Sample records for fronto-occipital fasciculus revisited

  1. The left inferior fronto-occipital fasciculus subserves language semantics: a multilevel lesion study.

    PubMed

    Almairac, Fabien; Herbet, Guillaume; Moritz-Gasser, Sylvie; de Champfleur, Nicolas Menjot; Duffau, Hugues

    2015-07-01

    Consequential works in cognitive neuroscience have led to the formulation of an interactive dual-stream model of language processing: the dorsal stream may process the phonological aspects of language, whereas the ventral stream may process the semantic aspects of language. While it is well-accepted that the dorsal route is subserved by the arcuate fasciculus, the structural connectivity of the semantic ventral stream is a matter of dispute. Here we designed a longitudinal study to gain new insights into this central but controversial question. Thirty-one patients harboring a left diffuse low-grade glioma-a rare neurological condition that infiltrates preferentially white matter associative pathways-were assessed with a prototypical task of language (i.e. verbal fluency) before and after surgery. All were operated under local anesthesia with a cortical and subcortical brain mapping-enabling to identify and preserve eloquent structures for language. We performed voxel-based lesion-symptom (VLSM) analyses on pre- and postoperative behavioral data. Preoperatively, we found a significant relationship between semantic fluency scores and the white matter fibers shaping the ventro-lateral connectivity (P < 0.05 corrected). The statistical map was found to substantially overlap with the spatial position of the inferior fronto-occipital fasciculus (IFOF) (37.7 %). Furthermore, a negative correlation was observed between semantic fluency scores and the infiltration volumes in this fasciculus (r = -0.4, P = 0.029). Postoperatively, VLSM analyses were inconclusive. Taken as a whole and when combined with the literature data, our findings strengthen the view that the IFOF plays an essential role in semantic processing and may subserve the direct ventral pathway of language. PMID:24744151

  2. Decreased white matter integrity in fronto-occipital fasciculus bundles: relation to visual information processing in alcohol-dependent subjects.

    PubMed

    Bagga, Deepika; Sharma, Aakansha; Kumari, Archana; Kaur, Prabhjot; Bhattacharya, Debajyoti; Garg, Mohan Lal; Khushu, Subash; Singh, Namita

    2014-02-01

    Chronic alcohol abuse is characterized by impaired cognitive abilities with a more severe deficit in visual than in verbal functions. Neuropathologically, it is associated with widespread brain structural compromise marked by gray matter shrinkage, ventricular enlargement, and white matter degradation. The present study sought to increase current understanding of the impairment of visual processing abilities in alcohol-dependent subjects, and its correlation with white matter microstructural alterations, using diffusion tensor imaging (DTI). To that end, a DTI study was carried out on 35 alcohol-dependent subjects and 30 healthy male control subjects. Neuropsychological tests were assessed for visual processing skills and deficits were reported as raw dysfunction scores (rDyS). Reduced FA (fractional anisotropy) and increased MD (mean diffusivity) were observed bilaterally in inferior and superior fronto-occipital fasciculus (FOF) fiber bundles. A significant inverse correlation in rDyS and FA values was observed in these fiber tracts whereas a positive correlation of these scores was found with the MD values. Our results suggest that FOF fiber bundles linking the frontal lobe to occipital lobe might be related to visual processing skills. This is the first report of an alteration of the white matter microstructure of FOF fiber bundles that might have functional consequences for visual processing in alcohol-dependent subjects who exhibit no neurological complications. PMID:24388377

  3. Neuropsychological evidence for the functional role of the uncinate fasciculus in semantic control.

    PubMed

    Harvey, Denise Y; Wei, Tao; Ellmore, Timothy M; Hamilton, A Cris; Schnur, Tatiana T

    2013-04-01

    Understanding a word requires mapping sounds to a word-form and then identifying its correct meaning, which in some cases necessitates the recruitment of cognitive control processes to direct the activation of semantic knowledge in a task appropriate manner (i.e., semantic control). Neuroimaging and neuropsychological studies identify a fronto-temporal network important for word comprehension. However, little is known about the connectional architecture subserving controlled retrieval and selection of semantic knowledge during word comprehension. We used diffusion tensor imaging (DTI) and resting-state functional magnetic resonance imaging (rs-fMRI) in aphasic individuals with varying degrees of word comprehension deficits to examine the role of three white matter pathways within this network: the uncinate fasciculus (UF), inferior longitudinal fasciculus (ILF), and inferior fronto-occipital fasciculus (IFOF). Neuroimaging data from a group of age-matched controls were also collected in order to establish that the patient group had decreased structural and functional connectivity profiles. We obtained behavioral data from aphasic participants on two measures of single word comprehension that involve semantic control, and assessed pathway functional significance by correlating patients' performance with indices of pathway structural integrity and the functional connectivity profiles of regions they connect. Both the structural integrity of the UF and the functional connectivity strength of regions it connects predicted patients' performance. This result suggests the semantic control impairment in word comprehension resulted from poor neural communication between regions the UF connects. Inspections of other subcortical and cortical structures revealed no relationship with patients' performance. We conclude that the UF mediates semantic control during word comprehension by connecting regions specialized for cognitive control with those storing word meanings. These findings also support a relationship between structural and functional connectivity measures, as the rs-fMRI results provide converging evidence with those obtained using DTI. PMID:23395830

  4. Cytotoxic constituents from Podocarpus fasciculus.

    PubMed

    Kuo, Yu-Jen; Hwang, Shy-Yuan; Wu, Ming-Der; Liao, Chia-Ching; Liang, Yu-Han; Kuo, Yao-Haur; Ho, Hsiu-O

    2008-04-01

    A new diterpene, 16-hydroxy communic acid (1), along with thirty one known compounds including five norditerpenes (2-6), twenty two flavonoids containing four biflavonoids (7-10), nine monoflavonoids (11-19) and nine flavanoid glycosides (20-28), as well as four phenolic constituents (29-32) were isolated from the 95% ethanolic extract of Podocarpus fasciculus. The structure of 1 was elucidated using spectral methods. Of these isolates, nagilactone C (2) showed the most significant inhibitory effects against DLD cells (human colon carcinoma) (ED(50)=2.57 microg/ml) and compounds 7, 8, 10, 11, and 12 had moderate cytotoxic activity against human KB (human oral epithelium carcinoma), Hela (human cervical carcinoma), Hepa (human hepatoma), DLD (colon carcinoma), and A-549 (human lung carcinoma) tumor cell lines. Preliminary structure-activity relationship studies of the isolated diterpenoids and biflavonoids are discussed. PMID:18379113

  5. Principal eigenvector field segmentation for reproducible diffusion tensor tractography of white matter structures

    Microsoft Academic Search

    Ram K. S. Rathore; Rakesh K. Gupta; Shruti Agarwal; Richa Trivedi; Rajendra P. Tripathi; Rishi Awasthi

    2011-01-01

    The study was aimed to test the feasibility of utilizing an algorithmically determinable stable fiber mass (SFM) map obtained by an unsupervised principal eigenvector field segmentation (PEVFS) for automatic delineation of 18 white matter (WM) tracts: (1) corpus callosum (CC), (2) tapetum (TP), (3) inferior longitudinal fasciculus (ILF), (4) uncinate fasciculus (UNC), (5) inferior fronto-occipital fasciculus (IFO), (6) optic pathways

  6. Dissecting the uncinate fasciculus: disorders, controversies and a hypothesis

    PubMed Central

    Von Der Heide, Rebecca J.; Skipper, Laura M.; Klobusicky, Elizabeth

    2013-01-01

    The uncinate fasciculus is a bidirectional, long-range white matter tract that connects lateral orbitofrontal cortex and Brodmann area 10 with the anterior temporal lobes. Although abnormalities in the uncinate fasciculus have been associated with several psychiatric disorders and previous studies suggest it plays a putative role in episodic memory, language and social emotional processing, its exact function is not well understood. In this review we summarize what is currently known about the anatomy of the uncinate, we review its role in psychiatric and neurological illnesses, and we evaluate evidence related to its putative functions. We propose that an overarching role of the uncinate fasciculus is to allow temporal lobe-based mnemonic associations (e.g. an individual’s name + face + voice) to modify behaviour through interactions with the lateral orbitofrontal cortex, which provides valence-based biasing of decisions. The bidirectionality of the uncinate fasciculus information flow allows orbital frontal cortex-based reward and punishment history to rapidly modulate temporal lobe-based mnemonic representations. According to this view, disruption of the uncinate may cause problems in the expression of memory to guide decisions and in the acquisition of certain types of learning and memory. Moreover, uncinate perturbation should cause problems that extend beyond memory to include social–emotional problems owing to people and objects being stripped of personal value and emotional history and lacking in higher-level motivational value. PMID:23649697

  7. The Role of the Arcuate Fasciculus in Conduction Aphasia

    ERIC Educational Resources Information Center

    Bernal, Byron; Ardila, Alfredo

    2009-01-01

    In aphasia literature, it has been considered that a speech repetition defect represents the main constituent of conduction aphasia. Conduction aphasia has frequently been interpreted as a language impairment due to lesions of the arcuate fasciculus (AF) that disconnect receptive language areas from expressive ones. Modern neuroradiological…

  8. Diffusion Tensor Anisotropy in Adolescents and Adults

    Microsoft Academic Search

    Jason S. Schneiderman; Monte S. Buchsbaum; M. Mehmet. Haznedar; Erin A. Hazlett; Adam M. Brickman; Lina Shihabuddin; Jesse G. Brand; Yuliya Torosjan; Randall E. Newmark; Cheuk Tang; Jonathan Aronowitz; Reshmi Paul-Odouard; William Byne; Patrick R. Hof

    2007-01-01

    We acquired diffusion tensor images on 33 normal adults aged 22–64 and 15 adolescents aged 14–21. We assessed relative anisotropy in stereotaxically located regions of interest in the internal capsule, corpus callosum, anterior thalamic radiations, frontal anterior fasciculus, fronto-occipital fasciculus, temporal lobe white matter, cingulum bundle, frontal inferior longitudinal fasciculus, frontal superior longitudinal fasciculus, and optic radiations. All of these

  9. Asymmetries of the Arcuate Fasciculus in Monozygotic Twins: Genetic and Nongenetic Influences

    PubMed Central

    Häberling, Isabelle S.; Badzakova-Trajkov, Gjurgjica; Corballis, Michael C.

    2013-01-01

    We assessed cerebral asymmetry for language in 35 monozygotic twin pairs. Using DTI, we reconstructed the arcuate fasciculus in each twin. Among the male twins, right-handed pairs showed greater left-sided asymmetry of connectivity in the arcuate fasciculus than did those with discordant handedness, and within the discordant group the right-handers had greater left-sided volume asymmetry of the arcuate fasciculus than did their left-handed co-twins. There were no such effects in the female twins. Cerebral asymmetry for language showed more consistent results, with the more left-cerebrally dominant twins also showing more leftward asymmetry of high anisotropic fibers in the arcuate fasciculus, a result applying equally to female as to male twins. Reversals of arcuate fasciculus asymmetry were restricted to pairs discordant for language dominance, with the left-cerebrally dominant twins showing leftward and the right-cerebrally dominant twins rightward asymmetry of anisotropic diffusion in the arcuate fasciculus. Because monozygotic twin pairs share the same genotype, our results indicate a strong nongenetic component in arcuate fasciculus asymmetry, particularly in those discordant for cerebral asymmetry. PMID:23300971

  10. Uncinate fasciculus abnormalities in recent onset schizophrenia and affective psychosis: A diffusion tensor imaging study

    E-print Network

    Uncinate fasciculus abnormalities in recent onset schizophrenia and affective psychosis of illness and specific to schizophrenia. Fifteen schizophrenia subjects and 15 affective psychosis within 4 years of first hospitalization (12 patients with schizophrenia and 12 patients with affective psychosis

  11. Am J Psychiatry 159:5, May 2002 813 Uncinate Fasciculus Findings in Schizophrenia

    E-print Network

    Am J Psychiatry 159:5, May 2002 813 Article Uncinate Fasciculus Findings in Schizophrenia in schizophrenia. Conventional magnetic resonance imaging (MRI) stud- ies, however, have not shown compelling integ- rity. The first three diffusion tensor imag- ing studies in schizophrenia showed lower

  12. Anatomical Properties of the Arcuate Fasciculus Predict Phonological and Reading Skills in Children

    ERIC Educational Resources Information Center

    Yeatman, Jason D.; Dougherty, Robert F.; Rykhlevskaia, Elena; Sherbondy, Anthony J.; Deutsch, Gayle K.; Wandell, Brian A.; Ben-Shachar, Michal

    2011-01-01

    For more than a century, neurologists have hypothesized that the arcuate fasciculus carries signals that are essential for language function; however, the relevance of the pathway for particular behaviors is highly controversial. The primary objective of this study was to use diffusion tensor imaging to examine the relationship between individual…

  13. Evaluating the Arcuate Fasciculus With Combined Diffusion-Weighted MRI Tractography and Electrocorticography

    PubMed Central

    Brown, Erik C.; Jeong, Jeong-Won; Muzik, Otto; Rothermel, Robert; Matsuzaki, Naoyuki; Juhász, Csaba; Sood, Sandeep; Asano, Eishi

    2014-01-01

    The conventional model of language-related brain structure describing the arcuate fasciculus as a key white matter tract providing a direct connection between Wernicke’s region and Broca’s area has been called into question. Specifically, the inferior precentral gyrus, possessing both primary motor (Brodmann Area [BA] 4) and premotor cortex (BA 6), has been identified as a potential alternative termination. The authors initially localized cortical sites involved in language using measurement of event-related gamma-activity on electrocorticography (ECoG). The authors then determined whether language-related sites of the temporal lobe were connected, via white matter structures, to the inferior frontal gyrus more tightly than to the precentral gyrus. The authors found that language-related sites of the temporal lobe were far more likely to be directly connected to the inferior precentral gyrus through the arcuate fasciculus. Furthermore, tractography was a significant predictor of frontal language-related ECoG findings. Analysis of an interaction between anatomy and tractography in this model revealed tractrography to have the highest predictive value for language-related ECoG findings of the precentral gyrus. This study failed to support the conventional model of language-related brain structure. More feasible models should include the inferior precentral gyrus as a termination of the arcuate fasciculus. The exact functional significance of direct connectivity between temporal language-related sites and the precentral gyrus requires further study. PMID:23982893

  14. Microstructural connectivity of the arcuate fasciculus in adolescents with high-functioning autism.

    PubMed

    Fletcher, P Thomas; Whitaker, Ross T; Tao, Ran; DuBray, Molly B; Froehlich, Alyson; Ravichandran, Caitlin; Alexander, Andrew L; Bigler, Erin D; Lange, Nicholas; Lainhart, Janet E

    2010-07-01

    The arcuate fasciculus is a white matter fiber bundle of great importance in language. In this study, diffusion tensor imaging (DTI) was used to infer white matter integrity in the arcuate fasciculi of a group of subjects with high-functioning autism and a control group matched for age, handedness, IQ, and head size. The arcuate fasciculus for each subject was automatically extracted from the imaging data using a new volumetric DTI segmentation algorithm. The results showed a significant increase in mean diffusivity (MD) in the autism group, due mostly to an increase in the radial diffusivity (RD). A test of the lateralization of DTI measurements showed that both MD and fractional anisotropy (FA) were less lateralized in the autism group. These results suggest that white matter microstructure in the arcuate fasciculus is affected in autism and that the language specialization apparent in the left arcuate of healthy subjects is not as evident in autism, which may be related to poorer language functioning. PMID:20132894

  15. Microstructural connectivity of the arcuate fasciculus in adolescents with high-functioning autism

    PubMed Central

    Fletcher, P. Thomas; Whitaker, Ross T.; Tao, Ran; DuBray, Molly B.; Froehlich, Alyson; Ravichandran, Caitlin; Alexander, Andrew L.; Bigler, Erin D.; Lange, Nicholas; Lainhart, Janet E.

    2010-01-01

    The arcuate fasciculus is a white matter fiber bundle of great importance in language. In this study, diffusion tensor imaging (DTI) was used to infer white matter integrity in the arcuate fasciculi of a group of subjects with high-functioning autism and a control group matched for age, handedness, IQ, and head size. The arcuate fasciculus for each subject was automatically extracted from the imaging data using a new volumetric DTI segmentation algorithm. The results showed a significant increase in mean diffusivity (MD) in the autism group, due mostly to an increase in the radial diffusivity (RD). A test of the lateralization of DTI measurements showed that both MD and fractional anisotropy (FA) were less lateralized in the autism group. These results suggest that white matter microstructure in the arcuate fasciculus is affected in autism and that the language specialization apparent in the left arcuate of healthy subjects is not as evident in autism, which may be related to poorer language functioning. PMID:20132894

  16. A Combined fMRI and DTI Examination of Functional Language Lateralization and Arcuate Fasciculus Structure: Effects of Degree versus Direction of Hand Preference

    ERIC Educational Resources Information Center

    Propper, Ruthe E.; O'Donnell, Lauren J.; Whalen, Stephen; Tie, Yanmei; Norton, Isaiah H.; Suarez, Ralph O.; Zollei, Lilla; Radmanesh, Alireza; Golby, Alexandra J.

    2010-01-01

    The present study examined the relationship between hand preference degree and direction, functional language lateralization in Broca's and Wernicke's areas, and structural measures of the arcuate fasciculus. Results revealed an effect of degree of hand preference on arcuate fasciculus structure, such that consistently-handed individuals,…

  17. Alterations in white matter integrity in first-episode, treatment-naive patients with somatization disorder.

    PubMed

    Zhang, Jian; Jiang, Muliang; Yao, Dapeng; Dai, Yi; Long, Liling; Yu, Miaoyu; Liu, Jianrong; Zhang, Zhikun; Xiao, Changqing; Guo, Wenbin

    2015-07-10

    White matter (WM) abnormality in somatization disorder (SD) has not been reported yet. This study was designed to elucidate the alterations in WM integrity in SD. A total of 25 patients with SD and 28 healthy controls were enrolled in the study. WM integrity was analyzed using tract-based spatial statistics. No differences were found between the patients and the controls for fractional anisotropy (FA) values, mean diffusivity (MD), axial diffusivity, and radial diffusivity values at the corrected p<0.05 level. Patients with SD had significantly decreased FA values in the cingulum and inferior fronto-occipital fasciculus, and significantly increased MD values in the anterior thalamic radiation and corticospinal tract compared with the controls at the uncorrected p<0.005 level. Somatization severity was correlated with the FA values of the cingulum and inferior fronto-occipital fasciculus in the patients. The patients exhibit suggestive alterations in WM integrity in the cingulum, inferior fronto-occipital fasciculus, anterior thalamic radiation, and corticospinal tract. PMID:26003450

  18. Left Hemisphere Diffusivity of the Arcuate Fasciculus: Influences of Autism Spectrum Disorder and Language Impairment

    PubMed Central

    Roberts, T.P.L.; Heiken, K.; Zarnow, D.; Dell, J.; Nagae, L.; Blaskey, L.; Solot, C.; Levy, S.E.; Berman, J.I.; Edgar, J.C.

    2014-01-01

    BACKGROUND AND PURPOSE There has been much discussion whether brain abnormalities associated with specific language impairment and autism with language impairment are shared or are disorder specific. Although white matter tract abnormalities are observed in both specific language impairment and autism spectrum disorders, the similarities and differences in the white matter abnormalities in these 2 disorders have not been fully determined. MATERIALS AND METHODS Diffusion tensor imaging diffusion parameters of the arcuate fasciculus were measured in 14 children with specific language impairment as well as in 16 children with autism spectrum disorder with language impairment, 18 with autism spectrum disorder without language impairment, and 25 age-matched typically developing control participants. RESULTS Language impairment and autism spectrum disorder both had (elevating) main effects on mean diffusivity of the left arcuate fasciculus, initially suggesting a shared white matter substrate abnormality. Analysis of axial and radial diffusivity components, however, indicated that autism spectrum disorder and language impairment differentially affect white matter microstructural properties, with a main effect of autism spectrum disorder on axial diffusivity and a main effect of language impairment on radial diffusivity. CONCLUSIONS Although white matter abnormalities appear similar in language impairment and autism spectrum disorder when examining broad white matter measures, a more detailed analysis indicates different mechanisms for the white matter microstructural anomalies associated with language impairment and autism spectrum disorder. PMID:24335547

  19. Psychopathic traits modulate microstructural integrity of right uncinate fasciculus in a community population

    PubMed Central

    Sobhani, Mona; Baker, Laura; Martins, Bradford; Tuvblad, Catherine; Aziz-Zadeh, Lisa

    2015-01-01

    Individuals with psychopathy possess emotional and behavioral abnormalities. Two neural regions, involved in behavioral control and emotion regulation, are often implicated: amygdala and ventromedial prefrontal cortex (VMPFC). Recently, in studies using adult criminal populations, reductions in microstructural integrity of the white matter connections (i.e., uncinate fasciculus (UF)) between these two neural regions have been discovered in criminals with psychopathy, supporting the notion of neural dysfunction in the amygdala–VMPFC circuit. Here, a young adult, community sample is used to assess whether psychopathic traits modulate microstructural integrity of UF, and whether this relationship is dependent upon levels of trait anxiety, which is sometimes used to distinguish subtypes of psychopathy. Results reveal a negative association between psychopathic traits and microstructural integrity of UF, supporting previous findings. However, no moderation of the relationship by trait anxiety was discovered. Findings provide further support for the notion of altered amygdala–VMPFC connectivity in association with higher psychopathic traits.

  20. Bilateral agenesis of arcuate fasciculus demonstrated by fiber tractography in congenital bilateral perisylvian syndrome.

    PubMed

    Kilinc, Ozden; Ekinci, Gazanfer; Demirkol, Ezgi; Agan, Kadriye

    2015-03-01

    Congenital bilateral perisylvian syndrome (CBPS) is a type of cortical developmental abnormality associated with distinctive clinical and imaging features. Clinical spectrum of this syndrome is quite heterogeneous, with different degrees of neurological impairment in affected individuals. High-definition magnetic resonance imaging (MRI) has a great importance in revealing the presence of CBPS, but is limited in elucidating the heterogeneous clinical spectrum. The arcuate fasciculus (AF) is a prominent language tract in the perisylvian region interconnecting Broca and Wernicke areas, and has a high probability of being affected developmentally in CBPS. Herein, we report a case of CBPS with investigation of AF using diffusion tensor imaging (DTI) and fiber tractography in relation to clinical findings. We postulated that proven absence of AF on DTI and fiber tractography would correlate with a severe phenotype of CBPS. PMID:24852949

  1. More is not always better: increased fractional anisotropy of superior longitudinal fasciculus associated with poor visuospatial abilities in Williams syndrome.

    PubMed

    Hoeft, Fumiko; Barnea-Goraly, Naama; Haas, Brian W; Golarai, Golijeh; Ng, Derek; Mills, Debra; Korenberg, Julie; Bellugi, Ursula; Galaburda, Albert; Reiss, Allan L

    2007-10-31

    We used diffusion tensor imaging to examine white matter integrity in the dorsal and ventral streams among individuals with Williams syndrome (WS) compared with two control groups (typically developing and developmentally delayed) and using three separate analysis methods (whole brain, region of interest, and fiber tractography). All analysis methods consistently showed that fractional anisotropy (FA; a measure of microstructural integrity) was higher in the right superior longitudinal fasciculus (SLF) in WS compared with both control groups. There was a significant association with deficits in visuospatial construction and higher FA in WS individuals. Comparable increases in FA across analytic methods were not observed in the left SLF or the bilateral inferior longitudinal fasciculus in WS subjects. Together, these findings suggest a specific role of right SLF abnormality in visuospatial construction deficits in WS. PMID:17978036

  2. Detection of the arcuate fasciculus in congenital amusia depends on the tractography algorithm

    PubMed Central

    Chen, Joyce L.; Kumar, Sukhbinder; Williamson, Victoria J.; Scholz, Jan; Griffiths, Timothy D.; Stewart, Lauren

    2015-01-01

    The advent of diffusion magnetic resonance imaging (MRI) allows researchers to virtually dissect white matter fiber pathways in the brain in vivo. This, for example, allows us to characterize and quantify how fiber tracts differ across populations in health and disease, and change as a function of training. Based on diffusion MRI, prior literature reports the absence of the arcuate fasciculus (AF) in some control individuals and as well in those with congenital amusia. The complete absence of such a major anatomical tract is surprising given the subtle impairments that characterize amusia. Thus, we hypothesize that failure to detect the AF in this population may relate to the tracking algorithm used, and is not necessarily reflective of their phenotype. Diffusion data in control and amusic individuals were analyzed using three different tracking algorithms: deterministic and probabilistic, the latter either modeling two or one fiber populations. Across the three algorithms, we replicate prior findings of a left greater than right AF volume, but do not find group differences or an interaction. We detect the AF in all individuals using the probabilistic 2-fiber model, however, tracking failed in some control and amusic individuals when deterministic tractography was applied. These findings show that the ability to detect the AF in our sample is dependent on the type of tractography algorithm. This raises the question of whether failure to detect the AF in prior studies may be unrelated to the underlying anatomy or phenotype. PMID:25653637

  3. Diffusivity of the uncinate fasciculus in heroin users relates to their levels of anxiety

    PubMed Central

    Wong, N M L; Cheung, S-H; Chan, C C H; Zeng, H; Liu, Y-P; So, K-F; Lee, T M C

    2015-01-01

    Heroin use is closely associated with emotional dysregulation, which may explain its high comorbidity with disorders such as anxiety and depression. However, the understanding of the neurobiological etiology of the association between heroin use and emotional dysregulation is limited. Previous studies have suggested an impact of heroin on diffusivity in white matter involving the emotional regulatory system, but the specificity of this finding remains to be determined. Therefore, this study investigated the association between heroin use and diffusivity of white matter tracts in heroin users and examined whether the tracts were associated with their elevated anxiety and depression levels. A sample of 26 right-handed male abstinent heroin users (25 to 42 years of age) and 32 matched healthy controls (19 to 55 years of age) was recruited for this study. Diffusion tensor imaging data were collected, and their levels of anxiety and depression were assessed using the Hospital Anxiety and Depression Scale. Our findings indicated that heroin users exhibited higher levels of anxiety and depression, but the heroin use-associated left uncinate fasciculus was only related to their anxiety level, suggesting that association between heroin and anxiety has an incremental organic basis but that for depression could be a threshold issue. This finding improves our understanding of heroin addiction and its comorbid affective disorder and facilitates future therapeutic development. PMID:25918991

  4. Uncinate Fasciculus Abnormalities in Recent Onset Schizophrenia and Affective Psychosis: A Diffusion Tensor Imaging Study

    PubMed Central

    Kawashima, Toshiro; Nakamura, Motoaki; Bouix, Sylvain; Kubicki, Marek; Salisbury, Dean F.; Westin, Carl-Fredrik; McCarley, Robert W.; Shenton, Martha E.

    2009-01-01

    Two of the most frequently investigated regions in diffusion tensor imaging studies in chronic schizophrenia are the uncinate fasciculus (UF) and cingulum bundle (CB). The purpose of the present study was to determine whether UF and CB white matter integrity were altered at the early stage of illness and specific to schizophrenia. Fifteen schizophrenia subjects and 15 affective psychosis within 4 years of first hospitalization (12 patients with schizophrenia and 12 patients with affective psychosis during their first hospitalization), and 15 psychiatrically healthy controls underwent line-scan diffusion tensor imaging. Fractional anisotropy (FA) and mean diffusivity (Dm) were used to quantify water diffusion, and cross-sectional area was defined with a directional threshold method. Bilaterally reduced FA, but not Dm, was present in the UF of schizophrenia compared with healthy controls. Affective psychosis was intermediate between schizophrenia subjects and healthy controls, but not significantly different from either. For CB, there was no significant group difference for FA or Dm. These findings suggested that UF, but not CB, white matter integrity is altered at the early stage of illness in schizophrenia although it may not be specific to schizophrenia. The CB abnormalities reported in chronic schizophrenia may develop during the later course of the disease. PMID:19328656

  5. The vertical occipital fasciculus: A century of controversy resolved by in vivo measurements

    PubMed Central

    Yeatman, Jason D.; Weiner, Kevin S.; Pestilli, Franco; Rokem, Ariel; Mezer, Aviv; Wandell, Brian A.

    2014-01-01

    The vertical occipital fasciculus (VOF) is the only major fiber bundle connecting dorsolateral and ventrolateral visual cortex. Only a handful of studies have examined the anatomy of the VOF or its role in cognition in the living human brain. Here, we trace the contentious history of the VOF, beginning with its original discovery in monkey by Wernicke (1881) and in human by Obersteiner (1888), to its disappearance from the literature, and recent reemergence a century later. We introduce an algorithm to identify the VOF in vivo using diffusion-weighted imaging and tractography, and show that the VOF can be found in every hemisphere (n = 74). Quantitative T1 measurements demonstrate that tissue properties, such as myelination, in the VOF differ from neighboring white-matter tracts. The terminations of the VOF are in consistent positions relative to cortical folding patterns in the dorsal and ventral visual streams. Recent findings demonstrate that these same anatomical locations also mark cytoarchitectonic and functional transitions in dorsal and ventral visual cortex. We conclude that the VOF is likely to serve a unique role in the communication of signals between regions on the ventral surface that are important for the perception of visual categories (e.g., words, faces, bodies, etc.) and regions on the dorsal surface involved in the control of eye movements, attention, and motion perception. PMID:25404310

  6. Atypical hemispheric asymmetry in the arcuate fasciculus of completely nonverbal children with autism

    PubMed Central

    Wan, Catherine Y.; Marchina, Sarah; Norton, Andrea; Schlaug, Gottfried

    2015-01-01

    Despite the fact that as many as 25% of the children diagnosed with autism spectrum disorders are nonverbal, surprisingly little research has been conducted on this population. In particular, the mechanisms that underlie their absence of speech remain unknown. Using diffusion tensor imaging, we compared the structure of a language-related white matter tract (the arcuate fasciculus, AF) in five completely nonverbal children with autism to that of typically developing children. We found that, as a group, the nonverbal children did not show the expected left–right AF asymmetry—rather, four of the five nonverbal children actually showed the reversed pattern. It is possible that this unusual pattern of asymmetry may underlie some of the severe language deficits commonly found in autism, particularly in children whose speech fails to develop. Furthermore, novel interventions (such as auditory-motor mapping training) designed to engage brain regions that are connected via the AF may have important clinical potential for facilitating expressive language in nonverbal children with autism. PMID:22524376

  7. Arthroscopic glenohumeral folds and microscopic glenohumeral ligaments: the fasciculus obliquus is the missing link.

    PubMed

    Pouliart, Nicole; Somers, Katia; Gagey, Olivier

    2008-01-01

    This study tested the hypotheses that the folds in the inferior glenohumeral capsule appear at the borders and crossings of the underlying capsular ligaments and that embalming may result in misinterpretation of these folds as ligaments. The inferior capsular structures in 80 unembalmed cadaver shoulders were compared with 24 embalmed shoulders. During arthroscopy and dissection, an anteroinferior fold was more prominently seen in internal rotation and was almost obliterated in external rotation. A posteroinferior fold appeared in external rotation and almost disappeared in internal rotation. During dissection, the anteroinferior fold developed at the border of the anterior band of the inferior glenohumeral ligament (ABIGHL) and where this ligament crossed with the fasciculus obliquus (FO). Several patterns of crossing of the ABIGHL and the FO were seen that determined the folding-unfolding mechanism of the anteroinferior fold and the appearance of possible synovial recesses. The axillary part of the IGHL is formed by the FO on the glenoid side and by the ABIGHL on the humeral side. The posteroinferior fold was determined by the posterior band of the IGHL. The folds in the embalmed specimens did not necessarily correspond with the underlying fibrous structure of the capsule. The folds and recesses observed during arthroscopy indicate the underlying capsular ligaments but are not the ligaments themselves. The IGHL complex is formed by its anterior and posterior bands and also by the FO. Both findings are important during shoulder instability procedures because the ligaments need to be restored to their appropriate anatomy and tension. Because the FO may also be involved, Bankart-type surgery may have to reach far inferiorly. Midsubstance capsular shift procedures also need to incorporate this ligament. PMID:18328738

  8. Lakatos Revisited.

    ERIC Educational Resources Information Center

    Court, Deborah

    1999-01-01

    Revisits and reviews Imre Lakatos' ideas on "Falsification and the Methodology of Scientific Research Programmes." Suggests that Lakatos' framework offers an insightful way of looking at the relationship between theory and research that is relevant not only for evaluating research programs in theoretical physics, but in the social sciences as…

  9. Effect of clozapine on white matter integrity in patients with schizophrenia: a diffusion tensor imaging study.

    PubMed

    Ozcelik-Eroglu, Elcin; Ertugrul, Aygun; Oguz, Kader Karli; Has, Arzu Ceylan; Karahan, Sevilay; Yazici, Mumin Kazim

    2014-09-30

    Several diffusion tensor imaging (DTI) studies have reported disturbed white matter integrity in various brain regions in patients with schizophrenia, whereas only a few studied the effect of antipsychotics on DTI measures. The aim of this study was to investigate the effect of 12 weeks of clozapine treatment on DTI findings in patients with schizophrenia, and to compare the findings with those in unaffected controls. The study included 16 patients with schizophrenia who were assessed with the Positive and Negative Syndrome Scale, a neurocognitive test battery, and DTI at baseline and 12 weeks after the initiation of clozapine treatment. Eight unaffected controls were assessed once with the neurocognitive test battery and DTI. Voxel-wise analysis of DTI data was performed via tract-based spatial statistics (TBSS). Compared with the control group, the patient group exhibited lower fractional anisotropy (FA) in 16 brain regions, including the bilateral superior longitudinal fasciculi, inferior fronto-occipital fasciculi, superior and inferior parietal lobules, cingulate bundles, cerebellum, middle cerebellar peduncles, and left inferior longitudinal fasciculus, whereas the patients had higher FA in six regions, including the right parahippocampus, left anterior thalamic radiation, and right posterior limb of the internal capsule before clozapine treatment. After 12 weeks of treatment with clozapine, white matter FA was increased in widespread brain regions. In two of the regions where FA had initially been lower in patients compared with controls (left inferior fronto-occipital fasciculus and superior parietal lobule), clozapine appeared to increase FA. An improvement in semantic fluency was correlated with the increase in FA value in the left inferior fronto-occipital fasciculus. An increase in FA following 12 weeks of treatment with clozapine suggests that this treatment alters white matter microstructural integrity in patients with schizophrenia previously treated with typical and/or atypical antipsychotics and, in some locations, reverses a previous deficit. PMID:25012780

  10. Vigintiphobia revisited.

    PubMed

    Watchko, Jon F

    2005-06-01

    In this review the historical tenets and evidence-based clinical research in support of a bilirubin exchange threshold of >20 mg/dL for the healthy term neonate are revisited. In addition, a hypothesis is ventured that recent cases of kernicterus are related in part to changes in population factors coupled with genetic predispositions that have unmasked an unappreciated potential for marked neonatal hyperbilirubinemia. PMID:15930239

  11. Revisiting Lasswell

    Microsoft Academic Search

    James Farr; Jacob S. Hacker; Nicole Kazee

    2008-01-01

    This article continues the line of argument and historical interpretation we offered in “The Policy Scientist of Democracy:\\u000a The Discipline of Harold D. Lasswell” by way of a response to Ronald Brunner’s “The Policy Scientist of Democracy Revisited.”\\u000a Problems regarding Lasswell’s capacious vision of the policy scientist and vagaries surrounding “democracy,” do not diminish\\u000a the importance of the questions Lasswell

  12. Altered integrity of the right arcuate fasciculus as a trait marker of schizophrenia: a sibling study using tractography-based analysis of the whole brain.

