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Sample records for mediolateral functional dichotomy

  1. Structural and functional dichotomy of human midcingulate cortex.

    PubMed

    Vogt, Brent A; Berger, Gail R; Derbyshire, Stuart W G

    2003-12-01

    Anterior cingulate cortex is comprised of perigenual and midcingulate regions based on cytology, imaging and connections. Its anterior (aMCC) and posterior (pMCC) parts and transition to posterior area 23 were evaluated in six human cingulate gyri with Nissl staining and immunoreactions for neuron-specific nuclear binding protein and intermediate neurofilament proteins (NFP), and their pain and emotion functions evaluated in standard coordinates. Morphological differences included a poorly differentiated layer III with few NFP-expressing neurons in aMCC and a very dense layer Va with small and large pyramids intermingled in pMCC. The density of NFP-positive, layer Vb neurons was higher in pMCC than in aMCC. The junction of pMCC with area 23 had a dysgranular area 23d with clumps of layer IV neurons and a very dense layer Va. Each case was co-registered to standard coordinates and the regional borders identified and measured. Although both regions had overall equivalent activations during noxious cutaneous thermal stimulation, the posterior two-thirds of pMCC was relatively inactive. About 60% of fear-induced activity was in aMCC, sadness and happiness activated perigenual cortex, and neither were activated with non-emotion tasks. Thus, pain activity is coupled to fear in aMCC, while other MCC processing is not related to affect. Beyond midcingulate duality, this is the first report of a very dense layer Va for areas p24' and 23 and the features of transitional area 23d. The MCC dichotomy suggests that two circuits differentially regulate the two cingulate motor areas, and involvement of aMCC in pain and fear make it selectively vulnerable to chronic pain and stress syndromes. PMID:14656310

  2. Neural dichotomy of word concreteness: a view from functional neuroimaging.

    PubMed

    Kumar, Uttam

    2016-02-01

    Our perception about the representation and processing of concrete and abstract concepts is based on the fact that concrete words are highly imagined and remembered faster than abstract words. In order to explain the processing differences between abstract and concrete concepts, various theories have been proposed, yet there is no unanimous consensus about its neural implication. The present study investigated the processing of concrete and abstract words during an orthography judgment task (implicit semantic processing) using functional magnetic resonance imaging to validate the involvement of the neural regions. Relative to non-words, both abstract and concrete words show activation in the regions of bilateral hemisphere previously associated with semantic processing. The common areas (conjunction analyses) observed for abstract and concrete words are bilateral inferior frontal gyrus (BA 44/45), left superior parietal (BA 7), left fusiform gyrus and bilateral middle occipital. The additional areas for abstract words were noticed in bilateral superior temporal and bilateral middle temporal region, whereas no distinct region was noticed for concrete words. This suggests that words with abstract concepts recruit additional language regions in the brain. PMID:26410213

  3. The dappled nature of causes of psychiatric illness: replacing the organic-functional/hardware-software dichotomy with empirically based pluralism.

    PubMed

    Kendler, K S

    2012-04-01

    Our tendency to see the world of psychiatric illness in dichotomous and opposing terms has three major sources: the philosophy of Descartes, the state of neuropathology in late nineteenth century Europe (when disorders were divided into those with and without demonstrable pathology and labeled, respectively, organic and functional), and the influential concept of computer functionalism wherein the computer is viewed as a model for the human mind-brain system (brain=hardware, mind=software). These mutually re-enforcing dichotomies, which have had a pernicious influence on our field, make a clear prediction about how 'difference-makers' (aka causal risk factors) for psychiatric disorders should be distributed in nature. In particular, are psychiatric disorders like our laptops, which when they dysfunction, can be cleanly divided into those with software versus hardware problems? I propose 11 categories of difference-makers for psychiatric illness from molecular genetics through culture and review their distribution in schizophrenia, major depression and alcohol dependence. In no case do these distributions resemble that predicted by the organic-functional/hardware-software dichotomy. Instead, the causes of psychiatric illness are dappled, distributed widely across multiple categories. We should abandon Cartesian and computer-functionalism-based dichotomies as scientifically inadequate and an impediment to our ability to integrate the diverse information about psychiatric illness our research has produced. Empirically based pluralism provides a rigorous but dappled view of the etiology of psychiatric illness. Critically, it is based not on how we wish the world to be but how the difference-makers for psychiatric illness are in fact distributed. PMID:22230881

  4. The dappled nature of causes of psychiatric illness: replacing the organic–functional/hardware–software dichotomy with empirically based pluralism

    PubMed Central

    Kendler, KS

    2012-01-01

    Our tendency to see the world of psychiatric illness in dichotomous and opposing terms has three major sources: the philosophy of Descartes, the state of neuropathology in late nineteenth century Europe (when disorders were divided into those with and without demonstrable pathology and labeled, respectively, organic and functional), and the influential concept of computer functionalism wherein the computer is viewed as a model for the human mind–brain system (brain = hardware, mind = software). These mutually re-enforcing dichotomies, which have had a pernicious influence on our field, make a clear prediction about how ‘difference-makers’ (aka causal risk factors) for psychiatric disorders should be distributed in nature. In particular, are psychiatric disorders like our laptops, which when they dysfunction, can be cleanly divided into those with software versus hardware problems? I propose 11 categories of difference-makers for psychiatric illness from molecular genetics through culture and review their distribution in schizophrenia, major depression and alcohol dependence. In no case do these distributions resemble that predicted by the organic–functional/hardware–software dichotomy. Instead, the causes of psychiatric illness are dappled, distributed widely across multiple categories. We should abandon Cartesian and computer-functionalism-based dichotomies as scientifically inadequate and an impediment to our ability to integrate the diverse information about psychiatric illness our research has produced. Empirically based pluralism provides a rigorous but dappled view of the etiology of psychiatric illness. Critically, it is based not on how we wish the world to be but how the difference-makers for psychiatric illness are in fact distributed. PMID:22230881

  5. Evidence for two distinct stellar initial mass functions: probing for clues to the dichotomy

    SciTech Connect

    Zaritsky, Dennis; Colucci, Janet E.; Bernstein, Rebecca A.; Pessev, Peter M.

    2014-12-01

    We present new measurements of the velocity dispersions of 11 Local Group globular clusters using spatially integrated spectra, to expand our sample of clusters with precise integrated-light velocity dispersions to 29, over 4 different host galaxies. This sample allows us to further our investigation of the stellar mass function among clusters, with a particular emphasis on a search for the driver of the apparent bimodal nature of the inferred stellar initial mass function (IMF). We confirm our previous result that clusters fall into two classes. If, as we argue, this behavior reflects a variation in the stellar IMF, the cause of that variation is not clear. The variations do not correlate with formation epoch as quantified by age, metallicity quantified by [Fe/H], host galaxy, or internal structure as quantified by velocity dispersion, physical size, relaxation time, or luminosity. The stellar mass-to-light ratios, Y{sub *}, of the high and low Y{sub *} cluster populations are well-matched to those found in recent studies of early and late type galaxies, respectively.

  6. Thalamic Responses to Nociceptive-Specific Input in Humans: Functional Dichotomies and Thalamo-Cortical Connectivity.

    PubMed

    Bastuji, Hélène; Frot, Maud; Mazza, Stéphanie; Perchet, Caroline; Magnin, Michel; Garcia-Larrea, Luis

    2016-06-01

    While nociceptive cortical activation is now well characterized in humans, understanding of the nociceptive thalamus remains largely fragmentary. We used laser stimuli and intracerebral electrodes in 17 human subjects to record nociceptive-specific field responses in 4 human thalamic nuclei and a number of cortical areas. Three nuclei known to receive spinothalamic (STT) projections in primates (ventro-postero-lateral [VPL], anterior pulvinar [PuA], and central lateral [CL]) exhibited responses with similar latency, indicating their parallel activation by nociceptive afferents. Phase coherence analysis, however, revealed major differences in their functional connectivity: while VPL and PuA drove a limited set of cortical targets, CL activities were synchronized with a large network including temporal, parietal, and frontal areas. Our data suggest that STT afferents reach simultaneously a set of lateral and medial thalamic regions unconstrained by traditional nuclear borders. The broad pattern of associated cortical networks suggests that a single nociceptive volley is able to trigger the sensory, cognitive, and emotional activities that underlie the complex pain experience. The medial pulvinar, an associative nucleus devoid of STT input, exhibited delayed responses suggesting its dependence on descending cortico-thalamic projections. Its widespread cortical connectivity suggests a role in synchronizing parietal, temporal, and frontal activities, hence contributing to the access of noxious input to conscious awareness. PMID:25994963

  7. A neuromechanical strategy for mediolateral foot placement in walking humans

    PubMed Central

    Rankin, Bradford L.; Buffo, Stephanie K.

    2014-01-01

    Stability is an important concern during human walking and can limit mobility in clinical populations. Mediolateral stability can be efficiently controlled through appropriate foot placement, although the underlying neuromechanical strategy is unclear. We hypothesized that humans control mediolateral foot placement through swing leg muscle activity, basing this control on the mechanical state of the contralateral stance leg. Participants walked under Unperturbed and Perturbed conditions, in which foot placement was intermittently perturbed by moving the right leg medially or laterally during the swing phase (by ∼50–100 mm). We quantified mediolateral foot placement, electromyographic activity of frontal-plane hip muscles, and stance leg mechanical state. During Unperturbed walking, greater swing-phase gluteus medius (GM) activity was associated with more lateral foot placement. Increases in GM activity were most strongly predicted by increased mediolateral displacement between the center of mass (CoM) and the contralateral stance foot. The Perturbed walking results indicated a causal relationship between stance leg mechanics and swing-phase GM activity. Perturbations that reduced the mediolateral CoM displacement from the stance foot caused reductions in swing-phase GM activity and more medial foot placement. Conversely, increases in mediolateral CoM displacement caused increased swing-phase GM activity and more lateral foot placement. Under both Unperturbed and Perturbed conditions, humans controlled their mediolateral foot placement by modulating swing-phase muscle activity in response to the mechanical state of the contralateral leg. This strategy may be disrupted in clinical populations with a reduced ability to modulate muscle activity or sense their body's mechanical state. PMID:24790168

  8. A neuromechanical strategy for mediolateral foot placement in walking humans.

    PubMed

    Rankin, Bradford L; Buffo, Stephanie K; Dean, Jesse C

    2014-07-15

    Stability is an important concern during human walking and can limit mobility in clinical populations. Mediolateral stability can be efficiently controlled through appropriate foot placement, although the underlying neuromechanical strategy is unclear. We hypothesized that humans control mediolateral foot placement through swing leg muscle activity, basing this control on the mechanical state of the contralateral stance leg. Participants walked under Unperturbed and Perturbed conditions, in which foot placement was intermittently perturbed by moving the right leg medially or laterally during the swing phase (by ∼50-100 mm). We quantified mediolateral foot placement, electromyographic activity of frontal-plane hip muscles, and stance leg mechanical state. During Unperturbed walking, greater swing-phase gluteus medius (GM) activity was associated with more lateral foot placement. Increases in GM activity were most strongly predicted by increased mediolateral displacement between the center of mass (CoM) and the contralateral stance foot. The Perturbed walking results indicated a causal relationship between stance leg mechanics and swing-phase GM activity. Perturbations that reduced the mediolateral CoM displacement from the stance foot caused reductions in swing-phase GM activity and more medial foot placement. Conversely, increases in mediolateral CoM displacement caused increased swing-phase GM activity and more lateral foot placement. Under both Unperturbed and Perturbed conditions, humans controlled their mediolateral foot placement by modulating swing-phase muscle activity in response to the mechanical state of the contralateral leg. This strategy may be disrupted in clinical populations with a reduced ability to modulate muscle activity or sense their body's mechanical state. PMID:24790168

  9. On Mishan's Rent Dichotomy.

    ERIC Educational Resources Information Center

    Piron, Robert

    1990-01-01

    States that many economics textbooks define economic rent in 1 of the 2 ways discussed 30 years ago by E. J. Mishan. Contends that the 2 definitions are not substantially different, rendering the dichotomy invalid. Examines 15 microeconomics textbooks to determine whether they validate Mishan's categories of rent definitions. (DB)

  10. Functional dichotomy of Vδ2 γδ T cells in chronic hepatitis C virus infections: role in cytotoxicity but not for IFN-γ production.

    PubMed

    Yin, Wenwei; Tong, Shiwen; Zhang, Qiongfang; Shao, Jianying; Liu, Qian; Peng, Hong; Hu, Huaidong; Peng, Mingli; Hu, Peng; Ren, Hong; Tian, Zhigang; Zhang, Dazhi

    2016-01-01

    Vδ2 γδ (Vδ2) T cells, a major human γδ T cell subset, exhibit broad anti-tumor and anti-infective activity; however, their precise role in chronic hepatitis C virus (HCV) infections remains unclear. In this study, we analyzed the phenotype and function of Vδ2 T cells in 43 HCV-infected patients compared to 39 healthy controls (HCs). Vδ2 T cells from HCV-infected patients were activated and differentiated into effector cells. Vδ2 T cells in patients expressed significantly higher levels of natural killer (NK) cell markers CD56 and CD16 than in HCs, acquiring cytotoxic NK-like phenotype. The Vδ2 T cell phenotype was associated with increased cytolytic effector molecules expression in HCV-infected patients with elevated serum ALT levels. Surprisingly, Vδ2 T cells in patients had a markedly impaired capacity to produce IFN-γ. Further in vitro and in vivo analysis showed that interferon-α, which was induced during HCV infection, caused Vδ2 T cell function bias toward cytotoxicity. These results suggest a functional dichotomy for Vδ2 T cells in chronic HCV infections: a role in cytotoxicity but not for IFN-γ production, which may contribute to both the liver inflammation and HCV persistence. PMID:27192960

  11. Functional dichotomy of Vδ2 γδ T cells in chronic hepatitis C virus infections: role in cytotoxicity but not for IFN-γ production

    PubMed Central

    Yin, Wenwei; Tong, Shiwen; Zhang, Qiongfang; shao, Jianying; Liu, Qian; Peng, Hong; Hu, Huaidong; Peng, Mingli; Hu, Peng; Ren, Hong; Tian, Zhigang; Zhang, Dazhi

    2016-01-01

    Vδ2 γδ (Vδ2) T cells, a major human γδ T cell subset, exhibit broad anti-tumor and anti-infective activity; however, their precise role in chronic hepatitis C virus (HCV) infections remains unclear. In this study, we analyzed the phenotype and function of Vδ2 T cells in 43 HCV-infected patients compared to 39 healthy controls (HCs). Vδ2 T cells from HCV-infected patients were activated and differentiated into effector cells. Vδ2 T cells in patients expressed significantly higher levels of natural killer (NK) cell markers CD56 and CD16 than in HCs, acquiring cytotoxic NK-like phenotype. The Vδ2 T cell phenotype was associated with increased cytolytic effector molecules expression in HCV-infected patients with elevated serum ALT levels. Surprisingly, Vδ2 T cells in patients had a markedly impaired capacity to produce IFN-γ. Further in vitro and in vivo analysis showed that interferon-α, which was induced during HCV infection, caused Vδ2 T cell function bias toward cytotoxicity. These results suggest a functional dichotomy for Vδ2 T cells in chronic HCV infections: a role in cytotoxicity but not for IFN-γ production, which may contribute to both the liver inflammation and HCV persistence. PMID:27192960

  12. Functional dichotomy in the 16S rRNA (m1A1408) methyltransferase family and control of catalytic activity via a novel tryptophan mediated loop reorganization

    PubMed Central

    Witek, Marta A.; Conn, Graeme L.

    2016-01-01

    Methylation of the bacterial small ribosomal subunit (16S) rRNA on the N1 position of A1408 confers exceptionally high-level resistance to a broad spectrum of aminoglycoside antibiotics. Here, we present a detailed structural and functional analysis of the Catenulisporales acidiphilia 16S rRNA (m1A1408) methyltransferase (‘CacKam’). The apo CacKam structure closely resembles other m1A1408 methyltransferases within its conserved SAM-binding fold but the region linking core β strands 6 and 7 (the ‘β6/7 linker’) has a unique, extended structure that partially occludes the putative 16S rRNA binding surface, and sequesters the conserved and functionally critical W203 outside of the CacKam active site. Substitution of conserved residues in the SAM binding pocket reveals a functional dichotomy in the 16S rRNA (m1A1408) methyltransferase family, with two apparently distinct molecular mechanisms coupling cosubstrate/ substrate binding to catalytic activity. Our results additionally suggest that CacKam exploits the W203-mediated remodeling of the β6/7 linker as a novel mechanism to control 30S substrate recognition and enzymatic turnover. PMID:26609134

  13. Antagonistic Gene Activities Determine the Formation of Pattern Elements along the Mediolateral Axis of the Arabidopsis Fruit

    PubMed Central

    González-Reig, Santiago; Ripoll, Juan José; Vera, Antonio; Yanofsky, Martin F.; Martínez-Laborda, Antonio

    2012-01-01

    The Arabidopsis fruit mainly consists of a mature ovary that shows three well defined territories that are pattern elements along the mediolateral axis: the replum, located at the medial plane of the flower, and the valve and the valve margin, both of lateral nature. JAG/FIL activity, which includes the combined functions of JAGGED (JAG), FILAMENTOUS FLOWER (FIL), and YABBY3 (YAB3), contributes to the formation of the two lateral pattern elements, whereas the cooperating genes BREVIPEDICELLUS (BP) and REPLUMLESS (RPL) promote replum development. A recent model to explain pattern formation along the mediolateral axis hypothesizes that JAG/FIL activity and BP/RPL function as antagonistic lateral and medial factors, respectively, which tend to repress each other. In this work, we demonstrate the existence of mutual exclusion mechanisms between both kinds of factors, and how this determines the formation and size of the three territories. Medial factors autonomously constrain lateral factors so that they only express outside the replum, and lateral factors negatively regulate the medially expressed BP gene in a non-autonomous fashion to ensure correct replum development. We also have found that ASYMMETRIC LEAVES1 (AS1), previously shown to repress BP both in leaves and ovaries, collaborates with JAG/FIL activity, preventing its repression by BP and showing synergistic interactions with JAG/FIL activity genes. Therefore AS gene function (the function of the interacting genes AS1 and AS2) has been incorporated in the model as a new lateral factor. Our model of antagonistic factors provides explanation for mutant fruit phenotypes in Arabidopsis and also may help to understand natural variation of fruit shape in Brassicaceae and other species, since subtle changes in gene expression may cause conspicuous changes in the size of the different tissue types. PMID:23133401

  14. The influence of a medio-lateral unstable sole on invertor and evertor activation while descending stairs

    PubMed Central

    Yang, Ki-sik; Park, Kyungyeon; Choi, Bo-ram

    2016-01-01

    [Purpose] This study examined the effects of a medio-lateral unstable sole on invertor and evertor activation while descending stairs. [Subjects and Methods] The subjects were 30 university students with no history of ankle sprain. They descended stairs while wearing the medio-lateral unstable sole or with bare feet. Electromyography was used to record the activity of the tibialis anterior and peroneus longus and brevis muscles and paired t-tests were used to assess statistical significance. [Results] The medio-lateral unstable sole group showed increased tibialis anterior and peroneus longus and brevis muscle activation compared to the barefoot group. [Conclusion] Medio-lateral unstable sole can be used with exercises to prevent further ankle damage by activating both the inversion and eversion muscles.

  15. Effects of narrow base gait on mediolateral balance control in young and older adults.

    PubMed

    Arvin, Mina; Mazaheri, Masood; Hoozemans, Marco J M; Pijnappels, Mirjam; Burger, Bart J; Verschueren, Sabine M P; van Dieën, Jaap H

    2016-05-01

    The aim of this study was to examine the effect of narrowing step width on mediolateral (ML) center of mass (COM) kinematics and margin of stability (MOS) in young and older adults. Fourteen young and 18 healthy older adults were asked to walk on a treadmill at preferred speed, stepping on projected lines at their predetermined preferred step width (PSW) and at a 50% narrowed step width (NSW). Linear trunk accelerations were recorded by an inertial sensor, attached at the level of the lumbar spine and foot placement was determined from force sensors in the treadmill. Mediolateral peak-to-peak COM displacement, COM velocity and MOS within strides were estimated. Mean ML-COM displacement and velocity, which were significantly higher in older compared to young adults, were significantly reduced in the NSW condition while the variability of ML-COM velocity was increased in the NSW condition. A significant interaction effect of step width and age was found for ML-COM velocity, showing larger decreases in older adults in the NSW condition. Walking with NSW reduced the ML-MOS significantly in both groups while it was smaller in the older group. Although reductions of ML-COM displacement and velocity may occur as direct mechanical effects of reduced step width, the larger variability of ML COM velocity in the older adults suggests active control of ML COM movements in response to the reduced base of support. Given the effects on MOS, narrowing step width might challenge ML-balance control and lead to less robust gait especially in older adults. PMID:27018156

  16. Challenging the Traditional/Communicative Dichotomy

    ERIC Educational Resources Information Center

    Beaumont, Mike; Chang, Kyung-Suk

    2011-01-01

    The primary aim of this paper is to explore a common dichotomy that characterizes debate about what has come to be termed "appropriate methodology". It is that between "traditional" and "communicative" approaches to language teaching, a distinction that persists despite arguments by some that the term "communicative" should be superseded or even…

  17. Reconceptualizing the Native/Nonnative Speaker Dichotomy

    ERIC Educational Resources Information Center

    Faez, Farahnaz

    2011-01-01

    This study reconceptualizes the native/nonnative dichotomy and provides a powerful lens to examine linguistic identities. In a study of 25 linguistically diverse teacher candidates in Canada, the respondents' native and nonnative self-ascription and self-assessed level of proficiency was juxtaposed with the judgment of their instructors. This…

  18. Algebraic dichotomies with an application to the stability of Riemann solutions of conservation laws

    NASA Astrophysics Data System (ADS)

    Lin, Xiao-Biao

    Recently, there has been some interest on the stability of waves where the functions involved grow or decay at an algebraic rate |. In this paper we define the so-called algebraic dichotomy that may aid in treating such problems. We discuss the basic properties of the algebraic dichotomy, methods of detecting it, and calculating the power of the weight function. We present several examples: (1) The Bessel equation. (2) The n-degree Fisher type equation. (3) Hyperbolic conservation laws in similarity coordinates. (4) A system of conservation laws with a Dafermos type viscous regularization. We show that the linearized system generates an analytic semigroup in the space of algebraic decay functions. This example motivates our work on algebraic dichotomies.

  19. Nervous system development in cephalopods: How egg yolk-richness modifies the topology of the mediolateral patterning system.

    PubMed

    Buresi, A; Andouche, A; Navet, S; Bassaglia, Y; Bonnaud-Ponticelli, L; Baratte, S

    2016-07-01

    Cephalopods possess the most complex centralized nervous system among molluscs and the molecular determinants of its development have only begun to be explored. To better understand how evolved their brain and body axes, we studied Sepia officinalis embryos and investigated the expression patterns of neural regionalization genes involved in the mediolateral patterning of the neuroectoderm in model species. SoxB1 expression reveals that the embryonic neuroectoderm is made of several distinct territories that constitute a large part of the animal pole disc. Concentric nkx2.1, pax6/gsx, and pax3/7/msx/pax2/5/8 positive domains subdivide this neuroectoderm. Looking from dorsal to ventral sides, the sequence of these expressions is reminiscent of the mediolateral subdivision in model species, which provides good evidence for "mediolateral patterning" conservation in cephalopods. A specific feature of cephalopod development, however, includes an unconventional orientation to this mediolateral sequence: median markers (like nkx2.1) are unexpectedly expressed at the periphery of the cuttlefish embryo and lateral markers (like Pax3/7) are expressed centrally. As the egg is rich with yolk, the lips of the blastopore (that classically organizes the neural midline) remain unclosed at the lateral side of the animal pole until late stages of organogenesis, therefore reversing the whole embryo topology. These findings confirm - by means of molecular tools - the location of both ventral and dorsal poles in cephalopod embryos. PMID:27151209

  20. Can explicit visual feedback of postural sway efface the effects of sensory manipulations on mediolateral balance performance?

    PubMed

    Cofré Lizama, L Eduardo; Pijnappels, Mirjam; Reeves, N Peter; Verschueren, Sabine M P; van Dieën, Jaap H

    2016-02-01

    Explicit visual feedback on postural sway is often used in balance assessment and training. However, up-weighting of visual information may mask impairments of other sensory systems. We therefore aimed to determine whether the effects of somatosensory, vestibular, and proprioceptive manipulations on mediolateral balance are reduced by explicit visual feedback on mediolateral sway of the body center of mass and by the presence of visual information. We manipulated sensory inputs of the somatosensory system by transcutaneous electric nerve stimulation on the feet soles (TENS) of the vestibular system by galvanic vestibular stimulation (GVS) and of the proprioceptive system by muscle-tendon vibration (VMS) of hip abductors. The effects of these manipulations on mediolateral sway were compared with a control condition without manipulation under three visual conditions: explicit feedback of sway of the body center of mass (FB), eyes open (EO), and eyes closed (EC). Mediolateral sway was quantified as the sum of energies in the power spectrum and as the energy at the dominant frequencies in each of the manipulation signals. Repeated-measures ANOVAs were used to test effects of each of the sensory manipulations, of visual conditions and their interaction. Overall, sensory manipulations increased body sway compared with the control conditions. Absence of normal visual information had no effect on sway, while explicit feedback reduced sway. Furthermore, interactions of visual information and sensory manipulation were found at specific dominant frequencies for GVS and VMS, with explicit feedback reducing the effects of the manipulations but not effacing these. PMID:26631143

  1. Interest of active posturography to detect age-related and early Parkinson's disease-related impairments in mediolateral postural control.

    PubMed

    Bonnet, Cédrick T; Delval, Arnaud; Defebvre, Luc

    2014-11-15

    Patients with Parkinson's disease display impairments of postural control most particularly in active, challenging conditions. The objective of the present study was to analyze early signs of disease-related and also age-related impairments in mediolateral body extension and postural control. Fifty-five participants (18 Hoehn and Yahr stage 2 patients in the off-drug condition, 18 healthy elderly control subjects, and 19 young adults) were included in the study. The participants performed a quiet stance task and two active tasks that analyzed the performance in mediolateral body motion: a limit of stability and a rhythmic weight shift task. As expected, the patients displayed significantly lower and slower body displacement (head, neck, lower back, center of pressure) than elderly control subjects when performing the two body excursion tasks. However, the behavioral variability in both tasks was similar between the groups. Under these active conditions, the patients showed significantly lower contribution of the hip postural control mechanisms compared with the elderly control subjects. Overall, the patients seemed to lower their performance in order to prevent a mediolateral postural instability. However, these patients, at an early stage of their disease, were not unstable in quiet stance. Complementarily, elderly control subjects displayed slower body performance than young adults, which therefore showed an additional age-related impairment in mediolateral postural control. Overall, the study illustrated markers of age-related and Parkinson's disease impairments in mediolateral postural control that may constrain everyday activities in elderly adults and even more in patients with Parkinson's disease. PMID:25143549

  2. Are the mediolateral joint forces in the lower limbs different between scoliotic and healthy subjects during gait?

    PubMed Central

    2015-01-01

    Introduction The quantification of internal joint efforts could be essential in the development of rehabilitation tools for patients with musculo-skeletal pathologies, such as scoliosis. In this context, the aim of this study was to compare the hips joint mediolateral forces during gait, between healthy subjects and adolescents with left lumbar or thoracolumbar scoliosis (AIS), categorized by their Cobb angle (CA). Material and methods Twelve healthy subjects, 12 AIS with CA between 20° and 40° and 16 AIS in pre-operative condition (CA : > 40°) walked at 4 km/h on an instrumented treadmill. The experimental set-up include six infrared cameras allow the computation of the tridimensional (3D) angular displacement and strain gauges located under the motor-driven treadmill allow the computation of ground reaction forces (GRF). The hips joint mediolateral forces were calculated using a 3D inverse dynamic of human body. One-way ANOVA was performed for the maximum, the minimum and the range of medio-lateral forces at each joint of the lower limbs. When appropriate, a Tukey's post hoc was performed to determine the differences. Results The mediolateral forces were significantly lower at the right hip for AIS with CA between 20° and 40° compared to healthy subject. Conclusion The spinal deformation leads to a reduced medio-lateral force at the right hip, which could gradually change the scheme of postural adjustments for AIS during gait. Further research on the quantification of the joint lower limb efforts should include the knee and ankle joints to evaluate the impact of spinal deformation on the lower limb dynamic behaviour in AIS patients. PMID:25810755

  3. Effects of Filtering the Center of Pressure Feedback Provided in Visually Guided Mediolateral Weight Shifting.

    PubMed

    Kennedy, Michael W; Crowell, Charles R; Villano, Michael; Schmiedeler, James P

    2016-01-01

    Thirty healthy adults completed a mediolateral weight-shifting balance task in which they were instructed to shift their weight to visually displayed target regions. A model-based filter and three different moving average filters employing 10, 34, and 58 samples were applied to the center of pressure visual feedback that guided the activity. The effects of filter selection on both the displayed feedback and the shift performance were examined in terms of shift time and non-minimum phase behavior. Shift time relates to feedback delay and shift speed, whereas non-minimum phase behavior relates to the force applied in shift initiation. Results indicated that increasing the number of samples in moving average filters (indicative of stronger filtering) significantly increases shift speed and shift initiation force. These effects indicate that careful selection and documentation of data filtering is warranted in future work and suggest opportunities for strategic filtering of visual feedback in clinical weight-shifting balance activities in order to improve outcomes based on such feedback. PMID:26991996

  4. Effects of Filtering the Center of Pressure Feedback Provided in Visually Guided Mediolateral Weight Shifting

    PubMed Central

    Kennedy, Michael W.; Crowell, Charles R.; Villano, Michael; Schmiedeler, James P.

    2016-01-01

    Thirty healthy adults completed a mediolateral weight-shifting balance task in which they were instructed to shift their weight to visually displayed target regions. A model-based filter and three different moving average filters employing 10, 34, and 58 samples were applied to the center of pressure visual feedback that guided the activity. The effects of filter selection on both the displayed feedback and the shift performance were examined in terms of shift time and non-minimum phase behavior. Shift time relates to feedback delay and shift speed, whereas non-minimum phase behavior relates to the force applied in shift initiation. Results indicated that increasing the number of samples in moving average filters (indicative of stronger filtering) significantly increases shift speed and shift initiation force. These effects indicate that careful selection and documentation of data filtering is warranted in future work and suggest opportunities for strategic filtering of visual feedback in clinical weight-shifting balance activities in order to improve outcomes based on such feedback. PMID:26991996

  5. Educational Psychology: Origins of a Dichotomy and the Parallel Dependence Model.

    ERIC Educational Resources Information Center

    Constas, Mark A.; Ripple, Richard E.

    1987-01-01

    This paper discusses some of the basic distinctions between the activities of inquiry and application and reviews the origins of the inquiry-application dichotomy. The parallel dependence model, designed to serve as a heuristic device, stresses the complementary potential of the inquiry and application functions. (LMO)

  6. An Apparatus to Quantify Anteroposterior and Mediolateral Shear Reduction in Shoe Insoles

    PubMed Central

    Belmont, Barry; Wang, Yancheng; Ammanath, Peethambaran; Wrobel, James S.; Shih, Albert

    2013-01-01

    Background Many of the physiological changes that lead to diabetic foot ulceration, such as muscle atrophy and skin hardening, are manifested at the foot–ground interface via pressure and shear points. Novel shear-reducing insoles have been developed, but their magnitude of shear stiffness has not yet been compared with regular insoles. The aim of this study was to develop an apparatus that would apply shear force and displacement to an insole’s forefoot region, reliably measure deformation, and calculate insole shear stiffness. Methods An apparatus consisting of suspended weights was designed to test the forefoot region of insoles. Three separate regions representing the hallux; the first and second metatarsals; and the third, fourth, and fifth metatarsals were sheared at 20 mm/min for displacements from 0.1 to 1.0 mm in both the anteroposterior and mediolateral directions for two types of insoles (regular and shear reducing). Results Shear reduction was found to be significant for the intervention insoles under all testing conditions. The ratio of a regular insole’s effective stiffness and the experimental insole’s effective stiffness across forefoot position versus shear direction, gait instance versus shear direction, and forefoot position versus gait instance was 270% ± 79%, 270% ± 96%, and 270% ± 86%, respectively. The apparatus was reliable with an average measured coefficient of variation of 0.034 and 0.069 for the regular and shear-reducing insole, respectively. Conclusions An apparatus consisting of suspended weights resting atop three locations of interest sheared across an insole was demonstrated to be capable of measuring the insole shear stiffness accurately, thus quantifying shear-reducing effects of a new type of insole. PMID:23567000

  7. Effect of Running Speed and Leg Prostheses on Mediolateral Foot Placement and Its Variability

    PubMed Central

    Arellano, Christopher J.; McDermott, William J.; Kram, Rodger; Grabowski, Alena M.

    2015-01-01

    This study examined the effects of speed and leg prostheses on mediolateral (ML) foot placement and its variability in sprinters with and without transtibial amputations. We hypothesized that ML foot placement variability would: 1. increase with running speed up to maximum speed and 2. be symmetrical between the legs of non-amputee sprinters but asymmetrically greater for the affected leg of sprinters with a unilateral transtibial amputation. We measured the midline of the body (kinematic data) and center of pressure (kinetic data) in the ML direction while 12 non-amputee sprinters and 7 Paralympic sprinters with transtibial amputations (6 unilateral, 1 bilateral) ran across a range of speeds up to maximum speed on a high-speed force measuring treadmill. We quantified ML foot placement relative to the body’s midline and its variability. We interpret our results with respect to a hypothesized relation between ML foot placement variability and lateral balance. We infer that greater ML foot placement variability indicates greater challenges with maintaining lateral balance. In non-amputee sprinters, ML foot placement variability for each leg increased substantially and symmetrically across speed. In sprinters with a unilateral amputation, ML foot placement variability for the affected and unaffected leg also increased substantially, but was asymmetric across speeds. In general, ML foot placement variability for sprinters with a unilateral amputation was within the range observed in non-amputee sprinters. For the sprinter with bilateral amputations, both affected legs exhibited the greatest increase in ML foot placement variability with speed. Overall, we find that maintaining lateral balance becomes increasingly challenging at faster speeds up to maximum speed but was equally challenging for sprinters with and without a unilateral transtibial amputation. Finally, when compared to all other sprinters in our subject pool, maintaining lateral balance appears to be the

  8. The dichotomy (generation of MAbs with functional heterogeneity) in antimalarial immune response in vaccinated/protected mice: a new concept in our understanding of the protective immune mechanisms in malaria.

    PubMed

    Singh, Prati Pal; Prakash, Bhanu

    2014-01-01

    Globally, vaccines have emerged as one of the most effective, safe, and cost-effective public health interventions, and are known to save 2-3 million lives, annually. However, despite various commendable efforts, a suitable human malaria vaccine is yet to see the light of the day. The lack of our complete understanding of the molecular mechanisms of pathogenesis and immune protection in malaria appears to be responsible for this state. Earlier, our laboratory has reported that Swiss mice vaccinated with Plasmodium yoelii nigeriensis-total parasite antigens soluble in culture medium and saponin, following a 100% lethal challenge, showed 60% protection. The monoclonal antibodies (MAbs) generated from the splenocytes of these vaccinated/protected mice, following characterization by in vitro merozoite invasion inhibition assay, ex vivo macrophage phagocytosis assay, and in vivo passive transfer of protection test, belonged to 2 distinct groups-a larger group of MAbs inhibited<58% Mz invasion and transferred 30% passive protection, whereas a smaller group of MAbs inhibited 86% Mz invasion and transferred 60% passive protection. Additionally, the MAbs of the smaller group, as compared with the larger one, mediated nearly 2.4-fold enhanced macrophage phagocytosis of infected-erythrocytes, in vitro. These results thus clearly showed a dichotomy among the generated MAbs. An exploration of the phenomenon of dichotomy in protective immunity in malaria by using various hosts and malaria parasite combinations, especially at the level of antibodies, cells, and cytokines, may add new insights to our understanding of the protective immunity, and help in the identification of biomarkers/biosignatures of immune protection and development of future human malaria vaccines. PMID:24632591

  9. Axial elongation in mouse embryos involves mediolateral cell intercalation behavior in the paraxial mesoderm

    NASA Astrophysics Data System (ADS)

    Yen, WeiWei; Burdsal, Carol; Periasamy, Ammasi; Sutherland, Ann E.

    2006-02-01

    The cell mechanical and signaling pathways involved in gastrulation have been studied extensively in invertebrates and amphibians, such as Xenopus, and more recently in non-mammalian vertebrates such as zebrafish and chick. However, because culturing mouse embryos extra-utero is very difficult, this fundamental process has been least characterized in the mouse. As the primary mammalian model for genetics, biochemistry, and the study of human disease and birth defects, it is important to investigate how gastrulation proceeds in murine embryos. We have developed a method of using 4D multiphoton excitation microscopy and extra-utero culture to visualize and characterize the morphogenetic movements in mouse embryos dissected at 8.5 days of gestation. Cells are labeled by expression of an X chromosome-linked enhanced green fluorescent protein (EGFP) transgene. This method has provided a unique approach, where, for the first time, patterns of cell behavior in the notochord and surrounding paraxial mesoderm can be visualized and traced quantitatively. Our observations of mouse embryos reveal both distinct differences as well as striking similarities in patterned cell motility relative to other vertebrate models such as Xenopus, where axial extension is driven primarily by mediolateral oriented cell behaviors in the notochord and paraxial somitic mesoderm. Unlike Xenopus, the width of the mouse notochord remains the same between 4-somite stage and 8-somite stage embryos. This implies the mouse notochord plays a lesser role in driving axial extension compared to Xenopus, although intercalation may occur where the anterior region of the node becomes notochordal plate. In contrast, the width of mouse paraxial mesoderm narrows significantly during this period and cells within the paraxial mesoderm are both elongated and aligned perpendicular to the midline. In addition, these cells are observed to intercalate, consistent with a role for paraxial mesoderm in driving convergence

  10. The dichotomy of p53 regulation by noncoding RNAs.

    PubMed

    Deng, Qipan; Becker, Lindsey; Ma, Xiaodong; Zhong, Xiaoming; Young, Ken; Ramos, Kenneth; Li, Yong

    2014-06-01

    The p53 tumor suppressor gene is the most frequently mutated gene in cancer. Significant progress has been made to discern the importance of p53 in coordinating cellular responses to DNA damage, oncogene activation, and other stresses. Noncoding RNAs are RNA molecules functioning without being translated into proteins. In this work, we discuss the dichotomy of p53 regulation by noncoding RNAs with four unconventional questions. First, is overexpression of microRNAs responsible for p53 inactivation in the absence of p53 mutation? Second, are there somatic mutations in the noncoding regions of the p53 gene? Third, is there a germline mutant in the noncoding regions of the p53 gene that predisposes carriers to cancer? Fourth, can p53 activation mediated by a noncoding RNA mutation cause cancer? This work highlights the prominence of noncoding RNAs in p53 dysregulation and tumorigenesis. PMID:24706938

  11. Age and Origin of the Crustal Dichotomy in Eastern Mars

    NASA Technical Reports Server (NTRS)

    Frey, H. V.

    2002-01-01

    The crustal dichotomy in eastern Mars is largely due to the very large impact which produced the Utopia Basin. Buried impact basins on the Utopia Basin constrain the Utopia impact (and therefore the dichotomy) to be very Early Noachian in age. Additional information is contained in the original extended abstract.

  12. Dichotomies in Music Education--Real or Unreal?

    ERIC Educational Resources Information Center

    Espeland, Magne

    2010-01-01

    In this keynote, the author discusses dichotomies having to do with: (1) technology/digital proponents versus non-technology/analogue proponents; (2) a formal/formalist position versus an informal/informalist position; and (3) educator/teacher views versus artist/musician views. The author often wonders what the essence of these dichotomies are,…

  13. Dynamical Origins of the Kepler Dichotomy

    NASA Astrophysics Data System (ADS)

    Spalding, Christopher; Batygin, Konstantin

    2016-05-01

    An overabundance of single-transiting planetary systems relative to those with multiple transits within the Kepler dataset, has been interpreted as evidence for mutual inclinations between planetary orbits. The physical origins of this so-called "Kepler Dichotomy,” however, remain elusive. Here we show that the observed prevalence of single-planet systems is a direct consequence of secular evolution of initially planar multi-planet systems that orbit stars whose spin-axes are inclined with respect to the protoplanetary disks they host. Such primordial misalignments arise naturally within the disk-hosting stage by way of gravitational torques from stellar companions, and have been previously invoked as explanations for the commonness of spin-orbit misalignments in hot Jupiter systems. Accordingly, our model places the early dynamical evolution of hot super-Earths and hot Jupiters into a unified theoretical framework.

  14. Age-related challenges in reactive control of mediolateral stability during compensatory stepping: A focus on the dynamics of restabilisation.

    PubMed

    Singer, Jonathan C; Prentice, Stephen D; McIlroy, William E

    2016-03-21

    Age-related mediolateral instability during forward stepping reactions evoked by whole-body perturbation is believed to occur independent of the initial temporospatial parameters prior to step-contact. Recent research is beginning to explore the restabilisation phase, following step-contact, as the origin of such instability. This work sought to uncover potential mechanisms underlying age-related mediolateral instability during restabilisation by examining whole-body centre of mass (COM) kinematics and the orientation of the net ground reaction force relative to the COM. Healthy younger (n=20) and older adults (n=20) were anchored to a rigid frame, via adjustable cable. After establishing a standardised initial forward lean, cable release occurred with pseudorandom timing. Participants regained their balance using a single self-selected step. The potential for lateral instability was quantified by COM kinematics. The angle of divergence of the line of action of the net ground reaction force relative to the COM was quantified and examined at three discrete points during restabilisation, as indices of COM control. Age-related differences in magnitude and trial-to-trial variability were analysed. Older adults exhibited increased ML COM incongruity and trial-to-trial variability, which were reduced with trial repetition. Older adults required an increased time to reorient the net ground reaction force, which was correlated with the increased lateral COM displacement during restabilisation. The present results support the idea that age-related mediolateral instability occurs during restabilisation and may be linked to the reactive control of the orientation of the net ground reaction force with respect to the centre of mass. PMID:26920512

  15. The Biological Implausibility of the Nature-Nurture Dichotomy and What It Means for the Study of Infancy

    ERIC Educational Resources Information Center

    Lewkowicz, David J.

    2011-01-01

    Since the time of the Greeks, philosophers and scientists have wondered about the origins of structure and function. Plato proposed that the origins of structure and function lie in the organism's nature whereas Aristotle proposed that they lie in its nurture. This nature-nurture dichotomy and the emphasis on the origins question has had a…

  16. CAN PLANETARY INSTABILITY EXPLAIN THE KEPLER DICHOTOMY?

    SciTech Connect

    Johansen, Anders; Davies, Melvyn B.; Church, Ross P.; Holmelin, Viktor

    2012-10-10

    The planet candidates discovered by the Kepler mission provide a rich sample to constrain the architectures and relative inclinations of planetary systems within approximately 0.5 AU of their host stars. We use the triple-transit systems from the Kepler 16 months data as templates for physical triple-planet systems and perform synthetic transit observations, varying the internal inclination variation of the orbits. We find that all the Kepler triple-transit and double-transit systems can be produced from the triple-planet templates, given a low mutual inclination of around 5 Degree-Sign . Our analysis shows that the Kepler data contain a population of planets larger than four Earth radii in single-transit systems that cannot arise from the triple-planet templates. We explore the hypothesis that high-mass counterparts of the triple-transit systems underwent dynamical instability to produce a population of massive double-planet systems of moderately high mutual inclination. We perform N-body simulations of mass-boosted triple-planet systems and observe how the systems heat up and lose planets by planet-planet collisions, and less frequently by ejections or collisions with the star, yielding transits in agreement with the large planets in the Kepler single-transit systems. The resulting population of massive double-planet systems nevertheless cannot explain the additional excess of low-mass planets among the observed single-transit systems and the lack of gas-giant planets in double-transit and triple-transit systems. Planetary instability of systems of triple gas-giant planets can be behind part of the dichotomy between systems hosting one or more small planets and those hosting a single giant planet. The main part of the dichotomy, however, is more likely to have arisen already during planet formation when the formation, migration, or scattering of a massive planet, triggered above a threshold metallicity, suppressed the formation of other planets in sub-AU orbits.

  17. The Germanium Dichotomy in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Humayun, M.; Yang, S.; Righter, K.; Zanda, B.; Hewins, R. H.

    2016-01-01

    Germanium is a moderately volatile and siderophile element that follows silicon in its compatibility during partial melting of planetary mantles. Despite its obvious usefulness in planetary geochemistry germanium is not analyzed routinely, with there being only three prior studies reporting germanium abundances in Martian meteorites. The broad range (1-3 ppm) observed in Martian igneous rocks is in stark contrast to the narrow range of germanium observed in terrestrial basalts (1.5 plus or minus 0.1 ppm). The germanium data from these studies indicates that nakhlites contain 2-3 ppm germanium, while shergottites contain approximately 1 ppm germanium, a dichotomy with important implications for core formation models. There have been no reliable germanium abundances on chassignites. The ancient meteoritic breccia, NWA 7533 (and paired meteorites) contains numerous clasts, some pristine and some impact melt rocks, that are being studied individually. Because germanium is depleted in the Martian crust relative to chondritic impactors, it has proven useful as an indicator of meteoritic contamination of impact melt clasts in NWA 7533. The germanium/silicon ratio can be applied to minerals that might not partition nickel and iridium, like feldspars. We report germanium in minerals from the 3 known chassignites, 2 nakhlites and 5 shergottites by LAICP- MS using a method optimized for precise germanium analysis.

  18. Buried mass anomalies along the hemispheric dichotomy in eastern Mars: Implications for the origin and evolution of the dichotomy

    NASA Astrophysics Data System (ADS)

    Kiefer, Walter S.

    2005-11-01

    Gravity observations indicate the presence of buried, high-density material along the hemispheric dichotomy in eastern Mars. This material is unrelated to present-day topography and is probably the result of localized thinning of the crust. This thinning may be the result of an epoch of edge-driven convection that occurred shortly after the dichotomy formed. Initiation of edge-driven convection requires that lateral variations in lithospheric structure be created on a timescale that is shorter than the conductive cooling time for the lithosphere, a few tens of million years at most. This timescale cannot be achieved if the dichotomy boundary is created solely by large-scale convective flow. Formation or modification of the boundary by large impact basins such as Utopia can create the required lithospheric structure in a geologic instant. This suggests that large impacts were important in shaping the dichotomy, at least on a regional scale.

  19. Constraints on Early Mars Evolution and Dichotomy Origin from Relaxation Modeling of Dichotomy Boundary in the Ismenius Region

    NASA Technical Reports Server (NTRS)

    Guest, A.; Smrekar, S. E.

    2004-01-01

    The Martian dichotomy is a global feature separating the northern and southern hemispheres. The 3.5 - 4 Gyr old feature is manifested by a topographic difference of 2-6 km and crustal thickness difference of approx. 15 - 30 km between the two hemispheres. In the Ismenius region, sections of the boundary are characterized by a single scarp with a slope of approx. 20 deg. - 23 deg. and are believed to be among the most well preserved parts of the dichotomy boundary. The origin of the dichotomy is unknown. Endogenic hypotheses do not predict the steep slopes (scarps) of the dichotomy boundary. Exogenic models for forming the northern lowlands by impact cratering, associate the scarps along the dichotomy boundary with craters' rims, but are not globally consistent with the topography and gravity. In order to better understand the origin of the Martian dichotomy, it is necessary to know if the steep scarps along the boundary represent the original shape of the dichotomy. Smrekar et al. presented evidence showing that the boundary scarp in Ismenius is a fault along which the highland crust was down faulted. We test whether the relaxation process could produce faulting along the dichotomy boundary and examine the crustal and mantle conditions that would allow for faulting to occur within 1 Gyr and preserve the long wavelength topography over another 3 Gyr. We approach the problem by a combination of numerical and semi-analytical modeling. We test different viscosity profiles and crustal thicknesses by comparing our modeled magnitude, location and timing of plastic strain and displacements to detailed geologic observations in the Ismenius region.

  20. Dawn: Testing Paradigms by Exploring Dichotomies

    NASA Astrophysics Data System (ADS)

    Russell, C. T.; Schmidt, B. E.; Wise, J.; Ristvey, J.; Raymond, C. A.

    2010-12-01

    NASA’s Dawn mission represents a series of “firsts” for major NASA missions. Dawn is the first major NASA science mission to use ion propulsion engines, allowing Dawn to be the first mission to orbit one target and then leave its gravity well to explore a second destination. Dawn is the first science mission to the main asteroid belt, reaching protoplanet Vesta in summer 2011, and will be the first mission to reach a “dwarf planet” when it arrives at Ceres in 2015. By targeting both Vesta and Ceres, Dawn explores two intriguing dichotomies in the solar system, that of the dry rocky planets and the wet icy bodies (Fire and Ice) and the dichotomy between planets and asteroids. Is there a clear dividing line here? Vesta, the second most massive asteroid, is a protoplanet: a round, mostly intact asteroid that bears more resemblance to a planet than to smaller asteroids. Vesta is also the likely parent body of the HED meteorites that richly populate Earth’s meteorite collections. It is possible to hold a piece of Vesta in your hands. From the HED meteorites, scientists have learned the Vesta is one of few differentiated asteroids. And from its spectrum, rich in basaltic minerals, it is known to be much like a mini-version of Earth’s Moon and Mercury. Vesta’s surface once was home to floods of lava not unlike those found still today on the Earth. Vesta is very similar to a terrestrial planet. Ceres is the giant of the asteroid belt with a hydrostatic shape that earns it a dwarf planet classification. Like its larger cousins, Ceres’ round shape suggests that the body may be differentiated, but due to its low density, Ceres’ interior is more like an icy moon of Jupiter. Beneath a relatively thin clay veneer probably lies an ice-rich mantle and rocky core, and even possibly a liquid ocean. With such enticing questions posed for Vesta and Ceres, Dawn will enable scientists and the public alike to explore how planets were born, how fire and ice have shaped

  1. The Effect of an Early Dichotomy on Mars Mantle Convection

    NASA Astrophysics Data System (ADS)

    King, S. D.

    2006-12-01

    Several attempts have been made to produce a crustal dichotomy followed by a single, stationary mantle plume, giving rise to the Tharsis volcanic province using 3D mantle convection models. If Mars evolved in such a scenario, two degree-1 (i.e., hemispherical) patterns would be required to develop at 90° to each other in the span of a few hundred million years. This has not yet been accomplished although recent numerical models (e.g. Roberts and Zhong, 2006) have made significant strides towards a solution including the use of both a lower mantle phase change and a layered viscosity mantle. Our goal is not to determine how the crustal dichotomy formed, but to assume it was already in place within the first 0.5 Ga of Mars' evolution. The presence of an early dichotomy boundary likely affected the planform of mantle convection and may have played a role in the formation of the Tharsis Rise based on the proximity of Tharsis to the dichotomy boundary. We model Martian mantle convection using the 3D finite element code CitComS (Zhong et al., 2000). Previous laboratory experiments have shown that an insulating lid overlying part of a temperature-dependent mantle will generate a large, stationary upwelling beneath the center of the lid. Thus, we incorporate a dry, Newtonian rheology with E*=300 kJ/mol and simulate a dichotomy boundary by integrating a high viscosity lid over the "southern hemisphere" of our model. Redmond and King (2004) illustrate that the effect of a strongly temperature-dependent rheology is the development of a stiff, rheological lithosphere. Thus, for small Rayleigh numbers, the initially imposed dichotomy boundary does not have an effect on the location of mantle upwellings because of the global lid that forms as a result of the temperature-dependent rheology. Our results suggest that an initially larger Rayleigh number, on the order of 107, will produce stationary upwellings beneath the imposed southern hemisphere lid before a global lid develops

  2. Topographic Change of the Dichotomy Boundary Suggested by Crustal Inversion

    NASA Technical Reports Server (NTRS)

    Neumann, G. A.

    2004-01-01

    Linear negative gravity anomalies in Acidalia Planitia along the eastern edge of Tempe Terra and along the northern edge of Arabia Terra have been noted in Mars Global Surveyor gravity fields. Once proposed to represent buried fluvial channels, it is now believed that these gravity troughs mainly arise from partial compensation of the hemispheric dichotomy topographic scarp. A recent inversion for crustal structure finds that mantle compensation of the scarp is offset from the present-day topographic expression of the dichotomy boundary. The offset suggests that erosion or other forms of mass wasting occurred after lithosphere thickened and no longer accomodated topographic change through viscous relaxation.

  3. Direct Instruction vs. Arts Integration: A False Dichotomy

    ERIC Educational Resources Information Center

    Aprill, Arnold

    2010-01-01

    In this article, the author takes on what he considers to be the false dichotomy between direct instruction and arts integration. He contends that at a time when national issues of sustainability and conservation of energy and resources become ever more urgent, it is time that those committed to quality arts education stop squandering time, money,…

  4. MOLA Topography of the Crustal Dichotomy Boundary Zone, Mars

    NASA Technical Reports Server (NTRS)

    Frey, Herbert V.; E. H., Susan; H., James

    1998-01-01

    Mars Orbiter Laser Altimeter (MOLA) profiles frequently cross the crustal dichotomy boundary where the transition zone (TZ) between cratered highland terrain (CT) and lowland smooth plains (SP) is marked by mesas and knobby terrain. The detailed topographic character of the boundary zone is longitudinally variable, as is the geomorphology of the TZ. Some portions of the boundary are associated with an outer ring of the Utopia impact basin; MOLA topography is consistent with this. The regional character of the boundary topography is a 2-4 km step function from nearly flat SP to almost as flat CT. This rise has a regional slope of 1-2 degrees, 50-100 times that of the Cr and SP away from TZ, which suggests a significant change in crustal properties (thickness, composition or both) across the TZ. The overall topography is very similar to that at some passive continent-oceanic crustal margins on the Earth, with the seafloor allowed to adjust upward after removal of the overlying water. A possible temporal constraint on the CT/SP elevation difference comes from two MOLA profiles which pass through two large (150 km diameter) craters located at the boundary in Aeolis. The N and S rims of the more degraded crater are at the same elevation; north of the N rim the topography drops by greater than 2 km to the floor of the TZ. This crater predates the elevation offset between CT and TZ floor. The better preserved crater (Gale) has a N rim 2 km lower than its S rim, and appears to have been emplaced on a pre-existing regional slope of about I degree. Gale probably post- dates the elevation difference between CT and TZ floor. Based on the stratigraphy of the units in which these craters are found, the elevation difference appears to have been in place in the Mid to Late Noachian.

  5. Medio-lateral stability of sit-to-walk performance in older individuals with and without fear of falling.

    PubMed

    Aberg, Anna Cristina; Frykberg, Gunilla Elmgren; Halvorsen, Kjartan

    2010-04-01

    Most falls in older people are due to loss of balance during everyday locomotion, e.g., when initiating walking from sitting; sit-to-walk (STW). It has been considered that the broader stride width in walking that is seen in many people with fear of falling (FoF) does not increase stability, but could be predictive of future falls because of increased medio-lateral (ML) velocity of the body centre of mass (CoM). This study was aimed to examine step-, velocity- and stability-related parameters, focusing on ML stability, in STW performance of people with and without FoF. Ten subjects with FoF and 10 matched controls, aged > or = 70 years, were included. Kinematic and kinetic data were collected in a laboratory. Stability parameters were calculated from a formula implying that the vertical projection of the CoM extrapolated by adding its velocity times a factor radicall/g (height of inverted pendulum divided by gravity) should fall within the base of support (BoS). A related spatial margin of stability (SMoS), defined as the minimum distance from the extrapolated CoM (XCoM) to the boundaries of the BoS, was also calculated. In the phase 'seat-off-second-toe-off', the FoF group had significantly (p<0.05) shorter and broader steps, lower forward but similar ML CoM velocity, and broader CoM and XCoM widths. The FoF group therefore exhibited a disproportionately large sideways velocity compared to the controls. This indicates that STW may be a hazardous transfer for older people with FoF, which should be relevant in assessment and training aimed at preventing falls. PMID:20189390

  6. The Biological Implausibility of the Nature-Nurture Dichotomy & What It Means for the Study of Infancy

    PubMed Central

    Lewkowicz, David J.

    2011-01-01

    Since the time of the Greeks, philosophers and scientists have wondered about the origins of structure and function. Plato proposed that the origins of structure and function lie in the organism's nature whereas Aristotle proposed that they lie in its nurture. This nature/nurture dichotomy and the emphasis on the origins question has had a powerful effect on our thinking about development right into modern times. Despite this, empirical findings from various branches of developmental science have made a compelling case that the nature/nurture dichotomy is biologically implausible and, thus, that a search for developmental origins must be replaced by research into developmental processes. This change in focus recognizes that development is an immensely complex, dynamic, embedded, interdependent, and probabilistic process and, therefore, renders simplistic questions such as whether a particular behavioral capacity is innate or acquired scientifically uninteresting. PMID:21709807

  7. The application of dichotomy in equilibrium position of journal bearing

    NASA Astrophysics Data System (ADS)

    Wu, G. K.; Luo, X. Q.

    2016-05-01

    The fluid lubricant force in the journal bearing is an important factor for the stability and dynamic characteristics of rotating machine. In order to obtain the dynamic coefficients of journal bearing, the equilibrium position must be known for further calculation. In this paper, the Reynolds equation is solved by finite difference method and the dichotomy is applied to acquire the equilibrium position of journal bearing by means of double loop. The effects of length, radius and clearance of journal bearing on the equilibrium position are also researched. The calculated results show that the dichotomy is an effective method for the equilibrium position of journal bearing and the geometry parameters play an important effect on the equilibrium position.

  8. Mega-impact formation of the Mars hemispheric dichotomy.

    PubMed

    Marinova, Margarita M; Aharonson, Oded; Asphaug, Erik

    2008-06-26

    The Mars hemispheric dichotomy is expressed as a dramatic difference in elevation, crustal thickness and crater density between the southern highlands and northern lowlands (which cover approximately 42% of the surface). Despite the prominence of the dichotomy, its origin has remained enigmatic and models for its formation largely untested. Endogenic degree-1 convection models with north-south asymmetry are incomplete in that they are restricted to simulating only mantle dynamics and they neglect crustal evolution, whereas exogenic multiple impact events are statistically unlikely to concentrate in one hemisphere. A single mega-impact of the requisite size has not previously been modelled. However, it has been hypothesized that such an event could obliterate the evidence of its occurrence by completely covering the surface with melt or catastrophically disrupting the planet. Here we present a set of single-impact initial conditions by which a large impactor can produce features consistent with the observed dichotomy's crustal structure and persistence. Using three-dimensional hydrodynamic simulations, large variations are predicted in post-impact states depending on impact energy, velocity and, importantly, impact angle, with trends more pronounced or unseen in commonly studied smaller impacts. For impact energies of approximately (3-6) x 10(29) J, at low impact velocities (6-10 km s(-1)) and oblique impact angles (30-60 degrees ), the resulting crustal removal boundary is similar in size and ellipticity to the observed characteristics of the lowlands basin. Under these conditions, the melt distribution is largely contained within the area of impact and thus does not erase the evidence of the impact's occurrence. The antiquity of the dichotomy is consistent with the contemporaneous presence of impactors of diameter 1,600-2,700 km in Mars-crossing orbits, and the impact angle is consistent with the expected distribution. PMID:18580945

  9. Tharsis: Consequence of Mars' Dichotomy and Layered Mantle

    NASA Astrophysics Data System (ADS)

    Wenzel, M. J.; Manga, M.; Jellinek, A. M.

    2003-12-01

    The two largest and most striking features on Mars are the crustal dichotomy, the nearly hemispheric division in topography, gravity, crustal thickness, and age, and Tharsis, a volcanic center active from the Noachian to the present. Tharsis' long-term persistence of localized volcanism is, to the best of our knowledge, unique in the solar system. Explaining the timing of Tharsis volcanism, from initiation early in martian history to recent activity, has been an enduring challenge. Here we present an model of the martian mantle that can explain early and persistent volcanism at Tharsis by incorporating the effects of the crustal dichotomy and a compositionally layered mantle. As the crust is expected to be enriched in heat-producing elements, this dichotomy in thickness leads to a dichotomous heat flux boundary condition on the mantle, which affects the internal dynamics. The evidence for layering includes the ability of a layered mantle to simultaneously meet a chondritic bulk composition and the moment-of-inertia factor (Elkins-Tanton et al., in revision), which can not be done with a one-layered mantle. In addition, studies of the martian meteorites suggest that the martian mantle is heterogeneous, a constraint that can be met with layering. We perform analog laboratory experiments with corn syrup to simulate Mars' thermal evolution. We vary the presence of a partial insulating lid, to simulate the effect of the dichotomy, and layering in the convecting fluid. We show that in the case of a layered mantle and an insulating lid, a large swell, which acts to localize upwelling plumes under the lid, forms early and endures for the scaled equivalent of billions of years. Linda T. Elkins-Tanton, E. M. Parmentier, and P. C. Hess, "Magma ocean fractional crystallization and cumulate overturn in terrestrial planets: implications for Mars," in revision for Meteoritics and Planetary Science.

  10. Dichotomy in the definition of prescriptive information suggests both prescribed data and prescribed algorithms: biosemiotics applications in genomic systems

    PubMed Central

    2012-01-01

    The fields of molecular biology and computer science have cooperated over recent years to create a synergy between the cybernetic and biosemiotic relationship found in cellular genomics to that of information and language found in computational systems. Biological information frequently manifests its "meaning" through instruction or actual production of formal bio-function. Such information is called Prescriptive Information (PI). PI programs organize and execute a prescribed set of choices. Closer examination of this term in cellular systems has led to a dichotomy in its definition suggesting both prescribed data and prescribed algorithms are constituents of PI. This paper looks at this dichotomy as expressed in both the genetic code and in the central dogma of protein synthesis. An example of a genetic algorithm is modeled after the ribosome, and an examination of the protein synthesis process is used to differentiate PI data from PI algorithms. PMID:22413926

  11. DICHOTOMY OF SOLAR CORONAL JETS: STANDARD JETS AND BLOWOUT JETS

    SciTech Connect

    Moore, Ronald L.; Cirtain, Jonathan W.; Sterling, Alphonse C.; Falconer, David A.

    2010-09-01

    By examining many X-ray jets in Hinode/X-Ray Telescope coronal X-ray movies of the polar coronal holes, we found that there is a dichotomy of polar X-ray jets. About two thirds fit the standard reconnection picture for coronal jets, and about one third are another type. We present observations indicating that the non-standard jets are counterparts of erupting-loop H{alpha} macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major coronal mass ejections. From the coronal X-ray movies we present in detail two typical standard X-ray jets and two typical blowout X-ray jets that were also caught in He II 304 A snapshots from STEREO/EUVI. The distinguishing features of blowout X-ray jets are (1) X-ray brightening inside the base arch in addition to the outside bright point that standard jets have, (2) blowout eruption of the base arch's core field, often carrying a filament of cool (T {approx} 10{sup 4} - 10{sup 5} K) plasma, and (3) an extra jet-spire strand rooted close to the bright point. We present cartoons showing how reconnection during blowout eruption of the base arch could produce the observed features of blowout X-ray jets. We infer that (1) the standard-jet/blowout-jet dichotomy of coronal jets results from the dichotomy of base arches that do not have and base arches that do have enough shear and twist to erupt open, and (2) there is a large class of spicules that are standard jets and a comparably large class of spicules that are blowout jets.

  12. A stellar population synthesis approach to the Oosterhoff dichotomy

    NASA Astrophysics Data System (ADS)

    Sollima, A.; Cassisi, S.; Fiorentino, G.; Gratton, R. G.

    2014-10-01

    We use colour-magnitude diagram synthesis together with theoretical relations from non-linear pulsation models to approach the long-standing problem of the Oosterhoff dichotomy related to the distribution of the mean periods of fundamental RR Lyrae variables in globular clusters. By adopting the chemical composition determined from spectroscopic observations and a criterion to account for the hysteresis mechanism, we tuned age and mass loss to simultaneously reproduce the morphology of both the turn-off and the horizontal branch of a sample of 17 globular clusters of the Milky Way and of nearby dwarf galaxies in the crucial metallicity range (-1.9 < [Fe/H] < -1.4) where the Oostheroff transition is apparent. We find that the Oosterhoff dichotomy among Galactic globular clusters is naturally reproduced by models. The analysis of the relative impact of the various involved parameters indicates that the main responsibles of the dichotomy are the peculiar distribution of clusters in the age-metallicity plane and the hysteresis. In particular, there is a clear connection between the two main branches of the age-metallicity relation for Galactic globular clusters and the Oosterhoff groups. The properties of clusters' RR Lyrae belonging to other Oostheroff groups (OoInt and OoIII) are instead not well reproduced. While for OoIII clusters a larger helium abundance for a fraction of the cluster's stars can reconcile the model prediction with observations, some other parameter affecting both the horizontal branch morphology and the RR Lyrae periods is required to reproduce the behaviour of OoInt clusters.

  13. Dichotomy of Solar Coronal Jets: Standard Jets and Blowout Jets

    NASA Technical Reports Server (NTRS)

    Moore, R. L.; Cirtain, J. W.; Sterling, A. C.; Falconer, D. A.

    2010-01-01

    By examining many X-ray jets in Hinode/XRT coronal X-ray movies of the polar coronal holes, we found that there is a dichotomy of polar X-ray jets. About two thirds fit the standard reconnection picture for coronal jets, and about one third are another type. We present observations indicating that the non-standard jets are counterparts of erupting-loop H alpha macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major CMEs. From the coronal X-ray movies we present in detail two typical standard X-ray jets and two typical blowout X-ray jets that were also caught in He II 304 Angstrom snapshots from STEREO/EUVI. The distinguishing features of blowout X-ray jets are (1) X-ray brightening inside the base arch in addition to the outside bright point that standard jets have, (2) blowout eruption of the base arch's core field, often carrying a filament of cool (T 10(exp 4) - 10(exp 5) K) plasma, and (3) an extra jet-spire strand rooted close to the bright point. We present cartoons showing how reconnection during blowout eruption of the base arch could produce the observed features of blowout X-ray jets. We infer that (1) the standard-jet/blowout-jet dichotomy of coronal jets results from the dichotomy of base arches that do not have and base arches that do have enough shear and twist to erupt open, and (2) there is a large class of spicules that are standard jets and a comparably large class of spicules that are blowout jets.

