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Functional Systems (functional + system)
Selected AbstractsNonuniform video coding by means of multifoveal geometriesINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 1 2002J.A. Rodríguez This paper presents a control mechanism for video transmission that relies on transmitting nonuniform resolution images depending on the delay of the communication channel. These images are built in an active way to keep the areas of interest of the image at the highest resolution available. In order to shift the areas of high resolution over the image and to achieve a data structure that is easy to process by using conventional algorithms, a shifted foveal multiresolution geometry of adaptive size is used. If delays are too high, the resolution areas of the image can be transmitted at different rates. A functional system has been developed for corridor surveillance with static cameras. Tests with real video images have proven that the method allows an almost constant rate of images per second as long as the channel is not collapsed. A new method for determining the areas of interest is also proposed, based on hierarchical object tracking by means of adaptive stabilization of pyramidal structures. © 2002 John Wiley & Sons, Inc. Int J Imaging Syst Technol 12, 27,34, 2002 [source] The human premotor oculomotor brainstem system , can it help to understand oculomotor symptoms in Huntington's disease?NEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 1 2009U. Rüb Recent progress in oculomotor research has enabled new insights into the functional neuroanatomy of the human premotor oculomotor brainstem network. In the present review, we provide an overview of its functional neuroanatomy and summarize the broad range of oculomotor dysfunctions that may occur in Huntington's disease (HD) patients. Although some of these oculomotor symptoms point to an involvement of the premotor oculomotor brainstem network in HD, no systematic analysis of this functional system has yet been performed in brains of HD patients. Therefore, its exact contribution to oculomotor symptoms in HD remains unclear. A possible strategy to clarify this issue is the use of unconventional 100-µm-thick serial tissue sections stained for Nissl substance and lipofuscin pigment (Nissl-pigment stain according to Braak). This technique makes it possible to identify the known nuclei of the premotor oculomotor brainstem network and to study their possible involvement in the neurodegenerative process. Studies applying this morphological approach and using the current knowledge regarding the functional neuroanatomy of this human premotor oculomotor brainstem network will help to elucidate the anatomical basis of the large spectrum of oculomotor dysfunctions that are observed in HD patients. This knowledge may aid clinicians in the diagnosis and monitoring of the disease. [source] Waving the Flag: National Symbolism, Social Identity, and Political Engagement*POLITICAL PSYCHOLOGY, Issue 3 2007Robert T. Schatz This research examined the psychological underpinnings of concern for national symbols and ritualistic-ceremonial activities or "symbolic involvement." We propose and test a distinction between symbolic and "instrumental" involvement or concern for the functionality of national institutions and their capability to provide instrumental benefits to citizens. Items comprising the two constructs were found to be empirically distinct, evidenced by statistically reliable and orthogonal dimensions in exploratory factor analysis. Moreover, evidence based on divergent patterns of relations with various forms of national membership indicates that symbolic and instrumental involvement are rooted in distinct motivational concerns related to identity expression and object appraisal, respectively. These findings suggest that national symbolism evokes a psychological attachment to the nation as an abstracted social entity, but not as a concrete functional system. [source] 3221: Pathophysiology of dry eye syndromeACTA OPHTHALMOLOGICA, Issue 2010J HORWATH-WINTER Dry eye or dysfunctional tear syndrome is a highly prevalent disease worldwide. It is related to a pathological condition of anyone of the parts of the "ocular surface system" that involves the cornea, conjunctiva, lacrimal gland, accessory lacrimal glands, nasolacrimal duct and the lids with the meibomian glands. These are linked as a functional system by innervation, the endocrine and immune system. Endogenous or exogenous caused alterations in one or several components of the ocular surface system or its secretions result in changes of the tear film or ocular surface provoking inflammation. With time, inflammatory reactions may lead to corneal neuropathy compromising the reflex response of the lacrimal glands. Additionally a self-perpetuating vicious circle with loss of function and damage can be initiated also by an immune-modulated