    PubMed

    Wu, Chen-Hao; Hwang, Tzung-Jeng; Chen, Yu-Jen; Hsu, Yun-Chin; Lo, Yu-Chun; Liu, Chih-Min; Hwu, Hai-Gwo; Liu, Chen-Chung; Hsieh, Ming H; Chien, Yi Ling; Chen, Chung-Ming; Tseng, Wen-Yih Isaac

    2015-03-01

    Trait markers of schizophrenia aid the dissection of the heterogeneous phenotypes into distinct subtypes and facilitate the genetic underpinning of the disease. The microstructural integrity of the white matter tracts could serve as a trait marker of schizophrenia, and tractography-based analysis (TBA) is the current method of choice. Manual tractography is time-consuming and limits the analysis to preselected fiber tracts. Here, we sought to identify a trait marker of schizophrenia from among 74 fiber tracts across the whole brain using a novel automatic TBA method. Thirty-one patients with schizophrenia, 31 unaffected siblings and 31 healthy controls were recruited to undergo diffusion spectrum magnetic resonance imaging at 3T. Generalized fractional anisotropy (GFA), an index reflecting tract integrity, was computed for each tract and compared among the three groups. Ten tracts were found to exhibit significant differences between the groups with a linear, stepwise order from controls to siblings to patients; they included the right arcuate fasciculus, bilateral fornices, bilateral auditory tracts, left optic radiation, the genu of the corpus callosum, and the corpus callosum to the bilateral dorsolateral prefrontal cortices, bilateral temporal poles, and bilateral hippocampi. Posthoc between-group analyses revealed that the GFA of the right arcuate fasciculus was significantly decreased in both the patients and unaffected siblings compared to the controls. Furthermore, the GFA of the right arcuate fasciculus exhibited a trend toward positive symptom scores. In conclusion, the right arcuate fasciculus may be a candidate trait marker and deserves further study to verify any genetic association. PMID:25366810

  13. Changes in maps of language function and the integrity of the arcuate fasciculus after therapy for chronic aphasia.

    PubMed

    Breier, Joshua I; Juranek, Jenifer; Papanicolaou, Andrew C

    2011-12-01

    A patient with chronic aphasia secondary to unilateral stroke in the left hemisphere underwent language testing, diffusion tensor imaging (DTI), and functional imaging using magnetoencephalography (MEG) at four time points: 3 weeks prior to, immediately prior to, immediately after, and 3 months after Constraint Induced Language Therapy (CILT). Performance on language tests involving visual naming and repetition of spoken sentences improved between the immediately prior to and immediately after CILT testing sessions, but not between the pre-CILT sessions. MEG activation in putative pre-morbid language areas of the left hemisphere and homotopic areas of the right hemisphere increased immediately after therapy, as did integrity within the arcuate fasciculus bilaterally. These changes were not evident between the two pre-CILT sessions. While some of these functional, neurophysiological and structural changes had regressed 3 months after therapy, all remained at or above baseline levels. Results provide evidence for an association between improvement in functional status and the increased integrity within a white matter tract known to be involved in language function and its contralateral homologue, as well as increased neurophysiological activity in areas that have the potential to subserve language function bilaterally. PMID:22111962

  14. Excellent recovery of aphasia in a patient with complete injury of the arcuate fasciculus in the dominant hemisphere.

    PubMed

    Kwon, Hyeok Gyu; Jang, Sung Ho

    2011-01-01

    The arcuate fasciculus (AF) is the neural tract that connects Wernicke's area and Broca's area. The main role of the AF is speech repetition; therefore, injury to the AF typically causes conduction aphasia. We report on a patient who showed excellent recovery of aphasia despite complete injury of the AF due to a cerebral infarct. A 54-year-old, right-handed male presented with aphasia and right hemiparesis. Brain MRI showed an infarct in the left centrum semiovale and corona radiata. Diffusion tensor tractography for the AF was reconstructed using DTI-studio software. The Korean-Western Aphasia Battery (K-WAB) was used for measurement of language function. On K-WAB at 1 week after onset, his aphasia type was compatible with global aphasia (aphasia quotient: 12‰, fluency: 5‰, comprehension: 24‰, repetition: 15‰, and naming: 31‰). The patient underwent rehabilitative therapy, including language therapy and medication, which is known to facilitate recovery from aphasia, for a period of 24 months. His aphasia had improved to a nearly normal state at 30 months after onset; aphasia quotient: 93‰ (fluency: 91‰, comprehension: 92‰, repetition: 85‰, and naming: 96‰). The left AF showed a complete disruption on 27-month diffusion tensor tractography. Findings from this study suggest the possibility that aphasia might show good recovery, even in cases of severe injury of the AF. PMID:22207068

  15. Grief revisited.

    PubMed

    Ng, B Y

    2005-06-01

    The article serves to examine the cultural influences on attitudes towards the deceased and bereaved, as well as on the practice of mourning, and to revisit normal and pathological variants of grief. Grief is a subjective state of psychological and physiological reaction to the loss of a loved one. Reaction to the loss is experienced internally in a uniform manner across cultures. However, mourning, the voluntary social expression of the loss, varies from culture to culture. Rituals provide a standardised mode of behaviour, which helps to relieve the sense of uncertainty or loss. There were reports of ghost sightings involving foreign tourists in the 6 worst-hit southern provinces in Thailand following the tsunami tragedy. This phenomenon of "mass hallucinations" is understandable from the cultural perspective. New models of grief have been developed to account for the individuality and diversity of grief and to encompass the social, behavioural and spiritual dimensions of loss as well as those of the psychological and physical. Clinically, the duration of grief reactions varies widely, depending on the nature of the loss and the connection to the deceased. In the case of the tsunami tragedy, with relatives missing, homes swept away and familiar neighbourhoods turned into wastelands, many victims are likely to have complicated grief. Traumatic grief, which includes a prominent component of separation distress characterised by yearning and searching and frequent "bittersweet" recollections of the deceased, has been associated with long-term dysfunction. Grief work utilising the traumatic grief treatment protocol appears to be a promising intervention. PMID:16021224

  16. Patterns of dysgraphia in primary progressive aphasia compared to post-stroke aphasia.

    PubMed

    Faria, Andreia V; Crinion, Jenny; Tsapkini, Kyrana; Newhart, Melissa; Davis, Cameron; Cooley, Shannon; Mori, Susumu; Hillis, Argye E

    2013-01-01

    We report patterns of dysgraphia in participants with primary progressive aphasia that can be explained by assuming disruption of one or more cognitive processes or representations in the complex process of spelling. These patterns are compared to those described in participants with focal lesions (stroke). Using structural imaging techniques, we found that damage to the left extrasylvian regions, including the uncinate, inferior fronto-occipital fasciculus, and sagittal stratum (including geniculostriate pathway and inferior longitudinal fasciculus), as well as other deep white and grey matter structures, was significantly associated with impairments in access to orthographic word forms and semantics (with reliance on phonology-to-orthography to produce a plausible spelling in the spelling to dictation task). These results contribute not only to our understanding of the patterns of dysgraphia following acquired brain damage but also the neural substrates underlying spelling. PMID:22713396

  17. Patterns of Dysgraphia in Primary Progressive Aphasia Compared to Post-Stroke Aphasia

    PubMed Central

    Faria, Andreia V.; Crinion, Jenny; Tsapkini, Kyrana; Newhart, Melissa; Davis, Cameron; Cooley, Shannon; Mori, Susumu; Hillis, Argye E.

    2013-01-01

    We report patterns of dysgraphia in participants with primary progressive aphasia that can be explained by assuming disruption of one or more cognitive processes or representations in the complex process of spelling. These patterns are compared to those described in participants with focal lesions (stroke). Using structural imaging techniques, we found that damage to the left extrasylvian regions, including the uncinate, inferior fronto-occipital fasciculus, and sagittal stratum (including geniculostriate pathway and inferior longitudinal fasciculus), as well as other deep white and grey matter structures, was significantly associated with impairments in access to orthographic word forms and semantics (with reliance on phonology-to-orthography to produce a plausible spelling in the spelling to dictation task). These results contribute not only to our understanding of the patterns of dysgraphia following acquired brain damage but also the neural substrates underlying spelling. PMID:22713396

  18. The language connectome: new pathways, new concepts.

    PubMed

    Dick, Anthony Steven; Bernal, Byron; Tremblay, Pascale

    2014-10-01

    The field of the neurobiology of language is experiencing a paradigm shift in which the predominant Broca-Wernicke-Geschwind language model is being revised in favor of models that acknowledge that language is processed within a distributed cortical and subcortical system. While it is important to identify the brain regions that are part of this system, it is equally important to establish the anatomical connectivity supporting their functional interactions. The most promising framework moving forward is one in which language is processed via two interacting "streams"--a dorsal and ventral stream--anchored by long association fiber pathways, namely the superior longitudinal fasciculus/arcuate fasciculus, uncinate fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and two less well-established pathways, the middle longitudinal fasciculus and extreme capsule. In this article, we review the most up-to-date literature on the anatomical connectivity and function of these pathways. We also review and emphasize the importance of the often overlooked cortico-subcortical connectivity for speech via the "motor stream" and associated fiber systems, including a recently identified cortical association tract, the frontal aslant tract. These pathways anchor the distributed cortical and subcortical systems that implement speech and language in the human brain. PMID:24342910

  19. 42 CFR 488.30 - Revisit user fee for revisit surveys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... false Revisit user fee for revisit surveys. 488.30 Section 488.30 Public...CONTINUED) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES...488.30 Revisit user fee for revisit surveys. (a) Definitions. As used...

  20. 42 CFR 488.30 - Revisit user fee for revisit surveys.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... false Revisit user fee for revisit surveys. 488.30 Section 488.30 Public...CONTINUED) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES...488.30 Revisit user fee for revisit surveys. (a) Definitions. As used...

  1. 42 CFR 488.30 - Revisit user fee for revisit surveys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... false Revisit user fee for revisit surveys. 488.30 Section 488.30 Public...CONTINUED) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES...488.30 Revisit user fee for revisit surveys. (a) Definitions. As used...

  2. Association of dorsal inferior frontooccipital fasciculus fibers in the deep parietal lobe with both reading and writing processes: a brain mapping study.

    PubMed

    Motomura, Kazuya; Fujii, Masazumi; Maesawa, Satoshi; Kuramitsu, Shunichiro; Natsume, Atsushi; Wakabayashi, Toshihiko

    2014-07-01

    Alexia and agraphia are disorders common to the left inferior parietal lobule, including the angular and supramarginal gyri. However, it is still unclear how these cortical regions interact with other cortical sites and what the most important white matter tracts are in relation to reading and writing processes. Here, the authors present the case of a patient who underwent an awake craniotomy for a left inferior parietal lobule glioma using direct cortical and subcortical electrostimulation. The use of subcortical stimulation allowed identification of the specific white matter tracts associated with reading and writing. These tracts were found as portions of the dorsal inferior frontooccipital fasciculus (IFOF) fibers in the deep parietal lobe that are responsible for connecting the frontal lobe to the superior parietal lobule. These findings are consistent with previous diffusion tensor imaging tractography and functional MRI studies, which suggest that the IFOF may play a role in the reading and writing processes. This is the first report of transient alexia and agraphia elicited through intraoperative direct subcortical electrostimulation, and the findings support the crucial role of the IFOF in reading and writing. PMID:24655122

  3. Failure to Identify the Left Arcuate Fasciculus at Diffusion Tractography Is a Specific Marker of Language Dysfunction in Pediatric Patients with Polymicrogyria

    PubMed Central

    Paldino, Michael J.; Hedges, Kara; Gaab, Nadine; Galaburda, Albert M.; Grant, P. Ellen

    2015-01-01

    Background. Polymicrogyric cortex demonstrates interindividual variation with regard to both extent of dyslamination and functional capacity. Given the relationship between laminar structure and white matter fibers, we sought to define the relationship between polymicrogyria (PMG), intrahemispheric association pathways, and network function. Methods. Each arcuate fasciculus (AF) was categorized as present or absent. Language was characterized by a pediatric neurologist. The presence of dysplastic cortex in the expected anatomic locations of Broca's (BA) and Wernicke's areas (WA) was evaluated by two pediatric neuroradiologists blinded to DTI and language data. Results. 16 PMG patients and 16 age/gender-matched controls were included. All normative controls had an identifiable left AF. 6/7 PMG patients with dysplastic cortex within BA and/or WA had no left AF; PMG patients without involvement of these regions had a lower frequency of absence of the left AF (p < 0.006). All patients without a left AF had some degree of language impairment. PMG patients without a left AF had a significantly greater frequency of language impairment compared to those PMG patients with a left AF (p < 0.003). Conclusion. In patients with PMG (1) the presence of dysplastic cortex within WA and/or BA is associated with absence of the left AF and (2) absence of the left AF is associated with language impairment.

  4. Google Scholar revisited

    Microsoft Academic Search

    Péter Jacsó

    2008-01-01

    Purpose – The purpose of this paper is to revisit Google Scholar. Design\\/methodology\\/approach – This paper discusses the strengths and weaknesses of Google Scholar. Findings – The Google Books project has given a massive and valuable boost to the already rich and diverse content of Google Scholar. The downside of the growth is that significant gaps remain for top ranking

  5. Italy Revisited: The Encyclopedia

    E-print Network

    Epstein, Steven A.

    2005-01-01

    , but so do many others who do not have their own entries. More justiªable and useful are the entries on Al- Farabi, Averroes, Avicenna, and other medieval Muslim authors, ITALY REVISITED | 561 though none of these people have any actual connection to medi...

  6. Anodic Polarization Curves Revisited

    ERIC Educational Resources Information Center

    Liu, Yue; Drew, Michael G. B.; Liu, Ying; Liu, Lin

    2013-01-01

    An experiment published in this "Journal" has been revisited and it is found that the curve pattern of the anodic polarization curve for iron repeats itself successively when the potential scan is repeated. It is surprising that this observation has not been reported previously in the literature because it immediately brings into…

  7. Widespread white matter tract aberrations in youth with familial risk for bipolar disorder.

    PubMed

    Roybal, Donna J; Barnea-Goraly, Naama; Kelley, Ryan; Bararpour, Layla; Howe, Meghan E; Reiss, Allan L; Chang, Kiki D

    2015-05-30

    Few studies have examined multiple measures of white matter (WM) differences in youth with familial risk for bipolar disorder (FR-BD). To investigate WM in the FR-BD group, we used three measures of WM structure and two methods of analysis. We used fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) to analyze diffusion tensor imaging (DTI) findings in 25 youth with familial risk for bipolar disorder, defined as having both a parent with BD and mood dysregulation, and 16 sex-, age-, and IQ-matched healthy controls. We conducted a whole brain voxelwise analysis using tract based spatial statistics (TBSS). Subsequently, we conducted a complementary atlas-based, region-of-interest analysis using Diffeomap to confirm results seen in TBSS. When TBSS was used, significant widespread between-group differences were found showing increased FA, increased AD, and decreased RD in the FR-BD group in the bilateral uncinate fasciculus, cingulum, cingulate, superior fronto-occipital fasciculus (SFOF), superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus, and corpus callosum. Atlas-based analysis confirmed significant between-group differences, with increased FA and decreased RD in the FR-BD group in the SLF, cingulum, and SFOF. We found significant widespread WM tract aberrations in youth with familial risk for BD using two complementary methods of DTI analysis. PMID:25779034

  8. Tract-based spatial statistics analysis of white matter changes in children with anisometropic amblyopia.

    PubMed

    Li, Qian; Zhai, Liying; Jiang, Qinying; Qin, Wen; Li, Qingji; Yin, Xiaohui; Guo, Mingxia

    2015-06-15

    Amblyopia is a neurological disorder of vision that follows abnormal binocular interaction or visual deprivation during early life. Previous studies have reported multiple functional or structural cortical alterations. Although white matter was also studied, it still cannot be clarified clearly which fasciculus was affected by amblyopia. In the present study, tract-based spatial statistics analysis was applied to diffusion tensor imaging (DTI) to investigate potential diffusion changes of neural tracts in anisometropic amblyopia. Fractional anisotropy (FA) value was calculated and compared between 20 amblyopic children and 18 healthy age-matched controls. In contrast to the controls, significant decreases in FA values were found in right optic radiation (OR), left inferior longitudinal fasciculus/inferior fronto-occipital fasciculus (ILF/IFO) and right superior longitudinal fasciculus (SLF) in the amblyopia. Furthermore, FA values of these identified tracts showed positive correlation with visual acuity. It can be inferred that abnormal visual input not only hinders OR from well developed, but also impairs fasciculi associated with dorsal and ventral visual pathways, which may be responsible for the amblyopic deficiency in object discrimination and stereopsis. Increased FA was detected in right posterior part of corpus callosum (CC) with a medium effect size, which may be due to compensation effect. DTI with subsequent measurement of FA is a useful tool for investigating neuronal tract involvement in amblyopia. PMID:25899779

  9. White Matter Abnormalities and Cognitive Impairment in Early-Onset Schizophrenia-Spectrum Disorders

    PubMed Central

    Epstein, Katherine A.; Cullen, Kathryn; Mueller, Bryon; Lee, Susanne; Kumra, Sanjiv

    2014-01-01

    OBJECTIVE To characterize white matter abnormalities in adolescents with early onset schizophrenia (EOS) relative to three comparison groups (adolescents at clinical high risk for developing schizophrenia [CHR], adolescents with cannabis use disorder [CUD], and healthy controls [HC]), and to identify neurocognitive correlates of white matter abnormalities in EOS. METHOD We used diffusion tensor imaging and tractography methods to examine fractional anisotropy (FA) of the cingulum bundle, superior longitudinal fasciculus, corticospinal tract (CST), inferior longitudinal fasciculus (ILF), inferior fronto-occipital fasciculus (IFOF), and uncinate fasciculus in adolescents with EOS (n=55), CHR (n=21), CUD (n=31), and HC (n=55). FA in tracts that were significantly altered in EOS was correlated with neurocognitive performance. RESULTS EOS and CHR groups had significantly lower FA than HC in four tracts: bilateral CST, left ILF, and left IFOF. CUD had lower FA than HC in left IFOF. Lower FA in left IFOF and left ILF predicted worse neurocognitive performance in EOS. CONCLUSIONS This study identified left ILF and left IFOF as possible biomarkers of vulnerability for developing schizophrenia. Lower FA in these tracts may disrupt functioning of ventral visual and language streams, producing domain-specific neurocognitive deficits that interfere with higher order cognitive abilities. PMID:24565363

  10. Not on speaking terms: hallucinations and structural network disconnectivity in schizophrenia.

    PubMed

    ?ur?i?-Blake, Branislava; Nanetti, Luca; van der Meer, Lisette; Cerliani, Leonardo; Renken, Remco; Pijnenborg, Gerdina H M; Aleman, André

    2015-01-01

    Auditory verbal hallucinations (AVH) in schizophrenia have previously been associated with functional deficiencies in language networks, specifically with functional disconnectivity in fronto-temporal connections in the left hemisphere and in interhemispheric connections between frontal regions. Here, we investigate whether AVH are accompanied by white matter abnormalities in tracts connecting the frontal, parietal and temporal lobes, also engaged during language tasks. We combined diffusion tensor imaging with tract-based spatial statistics and found white matter abnormalities in patients with schizophrenia as compared with healthy controls. The patients showed reduced fractional anisotropy bilaterally: in the anterior thalamic radiation (ATR), body of the corpus callosum (forceps minor), cingulum, temporal part of the superior longitudinal fasciculus (SLF) and a small area in the inferior fronto-occipital fasciculus (IFOF); and in the right hemisphere: in the visual cortex, forceps major, body of the corpus callosum (posterior parts) and inferior parietal cortex. Compared to patients without current hallucinations, patients with hallucinations revealed decreased fractional anisotropy in the left IFOF, uncinate fasciculus, arcuate fasciculus with SLF, corpus callosum (posterior parts-forceps major), cingulate, corticospinal tract and ATR. The severity of hallucinations correlated negatively with white matter integrity in tracts connecting the left frontal lobe with temporal regions (uncinate fasciculus, IFOF, cingulum, arcuate fasciculus anterior and long part and superior long fasciculus frontal part) and in interhemispheric connections (anterior corona radiata). These findings support the hypothesis that hallucinations in schizophrenia are accompanied by a complex pattern of white matter alterations that negatively affect the language, emotion and attention/perception networks. PMID:24185461

  11. Lesions of the Fasciculus Retroflexus Alter Footshock-Induced cFos Expression in the Mesopontine Rostromedial Tegmental Area of Rats

    PubMed Central

    Brown, Paul Leon; Shepard, Paul D.

    2013-01-01

    Midbrain dopamine neurons are an essential part of the circuitry underlying motivation and reinforcement. They are activated by rewards or reward-predicting cues and inhibited by reward omission. The lateral habenula (lHb), an epithalamic structure that forms reciprocal connections with midbrain dopamine neurons, shows the opposite response being activated by reward omission or aversive stimuli and inhibited by reward-predicting cues. It has been hypothesized that habenular input to midbrain dopamine neurons is conveyed via a feedforward inhibitory pathway involving the GABAergic mesopontine rostromedial tegmental area. Here, we show that exposing rats to low-intensity footshock (four, 0.5 mA shocks over 20 min) induces cFos expression in the rostromedial tegmental area and that this effect is prevented by lesions of the fasciculus retroflexus, the principal output pathway of the habenula. cFos expression is also observed in the medial portion of the lateral habenula, an area that receives dense DA innervation via the fr and the paraventricular nucleus of the thalamus, a stress sensitive area that also receives dopaminergic input. High-intensity footshock (120, 0.8 mA shocks over 40 min) also elevates cFos expression in the rostromedial tegmental area, medial and lateral aspects of the lateral habenula and the paraventricular thalamus. In contrast to low-intensity footshock, increases in cFos expression within the rostromedial tegmental area are not altered by fr lesions suggesting a role for non-habenular inputs during exposure to highly aversive stimuli. These data confirm the involvement of the lateral habenula in modulating the activity of rostromedial tegmental area neurons in response to mild aversive stimuli and suggest that dopamine input may contribute to footshock- induced activation of cFos expression in the lateral habenula. PMID:23593280

  12. Reconstruction of the arcuate fasciculus for surgical planning in the setting of peritumoral edema using two-tensor unscented Kalman filter tractography

    PubMed Central

    Chen, Zhenrui; Tie, Yanmei; Olubiyi, Olutayo; Rigolo, Laura; Mehrtash, Alireza; Norton, Isaiah; Pasternak, Ofer; Rathi, Yogesh; Golby, Alexandra J.; O'Donnell, Lauren J.

    2015-01-01

    Background Diffusion imaging tractography is increasingly used to trace critical fiber tracts in brain tumor patients to reduce the risk of post-operative neurological deficit. However, the effects of peritumoral edema pose a challenge to conventional tractography using the standard diffusion tensor model. The aim of this study was to present a novel technique using a two-tensor unscented Kalman filter (UKF) algorithm to track the arcuate fasciculus (AF) in brain tumor patients with peritumoral edema. Methods Ten right-handed patients with left-sided brain tumors in the vicinity of language-related cortex and evidence of significant peritumoral edema were retrospectively selected for the study. All patients underwent 3-Tesla magnetic resonance imaging (MRI) including a diffusion-weighted dataset with 31 directions. Fiber tractography was performed using both single-tensor streamline and two-tensor UKF tractography. A two-regions-of-interest approach was applied to perform the delineation of the AF. Results from the two different tractography algorithms were compared visually and quantitatively. Results Using single-tensor streamline tractography, the AF appeared disrupted in four patients and contained few fibers in the remaining six patients. Two-tensor UKF tractography delineated an AF that traversed edematous brain areas in all patients. The volume of the AF was significantly larger on two-tensor UKF than on single-tensor streamline tractography (p < 0.01). Conclusions Two-tensor UKF tractography provides the ability to trace a larger volume AF than single-tensor streamline tractography in the setting of peritumoral edema in brain tumor patients.

  13. Neuroanatomical Abnormalities and Cognitive Impairments Are Shared by Adults with Attention-Deficit/Hyperactivity Disorder and Their Unaffected First-Degree Relatives

    PubMed Central

    Pironti, Valentino Antonio; Lai, Meng-Chuan; Müller, Ulrich; Dodds, Chris Martin; Suckling, John; Bullmore, Edward Thomas; Sahakian, Barbara Jacquelyn

    2014-01-01

    Background Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable neurodevelopmental disorder, yet the search for genes with a definitive role in its etiology has been elusive. Deconstructing the disorder in its endophenotypic traits, where the variance is thought to be associated with a fewer number of genes, should boost the statistical power of molecular genetic studies and clarify the pathophysiology of ADHD. In this study, we tested for neuroanatomical and cognitive endophenotypes in a group of adults with ADHD, their unaffected first-degree relatives, and typically developing control subjects. Methods Sixty participants, comprising 20 adults with ADHD, 20 unaffected first-degree relatives, and 20 typically developing control subjects matched for age and gender undertook structural magnetic resonance imaging scans. Voxel-based morphometry with DARTEL was performed to obtain regional gray and white matter volumes. General linear analyses of the volumes of brain regions, adjusting for age and total intracranial volume, were used to compare groups. Sustained attention and response inhibition were also investigated as cognitive endophenotypes. Results Neuroanatomical abnormalities in gray matter volume in the right inferior frontal gyrus and white matter volume in the caudal portion of the right inferior fronto-occipital fasciculus were shared between ADHD probands and their unaffected first-degree relatives. In addition, impairments in sustained attention were also found to be shared between ADHD patients and their relatives. Conclusions Cognitive impairments in sustained attention and neuroanatomical abnormalities in the right inferior frontal gyrus and the posterior part of right inferior fronto-occipital fasciculus are putative neurocognitive endophenotypes in adult ADHD. PMID:24199662

  14. Reframing in dentistry: revisited.

    PubMed

    Nuvvula, Sivakumar; Kamatham, Rekalakshmi; Challa, Ramasubbareddy; Asokan, Sharath

    2013-01-01

    The successful practice of dentistry involves a good combination of technical skills and soft skills. Soft skills or communication skills are not taught extensively in dental schools and it can be challenging to learn and at times in treating dental patients. Guiding the child's behavior in the dental operatory is one of the preliminary steps to be taken by the pediatric dentist and one who can successfully modify the behavior can definitely pave the way for a life time comprehensive oral care. This article is an attempt to revisit a simple behavior guidance technique, reframing and explain the possible psychological perspectives behind it for better use in the clinical practice. PMID:24021326

  15. Involuntary switching into the native language induced by electrocortical stimulation of the superior temporal gyrus: a multimodal mapping study.

    PubMed

    Tomasino, Barbara; Marin, Dario; Canderan, Cinzia; Maieron, Marta; Budai, Riccardo; Fabbro, Franco; Skrap, Miran

    2014-09-01

    We describe involuntary language switching from L2 to L1 evoked by electro-stimulation in the superior temporal gyrus in a 30-year-old right-handed Serbian (L1) speaker who was also a late Italian learner (L2). The patient underwent awake brain surgery. Stimulation of other portions of the exposed cortex did not cause language switching as did not stimulation of the left inferior frontal gyrus, where we evoked a speech arrest. Stimulation effects on language switching were selective, namely, interfered with counting behaviour but not with object naming. The coordinates of the positive site were combined with functional and fibre tracking (DTI) data. Results showed that the language switching site belonged to a significant fMRI cluster in the left superior temporal gyrus/supramarginal gyrus found activated for both L1 and L2, and for both the patient and controls, and did not overlap with the inferior fronto-occipital fasciculus (IFOF), the inferior longitudinal fasciculus (ILF) and the superior longitudinal fasciculus (SLF). This area, also known as Stp, has a role in phonological processing. Language switching phenomenon we observed can be partly explained by transient dysfunction of the feed-forward control mechanism hypothesized by the DIVA (Directions Into Velocities of Articulators) model (Golfinopoulos, E., Tourville, J. A., & Guenther, F. H. (2010). The integration of large-scale neural network modeling and functional brain imaging in speech motor control. PMID:25058058

  16. Clinical correlations of microstructural changes in progressive supranuclear palsy.

    PubMed

    Tessitore, Alessandro; Giordano, Alfonso; Caiazzo, Giuseppina; Corbo, Daniele; De Micco, Rosa; Russo, Antonio; Liguori, Sara; Cirillo, Mario; Esposito, Fabrizio; Tedeschi, Gioacchino

    2014-10-01

    In patients with progressive supranuclear palsy (PSP), previous reports have shown a severe white matter (WM) damage involving supra and infratentorial regions including cerebellum. In the present study, we investigated potential correlations between WM integrity loss and clinical-cognitive features of patients with PSP. By using magnetic resonance imaging and diffusion tensor imaging with tract based spatial statistic analysis, we analyzed WM volume in 18 patients with PSP and 18 healthy controls (HCs). All patients and HCs underwent a detailed clinical and neuropsychological evaluation. Relative to HCs, patients with PSP showed WM changes encompassing supra and infratentorial areas such as corpus callosum, fornix, midbrain, inferior fronto-occipital fasciculus, anterior thalamic radiation, superior cerebellar peduncle, superior longitudinal fasciculus, uncinate fasciculus, cingulate gyrus, and cortico-spinal tract bilaterally. Among different correlations between motor-cognitive features and WM structural abnormalities, we detected a significant association between fronto-cerebellar WM loss and executive cognitive impairment in patients with PSP. Our findings, therefore, corroborate the hypothesis that cognitive impairment in PSP may result from both "intrinsic" and "extrinsic" frontal lobe dysfunction, likely related to cerebellar disconnection. PMID:24786632

  17. Childhood adversity, depression, age and gender effects on white matter microstructure: a DTI study.

    PubMed

    Ugwu, Izuchukwu D; Amico, Francesco; Carballedo, Angela; Fagan, Andrew J; Frodl, Thomas

    2015-07-01

    Previous diffusion tensor imaging (DTI) studies have shown that various factors can affect white matter (WM) tract diffusivity. The aim of the present study was to investigate the effects of childhood adversity (CA), age and gender on WM diffusivity in tracts that are thought to be involved in emotional regulation in individuals with major depressive disorder (MDD) and healthy controls (HC). DTI was obtained from 46 subjects with MDD and 46 HC subjects. Data were pre-processed and deterministic tractography was applied in the cingulum, uncinate fasciculus (UF), fornix, superior longitudinal fasciculus (SLF) and fronto-occipital fasciculus (FOF). In subjects with a history of CA, fractional anisotropy (FA) was greater in the rostral cingulum (RC) and dorsal cingulum, whereas radial diffusivity (RD) was smaller in the RC when compared with subjects with no history of CA. In the UF, FOF and parahippocampal cingulum, FA was greater in the left hemisphere in the subjects with CA when compared with those without CA. Age affected FA, longitudinal diffusivity and RD in the UF, fornix, FOF and SLF, reflecting axonal and myelin degeneration with increasing age. Depression or gender did not have any effects on the diffusivity measures. Due to the cross-sectional nature of the study, a recall bias for CA and possible effects of medical treatment on diffusivity measures could have played a role. CA and age could increase the likelihood to develop WM microstructural anomalies in the brain affective network. Moreover, subjects with CA could be more vulnerable to FA changes. PMID:24744150

  18. Revisiting the schism.

    PubMed

    Litsios, Socrates

    2014-01-01

    The schism between medicine and public health has deep historical roots. The Rockefeller Foundation's Clinical Epidemiology program, initiated in the late 1970s, was seen by Kerr White, its director, as the means to heal the schism. This article revisits the role that the Foundation played in creating that schism before reviewing post-World War II efforts on the part of both the Foundation and the World Health Organization to incorporate the teaching of preventive medicine in medical education curricula. White labeled these efforts as failures, but a closer look at the history raises questions concerning what evidence he used to make this judgment and whether clinical epidemiology has not instead widened the gap between cure and prevention. PMID:25626230

  19. 42 CFR 488.30 - Revisit user fee for revisit surveys.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...billing for a fee already paid, or assessment of a fee...toward any future revisit surveys conducted, if the provider...revisit user fee amount paid to the provider or supplier...request reconsideration of the survey findings or...

  20. 42 CFR 488.30 - Revisit user fee for revisit surveys.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...billing for a fee already paid, or assessment of a fee...toward any future revisit surveys conducted, if the provider...revisit user fee amount paid to the provider or supplier...request reconsideration of the survey findings or...

  1. Searle's"Dualism Revisited"

    SciTech Connect

    P., Henry

    2008-11-20

    A recent article in which John Searle claims to refute dualism is examined from a scientific perspective. John Searle begins his recent article 'Dualism Revisited' by stating his belief that the philosophical problem of consciousness has a scientific solution. He then claims to refute dualism. It is therefore appropriate to examine his arguments against dualism from a scientific perspective. Scientific physical theories contain two kinds of descriptions: (1) Descriptions of our empirical findings, expressed in an every-day language that allows us communicate to each other our sensory experiences pertaining to what we have done and what we have learned; and (2) Descriptions of a theoretical model, expressed in a mathematical language that allows us to communicate to each other certain ideas that exist in our mathematical imaginations, and that are believed to represent, within our streams of consciousness, certain aspects of reality that we deem to exist independently of their being perceived by any human observer. These two parts of our scientific description correspond to the two aspects of our general contemporary dualistic understanding of the total reality in which we are imbedded, namely the empirical-mental aspect and the theoretical-physical aspect. The duality question is whether this general dualistic understanding of ourselves should be regarded as false in some important philosophical or scientific sense.

  2. THE WATER CYCLE REVISITED:THE WATER CYCLE REVISITED: LINKAGES WITH ELEMENTLINKAGES WITH ELEMENT

    E-print Network

    Slatton, Clint

    THE WATER CYCLE REVISITED:THE WATER CYCLE REVISITED: LINKAGES WITH ELEMENTLINKAGES WITH ELEMENT?s to revisit? #12;USGCRP Water Cycle Science Plan Hornberger et al. 2001 (3rd Science Question) How will variability and changes in the cycling of water though terrestrial and freshwater ecosystems be linked

  3. Internet Governance revisited: Think decentralization!

    E-print Network

    Schweik, Charles M.

    Internet Governance revisited: Think decentralization! Brown-bag presentation given at the National Administration of the core technical resources of the Internet: ICANN: The mission... ,,preserving the public of the Internet" #12;unique identifiers basis for accurate routing of information (TCP/IP) IP-blocks managed

  4. Axion Quintessence Revisited Carl Gardner

    E-print Network

    Gardner, Carl

    Axion Quintessence Revisited Carl Gardner School of Mathematical & Statistical Sciences Arizona;Axion Quintessence Define /MP Focus on stable & unstable axion quintessence with DE,0 = 0.72 & -1 axion quintessence V() = A cos(), 0 i/ 0.23 produces a universe like

  5. Message Authentication, Revisited Yevgeniy Dodis

    E-print Network

    Message Authentication, Revisited Yevgeniy Dodis Eike Kiltz Krzysztof Pietrzak Daniel Wichs§ October 28, 2012 Abstract Traditionally, symmetric-key message authentication codes (MACs) are easily a state-of-the-art PRF instantiation under the corresponding assumption. For example, we obtain elegant

  6. Revisiting Money - Interest Rate Relationship

    Microsoft Academic Search

    Srivyal Vuyyuri; Ganesh S Mani; Chakrapani V Chaturvedula

    2003-01-01

    This paper tries to revisit the relationship between money supply and interest rates. Data for countries from 1981 to 1998 seem to support the positive relationship between the two variables as described by the Fisher equation. The empirical findings have been substantiated by a simple mathematical model. It incorporates the Fisher equation view as well as the liquidity effect and

  7. Revisiting constraint-directed search

    Microsoft Academic Search

    Magnus Ågren; Pierre Flener; Justin Pearson

    2009-01-01

    We revisit the exploration of constraint-directed neighbour- hoods, where a (small) set of constraints is picked before considering the neighbouring configurations where those constraints have a decreased (or preserved, or increased) penalty. Given the semantics of a constraint, such neighbourhoods can be represented via new attributes or primi- tives for the corresponding constraint object. We show how to define these

  8. Dragon curves revisited S. Tabachnikov

    E-print Network

    Tabachnikov, Sergei

    Dragon curves revisited S. Tabachnikov It has happened several times in recent history mathematical object of comparable beauty, the Dragon curves, whose theory was created by Chandler Davis with previously unpublished addendum).1 Mathematical Intelligencer wrote about Dragon curves more than 30 years

  9. Blockcipher-Based Hashing Revisited

    Microsoft Academic Search

    Martijn Stam

    2009-01-01

    We revisit the rate-1 blockcipher based hash functions as first studied by Preneel, Govaerts and Vandewalle (Crypto'93) and later extensively analysed by Black, Rogaway and Shrimpton (Crypto'02). We analyse a further generalization where any pre- and postprocessing is considered. This leads to a clearer under- standing of the current classification of rate-1 blockcipher based schemes as introduced by Preneel et

  10. Oxidative phosphorylation revisited.

    PubMed

    Nath, Sunil; Villadsen, John

    2015-03-01

    The fundamentals of oxidative phosphorylation and photophosphorylation are revisited. New experimental data on the involvement of succinate and malate anions respectively in oxidative phosphorylation and photophosphorylation are presented. These new data offer a novel molecular mechanistic explanation for the energy coupling and ATP synthesis carried out in mitochondria and chloroplast thylakoids. The mechanism does not suffer from the flaws in Mitchell's chemiosmotic theory that have been pointed out in many studies since its first appearance 50 years ago, when it was hailed as a ground-breaking mechanistic explanation of what is perhaps the most important process in cellular energetics. The new findings fit very well with the predictions of Nath's torsional mechanism of energy transduction and ATP synthesis. It is argued that this mechanism, based on at least 15 years of experimental and theoretical work by Sunil Nath, constitutes a fundamentally different theory of the energy conversion process that eliminates all the inconsistencies in Mitchell's chemiosmotic theory pointed out by other authors. It is concluded that the energy-transducing complexes in oxidative phosphorylation and photosynthesis are proton-dicarboxylic acid anion cotransporters and not simply electrogenic proton translocators. These results necessitate revision of previous theories of biological energy transduction, coupling, and ATP synthesis. The novel molecular mechanism is extended to cover ATP synthesis in prokaryotes, in particular to alkaliphilic and haloalkaliphilic bacteria, essentially making it a complete theory addressing mechanistic, kinetic, and thermodynamic details. Finally, based on the new interpretation of oxidative phosphorylation, quantitative values for the P/O ratio, the amount of ATP generated per redox package of the reduced substrates, are calculated and compared with experimental values for fermentation on different substrates. It is our hope that the presentation of oxidative phosphorylation and photophosphorylation from a wholly new perspective will rekindle scientific discussion of a key process in bioenergetics and catalyze new avenues of research in a truly interdisciplinary field. PMID:25384602

  11. Dynamic Topography Revisited

    NASA Astrophysics Data System (ADS)

    Moresi, Louis

    2015-04-01

    Dynamic Topography Revisited Dynamic topography is usually considered to be one of the trinity of contributing causes to the Earth's non-hydrostatic topography along with the long-term elastic strength of the lithosphere and isostatic responses to density anomalies within the lithosphere. Dynamic topography, thought of this way, is what is left over when other sources of support have been eliminated. An alternate and explicit definition of dynamic topography is that deflection of the surface which is attributable to creeping viscous flow. The problem with the first definition of dynamic topography is 1) that the lithosphere is almost certainly a visco-elastic / brittle layer with no absolute boundary between flowing and static regions, and 2) the lithosphere is, a thermal / compositional boundary layer in which some buoyancy is attributable to immutable, intrinsic density variations and some is due to thermal anomalies which are coupled to the flow. In each case, it is difficult to draw a sharp line between each contribution to the overall topography. The second definition of dynamic topography does seem cleaner / more precise but it suffers from the problem that it is not measurable in practice. On the other hand, this approach has resulted in a rich literature concerning the analysis of large scale geoid and topography and the relation to buoyancy and mechanical properties of the Earth [e.g. refs 1,2,3] In convection models with viscous, elastic, brittle rheology and compositional buoyancy, however, it is possible to examine how the surface topography (and geoid) are supported and how different ways of interpreting the "observable" fields introduce different biases. This is what we will do. References (a.k.a. homework) [1] Hager, B. H., R. W. Clayton, M. A. Richards, R. P. Comer, and A. M. Dziewonski (1985), Lower mantle heterogeneity, dynamic topography and the geoid, Nature, 313(6003), 541-545, doi:10.1038/313541a0. [2] Parsons, B., and S. Daly (1983), The relationship between surface topography, gravity anomalies, and temperature structure of convection, Journal of Geophysical Research: Solid Earth (1978-2012), 88(B2), 1129-1144, doi:10.1029/JB088iB02p01129. [3] Robinson, E. M., B. Parsons, and S. F. Daly (1987), The effect of a shallow low viscosity zone on the apparent compensation of mid-plate swells, Earth and Planetary Science Letters, 82(3-4), 335-348, doi:10.1016/0012-821X(87)90207-X.