  14. The geophysical signal of the martian global dichotomy

    NASA Technical Reports Server (NTRS)

    Phillips, Roger J.

    1992-01-01

    A first-order tectonic question for Mars is the origin and nature of the global dichotomy (GD) separating approximately the northern and southern hemispheres of the planet. It is appropriate to focus on hypotheses for the origin of the GD as well as on geophysical models of related internal structure that are constrained by present-day observations. There are basic planetary scale observations that relate to the GD: (1) the dichotomy boundary separates two fundamentally different elevations on the planet, as the terrain to the north is lower by an average of about 3 km; (2) the boundary separates terrain of regionally distinct crater ages, heavily cratered (older) in the south and sparsely cratered (younger) in the north; (3) the amount of ancient crust apparently removed from north of the dichotomy boundary cannot be accounted for by simple surface erosion and deposition in the south, and the constraint becomes particularly severe if isostatic adjustment is presumed to have accompanied this process. This last point leads to the supposition that some type of interior process must have been responsible for the creation of the GD. An obvious way to create the observed elevation difference between the two hemispheres is with a thinner crust in the north, although a denser cust would also work. Hypotheses for producing a thinner northern crust include preferential sub-crustal erosion, a giant impact, and simply invoking the crustal thickness difference as a primordial feature of the planet. If the GD represents a fundamental change in the crustal thickness of Mars, then there should be geophysical evidence of this. The center-of-figure to center-of-mass offset of the planet may be related to the GD, but the Tharsis topography must certainly also contribute. If the Tharsis and GD effects can be separated, then a crustal thickness model can be tested, though the results will not be unique. The gravity field provides another geophysical constraint on GD models. A simple

  15. Beyond the dichotomy: six religious views of homosexuality.

    PubMed

    Moon, Dawne

    2014-01-01

    Using published theological and scholarly evidence, this article disrupts the stereotypical "born gay"/"sinful choice" dichotomy widely assumed to characterize religious views of homosexuality in the United States. It argues that we need to keep moral questions separate from questions about the fixity or fluidity of sexual orientation. Rather than two, American Christian and Jewish views of homosexuality can been seen on a range from the "God Hates Fags" view through "Love the Sinner, Hate the Sin," "We Don't Talk About That," "They Can't Help It," "God's Good Gift," and a queer-theological view of the "Godly Calling." PMID:24871867

  16. Will The Kraepelinian Dichotomy Survive DSM-V?

    PubMed Central

    Fischer, Bernard A.; Carpenter, William T.

    2009-01-01

    Kraepelin proposed dementia praecox and manic-depressive illness as the two major psychotic disorders. This paradigm is still prevalent, but observations of overlapping boundaries between bipolar disorder and schizophrenia challenge this dichotomy. However, the concept of schizophrenia has been radically altered from the original Kraepelinian proposal. We defend the two psychoses position, but suggest two flaws in the heuristic application: 1) overlapping features such as psychotic symptoms are not decisive in differential diagnosis; and 2) each disorder is a syndrome, not a disease entity. An alternative paradigm based on domains of pathology is more powerful for studies of etiology, pathophysiology, and therapeutic discovery. PMID:19295511

  17. Dichotomy of some satellites of the outer Solar system

    NASA Astrophysics Data System (ADS)

    Kochemasov, G. G.

    2011-10-01

    Recently acquired by the Cas as ini' CIR a temperature map (11 -16 microns radiation) of small satellite Mimas caused a perplexity among the Cassini scientists (an interpretation of PIA12867). They expected to have a regular temperature map characteristic of a homogeneous spherical body heated by Sun. Instead, the bizarre map with two sharply divided temperature fields was produced (Fig. 1). The temperature difference between two fields is about 15 Kelvin that is rather remarkable. The warm part has typical temperature near 92 Kelvin, the cold part -about 77 Kelvin. Obviously there are two icy substances with different conductivity of heat composing two planetary segments (hemispheres). But in this result there is nothing new for explorers insisting for many years that all celestial bodies are tectonically dichotomous [1, 2, 3]. However, this new beautiful confirmat ion of the wave planetology theorem 1 (" Celes tial bodies are dichotomous ") is not s uperfluous , as many s cientis ts , es pecially in the USA, are not acquainted with the wave p lanetology. The fundamental wave 1 long 2πR warping any body aris es in them becaus e they move in elliptica l keple rian orbits with periodically changing acceleration. Having in rotating bodies (but all bodies rotate!) a stationary character and four interfering directions (ortho- and diagonal) these waves inevitably produce uplifting (+), subsiding (-), and neutral (0) tectonic blocks (Fig. 7). The uplifts and subsidences are in an opposition (the best examples are the terrestrial Eastern (+) and Western ( -) segments-hemispheres and mart ian Northern (-) and Southern (+) ones) [3]. The small icy Mimas (396 km in diameter) is no exclusion (Fig. 1). Its dichotomy is well pronounced in two temperature fields obviously reflect ing slightly different in composition icy materials composing two segments. Presence of two kinds of surface materials is also revealed by spectrometry under combination of the UV, green and IR

  18. Impact of posterior tibial nail malpositioning on iatrogenic injuries by distal medio-lateral interlocking screws. A cadaveric study on plastinated specimens.

    PubMed

    Wegmann, Kilian; Burkhart, Klaus Josef; Buhl, Jörg; Gausepohl, Thomas; Koebke, Jürgen; Müller, Lars Peter

    2012-12-01

    In intramedullary tibial nailing, multi-planar locking makes stabilization of proximal and distal metaphyseal fractures possible. A known complication in intramedullary nailing of the tibia is iatrogenic injury to neuro-vascular structures caused by the insertion of locking screws. As shown in previous studies, the distal positioning of the nail is important, as it determines the course of the locking bolts. The goal of the present study was to display the consequences of posterior nail malpositioning with respect to the safety of the distal medio-lateral locking screws and the available options. Human cadaveric legs were plastinated according to the sequential plastination technique after intramedullary nailing of the tibia and were then cut transversely. The tibial nails were placed centrally or posteriorly. Macroscopic analysis showed a distinct drawback of posterior nail positioning, with diminished options for the placement of the locking screws and thereby a risk of damaging the anterior and posterior neuro-vascular bundles by distal medio-lateral locking screws. PMID:23409576

  19. Hydrophobic-hydrophilic dichotomy of the butterfly proboscis.

    PubMed

    Lehnert, Matthew S; Monaenkova, Daria; Andrukh, Taras; Beard, Charles E; Adler, Peter H; Kornev, Konstantin G

    2013-08-01

    Mouthparts of fluid-feeding insects have unique material properties with no human-engineered analogue: the feeding devices acquire sticky and viscous liquids while remaining clean. We discovered that the external surface of the butterfly proboscis has a sharp boundary separating a hydrophilic drinking region and a hydrophobic non-drinking region. The structural arrangement of the proboscis provides the basis for the wetting dichotomy. Theoretical and experimental analyses show that fluid uptake is associated with enlargement of hydrophilic cuticular structures, the legulae, which link the two halves of the proboscis together. We also show that an elliptical proboscis produces a higher external meniscus than does a cylindrical proboscis of the same circumference. Fluid uptake is additionally facilitated in sap-feeding butterflies that have a proboscis with enlarged chemosensory structures forming a brush near the tip. This structural modification of the proboscis enables sap feeders to exploit films of liquid more efficiently. Structural changes along the proboscis, including increased legular width and presence of a brush-like tip, occur in a wide range of species, suggesting that a wetting dichotomy is widespread in the Lepidoptera. PMID:23760299

  20. Hydrophobic–hydrophilic dichotomy of the butterfly proboscis

    PubMed Central

    Lehnert, Matthew S.; Monaenkova, Daria; Andrukh, Taras; Beard, Charles E.; Adler, Peter H.; Kornev, Konstantin G.

    2013-01-01

    Mouthparts of fluid-feeding insects have unique material properties with no human-engineered analogue: the feeding devices acquire sticky and viscous liquids while remaining clean. We discovered that the external surface of the butterfly proboscis has a sharp boundary separating a hydrophilic drinking region and a hydrophobic non-drinking region. The structural arrangement of the proboscis provides the basis for the wetting dichotomy. Theoretical and experimental analyses show that fluid uptake is associated with enlargement of hydrophilic cuticular structures, the legulae, which link the two halves of the proboscis together. We also show that an elliptical proboscis produces a higher external meniscus than does a cylindrical proboscis of the same circumference. Fluid uptake is additionally facilitated in sap-feeding butterflies that have a proboscis with enlarged chemosensory structures forming a brush near the tip. This structural modification of the proboscis enables sap feeders to exploit films of liquid more efficiently. Structural changes along the proboscis, including increased legular width and presence of a brush-like tip, occur in a wide range of species, suggesting that a wetting dichotomy is widespread in the Lepidoptera. PMID:23760299

  1. The Prokaryote-Eukaryote Dichotomy: Meanings and Mythology

    PubMed Central

    Sapp, Jan

    2005-01-01

    Drawing on documents both published and archival, this paper explains how the prokaryote-eukaryote dichotomy of the 1960s was constructed, the purposes it served, and what it implied in terms of classification and phylogeny. In doing so, I first show how the concept was attributed to Edouard Chatton and the context in which he introduced the terms. Following, I examine the context in which the terms were reintroduced into biology in 1962 by Roger Stanier and C. B. van Niel. I study the discourse over the subsequent decade to understand how the organizational dichotomy took on the form of a natural classification as the kingdom Monera or superkingdom Procaryotae. Stanier and van Niel admitted that, in regard to constructing a natural classification of bacteria, structural characteristics were no more useful than physiological properties. They repeatedly denied that bacterial phylogenetics was possible. I thus examine the great historical irony that the “prokaryote,” in both its organizational and phylogenetic senses, was defined (negatively) on the basis of structure. Finally, we see how phylogenetic research based on 16S rRNA led by Carl Woese and his collaborators confronted the prokaryote concept while moving microbiology to the center of evolutionary biology. PMID:15944457

  2. The Martian Dichotomy: Numerical Investigations of the Impact Hypothesis

    NASA Astrophysics Data System (ADS)

    Hart, S.; Nimmo, F.; Korycansky, D.

    2006-12-01

    The Martian dichotomy is a first order feature of Martian topography and crustal thickness distribution [1]. We examine the hypothesis that a single large impact may have caused the dichotomy [2,3], using the radially- axisymmetric hydrocode ZeusMP [4,5]. We use a variable-resolution Eulerian grid to resolve near-surface processes, and have incorporated a set of Lagrangian tracer particles to track the displacement of crustal material allowing for robust crater size determination. We have explored parameter space by varying both impact velocity and mass, and have derived a preliminary scaling law for the amount of crustal material removed. The pattern of energy deposition is also being studied to better understand the spatial distribution of melted and excavated material. [1]Zuber, M.T., Nature 412, 220-27, 2001. [2]Willhelms, D.E., S.W. Squyres, Nature 309, 138-40, 1984. [3]Marinova, M.M., O. Aharonson, E. Asphaug 2005, Eos Trans. AGU, 86(52), Fall Meet. Suppl., Abstract P42A-06 [4]Stone, J. and M. Norman 1992, Ap. J. Supp. vol. 80, 753-790. [5]Korycansky, D. G., Zahnle, K. J., and M.-M. Mac Low 2000. Icarus, vol. 146, 387-403

  3. Going and stopping: dichotomies in behavioral control by the prefrontal cortex.

    PubMed

    Gourley, Shannon L; Taylor, Jane R

    2016-04-26

    The rodent dorsal medial prefrontal cortex (PFC), specifically the prelimbic cortex (PL), regulates the expression of conditioned fear and behaviors interpreted as reward seeking. Meanwhile, the ventral medial PFC, namely the infralimbic cortex (IL), is essential to extinction conditioning in both appetitive and aversive domains. Here we review evidence that supports, or refutes, this "PL-go/IL-stop" dichotomy. We focus on the extinction of conditioned fear and the extinction and reinstatement of cocaine- or heroin-reinforced responding following abstinence. We then synthesize evidence that the PL is essential for developing goal-directed response strategies, while the IL supports habit behavior. Finally, we propose that some functions of the orbital PFC parallel those of the medial PFC in the regulation of response selection. Integration of these discoveries may provide points of intervention for inhibiting untethered drug seeking in drug use disorders, extinction failures in post-traumatic stress disorder, or co-morbidities between the two. PMID:27116390

  4. MOLA Topographic Variations Along the Crustal Dichotomy Boundary Zone in Eastern and Western Mars

    NASA Technical Reports Server (NTRS)

    Frey, H; Sakimoto, S.; Roark, J.

    1999-01-01

    The topographic character of the martian crustal dichotomy boundary zone changes along the boundary, as does the morphological character of the boundary itself. Overall the elevation change from lowland plains to cratered uplands has the character of a step function, but the magnitude of the step and the slope of the ramp in the transition zone between the two relatively flat surfaces is different in different areas. Especially prominent is the difference between the boundaries in Deuteronilus-Ismenius Lacus and in Tempe Terra: Total relief in the transition zone in central Tempe is significantly greater than that in most of the eastern boundary zone. The correlation of topography with changing morphological character and mapped geologic units suggests that different parts of the boundary had different modification histories, and, perhaps, different origins as well.

  5. Knowledge of Being v. Practice of Becoming in Higher Education: Overcoming the Dichotomy in the Humanities

    ERIC Educational Resources Information Center

    Marquez, Ivan

    2006-01-01

    This essay suggests ways to overcome what I take to be a widespread problem of a dichotomy between the knowledge of being and the practice of becoming and an emphasis on the former at the expense of the latter within contemporary Humanities at the university. First, I trace the genealogy of this dichotomy and its effects on contemporary…

  6. The Borealis basin and the origin of the martian crustal dichotomy.

    PubMed

    Andrews-Hanna, Jeffrey C; Zuber, Maria T; Banerdt, W Bruce

    2008-06-26

    The most prominent feature on the surface of Mars is the near-hemispheric dichotomy between the southern highlands and northern lowlands. The root of this dichotomy is a change in crustal thickness along an apparently irregular boundary, which can be traced around the planet, except where it is presumably buried beneath the Tharsis volcanic rise. The isostatic compensation of these distinct provinces and the ancient population of impact craters buried beneath the young lowlands surface suggest that the dichotomy is one of the most ancient features on the planet. However, the origin of this dichotomy has remained uncertain, with little evidence to distinguish between the suggested causes: a giant impact or mantle convection/overturn. Here we use the gravity and topography of Mars to constrain the location of the dichotomy boundary beneath Tharsis, taking advantage of the different modes of compensation for Tharsis and the dichotomy to separate their effects. We find that the dichotomy boundary along its entire path around the planet is accurately fitted by an ellipse measuring approximately 10,600 by 8,500 km, centred at 67 degrees N, 208 degrees E. We suggest that the elliptical nature of the crustal dichotomy is most simply explained by a giant impact, representing the largest such structure thus far identified in the Solar System. PMID:18580944

  7. The Albedo Dichotomy of Iapetus Measured at UV Wavelengths

    NASA Technical Reports Server (NTRS)

    Hendrix, Amanda R.; Hansen, Candice J.

    2007-01-01

    The dramatic hemispheric dichotomy in albedo displayed by Saturn's moon Iapetus has intrigued astronomers for centuries. Here we report on far-ultraviolet observations of Iapetus' bright and dark terrains from Cassini. We compare the reflectance spectra of Iapetus's dark terrain, Hyperion and Phoebe and find that both Phoebe and Hyperion are richer in water ice than Iapetus' dark terrain. Spectra of the lowest latitudes of the dark terrain display the diagnostic water ice absorption feature; water ice amounts increase within the dark material away from the apex (at 90 deg W longitude, the center of the dark leading hemisphere), consistent with thermal segregation of water ice. The water ice in the darkest, warmest low latitude regions is not expected to be stable and may be a sign of ongoing or recent emplacement of the dark material from an exogenic source.

  8. Cassini VIMS Preliminary Exploration of Titan's Surface Hemispheric Albedo Dichotomy

    NASA Technical Reports Server (NTRS)

    Nelson, R. M.; Brown, R. H.; Hapke, B. W.; Smythe, W. D.; Kamp, L.; Boryta, M.; Baines, K. H.; Bellucci, G.; Bibring, J.-P.; Buratti, B. J.

    2005-01-01

    We present preliminary evidence that suggests a hemispheric albedo dichotomy on Titan, the largest planetary satellite in the Solar System. We have also studied the photometric properties of several dark circular features on Titan's surface to test if they might be of impact origin. The evidence is derived from photometric analysis of selected surface regions taken at different Titanian longitudes and solar phase angles using images from the Cassini Saturn Orbiter Visual and Infrared Mapping Spectrometer (VIMS). The VIMS instrument is able to image Titan's surface at spectral windows (e.g. 2.02 microns) in its atmosphere where methane, the principal atmospheric absorber is transparent. Additional information is included in the original extended abstract.

  9. The false dichotomy: a refutation of the Neandertal indistinguishability claim.

    PubMed

    Wynn, Thomas; Overmann, Karenleigh; Coolidge, Frederick

    2016-06-20

    In the debate about the demise of the Neandertal, several scholars have claimed that humanity's nearest relatives were indistinguishable archaeologically, and thus behaviorally and cognitively, from contemporaneous Homo sapiens. They suggest that to hold otherwise is to characterize Neandertals as inferior to H. sapiens, a false dichotomy that excludes the possibility that the two human types simply differed in ways visible to natural selection, including their cognition. Support of the Neandertal indistinguishability claim requires ignoring the cranial differences between the two human types, which have implications for cognition and behavior. Further, support of the claim requires minimizing asymmetries in the quantity and degree of behavioral differences as attested by the archaeological record. The present paper reviews the evidence for cognitive and archaeological differences between the two human types in support of the excluded middle position. PMID:26708102

  10. Workshop on Hemispheres Apart: The Origin and Modification of the Martian Crustal Dichotomy

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This volume contains abstracts that have been accepted for presentation at the Workshop on Hemispheres Apart: The Origin and Modification of the Martian Crustal Dichotomy, September 30-October 1, 2004, Houston, Texas.

  11. Quantifying the urban environment: a scale measure of urbanicity outperforms the urban-rural dichotomy

    PubMed Central

    Adair, Linda S

    2007-01-01

    The rapid urbanization of the developing world has important consequences for human health. Although several authorities have called for better research on the relationships between urbanicity and health, most researchers still use a poor measurement of urbanicity, the urban-rural dichotomy. Our goal was to construct a scale of urbanicity using community level data from the Cebu Longitudinal Health and Nutrition Survey. We used established scale development methods to validate the new measure and tested its performance against the dichotomy. The new scale illustrated misclassification by the urban-rural dichotomy, and was able to detect differences in urbanicity, both between communities and across time, that were not apparent before. Furthermore, using a continuous measure of urbanicity allowed for better illustrations of the relationships between urbanicity and health. The new scale is a better measure of urbanicity than the traditionally used urban-rural dichotomy. PMID:17196724

  12. Topographic Studies of Lobate Scarps Near the Martian Crustal Dichotomy Using MOLA Data

    NASA Astrophysics Data System (ADS)

    Watters, T. R.; Robinson, M. S.

    1999-03-01

    MOLA data is being used to study martian lobate scarps in the Amenthes region, near the crustal dichotomy. The dimensions and morphology of a lobate scarp crossed by a MOLA profile agree well with other scarps studied using photoclinometric data.

  13. Magnetometer Data Tests Models for the Origin of the Martian Crustal Dichotomy; Dichotomy Models Constrain Timing of Martian Magnetic Field

    NASA Technical Reports Server (NTRS)

    Gilmore, M. S.

    1999-01-01

    Measurements recently supplied by the MGS Magnetometer/Electron Reflectometer (MAG/ER) on MGS can be applied to test theories of the origin of the martian crustal dichotomy. Strong (+/- 1500 nT) magnetic anomalies are observed in the Martian crust. The observations can be summarized as follows: 1) strong crustal magnetic sources are generally confined to the southern highlands, although weaker (approx. 40 nT) anomalies were observed during close periapsis; 2) strong magnetic anomalies are absent in the vicinity of Hellas and Argyre; 3) the anomalies in the region 0 deg to 90 deg S, 120 deg to 240 deg west have a linear geometry, strike generally east west for 1000s km, and show several reversals. This latter point has led to the suggestion that some form of lateral plate tectonics may have been operative in the southern highlands of Mars. These observations have led previous workers to hypothesize that the magnetic anomalies were present prior to and were destroyed by the formation of Hellas and Argyre. As such large impacts are confined to the era of heavy bombardment, this places the time of formation of large magnetic anomalies prior to approx. 3.9 Ga. One obvious extension of this is that the northern lowlands lack significant anomalies because they were erased by impacts and/or the northern lowlands represent crust completely reheated above the Curie temperature. Preliminary observations of the distributions of the large crustal magnetic anomalies show that many of them extend continuously over the highland lowland boundary. This occurs particularly north of the boundary between 30 deg W and 270 deg W, corresponding to northern Arabia, but also occurs in southern Elysium (approx. 10 deg S, 200 deg) and the SW portion of Tharsis (approx. 15 deg S, 140 deg). This suggests that, in these areas, Noachian crust containing the greater than 3.9 Ga magnetic signature, lies beneath the northern highlands. This geometry can be used to test models for the formation of

  14. Self-consistent Model of Martian Dichotomy Formation and Tharsis Evolution?

    NASA Astrophysics Data System (ADS)

    Sramek, O.; Zhong, S.

    2010-12-01

    The hemispheric crustal dichotomy and the Tharsis volcanic province are major global physiographic features on Mars, whose origin has not yet been satisfactorily explained. Hypotheses for the dichotomy origin invoke both external causes (i.e., a giant impact) and mechanisms of internal dynamics (e.g., long-wavelength mantle convection, or a large-scale overturn of unstable post-magma ocean cumulates). Recently, Zhong (2009) proposed a link between the preexisting dichotomy, and the formation and early evolution of Tharsis. He considered lithospheric thickness with a strong hemispheric asymmetry, where thicker lithosphere below the thicker crust in the southern highlands represents devolatilized residue after more extensive partial melting assumed to be responsible for the dichotomy formation. The thermal upwellings of long-wavelength convection then first form below the thickest lithosphere. Subsequently, the strong lateral viscosity variations result in a relative motion between the one-plate lithosphere and the upwelling, such that the upwelling migrates toward regions of smaller lithospheric thickness. This model is capable of explaining the apparent early migration of the Tharsis volcanic centers and their stabilization near the dichotomy boundary (Sramek & Zhong, 2010). However, our previous models did not consider melting, which prevented us from addressing the question of how the large lithospheric thickness variation is produced. Recent modeling results of Keller & Tackley (2009) suggest that dichotomy may have been formed by partial melting of the mantle showing a spherical harmonic degree 1 convection pattern. However, they did not consider devolatilization effects of partial melting and the modulation of the flow by the stiff melt residue. We present a series of numerical experiments of long-wavelength convection in Martial mantle, where we consider the effect of partial melt residue stiffening on the plume-lithosphere dynamics, in order to asses the

  15. The MOLA Topographic signature at the crustal dichotomy boundary zone on Mars

    NASA Astrophysics Data System (ADS)

    Frey, Herbert; Sakimoto, Susan E.; Roark, James

    1998-12-01

    MOLA data collected during the aerobraking hiatus provide good longitudinal sampling of the crustal dichotomy boundary zone in eastern Mars and reveal a significant topographic signature associated with the transition from cratered highlands to lowland plains. Total relief between the two major units is always >2.5 km and sometimes >6 km; median elevation differences are about 4 km. Regional slopes are very low (<0.02°) in both cratered terrain south and in lowland plains north of the boundary. Within the transition zone where cratered terrain changes to detached plateaus, mesas and knobby terrain, slopes are 50-100 times steeper and over a few hundred kilometers average about 1°. The topographic signature of the boundary zone is best described as a 2-4 km step function between two nearly flat surfaces, similar in slope and amplitude to some terrestrial passive margins. This supports previous conclusions of a significant difference in crustal properties (thickness, composition, or both) between the lowland plains and cratered terrain, and suggests this difference occurs over a relatively short distance of a few to several hundred kilometers.

  16. Geologic Evolution of the Martian Dichotomy and Plains Magnetization in the Ismenius Area of Mars

    NASA Technical Reports Server (NTRS)

    Smrekar, S. E.; McGill, G. E.; Raymond, C. A.; Dimitriou, A. M.

    2004-01-01

    The global dichotomy divides the northern lowlands from the southern highlands, except where interrupted by relatively young volcanic provinces and impact basins. An elevation change of 2-4 km is typical across the dichotomy, and more than 6 km locally, over distances of several 100s km to as much as 1300 km [1,2]. A variety of exogenic and endogenic formation models have been proposed. Distinguishing between these models would help constrain the overall thermal evolution of the planet, possibly timing of core formation, and the associated mantle heat flux over time. A first step is to determine whether or not gravitational relaxation plays a role in modifying the boundary. Nimmo and Stevenson [3] examined 10 profiles across the dichotomy and used models of gravitational relaxation to conclude the relaxation has not occurred. In this study we begin by considering the geologic history in detail as inputs for modeling [4].

  17. Constraints on Thermal Evolution of Mars from Relaxation Models of Crustal and Topographic Dichotomy

    NASA Technical Reports Server (NTRS)

    Guest, A.; Smrekar, S. E.

    2005-01-01

    The early thermal evolution of Mars is largely unconstrained. Models such as degree one convection [1,2,3], plate tectonics [4], and a transition to stagnant lid [5] have been proposed to explain formation of the dichotomy, the Tharsis rise, crustal production, and dynamo evolution. Here we model both the early deformation of the dichotomy and the long-term preservation as a means of examining the plausibility of a range of early thermal evolution models. Constraints include the preservation of crustal thickness and topographic differences between the northern and southern hemispheres and the geologic history of the dichotomy [6]). Our previous modeling indicates that the lower crust must have been weak enough to allow for relaxation early on, but the Martian interior had to cool fast enough to preserve the crustal difference and the associated topographic difference (5 km) over approx. 3-3.5 Gyr [7].

  18. Relaxation of the Martian Crustal Dichotomy Boundary in the Ismenius Region

    NASA Technical Reports Server (NTRS)

    Guest, A.; Smrekar, S. E.

    2004-01-01

    The origin of the Martian crustal dichotomy remains a puzzle that when solved can provide an insight to the geological and geophysical evolution of Mars. In this study we model crustal relaxation in order to better constrain the original topographic shape, rheology, and temperature of the Martian crust. Our approach is to model the detailed geologic history of the Ismenius region of Mars, including slope, strain, and timing of faulting [1]. This region may contain the best preserved section of the dichotomy boundary as it is relatively unaffected by large impacts and erosion. So far the only study Martian crustal relaxation [2] suggests that the original topographic shape of the dichotomy is preserved. However, in this area strain from faulting implies at least some relaxation [1].

  19. Constraints on the Evolution of the Dichotomy Boundary at 50-90E

    NASA Technical Reports Server (NTRS)

    Smrekar, S. E.; Raymond, C. A.; Dimitriou, A.; McGill, G. E.

    2003-01-01

    The global dichotomy is a fundamental feature of Mars. It marks the boundary between the highly cratered, older southern highlands, and the northern plains. Recent analysis of buried craters in the northern lowlands confirms the long held suspicion that they are comparable in age to the southern highlands, but with surficial deposits of younger material. A variety of exogenic and endogenic models have been proposed for the origin of the dichotomy, including multiple impacts, plate tectonics, and degree one convection produced by core formation, a plume under the lowlands, or a plume under the highlands. New gravity and topography data from the Mars Global Surveyor (MGS) Mission favor endogenic processes. In this study we examine MGS topography, gravity and magnetic field data to constrain the tectonic history the dichotomy in the region 30-60N and 50-90E, which encompasses portions of the Ismenius Lacus quadrangle. The dichotomy formed very early the history of Mars and has undergone extensive modification by impact cratering, erosion, and faulting. This history must be carefully interpreted in order to reconstruct the original nature of the dichotomy boundary and ultimately discriminate between models of origin. In the study area boundary-parallel faults are well preserved, and may be the result of gravitational relaxation. The geologic history has been examined in detail, including estimates of volumes of material eroded. Further, it is one of the few regions where there is a correlation between the free air gravity, magnetic anomalies, and the geology. This allows to constrain subsurface faulting beneath the lowlands fill material. In addition to being an excellent location to unravel the complex history of the dichotomy, this area preserves the transition from a highly magnetized highlands crust to an unmagnetized or slightly magnetized lowlands crust.

  20. Continuous Time Random Walk and Migration-Proliferation Dichotomy of Brain Cancer

    NASA Astrophysics Data System (ADS)

    Iomin, A.

    2015-10-01

    A theory of fractional kinetics of glial cancer cells is presented. A role of the migration-proliferation dichotomy in the fractional cancer cell dynamics in the outer-invasive zone is discussed and explained in the framework of a continuous time random walk. The main suggested model is based on a construction of a 3D comb model, where the migration-proliferation dichotomy becomes naturally apparent and the outer-invasive zone of glioma cancer is considered as a fractal composite with a fractal dimension Dfr < 3.

  1. Continuous Time Random Walk and Migration-Proliferation Dichotomy of Brain Cancer

    NASA Astrophysics Data System (ADS)

    Iomin, A.

    A theory of fractional kinetics of glial cancer cells is presented. A role of the migration-proliferation dichotomy in the fractional cancer cell dynamics in the outer-invasive zone is discussed and explained in the framework of a continuous time random walk. The main suggested model is based on a construction of a 3D comb model, where the migration-proliferation dichotomy becomes naturally apparent and the outer-invasive zone of glioma cancer is considered as a fractal composite with a fractal dimension Dfr < 3.

  2. Radiowaves and Tectonic Dichotomy: Two Sides of One Coin

    NASA Astrophysics Data System (ADS)

    Kochemasov, G.

    The first theorem of the wave planetology states that "Celestial bodies are di- chotomic"[1]. This notion is best demonstrated by modulation of the high frequency orbiting in the Solar system (SS) by the low frequency orbiting the SS in Galaxy. Or- biting frequencies of all bodies in the SS -from 1/8 hours for Phobos to 1/248 years for Pluto - are high comparative to the SS orbiting in Galaxy -about 1/200 000 000 years. Modulation of a high frequency by a low frequency brings about side frequencies at both sides of a high frequency. Earlier we considered only one side of the modula- tion stressing that the lower side frequency in any celestial body can achieve only the fundamental wave and produce related to it inevitable tectonic dichotomy [2]. Now we consider the higher side frequencies and find that they are in the limits of the ra- dio frequencies. Dividing all possible orbiting frequencies of bodies in the SS by the SS orbiting frequency in Galaxy one comes to a range of side frequencies from mi- crowaves to kilometer waves. This finding is rather important as it is well known that all bodies of the SS emit often enigmatic radiowaves. Figuratively, the SS is wrapped by a cloud of crossing radiowaves of various frequencies. Some calculations below show modulation of tectonic granula sizes of some celestial bodies. A granula size is a half of a wavelength which is tied to an orbiting frequency. A scale is the Earth's orbiting period 1 year and the granula size pR/4. The tectonic granula sizes of bodies are proportional to their orbital periods (Theorem 3 [1[). The modulating frequency is 1/200 000 000 years. Jupiter (12 y : 200 000 000 y) pR= (12 : 200 000 000) 3.14°u 71400 km=13.4 m tectonic granula or 26.8 m wavelength. Varying orbital periods and bodies'radia one comes to the following wavelengths. Jupiter-26.8 m, Saturn-56.4 m, Uranus-67 m, Neptune-124 m, Pluto-10.9 m, Sun-1.46 m, Triton-11.4 m (for the cir- cumsolar frequency), 1.84 mm (circumneptunian fr

  3. Dichotomy Boundary Glaciation Models: Implications for Timing and Glacial Processes

    NASA Astrophysics Data System (ADS)

    Fastook, J. L.; Head, J. W.

    2008-12-01

    An integrated system with glacial features exists at 34E, 41N in the Deuteronilus-Protonilus Mensae region. This 30,000 km2 valley system is typical of dozens of fretted valleys in this region along the dichotomy boundary. We compare features described in current geological observations with results from the University of Maine Ice Sheet Model (UMISM) that we feel support the glacial interpretation of these features and also allow speculation as to the timing and processes responsible for the formation of these features. Geological observations identify evidence for a number of features that are felt to be indicative of glacial flow. These include: 1) localized alcoves from which emanate narrow, lobate concentric-ridged flows interpreted to be remnants of debris-covered glaciers; 2) alcove depressions perhaps indicating sublimation of material from relict ice-rich accumulation zones; 3) plateau-ridge remnants between alcoves typical of glacially eroded aretes; 4) horseshoe-shaped ridges upstream of topographic obstacles; 5) convergence and merging of LVF fabric in the down-valley direction; 6) deformation, distortion and folding of LVF in the vicinity of convergence; 7) LVF with pits and elongated troughs in distorted areas; 8) distinctive lobe-shaped termini with associated pitting where the LVF emerges into the northern lowlands. This evidence defines a coherent, unified flow regime extending from the upper valley reaches down to the northern lowlands. Additional support for the glacial hypothesis comes from a GCM for a dusty-atmosphere Mars with obliquity set to 35o and a water source in the Tharsis region. The GCM generates a pattern of ice accumulation in good agreement with these geological observations. This climate is what one might expect to follow a high- obliquity excursion of the sort that built ice sheets on the Tharsis volcanoes. UMISM as used here is an adaptation for the Martian environment of a thermo-mechanically coupled shallow- ice approximation

  4. The Dichotomy of Endoplasmic Reticulum Stress Response in Liver Ischemia-Reperfusion Injury.

    PubMed

    Zhou, Haomming; Zhu, Jianjun; Yue, Shi; Lu, Ling; Busuttil, Ronald W; Kupiec-Weglinski, Jerzy W; Wang, Xuehao; Zhai, Yuan

    2016-02-01

    Endoplasmic reticulum (ER) stress plays critical roles in the pathogenesis of liver ischemia-reperfusion injury (IRI). As ER stress triggers an adaptive cellular response, the question of what determines its functional outcome in liver IRI remains to be defined. In a murine liver partial warm ischemia model, we studied how transient (30 minutes) or prolonged (90 minutes) liver ischemia regulated local ER stress response and autophagy activities and their relationship with liver IRI. Effects of chemical chaperon 4-phenylbutyrate (4-PBA) or autophagy inhibitor 3-methyladenine (3-MA) were evaluated. Our results showed that although the activating transcription factor 6 branch of ER stress response was induced in livers by both types of ischemia, liver autophagy was activated by transient, but inhibited by prolonged, ischemia. Although 3-MA had no effects on liver IRI after prolonged ischemia, it significantly increased liver IRI after transient ischemia. The 4-PBA treatment protected livers from IRI after prolonged ischemia by restoring autophagy flux, and the adjunctive 3-MA treatment abrogated its liver protective effect. The same 4-PBA treatment, however, increased liver IRI and disrupted autophagy flux after transient ischemia. Although both types of ischemia activated 5' adenosine monophosphate-activated protein kinase and inactivated protein kinase B (Akt), prolonged ischemia also resulted in downregulations of autophagy-related gene 3 and autophagy-related gene 5 in ischemic livers. These results indicate a functional dichotomy of ER stress response in liver IRI via its regulation of autophagy. Transient ischemia activates autophagy to protect livers from IRI, whereas prolonged ischemia inhibits autophagy to promote the development of liver IRI. PMID:26683513

  5. Can medio-lateral baseplate position and load sharing induce asymptomatic local bone resorption of the proximal tibia? A finite element study

    PubMed Central

    Innocenti, Bernardo; Truyens, Evelyn; Labey, Luc; Wong, Pius; Victor, Jan; Bellemans, Johan

    2009-01-01

    Background Asymptomatic local bone resorption of the tibia under the baseplate can occasionally be observed after total knee arthroplasty (TKA). Its occurrence is not well documented, and so far no explanation is available. We report the incidence of this finding in our practice, and investigate whether it can be attributed to specific mechanical factors. Methods The postoperative radiographs of 500 consecutive TKA patients were analyzed to determine the occurrence of local medial bone resorption under the baseplate. Based on these cases, a 3D FE model was developed. Cemented and cementless technique, seven positions of the baseplate and eleven load sharing conditions were considered. The average VonMises stress was evaluated in the bone-baseplate interface, and the medial and lateral periprosthetic region. Results Sixteen cases with local bone resorption were identified. In each, bone loss became apparent at 3 months post-op and did not increase after one year. None of these cases were symptomatic and infection screening was negative for all. The FE analysis demonstrated an influence of baseplate positioning, and also of load sharing, on stresses. The average stress in the medial periprosthetic region showed a non linear decrease when the prosthetic baseplate was shifted laterally. Shifting the component medially increased the stress on the medial periprosthetic region, but did not significantly unload the lateral side. The presence of a cement layer decreases the stresses. Conclusion Local bone resorption of the proximal tibia can occur after TKA and might be attributed to a stress shielding effect. This FE study shows that the medial periprosthetic region of the tibia is more sensitive than the lateral region to mediolateral positioning of the baseplate. Medial cortical support of the tibial baseplate is important for normal stress transfer to the underlying bone. The absence of medial cortical support of the tibial baseplate may lead to local bone resorption at

  6. Reconciling Evidenced-Based Research Practice with Rehabilitation Philosophy, Ethics and Practice: From Dichotomy to Dialectic

    ERIC Educational Resources Information Center

    Tarvydas, Vilia; Addy, Amanda; Fleming, Allison

    2010-01-01

    The recent shift in the helping professions to the implementation of evidenced-based practice (EBP) presents challenges to the field of rehabilitation counseling, most notably in the areas of integrating rehabilitation philosophy, ethics, and the relationship between research and practice. A dichotomy between the history and the future of the…

  7. Dysfunctional Dichotomies? Deflating Bipolar Constructions of Curriculum and Pedagogy through Case Studies from Music and History

    ERIC Educational Resources Information Center

    Cain, Tim; Chapman, Arthur

    2014-01-01

    Recent public discussions of curriculum and pedagogy that have accompanied the English National Curriculum review have been structured around clichéd dichotomies that generate more heat than light and that, as Robin Alexander has argued, reduce complex educational debates to oppositional and incompatible slogans. This paper begins by exploring the…

  8. "Learning" and "Acquisition" -- How Real Is the Dichotomy: Some Neurophysical Evidence.

    ERIC Educational Resources Information Center

    Lueers, Nancy M.

    The dichotomy of language acquisition versus language learning is critically examined by comparing the concepts presented in Krashen's Monitor Model and Stevick's Levertov Machine to information from the field of neurophysiology regarding the brain's processes. It is proposed that support exists for the theory that two very different processes…

  9. Are You a Native Speaker of English? Moving beyond a Simplistic Dichotomy

    ERIC Educational Resources Information Center

    Faez, Farahnaz

    2011-01-01

    Despite considerable discussion and controversy over the native/nonnative distinction, there is no satisfactory definition of the terms. In addition, the literature tends to reduce the complexity of the distinction to an overly simplistic and problematic dichotomy. Using a qualitative case study approach, this research article examines the…

  10. Dichotomy, Dialectic and Dialogic: How Do Sociology Terms Assist Career Development Theory?

    ERIC Educational Resources Information Center

    Burns, Edgar A. M.

    2012-01-01

    Three concepts from sociology--dichotomy and two extensions, dialectic and dialogic--are considered here as social-psychological tools for career practitioners who analyse and investigate career patterns, career motivations and career pathways, whether at career start or at further points of transition. These terms have macro-social applications…

  11. Preferential States of the Dichotomy of Human Nature: Art and Science

    ERIC Educational Resources Information Center

    Legaspi, John G. Thomas Amador

    2007-01-01

    It is essential that the roots of the division in western culture presented by CP Snow's "Two Cultures" be examined in order to view their many present day ramifications and solutions. The purpose of this paper is to explore the dichotomy of our artistic and scientific origins biologically, socially, economically, spiritually and…

  12. Moving beyond the Deep and Surface Dichotomy; Using Q Methodology to Explore Students' Approaches to Studying

    ERIC Educational Resources Information Center

    Godor, Brian P.

    2016-01-01

    Student learning approaches research has been built upon the notions of deep and surface learning. Despite its status as part of the educational research canon, the dichotomy of deep/surface has been critiqued as constraining the debate surrounding student learning. Additionally, issues of content validity have been expressed concerning…

  13. Measuring Information Processing Speed in Mild Cognitive Impairment: Clinical Versus Research Dichotomy

    PubMed Central

    Haworth, Judy; Phillips, Michelle; Newson, Margaret; Rogers, Peter J.; Torrens-Burton, Anna; Tales, Andrea

    2016-01-01

    A substantial body of research evidence is indicative of disproportionately slowed information processing speed in a wide range of multi-trial, computer-based, neuroimaging- and electroencephalography-based reaction time (RT) tests in Alzheimer’s disease and mild cognitive impairment (MCI). However, in what is arguably a dichotomy between research evidence and clinical practice, RT associated with different brain functions is rarely assessed as part of their diagnosis. Indeed, often only the time taken to perform a single, specific task, commonly the Trail making test (TMT), is measured. In clinical practice therefore, there can be a failure to assess adequately the integrity of the rapid, serial information processing and response, necessary for efficient, appropriate, and safe interaction with the environment. We examined whether a typical research-based RT task could at least match the TMT in differentiating amnestic MCI (aMCI) from cognitively healthy aging at group level. As aMCI is a heterogeneous group, typically containing only a proportion of individuals for whom aMCI represents the early stages of dementia, we examined the ability of each test to provide intra-group performance variation. The results indicate that as well as significant slowing in performance of the operations involved in TMT part B (but not part A), individuals with aMCI also experience significant slowing in RT compared to controls. The results also suggest that research-typical RT tests may be superior to the TMT in differentiating between cognitively healthy aging and aMCI at group level and in revealing the performance variability one would expect from an etiologically heterogeneous disorder such as aMCI. PMID:26836171

  14. Measuring Information Processing Speed in Mild Cognitive Impairment: Clinical Versus Research Dichotomy.

    PubMed

    Haworth, Judy; Phillips, Michelle; Newson, Margaret; Rogers, Peter J; Torrens-Burton, Anna; Tales, Andrea

    2016-01-01

    A substantial body of research evidence is indicative of disproportionately slowed information processing speed in a wide range of multi-trial, computer-based, neuroimaging- and electroencephalography-based reaction time (RT) tests in Alzheimer's disease and mild cognitive impairment (MCI). However, in what is arguably a dichotomy between research evidence and clinical practice, RT associated with different brain functions is rarely assessed as part of their diagnosis. Indeed, often only the time taken to perform a single, specific task, commonly the Trail making test (TMT), is measured. In clinical practice therefore, there can be a failure to assess adequately the integrity of the rapid, serial information processing and response, necessary for efficient, appropriate, and safe interaction with the environment. We examined whether a typical research-based RT task could at least match the TMT in differentiating amnestic MCI (aMCI) from cognitively healthy aging at group level. As aMCI is a heterogeneous group, typically containing only a proportion of individuals for whom aMCI represents the early stages of dementia, we examined the ability of each test to provide intra-group performance variation. The results indicate that as well as significant slowing in performance of the operations involved in TMT part B (but not part A), individuals with aMCI also experience significant slowing in RT compared to controls. The results also suggest that research-typical RT tests may be superior to the TMT in differentiating between cognitively healthy aging and aMCI at group level and in revealing the performance variability one would expect from an etiologically heterogeneous disorder such as aMCI. PMID:26836171

  15. The great dichotomy of the Solar System: Small terrestrial embryos and massive giant planet cores

    NASA Astrophysics Data System (ADS)

    Morbidelli, A.; Lambrechts, M.; Jacobson, S.; Bitsch, B.

    2015-09-01

    The basic structure of the Solar System is set by the presence of low-mass terrestrial planets in its inner part and giant planets in its outer part. This is the result of the formation of a system of multiple embryos with approximately the mass of Mars in the inner disk and of a few multi-Earth-mass cores in the outer disk, within the lifetime of the gaseous component of the protoplanetary disk. What was the origin of this dichotomy in the mass distribution of embryos/cores? We show in this paper that the classic processes of runaway and oligarchic growth from a disk of planetesimals cannot explain this dichotomy, even if the original surface density of solids increased at the snowline. Instead, the accretion of drifting pebbles by embryos and cores can explain the dichotomy, provided that some assumptions hold true. We propose that the mass-flow of pebbles is two-times lower and the characteristic size of the pebbles is approximately ten times smaller within the snowline than beyond the snowline (respectively at heliocentric distance r rice , where rice is the snowline heliocentric distance), due to ice sublimation and the splitting of icy pebbles into a collection of chondrule-size silicate grains. In this case, objects of original sub-lunar mass would grow at drastically different rates in the two regions of the disk. Within the snowline these bodies would reach approximately the mass of Mars while beyond the snowline they would grow to ∼ 20 Earth masses. The results may change quantitatively with changes to the assumed parameters, but the establishment of a clear dichotomy in the mass distribution of protoplanets appears robust provided that there is enough turbulence in the disk to prevent the sedimentation of the silicate grains into a very thin layer.

  16. Familiarity for Associations? A Test of the Domain Dichotomy Theory

    ERIC Educational Resources Information Center

    Harlow, Iain M.; Mackenzie, Graham; Donaldson, David I.

    2010-01-01

    Episodic recognition memory is mediated by functionally separable retrieval processes, notably familiarity (a general sense of prior exposure) and recollection (the retrieval of contextual details), whose relative engagement depends partly on the nature of the information being retrieved. Currently, the specific contribution of familiarity to…

  17. The sense of smell, its signalling pathways, and the dichotomy of cilia and microvilli in olfactory sensory cells

    PubMed Central

    2007-01-01

    Smell is often regarded as an ancillary perception in primates, who seem so dominated by their sense of vision. In this paper, we will portray some aspects of the significance of olfaction to human life and speculate on what evolutionary factors contribute to keeping it alive. We then outline the functional architecture of olfactory sensory neurons and their signal transduction pathways, which are the primary detectors that render olfactory perception possible. Throughout the phylogenetic tree, olfactory neurons, at their apical tip, are either decorated with cilia or with microvilli. The significance of this dichotomy is unknown. It is generally assumed that mammalian olfactory neurons are of the ciliary type only. The existance of so-called olfactory microvillar cells in mammals, however, is well documented, but their nature remains unclear and their function orphaned. This paper discusses the possibility, that in the main olfactory epithelium of mammals ciliated and microvillar sensory cells exist concurrently. We review evidence related to this hypothesis and ask, what function olfactory microvillar cells might have and what signalling mechanisms they use. PMID:17903277

  18. Origin of the Martian global dichotomy by crustal thinning in the late Noachian or early Hesperian

    NASA Technical Reports Server (NTRS)

    Mcgill, George E.; Dimitriou, Andrew M.

    1990-01-01

    The marked dichotomy in topography, surface age, and crustal thickness between the northern lowland (NL) and southern upland of Mars has been explained as due to an initially inhomogeneous crust, a single megaimpact event, several overlapping large basin impacts, and first-order convective overtum of the Martian mantle. All of these hypotheses propose that the dichotomy was formed before the end of the primordial heavy bombardment. Geological data indicate episodes of fracturing and faulting in the late Noachian and the early Hesperian, within the NL and along the lowland/highland boundary. Igneous activity also peaked in the late Noachian and early Hesperian. These data suggest a tectonic event near the Noachian/Hesperian boundary characterized by enhanced heat loss and extensive fracturing, including formation of the faults that define much of the highland/lowland boundary. It is argued that the major result of this tectonic event was formation of the dichotomy by thinning of the crust above a large convection cell or plume.

  19. Maximum Power Point Tracking with Dichotomy and Gradient Method for Automobile Exhaust Thermoelectric Generators

    NASA Astrophysics Data System (ADS)

    Fang, W.; Quan, S. H.; Xie, C. J.; Tang, X. F.; Wang, L. L.; Huang, L.

    2016-03-01

    In this study, a direct-current/direct-current (DC/DC) converter with maximum power point tracking (MPPT) is developed to down-convert the high voltage DC output from a thermoelectric generator to the lower voltage required to charge batteries. To improve the tracking accuracy and speed of the converter, a novel MPPT control scheme characterized by an aggregated dichotomy and gradient (ADG) method is proposed. In the first stage, the dichotomy algorithm is used as a fast search method to find the approximate region of the maximum power point. The gradient method is then applied for rapid and accurate tracking of the maximum power point. To validate the proposed MPPT method, a test bench composed of an automobile exhaust thermoelectric generator was constructed for harvesting the automotive exhaust heat energy. Steady-state and transient tracking experiments under five different load conditions were carried out using a DC/DC converter with the proposed ADG and with three traditional methods. The experimental results show that the ADG method can track the maximum power within 140 ms with a 1.1% error rate when the engine operates at 3300 rpm@71 NM, which is superior to the performance of the single dichotomy method, the single gradient method and the perturbation and observation method from the viewpoint of improved tracking accuracy and speed.

  20. Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars

    NASA Technical Reports Server (NTRS)

    Bleamaster, Leslie F., III; Crown, David A.

    2009-01-01

    Geologic mapping studies at the 1:1M-scale are being used to assess geologic materials and processes that shape the highlands along the Arabia Terra dichotomy boundary. In particular, this mapping will evaluate the distribution, stratigraphic position, and lateral continuity of compositionally distinct outcrops in Mawrth Vallis and Nili Fossae as identified by spectral instruments currently in orbit. Placing these landscapes, their material units, structural features, and unique compositional outcrops into spatial and temporal context with the remainder of the Arabia Terra dichotomy boundary may provide constraints on: 1) origin of the dichotomy boundary, 2) paleo-environments and climate conditions, and 3) various fluvial-nival modification processes related to past and present volatile distribution and their putative reservoirs (aquifers, lakes and oceans, surface and ground ice) and the influences of nearby volcanic and tectonic features on hydrologic processes in these regions. The results of this work will include two 1:1M scale geologic maps of twelve MTM quadrangles (Mawrth Vallis - 20022, 20017, 20012, 25022, 25017, and 25012; and Nili Fossae - 20287, 20282, 25287, 25282, 30287, 30282).

  1. Geologic Mapping along the Arabia Terra Dichotomy Boundary: Mawrth Vallis and Nili Fossae, Mars: Introductory Report

    NASA Technical Reports Server (NTRS)

    Bleamaster, Leslie F., III; Crown, David A.

    2008-01-01

    Geologic mapping studies at the 1:1M-scale will be used to characterize geologic processes that have shaped the highlands along the Arabia Terra dichotomy boundary. In particular, this mapping will evaluate the distribution, stratigraphic position, and lateral continuity of compositionally distinct outcrops in Mawrth Vallis and Nili Fossae as identified by spectral instruments currently in orbit. Placing these landscapes, their material units, structural features, and unique compositional outcrops into spatial and temporal context with the remainder of the Arabia Terra dichotomy boundary will provide the ability to: 1) further test original dichotomy formation hypotheses, 2) constrain ancient paleoenvironments and climate conditions, and 3) evaluate various fluvial-nival modification processes related to past and present volatile distribution and their putative reservoirs (aquifers, lakes and oceans, surface and ground ice) and the influences of nearby volcanic and tectonic features on hydrologic processes in these regions. The result will be two 1:1M scale geologic maps of twelve MTM quadrangles (Mawrth Vallis - 20022, 20017, 20012, 25022, 25017, and 25012; and Nili Fossae - 20287, 20282, 25287, 25282, 30287, 30282).

  2. Reciprocal Activation of Transcription Factors Underlies the Dichotomy between Proliferation and Invasion of Glioma Cells

    PubMed Central

    Dhruv, Harshil D.; McDonough Winslow, Wendy S.; Armstrong, Brock; Tuncali, Serdar; Eschbacher, Jenny; Kislin, Kerri; Loftus, Joseph C.; Tran, Nhan L.; Berens, Michael E.

    2013-01-01

    Histology of malignant glioma depicts dense proliferative areas rich in angiogenesis as well as dissemination of neoplastic cells into adjacent brain tissue. Although the mechanisms that trigger transition from proliferative to invasive phenotypes are complex, the dichotomy of cell proliferation and migration, the “Go or Grow” hypothesis, argues for specific and coordinated regulation of these phenotypes. We investigated transcriptional elements that accompany the phenotypes of migration and proliferation, and consider the therapeutic significance of the “Go or Grow” hypothesis. Interrogation of matched core and rim regions from human glioblastoma biopsy specimens in situ (n = 44) revealed higher proliferation (Ki67 labeling index) in cells residing at the core compared to the rim. Profiling activated transcription factors in a panel of migration-activated versus migration-restricted GBM cells portrayed strong NF-κB activity in the migratory cell population. In contrast, increased c-Myc activity was found in migration-restricted proliferative cells. Validation of transcriptional activity by NF-κB- or c-Myc-driven GFP or RFP, respectively, showed an increased NF-κB activity in the active migrating cells, whereas the proliferative, migration restricted cells displayed increased c-Myc activity. Immunohistochemistry on clinical specimens validated a robust phosphorylated c-Myc staining in tumor cells at the core, whereas increased phosphorylated NF-κB staining was detected in the invasive tumor cells at the rim. Functional genomics revealed that depletion of c-Myc expression by siRNA oligonucleotides reduced cell proliferation in vitro, but surprisingly, cell migration was enhanced significantly. Conversely, inhibition of NF-κB by pharmacological inhibitors, SN50 or BAY-11, decreased both cell migration in vitro and invasion ex vivo. Notably, inhibition of NF-κB was found to have no effect on the proliferation rate of glioma cells. These findings

  3. Ganymede and Callisto - Surface textural dichotomies and photometric analysis

    NASA Technical Reports Server (NTRS)

    Buratti, Bonnie J.

    1991-01-01

    Complete solar phase curves of the Ganymede and Callisto leading and trailing hemispheres, which have been obtained by reducing Voyager imaging observations and combining them with ground-based telescopic data, are presently fit to scattering models in order to derive hemispherical values of the single scattering albedo, the single particle phase function (SPPF), the compaction state (CS) of the optically active portion of the regolith, and the mean slope angle of macroscopic features. While Callisto's leading side is composed of particles that are more strongly backscattering than the trailing side, no hemispheric differences are found in the CS, surface roughness, or SPPF.

  4. Neither metaphysical dichotomy nor pure identity: clarifying the emergentist creed.

    PubMed

    Sartenaer, Olivier

    2013-09-01

    Emergentism is often misleadingly described as a monolithic "third way" between radical monism and pluralism. In the particular case of biology, for example, emergentism is perceived as a middle course between mechanicism and vitalism. In the present paper I propose to show that the conceptual landscape between monism and pluralism is more complex than this classical picture suggests. On the basis of two successive analyses-distinguishing three forms of tension between monism and pluralism and a distinction between derivational and functional reduction-I define three different versions of emergentism that can be considered as consistent middle courses between monism and pluralism (respectively theoretical, explanatory and causal emergence). I then emphasise the advantage of this taxonomy of the concepts of emergence by applying the results of my analysis to the historical controversy that pertains to the relationship between life and matter. PMID:23701955

  5. Classical-quantum arbitrarily varying wiretap channel: Ahlswede dichotomy, positivity, resources, super-activation

    NASA Astrophysics Data System (ADS)

    Boche, Holger; Cai, Minglai; Deppe, Christian; Nötzel, Janis

    2016-08-01

    We establish the Ahlswede dichotomy for arbitrarily varying classical-quantum wiretap channels, i.e., either the deterministic secrecy capacity of the channel is zero, or it equals its randomness-assisted secrecy capacity. We analyze the secrecy capacity of these channels when the sender and the receiver use various resources. It turns out that randomness, common randomness, and correlation as resources are very helpful for achieving a positive secrecy capacity. We prove the phenomenon "super-activation" for arbitrarily varying classical-quantum wiretap channels, i.e., two channels, both with zero deterministic secrecy capacity, if used together allow perfect secure transmission.

  6. Regional Studies of Highland-Lowland Age Differences Across the Mars Crustal Dichotomy Boundary

    NASA Technical Reports Server (NTRS)

    Frey, H. V.; DeSoto, G. E.; Lazrus, R. M.

    2005-01-01

    Regional differences in crater retention ages (CRAs) across the Mars dichotomy boundary are compared to the global highland-lowland age difference previously determined from visible and buried impact basins based on MOLA-derived Quasi-Circular Depressions (QCDs). Here Western Arabia (WA) is compared with Ismenius Lacus (IL). We find the buried lowlands in the two regions have total CRAs essentially identical to the global average. Even more intriguing, the WA cratered terrain appears to have a CRA like that of the adjacent buried lowlands,

  7. "A temporary oversimplification": Mayr, Simpson, Dobzhansky, and the origins of the typology/population dichotomy (part 1 of 2).

    PubMed

    Witteveen, Joeri

    2015-12-01

    The dichotomy between 'typological thinking' and 'population thinking' features in a range of debates in contemporary and historical biology. The origins of this dichotomy are often traced to Ernst Mayr, who is said to have coined it in the 1950s as a rhetorical device that could be used to shield the Modern Synthesis from attacks by the opponents of population biology. In this two-part essay I argue that the origins of the typology/population dichotomy are considerably more complicated and more interesting than is commonly thought. In this first part, I will argue that Mayr's dichotomy was based on two distinct type/population contrasts that had been articulated much earlier by George Gaylord Simpson and Theodosius Dobzhansky. Their distinctions made eminent sense in their own, isolated contexts. In the second part, I will show how Mayr conflated these type/population distinctions and blended in some of his own, unrelated concerns with 'types' of a rather different sort. Although Mayr told his early critics that he was merely making "a temporary oversimplification," he ended up burdening the history and philosophy of biology with a troubled dichotomy. PMID:26471927

  8. "A temporary oversimplification": Mayr, Simpson, Dobzhansky, and the origins of the typology/population dichotomy (part 2 of 2).

    PubMed

    Witteveen, Joeri

    2016-06-01

    The dichotomy between 'typological thinking' and 'population thinking' features in a range of debates in contemporary and historical biology. The origins of this dichotomy are often traced to Ernst Mayr, who is said to have coined it in the 1950s as a rhetorical device that could be used to shield the Modern Synthesis from attacks by the opponents of population biology. In this two-part essay, I argue that the origins of the typology/population dichotomy are considerably more complicated and more interesting than is commonly thought. In the first part, I argued that Mayr's dichotomy was based on two distinct type/population contrasts that had been articulated much earlier by George Gaylord Simpson and Theodosius Dobzhansky. Their distinctions made eminent sense in their own, isolated contexts. In this second part, I will show how Mayr conflated these type/population distinctions and blended in some of his own, unrelated concerns with 'types' of a rather different sort. Although Mayr told his early critics that he was merely making "a temporary oversimplification," he ended up burdening the history and philosophy of biology with a troubled dichotomy. PMID:26471926

  9. On the dichotomy in auditory perception between temporal envelope and fine structure cues (L)

    NASA Astrophysics Data System (ADS)

    Zeng, Fan-Gang; Nie, Kaibao; Liu, Sheng; Stickney, Ginger; del Rio, Elsa; Kong, Ying-Yee; Chen, Hongbin

    2004-09-01

    It is important to know what cues the sensory system extracts from natural stimuli and how the brain uses them to form perception. To explore this issue, Smith, Delgutte, and Oxenham [Nature (London) 416, 87-90 (2002)] mixed one sound's temporal envelope with another sound's fine temporal structure to produce auditory chimaeras and found that ``the perceptual importance of the envelope increases with the number of frequency bands, while that of the fine structure diminishes.'' This study addressed two technical issues related to natural cochlear filtering and artificial filter ringing in the chimaerizing algorithm. In addition, this study found that the dichotomy in auditory perception revealed by auditory chimaeras is an epiphenomenon of the classic dichotomy between low- and high-frequency processing. Finally, this study found that the temporal envelope determines sound location as long as the interaural level difference cue is present. The present result reinforces the original hypothesis that the temporal envelope is critical for speech perception whereas temporal fine structure is critical for pitch perception, but does not support the assertion regarding the temporal envelope and fine structure as the acoustic basis for the ``what'' and ``where'' mechanisms.

  10. Impact Constraints on the Age and Origin of the Crustal Dichotomy on Mars

    NASA Technical Reports Server (NTRS)

    Frey, Herbert V.

    2004-01-01

    MOLA data have revealed a large population of 'Quasi-Circular Depressions' (QCDs) with little or no visible expression in image data. These likely buried impact basins have important implications for the age of the lowland crust, how that compares with original highland crust, and when and how the crustal dichotomy may have formed. The buried lowlands are of Early Noachian age, likely slightly younger than the buried highlands but older than the exposed (visible) highland surface. A depopulation of large visible basins at diameters 800 to 1300 km suggests some global scale event early in martian history, maybe related to the formation of the lowlands and/or the development of Tharsis. A suggested early disappearance of the global magnetic field can be placed within a temporal sequence of formation of the very largest impact basins. The global field appears to have disappeared at about the time the lowlands formed. It seems likely the topographic crustal dichotomy was produced very early in martian history by processes which operated very quickly. This and the preservation of large relic impact basins in the northern hemisphere, which themselves can account for the lowland topography, suggest that large impacts played the major role in the origin Mars fundamental crustal feature.

  11. Of natural bodies and antibodies: Parents' vaccine refusal and the dichotomies of natural and artificial.

    PubMed

    Reich, Jennifer A

    2016-05-01

    Despite eliminating incidences of many diseases in the United States, parents are increasingly rejecting vaccines for their children. This article examines the reasons parents offer for doing so. It argues that parents construct a dichotomy between the natural and the artificial, in which vaccines come to be seen as unnecessary, ineffective, and potentially dangerous. Using qualitative data from interviews and observations, this article shows first, how parents view their children's bodies, particularly from experiences of birth and with infants, as naturally perfect and in need of protection. Second, parents see vaccines as an artificial intervention that enters the body unnaturally, through injection. Third, parents perceive immunity occurring from illness to be natural and superior and immunity derived from vaccines as inferior and potentially dangerous. Finally, parents highlight the ways their own natural living serves to enhance their children's immunity rendering vaccines unnecessary. Taken together, this dichotomy allows parents to justify rejection of vaccines as a form of protecting children's health. These findings expose perceptions of science, technology, health, and the meanings of the body in ways that can inform public health efforts. PMID:27082021

  12. Indigenous Knowledge and Education from the Quechua Community to School: Beyond the Formal/Non-Formal Dichotomy

    ERIC Educational Resources Information Center

    Sumida Huaman, Elizabeth; Valdiviezo, Laura Alicia

    2014-01-01

    In this article, we propose to approach Indigenous education beyond the formal/non-formal dichotomy. We argue that there is a critical need to conscientiously include Indigenous knowledge in education processes from the school to the community; particularly, when formal systems exclude Indigenous cultures and languages. Based on ethnographic…

  13. Theory-Practice Dichotomy in Inquiry: Meanings and Preservice Teacher-Mentor Teacher Tension in Turkish Literacy Classrooms

    ERIC Educational Resources Information Center

    Yayli, Derya

    2008-01-01

    This study aims at exploring the meanings constructed by preservice teachers of literacy about theory-practice dichotomy and investigating the preservice teacher-mentor teacher tension during the internship period. Qualitative data were collected by preservice teachers as researchers in inquiry through field notes, reflective journals, observation…

  14. How Can We Overcome the Dichotomy That Western Culture Has Created between the Concepts of Independence and Dependence?

    ERIC Educational Resources Information Center

    Gross, Zehavit

    2015-01-01

    The purpose of this article, inspired by the works of Martin Buber, is to propose an alternative to the inherent dichotomy of Western culture. It may allow Western culture to transcend its fixed nature towards new directions and to suggest challenging solutions for reshaping the questions--what is the role of man in the world, and what is the…

  15. Components of Candidate Images: Statistical Analysis of the Issue-Persona Dichotomy in the Presidential Campaign of 1996.

    ERIC Educational Resources Information Center

    Hacker, Kenneth L.; Zakahi, Walter R.; Giles, Maury J.; McQuitty, Shaun

    2000-01-01

    Describes the results of a study intended to test a specific hypothesis and a research question related to the theoretical development of the candidate image construct in political communication. Tests the long-standing assumption that there is a dichotomy between candidate issue positions and candidate persona impressions ("images"). Finds no…

  16. Chaotic motion of Europa and Ganymede and the Ganymede-Callisto dichotomy

    NASA Technical Reports Server (NTRS)

    Tittemore, William C.

    1990-01-01

    Europa and Ganymede may have undergone an episode of chaotic motion before the establishment of the current Laplace resonance involving the three inner GAlilean satellites. During this episode, the orbital eccentricities of both satellites may have increased dramatically. As a result, the mechanical stresses due to tidal deformation of the satellites' icy lithospheres may have been large enough to result in extensive fracturing, and tidal heating may have melted water ice in the mantles of both satellites, triggering the geological activity that has modified their surfaces since the heavy cratering period. The tidal effects on Ganymede during this episode provide an explanation of the dichotomy between it and Callisto, which have similar bulk properties but very different geological histories.

  17. Multiple populations in globular clusters and the origin of the Oosterhoff dichotomy

    NASA Astrophysics Data System (ADS)

    Jang, S.; Lee, Y.-W.

    2016-05-01

    The globular cluster community is now facing a new paradigm of multiple stellar populations. In light of this, we have recently proposed a new model to explain the origin of the difference in mean period of type ab RR Lyrae variables between the two Oosterhoff groups. In our model, the instability strip in the metal-poor group II clusters, such as M15, is populated by second-generation stars (G2) with mildly enhanced helium and CNO abundances, while the RR Lyraes in the relatively metal-rich group I clusters such as M3 are produced mostly by first-generation stars (G1) without these enhancements. When these models are extended to all metallicity regimes, the observed dichotomies in the inner and outer halo globular clusters can be naturally reproduced. We found that specific star formation histories are required for the inner and outer halos, which is consistent with the dual origin of the Milky Way halo.