inflammation. [source] Neurotoxicity of methylenedioxyamphetamines (MDMA; ecstasy) in humans: how strong is the evidence for persistent brain damage?ADDICTION, Issue 3 2006E. Gouzoulis-Mayfrank ABSTRACT Background The popular dance drug ecstasy (3,4-methylenedioxymethamphetamine: MDMA and some analogues) causes selective and persistent neurotoxic damage of central serotonergic neurones in laboratory animals. Serotonin plays a role in numerous functional systems in the central nervous system (CNS). Consequently, various abnormalities including psychiatric, vegetative, neuroendocrine and cognitive disorders could be expected in humans following MDMA-induced neurotoxic brain damage. Aims In recent years, the question of ecstasy-induced neurotoxicity and possible functional sequelae has been addressed in several studies with drug users. The aim of this paper was to review this literature and weigh the strength of the evidence for persistent brain damage in ecstasy users. Methods We used Medline to view all available publications on ,ecstasy' or ,MDMA'. All available studies dealing with ecstasy users entered this analysis. Findings and conclusions Despite large methodological problems the bulk of evidence suggests residual alterations of serotonergic transmission in MDMA users, although at least partial restitution may occur after long-term abstinence. However, functional sequelae may persist even after longer periods of abstinence. To date, the most consistent findings associate subtle cognitive, particularly memory, impairments with heavy ecstasy use. However, the evidence cannot be considered definite and the issues of possible pre-existing traits or the effects of polydrug use are not resolved. Recommendations Questions about the neurotoxic effects of ecstasy on the brain remain highly topical in light of its popularity among young people. More longitudinal and prospective studies are clearly needed in order to obtain a better understanding of the possible long-term sequelae of ecstasy use in humans. [source] Reward-guided learning beyond dopamine in the nucleus accumbens: the integrative functions of cortico-basal ganglia networksEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2008Henry H. Yin Abstract Here we challenge the view that reward-guided learning is solely controlled by the mesoaccumbens pathway arising from dopaminergic neurons in the ventral tegmental area and projecting to the nucleus accumbens. This widely accepted view assumes that reward is a monolithic concept, but recent work has suggested otherwise. It now appears that, in reward-guided learning, the functions of ventral and dorsal striata, and the cortico-basal ganglia circuitry associated with them, can be dissociated. Whereas the nucleus accumbens is necessary for the acquisition and expression of certain appetitive Pavlovian responses and contributes to the motivational control of instrumental performance, the dorsal striatum is necessary for the acquisition and expression of instrumental actions. Such findings suggest the existence of multiple independent yet interacting functional systems that are implemented in iterating and hierarchically organized cortico-basal ganglia networks engaged in appetitive behaviors ranging from Pavlovian approach responses to goal-directed instrumental actions controlled by action-outcome contingencies. [source] MICRO- AND MACROEVOLUTIONARY DECOUPLING OF CICHLID JAWS: A TEST OF LIEM'S KEY INNOVATION HYPOTHESISEVOLUTION, Issue 10 2006C. D. Hulsey Abstract The extent to which elements of functional systems can change independently (modularity) likely influences the diversification of lineages. Major innovations in organismal design, like the pharyngeal jaw in cichlid fishes, may be key to a group's success when they relax constraints on diversification by increasing phenotypic modularity. In cichlid fishes, pharyngeal jaw modifications that enhanced the ability to breakdown prey may have freed their oral jaws from serving their ancestral dual role as a site of both prey capture and prey processing. This functional decoupling that allowed the oral jaws to become devoted solely to prey capture has been hypothesized to have permitted the two sets of cichlid jaws to evolve independently. We tested the hypothesis that oral and pharyngeal jaw mechanics are evolutionarily decoupled both within and among Neotropical Heroine cichlids. In the trophically polymorphic species Herichthys minckleyi, molariforms that exhibit enlarged molarlike pharyngeal jaw teeth were found to have approximately 400% greater lower jaw mass compared to H. minckleyi with the alternative papilliform pharyngeal morphology. However, oral jaw gape, lower jaw velocity ratios, anterior jaw linkage mechanics, and jaw protrusion did not differ between the morphotypes. In 40 other Heroine species, there was a weak correlation between oral jaw mechanics and pharyngeal jaw mass when phylogenetic history was ignored. Yet, after