  12. Revisiting niacin: reviewing the evidence

    Microsoft Academic Search

    Christopher S. Vaccari; Ramadan A. Hammoud; Sameer H. Nagamia; Kanni Ramasamy; Allen L. Dollar; Bobby V. Khan

    2007-01-01

    Atherogenic dyslipidemia, defined by a cluster of lipoprotein abnormalities, including low high?density lipoprotein cholesterol (HDL-C) and elevated serum triglycerides, represents an important potential target for reducing cardiovascular risk. This has paved the way for revisiting niacin as a therapy in preventing progression of atherosclerosis. Niacin remains the safest and most effective agent for raising HDL-C and is a logical choice

  13. Radiolytic Cryovolcanism Revisited

    NASA Astrophysics Data System (ADS)

    Cooper, J. F.; Cooper, P. D.; Sittler, E. C.; Wesenberg, R. P.

    2013-12-01

    Active geysers of water vapor and ice grains from the south pole of Enceladus are not yet definitively explained in terms of energy sources and processes. Other instances of hot (Io) and cold (Mars, Triton) volcanism beyond Earth are known if not fully understood. We revisit, in comparison to other models, the 'Old Faithful' theory of radiolytic gas-driven cryovolcanism first proposed by Cooper et al. [Plan. Sp. Sci. 2009]. In the energetic electron irradiation environment of Enceladus within Saturn's magnetosphere, a 10-percent duty cycle could be maintained for current geyser activity driven by gases from oxidation of ammonia to N2 and methane to CO2 in the thermal margins of a south polar sea. Much shorter duty cycles down to 0.01 percent would be required to account for thermal power output up to 16 GW, Steady accumulation of oxidant energy over four billion years could have powered all Enceladus emissions over the past four hundred thousand to four hundred million years. There could be separate energy sources driving mass flow and thermal emission over vastly different time scales. Since episodic tidal dissipation on 10 Myr time scales at 0.1 - 1 Gyr intervals [O'Neill and Nimmo, Nature 2010], and thus duty cycles 1 - 10 percent, could heat the polar sea to the current level, the radiolytic energy source could easily power and modulate the geyser mass flow on million-year time scales. Maximum thermal emission temperature 223 K [Abramov and Spencer, Icarus 2009] hints at thermal buffering in the basal and vent wall layers by a 1:1 H2O:H2O2 radiolytic eutectic, assuming deep ice crust saturation with H2O2 from long cumulative surface irradiation and downward ice convection. Due to density stratification the peroxide eutectic and salt water layers could separate, so that the denser peroxide layer (1.2 g/cc) descends to the polar sea while the lighter salt water (1.05 g/cc) rises along separate channels. Methane reservoirs could be found dissolved into the polar sea, or else trapped in hydrates [Kieffer et al., Science 2006] along flow paths and at the walls of the polar sea at surface depths below 20 km [Fortes, Icarus 2007]. Driver gas production for cryovolcanism could occur wherever these two layers come into contact under requisite temperature and pressure conditions, e.g. from 220 K and 10 bar at the 10-km basal layer of the overlying ice crust to 647 K and 220 bars at the liquid water limit, above the core-mantle boundary at 460 bars [Fortes, Icarus 2007]. We expect H2O2 oxidation to ignite at high temperatures but metallic minerals could catalyze reactions at lower temperatures nearer the basal layer. Pressure effects on oxidation rates are uncertain. Definitive modeling of Enceladus cryovolcanism likely involves synthesis of key processes from multiple models: Cold Faithful [Porco et al., Science 2006], Frigid Faithful [Keiffer et al., Science 2006], Frothy Faithful [Fortes, Icarus 2007], Old Faithful, and 'Perrier Ocean' recirculation [Matson et al., Icarus 2012].

  14. Individual differences in white matter anatomy predict dissociable components of reading skill in adults.

    PubMed

    Welcome, Suzanne E; Joanisse, Marc F

    2014-08-01

    We used diffusion tensor imaging (DTI) to investigate relationships between white matter anatomy and different reading subskills in typical-reading adults. A series of analytic approaches revealed that phonological decoding ability is associated with anatomical markers that do not relate to other reading-related cognitive abilities. Thus, individual differences in phonological decoding might relate to connectivity between a network of cortical regions, while skills like sight word reading might rely less strongly on integration across regions. Specifically, manually-drawn ROIs and probabilistic tractography revealed an association between the volume and integrity of white matter underlying primary auditory cortex and nonword reading ability. In a related finding, more extensive cross-hemispheric connections through the isthmus of the corpus callosum predicted better phonological decoding. Atlas-based white matter ROIs demonstrated that relationships with nonword reading were strongest in the inferior fronto-occipital fasciculus and uncinate fasciculus that connect occipital and anterior temporal cortex with inferior frontal cortex. In contrast, tract volume underlying the left angular gyrus was related to nonverbal IQ. Finally, connectivity underlying functional ROIs that are differentially active during phonological and semantic processing predicted nonword reading and reading comprehension, respectively. Together, these results provide important insights into how white matter anatomy may relate to both typical reading subskills, and perhaps a roadmap for understanding neural connectivity in individuals with reading impairments. PMID:24704456

  15. Emerging structure-function relations in the developing face processing system.

    PubMed

    Suzanne Scherf, K; Thomas, Cibu; Doyle, Jaime; Behrmann, Marlene

    2014-11-01

    To evaluate emerging structure-function relations in a neural circuit that mediates complex behavior, we investigated age-related differences among cortical regions that support face recognition behavior and the fiber tracts through which they transmit and receive signals using functional neuroimaging and diffusion tensor imaging. In a large sample of human participants (aged 6-23 years), we derived the microstructural and volumetric properties of the inferior longitudinal fasciculus (ILF), the inferior fronto-occipital fasciculus, and control tracts, using independently defined anatomical markers. We also determined the functional characteristics of core face- and place-selective regions that are distributed along the trajectory of the pathways of interest. We observed disproportionately large age-related differences in the volume, fractional anisotropy, and mean and radial, but not axial, diffusivities of the ILF. Critically, these differences in the structural properties of the ILF were tightly and specifically linked with an age-related increase in the size of a key face-selective functional region, the fusiform face area. This dynamic association between emerging structural and functional architecture in the developing brain may provide important clues about the mechanisms by which neural circuits become organized and optimized in the human cortex. PMID:23765156

  16. Neuroimaging abnormalities, neurocognitive function, and fatigue in patients with hepatitis C

    PubMed Central

    Castellon, Steven A.; Singer, Elyse J.; Nagarajan, Rajakumar; Sarma, Manoj K.; Smith, Jason; Thaler, Nicholas S.; Truong, Jonathan Hien; Schonfeld, Daniel; Thomas, M. Albert; Hinkin, Charles H.

    2015-01-01

    Objective: This study examined neurologic abnormalities (as measured by proton magnetic resonance spectroscopy imaging and diffusion tensor imaging), neurocognitive performance, and fatigue among a sample of adults with hepatitis C virus (HCV). We hypothesized that HCV+ individuals would demonstrate structural brain abnormalities and neurocognitive compromise consistent with frontostriatal dysfunction as well as increased fatigue compared to controls. Method: Participants were 76 individuals diagnosed with HCV and 20 controls who underwent a comprehensive neurocognitive evaluation and clinical assessments. A subset of the HCV+ participants (n = 29) and all controls underwent MRI. Results: Individuals diagnosed with chronic HCV infection demonstrated greater fractional anisotropy in the striatum as well as greater mean diffusivity in the fronto-occiptal fasciculus and external capsule compared to HCV? controls. HCV+ participants also demonstrated lower levels of N-acetylaspartate in bilateral parietal white matter and elevations in myo-inosital (mI) in bilateral frontal white matter compared to HCV? controls (all p values < 0.05). HCV+ participants also demonstrated significantly poorer neuropsychological performance, particularly in processing speed and verbal fluency. HCV+ patients reported higher levels of fatigue than controls, and fatigue was significantly correlated with diffusivity in the superior fronto-occipital fasciculus, elevations in mI in frontal white matter, and overall cognitive performance. Conclusions: Our results suggest that HCV-associated neurologic complications disrupt frontostriatal structures, which may result in increased fatigue and poorer cognitive performance, particularly in those cognitive domains regulated by frontostriatal regions. PMID:25610883

  17. White matter fractional anisotropy over two time points in early onset schizophrenia and adolescent cannabis use disorder: A naturalistic diffusion tensor imaging study.

    PubMed

    Epstein, Katherine A; Kumra, Sanjiv

    2015-04-30

    Recurrent exposure to cannabis in adolescence increases the risk for later development of psychosis, but there are sparse data regarding the impact of cannabis use on brain structure during adolescence. This pilot study investigated the effect of cannabis use disorder (CUD) upon white matter fractional anisotropy (WM FA) values in non-psychotic treatment-seeking adolescents relative to adolescents with early onset schizophrenia-spectrum disorders (EOSS) and to healthy control (HC) participants. Diffusion tensor imaging (DTI) and tractography methods were used to examine fractional anisotropy (FA) of the cingulum bundle, superior longitudinal fasciculus (SLF), corticospinal tract (CST), inferior longitudinal fasciculus (ILF), inferior fronto-occipital fasciculus (IFOF) and uncinate fasciculus in adolescents with EOSS (n=34), CUD (n=19) and HC (n=29). Participants received DTI and substance use assessments at baseline and at 18-month follow-up. Using multivariate analysis of variance, a significant main effect of diagnostic group was observed. Post-hoc testing revealed that adolescents with CUD showed an altered change in FA values in the left ILF and in the left IFOF (trend level) compared with HC adolescents. Greater consumption of cannabis during the inter-scan interval predicted a greater decrease in left ILF FA in CUD. These preliminary longitudinal data suggest that heavy cannabis use during adolescence, or some factor associated with cannabis use, is associated with an altered change in WM FA values in a fiber bundle that has been implicated in the pathophysiology of EOSS (i.e., the left ILF). Additional studies are needed to clarify the clinical significance of these findings. PMID:25779033

  18. Altered white matter microstructure is associated with social cognition and psychotic symptoms in 22q11.2 microdeletion syndrome.

    PubMed

    Jalbrzikowski, Maria; Villalon-Reina, Julio E; Karlsgodt, Katherine H; Senturk, Damla; Chow, Carolyn; Thompson, Paul M; Bearden, Carrie E

    2014-01-01

    22q11.2 Microdeletion Syndrome (22q11DS) is a highly penetrant genetic mutation associated with a significantly increased risk for psychosis. Aberrant neurodevelopment may lead to inappropriate neural circuit formation and cerebral dysconnectivity in 22q11DS, which may contribute to symptom development. Here we examined: (1) differences between 22q11DS participants and typically developing controls in diffusion tensor imaging (DTI) measures within white matter tracts; (2) whether there is an altered age-related trajectory of white matter pathways in 22q11DS; and (3) relationships between DTI measures, social cognition task performance, and positive symptoms of psychosis in 22q11DS and typically developing controls. Sixty-four direction diffusion weighted imaging data were acquired on 65 participants (36 22q11DS, 29 controls). We examined differences between 22q11DS vs. controls in measures of fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD), using both a voxel-based and region of interest approach. Social cognition domains assessed were: Theory of Mind and emotion recognition. Positive symptoms were assessed using the Structured Interview for Prodromal Syndromes. Compared to typically developing controls, 22q11DS participants showed significantly lower AD and RD in multiple white matter tracts, with effects of greatest magnitude for AD in the superior longitudinal fasciculus. Additionally, 22q11DS participants failed to show typical age-associated changes in FA and RD in the left inferior longitudinal fasciculus. Higher AD in the left inferior fronto-occipital fasciculus (IFO) and left uncinate fasciculus was associated with better social cognition in 22q11DS and controls. In contrast, greater severity of positive symptoms was associated with lower AD in bilateral regions of the IFO in 22q11DS. White matter microstructure in tracts relevant to social cognition is disrupted in 22q11DS, and may contribute to psychosis risk. PMID:25426042

  19. Smith Theory Revisited William G. Dwyer

    E-print Network

    Wilkerson, Clarence

    Smith Theory Revisited William G. Dwyer Clarence W. Wilkerson* 1 Introduction In the late 1930's, P. A. Smith began the investigation. This thread has continued now for almost fifty years. Smith was successful in calculating the cohomology

  20. SLIM--An Early Work Revisited

    SciTech Connect

    Chao, Alex; /SLAC

    2008-07-25

    An early, but at the time illuminating, piece of work on how to deal with a general, linearly coupled accelerator lattice is revisited. This work is based on the SLIM formalism developed in 1979-1981.

  1. Faraday rotation revisited: The thermodynamic limit

    E-print Network

    Cornean, H D

    2008-01-01

    This paper is the second in a series revisiting the (effect of) Faraday rotation. We formulate and prove the thermodynamic limit for the transverse electric conductivity of Bloch electrons, as well as for the Verdet constant.

  2. Adaptive Filters Revisited :Adaptive Filters Revisited : RFI Mitigation in PulsarRFI Mitigation in Pulsar

    E-print Network

    Ellingson, Steven W.

    Adaptive Filters Revisited :Adaptive Filters Revisited : RFI Mitigation in PulsarRFI Mitigation the IF ­ compatible with the downstream processing. We know the location of the RFI ­ a good reference copy is available. The RFI is strong. Can be implemented in real-time (on-line) hardware. The post

  3. Carbon Tariffs Revisited The Harvard Project on Climate Agreements

    E-print Network

    Liu, X. Shirley

    Carbon Tariffs Revisited The Harvard Project on Climate Agreements March 2014 Discussion Paper 14;#12;Carbon Tariffs Revisited Christoph Böhringer University of Oldenburg Germany André Müller ECOPLAN, and Jan Schneider. "Carbon Tariffs Revisited." Discussion Paper 2014-64. Cambridge, Mass.: Harvard Project

  4. ...... Frechet Distance Revisited and Extended Sariel Har-Peled1

    E-print Network

    Har-Peled, Sariel

    . ...... Fr´echet Distance Revisited and Extended Sariel Har-Peled1 Benjamin Raichel1 1UIUC, Illinois, USA June 15, 2011 Har-Peled and Raichel (UIUC) Fr´echet Distance Revisited and Extended June 15 recognition, etc. Har-Peled and Raichel (UIUC) Fr´echet Distance Revisited and Extended June 15, 2011 2 / 26

  5. Orthopaedic service lines-revisited.

    PubMed

    Patterson, Cheryl

    2008-01-01

    This article revisits the application of orthopaedic service lines from early introduction and growth of this organizational approach in the 1980s, through the 1990s, and into the current decade. The author has experienced and worked in various service-line structures through these three decades, as well as the preservice-line era of 1970s orthopaedics. Past lessons learned during earlier phases and then current trends and analysis by industry experts are summarized briefly, with indication given of the future for service lines. Variation versus consistency of certain elements in service-line definitions and in operational models is discussed. Main components of service-line structures and typical processes are described briefly, along with a more detailed section on the service-line director/manager role. Current knowledge contained here will help guide the reader to more "out-of-the-box" thinking toward comprehensive orthopaedic centers of excellence. PMID:18300683

  6. Secret Public Key Protocols Revisited

    NASA Astrophysics Data System (ADS)

    Lim, Hoon Wei; Paterson, Kenneth G.

    Password-based protocols are important and popular means of providing human-to-machine authentication. The concept of secret public keys was proposed more than a decade ago as a means of securing password-based authentication protocols against off-line password guessing attacks, but was later found vulnerable to various attacks. In this paper, we revisit the concept and introduce the notion of identity-based secret public keys. Our new identity-based approach allows secret public keys to be constructed in a very natural way using arbitrary random strings, eliminating the structure found in, for example, RSA or ElGamal keys. We examine identity-based secret public key protocols and give informal security analyses, indicating that they are secure against off-line password guessing and other attacks.

  7. Individual structural differences in left inferior parietal area are associated with schoolchildrens' arithmetic scores

    PubMed Central

    Li, Yongxin; Hu, Yuzheng; Wang, Yunqi; Weng, Jian; Chen, Feiyan

    2013-01-01

    Arithmetic skill is of critical importance for academic achievement, professional success and everyday life, and childhood is the key period to acquire this skill. Neuroimaging studies have identified that left parietal regions are a key neural substrate for representing arithmetic skill. Although the relationship between functional brain activity in left parietal regions and arithmetic skill has been studied in detail, it remains unclear about the relationship between arithmetic achievement and structural properties in left inferior parietal area in schoolchildren. The current study employed a combination of voxel-based morphometry (VBM) for high-resolution T1-weighted images and fiber tracking on diffusion tensor imaging (DTI) to examine the relationship between structural properties in the inferior parietal area and arithmetic achievement in 10-year-old schoolchildren. VBM of the T1-weighted images revealed that individual differences in arithmetic scores were significantly and positively correlated with the gray matter (GM) volume in the left intraparietal sulcus (IPS). Fiber tracking analysis revealed that the forceps major, left superior longitudinal fasciculus (SLF), bilateral inferior longitudinal fasciculus (ILF) and inferior fronto-occipital fasciculus (IFOF) were the primary pathways connecting the left IPS with other brain areas. Furthermore, the regression analysis of the probabilistic pathways revealed a significant and positive correlation between the fractional anisotropy (FA) values in the left SLF, ILF and bilateral IFOF and arithmetic scores. The brain structure-behavior correlation analyses indicated that the GM volumes in the left IPS and the FA values in the tract pathways connecting left IPS were both related to children's arithmetic achievement. The present findings provide evidence that individual structural differences in the left IPS are associated with arithmetic scores in schoolchildren. PMID:24367320

  8. Disconnection Mechanism and Regional Cortical Atrophy Contribute to Impaired Processing of Facial Expressions and Theory of Mind in Multiple Sclerosis: A Structural MRI Study

    PubMed Central

    Mike, Andrea; Strammer, Erzsebet; Aradi, Mihaly; Orsi, Gergely; Perlaki, Gabor; Hajnal, Andras; Sandor, Janos; Banati, Miklos; Illes, Eniko; Zaitsev, Alexander; Herold, Robert; Guttmann, Charles R. G.; Illes, Zsolt

    2013-01-01

    Successful socialization requires the ability of understanding of others’ mental states. This ability called as mentalization (Theory of Mind) may become deficient and contribute to everyday life difficulties in multiple sclerosis. We aimed to explore the impact of brain pathology on mentalization performance in multiple sclerosis. Mentalization performance of 49 patients with multiple sclerosis was compared to 24 age- and gender matched healthy controls. T1- and T2-weighted three-dimensional brain MRI images were acquired at 3Tesla from patients with multiple sclerosis and 18 gender- and age matched healthy controls. We assessed overall brain cortical thickness in patients with multiple sclerosis and the scanned healthy controls, and measured the total and regional T1 and T2 white matter lesion volumes in patients with multiple sclerosis. Performances in tests of recognition of mental states and emotions from facial expressions and eye gazes correlated with both total T1-lesion load and regional T1-lesion load of association fiber tracts interconnecting cortical regions related to visual and emotion processing (genu and splenium of corpus callosum, right inferior longitudinal fasciculus, right inferior fronto-occipital fasciculus, uncinate fasciculus). Both of these tests showed correlations with specific cortical areas involved in emotion recognition from facial expressions (right and left fusiform face area, frontal eye filed), processing of emotions (right entorhinal cortex) and socially relevant information (left temporal pole). Thus, both disconnection mechanism due to white matter lesions and cortical thinning of specific brain areas may result in cognitive deficit in multiple sclerosis affecting emotion and mental state processing from facial expressions and contributing to everyday and social life difficulties of these patients. PMID:24349280

  9. Multi-modal MRI of mild traumatic brain injury

    PubMed Central

    Narayana, Ponnada A.; Yu, Xintian; Hasan, Khader M.; Wilde, Elisabeth A.; Levin, Harvey S.; Hunter, Jill V.; Miller, Emmy R.; Patel, Vipul Kumar S.; Robertson, Claudia S.; McCarthy, James J.

    2014-01-01

    Multi-modal magnetic resonance imaging (MRI) that included high resolution structural imaging, diffusion tensor imaging (DTI), magnetization transfer ratio (MTR) imaging, and magnetic resonance spectroscopic imaging (MRSI) were performed in mild traumatic brain injury (mTBI) patients with negative computed tomographic scans and in an orthopedic-injured (OI) group without concomitant injury to the brain. The OI group served as a comparison group for mTBI. MRI scans were performed both in the acute phase of injury (~24 h) and at follow-up (~90 days). DTI data was analyzed using tract based spatial statistics (TBSS). Global and regional atrophies were calculated using tensor-based morphometry (TBM). MTR values were calculated using the standard method. MRSI was analyzed using LC Model. At the initial scan, the mean diffusivity (MD) was significantly higher in the mTBI cohort relative to the comparison group in several white matter (WM) regions that included internal capsule, external capsule, superior corona radiata, anterior corona radiata, posterior corona radiata, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, forceps major and forceps minor of the corpus callosum, superior longitudinal fasciculus, and corticospinal tract in the right hemisphere. TBSS analysis failed to detect significant differences in any DTI measures between the initial and follow-up scans either in the mTBI or OI group. No significant differences were found in MRSI, MTR or morphometry between the mTBI and OI cohorts either at the initial or follow-up scans with or without family wise error (FWE) correction. Our study suggests that a number of WM tracts are affected in mTBI in the acute phase of injury and that these changes disappear by 90 days. This study also suggests that none of the MRI-modalities used in this study, with the exception of DTI, is sensitive in detecting changes in the acute phase of mTBI. PMID:25610770

  10. Disconnection mechanism and regional cortical atrophy contribute to impaired processing of facial expressions and theory of mind in multiple sclerosis: a structural MRI study.

    PubMed

    Mike, Andrea; Strammer, Erzsebet; Aradi, Mihaly; Orsi, Gergely; Perlaki, Gabor; Hajnal, Andras; Sandor, Janos; Banati, Miklos; Illes, Eniko; Zaitsev, Alexander; Herold, Robert; Guttmann, Charles R G; Illes, Zsolt

    2013-01-01

    Successful socialization requires the ability of understanding of others' mental states. This ability called as mentalization (Theory of Mind) may become deficient and contribute to everyday life difficulties in multiple sclerosis. We aimed to explore the impact of brain pathology on mentalization performance in multiple sclerosis. Mentalization performance of 49 patients with multiple sclerosis was compared to 24 age- and gender matched healthy controls. T1- and T2-weighted three-dimensional brain MRI images were acquired at 3Tesla from patients with multiple sclerosis and 18 gender- and age matched healthy controls. We assessed overall brain cortical thickness in patients with multiple sclerosis and the scanned healthy controls, and measured the total and regional T1 and T2 white matter lesion volumes in patients with multiple sclerosis. Performances in tests of recognition of mental states and emotions from facial expressions and eye gazes correlated with both total T1-lesion load and regional T1-lesion load of association fiber tracts interconnecting cortical regions related to visual and emotion processing (genu and splenium of corpus callosum, right inferior longitudinal fasciculus, right inferior fronto-occipital fasciculus, uncinate fasciculus). Both of these tests showed correlations with specific cortical areas involved in emotion recognition from facial expressions (right and left fusiform face area, frontal eye filed), processing of emotions (right entorhinal cortex) and socially relevant information (left temporal pole). Thus, both disconnection mechanism due to white matter lesions and cortical thinning of specific brain areas may result in cognitive deficit in multiple sclerosis affecting emotion and mental state processing from facial expressions and contributing to everyday and social life difficulties of these patients. PMID:24349280

  11. Evaluation of diffusion-tensor imaging-based global search and tractography for tumor surgery close to the language system.

    PubMed

    Richter, Mirco; Zolal, Amir; Ganslandt, Oliver; Buchfelder, Michael; Nimsky, Christopher; Merhof, Dorit

    2013-01-01

    Pre-operative planning and intra-operative guidance in neurosurgery require detailed information about the location of functional areas and their anatomo-functional connectivity. In particular, regarding the language system, post-operative deficits such as aphasia can be avoided. By combining functional magnetic resonance imaging and diffusion tensor imaging, the connectivity between functional areas can be reconstructed by tractography techniques that need to cope with limitations such as limited resolution and low anisotropic diffusion close to functional areas. Tumors pose particular challenges because of edema, displacement effects on brain tissue and infiltration of white matter. Under these conditions, standard fiber tracking methods reconstruct pathways of insufficient quality. Therefore, robust global or probabilistic approaches are required. In this study, two commonly used standard fiber tracking algorithms, streamline propagation and tensor deflection, were compared with a previously published global search, Gibbs tracking and a connection-oriented probabilistic tractography approach. All methods were applied to reconstruct neuronal pathways of the language system of patients undergoing brain tumor surgery, and control subjects. Connections between Broca and Wernicke areas via the arcuate fasciculus (AF) and the inferior fronto-occipital fasciculus (IFOF) were validated by a clinical expert to ensure anatomical feasibility, and compared using distance- and diffusion-based similarity metrics to evaluate their agreement on pathway locations. For both patients and controls, a strong agreement between all methods was observed regarding the location of the AF. In case of the IFOF however, standard fiber tracking and Gibbs tracking predominantly identified the inferior longitudinal fasciculus that plays a secondary role in semantic language processing. In contrast, global search resolved connections in almost every case via the IFOF which could be confirmed by probabilistic fiber tracking. The results show that regarding the language system, our global search is superior to clinically applied conventional fiber tracking strategies with results similar to time-consuming global or probabilistic approaches. PMID:23308093

  12. Evaluation of Diffusion-Tensor Imaging-Based Global Search and Tractography for Tumor Surgery Close to the Language System

    PubMed Central

    Richter, Mirco; Zolal, Amir; Ganslandt, Oliver; Buchfelder, Michael; Nimsky, Christopher; Merhof, Dorit

    2013-01-01

    Pre-operative planning and intra-operative guidance in neurosurgery require detailed information about the location of functional areas and their anatomo-functional connectivity. In particular, regarding the language system, post-operative deficits such as aphasia can be avoided. By combining functional magnetic resonance imaging and diffusion tensor imaging, the connectivity between functional areas can be reconstructed by tractography techniques that need to cope with limitations such as limited resolution and low anisotropic diffusion close to functional areas. Tumors pose particular challenges because of edema, displacement effects on brain tissue and infiltration of white matter. Under these conditions, standard fiber tracking methods reconstruct pathways of insufficient quality. Therefore, robust global or probabilistic approaches are required. In this study, two commonly used standard fiber tracking algorithms, streamline propagation and tensor deflection, were compared with a previously published global search, Gibbs tracking and a connection-oriented probabilistic tractography approach. All methods were applied to reconstruct neuronal pathways of the language system of patients undergoing brain tumor surgery, and control subjects. Connections between Broca and Wernicke areas via the arcuate fasciculus (AF) and the inferior fronto-occipital fasciculus (IFOF) were validated by a clinical expert to ensure anatomical feasibility, and compared using distance- and diffusion-based similarity metrics to evaluate their agreement on pathway locations. For both patients and controls, a strong agreement between all methods was observed regarding the location of the AF. In case of the IFOF however, standard fiber tracking and Gibbs tracking predominantly identified the inferior longitudinal fasciculus that plays a secondary role in semantic language processing. In contrast, global search resolved connections in almost every case via the IFOF which could be confirmed by probabilistic fiber tracking. The results show that regarding the language system, our global search is superior to clinically applied conventional fiber tracking strategies with results similar to time-consuming global or probabilistic approaches. PMID:23308093

  13. Pharmacy School Survey Standards Revisited

    PubMed Central

    Barnett, Mitchell J.; Lenth, Russell V.; Knapp, Katherine K.

    2013-01-01

    In a series of 3 papers on survey practices published from 2008 to 2009, the editors of the American Journal of Pharmaceutical Education presented guidelines for reporting survey research, and these criteria are reflected in the Author Instructions provided on the Journal’s Web site. This paper discusses the relevance of these criteria for publication of survey research regarding pharmacy colleges and schools. In addition, observations are offered about surveying of small "universes" like that comprised of US colleges and schools of pharmacy. The reason for revisiting this issue is the authors’ concern that, despite the best of intentions, overly constraining publication standards might discourage research on US colleges and schools of pharmacy at a time when the interest in the growth of colleges and schools, curricular content, clinical education, competence at graduation, and other areas is historically high. In the best traditions of academia, the authors share these observations with the community of pharmacy educators in the hope that the publication standards for survey research about US pharmacy schools will encourage investigators to collect and disseminate valuable information. PMID:23459404

  14. Pathology of human influenza revisited.

    PubMed

    Kuiken, Thijs; Taubenberger, Jeffery K

    2008-09-12

    The pathology of human influenza has been studied most intensively during the three pandemics of the last century, the last of which occurred in 1968. It is important to revisit this subject because of the recent emergence of avian H5N1 influenza in humans as well as the threat of a new pandemic. Uncomplicated human influenza virus infection causes transient tracheo-bronchitis, corresponding with predominant virus attachment to tracheal and bronchial epithelial cells. The main complication is extension of viral infection to the alveoli, often with secondary bacterial infection, resulting in severe pneumonia. Complications in extra-respiratory tissues such as encephalopathy, myocarditis, and myopathy occur occasionally. Sensitive molecular and immunological techniques allow us to investigate whether these complications are a direct result of virus infection or an indirect result of severe pneumonia. Human disease from avian influenza virus infections is most severe for subtype H5N1, but also has been reported for H7 and H9 subtypes. In contrast to human influenza viruses, avian H5N1 virus attaches predominantly to alveolar and bronchiolar epithelium, corresponding with diffuse alveolar damage as the primary lesion. Viremia and extra-respiratory complications appear to be more common for infections with avian H5N1 virus than with human influenza viruses. Further understanding and comparison of the pathology of human and avian influenza virus infections only can be achieved by directed and careful pathological analysis of additional influenza cases. PMID:19230162

  15. Smith Theory Revisited William G. Dwyer

    E-print Network

    Wilkerson, Clarence

    Smith Theory Revisited William G. Dwyer Clarence W. Wilkerson \\Lambda 1 Introduction In the late 1930's, P. A. Smith began the investigation of the cohomological properties of a group G of prime order fifty years. Smith was successful in calculating the cohomology of the the fixed point sets

  16. Smith Theory Revisited William G. Dwyer

    E-print Network

    Wilkerson, Clarence

    Smith Theory Revisited William G. Dwyer Clarence W. Wilkerson 1 Introduction In the late 1930's, P. A. Smith began the investigation of the cohomological properties of a group G of prime order p. Smith was successful in calculating the cohomology of the the fixed point sets for involutions

  17. The 't Hooft vertex revisited Michael Creutz

    E-print Network

    Creutz, Michael

    The 't Hooft vertex revisited Michael Creutz Physics Department, Brookhaven National Laboratory Upton, NY 11973, USA Abstract In 1976 't Hooft introduced an elegant approach towards understanding 't Hooft [1,2] explored some of the physical conse- quences of topological structures [3] in non

  18. The Random Oracle Methodology, Revisited Ran Canetti

    E-print Network

    Goldreich, Oded

    The Random Oracle Methodology, Revisited Ran Canetti y Oded Goldreich z Shai Halevi x February 15 in the Random Oracle Model, and the security of the schemes that result from implementing the random oracle: There exist signature and encryption schemes that are secure in the Random Oracle Model, but for which any

  19. Attention to Form and Meaning Revisited

    ERIC Educational Resources Information Center

    Leow, Ronald P.; Hsieh, Hui-Chen; Moreno, Nina

    2008-01-01

    The present study revisited the issue of simultaneous attention to form and meaning from a methodological perspective that addressed several potential methodological issues of previous research in this strand of inquiry. Seventy-two second-semester-level participants were randomly assigned to one of five experimental groups, including a control,…

  20. Parallel Data Mining Revisited. Better, Not Faster

    E-print Network

    Berthold, Michael R.

    into two main themes: "big data" type analyses, where the goal is still the efficient mining of insightsParallel Data Mining Revisited. Better, Not Faster Zaenal Akbar, Violeta N. Ivanova, and Michael R is to tune data mining algorithms to produce better results in the same time rather than producing similar

  1. Modeling skin permeation revisited Gabriel Wittum

    E-print Network

    Hackbusch, Wolfgang

    Modeling skin permeation revisited Gabriel Wittum Computing diffusion through human skin is usually diffusion through human skin using two and three dimensional models. First computations for this problem were made a decade ago, yielding new insight into permeation pathways through human skin, which were

  2. Ant Foraging Revisited Liviu Alexandru Panait1

    E-print Network

    Luke, Sean

    Ant Foraging Revisited Liviu Alexandru Panait1 and Sean Luke1 1. Department of Computer Science: lpanait@cs.gmu.edu Abstract Previous artificial (non-biological) ant foraging models have to date relied ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

  3. The Do-Calculus Revisited Judea Pearl

    E-print Network

    California at Los Angeles, University of

    The Do-Calculus Revisited Judea Pearl Keynote Lecture, August 17, 2012 UAI-2012 Conference and Pearl, 2006] and the graphi- cal criteria of [Tian and Shpitser, 2010] have laid this identification areas: mediation analysis [Pearl, 2012], trans- portability [Pearl and Bareinboim, 2011] and meta

  4. Quantum Mechanics Revisited Jean Claude Dutailly

    E-print Network

    Boyer, Edmond

    Quantum Mechanics Revisited Jean Claude Dutailly Paris (France) August 20, 2014 Abstract The purpose of the paper is to study the foundations of the main axioms of Quantum Mechanics. From a general a new theoretical foundation. ii) The quantum mechanics (QM) which is presented in all the books

  5. Empirically Revisiting the Test Independence Assumption

    E-print Network

    Ernst, Michael

    Empirically Revisiting the Test Independence Assumption Sai Zhang, Darioush Jalali, Jochen Wuttke}@cs.washington.edu ABSTRACT In a test suite, all the test cases should be independent: no test should affect any other test's result, and running the tests in any order should produce the same test results. Techniques such as test

  6. Revisiting the Regenerative Possibilities of Ortiz

    ERIC Educational Resources Information Center

    Duques, Matthew

    2004-01-01

    The author of this article revisits Simon Ortiz's poem, "From Sand Creek," in which the latter can in so few words convey both the horrific tragedy of conquest and colonization, while at the same time find a space for possibility, a means for recovery that is never about forgetting but always occurs as a kind of recuperative remembering. Ortiz…

  7. REVISITING COMMONS – ARE COMMON PROPERTY REGIMES IRRATIONAL?

    Microsoft Academic Search

    Lubna Hasan

    2002-01-01

    This paper revisits the debate about communal management of natural resources and brings together various issues confronting it. Much of the criticism against common property regimes stems from an incorrect modeling of a common property situation, and misunderstandings about the terms and their wrong usage. Models of collective action (Hardin’s tragedy of the Commons, Olson’s Logic of Collective Action, and

  8. Revisiting Fletcher and Adler Checksums Theresa Maxino

    E-print Network

    Koopman, Philip

    Revisiting Fletcher and Adler Checksums Theresa Maxino Carnegie Mellon University Pittsburgh, PA and Adler checksums for random independent bit errors and burst er- rors. Our study reveals that in most cases the Fletcher checksum should be used instead of the Adler checksum. 1. Introduction Checksums

  9. ORIGINAL ARTICLE Cytosolic potassium homeostasis revisited: 42

    E-print Network

    Britto, Dev T.