  18. Spreading-vanishing dichotomy in a diffusive logistic model with a free boundary, II

    NASA Astrophysics Data System (ADS)

    Du, Yihong; Guo, Zongming

    We study the diffusive logistic equation with a free boundary in higher space dimensions and heterogeneous environment. Such a model may be used to describe the spreading of a new or invasive species, with the free boundary representing the expanding front. For simplicity, we assume that the environment and the solution are radially symmetric. In the special case of one space dimension and homogeneous environment, this free boundary problem was investigated in Du and Lin (2010) [10]. We prove that the spreading-vanishing dichotomy established in Du and Lin (2010) [10] still holds in the more general and ecologically realistic setting considered here. Moreover, when spreading occurs, we obtain best possible upper and lower bounds for the spreading speed of the expanding front. When the environment is asymptotically homogeneous at infinity, these two bounds coincide. Our results indicate that the asymptotic spreading speed determined by this model does not depend on the spatial dimension.

  19. The Crustal Dichotomy Boundary West of Tempe Terra: Speculation on Where it Lies Beneath Alba Patera Based on Mola Topography

    NASA Technical Reports Server (NTRS)

    Frey, H.; Roark, J.; Sakimoto, S.; McGovern, P.

    1999-01-01

    MOLA gridded data based on profiles collected during the Aerobraking Hiatus and Science Phasing Operations suggest the crustal dichotomy boundary west of Tempe continues beneath Alba volcanics, at least to 105 W at about 50 N. A broad shelf-like region in the Alba units is continuous with a similar region of Tempe in which Hesperian volcanics overlie Noachian cratered terrain. Perspective views show significant changes in the sloping character of the flanks of Alba east and west of 105W, with much more continuous steep topography to the west. We suggest that Alba sits astride the ancient crustal dichotomy boundary, not adjacent to it, and that its eastern half lies on old cratered terrain. If true, this would significantly affect the estimate of Alba volcanics volumes, and might also explain some of the observed asymmetries in the structure and the distribution of faults associated with this immense feature.

  20. Origin of the great dichotomy of the Solar System: small terrestrial embryos and massive giant planet cores

    NASA Astrophysics Data System (ADS)

    Morbidelli, Alessandro; Lambrechts, Michiel; Bitsch, Bertram; Jacobson, Seth

    2015-08-01

    The basic structure of the solar system is set by the presence of low-mass terrestrial planets in its inner part and giant planets in its outer part. This is the result of the formation of a system of multiple Mars-mass embryos in the inner disk and of a few multi-Earth-mass cores in the outer part, within the lifetime of the gaseous component of the protoplanetary disk. What was the origin of this dichotomy in the mass distribution of embryos/cores? We show in this paper that the classic processes of runaway and oligarchic growth from a disk of planetesimals can not explain this dichotomy, even if the original surface density of solids increased at the snowline. Instead, the accretion of drifting pebbles by embryos/cores can explain the dichotomy, provided that some assumptions hold true. We propose that the mass flow of pebbles is two-times lower and the characteristic size of the pebbles is ten times smaller within the snowline than beyond the snowline (respectively at r < r_ice and r > r_ice, where r_ice is the snowline heliocentric distance), due to ice sublimation and the splitting of icy pebbles into a collection of chondrule-size silicate grains. In this case, objects of original sub-lunar mass would grow at drastically different rates in the two regions of the disk. Within the snowline these bodies would reach approximately the mass of Mars while beyond the snowline they would grow to 20 Earth masses. The results may change quantitatively with the assumed parameters, but the establishment of a clear dichotomy in the mass distribution of protoplanets appears robust.

  1. Extensive aqueous deposits at the base of the dichotomy boundary in Nilosyrtis Mensae, Mars

    NASA Astrophysics Data System (ADS)

    Bandfield, Joshua L.; Amador, Elena S.

    2016-09-01

    Thermal emission imaging system (THEMIS) and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spectral datasets were used to identify high bulk SiO2 and hydrated compositions throughout the Nilosyrtis Mensae region. Four isolated locations were identified across the region showing short wavelength silicate absorptions within the 8-12 μm spectral region, indicating surfaces dominated by high Si phases. Much more extensive exposures of hydrated compositions are present throughout the region, indicated by a spectral absorption near 1.9 μm in CRISM data. Although limited in spatial coverage, detailed spectral observations indicate that the hydrated materials contain Fe/Mg-smectites and hydrated silica along with minor exposures of Mg-carbonates and an unidentified hydrated phase. The high SiO2 and hydrated materials are present in layered sediments near the base of topographic scarps at the hemispheric dichotomy boundary, typically near or within low albedo sand deposits. The source of the high SiO2 and hydrated materials appears to be from groundwater discharge from Nili Fossae and Syrtis Major to the south, where there is evidence for extensive aqueous alteration of the subsurface. Although discontinuous, the exposures of high SiO2 and hydrated materials span a wide area and are present in a similar geomorphological context to previously identified deposits in western Hellas Basin. These regional deposits may reflect aqueous conditions and alteration within the adjacent crust of the martian highlands.

  2. Universal tectonic dichotomy of small celestial bodies expressed in their common convexo-concave shapes

    NASA Astrophysics Data System (ADS)

    Kochemasov, G. G.

    2008-09-01

    The wave planetology [1, 2, 3 & others] declares in its first theorem that all celestial bodies are dichotomous. This is a result of a warping action of the fundamental wave (wave 1 long 2πR where R is a body radius) that appears in any body due to its movement in non-round (elliptical, parabolic) keplerian orbits with periodically changing accelerations. Having a standing character and four crossing directions in rotating bodies (but all bodies rotate!) these waves inevitably press in one hemisphere and bulge out the opposite one tending to impose on a body convexo-concave shape. This shape is leveled out in larger bodies due to enhanced gravity but is clearly observed in smaller ones with diminished gravity. Still, in the larger bodies as, for an example, in Earth the tectonic dichotomy is expressed as an opposition of the subsided western Pacific hemisphere and the uplifted eastern continental hemisphere. At Mars even sharper dichotomy is in the north-south direction. Small bodies (normally less than 400-500 km across) notwithstanding their type (asteroids, comets, satellites), size and composition (stones, metals, ices) are flattened and bended by the fundamental wave. That is why all asteroids in the main asteroid belt have an oblong shape what was established rather long ago but never was properly explained. Now a number of small satellites is observed by Cassini spacecraft in the saturnian system that makes together with jovian and martian small satellites a representative group for comparisons. In the figures below are shown asteroids, satellites and a comet arranged in a row of increasing sizes. They all are flattened except the largest in the row Enceladus (505 km) and bended tending to acquire a convexo-concave shape. Asteroids: Itokawa (0.5 km long), Eros (33 km, PIA03111). Satellites: Calypso (22 km, PIA07633), Atlas (32 km, PIA08233), Prometheus (102 km, PIA08192), Hyperion (350 km, PIA06645), Enceladus (505 km, PIA08258, comet-like behaviour). Comet

  3. Does black hole spin play a key role in the FSRQ/BL Lac dichotomy?

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Debbijoy; Sreekumar, Parameswaran; Mukhopadhyay, Banibrata; Tomar, Ishan

    2016-04-01

    Blazars are characterized by large intensity and spectral variations across the electromagnetic spectrum It is believed that jets emerging from them are almost aligned with the line-of-sight. The majority of identified extragalactic sources in γ-ray catalogs of EGRET and Fermi are blazars. Observationally, blazars can be divided into two classes: flat spectrum radio quasars (FSRQs) and BL Lacs. BL Lacs usually exhibit lower γ-ray luminosity and harder power law spectra at γ-ray energies than FSRQs. We attempt to explain the high energy properties of FSRQs and BL Lacs from Fermi γ-ray space telescope observations. It was argued previously that the difference in accretion rates is mainly responsible for the large mismatch in observed luminosity in γ-ray. However, when intrinsic luminosities are derived by correcting for beaming effects, this difference in γ-ray luminosity between the two classes is significantly reduced. In order to explain this difference in intrinsic luminosities, we propose that spin plays an important role in the luminosity distribution dichotomy of BL Lacs and FSRQs. As the outflow power of a blazar increases with increasing spin of a central black hole, we suggest that the spin plays a crucial role in making BL Lac sources low luminous and slow rotators compared to FSRQ sources.

  4. EMBRYO IMPACTS AND GAS GIANT MERGERS. I. DICHOTOMY OF JUPITER AND SATURN's CORE MASS

    SciTech Connect

    Li Shulin; Agnor, C.B.; Lin, D. N. C.

    2010-09-10

    Interior to the gaseous envelopes of Saturn, Uranus, and Neptune, there are high-density cores with masses larger than 10 Earth masses. According to the conventional sequential accretion hypothesis, such massive cores are needed for the onset of efficient accretion of their gaseous envelopes. However, Jupiter's gaseous envelope is more massive and its core may be less massive than those of Saturn. In order to account for this structural diversity and the super-solar metallicity in the envelope of Jupiter and Saturn, we investigate the possibility that they may have either merged with other gas giants or consumed several Earth-mass protoplanetary embryos during or after the rapid accretion of their envelope. In general, impinging sub-Earth-mass planetesimals disintegrate in gas giants' envelopes, deposit heavy elements well outside the cores, and locally suppress the convection. Consequently, their fragments sediment to promote the growth of cores. Through a series of numerical simulations, we show that it is possible for colliding super-Earth-mass embryos to reach the cores of gas giants. Direct parabolic collisions also lead to the coalescence of gas giants and merging of their cores. In these cases, the energy released from the impact leads to vigorous convective motion throughout the envelope and the erosion of the cores. This dichotomy contributes to the observed dispersion in the internal structure and atmospheric composition between Jupiter and Saturn and other gas giant planets and elsewhere.

  5. EXAMINING THE RADIO-LOUD/RADIO-QUIET DICHOTOMY WITH NEW CHANDRA AND VLA OBSERVATIONS OF 13 UGC GALAXIES

    SciTech Connect

    Kharb, P.; Axon, D. J.; Robinson, A.; Capetti, A.; Balmaverde, B.; Chiaberge, M.; Macchetto, D.; Grandi, P.; Giovannini, G.; Montez, R.

    2012-04-15

    We present the results from new {approx}15 ks Chandra-ACIS and 4.9 GHz Very Large Array (VLA) observations of 13 galaxies hosting low-luminosity active galactic nuclei (AGNs). This completes the multiwavelength study of a sample of 51 nearby early-type galaxies described in Capetti and Balmaverde and Balmaverde and Capetti. The aim of the three previous papers was to explore the connection between the host galaxies and AGN activity in a radio-selected sample. We detect nuclear X-ray emission in eight sources and radio emission in all but one (viz., UGC 6985). The new VLA observations improve the spatial resolution by a factor of 10: the presence of nuclear radio sources in 12 of the 13 galaxies confirms their AGN nature. As previously indicated, the behavior of the X-ray and radio emission in these sources depends strongly on the form of their optical surface brightness profiles derived from Hubble Space Telescope imaging, i.e., on their classification as 'core', 'power-law', or 'intermediate' galaxies. With more than twice the number of 'power-law' and 'intermediate' galaxies compared to previous work, we confirm with a much higher statistical significance that these galaxies lie well above the radio-X-ray correlation established in Fanaroff-Riley type I radio galaxies and the low-luminosity 'core' galaxies. This result highlights the fact that the 'radio-loud/radio-quiet' dichotomy is a function of the host galaxy's optical surface brightness profile. We present radio-optical-X-ray spectral indices for all 51 sample galaxies. Survival statistics point to significant differences in the radio-to-optical and radio-to-X-ray spectral indices between the 'core' and 'power-law galaxies (Gehan's Generalized Wilcoxon test probability p for the two classes being statistically similar is <10{sup -5}), but not in the optical-to-X-ray spectral indices (p = 0.25). Therefore, the primary difference between the 'core' and 'power-law' galaxies is in their ability to launch

  6. Mutational dichotomy in desmoplastic malignant melanoma corroborated by multigene panel analysis.

    PubMed

    Jahn, Stephan W; Kashofer, Karl; Halbwedl, Iris; Winter, Gerlinde; El-Shabrawi-Caelen, Laila; Mentzel, Thomas; Hoefler, Gerald; Liegl-Atzwanger, Bernadette

    2015-07-01

    Desmoplastic malignant melanoma is a distinct melanoma entity histologically subtyped into mixed and pure forms due to significantly reduced lymph node metastases in the pure form. Recent reports investigating common actionable driver mutations have demonstrated a lack of BRAF, NRAS, and KIT mutation in pure desmoplastic melanoma. In search for alternative driver mutations next generation amplicon sequencing for hotspot mutations in 50 genes cardinal to tumorigenesis was performed and in addition the RET G691S polymorphism was investigated. Data from 21 desmoplastic melanomas (12 pure and 9 mixed) were retrieved. Pure desmoplastic melanomas were either devoid of mutations (50%) or displayed mutations in tumor suppressor genes (TP53, CDKN2A, and SMAD4) singularly or in combination with the exception of a PIK3CA double-mutation lacking established biological relevance. Mixed desmoplastic melanomas on the contrary were frequently mutated (89%), and 67% exhibited activating mutations similar to common-type cutaneous malignant melanomas (BRAF, NRAS, FGFR2, and ERBB2). Separate analysis of morphologically heterogeneous tumor areas in four mixed desmoplastic malignant melanomas displayed no difference in mutation status and RET G691 status. GNAQ and GNA11, two oncogenes in BRAF and NRAS wild-type uveal melanomas, were not mutated in our cohort. The RET G691S polymorphism was found in 25% of pure and 38% of mixed desmoplastic melanomas. Apart from RET G691S our findings demonstrate absence of activating driver mutations in pure desmoplastic melanoma beyond previously investigated oncogenes (BRAF, NRAS, and KIT). The findings underline the therapeutic dichotomy of mixed versus pure desmoplastic melanoma with regard to activating mutations primarily of the mitogen-activated protein kinase pathway. PMID:25769001

  7. STRIKING DICHOTOMY IN OUTCOME OF MYCN-AMPLIFIED NEUROBLASTOMA IN THE CONTEMPORARY ERA

    PubMed Central

    Kushner, Brian H.; Modak, Shakeel; Kramer, Kim; LaQuaglia, Michael P.; Yataghene, Karima; Basu, Ellen M.; Roberts, Stephen S.; Cheung, Nai-Kong V.

    2014-01-01

    Background We exploited a large database to investigate the outcome of high-risk neuroblastoma (HR-NB) in the contemporary era. Methods We studied all HR-NB patients <12 years old treated during induction at our hospital in 2000–2011, including 118 patients with MYCN-amplified(+) disease, and 127 patients >18 months old with MYCN-non-amplified(−) stage 4. Results Complete/very good partial response (CR/VGPR) to induction correlated with significantly superior event-free (EFS) (p<0.001) and overall survival (OS) (p<0.001) compared to partial response or less (≤PR). MYCN(+) and MYCN(−) patients had similar rates of CR/VGPR to induction (p=0.366); MYCN(+) and MYCN(−) patients in CR/VGPR had similar EFS (p=0.346) and OS (p=0.542). In contrast, only MYCN(+) patients had progressive disease (PD) as response to induction (p<0.001), and early death from PD (<366 days post-diagnosis) was significantly more common (p<0.001) with MYCN(+) disease. Overall, among patients with ≤PR, MYCN(+) patients had significantly inferior EFS (p<0.001) and OS (p<0.001) compared to MYCN(−) patients, which accounted for the significantly worse EFS (p=0.008) and OS (p=0.002) of the entire MYCN(+) cohort versus MYCN(−) cohort. Conclusions MYCN(−) HR-NB patients display a broad, continuous spectrum as regards response and outcome, whereas MYCN(+) patients have either an excellent response to induction associated with good long-term outcome, or early PD with poor outcome. This extreme dichotomy in the clinical course of MYCN(+) patients points to underlying biological differences with MYCN(+) NB, the elucidation of which may have far-reaching implications, including improved risk classification at diagnosis and identification of targets for treatment. PMID:24691684

  8. Cyclin-dependent kinase 5 activates guanine nucleotide exchange factor GIV/Girdin to orchestrate migration–proliferation dichotomy

    PubMed Central

    Bhandari, Deepali; Lopez-Sanchez, Inmaculada; To, Andrew; Lo, I-Chung; Aznar, Nicolas; Leyme, Anthony; Gupta, Vijay; Niesman, Ingrid; Maddox, Adam L.; Garcia-Marcos, Mikel; Farquhar, Marilyn G.; Ghosh, Pradipta

    2015-01-01

    Signals propagated by receptor tyrosine kinases (RTKs) can drive cell migration and proliferation, two cellular processes that do not occur simultaneously—a phenomenon called “migration–proliferation dichotomy.” We previously showed that epidermal growth factor (EGF) signaling is skewed to favor migration over proliferation via noncanonical transactivation of Gαi proteins by the guanine exchange factor (GEF) GIV. However, what turns on GIV-GEF downstream of growth factor RTKs remained unknown. Here we reveal the molecular mechanism by which phosphorylation of GIV by cyclin-dependent kinase 5 (CDK5) triggers GIV's ability to bind and activate Gαi in response to growth factors and modulate downstream signals to establish a dichotomy between migration and proliferation. We show that CDK5 binds and phosphorylates GIV at Ser1674 near its GEF motif. When Ser1674 is phosphorylated, GIV activates Gαi and enhances promigratory Akt signals. Phosphorylated GIV also binds Gαs and enhances endosomal maturation, which shortens the transit time of EGFR through early endosomes, thereby limiting mitogenic MAPK signals. Consequently, this phosphoevent triggers cells to preferentially migrate during wound healing and transmigration of cancer cells. When Ser1674 cannot be phosphorylated, GIV cannot bind either Gαi or Gαs, Akt signaling is suppressed, mitogenic signals are enhanced due to delayed transit time of EGFR through early endosomes, and cells preferentially proliferate. These results illuminate how GIV-GEF is turned on upon receptor activation, adds GIV to the repertoire of CDK5 substrates, and defines a mechanism by which this unusual CDK orchestrates migration–proliferation dichotomy during cancer invasion, wound healing, and development. PMID:26286990

  9. Cyclin-dependent kinase 5 activates guanine nucleotide exchange factor GIV/Girdin to orchestrate migration-proliferation dichotomy.

    PubMed

    Bhandari, Deepali; Lopez-Sanchez, Inmaculada; To, Andrew; Lo, I-Chung; Aznar, Nicolas; Leyme, Anthony; Gupta, Vijay; Niesman, Ingrid; Maddox, Adam L; Garcia-Marcos, Mikel; Farquhar, Marilyn G; Ghosh, Pradipta

    2015-09-01

    Signals propagated by receptor tyrosine kinases (RTKs) can drive cell migration and proliferation, two cellular processes that do not occur simultaneously--a phenomenon called "migration-proliferation dichotomy." We previously showed that epidermal growth factor (EGF) signaling is skewed to favor migration over proliferation via noncanonical transactivation of Gαi proteins by the guanine exchange factor (GEF) GIV. However, what turns on GIV-GEF downstream of growth factor RTKs remained unknown. Here we reveal the molecular mechanism by which phosphorylation of GIV by cyclin-dependent kinase 5 (CDK5) triggers GIV's ability to bind and activate Gαi in response to growth factors and modulate downstream signals to establish a dichotomy between migration and proliferation. We show that CDK5 binds and phosphorylates GIV at Ser1674 near its GEF motif. When Ser1674 is phosphorylated, GIV activates Gαi and enhances promigratory Akt signals. Phosphorylated GIV also binds Gαs and enhances endosomal maturation, which shortens the transit time of EGFR through early endosomes, thereby limiting mitogenic MAPK signals. Consequently, this phosphoevent triggers cells to preferentially migrate during wound healing and transmigration of cancer cells. When Ser1674 cannot be phosphorylated, GIV cannot bind either Gαi or Gαs, Akt signaling is suppressed, mitogenic signals are enhanced due to delayed transit time of EGFR through early endosomes, and cells preferentially proliferate. These results illuminate how GIV-GEF is turned on upon receptor activation, adds GIV to the repertoire of CDK5 substrates, and defines a mechanism by which this unusual CDK orchestrates migration-proliferation dichotomy during cancer invasion, wound healing, and development. PMID:26286990

  10. Three-dimensional relativistic MHD simulations of active galactic nuclei jets: magnetic kink instability and Fanaroff-Riley dichotomy

    NASA Astrophysics Data System (ADS)

    Tchekhovskoy, Alexander; Bromberg, Omer

    2016-09-01

    Energy deposition by active galactic nuclei jets into the ambient medium can affect galaxy formation and evolution, the cooling of gas flows at the centres of galaxy clusters, and the growth of the supermassive black holes. However, the processes that couple jet power to the ambient medium and determine jet morphology are poorly understood. For instance, there is no agreement on the cause of the well-known Fanaroff-Riley (FR) morphological dichotomy of jets, with FRI jets being shorter and less stable than FRII jets. We carry out global 3D magnetohydrodynamic simulations of relativistic jets propagating through the ambient medium. We show that the flat density profiles of galactic cores slow down and collimate the jets, making them susceptible to the 3D magnetic kink instability. We obtain a critical power, which depends on the galaxy core mass and radius, below which jets become kink-unstable within the core, stall, and inflate cavities filled with relativistically hot plasma. Jets above the critical power stably escape the core and form powerful backflows. Thus, the kink instability controls the jet morphology and can lead to the FR dichotomy. The model-predicted dependence of the critical power on the galaxy optical luminosity agrees well with observations.

  11. Three-dimensional Relativistic MHD Simulations of Active Galactic Nuclei Jets: Magnetic Kink Instability and Fanaroff-Riley Dichotomy

    NASA Astrophysics Data System (ADS)

    Tchekhovskoy, Alexander; Bromberg, Omer

    2016-04-01

    Energy deposition by active galactic nuclei jets into the ambient medium can affect galaxy formation and evolution, the cooling of gas flows at the centres of galaxy clusters, and the growth of the supermassive black holes. However, the processes that couple jet power to the ambient medium and determine jet morphology are poorly understood. For instance, there is no agreement on the cause of the well-known Fanaroff-Riley (FR) morphological dichotomy of jets, with FRI jets being shorter and less stable than FRII jets. We carry out global 3D magnetohydrodynamic simulations of relativistic jets propagating through the ambient medium. We show that the flat density profiles of galactic cores slow down and collimate the jets, making them susceptible to the 3D magnetic kink instability. We obtain a critical power, which depends on the galaxy core mass and radius, below which jets become kink-unstable within the core, stall, and inflate cavities filled with relativistically-hot plasma. Jets above the critical power stably escape the galaxy cores and form powerful backflows. Thus, the kink instability controls the jet morphology and can lead to the FR dichotomy. The model-predicted dependence of the critical power on the galaxy optical luminosity agrees well with observations.

  12. Disclosing the Radio Loudness Distribution Dichotomy in Quasars: An Unbiased Monte Carlo Approach Applied to the SDSS-FIRST Quasar Sample

    NASA Astrophysics Data System (ADS)

    Baloković, M.; Smolčić, V.; Ivezić, Ž.; Zamorani, G.; Schinnerer, E.; Kelly, B. C.

    2012-11-01

    We investigate the dichotomy in the radio loudness distribution of quasars by modeling their radio emission and various selection effects using a Monte Carlo approach. The existence of two physically distinct quasar populations, the radio-loud and radio-quiet quasars, is controversial and over the last decade a bimodal distribution of radio loudness of quasars has been both affirmed and disputed. We model the quasar radio luminosity distribution with simple unimodal and bimodal distribution functions. The resulting simulated samples are compared to a fiducial sample of 8300 quasars drawn from the SDSS DR7 Quasar Catalog and combined with radio observations from the FIRST survey. Our results indicate that the SDSS-FIRST sample is best described by a radio loudness distribution which consists of two components, with (12 ± 1)% of sources in the radio-loud component. On the other hand, the evidence for a local minimum in the loudness distribution (bimodality) is not strong and we find that previous claims for its existence were probably affected by the incompleteness of the FIRST survey close to its faint limit. We also investigate the redshift and luminosity dependence of the radio loudness distribution and find tentative evidence that at high redshift radio-loud quasars were rarer, on average louder, and exhibited a smaller range in radio loudness. In agreement with other recent work, we conclude that the SDSS-FIRST sample strongly suggests that the radio loudness distribution of quasars is not a universal function, and that more complex models than presented here are needed to fully explain available observations.

  13. DISCLOSING THE RADIO LOUDNESS DISTRIBUTION DICHOTOMY IN QUASARS: AN UNBIASED MONTE CARLO APPROACH APPLIED TO THE SDSS-FIRST QUASAR SAMPLE

    SciTech Connect

    Balokovic, M.; Smolcic, V.; Ivezic, Z.; Zamorani, G.; Schinnerer, E.; Kelly, B. C.

    2012-11-01

    We investigate the dichotomy in the radio loudness distribution of quasars by modeling their radio emission and various selection effects using a Monte Carlo approach. The existence of two physically distinct quasar populations, the radio-loud and radio-quiet quasars, is controversial and over the last decade a bimodal distribution of radio loudness of quasars has been both affirmed and disputed. We model the quasar radio luminosity distribution with simple unimodal and bimodal distribution functions. The resulting simulated samples are compared to a fiducial sample of 8300 quasars drawn from the SDSS DR7 Quasar Catalog and combined with radio observations from the FIRST survey. Our results indicate that the SDSS-FIRST sample is best described by a radio loudness distribution which consists of two components, with (12 {+-} 1)% of sources in the radio-loud component. On the other hand, the evidence for a local minimum in the loudness distribution (bimodality) is not strong and we find that previous claims for its existence were probably affected by the incompleteness of the FIRST survey close to its faint limit. We also investigate the redshift and luminosity dependence of the radio loudness distribution and find tentative evidence that at high redshift radio-loud quasars were rarer, on average louder, and exhibited a smaller range in radio loudness. In agreement with other recent work, we conclude that the SDSS-FIRST sample strongly suggests that the radio loudness distribution of quasars is not a universal function, and that more complex models than presented here are needed to fully explain available observations.

  14. Individuality beyond the Dichotomy of "Small Self and Big Self" in Contemporary Chinese Education: Lessons from Hu Shi and Liang Shuming

    ERIC Educational Resources Information Center

    Zhang, Huajun

    2013-01-01

    This article identifies the problem that an instrumentalist mode of thinking dominates China's contemporary education practice and suggests that the dichotomy between the "small self and big self," a notion that has been present throughout modern Chinese history, exacerbates this instrumentalism. It parallels the loss of…

  15. The cool component and the dichotomy, lateral expansion, and axial rotation of solar X-ray jets

    SciTech Connect

    Moore, Ronald L.; Sterling, Alphonse C.; Falconer, David A.; Robe, Dominic

    2013-06-01

    We present results from a study of 54 polar X-ray jets that were observed in coronal X-ray movies from the X-ray Telescope on Hinode and had simultaneous coverage in movies of the cooler transition region (T ∼ 10{sup 5} K) taken in the He II 304 Å band of the Atmospheric Imaging Assembly (AIA) on Solar Dynamics Observatory. These dual observations verify the standard-jet/blowout-jet dichotomy of polar X-ray jets previously found primarily from XRT movies alone. In accord with models of blowout jets and standard jets, the AIA 304 Å movies show a cool (T ∼ 10{sup 5} K) component in nearly all blowout X-ray jets and in a small minority of standard X-ray jets, obvious lateral expansion in blowout X-ray jets but none in standard X-ray jets, and obvious axial rotation in both blowout X-ray jets and standard X-ray jets. In our sample, the number of turns of axial rotation in the cool-component standard X-ray jets is typical of that in the blowout X-ray jets, suggesting that the closed bipolar magnetic field in the jet base has substantial twist not only in all blowout X-ray jets but also in many standard X-ray jets. We point out that our results for the dichotomy, lateral expansion, and axial rotation of X-ray jets add credence to published speculation that type-II spicules are miniature analogs of X-ray jets, are generated by granule-size emerging bipoles, and thereby carry enough energy to power the corona and solar wind.

  16. Fire-mediated disruptive selection can explain the reseeder-resprouter dichotomy in Mediterranean-type vegetation.

    PubMed

    Altwegg, Res; De Klerk, Helen M; Midgley, Guy F

    2015-02-01

    Crown fire is a key selective pressure in Mediterranean-type plant communities. Adaptive responses to fire regimes involve trade-offs between investment for persistence (fire survival and resprouting) and reproduction (fire mortality, fast growth to reproductive maturity, and reseeding) as investments that enhance adult survival lower growth and reproductive rates. Southern hemisphere Mediterranean-type ecosystems are dominated by species with either endogenous regeneration from adult resprouting or fire-triggered seedling recruitment. Specifically, on nutrient-poor soils, these are either resprouting or reseeding life histories, with few intermediate forms, despite the fact that the transition between strategies is evolutionarily labile. How did this strong dichotomy evolve? We address this question by developing a stochastic demographic model to assess determinants of relative fitness of reseeders, resprouters and hypothetical intermediate forms. The model was parameterised using published demographic data from South African protea species and run over various relevant fire regime parameters facets. At intermediate fire return intervals, trade-offs between investment in growth versus fire resilience can cause fitness to peak at either of the extremes of the reseeder-resprouter continuum, especially when assuming realistic non-linear shapes for these trade-offs. Under these circumstances, the fitness landscape exhibits a saddle which could lead to disruptive selection. The fitness gradient between the peaks was shallow, which may explain why this life-history trait is phylogenetically labile. Resprouters had maximum fitness at shorter fire-return intervals than reseeders. The model suggests that a strong dichotomy in fire survival strategy depends on a non-linear trade-off between growth and fire persistence traits. PMID:25348575

  17. Toward Understanding the Fanaroff-Riley Dichotomy in Radio Source Morphology and Power

    NASA Astrophysics Data System (ADS)

    Baum, Stefi A.; Zirbel, Esther L.; O'Dea, Christopher P.

    1995-09-01

    of the total energy output from the AGNs into jet kinetic energy versus radiant energy than do FR 2 sources. If this interpretation is correct, then this suggests that there is a fundamental difference in the central engine and/or in the immediate "accretion region" around the engine in FR 1 and FR 2 radio galaxies. We note also the absence of FR 1 sources with nuclear broad line regions and suggest that the absence of the BLR is tied to the absence of the "isotropic" nuclear UV continuum source in FR 1 sources. We put forth the possibility that the FR 1/FR 2 dichotomy (i.e., the observed differences in the properties of low- and high-power radio sources) is due to qualitative differences in the structural properties of the central engines in these two types of sources. Following early work by Rees et al. (1982), we suggest the possibility that FR 1 sources are produced when the central engine is fed at a lower accretion rate, leading to the creation of a source in which the ratio of radiant to jet bulk kinetic energy is low, while FR 2 sources are produced when the central engine is fed at a higher accretion rate, causing the central engine to deposit a higher fraction of its energy in radiant energy. We further suggest the possibility that associated differences in the spin properties of the central black hole between FR 1 (lower spin) and FR 2 (higher spin) sources may be responsible for the different collimation properties and Mach numbers of the jets produced by these two types of radio-loud galaxies. This scenario, although currently clearly speculative, is nicely consistent with our current picture of the triggering, feeding, environments, and evolution of powerful radio galaxies. This model allows for evolution of these properties with time for example, the mass accretion rate and BH spin may decline with time causing an FR 2 radio source or quasar to evolve into a FR 1 radio source.

  18. Understanding the Dorsal and Ventral Systems of the Human Cerebral Cortex: Beyond Dichotomies

    ERIC Educational Resources Information Center

    Borst, Gregoire; Thompson, William L.; Kosslyn, Stephen M.

    2011-01-01

    Traditionally, characterizations of the macrolevel functional organization of the human cerebral cortex have focused on the left and right cerebral hemispheres. However, the idea of left brain versus right brain functions has been shown to be an oversimplification. We argue here that a top-bottom divide, rather than a left-right divide, is a more…

  19. The Smoking Gun: Remanent Magnetic Anomalies on Mars and the Formation of the Crustal Dichotomy via Giant Impact

    NASA Astrophysics Data System (ADS)

    Dombard, A. J.; Johnson, C. L.

    2011-12-01

    The formation of large-scale crustal magnetic anomalies in the Southern Highlands of Mars is equivocal. Though some are indeed elongated primarily in the east-west direction, initial map projections exacerbated their linear nature, leading to the hypothesis that the anomalies are equivalent to magnetic stripes due to spreading of Earth's sea floor and hence to the proposal of plate tectonics on Mars. This interpretation, however, is inconsistent with Martian geology. For instance, a plate-tectonics model predicts the anomalies should be formed in thin, oceanic crust at low elevation, but instead they are found in the thick crust of the Highlands, not in the thin crust of the Northern Lowlands. Indeed, the formation of this Crustal Dichotomy is also equivocal, with models ranging from a giant impact (or multiple smaller impacts) near either the current north or south poles, to plate tectonics-like processes, to mantle convection, either eroding the crust in the northern hemisphere or thickening the crust in the south. Recently, the idea of a giant impact in the north has been resurrected, with the proposal that the Dichotomy results from the formation of an elliptical basin by a giant impact very early in Martian history. While it may be tempting to suggest that the current, generally demagnetized state of the Northern Lowlands may be related to this impact, this linkage makes implicit assumptions about the timing of dynamo shut-off on Mars, and it neglects other demagnetization mechanisms possibly operating in the Lowlands after such an impact (e.g., later hydrothermal processing). More direct magnetic evidence for the giant impact hypothesis would come if the remanent magnetism in Southern Highlands were relatable in a unique way to the putative impact. Here, we show that the positions of many of the dominant elongated magnetic anomalies on Mars are consistent with the first ring of a multi-ring basin. The best match comes from an ellipse ~2200 km wider than the

  20. The Dichotomy of Tumor Exosomes (TEX) in Cancer Immunity: Is It All in the ConTEXt?

    PubMed Central

    Kunigelis, Katherine E.; Graner, Michael W.

    2015-01-01

    Exosomes are virus-sized nanoparticles (30–130 nm) formed intracellularly as intravesicular bodies/intralumenal vesicles within maturing endosomes (“multivesicular bodies”, MVBs). If MVBs fuse with the cell’s plasma membrane, the interior vesicles may be released extracellularly, and are termed “exosomes”. The protein cargo of exosomes consists of cytosolic, membrane, and extracellular proteins, along with membrane-derived lipids, and an extraordinary variety of nucleic acids. As such, exosomes reflect the status and identity of the parent cell, and are considered as tiny cellular surrogates. Because of this closely entwined relationship between exosome content and the source/status of the parental cell, conceivably exosomes could be used as vaccines against various pathologies, as they contain antigens associated with a given disease, e.g., cancer. Tumor-derived exosomes (TEX) have been shown to be potent anticancer vaccines in animal models, driving antigen-specific T and B cell responses, but much recent literature concerning TEX strongly places the vesicles as powerfully immunosuppressive. This dichotomy suggests that the context in which the immune system encounters TEX is critical in determining immune stimulation versus immunosuppression. Here, we review literature on both sides of this immune coin, and suggest that it may be time to revisit the concept of TEX as anticancer vaccines in clinical settings. PMID:26694473

  1. Non-Markovian models for migration-proliferation dichotomy of cancer cells: anomalous switching and spreading rate.

    PubMed

    Fedotov, Sergei; Iomin, Alexander; Ryashko, Lev

    2011-12-01

    Proliferation and migration dichotomy of the tumor cell invasion is examined within two non-Markovian models. We consider the tumor spheroid, which consists of the tumor core with a high density of cells and the outer invasive zone. We distinguish two different regions of the outer invasive zone and develop models for both zones. In model I we analyze the near-core-outer region, where biased migration away from the tumor spheroid core takes place. We suggest non-Markovian switching between the migrating and proliferating phenotypes of tumor cells. Nonlinear master equations for mean densities of cancer cells of both phenotypes are derived. In anomalous switching case we estimate the average size of the near-core-outer region that corresponds to sublinear growth (r(t)) ~ t(μ) for 0 < μ < 1. In model II we consider the outer zone, where the density of cancer cells is very low. We suggest an integrodifferential equation for the total density of cancer cells. For proliferation rate we use the classical logistic growth, while the migration of cells is subdiffusive. The exact formulas for the overall spreading rate of cancer cells are obtained by a hyperbolic scaling and Hamilton-Jacobi techniques. PMID:22304064

  2. The Dichotomy of Tumor Exosomes (TEX) in Cancer Immunity: Is It All in the ConTEXt?

    PubMed

    Kunigelis, Katherine E; Graner, Michael W

    2015-01-01

    Exosomes are virus-sized nanoparticles (30-130 nm) formed intracellularly as intravesicular bodies/intralumenal vesicles within maturing endosomes ("multivesicular bodies", MVBs). If MVBs fuse with the cell's plasma membrane, the interior vesicles may be released extracellularly, and are termed "exosomes". The protein cargo of exosomes consists of cytosolic, membrane, and extracellular proteins, along with membrane-derived lipids, and an extraordinary variety of nucleic acids. As such, exosomes reflect the status and identity of the parent cell, and are considered as tiny cellular surrogates. Because of this closely entwined relationship between exosome content and the source/status of the parental cell, conceivably exosomes could be used as vaccines against various pathologies, as they contain antigens associated with a given disease, e.g., cancer. Tumor-derived exosomes (TEX) have been shown to be potent anticancer vaccines in animal models, driving antigen-specific T and B cell responses, but much recent literature concerning TEX strongly places the vesicles as powerfully immunosuppressive. This dichotomy suggests that the context in which the immune system encounters TEX is critical in determining immune stimulation versus immunosuppression. Here, we review literature on both sides of this immune coin, and suggest that it may be time to revisit the concept of TEX as anticancer vaccines in clinical settings. PMID:26694473

  3. A Dichotomy of Information-Seeking and Information-Trusting: Stem Cell Interventions and Children with Neurodevelopmental Disorders.

    PubMed

    Sharpe, Kimberly; Di Pietro, Nina; Jacob, Karen J; Illes, Judy

    2016-08-01

    Parents and primary caregivers of children with Cerebral Palsy (CP) and Autism Spectrum Disorder (ASD) are faced with difficult treatment choices and management options for their children. The potential of stem cell technologies as an interventional strategy for CP and ASD has gained attention in the last decade. Information about these interventions varies in quality, resulting in a complex landscape for parent decision making for a child's care. Further complicating this landscape are clinics that advertise these interventions as a legitimate treatment for a fee. In this study, we surveyed individuals who considered taking their child with ASD or CP abroad for stem cell interventions on their use of different sources of stem cell related health information and their level of trust in these sources. Participants reported that while the Internet was their most frequent source of information, it was not well-trusted. Rather, information sources trusted most were researchers and the science journals in which they publish, other parents of children with CP and ASD, and healthcare providers. These findings highlight a dichotomy between information-seeking preferences and information-trusted sources. We discuss the challenges of health science communication and present innovative opportunities to increase communication with trusted and reliable sources as part of an integrated multi-pronged approach. PMID:27286955

  4. Dichotomy in the Epigenetic Mark Lysine Acetylation is Critical for the Proliferation of Prostate Cancer Cells

    PubMed Central

    Pathak, Ravi; Philizaire, Marc; Mujtaba, Shiraz

    2015-01-01

    The dynamics of lysine acetylation serve as a major epigenetic mark, which regulates cellular response to inflammation, DNA damage and hormonal changes. Microarray assays reveal changes in gene expression, but cannot predict regulation of a protein function by epigenetic modifications. The present study employs computational tools to inclusively analyze microarray data to understand the potential role of acetylation during development of androgen-independent PCa. The data revealed that the androgen receptor interacts with 333 proteins, out of which at least 92 proteins were acetylated. Notably, the number of cellular proteins undergoing acetylation in the androgen-dependent PCa was more as compared to the androgen-independent PCa. Specifically, the 32 lysine-acetylated proteins in the cellular models of androgen-dependent PCa were mainly involved in regulating stability as well as pre- and post-processing of mRNA. Collectively, the data demonstrate that protein lysine acetylation plays a crucial role during the transition of androgen-dependent to -independent PCa, which importantly, could also serve as a functional axis to unravel new therapeutic targets. PMID:26295410

  5. DichotomY IdentitY: Euler-Bernoulli Numbers, Sets-Multisets, FD-BE Quantum-Statistics, 1 /f0 - 1 /f1 Power-Spectra, Ellipse-Hyperbola Conic-Sections, Local-Global Extent: ``Category-Semantics''

    NASA Astrophysics Data System (ADS)

    Rota, G.-C.; Siegel, Edward Carl-Ludwig

    2011-03-01

    Seminal Apostol[Math.Mag.81,3,178(08);Am.Math.Month.115,9,795(08)]-Rota[Intro.Prob. Thy.(95)-p.50-55] DichotomY equivalence-class: set-theory: sets V multisets; closed V open; to Abromowitz-Stegun[Hdbk.Math.Fns.(64)]-ch.23,p.803!]: numbers/polynomials generating-functions: Euler V Bernoulli; to Siegel[Schrodinger Cent.Symp.(87); Symp.Fractals, MRS Fall Mtg.,(1989)-5-papers!] power-spectrum: 1/ f {0}-White V 1/ f {1}-Zipf/Pink (Archimedes) HYPERBOLICITY INEVITABILITY; to analytic-geometry Conic-Sections: Ellipse V (via Parabola) V Hyperbola; to Extent/Scale/Radius: Locality V Globality, Root-Causes/Ultimate-Origins: Dimensionality: odd-Z V (via fractal) V even-Z, to Symmetries/(Noether's-theorem connected)/Conservation-Laws Dichotomy: restored/conservation/convergence=0- V broken/non-conservation/divergence=/=0: with asymptotic-limit antipodes morphisms/ crossovers: Eureka!!!; "FUZZYICS"=''CATEGORYICS''!!! Connection to Kummer(1850) Bernoulli-numbers proof of FLT is via Siegel(CCNY;1964) < (1994)[AMS Joint Mtg. (2002)-Abs.973-60-124] short succinct physics proof: FLT = Least-Action Principle!!!

  6. Towards self-consistent modelling of the Martian dichotomy: Coupled models of simultaneous core and crust formation

    NASA Astrophysics Data System (ADS)

    Keller, T.; Golabek, G.; Gerya, T. V.; Connolly, J.

    2009-04-01

    One of the most striking surface features on Mars is the crustal dichotomy. The crustal dichotomy, a large difference in elevation and crustal thickness between the southern highlands and the northern lowlands, is the oldest geological feature on Mars. It was formed more than 4.1 Ga ago [Solomon et al., 2005; Nimmo and Tanaka, 2005; Frey, 2006] owing to either exogenic [e.g. Nimmo et al., 2008; Andrews-Hanna et al., 2008] or endogenic processes [e.g. Zhong and Zuber, 2001; Roberts and Zhong, 2006; Keller and Tackley, 2009]. Based on the geochemical analysis of SNC meteorites it was suggested that a primordial crust with up to 45 km thickness can be formed already during the Martian core formation [Norman, 1999]. The final accretion stage of terrestrial planets is based on stochastically distributed impacts [e.g. Chambers, 2004; Rubie et al., 2007]. Therefore we suggest that the sinking of iron diapirs, delivered by late pre-differentiated impactors, might have induced shear heating-related temperature anomalies in the mantle, which fostered the formation of early Martian crust. In this study, we examine parameter sets that will likely cause an onset of hemispherical low-degree mantle convection directly after, and coupled to, an already asymmetrical core formation. To test this hypothesis we use a numerical model, where we self-consistently couple the formation of the Martian iron core to the onset of mantle convection and crust formation. We perform 2D spherical simulations using the code I2ELVIS applying the newly developed "spherical-Cartesian" methodology [Gerya and Yuen, 2007]. It combines finite differences on a fully staggered rectangular Eulerian grid and Lagrangian marker-in-cell technique for solving momentum, continuity and temperature equations as well as Poisson equation for gravity potential in a self-gravitating planetary body. In this model, the planet is surrounded by a low viscosity, massless fluid ("sticky air") to simulate a free surface

  7. Towards self-consistent modelling of the Martian dichotomy: Coupled models of simultaneous core and crust formation

    NASA Astrophysics Data System (ADS)

    Golabek, Gregor; Keller, Tobias; Gerya, Taras; Zhu, Guizhi; Tackley, Paul

    2010-05-01

    One of the most striking surface features on Mars is the crustal dichotomy. It is the oldest geological feature on Mars and was formed more than 4.1 Ga ago by either exogenic or endogenic processes (e.g. Keller and Tackley, 2009). In order to find an internal origin of the crustal dichotomy, located within a maximum of 400 Ma of planetary differentiation, the thermal state of the planet resulting from core formation needs to be considered. Additionally, it was suggested that a primordial crust with up to 45 km thickness can be formed already during the Martian core formation (Norman, 1999). We suggest that the sinking of iron diapirs delivered by pre-differentiated impactors induced impact- and shear heating-related temperature anomalies in the mantle that fostered the formation of early Martian crust. Thus, the crustal thickness distribution would largely be a result of planetary core formation, late impact history and the onset of mantle convection. In this study, we examine parameter sets that will likely cause hemispherical asymmetry in both core formation and onset of mantle convection. To test this hypothesis we use numerical models to simulate the formation of the Martian iron core and the resulting mantle convection pattern, while peridotite melting is enabled to track melting caused by shear and radioactive heating.
We perform 2D simulations using the spherical-Cartesian code I2ELVIS (Gerya and Yuen, 2007) for planetary accretion and the spherical code STAGYY (Tackley, 2008) for the consequent onset of mantle convection. We apply a temperature-, stress- and melt-fraction dependent viscoplastic rheology inside a Mars-sized planet. Radioactive and shear heating as well as consumption of latent heat by silicate melting are taken into account. The depth of neutral buoyancy of silicate melt with respect to solid silicates is determined by the difference in compressibility of the liquid and solid phase. To self-consistently simulate the silicate phase changes

  8. RR Lyrae Luminosity Differences between Oosterhoff Group I and II Cluster Systems and the Origin of the Oosterhoff Dichotomy

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Woo; Carney, Bruce W.

    1999-09-01

    We present a comparative study of the Oosterhoff II cluster M2 and the Oosterhoff I cluster M3. Both have similar metallicities, [Fe/H]=-1.62 for M2 and -1.66 for M3, but very different horizontal-branch (HB) morphologies (B-R)/(B+V+R)=0.92 for M2 and 0.08 for M3. A period shift analysis and main-sequence fitting show that RRab variables in M2 are about 0.2 mag brighter than those in M3. Comparisons of the M2 period shift with Oosterhoff I clusters NGC 3201 and NGC 7006 also yield similar results, while a comparison between M2 and the Oosterhoff II cluster NGC 5986 reveals that the RR Lyrae luminosities are very similar. The luminosity difference is thought to be due to the evolutionary effect described in 1990 by Lee, Demarque, & Zinn: the M2 RRab variables have evolved away from the zero-age horizontal branch (ZAHB), while most M3 RRab variables lie near the ZAHB. A comparison of the mean period change rates of two clusters supports this hypothesis. Our relative age estimation using the difference in color between the base of giant branch and turn-off point shows that M2 is about 2 Gyr older than M3. Our result strongly suggests that the Oosterhoff dichotomy is due to age differences between Oosterhoff group I and II. This is consistent with the idea that the global second parameter is age. We discuss the kinematic differences between Oosterhoff group I and II clusters. Our result shows that the Oosterhoff group I clusters have zero or retrograde rotation with =-68+/-56 km s^-1 and sigma_los=131+/-28 km s^-1, while the Oosterhoff group II clusters have prograde rotation with =+94+/-47 km s^-1 and sigma_los=115+/-29 km s^-1, confirming a similar conclusion of van den Bergh. The difference in kinematics and ages between Oosterhoff group I and II clusters suggests that they may have different origins: The Oosterhoff II clusters were formed very early in the proto-Galaxy while the Oosterhoff I clusters were formed at different locations and at a later

  9. Towards self-consistent modelling of the Martian dichotomy: Coupled models of simultaneous core and crust formation

    NASA Astrophysics Data System (ADS)

    Keller, T.; Golabek, G. J.; Gerya, T.; Connolly, J.

    2009-12-01

    One of the most striking surface features on Mars is the crustal dichotomy. It is the oldest geological features on Mars and was formed more than 4.1 Ga ago by either exogenic or endogenic processes (e.g. Keller and Tackley, 2009). In order to find an internal origin of the crustal dichotomy, located within a maximum of 400 Ma of planetary differentiation, the thermal state of the planet resulting from core formation needs to be considered. It was suggested that a primordial crust with up to 45 km thickness can be formed already during the Martian core formation (Norman, 1999). Therefore we suggest that the sinking of iron diapirs delivered by pre-differentiated impactors induced impact- and shear heating-related temperature anomalies in the mantle that fostered the formation of early Martian crust. In this study, we examine parameter sets that will likely cause an onset of hemispherical low-degree mantle convection directly after, and coupled to, an already hemispherical core formation. To test this hypothesis we use a numerical model to simulate the formation of the Martian iron core, while peridotite melting is enabled to track melting caused by shear and radioactive heating. We perform 2D simulations using the spherical-Cartesian code I2ELVIS (Gerya and Yuen, 2007). It combines finite differences on a fully staggered rectangular Eulerian grid with Lagrangian marker-in-cell technique. In our model setup, the planet is surrounded by a low viscosity, massless fluid (“sticky air”) to simulate a free surface. We apply a temperature- and stress-dependent viscoplastic rheology inside a Mars-sized planet. Radioactive and shear-heating as well as consumption of latent heat by silicate melting are taken into account. The depth of neutral buoyancy of silicate melt with respect to solid silicates is determined by the difference in compressibility of the liquid and solid phase. To self-consistently simulate the silicate phase changes expected inside a Mars-sized body

  10. 3C 57 as an atypical radio-loud quasar: implications for the radio-loud/radio-quiet dichotomy

    NASA Astrophysics Data System (ADS)

    Sulentic, J. W.; Martínez-Carballo, M. A.; Marziani, P.; del Olmo, A.; Stirpe, G. M.; Zamfir, S.; Plauchu-Frayn, I.

    2015-06-01

    Lobe-dominated radio-loud (LD RL) quasars occupy a restricted domain in the 4D Eigenvector 1 (4DE1) parameter space which implies restricted geometry/physics/kinematics for this subclass compared to the radio-quiet (RQ) majority of quasars. We discuss how this restricted domain for the LD RL parent population supports the notion for a RQ-RL dichotomy among type 1 sources. 3C 57 is an atypical RL quasar that shows both uncertain radio morphology and falls in a region of 4DE1 space where RL quasars are rare. We present new radio flux and optical spectroscopic measures designed to verify its atypical optical/UV spectroscopic behaviour and clarify its radio structure. The former data confirms that 3C 57 falls off the 4DE1 quasar `main sequence' with both extreme optical Fe II emission (R_{Fe II} ˜ 1) and a large C IV λ1549 profile blueshift (˜-1500 km s-1). These parameter values are typical of extreme Population A sources which are almost always RQ. New radio measures show no evidence for flux change over a 50+ year time-scale consistent with compact steep-spectrum (or young LD) over core-dominated morphology. In the 4DE1 context where LD RL are usually low L/LEdd quasars, we suggest that 3C 57 is an evolved RL quasar (i.e. large blackhole mass) undergoing a major accretion event leading to a rejuvenation reflected by strong Fe II emission, perhaps indicating significant heavy metal enrichment, high bolometric luminosity for a low-redshift source and resultant unusually high Eddington ratio giving rise to the atypical C IV λ1549.

  11. Neuroanatomical dichotomy of sexual behaviors in rodents: a special emphasis on brain serotonin

    PubMed Central

    Angoa-Pérez, Mariana; Kuhn, Donald M.

    2016-01-01

    Much of the social behavior in which rodents engage is related to reproduction, such as maintaining a breeding territory, seeking mates, mating, and caring for young. Rodents belong to the internally fertilizing species that require sexual behavior for reproduction. The dyadic, heterosexual patterns of most mammalian species are sexually dimorphic, but they also share mutual components in both sexes: sexual attraction is reciprocal, sexual initiative is assumed, appetitive behavior is engaged in and mating involves consummatory and postconsummatory phases in females as well as in males. Serotonin, a phylogenetically ancient molecule, is the most widely distributed neurotransmitter in the brain and its signaling pathways are essential for numerous functions including sexual behavior. Since the late 1960’s, brain serotonergic neurotransmission has been considered to exert an inhibitory influence on the neural mechanisms mediating sexual behavior. This contention was based mainly on the observations that a decrease in central serotonergic activity facilitated the elicitation of sexual behavior while an increase in central serotonergic activity attenuated it. However, the discovery of over 14 types of serotonin receptors has added numerous layers of complexity to the study of serotonin and sexual behavior. Evidence shows that upon activation, certain receptor subtypes facilitate while some others suppress sexual behavior as well as sexual arousal and motivation. Furthermore, the role of these receptors has been shown to be differential in males versus females. The use of serotonergic pharmacological interventions, mouse strains with genetic polymorphisms causing alterations in the levels of brain serotonin as well as animal models with genetic manipulations of various serotonin effectors has helped delineate the fundamental role of this neurotransmitter in the regulation of sexual behavior. This review aims to examine the basics of the components of female and male

  12. Modeling Transient Root-zone Soil Moisture Dichotomies in Landscapes with Intermixed Land Covers

    NASA Astrophysics Data System (ADS)

    Patrignani, A.; Ochsner, T. E.

    2015-12-01

    Although large-scale in situ soil moisture monitoring networks are becoming increasingly valuable research tools, deficiencies of many existing networks include the small spatial support of each station, the low spatial density of stations, and the almost exclusive deployment of stations in grassland vegetation. These grassland soil moisture observations may not adequately represent the real soil moisture patterns in landscapes with intermixed land cover types. The objectives of this study were i) to compare root-zone soil moisture dynamics of two dominant vegetation types across Oklahoma, grassland (observed) and winter wheat cropland (simulated); ii) to relate the soil moisture dynamics of grassland and cropland vegetation using an artificial neural network (ANN) as a transfer function; and iii) to use the resulting ANN to estimate the soil moisture spatial patterns for a landscape of intermixed grassland and wheat cropland. Root-zone soil moisture was represented by plant available water (PAW) in the top 0.8 m of the soil profile. PAW under grassland was calculated from 18 years of soil moisture observations at 78 stations of the Oklahoma Mesonet, whereas PAW under winter wheat was simulated for the same 78 locations using a soil water balance model. Then, we trained an ANN to reproduce the simulated PAW under winter wheat using only seven inputs: day of the year, latitude and longitude, measured PAW under grassland, and percent sand, silt, and clay. The resulting ANN was used, along with grassland soil moisture observations, to estimate the detailed soil moisture pattern for a 9x9 km2 Soil Moisture Active Passive (SMAP) grid cell. The seasonal dynamics of root-zone PAW for grassland and winter wheat were strongly asynchronous, so grassland soil moisture observations rarely reflect cropland soil moisture conditions in the region. The simple ANN approach facilitated efficient and accurate prediction of the simulated PAW under winter wheat, RMSE = 24 mm, using

  13. The Urban/Rural Dichotomy in the Distribution of Breast Cancer Across Pennsylvania.

    PubMed

    Boukovalas, Stefanos; Sariego, Jack

    2015-09-01

    Breast cancer rates clearly differ across the United States. This is due to a variety of factors, but at least one determinant is the population density. Breast cancer detection rates and treatment paradigms may differ in rural areas when compared with more urban ones. As the population becomes more mobile and diffuse, this may or may not be a worsening problem. The current analysis was undertaken to examine the breast cancer incidence and outcomes in a single state in an attempt to plan for resource allocation in the future. A retrospective analysis was performed using data available from the Pennsylvania Department of Health regarding breast cancer rates by county, the distribution of cases with regard to degree of rurality, death rates by county as a function of rurality, and the age distribution of all presenting cases. Data from 1999 were compared with those of 2009. The United States Census Bureau definition of rurality was used, which specifies that a county be classified as rural if the population density is less than 284 persons/square mile. Between 1999 and 2009, the population of Pennsylvania increased by approximately 3.4 per cent (421,325 people). The urban population increased by 3.9 per cent, whereas the rural population increased by only 2.2 per cent. During that same period, the number of cancer cases/100,000 population remained about the same: 391.41 in 1999; 390.7 in 2009. However, the distribution of cases shifted during that time toward more rural areas of the state: in 1999, there were 372.3 breast cancer cases/100,000 population compared with 2009 when the rate was 384.4/100,000 population. The number of cancer deaths/100,000 population actually dropped overall during the decade: 98.5 in 1999 versus 82.3 in 2009. Though this was true in both urban and rural counties, the decrease was much less pronounced in the rural areas. In urban counties, the death rate dropped from 100.5 to 81.5/100,000 population, whereas in rural counties, the drop was

  14. New insights on the QSO radio-loud/radio-quiet dichotomy: SDSS spectra in the context of the 4D eigenvector1 parameter space

    NASA Astrophysics Data System (ADS)

    Zamfir, S.; Sulentic, J. W.; Marziani, P.

    2008-06-01

    We search for a dichotomy/bimodality between radio-loud (RL) and radio-quiet (RQ) type 1 active galactic nuclei (AGN). We examine several samples of Slogan Digital Sky Survey (SDSS) quasi-stellar objects (QSOs) with high signal-to-noise ratio optical spectra and matching Faint Images of the Radio Sky at Twenty-cm/NRAO VLA Sky Survey (FIRST/NVSS) radio observations. We use the radio data to identify the weakest RL sources with a Fanaroff-Riley type II (FRII) structure to define a RL/RQ boundary which corresponds to log L1.4GHz = 31.6 ergs-1 Hz-1. We measure the properties of broad-line Hβ and FeII emission to define the optical plane of a 4DE1 spectroscopic diagnostic space. The RL quasars occupy a much more restricted domain in this optical plane compared to the RQ sources, which a 2D Kolmogorov-Smirnov test finds to be highly significant. This tells us that the range of broad-line region kinematics and structure for RL sources is more restricted than for the RQ QSOs, which supports the notion of dichotomy. FRII and CD RL sources also show significant 4DE1 domain differences that likely reflect differences in line-of-sight orientation (inclined versus face-on, respectively) for these two classes. The possibility of a distinct radio-intermediate (RI) population between RQ and RL source is disfavoured because a 4DE1 diagnostic space comparison shows no difference between RI and RQ sources. We show that searches for dichotomy in radio versus bolometric luminosity diagrams will yield ambiguous results mainly because in a reasonably complete sample, the radio brightest RQ sources will be numerous enough to blur the gap between RQ and RL sources. Within resolution constraints of NVSS and FIRST, we find no FRI sources among the broad-line quasar population.

  15. Madonna: Like a Dichotomy.

    ERIC Educational Resources Information Center

    Burns, Gary; Kizer, Elizabeth

    Students in communication classes find it useful to study Madonna because she is a fascinating and prolific cultural figure whose merit and intentions are matters of great controversy. As the quintessential music-video star, she is also perhaps the medium's most significant auteur. In the areas of women's roles, motherhood, sexuality, race and…

  16. Relative Ages of the Highlands, Lowlands, and Transition Zone Along a Portion of the Mars Crustal Dichotomy from Densities of Visible and Buried Impact Craters

    NASA Technical Reports Server (NTRS)

    DeSoto, G. E.; Frey, H. V.

    2005-01-01

    Understanding the fundamental age relationships of the different parts of the Mars Crustal Dichotomy is essential to fully understanding the events that shaped the early history and formation of the surface of Mars. A dominant question is what are the true relative ages of the Northern Lowlands and the Southern Highlands? Using MOLA data from the Mars Global Surveyor and Viking visual images, a dataset of both buried and visible crater diameters was created over a nine million sq km study area of a section of the dichotomy boundary stretching from Arabia Terra to Utopia Planitia. Cumulative frequency plots on a log-log scale were used to determine the relative ages for the Highlands, the Lowlands, and the Transition Zone, separately for the visible, the buried and the combined total (visible+ buried) populations. We find the overall Highland crater population in this area is slightly older than the Lowlands, consistent with previous global studies, but the Lowlands and Transition Zone are also very old and formed at roughly the same time. It appears that the formation of the Lowlands in this region formed contemporaneously with a large-scale resurfacing event in the Highlands, perhaps caused by the process responsible for the Lowland formation.

  17. A structure for quasars under the scope of polarization - I. The UV/optical polarization dichotomy of type-1 and type-2 AGN

    NASA Astrophysics Data System (ADS)

    Marin, F.; Goosmann, R. W.

    2013-12-01

    We present ultraviolet/optical spectropolarimetric modelling of the phenomenologically based structure for quasars proposed by Elvis (2000). In this first paper of a series, we explore the continuum polarization emerging from radiatively accelerated and bent winds that were vertically launched from the accretion disc in an active galactic nucleus (AGN). We simulate the radiative transfer occurring in Thomson scattering and dust extinction media over a range of morphological parameters and optical depths of the wind. We demonstrate that the wind geometry proposed by Elvis with a phenomenologically derived bending angle of θ = 60° still underestimates the observed optical polarization percentage of type-1 and type-2 AGN and does not yet reproduce the expected dichotomy of the polarization position angle. To recover the observed polarization properties, a smaller bending angle and some amount of dust shielding in the equatorial region should be considered. A two-phase outflow is found to generate both the observed polarization dichotomy and acceptable levels of polarization degree if the wind has a bending angle θ = 45°, and the conical shells have a half-opening angle of 3° < δθ < 10°. The absorbing dust column at the wind base should be in the range 1 < τdust ≤ 4 (τ being integrated over 2000-8000 Å). Straightforward observational tests from spectropolarimetry and from determining the number density of different AGN types can be performed to further constrain the wind geometry.

  18. Photometric properties of Titan's surface from Cassini VIMS: Relevance to titan's hemispherical albedo dichotomy and surface stability

    USGS Publications Warehouse

    Nelson, R.M.; Brown, R.H.; Hapke, B.W.; Smythe, W.D.; Kamp, L.; Boryta, M.D.; Leader, F.; Baines, K.H.; Bellucci, G.; Bibring, J.-P.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Combes, M.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Formisano, V.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nicholson, P.D.; Sicardy, B.; Sotin, C.

    2006-01-01

    The Visual and Infrared Mapping Spectrometer (VIMS) instrument on the Cassini Saturn Orbiter returned spectral imaging data as the spacecraft undertook six close encounters with Titan beginning 7 July, 2004. Three of these flybys each produced overlapping coverage of two distinct regions of Titan's surface. Twenty-four points were selected on approximately opposite hemispheres to serve as photometric controls. Six points were selected in each of four reflectance classes. On one hemisphere each control point was observed at three distinct phase angles. From the derived phase coefficients, preliminary normal reflectances were derived for each reflectance class. The normal reflectance of Titan's surface units at 2.0178 ??m ranged from 0.079 to 0.185 for the most absorbing to the most reflective units assuming no contribution from absorbing haze. When a modest haze contribution of ??=0.1 is considered these numbers increase to 0.089-0.215. We find that the lowest three reflectance classes have comparable normal reflectance on either hemisphere. However, for the highest brightness class the normal reflectance is higher on the hemisphere encompassing longitude 14-65?? compared to the same high brightness class for the hemisphere encompassing 122-156?? longitude. We conclude that an albedo dichotomy observed in continental sized units on Titan is due not only to one unit having more areal coverage of reflective material than the other but the material on the brighter unit is intrinsically more reflective than the most reflective material on the other unit. This suggests that surface renewal processes are more widespread on Titan's more reflective units than on its less reflective units. We note that one of our photometric control points has increased in reflectance by 12% relative to the surrounding terrain from July of 2004 to April and May of 2005. Possible causes of this effect include atmospheric processes such as ground fog or orographic clouds; the suggestion of

  19. LOSS OF OTOLITH FUNCTION WITH AGE IS ASSOCIATED WITH INCREASED POSTURAL SWAY MEASURES

    PubMed Central

    Serrador, Jorge M.; Lipsitz, Lewis A.; Gopalakrishnan, Gosala S.; Black, F. Owen; Wood, Scott J.

    2009-01-01

    Background Loss of balance and increased fall risk is a common problem associated with aging. Changes in vestibular function occur with aging but the contribution of reduced vestibular otolith function to fall risk remains unknown. Methods We examined a population of 151 healthy individuals (aged 21–93) for both balance (sway measures) and otolith counter-rolling (OCR) function. We assessed balance function with eyes open and closed on a firm surface, eyes open and closed on a foam surface and OCR during ±20 degree roll tilt at 0.005 Hz. Results Subjects demonstrated a significant age-related reduction in OCR and increased postural sway. The effect of age on OCR was greater in females than males. The reduction in OCR was strongly correlated with the mediolateral measures of sway with eyes closed. This correlation was also present in the elderly group alone, suggesting that aging alone does not account for this effect. Conclusions OCR decreases linearly with age and at a greater rate in females than males. This loss of vestibular otolith-ocular function is associated with increased mediolateral measures of sway which have been shown to be related to increased risk of falls. These data suggest a role for loss of otolith function in contributing to fall risk in the elderly. Further prospective, longitudinal studies are necessary to confirm these findings. PMID:19716400

  20. Dichotomy Between the age of the Penultimate Glaciation for Different Source Areas of the Northern Cordilleran Ice Sheet, Yukon Territory, Canada.

    NASA Astrophysics Data System (ADS)

    Ward, B. C.; Bond, J. D.; Gosse, J. C.

    2006-12-01

    Terrestrial in situ cosmogenic 10Be was measured to date large boulders that were exposed following deglaciation of the penultimate glaciation of the Cordilleran ice sheet (CIS) in western Yukon Territory, Canada. Ages of 54-51 ka indicate a Marine Oxygen Isotope Stage (MIS) 4 (early Wisconsinan) age for this glaciation, the first such confirmed evidence in the Canadian Cordillera. These results are in apparent contrast to the MIS 6 age of the penultimate Reid glaciation to the east in central Yukon, but are equivalent to exposure ages on penultimate drift in Alaska. Thus there is a dichotomy between MIS 4 and 6 glacial extents for at least two of the source areas for the northern portion of Cordilleran ice sheet, the St. Elias - Coast mountains lobes and the more easterly Selwyn Lobe, indicating different responses to climatic forcing during glaciations. The northern CIS was a precipitation-limited system and we propose variation in regional moisture, specifically how moisture penetrates the St. Elias and Coast mountains, as the possible cause of the dichotomy between glacial advances. Causes for regional variation in precipitation remain unclear but likely involve the style of precipitation delivery over the St. Elias Mountains as controlled by the extent of the Laurentide Ice Sheet and broad variations in position and intensity of the Aleutian Low. When the Aleutian Low is well developed and/or more easterly, meridional flow occurs. This results in strengthened moisture flux from the Pacific, and an increase in the size of the rain shadow. When the Aleutian Low is weaker and/or located further west, atmospheric flow is more zonal, with flow westward over the St. Elias/Coast mountains. There is a reduced moisture flux but the orographic affect is reduced as is the size and magnitude of the rain shadow. Zonal conditions were used to explain periods during the Holocene when O-isotopes indicated more effective precipitation in the present rain shadow area. A similar

  1. Venomic Analysis of the Poorly Studied Desert Coral Snake, Micrurus tschudii tschudii, Supports the 3FTx/PLA2 Dichotomy across Micrurus Venoms

    PubMed Central

    Sanz, Libia; Pla, Davinia; Pérez, Alicia; Rodríguez, Yania; Zavaleta, Alfonso; Salas, Maria; Lomonte, Bruno; Calvete, Juan J.