expansion of the cytochrome b phylogeny for Heroines, change in oral jaw mechanics was found to be independent of evolutionary change in pharyngeal jaw mass based on independent contrasts. Evolutionary decoupling of oral and pharyngeal jaw mechanics has likely played a critical role in the unparalleled trophic diversification of cichlid fishes. [source] Brain Imaging in Migraine ResearchHEADACHE, Issue 9 2010David Borsook MD Understanding the pathophysiology and pharmacology of migraine has been driven by astute clinical observations, elegant experimental medicine studies, and importantly by studying highly effective anti-migraine agents in the laboratory and the clinic. Significant progress has been made in the use of functional brain imaging to compliment observational studies of migraine phenotypes by highlighting pathways within the brain that may be involved in predisposition to migraine, modulating migraine pain or that could be sensitive to pharmacological or behavioral therapeutic intervention (Fig. 1). In drug discovery, molecular imaging approaches compliment functional neuroimaging by visualizing migraine drug targets within the brain. Molecular imaging enables the selection and evaluation of drug candidates by confirming that they engage their targets sufficiently at well tolerated doses to test our therapeutic hypotheses. Figure 1.,. Imaging and defining the migraine brain disease state: from anatomy to chemical entities (targets) to functional systems (function and pathways) (from Borsook et al31 with permission, Nature Publishing Group). Migraine is a progressive disorder. Developing our knowledge of where drugs act in the brain and of how the brain is altered in both episodic migraine (interictal state and ictal state) and chronic migraine are important steps to understanding why there is such differential responsiveness to therapeutics among migraine patients and to improving how they are evaluated and treated. [source] Efficient Visible-Light Emission from Dye-Doped Mesostructured OrganosilicaADVANCED MATERIALS, Issue 47 2009Norihiro Mizoshita Efficient and color-tunable visible-light emission is achieved in fluorescent dye-doped oligo(phenylenevinylene),silica mesostructured films through fluorescence resonance energy transfer from a blue-light-emitting organosilica to a yellow-light-emitting dye (see figure). Tuning of the composition realizes pseudo white-light emission with a quantum yield of 67%. Utilization of both walls and pores of the mesostructured organosilicas is effective to construct highly functional systems. [source] Quantifying temporal bone morphology of great apes and humans: an approach using geometric morphometricsJOURNAL OF ANATOMY, Issue 6 2002Charles A. Lockwood Abstract The hominid temporal bone offers a complex array of morphology that is linked to several different functional systems. Its frequent preservation in the fossil record gives the temporal bone added significance in the study of human evolution, but its morphology has proven difficult to quantify. In this study we use techniques of 3D geometric morphometrics to quantify differences among humans and great apes and discuss the results in a phylogenetic context. Twenty-three landmarks on the ectocranial surface of the temporal bone provide a high level of anatomical detail. Generalized Procrustes analysis (GPA) is used to register (adjust for position, orientation and scale) landmark data from 405 adults representing Homo, Pan, Gorilla and Pongo. Principal components analysis of residuals from the GPA shows that the major source of variation is between humans and apes. Human characteristics such as a coronally orientated petrous axis, a deep mandibular fossa, a projecting mastoid process, and reduced lateral extension of the tympanic element strongly impact the analysis. In phenetic cluster analyses, gorillas and orangutans group together with respect to chimpanzees, and all apes group together with respect to humans. Thus, the analysis contradicts depictions of African apes as a single morphotype. Gorillas and orangutans lack the extensive preglenoid surface of chimpanzees, and their mastoid processes are less medially inflected. These and other characters shared by gorillas and orangutans are probably primitive for the African hominid clade. [source] Novel identification of peripheral dopaminergic D2 receptor in male germ cells,JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2007Carola Otth Abstract Dopamine is a recognized modulator in the central nervous system (CNS) and peripheral organ functions. The presence of peripheral dopamine receptors outside the CNS has suggested an intriguing interaction between the nervous system and other functional systems, such as the reproductive system. In the present study we analyzed the expression of D2R receptors in rat testis, rat spermatogenic cells and spermatozoa, in different mammals. The RT-PCR analysis of rat testis mRNA showed