    ORIGINAL ARTICLE Cytosolic potassium homeostasis revisited: 42 K-tracer analysis in Hordeum vulgare of the flexibility, rather than strict homeostasis, of cellular K+ maintenance, and of the dynamic interaction analysis Æ 42 K Æ Hordeum Ion transport Æ Homeostasis Introduction Potassium (K+ ) availability in both

  10. Phenomenology of n -n ¯ oscillations revisited

    NASA Astrophysics Data System (ADS)

    Gardner, S.; Jafari, E.

    2015-05-01

    We revisit the phenomenology of n -n ¯ oscillations in the presence of external magnetic fields, highlighting the role of spin. We show, contrary to long-held belief, that the n -n ¯ transition rate need not be suppressed, opening new opportunities for its empirical study.

  11. Women's Place, Revisited (NYT) 421 words

    E-print Network

    Lopez-Carr, David

    Women's Place, Revisited (NYT) 421 words Published: January 19, 2006 The election on Sunday of Michelle Bachelet as Chile's president completes a three- continent long jump for women in politics. Ms without rancor. These new chief executives are not the first women to lead major democracies. Margaret

  12. The Faraday effect revisited: Thermodynamic limit

    E-print Network

    H. D. Cornean; G. Nenciu

    2009-06-22

    This paper is the second in a series revisiting the (effect of) Faraday rotation. We formulate and prove the thermodynamic limit for the transverse electric conductivity of Bloch electrons, as well as for the Verdet constant. The main mathematical tool is a regularized magnetic and geometric perturbation theory combined with elliptic regularity and Agmon-Combes-Thomas uniform exponential decay estimates.

  13. Tansley review Seed dispersal effectiveness revisited

    E-print Network

    Jordano, Pedro

    , it is a necessary expansion if we are to understand the central relevance of seed dispersal in plant ecology by increasing appre- ciation that seed dispersal is critical to many ecological questions; it is centralTansley review Seed dispersal effectiveness revisited: a conceptual review Author

  14. Biodiversity measures revisited Natalia Petrovskaya a

    E-print Network

    Petrovskaya, Natalia B.

    Biodiversity measures revisited Natalia Petrovskaya a , Sergei Petrovskii b,c,*, Bai-Lian Li c, Riverside, CA 92521-0124, USA 1. Introduction Loss of biodiversity in various ecosystems all over the world to recognize the main threats for communities functioning and reasons for biodiversity loss; examples

  15. Dependent Record Types Revisited Zhaohui Luo

    E-print Network

    Luo, Zhaohui

    Dependent Record Types Revisited Zhaohui Luo Department of Computer Science Royal Holloway, University of London Egham, Surrey TW20 0EX, U.K. zhaohui@cs.rhul.ac.uk ABSTRACT Dependently-typed records an improved formulation of dependent record types in the con- text of studying manifest fields of module types

  16. Internal waves revisited B.R. Sutherland

    E-print Network

    Sutherland, Bruce

    Internal waves revisited B.R. Sutherland , G.O. Hughes y, S.B. Dalziel and P.F. Linden z Department and amplitude of internal waves. As well as being relatively inexpensive to set up, the technique is sensitive to small density uctuations: heat rising from a hand can easily be seen. If the internal wave eld

  17. Revisiting IR Techniques for Collaborative Search Strategies

    Microsoft Academic Search

    Hideo Joho; David Hannah; Joemon M. Jose

    2009-01-01

    This paper revisits some of the established Information Re- trieval (IR) techniques to investigate eective collaborative search strate- gies. We devised eight search strategies that divided labour and shared knowledge in teams using relevance feedback and clustering. We evalu- ated the performance of strategies with a user simulation enhanced by a query-pooling method. Our results show that relevance feedback is

  18. The Evil of Banality: Arendt Revisited

    ERIC Educational Resources Information Center

    Minnich, Elizabeth

    2014-01-01

    "The banality of evil" (Arendt) remains controversial and useful. Ironically, the concept is now itself a banality. To revisit and extend it, we consider the "evil of banality", the profound dangers of cliched thoughtlessness. A distinction is proposed: "intensive" versus "extensive evils". The former takes…

  19. Racial bias in baseball card collecting revisited

    Microsoft Academic Search

    Eric Primm; Nicole L. Piquero; Robert M. Regoli; Alex R. Piquero

    2010-01-01

    Although research examining the role of racial bias in the secondary sports card market has been an emerging area of inquiry, empirical knowledge on the question: “Does the race of the player on a sports card affect the value of the card?” remains inconclusive. This paper revisits one of the first studies on this topic. Data were derived for 66

  20. k-Anonymization Revisited Aristides Gionis #1

    E-print Network

    Beimel, Amos

    k-Anonymization Revisited Aristides Gionis #1 , Arnon Mazza 2 , Tamir Tassa 3 # Yahoo! Research of k-type anonymizations. Those notions achieve similar privacy goals as those aimed by Sweenie and Samarati when proposing the concept of k-anonymization: an adversary who knows the public data

  1. Phenomenology of n - n ¯ oscillations revisited

    DOE PAGESBeta

    Gardner, S.; Jafari, E.

    2015-05-01

    We revisit the phenomenology of n-n¯ oscillations in the presence of external magnetic fields, highlighting the role of spin. We show, contrary to long-held belief, that the n-n¯ transition rate need not be suppressed, opening new opportunities for its empirical study.

  2. Pair Production Constraints on Superluminal Neutrinos Revisited

    E-print Network

    Brodsky, Stanley J

    2011-01-01

    We revisit the pair creation constraint on superluminal neutrinos considered by Cohen and Glashow in order to clarify which types of superluminal models are constrained. We show that a model in which the superluminal neutrino is effectively light-like can evade the Cohen-Glashow constraint.

  3. Preparing for STEREO - Revisit Helios!

    NASA Astrophysics Data System (ADS)

    Schwenn, R.

    2004-12-01

    Exactly 30 years ago, the first Helios solar probe was launched into an elliptical heliocentric orbit, with a perihelion of 0.3 AU. It had a set of then modern particle and field instruments on board, but no imagers. One year later, an almost identical probe was put into a very similar orbit, approaching the Sun even a bit closer. For most of their common lifetime of 4 years, the two probes were separated in longitude by no more than about 30 degrees. Further, due to their special orbits, they spent many months above the Sun's limb (as seen from Earth). In conjunction with the Earth-orbiting IMP 7&8 satellites and the Voyager 1&2, and the Pioneer 10&11 space probes, real multipoint studies covering large parts of the heliosphere could be performed successfully for the first time. The Helios mission resembled the upcoming STEREO mission in several respects and was indeed of good use for defining the STEREO science goals. For example, Helios could reveal details about the longitudinal and latitudinal solar wind stream structure, it allowed unique associations between limb CMEs and their radial propagation towards an in-situ observer, and the propagation of solar energetic particles could be studied. However, since then our understanding of the heliosphere has improved considerably, thanks to recent space missions (Ulysses, Yohkoh, SOHO, Wind, ACE) and to more and more refined theoretical models. In view of these new results, it appears worthwhile to revisit the huge Helios data sets since they certainly keep hiding some answers that future observations from STEREO might benefit from.

  4. Zero Knowledge in the Random Oracle Model, Revisited Hoeteck Wee

    E-print Network

    Wee, Hoeteck

    Zero Knowledge in the Random Oracle Model, Revisited Hoeteck Wee Queens College, CUNY hoeteck@cs.qc.cuny.edu Abstract. We revisit previous formulations of zero knowledge in the random oracle model due to Bellare of these formulations. The hierarchy relates to the programmability of the random oracle, previously studied by Nielsen

  5. Revisiting the Diffusion Problem in a Capillary Tube Geometry

    E-print Network

    Eric Sullivan; Lynn Schreyer-Bennethum

    2013-03-12

    The present work revisits the problem of modeling diffusion above a stagnant liquid interface in a capillary tube geometry. In this revisitation we elucidate a misconception found in the classical model proposed by Bird et. al. Furthermore, we propose alternative explanations for thermally forced diffusion and provide a description of natural convection in the absence of forcing terms.

  6. Revisiting Wiener's Attack New Weak Keys in RSA

    E-print Network

    Revisiting Wiener's Attack ­ New Weak Keys in RSA Subhamoy Maitra and Santanu Sarkar Indian. In this paper we revisit Wiener's method (IEEE-IT 1990) of continued fraction (CF) to find new weaknesses in RSA. We consider RSA with N = pq, q

  7. RED Revisited Tuan Anh Trinh and Sandor Molnar

    E-print Network

    Molnár, Sándor

    RED Revisited Tuan Anh Trinh and Sâ??andor Molnâ??ar High Speed Networks Laboratory Department­ ternet is RED. However, research results on RED perfor­ mance are highly mixed, especially in the field of tuning its parameters. In this paper, we revisit some features in RED and study them in greater details

  8. RED Revisited Tuan Anh Trinh and Sandor Molnar

    E-print Network

    Molnár, Sándor

    RED Revisited Tuan Anh Trinh and S´andor Moln´ar High Speed Networks Laboratory Department- ternet is RED. However, research results on RED perfor- mance are highly mixed, especially in the field of tuning its parameters. In this paper, we revisit some features in RED and study them in greater details

  9. The flow along an external corner revisited

    NASA Astrophysics Data System (ADS)

    Denier, Jim; Jewell, Nathaniel

    2013-11-01

    We revisit the problem of the flow of an almost inviscid fluid along an external corner made from the junction of two quarter infinite plates joined at an angle 0 < ? < ? / 2 . The structure of the boundary layer which develops along the corner is explored using a computational approach based upon a spectral element discretisation of the steady two-dimensional boundary-layer equations. We pay particular attention to the case when the angle ? is small, thus approximating the semi-infinte quarter plate problem considered by Stewartson (1961) and recently revisited by Duck & Hewitt (2012). Our results, which demonstrate a thickening of the boundary-layer near the sharp corner, will be discussed in the context of the asymptotic theory developed in the aforementioned papers.

  10. Phenomenology of Neutron-Antineutron Oscillations Revisited

    NASA Astrophysics Data System (ADS)

    Gardner, Susan; Jafari, Ehsan

    2014-09-01

    We revisit the phenomenology of neutron-antineutron (n- n) oscillations in the presence of external magnetic fields, highlighting the role of spin. We show, contrary to long-held belief, that the n- n transition rate can be enhanced under special conditions, opening new pathways for its empirical study. We revisit the phenomenology of neutron-antineutron (n- n) oscillations in the presence of external magnetic fields, highlighting the role of spin. We show, contrary to long-held belief, that the n- n transition rate can be enhanced under special conditions, opening new pathways for its empirical study. Supported in part by the U.S. Department of Energy Office of Nuclear Physics under grant DE-FG02-96ER40989.

  11. (h, x) (ah, ax) Bretherton revisited

    E-print Network

    Snoeijer, Jacco

    (h, x) (ah, ax) h = 3Ca h - hf h3 Bretherton revisited film region: lubrication equation The goal" condition: h(x) = Ca H x Ca hf Ca2/3 h(x ) = x2 2 #12;h(x=0,t) ~ t h t + 3 x h3 3 h x3 = 0 1D in the paper by Hernandez-Sanchez et al. how C and are determined from other boundary conditions. h(x, t

  12. THE MATHEMATICAL FOUNDATIONS OF GAUGE THEORY REVISITED

    E-print Network

    Paris-Sud XI, Université de

    @cermics.enpc.fr ABSTRACT We start recalling with critical eyes the mathematical methods used in gauge theory and prove also [4,6,7,30]). The pupose of this introduction is to revisit these foundations with critical eyes of G if 1 hal-00874139,version1-17Oct2013 #12;aS S, a G and the orbit of x X is the invariant subset

  13. READINESS OF THE GULF MONETARY UNION: REVISITED

    Microsoft Academic Search

    Rock-Antoine Mehanna; M. Kabir Hassan

    2008-01-01

    This paper revisits Mehanna’s (2004) assessment of the viability of the future project of the Gulf Monetary Union (a goal set for 2010) while examining member countries over three time periods: (1) 1990-1999; (2) 2000-2006; and (3) average period 1990-2006. It follows the theory of Optimum Currency Areas and borrows from the European Monetary Union (the Maastricht Agreement’s convergence criteria)

  14. The Actinide Transition Revisited by Gutzwiller Approximation

    NASA Astrophysics Data System (ADS)

    Xu, Wenhu; Lanata, Nicola; Yao, Yongxin; Kotliar, Gabriel

    2015-03-01

    We revisit the problem of the actinide transition using the Gutzwiller approximation (GA) in combination with the local density approximation (LDA). In particular, we compute the equilibrium volumes of the actinide series and reproduce the abrupt change of density found experimentally near plutonium as a function of the atomic number. We discuss how this behavior relates with the electron correlations in the 5 f states, the lattice structure, and the spin-orbit interaction. Our results are in good agreement with the experiments.

  15. T. W. Patzek, Fick's Diffusion Experiments Revisited, 6/22/06 1 Fick's Diffusion Experiments Revisited

    E-print Network

    Patzek, Tadeusz W.

    T. W. Patzek, Fick's Diffusion Experiments Revisited, 6/22/06 1 Fick's Diffusion Experiments Fick's original diffusion experiments and reconstruct the geometry of his inverted funnel. We show derivation and the underlying experiments in a graduate course taught at Cal. To my surprise, Fick's own

  16. The Microstructural Status of the Corpus Callosum Is Associated with the Degree of Motor Function and Neurological Deficit in Stroke Patients

    PubMed Central

    Liang, Fanrong; Huang, Wenhua

    2015-01-01

    Human neuroimaging studies and animal models have suggested that white matter damage from ischemic stroke leads to the functional and structural reorganization of perilesional and remote brain regions. However, the quantitative relationship between the transcallosal tract integrity and clinical motor performance score after stroke remains unexplored. The current study employed a tract-based spatial statistics (TBSS) analysis on diffusion tensor imaging (DTI) to investigate the relationship between white matter diffusivity changes and the clinical scores in stroke patients. Probabilistic fiber tracking was also used to identify structural connectivity patterns in the patients. Thirteen ischemic stroke patients and fifteen healthy control subjects participated in this study. TBSS analyses showed that the corpus callosum (CC) and bilateral corticospinal tracts (CST) in the stroke patients exhibited significantly decreased fractional anisotropy and increased axial and radial diffusivity compared with those of the controls. Correlation analyses revealed that the motor and neurological deficit scores in the stroke patients were associated with the value of diffusivity indices in the CC. Compared with the healthy control group, probabilistic fiber tracking analyses revealed that significant changes in the inter-hemispheric fiber connections between the left and right motor cortex in the stroke patients were primarily located in the genu and body of the CC, left anterior thalamic radiation and inferior fronto-occipital fasciculus, bilateral CST, anterior/superior corona radiate, cingulum and superior longitudinal fasciculus, strongly suggesting that ischemic induces inter-hemispheric network disturbances and disrupts the white matter fibers connecting motor regions. In conclusion, the results of the present study show that DTI-derived measures in the CC can be used to predict the severity of motor skill and neurological deficit in stroke patients. Changes in structural connectivity pattern tracking between the left and right motor areas, particularly in the body of the CC, might reflect functional reorganization and behavioral deficit. PMID:25875333

  17. Altered Structural and Functional Connectivity in Late Preterm Preadolescence: An Anatomic Seed-Based Study of Resting State Networks Related to the Posteromedial and Lateral Parietal Cortex

    PubMed Central

    Degnan, Andrew J.; Wisnowski, Jessica L.; Choi, SoYoung; Ceschin, Rafael; Bhushan, Chitresh; Leahy, Richard M.; Corby, Patricia; Schmithorst, Vincent J.; Panigrahy, Ashok

    2015-01-01

    Objective Late preterm birth confers increased risk of developmental delay, academic difficulties and social deficits. The late third trimester may represent a critical period of development of neural networks including the default mode network (DMN), which is essential to normal cognition. Our objective is to identify functional and structural connectivity differences in the posteromedial cortex related to late preterm birth. Methods Thirty-eight preadolescents (ages 9–13; 19 born in the late preterm period (?32 weeks gestational age) and 19 at term) without access to advanced neonatal care were recruited from a low socioeconomic status community in Brazil. Participants underwent neurocognitive testing, 3-dimensional T1-weighted imaging, diffusion-weighted imaging and resting state functional MRI (RS-fMRI). Seed-based probabilistic diffusion tractography and RS-fMRI analyses were performed using unilateral seeds within the posterior DMN (posterior cingulate cortex, precuneus) and lateral parietal DMN (superior marginal and angular gyri). Results Late preterm children demonstrated increased functional connectivity within the posterior default mode networks and increased anti-correlation with the central-executive network when seeded from the posteromedial cortex (PMC). Key differences were demonstrated between PMC components with increased anti-correlation with the salience network seen only with posterior cingulate cortex seeding but not with precuneus seeding. Probabilistic tractography showed increased streamlines within the right inferior longitudinal fasciculus and inferior fronto-occipital fasciculus within late preterm children while decreased intrahemispheric streamlines were also observed. No significant differences in neurocognitive testing were demonstrated between groups. Conclusion Late preterm preadolescence is associated with altered functional connectivity from the PMC and lateral parietal cortex to known distributed functional cortical networks despite no significant executive neurocognitive differences. Selective increased structural connectivity was observed in the setting of decreased posterior interhemispheric connections. Future work is needed to determine if these findings represent a compensatory adaptation employing alternate neural circuitry or could reflect subtle pathology resulting in emotional processing deficits not seen with neurocognitive testing. PMID:26098888

  18. Anatomo-functional study of the temporo-parieto-occipital region: dissection, tractographic and brain mapping evidence from a neurosurgical perspective.

    PubMed

    De Benedictis, Alessandro; Duffau, Hugues; Paradiso, Beatrice; Grandi, Enrico; Balbi, Sergio; Granieri, Enrico; Colarusso, Enzo; Chioffi, Franco; Marras, Carlo Efisio; Sarubbo, Silvio

    2014-08-01

    The temporo-parieto-occipital (TPO) junction is a complex brain territory heavily involved in several high-level neurological functions, such as language, visuo-spatial recognition, writing, reading, symbol processing, calculation, self-processing, working memory, musical memory, and face and object recognition. Recent studies indicate that this area is covered by a thick network of white matter (WM) connections, which provide efficient and multimodal integration of information between both local and distant cortical nodes. It is important for neurosurgeons to have good knowledge of the three-dimensional subcortical organisation of this highly connected region to minimise post-operative permanent deficits. The aim of this dissection study was to highlight the subcortical functional anatomy from a topographical surgical perspective. Eight human hemispheres (four left, four right) obtained from four human cadavers were dissected according to Klingler's technique. Proceeding latero-medially, the authors describe the anatomical courses of and the relationships between the main pathways crossing the TPO. The results obtained from dissection were first integrated with diffusion tensor imaging reconstructions and subsequently with functional data obtained from three surgical cases, all resection of infiltrating glial tumours using direct electrical mapping in awake patients. The subcortical limits for performing safe lesionectomies within the TPO region are as follows: within the parietal region, the anterior horizontal part of the superior longitudinal fasciculus and, more deeply, the arcuate fasciculus; dorsally, the vertical projective thalamo-cortical fibres. For lesions located within the temporal and occipital lobes, the resection should be tailored according to the orientation of the horizontal associative pathways (the inferior fronto-occipital fascicle, inferior longitudinal fascicle and optic radiation). The relationships between the WM tracts and the ventricle system were also examined. These results indicate that a detailed anatomo-functional awareness of the WM architecture within the TPO area is mandatory when approaching intrinsic brain lesions to optimise surgical results and to minimise post-operative morbidity. PMID:24975421

  19. Distinct loci of lexical and semantic access deficits in aphasia: Evidence from voxel-based lesion-symptom mapping and diffusion tensor imaging.

    PubMed

    Harvey, Denise Y; Schnur, Tatiana T

    2015-06-01

    Naming pictures and matching words to pictures belonging to the same semantic category negatively affects language production and comprehension. By most accounts, semantic interference arises when accessing lexical representations in naming (e.g., Damian, Vigliocco, & Levelt, 2001) and semantic representations in comprehension (e.g., Forde & Humphreys, 1997). Further, damage to the left inferior frontal gyrus (LIFG), a region implicated in cognitive control, results in increasing semantic interference when items repeat across cycles in both language production and comprehension (Jefferies, Baker, Doran, & Lambon Ralph, 2007). This generates the prediction that the LIFG via white matter connections supports resolution of semantic interference arising from different loci (lexical vs semantic) in the temporal lobe. However, it remains unclear whether the cognitive and neural mechanisms that resolve semantic interference are the same across tasks. Thus, we examined which gray matter structures [using whole brain and region of interest (ROI) approaches] and white matter connections (using deterministic tractography) when damaged impact semantic interference and its increase across cycles when repeatedly producing and understanding words in 15 speakers with varying lexical-semantic deficits from left hemisphere stroke. We found that damage to distinct brain regions, the posterior versus anterior temporal lobe, was associated with semantic interference (collapsed across cycles) in naming and comprehension, respectively. Further, those with LIFG damage compared to those without exhibited marginally larger increases in semantic interference across cycles in naming but not comprehension. Lastly, the inferior fronto-occipital fasciculus, connecting the LIFG with posterior temporal lobe, related to semantic interference in naming, whereas the inferior longitudinal fasciculus (ILF), connecting posterior with anterior temporal regions related to semantic interference in comprehension. These neuroanatomical-behavioral findings have implications for models of the lexical-semantic language network by demonstrating that semantic interference in language production and comprehension involves different representations which differentially recruit a cognitive control mechanism for interference resolution. PMID:25880795

  20. Magnetic Resonance Imaging Measures of Brain Structure to Predict Antidepressant Treatment Outcome in Major Depressive Disorder

    PubMed Central

    Korgaonkar, Mayuresh S.; Rekshan, William; Gordon, Evian; Rush, A. John; Williams, Leanne M.; Blasey, Christine; Grieve, Stuart M.

    2014-01-01

    Background Less than 50% of patients with Major Depressive Disorder (MDD) reach symptomatic remission with their initial antidepressant medication (ADM). There are currently no objective measures with which to reliably predict which individuals will achieve remission to ADMs. Methods 157 participants with MDD from the International Study to Predict Optimized Treatment in Depression (iSPOT-D) underwent baseline MRIs and completed eight weeks of treatment with escitalopram, sertraline or venlafaxine-ER. A score at week 8 of 7 or less on the 17 item Hamilton Rating Scale for Depression defined remission. Receiver Operator Characteristics (ROC) analysis using the first 50% participants was performed to define decision trees of baseline MRI volumetric and connectivity (fractional anisotropy) measures that differentiated non-remitters from remitters with maximal sensitivity and specificity. These decision trees were tested for replication in the remaining participants. Findings Overall, 35% of all participants achieved remission. ROC analyses identified two decision trees that predicted a high probability of non-remission and that were replicated: 1. Left middle frontal volume < 14 · 8 mL & right angular gyrus volume > 6 · 3 mL identified 55% of non-remitters with 85% accuracy; and 2. Fractional anisotropy values in the left cingulum bundle < 0 · 63, right superior fronto-occipital fasciculus < 0 · 54 and right superior longitudinal fasciculus < 0 · 50 identified 15% of the non-remitters with 84% accuracy. All participants who met criteria for both decision trees were correctly identified as non-remitters. Interpretation Pretreatment MRI measures seem to reliably identify a subset of patients who do not remit with a first step medication that includes one of these commonly used medications. Findings are consistent with a neuroanatomical basis for non-remission in depressed patients. Funding Brain Resource Ltd is the sponsor for the iSPOT-D study (NCT00693849).

  1. Abnormalities of cortical thickness, subcortical shapes, and white matter integrity in subcortical vascular cognitive impairment.

    PubMed

    Thong, Jamie Yu Jin; Du, Jia; Ratnarajah, Nagulan; Dong, Yanhong; Soon, Hock Wei; Saini, Monica; Tan, Ming Zhen; Ta, Anh Tuan; Chen, Christopher; Qiu, Anqi

    2014-05-01

    Subcortical vascular cognitive impairment (sVCI) is caused by lacunar infarcts or extensive and/or diffuse lesions in the white matter that may disrupt the white matter circuitry connecting cortical and subcortical regions and result in the degeneration of neurons in these regions. This study used structural magnetic resonance imaging (MRI) and high angular resolution diffusion imaging (HARDI) techniques to examine cortical thickness, subcortical shapes, and white matter integrity in mild vascular cognitive impairment no dementia (VCIND Mild) and moderate-to-severe VCI (MSVCI). Our study found that compared to controls (n = 25), VCIND Mild (n = 25), and MSVCI (n = 30) showed thinner cortex predominantly in the frontal cortex. The cortex in MSVCI was thinner in the parietal and lateral temporal cortices than that in VCIND Mild. Moreover, compared to controls, VCIND Mild and MSVCI showed smaller shapes (i.e., volume reduction) in the thalamus, putamen, and globus pallidus and ventricular enlargement. Finally, compared to controls, VCIND Mild, and MSVCI showed an increased mean diffusivity in the white matter, while decreased generalized fractional anisotropy was only found in the MSVCI subjects. The major axonal bundles involved in the white matter abnormalities were mainly toward the frontal regions, including the internal capsule/corona radiata, uncinate fasciculus, and anterior section of the inferior fronto-occipital fasciculus, and were anatomically connected to the affected cortical and subcortical structures. Our findings suggest that abnormalities in cortical, subcortical, and white matter morphology in sVCI occur in anatomically connected structures, and that abnormalities progress along a similar trajectory from the mild to moderate and severe conditions. PMID:23861356

  2. Joint source based morphometry identifies linked gray and white matter group differences

    PubMed Central

    Xu, Lai; Pearlson, Godfrey; Calhoun, Vince D.

    2009-01-01

    We present a multivariate approach called joint source based morphometry (jSBM), to identify linked gray and white matter regions which differ between groups. In jSBM, joint independent component analysis (jICA) is used to decompose preprocessed gray and white matter images into joint sources and statistical analysis is used to determine the significant joint sources showing group differences and their relationship to other variables of interest (e.g. age or sex). The identified joint sources are groupings of linked gray and white matter regions with common covariation among subjects. In this study, we first provide a simulation to validate the jSBM approach. To illustrate our method on real data, jSBM is then applied to structural magnetic resonance imaging (sMRI) data obtained from 120 chronic schizophrenia patients and 120 healthy controls to identify group differences. JSBM identified four joint sources as significantly associated with schizophrenia. Linked gray–white matter regions identified in each of the joint sources included: 1) temporal — corpus callosum, 2) occipital/frontal — inferior fronto-occipital fasciculus, 3) frontal/parietal/occipital/temporal —superior longitudinal fasciculus and 4) parietal/frontal — thalamus. Age effects on all four joint sources were significant, but sex effects were significant only for the third joint source. Our findings demonstrate that jSBM can exploit the natural linkage between gray and white matter by incorporating them into a unified framework. This approach is applicable to a wide variety of problems to study linked gray and white matter group differences. PMID:18992825

  3. Revisiting Interval Graphs for Network Science

    E-print Network

    Loe, Chuan Wen

    2015-01-01

    The vertices of an interval graph represent intervals over a real line where overlapping intervals denote that their corresponding vertices are adjacent. This implies that the vertices are measurable by a metric and there exists a linear structure in the system. The generalization is an embedding of a graph onto a multi-dimensional Euclidean space and it was used by scientists to study the multi-relational complexity of ecology. However the research went out of fashion in the 1980s and was not revisited when Network Science recently expressed interests with multi-relational networks known as multiplexes. This paper studies interval graphs from the perspective of Network Science.

  4. Sloan Digital Sky Survey Photometric Calibration Revisited

    SciTech Connect

    Marriner, John; /Fermilab

    2012-06-29

    The Sloan Digital Sky Survey calibration is revisited to obtain the most accurate photometric calibration. A small but significant error is found in the flat-fielding of the Photometric telescope used for calibration. Two SDSS star catalogs are compared and the average difference in magnitude as a function of right ascension and declination exhibits small systematic errors in relative calibration. The photometric transformation from the SDSS Photometric Telescope to the 2.5 m telescope is recomputed and compared to synthetic magnitudes computed from measured filter bandpasses.

  5. Revisiting Fermat's Factorization for the RSA Modulus

    E-print Network

    Gupta, Sounak

    2009-01-01

    We revisit Fermat's factorization method for a positive integer $n$ that is a product of two primes $p$ and $q$. Such an integer is used as the modulus for both encryption and decryption operations of an RSA cryptosystem. The security of RSA relies on the hardness of factoring this modulus. As a consequence of our analysis, two variants of Fermat's approach emerge. We also present a comparison between the two methods' effective regions. Though our study does not yield a new state-of-the-art algorithm for integer factorization, we believe that it reveals some interesting observations that are open for further analysis.

  6. A Revisiting of Scientific and Philosophical Perspectives on

    E-print Network

    Broschat, Shira Lynn

    by James Clerk Maxwell is generally acknowledged as one of the most innovative concepts ever introducedA Revisiting of Scientific and Philosophical Perspectives on Maxwell's Displacement Current; Maxwell equations; Maxwell; scientific approach 1. Introduction Maxwell's electromagnetic theory is one

  7. Revisiting Non-coherent Detection in Doubly Selective Multipath

    E-print Network

    Sayeed, Akbar M.

    and Akbar M. Sayeed, Fellow, IEEE Abstract--We revisit the problem of non-coherent signal detec- tion Monticello, IL, [1] [2]. M. L. Malloy and A. M. Sayeed are with the Department of Electrical and Computer

  8. CALCULUS REVISITED: AN INTRODUCTORY COURSE IN K. GRACE KENNEDY

    E-print Network

    Bigelow, Stephen

    CALCULUS REVISITED: AN INTRODUCTORY COURSE IN MATLAB K. GRACE KENNEDY When beginning to think about of programming language. 1 #12;2 K. GRACE KENNEDY · the relationship between secant lines, the tangent line

  9. Poisson Compound and Empirical Bayes Estimation, Revisited1 Lawrence Brown

    E-print Network

    Brown, Lawrence D.

    1 Poisson Compound and Empirical Bayes Estimation, Revisited1 Lawrence investigate a classical non-parametric Poisson empirical Bayes estimation problem,!( )= EG R ",!( )( ). The Bayes procedure is !G y( )= E " Y = y( ) (with the conditional

  10. Layered Connectors Revisiting the Formal Basis of Architectural Connection

    E-print Network

    Boyer, Edmond

    Layered Connectors Revisiting the Formal Basis of Architectural Connection for Complex Distributed using layered connectors. Layered connectors describe components interaction at both the application provide formal semantics of layered connectors and present an approach for the synthesis of layered

  11. Distance Perception in Immersive Virtual Environments, Revisited Victoria Interrante

    E-print Network

    Interrante, Victoria

    Distance Perception in Immersive Virtual Environments, Revisited Victoria Interrante 1 , Lee experiments in which we assess egocentric distance perception in a high fidelity, low latency, immersive perception appears not to be significantly compressed in the immersive virtual environment, relative

  12. ``Interval Rational = Algebraic'' Revisited: A More Computer Realistic Result

    E-print Network

    Kreinovich, Vladik

    the numbers representable in a computer are rational and therefore, form a set of Lebesgue measure 0, only rational numbers ``Interval Rational = Algebraic'' Revisited: A More Computer Realistic Result Anatoly V. Lakeyev 1

  13. Herpetologists' League The Polytypic Species Revisited: Morphological Differentiation among Tiger Salamanders

    E-print Network

    Shaffer, H. Bradley

    Herpetologists' League The Polytypic Species Revisited: Morphological Differentiation among Tiger REVISITED: MORPHOLOGICAL DIFFERENTIATION AMONG TIGER SALAMANDERS (AMBYSTOMA TIGRINUM) (AMPHIBIA: CAUDATA Ambystoma tigrinum and two closely related members of the tiger salamander complex, A. californiense and A

  14. Resonance on the web: web dynamics and revisitation patterns

    Microsoft Academic Search

    Eytan Adar; Jaime Teevan; Susan T. Dumais

    2009-01-01

    The Web is a dynamic, ever-changing collection of information accessed in a dynamic way. This paper explores the relationship between Web page content change (obtained from an hourly crawl of over 40K pages) and people's revisitation to those pages (collected via a large scale log analysis of 2.3M users). We identify the relationship, or resonance, between revisitation behavior and the

  15. Waugh revisited : destabilizing language and structure in Vile bodies, A handful of dust, and Brideshead revisited by Jabe Ziino.

    E-print Network

    Ziino, Jabe (Jabe S.)

    2011-01-01

    Introduction: Last Fall semester I had only a very vague idea of a thesis topic: with a broad interest in the conflict between romantic love and religion inspired in part by a summertime reading of Brideshead Revisited, I ...

  16. Revisiting Resistance Speeds Up I\\/O-Efficient LTL Model Checking

    Microsoft Academic Search

    Jiri Barnat; Lubos Brim; Pavel Simecek; M. Weber; C. R. Ramakrishnan; J Rehof

    2008-01-01

    Revisiting resistant graph algorithms are those that can tolerate re- exploration of edges without yielding incorrect results. Revisiting resistant I\\/O efficient graph algorithms exhibit considerable speed-up in practice in compari- son to non-revisiting resistant algorithms. In the paper we present a new revisiting resistant I\\/O efficient LTL model checking algorithm. We analyze its theoretical I\\/O complexity and we experimentally compare

  17. Magnetic resonance imaging correlates of first-episode psychosis in young adult male patients: combined analysis of grey and white matter

    PubMed Central

    Ruef, Anne; Curtis, Logos; Moy, Guenael; Bessero, Severine; Bâ, Maryse Badan; Lazeyras, François; Lövblad, Karl-Olof; Haller, Sven; Malafosse, Alain; Giannakopoulos, Panteleimon; Merlo, Marco

    2012-01-01

    Background Several patterns of grey and white matter changes have been separately described in young adults with first-episode psychosis. Concomitant investigation of grey and white matter densities in patients with first-episode psychosis without other psychiatric comorbidities that include all relevant imaging markers could provide clues to the neurodevelopmental hypothesis in schizophrenia. Methods We recruited patients with first-episode psychosis diagnosed according to the DSM-IV-TR and matched controls. All participants underwent magnetic resonance imaging (MRI). Voxel-based morphometry (VBM) analysis and mean diffusivity voxel-based analysis (VBA) were used for grey matter data. Fractional anisotropy and axial, radial and mean diffusivity were analyzed using tract-based spatial statistics (TBSS) for white matter data. Results We included 15 patients and 16 controls. The mean diffusivity VBA showed significantly greater mean diffusivity in the first-episode psychosis than in the control group in the lingual gyrus bilaterally, the occipital fusiform gyrus bilaterally, the right lateral occipital gyrus and the right inferior temporal gyrus. Moreover, the TBSS analysis revealed a lower fractional anisotropy in the first-episode psychosis than in the control group in the genu of the corpus callosum, minor forceps, corticospinal tract, right superior longitudinal fasciculus, left middle cerebellar peduncle, left inferior longitudinal fasciculus and the posterior part of the fronto-occipital fasciculus. This analysis also revealed greater radial diffusivity in the first-episode psychosis than in the control group in the right corticospinal tract, right superior longitudinal fasciculus and left middle cerebellar peduncle. Limitations The modest sample size and the absence of women in our series could limit the impact of our results. Conclusion Our results highlight the structural vulnerability of grey matter in posterior areas of the brain among young adult male patients with first-episode psychosis. Moreover, the concomitant greater radial diffusivity within several regions already revealed by the fractional anisotropy analysis supports the idea of a late myelination in patients with first-episode psychosis. PMID:22748698

  18. Fuzz Revisited ...... Page 26Copyright 1995 Barton P. Miller For More Information

    E-print Network

    Liblit, Ben

    Fuzz Revisited ...... Page 26Copyright © 1995 Barton P. Miller For More Information The full://www.cs.wisc.edu/~paradyn/fuzz-revisited/ (check the READ_ME file) #12;Fuzz Revisited ...... Page 25Copyright © 1995 Barton P. Miller Discussion ...... Page 24Copyright © 1995 Barton P. Miller Summary of Malloc Test Results Tested programs in /bin

  19. Ebola revisited: lessons in managing global epidemics.

    PubMed

    Boulton, Jacqueline

    2015-07-01

    The latest statistics for the number of new cases of Ebola virus disease (EVD) in West Africa point to the near containment of the virus. While the current threat will not be deemed over until 42 days after the last case to be diagnosed has twice tested negative, there is now a shift in focus from an emphasis on containment to that of policy review and capacity building in light of lessons learned. This article primarily focuses on Sierra Leone. It revisits the issues surrounding the epidemic, seeking to summarise both the negative and positive aspects of the response at local and global levels, as well as highlights fresh perspectives from healthcare workers in the field for the management of similar epidemics. PMID:26153804

  20. ALFVEN WAVES IN SHEAR FLOWS REVISITED

    SciTech Connect

    Hollweg, Joseph V. [Space Science Center, Morse Hall, University of New Hampshire, Durham, NH 03824 (United States); Kaghashvili, Edisher Kh., E-mail: joe.hollweg@unh.edu [Atmospheric and Environmental Research, Inc., 131 Hartwell Avenue, Lexington, MA 02421 (United States)

    2012-01-10

    We revisit our earlier study of the evolution of an initial propagating Alfven wave in a magnetic-field-aligned flow with a cross-field velocity shear. Our goal is to show how the Alfven wave drives up plasma density fluctuations which might be observed and serve as a signature of the presence of Alfven waves in regions such as the solar corona which are inaccessible to direct observations. Here, we introduce a new initial condition which takes into account the initial distortion of the streamlines by the Alfven wave, and we present new analytical results for the driven waves. We find that the density fluctuations of a properly placed linearly polarized Alfven wave in a shear flow are much smaller than we originally estimated.

