to a minimum. In this study, we demonstrate how targeted analysis of phospholipids as well as unbiased profiling is achievable using a benchtop orbitrap instrument after high-speed reversed-phase chromatography. The ability to apply both strategies in one experiment is an important step forward in comprehensive analysis of the metabolome. Copyright © 2009 John Wiley & Sons, Ltd. [source] The Development of the Epicardium in the Sturgeon Acipenser naccariiTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 10 2009José M. Icardo Abstract This article reports on the development of the epicardium in alevins of the sturgeon Acipenser naccarii, aged 4,25 days post-hatching (dph). Epicardial development starts at 4 dph with formation of the proepicardium (PE) that arises as a bilateral structure at the boundary between the sinus venosus and the duct of Cuvier. The PE later becomes a midline organ arising from the wall of the sinus venosus and ending at the junction between the liver, the sinus venosus and the transverse septum. This relative displacement appears related to venous reorganization at the caudal pole of the heart. The mode and time of epicardium formation is different in the various heart chambers. The conus epicardium develops through migration of a cohesive epithelium from the PE villi, and is completed through bleb-like aggregates detached from the PE. The ventricular epicardium develops a little later, and mostly through bleb-like aggregates. The bulbus epicardium appears to derive from the mesothelium located at the junction between the outflow tract and the pericardial cavity. Strikingly, formation of the epicardium of the atrium and the sinus venosus is a very late event occurring after the third month of development. Associated to the PE, a sino-ventricular ligament develops as a permanent connection. This ligament contains venous vessels that communicate the subepicardial coronary plexus and the sinus venosus, and carries part of the heart innervation. The development of the sturgeon epicardium shares many features with that of other vertebrate groups. This speaks in favour of conservative mechanisms across the evolutionary scale. Anat Rec, 2009. © 2009 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||