    2016-01-01

    The venom proteome of the poorly studied desert coral snake Micrurus tschudii tschudii was unveiled using a venomic approach, which identified ≥38 proteins belonging to only four snake venom protein families. The three-finger toxins (3FTxs) constitute, both in number of isoforms (~30) and total abundance (93.6% of the venom proteome), the major protein family of the desert coral snake venom. Phospholipases A2 (PLA2s; seven isoforms, 4.1% of the venom proteome), 1–3 Kunitz-type proteins (1.6%), and 1–2 l-amino acid oxidases (LAO, 0.7%) complete the toxin arsenal of M. t. tschudii. Our results add to the growing evidence that the occurrence of two divergent venom phenotypes, i.e., 3FTx- and PLA2-predominant venom proteomes, may constitute a general trend across the cladogenesis of Micrurus. The occurrence of a similar pattern of venom phenotypic variability among true sea snake (Hydrophiinae) venoms suggests that the 3FTx/PLA2 dichotomy may be widely distributed among Elapidae venoms. PMID:27338473

  2. Venomic Analysis of the Poorly Studied Desert Coral Snake, Micrurus tschudii tschudii, Supports the 3FTx/PLA₂ Dichotomy across Micrurus Venoms.

    PubMed

    Sanz, Libia; Pla, Davinia; Pérez, Alicia; Rodríguez, Yania; Zavaleta, Alfonso; Salas, Maria; Lomonte, Bruno; Calvete, Juan J

    2016-01-01

    The venom proteome of the poorly studied desert coral snake Micrurus tschudii tschudii was unveiled using a venomic approach, which identified ≥38 proteins belonging to only four snake venom protein families. The three-finger toxins (3FTxs) constitute, both in number of isoforms (~30) and total abundance (93.6% of the venom proteome), the major protein family of the desert coral snake venom. Phospholipases A₂ (PLA₂s; seven isoforms, 4.1% of the venom proteome), 1-3 Kunitz-type proteins (1.6%), and 1-2 l-amino acid oxidases (LAO, 0.7%) complete the toxin arsenal of M. t. tschudii. Our results add to the growing evidence that the occurrence of two divergent venom phenotypes, i.e., 3FTx- and PLA₂-predominant venom proteomes, may constitute a general trend across the cladogenesis of Micrurus. The occurrence of a similar pattern of venom phenotypic variability among true sea snake (Hydrophiinae) venoms suggests that the 3FTx/PLA₂ dichotomy may be widely distributed among Elapidae venoms. PMID:27338473

  3. Stable symbionts across the HMA-LMA dichotomy: low seasonal and interannual variation in sponge-associated bacteria from taxonomically diverse hosts.

    PubMed

    Erwin, Patrick M; Coma, Rafel; López-Sendino, Paula; Serrano, Eduard; Ribes, Marta

    2015-10-01

    Marine sponges host bacterial communities with important ecological and economic roles in nature and society, yet these benefits depend largely on the stability of host-symbiont interactions and their susceptibility to changing environmental conditions. Here, we investigated the temporal stability of complex host-microbe symbioses in a temperate, seasonal environment over three years, targeting sponges across a range of symbiont density (high and low microbial abundance, HMA and LMA) and host taxonomy (six orders). Symbiont profiling by terminal restriction fragment length polymorphism analysis of 16S rRNA gene sequences revealed that bacterial communities in all sponges exhibited a high degree of host specificity, low seasonal dynamics and low interannual variability: results that represent an emerging trend in the field of sponge microbiology and contrast sharply with the seasonal dynamics of free-living bacterioplankton. Further, HMA sponges hosted more diverse, even and similar symbiont communities than LMA sponges and these differences in community structure extended to core members of the microbiome. Together, these findings show clear distinctions in symbiont structure between HMA and LMA sponges while resolving notable similarities in their stability over seasonal and inter-annual scales, thus providing insight into the ecological consequences of the HMA-LMA dichotomy and the temporal stability of complex host-microbe symbioses. PMID:26405300

  4. Differentiability of Palmer's linearization theorem and converse result for density functions

    NASA Astrophysics Data System (ADS)

    Castañeda, Álvaro; Robledo, Gonzalo

    2015-11-01

    We study differentiability properties in a particular case of the Palmer's linearization theorem, which states the existence of a homeomorphism H between the solutions of a linear ODE system having exponential dichotomy and a quasilinear system. Indeed, if the linear system is uniformly asymptotically stable, sufficient conditions ensuring that H is a C2 preserving orientation diffeomorphism are given. As an application, we generalize a converse result of density functions for a nonlinear system in the nonautonomous case.

  5. Design and analysis of phase III trials with ordered outcome scales: the concept of the sliding dichotomy.

    PubMed

    Murray, Gordon D; Barer, David; Choi, Sung; Fernandes, Helen; Gregson, Barbara; Lees, Kennedy R; Maas, Andrew I R; Marmarou, Anthony; Mendelow, A David; Steyerberg, Ewout W; Taylor, Gillian S; Teasdale, Graham M; Weir, Christopher J

    2005-05-01

    The conventional approach to the analysis of a Phase III trial in head injury or stroke takes an ordered scale measuring functional outcome and collapses the scale to a binary outcome of favorable versus unfavorable. This discards potentially relevant information which limits statistical power and moreover is not in accord with clinical practice. We propose an alternative approach where a favorable outcome is defined as better than would be expected, taking account of each individual patient's baseline prognosis. This is illustrated through a worked example based on data from a Phase III trial in head injury. The approach is also compared with the proportional odds model, which is another statistical approach that can exploit an ordered outcome scale. The approach raises issues of clinical, statistical, and regulatory importance, and we initiate what we believe needs to become a widespread debate amongst the community involved in clinical research in head injury and stroke. PMID:15892597

  6. Dichotomy of short and long thymic stromal lymphopoietin isoforms in inflammatory disorders of the bowel and skin

    PubMed Central

    Fornasa, Giulia; Tsilingiri, Katerina; Caprioli, Flavio; Botti, Fiorenzo; Mapelli, Marina; Meller, Stephan; Kislat, Andreas; Homey, Bernhard; Di Sabatino, Antonio; Sonzogni, Angelica; Viale, Giuseppe; Diaferia, Giuseppe; Gori, Alessandro; Longhi, Renato; Penna, Giuseppe; Rescigno, Maria

    2015-01-01

    Background Thymic stromal lymphopoietin (TSLP) is a cytokine with pleiotropic functions in the immune system. It has been associated with allergic reactions in the skin and lungs but also homeostatic tolerogenic responses in the thymus and gut. Objective In human subjects TSLP is present in 2 isoforms, short and long. Here we wanted to investigate the differential expression of the TSLP isoforms and discern their biological implications under homeostatic or inflammatory conditions. Methods We evaluated the expression of TSLPs in tissues from healthy subjects, patients with ulcerative colitis, patients with celiac disease, and patients with atopic dermatitis and on epithelial cells and keratinocytes under steady-state conditions or after stimulation. We then tested the immune activity of TSLP isoforms both in vitro and in vivo. Results We showed that TSLP isoforms are responsible for 2 opposite immune functions. The short isoform is expressed under steady-state conditions and exerts anti-inflammatory activities by affecting the capacity of PBMCs and dendritic cells to produce inflammatory cytokines. Moreover, the short isoform TSLP ameliorates experimental colitis in mice and prevents endotoxin shock. The long isoform of TSLP is proinflammatory and is only expressed during inflammation. The isoforms are differentially regulated by pathogenic bacteria, such as Salmonella species and adhesive-invasive Escherichia coli. Conclusions We have solved the dilemma of TSLP being both homeostatic and inflammatory. The TSLP isoform ratio is altered during several inflammatory disorders, with strong implications in disease treatment and prevention. Indeed, targeting of the long isoform of TSLP at the C-terminal portion, which is common to both isoforms, might lead to unwanted side effects caused by neutralization of the homeostatic short isoform. PMID:26014813

  7. Hot versus Cold: the Dichotomy in Spherical Accretion of Cooling Flows onto Supermassive Black Holes in Elliptical Galaxies, Galaxy Groups, and Clusters

    NASA Astrophysics Data System (ADS)

    Guo, Fulai; Mathews, William G.

    2014-01-01

    Feedback heating from active galactic nuclei (AGNs) has been commonly invoked to suppress cooling flows predicted in hot gas in elliptical galaxies, galaxy groups, and clusters. Previous studies have focused on if and how AGN feedback heats the gas but have little paid attention to its triggering mechanism. Using spherically symmetric simulations, we investigate how large-scale cooling flows are accreted by central supermassive black holes (SMBHs) in eight well-observed systems and find an interesting dichotomy. In massive clusters, the gas develops a central cooling catastrophe within about the cooling time (typically ~100-300 Myr), resulting in cold-mode accretion onto SMBHs. However, in our four simulated systems on group and galaxy scales at a low metallicity Z = 0.3 Z ⊙, the gas quickly settles into a long-term state that has a cuspy central temperature profile extending to several tens to about 100 pc. At the more realistic solar metallicity, two groups (with R e ~ 4 kpc) still host the long-term, hot-mode accretion. Both accretion modes naturally appear in our idealized calculations where only cooling, gas inflow, and compressional heating are considered. The long-term, hot-mode accretion is maintained by the quickly established closeness between the timescales of these processes, preferably in systems with low gas densities, low gas metallicities, and importantly, compact central galaxies, which result in strong gravitational acceleration and compressional heating at the intermediate radii. Our calculations predict that central cuspy temperature profiles appear more often in smaller systems than galaxy clusters, which instead often host significant cold gas and star formation.

  8. Hot versus cold: The dichotomy in spherical accretion of cooling flows onto supermassive black holes in elliptical galaxies, galaxy groups, and clusters

    SciTech Connect

    Guo, Fulai; Mathews, William G.

    2014-01-10

    Feedback heating from active galactic nuclei (AGNs) has been commonly invoked to suppress cooling flows predicted in hot gas in elliptical galaxies, galaxy groups, and clusters. Previous studies have focused on if and how AGN feedback heats the gas but have little paid attention to its triggering mechanism. Using spherically symmetric simulations, we investigate how large-scale cooling flows are accreted by central supermassive black holes (SMBHs) in eight well-observed systems and find an interesting dichotomy. In massive clusters, the gas develops a central cooling catastrophe within about the cooling time (typically ∼100-300 Myr), resulting in cold-mode accretion onto SMBHs. However, in our four simulated systems on group and galaxy scales at a low metallicity Z = 0.3 Z {sub ☉}, the gas quickly settles into a long-term state that has a cuspy central temperature profile extending to several tens to about 100 pc. At the more realistic solar metallicity, two groups (with R {sub e} ∼ 4 kpc) still host the long-term, hot-mode accretion. Both accretion modes naturally appear in our idealized calculations where only cooling, gas inflow, and compressional heating are considered. The long-term, hot-mode accretion is maintained by the quickly established closeness between the timescales of these processes, preferably in systems with low gas densities, low gas metallicities, and importantly, compact central galaxies, which result in strong gravitational acceleration and compressional heating at the intermediate radii. Our calculations predict that central cuspy temperature profiles appear more often in smaller systems than galaxy clusters, which instead often host significant cold gas and star formation.

  9. A genetic dichotomy between pure sclerosing epithelioid fibrosarcoma (SEF) and hybrid SEF/low-grade fibromyxoid sarcoma: a pathologic and molecular study of 18 cases.

    PubMed

    Prieto-Granada, Carlos; Zhang, Lei; Chen, Hsiao-Wei; Sung, Yun-Shao; Agaram, Narasimhan P; Jungbluth, Achim A; Antonescu, Cristina R

    2015-01-01

    Sclerosing epithelioid fibrosarcoma (SEF) is a rare soft tissue tumor exhibiting considerable morphologic overlap with low-grade fibromyxoid sarcoma (LGFMS). Moreover, both SEF and LGFMS show MUC4 expression by immunohistochemistry. While the majority of LGFMS cases are characterized by a FUS-CREB3L1 fusion, both FUS-CREB3L2 and EWSR1-CREB3L1 fusions were recently demonstrated in a small number of LGFMS and SEF/LGFMS hybrid tumors. In contrast, recent studies pointed out that SEF harbor frequent EWSR1 rearrangements, with only a minority of cases showing FUS-CREB3L2 fusions. In an effort to further characterize the molecular characteristics of pure SEF and hybrid SEF/LGFMS lesions, we undertook a clinicopathologic, immunohistochemical and genetic analysis of a series of 10 SEF and 8 hybrid SEF/LGFMS tumors. The mortality rate was similar between the two groups, 44% within the pure SEF group and 37% in the hybrid SEF/LGFMS with a mean overall follow-up of 66 months. All but one pure SEF and all hybrid SEF/LGFMS-tested cases showed MUC4 immunoreactivity. The majority (90%) of pure SEF cases showed EWSR1 gene rearrangements by fluorescence in situ hybridization with only one case exhibiting FUS rearrangement. Of the nine EWSR1 positive cases, six cases harbored CREB3L1 break-apart, two had CREB3L2 rearrangement (a previously unreported finding) and one lacked evidence of CREB3L1/2 abnormalities. In contrast, all hybrid SEF/LGFMS tumors exhibited FUS and CREB3L2 rearrangements. These results further demarcate a relative cytogenetic dichotomy between pure SEF, often characterized by EWSR1 rearrangements, and hybrid SEF/LGFMS, harboring FUS-CREB3L2 fusion; the latter group recapitulating the genotype of LGFMS. PMID:25231134

  10. Dichotomy in perceptual learning of interval timing: calibration of mean accuracy and precision differ in specificity and time course.

    PubMed

    Sohn, Hansem; Lee, Sang-Hun

    2013-01-01

    Our brain is inexorably confronted with a dynamic environment in which it has to fine-tune spatiotemporal representations of incoming sensory stimuli and commit to a decision accordingly. Among those representations needing constant calibration is interval timing, which plays a pivotal role in various cognitive and motor tasks. To investigate how perceived time interval is adjusted by experience, we conducted a human psychophysical experiment using an implicit interval-timing task in which observers responded to an invisible bar drifting at a constant speed. We tracked daily changes in distributions of response times for a range of physical time intervals over multiple days of training with two major types of timing performance, mean accuracy and precision. We found a decoupled dynamics of mean accuracy and precision in terms of their time course and specificity of perceptual learning. Mean accuracy showed feedback-driven instantaneous calibration evidenced by a partial transfer around the time interval trained with feedback, while timing precision exhibited a long-term slow improvement with no evident specificity. We found that a Bayesian observer model, in which a subjective time interval is determined jointly by a prior and likelihood function for timing, captures the dissociative temporal dynamics of the two types of timing measures simultaneously. Finally, the model suggested that the width of the prior, not the likelihoods, gradually shrinks over sessions, substantiating the important role of prior knowledge in perceptual learning of interval timing. PMID:23076112

  11. THE ROLE OF CORE MASS IN CONTROLLING EVAPORATION: THE KEPLER RADIUS DISTRIBUTION AND THE KEPLER-36 DENSITY DICHOTOMY

    SciTech Connect

    Lopez, Eric D.; Fortney, Jonathan J.

    2013-10-10

    We use models of coupled thermal evolution and photo-evaporative mass loss to understand the formation and evolution of the Kepler-36 system. We show that the large contrast in mean planetary density observed by Carter et al. can be explained as a natural consequence of photo-evaporation from planets that formed with similar initial compositions. However, rather than being due to differences in XUV irradiation between the planets, we find that this contrast is due to the difference in the masses of the planets' rock/iron cores and the impact that this has on mass-loss evolution. We explore in detail how our coupled models depend on irradiation, mass, age, composition, and the efficiency of mass loss. Based on fits to large numbers of coupled evolution and mass-loss runs, we provide analytic fits to understand threshold XUV fluxes for significant atmospheric loss, as a function of core mass and mass-loss efficiency. Finally we discuss these results in the context of recent studies of the radius distribution of Kepler candidates. Using our parameter study, we make testable predictions for the frequency of sub-Neptune-sized planets. We show that 1.8-4.0 R{sub ⊕} planets should become significantly less common on orbits within 10 days and discuss the possibility of a narrow 'occurrence valley' in the radius-flux distribution. Moreover, we describe how photo-evaporation provides a natural explanation for the recent observations of Ciardi et al. that inner planets are preferentially smaller within the systems.

  12. Functional integration across a gradient of corticostriatal channels controls UP state transitions in the dorsal striatum

    PubMed Central

    Kasanetz, Fernando; Riquelme, Luis A.; Della-Maggiore, Valeria; O'Donnell, Patricio; Murer, M. Gustavo

    2008-01-01

    Coordinated near-threshold depolarized states in cortical and striatal neurons may contribute to form functionally segregated channels of information processing. Recent anatomical studies have identified pathways that could support spiraling interactions across corticostriatal channels, but a functional outcome of such spiraling remains to be identified. Here, we examined whether plateau depolarizations (UP states) in striatal neurons relate better to active epochs in local field potentials recorded from closely related cortical areas than to those recorded in less-related cortical areas. Our results show that, in anesthetized rats, the coordination between cortical areas and striatal regions obeys a mediolateral gradient and keeps track of slow wave trajectory across the neocortex. Moreover, activity in one cortical area induced phase advances in UP state onset and phase delays in UP state termination in nonmatching striatal regions, reflecting the existence of functional connections that could encode large-scale interactions between corticostriatal channels as subthreshold influences on striatal projection neurons. PMID:18523020

  13. Jargonial-Obfuscation(J-O) DISambiguation Elimination via Siegel-Baez Cognition Category-Semantics(C-S) in Siegel FUZZYICS=CATEGORYICS (Son of TRIZ)/(F=C) Tabular List-Format Dichotomy Truth-Table Matrix Analytics

    NASA Astrophysics Data System (ADS)

    Siegel, Carl Ludwig; Siegel, Edward Carl-Ludwig

    2011-03-01

    NOT "philosophy" per se but raising serious salient Arnol'd [Huygens and Barrow, Newton and Hooke(96)] questions begged is Rota empiricism Husserl VS. Frege maths-objects Dichotomy controversy: Hill-Haddock[Husserl or Frege?(00)]as manifestly-demonstrated by Hintikka[B.U.]-Critchey[Derrida Deconstruction Ethics(78)] deconstruction; Altshuler TRIZ; Siegel F=C/C-S; Siegel-Baez(UCR) Cognition C-S = "Category-theory ``+'' Cognitive-Semantics[Wierzbica-Langacker-Lakoff-Nunez[Where Maths Comes From(00)]-Fauconnier-Turner[Blending(98)]-Coulson[Semantic-Leaps (00)

  14. The Land Use and Land Cover Dichotomy: A Comparison of Two Land Classification Systems in Support of Urban Earth Science Applications

    NASA Technical Reports Server (NTRS)

    McAllister, William K.

    2003-01-01

    One is likely to read the terms 'land use' and 'land cover' in the same sentence, yet these concepts have different origins and different applications. Land cover is typically analyzed by earth scientists working with remotely sensed images. Land use is typically studied by urban planners who must prescribe solutions that could prevent future problems. This apparent dichotomy has led to different classification systems for land-based data. The works of earth scientists and urban planning practitioners are beginning to come together in the field of spatial analysis and in their common use of new spatial analysis technology. In this context, the technology can stimulate a common 'language' that allows a broader sharing of ideas. The increasing amount of land use and land cover change challenges the various efforts to classify in ways that are efficient, effective, and agreeable to all groups of users. If land cover and land uses can be identified by remote methods using aerial photography and satellites, then these ways are more efficient than field surveys of the same area. New technology, such as high-resolution satellite sensors, and new methods, such as more refined algorithms for image interpretation, are providing refined data to better identify the actual cover and apparent use of land, thus effectiveness is improved. However, the closer together and the more vertical the land uses are, the more difficult the task of identification is, and the greater is the need to supplement remotely sensed data with field study (in situ). Thus, a number of land classification methods were developed in order to organize the greatly expanding volume of data on land characteristics in ways useful to different groups. This paper distinguishes two land based classification systems, one developed primarily for remotely sensed data, and the other, a more comprehensive system requiring in situ collection methods. The intent is to look at how the two systems developed and how they

  15. Evidence of stratabound liquefaction in the formation of fractured topographic margins, cone chains and pit catenas along the Martian Dichotomy Boundary and in Isidis Planitia, Mars.

    NASA Astrophysics Data System (ADS)

    Gallagher, C.; Balme, M. R.

    2012-04-01

    On the low-lying plains along much of the Martian Dichotomy Boundary (MDB) and in the Isidis impact basin, cones and curving chains of cones, referred to as thumbprint terrain (TPT), are common. In the same settings, pit chains (catenas) occur in orthogonal to curving and conchoidal fracture sets between mesa-like crustal blocks, generally at or near topographic margins. Many of the fractures consist of linked pits rather than simple propagated cracks. These assemblages are often associated with the more disaggregated populations of blocks comprising chaos terrain. We show that the local planimetric arrangement of the cone chains, fractures and pit catenas is strikingly similar in both shape and scale, including lateral separation, length, longitudinal slope and radius of curvature. The summits of cones tend to be closely accordant along individual cone chains. Neighbouring cone chains tend to be mutually accordant on low gradient basin surfaces but generally stepped en echelon closer to the fractured basin margins. Similarly, the crustal blocks (including very isolated block sets) are often mutually stepped, and fractures between these en echelon blocks tend to be very close to horizontal. Hence, many cone chains, fractures and pit catenas in fractures share the property of being arranged along strike. They diverge morphologically by the cone chains being positive forms separated by narrow gulfs but the pit catenas being negative forms separated by planar blocks. All of these characteristics point to the possibility that the arcuate cone chains and the arcuate pit catenas have a common origin. In particular, we hypothesise that the cone chains characteristic of TPT along the MDB and in Isidis are filled, indurated and then exhumed pit catenas revealed by the stripping-away of intervening blocks [cf. 1]. Many other surfaces on Mars are pervaded by pits and pit catenas, with evidence of former water flow through the catenas suggesting that ground-ice thaw played a

  16. Comparative morphology of porpoise (Cetacea: Phocoenidae) pterygoid sinuses: phylogenetic and functional implications.

    PubMed

    Racicot, Rachel A; Berta, Annalisa

    2013-01-01

    High-resolution X-ray computed tomographic scans were used to examine pterygoid sinus morphology within extant porpoise species and one delphinid (Tursiops truncatus), in order to consider: 1) intraspecific and interspecific variation among the studied species; 2) the most parsimonious sequence of character acquisition; and 3) the potential functional roles of the preorbital lobes of the sinuses in sound reflection. Scans revealed that the pterygoid/palatine regions are mediolaterally broader in the earliest diverging phocoenid (Neophocaena phocaenoides) and Tursiops truncatus than the dorsoventrally elongated sinuses observed in other species. Rostrocaudal lengths of the sphenoidal regions of the sinuses in all individuals studied are proportionally similar, indicating conservatism in this region across species. The neonate Phocoena phocoena has shorter preorbital lobes than adults, but they are still proportionally longer than Neophocaena phocaenoides and Phocoena spinipinnis. The preorbital lobes broaden mediolaterally to varying degrees across species; in particular, Phocoenoides dalli has the largest dorsal and lateral expansion of this region. Assuming the highest pulse frequency produced by porpoises is 150 kHz, all regions of the preorbital lobes are thick enough to reflect the wavelengths produced. In addition, the neonate preorbital lobes are not as elongated as they are in adults, and the dorsal third of this region may not reflect sound to the same extent. This study reinforces the importance of using nondestructive methods to quantify variation in endocranial anatomy and the value of CT data for recovering phylogenetically useful information, as well as functional roles sinuses play in concert with the soft tissue head anatomy for biosonar. PMID:22965565

  17. Evidence of stratabound liquefaction in the formation of fractured topographic margins, cone chains and pit catenas along the Martian Dichotomy Boundary and in Isidis Planitia, Mars.

    NASA Astrophysics Data System (ADS)

    Gallagher, C.; Balme, M. R.

    2012-04-01

    On the low-lying plains along much of the Martian Dichotomy Boundary (MDB) and in the Isidis impact basin, cones and curving chains of cones, referred to as thumbprint terrain (TPT), are common. In the same settings, pit chains (catenas) occur in orthogonal to curving and conchoidal fracture sets between mesa-like crustal blocks, generally at or near topographic margins. Many of the fractures consist of linked pits rather than simple propagated cracks. These assemblages are often associated with the more disaggregated populations of blocks comprising chaos terrain. We show that the local planimetric arrangement of the cone chains, fractures and pit catenas is strikingly similar in both shape and scale, including lateral separation, length, longitudinal slope and radius of curvature. The summits of cones tend to be closely accordant along individual cone chains. Neighbouring cone chains tend to be mutually accordant on low gradient basin surfaces but generally stepped en echelon closer to the fractured basin margins. Similarly, the crustal blocks (including very isolated block sets) are often mutually stepped, and fractures between these en echelon blocks tend to be very close to horizontal. Hence, many cone chains, fractures and pit catenas in fractures share the property of being arranged along strike. They diverge morphologically by the cone chains being positive forms separated by narrow gulfs but the pit catenas being negative forms separated by planar blocks. All of these characteristics point to the possibility that the arcuate cone chains and the arcuate pit catenas have a common origin. In particular, we hypothesise that the cone chains characteristic of TPT along the MDB and in Isidis are filled, indurated and then exhumed pit catenas revealed by the stripping-away of intervening blocks [cf. 1]. Many other surfaces on Mars are pervaded by pits and pit catenas, with evidence of former water flow through the catenas suggesting that ground-ice thaw played a

  18. Physics Proofs of Four Millennium-Problems(MP) via CATEGORY-SEMANTICS(C-S)/F=C Aristotle SQUARE-of-OPPOSITION(SoO) DEduction-LOGIC DichotomY

    NASA Astrophysics Data System (ADS)

    Clay, London; Siegel, Edward Carl-Ludwig

    2011-03-01

    Siegel-Baez Cognitive-Category-Semantics"(C-C-S) tabular list-format matrix truth-table analytics SoO jargonial-obfuscation elimination query WHAT? yields four "pure"-maths MP "Feet of Clay!!!" proofs: (1) Siegel [AMS Natl.Mtg.(02)-Abs.973-03-126: (CCNY;64)(94;Wiles)] Fermat's: Last-Thm. = Least-Action Ppl.; (2) P=/=NP TRIVIAL simple Euclid geometry/dimensions: NO computer anything"Feet of Clay!!!"; (3) Birch-Swinnerton-Dyer conjecture; (4) Riemann-hypotheses via COMBO.: Siegel[AMS Natl.Mtg.(02)-Abs.973-60-124] digits log-law inversion to ONLY BEQS with ONLY zero-digit BEC, AND Rayleigh[1870;graph-thy."short-CUT method"[Doyle-Snell, Random-Walks & Electric-Nets,MAA(81)]-"Anderson"[(58)] critical-strip C-localization!!! SoO DichotomY ("V") IdentitY: #s:(Euler v Bernoulli) = (Sets v Multisets) = Quantum-Statistics(FD v BE) = Power-Spectra(1/f(0) v 1/f(1)) = Conic-Sections(Ellipse v Hyperbola) = Extent(Locality v Globality);Siegel[(89)] (so MIScalled) "complexity" as UTTER-SIMPLICITY(!!!) v COMPLICATEDNESS MEASURE(S) definition.

  19. Physics Proofs of Four Millennium-Problems(MP) via CATEGORY-SEMANTICS(C-S)/F=C Aristotle SQUARE-of-OPPOSITION(SoO) DEduction-LOGIC DichotomY

    NASA Astrophysics Data System (ADS)

    Clay, L.; Siegel, E.

    2010-03-01

    Siegel-Baez C-S/F=C tabular list-format matrix truth-table analytics SoO jargonial-obfuscation elimination query WHAT? yields four ``pure''-maths MP ``Feet of Clay!!!'' proofs:(1)Siegel [AMS Natl.Mtg.(2002)-Abs.#:973-03-126:(@CCNY;1964!!!)<<<(1994; Wiles)]Fermat's: Last-Theorem = Least-Action Principle; (2) P=/=NP TRIVIAL simple Euclid geometry/dimensions: NO computer anything;``Feet of Clay!!!''; (3)Birch-Swinnerton-Dyer conjecture; (4)Riemann-hypotheses via combination of: Siegel [AMS Natl.Mtg. (2002)-Abs.#:973-60-124 digits logarithmic-law simple algebraic- inversion to ONLY BEQS with ONLY zero-digit BEC, AND Rayleigh [(1870);graph-theory ``short-CUT method''[Doyle- Snell,Random- Walks & Electric-Networks,MAA(1981)]-``Anderson'' [PRL(1958)] critical-strip 1/2 complex-plane localization!!! SoO DichotomY (``v'') IdentitY: numbers(Euler v Bernoulli) = (Sets v Multisets) = Quantum-Statistics(F.-D. v B.-E.) = Power- Spectra(1/f^(0) v 1/f^(1.000...) = Conic-Sections(Ellipse v (Parabola) v Hyperbola) = Extent(Locality v Globality); Siegel [MRS Fractals Symp.(1989)](so MIScalled)``complexity'' as UTTER- SIMPLICITY (!!!) v COMPLICATEDNESS MEASURE(S) definition.

  20. The effects of hippotherapy on postural balance and functional ability in children with cerebral palsy

    PubMed Central

    Moraes, Andréa Gomes; Copetti, Fernando; Angelo, Vera Regina; Chiavoloni, Luana Leonardo; David, Ana Cristina

    2016-01-01

    [Purpose] This study evaluated the effects of hippotherapy on seated postural balance, dynamic balance, and functional performance in children with cerebral palsy and compared the effects of 12 and 24 sessions on seated postural balance. [Subjects and Methods] This study included 15 children with cerebral palsy aged between 5 and 10 years. Interventions: A hippotherapy protocol was performed for 30 minutes, twice a week, for 12 weeks. Postural balance in a sitting position was measured using an AMTI AccuSway Plus force platform 1 week before initiating the hippotherapy program and after 12 and 24 weeks. The Berg Balance Scale (BBS) and Pediatric Evaluation of Disability Inventory (PEDI) were used before and after 24 sessions. [Results] Significant differences were observed for center of pressure (COP) variables, including medio-lateral (COPml), anteroposterior displacement (COPap), and velocity of displacement (VelCOP), particularly after 24 sessions. There were also significant differences in BBS scores and PEDI score increases associated with functional skills (self-care, social function, and mobility), caregiver assistance (self-care), social function, and mobility. [Conclusion] Hippotherapy resulted in improvement in postural balance in the sitting position, dynamic balance, and functionality in children with cerebral palsy, an effect particularly significant after 24 hippotherapy sessions.

  1. Dynamic morphological changes in the skulls of mice mimicking human Apert syndrome resulting from gain-of-function mutation of FGFR2 (P253R)

    PubMed Central

    Du, Xiaolan; Weng, Tujun; Sun, Qidi; Su, Nan; Chen, Zhi; Qi, Huabing; Jin, Ming; Yin, Liangjun; He, Qifen; Chen, Lin

    2010-01-01

    Apert syndrome is caused mainly by gain-of-function mutations of fibroblast growth factor receptor 2. We have generated a mouse model (Fgfr2+/P253R) mimicking human Apert syndrome resulting from fibroblast growth factor receptor 2 Pro253Arg mutation using the knock-in approach. This mouse model in general has the characteristic skull morphology similar to that in humans with Apert syndrome. To characterize the detailed changes of form in the overall skull and its major anatomic structures, euclidean distance matrix analysis was used to quantitatively compare the form and growth difference between the skulls of mutants and their wild-type controls. There were substantial morphological differences between the skulls of mutants and their controls at 4 and 8 weeks of age (P<0.01). The mutants showed shortened skull dimensions along the rostrocaudal axis, especially in their face. The width of the frontal bone and the distance between the two orbits were broadened mediolaterally. The neurocrania were significantly increased along the dorsoventral axis and slightly increased along the mediolateral axis, and also had anteriorly displayed opisthion along the rostrocaudal axis. Compared with wild-type, the mutant mandible had an anteriorly displaced coronoid process and mandibular condyle along the rostrocaudal axis. We further found that there was catch-up growth in the nasal bone, maxilla, zygomatic bone and some regions of the mandible of the mutant skulls during the 4–8-week interval. The above-mentioned findings further validate the Fgfr2+/P253R mouse strain as a good model for human Apert syndrome. The changes in form characterized in this study will help to elucidate the mechanisms through which the Pro253Arg mutation in fibroblast growth factor receptor 2 affects craniofacial development and causes Apert syndrome. PMID:20557404

  2. Dynamic morphological changes in the skulls of mice mimicking human Apert syndrome resulting from gain-of-function mutation of FGFR2 (P253R).

    PubMed

    Du, Xiaolan; Weng, Tujun; Sun, Qidi; Su, Nan; Chen, Zhi; Qi, Huabing; Jin, Ming; Yin, Liangjun; He, Qifen; Chen, Lin

    2010-08-01

    Apert syndrome is caused mainly by gain-of-function mutations of fibroblast growth factor receptor 2. We have generated a mouse model (Fgfr2(+/P253R)) mimicking human Apert syndrome resulting from fibroblast growth factor receptor 2 Pro253Arg mutation using the knock-in approach. This mouse model in general has the characteristic skull morphology similar to that in humans with Apert syndrome. To characterize the detailed changes of form in the overall skull and its major anatomic structures, euclidean distance matrix analysis was used to quantitatively compare the form and growth difference between the skulls of mutants and their wild-type controls. There were substantial morphological differences between the skulls of mutants and their controls at 4 and 8 weeks of age (P < 0.01). The mutants showed shortened skull dimensions along the rostrocaudal axis, especially in their face. The width of the frontal bone and the distance between the two orbits were broadened mediolaterally. The neurocrania were significantly increased along the dorsoventral axis and slightly increased along the mediolateral axis, and also had anteriorly displayed opisthion along the rostrocaudal axis. Compared with wild-type, the mutant mandible had an anteriorly displaced coronoid process and mandibular condyle along the rostrocaudal axis. We further found that there was catch-up growth in the nasal bone, maxilla, zygomatic bone and some regions of the mandible of the mutant skulls during the 4-8-week interval. The above-mentioned findings further validate the Fgfr2(+/P253R) mouse strain as a good model for human Apert syndrome. The changes in form characterized in this study will help to elucidate the mechanisms through which the Pro253Arg mutation in fibroblast growth factor receptor 2 affects craniofacial development and causes Apert syndrome. PMID:20557404

  3. Th1/Th2 cell dichotomy in acquired immunity to Bordetella pertussis: variables in the in vivo priming and in vitro cytokine detection techniques affect the classification of T-cell subsets as Th1, Th2 or Th0.

    PubMed Central

    Barnard, A; Mahon, B P; Watkins, J; Redhead, K; Mills, K H

    1996-01-01

    In studies of the mechanism of immunity to Bordetella pertussis in a murine respiratory infection model, we have previously demonstrated that natural infection of immunization with a whole cell vaccine induces a potent protective immune response, which is mediated by T-helper type-1 (Th1) cells. In contrast an acellular vaccine generates Th2 cells and is associated with delayed bacterial clearance following respiratory challenge. In the present study we have investigated the apparent Th1/Th2 cell dichotomy in acquired immunity and have examined the factors that affect their induction or detection. The cytokine profiles of B. pertussis-specific T cells in immune animals were determined using antigen-stimulated ex vivo spleen cells or CD4+ T-cell lines and clones established in the presence of interleukin-2 (IL-2) or IL-4. Antigen-specific T cells derived from mice immunized with the acellular vaccine were almost exclusively of the Th2 cell type. In contrast, T-cell lines and clones established following respiratory infection or immunization with the whole cell vaccine were predominantly of the Th1 type. However, a proportion of T cells from convalescent mice, especially when cultured in the presence of IL-4, secreted IL-4 and IL-5 with or without detectable IL-2 and interferon-gamma (IFN-gamma), suggesting that Th0 or Th2 cells were also primed during natural infection in vivo. Furthermore, when mice were assessed 6 months after infection, spleen cells produced significant levels of IL-4 and IL-5, which were not evident at 6 weeks. The route of immunization and the genetic background of the mice were also found to influence the preferential priming of Th1 cells, and this was directly related to the level of protection against respiratory or intracerebral (i.c.) challenge. Our findings underline the critical role of CD4+ Th1 cells in immunity to B. pertussis, but also demonstrate that a number of factors in the in vivo priming and in vitro restimulation can skew the

  4. A Revelation: Quantum-Statistics and Classical-Statistics are Analytic-Geometry Conic-Sections and Numbers/Functions: Euler, Riemann, Bernoulli Generating-Functions: Conics to Numbers/Functions Deep Subtle Connections

    NASA Astrophysics Data System (ADS)

    Descartes, R.; Rota, G.-C.; Euler, L.; Bernoulli, J. D.; Siegel, Edward Carl-Ludwig

    2011-03-01

    Quantum-statistics Dichotomy: Fermi-Dirac(FDQS) Versus Bose-Einstein(BEQS), respectively with contact-repulsion/non-condensation(FDCR) versus attraction/ condensationBEC are manifestly-demonstrated by Taylor-expansion ONLY of their denominator exponential, identified BOTH as Descartes analytic-geometry conic-sections, FDQS as Elllipse (homotopy to rectangle FDQS distribution-function), VIA Maxwell-Boltzmann classical-statistics(MBCS) to Parabola MORPHISM, VS. BEQS to Hyperbola, Archimedes' HYPERBOLICITY INEVITABILITY, and as well generating-functions[Abramowitz-Stegun, Handbook Math.-Functions--p. 804!!!], respectively of Euler-numbers/functions, (via Riemann zeta-function(domination of quantum-statistics: [Pathria, Statistical-Mechanics; Huang, Statistical-Mechanics]) VS. Bernoulli-numbers/ functions. Much can be learned about statistical-physics from Euler-numbers/functions via Riemann zeta-function(s) VS. Bernoulli-numbers/functions [Conway-Guy, Book of Numbers] and about Euler-numbers/functions, via Riemann zeta-function(s) MORPHISM, VS. Bernoulli-numbers/ functions, visa versa!!! Ex.: Riemann-hypothesis PHYSICS proof PARTLY as BEQS BEC/BEA!!!

  5. Returners and explorers dichotomy in human mobility.

    PubMed

    Pappalardo, Luca; Simini, Filippo; Rinzivillo, Salvatore; Pedreschi, Dino; Giannotti, Fosca; Barabási, Albert-László

    2015-01-01

    The availability of massive digital traces of human whereabouts has offered a series of novel insights on the quantitative patterns characterizing human mobility. In particular, numerous recent studies have lead to an unexpected consensus: the considerable variability in the characteristic travelled distance of individuals coexists with a high degree of predictability of their future locations. Here we shed light on this surprising coexistence by systematically investigating the impact of recurrent mobility on the characteristic distance travelled by individuals. Using both mobile phone and GPS data, we discover the existence of two distinct classes of individuals: returners and explorers. As existing models of human mobility cannot explain the existence of these two classes, we develop more realistic models able to capture the empirical findings. Finally, we show that returners and explorers play a distinct quantifiable role in spreading phenomena and that a correlation exists between their mobility patterns and social interactions. PMID:26349016

  6. Returners and explorers dichotomy in human mobility

    NASA Astrophysics Data System (ADS)

    Pappalardo, Luca; Simini, Filippo; Rinzivillo, Salvatore; Pedreschi, Dino; Giannotti, Fosca; Barabási, Albert-László

    2015-09-01

    The availability of massive digital traces of human whereabouts has offered a series of novel insights on the quantitative patterns characterizing human mobility. In particular, numerous recent studies have lead to an unexpected consensus: the considerable variability in the characteristic travelled distance of individuals coexists with a high degree of predictability of their future locations. Here we shed light on this surprising coexistence by systematically investigating the impact of recurrent mobility on the characteristic distance travelled by individuals. Using both mobile phone and GPS data, we discover the existence of two distinct classes of individuals: returners and explorers. As existing models of human mobility cannot explain the existence of these two classes, we develop more realistic models able to capture the empirical findings. Finally, we show that returners and explorers play a distinct quantifiable role in spreading phenomena and that a correlation exists between their mobility patterns and social interactions.

  7. Chimaeric sounds reveal dichotomies in auditory perception

    NASA Astrophysics Data System (ADS)

    Smith, Zachary M.; Delgutte, Bertrand; Oxenham, Andrew J.

    2002-03-01

    By Fourier's theorem, signals can be decomposed into a sum of sinusoids of different frequencies. This is especially relevant for hearing, because the inner ear performs a form of mechanical Fourier transform by mapping frequencies along the length of the cochlear partition. An alternative signal decomposition, originated by Hilbert, is to factor a signal into the product of a slowly varying envelope and a rapidly varying fine time structure. Neurons in the auditory brainstem sensitive to these features have been found in mammalian physiological studies. To investigate the relative perceptual importance of envelope and fine structure, we synthesized stimuli that we call `auditory chimaeras', which have the envelope of one sound and the fine structure of another. Here we show that the envelope is most important for speech reception, and the fine structure is most important for pitch perception and sound localization. When the two features are in conflict, the sound of speech is heard at a location determined by the fine structure, but the words are identified according to the envelope. This finding reveals a possible acoustic basis for the hypothesized `what' and `where' pathways in the auditory cortex.

  8. Dichotomies in Teaching, Application, and Ethics

    ERIC Educational Resources Information Center

    Heames, Joyce T.; Service, Robert W.

    2003-01-01

    In this article, the authors propose a move from the old control model of teaching, managing, and leading based on stability and power to a new enterprise model based on speed and constant self-innovation. They hope to promote the practice of a rapid incremental innovation strategy that produces practitioners and educators dedicated to continuous…

  9. Developers and Deliverers: The Potential Dichotomy.

    ERIC Educational Resources Information Center

    Luoma-Overstreet, Kristine

    1993-01-01

    Examines the relationship between course developers and instructors in large corporations. Highlights include hiring practices for training department personnel; qualifications sought by the organization; self-report of competencies; separation of responsibilities; job frustrations; role of technology; and management's role in facilitating…

  10. Returners and explorers dichotomy in human mobility

    PubMed Central

    Pappalardo, Luca; Simini, Filippo; Rinzivillo, Salvatore; Pedreschi, Dino; Giannotti, Fosca; Barabási, Albert-László

    2015-01-01

    The availability of massive digital traces of human whereabouts has offered a series of novel insights on the quantitative patterns characterizing human mobility. In particular, numerous recent studies have lead to an unexpected consensus: the considerable variability in the characteristic travelled distance of individuals coexists with a high degree of predictability of their future locations. Here we shed light on this surprising coexistence by systematically investigating the impact of recurrent mobility on the characteristic distance travelled by individuals. Using both mobile phone and GPS data, we discover the existence of two distinct classes of individuals: returners and explorers. As existing models of human mobility cannot explain the existence of these two classes, we develop more realistic models able to capture the empirical findings. Finally, we show that returners and explorers play a distinct quantifiable role in spreading phenomena and that a correlation exists between their mobility patterns and social interactions. PMID:26349016

  11. Effects of virtual reality programs on balance in functional ankle instability

    PubMed Central

    Kim, Ki-Jong; Heo, Myoung

    2015-01-01

    [Purpose] The aim of present study was to identify the impact that recent virtual reality training programs used in a variety of fields have had on the ankle’s static and dynamic senses of balance among subjects with functional ankle instability. [Subjects and Methods] This study randomly divided research subjects into two groups, a strengthening exercise group (Group I) and a balance exercise group (Group II), with each group consisting of 10 people. A virtual reality program was performed three times a week for four weeks. Exercises from the Nintendo Wii Fit Plus program were applied to each group for twenty minutes along with ten minutes of warming up and wrap-up exercises. [Results] Group II showed a significant decrease of post-intervention static and dynamic balance overall in the anterior-posterior, and mediolateral directions, compared with the pre-intervention test results. In comparison of post-intervention static and dynamic balance between Group I and Group II, a significant decrease was observed overall. [Conclusion] Virtual reality programs improved the static balance and dynamic balance of subjects with functional ankle instability. Virtual reality programs can be used more safely and efficiently if they are implemented under appropriate monitoring by a physiotherapist. PMID:26644652

  12. Effects of virtual reality programs on balance in functional ankle instability.

    PubMed

    Kim, Ki-Jong; Heo, Myoung

    2015-10-01

    [Purpose] The aim of present study was to identify the impact that recent virtual reality training programs used in a variety of fields have had on the ankle's static and dynamic senses of balance among subjects with functional ankle instability. [Subjects and Methods] This study randomly divided research subjects into two groups, a strengthening exercise group (Group I) and a balance exercise group (Group II), with each group consisting of 10 people. A virtual reality program was performed three times a week for four weeks. Exercises from the Nintendo Wii Fit Plus program were applied to each group for twenty minutes along with ten minutes of warming up and wrap-up exercises. [Results] Group II showed a significant decrease of post-intervention static and dynamic balance overall in the anterior-posterior, and mediolateral directions, compared with the pre-intervention test results. In comparison of post-intervention static and dynamic balance between Group I and Group II, a significant decrease was observed overall. [Conclusion] Virtual reality programs improved the static balance and dynamic balance of subjects with functional ankle instability. Virtual reality programs can be used more safely and efficiently if they are implemented under appropriate monitoring by a physiotherapist. PMID:26644652

  13. Relationship between static postural control and the level of functional abilities in children with cerebral palsy

    PubMed Central

    Pavão, Sílvia L.; Nunes, Gabriela S.; Santos, Adriana N.; Rocha, Nelci A. C. F.

    2014-01-01

    Background: Postural control deficits can impair functional performance in children with cerebral palsy (CP) in daily living activities. Objective: To verify the relationship between standing static postural control and the functional ability level in children with CP. Method: The postural control of 10 children with CP (gross motor function levels I and II) was evaluated during static standing on a force platform for 30 seconds. The analyzed variables were the anteroposterior (AP) and mediolateral (ML) displacement of the center of pressure (CoP) and the area and velocity of the CoP oscillation. The functional abilities were evaluated using the mean Pediatric Evaluation of Disability Inventory (PEDI) scores, which evaluated self-care, mobility and social function in the domains of functional abilities and caregiver assistance. Results: Spearman's correlation test found a relationship between postural control and functional abilities. The results showed a strong negative correlation between the variables of ML displacement of CoP, the area and velocity of the CoP oscillation and the PEDI scores in the self-care and caregiver assistance domains. Additionally, a moderate negative correlation was found between the area of the CoP oscillation and the mobility scores in the caregiver assistance domain. We used a significance level of 5% (p <0.05). Conclusions: We observed that children with cerebral palsy with high CoP oscillation values had lower caregiver assistance scores for activities of daily living (ADL) and consequently higher levels of caregiver dependence. These results demonstrate the repercussions of impairments to the body structure and function in terms of the activity levels of children with CP such that postural control impairments in these children lead to higher requirements for caregiver assistance. PMID:25054383

  14. Correlation between center of pressure and functional balance in non-faller elderly practitioners of Tai Chi Chuan

    PubMed Central

    Gatica-Rojas, Valeska; Cartes-Velásquez, Ricardo; Salgado-Méndez, Rodrigo; Castro-Ramírez, Rodolfo

    2016-01-01

    [Purpose] This study aimed to determine the correlation between center of pressure and functional balance in non-faller elderly practitioners of Tai Chi. [Subjects and Methods] For the study, nine non-faller elderly practitioners of Tai Chi who were able to maintain a standing posture and walk independently were recruited. Timed one-leg standing and timed up-and-go tests were used as functional balance tests and force platform to measure the center of pressure. The Pearson correlation coefficient was calculated for the timed up-and-go/timed one-leg standing test scores and center of pressure parameter values. [Results] None of the correlations was statistically significant, but moderate correlations were observed between the pairs timed one-leg standing/sway area of center of pressure, timed one-leg standing/standard deviation of center of pressure in the mediolateral direction, timed one-leg standing/mean velocity of center of pressure in the anteroposterior direction, and timed up-and-go test sway area of center of pressure. [Conclusion] Timed one-leg standing is more appropriate than timed up-and-go test for the measurement of functional balance in non-faller elderly practitioners of Tai Chi.

  15. Morphological and functional changes in the vertebral column with increasing aquatic adaptation in crocodylomorphs

    PubMed Central

    Molnar, Julia L.; Pierce, Stephanie E.; Bhullar, Bhart-Anjan S.; Turner, Alan H.; Hutchinson, John R.

    2015-01-01

    The lineage leading to modern Crocodylia has undergone dramatic evolutionary changes in morphology, ecology and locomotion over the past 200+ Myr. These functional innovations may be explained in part by morphological changes in the axial skeleton, which is an integral part of the vertebrate locomotor system. Our objective was to estimate changes in osteological range of motion (RoM) and intervertebral joint stiffness of thoracic and lumbar vertebrae with increasing aquatic adaptation in crocodylomorphs. Using three-dimensional virtual models and morphometrics, we compared the modern crocodile Crocodylus to five extinct crocodylomorphs: Terrestrisuchus, Protosuchus, Pelagosaurus, Steneosaurus and Metriorhynchus, which span the spectrum from terrestrial to fully aquatic. In Crocodylus, we also experimentally measured changes in trunk flexibility with sequential removal of osteoderms and soft tissues. Our results for the more aquatic species matched our predictions fairly well, but those for the more terrestrial early crocodylomorphs did not. A likely explanation for this lack of correspondence is the influence of other axial structures, particularly the rigid series of dorsal osteoderms in early crocodylomorphs. The most important structures for determining RoM and stiffness of the trunk in Crocodylus were different in dorsoventral versus mediolateral bending, suggesting that changes in osteoderm and rib morphology over crocodylomorph evolution would have affected movements in some directions more than others. PMID:26716001

  16. Morphological and functional changes in the vertebral column with increasing aquatic adaptation in crocodylomorphs.

    PubMed

    Molnar, Julia L; Pierce, Stephanie E; Bhullar, Bhart-Anjan S; Turner, Alan H; Hutchinson, John R

    2015-11-01

    The lineage leading to modern Crocodylia has undergone dramatic evolutionary changes in morphology, ecology and locomotion over the past 200+ Myr. These functional innovations may be explained in part by morphological changes in the axial skeleton, which is an integral part of the vertebrate locomotor system. Our objective was to estimate changes in osteological range of motion (RoM) and intervertebral joint stiffness of thoracic and lumbar vertebrae with increasing aquatic adaptation in crocodylomorphs. Using three-dimensional virtual models and morphometrics, we compared the modern crocodile Crocodylus to five extinct crocodylomorphs: Terrestrisuchus, Protosuchus, Pelagosaurus, Steneosaurus and Metriorhynchus, which span the spectrum from terrestrial to fully aquatic. In Crocodylus, we also experimentally measured changes in trunk flexibility with sequential removal of osteoderms and soft tissues. Our results for the more aquatic species matched our predictions fairly well, but those for the more terrestrial early crocodylomorphs did not. A likely explanation for this lack of correspondence is the influence of other axial structures, particularly the rigid series of dorsal osteoderms in early crocodylomorphs. The most important structures for determining RoM and stiffness of the trunk in Crocodylus were different in dorsoventral versus mediolateral bending, suggesting that changes in osteoderm and rib morphology over crocodylomorph evolution would have affected movements in some directions more than others. PMID:26716001

  17. Morphology and behaviour: functional links in development and evolution

    PubMed Central

    Bertossa, Rinaldo C.

    2011-01-01

    Development and evolution of animal behaviour and morphology are frequently addressed independently, as reflected in the dichotomy of disciplines dedicated to their study distinguishing object of study (morphology versus behaviour) and perspective (ultimate versus proximate). Although traits are known to develop and evolve semi-independently, they are matched together in development and evolution to produce a unique functional phenotype. Here I highlight similarities shared by both traits, such as the decisive role played by the environment for their ontogeny. Considering the widespread developmental and functional entanglement between both traits, many cases of adaptive evolution are better understood when proximate and ultimate explanations are integrated. A field integrating these perspectives is evolutionary developmental biology (evo-devo), which studies the developmental basis of phenotypic diversity. Ultimate aspects in evo-devo studies—which have mostly focused on morphological traits—could become more apparent when behaviour, ‘the integrator of form and function’, is integrated into the same framework of analysis. Integrating a trait such as behaviour at a different level in the biological hierarchy will help to better understand not only how behavioural diversity is produced, but also how levels are connected to produce functional phenotypes and how these evolve. A possible framework to accommodate and compare form and function at different levels of the biological hierarchy is outlined. At the end, some methodological issues are discussed. PMID:21690124

  18. Diagnosis and management of functional symptoms in inflammatory bowel disease in remission

    PubMed Central

    Teruel, Carlos; Garrido, Elena; Mesonero, Francisco

    2016-01-01

    Inflammatory bowel disease (IBD) patients in remission may suffer from gastrointestinal symptoms that resemble irritable bowel syndrome (IBS). Knowledge on this issue has increased considerably in the last decade, and it is our intention to review and summarize it in the present work. We describe a problematic that comprises physiopathological uncertainties, diagnostic difficulties, as IBS-like symptoms are very similar to those produced by an inflammatory flare, and the necessity of appropriate management of these patients, who, although in remission, have impaired quality of life. Ultimately, from almost a philosophical point of view, the presence of IBS-like symptoms in IBD patients in remission supposes a challenge to the traditional functional-organic dichotomy, suggesting the need for a change of paradigm. PMID:26855814

  19. A sharp cadherin-6 gene expression boundary in the developing mouse cortical plate demarcates the future functional areal border.

    PubMed

    Terakawa, Youhei W; Inoue, Yukiko U; Asami, Junko; Hoshino, Mikio; Inoue, Takayoshi

    2013-10-01

    The mammalian cerebral cortex can be tangentially subdivided into tens of functional areas with distinct cyto-architectures and neural circuitries; however, it remains elusive how these areal borders are genetically elaborated during development. Here we establish original bacterial artificial chromosome transgenic mouse lines that specifically recapitulate cadherin-6 (Cdh6) mRNA expression profiles in the layer IV of the somatosensory cortex and by detailing their cortical development, we show that a sharp Cdh6 gene expression boundary is formed at a mediolateral coordinate along the cortical layer IV as early as the postnatal day 5 (P5). By further applying mouse genetics that allows rigid cell fate tracing with CreERT2 expression, it is demonstrated that the Cdh6 gene expression boundary set at around P4 eventually demarcates the areal border between the somatosensory barrel and limb field at P20. In the P6 cortical cell pellet culture system, neurons with Cdh6 expression preferentially form aggregates in a manner dependent on Ca(2+) and electroporation-based Cdh6 overexpression limited to the postnatal stages perturbs area-specific cell organization in the barrel field. These results suggest that Cdh6 expression in the nascent cortical plate may serve solidification of the protomap for cortical functional areas. PMID:22875867

  20. Motor Cortical Functional Geometry in Cerebral Palsy and its Relationship to Disability

    PubMed Central

    Kesar, T.M.; Sawaki, L.; Burdette, J. H.; Cabrera, N.; Kolaski, K.; Smith, B.P.; O’Shea, T. M.; Koman, L. A.; Wittenberg, G. F.

    2011-01-01

    Objective To investigate motor cortical map patterns in children with diplegic and hemiplegic cerebral palsy (CP), and the relationships between motor cortical geometry and motor function in CP. Methods Transcranial magnetic stimulation (TMS) was used to map motor cortical representations of the first dorsal interosseus (FDI) and tibialis anterior (TA) muscles in 13 children with CP (age 9–16 years, 6 males.) The Gross Motor Function Measure (GMFM) and Melbourne upper extremity function were used to quantify motor ability. Results In the hemiplegic participants (N=7), the affected (right) FDI cortical representation was mapped on the ipsilateral (N=4), contralateral (N=2), or bilateral (N=1) cortex. Participants with diplegia (N=6) showed either bilateral (N=2) or contralateral (N=4) cortical hand maps. The FDI and TA motor map center-of-gravity mediolateral location ranged from 2–8 cm and 3–6 cm from the midline, respectively. Among diplegics, more lateral FDI representation locations were associated with lower Melbourne scores, i.e. worse hand motor function (Spearman’s Rho = −0.841, p=0.036) Conclusions Abnormalities in TMS-derived motor maps cut across the clinical classifications of hemiplegic and diplegic CP. The lateralization of the upper and lower extremity motor representation demonstrates reorganization after insults to the affected hemispheres of both diplegic and hemiplegic children. Significance The current study is a step towards defining the relationship between changes in motor maps and functional impairments in CP. These results suggest the need for further work to develop improved classification schemes that integrate clinical, radiologic, and neurophysiologic measures in CP. PMID:22153667

  1. Multifactorial inheritance, rates of maturation and psychiatry's taxonomic dilemma: on Saugstad's "radical proposition" for two extremes of brain function and structure.

    PubMed

    deVries, Marten W

    2008-06-01

    This paper reviews aspects of Letten F. Saugstad's Maturation Theory in relation to the Kraepelinian dichotomy and psychiatric classification. The maturation theory is based on existing neuroscience, cross-national and mental health case register data and offers an innovative alternative to current etiological formulations. The maturational theory holds (1) that manic depressive illness relates to early maturation and (2) the schizophrenic syndrome relates to late maturation. The foundation of these processes lies in cerebral pruning of excitatory synapses particularly at puberty but also at a number of earlier crucial periods in development. The process of synaptic pruning has by puberty eliminated some 40% of the synapses, leading to the disappearance of glutematergic excitatory synapses without apparently appreciably influencing inhibitory GABAergic neurons. As a consequence, early maturation is related to the manic-depressive syndrome and characterized by increased neural excitability. Conversely, late maturation is related to schizophrenia characterized by diminished neural activity. Saugstad demonstrates using cross-national and neuroscience studies the multifactoral and environmental influences on rates of maturation and thereby mental illness. Using these data Saugstad reasons her agreement with the Kraepelinian dichotomy based on the existence of two extremes in brain structure and function developed through interactions between the person and the environment. PMID:18516513

  2. Functional magnetic resonance imaging of the rat cerebellum during electrical stimulation of the fore- and hindpaw at 7 T

    NASA Astrophysics Data System (ADS)

    Peeters, Ronald; Verhoye, Marleen; Vos, Bart; De Schutter, Erik; Van der Linden, Anne-Marie

    1999-05-01

    Blood oxygenation level dependent contrast (BOLD) functional MRI responses at 7T were observed in the cerebellum of alpha- chloralose anesthetized rats in response to innocuous electrical stimulation of a forepaw or hindpaw. The responses were imaged in both coronal and sagittal slices which allowed for a clear delineation and localization of the observed activations. We demonstrate the validity of our fMRI protocol by imaging the responses in somatosensory cortex to the same stimuli and by showing a high level of reproducibility of the cerebellar responses. Widespread bilateral activations were found with mainly a patchy and medio-lateral band organization, more pronounced ipsilaterally. There was no overlap between the cerebellar activations caused by forepaw or hindpaw stimulation. Most remarkable was the overall horizontal organization of these responses: for both stimulation paradigms the patches and bands of activation were roughly positioned in either a cranial or caudal plane running antero-posteriorly through the whole cerebellum. This is the first fMRI study in the cerebellum of the rat. We relate our findings to the known projection patterns found with other techniques and to human fMRI studies. The horizontal organization found wasn't observed before in other studies using other techniques.

  3. Using Low Levels of Stochastic Vestibular Stimulation to Improve Balance Function

    PubMed Central

    Goel, Rahul; Kofman, Igor; Jeevarajan, Jerome; De Dios, Yiri; Cohen, Helen S.; Bloomberg, Jacob J.; Mulavara, Ajitkumar P.

    2015-01-01

    Low-level stochastic vestibular stimulation (SVS) has been associated with improved postural responses in the medio-lateral (ML) direction, but its effect in improving balance function in both the ML and anterior-posterior (AP) directions has not been studied. In this series of studies, the efficacy of applying low amplitude SVS in 0–30 Hz range between the mastoids in the ML direction on improving cross-planar balance function was investigated. Forty-five (45) subjects stood on a compliant surface with their eyes closed and were instructed to maintain a stable upright stance. Measures of stability of the head, trunk, and whole body were quantified in ML, AP and combined APML directions. Results show that binaural bipolar SVS given in the ML direction significantly improved balance performance with the peak of optimal stimulus amplitude predominantly in the range of 100–500 μA for all the three directions, exhibiting stochastic resonance (SR) phenomenon. Objective perceptual and body motion thresholds as estimates of internal noise while subjects sat on a chair with their eyes closed and were given 1 Hz bipolar binaural sinusoidal electrical stimuli were also measured. In general, there was no significant difference between estimates of perceptual and body motion thresholds. The average optimal SVS amplitude that improved balance performance (peak SVS amplitude normalized to perceptual threshold) was estimated to be 46% in ML, 53% in AP, and 50% in APML directions. A miniature patch-type SVS device may be useful to improve balance function in people with disabilities due to aging, Parkinson’s disease or in astronauts returning from long-duration space flight. PMID:26295807

  4. Using Low Levels of Stochastic Vestibular Stimulation to Improve Balance Function.

    PubMed

    Goel, Rahul; Kofman, Igor; Jeevarajan, Jerome; De Dios, Yiri; Cohen, Helen S; Bloomberg, Jacob J; Mulavara, Ajitkumar P

    2015-01-01

    Low-level stochastic vestibular stimulation (SVS) has been associated with improved postural responses in the medio-lateral (ML) direction, but its effect in improving balance function in both the ML and anterior-posterior (AP) directions has not been studied. In this series of studies, the efficacy of applying low amplitude SVS in 0-30 Hz range between the mastoids in the ML direction on improving cross-planar balance function was investigated. Forty-five (45) subjects stood on a compliant surface with their eyes closed and were instructed to maintain a stable upright stance. Measures of stability of the head, trunk, and whole body were quantified in ML, AP and combined APML directions. Results show that binaural bipolar SVS given in the ML direction significantly improved balance performance with the peak of optimal stimulus amplitude predominantly in the range of 100-500 μA for all the three directions, exhibiting stochastic resonance (SR) phenomenon. Objective perceptual and body motion thresholds as estimates of internal noise while subjects sat on a chair with their eyes closed and were given 1 Hz bipolar binaural sinusoidal electrical stimuli were also measured. In general, there was no significant difference between estimates of perceptual and body motion thresholds. The average optimal SVS amplitude that improved balance performance (peak SVS amplitude normalized to perceptual threshold) was estimated to be 46% in ML, 53% in AP, and 50% in APML directions. A miniature patch-type SVS device may be useful to improve balance function in people with disabilities due to aging, Parkinson's disease or in astronauts returning from long-duration space flight. PMID:26295807

  5. A role for PHANTASTICA in medio-lateral regulation of adaxial domain development on tomato and tobacco leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diverse leaf forms in nature can be categorized into two groups: simple and compound. A simple leaf has a single blade unit, whilst a compound leaf is dissected into leaflets. For both simple and compound leaves, a MYB domain transcription factor PHANTASTICA (PHAN) plays an important role in establi...

  6. Steady-state probability density function of the phase error for a DPLL with an integrate-and-dump device

    NASA Technical Reports Server (NTRS)

    Simon, M.; Mileant, A.

    1986-01-01

    The steady-state behavior of a particular type of digital phase-locked loop (DPLL) with an integrate-and-dump circuit following the phase detector is characterized in terms of the probability density function (pdf) of the phase error in the loop. Although the loop is entirely digital from an implementation standpoint, it operates at two extremely different sampling rates. In particular, the combination of a phase detector and an integrate-and-dump circuit operates at a very high rate whereas the loop update rate is very slow by comparison. Because of this dichotomy, the loop can be analyzed by hybrid analog/digital (s/z domain) techniques. The loop is modeled in such a general fashion that previous analyses of the Real-Time Combiner (RTC), Subcarrier Demodulator Assembly (SDA), and Symbol Synchronization Assembly (SSA) fall out as special cases.

  7. Functional aspects of metatarsal head shape in humans, apes, and Old World monkeys.

    PubMed

    Fernández, Peter J; Almécija, Sergio; Patel, Biren A; Orr, Caley M; Tocheri, Matthew W; Jungers, William L

    2015-09-01

    Modern human metatarsal heads are typically described as "dorsally domed," mediolaterally wide, and dorsally flat. Despite the apparent functional importance of these features in forefoot stability during bipedalism, the distinctiveness of this morphology has not been quantitatively evaluated within a broad comparative framework. In order to use these features to reconstruct fossil hominin locomotor behaviors with any confidence, their connection to human bipedalism should be validated through a comparative analysis of other primates with different locomotor behaviors and foot postures, including species with biomechanical demands potentially similar to those of bipedalism (e.g., terrestrial digitigrady). This study explores shape variation in the distal metatarsus among humans and other extant catarrhines using three-dimensional geometric morphometrics (3 DGM). Shape differences among species in metatarsal head morphology are well captured by the first two principal components of Procrustes shape coordinates, and these two components summarize most of the variance related to "dorsal doming" and "dorsal expansion." Multivariate statistical tests reveal significant differences among clades in overall shape, and humans are reliably distinguishable from other species by aspects of shape related to a greater degree of dorsal doming. Within quadrupeds, terrestrial species also trend toward more domed metatarsal heads, but not to the extent seen in humans. Certain aspects of distal metatarsus shape are likely related to habitual dorsiflexion of the metatarsophalangeal joints, but the total morphological pattern seen in humans is distinct. These comparative results indicate that this geometric morphometric approach is useful to characterize the complexity of metatarsal head morphology and will help clarify its relationship with function in fossil primates, including early hominins. PMID:26276534

  8. Highly specific role of hypocretin (orexin) neurons: differential activation as a function of diurnal phase, operant reinforcement vs. operant avoidance and light level

    PubMed Central

    McGregor, Ronald; Wu, Ming-Fung; Barber, Grace; Ramanathan, Lalini; Siegel, Jerome M.