  1. The dynamical equivalence of modified gravity revisited

    E-print Network

    Ippocratis D. Saltas; Mark Hindmarsh

    2011-01-03

    We revisit the dynamical equivalence between different representations of vacuum modified gravity models in view of Legendre transformations. The equivalence is discussed for both bulk and boundary space, by including in our analysis the relevant Gibbons-Hawking terms. In the f(R) case, the Legendre transformed action coincides with the usual Einstein frame one. We then re-express the R+f(G) action, where G is the Gauss-Bonnet term, as a second order theory with a new set of field variables, four tensor fields and one scalar and study its dynamics. For completeness, we also calculate the conformal transformation of the full Jordan frame R+f(G) action. All the appropriate Gibbons-Hawking terms are calculated explicitly.

  2. Visser's massive graviton bimetric theory revisited

    SciTech Connect

    Roany, Alain de; Chauvineau, Bertrand; Freitas Pacheco, Jose A. de [University of Nice-Sophia Antipolis, Observatoire de la Cote d'Azur, Laboratoire Cassiopee, BP 4229, Nice Cedex 4 (France)

    2011-10-15

    A massive gravity theory was proposed by Visser in the late 1990s. This theory, based on a background metric b{sub {alpha}{beta}} and on an usual dynamical metric g{sub {alpha}{beta}} has the advantage of being free of ghosts as well as discontinuities present in other massive theories proposed in the past. In the present investigation, the equations of Visser's theory are revisited with particular care on the related conservation laws. It will be shown that a multiplicative factor is missing in the graviton tensor originally derived by Visser, which has no incidence on the weak field approach but becomes important in the strong field regime when, for instance, cosmological applications are considered. In this case, contrary to some previous claims found in the literature, we conclude that a nonstatic background metric is required in order to obtain a solution able to mimic the {Lambda}CDM cosmology.

  3. Trace anomalies in chiral theories revisited

    E-print Network

    Loriano Bonora; Stefano Giaccari; Bruno Lima de Souza

    2014-08-29

    Motivated by the search for possible CP violating terms in the trace of the energy-momentum tensor in theories coupled to gravity we revisit the problem of trace anomalies in chiral theories. We recalculate the latter and ascertain that in the trace of the energy-momentum tensor of theories with chiral fermions at one-loop the Pontryagin density appears with an imaginary coefficient. We argue that this may break unitarity, in which case the trace anomaly has to be used as a selective criterion for theories, analogous to the chiral anomalies in gauge theories. We analyze some remarkable consequences of this fact, that seem to have been overlooked in the literature.

  4. Nursing knowledge, theory and method revisited.

    PubMed

    Booth, K; Kenrick, M; Woods, S

    1997-10-01

    With the approach of the 21st century, nursing is having to respond to diverse influences which are remoulding the professional landscape. Not least of these is the changing status of western economies which underpins a drive towards evidence-based practice and an increased emphasis on multidisciplinary approaches to health care delivery. Certainty in health care is now a thing of the past. Central to the way the nursing profession embraces the future is its underlying philosophy: that which articulates professional values and shapes practice, research, education and management. In a time of change it is therefore essential to revisit the philosophical framework which underpins nursing. The debate in nursing research and theory appears to have stressed the polarization of viewpoints. It may be the case that feminist writers, ethnographers, positivist researchers and nursing theorists, in defending their own points of view, diminish rather than enhance professional dialogue. This paper reviews the nature of this debate within nursing and considers the implications that a dichotomous position may have for knowledge, theory and research method within the current context of health care. It then suggests a philosophical framework which could be relevant and accessible across the whole spectrum of nursing activity. In so doing, the paper aims to contribute to the discussion around epistemology and method in a way which encompasses the diversity found within the broad church of nursing. PMID:9354995

  5. Charge symmetry breaking in ? hypernuclei revisited

    NASA Astrophysics Data System (ADS)

    Gal, Avraham

    2015-05-01

    The large charge symmetry breaking (CSB) implied by the ? binding energy difference ? B?4 (0g.s.+) ?B? (He4?) -B? (H4?) = 0.35 ± 0.06 MeV of the A = 4 mirror hypernuclei ground states, determined from emulsion studies, has defied theoretical attempts to reproduce it in terms of CSB in hyperon masses and in hyperon-nucleon interactions, including one pion exchange arising from ?-?0 mixing. Using a schematic strong-interaction ?N ? ?N coupling model developed by Akaishi and collaborators for s-shell ? hypernuclei, we revisit the evaluation of CSB in the A = 4 ? hypernuclei and extend it to p-shell mirror ? hypernuclei. The model yields values of ? B?4 (0g.s.+) ? 0.25 MeV. Smaller size and mostly negative p-shell binding energy differences are calculated for the A = 7- 10 mirror hypernuclei, in rough agreement with the few available data. CSB is found to reduce by almost 30 keV the 110 keV B10? g.s. doublet splitting anticipated from the hyperon-nucleon strong-interaction spin dependence, thereby explaining the persistent experimental failure to observe the 2exc- ? 1g.s.- ?-ray transition.

  6. Carbon emission from global hydroelectric reservoirs revisited.

    PubMed

    Li, Siyue; Zhang, Quanfa

    2014-12-01

    Substantial greenhouse gas (GHG) emissions from hydropower reservoirs have been of great concerns recently, yet the significant carbon emitters of drawdown area and reservoir downstream (including spillways and turbines as well as river reaches below dams) have not been included in global carbon budget. Here, we revisit GHG emission from hydropower reservoirs by considering reservoir surface area, drawdown zone and reservoir downstream. Our estimates demonstrate around 301.3 Tg carbon dioxide (CO2)/year and 18.7 Tg methane (CH4)/year from global hydroelectric reservoirs, which are much higher than recent observations. The sum of drawdown and downstream emission, which is generally overlooked, represents 42 % CO2 and 67 % CH4 of the total emissions from hydropower reservoirs. Accordingly, the global average emissions from hydropower are estimated to be 92 g CO2/kWh and 5.7 g CH4/kWh. Nonetheless, global hydroelectricity could currently reduce approximate 2,351 Tg CO2eq/year with respect to fuel fossil plant alternative. The new findings show a substantial revision of carbon emission from the global hydropower reservoirs. PMID:24943886

  7. The Casimir effect for parallel plates revisited

    SciTech Connect

    Kawakami, N. A.; Nemes, M. C.; Wreszinski, Walter F. [Departamento de Fisica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, Caixa Postal 970, Belo Horizonte, CEP 30161-970 Minas Gerais (Brazil); Departamento de Fisica Matematica, Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970 Sao Paulo (Brazil)

    2007-10-15

    The Casimir effect for a massless scalar field with Dirichlet and periodic boundary conditions (bc's) on infinite parallel plates is revisited in the local quantum field theory (lqft) framework introduced by Kay [Phys. Rev. D 20, 3052 (1979)]. The model displays a number of more realistic features than the ones he treated. In addition to local observables, as the energy density, we propose to consider intensive variables, such as the energy per unit area {epsilon}, as fundamental observables. Adopting this view, lqft rejects Dirichlet (the same result may be proved for Neumann or mixed) bc, and accepts periodic bc: in the former case {epsilon} diverges, in the latter it is finite, as is shown by an expression for the local energy density obtained from lqft through the use of the Poisson summation formula. Another way to see this uses methods from the Euler summation formula: in the proof of regularization independence of the energy per unit area, a regularization-dependent surface term arises upon use of Dirichlet bc, but not periodic bc. For the conformally invariant scalar quantum field, this surface term is absent due to the condition of zero trace of the energy momentum tensor, as remarked by De Witt [Phys. Rep. 19, 295 (1975)]. The latter property does not hold in the application to the dark energy problem in cosmology, in which we argue that periodic bc might play a distinguished role.

  8. Revisiting the relaxation dynamics of isolated pyrrole

    SciTech Connect

    Montero, Raúl; Ovejas, Virginia; Fernández-Fernández, Marta; Longarte, Asier, E-mail: asier.longarte@ehu.es [Departamento de Química Física, Universidad del País Vasco (UPV/EHU), Apart. 644, 48080 Bilbao (Spain); Peralta Conde, Álvaro [Centro de Láseres Pulsados (CLPU), Edificio M3, Parque Científico, 37185 Villamayor (Spain)

    2014-07-07

    Herein, the interpretation of the femtosecond-scale temporal evolution of the pyrrole ion signal, after excitation in the 267–217 nm interval, recently published by our group [R. Montero, A. Peralta Conde, V. Ovejas, M. Fernández-Fernández, F. Castaño, J. R. Vázquez de Aldana, and A. Longarte, J. Chem. Phys.137, 064317 (2012)] is re-visited. The observation of a shift in the pyrrole{sup +} transient respect to zero delay reference, initially attributed to ultrafast dynamics on the ??{sup *} type state (3s a{sub 1} ? ? 1a{sub 2}), is demonstrated to be caused by the existence of pump + probe populated states, along the ionization process. The influence of these resonances in pump-prone ionization experiments, when multi-photon probes are used, and the significance of a proper zero-time reference, is discussed. The possibility of preparing the ??{sup *} state by direct excitation is investigated by collecting 1 + 1 photoelectron spectra, at excitation wavelengths ranging from 255 to 219 nm. No conclusive evidences of ionization through this state are found.

  9. Charge symmetry breaking in $?$ hypernuclei revisited

    E-print Network

    Avraham Gal

    2015-04-19

    The large charge symmetry breaking (CSB) implied by the $\\Lambda$ binding energy difference $\\Delta B^{4}_{\\Lambda}(0^+_{\\rm g.s.})\\equiv B_{\\Lambda}(_{\\Lambda}^4$He)$-$$B_{\\Lambda}(_{\\Lambda}^4$H) = 0.35$\\pm$0.06 MeV of the $A=4$ mirror hypernuclei ground states, determined from emulsion studies, has defied theoretical attempts to reproduce it in terms of CSB in hyperon masses and in hyperon-nucleon interactions, including one pion exchange arising from $\\Lambda-\\Sigma^0$ mixing. Using a schematic strong-interaction $\\Lambda N\\leftrightarrow\\Sigma N$ coupling model developed by Akaishi and collaborators for $s$-shell $\\Lambda$ hypernuclei, we revisit the evaluation of CSB in the $A=4$ $\\Lambda$ hypernuclei and extend it to $p$-shell mirror $\\Lambda$ hypernuclei. The model yields values of $\\Delta B^{4}_{\\Lambda} (0^+_{\\rm g.s.})\\sim 0.25$ MeV. Smaller size and mostly negative $p$-shell binding energy differences are calculated for the $A=7-10$ mirror hypernuclei, in rough agreement with the few available data. CSB is found to reduce by almost 30 keV the 110 keV $_{~\\Lambda}^{10}$B g.s. doublet splitting anticipated from the hyperon-nucleon strong-interaction spin dependence, thereby explaining the persistent experimental failure to observe the $2^-_{\\rm exc}\\to 1^-_{\\rm g.s.}$ $\\gamma$-ray transition.

  10. Spin-orbit evolution of Mercury revisited

    E-print Network

    Noyelles, Benoit; Makarov, Valeri; Efroimsky, Michael

    2013-01-01

    Mercury is a peculiar case, in that it is locked into the 3:2 spin-orbit resonance. Its rotation period, 58 days, is exactly two thirds of its orbital period. It is accepted that the eccentricity of Mercury (0.206) favours the trapping into this resonance. More controversial is how the capture took place. A recent study by Makarov has shown that entrapment into this resonance is certain if the eccentricity is larger than 0.2, provided that we use a realistic tidal model, based on the Darwin-Kaula expansion of the tidal torque, including both the elastic rebound and anelastic creep of solids. We here revisit the scenario of Mercury's capture into the supersynchronous spin-orbit resonances. The study is based on a realistic model of tidal friction in solids, that takes into account the rheology and the self-gravitation of the planet. Developed in Efroimsky, it was employed by Makarov et al. to determine the likely spin state of the planet GJ581d, with its eccentricity evolution taken into account. It was also u...

  11. Gerogogy in patient education--revisited.

    PubMed

    Pearson, Mary

    2011-01-01

    Gerogogy in Patient Education was first printed in Home Healthcare Nurse, Volume 14, Number 8, (1996), Lippincott. Writers Mary Pearson, M.Ed, RN- BC and Joan Wessman, MA. have revisited and updated the material to meet the needs of a new generation of health care professionals. Baby Boomers are retiring; they will reach their peak in 2030, with an estimated 72 million drawing social security. With these numbers comes an increase in services to the elderly, mostly in the form of medical expenditure. The problem will not only impact the financial system of Medicare but will have a great toll on families. How will the retirees remain independent in their homes? How will they learn new medical information? Will new health care professions be able to teach them while taking into consideration the physical and psychological alterations that occur with aging and illness? Gerogogy takes into account the person's disease process, age-related changes, educational level and motivation. Then incorporates these factors into practice, utilizing the same foundations found within the nursing process: assessment, planning, implementation, and evaluation. As stated, the methods for teaching the elderly are unique and require modifications. Gerogogy meets these needs so individuals can remain at home while also reducing unnecessary medical costs. PMID:21874787

  12. Karl Pearson's meta-analysis revisited

    E-print Network

    Owen, Art B

    2009-01-01

    This paper revisits a meta-analysis method proposed by Pearson [Biometrika 26 (1934) 425--442] and first used by David [Biometrika 26 (1934) 1--11]. It was thought to be inadmissible for over fifty years, dating back to a paper of Birnbaum [J. Amer. Statist. Assoc. 49 (1954) 559--574]. It turns out that the method Birnbaum analyzed is not the one that Pearson proposed. We show that Pearson's proposal is admissible. Because it is admissible, it has better power than the standard test of Fisher [Statistical Methods for Research Workers (1932) Oliver and Boyd] at some alternatives, and worse power at others. Pearson's method has the advantage when all or most of the nonzero parameters share the same sign. Pearson's test has proved useful in a genomic setting, screening for age-related genes. This paper also presents an FFT-based method for getting hard upper and lower bounds on the CDF of a sum of nonnegative random variables.

  13. Orientation Distance Graphs Revisited Wayne Goddard, Kiran Kanakadandi

    E-print Network

    Goddard, Wayne

    Orientation Distance Graphs Revisited Wayne Goddard, Kiran Kanakadandi Dept of Computer Science, Clemson University Abstract The orientation distance graph Do(G) of a graph G is defined as the graph whose vertex set is the pair-wise non-isomorphic orientations of G, and two orientations are adjacent

  14. Stuck Schools Revisited: Beneath the Averages. K-12 Policy

    ERIC Educational Resources Information Center

    Ushomirsky, Natasha

    2011-01-01

    "Stuck Schools Revisited: Beneath the Averages" shows why a national focus on turning around the lowest performing schools, while needed, is not enough to raise achievement and close gaps. The report analyzes student achievement data from Maryland and Indiana, which reflect the outcomes seen in other states. The results confirm a troubling…

  15. Obsidian provenance studies in Colombia and Ecuador: obsidian sources revisited

    Microsoft Academic Search

    Ludovic Bellot-Gurlet; Olivier Dorighel; Gérard Poupeau

    2008-01-01

    The field occurrences, elemental compositions and formation ages of Colombian and Ecuadorian obsidians are revisited. It is shown that the regional sources of this raw material are linked to two major volcanic structures: the Chacana and the Paletara calderas, localised on the eastern cordillera of Ecuador and on the central Andean cordillera of south Colombia respectively. Seventy-two samples were analysed

  16. Hotelling Revisited: Oil Prices and Endogenous Technological Progress1

    E-print Network

    Lin, C.-Y. Cynthia

    Hotelling Revisited: Oil Prices and Endogenous Technological Progress1 C.-Y. Cynthia Lin,2 Haoying prices have been trendless despite resource scarcity. In particular, we examine how endoge- nous a constant market price for nonrenewable resources. We calibrate our model using empirical data on world oil

  17. Revisiting the dissociation between singing and speaking in expressive aphasia

    E-print Network

    Revisiting the dissociation between singing and speaking in expressive aphasia Sylvie HeÂbert,1 Ame a severe expressive aphasia following a right-hemisphere stroke, but whose language comprehension from the operation of same mechanisms. Keywords: aphasia; melody intonation therapy; singing; songs

  18. 2-Hydroxy-3-methoxybenzaldehyde (o-vanillin) revisited

    E-print Network

    Shin, David

    The structure of ortho-vanillin, C[subscript 8]H[subscript 8]O[subscript 3], has been revisited with modern methods and at low temperature (100 K). The previous structure [Iwasaki et al. (1976). Acta Cryst. B32, 1264-1266] ...

  19. Revisiting Gender Role Stereotyping in the Sales Profession

    Microsoft Academic Search

    Andrew Crane

    2002-01-01

    This paper revisits the issue of gender stereotypes in sales professions given new views of what makes for effective sales performance and sales management. Women's continued disadvantaged position in the sales profession is documented, and the role of gender role stereotypes in sustaining this situation in the profession is examined. The paper then turns to the newly emerging, ostensibly \\

  20. ARTIFICIAL INTELLIGENCE 221 Pathology on Game Trees Revisited,

    E-print Network

    Nau, Dana S.

    ARTIFICIAL INTELLIGENCE 221 Pathology on Game Trees Revisited, and an Alternative to Minimaxing the existence of many game trees and evaluation functions which are 'pathological' in the sense that searching, it is shown that whenever the evaluation function satisfies certain properties, pathology will occur on any

  1. How to Make the Hidden Visible Code Clone Presentation Revisited

    E-print Network

    Nierstrasz, Oscar

    How to Make the Hidden Visible ­ Code Clone Presentation Revisited Sandro Schulze University of clone detection approaches exists, producing a lot of clone data. This data needs to be analyzed, either or actions from the analyzed data. In particular, we argue that it is often unclear how the cloning

  2. Revisiting Oligopolistic Reaction: Are Decisions on Foreign Direct

    E-print Network

    Boyer, Edmond

    Revisiting Oligopolistic Reaction: Are Decisions on Foreign Direct Investment Strategic Complements. Introduction Research on foreign direct investment (FDI) has long recognized two important motives for choosing-the-leader behavior. We find that rival foreign investment will make risk-neutral firms less inclined to move abroad

  3. Prediction of Prokaryotic Transcription Units from Microarray Data Revisited

    E-print Network

    Hochreiter, Sepp

    Prediction of Prokaryotic Transcription Units from Microarray Data Revisited Ulrich Bodenhofer, Wilhelm Lichtberger, Frank Klawonn In prokaryotic genomes, a transcription unit is a set of one or more co the knowledge about E.coli. For less investigated prokaryotes, it allows to infer hypotheses about transcription

  4. REVISITING MALARIA: MOVING FROM CONTROL TO SUSTAINABLE ELIMINATION

    E-print Network

    Yehoshua, Kolodny

    REVISITING MALARIA: MOVING FROM CONTROL TO SUSTAINABLE ELIMINATION December 8-12, 2013 Hebrew, Malaria and Professor Israel Kligler" (Room 436) 20:30-21:00 Discuss Conference agenda, format;9:30 ­ 13:15 HISTORICAL MODELS OF MALARIA ERADICATION Moderator: Prof. Nadav Davidovitch, Chair, Center

  5. Nurse Rostering and Integer Programming Revisited John Thornton

    E-print Network

    Thornton, John

    are violated. The allocation of nursing staff is a critical task in hospital management. Typically, nursing). Of the soft constraints some are more important than others. The objective of nurse rostering is to findNurse Rostering and Integer Programming Revisited John Thornton School of Information Technology

  6. Introduction: the Asia-Pacific HRM model revisited

    Microsoft Academic Search

    Malcolm Warner

    2000-01-01

    This article introduces a symposium which 'revisits' the Asia-Pacific HRM model, much discussed in recent literature. It argues that, while the IR\\/HRM systems of the countries in the region are prima facie heterogeneous, there is both commonality and diversity. It posits the four logical cases of 'hard convergence', 'soft convergence', 'soft divergence' and 'hard divergence'. It argues that the most

  7. Literary Origins of the Term "School Psychologist" Revisited

    ERIC Educational Resources Information Center

    Fagan, Thomas K.

    2005-01-01

    Previous research on the literary origins of the term "school psychologist" is revisited, and conclusions are revised in light of new evidence. It appears that the origin of the term in the American literature occurred as early as 1898 in an article by Hugo Munsterberg, predating the usage by Wilhelm Stern in 1911. The early references to the…

  8. Honors question 3: Complex numbers (revisited). Arithmetic of complex numbers

    E-print Network

    Leininger, Christopher J.

    Honors question 3: Complex numbers (revisited). Arithmetic of complex numbers Recall that the complex numbers are formally defined as C = {a + bi} where a and b can be any real numbers and i is treated as a variable (so we can identify the complex numbers with the set of linear polynomials with real

  9. Revisiting the Cost of the Stockholm Congestion Charging System

    Microsoft Academic Search

    Carl Hamilton

    2010-01-01

    This study revisits some of the key project participants and archive data, to provide a deeper understanding of what were the major cost drivers and whether it can be lower in future installations. The approach taken is to emphasise understanding of the particular circumstances rather than comparing aggregates with other seemingly similar systems. A main conclusion is that the political

  10. Ant Foraging Revisited Liviu A. Panait and Sean Luke

    E-print Network

    George Mason University

    Ant Foraging Revisited Liviu A. Panait and Sean Luke George Mason University, Fairfax, VA 22030 lpanait@cs.gmu.edu, sean@cs.gmu.edu Abstract Most previous artificial ant foraging models have to date re the artificial ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

  11. Ant Foraging Revisited Liviu A. Panait and Sean Luke

    E-print Network

    Turk, Greg

    Ant Foraging Revisited Liviu A. Panait and Sean Luke George Mason University, Fairfax, VA 22030 lpanait@cs.gmu.edu, sean@cs.gmu.edu Abstract Most previous artificial ant foraging algorithms have to date the artificial ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

  12. Rural-Nonrural Disparities in Postsecondary Educational Attainment Revisited

    ERIC Educational Resources Information Center

    Byun, Soo-yong; Meece, Judith L.; Irvin, Matthew J.

    2012-01-01

    Using data from the National Educational Longitudinal Study, this study revisited rural-nonrural disparities in educational attainment by considering a comprehensive set of factors that constrain and support youth's college enrollment and degree completion. Results showed that rural students were more advantaged in community social resources…

  13. A Truly Early Starter Model of Antisocial Behavior Revisited

    Microsoft Academic Search

    Daniel S. Shaw; Richard Q. Bell; Miles Gilliom

    2000-01-01

    This paper revisits a developmental model of the origins of early conduct problems. Several of the model's primary tenets have now been validated in two samples of at-risk children followed prospectively from infancy to school-age. In both cohorts, child, family, and sociodemographic factors all play a significant role in the development of early conduct problems. In particular, the quality of

  14. Cascade Encryption Revisited Peter Gazi1,2

    E-print Network

    Cascade Encryption Revisited Peter Gazi1,2 and Ueli Maurer1 1 ETH Z¨urich, Switzerland Department of Computer Science gazi@dcs.fmph.uniba.sk Abstract. The security of cascade blockcipher encryption-known that double encryption improves the secu- rity only marginally, leaving triple encryption as the shortest

  15. Cascade Encryption Revisited Peter Gazi1,2

    E-print Network

    Maurer, Ueli

    Cascade Encryption Revisited Peter Gazi1,2 and Ueli Maurer1 1 ETH Z¨urich, Switzerland Department of Computer Science Abstract. The security of cascade blockcipher encryption is an impor- tant and well-studied problem in theoretical cryptography with practical implications. It is well-known that double encryption

  16. Revisiting the Continua of Biliteracy: International and Critical Perspectives.

    ERIC Educational Resources Information Center

    Hornberger, Nancy H.; Skilton-Sylvester, Ellen

    2000-01-01

    The continua model of biliteracy offers a framework to situate research, teaching, and language planning in linguistically diverse settings. The continua model is revisited from the perspective of international cases of educational policy and practice in linguistically diverse settings, and from a critical perspective that seeks to make explicit…

  17. The relationship between economic development and business ownership revisited

    Microsoft Academic Search

    Martin Carree; André Van Stel; Roy Thurik; Sander Wennekers

    2007-01-01

    This paper revisits the two-equation model of Carree, van Stel, Thurik and Wennekers (2002) where deviations from the ‘equilibrium’ rate of business ownership play a central role in determining both the growth of business ownership and that of economic development. Two extensions of the original set-up are addressed: using longer time series of averaged data of 23 OECD countries (up

  18. Revisiting the Role of Communication in Adolescent Intimate Partner Violence

    ERIC Educational Resources Information Center

    Messinger, Adam M.; Rickert, Vaughn I.; Fry, Deborah A.; Lessel, Harriet; Davidson, Leslie L.

    2012-01-01

    A growing literature suggests that communication strategies can promote or inhibit intimate partner violence (IPV). Research on communication is still needed on a group ripe for early IPV intervention: high school-aged adolescents. This article revisits our previous analyses of young female reproductive clinic patients (Messinger, Davidson, &…

  19. Proliferation and tissue remodeling in cancer: the hallmarks revisited

    E-print Network

    Vazquez, Alexei

    with poor outcome in lung, prostate, breast and brain cancer, whereas remodeling increases mortality ratesProliferation and tissue remodeling in cancer: the hallmarks revisited EK Markert1 , AJ Levine1,2,3 and A Vazquez*,1,2,4 Although cancers are highly heterogeneous at the genomic level, they can manifest common

  20. The Master-Slave Architecture for Evolutionary Computations Revisited

    E-print Network

    Fernandez, Thomas

    The Master-Slave Architecture for Evolutionary Computations Revisited Christian Gagn´e, Marc efficiently both Beowulfs and networks of heterogeneous workstations we argue that the classic master-slave with processing nodes. In contrast, the master-slave model has all required features. One issue that needs

  1. December 2007December 2007 2121 Dutchwoman Butte Revisited

    E-print Network

    December 2007December 2007 2121 Dutchwoman Butte Revisited Examining paradigms for livestock on the allotment is a 100-acre isolated landform (Photo 1) support- ing relict vegetation, Dutchwoman Butte (DWB%­40%) of perennial grasses than the grazed Photo 1. Dutchwoman Butte, a 100-acre isolated landform protected from

  2. Revisiting the Tradespace Exploration Paradigm: Structuring the Exploration Process

    E-print Network

    de Weck, Olivier L.

    Revisiting the Tradespace Exploration Paradigm: Structuring the Exploration Process Adam M. Ross in Tradespace Exploration · Question-guided TSE· Question-guided TSE · Discussion · Conclusion seari as well, making "good" decisions more difficult Tradespace database to be explored g ­ Many possible

  3. The classification of glomerulonephritis in systemic lupus erythematosus revisited

    Microsoft Academic Search

    Jan J. Weening; Vivette D. D'Agati; Melvin M. Schwartz; Surya V. Seshan; Charles E. Alpers; Gerald B. Appel; James E. Balow; Jan A. Bruijn; TERENCE COOK; FRANCO FERRARIO; Agnes B. Fogo; Ellen M. Ginzler; LEE HEBERT; GARY HILL; PRUE HILL; J. Charles Jennette; Norella C. Kong; PHILIPPE LESAVRE; MICHAEL LOCKSHIN; LAI-MENG LOOI; HIROFUMI MAKINO; Luiz A. Moura; MICHIO NAGATA

    2004-01-01

    The classification of glomerulonephritis in systemic lupus erythematosus revisited. The currently used classification reflects our understanding of the pathogenesis of the various forms of lupus nephritis, but clinicopathologic studies have revealed the need for improved categorization and terminology. Based on the 1982 classification published under the auspices of the World Health Organization (WHO) and subsequent clinicopathologic data, we propose that

  4. The Proof of the Gibbard-Satterthwaite Theorem Revisited

    E-print Network

    Procaccia, Ariel

    The Proof of the Gibbard-Satterthwaite Theorem Revisited Lars-Gunnar Svensson¤y First version is gratefully acknowl- edged. y address: Lars-Gunnar Svensson, Deparment of Economics, Lund university, P.O. Box 7082, S-22007 LUND, Sweden; e-mail: Lars-Gunnar.Svensson@nek.lu.se; telephone num- ber: +46 46 222 86

  5. Projected Tetrahedra Revisited: A Barycentric Formulation Applied to Digital

    E-print Network

    Cohen, Jonathan

    -3D" deformable registration of anatomical models. We discuss the impact of using higher directions. An example application of DRRs is intraoperative "2D-3D" registration, i.e., finding the poseProjected Tetrahedra Revisited: A Barycentric Formulation Applied to Digital Radiograph

  6. Weighted Geometric Set Cover Problems Revisited Sariel Har-Peled

    E-print Network

    Har-Peled, Sariel

    Weighted Geometric Set Cover Problems Revisited Sariel Har-Peled Mira Lee May 14, 2012 Abstract We study several set cover problems in low dimensional geometric settings. Specif- ically, we describe a PTAS for the problem of computing a minimum cover of given points by a set of weighted fat objects

  7. Set Cover Revisited: Hypergraph Cover with Hard Barna Saha1

    E-print Network

    Khuller, Samir

    Set Cover Revisited: Hypergraph Cover with Hard Capacities Barna Saha1 and Samir Khuller2 1 AT capacities. In the hard capacitated set cover problem, addi- tionally each set has a covering capacity which we are not allowed to exceed. In other words, after picking a set, we may cover at most a specified

  8. Titan interaction with Saturn's magnetosphere: Voyager 1 results revisited

    E-print Network

    Johnson, Robert E.

    Titan interaction with Saturn's magnetosphere: Voyager 1 results revisited E. C. Sittler Jr., R. E March 2005; published 10 September 2005. [1] We investigate the details of Titan's interaction in the outermost region with respect to Titan's ``ionopause,'' followed by CH4 + at intermediate distances and N2

  9. Axial Electron Heat Loss From Mirror Devices Revisited

    Microsoft Academic Search

    Ryutov

    2004-01-01

    An issue of the axial electron heat loss is of a significant importance for mirror-based fusion devices. This problem has been considered in a number of publications but it is still shrouded in misconceptions. In this paper we revisit it once again. We discuss the following issues: (1) Formation of the electron distribution function in the end tank at large

  10. Axial Electron Heat Loss from Mirror Devices Revisited

    Microsoft Academic Search

    Ryutov

    2005-01-01

    An issue of the axial electron heat loss is of a significant importance for mirror-based fusion devices. This problem has been considered in a number of publications but it is still shrouded in misconceptions. In this paper we revisit it once again. We discuss the following issues: 1) Formation of the electron distribution function in the end tank at large

  11. "Interval Rational = Algebraic" Revisited: A More Computer Realistic Result

    E-print Network

    Kreinovich, Vladik

    numbers are represented. The set of all rational numbers is countable and has, therefore, Lebesgue measure"Interval Rational = Algebraic" Revisited: A More Computer Realistic Result Anatoly V. Lakeyev1 rational functions, then the resulting class of "interval-rational" functions practically coincides

  12. Stochastic search in a forest revisited Jay Sethuraman

    E-print Network

    Sethuraman, Jay

    Stochastic search in a forest revisited Jay Sethuraman John N. Tsitsiklis November 12, 2005 Abstract We consider a generalization of the model of stochastic search in an out-forest, introduced and studied by Denardo, Rothblum, and Van der Heyden [1]. We provide a simple proof of the optimality of index

  13. Revisiting Maya Blue and Designing Hybrid Pigments by Archaeomimetism**

    E-print Network

    Paris-Sud XI, Université de

    1 Revisiting Maya Blue and Designing Hybrid Pigments by Archaeomimetism** Catherine Dejoie, Eric led several past civilizations to develop artificial pigments. Maya Blue (MB), manufactured in pre. The Mayas invented a remarkable hybrid material by "mineralizing" the añil organic dye in palygorskite via

  14. A Multi-Level Model of Moral Functioning Revisited

    ERIC Educational Resources Information Center

    Reed, Don Collins

    2009-01-01

    The model of moral functioning scaffolded in the 2008 "JME" Special Issue is here revisited in response to three papers criticising that volume. As guest editor of that Special Issue I have formulated the main body of this response, concerning the dynamic systems approach to moral development, the problem of moral relativism and the role of…

  15. The angular momentum of baryons and dark matter halos revisited

    Microsoft Academic Search

    Taysun Kimm; Julien Devriendt; Adrianne Slyz; Christophe Pichon; Susan A. Kassin; Yohan Dubois

    2011-01-01

    Recent theoretical studies have shown that galaxies at high redshift are fed by cold, dense gas filaments, suggesting angular momentum transport by gas differs from that by dark matter. Revisiting this issue using high-resolution cosmological hydrodynamics simulations with adaptive mesh refinement, we find that at the time of accretion, gas and dark matter do carry a similar amount of specific

  16. DNA Compression Challenge Revisited: a Dynamic Programming Approach

    E-print Network

    Lonardi, Stefano

    DNA Compression Challenge Revisited: a Dynamic Programming Approach Behshad Behzadi and Fabrice Le Fessant LIX, Ecole Polytechnique, Paris, FRANCE June 21 2005 B. Behzadi, F. Le Fessant (LIX) DNA Compression June 21 2005 1 / 38 #12;Outline 1 DNA Compression Challenge 2 Tools and Methods 3 DNA Compression

  17. Concurrent Zero-Knowledge With Timing, Revisited Oded Goldreich

    E-print Network

    Goldreich, Oded

    Concurrent Zero-Knowledge With Timing, Revisited Oded Goldreich Department of Computer Science-coming messages and delay out-going messages). We show that the constant-round zero-knowledge proof for NP zero-knowledge of interactive proofs, whereas the results of Dwork et. al. are either for zero

  18. Concurrent Zero-Knowledge With Timing, Revisited Oded Goldreich

    E-print Network

    Goldreich, Oded

    Concurrent Zero-Knowledge With Timing, Revisited Oded Goldreich Department of Computer Science-coming messages and delay out-going messages). We show that the constant-round zero-knowledge proof for NP to zero-knowledge of interactive proofs, whereas the results of Dwork et. al. are either for zero

  19. Concurrent Zero-Knowledge With Timing, Revisited Oded Goldreich

    E-print Network

    Goldreich, Oded

    Concurrent Zero-Knowledge With Timing, Revisited Oded Goldreich Department of Computer Science-going messages). We show that the constant-round zero-knowledge proof for NP of Goldreich and Kahan (Jour under the above timing model. We stress that our main result refers to zero-knowledge of interactive

  20. THE HEIGHWAY DRAGON REVISITED SZEMAN NGAI AND NHU NGUYEN

    E-print Network

    Nguyen, Nhu

    THE HEIGHWAY DRAGON REVISITED SZE­MAN NGAI AND NHU NGUYEN Abstract. We prove that the Heighway dragon is a countable union of closed disk­like planar sets which intersect each other in a linear order with an empty intersection. Consequently, the interior of the Heighway dragon is a countable union of disjoint

  1. Normalized Completion Revisited Sarah Winkler and Aart Middeldorp

    E-print Network

    Middeldorp, Aart

    Normalized Completion Revisited Sarah Winkler and Aart Middeldorp Institute of Computer Science University of Innsbruck, Austria {sarah.winkler, aart.middeldorp}@uibk.ac.at Abstract Normalized completion. © Sarah Winkler and Aart Middeldorp; licensed under Creative Commons License CC-BY 24th International

  2. Innate phonetic boundaries revisited (L) Richard N. Aslina)

    E-print Network

    Aslin, Richard N.