specific bands corresponding to the two dopamine receptor D2R (L and S) isoforms previously described in the brain. Using Western blot analysis, we confirmed that the protein is present in rat testis, isolated spermatogenic cells and also in spermatozoa of a range of different mammals, such as rat, mouse, bull, and human. The immunohistochemistry analysis of rat adult testis showed that the receptor was expressed in all germ cells (pre- and post-meiotic phase) of the tubule with staining predominant in spermatogonia. Confocal analysis by indirect immunofluorescence revealed that in non-capacitated spermatozoa of rat, mouse, bull, and human, D2R is mainly localized in the flagellum, and is also observed in the acrosomal region of the sperm head (except in human spermatozoa). Our findings demonstrate that the two D2 receptor isoforms are expressed in rat testis and that the receptor protein is present in different mammalian spermatozoa. The presence of D2R receptors in male germ cells implies new and unsuspected roles for dopamine signaling in testicular and sperm physiology. J. Cell. Biochem. 100: 141,150, 2007. © 2006 Wiley-Liss, Inc. [source] Disintegration, recognition, and violence: A theoretical perspectiveNEW DIRECTIONS FOR YOUTH DEVELOPMENT, Issue 119 2008Wilhelm Heitmeyer The literature explaining deviance, criminality, or violence offers a broad spectrum of approaches in criminology and sociology. Mostly the theories focus on specific levels of explanation like the macrolevel (for example, strain theories) or the microlevel (for example, self-control theory). This article presents a relatively new theoretical approach combining different levels and focusing on three dimensions associated with specific kinds of recognition: social-structural, institutional, and socioemotional. The social-structural dimension refers to access to the functional systems of society and the accompanying recognition of position, status, and so on. The institutional dimension concentrates on the opportunity to participate in public affairs with the aim of getting moral recognition. The socioemotional dimension emphasizes the quantity and quality of integration in and social support from families, friends, partners, and so on, which provide emotional recognition. The underlying idea is that lack of access, participation, and belonging causes a lack of recognition. When this happens, social and individual problems increase. Thus, deviant and violent behavior can be seen as one potential reaction to a lack of recognition and as a way to gain status and recognition in a different manner (for example, with a delinquent peer group or other gang). [source] Proteomics of ischemia/reperfusion injury in rabbit myocardium reveals alterations to proteins of essential functional systemsPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 5 2005Melanie Y. White Abstract Brief periods of myocardial ischemia prior to timely reperfusion result in prolonged, yet reversible, contractile dysfunction of the myocardium, or "myocardial stunning". It has been hypothesized that the delayed recovery of contractile function in stunned myocardium reflects damage to one or a few key sarcomeric proteins. However, damage to such proteins does not explain observed physiological alterations to myocardial oxygen consumption and ATP requirements observed following myocardial stunning, and therefore the impact of alterations to additional functional groups is unresolved. We utilized two-dimensional gel electrophoresis and mass spectrometry to identify changes to the protein profiles in whole cell, cytosolic- and myofilament-enriched subcellular fractions from isolated, perfused rabbit hearts following 15 min or 60 min low-flow (1 mL/min) ischemia. Comparative gel analysis revealed 53 protein spot differences (> 1.5-fold difference in visible abundance) in reperfused myocardium. The majority of changes were observed to proteins from four functional groups: (i) the sarcomere and cytoskeleton, notably myosin light chain-2 and troponin C; (ii) redox regulation, in particular several components of the NADH ubiquinone oxidoreductase complex; (iii) energy metabolism, encompassing creatine kinase; and (iv) the stress response. Protein differences appeared to be the result of isoelectric point shifts most probably resulting from chemical modifications, and molecular mass shifts resulting from proteolytic or physical fragmentation. This is consistent with our hypothesis that the time course for the onset of injury associated with myocardial stunning is too brief to be mediated by large changes to gene/protein expression, but rather that more subtle, rapid and potentially transient changes are occurring to the proteome. The physical manifestation of stunned myocardium is therefore the likely result of the summed functional impairment resulting from these multiple changes, rather than a result of damage to a single key protein. [source] | |||||||||||||