    2011-01-01

    Hypocretin (Hcrt) cell loss is responsible for narcolepsy, but Hcrt's role in normal behavior is unclear. We found that Hcrt KO mice were unable to work for food or water reward during the light phase. However, they were unimpaired relative to wild type (WT) mice when working for reward during the dark phase or when working to avoid shock in the light or dark phases. In WT, expression of Fos in Hcrt neurons occurs only in the light phase when working for positive reinforcement. Expression was seen throughout the medio-lateral extent of the Hcrt field. Fos was not expressed when expected or unexpected, unearned rewards were presented, when working to avoid negative reinforcement, or when given or expecting shock, even though these conditions elicit maximal electroencephalographic (EEG) arousal. Fos was not expressed in the light phase when light was removed. This may explain the lack of light induced arousal in narcoleptics and its presence in normal individuals. This is the first demonstration of such specificity of arousal system function and has implications for understanding the motivational and circadian consequences of arousal system dysfunction. The current results also indicate that comparable and complementary specificities must exist in other “arousal” systems. PMID:22031892

  9. Instrumented Functional Reach Test Differentiates Individuals at High Risk for Parkinson’s Disease from Controls

    PubMed Central

    Hasmann, Sandra E.; Berg, Daniela; Hobert, Markus A.; Weiss, David; Lindemann, Ulrich; Streffer, Johannes; Liepelt-Scarfone, Inga; Maetzler, Walter

    2014-01-01

    The functional reach (FR) test as a complex measure of balance including limits of stability has been proven to differentiate between patients with Parkinson’s disease (PD) and controls (CO). Recently, it has been shown that the instrumentation of the FR (iFR) with a wearable sensor may increase this diagnostic accuracy. This cross-sectional study aimed at investigating whether the iFR has the potential to differentiate individuals with high risk for PD (HRPD) from CO, as the delineation of such individuals would allow for, e.g., early neuromodulation. Thirteen PD patients, 13 CO, and 31 HRPD were investigated. HRPD was defined by presence of an enlarged area of hyperechogenicity in the mesencephalon on transcranial sonography and either one motor sign or two risk and prodromal markers of PD. All participants were asked to reach with their right arm forward as far as possible and hold this position for 10 s. During this period, sway parameters were assessed with an accelerometer (Dynaport, McRoberts) worn at the lower back. Extracted parameters that differed significantly between PD patients and CO in our cohort [FR distance (shorter in PD), anterior–posterior and mediolateral acceleration (both lower in PD)] as well as JERK, which has been shown to differentiate HRPD from CO and PD in a previous study, were included in a model, which was then used to differentiate HRPD from CO. The model yielded an area under the curve of 0.77, with a specificity of 85%, and a sensitivity of 74%. These results suggest that the iFR can contribute to an assessment panel focusing on the definition of HRPD individuals. PMID:25386137

  10. Does extending the dual-task functional exercises workout improve postural balance in individuals with ID?

    PubMed

    Mikolajczyk, Edyta; Jankowicz-Szymanska, Agnieszka

    2015-03-01

    Maintaining postural balance, overcoming visual and motor coordination disorders and experiencing problems with low general fitness - typical of intellectually disabled individuals - adversely affect the performance quality of their activities of daily living (ADLs). Physical fitness and postural balance can be improved by taking part in special intervention programs. Our study was designed to test whether extending the dual-task intervention program (combining ADLs with balance exercises on unstable surfaces) from 12 to 24 weeks additionally improved postural balance in individuals with intellectual disability (ID). We also attempted to assess whether the effects of the above intervention program were still noticeable after 8 weeks of holidays, in which participants did not take any rehabilitation exercises. A total of 34 adolescents, aged 14-16 years (15.06±0.9), with moderate ID took part in our study. The experimental group (E) consisted of 17 individuals, who continued the intervention program originated 3 months earlier, and the control group (C) comprised the same number of participants. Postural balance was assessed on a stabilometric platform Alfa. Having extended the workout period by another 12 weeks, we noticed that the path length of the center of pressure (COP) covered by participants on tests with their eyes open and closed significantly shortened. After a lapse of 8 weeks from the completion of the program, the experimental group revealed a statistically significant decrease in the velocity along the medio-lateral (M/L) and anterior-posterior (A/P) axes. The remaining variables stayed at the same level and the control group did not demonstrate any statistically significant changes. Dual-task exercises, in which enhancing functional tasks of daily living is combined with a parallel stimulation of balance reactions, may improve static balance in persons with ID. PMID:25553534

  11. Functional paraganglioma.

    PubMed

    Balasubramanian, Gokulakrishnan; Nellaiappan, Vallikantha

    2014-01-01

    Paraganglioma are tumours arising from neural crest cells of the sympathetic and parasympathetic paraganglia. Functional paraganglioma presents with symptoms of catecholamine excess that includes hypertension, flushing, diaphoresis, etc. Non-functional paraganglioma are usually found incidentally during imaging studies. Early diagnoses of functional paraganglioma are important because their removal is often curative. We present the case of a young man who presented with hypertensive crisis and severe headache, who was later found to have functional paraganglioma. PMID:24557481

  12. Improving balance function using vestibular stochastic resonance: optimizing stimulus characteristics.

    PubMed

    Mulavara, Ajitkumar P; Fiedler, Matthew J; Kofman, Igor S; Wood, Scott J; Serrador, Jorge M; Peters, Brian; Cohen, Helen S; Reschke, Millard F; Bloomberg, Jacob J

    2011-04-01

    Stochastic resonance (SR) is a phenomenon whereby the response of a non-linear system to a weak periodic input signal is optimized by the presence of a particular non-zero level of noise. Stochastic resonance using imperceptible stochastic vestibular electrical stimulation, when applied to normal young and elderly subjects, has been shown to significantly improve ocular stabilization reflexes in response to whole-body tilt; improved balance performance during postural disturbances and optimize covariance between the weak input periodic signals introduced via venous blood pressure receptors and the heart rate responses. In our study, 15 subjects stood on a compliant surface with their eyes closed. They were given low-amplitude binaural bipolar stochastic electrical stimulation of the vestibular organs in two frequency ranges of 1-2 and 0-30 Hz over the amplitude range of 0 to ±700 μA. Subjects were instructed to maintain an upright stance during 43-s trials, which consisted of baseline (zero amplitude) and stimulation (non-zero amplitude) periods. Measures of stability of the head and trunk using inertial motion unit sensors attached to these segments and the whole body using a force plate were measured and quantified in the mediolateral plane. Using a multivariate optimization criterion, our results show that the low levels of vestibular stimulation given to the vestibular organs improved balance performance in normal healthy subjects in the range of 5-26% consistent with the stochastic resonance phenomenon. In our study, 8 of 15 and 10 of 15 subjects were responsive for the 1-2- and 0-30-Hz stimulus signals, respectively. The improvement in balance performance did not differ significantly between the stimulations in the two frequency ranges. The amplitude of optimal stimulus for improving balance performance was predominantly in the range of ±100 to ±400 μA. A device based on SR stimulation of the vestibular system might be useful as either a training

  13. Rhinoplasty (Functional)

    MedlinePlus

    ... Turbinate Surgery CSF Leak Repair Sinus Tumors Rhinoplasty Overview Rhinoplasty (Functional) Orbital Decompression Optic Nerve Decompression Dacryocystorhinostomy (DCR) Disclosure Statement FIND A ...

  14. Riemann-Hypothesis Millennium-Problem(MP) Physics Proof via CATEGORY-SEMANTICS(C-S)/F=C Aristotle SQUARE-of-OPPOSITION(SoO) DEduction-LOGIC DichotomY

    NASA Astrophysics Data System (ADS)

    Baez, J.; Lapidaryus, M.; Siegel, Edward Carl-Ludwig

    2011-03-01

    Riemann-hypothesis physics-proof combines: Siegel-Antonoff-Smith[AMS Joint Mtg.(2002)-Abs.973-03-126] digits on-average statistics HIll[Am. J. Math 123, 3, 887(1996)] logarithm-function's (1,0)-fixed-point base=units=scale-invariance proven Newcomb[Am. J. Math. 4, 39(1881)]-Weyl[Goett. Nachr.(1914); Math. Ann. 7, 313(1916)]-Benford[Proc. Am. Phil. Soc. 78, 4, 51(1938)]-law [Kac, Math. of Stat.-Reasoning(1955); Raimi, Sci. Am. 221, 109(1969)] algebraic-inversion to ONLY Bose-Einstein quantum-statistics(BEQS) with digit d = 0 gapFUL Bose-Einstein Condensation(BEC) insight that digits are quanta are bosons were always digits, via Siegel-Baez category-semantics tabular list-format matrix truth-table analytics in Plato-Aristotle classic "square-of-opposition" : FUZZYICS=CATEGORYICS/Category-Semantics, with Goodkind Bose-Einstein condensation(BEC) ABOVE ground-state with/and Rayleigh(cut-limit of "short-cut method";1870)-Polya(1922)-"Anderson"(1958) localization [Doyle and Snell, Random-Walks and Electrical-Networks, MAA(1981)-p.99-100!!!].

  15. Riemann-Hypothesis Millennium-Problem(MP) Physics Proof via CATEGORY-SEMANTICS(C-S)/F =C Aristotle SQUARE-of-OPPOSITION(SoO) DEduction-LOGIC DichotomY

    NASA Astrophysics Data System (ADS)

    Baez, Joao-Joan; Lapidaryus, Michelle; Siegel, Edward Carl-Ludwig

    2013-03-01

    Riemann-hypothesis physics-proof combines: Siegel-Antono®-Smith[AMS Joint Mtg.(2002)- Abs.973-03-126] digits on-average statistics HIll[Am. J. Math 123, 3, 887(1996)] logarithm-function's (1,0)- xed-point base =units =scale-invariance proven Newcomb [Am. J. Math. 4, 39(1881)]-Weyl[Goett. Nachr.(1914); Math. Ann.7, 313(1916)]-Benford[Proc. Am. Phil. Soc. 78, 4, 51(1938)]-law [Kac,Math. of Stat.-Reasoning(1955); Raimi, Sci. Am. 221, 109(1969)] algebraic-inversion to ONLY Bose-Einstein quantum-statistics(BEQS) with digit d = 0 gapFUL Bose-Einstein Condensation(BEC) insight that digits are quanta are bosons because bosons are and always were quanta are and always were digits, via Siegel-Baez category-semantics tabular list-format matrix truth-table analytics in Plato-Aristotle classic ''square-of-opposition'' : FUZZYICS =CATEGORYICS/Category-Semantics, with Goodkind Bose-Einstein Condensation (BEC) ABOVE ground-state with/and Rayleigh(cut-limit of ''short-cut method''1870)-Polya(1922)-''Anderson''(1958) localization [Doyle and Snell,Random-Walks and Electrical-Networks, MAA(1981)-p.99-100!!!] in Brillouin[Wave-Propagation in Periodic-Structures(1946) Dover(1922)]-Hubbard-Beeby[J.Phys.C(1967)] Siegel[J.Nonxline-Sol.40,453(1980)] generalized-disorder collective-boson negative-dispersion mode-softening universality-principle(G...P) first use of the ``square-of-opposition'' in physics since Plato and Aristote!!!

  16. Glycosphingolipid Functions

    PubMed Central

    Lingwood, Clifford A.

    2011-01-01

    The combination of carbohydrate and lipid generates unusual molecules in which the two distinctive halves of the glycoconjugate influence the function of each other. Membrane glycolipids can act as primary receptors for carbohydrate binding proteins to mediate transmembrane signaling despite restriction to the outer bilayer leaflet. The extensive heterogeneity of the lipid moiety plays a significant, but still largely unknown, role in glycosphingolipid function. Potential interplay between glycolipids and their fatty acid isoforms, together with their preferential interaction with cholesterol, generates a complex mechanism for the regulation of their function in cellular physiology. PMID:21555406

  17. Transfer functions

    NASA Technical Reports Server (NTRS)

    Taback, I.

    1979-01-01

    The vulnerability of electronic equipment to carbon fibers is studied. The effectiveness of interfaces, such as filters, doors, window screens, and cabinets, which affect the concentration, exposure, or deposition of carbon fibers on both (internal and external) sides of the interface is examined. The transfer function of multilayer aluminum mesh, wet and dry, polyurethane foam, and window screen are determined as a function of air velocity. FIlters installed in typical traffic control boxes and air conditioners are also considered.

  18. Turning Semicircular Canal Function on Its Head: Dinosaurs and a Novel Vestibular Analysis

    PubMed Central

    Georgi, Justin A.; Sipla, Justin S.; Forster, Catherine A.

    2013-01-01

    Previous investigations have correlated vestibular function to locomotion in vertebrates by scaling semicircular duct radius of curvature to body mass. However, this method fails to discriminate bipedal from quadrupedal non-avian dinosaurs. Because they exhibit a broad range of relative head sizes, we use dinosaurs to test the hypothesis that semicircular ducts scale more closely with head size. Comparing the area enclosed by each semicircular canal to estimated body mass and to two different measures of head size, skull length and estimated head mass, reveals significant patterns that corroborate a connection between physical parameters of the head and semicircular canal morphology. Head mass more strongly correlates with anterior semicircular canal size than does body mass and statistically separates bipedal from quadrupedal taxa, with bipeds exhibiting relatively larger canals. This morphologic dichotomy likely reflects adaptations of the vestibular system to stability demands associated with terrestrial locomotion on two, versus four, feet. This new method has implications for reinterpreting previous studies and informing future studies on the connection between locomotion type and vestibular function. PMID:23516495

  19. The evolutionary continuum of limb function from early theropods to birds

    NASA Astrophysics Data System (ADS)

    Hutchinson, John R.; Allen, Vivian

    2009-04-01

    The bipedal stance and gait of theropod dinosaurs evolved gradually along the lineage leading to birds and at some point(s), flight evolved. How and when did these changes occur? We review the evidence from neontology and palaeontology, including pectoral and pelvic limb functional morphology, fossil footprints/trackways and biomechanical models and simulations. We emphasise that many false dichotomies or categories have been applied to theropod form and function, and sometimes, these impede research progress. For example, dichotomisation of locomotor function into ‘non-avian’ and ‘avian’ modes is only a conceptual crutch; the evidence supports a continuous transition. Simplification of pelvic limb function into cursorial/non-cursorial morphologies or flexed/columnar poses has outlived its utility. For the pectoral limbs, even the classic predatory strike vs. flight wing-stroke distinction and separation of theropods into non-flying and flying—or terrestrial and arboreal—categories may be missing important subtleties. Distinguishing locomotor function between taxa, even with quantitative approaches, will always be fraught with ambiguity, making it difficult to find real differences if that ambiguity is properly acknowledged. There must be an ‘interpretive asymptote’ for reconstructing dinosaur limb function that available methods and evidence cannot overcome. We may be close to that limit, but how far can it be stretched with improved methods and evidence, if at all? The way forward is a combination of techniques that emphasises integration of neontological and palaeontological evidence and quantitative assessment of limb function cautiously applied with validated techniques and sensitivity analysis of unknown variables.

  20. Defining Planktonic Protist Functional Groups on Mechanisms for Energy and Nutrient Acquisition: Incorporation of Diverse Mixotrophic Strategies.

    PubMed

    Mitra, Aditee; Flynn, Kevin J; Tillmann, Urban; Raven, John A; Caron, David; Stoecker, Diane K; Not, Fabrice; Hansen, Per J; Hallegraeff, Gustaaf; Sanders, Robert; Wilken, Susanne; McManus, George; Johnson, Mathew; Pitta, Paraskevi; Våge, Selina; Berge, Terje; Calbet, Albert; Thingstad, Frede; Jeong, Hae Jin; Burkholder, JoAnn; Glibert, Patricia M; Granéli, Edna; Lundgren, Veronica

    2016-04-01

    Arranging organisms into functional groups aids ecological research by grouping organisms (irrespective of phylogenetic origin) that interact with environmental factors in similar ways. Planktonic protists traditionally have been split between photoautotrophic "phytoplankton" and phagotrophic "microzooplankton". However, there is a growing recognition of the importance of mixotrophy in euphotic aquatic systems, where many protists often combine photoautotrophic and phagotrophic modes of nutrition. Such organisms do not align with the traditional dichotomy of phytoplankton and microzooplankton. To reflect this understanding, we propose a new functional grouping of planktonic protists in an eco-physiological context: (i) phagoheterotrophs lacking phototrophic capacity, (ii) photoautotrophs lacking phagotrophic capacity, (iii) constitutive mixotrophs (CMs) as phagotrophs with an inherent capacity for phototrophy, and (iv) non-constitutive mixotrophs (NCMs) that acquire their phototrophic capacity by ingesting specific (SNCM) or general non-specific (GNCM) prey. For the first time, we incorporate these functional groups within a foodweb structure and show, using model outputs, that there is scope for significant changes in trophic dynamics depending on the protist functional type description. Accordingly, to better reflect the role of mixotrophy, we recommend that as important tools for explanatory and predictive research, aquatic food-web and biogeochemical models need to redefine the protist groups within their frameworks. PMID:26927496

  1. Foot pain and functional limitation in healthy adults with hallux valgus: a cross-sectional study

    PubMed Central

    2012-01-01

    Background Hallux valgus (HV) is a very common deformity of the first metatarsophalangeal joint that often requires surgical correction. However, the association between structural HV deformity and related foot pain and disability is unclear. Furthermore, no previous studies have investigated concerns about appearance and difficulty with footwear in a population with HV not seeking surgical correction. The aim of this cross-sectional study was to investigate foot pain, functional limitation, concern about appearance and difficulty with footwear in otherwise healthy adults with HV compared to controls. Methods Thirty volunteers with HV (radiographic HV angle >15 degrees) and 30 matched controls were recruited for this study (50 women, 10 men; mean age 44.4 years, range 20 to 76 years). Differences between groups were examined for self-reported foot pain and disability, satisfaction with appearance, footwear difficulty, and pressure-pain threshold at the first metatarsophalangeal joint. Functional measures included balance tests, walking performance, and hallux muscle strength (abduction and plantarflexion). Mean differences (MD) and 95% confidence intervals (CI) were calculated. Results All self-report measures showed that HV was associated with higher levels of foot pain and disability and significant concerns about appearance and footwear (p < 0.001). Lower pressure-pain threshold was measured at the medial first metatarsophalangeal joint in participants with HV (MD = −133.3 kPa, CI: -251.5 to −15.1). Participants with HV also showed reduced hallux plantarflexion strength (MD = −37.1 N, CI: -55.4 to −18.8) and abduction strength (MD = −9.8 N, CI: -15.6 to −4.0), and increased mediolateral sway when standing with both feet with eyes closed (MD = 0.34 cm, CI: 0.04 to 0.63). Conclusions These findings show that HV negatively impacts on self-reported foot pain and function, and concerns about foot appearance and footwear in otherwise healthy adults. There

  2. Elementary Functions

    Energy Science and Technology Software Center (ESTSC)

    1986-05-01

    The ALTERNATIVE LIBRARY is a library of elementary functions prepared for use with the standard FORTRAN compiler under 4.2 BSD UNIX as an alternative to the standard system library. The library offers improved accuracy as well as additional capabilities. It includes routines ASIN, ACOS, COSH, EXP, LOG, LOG10, POW, SIN, COS, SINH, TAN, and TANH. These alternative routines have slightly modified domains and slightly different responses to invalid arguments. Four routines, not part of themore » standard library, are provided: ADX(X,N), a double-precision function that returns the double-precision argument X scaled by 2 raised to the Nth power; INTXP(X), an integer function that returns as a signed integer the exponent of the double-precision argument X; SETXP(X,N), a double-precision function that returns the double-precision argument X with its exponent replaced by N; and DCOTAN(X), a double-precision function that returns the cotangent of the double-precision argument X, where X is given in radians.« less

  3. Carcinoma origin dictates differential skewing of monocyte function

    PubMed Central

    Bögels, Marijn; Braster, Rens; Nijland, Philip G.; Gül, Nuray; van de Luijtgaarden, Wendy; Fijneman, Remond J.A.; Meijer, Gerrit A.; Jimenez, Connie R.; Beelen, Robert H.J.; van Egmond, Marjolein

    2012-01-01

    Macrophages are versatile cells, which phenotype is profoundly influenced by their environment. Pro-inflammatory classically activated or M1 macrophages, and anti-inflammatory alternatively-activated or M2 macrophages represent two extremes of a continuum of functional states. Consequently, macrophages that are present in tumors can exert tumor-promoting and tumor-suppressing activity, depending on the tumor milieu. In this study we investigated how human monocytes—the precursors of macrophages—are influenced by carcinoma cells of different origin. We demonstrate that monocytes, stimulated with breast cancer supernatant, showed increased expression of interleukin (IL)-10, IL-8 and chemokines CCL17 and CCL22, which are associated with an alternatively-activated phenotype. By contrast, monocytes that were cultured in supernatants of colon cancer cells produced more pro-inflammatory cytokines (e.g., IL-12 and TNFα) and reactive oxygen species. Secretome analysis revealed differential secretion of proteins by colon and breast cancer cell lines, of which the proteoglycan versican was exclusively secreted by colon carcinoma cell lines. Reducing active versican by blocking with monoclonal antibodies or shRNA diminished pro-inflammatory cytokine production by monocytes. Thus, colon carcinoma cells polarize monocytes toward a more classically-activated anti-tumorigenic phenotype, whereas breast carcinomas predispose monocytes toward an alternatively activated phenotype. Interestingly, presence of macrophages in breast or colon carcinomas correlates with poor or good prognosis in patients, respectively. The observed discrepancy in macrophage activation by either colon or breast carcinoma cells may therefore explain the dichotomy between patient prognosis and macrophage presence in these different tumors. Designing new therapies, directing development of monocytes toward M1 activated tumor macrophages in cancer patients, may have great clinical benefits. PMID:23162747

  4. Pedotransfer Functions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Often, there is a need to estimate parameters governing retention and transport of water and chemicals in soils from other, readily available data. Equations expressing relationships between soil properties were proposed to be called pedotransfer functions. This entry provides the overview of the st...

  5. Kalela, Beni, Asafo, Ingoma and the rural-urban dichotomy.

    PubMed

    Argyle, J

    1991-01-01

    The author provides a critical examination of the arguments and support for conclusions in "copperbelt writings" about the urban Kalela dance and the relationship to urban and rural differences. There is a critical discussion of relationships between the dance forms: the kalela, asafo, beni, and ingoma. The origins of the dance are traced to the rural Beni in the writings of Mitchel, however Ranger's treatise on the Beni in east Africa indicates a locally quite distinct tradition associated with Swahili dance associations in towns. The author finds strong parallels between the Beni and Swahili dance associations and derivation from the Akan asafo companies. It is suggested that both east and west African dances reflected a European impact and the fundamental values of African people as well as a form of entertainment. It was a public display of progress and skill. The spread of the Swahili Beni between the 2 World Wars was complex and varied, but the form conformed well to rural villages which traditionally competed against each other. The Mitchel assertion that the costumes which imitated the uniforms of colonial civil and military hierarchy allowed vicarious participation in social relationships which they were excluded from is refuted. It is suggested by the author and Ranger that African dancers were asserting as traditional their individual and collective status and prestige in their own society and the costumes were the new fashion. The change to modern dress is though by Mitchell to reflect similarly a fictitious upward mobility and urban influence, and is considered to be unsubstantiated by the lower class population assuming the behavior. The author views the behavior as directed to unskilled, uneducated migrant workers groups which included them and provided a strong link to their rural homes and children. In dispute is also the Mitchell interpretation of lyrics to the songs which the author finds reflect rural themes and influences as well. It is recognized that there were new urban references. The Kalela dance is considered by the author to be an example of the encapsulation of rural migrants within an urban environment. This view is reflected in Mayer's Townsmen and Tribemen and the writings of H.J. Thomas on the ingoma dance groups of Durban, which also reflected lyrics pertained to rural life. The songs are a traditional, spontaneous, unsolicited testimony to rural life. PMID:12285291

  6. The aging-disease false dichotomy: understanding senescence as pathology.

    PubMed

    Gems, David

    2015-01-01

    From a biological perspective aging (senescence) appears to be a form of complex disease syndrome, though this is not the traditional view. This essay aims to foster a realistic understanding of aging by scrutinizing ideas old and new. The conceptual division between aging-related diseases and an underlying, non-pathological aging process underpins various erroneous traditional ideas about aging. Among biogerontologists, another likely error involves the aspiration to treat the entire aging process, which recent advances suggest is somewhat utopian. It also risks neglecting a more modest but realizable goal: to develop preventative treatments that partially protect against aging. PMID:26136770

  7. Localising News: Translation and the "Global-National" Dichotomy

    ERIC Educational Resources Information Center

    Orengo, Alberto

    2005-01-01

    Due to the peculiar nature of news texts, the adoption of a theory of "localisation" rather than conventional translation theories accounts more easily for both the commercial nature and the global scale of news distribution. News texts are global products which are distributed through a localisation process involving not only reception by locales…

  8. Dichotomy and perceptual distortions in absolute pitch ability

    PubMed Central

    Athos, E. Alexandra; Levinson, Barbara; Kistler, Amy; Zemansky, Jason; Bostrom, Alan; Freimer, Nelson; Gitschier, Jane

    2007-01-01

    Absolute pitch (AP) is the rare ability to identify the pitch of a tone without the aid of a reference tone. Understanding both the nature and genesis of AP can provide insights into neuroplasticity in the auditory system. We explored factors that may influence the accuracy of pitch perception in AP subjects both during the development of the trait and in later age. We used a Web-based survey and a pitch-labeling test to collect perceptual data from 2,213 individuals, 981 (44%) of whom proved to have extraordinary pitch-naming ability. The bimodal distribution in pitch-naming ability signifies AP as a distinct perceptual trait, with possible implications for its genetic basis. The wealth of these data has allowed us to uncover unsuspected note-naming irregularities suggestive of a “perceptual magnet” centered at the note “A.” In addition, we document a gradual decline in pitch-naming accuracy with age, characterized by a perceptual shift in the “sharp” direction. These findings speak both to the process of acquisition of AP and to its stability. PMID:17724340

  9. Disciplinary versus Academic Sanctions in Higher Education: A Doomed Dichotomy?

    ERIC Educational Resources Information Center

    Dutile, Fernand N.

    2003-01-01

    Explains that courts have generally subjected disciplinary action to procedural due process under the Fourteenth Amendment, while academic sanctions have garnered greater deference. Examines the judicial history of this dual track, establishes the difficulty of characterizing as either disciplinary or academic the countless situations reflecting…

  10. Managerial Intuition across Cultures: Beyond a "West-East Dichotomy"

    ERIC Educational Resources Information Center

    Wozniak, Anna

    2006-01-01

    Purpose: Studies investigating intuition from a cultural and cross-cultural perspective have a long tradition in various disciplines but, due to the increased internationalization of business, an understanding of the mental lives of other cultures became one of the priorities of management practitioners and theoreticians. Cultures of…

  11. John Dewey's pragmatist alternative to the belief-acceptance dichotomy.

    PubMed

    Brown, Matthew J

    2015-10-01

    Defenders of value-free science appeal to cognitive attitudes as part of a wedge strategy, to mark a distinction between science proper and the uses of science for decision-making, policy, etc. Distinctions between attitudes like belief and acceptance have played an important role in defending the value-free ideal. In this paper, I will explore John Dewey's pragmatist philosophy of science as an alternative to the philosophical framework the wedge strategy rests on. Dewey does draw significant and useful distinctions between different sorts of cognitive attitudes taken by inquirers, but none can be used to support the wedge strategy. PMID:26386531

  12. Paradigms, Perspectives and Dichotomies amongst Teacher Educators in Hong Kong

    ERIC Educational Resources Information Center

    Katyal, Kokila Roy; Fai, Pang Ming

    2010-01-01

    This paper argues that the concepts, beliefs and understandings of local and non-local teacher educators in a Hong Kong university are grounded in their own cultural cognition and antecedents. It presents the viewpoint that contemporary notions of good practice were compromised when applied to a context that is strongly influenced by the tenets of…

  13. The aging-disease false dichotomy: understanding senescence as pathology

    PubMed Central

    Gems, David

    2015-01-01

    From a biological perspective aging (senescence) appears to be a form of complex disease syndrome, though this is not the traditional view. This essay aims to foster a realistic understanding of aging by scrutinizing ideas old and new. The conceptual division between aging-related diseases and an underlying, non-pathological aging process underpins various erroneous traditional ideas about aging. Among biogerontologists, another likely error involves the aspiration to treat the entire aging process, which recent advances suggest is somewhat utopian. It also risks neglecting a more modest but realizable goal: to develop preventative treatments that partially protect against aging. PMID:26136770

  14. Theory, Practice, and Educational Administration: Bridging Troublesome Dichotomies

    ERIC Educational Resources Information Center

    Boldman, Lee

    1976-01-01

    Education which enables students to integrate theory and practice can be viewed as the primary task of the professional school, but a task that is rarely performed. A set of conditions that facilitate this are given. (Author/AM)

  15. Content vs. Learning: An Old Dichotomy in Science Courses

    ERIC Educational Resources Information Center

    Bergtrom, Gerald

    2011-01-01

    The principles of course redesign that were applied to a gateway Cell Biology course at the University of Wisconsin-Milwaukee are applicable to courses large and small, and to institutions of any size. The challenge was to design a content-rich science course that kept pace with present and future content and at the same time use principles of…

  16. The Rural Education Dichotomy: Disadvantaged Systems and School Strengths.

    ERIC Educational Resources Information Center

    Dunn, Randy J.

    The educational advantages conferred by rurality and smallness have their greatest impact at the school and classroom level, but this same rurality creates district or system-level problems that have often been solved by consolidation. Consolidation efforts have been waning because they are politically unpopular, good economic times allow states…

  17. Psychotherapy across cultures: the form-content dichotomy.

    PubMed

    Jacob, K S; Kuruvilla, Anju

    2012-01-01

    The diversity of patients, problems, beliefs and cultures mandates the need to educate, match, negotiate and integrate psychological interventions. This is necessary in all cultures and in every setting. Many schools of psychotherapy offer specific theories and particular techniques, yet they share many common approaches. Their individual techniques allow therapists form and structure to treat different clinical problems, discuss diverse content and use them in varied settings and among people with assorted cultural backgrounds. The heterogeneity within cultures, regions and populations demands that therapists understand the local and individual reality. The apparent contradictions between standard psychological therapies and their use across cultures, when viewed through a form-content framework, allow for matching strategies for specific individuals and their distress, and for choosing the best treatment options from a diverse therapeutic armamentarium. Psychotherapies are at their weakest when they attempt to provide explanations across cultures and are at their strongest when they are used as vehicles for engagement with patients. The challenge is to find a common psychotherapeutic language, which attempts to bridge the divide between the issues facing the patient and the armamentarium of the therapist. The form-content paradigm at least partly explains the complexity of the issues within psychotherapy. It also allows the therapist to move from the therapy-centric orientation of Western approaches to the patient-centric orientations required for success in psychological therapies. PMID:22232048

  18. A false dichotomy? Mental illness and lone-actor terrorism.

    PubMed

    Corner, Emily; Gill, Paul

    2015-02-01

    We test whether significant differences in mental illness exist in a matched sample of lone- and group-based terrorists. We then test whether there are distinct behavioral differences between lone-actor terrorists with and without mental illness. We then stratify our sample across a range of diagnoses and again test whether significant differences exist. We conduct a series of bivariate, multivariate, and multinomial statistical tests using a unique dataset of 119 lone-actor terrorists and a matched sample of group-based terrorists. The odds of a lone-actor terrorist having a mental illness is 13.49 times higher than the odds of a group actor having a mental illness. Lone actors who were mentally ill were 18.07 times more likely to have a spouse or partner who was involved in a wider movement than those without a history of mental illness. Those with a mental illness were more likely to have a proximate upcoming life change, more likely to have been a recent victim of prejudice, and experienced proximate and chronic stress. The results identify behaviors and traits that security agencies can utilize to monitor and prevent lone-actor terrorism events. The correlated behaviors provide an image of how risk can crystalize within the individual offender and that our understanding of lone-actor terrorism should be multivariate in nature. PMID:25133916

  19. Toward Integration Through Education: Dichotomies of Purposes and Processes.

    ERIC Educational Resources Information Center

    Gibson, John S.

    Beginning with the thesis that integrated education is indispensable to achieving an integrated society, the author examines first whether these assumptions behind school desegregation are valid or not, and why: that students will perform better academically, and that more democratic human relations will ensue. He presents evidence to show that…

  20. Tolerance to Alliance: Deconstructing Dichotomies to Advocate for All Students

    ERIC Educational Resources Information Center

    Berg, Margaret

    2013-01-01

    This article argues that teachers in the twenty-first century need to incorporate queer theory into their teaching practice and their discussions about individual differences in order to advocate for those students most likely to be bullied in schools. It provides a brief background on queer theory, gives an introduction to central ideas of the…

  1. The dichotomy of pathogens and allergens in vaccination approaches.

    PubMed

    Baird, Fiona J; Lopata, Andreas L

    2014-01-01

    Traditional prophylactic vaccination to prevent illness is the primary objective of many research activities worldwide. The golden age of vaccination began with an approach called variolation in ancient China and the evolution of vaccines still continues today with modern developments such as the production of Gardasil(TM) against HPV and cervical cancer. The historical aspect of how different forms of vaccination have changed the face of medicine and communities is important as it dictates our future approaches on both a local and global scale. From the eradication of smallpox to the use of an experimental vaccine to save a species, this review will explore these successes in infectious disease vaccination and also discuss a few significant failures which have hampered our efforts to eradicate certain diseases. The second part of the review will explore designing a prophylactic vaccine for the growing global health concern that is allergy. Allergies are an emerging global health burden. Of particular concern is the rise of food allergies in developed countries where 1 in 10 children is currently affected. The formation of an allergic response results from the recognition of a foreign component by our immune system that is usually encountered on a regular basis. This may be a dust-mite or a prawn but this inappropriate immune response can result in a life-time of food avoidance and lifestyle restrictions. These foreign components are very similar to antigens derived from infectious pathogens. The question arises: should the allergy community be focussing on protective measures rather than ongoing therapeutic interventions to deal with these chronic inflammatory conditions? We will explore the difficulties and benefits of prophylactic vaccination against various allergens by means of genetic technology that will dictate how vaccination against allergens could be utilized in the near future. PMID:25076945

  2. Educating Moral Emotions or Moral Selves: A False Dichotomy?

    ERIC Educational Resources Information Center

    Kristjansson, Kristjan

    2010-01-01

    In the post-Kohlbergian era of moral education, a "moral gap" has been identified between moral cognition and moral action. Contemporary moral psychologists lock horns over how this gap might be bridged. The two main contenders for such bridge-building are moral emotions and moral selves. I explore these two options from an Aristotelian…

  3. The Multilingual/Bilingual Dichotomy: An Exploration of Individual Differences

    ERIC Educational Resources Information Center

    Thompson, Amy S.

    2009-01-01

    Bilingualism (Sanz, 2000), motivation (Pintrich, 1989), and language aptitude (Grigorenko, Sternberg, and Ehrman, 2000) are crucial individual differences that contribute to successful adult language learning. Since Gardner's (1985) seminal work on motivation, many studies have shown that motivation is dynamic and that it affects language…

  4. [The development of gender identity beyond rigid dichotomy].

    PubMed

    Quindeau, Ilka

    2014-01-01

    The conflicts individuals with ambiguous sexual characteristics suffer from are not the result of genetic features but of the rigid and dichotomous gender order, which is currently undergoing a renaissance. This also applies to individuals with an uncertain gender identity. In the best interests of the child a concept of gender seems necessary, that goes beyond a binary separation and allows gender-specific intermediary stages in the personal development of identity. Such a gender concept can be developed following psychoanalytic theories. The present discourse contains a scale of connecting factors for a differentiated and less normative conceptualization of gender development. Starting from Freud's concept of constitutional bisexuality, Robert Stoller's theory, which has been firmly rooted in the mainstream of psychoanalysis for more than 40 years, will be critically reviewed. By involving Reimut Reiche's and Jean Laplanche's arguments, a continuative psychological gender theory will be drafted, which does not normatively and reductively claim the demarcation of gender, but rather opens up a space for gender diversity. PMID:25296507

  5. The Demise of the Nature-Nurture Dichotomy.

    ERIC Educational Resources Information Center

    Lerner, Richard M.

    1993-01-01

    Maintains that "Individual Development and Evolution: The Genesis of Novel Behavior" (Gilbert Gottlieb) is one of the most creative, integrative, and important works in the field of developmental comparative science. Gottlieb's work has provided scientific basis for the concept that developmental systems, and not genetic reductionism, is the only…

  6. The dichotomy of pathogens and allergens in vaccination approaches

    PubMed Central

    Baird, Fiona J.; Lopata, Andreas L.

    2014-01-01

    Traditional prophylactic vaccination to prevent illness is the primary objective of many research activities worldwide. The golden age of vaccination began with an approach called variolation in ancient China and the evolution of vaccines still continues today with modern developments such as the production of GardasilTM against HPV and cervical cancer. The historical aspect of how different forms of vaccination have changed the face of medicine and communities is important as it dictates our future approaches on both a local and global scale. From the eradication of smallpox to the use of an experimental vaccine to save a species, this review will explore these successes in infectious disease vaccination and also discuss a few significant failures which have hampered our efforts to eradicate certain diseases. The second part of the review will explore designing a prophylactic vaccine for the growing global health concern that is allergy. Allergies are an emerging global health burden. Of particular concern is the rise of food allergies in developed countries where 1 in 10 children is currently affected. The formation of an allergic response results from the recognition of a foreign component by our immune system that is usually encountered on a regular basis. This may be a dust-mite or a prawn but this inappropriate immune response can result in a life-time of food avoidance and lifestyle restrictions. These foreign components are very similar to antigens derived from infectious pathogens. The question arises: should the allergy community be focussing on protective measures rather than ongoing therapeutic interventions to deal with these chronic inflammatory conditions? We will explore the difficulties and benefits of prophylactic vaccination against various allergens by means of genetic technology that will dictate how vaccination against allergens could be utilized in the near future. PMID:25076945

  7. Transcending the Mind-Body Dichotomy: Schizophrenia Reexamined.

    ERIC Educational Resources Information Center

    Bemak, Fred; Epp, Lawrence R.

    2002-01-01

    Discusses how the genetic aspects of schizophrenia must be described within the interactive context of psychosocial stress. Suggests that the mental health profession must consider the environmental and social components of this condition, including the clients' relationships, families, and communities. States that psychotherapeutic interventions…

  8. A Magnetic Perspective on the Martian Crustal Dichotomy

    NASA Technical Reports Server (NTRS)

    Connerney, J. E. P.; Acuna, M. H.; Ness, N. F.; Mitchell, D. L.; Lin, R. P.; Reme, H.

    2004-01-01

    The Mars Global Surveyor spacecraft has completed two Mars years in nearly circular polar orbit at a nominal altitude of 400 km. The Mars crust is at least an order of magnitude more intensely magnetized than that of the Earth, and intriguing in both its global distribution and geometric properties. Measurements of the vector magnetic field have been used to map the magnetic field of crustal origin to high accuracy. This most recent map is assembled from > 2 full years of MGS night-side observations, and uses along-track filtering to greatly reduce noise due to external field variations. Additional information is included in the original extended abstract.

  9. The Dialectics of Gender: A Move beyond Dichotomies Constraining Growth.

    ERIC Educational Resources Information Center

    Ranieri, Paul W.

    The conceptual starting point for almost all recent gender related theory and research is to identify the characteristics of current educational practice as rooted in a type of thought that is linear, analytical, stage dependent, discursive, and "objective," and that separates thought and language--this is the mode that is typically associated…

  10. Isotope Analysis Reveals Foraging Area Dichotomy for Atlantic Leatherback Turtles

    PubMed Central

    Angulo, Elena; Das, Krishna; Girondot, Marc

    2008-01-01

    Background The leatherback turtle (Dermochelys coriacea) has undergone a dramatic decline over the last 25 years, and this is believed to be primarily the result of mortality associated with fisheries bycatch followed by egg and nesting female harvest. Atlantic leatherback turtles undertake long migrations across ocean basins from subtropical and tropical nesting beaches to productive frontal areas. Migration between two nesting seasons can last 2 or 3 years, a time period termed the remigration interval (RI). Recent satellite transmitter data revealed that Atlantic leatherbacks follow two major dispersion patterns after nesting season, through the North Gulf Stream area or more eastward across the North Equatorial Current. However, information on the whole RI is lacking, precluding the accurate identification of feeding areas where conservation measures may need to be applied. Methodology/Principal Findings Using stable isotopes as dietary tracers we determined the characteristics of feeding grounds of leatherback females nesting in French Guiana. During migration, 3-year RI females differed from 2-year RI females in their isotope values, implying differences in their choice of feeding habitats (offshore vs. more coastal) and foraging latitude (North Atlantic vs. West African coasts, respectively). Egg-yolk and blood isotope values are correlated in nesting females, indicating that egg analysis is a useful tool for assessing isotope values in these turtles, including adults when not available. Conclusions/Significance Our results complement previous data on turtle movements during the first year following the nesting season, integrating the diet consumed during the year before nesting. We suggest that the French Guiana leatherback population segregates into two distinct isotopic groupings, and highlight the urgent need to determine the feeding habitats of the turtle in the Atlantic in order to protect this species from incidental take by commercial fisheries. Our results also emphasize the use of eggs, a less-invasive sampling material than blood, to assess isotopic data and feeding habits for adult female leatherbacks. PMID:18365003

  11. The dual functions of the extreme N-terminus of TDP-43 in regulating its biological activity and inclusion formation.

    PubMed

    Zhang, Yong-Jie; Caulfield, Thomas; Xu, Ya-Fei; Gendron, Tania F; Hubbard, Jaime; Stetler, Caroline; Sasaguri, Hiroki; Whitelaw, Ena C; Cai, Shuyi; Lee, Wing Cheung; Petrucelli, Leonard

    2013-08-01

    TAR DNA-binding protein-43 (TDP-43) is the principal component of ubiquitinated inclusions in amyotrophic lateral sclerosis (ALS) and the most common pathological subtype of frontotemporal dementia-frontotemporal lobar degeneration with TDP-43-positive inclusions (FTLD-TDP). To date, the C-terminus of TDP-43, which is aggregation-prone and contains almost all ALS-associated mutations, has garnered much attention while the functions of the N-terminus of TDP-43 remain largely unknown. To bridge this gap in our knowledge, we utilized novel cell culture and computer-assisted models to evaluate which region(s) of TDP-43 regulate its folding, self-interaction, biological activity and aggregation. We determined that the extreme N-terminus of TDP-43, specifically the first 10 residues, regulates folding of TDP-43 monomers necessary for proper homodimerization and TDP-43-regulated splicing. Despite such beneficial functions, we discovered an interesting dichotomy: full-length TDP-43 aggregation, which is believed to be a pathogenic process, also requires the extreme N-terminus of TDP-43. As such, we provide new insight into the structural basis for TDP-43 function and aggregation, and we suggest that stabilization of TDP-43 homodimers, the physiologically active form of TDP-43, may be a promising therapeutic strategy for ALS and FTLD-TDP. PMID:23575225

  12. Midcingulate cortex: Structure, connections, homologies, functions and diseases.

    PubMed

    Vogt, Brent A

    2016-07-01

    the unique organization of MCC and supports the predictive validity of the MCC dichotomy. Vulnerability of aMCC is shown in chronic pain, obsessive-compulsive disorder with checking symptoms and attention-deficit/hyperactivity disorder and methylphenidate and pain medications selectively impact aMCC. In contrast, pMCC vulnerabilities are for progressive supranuclear palsy, unipolar depression and posttraumatic stress disorder. Thus, there is an emerging picture of the organization, functions and diseases of MCC. Future work will take this type of modular analysis to individual areas of which there are at least 10 in MCC. PMID:26993424

  13. Functional dyspepsia.

    PubMed

    Brun, Rita; Kuo, Braden

    2010-05-01

    Dyspepsia is a common term used for a heterogeneous group of abdominal symptoms. Functional dyspepsia (FD) is the focus of this review. The 2006 Rome III criteria defined FD and its subgroups, postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). FD is a very common condition with a high prevalence throughout the world, adversely affecting the quality of life of patients. The pathophysiology of FD has been under investigation during the past two decades. Multiple mechanisms such as abnormal gastric emptying, visceral hypersensitivity, impaired gastric accommodation, and central nervous system factors are likely involved. Several tests are available for the assessment of various physiologic functions possibly involved in the pathogenesis of FD, and some of these could be used in clinical practice, helping to understand the abnormalities underlining patients' complaints. Currently, the possibilities of pharmacological therapy for FD are still limited, however, experience of using prokinetics, tricyclic antidepressants, selective serotonin-reuptake inhibitors (SSRIs), proton-pump inhibitors (PPIs), and several alternative techniques has been accumulated. The different combinations of alterations in physiologic gastrointestinal and central nervous system functions result in the very heterogeneous nature of FD so combined approaches to these patients could be beneficial in challenging cases. PMID:21180597

  14. The Middle Miocene Ape Pierolapithecus catalaunicus Exhibits Extant Great Ape-Like Morphometric Affinities on Its Patella: Inferences on Knee Function and Evolution

    PubMed Central

    Pina, Marta; Almécija, Sergio; Alba, David M.; O'Neill, Matthew C.; Moyà-Solà, Salvador

    2014-01-01

    The mosaic nature of the Miocene ape postcranium hinders the reconstruction of the positional behavior and locomotion of these taxa based on isolated elements only. The fossil great ape Pierolapithecus catalaunicus (IPS 21350 skeleton; 11.9 Ma) exhibits a relatively wide and shallow thorax with moderate hand length and phalangeal curvature, dorsally-oriented metacarpophalangeal joints, and loss of ulnocarpal articulation. This evidence reveals enhanced orthograde postures without modern ape-like below-branch suspensory adaptations. Therefore, it has been proposed that natural selection enhanced vertical climbing (and not suspension per se) in Pierolapithecus catalaunicus. Although limb long bones are not available for this species, its patella (IPS 21350.37) can potentially provide insights into its knee function and thus on the complexity of its total morphological pattern. Here we provide a detailed description and morphometric analyses of IPS 21350.37, which are based on four external dimensions intended to capture the overall patellar shape. Our results reveal that the patella of Pierolapithecus is similar to that of extant great apes: proximodistally short, mediolaterally broad and anteroposteriorly thin. Previous biomechanical studies of the anthropoid knee based on the same measurements proposed that the modern great ape patella reflects a mobile knee joint while the long, narrow and thick patella of platyrrhine and especially cercopithecoid monkeys would increase the quadriceps moment arm in knee extension during walking, galloping, climbing and leaping. The patella of Pierolapithecus differs not only from that of monkeys and hylobatids, but also from that of basal hominoids (e.g., Proconsul and Nacholapithecus), which display slightly thinner patellae than extant great apes (the previously-inferred plesiomorphic hominoid condition). If patellar shape in Pierolapithecus is related to modern great ape-like knee function, our results suggest that increased

  15. The Middle Miocene ape Pierolapithecus catalaunicus exhibits extant great ape-like morphometric affinities on its patella: inferences on knee function and evolution.

    PubMed

    Pina, Marta; Almécija, Sergio; Alba, David M; O'Neill, Matthew C; Moyà-Solà, Salvador

    2014-01-01

    The mosaic nature of the Miocene ape postcranium hinders the reconstruction of the positional behavior and locomotion of these taxa based on isolated elements only. The fossil great ape Pierolapithecus catalaunicus (IPS 21350 skeleton; 11.9 Ma) exhibits a relatively wide and shallow thorax with moderate hand length and phalangeal curvature, dorsally-oriented metacarpophalangeal joints, and loss of ulnocarpal articulation. This evidence reveals enhanced orthograde postures without modern ape-like below-branch suspensory adaptations. Therefore, it has been proposed that natural selection enhanced vertical climbing (and not suspension per se) in Pierolapithecus catalaunicus. Although limb long bones are not available for this species, its patella (IPS 21350.37) can potentially provide insights into its knee function and thus on the complexity of its total morphological pattern. Here we provide a detailed description and morphometric analyses of IPS 21350.37, which are based on four external dimensions intended to capture the overall patellar shape. Our results reveal that the patella of Pierolapithecus is similar to that of extant great apes: proximodistally short, mediolaterally broad and anteroposteriorly thin. Previous biomechanical studies of the anthropoid knee based on the same measurements proposed that the modern great ape patella reflects a mobile knee joint while the long, narrow and thick patella of platyrrhine and especially cercopithecoid monkeys would increase the quadriceps moment arm in knee extension during walking, galloping, climbing and leaping. The patella of Pierolapithecus differs not only from that of monkeys and hylobatids, but also from that of basal hominoids (e.g., Proconsul and Nacholapithecus), which display slightly thinner patellae than extant great apes (the previously-inferred plesiomorphic hominoid condition). If patellar shape in Pierolapithecus is related to modern great ape-like knee function, our results suggest that increased

  16. GeoChip-based insights into the microbial functional gene repertoire of marine sponges (high microbial abundance, low microbial abundance) and seawater.

    PubMed

    Bayer, Kristina; Moitinho-Silva, Lucas; Brümmer, Franz; Cannistraci, Carlo V; Ravasi, Timothy; Hentschel, Ute

    2014-12-01

    The GeoChip 4.2 gene array was employed to interrogate the microbial functional gene repertoire of sponges and seawater collected from the Red Sea and the Mediterranean. Complementary amplicon sequencing confirmed the microbial community composition characteristic of high microbial abundance (HMA) and low microbial abundance (LMA) sponges. By use of GeoChip, altogether 20,273 probes encoding for 627 functional genes and representing 16 gene categories were identified. Minimum curvilinear embedding analyses revealed a clear separation between the samples. The HMA/LMA dichotomy was stronger than any possible geographic pattern, which is shown here for the first time on the level of functional genes. However, upon inspection of individual genes, very few specific differences were discernible. Differences were related to microbial ammonia oxidation, ammonification, and archaeal autotrophic carbon fixation (higher gene abundance in sponges over seawater) as well as denitrification and radiation-stress-related genes (lower gene abundance in sponges over seawater). Except for few documented specific differences the functional gene repertoire between the different sources appeared largely similar. This study expands previous reports in that functional gene convergence is not only reported between HMA and LMA sponges but also between sponges and seawater. PMID:25318900

  17. Determine Optimal Stimulus Amplitude for Using Vestibular Stochastic Stimulation to Improve Balance Function

    NASA Technical Reports Server (NTRS)

    Goel, R.; Kofman, I.; DeDios, Y. E.; Jeevarajan, J.; Stepanyan, V.; Nair, M.; Congdon, S.; Fregia, M.; Cohen, H.; Bloomberg, J.J.; Mulavara, A.P.

    2015-01-01

    Sensorimotor changes such as postural and gait instabilities can affect the functional performance of astronauts when they transition across different gravity environments. We are developing a method, based on stochastic resonance (SR), to enhance information transfer by applying non-zero levels of external noise on the vestibular system (vestibular stochastic resonance, VSR). Our previous work has shown the advantageous effects of VSR in a balance task of standing on an unstable surface [1]. This technique to improve detection of vestibular signals uses a stimulus delivery system that provides imperceptibly low levels of white noise-based binaural bipolar electrical stimulation of the vestibular system. The goal of this project is to determine optimal levels of stimulation for SR applications by using a defined vestibular threshold of motion detection. A series of experiments were carried out to determine a robust paradigm to identify a vestibular threshold that can then be used to recommend optimal stimulation levels for sensorimotor adaptability (SA) training applications customized to each crewmember. The amplitude of stimulation to be used in the VSR application has varied across studies in the literature such as 60% of nociceptive stimulus thresholds [2]. We compared subjects' perceptual threshold with that obtained from two measures of body sway. Each test session was 463s long and consisted of several 15s long sinusoidal stimuli, at different current amplitudes (0-2 mA), interspersed with 20-20.5s periods of no stimulation. Subjects sat on a chair with their eyes closed and had to report their perception of motion through a joystick. A force plate underneath the chair recorded medio-lateral shear forces and roll moments. Comparison of threshold of motion detection obtained from joystick data versus body sway suggests that perceptual thresholds were significantly lower. In the balance task, subjects stood on an unstable surface and had to maintain balance

  18. Blockade of immunosuppressive cytokines restores NK cell antiviral function in chronic hepatitis B virus infection.

    PubMed

    Peppa, Dimitra; Micco, Lorenzo; Javaid, Alia; Kennedy, Patrick T F; Schurich, Anna; Dunn, Claire; Pallant, Celeste; Ellis, Gidon; Khanna, Pooja; Dusheiko, Geoffrey; Gilson, Richard J; Maini, Mala K

    2010-01-01

    NK cells are enriched in the liver, constituting around a third of intrahepatic lymphocytes. We have previously demonstrated that they upregulate the death ligand TRAIL in patients with chronic hepatitis B virus infection (CHB), allowing them to kill hepatocytes bearing TRAIL receptors. In this study we investigated whether, in addition to their pathogenic role, NK cells have antiviral potential in CHB. We characterised NK cell subsets and effector function in 64 patients with CHB compared to 31 healthy controls. We found that, in contrast to their upregulated TRAIL expression and maintenance of cytolytic function, NK cells had a markedly impaired capacity to produce IFN-γ in CHB. This functional dichotomy of NK cells could be recapitulated in vitro by exposure to the immunosuppressive cytokine IL-10, which was induced in patients with active CHB. IL-10 selectively suppressed NK cell IFN-γ production without altering cytotoxicity or death ligand expression. Potent antiviral therapy reduced TRAIL-expressing CD56(bright) NK cells, consistent with the reduction in liver inflammation it induced; however, it was not able to normalise IL-10 levels or the capacity of NK cells to produce the antiviral cytokine IFN-γ. Blockade of IL-10 +/- TGF-β restored the capacity of NK cells from both the periphery and liver of patients with CHB to produce IFN-γ, thereby enhancing their non-cytolytic antiviral capacity. In conclusion, NK cells may be driven to a state of partial functional tolerance by the immunosuppressive cytokine environment in CHB. Their defective capacity to produce the antiviral cytokine IFN-γ persists in patients on antiviral therapy but can be corrected in vitro by IL-10+/- TGF-β blockade. PMID:21187913

  19. Executive Functions

    PubMed Central

    Diamond, Adele

    2014-01-01

    Executive functions (EFs) make possible mentally playing with ideas; taking the time to think before acting; meeting novel, unanticipated challenges; resisting temptations; and staying focused. Core EFs are inhibition [response inhibition (self-control—resisting temptations and resisting acting impulsively) and interference control (selective attention and cognitive inhibition)], working memory, and cognitive flexibility (including creatively thinking “outside the box,” seeing anything from different perspectives, and quickly and flexibly adapting to changed circumstances). The developmental progression and representative measures of each are discussed. Controversies are addressed (e.g., the relation between EFs and fluid intelligence, self-regulation, executive attention, and effortful control, and the relation between working memory and inhibition and attention). The importance of social, emotional, and physical health for cognitive health is discussed because stress, lack of sleep, loneliness, or lack of exercise each impair EFs. That EFs are trainable and can be improved with practice is addressed, including diverse methods tried thus far. PMID:23020641

  20. On the sampling of functions and operators with an application to multiple-input multiple-output channel identification

    NASA Astrophysics Data System (ADS)

    Pfander, G. E.; Walnut, D. F.

    2007-09-01

    The classical sampling theorem, attributed to Whittaker, Shannon, Nyquist, and Kotelnikov, states that a bandlimited function can be recovered from its samples, as long as we use a sufficiently dense sampling grid. Here, we review the recent development of an operator sampling theory which allows for a "widening" of the classical sampling theorem. In this realm, bandlimited functions are replaced by "bandlimited operators". that is, by pseudodifferential operators which have bandlimited Kohn-Nirenberg symbols. Similar to the Nyquist sampling density condition alluded to above, we discuss sufficient and necessary conditions on the bandlimitation of pseudodifferential operators to ensure that they can be recovered by their action on a single distribution. In fact, we show that an operator with Kohn-Nirenberg symbol bandlimited to a Jordan domain of measure less than one can be recovered through its action on a distribution defined on a appropriately chosen sampling grid. Further, an operator with bandlimitation to a Jordan domain of measure larger than one cannot be recovered through its action on any tempered distribution whatsoever, pointing towards a fundamental difference to the classical sampling theorem where a large bandwidth could always be compensated through a sufficiently fine sampling grid. The dichotomy depending on the size of the bandlimitation is related to Heisenberg's uncertainty principle. Further, we discuss an application of this theory to the channel measurement problem for Multiple-Input Multiple-Output (MIMO) channels.

  1. Bayesian function-on-function regression for multilevel functional data.

    PubMed

    Meyer, Mark J; Coull, Brent A; Versace, Francesco; Cinciripini, Paul; Morris, Jeffrey S

    2015-09-01

    Medical and public health research increasingly involves the collection of complex and high dimensional data. In particular, functional data-where the unit of observation is a curve or set of curves that are finely sampled over a grid-is frequently obtained. Moreover, researchers often sample multiple curves per person resulting in repeated functional measures. A common question is how to analyze the relationship between two functional variables. We propose a general function-on-function regression model for repeatedly sampled functional data on a fine grid, presenting a simple model as well as a more extensive mixed model framework, and introducing various functional Bayesian inferential procedures that account for multiple testing. We examine these models via simulation and a data analysis with data from a study that used event-related potentials to examine how the brain processes various types of images. PMID:25787146

  2. Assessing function and functional outcome in schizophrenia.

    PubMed

    Bromley, Elizabeth; Brekke, John S

    2010-01-01

    The diagnosis of schizophrenia can only be made in the presence of a loss of functioning in domains such as employment, independent living, and social functioning. Accurately measuring functioning is central to research on the course of the disorder, treatment and rehabilitation outcomes, and biosocial factors in schizophrenia. Assessments of functional disability have described three dimensions of functioning: functional capacity, functional performance, and functional outcome. The "competence/performance" distinction refers to the observation that an individual may demonstrate an ability to perform a functional task (capacity) but may not do so in her own community environment (performance). Functional outcomes are the result of both capacity and performance. Several recent reviews have compared the characteristics, reliability, and validity of various functional assessment instruments. Two major initiatives are underway to gather additional comparative data about functional assessment strategies. Recently, both the recovery movement and the recognition of the role of environmental factors in functioning have raised questions about the conceptual content of the functioning construct (construct validity). For instance, several studies have demonstrated that features of functioning need not track together over the course of the illness. In addition, the notion of recovery emphasizes processes like community integration and subjective well-being that are not static outcomes but are continually evolving features of the life course in chronic illness. Findings on the dynamic role of environmental moderators such as support and opportunity also present challenges to scientific constructs. For these reasons and others, the ecological validity of functional assessments has become a central concern. Both the verisimilitude and veridicality of functional assessments can be empirically assessed, but to date very few studies have measured the extent to which functional

  3. Functional Training Revisited.

    ERIC Educational Resources Information Center

    Siff, Mel C.

    2002-01-01

    Asserts that though functional training is vital in all sporting preparation, it is only one aspect of the overall process. The paper defines functional training; discusses facets of functionality, functionality and balancing drills, and functional training and periodization; and concludes that functionality is best defined in terms of the outcome…

  4. Functional bowel disorders and functional abdominal pain

    PubMed Central

    Thompson, W; Longstreth, G; Drossman, D; Heaton, K; Irvine, E; Muller-Lissner, S

    1999-01-01

    The Rome diagnostic criteria for the functional bowel disorders and functional abdominal pain are used widely in research and practice. A committee consensus approach, including criticism from multinational expert reviewers, was used to revise the diagnostic criteria and update diagnosis and treatment recommendations, based on research results. The terminology was clarified and the diagnostic criteria and management recommendations were revised. A functional bowel disorder (FBD) is diagnosed by characteristic symptoms for at least 12 weeks during the preceding 12 months in the absence of a structural or biochemical explanation. The irritable bowel syndrome, functional abdominal bloating, functional constipation, and functional diarrhea are distinguished by symptom-based diagnostic criteria. Unspecified FBD lacks criteria for the other FBDs. Diagnostic testing is individualized, depending on patient age, primary symptom characteristics, and other clinical and laboratory features. Functional abdominal pain (FAP) is defined as either the FAP syndrome, which requires at least six months of pain with poor relation to gut function and loss of daily activities, or unspecified FAP, which lacks criteria for the FAP syndrome. An organic cause for the pain must be excluded, but aspects of the patient's pain behavior are of primary importance. Treatment of the FBDs relies upon confident diagnosis, explanation, and reassurance. Diet alteration, drug treatment, and psychotherapy may be beneficial, depending on the symptoms and psychological features.


Keywords: functional bowel disorder; functional constipation; functional diarrhea; irritable bowel syndrome; functional abdominal pain; functional abdominal bloating; Rome II PMID:10457044

  5. Ocular-Motor Function and Information Processing: Implications for the Reading Process.

    ERIC Educational Resources Information Center

    Leisman, Gerald; Schwartz, Joddy

    This paper discusses the dichotomy between continually moving eyes and the lack of blurred visual experience. A discontinuous model of visual perception is proposed, with the discontinuities being phase and temporally related to saccadic eye movements. It is further proposed that deviant duration and angular velocity characteristics of saccades in…

  6. The development of vestibular system and related functions in mammals: impact of gravity

    PubMed Central

    Jamon, Marc

    2013-01-01

    This chapter reviews the knowledge about the adaptation to Earth gravity during the development of mammals. The impact of early exposure to altered gravity is evaluated at the level of the functions related to the vestibular system, including postural control, homeostatic regulation, and spatial memory. The hypothesis of critical periods in the adaptation to gravity is discussed. Demonstrating a critical period requires removing the gravity stimulus during delimited time windows, what is impossible to do on Earth surface. The surgical destruction of the vestibular apparatus, and the use of mice strains with defective graviceptors have provided useful information on the consequences of missing gravity perception, and the possible compensatory mechanisms, but transitory suppression of the stimulus can only be operated during spatial flight. The rare studies on rat pups housed on board of space shuttle significantly contributed to this problem, but the use of hypergravity environment, produced by means of chronic centrifugation, is the only available tool when repeated experiments must be carried out on Earth. Even though hypergravity is sometimes considered as a mirror situation to microgravity, the two situations cannot be confused because a gravitational force is still present. The theoretical considerations that validate the paradigm of hypergravity to evaluate critical periods are discussed. The question of adaption of graviceptor is questioned from an evolutionary point of view. It is possible that graviception is hardwired, because life on Earth has evolved under the constant pressure of gravity. The rapid acquisition of motor programming by precocial mammals in minutes after birth is consistent with this hypothesis, but the slow development of motor skills in altricial species and the plasticity of vestibular perception in adults suggest that gravity experience is required for the tuning of graviceptors. The possible reasons for this dichotomy are discussed

  7. The effects of exercise on pubertal progression and reproductive function in girls.

    PubMed

    Warren, M P

    1980-11-01

    To determine whether a significant energy drain during adolescence had a significant effect on puberty and normal reproductive function, 15 ballet dancers, aged 13--15 yr, who maintained a high level of physical activity from early adolescence were followed for 4.0 yr. Menarche was remarkably delayed in this group, occurring at a mean of 15.4 yr, significantly different (P < 0.01) from normal controls (12.5 yr) and normal music students (12.6 yr). In 2 dancers aged 18 yr, primary amenorrhea has persisted. While premenarchial, all of the dancers had varying breast development (Tanner stages 2--4) and low to low normal gonadotropin levels, normal PRL and T4 levels, and normal skull x-rays. The dancers' mean body weight and calculated body fat were significantly less than in controls (P < 0.05). The progression of sexual development and the onset of menarche correlated in 10 or 15 subjects with a decrease in exercise and/or injury causing forced rest of at least 2-month duration. During this interval, weight gain was minimal or absent, with no significant change in body composition. A significant dichotomy in the order of pubertal development was also noted; while breast development and menarche were delayed, pubic hair development was not affected. Reversion to the amenorrheic state occurred in 11 of 13 patients with a return to exercise without a change in weight. In conclusion, energy drain may have an important modulatory effect on the hypothalamic pituitary set point at puberty and, in combination with low body weight, may prolong the prepubertal state and induce amenorrhea. PMID:6775000

  8. The development of vestibular system and related functions in mammals: impact of gravity.

    PubMed

    Jamon, Marc

    2014-01-01

    This chapter reviews the knowledge about the adaptation to Earth gravity during the development of mammals. The impact of early exposure to altered gravity is evaluated at the level of the functions related to the vestibular system, including postural control, homeostatic regulation, and spatial memory. The hypothesis of critical periods in the adaptation to gravity is discussed. Demonstrating a critical period requires removing the gravity stimulus during delimited time windows, what is impossible to do on Earth surface. The surgical destruction of the vestibular apparatus, and the use of mice strains with defective graviceptors have provided useful information on the consequences of missing gravity perception, and the possible compensatory mechanisms, but transitory suppression of the stimulus can only be operated during spatial flight. The rare studies on rat pups housed on board of space shuttle significantly contributed to this problem, but the use of hypergravity environment, produced by means of chronic centrifugation, is the only available tool when repeated experiments must be carried out on Earth. Even though hypergravity is sometimes considered as a mirror situation to microgravity, the two situations cannot be confused because a gravitational force is still present. The theoretical considerations that validate the paradigm of hypergravity to evaluate critical periods are discussed. The question of adaption of graviceptor is questioned from an evolutionary point of view. It is possible that graviception is hardwired, because life on Earth has evolved under the constant pressure of gravity. The rapid acquisition of motor programming by precocial mammals in minutes after birth is consistent with this hypothesis, but the slow development of motor skills in altricial species and the plasticity of vestibular perception in adults suggest that gravity experience is required for the tuning of graviceptors. The possible reasons for this dichotomy are discussed

  9. Calculator Function Approximation.

    ERIC Educational Resources Information Center

    Schelin, Charles W.

    1983-01-01

    The general algorithm used in most hand calculators to approximate elementary functions is discussed. Comments on tabular function values and on computer function evaluation are given first; then the CORDIC (Coordinate Rotation Digital Computer) scheme is described. (MNS)

  10. Liver Function Tests

    MedlinePlus

    ... herbal supplements you are taking. What are normal ranges for liver function tests? Normal ranges for liver function tests can vary by age, ... other factors. Laboratory test results usually provide normal ranges for each liver function test with your results. ...