    Innate phonetic boundaries revisited (L) Richard N. Aslina) Department of Brain and Cognitive serious concerns with the so-called Universal Theory of phonetic category development that she the entire notion of phonetic categories. Here we argue that Nittrouer not only misrepresented Universal

  3. Agent UML Class Diagrams Revisited Marc-Philippe Huget

    E-print Network

    Atkinson, Katie

    Agent UML Class Diagrams Revisited Marc-Philippe Huget Agent ART Group University of Liverpool Agent UML in order to represent the interaction protocols [8] [2]. Agent UML is a graphical modeling language based on UML. As UML, Agent UML provides sev- eral types of representation covering

  4. Revisiting the Trust Effect in Urban Elementary Schools

    ERIC Educational Resources Information Center

    Adams, Curt M.; Forsyth, Patrick B.

    2013-01-01

    More than a decade after Goddard, Tschannen-Moran, and Hoy (2001) found that collective faculty trust in clients predicts student achievement in urban elementary schools, we sought to identify a plausible link for this relationship. Our purpose in revisiting the trust effect was twofold: (1) to test the main effect of collective faculty trust on…

  5. Modal Intervals Revisited Part 1: A Generalized Interval Natural Extension

    E-print Network

    Paris-Sud XI, Université de

    Modal Intervals Revisited Part 1: A Generalized Interval Natural Extension Alexandre Goldsztejn Abstract The modal intervals theory is an extension of the classical intervals theory which provides richer of its promising potential, the modal intervals theory is not widely used today because of its original

  6. DISPERSIVE BLOW UP FOR NONLINEAR SCHRODINGER EQUATIONS REVISITED

    E-print Network

    Sparber, Christof

    DISPERSIVE BLOW UP FOR NONLINEAR SCHR¨ODINGER EQUATIONS REVISITED J. L. BONA, G. PONCE, J.-C. SAUT. G. P. and C. S. acknowledge support of the NSF through grants DMS-1101499 and DMS-1161580 partial support from the project GEODISP of the ANR. 1 #12;2 J. L. BONA, G. PONCE, J.-C. SAUT, AND C

  7. Genome Rearrangement and Planning: Revisited Tansel Uras and Esra Erdem

    E-print Network

    Erdem, Esra

    Genome Rearrangement and Planning: Revisited Tansel Uras and Esra Erdem Faculty of Engineering be reconstructed by pair- wise comparison of their entire genomes. Such a comparison can be quantified by determining the number of events that change the order of genes in a genome. Earlier Erdem and Tillier

  8. NOTES AND COMMENTS Revisiting powdered sugar for varroa control on

    E-print Network

    Delaplane, Keith S.

    NOTES AND COMMENTS Revisiting powdered sugar for varroa control on honey bees (Apis mellifera L, accepted for publication 1 September 2012. Keywords: Varroa destructor, IPM, powdered sugar, dusts Journal sugar has been examined as a remedial control for Varroa destructor Anderson and Trueman (varroa). Two

  9. January 2013 BEE CULTURE 23 Revisiting Powdered Sugar For

    E-print Network

    Delaplane, Keith S.

    January 2013 BEE CULTURE 23 Revisiting Powdered Sugar For Varroa Control On Honey Bees (Apis dust bees with powder sugar as a means of removing mites. Dusting with powder sugar was also gaining conducted a study which examined the efficacy of powder sugar and found it did not help in controlling

  10. VIRTUE EPISTEMOLOGY AND EPISTEMIC LUCK, REVISITED DUNCAN PRITCHARD

    E-print Network

    Edinburgh, University of

    1 VIRTUE EPISTEMOLOGY AND EPISTEMIC LUCK, REVISITED DUNCAN PRITCHARD ABSTRACT. In this paper I return to an argument that I presented in earlier work to the effect that virtue epistemology is at worse. KEYWORDS: Epistemology; Luck; Reliabilism; Virtue. 0. INTRODUCTION In recent worksee especially Pritchard

  11. Revisiting Size-Based Scheduling with Estimated Job Sizes

    E-print Network

    Carra, Damiano

    Revisiting Size-Based Scheduling with Estimated Job Sizes Matteo Dell'Amico EURECOM, France Damiano--We study size-based schedulers, and focus on the impact of inaccurate job size information on response time errors on job size estimates, thus limiting the applicability of size-based schedulers. We show

  12. Climate determinism revisited: multiple equilibria in a complex climate model

    E-print Network

    Marshall, John

    Climate determinism revisited: multiple equilibria in a complex climate model David Ferreira, John of Technology, Cambridge, Massachusetts June 17th, 2010 Submitted to Journal of Climate Corresponding author `snowball' state. Although low-order energy balance models of the climate are known to exhibit

  13. Revisiting Extinction in National Parks: Mountain Caribou in Banff

    E-print Network

    Hebblewhite, Mark

    's backcountry, Parks Canada staff dug a dead cari- bou (Rangifer tarandus) out of a snow avalancheDiversity Revisiting Extinction in National Parks: Mountain Caribou in Banff M. HEBBLEWHITE, C. This individual was likely the last southern mountain wood- land caribou, also a SARA-listed species, in the park

  14. Revisiting rainfall clustering and intermittency across different climatic regimes

    E-print Network

    Katul, Gabriel

    Revisiting rainfall clustering and intermittency across different climatic regimes Annalisa Molini; accepted 3 August 2009; published 3 November 2009. [1] One of the vexing questions in rainfall research of universal behavior is due to the bursting patterns in rainfall intensity or the alternation between long dry

  15. Educational Administration and the Management of Knowledge: 1980 Revisited

    ERIC Educational Resources Information Center

    Bates, Richard

    2013-01-01

    This paper revisits the thesis of a 1980 paper that suggested a new approach to educational administration based upon the New Sociology of Education. In particular it updates answers to the six key questions asked by that paper: what counts as knowledge; how is what counts as knowledge organised; how is what counts as knowledge transmitted; how is…

  16. Revisiting mu suppression in autism spectrum disorder.

    PubMed

    Dumas, Guillaume; Soussignan, Robert; Hugueville, Laurent; Martinerie, Jacques; Nadel, Jacqueline

    2014-10-17

    Two aspects of the EEG literature lead us to revisit mu suppression in Autism Spectrum Disorder (ASD). First and despite the fact that the mu rhythm can be functionally segregated in two discrete sub-bands, 8-10 Hz and 10-12/13 Hz, mu-suppression in ASD has been analyzed as a homogeneous phenomenon covering the 8-13 Hz frequency. Second and although alpha-like activity is usually found across the entire scalp, ASD studies of action observation have focused on the central electrodes (C3/C4). The present study was aimed at testing on the whole brain the hypothesis of a functional dissociation of mu and alpha responses to the observation of human actions in ASD according to bandwidths. Electroencephalographic (EEG) mu and alpha responses to execution and observation of hand gestures were recorded on the whole scalp in high functioning subjects with ASD and typical subjects. When two bandwidths of the alpha-mu 8-13 Hz were distinguished, a different mu response to observation appeared for subjects with ASD in the upper sub-band over the sensorimotor cortex, whilst the lower sub-band responded similarly in the two groups. Source reconstructions demonstrated that this effect was related to a joint mu-suppression deficit over the occipito-parietal regions and an increase over the frontal regions. These findings suggest peculiarities in top-down response modulation in ASD and question the claim of a global dysfunction of the MNS in autism. This research also advocates for the use of finer grained analyses at both spatial and spectral levels for future directions in neurophysiological accounts of autism. PMID:25148709

  17. Autosomal recessive cutis laxa syndrome revisited

    PubMed Central

    Morava, Éva; Guillard, Maïlys; Lefeber, Dirk J; Wevers, Ron A

    2009-01-01

    The clinical spectrum of the autosomal recessive cutis laxa syndromes is highly heterogeneous with respect to organ involvement and severity. One of the major diagnostic criteria is to detect abnormal elastin fibers. In several other clinically similar autosomal recessive syndromes, however, the classic histological anomalies are absent, and the definite diagnosis remains uncertain. In cutis laxa patients mutations have been demonstrated in elastin or fibulin genes, but in the majority of patients the underlying genetic etiology remains unknown. Recently, we found mutations in the ATP6V0A2 gene in families with autosomal recessive cutis laxa. This genetic defect is associated with abnormal glycosylation leading to a distinct combined disorder of the biosynthesis of N- and O-linked glycans. Interestingly, similar mutations have been found in patients with wrinkly skin syndrome, without the presence of severe skin symptoms of elastin deficiency. These findings suggest that the cutis laxa and wrinkly skin syndromes are phenotypic variants of the same disorder. Interestingly many phenotypically similar patients carry no mutations in the ATP6V0A2 gene. The variable presence of protein glycosylation abnormalities in the diverse clinical forms of the wrinkled skin-cutis laxa syndrome spectrum necessitates revisiting the diagnostic criteria to be able to offer adequate prognosis assessment and counseling. This paper aims at describing the spectrum of clinical features of the various forms of autosomal recessive cutis laxa syndromes. Based on the recently unraveled novel genetic entity we also review the genetic aspects in cutis laxa syndromes including genotype–phenotype correlations and suggest a practical diagnostic approach. PMID:19401719

  18. Effects of a Balanced Translocation between Chromosomes 1 and 11 Disrupting the DISC1 Locus on White Matter Integrity

    PubMed Central

    Whalley, Heather C.; Dimitrova, Rali; Sprooten, Emma; Dauvermann, Maria R.; Romaniuk, Liana; Duff, Barbara; Watson, Andrew R.; Moorhead, Bill; Bastin, Mark; Semple, Scott I.; Giles, Stephen; Hall, Jeremy; Thomson, Pippa; Roberts, Neil; Hughes, Zoe A.; Brandon, Nick J.; Dunlop, John; Whitcher, Brandon; Blackwood, Douglas H. R.; McIntosh, Andrew M.; Lawrie, Stephen M.

    2015-01-01

    Objective Individuals carrying rare, but biologically informative genetic variants provide a unique opportunity to model major mental illness and inform understanding of disease mechanisms. The rarity of such variations means that their study involves small group numbers, however they are amongst the strongest known genetic risk factors for major mental illness and are likely to have large neural effects. DISC1 (Disrupted in Schizophrenia 1) is a gene containing one such risk variant, identified in a single Scottish family through its disruption by a balanced translocation of chromosomes 1 and 11; t(1;11) (q42.1;q14.3). Method Within the original pedigree, we examined the effects of the t(1;11) translocation on white matter integrity, measured by fractional anisotropy (FA). This included family members with (n = 7) and without (n = 13) the translocation, along with a clinical control sample of patients with psychosis (n = 34), and a group of healthy controls (n = 33). Results We report decreased white matter integrity in five clusters in the genu of the corpus callosum, the right inferior fronto-occipital fasciculus, acoustic radiation and fornix. Analysis of the mixed psychosis group also demonstrated decreased white matter integrity in the above regions. FA values within the corpus callosum correlated significantly with positive psychotic symptom severity. Conclusions We demonstrate that the t(1;11) translocation is associated with reduced white matter integrity in frontal commissural and association fibre tracts. These findings overlap with those shown in affected patients with psychosis and in DISC1 animal models and highlight the value of rare but biologically informative mutations in modeling psychosis. PMID:26102360

  19. White matter disruptions in adolescents exposed to childhood maltreatment and vulnerability to psychopathology.

    PubMed

    Huang, Hao; Gundapuneedi, Tejasvi; Rao, Uma

    2012-11-01

    Childhood maltreatment has been known to produce long-lasting impairments in behavioral, cognitive and social functioning, but their underlying mechanisms are not well-understood. A better understanding of their underlying mechanisms will aid in developing effective preventive interventions. Nineteen adolescent volunteers with no personal history of a psychiatric illness, but who were exposed to maltreatment during childhood, and 13 adolescent volunteers with no personal or family history of a psychiatric disorder (controls) underwent diffusion tensor imaging (DTI) studies. The participants were then followed longitudinally at 6-month intervals for up to 5 years to determine the onset of mood and substance use disorders. The associations among fractional anisotropy (FA) values obtained from the DTI scans at baseline and psychopathology at follow-up were examined. At baseline, adolescents exposed to childhood maltreatment had significantly lower FA values in the left and right superior longitudinal fasciculi, right cingulum bundle projecting to the hippocampus, left inferior fronto-occipital fasciculus, and splenium of the corpus callosum compared with controls. Adolescents who developed major depressive disorder at follow-up had significantly lower FA values in the superior longitudinal fasciculi and the right cingulum-hippocampal projection compared with their counterparts who did not develop the illness. Adolescents who developed substance use disorder during follow-up had significantly lower FA values in the right cingulum-hippocampal projection than their counterparts without the disorder. These preliminary results suggest that white matter disruptions observed in adolescents exposed to childhood maltreatment may be associated with increased vulnerability to psychopathology, specifically depressive and substance use disorders. PMID:22850736

  20. GENETICS OF BRAIN FIBER ARCHITECTURE AND INTELLECTUAL PERFORMANCE

    PubMed Central

    Chiang, Ming-Chang; Barysheva, Marina; Shattuck, David W.; Lee, Agatha D.; Madsen, Sarah; Avedissian, Christina; Klunder, Andrea D.; Toga, Arthur W.; McMahon, Katie L.; de Zubicaray, Greig I.; Wright, Margaret J.; Srivastava, Anuj; Balov, Nikolay; Thompson, Paul M.

    2009-01-01

    The paper is the first to analyze genetic and environmental factors that affect brain fiber architecture and its genetic linkage with cognitive function. We assessed white matter integrity voxelwise using diffusion tensor imaging (DTI) at high magnetic field (4 Tesla), in 92 identical and fraternal twins. White matter integrity, quantified using fractional anisotropy (FA), was used to fit structural equation models (SEM) at each point in the brain, generating 3D maps of heritability. We visualized the anatomical profile of correlations between white matter integrity and full-scale, verbal, and performance intelligence quotients (FIQ, VIQ, and PIQ). White matter integrity (FA) was under strong genetic control and was highly heritable in bilateral frontal (a2 = 0.55, P = 0.04, left; a2 = 0.74, P = 0.006, right), bilateral parietal (a2 = 0.85, P < 0.001, left; a2 = 0.84, P < 0.001, right) and left occipital (a2 = 0.76, P = 0.003) lobes, and was correlated with FIQ and PIQ in the cingulum, optic radiations, superior fronto-occipital fasciculus, internal capsule, callosal isthmus, and the corona radiata (P = 0.04 for FIQ and P = 0.01 for PIQ, corrected for multiple comparisons). In a cross-trait mapping approach, common genetic factors mediated the correlation between IQ and white matter integrity, suggesting a common physiological mechanism for both, and common genetic determination. These genetic brain maps reveal heritable aspects of white matter integrity and should expedite the discovery of single-nucleotide polymorphisms affecting fiber connectivity and cognition. PMID:19228974

  1. Frontiers of Language and Teaching ............................................................. Volume 3 (2012) Revisiting Foreign Language Teacher Beliefs

    E-print Network

    Paris-Sud XI, Université de

    2012-01-01

    ............................................................. Volume 3 (2012) 190 Revisiting Foreign Language Teacher Beliefs Zehra Gabillon Laboratoire EA Sociétés.gabillon@gmail.com Abstract This state of the art paper revisits foreign language teacher beliefs. The first part of the paper reviews some factors that have an impact on foreign/second language (L2) teachers

  2. Long's vortex revisited R.E. Hewitt and P.W. Duck

    E-print Network

    Heil, Matthias

    Long's vortex revisited R.E. Hewitt and P.W. Duck 2009 MIMS EPrint: 2012.23 Manchester Institute:10.1017/S0022112009007502 Printed in the United Kingdom 91 Long's vortex revisited RICHARD E. HEWITT for correspondence: richard.e.hewitt@manchester.ac.uk #12;92 R. E. Hewitt and P. W. Duck related half-line vortex

  3. Patronage at What Cost?: Revisiting an Old Problem in the Social Audra J. Wolfe

    E-print Network

    Solovey, Mark

    Patronage at What Cost?: Revisiting an Old Problem in the Social Sciences Audra J. Wolfe Reviews by University of Toronto Library (2 Feb 2014 13:52 GMT) http://muse.jhu.edu/journals/rah/summary/v041/41.4.wolfe.html #12;PATRONAGE AT WHAT COST? REVISITING AN OLD PROBLEM IN THE SOCIAL SCIENCES Audra J. Wolfe Mark

  4. IODINE IN THE ENVIRONMENT REVISITED. AN EVALUATION OF THE CHEMICAL-AND PHYSICO CHEMICAL

    E-print Network

    is caused by iodine deficiency, major efforts were devoted to studies of the distribution, concentrationsIODINE IN THE ENVIRONMENT REVISITED. AN EVALUATION OF THE CHEMICAL- AND PHYSICO CHEMICAL PROCESSES-M-2791 IODINE IN THE ENVIRONMENT REVISITED. AN EVALUATION OF THE CHEMICAL- AND PHYSICO CHEMICAL PROCESSES

  5. Modal Intervals Revisited Part 2: A Generalized Interval Mean-Value

    E-print Network

    Paris-Sud XI, Université de

    Modal Intervals Revisited Part 2: A Generalized Interval Mean-Value Extension Alexandre Goldsztejn Abstract In Modal Intervals Revisited Part 1, new extensions to generalized in- tervals (intervals whose interpretations as the extensions to modal intervals and therefore enhance the interpreta- tions of the classical

  6. Gate Sizing by Lagrangian Relaxation Revisited Jia Wang, Debasish Das, and Hai Zhou

    E-print Network

    Zhou, Hai

    Gate Sizing by Lagrangian Relaxation Revisited Jia Wang, Debasish Das, and Hai Zhou Electrical formulate the Generalized Convex Sizing (GCS) problem that unifies and generalizes the sizing problems. We revisit the approach to solve the sizing problem by Lagrangian relaxation, point out several

  7. Indoor air and human health revisited: A recent IAQ symposium

    SciTech Connect

    Gammage, R.B.

    1994-12-31

    Indoor Air and Human Health Revisited was a speciality symposium examining the scientific underpinnings of sensory and sensitivity effects, allergy and respiratory disease, neurotoxicity and cancer. An organizing committee selected four persons to chain the sessions and invite experts to give state-of-the-art presentations that will be published as a book. A summary of the presentations is made and some critical issues identified.

  8. Faraday effect revisited: sum rules and convergence issues

    E-print Network

    Cornean, Horia D

    2010-01-01

    This is the third paper of a series revisiting the Faraday effect. The question of the absolute convergence of the sums over the band indices entering the Verdet constant is considered. In general, sum rules and traces per unit volume play an important role in solid state physics, and they give rise to certain convergence problems widely ignored by physicists. We give a complete answer in the case of smooth potentials and formulate an open problem related to less regular perturbations.

  9. Faraday effect revisited: sum rules and convergence issues

    E-print Network

    Horia D. Cornean; Gheorghe Nenciu

    2010-05-13

    This is the third paper of a series revisiting the Faraday effect. The question of the absolute convergence of the sums over the band indices entering the Verdet constant is considered. In general, sum rules and traces per unit volume play an important role in solid state physics, and they give rise to certain convergence problems widely ignored by physicists. We give a complete answer in the case of smooth potentials and formulate an open problem related to less regular perturbations.

  10. Distant future of the Sun and Earth revisited

    Microsoft Academic Search

    Klaus-Peter Schroder; Robert Connon Smith

    2008-01-01

    We revisit the distant future of the Sun and the solar system, based on\\u000astellar models computed with a thoroughly tested evolution code. For the solar\\u000agiant stages, mass-loss by the cool (but not dust-driven) wind is considered in\\u000adetail. Using the new and well-calibrated mass-loss formula of Schroder & Cuntz\\u000a(2005, 2007), we find that the mass lost by

  11. Distant future of the Sun and Earth revisited

    Microsoft Academic Search

    K.-P. Schröder; Robert Connon Smith

    2008-01-01

    We revisit the distant future of the Sun and the Solar system, based on stellar models computed with a thoroughly tested evolution code. For the solar giant stages, mass loss by the cool (but not dust-driven) wind is considered in detail. Using the new and well-calibrated mass-loss formula of Schröder & Cuntz, we find that the mass lost by the

  12. Topological Twisted Sigma Model with H-flux Revisited

    SciTech Connect

    Chuang, Wu-yen

    2006-08-18

    In this paper we revisit the topological twisted sigma model with H-flux. We explicitly expand and then twist the worldsheet Lagrangian for bi-Hermitian geometry. we show that the resulting action consists of a BRST exact term and pullback terms, which only depend on one of the two generalized complex structures and the B-field. We then discuss the topological feature of the model.

  13. Theory of magnetohydrodynamic waves - The WKB approximation revisited

    NASA Technical Reports Server (NTRS)

    Barnes, Aaron

    1992-01-01

    The present paper revisits the derivation of the WKB approximation for small-amplitude magnetohydrodynamic waves, allowing for possible spatial variation of the background entropy. The equation of variation of wave amplitude is rederived; it is a bilinear equation which, it turns out, can be recast in the action conservation form. It is shown that this action conservation equation is in fact equivalent to the action conservation law obtained from Lagrangian treatments.

  14. Diffuse alterations in grey and white matter associated with cognitive impairment in Shwachman–Diamond syndrome: Evidence from a multimodal approach

    PubMed Central

    Perobelli, Sandra; Alessandrini, Franco; Zoccatelli, Giada; Nicolis, Elena; Beltramello, Alberto; Assael, Baroukh M.; Cipolli, Marco

    2015-01-01

    Shwachman–Diamond syndrome is a rare recessive genetic disease caused by mutations in SBDS gene, at chromosome 7q11. Phenotypically, the syndrome is characterized by exocrine pancreatic insufficiency, bone marrow dysfunction, skeletal dysplasia and variable cognitive impairments. Structural brain abnormalities (smaller head circumference and decreased brain volume) have also been reported. No correlation studies between brain abnormalities and neuropsychological features have yet been performed. In this study we investigate neuroanatomical findings, neurofunctional pathways and cognitive functioning of Shwachman–Diamond syndrome subjects compared with healthy controls. To be eligible for inclusion, participants were required to have known SBDS mutations on both alleles, no history of cranial trauma or any standard contraindication to magnetic resonance imaging. Appropriate tests were used to assess cognitive functions. The static images were acquired on a 3 × 0 T magnetic resonance scanner and blood oxygen level-dependent functional magnetic resonance imaging data were collected both during the execution of the Stroop task and at rest. Diffusion tensor imaging was used to assess brain white matter. The Tract-based Spatial Statistics package and probabilistic tractography were used to characterize white matter pathways. Nine participants (5 males), half of all the subjects aged 9–19 years included in the Italian Shwachman–Diamond Syndrome Registry, were evaluated and compared with nine healthy subjects, matched for sex and age. The patients performed less well than norms and controls on cognitive tasks (p = 0.0002). Overall, cortical thickness was greater in the patients, both in the left (+10%) and in the right (+15%) hemisphere, significantly differently increased in the temporal (left and right, p = 0.04), and right parietal (p = 0.03) lobes and in Brodmann area 44 (p = 0.04) of the right frontal lobe. The greatest increases were observed in the left limbic-anterior cingulate cortex (?43%, p < 0.0004). Only in Broca's area in the left hemisphere did the patients show a thinner cortical thickness than that of controls (p = 0.01). Diffusion tensor imaging showed large, significant difference increases in both fractional anisotropy (+37%, p < 0.0001) and mean diffusivity (+35%, p < 0.005); the Tract-based Spatial Statistics analysis identified six abnormal clusters of white matter fibres in the fronto-callosal, right fronto-external capsulae, left fronto-parietal, right pontine, temporo-mesial and left anterior–medial–temporal regions. Brain areas activated during the Stroop task and those active during the resting state, are different, fewer and smaller in patients and correlate with worse performance (p = 0.002). Cognitive impairment in Shwachman–Diamond syndrome subjects is associated with diffuse brain anomalies in the grey matter (verbal skills with BA44 and BA20 in the right hemisphere; perceptual skills with BA5, 37, 20, 21, 42 in the left hemisphere) and white matter connectivity (verbal skills with alterations in the fronto-occipital fasciculus and with the inferior-longitudinal fasciculus; perceptual skills with the arcuate fasciculus, limbic and ponto-cerebellar fasciculus; memory skills with the arcuate fasciculus; executive functions with the anterior cingulated and arcuate fasciculus). PMID:25844324

  15. Artifact quantification and tractography from 3T MRI after placement of aneurysm clips in subarachnoid hemorrhage patients

    PubMed Central

    2011-01-01

    Background The application of advanced 3T MRI imaging techniques to study recovery after subarachnoid hemorrhage (SAH) is complicated by the presence of image artifacts produced by implanted aneurysm clips. To characterize the effect of these artifacts on image quality, we sought to: 1) quantify extent of image artifact in SAH patients with implanted aneurysm clips across a range of MR sequences typically used in studies of volumetry, blood oxygen level dependent signal change (BOLD-fMRI), and diffusion-weighted imaging (DW-MRI) and 2) to explore the ability to reconstruct white matter pathways in these patients. Methods T1- and T2-weighted structural, BOLD-fMRI, and DW-MRI scans were acquired at 3T in two patients with titanium alloy clips in ACOM and left ACA respectively. Intensity-based planimetric contouring was performed on aligned image volumes to define each artifact. Artifact volumes were quantified by artifact/clip length and artifact/brain volume ratios and analyzed by two-way (scan-by-rater) ANOVAs. Tractography pathways were reconstructed from DW-MRI at varying distances from the artifacts using deterministic methods. Results Artifact volume varied by MR sequence for length (p = 0.007) and volume (p < 0.001) ratios: it was smallest for structural images, larger for DW-MRI acquisitions, and largest on fMRI images. Inter-rater reliability was high (r = 0.9626, p < 0.0001), and reconstruction of white matter connectivity characteristics increased with distance from the artifact border. In both patients, reconstructed white matter pathways of the uncinate fasciculus and inferior fronto-occipital fasciculus were clearly visible within 2 mm of the artifact border. Conclusions Advanced 3T MR can successfully image brain tissue around implanted titanium aneurysm clips at different spatial ranges depending on sequence type. White matter pathways near clip artifacts can be reconstructed and visualized. These findings provide a reference for designing functional and structural neuroimaging studies of recovery in aSAH patients after clip placement. PMID:21970560

  16. Sentiment and Stock Returns: The SAD Anomaly Revisited

    E-print Network

    Meschke, Felix; Kelly, Patrick J.

    2010-06-01

    ://ssrn.com/abstract=571144 Sentiment and stock returns: The SAD anomaly revisited Patrick Kelly Department of Finance University of South Florida 4202 E. Fowler Ave, BSN 3403 Tampa, FL 33620, USA (813) 974-6358 patrick@usf.edu Felix Meschke Carlson... in the general population. Second, we replicate the original KKL2003 study and extend the sample from 9 countries (12 indices) to 36 countries (47 indices). Third, we use the extended sample to see whether there are more pronounced stock market effects due...

  17. Faraday effect revisited: sum rules and convergence issues

    NASA Astrophysics Data System (ADS)

    Cornean, Horia D.; Nenciu, Gheorghe

    2010-11-01

    This is the third paper of a series revisiting the Faraday effect. The question of the absolute convergence of the sums over the band indices entering the Verdet constant is considered. In general, sum rules and traces per unit volume play an important role in solid-state physics, and they give rise to certain convergence problems widely ignored by physicists. We give a complete answer in the case of smooth potentials and formulate a number of open problems related to less regular perturbations.

  18. Revisiting and Computing Reaction Coordinates with Directional Milestoning

    PubMed Central

    Kirmizialtin, Serdal; Elber, Ron

    2011-01-01

    The method of Directional Milestoning is revisited. We start from an exact and more general expression and state the conditions and validity of the memory-loss approximation. An algorithm to compute a reaction coordinate from Directional Milestoning data is presented. The reaction coordinate is calculated as a set of discrete jumps between Milestones that maximizes the flux between two stable states. As an application we consider a conformational transition in solvated Adenosine. We compare a long molecular dynamic trajectory with Directional Milestoning and discuss the differences between the maximum flux path and minimum energy coordinates. PMID:21500798

  19. [Perinatal risk at term and post-term revisited].

    PubMed

    Vercoustre, L; Nizard, J

    2007-11-01

    The aim of this review was to revisit the evaluation of risk of foetal and neonatal mortality at term. We analyse the meaning of term period and difficulty to determine the normal duration of the pregnancy. Specific complications associated with post term and the statistic approach of the perinatal risk are analysed, together with various mortality rates and especially the prospective risk introducing foetal term as a new concept. We study various aspect and evolution of non specific morbidity of the term period. An optimal decision for term management should involve pregnant women and the analysed parameters should be taken into consideration. PMID:17537588

  20. Zero Knowledge in the Random Oracle Model, Revisited

    Microsoft Academic Search

    Hoeteck Wee

    2009-01-01

    We revisit previous formulations of zero knowledge in the random oracle model due to Bellare and Rogaway (CCS ’93) and Pass\\u000a (Crypto ’03), and present a hierarchy for zero knowledge that includes both of these formulations. The hierarchy relates to\\u000a the programmability of the random oracle, previously studied by Nielsen (Crypto ’02).\\u000a \\u000a \\u000a \\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a We establish a subtle separation between the

  1. Occupational asthma and occupational rhinitis: The united airways disease model revisited

    E-print Network

    Boyer, Edmond

    1 Occupational asthma and occupational rhinitis: The united airways disease model revisited Jacques number: +33147107754; Fax number:+33147107768 Key words: occupational asthma, occupational rhinitis, high) Objectives: Whereas accumulating evidence indicates close associations between rhinitis and asthma, little

  2. Revisiting Calendar Anomalies in Asian Stock Markets Using a Stochastic Dominance Approach

    E-print Network

    Chaudhuri, Sanjay

    Revisiting Calendar Anomalies in Asian Stock Markets Using a Stochastic Dominance Approach Hooi Abstract Extensive evidence on the prevalence of calendar effects suggests that there exist abnormal returns. Some recent studies, however, have concluded that calendar effects have largely disappeared

  3. Thee'tale Tits process of Jordan algebras revisited Holger P. Petersson

    E-print Network

    Thee'tale Tits process of Jordan algebras revisited Holger. Geburtstag gewidmet 0. Introduction The 'etale Tits process, which was called the toral Tits process by Petersson-R* *acine [12], may be viewed as a Jordan-theoretical method

  4. Generated using version 3.0 of the official AMS LATEX template Croll Revisited

    E-print Network

    , in the annual mean, the Northern Hemisphere is warmer than the Southern Hemisphere is addressed, revisiting fraction and heats up faster than the more oceanic SH. While the inter-hemispheric temperature asymmetry

  5. Evidence based practice: decreasing psychiatric revisits to the emergency department.

    PubMed

    Adams, Priscilla; Nielson, Heather

    2012-08-01

    Inpatient psychiatric settings anticipate changes in reimbursement that will link payment rates to objective quality measures. Readmission rates are expected to be one of the quality measures. Inpatient areas are undertaking initiatives to decrease readmission rates in preparation for this change. The emphasis on avoiding readmission could cause an increase in emergency room revisit rates by psychiatric patients. In preparation for this potential impact, the mental health emergency service within the Emergency Department of a not-for-profit community based hospital implemented a proactive process improvement plan. The plan's goal was to insure that all patients' care was provided according to a defined standardize best practice process. Steps of the plan focused on (1) improving treatment providers' communications across the continuum of care, (2) enhancing communication between the mental health emergency department nurses and the on-call psychiatrists, (3) developing on-line decisional support to enhance communication, and (4) providing providers with feedback on the impact of changes. Implementation of the improvement process decreased the mean psychiatric emergency revisit rate from 5.7% to 4.3% and decreased the variability in monthly rates from a range of 1.83%-9.53% to a range of 3.53%-5.56%. PMID:22849781

  6. The contact of elastic regular wavy surfaces revisited

    E-print Network

    Vladislav A. Yastrebov; Guillaume Anciaux Jean-Francois Molinari

    2014-09-05

    We revisit the classic problem of an elastic solid with a two-dimensional wavy surface squeezed against an elastic flat half-space from infinitesimal to full contact. Through extensive numerical calculations and analytic derivations, we discover previously overlooked transition regimes. These are seen in particular in the evolution with applied load of the contact area and perimeter, the mean pressure and the probability density of contact pressure. These transitions are correlated with the contact area shape, which is affected by long range elastic interactions. Our analysis has implications for general random rough surfaces, as similar local transitions occur continuously at detached areas or coalescing contact zones. We show that the probability density of null contact pressures is non-zero at full contact. This might suggest revisiting the conditions necessary for applying Persson's model at partial contacts and guide the comparisons with numerical simulations. We also address the evaluation of the contact perimeter for discrete geometries and the applicability of Westergaard's solution for three-dimensional geometries.

  7. Neutrino dark energy-revisiting the stability issue

    SciTech Connect

    Bjaelde, Ole Eggers; Hannestad, Steen [Department of Physics and Astronomy, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C (Denmark); Brookfield, Anthony W; Van de Bruck, Carsten [Department of Applied Mathematics, Astro-Particle Theory and Cosmology Group, Hounsfield Road, Hicks Building, University of Sheffield, Sheffield S3 7RH (United Kingdom); Mota, David F [Institute for Theoretical Physics, University of Heidelberg, D-69120 Heidelberg (Germany); Schrempp, Lily [Deutsches Elektron-Synchroton DESY, Hamburg, Notkestrasse 85, 22607 Hamburg (Germany); Tocchini-Valentini, Domenico, E-mail: oeb@phys.au.dk, E-mail: php04awb@sheffield.ac.uk, E-mail: C.vandebruck@sheffield.ac.uk, E-mail: sth@phys.au.dk, E-mail: d.mota@thphys.uni-heidelberg.de, E-mail: lily.schrempp@desy.de, E-mail: dtv@skysrv.pha.jhu.edu [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2008-01-15

    A coupling between a light scalar field and neutrinos has been widely discussed as a mechanism for linking (time varying) neutrino masses and the present energy density and equation of state of dark energy. However, it has been pointed out that the viability of this scenario in the non-relativistic neutrino regime is threatened by the strong growth of hydrodynamic perturbations associated with a negative adiabatic sound speed squared. In this paper we revisit the stability issue in the framework of linear perturbation theory in a model independent way. The criterion for the stability of a model is translated into a constraint on the scalar-neutrino coupling, which depends on the ratio of the energy densities in neutrinos and cold dark matter. We illustrate our results by providing meaningful examples for both stable and unstable models.

  8. Tidal Disruption Revisited - Creating Bifurcated Shapes Among Rubble Pile Asteroids

    NASA Astrophysics Data System (ADS)

    Walsh, Kevin J.; Richardson, Derek C.; Schwartz, Stephen R.

    2014-11-01

    We revisit the tidal disruption of rubble pile asteroids encountering terrestrial planets. The rubble pile structure of the asteroid is modeled with spherical particles that interact with full ``soft-sphere'' descriptions of the particles interactions - including static, sliding, and rolling friction. Using friction parameters that have matched the behavior of irregularly shaped gravel particles dynamically evolving [1], we have run a suite of tidal disruption simulations to compare with previous simulations that used more simplistic particle interactions. We find that the soft-sphere description of the asteroids's mechanics is very important and dramatically change the dynamics of the disruption, particularly the resulting shapes of remnants. Here we find many elongated and bifurcated shapes, reminiscent of some of the irregularly shaped bodies recently imaged with delay-doppler radar.[1] Yu, Y. et al. 2014, Icarus, 10.1016/j.icarus.2014.07.027

  9. Axial Electron Heat Loss from Mirror Devices Revisited

    SciTech Connect

    Ryutov, D.D. [Lawrence Livermore National Laboratory (United States)

    2005-01-15

    An issue of the axial electron heat loss is of a significant importance for mirror-based fusion devices. This problem has been considered in a number of publications but it is still shrouded in misconceptions. In this paper we revisit it once again. We discuss the following issues: 1) Formation of the electron distribution function in the end tank at large expansion ratios; 2) The secondary emission from the end plates and the ways of suppressing it (if needed); 3) Ionization and charge exchange in the presence of neutrals in the end tanks; 4) Instabilities caused by the peculiar shape of the electron distribution function and their possible impact on the electron heat losses; 5) Electron heat losses in the pulsed mode of operation of mirror devices.