  11. Functional microorganisms for functional food quality.

    PubMed

    Gobbetti, M; Cagno, R Di; De Angelis, M

    2010-09-01

    Functional microorganisms and health benefits represent a binomial with great potential for fermented functional foods. The health benefits of fermented functional foods are expressed either directly through the interactions of ingested live microorganisms with the host (probiotic effect) or indirectly as the result of the ingestion of microbial metabolites synthesized during fermentation (biogenic effect). Since the importance of high viability for probiotic effect, two major options are currently pursued for improving it--to enhance bacterial stress response and to use alternative products for incorporating probiotics (e.g., ice cream, cheeses, cereals, fruit juices, vegetables, and soy beans). Further, it seems that quorum sensing signal molecules released by probiotics may interact with human epithelial cells from intestine thus modulating several physiological functions. Under optimal processing conditions, functional microorganisms contribute to food functionality through their enzyme portfolio and the release of metabolites. Overproduction of free amino acids and vitamins are two classical examples. Besides, bioactive compounds (e.g., peptides, γ-amino butyric acid, and conjugated linoleic acid) may be released during food processing above the physiological threshold and they may exert various in vivo health benefits. Functional microorganisms are even more used in novel strategies for decreasing phenomenon of food intolerance (e.g., gluten intolerance) and allergy. By a critical approach, this review will aim at showing the potential of functional microorganisms for the quality of functional foods. PMID:20830633

  12. Optimal Stimulus Amplitude for Vestibular Stochastic Stimulation to Improve Sensorimotor Function

    NASA Technical Reports Server (NTRS)

    Goel, R.; Kofman, I.; DeDios, Y. E.; Jeevarajan, J.; Stepanyan, V.; Nair, M.; Congdon, S.; Fregia, M.; Cohen, H.; Bloomberg, J. J.; Mulavara, A. P.

    2014-01-01

    Sensorimotor changes such as postural and gait instabilities can affect the functional performance of astronauts when they transition across different gravity environments. We are developing a method, based on stochastic resonance (SR), to enhance information transfer by applying non-zero levels of external noise on the vestibular system (vestibular stochastic resonance, VSR). Our previous work has shown the advantageous effects of VSR in a balance task of standing on an unstable surface. This technique to improve detection of vestibular signals uses a stimulus delivery system that is wearable or portable and provides imperceptibly low levels of white noise-based binaural bipolar electrical stimulation of the vestibular system. The goal of this project is to determine optimal levels of stimulation for SR applications by using a defined vestibular threshold of motion detection. A series of experiments were carried out to determine a robust paradigm to identify a vestibular threshold that can then be used to recommend optimal stimulation levels for SR training applications customized to each crewmember. Customizing stimulus intensity can maximize treatment effects. The amplitude of stimulation to be used in the VSR application has varied across studies in the literature such as 60% of nociceptive stimulus thresholds. We compared subjects' perceptual threshold with that obtained from two measures of body sway. Each test session was 463s long and consisted of several 15s sinusoidal stimuli, at different current amplitudes (0-2 mA), interspersed with 20-20.5s periods of no stimulation. Subjects sat on a chair with their eyes closed and had to report their perception of motion through a joystick. A force plate underneath the chair recorded medio-lateral shear forces and roll moments. First we determined the percent time during stimulation periods for which perception of motion (activity above a pre-defined threshold) was reported using the joystick, and body sway (two

  13. THE ACS FORNAX CLUSTER SURVEY. VIII. THE LUMINOSITY FUNCTION OF GLOBULAR CLUSTERS IN VIRGO AND FORNAX EARLY-TYPE GALAXIES AND ITS USE AS A DISTANCE INDICATOR

    SciTech Connect

    Villegas, Daniela; Kissler-Patig, Markus; Jordan, Andres; Infante, Leopoldo; Peng, Eric W.; Blakeslee, John P.; Cote, Patrick; Ferrarese, Laura; Mei, Simona; Tonry, John L.; West, Michael J.

    2010-07-10

    We use a highly homogeneous set of data from 132 early-type galaxies in the Virgo and Fornax clusters in order to study the properties of the globular cluster luminosity function (GCLF). The globular cluster system of each galaxy was studied using a maximum likelihood approach to model the intrinsic GCLF after accounting for contamination and completeness effects. The results presented here update our Virgo measurements and confirm our previous results showing a tight correlation between the dispersion of the GCLF and the absolute magnitude of the parent galaxy. Regarding the use of the GCLF as a standard candle, we have found that the relative distance modulus between the Virgo and Fornax clusters is systematically lower than the one derived by other distance estimators, and in particular, it is 0.22 mag lower than the value derived from surface brightness fluctuation measurements performed on the same data. From numerical simulations aimed at reproducing the observed dispersion of the value of the turnover magnitude in each galaxy cluster we estimate an intrinsic dispersion on this parameter of 0.21 mag and 0.15 mag for Virgo and Fornax, respectively. All in all, our study shows that the GCLF properties vary systematically with galaxy mass showing no evidence for a dichotomy between giant and dwarf early-type galaxies. These properties may be influenced by the cluster environment as suggested by cosmological simulations.

  14. Insights into the distribution and functions of the eukaryotic GPI-like anchored genes among Mycobacterium from a comparative genomic perspective.

    PubMed

    Deng, Wanyan; Zeng, Jie; Xiang, Xiaohong; Xie, Jianping

    2012-01-01

    Glycosylphosphatidylinositol (GPI)-anchored proteins range from small peptides to larger antigens and fulfill a variety of cellular functions in eukaryotes. We speculated there should be such molecules in intracellular pathogens such as Mycobacterium due to their complex interplay with the host. However, no prior publications have touched this topic. To explore the existence and distribution of GPI-like molecules among Mycobacterium, we exhaustively analyzed all publicly available Mycobacterium genomes and found that the GPI-like signal sequences are prevalent among Mycobacterium, and a significant dichotomy between nonpathogenic Mycobacterium (exemplified by Mycobacterium smegmatis) and pathogenic Mycobacterium (exemplified by Mycobacterium tuberculosis), through genome-wide GPI-SOM analysis. Some well-documented anti-tuberculosis drug targets are predicted to have GPI-like anchored signals, such as KasA and atpE. Interestingly, Pro-Glu (PE) and Pro-Pro-Glu (PPE) proteins predicted to have GPI-anchoring sequence are unique to pathogenic Mycobacterium. These results can be further explored for better control measures against tuberculosis. PMID:23272800

  15. CD8 sup + T lymphocytes of patients with AIDS maintain normal broad cytolytic function despite the loss of human immunodeficiency virus-specific cytotoxicity

    SciTech Connect

    Pantaleo, G.; De Maria, A.; Koenig, S.; Butini, L.; Moss, B.; Lane, H.C.; Fauci, A.S. ); Baseler, M. )

    1990-06-01

    In this study, the authors have investigated the potential mechanisms responsible for the loss of human immunodeficiency virus type 1 (HIV-1)-specific cytolytic activity in the advanced stages of HIV-1 infection. They have demonstrated that HIV-1-specific cytotoxic T lymphocytes are predominantly contained within the CD8{sup +}DR{sup +} subset. Furthermore, they have shown by a redirected killing assay that there is a dichotomy between HIV-1-specific cytolytic activity and broad cytolytic potential since the cytolytic machinery of CD8{sup +}DR{sup +} cells is still functioning even in patients with AIDS who have lost their HIV-1-specific cytolytic activity. In addition, by comparative analysis of these two types of cytolytic activity over time they have demonstrated a progressive loss of HIV-1-specific cytolytic activity in the advanced stages of the disease, whereas the cytolytic potential remained unchanged regardless of the clinical stage. On the basis of these results, they propose that the loss of HIV-1-specific cytolytic activity in HIV-1-infected individuals may result at least in part from a progressive decrease in the pool of HIV-1-specific cytotoxic T lymphocytes belonging to the CD8{sup +}DR{sup +} subset whose ability to expand has been impaired.

  16. Sampling functions for geophysics

    NASA Technical Reports Server (NTRS)

    Giacaglia, G. E. O.; Lunquist, C. A.

    1972-01-01

    A set of spherical sampling functions is defined such that they are related to spherical-harmonic functions in the same way that the sampling functions of information theory are related to sine and cosine functions. An orderly distribution of (N + 1) squared sampling points on a sphere is given, for which the (N + 1) squared spherical sampling functions span the same linear manifold as do the spherical-harmonic functions through degree N. The transformations between the spherical sampling functions and the spherical-harmonic functions are given by recurrence relations. The spherical sampling functions of two arguments are extended to three arguments and to nonspherical reference surfaces. Typical applications of this formalism to geophysical topics are sketched.

  17. Functionalized boron nitride nanotubes

    DOEpatents

    Sainsbury, Toby; Ikuno, Takashi; Zettl, Alexander K

    2014-04-22

    A plasma treatment has been used to modify the surface of BNNTs. In one example, the surface of the BNNT has been modified using ammonia plasma to include amine functional groups. Amine functionalization allows BNNTs to be soluble in chloroform, which had not been possible previously. Further functionalization of amine-functionalized BNNTs with thiol-terminated organic molecules has also been demonstrated. Gold nanoparticles have been self-assembled at the surface of both amine- and thiol-functionalized boron nitride Nanotubes (BNNTs) in solution. This approach constitutes a basis for the preparation of highly functionalized BNNTs and for their utilization as nanoscale templates for assembly and integration with other nanoscale materials.

  18. Combining belief functions and fuzzy membership functions

    NASA Astrophysics Data System (ADS)

    Florea, Mihai C.; Jousselme, Anne-Laure; Grenier, Dominic; Bosse, Eloi

    2003-04-01

    In several practical applications of data fusion and more precisely in object identification problems, we need to combine imperfect information coming from different sources (sensors, humans, etc.), the resulting uncertainty being naturally of different kinds. In particular, one information could naturally been expressed by a membership function while the other could best be represented by a belief function. Usually, information modeled in the fuzzy sets formalism (by a membership function) concerns attributes like speed, length, or Radar Cross Section whose domains of definition are continuous. However, the object identification problem refers to a discrete and finite framework (the number of objects in the data base is finite and known). This implies thus a natural but unavoidable change of domain. To be able to respect the intrinsic characteristic of uncertainty arising from the different sources and fuse it in order to identify an object among a list of possible ones in the data base, we need (1) to use a unified framework where both fuzzy sets and belief functions can be expressed, (2) to respect the natural discretization of the membership function through the change of domain (from attribute domain to frame of discernment). In this paper, we propose to represent both fuzzy sets and belief function by random sets. While the link between belief functions and random sets is direct, transforming fuzzy sets into random sets involves the use of α-cuts for the construction of the focal elements. This transformation usually generates a large number of focal elements often unmanageable in a fusion process. We propose a way to reduce the number of focal elements based on some parameters like the desired number of focal elements, the acceptable distance from the approximated random set to the original discrete one, or the acceptable loss of information.

  19. Extraocular muscle function testing

    MedlinePlus

    Extraocular muscle function testing examines the function of the eye muscles. A health care provider observes the movement of ... evaluate weakness or other problem in the extraocular muscles. These problems may result in double vision or ...

  20. Liver Function Tests

    MedlinePlus

    ... food, store energy, and remove poisons. Liver function tests are blood tests that check to see how well your liver ... hepatitis and cirrhosis. You may have liver function tests as part of a regular checkup. Or you ...

  1. Functional Task Test (FTT)

    NASA Technical Reports Server (NTRS)

    Bloomberg, Jacob J.; Mulavara, Ajitkumar; Peters, Brian T.; Rescheke, Millard F.; Wood, Scott; Lawrence, Emily; Koffman, Igor; Ploutz-Snyder, Lori; Spiering, Barry A.; Feeback, Daniel L.; Platts, Steven H.; Stenger, Michael B.; Lee, Stuart M.C.; Arzeno, Natalia; Feiveson, Alan H.; Ryder, Jeffrey; Garcia, Yamil; Guilliams, Mark E.

    2009-01-01

    This slide presentation reviews the Functional Task Test (FTT), an interdisciplinary testing regimen that has been developed to evaluate astronaut postflight functional performance and related physiological changes. The objectives of the project are: (1) to develop a set of functional tasks that represent critical mission tasks for the Constellation Program, (2) determine the ability to perform these tasks after space flight, (3) Identify the key physiological factors that contribute to functional decrements and (4) Use this information to develop targeted countermeasures.

  2. Piecing Together Piecewise Functions.

    ERIC Educational Resources Information Center

    King, Sybrina L.

    1997-01-01

    Presents an activity to teach piecewise functions using wax paper and rectangular grids. Helps students understand the idea of different pieces by literally "piecing" together a new type of mathematical function. Also describes a followup activity and explains how piecewise functions can be graphed using graphing calculators. (NB)

  3. Two Functions of Language

    ERIC Educational Resources Information Center

    Feldman, Carol Fleisher

    1977-01-01

    Author advocates the view that meaning is necessarily dependent upon the communicative function of language and examines the objections, particularly those of Noam Chomsky, to this view. Argues that while Chomsky disagrees with the idea that communication is the essential function of language, he implicitly agrees that it has a function.…

  4. Pediatric functional gastrointestinal disorders

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Functional gastrointestinal disorders continue to be a prevalent set of conditions faced by the healthcare team and have a significant emotional and economic impact. In this review, the authors highlight some of the common functional disorders seen in pediatric patients (functional dyspepsia, irrita...

  5. What Is Functionalism?

    ERIC Educational Resources Information Center

    Bates, Elizabeth; MacWhinney, Brian

    A defense of functionalism in linguistics, and more specifically the competition model of linguistic performance, examines six misconceptions about the functionalist approach. Functionalism is defined as the belief that the forms of natural languages are created, governed, constrained, acquired, and used for communicative functions. Functionalism…

  6. Functioning Mathematically: 1

    ERIC Educational Resources Information Center

    Cain, David

    2007-01-01

    This article presents the first part of the closing address given by the author to the 2007 Association of Teachers of Mathematics (ATM) Easter conference at Loughborough. In his closing address, the author focuses on functioning mathematically as opposed to functional mathematics. His view of functional mathematics is that the focus is on someone…

  7. An Exceptional Exponential Function

    ERIC Educational Resources Information Center

    Curgus, Branko

    2006-01-01

    We show that there is a link between a standard calculus problem of finding the best view of a painting and special tangent lines to the graphs of exponential functions. Surprisingly, the exponential function with the "best view" is not the one with the base "e." A similar link is established for families of functions obtained by composing…

  8. Measuring Attitude Functions.

    ERIC Educational Resources Information Center

    Anderson, Deborah S.; Kristiansen, Connie M.

    1990-01-01

    Discusses the Attitude Functions Inventory (AFI), which assesses the extent to which a person's attitude fulfills each of four psychological functions. Reports findings of a study, involving 249 undergraduates, that tested the construct validity of the AFI. Suggests that the AFI provides conceptually meaningful measures of the functions of…

  9. Cross-functional systems

    NASA Technical Reports Server (NTRS)

    Lee, Mark

    1991-01-01

    Many companies, including Xerox and Texas Instruments, are using cross functional systems to deal with the increasingly complex and competitive business environment. However, few firms within the aerospace industry appear to be aware of the significant benefits that cross functional systems can provide. Those benefits are examined and a flexible methodology is discussed that companies can use to identify and develop cross functional systems that will help improve organizational performance. In addition, some of the managerial issues are addressed that cross functional systems may raise and specific examples are used to explore networking's contributions to cross functional systems.

  10. The Cosmological Mass Function

    NASA Astrophysics Data System (ADS)

    Monaco, Pierluigi

    1997-10-01

    This thesis aims to review the cosmological mass function problem, both from the theoretical and the observational point of view, and to present a new mass function theory, based on realistic approximations for the dynamics of gravitational collapse. Chapter 1 gives a general introduction on gravitational dynamics in cosmological models. Chapter 2 gives a complete review of the mass function theory. Chapters 3 and 4 present the ``dynamical'' mass function theory, based on truncated Lagrangian dynamics and on the excursion set approach. Chapter 5 reviews the observational state-of-the-art and the main applications of the mass function theories described before. Finally, Chapter 6 gives conclusions and future prospects.

  11. Inverse structure functions

    SciTech Connect

    Pearson, Bruce R.; Water, Willem van de

    2005-03-01

    While the ordinary structure function in turbulence is concerned with the statistical moments of the velocity increment {delta}u measured over a distance r, the inverse structure function is related to the distance r where the turbulent velocity exits the interval {delta}u. We study inverse structure functions of wind-tunnel turbulence which covers a range of Reynolds numbers Re{sub {lambda}}=400-1100. We test a recently proposed relation between the scaling exponents of the ordinary structure functions and those of the inverse structure functions [S. Roux and M. H. Jensen, Phys. Rev. E 69, 16309 (2004)]. The relatively large range of Reynolds numbers in our experiment also enables us to address the scaling with Reynolds number that is expected to highlight the intermediate dissipative range. While we firmly establish the (relative) scaling of inverse structure functions, our experimental results fail both predictions. Therefore, the question of the significance of inverse structure functions remains open.

  12. On genetic map functions

    SciTech Connect

    Zhao, Hongyu; Speed, T.P.

    1996-04-01

    Various genetic map functions have been proposed to infer the unobservable genetic distance between two loci from the observable recombination fraction between them. Some map functions were found to fit data better than others. When there are more than three markers, multilocus recombination probabilities cannot be uniquely determined by the defining property of map functions, and different methods have been proposed to permit the use of map functions to analyze multilocus data. If for a given map function, there is a probability model for recombination that can give rise to it, then joint recombination probabilities can be deduced from this model. This provides another way to use map functions in multilocus analysis. In this paper we show that stationary renewal processes give rise to most of the map functions in the literature. Furthermore, we show that the interevent distributions of these renewal processes can all be approximated quite well by gamma distributions. 43 refs., 4 figs.

  13. Functional Explanation and the Function of Explanation

    ERIC Educational Resources Information Center

    Lombrozo, Tania; Carey, Susan

    2006-01-01

    Teleological explanations (TEs) account for the existence or properties of an entity in terms of a function: we have hearts because they pump blood, and telephones for communication. While many teleological explanations seem appropriate, others are clearly not warranted--for example, that rain exists for plants to grow. Five experiments explore…

  14. Bayesian Error Estimation Functionals

    NASA Astrophysics Data System (ADS)

    Jacobsen, Karsten W.

    The challenge of approximating the exchange-correlation functional in Density Functional Theory (DFT) has led to the development of numerous different approximations of varying accuracy on different calculated properties. There is therefore a need for reliable estimation of prediction errors within the different approximation schemes to DFT. The Bayesian Error Estimation Functionals (BEEF) have been developed with this in mind. The functionals are constructed by fitting to experimental and high-quality computational databases for molecules and solids including chemisorption and van der Waals systems. This leads to reasonably accurate general-purpose functionals with particual focus on surface science. The fitting procedure involves considerations on how to combine different types of data, and applies Tikhonov regularization and bootstrap cross validation. The methodology has been applied to construct GGA and metaGGA functionals with and without inclusion of long-ranged van der Waals contributions. The error estimation is made possible by the generation of not only a single functional but through the construction of a probability distribution of functionals represented by a functional ensemble. The use of the functional ensemble is illustrated on compound heat of formation and by investigations of the reliability of calculated catalytic ammonia synthesis rates.

  15. B Plant function analysis report

    SciTech Connect

    Lund, D.P.; B Plant Working Group

    1995-09-01

    The document contains the functions, function definitions, function interfaces, function interface definitions, Input Computer Automated Manufacturing Definition (IDEFO) diagrams, and a function hierarchy chart that describe what needs to be performed to deactivate B Plant.

  16. Toll-Like Receptors and Dectin-1, a C-Type Lectin Receptor, Trigger Divergent Functions in CNS Macrophages

    PubMed Central

    Wang, Yan; Guan, Zhen; Beckwith, Kyle A.; Braun, Kaitlyn J.; Wei, Ping; McTigue, Dana M.

    2015-01-01

    Spinal cord injury (SCI) activates macrophages, endowing them with both reparative and pathological functions. The mechanisms responsible for these divergent functions are unknown but are likely controlled through stochastic activation of different macrophage receptor subtypes. Various danger-associated molecular patterns released from dying cells in the injured spinal cord likely activate distinct subtypes of macrophage pattern recognition receptors, including bacterial toll-like receptors (TLRs) and fungal C-type lectin receptors (e.g., dectin-1). To determine the in vivo consequences of activating these receptors, ligands specific for TLR2 or dectin-1 were microinjected, alone or in combination, into intact spinal cord. Both ligands elicit a florid macrophage reaction; however, only dectin-1 activation causes macrophage-mediated demyelination and axonal injury. Coactivating TLR2 reduced the injurious effects of dectin-1 activation. When injected into traumatically injured spinal cord, TLR2 agonists enhance the endogenous macrophage reaction while conferring neuroprotection. Indeed, dieback of axons was reduced, leading to smaller lesion volumes at the peak of the macrophage response. Moreover, the density of NG2+ cells expressing vimentin increased in and near lesions that were enriched with TLR2-activated macrophages. In dectin-1-null mutant (knock-out) mice, dieback of corticospinal tract axons also is reduced after SCI. Collectively, these data support the hypothesis that the ability of macrophages to create an axon growth-permissive microenvironment or cause neurotoxicity is receptor dependent and it may be possible to exploit this functional dichotomy to enhance CNS repair. SIGNIFICANCE STATEMENT There is a growing appreciation that macrophages exert diverse functions in the injured and diseased CNS. Indeed, both macrophage-mediated repair and macrophage-mediated injury occur, and often these effector functions are elicited simultaneously. Understanding the

  17. Functional Visual Loss

    PubMed Central

    Bruce, Beau B; Newman, Nancy J

    2010-01-01

    Synopsis Neurologists frequently evaluate patients complaining of vision loss, especially when the patient has been examined by an ophthalmologist who has found no ocular disease. A significant proportion of patients presenting to the neurologist with visual complaints will have non-organic or functional visual loss. While there are examination techniques which can aid in the detection and diagnosis of functional visual loss, the frequency with which functional visual loss occurs concomitantly with organic disease warrants substantial caution on the part of the clinician. Furthermore, purely functional visual loss is never a diagnosis of exclusion, and must be supported by positive findings on examination that demonstrate normal visual function. The relationship of true psychological disease and functional visual loss is unclear and most patients respond well to simple reassurance. PMID:20638000

  18. Function photonic crystals

    NASA Astrophysics Data System (ADS)

    Wu, Xiang-Yao; Zhang, Bai-Jun; Yang, Jing-Hai; Liu, Xiao-Jing; Ba, Nuo; Wu, Yi-Heng; Wang, Qing-Cai

    2011-07-01

    In this paper, we present a new kind of function photonic crystals (PCs), whose refractive index is a function of space position. Conventional PCs structure grows from two materials, A and B, with different dielectric constants εA and εB. Based on Fermat principle, we give the motion equations of light in one-dimensional, two-dimensional and three-dimensional function photonic crystals. For one-dimensional function photonic crystals, we give the dispersion relation, band gap structure and transmissivity, and compare them with conventional photonic crystals, and we find the following: (1) For the vertical and non-vertical incidence light of function photonic crystals, there are band gap structures, and for only the vertical incidence light, the conventional PCs have band gap structures. (2) By choosing various refractive index distribution functions n( z), we can obtain more wider or more narrower band gap structure than conventional photonic crystals.

  19. Balance Function Disorders

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Researchers at the Balance Function Laboratory and Clinic at the Minneapolis (MN) Neuroscience Institute on the Abbot Northwestern Hospital Campus are using a rotational chair (technically a "sinusoidal harmonic acceleration system") originally developed by NASA to investigate vestibular (inner ear) function in weightlessness to diagnose and treat patients with balance function disorders. Manufactured by ICS Medical Corporation, Schaumberg, IL, the chair system turns a patient and monitors his or her responses to rotational stimulation.

  20. Time functions revisited

    NASA Astrophysics Data System (ADS)

    Fathi, Albert

    2015-07-01

    In this paper we revisit our joint work with Antonio Siconolfi on time functions. We will give a brief introduction to the subject. We will then show how to construct a Lipschitz time function in a simplified setting. We will end with a new result showing that the Aubry set is not an artifact of our proof of existence of time functions for stably causal manifolds.

  1. Distributed processing; distributed functions?

    PubMed Central

    Fox, Peter T.; Friston, Karl J.

    2016-01-01

    After more than twenty years busily mapping the human brain, what have we learned from neuroimaging? This review (coda) considers this question from the point of view of structure–function relationships and the two cornerstones of functional neuroimaging; functional segregation and integration. Despite remarkable advances and insights into the brain’s functional architecture, the earliest and simplest challenge in human brain mapping remains unresolved: We do not have a principled way to map brain function onto its structure in a way that speaks directly to cognitive neuroscience. Having said this, there are distinct clues about how this might be done: First, there is a growing appreciation of the role of functional integration in the distributed nature of neuronal processing. Second, there is an emerging interest in data-driven cognitive ontologies, i.e., that are internally consistent with functional anatomy. We will focus this review on the growing momentum in the fields of functional connectivity and distributed brain responses and consider this in the light of meta-analyses that use very large data sets to disclose large-scale structure–function mappings in the human brain. PMID:22245638

  2. Renormalization group functional equations

    SciTech Connect

    Curtright, Thomas L.; Zachos, Cosmas K.

    2011-03-15

    Functional conjugation methods are used to analyze the global structure of various renormalization group trajectories and to gain insight into the interplay between continuous and discrete rescaling. With minimal assumptions, the methods produce continuous flows from step-scaling {sigma} functions and lead to exact functional relations for the local flow {beta} functions, whose solutions may have novel, exotic features, including multiple branches. As a result, fixed points of {sigma} are sometimes not true fixed points under continuous changes in scale and zeroes of {beta} do not necessarily signal fixed points of the flow but instead may only indicate turning points of the trajectories.

  3. Functional & para-functional parallel processing

    SciTech Connect

    Not Available

    1994-11-01

    For years (about 20, in fact) dataflow researchers have argued for the use of dataflow (a subset of functional) languages for parallel computing, resting their proof on the ability to construct large-scale dataflow machines to realize the inherent parallelism in Functional programs. Unfortunately, such machines have never materialized as commercial products - instead, the market shows a vast variety of parallel multiprocessors that require special skills to program. It may be the case that these machines reflect a wrong direction in computer architecture design, and it may be the case that dataflow machines are the right way to go, but the proof is in the pudding, and thus far there does not exist even a prototype dataflow machine that can prove the {open_quote}dataflow thesis.{close_quote} Under the circumstances it would seem rather foolhardy simply to ignore the commercial parallel machines that are available now, regardless of one`s favorite programming methodology or concurrency model. It has been the authors` thesis that one can in fact use such machines effectively, while maintaining the concomitant thesis that functional programming is good for parallel computation. During the last two years the author has made considerable progress to support this two-fold thesis, and is now prepared to extend this work in several ways. The authors` particular interest, and presumably the primary interest to DOE, is to concentrate the work in the area of scientific computing, including functional language features, program development tools, and systems support tailored for scientific computing applications. The authors` desire to do this reflects confidence that this approach really will work for scientific computing - the author has spent two years proving the viability of the ideas, and now it`s time to put them into action.

  4. Brain Hemispheric Functioning.

    ERIC Educational Resources Information Center

    Roeper Review, 1981

    1981-01-01

    Four articles consider brain hemisphere functioning of gifted students as it relates to gifted programs; alternation of education methodologies; spatial ability as an element of intellectual gifted functioning; and the interaction between hemisphere specialization, imagery, creative imagination, and sex differentiation. (SB)

  5. Modeling Protein Domain Function

    ERIC Educational Resources Information Center

    Baker, William P.; Jones, Carleton "Buck"; Hull, Elizabeth

    2007-01-01

    This simple but effective laboratory exercise helps students understand the concept of protein domain function. They use foam beads, Styrofoam craft balls, and pipe cleaners to explore how domains within protein active sites interact to form a functional protein. The activity allows students to gain content mastery and an understanding of the…

  6. Program Computes Thermodynamic Functions

    NASA Technical Reports Server (NTRS)

    Mcbride, Bonnie J.; Gordon, Sanford

    1994-01-01

    PAC91 is latest in PAC (Properties and Coefficients) series. Two principal features are to provide means of (1) generating theoretical thermodynamic functions from molecular constants and (2) least-squares fitting of these functions to empirical equations. PAC91 written in FORTRAN 77 to be machine-independent.

  7. Functional Generalized Additive Models.

    PubMed

    McLean, Mathew W; Hooker, Giles; Staicu, Ana-Maria; Scheipl, Fabian; Ruppert, David

    2014-01-01

    We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F{X(t), t} where F(·,·) is an unknown regression function and X(t) is a functional covariate. Rather than having an additive model in a finite number of principal components as in Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F(·,·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X(t) is a signal from diffusion tensor imaging at position, t, along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. R code for performing the simulations and fitting the FGAM can be found in supplemental materials available online. PMID:24729671

  8. Pulmonary Function Tests

    PubMed Central

    Ranu, Harpreet; Wilde, Michael; Madden, Brendan

    2011-01-01

    Pulmonary function tests are valuable investigations in the management of patients with suspected or previously diagnosed respiratory disease. They aid diagnosis, help monitor response to treatment and can guide decisions regarding further treatment and intervention. The interpretation of pulmonary functions tests requires knowledge of respiratory physiology. In this review we describe investigations routinely used and discuss their clinical implications. PMID:22347750

  9. Antigravitational Functional System

    NASA Astrophysics Data System (ADS)

    Dorogovtsev, V. N.

    2008-06-01

    The purpose of this paper is the description of the main components and basic functioning principles of the antigravitational functional system (AFS). Methods: literary review and theoretical analysis of the neurogenic regulation functional system. The concept of a functional system was formulated in the beginning of the 20th century. Functional system was described as dynamic, self-organizing, central-peripheral functional integration structures of the nervous system whose activity was aiming at achieving adaptive useful results. The main difference between functional system and proposed regulating principles is the physiological mechanism presence of the prospective result prediction (action result acceptor). Action is programmed for defined result receiving. This is anticipatory regulation principle. Using this principle AFS provides timely cardiovascular system preparing for its impending functional conditions changes. It seems that gravity intolerance in the beginning and after space flight is related with AFS regulation peculiarities. There is a necessity for the AFS advanced study. It is very important to create safe and comfort conditions for astronauts adaptation during gravitational loading changes as well as for certain diseases prophylaxis on the Earth.

  10. Functional performance of pyrovalves

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.

    1996-01-01

    Following several flight and ground test failures of spacecraft systems using single-shot, 'normally closed' pyrotechnically actuated valves (pyrovalves), a Government/Industry cooperative program was initiated to assess the functional performance of five qualified designs. The goal of the program was to provide information on functional performance of pyrovalves to allow users the opportunity to improve procurement requirements. Specific objectives included the demonstration of performance test methods, the seating; these gases/particles entered the fluid path of measurement of 'blowby' (the passage of gases from the pyrotechnic energy source around the activating piston into the valve's fluid path), and the quantification of functional margins for each design. Experiments were conducted at NASA's Langley Research Center on several units for each of the five valve designs. The test methods used for this program measured the forces and energies required to actuate the valves, as well as the energies and the pressures (where possible) delivered by the pyrotechnic sources. Functional performance ranged widely among the designs. Blowby cannot be prevented by o-ring seals; metal-to-metal seals were effective. Functional margin was determined by dividing the energy delivered by the pyrotechnic sources in excess to that required to accomplish the function by the energy required for that function. Two of the five designs had inadequate functional margins with the pyrotechnic cartridges evaluated.

  11. Thyroid function in pregnancy☆

    PubMed Central

    Leung, Angela M.

    2014-01-01

    Iodine is required for the production of thyroid hormones. Normal thyroid function during pregnancy is important for both the mother and developing fetus. This review discusses the changes in thyroid physiology that occur during pregnancy, the significance of thyroid function tests and thyroid antibody titers assessed during pregnancy, and the potential obstetric complications associated with maternal hypothyroidism. PMID:22658718

  12. Functional foods innovations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of the Dairy and Functional Foods Research Unit (DFFRU), ERRC, ARS, USDA, is to improve human health and well being by developing functional food and consumer products that utilize milk and fruit and vegetable processing residues of specialty crops. Major research approaches involve: biotec...

  13. Platelet Function Tests

    MedlinePlus

    ... of the clotting process in the body ( in vivo ). A person with normal platelet function test results may still experience excessive bleeding or inappropriate clotting during and after a surgery. Most samples for platelet function testing are only stable for a very short period ...

  14. Functional Magnetic Resonance Imaging

    ERIC Educational Resources Information Center

    Voos, Avery; Pelphrey, Kevin

    2013-01-01

    Functional magnetic resonance imaging (fMRI), with its excellent spatial resolution and ability to visualize networks of neuroanatomical structures involved in complex information processing, has become the dominant technique for the study of brain function and its development. The accessibility of in-vivo pediatric brain-imaging techniques…

  15. Functionalization of Semiconductor Nanoparticles

    NASA Astrophysics Data System (ADS)

    Baraton, M.-I.

    Functionalization of nanoparticles surface by attachment of organic entities is used to achieve and tailor many new properties, such as lubrication, optical response, chemical sensing, or biocompatibility. But because at the nanometer scale the surface properties significantly contribute to the overall properties, the consequences of the surface modifications have to be thoroughly evaluated. This paper demonstrates the relevance of Fourier transform infrared spectroscopy to the study of the surface reactions leading to the functionalization, and of the stability of the functionalized surface under the expected working conditions. In the case of semiconductor nanoparticles, this technique additionally allows the analysis of the impact of the functionalization on the electrical properties. This will be illustrated by the case study of tin oxide nanoparticles for chemical gas sensors. The correlation between surface chemistry and electrical properties is critical to optimize the nanoparticles functionalization for the targeted properties.

  16. Time Functions as Utilities

    NASA Astrophysics Data System (ADS)

    Minguzzi, E.

    2010-09-01

    Every time function on spacetime gives a (continuous) total preordering of the spacetime events which respects the notion of causal precedence. The problem of the existence of a (semi-)time function on spacetime and the problem of recovering the causal structure starting from the set of time functions are studied. It is pointed out that these problems have an analog in the field of microeconomics known as utility theory. In a chronological spacetime the semi-time functions correspond to the utilities for the chronological relation, while in a K-causal (stably causal) spacetime the time functions correspond to the utilities for the K + relation (Seifert’s relation). By exploiting this analogy, we are able to import some mathematical results, most notably Peleg’s and Levin’s theorems, to the spacetime framework. As a consequence, we prove that a K-causal (i.e. stably causal) spacetime admits a time function and that the time or temporal functions can be used to recover the K + (or Seifert) relation which indeed turns out to be the intersection of the time or temporal orderings. This result tells us in which circumstances it is possible to recover the chronological or causal relation starting from the set of time or temporal functions allowed by the spacetime. Moreover, it is proved that a chronological spacetime in which the closure of the causal relation is transitive (for instance a reflective spacetime) admits a semi-time function. Along the way a new proof avoiding smoothing techniques is given that the existence of a time function implies stable causality, and a new short proof of the equivalence between K-causality and stable causality is given which takes advantage of Levin’s theorem and smoothing techniques.

  17. Plant functional genomics

    NASA Astrophysics Data System (ADS)

    Holtorf, Hauke; Guitton, Marie-Christine; Reski, Ralf

    2002-04-01

    Functional genome analysis of plants has entered the high-throughput stage. The complete genome information from key species such as Arabidopsis thaliana and rice is now available and will further boost the application of a range of new technologies to functional plant gene analysis. To broadly assign functions to unknown genes, different fast and multiparallel approaches are currently used and developed. These new technologies are based on known methods but are adapted and improved to accommodate for comprehensive, large-scale gene analysis, i.e. such techniques are novel in the sense that their design allows researchers to analyse many genes at the same time and at an unprecedented pace. Such methods allow analysis of the different constituents of the cell that help to deduce gene function, namely the transcripts, proteins and metabolites. Similarly the phenotypic variations of entire mutant collections can now be analysed in a much faster and more efficient way than before. The different methodologies have developed to form their own fields within the functional genomics technological platform and are termed transcriptomics, proteomics, metabolomics and phenomics. Gene function, however, cannot solely be inferred by using only one such approach. Rather, it is only by bringing together all the information collected by different functional genomic tools that one will be able to unequivocally assign functions to unknown plant genes. This review focuses on current technical developments and their impact on the field of plant functional genomics. The lower plant Physcomitrella is introduced as a new model system for gene function analysis, owing to its high rate of homologous recombination.

  18. Biomechanics of Cardiac Function.

    PubMed

    Voorhees, Andrew P; Han, Hai-Chao

    2015-10-01

    The heart pumps blood to maintain circulation and ensure the delivery of oxygenated blood to all the organs of the body. Mechanics play a critical role in governing and regulating heart function under both normal and pathological conditions. Biological processes and mechanical stress are coupled together in regulating myocyte function and extracellular matrix structure thus controlling heart function. Here, we offer a brief introduction to the biomechanics of left ventricular function and then summarize recent progress in the study of the effects of mechanical stress on ventricular wall remodeling and cardiac function as well as the effects of wall mechanical properties on cardiac function in normal and dysfunctional hearts. Various mechanical models to determine wall stress and cardiac function in normal and diseased hearts with both systolic and diastolic dysfunction are discussed. The results of these studies have enhanced our understanding of the biomechanical mechanism in the development and remodeling of normal and dysfunctional hearts. Biomechanics provide a tool to understand the mechanism of left ventricular remodeling in diastolic and systolic dysfunction and guidance in designing and developing new treatments. PMID:26426462

  19. Hantush Well Function revisited

    NASA Astrophysics Data System (ADS)

    Veling, E. J. M.; Maas, C.

    2010-11-01

    SummaryIn this paper, we comment on some recent numerical and analytical work to evaluate the Hantush Well Function. We correct an expression found in a Comment by Nadarajah [Nadarajah, S., 2007. A comment on numerical evaluation of Theis and Hantush-Jacob well functions. Journal of Hydrology 338, 152-153] to a paper by Prodanoff et al. [Prodanoff, J.A., Mansur, W.J., Mascarenhas, F.C.B., 2006. Numerical evaluation of Theis and Hantush-Jacob well functions. Journal of Hydrology 318, 173-183]. We subsequently derived another analytic representation based on a generalized hypergeometric function in two variables and from the hydrological literature we cite an analytic representation by Hunt [Hunt, B., 1977. Calculation of the leaky aquifer function. Journal of Hydrology 33, 179-183]. We have implemented both representations and compared the results. Using a convergence accelerator Hunt's representation of Hantush Well Function is efficient and accurate. While checking our implementations we found that Bear's table of the Hantush Well Function [Bear, J., 1979. Hydraulics of Groundwater. McGraw-Hill, New York, Tables 8-6] contains a number of typographical errors that are not present in the original table published by Hantush [Hantush, M.S., 1956. Analysis of data from pumping tests in leaky aquifers. Transactions, American Geophysical Union 37, 702-714]. Finally, we offer a very fast approximation with a maximum relative error of 0.0033 for the parameter range in the table given by Bear.

  20. Functional Performance of Pyrovalves

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.

    1996-01-01

    Following several flight and ground test failures of spacecraft systems using single-shot, 'normally closed' pyrotechnically actuated valves (pyrovalves), a government/industry cooperative program was initiated to assess the functional performance of five qualified designs. The goal of the program was to improve performance-based requirements for the procurement of pyrovalves. Specific objectives included the demonstration of performance test methods, the measurement of 'blowby' (the passage of gases from the pyrotechnic energy source around the activating piston into the valve's fluid path), and the quantification of functional margins for each design. Experiments were conducted in-house at NASA on several units each of the five valve designs. The test methods used for this program measured the forces and energies required to actuate the valves, as well as the energies and the pressures (where possible) delivered by the pyrotechnic sources. Functional performance ranged widely among the designs. Blowby cannot be prevented by o-ring seals; metal-to-metal seals were effective. Functional margin was determined by dividing the energy delivered by the pyrotechnic sources in excess to that required to accomplish the function by the energy required for that function. All but two designs had adequate functional margins with the pyrotechnic cartridges evaluated.

  1. Approximation by hinge functions

    SciTech Connect

    Faber, V.

    1997-05-01

    Breiman has defined {open_quotes}hinge functions{close_quotes} for use as basis functions in least squares approximations to data. A hinge function is the max (or min) function of two linear functions. In this paper, the author assumes the existence of smooth function f(x) and a set of samples of the form (x, f(x)) drawn from a probability distribution {rho}(x). The author hopes to find the best fitting hinge function h(x) in the least squares sense. There are two problems with this plan. First, Breiman has suggested an algorithm to perform this fit. The author shows that this algorithm is not robust and also shows how to create examples on which the algorithm diverges. Second, if the author tries to use the data to minimize the fit in the usual discrete least squares sense, the functional that must be minimized is continuous in the variables, but has a derivative which jumps at the data. This paper takes a different approach. This approach is an example of a method that the author has developed called {open_quotes}Monte Carlo Regression{close_quotes}. (A paper on the general theory is in preparation.) The author shall show that since the function f is continuous, the analytic form of the least squares equation is continuously differentiable. A local minimum is solved for by using Newton`s method, where the entries of the Hessian are estimated directly from the data by Monte Carlo. The algorithm has the desirable properties that it is quadratically convergent from any starting guess sufficiently close to a solution and that each iteration requires only a linear system solve.

  2. Special Issue: "Functional Dendrimers".

    PubMed

    Tomalia, Donald A

    2016-01-01

    This special issue entitled "Functional Dendrimers" focuses on the manipulation of at least six "critical nanoscale design parameters" (CNDPs) of dendrimers including: size, shape, surface chemistry, flexibility/rigidity, architecture and elemental composition. These CNDPs collectively define properties of all "functional dendrimers". This special issue contains many interesting examples describing the manipulation of certain dendrimer CNDPs to create new emerging properties and, in some cases, predictive nanoperiodic property patterns (i.e., dendritic effects). The systematic engineering of CNDPs provides a valuable strategy for optimizing functional dendrimer properties for use in specific applications. PMID:27517890

  3. Neuronal Functions of ESCRTs

    PubMed Central

    Gao, Fen-Biao

    2012-01-01

    The endosomal sorting complexes required for transport (ESCRTs) regulate protein trafficking from endosomes to lysosomes. Recent studies have shown that ESCRTs are involved in various cellular processes, including membrane scission, microRNA function, viral budding, and the autophagy pathway in many tissues, including the nervous system. Indeed, dysfunctional ESCRTs are associated with neurodegeneration. However, it remains largely elusive how ESCRTs act in post-mitotic neurons, a highly specialized cell type that requires dynamic changes in neuronal structures and signaling for proper function. This review focuses on our current understandings of the functions of ESCRTs in neuronal morphology, synaptic plasticity, and neurodegenerative diseases. PMID:22438674

  4. Thyroid function and obesity.

    PubMed

    Longhi, Silvia; Radetti, Giorgio

    2013-01-01

    Nowadays, childhood obesity is one of the biggest health emergencies in the developed countries. Obesity leads to multiple metabolic alterations which increase the risk of developing diabetes and cardiovascular diseases. Thyroid function has been often described as altered in obese children, however, it is not clear whether the altered thyroid function is the cause or the consequence of fat excess. On the other hand, thyroid structure seems also to be affected. Nevertheless, both functional and structural alterations seem to improve after weight loss and therefore no treatment is needed. PMID:23149391

  5. Parametric Hazard Function Estimation.

    Energy Science and Technology Software Center (ESTSC)

    1999-09-13

    Version 00 Phaze performs statistical inference calculations on a hazard function (also called a failure rate or intensity function) based on reported failure times of components that are repaired and restored to service. Three parametric models are allowed: the exponential, linear, and Weibull hazard models. The inference includes estimation (maximum likelihood estimators and confidence regions) of the parameters and of the hazard function itself, testing of hypotheses such as increasing failure rate, and checking ofmore » the model assumptions.« less

  6. Functionalized expanded porphyrins

    DOEpatents

    Sessler, Jonathan L; Pantos, Patricia J

    2013-11-12

    Disclosed are functionalized expanded porphyrins that can be used as spectrometric sensors for high-valent actinide cations. The disclosed functionalized expanded porphyrins have the advantage over unfunctionalized systems in that they can be immobilized via covalent attachment to a solid support comprising an inorganic or organic polymer or other common substrates. Substrates comprising the disclosed functionalized expanded porphyrins are also disclosed. Further, disclosed are methods of making the disclosed compounds (immobilized and free), methods of using them as sensors to detect high valent actinides, devices that comprise the disclosed compounds, and kits.

  7. A universal functional object

    NASA Technical Reports Server (NTRS)

    Roth, J. P.

    1972-01-01

    A scheme is presented for realizing any function, combinational or sequential, in a single universal function scheme, termed the universal function object UF. This scheme is addressed to the problem of the proliferation of the number of parts (cards, chips) necessary for conventional implementation in an LSI technology of a computer system. The UF implementation will use about ten times more circuits than a conventional implementation regardless of the size of the design. The UF approach also includes general-purpose spares for failing circuits. The procedure could be used both at manufacture to increase yields, as well as to achieve automatic repair.

  8. On bissubmodular functions

    SciTech Connect

    Fujishige, S.; Ando, K.; Naitoh, T.

    1994-12-31

    We consider the so-called bisubmodular functions, i.e., a kind of submodular functions, on 3{sup E} for a finite set E. The bisubmodular polyhedron associated with a bisubmodular function is defined. We reveal structural properties of bisubmodular polyhedra, especially characterizations of extreme points, adjacency, faces, dimensions, connected components etc. in terms of signed poset and exchangeability (bidirected) graph. We also show a min-max theorem on the bisubmodular polyhedron, which can be applied to a separable convex optimization problem over a bisubmodular polyhedron.

  9. Restoration of Shoulder Function.

    PubMed

    Boe, Chelsea C; Elhassan, Bassem T

    2016-08-01

    Restoration of shoulder function in patients with brachial plexus injury can be challenging. Initial reported efforts were focused on stabilizing the shoulder, improving inferior subluxation and restoring abduction and flexion of the joint. Recent advancements and improved understanding of coordinated shoulder motion and the biomechanical properties of the muscles around the shoulder applicable to tendon transfer have expanded available surgical options to improve shoulder function, specifically external rotation. Despite the advances in reconstructive options, brachial plexus injury remains a serious problem that requires complex surgical solutions, prolonged recovery, and acceptance of functional loss. PMID:27387074

  10. Reasoning about Function Objects

    NASA Astrophysics Data System (ADS)

    Nordio, Martin; Calcagno, Cristiano; Meyer, Bertrand; Müller, Peter; Tschannen, Julian

    Modern object-oriented languages support higher-order implementations through function objects such as delegates in C#, agents in Eiffel, or closures in Scala. Function objects bring a new level of abstraction to the object-oriented programming model, and require a comparable extension to specification and verification techniques. We introduce a verification methodology that extends function objects with auxiliary side-effect free (pure) methods to model logical artifacts: preconditions, postconditions and modifies clauses. These pure methods can be used to specify client code abstractly, that is, independently from specific instantiations of the function objects. To demonstrate the feasibility of our approach, we have implemented an automatic prover, which verifies several non-trivial examples.

  11. Normal Functioning Family

    MedlinePlus

    ... Spread the Word Shop AAP Find a Pediatrician Family Life Medical Home Family Dynamics Adoption & Foster Care ... Español Text Size Email Print Share Normal Functioning Family Page Content Article Body Is there any way ...

  12. Muscle function loss

    MedlinePlus

    ... nervous system that cause muscle function loss include: Amyotrophic lateral sclerosis (ALS, or Lou Gehrig's disease) Bell's palsy Botulism ... of recent progress. Curr Opin Rheum Read More Amyotrophic lateral sclerosis Botulism Broken bone Guillain-Barré syndrome Muscle cramps ...

  13. Bioprinting: Functional droplet networks

    NASA Astrophysics Data System (ADS)

    Durmus, Naside Gozde; Tasoglu, Savas; Demirci, Utkan

    2013-06-01

    Tissue-mimicking printed networks of droplets separated by lipid bilayers that can be functionalized with membrane proteins are able to spontaneously fold and transmit electrical currents along predefined paths.

  14. The Chandrasekhar function revisited

    NASA Astrophysics Data System (ADS)

    Jablonski, A.

    2015-11-01

    The need for an accurate (better than 10 significant digits) and fast algorithm for calculating the Chandrasekhar function, H(μ , ω) , has stimulated the present analysis of different solutions of the relevant integral equation. It has been found that a very accurate analytical solution can be derived that is conveniently used in the range of small arguments, μ and ω. In a limited range of arguments, the H function can be expressed in terms of a rapidly converging series of Bernoulli constants. For example, the H function for μ = 1 and ω = 1 was readily calculated with an accuracy of 31 digits. A new algorithm, derived from an integral representation, is proposed for efficient calculations. Together with an algorithm published by Stibbs and Weir (1959), this algorithm was used in calculations of extensive tables of the H function with an accuracy of 21 significant digits. Based on the above analysis, a mixed algorithm optimized with respect to the execution time was designed.

  15. The Neutron Structure Function

    NASA Astrophysics Data System (ADS)

    Holt, Roy

    2013-10-01

    Knowledge of the neutron structure function is important for testing models of the nucleon, for a complete understanding of deep inelastic scattering (DIS) from nuclei, and for high energy experiments. As there exist no free neutron targets, neutron structure functions have been determined from deep inelastic scattering from the deuteron. Unfortunately, the short-range part of the deuteron wave function becomes important in extracting the neutron structure function at very high Bjorken x. New methods have been devised for Jefferson Lab experiments to mitigate this problem. The BONUS experiment involves tagging spectator neutrons in the deuteron, while the MARATHON experiment minimizes nuclear structure effects by a comparison of DIS from 3H and 3He. A summary of the status and future plans will be presented. This work supported by the U. S. Department of Energy, Office of Nuclear Physics, under contract DE-AC02-06CH11357.

  16. Functional Task Test: Data Review

    NASA Technical Reports Server (NTRS)

    Cromwell, Ronita

    2014-01-01

    After space flight there are changes in multiple physiological systems including: Cardiovascular function; Sensorimotor function; and Muscle function. How do changes in these physiological system impact astronaut functional performance?

  17. Polarized Antenna Splitting Functions

    SciTech Connect

    Larkoski, Andrew J.; Peskin, Michael E.; /SLAC

    2009-10-17

    We consider parton showers based on radiation from QCD dipoles or 'antennae'. These showers are built from 2 {yields} 3 parton splitting processes. The question then arises of what functions replace the Altarelli-Parisi splitting functions in this approach. We give a detailed answer to this question, applicable to antenna showers in which partons carry definite helicity, and to both initial- and final-state emissions.

  18. Center for Functional Nanomaterials

    SciTech Connect

    BNL

    2008-08-12

    Staff from Brookhaven's new Center for Functional Nanomaterials (CFN) describe how this advanced facility will focus on the development and understanding of nanoscale materials. The CFN provides state-of-the-art capabilities for the fabrication and study of nanoscale materials, with an emphasis on atomic-level tailoring to achieve desired properties and functions. The overarching scientific theme of the CFN is the development and understanding of nanoscale materials that address the Nation's challenges in energy security.

  19. A Function Machine

    ERIC Educational Resources Information Center

    Hewitt, Dave

    2008-01-01

    In this article, the author describes a lesson he observed involving a function machine. This function machine was a box with a slot at the top of one side and a large cut-out hole at the bottom of the opposite side. A card with a number written on it (the input) was pushed into the slot and the teacher put their hand through the hole of the other…

  20. Functional Molecular Ecological Networks

    PubMed Central

    Zhou, Jizhong; Deng, Ye; Luo, Feng; He, Zhili; Tu, Qichao; Zhi, Xiaoyang

    2010-01-01

    Biodiversity and its responses to environmental changes are central issues in ecology and for society. Almost all microbial biodiversity research focuses on “species” richness and abundance but not on their interactions. Although a network approach is powerful in describing ecological interactions among species, defining the network structure in a microbial community is a great challenge. Also, although the stimulating effects of elevated CO2 (eCO2) on plant growth and primary productivity are well established, its influences on belowground microbial communities, especially microbial interactions, are poorly understood. Here, a random matrix theory (RMT)-based conceptual framework for identifying functional molecular ecological networks was developed with the high-throughput functional gene array hybridization data of soil microbial communities in a long-term grassland FACE (free air, CO2 enrichment) experiment. Our results indicate that RMT is powerful in identifying functional molecular ecological networks in microbial communities. Both functional molecular ecological networks under eCO2 and ambient CO2 (aCO2) possessed the general characteristics of complex systems such as scale free, small world, modular, and hierarchical. However, the topological structures of the functional molecular ecological networks are distinctly different between eCO2 and aCO2, at the levels of the entire communities, individual functional gene categories/groups, and functional genes/sequences, suggesting that eCO2 dramatically altered the network interactions among different microbial functional genes/populations. Such a shift in network structure is also significantly correlated with soil geochemical variables. In short, elucidating network interactions in microbial communities and their responses to environmental changes is fundamentally important for research in microbial ecology, systems microbiology, and global change. PMID:20941329

  1. Adaptive transfer functions

    SciTech Connect

    Goulding, J.R. )

    1991-01-01

    This paper details the approach and methodology used to build adaptive transfer functions in a feed-forward Back-Propagation neural network, and provides insight into the structure dependent properties of using non-scaled analog inputs. The results of using adaptive transfer functions are shown to outperform conventional architectures in the implementation of a mechanical power transmission gearbox design expert system knowledge base. 4 refs., 4 figs., 1 tab.

  2. Functional molecular ecological networks.

    PubMed

    Zhou, Jizhong; Deng, Ye; Luo, Feng; He, Zhili; Tu, Qichao; Zhi, Xiaoyang

    2010-01-01

    Biodiversity and its responses to environmental changes are central issues in ecology and for society. Almost all microbial biodiversity research focuses on "species" richness and abundance but not on their interactions. Although a network approach is powerful in describing ecological interactions among species, defining the network structure in a microbial community is a great challenge. Also, although the stimulating effects of elevated CO(2) (eCO(2)) on plant growth and primary productivity are well established, its influences on belowground microbial communities, especially microbial interactions, are poorly understood. Here, a random matrix theory (RMT)-based conceptual framework for identifying functional molecular ecological networks was developed with the high-throughput functional gene array hybridization data of soil microbial communities in a long-term grassland FACE (free air, CO(2) enrichment) experiment. Our results indicate that RMT is powerful in identifying functional molecular ecological networks in microbial communities. Both functional molecular ecological networks under eCO(2) and ambient CO(2) (aCO(2)) possessed the general characteristics of complex systems such as scale free, small world, modular, and hierarchical. However, the topological structures of the functional molecular ecological networks are distinctly different between eCO(2) and aCO(2), at the levels of the entire communities, individual functional gene categories/groups, and functional genes/sequences, suggesting that eCO(2) dramatically altered the network interactions among different microbial functional genes/populations. Such a shift in network structure is also significantly correlated with soil geochemical variables. In short, elucidating network interactions in microbial communities and their responses to environmental changes is fundamentally important for research in microbial ecology, systems microbiology, and global change. PMID:20941329

  3. Structure function monitor

    SciTech Connect

    McGraw, John T.; Zimmer, Peter C.; Ackermann, Mark R.

    2012-01-24

    Methods and apparatus for a structure function monitor provide for generation of parameters characterizing a refractive medium. In an embodiment, a structure function monitor acquires images of a pupil plane and an image plane and, from these images, retrieves the phase over an aperture, unwraps the retrieved phase, and analyzes the unwrapped retrieved phase. In an embodiment, analysis yields atmospheric parameters measured at spatial scales from zero to the diameter of a telescope used to collect light from a source.

  4. Center for Functional Nanomaterials

    ScienceCinema

    BNL

    2009-09-01

    Staff from Brookhaven's new Center for Functional Nanomaterials (CFN) describe how this advanced facility will focus on the development and understanding of nanoscale materials. The CFN provides state-of-the-art capabilities for the fabrication and study of nanoscale materials, with an emphasis on atomic-level tailoring to achieve desired properties and functions. The overarching scientific theme of the CFN is the development and understanding of nanoscale materials that address the Nation's challenges in energy security.

  5. Functional neuroimaging in psychiatry.

    PubMed Central

    Fu, C H; McGuire, P K

    1999-01-01

    Functional neuroimaging is one of the most powerful means available for investigating the pathophysiology of psychiatric disorders. In this review, we shall focus on the different ways that it can be employed to this end, describing the major findings in the field in the context of different methodological approaches. We will also discuss practical issues that are particular to studying psychiatric disorders and the potential contribution of functional neuroimaging to future psychiatric research. PMID:10466156

  6. Function transformation without reinforcement.

    PubMed

    Tonneau, Franćois; Arreola, Fara; Martínez, Alma Gabriela

    2006-05-01

    In studies of function transformation, participants initially are taught to match stimuli in the presence of a contextual cue, X; the stimuli to be matched bear some formal relation to each other, for example, a relation of opposition or difference. In a second phase, the participants are taught to match arbitrary stimuli (say, A and B) in the presence of X. In a final test, A often displays behavioral functions that differ from those of B, and can be predicted from the nature of the relation associated with X in the initial training phase. Here we report function-transformation effects in the absence of selection responses and of their reinforcers. In three experiments with college students, exposure to relations of difference or identity modified the responses given to later stimuli. In Experiment 1, responses to a test stimulus A varied depending on preexposure to pairs of colors that were distinct from A but exemplified relations of difference or identity. In Experiment 2, a stimulus A acquired distinct functions, depending on its previous pairing with a contextual cue X that had itself been paired with identity or difference among colors. Experiment 3 confirmed the results of Experiment 2 with a modified design. Our data are consistent with the notion that relations of identity or difference can serve as stimuli for Pavlovian processes, and, in compound with other cues, produce apparent function-transformation effects. PMID:16776058

  7. Function Transformation without Reinforcement

    PubMed Central

    Tonneau, François; Arreola, Fara; Martínez, Alma Gabriela

    2006-01-01

    In studies of function transformation, participants initially are taught to match stimuli in the presence of a contextual cue, X; the stimuli to be matched bear some formal relation to each other, for example, a relation of opposition or difference. In a second phase, the participants are taught to match arbitrary stimuli (say, A and B) in the presence of X. In a final test, A often displays behavioral functions that differ from those of B, and can be predicted from the nature of the relation associated with X in the initial training phase. Here we report function-transformation effects in the absence of selection responses and of their reinforcers. In three experiments with college students, exposure to relations of difference or identity modified the responses given to later stimuli. In Experiment 1, responses to a test stimulus A varied depending on preexposure to pairs of colors that were distinct from A but exemplified relations of difference or identity. In Experiment 2, a stimulus A acquired distinct functions, depending on its previous pairing with a contextual cue X that had itself been paired with identity or difference among colors. Experiment 3 confirmed the results of Experiment 2 with a modified design. Our data are consistent with the notion that relations of identity or difference can serve as stimuli for Pavlovian processes, and, in compound with other cues, produce apparent function-transformation effects. PMID:16776058

  8. CAVEOLINS AND LUNG FUNCTION

    PubMed Central

    Maniatis, Nikolaos A.; Chernaya, Olga; Shinin, Vasily; Minshall, Richard D.

    2012-01-01

    The primary function of the mammalian lung is to facilitate diffusion of oxygen to venous blood and to ventilate carbon dioxide produced by catabolic reactions within cells. However, it is also responsible for a variety of other important functions, including host defense and production of vasoactive agents to regulate not only systemic blood pressure, but also water, electrolyte and acid-base balance. Caveolin-1 is highly expressed in the majority of cell types in the lung, including epithelial, endothelial, smooth muscle, connective tissue cells, and alveolar macrophages. Deletion of caveolin-1 in these cells results in major functional aberrations, suggesting that caveolin-1 may be crucial to lung homeostasis and development. Furthermore, generation of mutant mice that under-express caveolin-1 results in severe functional distortion with phenotypes covering practically the entire spectrum of known lung diseases, including pulmonary hypertension, fibrosis, increased endothelial permeability, and immune defects. In this Chapter, we outline the current state of knowledge regarding caveolin-1-dependent regulation of pulmonary cell functions and discuss recent research findings on the role of caveolin-1 in various pulmonary disease states, including obstructive and fibrotic pulmonary vascular and inflammatory diseases. PMID:22411320

  9. Functional imaging and endoscopy

    PubMed Central

    Zhang, Jian-Guo; Liu, Hai-Feng

    2011-01-01

    The emergence of endoscopy for the diagnosis of gastrointestinal diseases and the treatment of gastrointestinal diseases has brought great changes. The mere observation of anatomy with the imaging mode using modern endoscopy has played a significant role in this regard. However, increasing numbers of endoscopies have exposed additional deficiencies and defects such as anatomically similar diseases. Endoscopy can be used to examine lesions that are difficult to identify and diagnose. Early disease detection requires that substantive changes in biological function should be observed, but in the absence of marked morphological changes, endoscopic detection and diagnosis are difficult. Disease detection requires not only anatomic but also functional imaging to achieve a comprehensive interpretation and understanding. Therefore, we must ask if endoscopic examination can be integrated with both anatomic imaging and functional imaging. In recent years, as molecular biology and medical imaging technology have further developed, more functional imaging methods have emerged. This paper is a review of the literature related to endoscopic optical imaging methods in the hopes of initiating integration of functional imaging and anatomical imaging to yield a new and more effective type of endoscopy. PMID:22090783

  10. Space race functional responses.

    PubMed

    Sjödin, Henrik; Brännström, Åke; Englund, Göran

    2015-02-22

    We derive functional responses under the assumption that predators and prey are engaged in a space race in which prey avoid patches with many predators and predators avoid patches with few or no prey. The resulting functional response models have a simple structure and include functions describing how the emigration of prey and predators depend on interspecific densities. As such, they provide a link between dispersal behaviours and community dynamics. The derived functional response is general but is here modelled in accordance with empirically documented emigration responses. We find that the prey emigration response to predators has stabilizing effects similar to that of the DeAngelis-Beddington functional response, and that the predator emigration response to prey has destabilizing effects similar to that of the Holling type II response. A stability criterion describing the net effect of the two emigration responses on a Lotka-Volterra predator-prey system is presented. The winner of the space race (i.e. whether predators or prey are favoured) is determined by the relationship between the slopes of the species' emigration responses. It is predicted that predators win the space race in poor habitats, where predator and prey densities are low, and that prey are more successful in richer habitats. PMID:25589602

  11. Sperm function test

    PubMed Central

    Talwar, Pankaj; Hayatnagarkar, Suryakant

    2015-01-01

    With absolute normal semen analysis parameters it may not be necessary to shift to specialized tests early but in cases with borderline parameters or with history of fertilization failure in past it becomes necessary to do a battery of tests to evaluate different parameters of spermatozoa. Various sperm function tests are proposed and endorsed by different researchers in addition to the routine evaluation of fertility. These tests detect function of a certain part of spermatozoon and give insight on the events in fertilization of the oocyte. The sperms need to get nutrition from the seminal plasma in the form of fructose and citrate (this can be assessed by fructose qualitative and quantitative estimation, citrate estimation). They should be protected from the bad effects of pus cells and reactive oxygen species (ROS) (leukocyte detection test, ROS estimation). Their number should be in sufficient in terms of (count), structure normal to be able to fertilize eggs (semen morphology). Sperms should have intact and functioning membrane to survive harsh environment of vagina and uterine fluids (vitality and hypo-osmotic swelling test), should have good mitochondrial function to be able to provide energy (mitochondrial activity index test). They should also have satisfactory acrosome function to be able to burrow a hole in zona pellucida (acrosome intactness test, zona penetration test). Finally, they should have properly packed DNA in the nucleus to be able to transfer the male genes (nuclear chromatic decondensation test) to the oocyte during fertilization. PMID:26157295

  12. Caveolins and lung function.

    PubMed

    Maniatis, Nikolaos A; Chernaya, Olga; Shinin, Vasily; Minshall, Richard D

    2012-01-01

    The primary function of the mammalian lung is to facilitate diffusion of oxygen to venous blood and to ventilate carbon dioxide produced by catabolic reactions within cells. However, it is also responsible for a variety of other important functions, including host defense and production of vasoactive agents to regulate not only systemic blood pressure, but also water, electrolyte and acid-base balance. Caveolin-1 is highly expressed in the majority of cell types in the lung, including epithelial, endothelial, smooth muscle, connective tissue cells, and alveolar macrophages. Deletion of caveolin-1 in these cells results in major functional aberrations, suggesting that caveolin-1 may be crucial to lung homeostasis and development. Furthermore, generation of mutant mice that under-express caveolin-1 results in severe functional distortion with phenotypes covering practically the entire spectrum of known lung diseases, including pulmonary hypertension, fibrosis, increased endothelial permeability, and immune defects. In this Chapter, we outline the current state of knowledge regarding caveolin-1-dependent regulation of pulmonary cell functions and discuss recent research findings on the role of caveolin-1 in various pulmonary disease states, including obstructive and fibrotic pulmonary vascular and inflammatory diseases. PMID:22411320

  13. Space race functional responses

    PubMed Central

    Sjödin, Henrik; Brännström, Åke; Englund, Göran

    2015-01-01

    We derive functional responses under the assumption that predators and prey are engaged in a space race in which prey avoid patches with many predators and predators avoid patches with few or no prey. The resulting functional response models have a simple structure and include functions describing how the emigration of prey and predators depend on interspecific densities. As such, they provide a link between dispersal behaviours and community dynamics. The derived functional response is general but is here modelled in accordance with empirically documented emigration responses. We find that the prey emigration response to predators has stabilizing effects similar to that of the DeAngelis–Beddington functional response, and that the predator emigration response to prey has destabilizing effects similar to that of the Holling type II response. A stability criterion describing the net effect of the two emigration responses on a Lotka–Volterra predator–prey system is presented. The winner of the space race (i.e. whether predators or prey are favoured) is determined by the relationship between the slopes of the species' emigration responses. It is predicted that predators win the space race in poor habitats, where predator and prey densities are low, and that prey are more successful in richer habitats. PMID:25589602

  14. Sperm function test.

    PubMed

    Talwar, Pankaj; Hayatnagarkar, Suryakant

    2015-01-01

    With absolute normal semen analysis parameters it may not be necessary to shift to specialized tests early but in cases with borderline parameters or with history of fertilization failure in past it becomes necessary to do a battery of tests to evaluate different parameters of spermatozoa. Various sperm function tests are proposed and endorsed by different researchers in addition to the routine evaluation of fertility. These tests detect function of a certain part of spermatozoon and give insight on the events in fertilization of the oocyte. The sperms need to get nutrition from the seminal plasma in the form of fructose and citrate (this can be assessed by fructose qualitative and quantitative estimation, citrate estimation). They should be protected from the bad effects of pus cells and reactive oxygen species (ROS) (leukocyte detection test, ROS estimation). Their number should be in sufficient in terms of (count), structure normal to be able to fertilize eggs (semen morphology). Sperms should have intact and functioning membrane to survive harsh environment of vagina and uterine fluids (vitality and hypo-osmotic swelling test), should have good mitochondrial function to be able to provide energy (mitochondrial activity index test). They should also have satisfactory acrosome function to be able to burrow a hole in zona pellucida (acrosome intactness test, zona penetration test). Finally, they should have properly packed DNA in the nucleus to be able to transfer the male genes (nuclear chromatic decondensation test) to the oocyte during fertilization. PMID:26157295

  15. Effect of functional overreaching on executive functions.

    PubMed

    Dupuy, O; Renaud, M; Bherer, L; Bosquet, L

    2010-09-01

    The aim of this study was to investigate whether cognitive performance was a valid marker of overreaching. 10 well-trained male endurance athletes increased their training load by 100% for 2 weeks. They performed a maximal graded test, a constant speed test, a reaction time task and a computerized version of the Stroop color word-test before and after this overload period. Regarding performance results, five participants were considered as overreached and the five remaining were considered as well-trained. We found no significant differences between groups in performing the Stroop test. Noteworthy, we found a small increase in response time in the more complex condition in overreached athletes (1 188+/-261 to 1 297+/-231 ms, effect size=0.44), while it decreased moderately in the well-trained athletes (1 066+/-175 to 963+/-171 ms, effect size=-0.59). Furthermore, we found an interaction between time and group on initiation time of the reaction time task, since it increased in overreached athletes after the overload period (246+/-24 to 264+/-26 ms, p<0.05), while it remained unchanged in well-trained participants. Participants made very few anticipation errors, whatever the group or the period (error rate <2%).We concluded that an unaccustomed increase in training volume which is accompanied by a decrement in physical performance induces a deterioration of some executive functions. PMID:20544582

  16. Tendon Functional Extracellular Matrix

    PubMed Central

    Screen, H.R.C.; Birk, D.E.; Kadler, K.E.; Ramirez, F; Young, M.F.