  10. Axial Electron Heat Loss From Mirror Devices Revisited

    SciTech Connect

    Ryutov, D

    2004-08-16

    An issue of the axial electron heat loss is of a significant importance for mirror-based fusion devices. This problem has been considered in a number of publications but it is still shrouded in misconceptions. In this paper we revisit it once again. We discuss the following issues: (1) Formation of the electron distribution function in the end tank at large expansion ratios; (2) The secondary emission from the end plates and the ways of suppressing it (if needed); (3) Ionization and charge exchange in the presence of neutrals in the end tanks; (4) Instabilities caused by the peculiar shape of the electron distribution function and their possible impact on the electron heat losses; (5) Electron heat losses in the pulsed mode of operation of mirror devices.

  11. Neutron electric dipole moment induced by strangeness revisited

    NASA Astrophysics Data System (ADS)

    Fuyuto, Kaori; Hisano, Junji; Nagata, Natsumi

    2013-03-01

    We have revisited the calculation of the neutron electric dipole moment in the presence of the CP-violating operators up to dimension 5 based on the chiral perturbation theory. In particular, we focus on the contribution of strangeness content. In the calculation, we extract the nucleon matrix elements of scalar-type quark operators from the results of the lattice QCD simulations, while those of the dipole-type quark-gluon operators are evaluated by using the method of the QCD sum rules. As a result, it is found that although the strangeness quantity in nucleons is small, the contribution of the chromoelectric dipole moment of strange quarks may still be sizable, and thus may offer a sensitive probe for the CP-violating interactions in physics beyond the Standard Model.

  12. Hadronization revisited: the dynamics behind hadro-chemical equilibrium

    E-print Network

    Reinhard Stock

    2007-03-15

    The multiplicity of hadronic species created in elementary, and in nucleus-nucleus collisions, are known to be well reproduced by the statistical hadronization model, in its canonical and grand-canonical versions.To understand the origin of the implied equilibrium we revisit the hadronization models developed for e+e- annihilation to hadrons which imply spatial color pre-confinement clusters forming at the end of the pQCD evolution, which decays into on-shell hadrons/resonances. The classical ensemble description arises as a consequence of decoherence and phase space dominance during cluster formation, and decay.For A+A collisions we assume that hadronization occurs from similar singlet clusters which will overlap spatially owing to the extreme density. This is imaged in the transition to the grand-canonical ensemble.This transition sets in with increasing A and collision centrality. It can be described by a percolation model.

  13. Neural network modelling of CIMIS-ET0 (revisited)

    NASA Astrophysics Data System (ADS)

    Abrahart, R. J.; Ghani, N. Ab

    2009-04-01

    This paper will revisit the use of four independent hydrometeorological variables to predict 'reference crop evapotranspiration' in a neural network model - calculated as CIMIS-ET0 (Kisi, 2006; Aytek et al., 2008). The two earlier studies are coalesced and their published findings positioned in a broader environmental modelling context. Four models developed on similar datasets are compared and contrasted in the current exercise: a multiple linear regression model (MLIN: Pearson, 1896), a piecewise multiple linear regression model (M5 Model Tree; M5MT: Quinlan, 1992; Wang & Witten, 1997) and two neural network models developed on different optimisation algorithms - Conjugate Gradient (CGNN: Hestenes & Stiefel, 1952) and Levenberg-Marquet (LMNN: Levenberg, 1944; Marquardt, 1963). The results are presented using residual scatterplots so that the exact nature of the each individual modelling solution can be determined: permitting outputs to be interpreted in terms of structures, symmetries, orientations, local features and outliers. The reported inspection and interpretation of plots is matched against a selection of traditional numerical modelling statistics that were computed on HydroTest (http://www.hydrotest.org.uk; Dawson et al., 2007). The reported closeness of earlier neurocomputing outputs to predicted values estimated using a counterpart multiple linear regression model is explained in detail.

  14. Revisiting multicomponent dark matter with new AMS-02 data

    NASA Astrophysics Data System (ADS)

    Geng, Chao-Qiang; Huang, Da; Lai, Chang

    2015-05-01

    We revisit the multicomponent leptonically decaying dark matter (DM) scenario to explain the possible electron/positron excesses with the recently updated AMS-02 data. We find that both the single- and two-component DM models can fit the positron fraction and e+/e- respective fluxes, in which the two-component ones provide better fits. However, for the single-component models, the recent AMS-02 data on the positron fraction limit the DM cutoff to be smaller than 1 TeV, which conflicts with the high-energy behavior of the AMS-02 total e++e- flux spectrum, while the two-component DM models do not possess such a problem. We also discuss the constraints from the Fermi-LAT measurement of the diffuse ? -ray spectrum. We show that the two-component DM models are consistent with the current DM lifetime bounds. In contrast, the best-fit DM lifetimes in the single-component models are actually excluded.

  15. Distant future of the Sun and Earth revisited

    E-print Network

    Schroder, Klaus-Peter

    2008-01-01

    We revisit the distant future of the Sun and the solar system, based on stellar models computed with a thoroughly tested evolution code. For the solar giant stages, mass-loss by the cool (but not dust-driven) wind is considered in detail. Using the new and well-calibrated mass-loss formula of Schroder & Cuntz (2005, 2007), we find that the mass lost by the Sun as an RGB giant (0.332 M_Sun, 7.59 Gy from now) potentially gives planet Earth a significant orbital expansion, inversely proportional to the remaining solar mass. According to these solar evolution models, the closest encounter of planet Earth with the solar cool giant photosphere will occur during the tip-RGB phase. During this critical episode, for each time-step of the evolution model, we consider the loss of orbital angular momentum suffered by planet Earth from tidal interaction with the giant Sun, as well as dynamical drag in the lower chromosphere. We find that planet Earth will not be able to escape engulfment, despite the positive effect o...

  16. Tyramine electropolymerization revisited by DFT and experimental study

    NASA Astrophysics Data System (ADS)

    Abrahão Odonírio, Jr.; da Hara Machado, Antonio Eduardo; Silva, Fernando Freitas Siqueira; Madurro, João Marcos; de Castro, Cláudio Márcio; Sonoda, Milton Taidi

    2013-04-01

    This work revisits tyramine electropolymerization on graphite electrodes through both theoretical and experimental investigation. Minimum energy structures of poly-tyramine oligomers were obtained with Monte Carlo Multiple Minimum conformational searches. Poly-tyramine octamer models were selected for electronic structure calculations based on the DFT hybrid functional B3LYP and the 6-31G(d,p) basis set, for the isolated, deprotonated and protonated forms with implicit solvation (IEFPCM). The theoretical vibrational and excitation (UV) spectra of the protonated octamer with IEFPCM implied solvation are in good agreement with available experimental data. The analysis of the excitation spectrum suggests expressive charge transfer from the electronic excitation of the polymer. The conformation of the model suggests that the preferred polymer structure has a helical backbone with ethylamine groups projected toward the bulk. This preferred conformation can be related to the low electrical conductivity of the polymer, sufficient in amplifying expected signals in electrochemical biosensors. Based on the analysis of the results, it is possible to propose a reaction mechanism which explains the greater yield obtained in cyclic voltammetry experiments conducted in acidic medium.

  17. Maturation of the human medial efferent reflex revisited

    PubMed Central

    Abdala, Carolina; Mishra, Srikanta; Garinis, Angela

    2013-01-01

    Past work applying otoacoustic emissions to gauge maturational status of the medial olivocochlear (MOC) reflex in human newborns has produced mixed results. The present study revisits the question while considering the dual nature of the 2f1 – f2 distortion product otoacoustic emission (DPOAE) and expanding measures of medial efferent function. Subjects included premature and term-born neonates, 6-month-old infants and young adults. The MOC reflex was elicited with contralateral acoustic stimulation (CAS) while shifts in amplitude and phase of the DPOAE, and its distortion and reflection components, were monitored. Overall, CAS-elicited reductions in DPOAE level did not differ among age groups. For all ages, the MOC reflex was strongest at frequencies below 1.5 kHz, and the reflection component of the DPOAE was most affected, showing maximally reduced amplitude and shallower phase slope when contralateral noise was presented. Results suggest that the MOC reflex likely reaches maturation prior to full-term birth. However, prematurely born neonates show markedly more episodes of CAS-induced DPOAE level enhancement. This may be due to more intrusive component mixing in this age group or disruptions in the formation of the MOC pathway or synapse in the most premature neonates. PMID:23363111

  18. Revisited LeRoy-Bernstein formula for weakly bound molecules

    NASA Astrophysics Data System (ADS)

    Pruvost, Laurence; Jelassi, Haikel; Viaris de Lesegno, Bruno

    2008-05-01

    The energy law giving the eigen energies of a -cn/Rn-cm/Rm potential (studied by LeRoy in 1980 [1]) is revisited. For n=3, m=6, an analytical law giving the density of states is deduced. In the context of weakly bound levels an energy law giving the vibrational number v versus the binding energy is given. We show that the well-known LeRoy-Bernstein formula [2] [3] has to be corrected by additional terms, with the first one varying as the binding energy , the second one as its square and the third as a power to 7/6. The use of such a law is discussed in the context of the photo-association spectroscopy of long range molecular levels. References [1] Theory of deviations from the limiting near-dissociation behaviour of diatomic molecules, R. J. LeRoy, J. Chem. Phys. 73, 6003 (1980). [2] Dissociation energy and long-range potential of diatomic molecules from vibrational spacings of higher levels, R. J. LeRoy and R. B. Bernstein, J. Chem. Phys. 52, 3869 (1970). [3] The Dissociation Energy of the Hydrogen Molecule Using Long-Range Forces, W. C. Stwalley, Chem. Phys. Lett. 6, 241,1970.

  19. Cherry Hill revisited: Background events and photovoltaic technology status

    NASA Astrophysics Data System (ADS)

    Herwig, Lloyd O.

    1999-03-01

    The workshop on "Photovoltaic Conversion of Solar Energy for Terrestrial Applications" was held in Cherry Hill, New Jersey, on October 23-25, 1973, under the sponsorship of the Research Applied to National Needs (RANN) program of the National Science Foundation (NSF). The workshop was organized in recognition of several pressing needs. These included (1) promoting dialog and exchange of information among participants in the field: (2) setting and documenting of consensus photovoltaic technology goals, plans, and budget resources for potential use in NSF/RANN program development: and, (3) coordinating the research, manufacturing, and commercialization communities. There were about 135 participants in the workshop, which was organized by NSF/RANN staff with major assistance from Jet Propulsion Laboratory (JPL) staff. Cherry Hill Revisited is presented in two parts: Part 1 by Dr. Lloyd O. Herwig, former Director of Advanced Solar Energy Research and Development Division in the NSF's Research Applied to National Needs Directorate; and, Part 2 by Dr. H. Richard Blieden, former Chief of the Photovoltaic Branch within the Advanced Solar Energy Research and Development Division. Part 1 is an overview of prior technology development and the background events surrounding the start-up and early years of the terrestrial solar technologies initiative leading up to the Cherry Hill Photovoltaic Workshop. Part 2 summarizes the conclusions and general outcome of the workshop.

  20. Rim curvature anomaly in thin conical sheets revisited

    E-print Network

    Jin W. Wang

    2011-12-01

    This paper revisits one of the puzzling behaviors in a developable cone (d-cone), the shape obtained by pushing a thin sheet into a circular container of radius $ R $ by a distance $ \\eta $ [E. Cerda, S. Chaieb, F. Melo, and L. Mahadevan, {\\sl Nature} {\\bf 401}, 46 (1999)]. The mean curvature was reported to vanish at the rim where the d-cone is supported [T. Liang and T. A. Witten, {\\sl Phys. Rev. E} {\\bf 73}, 046604 (2006)]. We investigate the ratio of the two principal curvatures versus sheet thickness $h$ over a wider dynamic range than was used previously, holding $ R $ and $ \\eta $ fixed. Instead of tending towards 1 as suggested by previous work, the ratio scales as $(h/R)^{1/3}$. Thus the mean curvature does not vanish for very thin sheets as previously claimed. Moreover, we find that the normalized rim profile of radial curvature in a d-cone is identical to that in a "c-cone" which is made by pushing a regular cone into a circular container. In both c-cones and d-cones, the ratio of the principal curvatures at the rim scales as $ (R/h)^{5/2}F/(YR^{2}) $, where $ F $ is the pushing force and $ Y $ is the Young's modulus. Scaling arguments and analytical solutions confirm the numerical results.

  1. Revisiting the Source Process of the 2007 Tocopilla, Chile Earthquake

    NASA Astrophysics Data System (ADS)

    Simons, M.; Minson, S. E.; Jolivet, R.; Jiang, J.; Beck, J. L.

    2013-12-01

    We revisit the 2007 Mw 7.7 Tocopilla, Chile earthquake to create a finite fault kinematic source model based on the current best practices in data analysis and inversion methods. The data used to constrain the source model include both static GPS offsets and 1 Hz kinematic GPS time series, as well as interferograms which have been reanalyzed to remove tropospheric effects which can be quite significant in this region. Our inversion methodology is a Bayesian approach that uses only physics-based constraints on the rupture evolution, and which utilizes models of both the observational noise and the errors in our forward model to obtain the ensemble of all plausible rupture models which satisfy both the data and our a priori assumptions. This approach allows us to better understand which parts of the rupture process are well-constrained and which are not, and thus to better understand how the 2007 Tocopilla, Chile earthquake rupture fits into the sequence of large earthquakes which have been mosaicking the northern Chile subduction zone.

  2. V838 Monocerotis revisited: Space phenomenon imitates art

    NASA Astrophysics Data System (ADS)

    2004-03-01

    V838 Monocerotis revisited: Space phenomenon imitates art hi-res Size hi-res: 558 Kb Credits: NASA, the Hubble Heritage Team (AURA/STScI) and ESA V838 Monocerotis revisited: Space phenomenon imitates art "Starry Night", Vincent van Gogh's famous painting, is renowned for its bold whorls of light sweeping across a raging night sky. Although this image of the heavens came only from the artist's restless imagination, a new picture from the NASA/ESA Hubble Space Telescope bears remarkable similarities to the van Gogh work, complete with never-before-seen spirals of dust swirling across trillions of kilometres of interstellar space. This image, obtained with the Advanced Camera for Surveys on February 8, 2004, is Hubble's latest view of an expanding halo of light around a distant star, named V838 Monocerotis (V838 Mon). The illumination of interstellar dust comes from the red supergiant star at the middle of the image, which gave off a flashbulb-like pulse of light two years ago. V838 Mon is located about 20,000 light-years away from Earth in the direction of the constellation Monoceros, placing the star at the outer edge of our Milky Way galaxy V838 Monocerotis revisited: Space phenomenon imitates art hi-res Size hi-res: 1989 kb Credits: NASA, the Hubble Heritage Team (AURA/STScI) and ESA V838 Monocerotis revisited: Space phenomenon imitates art "Starry Night", Vincent van Gogh's famous painting, is renowned for its bold whorls of light sweeping across a raging night sky. Although this image of the heavens came only from the artist's restless imagination, a new picture from the NASA/ESA Hubble Space Telescope bears remarkable similarities to the van Gogh work, complete with never-before-seen spirals of dust swirling across trillions of kilometres of interstellar space. This image, obtained with the Advanced Camera for Surveys on February 8, 2004, is Hubble's latest view of an expanding halo of light around a distant star, named V838 Monocerotis (V838 Mon). The illumination of interstellar dust comes from the red supergiant star at the middle of the image, which gave off a flashbulb-like pulse of light two years ago. V838 Mon is located about 20,000 light-years away from Earth in the direction of the constellation Monoceros, placing the star at the outer edge of our Milky Way galaxy This image, obtained with the Advanced Camera for Surveys on 8 February 2004, is Hubble's latest view of an expanding halo of light around a distant star, named V838 Monocerotis (V838 Mon). The illumination of interstellar dust comes from the red supergiant star at the middle of the image, which gave off a flashbulb-like pulse of light two years ago. V838 Mon is located about 20 000 light-years away from Earth in the direction of the constellation Monoceros, placing the star at the outer edge of our Milky Way galaxy. Called a 'light echo', the expanding illumination of a dusty cloud around the star has been revealing remarkable structures ever since the star suddenly brightened for several weeks in early 2002. Though Hubble has followed the light echo in several snapshots, this new image shows swirls or eddies in the dusty cloud for the first time. These eddies are probably caused by turbulence in the dust and gas around the star as they slowly expand away. The dust and gas were likely ejected from the star in a previous explosion, similar to the 2002 event, which occurred some tens of thousands of years ago. The surrounding dust remained invisible and unsuspected until suddenly illuminated by the brilliant explosion of the central star two years ago. The Hubble Space Telescope has imaged V838 Mon and its light echo several times since the star's outburst in January 2002, in order to follow the constantly changing appearance of the dust as the pulse of illumination continues to expand away from the star at the speed of light. During the outburst event, the normally faint star suddenly brightened, becoming 600 000 times more luminous than our Sun. It was thus one of the most luminous stars in the entire Milky Way, until it faded

  3. On kaonic hydrogen. Phenomenological quantum field theoretic model revisited

    NASA Astrophysics Data System (ADS)

    Ivanov, A. N.; Cargnelli, M.; Faber, M.; Fuhrmann, H.; Ivanova, V. A.; Marton, J.; Troitskaya, N. I.; Zmeskal, J.

    2005-09-01

    We argue that due to isospin and U-spin invariance of strong low-energy interactions the S-wave scattering lengths a 0 0 and a 1 0 of ¯N scattering with isospin I = 0 and I = 1 satisfy the low-energy theorem a 0 0 +3a 1 0 = 0 valid to leading order in chiral expansion. In the model of strong low-energy ¯N interactions at threshold (Eur. Phys. J. A 21, 11 (2004)) we revisit the contribution of the ?(1750) resonance, which does not saturate the low-energy theorem a 0 0 +3a 1 0 = 0, and replace it by the baryon background with properties of an SU(3) octet. We calculate the S-wave scattering amplitudes of K-N and K-d scattering at threshold. We calculate the energy level displacements of the ground states of kaonic hydrogen and deuterium. The result obtained for kaonic hydrogen agrees well with recent experimental data by the DEAR Collaboration. We analyse the cross-sections for elastic and inelastic K-p scattering for laboratory momenta 70MeV/c < p K < 150MeV/c of the incident K--meson. The theoretical results agree with the available experimental data within two standard deviations.

  4. Revisiting the quantum Szilard engine with fully quantum considerations

    SciTech Connect

    Li, Hai [School of Physics, Beijing Institute of Technology, Beijing 100081 (China) [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); School of Information and Electronics Engineering, Shandong Institute of Business and Technology, Yantai 264000 (China); Zou, Jian, E-mail: zoujian@bit.edu.cn [School of Physics, Beijing Institute of Technology, Beijing 100081 (China)] [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Li, Jun-Gang; Shao, Bin [School of Physics, Beijing Institute of Technology, Beijing 100081 (China)] [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Wu, Lian-Ao [Department of Theoretical Physics and History of Science, The Basque Country University (EHU/UPV), P.O. Box 644, ES-48080 Bilbao (Spain) [Department of Theoretical Physics and History of Science, The Basque Country University (EHU/UPV), P.O. Box 644, ES-48080 Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, ES-48011 Bilbao (Spain)

    2012-12-15

    By considering level shifting during the insertion process we revisit the quantum Szilard engine (QSZE) with fully quantum consideration. We derive the general expressions of the heat absorbed from thermal bath and the total work done to the environment by the system in a cycle with two different cyclic strategies. We find that only the quantum information contributes to the absorbed heat, and the classical information acts like a feedback controller and has no direct effect on the absorbed heat. This is the first demonstration of the different effects of quantum information and classical information for extracting heat from the bath in the QSZE. Moreover, when the well width L{yields}{infinity} or the temperature of the bath T{yields}{infinity} the QSZE reduces to the classical Szilard engine (CSZE), and the total work satisfies the relation W{sub tot}=k{sub B}Tln2 as obtained by Sang Wook Kim et al. [S.W. Kim, T. Sagawa, S. De Liberato, M. Ueda, Phys. Rev. Lett. 106 (2011) 070401] for one particle case. - Highlights: Black-Right-Pointing-Pointer For the first time analyze the QSZE by considering energy level shifts. Black-Right-Pointing-Pointer Find different roles played by classical and quantum information in the QSZE. Black-Right-Pointing-Pointer The amount of work extracted depends on the cyclic strategies of the QSZE. Black-Right-Pointing-Pointer Verify that the QSZE will reduce to the CSZE in the classical limits.

  5. Revisiting the sadomasochistic marriage: the paranoid-masochistic relationship.

    PubMed

    Mendelsohn, Robert

    2014-10-01

    The sadomasochistic marriage is thought to be very resistant to change because of the object relations of each member of a couple as well as the sadomasochistic dynamics within the couple. However, the picture may be even more complex because there are times when a psychoanalytic therapist may mistakenly believe he or she is treating a sadomasochistic couple when the couple actually is functioning in a paranoid-masochistic relationship. The present paper reexamines the sadomasochistic marriage by revisiting the work of Nydes, who formulated the concept of paranoid-masochism in individuals and contrasted it to the more commonly understood sadomasochist dynamic. This paper applies his concepts to couples: Just as we understand some couples to be sadomasochistic, other couples may have paranoid-masochistic dynamics, which may require a somewhat different kind of understanding and technical approach than the dynamics of a sadomasochistic couple at the same level of object relations. This may be the reason why some marriages, misdiagnosed as sadomasochistic, are even more difficult to treat than others, because they might be more accurately treated as paranoid-masochistic. PMID:25247285

  6. Impulsive Spot Heating and Thermal Explosion of Interstellar Grains Revisited

    NASA Astrophysics Data System (ADS)

    Ivlev, A. V.; Röcker, T. B.; Vasyunin, A.; Caselli, P.

    2015-05-01

    The problem of the impulsive heating of dust grains in cold, dense interstellar clouds is revisited theoretically with the aim of better understanding the leading mechanisms of the explosive desorption of icy mantles. We rigorously show that if the heating of a reactive medium occurs within a sufficiently localized spot (e.g., the heating of mantles by cosmic rays (CRs)), then the subsequent thermal evolution is characterized by a single dimensionless number ?. This number identifies a bifurcation between two distinct regimes: when ? exceeds a critical value (threshold), the heat equation exhibits the explosive solution, i.e., the thermal (chemical) explosion is triggered. Otherwise, thermal diffusion causes the deposited heat to spread over the entire grain—this regime is commonly known as whole-grain heating. The theory allows us to find a critical combination of physical parameters that govern the explosion of icy mantles due to impulsive spot heating. In particular, our calculations suggest that heavy CR species (e.g., iron ions) colliding with dust are able to trigger the explosion. Based on recently calculated local CR spectra, we estimate the expected rate of explosive desorption. The efficiency of the desorption, which in principle affects all solid species independent of their binding energy, is shown to be comparable to other CR desorption mechanisms typically considered in the literature. Also, the theory allows us to estimate the maximum abundances of reactive species that may be stored in the mantles, which provides important constraints on the available astrochemical models.

  7. Automated Guidance for Thermodynamics Essays: Critiquing Versus Revisiting

    NASA Astrophysics Data System (ADS)

    Donnelly, Dermot F.; Vitale, Jonathan M.; Linn, Marcia C.

    2015-05-01

    Middle school students struggle to explain thermodynamics concepts. In this study, to help students succeed, we use a natural language processing program to analyze their essays explaining the aspects of thermodynamics and provide guidance based on the automated score. The 346 sixth-grade students were assigned to either the critique condition where they criticized an explanation or the revisit condition where they reviewed visualizations. Within each condition, the student was assigned one of two types of tailored guidance based on the sophistication of their original essay. Both forms of guidance led to significant improvement in student understanding on the posttest. Guidance was more effective for students with low prior knowledge than for those with high prior knowledge (consistent with regression toward the mean). However, analysis of student responses to the guidance illustrates the value of aligning guidance with prior knowledge. All students were required to revise their essay as an embedded assessment. While effective, teachers involved in this study reported that revising is resisted by students and does not align with typical, vocabulary-focused classroom writing activities.

  8. Concluding Messages: The Toolbox Revisited--Paths to Degree Completion from High School through College

    ERIC Educational Resources Information Center

    Adelman, Clifford

    2005-01-01

    Compared to its predecessor, "Answers in the Tool Box," the preponderance of the "Toolbox Revisited" story has been on the postsecondary side of the matriculation line. Implicitly, it calls on colleges, universities, and community colleges to be a great deal more interventionary in the precollegiate world, to be more self-reflective about the…

  9. DISAVOWAL AND THE CULTURE OF DEADENING: Revisiting Stanley Kubrick's Eyes Wide Shut

    Microsoft Academic Search

    Beatriz E. Dujovne

    2004-01-01

    Using psychoanalytic constructs of necrophilia and disavowal, the author revisits Stanley Kubrick's (1999) film Eyes Wide Shut from a cultural perspective. Disavowal, the failure to fully grasp the meaning of what is perceived, may help explain why viewers missed disturbing necrophilia meanings in this film. Various faces of necrophilia (as orientations against life, neurotic fantasies, and true perversions) are discussed.

  10. Bearing capacity of spatially random soil: the undrained clay Prandtl problem revisited

    E-print Network

    Bearing capacity of spatially random soil: the undrained clay Prandtl problem revisited D. V, an investigation has been performed into the bearing capacity of undrained clays with spatially vary- ing shear- tion of the soil's undrained shear strength impact on the statistics of the bearing capacity

  11. The Hypervolume Indicator Revisited: On the Design of Pareto-compliant Indicators Via

    E-print Network

    Zitzler, Eckart

    The Hypervolume Indicator Revisited: On the Design of Pareto-compliant Indicators Via Weighted,brockho,thiele}@tik.ee.ethz.ch http://www.tik.ee.ethz.ch/sop/ Abstract. The design of quality measures for approximations be obtained. This paper proposes a methodology for quality measure design based on the hypervolume measure

  12. The Amorphous Fixation Measure Revisited: with Applications to Autism Frederick Shic (frederick.shic@yale.edu)

    E-print Network

    Scassellati, Brian

    The Amorphous Fixation Measure Revisited: with Applications to Autism Frederick Shic (frederick interact with quantitative eye-tracking measures. In this study we show that by manipulating aspects duration, a measure traditionally associated with cognitive load. However, by linearly mapping mean

  13. Memory Organization in MultiChannel Optical Networks: NUMA and COMA Revisited

    E-print Network

    Bennett, John K.

    Memory Organization in Multi­Channel Optical Networks: NUMA and COMA Revisited YanYang Xiao access (COMA) architec­ ture. This paper examines the choice of memory system architecture­NUMA and COMA memory architectures in a multi­channel optical network multiprocessor system. Seven well

  14. The Random Oracle Methodology, Revisited \\Lambda Ran Canetti y Oded Goldreich z Shai Halevi x

    E-print Network

    Goldreich, Oded

    The Random Oracle Methodology, Revisited \\Lambda Ran Canetti y Oded Goldreich z Shai Halevi x of cryptographic schemes in the Random Oracle Model, and the security of the schemes that result from implementing the random oracle by so called ``cryptographic hash functions''. The main result of this paper is a negative

  15. Contribution of thermal expansion to present-day sea level rise revisited

    Microsoft Academic Search

    A. Lombard; A. Cazenave; C. Cabanes; R. Nerem

    2004-01-01

    In this study, we revisit the contribution of thermal expansion to sea level rise of the last fifty years, comparing two global ocean temperature data sets from Levitus et al. (2000) and Ishii et al. (2003). We apply the method developed by Cabanes et al. (2001) which consists of comparing sea level records of historical tide gauges with thermosteric sea

  16. The Toolbox Revisited: Paths to Degree Completion From High School Through College

    ERIC Educational Resources Information Center

    Adelman, Clifford

    2006-01-01

    The Toolbox Revisited is a data essay that follows a nationally representative cohort of students from high school into postsecondary education, and asks what aspects of their formal schooling contribute to completing a bachelor's degree by their mid-20s. The universe of students is confined to those who attended a four-year college at any time,…

  17. Revisiting Bug Triage and Resolution Practices Olga Baysal, Reid Holmes, and Michael W. Godfrey

    E-print Network

    Godfrey, Michael W.

    ]. We would like to revisit bug reporting and fixing practices to find out if bug tracking systems have. However, little qualitative research has been done on the actual use of bug tracking systems, bug triage and fixing process, as well as bug reassignments and reopens. We will study interviews conducted with Mozilla

  18. THE BOY WHO CRIED WOLF REVISITED: THE IMPACT OF FALSE ALARM INTOLERANCE ON

    E-print Network

    Stevenson, Paul

    THE BOY WHO CRIED WOLF REVISITED: THE IMPACT OF FALSE ALARM INTOLERANCE ON COST-LOSS SCENARIOS M's fable about the "The Boy who Cried Wolf", a young shepherd boy guarding the village flock cries. This event is repeated two or three times before a wolf actually does show up on the hillside. The boy cries

  19. Spectral structure of laser light scattering revisited: bandwidths of nonresonant scattering lidars

    E-print Network

    Spectral structure of laser light scattering revisited: bandwidths of nonresonant scattering lidars of the procedure of laser light scattering has led to a number of powerful lidar instruments for remote sensing in Rayleigh scattered light: a Doppler-broadened central peak, called the Cabannes line, and sidebands

  20. Revisiting the method of cumulants for the analysis of dynamic light-scattering data

    E-print Network

    Revisiting the method of cumulants for the analysis of dynamic light-scattering data Barbara J. Frisken The method of cumulants is a standard technique used to analyze dynamic light-scattering data mea of the scattered light, can be described in terms of a distribution of decay rates. The method of cumulants

  1. The Anatomy and Physiology of the Grid Revisited Chris A. Mattmann1,2

    E-print Network

    Mattmann, Chris

    related such technologies. The first, OODT [7], is a data grid platform currently in use at NASA California Institute of Technology Pasadena, CA 91109, USA mattmann@jpl.nasa.gov Abstract A domain software systems within a given appli- cation domain. In this paper, we revisit the widely cited DSSA

  2. How to Compute the Area of a Triangle: a Formal Revisit with a tighter error bound

    E-print Network

    Paris-Sud XI, Université de

    1 How to Compute the Area of a Triangle: a Formal Revisit with a tighter error bound Sylvie Boldo for the computation of the area of a triangle. When the triangle is needle-like, the common formula has a very poor--floating-point arithmetic, formal proof, Coq, triangle, underflow ! 1 INTRODUCTION Floating-point (FP) arithmetic is seen

  3. Climate trends and glacier retreat in the Cordillera Blanca, Peru, revisited S. Schauwecker a,d,

    E-print Network

    Vuille, Mathias

    Climate trends and glacier retreat in the Cordillera Blanca, Peru, revisited S. Schauwecker aH, Technoparkstr. 1, 8005 Zurich, Switzerland b SENAMHI, av. Las Palmas s/n, Lima, Peru c ANA, UGRH, Huaraz, Peru d Huascarán, Huaraz, Peru f Institute of Geography, University of Berne, Hallerstr. 12, 3012 Berne

  4. Re-Visit to the School Nurse and Adolescents' Medicine Use

    ERIC Educational Resources Information Center

    Borup, Ina K.; Andersen, Anette; Holstein, Bjorn E.

    2011-01-01

    Objective: To examine if students who re-visit the school nurse use medicines differently than other students when exposed to aches and psychological problems. Methods: The study includes all 11-, 13- and 15-year-old students from a random sample of schools in Denmark, response rate 87 per cent, n = 5,205. The data collection followed the…

  5. Revisiting TCP Congestion Control using Delay David A. Hayes and Grenville Armitage

    E-print Network

    Armitage, Grenville

    Revisiting TCP Congestion Control using Delay Gradients David A. Hayes and Grenville Armitage unrelated to congestion. Delay-based TCP CC algorithms infer congestion from delay measurements and tend of congestion. We propose and implement a delay-gradient CC algorithm (CDG) that no longer requires knowledge

  6. Kosovo Revisited: Humanitarian Intervention on the Fault Lines of International Law

    Microsoft Academic Search

    Nigel S. Rodley; Ba?ak Çal?

    2007-01-01

    The asserted doctrine of unilateral humanitarian intervention has given rise to considerable debate in international law. This article revisits the use of force in Kosovo to critically appraise this debate. The arguments for and against the doctrine are schematically compared and contrasted. Their differences are methodological, but underlying factors are relevant. These may include a conflict of values (notably, sovereignty

  7. Cascade Encryption Revisited Peter Gazi 1,2 and Ueli Maurer 1

    E-print Network

    Cascade Encryption Revisited Peter GaŸzi 1,2 and Ueli Maurer 1 1 ETH ZË?urich, Switzerland encryption is an impor­ tant and well­studied problem in theoretical cryptography with practical implications. It is well­known that double encryption improves the secu­ rity only marginally, leaving triple encryption

  8. The Peter Effect Revisited: Reading Habits and Attitudes of College Students

    ERIC Educational Resources Information Center

    Applegate, Anthony J.; Applegate, Mary DeKonty; Mercantini, Martha A.; McGeehan, Catherine M.; Cobb, Jeanne B.; DeBoy, Joanne R.; Modla, Virginia B.; Lewinski, Kimberly E.

    2014-01-01

    Certainly a primary goal of literacy education is the creation of avid, enthusiastic, and highly motivated readers. However, in this article revisiting the Peter Effect (Applegate & Applegate, 2004), researchers surveyed more than 1,000 college sophomores and found strikingly low levels of enthusiasm for reading. Only 46.6% of surveyed…

  9. Revisiting frequency and storage in morphological processing* Constantine Lignos and Kyle Gorman

    E-print Network

    Plotkin, Joshua B.