    2015-01-01

    This article is one of a series, summarising views expressed at the Orthopaedic Research Society New Frontiers in Tendon Research Conference. This particular article reviews the three workshops held under the “Functional Extracellular Matrix” stream. The workshops focused on the roles of the tendon extracellular matrix, such as performing the mechanical functions of tendon, creating the local cell environment and providing cellular cues. Tendon is a complex network of matrix and cells, and its biological functions are influenced by widely-varying extrinsic and intrinsic factors such as age, nutrition, exercise levels and biomechanics. Consequently, tendon adapts dynamically during development, ageing and injury. The workshop discussions identified research directions associated with understanding cell-matrix interactions to be of prime importance for developing novel strategies to target tendon healing or repair. PMID:25640030

  17. SCARF SOCIAL FUNCTIONING INDEX

    PubMed Central

    Padmavathi, R.; Thara, R.; Srinivasan, Latha; Kumar, Shuba

    1995-01-01

    Several instruments measuring social functioning have been developed in the last four decades, as a result of the increasing interest in community care of the chronic mentally ill. SCARF Social Functioning Index (SSFI) was developed to meet the pressing need for an instrument which was easy to administer and which could be used by all mental health professionals. The SSFI comprises four main sections: self concern, occupational role, role in the family and other social roles. Each section has several subsections covering different areas of social functioning. Validity and reliability have been established for a group of normals, patients suffering from schizophrenia and from Hansen's disease. Internal consistencies of these factors were high Factor analysis derived four main factors, which included nearly all items of the SSFI. This paper reports on the development and standardization of the instrument. PMID:21743742

  18. Diaphragmatic function during immersion.

    PubMed

    Minh, V D; Dolan, G F; Linaweaver, P G; Friedman, P J; Konopka, R G; Brach, B B

    1977-08-01

    Diaphragmatic function during immersion to midneck level was studied in upright mongrel dogs, using constant electrophrenic stimulation. Effectiveness of diaphragmatic contraction was analyzed in terms of inspired volume (VT) (with airways open), and change in intrathoracic pressure (Pmus) (with the respiratory system occluded). Hydrostatic compression of the immersed body decreased functional residual capacity (FRC) to 55% base-line value (FRCO), resulting in a 2.8-fold increase in Pmus. In spite of this Pmus increase, VT often decreased during immersion, averaging only 83% VTO (base-line value in air). Hence, immersion was associated with a marked stiffening of the respiratory system. The Pmus increase during immersion persisted after restoration of FRC to FRCO, and was related to diaphragmatic length being greater in water than in air under condition of iso-lung volume. In all, there were three factors affecting diaphragmatic function during immersion: FRC reduction, change in thoracic configuration, and stiffening of the respiratory system. PMID:893286

  19. Fun with Type Functions

    NASA Astrophysics Data System (ADS)

    Kiselyov, Oleg; Jones, Simon Peyton; Shan, Chung-Chieh

    Tony Hoare has always been a leader in writing down and proving properties of programs. To prove properties of programs automatically, the most widely used technology today is the ubiquitous type checker. Alas, static type systems inevitably exclude some good programs and allow some bad ones. Thus motivated, we describe some fun we have been having with Haskell, by making the type system more expressive without losing the benefits of automatic proof and compact expression. Specifically, we offer a programmer's tour of so-calledtype families, a recent extension to Haskell that allows functions on types to be expressed as straightforwardly as functions on values. This facility makes it easier for programmers to effectively extend the compiler by writing functional programs that execute during type checking. Source code for all the examples is available at http://research.microsoft.com/simonpj/papers/assoc-types/fun-with-type-funs.zip.

  20. Algal functional annotation tool

    SciTech Connect

    Lopez, D.; Casero, D.; Cokus, S. J.; Merchant, S. S.; Pellegrini, M.

    2012-07-01

    The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on KEGG pathway maps and batch gene identifier conversion.

  1. Adaptive multiconfigurational wave functions

    SciTech Connect

    Evangelista, Francesco A.

    2014-03-28

    A method is suggested to build simple multiconfigurational wave functions specified uniquely by an energy cutoff Λ. These are constructed from a model space containing determinants with energy relative to that of the most stable determinant no greater than Λ. The resulting Λ-CI wave function is adaptive, being able to represent both single-reference and multireference electronic states. We also consider a more compact wave function parameterization (Λ+SD-CI), which is based on a small Λ-CI reference and adds a selection of all the singly and doubly excited determinants generated from it. We report two heuristic algorithms to build Λ-CI wave functions. The first is based on an approximate prescreening of the full configuration interaction space, while the second performs a breadth-first search coupled with pruning. The Λ-CI and Λ+SD-CI approaches are used to compute the dissociation curve of N{sub 2} and the potential energy curves for the first three singlet states of C{sub 2}. Special attention is paid to the issue of energy discontinuities caused by changes in the size of the Λ-CI wave function along the potential energy curve. This problem is shown to be solvable by smoothing the matrix elements of the Hamiltonian. Our last example, involving the Cu{sub 2}O{sub 2}{sup 2+} core, illustrates an alternative use of the Λ-CI method: as a tool to both estimate the multireference character of a wave function and to create a compact model space to be used in subsequent high-level multireference coupled cluster computations.

  2. Apical Functionalization of Tribenzotriquinacenes.

    PubMed

    Dhara, Ayan; Weinmann, Joshua; Krause, Ana-Maria; Beuerle, Florian

    2016-08-22

    The introduction of one alkyne moiety at the central carbon atom of the tripodal tribenzotriquinacene scaffold allows easy access to a great variety of apically functionalized derivatives. The spatially well-separated arrangement of different functional units on the convex face and outer rim was further proven by single-crystal X-ray studies. Subsequent modifications that feature a general protecting group-free strategy for the demethylation of protected catechols in the presence of a terminal alkyne group, an azide-alkyne Huisgen cycloaddition, and Sonogashira cross-coupling reactions showcase the high synthetic potential of this modular approach for tribenzotriquinacene derivatization. PMID:27444414

  3. Peroxisome Biogenesis and Function

    PubMed Central

    Kaur, Navneet; Reumann, Sigrun; Hu, Jianping

    2009-01-01

    Peroxisomes are small and single membrane-delimited organelles that execute numerous metabolic reactions and have pivotal roles in plant growth and development. In recent years, forward and reverse genetic studies along with biochemical and cell biological analyses in Arabidopsis have enabled researchers to identify many peroxisome proteins and elucidate their functions. This review focuses on the advances in our understanding of peroxisome biogenesis and metabolism, and further explores the contribution of large-scale analysis, such as in sillco predictions and proteomics, in augmenting our knowledge of peroxisome function In Arabidopsis. PMID:22303249

  4. Functional Hybrid Materials

    NASA Astrophysics Data System (ADS)

    Gómez-Romero, Pedro; Sanchez, Clément

    2004-04-01

    Functional Hybrid Materials consist of both organic and inorganic components, assembled for the purpose of generating desirable properties and functionalities. The aim is twofold: to bring out or enhance advantageous chemical, electrochemical, magnetic or electronic characteristics and at the same time to reduce or wholly suppress undesirable properties or effects. Another target is the creation of entirely new material behavior. The vast number of hybrid material components available has opened up a wide and diversified field of fascinating research. In this book, a team of highly renowned experts gives an in-depth overview, illustrating the superiority of well-designed hybrid materials and their potential applications.

  5. Algal functional annotation tool

    Energy Science and Technology Software Center (ESTSC)

    2012-07-12

    Abstract BACKGROUND: Progress in genome sequencing is proceeding at an exponential pace, and several new algal genomes are becoming available every year. One of the challenges facing the community is the association of protein sequences encoded in the genomes with biological function. While most genome assembly projects generate annotations for predicted protein sequences, they are usually limited and integrate functional terms from a limited number of databases. Another challenge is the use of annotations tomore » interpret large lists of 'interesting' genes generated by genome-scale datasets. Previously, these gene lists had to be analyzed across several independent biological databases, often on a gene-by-gene basis. In contrast, several annotation databases, such as DAVID, integrate data from multiple functional databases and reveal underlying biological themes of large gene lists. While several such databases have been constructed for animals, none is currently available for the study of algae. Due to renewed interest in algae as potential sources of biofuels and the emergence of multiple algal genome sequences, a significant need has arisen for such a database to process the growing compendiums of algal genomic data. DESCRIPTION: The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on

  6. Neurally augmented sexual function.

    PubMed

    Meloy, S

    2007-01-01

    Neurally Augmented Sexual Function (NASF) is a technique utilizing epidural electrodes to restore and improve sexual function. Orgasmic dysfunction is common in adult women, affecting roughly one quarter of populations studied. Many male patients suffering from erectile dysfunction are not candidates for phosphdiesterase therapy due to concomitant nitrate therapy. Positioning the electrodes at roughly the level of the cauda equina allows for stimulation of somatic efferents and afferents as well as modifying sympathetic and parasympathetic activity. Our series of women treated by NASF is described. Our experience shows that the evaluation of potential candidates for both correctable causes and psychological screening are important considerations. PMID:17691397

  7. Adaptive Transfer Function Networks

    SciTech Connect

    Goulding, J.R. |

    1993-06-01

    Real-time pattern classification and time-series forecasting applications continue to drive artificial neural network (ANN) technology. As ANNs increase in complexity, the throughput of digital computer simulations decreases. A novel ANN, the Adaptive Transfer Function Network (ATF-Net), directly addresses the issue of throughput. ATF-Nets are global mapping equations generated by the superposition of ensembles of neurodes having arbitrary continuous functions receiving encoded input data. ATF-Nets may be implemented on parallel digital computers. An example is presented which illustrates a four-fold increase in computational throughput.

  8. Adaptive Transfer Function Networks

    SciTech Connect

    Goulding, J.R. Portland State Univ., OR . Dept. of Electrical Engineering)

    1993-01-01

    Real-time pattern classification and time-series forecasting applications continue to drive artificial neural network (ANN) technology. As ANNs increase in complexity, the throughput of digital computer simulations decreases. A novel ANN, the Adaptive Transfer Function Network (ATF-Net), directly addresses the issue of throughput. ATF-Nets are global mapping equations generated by the superposition of ensembles of neurodes having arbitrary continuous functions receiving encoded input data. ATF-Nets may be implemented on parallel digital computers. An example is presented which illustrates a four-fold increase in computational throughput.

  9. Sexual Function Across Aging.

    PubMed

    Clayton, Anita H; Harsh, Veronica

    2016-03-01

    Women experience multiple changes in social and reproductive statuses across the life span which can affect sexual functioning. Various phases of the sexual response cycle may be impacted and can lead to sexual dysfunction. Screening for sexual problems and consideration of contributing factors such as neurobiology, reproductive life events, medical problems, medication use, and depression can help guide appropriate treatment and thereby improve the sexual functioning and quality of life of affected women. Treatment options include psychotropic medications, hormone therapy, and psychotherapy. PMID:26830886

  10. GADRAS Detector Response Function.

    SciTech Connect

    Mitchell, Dean J.; Harding, Lee; Thoreson, Gregory G; Horne, Steven M.

    2014-11-01

    The Gamma Detector Response and Analysis Software (GADRAS) applies a Detector Response Function (DRF) to compute the output of gamma-ray and neutron detectors when they are exposed to radiation sources. The DRF is fundamental to the ability to perform forward calculations (i.e., computation of the response of a detector to a known source), as well as the ability to analyze spectra to deduce the types and quantities of radioactive material to which the detectors are exposed. This document describes how gamma-ray spectra are computed and the significance of response function parameters that define characteristics of particular detectors.

  11. Functionalization of Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Khare, Bishun N. (Inventor); Meyyappan, Meyya (Inventor)

    2007-01-01

    Method and system for functionalizing a collection of carbon nanotubes (CNTs). A selected precursor gas (e.g., H2, or F2, or CnHm) is irradiated to provide a cold plasma of selected target particles, such as atomic H or F, in a first chamber. The target particles are directed toward an array of CNTs located in a second chamber while suppressing transport of ultraviolet radiation to the second chamber. A CNT array is functionalized with the target particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec.

  12. Functionalization of carbon nanotubes

    NASA Technical Reports Server (NTRS)

    Khare, Bishun N. (Inventor); Meyyappan, Meyya (Inventor)

    2007-01-01

    Method and system for functionalizing a collection of carbon nanotubes (CNTs). A selected precursor gas (e.g., H.sub.2 or F.sub.2 or C.sub.nH.sub.m) is irradiated to provide a cold plasma of selected target particles, such as atomic H or F, in a first chamber. The target particles are directed toward an array of CNTs located in a second chamber while suppressing transport of ultraviolet radiation to the second chamber. A CNT array is functionalized with the target particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec.

  13. Algal functional annotation tool

    SciTech Connect

    2012-07-12

    Abstract BACKGROUND: Progress in genome sequencing is proceeding at an exponential pace, and several new algal genomes are becoming available every year. One of the challenges facing the community is the association of protein sequences encoded in the genomes with biological function. While most genome assembly projects generate annotations for predicted protein sequences, they are usually limited and integrate functional terms from a limited number of databases. Another challenge is the use of annotations to interpret large lists of 'interesting' genes generated by genome-scale datasets. Previously, these gene lists had to be analyzed across several independent biological databases, often on a gene-by-gene basis. In contrast, several annotation databases, such as DAVID, integrate data from multiple functional databases and reveal underlying biological themes of large gene lists. While several such databases have been constructed for animals, none is currently available for the study of algae. Due to renewed interest in algae as potential sources of biofuels and the emergence of multiple algal genome sequences, a significant need has arisen for such a database to process the growing compendiums of algal genomic data. DESCRIPTION: The Algal Functional Annotation Tool is a web-based comprehensive analysis suite integrating annotation data from several pathway, ontology, and protein family databases. The current version provides annotation for the model alga Chlamydomonas reinhardtii, and in the future will include additional genomes. The site allows users to interpret large gene lists by identifying associated functional terms, and their enrichment. Additionally, expression data for several experimental conditions were compiled and analyzed to provide an expression-based enrichment search. A tool to search for functionally-related genes based on gene expression across these conditions is also provided. Other features include dynamic visualization of genes on KEGG

  14. CD8+ T lymphocytes of patients with AIDS maintain normal broad cytolytic function despite the loss of human immunodeficiency virus-specific cytotoxicity.

    PubMed Central

    Pantaleo, G; De Maria, A; Koenig, S; Butini, L; Moss, B; Baseler, M; Lane, H C; Fauci, A S

    1990-01-01

    In this study, we have investigated the potential mechanisms responsible for the loss of human immunodeficiency virus type 1 (HIV-1)-specific cytolytic activity in the advanced stages of HIV-1 infection. We have demonstrated that HIV-1-specific cytotoxic T lymphocytes are predominantly contained within the CD8+DR+ subset. Furthermore, we have shown by a redirected killing assay that there is a dichotomy between HIV-1-specific cytolytic activity and broad cytolytic potential since the cytolytic machinery of CD8+DR+ cells is still functioning even in patients with AIDS who have lost their HIV-1-specific cytolytic activity. In addition, by comparative analysis of these two types of cytolytic activity over time we have demonstrated a progressive loss of HIV-1-specific cytolytic activity in the advanced stages of the disease, whereas the cytolytic potential remained unchanged regardless of the clinical stage. As previously shown in patients with AIDS, even in asymptomatic HIV-1-seropositive patients, CD8+DR+ cells from the same patient, compared to CD8+DR- lymphocytes, showed a substantial reduction in their ability to proliferate in vitro in response to different stimuli, such as mitogens (phytohemagglutinin and phorbol 12-myristate 13-acetate) and monoclonal antibodies directed against CD3, CD2, and CD28 molecules, and displayed a defective clonogenic potential. Thus, on the basis of these results we propose that the loss of HIV-1-specific cytolytic activity in HIV-1-infected individuals may result at least in part from a progressive decrease in the pool of HIV-1-specific cytotoxic T lymphocytes belonging to the CD8+DR+ subset whose ability to expand has been impaired. Images PMID:2112749

  15. Split Brain Functioning.

    ERIC Educational Resources Information Center

    Cassel, Russell N.

    1978-01-01

    Summarizing recent research, this article defines the functions performed by the left and right sides of the human brain. Attention is given to the right side, or the nondominant side, of the brain and its potential in terms of perception of the environment, music, art, geometry, and the aesthetics. (JC)

  16. Empirical microeconomics action functionals

    NASA Astrophysics Data System (ADS)

    Baaquie, Belal E.; Du, Xin; Tanputraman, Winson

    2015-06-01

    A statistical generalization of microeconomics has been made in Baaquie (2013), where the market price of every traded commodity, at each instant of time, is considered to be an independent random variable. The dynamics of commodity market prices is modeled by an action functional-and the focus of this paper is to empirically determine the action functionals for different commodities. The correlation functions of the model are defined using a Feynman path integral. The model is calibrated using the unequal time correlation of the market commodity prices as well as their cubic and quartic moments using a perturbation expansion. The consistency of the perturbation expansion is verified by a numerical evaluation of the path integral. Nine commodities drawn from the energy, metal and grain sectors are studied and their market behavior is described by the model to an accuracy of over 90% using only six parameters. The paper empirically establishes the existence of the action functional for commodity prices that was postulated to exist in Baaquie (2013).

  17. Iridescence: a functional perspective

    PubMed Central

    Doucet, Stéphanie M.; Meadows, Melissa G.

    2009-01-01

    In animals, iridescence is generated by the interaction of light with biological tissues that are nanostructured to produce thin films or diffraction gratings. Uniquely among animal visual signals, the study of iridescent coloration contributes to biological and physical sciences by enhancing our understanding of the evolution of communication strategies, and by providing insights into physical optics and inspiring biomimetic technologies useful to humans. Iridescent colours are found in a broad diversity of animal taxa ranging from diminutive marine copepods to terrestrial insects and birds. Iridescent coloration has received a surge of research interest of late, and studies have focused on both characterizing the nanostructures responsible for producing iridescence and identifying the behavioural functions of iridescent colours. In this paper, we begin with a brief description of colour production mechanisms in animals and provide a general overview of the taxonomic distribution of iridescent colours. We then highlight unique properties of iridescent signals and review the proposed functions of iridescent coloration, focusing, in particular, on the ways in which iridescent colours allow animals to communicate with conspecifics and avoid predators. We conclude with a brief overview of non-communicative functions of iridescence in animals. Despite the vast amount of recent work on animal iridescence, our review reveals that many proposed functions of iridescent coloration remain virtually unexplored, and this area is clearly ripe for future research. PMID:19336344

  18. Functional Group Analysis.

    ERIC Educational Resources Information Center

    Smith, Walter T., Jr.; Patterson, John M.

    1984-01-01

    Literature on analytical methods related to the functional groups of 17 chemical compounds is reviewed. These compounds include acids, acid azides, alcohols, aldehydes, ketones, amino acids, aromatic hydrocarbons, carbodiimides, carbohydrates, ethers, nitro compounds, nitrosamines, organometallic compounds, peroxides, phenols, silicon compounds,…

  19. Objectification and Semiotic Function

    ERIC Educational Resources Information Center

    Santi, George

    2011-01-01

    The objective of this paper is to study students' difficulties when they have to ascribe the same meaning to different representations of the same mathematical object. We address two theoretical tools that are at the core of Radford's cultural semiotic and Godino's onto-semiotic approaches: objectification and the semiotic function. The analysis…

  20. Functional Handwriting Manual.

    ERIC Educational Resources Information Center

    Metzger, Louise; Lehotsky, Rutheda R.

    An inservice project to review the functional handwriting being taught in the Williamsport, Pennsylvania, school district produced a handwriting manual that provides teachers and students with models of letter forms and instructional exercises leading to the development of an individualized style of handwriting. The manual describes student…

  1. Choreographing Patterns and Functions

    ERIC Educational Resources Information Center

    Hawes, Zachary; Moss, Joan; Finch, Heather; Katz, Jacques

    2012-01-01

    In this article, the authors begin with a description of an algebraic dance--the translation of composite linear growing patterns into choreographed movement--which was the last component of a research-based instructional unit that focused on fostering an understanding of linear functional rules through geometric growing patterns and…

  2. COPPER AND BRAIN FUNCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing evidence shows that brain development and function are impaired when the brain is deprived of copper either through dietary copper deficiency or through genetic defects in copper transport. A number of copper-dependent enzymes whose activities are lowered by copper deprivation form the ba...

  3. Family Preservation & Family Functioning.

    ERIC Educational Resources Information Center

    McCroskey, Jacquelyn; Meezan, William

    This book reports a study of the outcomes of home-based family preservation services for abusive and neglectful families in Los Angeles County. Using the Family Assessment Form, the research project evaluated services provided by two voluntary agencies, and focused on changes in family functioning between the opening and closing of services during…

  4. Functions of Industry.

    ERIC Educational Resources Information Center

    Georgia Southern Coll., Statesboro.

    Intended for teachers of industrial arts in teaching the functions of industry, this course of study was compiled as a result of the EPDA Institute in Industrial and Career Development at Georgia Southern College. Contents are: (1) Introduction, (2) Organization, (3) Research and Development, (4) Production, (5) Marketing, (6) Finance and Control,…

  5. Wine and endothelial function.

    PubMed

    Caimi, G; Carollo, C; Lo Presti, R

    2003-01-01

    In recent years many studies have focused on the well-known relationship between wine consumption and cardiovascular risk. Wine exerts its protective effects through various changes in lipoprotein profile, coagulation and fibrinolytic cascades, platelet aggregation, oxidative mechanisms and endothelial function. The last has earned more attention for its implications in atherogenesis. Endothelium regulates vascular tone by a delicate balancing among vasorelaxing (nitric oxide [NO]) and vasoconstrincting (endothelins) factors produced by endothelium in response to various stimuli. In rat models, wine and other grape derivatives exerted an endothelium-dependent vasorelaxing capacity especially associated with the NO-stimulating activity of their polyphenol components. In experimental conditions, reservatrol (a stilbene polyphenol) protected hearts and kidneys from ischemia-reperfusion injury through antioxidant activity and upregulation of NO production. Wine polyphenols are also able to induce the expression of genes involved in the NO pathway within the arterial wall. The effects of wine on endothelial function in humans are not yet clearly understood. A favorable action of red wine or dealcoholized wine extract or purple grape juice on endothelial function has been observed by several authors, but discrimination between ethanol and polyphenol effects is controversial. It is, however likely that regular and prolonged moderate wine drinking positively affects endothelial function. The beneficial effects of wine on cardiovascular health are greater if wine is associated with a healthy diet. The most recent nutritional and epidemiologic studies show that the ideal diet closely resembles the Mediterranean diet. PMID:15134380

  6. Functional Business Games.

    ERIC Educational Resources Information Center

    Biggs, William D.

    1987-01-01

    Defines computerized functional business games as those focusing on decision making and integration in the areas of accounting/finance, marketing, personnel/human resources, and production/operations. Nine currently available games are reviewed and evaluated in the context of a learning model. (Author/LRW)

  7. Gaming and "Functional Democracy".

    ERIC Educational Resources Information Center

    Goodman, F. L.

    An example of the way gaming can be used to bring attention to, and improve skills in, making democracy function better is presented. The game is played by seven people seated around two triangular playing boards; it involves making choices among least, intermediate, and most preferred alternatives, keeping the preferences of the majority in…

  8. Process for functionalizing alkanes

    DOEpatents

    Bergman, R.G.; Janowicz, A.H.; Periana, R.A.

    1988-05-24

    Process for functionalizing saturated hydrocarbons comprises: (a) reacting said saturated hydrocarbons of the formula: R[sub 1]H wherein H represents a hydrogen atom; and R[sub 1] represents a saturated hydrocarbon radical, with a metal complex of the formula: CpRh[P(R[sub 2])[sub 3

  9. Functional Communication Training

    ERIC Educational Resources Information Center

    Durand, V. Mark; Moskowitz, Lauren

    2015-01-01

    Thirty years ago, the first experimental demonstration was published showing that educators could improve significant challenging behavior in children with disabilities by replacing these behaviors with forms of communication that served the same purpose, a procedure called functional communication training (FCT). Since the publication of that…

  10. Conjugate flow action functionals

    SciTech Connect

    Venturi, Daniele

    2013-11-15

    We present a new general framework to construct an action functional for a non-potential field theory. The key idea relies on representing the governing equations relative to a diffeomorphic flow of curvilinear coordinates which is assumed to be functionally dependent on the solution field. Such flow, which will be called the conjugate flow, evolves in space and time similarly to a physical fluid flow of classical mechanics and it can be selected in order to symmetrize the Gâteaux derivative of the field equations with respect to suitable local bilinear forms. This is equivalent to requiring that the governing equations of the field theory can be derived from a principle of stationary action on a Lie group manifold. By using a general operator framework, we obtain the determining equations of such manifold and the corresponding conjugate flow action functional. In particular, we study scalar and vector field theories governed by second-order nonlinear partial differential equations. The identification of transformation groups leaving the conjugate flow action functional invariant could lead to the discovery of new conservation laws in fluid dynamics and other disciplines.

  11. Functional esophageal disorders

    PubMed Central

    Clouse, R; Richter, J; Heading, R; Janssens, J; Wilson, J

    1999-01-01

    The functional esophageal disorders include globus, rumination syndrome, and symptoms that typify esophageal diseases (chest pain, heartburn, and dysphagia). Factors responsible for symptom production are poorly understood. The criteria for diagnosis rest not only on compatible symptoms but also on exclusion of structural and metabolic disorders that might mimic the functional disorders. Additionally, a functional diagnosis is precluded by the presence of a pathology-based motor disorder or pathological reflux, defined by evidence of reflux esophagitis or abnormal acid exposure time during ambulatory esophageal pH monitoring. Management is largely empirical, although efficacy of psychopharmacological agents and psychological or behavioral approaches has been established for serveral of the functional esophageal disorders. As gastroesophageal reflux disease overlaps in presentation with most of these disorders and because symptoms are at least partially provoked by acid reflux events in many patients, antireflux therapy also plays an important role both in diagnosis and management. Further understanding of the fundamental mechanisms responsible for symptoms is a priority for future research efforts, as is the consideration of treatment outcome in a broader sense than reduction in esophageal symptoms alone. Likewise, the value of inclusive rather than restrictive diagnostic criteria that encompass other gastrointestinal and non-gastrointestinal symptoms should be examined to improve the accuracy of symptom-based criteria and reduce the dependence on objective testing.


Keywords: globus; rumination; chest pain; esophageal motility disorders; esophageal spasm; gastroesophageal reflux disease; Rome II PMID:10457042

  12. Linear Classification Functions.

    ERIC Educational Resources Information Center

    Huberty, Carl J.; Smith, Jerry D.

    Linear classification functions (LCFs) arise in a predictive discriminant analysis for the purpose of classifying experimental units into criterion groups. The relative contribution of the response variables to classification accuracy may be based on LCF-variable correlations for each group. It is proved that, if the raw response measures are…

  13. Transfer function matrix

    NASA Technical Reports Server (NTRS)

    Seraji, H.

    1987-01-01

    Given a multivariable system, it is proved that the numerator matrix N(s) of the transfer function evaluated at any system pole either has unity rank or is a null matrix. It is also shown that N(s) evaluated at any transmission zero of the system has rank deficiency. Examples are given for illustration.

  14. Multisensory Executive Functioning

    ERIC Educational Resources Information Center

    Hunt, Amelia R.; Kingstone, Alan

    2004-01-01

    To better understand the prefrontal circuitry that putatively supports executive functions, such as those involved in switching tasks, we asked whether a current task set is open equally to receiving information from any sensory modality or if it is to some degree modality-specific. Subjects were presented with a sequence of digits to be…

  15. Conjugate flow action functionals

    NASA Astrophysics Data System (ADS)

    Venturi, Daniele

    2013-11-01

    We present a new general framework to construct an action functional for a non-potential field theory. The key idea relies on representing the governing equations relative to a diffeomorphic flow of curvilinear coordinates which is assumed to be functionally dependent on the solution field. Such flow, which will be called the conjugate flow, evolves in space and time similarly to a physical fluid flow of classical mechanics and it can be selected in order to symmetrize the Gâteaux derivative of the field equations with respect to suitable local bilinear forms. This is equivalent to requiring that the governing equations of the field theory can be derived from a principle of stationary action on a Lie group manifold. By using a general operator framework, we obtain the determining equations of such manifold and the corresponding conjugate flow action functional. In particular, we study scalar and vector field theories governed by second-order nonlinear partial differential equations. The identification of transformation groups leaving the conjugate flow action functional invariant could lead to the discovery of new conservation laws in fluid dynamics and other disciplines.

  16. Pulmonary function in space.

    PubMed

    West, J B; Elliott, A R; Guy, H J; Prisk, G K

    1997-06-25

    The lung is exquisitely sensitive to gravity, and so it is of interest to know how its function is altered in the weightlessness of space. Studies on National Aeronautics and Space Administration (NASA) Spacelabs during the last 4 years have provided the first comprehensive data on the extensive changes in pulmonary function that occur in sustained microgravity. Measurements of pulmonary function were made on astronauts during space shuttle flights lasting 9 and 14 days and were compared with extensive ground-based measurements before and after the flights. Compared with preflight measurements, cardiac output increased by 18% during space flight, and stroke volume increased by 46%. Paradoxically, the increase in stroke volume occurred in the face of reductions in central venous pressure and circulating blood volume. Diffusing capacity increased by 28%, and the increase in the diffusing capacity of the alveolar membrane was unexpectedly large based on findings in normal gravity. The change in the alveolar membrane may reflect the effects of uniform filling of the pulmonary capillary bed. Distributions of blood flow and ventilation throughout the lung were more uniform in space, but some unevenness remained, indicating the importance of nongravitational factors. A surprising finding was that airway closing volume was approximately the same in microgravity and in normal gravity, emphasizing the importance of mechanical properties of the airways in determining whether they close. Residual volume was unexpectedly reduced by 18% in microgravity, possibly because of uniform alveolar expansion. The findings indicate that pulmonary function is greatly altered in microgravity, but none of the changes observed so far will apparently limit long-term space flight. In addition, the data help to clarify how gravity affects pulmonary function in the normal gravity environment on Earth. PMID:9200637

  17. Pulmonary function in space

    NASA Technical Reports Server (NTRS)

    West, J. B.; Elliott, A. R.; Guy, H. J.; Prisk, G. K.

    1997-01-01

    The lung is exquisitely sensitive to gravity, and so it is of interest to know how its function is altered in the weightlessness of space. Studies on National Aeronautics and Space Administration (NASA) Spacelabs during the last 4 years have provided the first comprehensive data on the extensive changes in pulmonary function that occur in sustained microgravity. Measurements of pulmonary function were made on astronauts during space shuttle flights lasting 9 and 14 days and were compared with extensive ground-based measurements before and after the flights. Compared with preflight measurements, cardiac output increased by 18% during space flight, and stroke volume increased by 46%. Paradoxically, the increase in stroke volume occurred in the face of reductions in central venous pressure and circulating blood volume. Diffusing capacity increased by 28%, and the increase in the diffusing capacity of the alveolar membrane was unexpectedly large based on findings in normal gravity. The change in the alveolar membrane may reflect the effects of uniform filling of the pulmonary capillary bed. Distributions of blood flow and ventilation throughout the lung were more uniform in space, but some unevenness remained, indicating the importance of nongravitational factors. A surprising finding was that airway closing volume was approximately the same in microgravity and in normal gravity, emphasizing the importance of mechanical properties of the airways in determining whether they close. Residual volume was unexpectedly reduced by 18% in microgravity, possibly because of uniform alveolar expansion. The findings indicate that pulmonary function is greatly altered in microgravity, but none of the changes observed so far will apparently limit long-term space flight. In addition, the data help to clarify how gravity affects pulmonary function in the normal gravity environment on Earth.

  18. Engineering Living Functional Materials

    PubMed Central

    2016-01-01

    Natural materials, such as bone, integrate living cells composed of organic molecules together with inorganic components. This enables combinations of functionalities, such as mechanical strength and the ability to regenerate and remodel, which are not present in existing synthetic materials. Taking a cue from nature, we propose that engineered ‘living functional materials’ and ‘living materials synthesis platforms’ that incorporate both living systems and inorganic components could transform the performance and the manufacturing of materials. As a proof-of-concept, we recently demonstrated that synthetic gene circuits in Escherichia coli enabled biofilms to be both a functional material in its own right and a materials-synthesis platform. To demonstrate the former, we engineered E. coli biofilms into a chemical-inducer-responsive electrical switch. To demonstrate the latter, we engineered E. coli biofilms to dynamically organize biotic-abiotic materials across multiple length scales, template gold nanorods, gold nanowires, and metal/semiconductor heterostructures, and synthesize semiconductor nanoparticles (Chen, A. Y. et al. (2014) Synthesis and patterning of tunable multiscale materials with engineered cells. Nat. Mater.13, 515–523.). Thus, tools from synthetic biology, such as those for artificial gene regulation, can be used to engineer the spatiotemporal characteristics of living systems and to interface living systems with inorganic materials. Such hybrids can possess novel properties enabled by living cells while retaining desirable functionalities of inorganic systems. These systems, as living functional materials and as living materials foundries, would provide a radically different paradigm of materials performance and synthesis–materials possessing multifunctional, self-healing, adaptable, and evolvable properties that are created and organized in a distributed, bottom-up, autonomously assembled, and environmentally sustainable manner. PMID

  19. Engineering living functional materials.

    PubMed

    Chen, Allen Y; Zhong, Chao; Lu, Timothy K

    2015-01-16

    Natural materials, such as bone, integrate living cells composed of organic molecules together with inorganic components. This enables combinations of functionalities, such as mechanical strength and the ability to regenerate and remodel, which are not present in existing synthetic materials. Taking a cue from nature, we propose that engineered 'living functional materials' and 'living materials synthesis platforms' that incorporate both living systems and inorganic components could transform the performance and the manufacturing of materials. As a proof-of-concept, we recently demonstrated that synthetic gene circuits in Escherichia coli enabled biofilms to be both a functional material in its own right and a materials-synthesis platform. To demonstrate the former, we engineered E. coli biofilms into a chemical-inducer-responsive electrical switch. To demonstrate the latter, we engineered E. coli biofilms to dynamically organize biotic-abiotic materials across multiple length scales, template gold nanorods, gold nanowires, and metal/semiconductor heterostructures, and synthesize semiconductor nanoparticles (Chen, A. Y. et al. (2014) Synthesis and patterning of tunable multiscale materials with engineered cells. Nat. Mater. 13, 515-523.). Thus, tools from synthetic biology, such as those for artificial gene regulation, can be used to engineer the spatiotemporal characteristics of living systems and to interface living systems with inorganic materials. Such hybrids can possess novel properties enabled by living cells while retaining desirable functionalities of inorganic systems. These systems, as living functional materials and as living materials foundries, would provide a radically different paradigm of materials performance and synthesis-materials possessing multifunctional, self-healing, adaptable, and evolvable properties that are created and organized in a distributed, bottom-up, autonomously assembled, and environmentally sustainable manner. PMID:25592034

  20. Partition density functional theory

    NASA Astrophysics Data System (ADS)

    Nafziger, Jonathan

    Partition density functional theory (PDFT) is a method for dividing a molecular electronic structure calculation into fragment calculations. The molecular density and energy corresponding to Kohn Sham density-functional theory (KS-DFT) may be exactly recovered from these fragments. Each fragment acts as an isolated system except for the influence of a global one-body 'partition' potential which deforms the fragment densities. In this work, the developments of PDFT are put into the context of other fragment-based density functional methods. We developed three numerical implementations of PDFT: One within the NWChem computational chemistry package using basis sets, and the other two developed from scratch using real-space grids. It is shown that all three of these programs can exactly reproduce a KS-DFT calculation via fragment calculations. The first of our in-house codes handles non-interacting electrons in arbitrary one-dimensional potentials with any number of fragments. This code is used to explore how the exact partition potential changes for different partitionings of the same system and also to study features which determine which systems yield non-integer PDFT occupations and which systems are locked into integer PDFT occupations. The second in-house code, CADMium, performs real-space calculations of diatomic molecules. Features of the exact partition potential are studied for a variety of cases and an analytical formula determining singularities in the partition potential is derived. We introduce an approximation for the non-additive kinetic energy and show how this quantity can be computed exactly. Finally a PDFT functional is developed to address the issues of static correlation and delocalization errors in approximations within DFT. The functional is applied to the dissociation of H2 + and H2.

  1. Structure and composition of the Trinil femora: functional and taxonomic implications.

    PubMed

    Ruff, Christopher B; Puymerail, Laurent; Macchiarelli, Roberto; Sipla, Justin; Ciochon, Russell L

    2015-03-01

    The original hominin femur (Femur I) and calotte discovered at Trinil, Java by Eugene Dubois in 1891/1892 played a key role in the early history of human paleontology by purportedly demonstrating the contemporaneity of archaic cranial form with modern human erect (bipedal) posture. On this basis, both specimens were subsequently assigned to Pithecanthropus erectus, later transferred to Homo erectus. However, chronological and phylogenetic links between the two have been questioned from the beginning. Four additional hominin partial femora (Femora II-V) from Trinil were subsequently described but have played a relatively minor part in evolutionary scenarios. Here we present the results of a new analysis of structural and density characteristics of the Trinil femora obtained using computed tomography. Trinil Femur I shows none of the characteristics typical of early Homo femora from elsewhere in Asia or Africa, including a relatively long neck, increased mediolateral bending rigidity of the mid-proximal shaft, or a low position of minimum mediolateral breath on the shaft. In contrast, Femora II-V all demonstrate features that are more consistent with this pattern. In addition, material density distributions within the specimens imply more recent and less complete fossilization of Femur I than Femora II-V. Thus, it is very likely that Trinil Femur I derives from a much more recent time period than the calotte, while the less famous and less complete Femora II-V may represent H. erectus at Trinil. The morphological variation within the Trinil femora can be attributed to broader changes in pelvic morphology occurring within the Homo lineage between the Early and late Middle Pleistocene. PMID:25681015

  2. Functional Performance Evaluation

    NASA Technical Reports Server (NTRS)

    Greenisen, Michael C.; Hayes, Judith C.; Siconolfi, Steven F.; Moore, Alan D.

    1999-01-01

    The Extended Duration Orbiter Medical Project (EDOMP) was established to address specific issues associated with optimizing the ability of crews to complete mission tasks deemed essential to entry, landing, and egress for spaceflights lasting up to 16 days. The main objectives of this functional performance evaluation were to investigate the physiological effects of long-duration spaceflight on skeletal muscle strength and endurance, as well as aerobic capacity and orthostatic function. Long-duration exposure to a microgravity environment may produce physiological alterations that affect crew ability to complete critical tasks such as extravehicular activity (EVA), intravehicular activity (IVA), and nominal or emergency egress. Ultimately, this information will be used to develop and verify countermeasures. The answers to three specific functional performance questions were sought: (1) What are the performance decrements resulting from missions of varying durations? (2) What are the physical requirements for successful entry, landing, and emergency egress from the Shuttle? and (3) What combination of preflight fitness training and in-flight countermeasures will minimize in-flight muscle performance decrements? To answer these questions, the Exercise Countermeasures Project looked at physiological changes associated with muscle degradation as well as orthostatic intolerance. A means of ensuring motor coordination was necessary to maintain proficiency in piloting skills, EVA, and IVA tasks. In addition, it was necessary to maintain musculoskeletal strength and function to meet the rigors associated with moderate altitude bailout and with nominal or emergency egress from the landed Orbiter. Eight investigations, referred to as Detailed Supplementary Objectives (DSOs) 475, 476, 477, 606, 608, 617, 618, and 624, were conducted to study muscle degradation and the effects of exercise on exercise capacity and orthostatic function (Table 3-1). This chapter is divided into

  3. Pseudoproteases: mechanisms and function.

    PubMed

    Reynolds, Simone L; Fischer, Katja

    2015-05-15

    Catalytically inactive enzymes (also known as pseudoproteases, protease homologues or paralogues, non-peptidase homologues, non-enzymes and pseudoenzymes) have traditionally been hypothesized to act as regulators of their active homologues. However, those that have been characterized demonstrate that inactive enzymes have an extensive and expanding role in biological processes, including regulation, inhibition and immune modulation. With the emergence of each new genome, more inactive enzymes are being identified, and their abundance and potential as therapeutic targets has been realized. In the light of the growing interest in this emerging field the present review focuses on the classification, structure, function and mechanism of inactive enzymes. Examples of how inactivity is defined, how this is reflected in the structure, functions of inactive enzymes in biological processes and their mode of action are discussed. PMID:25940733

  4. Bioinspired Functional Materials

    SciTech Connect

    Zheng, Yongmei; Wang, Jingxia; Hou, Yongping; Bai, Hao; Hu, Michael Z.

    2014-11-25

    This special issue is focused on the nanoscale or micro-/nanoscale structures similar to the biological features in multilevels or hierarchy and so on. Research by mimicking biological systems has shown more impact on many applications due to the well-designed micro-/nanostructures inspired from the biological surfaces or interfaces; therefore, the materials may achieve the fascinating functionality. In conclusion, the bioinspired functional materials may be fabricated by developing novel technology or methods such as synthesis, self-assembly, and soft lithography at micro- or nanolevel or multilevels and, in addition, the multidisciplinary procedures of physical or chemical methods and nanotechnology to mimic the biological multiscale micro-/nanostructures onto one-/two-dimensional surface materials.

  5. Assessment of olfactory function.

    PubMed

    Hummel, Thomas; Welge-Lüessen, Antje

    2006-01-01

    Numerous techniques are available for the investigation of chemosensory functions in humans. They include psychophysical measures of chemosensory function, e.g. odor identification, odor discrimination, odor thresholds, odor memory, and retronasal perception of odors. In order to assess changes related to the patients' quality of life or effects of qualitative olfactory dysfunction, questionnaires are being used. Measures relying to a lesser degree on the subjects' cooperation are e.g. chemosensory event-related potentials, odor-induced changes of the EEG, the electroolfactogram, imaging techniques, or measures of respiration. In a clinical context, however, psychophysical techniques are most frequently used, e.g. tests for odor identification, and odor thresholds. Interpretation of results from these measures is frequently supported by the assessment of chemosensory event-related potentials. Other techniques await further standardization before they will become useful in a clinical context. PMID:16733334

  6. Roughness and function

    NASA Astrophysics Data System (ADS)

    Thomas, T. R.

    2014-01-01

    A function map is used to locate applications of roughness in separation-velocity space. The importance of roughness in contact mechanics is demonstrated and versions of the plasticity index are introduced and compared. Case studies of roughness and function are presented from tribology and the life sciences. Tribological examples are taken from the automotive industry and include the manufacture of vehicle bodies, and drive train tribology, particularly cylinder liner, cam and gearbox friction and wear. From the life sciences, problems of prosthetic fixation and tribology are shown to depend on roughness. The interaction of haptics and surface finish is described and illustrated. A number of other areas of application are listed. Finally the likely future importance of structured surfaces is discussed.

  7. Parkin structure and function

    PubMed Central

    Seirafi, Marjan; Kozlov, Guennadi; Gehring, Kalle

    2015-01-01

    Mutations in the parkin or PINK1 genes are the leading cause of the autosomal recessive form of Parkinson’s disease. The gene products, the E3 ubiquitin ligase parkin and the serine/threonine kinase PINK1, are neuroprotective proteins, which act together in a mitochondrial quality control pathway. Here, we review the structure of parkin and mechanisms of its autoinhibition and function as a ubiquitin ligase. We present a model for the recruitment and activation of parkin as a key regulatory step in the clearance of depolarized or damaged mitochondria by autophagy (mitophagy). We conclude with a brief overview of other functions of parkin and considerations for drug discovery in the mitochondrial quality control pathway. PMID:25712550

  8. Bioinspired Functional Materials

    DOE PAGESBeta

    Zheng, Yongmei; Wang, Jingxia; Hou, Yongping; Bai, Hao; Hu, Michael Z.

    2014-11-25

    This special issue is focused on the nanoscale or micro-/nanoscale structures similar to the biological features in multilevels or hierarchy and so on. Research by mimicking biological systems has shown more impact on many applications due to the well-designed micro-/nanostructures inspired from the biological surfaces or interfaces; therefore, the materials may achieve the fascinating functionality. In conclusion, the bioinspired functional materials may be fabricated by developing novel technology or methods such as synthesis, self-assembly, and soft lithography at micro- or nanolevel or multilevels and, in addition, the multidisciplinary procedures of physical or chemical methods and nanotechnology to mimic the biologicalmore » multiscale micro-/nanostructures onto one-/two-dimensional surface materials.« less

  9. Functional Biomimetic Architectures

    NASA Astrophysics Data System (ADS)

    Levine, Paul M.

    N-substituted glycine oligomers, or 'peptoids,' are a class of sequence--specific foldamers composed of tertiary amide linkages, engendering proteolytic stability and enhanced cellular permeability. Peptoids are notable for their facile synthesis, sequence diversity, and ability to fold into distinct secondary structures. In an effort to establish new functional peptoid architectures, we utilize the copper-catalyzed azide-alkyne [3+2] cycloaddition (CuAAC) reaction to generate peptidomimetic assemblies bearing bioactive ligands that specifically target and modulate Androgen Receptor (AR) activity, a major therapeutic target for prostate cancer. Additionally, we explore chemical ligation protocols to generate semi-synthetic hybrid biomacromolecules capable of exhibiting novel structures and functions not accessible to fully biosynthesized proteins.

  10. [Endothelial function test].

    PubMed

    Tomiyama, Hirofumi

    2015-11-01

    Endothelial dysfunction is thought to have pivotal roles for the development of hypertension, initiation/progression of hypertensive organ damages, and prognosis. In clinical setting, flow-mediated vasodilatation (FMD) of brachial artery is used as a marker of endothelial function. However, well-trained sonographer is needed to conduct FMD measurement, and therefore, FMD has not been fully standardized (i.e., the reference value of FMD has not been established). Even so, FMD predicts future cardiovascular events. Lifestyle modifications (i.e., smoking cessation, exercise, or weight loss) and antihypertensive medication provide beneficial effects on endothelial function. Thus, FMD have a potential as a useful surrogate marker for the management of hypertension. PMID:26619655

  11. Functionalization of Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Khare, Bishun N. (Inventor); Meyyappan, Meyya (Inventor)

    2009-01-01

    Method and system for functionalizing a collection of carbon nanotubes (CNTs). A selected precursor gas (e.g., H2 or F2 or CnHm) is irradiated to provide a cold plasma of selected target species particles, such as atomic H or F, in a first chamber. The target species particles are d irected toward an array of CNTs located in a second chamber while suppressing transport of ultraviolet radiation to the second chamber. A CNT array is functionalized with the target species particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec. *Discrimination against non-target species is provided by (i) use of a target species having a lifetime that is much greater than a lifetime of a non-target species and/or (2) use of an applied magnetic field to discriminate between charged particle trajectories for target species and for non-target species.

  12. [Neutrophilic functional heterogeneity].

    PubMed

    2006-02-01

    Blood neutrophilic functional heterogeneity is under discussion. The neutrophils of one subpopulation, namely killer neutrophils (Nk), potential phagocytes, constitute a marginal pool and a part of the circulating pool, intensively produce active oxygen forms (AOF) and they are adherent to the substrate. The neutrophils of another subpopulation, cager neutrophils (Nc), seem to perform a transport function of delivering foreign particles to the competent organs, to form about half of the circulating pool, to produce APC to a lesser extent, exclusively for self-defense and, probably, in usual conditions, to fail to interact with substrate. Analysis of the experimental findings suggests that the phylogenetic age of Nk is older than that of Nc and Nk has predominantly a tendency to spontaneous apoptosis under physiological conditions. PMID:16610631

  13. Process for functionalizing alkanes

    DOEpatents

    Bergman, R.G.; Janowicz, A.H.; Periana-Pillai, R.A.

    1984-06-12

    Process for functionalizing saturated hydrocarbons selectively in the terminal position comprises: (a) reacting said saturated hydrocarbons with a metal complex CpRhPMe/sub 3/H/sub 2/ in the presence of ultraviolet radiation at -60/sup 0/ to -17/sup 0/C to form a hydridoalkyl complex CpRhPMe/sub 3/RH; (b) reacting said hydridoalkyl complex with a haloform CHX/sub 3/ at -60/sup 0/ to -17/sup 0/C to form the corresponding haloalkyl complex of step (a) CpRhPMe/sub 3/RX; and (c) reacting said haloalkyl complex with halogen -60 to 25/sup 0/C to form a functional haloalkyl compound.

  14. Superconducting combined function magnets

    SciTech Connect

    Hahn, H.; Fernow, R.C.

    1983-01-01

    Superconducting accelerators and storage rings, presently under construction or in the design phase, are based on separate dipole and quadrupole magnets. It is here suggested that a hybrid lattice configuration consisting of dipoles and combined function gradient magnets would: (1) reduce the number of magnet units and their total cost; and (2) increase the filling factor and thus the energy at a given field. Coil cross sections are presented for the example of the Brookhaven Colliding Beam Accelerator. An asymmetric two-layer cable gradient magnet would have transfer functions of 10.42 G/A and 0.628 G cm/sup -1//A versus 15.77 G/A and 2.03 G cm/sup -1//A of the present separate dipoles and quadrupoles.

  15. Nuclear Parton Distribution Functions

    SciTech Connect

    I. Schienbein, J.Y. Yu, C. Keppel, J.G. Morfin, F. Olness, J.F. Owens

    2009-06-01

    We study nuclear effects of charged current deep inelastic neutrino-iron scattering in the framework of a {chi}{sup 2} analysis of parton distribution functions (PDFs). We extract a set of iron PDFs which are used to compute x{sub Bj}-dependent and Q{sup 2}-dependent nuclear correction factors for iron structure functions which are required in global analyses of free nucleon PDFs. We compare our results with nuclear correction factors from neutrino-nucleus scattering models and correction factors for charged-lepton--iron scattering. We find that, except for very high x{sub Bj}, our correction factors differ in both shape and magnitude from the correction factors of the models and charged-lepton scattering.

  16. Functional magnetic microspheres

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Rembaum, Alan (Inventor); Landel, Robert F. (Inventor)

    1981-01-01

    Functional magnetic particles are formed by dissolving a mucopolysaccharide such as chitosan in acidified aqueous solution containing a mixture of ferrous chloride and ferric chloride. As the pH of the solution is raised magnetite is formed in situ in the solution by raising the pH. The dissolved chitosan is a polyelectrolyte and forms micelles surrounding the granules at pH of 8-9. The chitosan precipitates on the granules to form microspheres containing the magnetic granules. On addition of the microspheres to waste aqueous streams containing dissolved ions, the hydroxyl and amine functionality of the chitosan forms chelates binding heavy metal cations such as lead, copper, and mercury and the chelates in turn bind anions such as nitrate, fluoride, phosphate and borate.

  17. The Relationships between Weight Functions, Geometric Functions,and Compliance Functions in Linear Elastic Fracture Mechanics

    SciTech Connect

    Yuan, Rong

    2007-02-06

    Linear elastic fracture mechanics is widely used in industry because it established simple and explicit relationships between the permissible loading conditions and the critical crack size that is allowed in a structure. Stress intensity factors are the above-mentioned functional expressions that relate load with crack size through geometric functions or weight functions. Compliance functions are to determine the crack/flaw size in a structure when optical inspection is inconvenient. As a result, geometric functions, weight functions and compliance functions have been intensively studied to determine the stress intensity factor expressions for different geometries. However, the relations between these functions have received less attention. This work is therefore to investigate the intrinsic relationships between these functions. Theoretical derivation was carried out and the results were verified on single-edge cracked plate under tension and bending. It is found out that the geometric function is essentially the non-dimensional weight function at the loading point. The compliance function is composed of two parts: a varying part due to crack extension and a constant part from the intact structure if no crack exists. The derivative of the compliance function at any location is the product of the geometric function and the weight function at the evaluation point. Inversely, the compliance function can be acquired by the integration of the product of the geometric function and the weight function with respect to the crack size. The integral constant is just the unchanging compliance from the intact structure. Consequently, a special application of the relations is to obtain the compliance functions along a crack once the geometric function and weight functions are known. Any of the three special functions can be derived once the other two functions are known. These relations may greatly simplify the numerical process in obtaining either geometric functions, weight

  18. Functionalization of Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Webber, Stephen E.

    2003-01-01

    These project will explore the functionalization of carbon nanotubes via the formation of molecular complexes with perylene diimide based systems. It is anticipated that these complexes would be soluble in organic solvent and enable the homogenous dispersion of carbon nanotubes in polymer films. Molecular complexes will be prepared and characterized using standard spectroscopic and thermal analytical techniques. Polymer films will be prepared with these complexes and their properties (electrical and thermal conductivity, mechanical properties, stability) evaluated.

  19. Dynamics of cholinergic function

    SciTech Connect

    Hanin, I.

    1986-01-01

    This book presents information on the following topics; cholinergic pathways - anatomy of the central nervous system; aging, DSAT and other clinical conditions; cholinergic pre- and post-synaptic receptors; acetylcholine release; cholinesterases, anticholinesterases and reactivators; acetylcholine synthesis, metabolism and precursors; second messenger messenger mechanisms; interaction of acetylcholine with other neurotransmitter systems; cholinergic mechanisms in physiological function, including cardiovascular events; and neurotoxic agents and false transmitters.

  20. Analyzing Pseudophosphatase Function.

    PubMed

    Hinton, Shantá D

    2016-01-01

    Pseudophosphatases regulate signal transduction cascades, but their mechanisms of action remain enigmatic. Reflecting this mystery, the prototypical pseudophosphatase STYX (phospho-serine-threonine/tyrosine-binding protein) was named with allusion to the river of the dead in Greek mythology to emphasize that these molecules are "dead" phosphatases. Although proteins with STYX domains do not catalyze dephosphorylation, this in no way precludes their having other functions as integral elements of signaling networks. Thus, understanding their roles in signaling pathways may mark them as potential novel drug targets. This chapter outlines common strategies used to characterize the functions of pseudophosphatases, using as an example MK-STYX [mitogen-activated protein kinase (MAPK) phospho-serine-threonine/tyrosine binding], which has been linked to tumorigenesis, apoptosis, and neuronal differentiation. We start with the importance of "restoring" (when possible) phosphatase activity in a pseudophosphatase so that the active mutant may be used as a comparison control throughout immunoprecipitation and mass spectrometry analyses. To this end, we provide protocols for site-directed mutagenesis, mammalian cell transfection, co-immunoprecipitation, phosphatase activity assays, and immunoblotting that we have used to investigate MK-STYX and the active mutant MK-STYXactive. We also highlight the importance of utilizing RNA interference (RNAi) "knockdown" technology to determine a cellular phenotype in various cell lines. Therefore, we outline our protocols for introducing short hairpin RNA (shRNA) expression plasmids into mammalians cells and quantifying knockdown of gene expression with real-time quantitative PCR (qPCR). A combination of cellular, molecular, biochemical, and proteomic techniques has served as powerful tools in identifying novel functions of the pseudophosphatase MK-STYX. Likewise, the information provided here should be a helpful guide to elucidating the

  1. Vestibular Function Measurement Devices

    PubMed Central

    Miles, Richard D.; Zapala, David A.

    2015-01-01

    Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments. PMID:27516710

  2. Executive functioning in schizophrenia.

    PubMed

    Orellana, Gricel; Slachevsky, Andrea

    2013-01-01

    The executive function (EF) is a set of abilities, which allows us to invoke voluntary control of our behavioral responses. These functions enable human beings to develop and carry out plans, make up analogies, obey social rules, solve problems, adapt to unexpected circumstances, do many tasks simultaneously, and locate episodes in time and place. EF includes divided attention and sustained attention, working memory (WM), set-shifting, flexibility, planning, and the regulation of goal directed behavior and can be defined as a brain function underlying the human faculty to act or think not only in reaction to external events but also in relation with internal goals and states. EF is mostly associated with dorsolateral prefrontal cortex (PFC). Besides EF, PFC is involved in self-regulation of behavior, i.e., the ability to regulate behavior according to internal goals and constraints, particularly in less structured situations. Self-regulation of behavior is subtended by ventral medial/orbital PFC. Impairment of EF is one of the most commonly observed deficits in schizophrenia through the various disease stages. Impairment in tasks measuring conceptualization, planning, cognitive flexibility, verbal fluency, ability to solve complex problems, and WM occur in schizophrenia. Disorders detected by executive tests are consistent with evidence from functional neuroimaging, which have shown PFC dysfunction in patients while performing these kinds of tasks. Schizophrenics also exhibit deficit in odor identifying, decision-making, and self-regulation of behavior suggesting dysfunction of the orbital PFC. However, impairment in executive tests is explained by dysfunction of prefronto-striato-thalamic, prefronto-parietal, and prefronto-temporal neural networks mainly. Disorders in EFs may be considered central facts with respect to schizophrenia and it has been suggested that negative symptoms may be explained by that executive dysfunction. PMID:23805107

  3. Platelet function and ageing.

    PubMed

    Jones, Chris I

    2016-08-01

    There are clear age-related changes in platelet count and function, driven by changes in hematopoietic tissue, the composition of the blood and vascular health. Platelet count remains relatively stable during middle age (25-60 years old) but falls in older people. The effect of age on platelet function is slightly less clear. The longstanding view is that platelet reactivity increases with age in an almost linear fashion. There are, however, serious limitations to the data supporting this dogma. We can conclude that platelet function increases during middle age, but little evidence exists on the changes in platelet responsiveness in old age (>75 years old). This change in platelet function is driven by differential mRNA and microRNA expression, an increase in oxidative stress and changes in platelet receptors. These age-related changes in platelets are particularly pertinent given that thrombotic disease and use of anti-platelet drugs is much more prevalent in the elderly population, yet the majority of platelet research is carried out in young to middle-aged (20-50 years old) human volunteers and young mice (2-6 months old). We know relatively little about exactly how platelets from people over 75 years old differ from those of middle-aged subjects, and we know even less about the mechanisms that drive these changes. Addressing these gaps in our knowledge will provide substantial understanding in how cell signalling changes during ageing and will enable the development of more precise anti-platelet therapies. PMID:27068925

  4. Executive Functioning in Schizophrenia

    PubMed Central

    Orellana, Gricel; Slachevsky, Andrea

    2013-01-01

    The executive function (EF) is a set of abilities, which allows us to invoke voluntary control of our behavioral responses. These functions enable human beings to develop and carry out plans, make up analogies, obey social rules, solve problems, adapt to unexpected circumstances, do many tasks simultaneously, and locate episodes in time and place. EF includes divided attention and sustained attention, working memory (WM), set-shifting, flexibility, planning, and the regulation of goal directed behavior and can be defined as a brain function underlying the human faculty to act or think not only in reaction to external events but also in relation with internal goals and states. EF is mostly associated with dorsolateral prefrontal cortex (PFC). Besides EF, PFC is involved in self-regulation of behavior, i.e., the ability to regulate behavior according to internal goals and constraints, particularly in less structured situations. Self-regulation of behavior is subtended by ventral medial/orbital PFC. Impairment of EF is one of the most commonly observed deficits in schizophrenia through the various disease stages. Impairment in tasks measuring conceptualization, planning, cognitive flexibility, verbal fluency, ability to solve complex problems, and WM occur in schizophrenia. Disorders detected by executive tests are consistent with evidence from functional neuroimaging, which have shown PFC dysfunction in patients while performing these kinds of tasks. Schizophrenics also exhibit deficit in odor identifying, decision-making, and self-regulation of behavior suggesting dysfunction of the orbital PFC. However, impairment in executive tests is explained by dysfunction of prefronto-striato-thalamic, prefronto-parietal, and prefronto-temporal neural networks mainly. Disorders in EFs may be considered central facts with respect to schizophrenia and it has been suggested that negative symptoms may be explained by that executive dysfunction. PMID:23805107

  5. Functions of Multivector Variables

    PubMed Central

    Chappell, James M.; Iqbal, Azhar; Gunn, Lachlan J.; Abbott, Derek

    2015-01-01

    As is well known, the common elementary functions defined over the real numbers can be generalized to act not only over the complex number field but also over the skew (non-commuting) field of the quaternions. In this paper, we detail a number of elementary functions extended to act over the skew field of Clifford multivectors, in both two and three dimensions. Complex numbers, quaternions and Cartesian vectors can be described by the various components within a Clifford multivector and from our results we are able to demonstrate new inter-relationships between these algebraic systems. One key relationship that we discover is that a complex number raised to a vector power produces a quaternion thus combining these systems within a single equation. We also find a single formula that produces the square root, amplitude and inverse of a multivector over one, two and three dimensions. Finally, comparing the functions over different dimension we observe that Cℓ(ℜ3) provides a particularly versatile algebraic framework. PMID:25774689

  6. [Visuospatial functions and prematurity].

    PubMed

    Miranda-Herrero, M C; Pascual-Pascual, S I; Barredo-Valderrama, E; Vazquez-Lopez, M; de Castro-De Castro, P

    2014-11-01

    Visuospatial functions are very important in learning process and development of abstract thought during childhood. Several studies show that preterm and low birth weight infants obtain lower scores in test that assess cognitive functions, specially in the first year of life. These differences are attenuated over time, but a developmental delay that affects working memory and visuospatial process still persists. It is unclear what factors are involved in development of these functions, and pre- or perinatal factors may interfere with the proper conduct of the same, but have been described anatomical and physiological differences between the preterm and term brain that could explain somewhere in these alterations. The different selective vulnerability to hypoxia between immature brain in which preoligodendrocytes and subplate neurons predominate, and mature brain, determine differences in the pattern of injury from hypoxia with greater involvement of the periventricular white matter in preterm children. This lesional pattern leaves to a dysfunction in attentional and visuospatial process, due to the increased vulnerability of the regions involved in the dorsal pathway of visual processing. PMID:25342055

  7. Functions of multivector variables.

    PubMed

    Chappell, James M; Iqbal, Azhar; Gunn, Lachlan J; Abbott, Derek

    2015-01-01

    As is well known, the common elementary functions defined over the real numbers can be generalized to act not only over the complex number field but also over the skew (non-commuting) field of the quaternions. In this paper, we detail a number of elementary functions extended to act over the skew field of Clifford multivectors, in both two and three dimensions. Complex numbers, quaternions and Cartesian vectors can be described by the various components within a Clifford multivector and from our results we are able to demonstrate new inter-relationships between these algebraic systems. One key relationship that we discover is that a complex number raised to a vector power produces a quaternion thus combining these systems within a single equation. We also find a single formula that produces the square root, amplitude and inverse of a multivector over one, two and three dimensions. Finally, comparing the functions over different dimension we observe that Cl(R(3)) provides a particularly versatile algebraic framework. PMID:25774689

  8. Development of Functional Foods

    PubMed Central

    MITSUOKA, Tomotari

    2014-01-01

    Recent advances in intestinal microbiota research are the background for the appearance of functional foods. Lactic fermentation products are included in the functional foods and classified into 3 groups based on their mechanisms of action: probiotics, prebiotics and biogenics. Probiotics are viable microorganisms, such as lactobacilli and bifidobacteria, that beneficially affect the host by improving the intestinal bacterial balance. Prebiotics are nondigestible food ingredients, such as oligosaccharides and dietary fiber, that beneficially affect the host by selectively stimulating the growth or activities of beneficial intestinal bacteria in the colon and thus improve the health of the hosts. Biogenics are biologically active peptides, including immunopotentiators (biological response modifier: BRM), plant flavonoids, etc. They act directly or indirectly through modulation of intestinal microbiota on the health of the hosts. Thus, functional foods enhance bioregulation such as stresses, appetite and absorption; biodefence, such as immunity and suppression of allergies; prevent diseases, including diarrhea, constipation, cancer, cholesterolemia and diabetes; and suppress aging through immunostimulation as well as suppression of mutagenesis, carcinogenesis, oxidation processes, intestinal putrefaction, and cholesterolemia. PMID:25032085

  9. Functional Hemodynamic Monitoring

    PubMed Central

    Pinsky, Michael R.

    2014-01-01

    Functional hemodynamic monitoring is the assessment of the dynamic interactions of hemodynamic variables in response to a defined perturbation. Dynamic tissue O2 saturation (StO2) responses to complete stop flow conditions (vascular occlusion test), which can be created by measuring hand StO2 and occluding flow with a blood pressure cuff, assesses cardiovascular sufficiency and microcirculatory blood flow distribution. Recent interest in functional hemodynamic monitoring for the bedside assessment of cardiovascular insufficiency has heightened with the documentation of its accuracy in predicting volume responsiveness using a wide variety of monitoring devices both invasive and non-invasive and across multiple patient groups and clinical conditions. Accordingly, fluid responsiveness can be predicted in a quantities fashion by measuring as arterial pulse pressure variation, left ventricular stroke volume variation or their surrogates during positive pressure breathing or the change in cardiac output response to a passive leg raising maneuver. However, volume responsiveness, though important, reflects only part of the overall spectrum of functional physiological variables that can be measured to define physiologic state and monitor response to therapy. PMID:25435480

  10. Functional magnetic resonance imaging.

    PubMed

    Buchbinder, Bradley R

    2016-01-01

    Functional magnetic resonance imaging (fMRI) maps the spatiotemporal distribution of neural activity in the brain under varying cognitive conditions. Since its inception in 1991, blood oxygen level-dependent (BOLD) fMRI has rapidly become a vital methodology in basic and applied neuroscience research. In the clinical realm, it has become an established tool for presurgical functional brain mapping. This chapter has three principal aims. First, we review key physiologic, biophysical, and methodologic principles that underlie BOLD fMRI, regardless of its particular area of application. These principles inform a nuanced interpretation of the BOLD fMRI signal, along with its neurophysiologic significance and pitfalls. Second, we illustrate the clinical application of task-based fMRI to presurgical motor, language, and memory mapping in patients with lesions near eloquent brain areas. Integration of BOLD fMRI and diffusion tensor white-matter tractography provides a road map for presurgical planning and intraoperative navigation that helps to maximize the extent of lesion resection while minimizing the risk of postoperative neurologic deficits. Finally, we highlight several basic principles of resting-state fMRI and its emerging translational clinical applications. Resting-state fMRI represents an important paradigm shift, focusing attention on functional connectivity within intrinsic cognitive networks. PMID:27432660

  11. Thyroid Function and Obesity

    PubMed Central

    Laurberg, Peter; Knudsen, Nils; Andersen, Stig; Carlé, Allan; Pedersen, Inge Bülow; Karmisholt, Jesper

    2012-01-01

    Important interaction exists between thyroid function, weight control, and obesity. Several mechanisms seem to be involved, and in studies of groups of people the pattern of thyroid function tests depends on the balance of obesity and underlying thyroid disease in the cohort studied. Obese people with a normal thyroid gland tend to have activation of the hypothalamic-pituitary-thyroid axis with higher serum TSH and thyroid hormones in serum. On the other hand, small differences in thyroid function are associated with up to 5 kg difference in body weight. The weight loss after therapy of overt hypothyroidism is caused by excretion of water bound in tissues (myxoedema). Many patients treated for hyperthyroidism experience a gain of more weight than they lost during the active phase of the disease. The mechanism for this excessive weight gain has not been fully elucidated. New studies on the relation between L-T3 therapy and weight control are discussed. The interaction between weight control and therapy of thyroid disease is important to many patients and it should be studied in more detail. PMID:24783015

  12. Leptin and reproductive function.

    PubMed

    Hausman, Gary J; Barb, C Richard; Lents, Clay A

    2012-10-01

    Adipose tissue plays a dynamic role in whole-body energy homeostasis by acting as an endocrine organ. Collective evidence indicates a strong link between neural influences and adipocyte expression and secretion of leptin. Developmental changes in these relationships are considered important for pubertal transition in reproductive function. Leptin augments secretion of gonadotropin hormones, which are essential for initiation and maintenance of normal reproductive function, by acting centrally at the hypothalamus to regulate gonadotropin-releasing hormone (GnRH) neuronal activity and secretion. The effects of leptin on GnRH are mediated through interneuronal pathways involving neuropeptide-Y, proopiomelanocortin and kisspeptin. Increased infertility associated with diet induced obesity or central leptin resistance are likely mediated through the kisspeptin-GnRH pathway. Furthermore, Leptin regulates reproductive function by altering the sensitivity of the pituitary gland to GnRH and acting at the ovary to regulate follicular and luteal steroidogenesis. Thus leptin serves as a putative signal that links metabolic status with the reproductive axis. The intent of this review is to examine the biological role of leptin with energy metabolism, and reproduction. PMID:22980196

  13. Carbasugars: Synthesis and Functions

    NASA Astrophysics Data System (ADS)

    Kobayashi, Yoshiyuki

    It is well recognized that glycosidase inhibitors are not only tools to elucidate the mechanism of a living system manipulated by glycoconjugates but also potential clinical drugs and insecticides by inducing the failure of glycoconjugates to perform their function. In this chapter, the syntheses and functions of natural glycosidase inhibitors (cyclophelitol , allosamidine , and trehazoilin ), which possess highly oxygenated and functionalized cyclohexanes or cyclopentanes in their structures and are defined as carbasugars , and the structure and activity relationships (SAR) of their derivatives are described. Also, recently much attention has been focused on neuraminidase inhibitors as anti-influenza drugs since relenza , which was derived from sialic acid, and also, tamiflu , which is the artificial carbasugar designed as a transition state analogue in the hydrolysis pathway of substrates by neuraminidase, were launched in the market. Herein, the medicinal chemistry efforts to discover tamiflu and some efficient syntheses applicable to process chemistry are described. Finally, useful synthetic methodologies for carbasugar formation from sugars are also introduced in this chapter.

  14. Thyroid function and obesity.

    PubMed

    Laurberg, Peter; Knudsen, Nils; Andersen, Stig; Carlé, Allan; Pedersen, Inge Bülow; Karmisholt, Jesper

    2012-10-01

    Important interaction exists between thyroid function, weight control, and obesity. Several mechanisms seem to be involved, and in studies of groups of people the pattern of thyroid function tests depends on the balance of obesity and underlying thyroid disease in the cohort studied. Obese people with a normal thyroid gland tend to have activation of the hypothalamic-pituitary-thyroid axis with higher serum TSH and thyroid hormones in serum. On the other hand, small differences in thyroid function are associated with up to 5 kg difference in body weight. The weight loss after therapy of overt hypothyroidism is caused by excretion of water bound in tissues (myxoedema). Many patients treated for hyperthyroidism experience a gain of more weight than they lost during the active phase of the disease. The mechanism for this excessive weight gain has not been fully elucidated. New studies on the relation between L-T3 therapy and weight control are discussed. The interaction between weight control and therapy of thyroid disease is important to many patients and it should be studied in more detail. PMID:24783015

  15. Pediatric Arm Function Test

    PubMed Central

    Uswatte, Gitendra; Taub, Edward; Griffin, Angi; Rowe, Jan; Vogtle, Laura; Barman, Joydip

    2012-01-01

    Objective Although there are several validated upper-extremity measures in young children with cerebral palsy (CP), none primarily assess capacity to carry out actions and tasks with the more-affected arm. To address this need, we developed the Pediatric Arm Function Test (PAFT), which involves behavioral observation of how children use their more-affected arm during structured play in the laboratory or clinic. This paper evaluates the reliability and validity of the PAFT Functional Ability scale. Design In Study 1, 20 children between 2–8 years with a wide range of upper-extremity hemiparesis due to CP completed the PAFT on two occasions separated by three weeks. In Study 2, 41 children between 2–6 years with similar characteristics completed the PAFT and received a grade reflecting severity of more-affected arm motor impairment. Results In Study 1, the PAFT test-retest reliability correlation coefficient was 0.74. In Study 2, convergent validity was supported by a strong, inverse correlation (r = −0.6, p < .001) between PAFT scores and grade of impairment. Conclusions The PAFT Functional Ability scale is a reliable and valid measure of more-affected arm motor capacity in children with CP between 2–6 years. It can be employed to measure upper-extremity neurorehabilitation outcome. PMID:23103486

  16. Lutein and Brain Function

    PubMed Central

    Erdman, John W.; Smith, Joshua W.; Kuchan, Matthew J.; Mohn, Emily S.; Johnson, Elizabeth J.; Rubakhin, Stanislav S.; Wang, Lin; Sweedler, Jonathan V.; Neuringer, Martha

    2015-01-01

    Lutein is one of the most prevalent carotenoids in nature and in the human diet. Together with zeaxanthin, it is highly concentrated as macular pigment in the foveal retina of primates, attenuating blue light exposure, providing protection from photo-oxidation and enhancing visual performance. Recently, interest in lutein has expanded beyond the retina to its possible contributions to brain development and function. Only primates accumulate lutein within the brain, but little is known about its distribution or physiological role. Our team has begun to utilize the rhesus macaque (Macaca mulatta) model to study the uptake and bio-localization of lutein in the brain. Our overall goal has been to assess the association of lutein localization with brain function. In this review, we will first cover the evolution of the non-human primate model for lutein and brain studies, discuss prior association studies of lutein with retina and brain function, and review approaches that can be used to localize brain lutein. We also describe our approach to the biosynthesis of 13C-lutein, which will allow investigation of lutein flux, localization, metabolism and pharmacokinetics. Lastly, we describe potential future research opportunities. PMID:26566524

  17. Lymphocyte Functions in Microgravity

    NASA Technical Reports Server (NTRS)

    Pellis, Neal R.; Risin, Diane; Sundaresan, A.; Cooper, D.; Dawson, David L. (Technical Monitor)

    1999-01-01

    To understand the mechanism of immunity impairment in space it is important to analyze the direct effects of space-related conditions on different lymphocytes functions. Since 1992, we are investigating the effect of modeled and true microgravity (MG) on numerous lymphocyte functions. We had shown that modeled (MMG) and true microgravity inhibit lymphocyte locomotion through type I collagen. Modeled microgravity also suppresses polyclonal and antigen-specific lymphocyte activation. Polyclonal activation of lymphocytes prior to exposure to MMG abrogates the MG-induced inhibition of lymphocyte locomotion. The relationship between activation deficits and the loss of locomotion in MG was investigated using PKC activation by phorbol ester (PMA) and calcium ionophore (ionomycin). Direct activation of PKC by PMA substantially restored the MMG-inhibited lymphocyte locomotion and PHA-induced lymphocyte activation lonomycin by itself did not restore either locomotion or activation of the lymphocytes, indicating that these changes are not related to the impairment in the calcium flux in MMG. Treatment of lymphocytes with PMA before exposure to MMG prevented the loss of locomotion. It was observed that DNA synthesis is not necessary for restoration of locomotion since mitomicin C treated and untreated cells recovered their locomotion to the same level after PKC activation. Our recent data indicate that microgravity may selectively effect the expression of novel Ca2+ independent isoforms of PKC, in particularly PKC sigma and delta. This provides a new insight in understanding of the mechanisms of MG-sensitive cellular functions.

  18. Functionalized Amorphous Aluminosilicates

    NASA Astrophysics Data System (ADS)

    Mesgar, Milad

    Alkali treated aluminosilicate (geopolymer) was functionalized by surfactant to increase the hydrophobicity for making Pickering emulsion for the first part of this work. In the first part of this study, alkali treated metakaolin was functionalized with cetyltrimethylammonium bromide ((C16H33)N(CH 3)3Br, CTAB). The electrostatic interaction between this quaternary ammonium and the surface of the aluminosilicate which has negative charge has taken place. The particles then were used to prepare Pickering emulsion. The resulting stable dispersions, obtained very fast at very simple conditions with low ratio of aluminosilicate to liquid phase. In the second part, the interaction between geopolymer and glycerol was studied to see the covalent grafting of the geopolymer for making geopolymer composite. The composite material would be the basis material to be used as support catalyst, thin coating reagent and flame retardant material and so on, Variety of techniques, Thermogravimetric (TGA), Particle-induced X-ray emission (PIXE), FTIR, Solid state NMR, Powder X-ray diffraction (PXRD), BET surface area, Elemental analysis (CHN), TEM, SEM and Optical microscopy were used to characterize the functionalized geopolymer.

  19. Functional ingredients from microalgae.

    PubMed

    Buono, Silvia; Langellotti, Antonio Luca; Martello, Anna; Rinna, Francesca; Fogliano, Vincenzo

    2014-08-01

    A wide variety of natural sources are under investigation to evaluate their possible use for new functional ingredient formulation. Some records attested the traditional and ancient use of wild harvested microalgae as human food but their cultivation for different purposes started about 40 years ago. The most popular species are Arthrospira (traditional name, Spirulina), Chlorella spp., Dunaliella spp. and Haematococcus spp. Microalgae provide a bewildering array of opportunities to develop healthier food products using innovative approaches and a number of different strategies. Compared to other natural sources of bioactive ingredients, microalgae have many advantages such as their huge biodiversity, the possibility to grow in arid land and with limited fresh water consumption and the flexibility of their metabolism, which could be adapted to produce specific molecules. All these factors led to very sustainable production making microalgae eligible as one of the most promising foods for the future, particularly as source of proteins, lipids and phytochemicals. In this work, a revision of the knowledge about the use of microalgae as food and as a source of functional ingredients has been performed. The most interesting results in the field are presented and commented upon, focusing on the different species of microalgae and the activity of the nutritionally relevant compounds. A summary of the health effects obtained together with pros and cons in the adoption of this natural source as functional food ingredients is also proposed. PMID:24957182

  20. Nicotinamide and neurocognitive function.

    PubMed

    Rennie, George; Chen, Andrew C; Dhillon, Haryana; Vardy, Janette; Damian, Diona L

    2015-07-01

    Nicotinamide, or vitamin B3, is a precursor of nicotinamide adenine dinucleotide (NAD(+)) and is involved in a multitude of intra- and inter-cellular processes, which regulate some of the cell's metabolic, stress, and immune responses to physiological or pathological signals. As a precursor of NAD(+), which is a key coenzyme in the production of adenosine triphosphate or cellular energy, nicotinamide has been investigated for potential neuroprotective effects in cellular, animal, and human studies. Objectives We aimed to summarize the current evidence on the effect of dietary and supplemental nicotinamide on cognitive function. Methods A literature review was conducted on the effects of nicotinamide and its derivatives as a preventive and therapeutic agent for disorders of neurocognitive function. Specific conditions examined include age-related cognitive decline, Alzheimer's disease, Parkinson's disease, and ischaemic and traumatic brain injury. Results Data from animal and human interventional studies and epidemiological research suggests that nicotinamide may be beneficial in preserving and enhancing neurocognitive function. Discussion Nicotinamide is non-toxic, inexpensive and widely available, and interventional studies in humans, using supplemental doses of nicotinamide, are now warranted. PMID:24559077

  1. Galaxy cosmological mass function

    NASA Astrophysics Data System (ADS)

    Lopes, Amanda R.; Iribarrem, Alvaro; Ribeiro, Marcelo B.; Stoeger, William R.

    2014-12-01

    Aims: This paper studies the galaxy cosmological mass function (GCMF) in a semi-empirical relativistic approach that uses observational data provided by recent galaxy redshift surveys. Methods: Starting from a previously presented relation between the mass-to-light ratio, the selection function obtained from the luminosity function (LF) data and the luminosity density, the average luminosity L, and the average galactic mass ℳg were computed in terms of the redshift. ℳg was also alternatively estimated by means of a method that uses the galaxy stellar mass function (GSMF). Comparison of these two forms of deriving the average galactic mass allowed us to infer a possible bias introduced by the selection criteria of the survey. We used the FORS Deep Field galaxy survey sample of 5558 galaxies in the redshift range 0.5 function, but whose fitted parameter values are different from the values found in the literature for the GSMF. Conclusions: This GCMF behavior follows the theoretical predictions from the cold dark matter models in which the less massive objects form first, followed later by more massive ones. In the range 0.5

  2. [Functional pathophysiology of consciousness].

    PubMed

    Jellinger, Kurt A

    2009-01-01

    Consciousness (Latin conscientia "moral conscience"), according to the English philosopher John Locke (1632-1704) [103], is the awareness of all that occurs in the mind of a person, whereas the American philosopher John Searle (2000) defined it as "inner qualitative, subjective states and processes of awareness". In modern science it is defined as a continuous state of full awareness of the Self and one's relationship to the external and internal environment, describing the degree of wakefulness in which an organism recognizes stimuli. This widely discussed biological term for complex neuronal processes that allow an individuum to recognize itself and its environment and to act accordingly, has been and still is the subject of much research in philosophy and natural/neuroscience. Its definition is often used for awareness and recognition, too. While the Egyptians in the papyrus Edwin Smith already recognized the brain as the seat of consciousness, René Descartes (1644 [36]) believed its special structure should be "a small gland in the middle", but the anatomical structures and physiological processes involved in consciousness were elucidated only in the middle of the 20th century. Neuronal substrates include several functional networks that are hierarchically organized and cooperate functionally. The lowest level is the mesencephalic formatio reticularis and its projections to the thalamus that were identified als ascending reticular system (ARAS) by the classical experiments of Moruzzi and Magoun, whereas later analyses of patients with impaired consciousness provided further insights. The mesencephalic ARAS as motor of the function of higher structures projects 1. via the reticular thalamus diffusely to the cortex, 2. via hypothalamus to the basal forebrain and limbic system, and 3. to the medial raphe of the brainstem and locus coeruleus and their diffuse cortical projections. The reticular system is stimulated directly and indirectly via numerous collaterals

  3. Generating functionals for Green's functions in gauge field theories

    SciTech Connect

    Bordag, M.; Kaschlun, L.; Matveev, V.A.; Robaschik, D.

    1987-09-01

    The structure of the generating functional of the one-particle-irreducible Green's functions in gauge field theories is investigated. Both axial as well as covariant gauge conditions are considered. For both cases, the general structure of the functionals is obtained, and a functional expansion with respect to nonlocal operators is given. The appearance of gauge-dependent operators in the case of the covariant gauge follows in a natural manner from the structure of the corresponding functional.

  4. Challenging the Dichotomy between "Urban" and "Suburban" in Educational Discourse and Policy

    ERIC Educational Resources Information Center

    Posey-Maddox, Linn

    2016-01-01

    This article builds a case for nuanced conceptualizations of "urban" and "-suburban" educational contexts and issues. The author analyzes data across two studies--one of upper-middle-class White parents with children in Chicago public schools, and the other of Black low-income and working-class parents who moved from Chicago to…

  5. Activity-dependent neuroprotective protein (ADNP) exhibits striking sexual dichotomy impacting on autistic and Alzheimer's pathologies.

    PubMed

    Malishkevich, A; Amram, N; Hacohen-Kleiman, G; Magen, I; Giladi, E; Gozes, I

    2015-01-01

    Activity-dependent neuroprotective protein (ADNP) is a most frequent autism spectrum disorder (ASD)-associated gene and the only protein significantly decreasing in the serum of Alzheimer's disease (AD) patients. Is ADNP associated with ASD being more prevalent in boys and AD more prevalent in women? Our results revealed sex-related learning/memory differences in mice, reflecting hippocampal expression changes in ADNP and ADNP-controlled AD/ASD risk genes. Hippocampal ADNP transcript content was doubled in male vs female mice, with females showing equal expression to ADNP haploinsufficient (ADNP(+/)(-)) males and no significant genotype-associated reduction. Increased male ADNP expression was replicated in human postmortem hippocampal samples. The hippocampal transcript for apolipoprotein E (the major risk gene for AD) was doubled in female mice compared with males, and further doubled in the ADNP(+/-) females, contrasting a decrease in ADNP(+/-) males. Previously, overexpression of the eukaryotic translation initiation factor 4E (eIF4E) led to ASD-like phenotype in mice. Here, we identified binding sites on ADNP for eIF4E and co-immunoprecipitation. Furthermore, hippocampal eIF4E expression was specifically increased in young ADNP(+/-) male mice. Behaviorally, ADNP(+/-) male mice exhibited deficiencies in object recognition and social memory compared with ADNP(+/+) mice, while ADNP(+/-) females were partially spared. Contrasting males, which preferred novel over familiar mice, ADNP(+/+) females showed no preference to novel mice and ADNP(+/-) females did not prefer mice over object. ADNP expression, positioned as a master regulator of key ASD and AD risk genes, introduces a novel concept of hippocampal gene-regulated sexual dimorphism and an ADNP(+/-) animal model for translational psychiatry. PMID:25646590

  6. Dichotomy Between Black Hole and Neutron Star Accretion: Effect of Hard Surface

    NASA Astrophysics Data System (ADS)

    Dhang, Prasun; Mukhopadhyay, Banibrata; Sharma, Prateek

    2016-07-01

    Estimates of accretion rate on to compact objects have been explored based on the well-known, spherically symmetric, inviscid, steady-state solution given by Bondi. This solution assumes that there is a sink of mass at the center -- which in case of a black hole (BH) corresponds to the advection of matter across the event horizon. Other stars, such as a neutron star (NS), have surfaces and hence the infalling matter has to come to rest at the surface. We study the initial value problem in which the matter distribution is uniform and at rest at time t=0 with different inner radial boundary conditions for BHs and NSs: inflow boundary condition valid for BHs; and reflective or settling boundary condition for NSs. We obtain a similarity solution for the flow with inner inflow and reflective boundary conditions (assuming a cold ambient medium) and compare with numerical simulations of the Euler equations. One-dimensional simulations show the formation of an outward propagating and a standing shock in NS system for reflective and settling boundary conditions respectively. Two-dimensional simulations show that both these flows are unstable (locally to convection and globally to a standing shock instability). Numerical simulations show that in steady state, spherical accretion rate on to a NS for reflective boundary condition is suppressed by orders of magnitude compared to that on to a BH.

  7. Teaching Comparative Law in the 21st Century: Beyond the Civil/Common Law Dichotomy.

    ERIC Educational Resources Information Center

    Waxman, Michael P.

    2001-01-01

    Asserts that the inexorable shift to transnational and global legal practice demands a comparable shift in methods of teaching comparative law to move it beyond its current American common law/European civil law myopia. Proposes an introductory course, Law in Comparative Cultures, which exposes students to a panoply of international legal systems.…

  8. Disseminated histiocytic sarcoma in a child: a clinicopathological dichotomy with 8 years survival.

    PubMed

    Sharma, Shilpa; Das, Prasenjit; Dinda, Amit K; Gupta, Devendra K

    2016-01-01

    A 3-year-old girl presented with a non-healing ulcer, originating as a pustule over the right anterior chest wall of 1½ month duration associated with high fever. A subcutaneous nodule along with right apical and anterior axillary lymph nodes was palpable. Abdominal ultrasound and chest skiagram were normal. Fine needle aspiration cytology (FNAC) from the axillary lymph node was suggestive of embryonal rhabdomyosarcoma. Bone marrow aspirate was normal. The ulcer and subcutaneous nodule were excised completely with adequate margins. Histopathological examinations were compatible with malignancy of histiocytic origin with clear resected margins. The axillary nodes were free of tumour. Adjuvant chemotherapy was given for 13 months. The patient is doing well at 8 years follow-up. PMID:27190112

  9. Is it dichotomy or tension: I am a scientist. No, wait! I am a teacher!

    NASA Astrophysics Data System (ADS)

    Aydeniz, Mehmet; Hodge, Lynn Liao

    2011-03-01

    This study explores through a naturalistic inquiry the tensions between a science professor's two enacted identities. More specifically, this study looks at how a biology professor's identity-in-practice shifts and evolves over time through collaborations with a science education professor. These shifts were marked by an emphasis on teaching, rather than solely a focus on science. Data were collected through formal interviews and notes taken during planning sessions that took place between the biology professor and the science educator. Findings reveal that although the biology professor is able to reconcile both his science and teacher identity, structural elements of his workplace do not encourage him to enact his teacher identity. Recommendations for college science teaching are discussed.

  10. Calcium metabolism in lithium-treated patients. Relation to uni-bipolar dichotomy.

    PubMed

    Baastrup, P C; Christiansen, C; Transbøl, I

    1978-02-01

    The bone mineral content (BMC) together with biochemical indices of calcium metabolism were measured in 83 manic-depressive patients on long-term lithium therapy. The patients were diagnosed and divided into a unipolar and a bipolar group according to strict symptomatic course criteria. The patients with bipolar course had a significantly decreased BMC (88% of normal, P is less than 0.001), while the unipolar patients had normal BMC. Both groups had biochemical changes consistent with primary hyperparathyroidism. PMID:636904

  11. Cause and effect in biology revisited: is Mayr's proximate-ultimate dichotomy still useful?

    PubMed

    Laland, Kevin N; Sterelny, Kim; Odling-Smee, John; Hoppitt, William; Uller, Tobias

    2011-12-16

    Fifty years ago, Ernst Mayr published a hugely influential paper on the nature of causation in biology, in which he distinguished between proximate and ultimate causes. Mayr equated proximate causation with immediate factors (for example, physiology) and ultimate causation with evolutionary explanations (for example, natural selection). He argued that proximate and ultimate causes addressed different questions and were not alternatives. Mayr's account of causation remains widely accepted today, with both positive and negative ramifications. Several current debates in biology (for example, over evolution and development, niche construction, cooperation, and the evolution of language) are linked by a common axis of acceptance/rejection of Mayr's model of causation. We argue that Mayr's formulation has acted to stabilize the dominant evolutionary paradigm against change but may now hamper progress in the biological sciences. PMID:22174243

  12. Questioning the dichotomy between vegetative state and minimally conscious state: a review of the statistical evidence

    PubMed Central

    Liberati, Giulia; Hünefeldt, Thomas; Olivetti Belardinelli, Marta

    2014-01-01

    Given the enormous consequences that the diagnosis of vegetative state (VS) vs. minimally conscious state (MCS) may have for the treatment of patients with disorders of consciousness, it is particularly important to empirically legitimate the distinction between these two discrete levels of consciousness. Therefore, the aim of this contribution is to review all the articles reporting statistical evidence concerning the performance of patients in VS vs. patients in MCS, on behavioral or neurophysiological measures. Twenty-three articles matched these inclusion criteria, and comprised behavioral, electroencephalographic (EEG), positron emission tomography (PET) and magnetic resonance imaging (MRI) measures. The analysis of these articles yielded 47 different statistical findings. More than half of these findings (n = 24) did not reveal any statistically significant difference between VS and MCS. Overall, there was no combination of variables that allowed reliably discriminating between VS and MCS. This pattern of results casts doubt on the empirical validity of the distinction between VS and MCS. PMID:25404905

  13. The Kepler Dichotomy among the M Dwarfs: Half of Systems Contain Five or More Coplanar Planets

    NASA Astrophysics Data System (ADS)

    Ballard, Sarah; Johnson, John Asher

    2016-01-01

    We present a statistical analysis of the Kepler M dwarf planet hosts, with a particular focus on the fractional number of systems hosting multiple transiting planets. We manufacture synthetic planetary systems within a range of planet multiplicity and mutual inclination for comparison to the Kepler yield. Similarly to studies of Kepler exoplanetary systems around more massive stars, we report that the number of singly transiting planets found by Kepler is too high to be consistent with a single population of multi-planet systems, a finding that cannot be attributed to selection biases. To account for the excess singleton planetary systems we adopt a mixture model and find that 53 ± 10% of planetary systems are either single or contain multiple planets with large mutual inclinations. The other 47 ± 10% of systems contain {7.5}-1.5+0.5 planets with mutual inclinations of 2.°0 ± 1.°3. This mutual inclination range is consistent with studies of transit durations within multiply transiting systems. The mixture model is preferred 8:1 to a model with only one architecture. Thus, we find that the so-called “Kepler dichotomy” holds for planets orbiting M dwarfs as well as Sun-like stars.

  14. "Formative Good, Summative Bad?"--A Review of the Dichotomy in Assessment Literature

    ERIC Educational Resources Information Center

    Lau, Alice Man Sze

    2016-01-01

    The debate between summative and formative assessment is creating a situation that increasingly calls to mind the famous slogan in George Orwell's (1945) "Animal Farm"--"Four legs good, two legs bad". Formative assessment is increasingly being portrayed in the literature as "good" assessment, which tutors should…

  15. "Ownership" of English in the Outer Circle: An Alternative to the NS-NNS Dichotomy

    ERIC Educational Resources Information Center

    Higgins, Christina

    2003-01-01

    The linguistic classification of English speakers from outer-circle countries, such as India, Malaysia, and Singapore, is often ambiguous because the Englishes they speak are considered different from interlanguages yet are not considered native varieties. This study investigates whether outer-circle speakers can be viewed as equivalent to…

  16. The dichotomy of memantine treatment for ischemic stroke: dose-dependent protective and detrimental effects

    PubMed Central

    Trotman, Melissa; Vermehren, Philipp; Gibson, Claire L; Fern, Robert

    2015-01-01

    Excitotoxicity is a major contributor to cell death during the acute phase of ischemic stroke but aggressive pharmacological targeting of excitotoxicity has failed clinically. Here we investigated whether pretreatment with low doses of memantine, within the range currently used and well tolerated for the treatment of Alzheimer's disease, produce a protective effect in stroke. A coculture preparation exposed to modeled ischemia showed cell death associated with rapid glutamate rises and cytotoxic Ca2+ influx. Cell death was significantly enhanced in the presence of high memantine concentrations. However, low memantine concentrations significantly protected neurons and glia via excitotoxic cascade interruption. Mice were systemically administered a range of memantine doses (0.02, 0.2, 2, 10, and 20 mg/kg/day) starting 24 hours before 60 minutes reversible focal cerebral ischemia and continuing for a 48-hour recovery period. Low dose (0.2 mg/kg/day) memantine treatment significantly reduced lesion volume (by 30% to 50%) and improved behavioral outcomes in stroke lesions that had been separated into either small/striatal or large/striatocortical infarcts. However, higher doses of memantine (20 mg/kg/day) significantly increased injury. These results show that clinically established low doses of memantine should be considered for patients ‘at risk' of stroke, while higher doses are contraindicated. PMID:25407270

  17. Dichotomy in mode propagation of coseismic ionospheric disturbance: Observations from 11 April 2012 Indian Ocean earthquake

    NASA Astrophysics Data System (ADS)

    Catherine, J. K.; Vijayan, M. S. M.; Syeda Rabiya, U. B.; Shimna, K.; Gahalaut, Vineet K.; Ramesh, D. S.

    2015-05-01

    The ionosphere response to the great intraplate Indian Ocean earthquake of 11 April 2012 (Mw 8.6) and its largest aftershock (Mw 8.2) is analyzed using GPS-aided total electron content (TEC) measurements. Data from the dense GPS networks, SuGAr (Sumatran GPS Array) and the permanent Andaman-Nicobar array, formed the near-field observations at distances 250-1200 km from the epicenter. Stations such as IISC, DGAR, and few others provided measurements over 2000 km from the epicenter. The coseismic ionospheric disturbances (CIDs) with a propagation velocity of 930-1262 m/s, equals the speeds of the shock acoustic waves, arrive within 10-18 min after the earthquake occurrence. The observed phenomenon of CID splitting into two modes, north and south of the epicenter, is akin to the well-documented effects of anisotropy on wave propagation. Closer to the epicenter, to its south, the propagation velocity of CID is ~1 km/s, and farther southeast of the network the velocity reduces to 500-600 m/s. In contrast, toward Andaman in the north, the CID propagation velocity increases to 2-3.5 km/s. The zenith angle of the line of sight between the GPS receiver and satellite appears to influence the amplitude of the TEC fluctuations. The anomalous azimuthal variation of the Rayleigh wave radiation pattern best explains the observed N-S asymmetry of CID.

  18. Mars Human Science Exploration and Resource Utilization: The Dichotomy Boundary Deuteronilus Mensae Exploration Zone

    NASA Astrophysics Data System (ADS)

    Head, J. W.; Dickson, J.; Milliken, R.; Scott, D.; Johnson, B.; Marchant, D.; Levy, J.; Kinch, K.; Hvidberg, C.; Forget, F.; Boucher, D.; Mikucki, J.; Fastook, J.; Klaus, K.

    2015-10-01

    Deuteronilus Mensae EZ combines: 1) Fundamental MEPAG scientific objectives; 2) Samples from the Noachian, Hesperian and Amazonian); 3) ISRU access to abundant water ice mapped by SHARAD; 4) Civil Engineering to reduce reliance on Earth supplies.

  19. Reassessing the relationship between brain size, life history, and metabolism at the marsupial/placental dichotomy.

    PubMed

    Weisbecker, Vera; Goswami, Anjali

    2014-09-01

    A vigorous discussion surrounds the question as to what enables some mammals--including primates and cetaceans--to evolve large brains. We recently published a study suggesting that the radiation of marsupial mammals is highly relevant to this question because of the unique reproductive and metabolic traits within this clade. In particular, we controversially suggested that marsupial brain sizes are not systematically smaller than those of placentals, and that elevated basal metabolic rates (BMR) are not linked to larger marsupial brains. As our dataset was found to contain some erroneous body size data, derived from a published source, we here use an updated and corrected dataset and employ standard as well as phylogenetically corrected analyses to re-assess and elaborate on our original conclusions. Our proposal that marsupials are not systematically smaller-brained than placentals remains supported, particularly when the unusually large-brained placental clade, Primates, is excluded. Use of the new dataset not only confirms that high metabolic rates are not associated with larger brain size in marsupials, but we additionally find some support for a striking negative correlation between BMR and brain size. The best supported correlates of large brain size remain the reproductive traits of weaning age and litter size. These results support our suggestion that mammalian brain sizes (including, by inference, those of monotremes) are predominantly constrained by the ability of females to fuel the growth of their offspring's large brains, rather than by the maintenance requirements of the adult brain. PMID:25186933

  20. Causal reasoning versus associative learning: A useful dichotomy or a strawman battle in comparative psychology?

    PubMed

    Hanus, Daniel

    2016-08-01

    The debate about whether or not one could/should ascribe reasoning abilities to animals has deep historical roots and seems very up-to-date in the light of the immense body of new empirical data originating from various species and research paradigms. Associative learning (AL) seems to be a ubiquitous low-level contender for any cognitive interpretation of animal behavior, mostly because of the assumed mechanistic simplicity and phylogenetic prevalence. However, the implicit assumption that AL is simple and therefore the most parsimonious mechanism to describe seemingly complex behavior can and must be questioned on various grounds. Using recent empirical findings with chimpanzees as an example, I argue that at times inferential reasoning might be the most likely candidate to account for performance differences between experimental and control conditions. Finally, a general conclusion drawn from the current debate(s) in the field of comparative psychology could be that a dichotomist battle of 2 conceptual camps-each of which is lacking a clear and homogeneous theoretical framework-is a scientific deadlock. (PsycINFO Database Record PMID:27512825

  1. Activity as Object-Related: Resolving the Dichotomy of Individual and Collective Planes of Activity

    ERIC Educational Resources Information Center

    Stetsenko, Anna

    2005-01-01

    This article suggests that the principle of object-relatedness, introduced by Vygotsky and expanded by A. N. Leontiev, can be used to conceptualize human subjectivity within a profoundly social view of human development. This is achieved by reformulating the premises of cultural-historical activity theory to include the notion that material…

  2. A Computer Program to Determine Relations among Genuine Dichotomies: The Phi and G Statistics

    ERIC Educational Resources Information Center

    Chamberlain, Howard; Van Fleet, David D.

    1975-01-01

    The Phi and G statistics for dichotomous variables are discussed and a Fortran program to compute them is described. Input is to be in card form, output may be printed, punched, or placed on magnetic tape. The punch or tape output is designed to be used as input for the BMD X72 factor analysis program. (Author)

  3. Solitary Fibrous Tumor/Hemangiopericytoma Dichotomy Revisited: A Restless Family of Neoplasms in the CNS.

    PubMed

    Yalcin, Can Ege; Tihan, Tarik

    2016-03-01

    Solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) both entered the literature as separate entities in the early to mid 1900s. In contrast to their central nervous system (CNS) counterparts, there has been a tendency to consider these 2 entities as 1 since the early 1990s, as soft tissue SFT gradually included the tumors previously diagnosed as HPC. The most recent World Health Organization (WHO) classification of the tumors of soft tissue considered the term HPC obsolete, and places all such tumors within the extrapleural SFT category. In contrast, CNS SFT and HPC continue to be regarded as different entities in the latest version of the WHO CNS tumor classification. A change in this approach is currently being considered for the upcoming revision of the WHO scheme, but it is not quite clear whether such a change will be as drastic as the one adopted by the soft tissue and bone tumor working group. This article focuses on the historical evolution of these 2 labels as primary CNS neoplasms, and reviews their differences and similarities in terms of clinical, pathologic, and molecular features. PMID:26849816

  4. Gender Neutralities, Dichotomies and Hidden Inequalities: Analysis of Vocational Teachers' Reflections on Gender in the Profession

    ERIC Educational Resources Information Center

    Lappalainen, Sirpa; Lahelma, Elina; Pehkonen, Leila; Isopahkala-Bouret, Ulpukka

    2012-01-01

    This article analyses how Finnish vocational teachers make sense of the meanings of gender in their work. The context of the study consists of the two most gender segregated environments of vocational education: the female-dominated Sector of Health and Social Services and the male-dominated Sector of Technology and Transport. Our analysis draws…

  5. The dichotomy of memantine treatment for ischemic stroke: dose-dependent protective and detrimental effects.

    PubMed

    Trotman, Melissa; Vermehren, Philipp; Gibson, Claire L; Fern, Robert

    2015-02-01

    Excitotoxicity is a major contributor to cell death during the acute phase of ischemic stroke but aggressive pharmacological targeting of excitotoxicity has failed clinically. Here we investigated whether pretreatment with low doses of memantine, within the range currently used and well tolerated for the treatment of Alzheimer's disease, produce a protective effect in stroke. A coculture preparation exposed to modeled ischemia showed cell death associated with rapid glutamate rises and cytotoxic Ca(2+) influx. Cell death was significantly enhanced in the presence of high memantine concentrations. However, low memantine concentrations significantly protected neurons and glia via excitotoxic cascade interruption. Mice were systemically administered a range of memantine doses (0.02, 0.2, 2, 10, and 20 mg/kg/day) starting 24 hours before 60 minutes reversible focal cerebral ischemia and continuing for a 48-hour recovery period. Low dose (0.2 mg/kg/day) memantine treatment significantly reduced lesion volume (by 30% to 50%) and improved behavioral outcomes in stroke lesions that had been separated into either small/striatal or large/striatocortical infarcts. However, higher doses of memantine (20 mg/kg/day) significantly increased injury. These results show that clinically established low doses of memantine should be considered for patients 'at risk' of stroke, while higher doses are contraindicated. PMID:25407270

  6. Multi-paddock grazing on rangelands: why the perceptual dichotomy between research results and rancher experience?

    PubMed

    Teague, Richard; Provenza, Fred; Kreuter, Urs; Steffens, Tim; Barnes, Matt

    2013-10-15

    Maintaining or enhancing the productive capacity and resilience of rangeland ecosystems is critical for the continued support of people who depend on them for their livelihoods, especially in the face of climatic change. This is also necessary for the continued delivery of ecosystem services derived from rangelands for the broader benefit of societies around the world. Multi-paddock grazing management has been recommended since the mid-20th century as an important tool to adaptively manage rangelands ecosystems to sustain productivity and improve animal management. Moreover, there is much anecdotal evidence from producers that, if applied appropriately, multi-paddock grazing can improve forage and livestock production. By contrast, recent reviews of published rangeland-based grazing systems studies have concluded that, in general, field trials show no superiority of vegetation or animal production in multi-paddock grazing relative to continuous yearlong stocking of single-paddock livestock production systems. Our goal is to provide a framework for rangeland management decisions that support the productivity and resiliency of rangelands and then to identify why different perceptions exist among rangeland managers who have effectively used multi-paddock grazing systems and research scientists who have studied them. First, we discuss the ecology of grazed ecosystems under free-ranging herbivores and under single-paddock fenced conditions. Second, we identify five principles underpinning the adaptive management actions used by successful grazing managers and the ecological, physiological, and behavioral framework they use to achieve desired conservation, production, and financial goals. Third, we examine adaptive management principles needed to successfully manage rangelands subjected to varying environmental conditions. Fourth, we describe the differences between the interpretation of results of grazing systems research reported in the scientific literature and the results reported by successful grazing managers; we highlight the shortcomings of most of the previously conducted grazing systems research for providing information relevant for rangeland managers who aim to achieve desired environmental and economic goals. Finally, we outline knowledge gaps and present testable hypotheses to broaden our understanding of how planned multi-paddock grazing management can be used at the ranching enterprise scale to facilitate the adaptive management of rangelands under dynamic environmental conditions. PMID:23850765

  7. Erasing a false dichotomy: The complex nature of broad absorption line quasars

    NASA Astrophysics Data System (ADS)

    DiPompeo, Michael A.

    The main goal of this thesis is to test the various models proposed to explain the important subclass of quasars known as broad absorption line (BAL) quasars. In particular, I focus on whether viewing angle alone can explain why only a fraction of quasars exhibit BALs in their optical/ultraviolet spectra, or if some other model or combination of models is more likely. Much of the work contained here focuses on radio-selected BAL quasars, a relatively poorly studied class to this point, and so a secondary goal is to provide a detailed analysis of their properties. Finally, I provide a large spectropolarimetric atlas of BAL quasars for use by the community. Using new multi-frequency radio observations of a large sample of BAL quasars, and a carefully selected, well-matched sample of unabsorbed quasars, I show that there does appear to be an overabundance of steep-spectrum BAL sources, though they cover a wide range of spectral slopes. Monte-Carlo modeling of these distributions show that BAL quasars are seen from a range of viewing angles, including all of the viewing angles that unabsorbed quasars are seen from. However, at the largest viewing angles, we will generally see BAL quasars. No other spectral features or quasar outflow properties correlate with viewing angle, suggesting that BAL winds in all directions are driven by the same mechanism. BAL quasars are indeed more likely to be polarized than non-BAL sources. However, this is not simply due to orientation or extinction of the direct un-polarized continuum light, as polarization does not correlate with viewing angle or dust extinction. It seems that there is much variation in the polarizing scattering material, both in its location and geometry, between individual sources. This makes it difficult to use polarization studies to constrain BAL quasar models, though it is likely useful for detailed study of individual objects. Simple explanations using only one parameter are clearly no longer sufficient, and we must move toward a more complex picture to explain these objects.

  8. Stimulus-parity synaesthesia versus stimulus-dichotomy synaesthesia: Odd, even or something else?

    PubMed Central

    White, Rebekah C.; Plassart, Anna

    2015-01-01

    In stimulus-parity synaesthesia, a range of stimuli—for example, letters, numbers, weekdays, months, and colours (the inducers)—elicit an automatic feeling of oddness or evenness (the concurrent). This phenomenon was first described by Théodore Flournoy in 1893, and has only recently been “rediscovered.” Here, we describe an individual who experiences a comparable phenomenon, but uses the labels negative and positive rather than odd and even. Stimulus-parity synaesthesia may be broader than first supposed, and it is important that assessments are sensitive to this breadth. PMID:26034572

  9. Caught in a "West/China Dichotomy": Doing Critical Sociolinguistic Ethnography in Zhejiang Schools

    ERIC Educational Resources Information Center

    Perez-Milans, Miguel

    2011-01-01

    This article focuses on how issues of power and identity were negotiated when doing a critical sociolinguistic ethnography as a Spanish researcher in the Chinese educational context. Data come from fieldwork conducted in 3 different primary and secondary schools together in Zhejiang province, where inside- and outside-classroom…

  10. Predicting the 'where' and resolving the 'what' of a moving target: a dichotomy of abilities.

    PubMed

    Long, G M; Vogel, C A

    1998-01-01

    Anticipation timing (AT) and dynamic visual acuity (DVA) were assessed in a group of college students (n = 60) under a range of velocity and duration conditions. Subjects participated in two identical sessions 1 week apart. Consistently with previous work, DVA performance worsened as velocity increased and as target duration decreased; and there was a significant improvement from the first to the second session. In contrast, AT performance improved as velocity increased, whereas no improvement from the first to the second session was indicated; but increasing duration again benefited performance. Correlational analyses comparing DVA and AT did not reveal any systematic relationship between the two visual tasks. A follow-up study with different instructions on the AT task revealed the same pattern of AT performance, suggesting the generalizability of the obtained stimulus relationships for the AT task. The importance of the often-overlooked role of stimulus variables on the AT task is discussed. PMID:9797917

  11. Is It Dichotomy or Tension: I Am a Scientist. No, Wait! I Am a Teacher!

    ERIC Educational Resources Information Center

    Aydeniz, Mehmet; Hodge, Lynn Liao

    2011-01-01

    This study explores through a naturalistic inquiry the tensions between a science professor's two enacted identities. More specifically, this study looks at how a biology professor's identity-in-practice shifts and evolves over time through collaborations with a science education professor. These shifts were marked by an emphasis on teaching,…

  12. Moving beyond the Dichotomy: Meeting the Needs of Urban Students through Contextually-Relevant Education Practices

    ERIC Educational Resources Information Center

    Seaton, Gregory; Dell'Angelo, Tabitha; Spencer, Margaret Beale; Youngblood, Joseph

    2007-01-01

    The goal of this article is to move beyond the more traditional question, "Does business have a role in public education?" A historical overview of education suggests that the involvement of the private sector is not a new phenomenon and is not likely to end in the near future. Here, the authors argue that a much more fruitful line of inquiry is…

  13. From Dichotomy to Divergence: Number/Gender Marking on Hebrew Nouns and Adjectives across School Ages

    ERIC Educational Resources Information Center

    Ravid, Dorit; Schiff, Rachel

    2012-01-01

    This study investigates the development of plural adjective agreement in Hebrew, focusing on the consolidation of Hebrew number/gender morphology in children and adolescents across the school years in comparison with adults. A total of 240 Hebrew-speaking participants in seven consecutive grade levels (kindergarten to sixth grade) plus a group of…

  14. [Population distribution and economic crisis in the 1980s: dichotomies and speculations].

    PubMed

    Ruiz Chiapetto, C

    1990-01-01

    The author attempts to determine whether the economic crisis of the 1980s has caused an increase or a decrease in population concentration in Mexico. Theories related to the topic are summarized, and data on past and current trends in population and economy in Mexico are analyzed. A forecast of future trends in population distribution and urbanization is also provided. PMID:12316454

  15. "Glocalization": Going beyond the Dichotomy of Global versus Local through Additive Multilingualism

    ERIC Educational Resources Information Center

    Joseph, Michael; Ramani, Esther

    2012-01-01

    This article interrogates the notion of "glocalization" (Moja, 2004, based on Castells, 2001) as a concept that seeks to integrate the local and the global to address both the need for social justice and the need to participate in a global market economy. The article argues that the relation between the global and the local cannot be explored…

  16. Academic Staff Performance and Workload in Higher Education in the UK: The Conceptual Dichotomy

    ERIC Educational Resources Information Center

    Graham, Andrew T.

    2015-01-01

    Higher education in the UK is under increasing pressure to manage the workload of its academic staff in a way that maximises the outputs from teaching and research. The emergence of this trend can be traced back to 1989 and the government legislation that introduced neo-liberal managerialism into the sector mirroring the laissez-faire approach to…

  17. Institutional Academic Freedom vs. Faculty Academic Freedom in Public Colleges and Universities: A Dubious Dichotomy.

    ERIC Educational Resources Information Center

    Hiers, Richard H.

    2002-01-01

    Analyzes the origins of recent federal appellate decisions' divergence from the Supreme Court's identification of teachers' or faculty's academic freedom as "a special concern of the First Amendment." Suggests ways in which academic freedom might better be accorded its rightful importance within the framework of current Supreme Court First…

  18. The Clinical-Forensic Dichotomy in Sexual Abuse Evaluations: Moving toward an Integrative Model

    ERIC Educational Resources Information Center

    Tishelman, Amy C.; Meyer, Susanne K.; Haney, Penny; McLeod, Sara K.

    2010-01-01

    We propose the use of an approach to evaluation that can be undertaken in a clinical setting when concerns regarding child sexual abuse are unclear or ambiguous and other systems are not involved, thus providing an option for the nondisclosing child often discussed in the "delayed disclosure" literature. This approach can also be appropriate for a…

  19. Dichotomy in the population of young AGN: Optical, radio, and X-ray properties

    NASA Astrophysics Data System (ADS)

    Kunert-Bajraszewska, M.

    2016-02-01

    There are numerous examples of radio sources with various sizes which surprisingly exhibit very similar morphology. This observational fact helped to create a standard evolutionary model in which young and small radio-loud active galactic nuclei (AGN), called gigahertz-peaked spectrum (GPS) sources and compact steep spectrum (CSS) sources, become large-scale radio objects. However, many details of this evolutionary process are still unclear. We explored evolution scenarios of radio-loud AGN using new radio, optical and X-ray data of so far unstudied low luminosity compact (LLC) sources and we summarize the results in this paper. Our studies show that the evolutionary track is very ``individualized'' although we can mention common factors affecting it. These are interaction with the ambient medium and AGN power. The second feature affects the production of the radio jets which, if they are weak, are more vulnerable for instabilities and disruption. Thus not all GPS and CSS sources will be able to develop large scale morphologies. Many will fade away being middle-aged (105 yr). It seems that only radio strong, high excitation compact AGN can be progenitors of large-scale FR II radio sources.

  20. Culture Consciousness among Hmong Immigrant Leaders: Beyond the Dichotomy of Cultural Essentialism and Cultural Hybridity

    ERIC Educational Resources Information Center

    Ngo, Bic

    2013-01-01

    This article illustrates the culture consciousness of Hmong immigrant community leaders as they made sense of the educational experiences of Hmong American children and families. It draws on the work of scholars who have theorized "critical" essentialism to suggest that Hmong leaders are critically aware of the role and import of…

  1. The Displaced vs. the Disadvantaged: A Necessary Dichotomy? Occasional Paper 1994-2.

    ERIC Educational Resources Information Center

    Levitan, Sar A.; Mangum, Stephen L.

    The current displaced worker initiative towers over the 30-year effort to bring the economically disadvantaged into the mainstream of the labor market. The Congressional Budget Office defines displacement as all workers 18 years of age and older who lose full-time employment due to slack work, job abolition, or plant closure. Major displaced…

  2. Does a String-Particle Dualism Indicate the Uncertainty Principle's Philosophical Dichotomy?

    NASA Astrophysics Data System (ADS)

    Mc Leod, David; Mc Leod, Roger

    2007-04-01

    String theory may allow resonances of neutrino-wave-strings to account for all experimentally detected phenomena. Particle theory logically, and physically, provides an alternate, contradictory dualism. Is it contradictory to symbolically and simultaneously state that λp = h, but, the product of position and momentum must be greater than, or equal to, the same (scaled) Plank's constant? Our previous electron and positron models require `membrane' vibrations of string-linked neutrinos, in closed loops, to behave like traveling waves, Tws, intermittently metamorphosing into alternately ascending and descending standing waves, Sws, between the nodes, which advance sequentially through 360 degrees. Accumulated time passages as Tws detail required ``loop currents'' supplying magnetic moments. Remaining time partitions into the Sws' alternately ascending and descending phases: the physical basis of the experimentally established 3D modes of these ``particles.'' Waves seem to indicate that point mass cannot be required to exist instantaneously at one point; Mott's and Sneddon's Wave Mechanics says that a constant, [mass], is present. String-like resonances may also account for homeopathy's efficacy, dark matter, and constellations' ``stick-figure projections,'' as indicated by some traditional cultures, all possibly involving neutrino strings. To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.NES07.C2.5

  3. Straw Men and False Dichotomies: Overcoming Philosophical Confusion in Chemical Education

    ERIC Educational Resources Information Center

    Taber, Keith S.

    2010-01-01

    Constructivism has been widely considered the most influential perspective in science education research for some decades, and has been the basis of widespread pedagogic advice in many educational contexts. Yet it has been claimed in this "Journal" that the philosophical basis of constructivist thought in chemical education is confused, and…

  4. Gender as Contradiction: From Dichotomies to Diversity in Natural Resource Extraction

    ERIC Educational Resources Information Center

    O'Shaughnessy, Sara; Krogman, Naomi T.

    2011-01-01

    Given the varied nature of resource dependent communities, the gendered experiences of women and men may vary in unexpected and contradictory ways. Building on a review and critique of existing theoretical approaches and studies of US and Canadian extractive resource communities in both the feminist and rural social science literature, we provide…

  5. The syn/anti-Dichotomy in the Palladium-Catalyzed Addition of Nucleophiles to Alkenes

    PubMed Central

    Kočovský, Pavel; Bäckvall, Jan-E

    2015-01-01

    In this review the stereochemistry of palladium-catalyzed addition of nucleophiles to alkenes is discussed, and examples of these reactions in organic synthesis are given. Most of the reactions discussed involve oxygen and nitrogen nucleophiles; the Wacker oxidation of ethylene has been reviewed in detail. An anti-hydroxypalladation in the Wacker oxidation has strong support from both experimental and computational studies. From the reviewed material it is clear that anti-addition of oxygen and nitrogen nucleophiles is strongly favored in intermolecular addition to olefin–palladium complexes even if the nucleophile is coordinated to the metal. On the other hand, syn-addition is common in the case of intramolecular oxy- and amidopalladation as a result of the initial coordination of the internal nucleophile to the metal. PMID:25378278

  6. DOES THE OOSTERHOFF DICHOTOMY EXIST IN THE ANDROMEDA GALAXY? I. THE CASE OF G11

    SciTech Connect

    Contreras Ramos, Rodrigo; Clementini, Gisella; Federici, Luciana E-mail: gisella.clementini@oabo.inaf.it; and others

    2013-03-01

    We present the first evidence that Oosterhoff type II globular clusters exist in the Andromeda galaxy (M31). On the basis of time-series photometry of the moderately metal-poor ([Fe/H] {approx}-1.6 dex) M31 globular cluster G11, obtained with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope, we detected and derived periods for 14 RR Lyrae stars, of which five are found to lie inside the cluster tidal radius. They include three fundamental-mode (RRab) and two first-overtone (RRc) pulsators, with average periods (P{sub ab} ) = 0.70 days, and (P{sub c} ) = 0.40 days, respectively. These mean periods and the position of the cluster variable stars in the period-amplitude and period-metallicity diagrams all suggest that G11 is likely to be an Oosterhoff type II globular cluster. This appears to be in agreement with the general behavior of Milky Way globular clusters with similar metallicity and horizontal branch morphology.

  7. A convenient dichotomy: critical eyes on the limits to biological knowledge

    NASA Astrophysics Data System (ADS)

    Milne, Catherine

    2011-06-01

    In The Secret Identity of a Biology Textbook: straight and naturally sexed, Jesse Bazzul and Heather Sykes conduct a case study of a biology textbook as an oppressive instructional material. Using queer theory they explore how the text of the biology textbook produces "truths" about sex, gender, and sexuality. Their analysis is complemented by the Forum papers by Jay Lemke and Francis Broadway who broaden the analysis examining the way that what counts as knowledge in science is a political decision while also encouraging authors, including Bazzul and Sykes, to also look critically at their own theoretical lenses. In this paper I pull together their ideas while exploring cultural contexts for a more nuanced representation of biological knowledge and the politics of what it means to know science.

  8. Impact of the Changing Environment on Academic Library Administration: Conflicts, Incongruities, Contradictions and Dichotomies.

    ERIC Educational Resources Information Center

    Moore, Mary

    1995-01-01

    The application of business skills and practices to the operation of academic libraries is becoming popular. Management skills will be useful as increased information production and technological complexity are being offset by shortages in resources and labor. To avoid conflict, managers must focus on teamwork, quality, customer service,…

  9. Ethical/Legal Dichotomies on the First Amendment Rights of the Student Press.

    ERIC Educational Resources Information Center

    Broussard, E. Joseph; Blackmon, C. Robert

    A survey was conducted of 260 high school principals in 48 states concerning their knowledge of communication law as it related to freedom of the press under the First Amendment of the United States Constitution. The survey instrument contained information concerning nine composite court cases, and respondents were asked to indicate for each case…

  10. Beyond the 'east-west' dichotomy: Global variation in cultural models of selfhood.

    PubMed

    Vignoles, Vivian L; Owe, Ellinor; Becker, Maja; Smith, Peter B; Easterbrook, Matthew J; Brown, Rupert; González, Roberto; Didier, Nicolas; Carrasco, Diego; Cadena, Maria Paz; Lay, Siugmin; Schwartz, Seth J; Des Rosiers, Sabrina E; Villamar, Juan A; Gavreliuc, Alin; Zinkeng, Martina; Kreuzbauer, Robert; Baguma, Peter; Martin, Mariana; Tatarko, Alexander; Herman, Ginette; de Sauvage, Isabelle; Courtois, Marie; Garðarsdóttir, Ragna B; Harb, Charles; Schweiger Gallo, Inge; Prieto Gil, Paula; Lorente Clemares, Raquel; Campara, Gabriella; Nizharadze, George; Macapagal, Ma Elizabeth J; Jalal, Baland; Bourguignon, David; Zhang, Jianxin; Lv, Shaobo; Chybicka, Aneta; Yuki, Masaki; Zhang, Xiao; Espinosa, Agustín; Valk, Aune; Abuhamdeh, Sami; Amponsah, Benjamin; Özgen, Emre; Güner, E Ülkü; Yamakoğlu, Nil; Chobthamkit, Phatthanakit; Pyszczynski, Tom; Kesebir, Pelin; Vargas Trujillo, Elvia; Balanta, Paola; Cendales Ayala, Boris; Koller, Silvia H; Jaafar, Jas Laile; Gausel, Nicolay; Fischer, Ronald; Milfont, Taciano L; Kusdil, Ersin; Çağlar, Selinay; Aldhafri, Said; Ferreira, M Cristina; Mekonnen, Kassahun Habtamu; Wang, Qian; Fülöp, Márta; Torres, Ana; Camino, Leoncio; Lemos, Flávia Cristina Silveira; Fritsche, Immo; Möller, Bettina; Regalia, Camillo; Manzi, Claudia; Brambilla, Maria; Bond, Michael Harris

    2016-08-01

    Markus and Kitayama's (1991) theory of independent and interdependent self-construals had a major influence on social, personality, and developmental psychology by highlighting the role of culture in psychological processes. However, research has relied excessively on contrasts between North American and East Asian samples, and commonly used self-report measures of independence and interdependence frequently fail to show predicted cultural differences. We revisited the conceptualization and measurement of independent and interdependent self-construals in 2 large-scale multinational surveys, using improved methods for cross-cultural research. We developed (Study 1: N = 2924 students in 16 nations) and validated across cultures (Study 2: N = 7279 adults from 55 cultural groups in 33 nations) a new 7-dimensional model of self-reported ways of being independent or interdependent. Patterns of global variation support some of Markus and Kitayama's predictions, but a simple contrast between independence and interdependence does not adequately capture the diverse models of selfhood that prevail in different world regions. Cultural groups emphasize different ways of being both independent and interdependent, depending on individualism-collectivism, national socioeconomic development, and religious heritage. Our 7-dimensional model will allow future researchers to test more accurately the implications of cultural models of selfhood for psychological processes in diverse ecocultural contexts. (PsycINFO Database Record PMID:27359126

  11. Overcoming Modern-Postmodern Dichotomies: Some Possible Benefits for the Counselling Profession

    ERIC Educational Resources Information Center

    Bekerman, Zvi; Tatar, Moshe

    2005-01-01

    The rhetorical/discursive turn, in its multiple disciplinary masks, is here to stay. Even psychology is giving in to its charm. The Sophists can smile again, the agora is back, and the solipsistic self is in retreat. Dialogical, narrative, and cultural psychologies, as well as the counselling profession, triumph the return of the social, the…

  12. Current dichotomy between traditional molecular biological and omic research in cancer biology and pharmacology.

    PubMed

    Reinhold, William C

    2015-12-10

    There is currently a split within the cancer research community between traditional molecular biological hypothesis-driven and the more recent "omic" forms or research. While the molecular biological approach employs the tried and true single alteration-single response formulations of experimentation, the omic employs broad-based assay or sample collection approaches that generate large volumes of data. How to integrate the benefits of these two approaches in an efficient and productive fashion remains an outstanding issue. Ideally, one would merge the understandability, exactness, simplicity, and testability of the molecular biological approach, with the larger amounts of data, simultaneous consideration of multiple alterations, consideration of genes both of known interest along with the novel, cross-sample comparisons among cell lines and patient samples, and consideration of directed questions while simultaneously gaining exposure to the novel provided by the omic approach. While at the current time integration of the two disciplines remains problematic, attempts to do so are ongoing, and will be necessary for the understanding of the large cell line screens including the Developmental Therapeutics Program's NCI-60, the Broad Institute's Cancer Cell Line Encyclopedia, and the Wellcome Trust Sanger Institute's Cancer Genome Project, as well as the the Cancer Genome Atlas clinical samples project. Going forward there is significant benefit to be had from the integration of the molecular biological and the omic forms or research, with the desired goal being improved translational understanding and application. PMID:26677427

  13. A Convenient Dichotomy: Critical Eyes on the Limits to Biological Knowledge

    ERIC Educational Resources Information Center

    Milne, Catherine

    2011-01-01

    In "The Secret Identity of a Biology Textbook: straight and naturally sexed," Jesse Bazzul and Heather Sykes conduct a case study of a biology textbook as an oppressive instructional material. Using queer theory they explore how the text of the biology textbook produces "truths" about sex, gender, and sexuality. Their analysis is complemented by…

  14. [Dichotomy of psychiatric and somatic emergency care; fundamental flaw should be addressed].

    PubMed

    Tuerlings, Joep H A M; Pelger, E C M Noor; de Pont, Boudewijn J H B; van Waarde, Jeroen A

    2015-01-01

    In the Netherlands, acute psychiatric care is characterised by mind-body dualism. For acute psychiatric patients, the first port of call is the general practitioner (GP); after-hour care is provided by the out-of-hours GP service. In contrast to patients with other medical illnesses, the out-of-hours GP service does not usually refer patients with acute psychiatric issues to the accident and emergency (A&E) department of the general hospital, but to the local ambulant psychiatric 'crisis' service. However, some of these patients still end up at the A&E department, as our three cases demonstrate. Integration of the out-of-hours GP service, A&E and acute psychiatric care, therefore, would enable elimination of the current partitioning of somatic and psychiatric medicine in acute emergency care. This solution would not only improve acute emergency care, but would also ensure a targeted and efficient implementation of services and might even lead to a decreased stigmatisation of psychiatric patients in general. PMID:26230348

  15. ABA and PBS: The Dangers in Creating Artificial Dichotomies in Behavioral Intervention

    ERIC Educational Resources Information Center

    Weiss, Mary Jane; DelPizzo-Cheng, Eliza; LaRue, Robert H.; Sloman, Kimberly

    2009-01-01

    In recent years, there has been a great deal of controversy regarding the definition and independence of Positive Behavioral Supports (PBS) within the context of behavioral intervention. Specifically, behavior analysts have argued over whether PBS is subsumed within Applied Behavior Analysis (ABA) or whether it can be considered a separate…

  16. Affective Aspects on Mathematics Conceptualization: From Dichotomies to an Integrated Approach

    ERIC Educational Resources Information Center

    Araujo, Claudia Roberta; Andrade, Fernanda; Hazin, Izabel; Falcao, Jorge Tarcisio da Rocha; do Nascimento, Jorge Costa; Lessa, Monica Maria Lins

    2003-01-01

    The present paper aims to propose a theoretical reflection in order to overcome a strong tradition in psychology concerning the analysis of cognition and affectivity as dichotomic processes explaining human behaviours. A general theory of the human subject is presented to discussion, followed by the proposition of a new unit of analysis for the…

  17. Thermodynamics versus Kinetics Dichotomy in the Linear Self-Assembly of Mixed Nanoblocks.

    PubMed

    Ruiz, L; Keten, S

    2014-06-01

    We report classical and replica exchange molecular dynamics simulations that establish the mechanisms underpinning the growth kinetics of a binary mix of nanorings that form striped nanotubes via self-assembly. A step-growth coalescence model captures the growth process of the nanotubes, which suggests that high aspect ratio nanostructures can grow by obeying the universal laws of self-similar coarsening, contrary to systems that grow through nucleation and elongation. Notably, striped patterns do not depend on specific growth mechanisms, but are governed by tempering conditions that control the likelihood of depropagation and fragmentation. PMID:26273889

  18. Synergy or dichotomy: vapor and particle sampling in the detection of contraband

    NASA Astrophysics Data System (ADS)

    Davidson, William R.; Stott, William R.; Sleeman, Richard; Akery, Alan K.

    1994-03-01

    Chemical detection techniques for explosive and illicit drug identification were originally directed towards the detection of vapors, with research groups aiming toward the specific target of creating a mechanical dog. With the advent of the mass spectrometry based contraband detection systems, exemplified by the CONDORTM which relies on both the detection of vapors and particles, research groups and instrument manufacturers changed direction and began to develop techniques mainly oriented toward the detection of trace particles. The major advantage to the use of trace particulate residues in the detection of hazardous material is that the actual substance can be identified in nearly all cases. On the other hand, as is discussed in detail in later sections of this document, sampling of complex items can be difficult. Both vapor and particulate sampling can be invaluable in the detection of hazardous materials. In many instances the techniques offer complementary information, and results obtained via one route may lead to the use of the alternative method (for example, the vapor detection of taggants as a screening technique followed by particulate analysis for the actual target). The concepts discussed in the remainder of this paper focus on the use of tandem mass spectrometry as an analytical device in the detection of contraband materials.

  19. Muslim American University Students' Perceptions of Islam and Democracy: Deconstructing the Dichotomy

    ERIC Educational Resources Information Center

    Lamont, Sarah; Collet, Bruce

    2013-01-01

    The aftermath of 9/11 and the current surge of revolutions in North Africa and the Middle East have caused Muslim Americans to be either demonized or forgotten altogether, despite the significance of their everyday navigation of both Islamic and democratic values and unique efforts toward identity construction. The neglect of the Muslim American…

  20. Reconstructing Multicultural Education through Personal Story: Transcending the Essentialist/Relativist Dichotomy

    ERIC Educational Resources Information Center

    Lake, Robert

    2010-01-01

    Like so many other concepts in education, multiculturalism is a term that has lost its potency because of miseducative examples that serve to maintain Whiteness as the cultural norm. At first it offered great promise, but now as a "social science" quite often one is just exchanging one type of essentialism for another. The "packet" approach that…