    ). The atoms of lexical memory that are implicated in lexical processing experiments--be they whole words subjects judge whether a written or spoken stimulus is a real word and processing complexity is measuredRevisiting frequency and storage in morphological processing* Constantine Lignos and Kyle Gorman

  10. Revisiting the Closed Loop Response of PWM Converters Controlled by Voltage Feedback

    E-print Network

    Revisiting the Closed Loop Response of PWM Converters Controlled by Voltage Feedback Mor Mordechai response of a PID controlled system is incomplete due to the contribution of previously neglected factors With the rising interest in digital power management, the use of voltage feedback control in PWM DC-DC converters

  11. Revisiting the Training of Logic Models of Protein Signaling Networks with a Formal

    E-print Network

    Paris-Sud XI, Université de

    Revisiting the Training of Logic Models of Protein Signaling Networks with a Formal Approach based Science, Springer Abstract. A fundamental question in systems biology is the construc- tion and training to data of mathematical models. Logic formalisms have become very popular to model signaling networks

  12. Revisiting the Training of Logic Models of Protein Signaling Networks with a Formal

    E-print Network

    in systems biology is the construc- tion and training to data of mathematical models. Logic formalisms haveRevisiting the Training of Logic Models of Protein Signaling Networks with a Formal Approach based encompassing hundreds of proteins. An approach to train (Boolean) logic models to high-throughput phospho

  13. REVISITING THE VARIANCE-BASED SELECTION MODEL OF DIPLOID DRONE PRODUCTION FOR MULTIPLE MATING IN

    E-print Network

    Saidak, Filip

    REVISITING THE VARIANCE-BASED SELECTION MODEL OF DIPLOID DRONE PRODUCTION FOR MULTIPLE MATING with comprehensive theoretical analysis lacking behind. We report on the mathematical analysis of the diploid drone mating does not reduce the average value of diploid drone production but reduces its variance. We combine

  14. Shake-Your-Head: Revisiting Walking-In-Place for Desktop Virtual Reality Leo Terziman

    E-print Network

    Paris-Sud XI, Université de

    Shake-Your-Head: Revisiting Walking-In-Place for Desktop Virtual Reality L´eo Terziman INSA / INRIA it notably to the context of desktop Virtual Reality. With our novel "Shake-Your-Head" technique, the user.7 [Computer Graphics]: Three- Dimensional Graphics and Realism--Virtual Reality Keywords: Walking, Walking

  15. LINEAR TIME SPLIT DECOMPOSITION REVISITED PIERRE CHARBIT, FABIEN DE MONTGOLFIER, AND MATHIEU RAFFINOT

    E-print Network

    Paris-Sud XI, Université de

    LINEAR TIME SPLIT DECOMPOSITION REVISITED PIERRE CHARBIT, FABIEN DE MONTGOLFIER, AND MATHIEU RAFFINOT Abstract. Given a family F of subsets of a ground set V , its orthogonal is defined to be the fam of designing a simple linear time algorithm for undirected graph split (also known as 1-join) decomposition

  16. The must preorder revisited an algebraic theory for web services contracts

    E-print Network

    Torino, Università di

    The must preorder revisited ­ an algebraic theory for web services contracts ­ Cosimo Laneve1 and Technology Institute, University of Urbino Abstract. We define a language for Web services contracts in terms of their corresponding contracts. The induced contract preorder turns out to be valuable

  17. Revisiting Marshall's Agglomeration Economies: Technological Relatedness and the Evolution of the Sheffield Metals Cluster

    Microsoft Academic Search

    Antony Potter; H. Doug Watts

    2012-01-01

    Potter A. and Watts H. D. Revisiting Marshall's agglomeration economies: technological relatedness and the evolution of the Sheffield metals cluster, Regional Studies. According to Alfred Marshall, firms receive increasing returns from a trinity of agglomeration economies: a local pool of skilled labour, local supplier linkages and local knowledge spillovers. This article re-examines the mechanisms underlying Marshall's agglomeration economies in the

  18. ccsd-00008676,version1-13Sep2005 Quadratic Quantum Hamiltonians revisited

    E-print Network

    Boyer, Edmond

    is a survey concerning exact useful formulas for time dependent Schr¨odinger equations with quadratic quadratic Schr¨odinger equation and Gaus- sian Coherent States. It is well known and clearccsd-00008676,version1-13Sep2005 Quadratic Quantum Hamiltonians revisited Monique Combescure IPNL

  19. Boundary-trapped, inhalant siphon, and drain flows: Pipe entry revisited numerically

    E-print Network

    Jumars, Pete

    Boundary-trapped, inhalant siphon, and drain flows: Pipe entry revisited numerically Peter A length, siphon flows, pipe entry, inhalant siphon, bifurcation, Coanda effect Introduction A nearby--produce inhalant and exhalant flows, largely in suspension feeding and respi- ration (Wildish and Kristmanson 1997

  20. Measurement Program Success Factors Revisited Frank Niessink and Hans van Vliet

    E-print Network

    van Vliet, Hans

    Measurement Program Success Factors Revisited Frank Niessink and Hans van Vliet Division.vu.nl Abstract Success factors for measurement programs as identified in the literature typically focus on the `internals' of the measurement program: incremental implementation, support from manage- ment, a well

  1. Towards a practical approach to responsible innovation in finance: New Product Committees revisited

    E-print Network

    Paris-Sud XI, Université de

    with a series of policy implications and recommendations. Keywords: Financial Innovation, New Product Committees to develop a more responsible way to handle financial innovation (Crouhy et al., 2008). But measuresTowards a practical approach to responsible innovation in finance: New Product Committees revisited

  2. TCP Vegas Revisited U. Hengartner 1 , J. Bolliger 1 and Th. Gross 1;2

    E-print Network

    Hengartner, Urs

    TCP Vegas Revisited U. Hengartner 1 , J. Bolliger 1 and Th. Gross 1;2 1 Departement Informatik 2 Abstract--- The innovative techniques of TCP Vegas have been the sub­ ject of much debate in recent years. Several studies have reported that TCP Vegas provides better performance than TCP Reno. However, the ques

  3. TCP Vegas Revisited U. Hengartner1, J. Bolliger1 and Th. Gross1 2

    E-print Network

    Hengartner, Urs

    TCP Vegas Revisited U. Hengartner1, J. Bolliger1 and Th. Gross1 2 1 Departement Informatik 2 School--The innovative techniques of TCP Vegas have been the sub- ject of much debate in recent years. Several studies have reported that TCP Vegas provides better performance than TCP Reno. However, the ques- tion which

  4. Boserup versus Malthus revisited: Evolution of farming systems in northern Côte d’Ivoire

    Microsoft Academic Search

    Matty Demont; Philippe Jouve; Johan Stessens; Eric Tollens

    2007-01-01

    In the literature on the evolution of farming systems in Sub-Saharan Africa, the theses of Malthus and Boserup seem to offer contrasting views on rural development. The purpose of the present study is to revisit these theses and empirically examine them through a case study of northern Côte d’Ivoire. We surveyed a sample of farms in four villages in the

  5. Revisiting the Metaphor of the Island: Challenging "World Culture" from an Island Misunderstood

    ERIC Educational Resources Information Center

    Rappleye, Jeremy

    2015-01-01

    This article revisits the newly "discovered" island that world culture theorists have repeatedly utilised to explain their theoretical stance, conceptual preferences and methodological approach. Yet, it seeks to (re)connect world culture with the real world by replacing their imagined atoll with a real one--the island-nation of Japan. In…

  6. Acoustic scattering from a thermally driven buoyant plume revisited John Oeschger

    E-print Network

    Goodman, Louis

    Acoustic scattering from a thermally driven buoyant plume revisited John Oeschger Coastal Systems and L. Goodman, JASA, Acoustic scattering 1 #12;Far-field weak scattering theory is applied to the case of high frequency broadbandwidth acoustic scattering from a thermally generated buoyant plume

  7. EPR before EPR: A 1930 Einstein-Bohr thought Experiment Revisited

    ERIC Educational Resources Information Center

    Nikolic, Hrvoje

    2012-01-01

    In 1930, Einstein argued against the consistency of the time-energy uncertainty relation by discussing a thought experiment involving a measurement of the mass of the box which emitted a photon. Bohr seemingly prevailed over Einstein by arguing that Einstein's own general theory of relativity saves the consistency of quantum mechanics. We revisit…

  8. Weighted Geometric Set Cover Problems Revisited # Sariel HarPeled + Mira Lee #

    E-print Network

    Har-Peled, Sariel

    Weighted Geometric Set Cover Problems Revisited # Sariel Har­Peled + Mira Lee # February 1, 2012 Abstract We study several set cover problems in low dimensional geometric settings. Specif­ ically, we describe a PTAS for the problem of computing a minimum cover of given points by a set of weighted fat

  9. The Origin and Evolution of DQ White Dwarfs: The Carbon Pollution Problem Revisited

    Microsoft Academic Search

    P. Brassard; G. Fontaine; P. Dufour; P. Bergeron

    2007-01-01

    We summarize some of the results we obtained using detailed evolutionary calculations that take into account diffusion and mass loss to revisit the question of the carbon pollution observed in the atmospheres of DQ white dwarfs and in some DB stars. Our basic premise is that gravitational settling of C and O is slowed down by dying residual winds in

  10. Proof of Plaintext Knowledge for Code-Based Public-Key Encryption Revisited

    E-print Network

    Morozov, Kirill

    in security arguments of proof of plaintext knowledge (PPK) and verifiable encryption for the McEliece public consider zero-knowledge (ZK) proofs which means that PPK does not leak any information on m to VProof of Plaintext Knowledge for Code-Based Public-Key Encryption Revisited Rong Hu , Kirill

  11. Modular Ontology Languages Revisited Bernardo Cuenca-Grau and Oliver Kutz

    E-print Network

    Grau, Bernardo Cuenca

    Modular Ontology Languages Revisited Bernardo Cuenca-Grau and Oliver Kutz The University, ontology integration, and related topics; in particular, we focus on E-connections, Distributed Description the modeler in ontology inte- gration and knowledge reuse tasks, such as locality of an ontology

  12. The CH4 structure in Titan's upper atmosphere revisited R. V. Yelle,2

    E-print Network

    Yelle, Roger V.

    The CH4 structure in Titan's upper atmosphere revisited J. Cui,1 R. V. Yelle,2 D. F. Strobel,3 I. C the CH4 structure in Titan's upper atmosphere combining the Cassini Ion Neutral Mass Spectrometer (INMS on Titan. Ignoring ionospheric chemistry, the optimal CH4 loss rate is $3 Â 1027 sÀ1 or 80 kg sÀ1

  13. DIVERGENCE TIMES AND THE EVOLUTION OF EPIPHYTISM IN FILMY FERNS (HYMENOPHYLLACEAE) REVISITED

    E-print Network

    Schuettpelz, Eric

    DIVERGENCE TIMES AND THE EVOLUTION OF EPIPHYTISM IN FILMY FERNS (HYMENOPHYLLACEAE) REVISITED Sabine and Science, 4-1-1 Amakubo, Tsukuba 305-0005, Japan Although the phylogeny of the filmy fern family to examine the diversification of filmy ferns and the evolution of their ecology within a temporal context

  14. Revisiting First-Year College Students' Mattering: Social Support, Academic Stress, and the Mattering Experience

    ERIC Educational Resources Information Center

    Rayle, Andrea Dixon; Chung, Kuo-Yi

    2008-01-01

    In this study, Nancy Schlossberg's (1989) theory of college students' mattering to others was revisited. Mattering is the experience of others depending on us, being interested in us, and being concerned with our fate. The relationships of gender, mattering to college friends and the college environment, and friend and family social support with…

  15. Short Signatures from Diffie-Hellman, Revisited: Sublinear Public Key, CMA Security, and Tighter Reduction

    E-print Network

    Short Signatures from Diffie-Hellman, Revisited: Sublinear Public Key, CMA Security, and Tighter UnForgeability against Chosen Message Attack (EUF-CMA) with nearly optimal reduction. However's approach could prove only a rather weak security, called the bounded CMA security, and B¨ohl et al

  16. HOW TO BECOME A SUCCESFUL LANGUAGE LEARNER LEARNER AUTONOMY, STYLES AND STRATEGIES REVISITED

    Microsoft Academic Search

    Inez De Florio-Hansen

    The aim of the present paper is to revisit the construct of learner autonomy and its interrelatedness with learning styles and learner strategies in the context of foreign language learning. In a brief overview the role of learning and teaching languages, especially English, is considered in the context of globalization. In the following, autonomy is defined and described drawing on

  17. Decoding information in the honeybee dance: revisiting the tactile hypothesis Mariana Gil*, Rodrigo J. De Marco

    E-print Network

    Menzel, Randolf - Institut für Biologie

    Decoding information in the honeybee dance: revisiting the tactile hypothesis Mariana Gil*, Rodrigo-00526 Keywords: Apis mellifera dance communication honeybee mechanosensory input tactile stimulus waggle dance The waggle dance of honeybees, Apis mellifera, is one of the most remarkable communication systems

  18. Increasing the Degrees of Freedom in Future Group Randomized Trials: The "df*" Method Revisited

    ERIC Educational Resources Information Center

    Murray, David M.; Blitstein, Jonathan L.; Hannan, Peter J.; Shadish, William R.

    2012-01-01

    Background: This article revisits an article published in Evaluation Review in 2005 on sample size estimation and power analysis for group-randomized trials. With help from a careful reader, we learned of an important error in the spreadsheet used to perform the calculations and generate the results presented in that article. As we studied the…

  19. Feature Interaction Faults Revisited: An Exploratory Study Brady J. Garvin and Myra B. Cohen

    E-print Network

    Cohen, Myra

    Feature Interaction Faults Revisited: An Exploratory Study Brady J. Garvin and Myra B. Cohen software, there has been little work that examines what constitutes such a fault at the code level. In consequence, we do not know how prevalent real interaction faults are in practice, what a typical interaction

  20. OptimalSupply of a Depletable Resource with a Backstop Technology: Heal's Theorem Revisited

    E-print Network

    Oren, Shmuel S.

    and of production of the backstop technology. We then present two examples that show how this method can be usedOptimalSupply of a Depletable Resource with a Backstop Technology: Heal's Theorem Revisited SHMUEL, and if a backstop technology exists, the user cost of the depletable resource declines to zero at the date

  1. Making Productive Use of Four Models of School English: A Case Study Revisited

    ERIC Educational Resources Information Center

    Macken-Horarik, Mary

    2014-01-01

    At a time when political leaders and media pundits seek to narrow the English curriculum and reduce its knowledge structure to the "basics," it is helpful to revisit the potential of different approaches to learning in English that have evolved over time. In this paper I reflect on the semantic features of personal growth, cultural…

  2. The Hare and the Tortoise Revisited : The New Politics of Consumer and Environmental Regulation in Europe

    E-print Network

    Kammen, Daniel M.

    in Europe David Vogel A paper submitted to the British Journal of Political Science Revised August, 20021 The Hare and the Tortoise Revisited : The New Politics of Consumer and Environmental Regulation. At the same time, regulatory politics and policies continue to exhibit substantial cross-national variation

  3. The Concept of Experience by John Dewey Revisited: Conceiving, Feeling and "Enliving"

    ERIC Educational Resources Information Center

    Hohr, Hansjorg

    2013-01-01

    "The concept of experience by John Dewey revisited: conceiving, feeling and 'enliving'." Dewey takes a few steps towards a differentiation of the concept of experience, such as the distinction between primary and secondary experience, or between ordinary (partial, raw, primitive) experience and complete, aesthetic experience. However, he does not…

  4. Structuralism's Relevance in a Post-Structural Era: Re-Visiting Research on Multicultural Curricular Studies

    ERIC Educational Resources Information Center

    Shim, Jenna Min

    2011-01-01

    At the current historical juncture in which differences and inequalities are surfacing greater than ever in the world, societies, and schools, the main goal of this essay is to revisit the aspects of structuralism that can potentially contribute productively to understanding the invisible structures and forces that everyone carries (mostly…

  5. Atmospheric Entry Heating of Micrometeorites Revisited: Higher Temperatures and Potential Biases

    NASA Technical Reports Server (NTRS)

    Love, S.; Alexander, C. M. OD.

    2001-01-01

    The atmospheric entry heating model of Love and Brownlee appears to have overestimated evaporation rates by as much as two orders of magnitude. Here we revisit the issue of atmospheric entry heating, using a revised prescription for evaporation rates. Additional information is contained in the original extended abstract.

  6. Revisiting the use of 15 N in meso-scale studies of marine food webs by

    E-print Network

    Paris-Sud XI, Université de

    Revisiting the use of 15 N in meso-scale studies of marine food webs by considering spatio using 13 C and especially 15 N values in open ecosystems with complex food webs, using the Bay of Biscay of a consumer directly reflects that of its food. Nevertheless, few studies have attempted to define the limits

  7. The Markov approximation revisited: Inconsistency of the standard quantum Brownian motion model

    E-print Network

    A. Rocco; P. Grigolini

    1999-09-16

    We revisit the Markov approximation necessary to derive ordinary Brownian motion from a model widely adopted in literature for this specific purpose. We show that this leads to internal inconsistencies, thereby implying that further search for a more satisfactory model is required.

  8. The Native Bee Fauna of Carlinville, Illinois, Revisited After 75 Years: a Case for Persistence

    Microsoft Academic Search

    John C. Marlin; Wallace E. LaBerge

    2009-01-01

    As a follow-up to the observations of Charles Robertson from 1884 to 1916, we revisited the Carlinville, Illinois, area between 18 August 1970 and 13 September1972 to sample and identify bee species (Hymenoptera: Apoidea). We concentrated on collecting nonparasitic bees (and excluded Apis and Bombus) visiting 24 plant species that bloomed at various times of the year, and upon which

  9. ON FREYD'S GENERATING HYPOTHESIS Abstract. We revisit Freyd's generating hypothesis in stable homotopy the-

    E-print Network

    Hovey, Mark

    ON FREYD'S GENERATING HYPOTHESIS MARK HOVEY Abstract. We revisit Freyd's generating hypothesis in stable homotopy the- ory. We derive new equivalent forms of the generating hypothesis and some new- quence of the generating hypothesis, that the homotopy of a finite spectrum that is not a wedge

  10. Critical Language Awareness in the United States: Revisiting Issues and Revising Pedagogies in a Resegregated Society

    ERIC Educational Resources Information Center

    Alim, H. Samy

    2005-01-01

    As scholars examine the successes and failures of more than 50 years of court-ordered desegregation since "Brown v. Board of Education of Topeka, Kansas," and 25 years of language education of Black youth since "Martin Luther King Elementary School Children v. Ann Arbor School District Board," this article revisits the key issues involved in those…

  11. 54 IEEE MICROWAVE AND GUIDED WAVE LETTERS, VOL. 9, NO. 2, FEBRUARY 1999 FDTD Dispersion Revisited

    E-print Network

    Schneider, John B.

    54 IEEE MICROWAVE AND GUIDED WAVE LETTERS, VOL. 9, NO. 2, FEBRUARY 1999 FDTD Dispersion Revisited-domain (FDTD) grid was derived several years ago. In this letter a different interpretation is given phase velocity are shown to propagate, albeit with exponential decay. Index Terms--FDTD methods. I

  12. Revisiting the Local Scaling Hypothesis in Stably Stratified Atmospheric Boundary Layer Turbulence: an Integration

    E-print Network

    Foufoula-Georgiou, Efi

    Revisiting the Local Scaling Hypothesis in Stably Stratified Atmospheric Boundary Layer Turbulence decades ago, describes the turbulence structure of stable boundary layers in a very succinct way this controversial issue by performing extensive analyses of turbulence data from several field campaigns, wind-tunnel

  13. HIV-1 dynamics revisited: biphasic decay by cytotoxic T lymphocyte killing?

    E-print Network

    Nowak, Martin A.

    HIV-1 dynamics revisited: biphasic decay by cytotoxic T lymphocyte killing? Ramy A. Arnaout1 treated for human immunode¢ciency virus type 1 (HIV-1) infection has been explained as the decay of two infections. Keywords: human immunode¢ciency virus (HIV); hepatitis C virus (HCV); mathematical model

  14. A lumped mucosal wave model of the vocal folds revisited: Recent extensions and oscillation hysteresis

    E-print Network

    A lumped mucosal wave model of the vocal folds revisited: Recent extensions and oscillation an updated version of a lumped mucosal wave model of the vocal fold oscilla- tion during phonation. Threshold against pressure data collected from a mechanical rep- lica of the vocal folds, and oral airflow data

  15. Curve: Revisiting the Digital Desk Raphael Wimmer, Fabian Hennecke, Florian Schulz

    E-print Network

    .g., the physical desk). Daily working activities benefit from different intrinsic properties of both of these arCurve: Revisiting the Digital Desk Raphael Wimmer, Fabian Hennecke, Florian Schulz , Sebastian desks, direct-touch, ergonomics, interactive surfaces, workplace, tabletop interfaces INTRODUCTION

  16. Revisiting the protein-coding gene catalog of Drosophila melanogaster using twelve fly genomes

    E-print Network

    Kellis, Manolis

    to enhance our understanding of genome organization, even in a model organism as intensively studied as D understanding the functional elements in any genome. In D. melanogaster, a century of classical genetics, large-scale1 Revisiting the protein-coding gene catalog of Drosophila melanogaster using twelve fly genomes

  17. Resampling Methods Revisited: Advancing the Understanding and Applications in Educational Research

    ERIC Educational Resources Information Center

    Bai, Haiyan; Pan, Wei

    2008-01-01

    Resampling methods including randomization test, cross-validation, the jackknife and the bootstrap are widely employed in the research areas of natural science, engineering and medicine, but they lack appreciation in educational research. The purpose of the present review is to revisit and highlight the key principles and developments of…

  18. Instant Video Revisiting for Reflection: Extending the Learning of Children and Teachers.

    ERIC Educational Resources Information Center

    Hong, Seong B.; Broderick, Jane T.

    This article discusses how instant video revisiting (IVR) promotes reflective thinking for both teachers and children. IVR was used as a daily classroom experience with both the children and the teachers throughout one semester in two preschool classrooms with children 2.5 to 5 years old. The teachers used a digital video camera to generate data…

  19. Revisiting potential physico-chemical hazards of ionic liquids Alpha O. Diallo,a,b

    E-print Network

    Paris-Sud XI, Université de

    1 Revisiting potential physico-chemical hazards of ionic liquids Alpha O. Diallo,a,b Christophe Len pertaining to ionic liquids. Indeed safety performance of ionic liquids relating to physico-chemical hazards- chemical hazard rating systems and their limitation in the context of overall risk evaluation, and d

  20. Raman scattering in carbon nanotubes revisited J. Maultzsch, S. Reich, and C. Thomsen

    E-print Network

    Nabben, Reinhard

    nano- tubes, the radial breathing mode at 200 cm 1 Refs. 1 and 2 and the high-energy graphitelike modeRaman scattering in carbon nanotubes revisited J. Maultzsch, S. Reich, and C. Thomsen Institut fu spectra of single-walled carbon nanotubes by double-resonant scattering. Following this interpretation, we

  1. A Gender Lens on Pedagogical Choice in Academia: Revisiting Hartlaub and Lancaster's Study on Teaching Methodologies

    ERIC Educational Resources Information Center

    Wigfall, Patricia Moss; Hall, Paula Quick

    2010-01-01

    This paper focuses on the role of gender in faculty choice of teaching methodologies at colleges and universities in North Carolina. We replicate research conducted by Hartlaub and Lancaster who examined pedagogical preference among a national sample of political science instructors. In revisiting that inquiry, published in 2008, we have explored…

  2. Alkaline Phosphatase Revisited: Hydrolysis of Alkyl Phosphates Patrick J. O'Brien and Daniel Herschlag*

    E-print Network

    Herschlag, Dan

    Alkaline Phosphatase Revisited: Hydrolysis of Alkyl Phosphates Patrick J. O'Brien and DanielVed December 18, 2001 ABSTRACT: Escherichia coli alkaline phosphatase (AP) is the prototypical two metal ion enhancements of two metal ion catalysts are among the largest known (3, 4). E. coli alkaline phosphatase (AP)1

  3. Mantle pseudo-isochrons revisited John F. Rudge a,b,

    E-print Network

    Rudge, John

    Mantle pseudo-isochrons revisited John F. Rudge a,b, aBullard Laboratories, Department of Earth. Abstract The 2.0 Ga pseudo-isochron age inferred from the mid-ocean ridge basalt 207Pb/204Pb against 206Pb equations are presented which relate the pseudo-isochron age to the decay constants and distribution

  4. REVISITING THE CLASSICS: CONSIDERING NONCONSUMPTIVE EFFECTS IN TEXTBOOK EXAMPLES OF PREDATOR–PREY INTERACTIONS

    Microsoft Academic Search

    Barbara L. Peckarsky; Peter A. Abrams; Daniel I. Bolnick; Lawrence M. Dill; Jonathan H. Grabowski; Barney Luttbeg; John L. Orrock; Scott D. Peacor; Evan L. Preisser; Oswald J. Schmitz; Geoffrey C. Trussell

    2008-01-01

    Predator effects on prey dynamics are conventionally studied by measuring changes in prey abundance attributed to consumption by predators. We revisit four classic examples of predator-prey systems often cited in textbooks and incorporate subsequent studies of nonconsumptive effects of predators (NCE), defined as changes in prey traits (e.g., behavior, growth, development) measured on an ecological time scale. Our review revealed

  5. Journal of Electrostatics 65 (2007) 296306 The lightning striking distance--Revisited

    E-print Network

    Florida, University of

    2007-01-01

    of lightning protection to formulate the criterion for the onset of the upward connecting leader in termsJournal of Electrostatics 65 (2007) 296­306 The lightning striking distance--Revisited Vernon Cooraya,Ã, Vladimir Rakovb , Nelson Theethayia a Division for Electricity and Lightning Research, Uppsala

  6. Teacher Communication Concerns Revisited: Calling into Question the Gnawing Pull towards Equilibrium

    ERIC Educational Resources Information Center

    Dannels, Deanna P.

    2015-01-01

    This study revisits the long-standing teacher communication concerns framework originating over three decades ago. Analysis of 10 years of contemporary GTA teacher communication concerns reveals a typology of 10 concerns, which taken together construct teaching as a process of negotiating relationships, managing identities, and focusing attention.…

  7. GLA: Gate-Level Abstraction Revisited Alan Mishchenko Niklas Een Robert Brayton Jason Baumgartner Hari Mony Pradeep Nalla

    E-print Network

    Mishchenko, Alan

    GLA: Gate-Level Abstraction Revisited Alan Mishchenko Niklas Een Robert Brayton Jason Baumgartner and Technology Group {alanmi, brayton}@eecs.berkeley.edu niklas@een.se {baumgarj, harimony}@us.ibm.com pranalla

  8. mb:Ms Screening Revisited for Large Events

    NASA Astrophysics Data System (ADS)

    Ford, S. R.; Walter, W. R.

    2013-12-01

    Event screening of large magnitude events (Mw ~> 5) based on mb:Ms is revisited to account for the effect of the source corner-frequency relative to the fixed-frequencies of the long-period MS and short-period mb. For large events this source effect increases the slope of mb:Ms relative to the 1:1 value expected for small events. The effect is demonstrated in the large earthquake mb:Ms population and its behavior is transferred to the more limited explosion population to create a more conservative screening criteria. The change in criteria ensures large explosions are not inadvertently screened out by mb:Ms while not appreciably decreasing the number of screened earthquakes. This change also makes the variance of the earthquake and explosion populations more equal, which is of utility in statistical analysis. A slight trend in the explosion population and a case study of two large US underground nuclear tests provide support for adopting a more conservative approach. Prepared by LLNL under Contract DE-AC52-07NA27344, LLNL-JRNL-640677. Running mb:Ms means of earthquake (blue circles) and explosion (red circles) population along with explosions (gray crosses from Selby et al. (2012)). Ms ? mb and Ms ? 3×mb fits to the small and large magnitude earthquake means (light blue lines), respectively, are plotted and the change in slope is transferred to the explosion population (dashed light red line) to form the proposal for a change (dashed black line) to the revised screening line (black line).

  9. Revisiting the Interpretation of Thorium Abundances at Hansteen Alpha

    NASA Technical Reports Server (NTRS)

    Lawrence, D. J.; Hawke, B. R.; Elphic, R. C.; Feldman, W. C.; Prettyman, T. H.; Vaniman, D. T.

    2004-01-01

    Hansteen Alpha is one of the few remaining locations on the Moon thought to be formed by highlands volcanism. Hansteen Alpha is a triangular shaped feature located in the southern portion of Oceanus Procellarum (12 degrees W, 50 degrees S) and its size is approximately 25 km on each side. As described by Hawke et al., there is clear evidence that: 1) Hansteen Alpha was emplaced by extrusive volcanic processes; and 2) it was formed by a viscous lava that should be enriched in Th. However, in the study of Hawke et al. using available Lunar Prospector (LP) Th data, it was concluded that the Hansteen Alpha region was not greatly enriched in Th as would be expected for a highly evolved, viscous lava. It was further concluded based on other compositional data that the magma that formed Hansteen Alpha did not correspond to any known rock type. Here we revisit the interpretation of Th abundances at Hansteen Alpha for a couple of reasons. First, the size of Hansteen Alpha is smaller than the spatial resolution of the LP Gamma-ray Spectrometer (LP-GRS) from which the Th abundances were derived. Therefore, the LP-GRS pixels covering Hansteen Alpha may not truly represent the Th abundance of the Hansteen Alpha feature. Second, recent work has led to a much greater understanding of the Th spatial distribution for small-area features on the lunar surface. In particular, using forward modeling techniques, we have developed the ability to obtain information about Th abundances for features that are at or smaller than the FWHM spatial resolution (approximately [80 square kilometers]) of the LP-GRS data.

  10. Antisolar differential rotation of the K1-giant ? Geminorum revisited

    NASA Astrophysics Data System (ADS)

    K?vári, Zs.; Kriskovics, L.; Künstler, A.; Carroll, T. A.; Strassmeier, K. G.; Vida, K.; Oláh, K.; Bartus, J.; Weber, M.

    2015-01-01

    Context. Surface differential rotation and other global surface flows on magnetically active stars are among the observable manifestations of the underlying stellar dynamo. Therefore, these types of observations are important for stellar dynamo theory and useful constraints for solar dynamo studies as well. Aims: We revisit the active K1-giant component of the long-period RS CVn-type binary system ? Gem and its global surface flow pattern. Methods: We refine the differential rotation law from recovering the spot migration pattern. We apply a detailed cross-correlation technique to a unique set of 34 time-series Doppler images recovered using data from 1996-97. By increasing the number of the available cross-correlation function maps, we expect a more robust determination of the differential surface rotation law. In addition, we present a new time-series Doppler imaging study of ? Gem using our advanced surface reconstruction code iMap for a data set collected in 2006-07. Results: Results from the reprocessed cross-correlation study confirm that the star performs antisolar-type differential rotation with a surface shear ? of - 0.04 ± 0.01, i.e., almost a factor of two larger compared to the previously claimed value. We also confirm the evidence of a global poleward spot migration, with an average velocity of 0.21 ± 0.03 km s-1, in accordance with theoretical predictions. From the new observations, we obtain three subsequent Doppler images. The time evolution of these images confirms the antisolar-type differential rotation of the same amount.

  11. Practical Considerations for Perforator Flap Thinning Procedures Revisited

    PubMed Central

    Bangun, Kristaninta; Buchari, Frank B; Rezkini, Putri

    2014-01-01

    Background A thin perforator flap is one of the best methods for covering defects. This study aimed to revisit and further test the rapidly advancing field of flap thinning techniques. Methods We performed two cadaveric studies to test the known flap thinning methods, and then applied these methods to a clinical series. In the first study, five cadavers were used to observe the anatomical relation of the perforator with the subdermal plexuses and the subcutaneous fat layer by injecting a colored latex solution. The second study was done on four cadavers independently from the first study. Last, a clinical series was performed on 15 patients. Results The areolar fat lobules of 10 anterolateral thigh perforator (ALT), seven deep inferior epigastric artery perforator (DIEAP), and six thoracodorsal artery perforator (TAP) flaps were dissected to reduce the flap thickness guided by the colored vascular pattern. On average, the ALT, DIEAP, and TAP flaps were reduced to 32.76%±9.76%, 37.01%±9.21%, and 35.42%±9.41%, respectively. In the second study, the areolar fat lobules were directly dissected in six ALT, six TAP, and four MSAP flaps, and an average reduction in flap thickness of 53.41%±5.64%, 52.30%±2.88%, and 47.87%±6.41%, respectively, was found. In the clinical series, 13 out of the 15 cases yielded satisfactory outcomes with an average thickness reduction of 37.91%±7.15%. Conclusions These multiple studies showed that the deep fat layer could be safely removed to obtain a thin yet viable perforator flap. This evidence suggests that the macroscopic flap thinning technique can achieve thin flaps. Surgeons should consider this technique before embracing the latest technique of supermicrosurgery. PMID:25396182

  12. REVISITING ACCELERATION OF CHARGED GRAINS IN MAGNETOHYDRODYNAMIC TURBULENCE

    SciTech Connect

    Hoang, Thiem; Lazarian, A. [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States); Schlickeiser, R. [Institut fuer Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany)

    2012-03-01

    We study the acceleration of charged grains by magnetohydrodynamic (MHD) turbulence in the interstellar medium (ISM). We begin with revisiting gyroresonance acceleration by taking into account the fluctuations of grain guiding center along a uniform magnetic field (i.e., nonlinear theory-NLT). We calculate grain velocities due to gyroresonance by fast MHD modes using the NLT for different phases of the ISM and compare them with results obtained using quasi-linear theory (QLT). We find for the parameters applicable to the typical ISM phases that the fluctuations of the grain guiding center reduce grain velocities by less than 15%, but they can be important for more special circumstances. We confirm that large grains can be accelerated to super-Alfvenic velocities through gyroresonance. For such super-Alfvenic grains, we investigate the effect of further acceleration via transit-time damping (TTD) by fast modes. We find that due to the broadening of the resonance condition in the NLT, the TTD acceleration is not only important for the cosines of grain pitch angle relative to the magnetic field {mu} > V{sub A}/v, but also for {mu} < V{sub A}/v where v is the grain velocity and V{sub A} is the Alfven speed. We show that the TTD acceleration is dominant over the gyroresonance for large grains, and can increase substantially grain velocities induced by gyroresonance acceleration. We quantify another stochastic acceleration mechanism arising from low-frequency Alfven waves. We discuss the range of applicability of the mechanisms and their implications.

  13. Mental health and poverty in developing countries: revisiting the relationship.

    PubMed

    Das, Jishnu; Do, Quy-Toan; Friedman, Jed; McKenzie, David; Scott, Kinnon

    2007-08-01

    The relationship between poverty and mental health has received considerable attention in the recent literature. However, the associations presented in existing studies typically rely on limited samples of individuals and on proxy indicators for poverty such as education, the lack of tap water, or being unemployed. We revisit the relationship between poverty and mental health using data from nationally representative household surveys in Bosnia and Herzegovina, Indonesia and Mexico, along with special surveys from India and Tonga. As in previous studies, we find that individuals who are older, female, widowed, and in poor health are more likely to report worse mental health outcomes. Individuals living with others with poor mental health are significantly more likely to report worse mental health themselves. The size of the coefficients and their significance are comparable across the five countries. In contrast to previous studies, the relationship between higher education and better mental health is weak or non-existent. Furthermore, there is no consistent association between consumption poverty and mental health - in two countries mental health measures are marginally worse for the poor; in two countries there is no association; and in one country mental health measures are better for the poor compared to the non-poor. Moreover, the sizes of the coefficients for both education and consumption poverty are small compared to other factors considered here. While the lack of an association between consumption poverty and mental health implies that poor mental health is not a "disease of affluence", neither is it a disease of poverty. Changes in life circumstances brought on, for instance, by illness may have a greater impact on mental health than levels of poverty. Effective public health policy for mental health should focus on protecting individuals and households from adverse events and on targeted interventions following such adverse changes. PMID:17462803

  14. Distant future of the Sun and Earth revisited

    E-print Network

    Klaus-Peter Schroder; Robert C. Smith

    2008-01-25

    We revisit the distant future of the Sun and the solar system, based on stellar models computed with a thoroughly tested evolution code. For the solar giant stages, mass-loss by the cool (but not dust-driven) wind is considered in detail. Using the new and well-calibrated mass-loss formula of Schroder & Cuntz (2005, 2007), we find that the mass lost by the Sun as an RGB giant (0.332 M_Sun, 7.59 Gy from now) potentially gives planet Earth a significant orbital expansion, inversely proportional to the remaining solar mass. According to these solar evolution models, the closest encounter of planet Earth with the solar cool giant photosphere will occur during the tip-RGB phase. During this critical episode, for each time-step of the evolution model, we consider the loss of orbital angular momentum suffered by planet Earth from tidal interaction with the giant Sun, as well as dynamical drag in the lower chromosphere. We find that planet Earth will not be able to escape engulfment, despite the positive effect of solar mass-loss. In order to survive the solar tip-RGB phase, any hypothetical planet would require a present-day minimum orbital radius of about 1.15 AU. Furthermore, our solar evolution models with detailed mass-loss description predict that the resulting tip-AGB giant will not reach its tip-RGB size. The main reason is the more significant amount of mass lost already in the RGB phase of the Sun. Hence, the tip-AGB luminosity will come short of driving a final, dust-driven superwind, and there will be no regular solar planetary nebula (PN). But a last thermal pulse may produce a circumstellar (CS) shell similar to, but rather smaller than, that of the peculiar PN IC 2149 with an estimated total CS shell mass of just a few hundredths of a solar mass.

  15. Visual-motor deficits relate to altered gray and white matter in young adults born preterm with very low birth weight.

    PubMed

    Sripada, Kam; Løhaugen, Gro C; Eikenes, Live; Bjørlykke, Kjerstin M; Håberg, Asta K; Skranes, Jon; Rimol, Lars M

    2015-04-01

    Individuals born preterm and at very low birth weight (birth weight ? 1500 g) are at an increased risk of perinatal brain injury and neurodevelopmental deficits over the long term. This study examined whether this clinical group has more problems with visual-motor integration, motor coordination, and visual perception compared to term-born controls, and related these findings to cortical surface area and thickness and white matter fractional anisotropy. Forty-seven preterm-born very low birth weight individuals and 56 term-born controls were examined at 18-22 years of age with a combined cognitive, morphometric MRI, and diffusion tensor imaging evaluation in Trondheim, Norway. Visual-motor skills were evaluated with the Beery-Buktenica Developmental Test of Visual-Motor Integration-V (VMI) copying test and its supplemental tests of motor coordination and visual perception. 3D T1-weighted MPRAGE images and diffusion tensor imaging were done at 1.5 T. Cortical reconstruction generated in FreeSurfer and voxelwise maps of fractional anisotropy calculated with Tract-Based Spatial Statistics were used to explore the relationship between MRI findings and cognitive results. Very low birth weight individuals had significantly lower scores on the copying and motor coordination tests compared with controls. In the very low birth weight group, VMI scores showed significant positive relationships with cortical surface area in widespread regions, with reductions of the superior temporal gyrus, insula, and medial occipital lobe in conjunction with the posterior ventral temporal lobe. Visual perception scores also showed positive relationships with cortical thickness in the very low birth weight group, primarily in the lateral occipito-temporo-parietal junction, the superior temporal gyrus, insula, and superior parietal regions. In the very low birth weight group, visual-motor performance correlated positively with fractional anisotropy especially in the corpus callosum, inferior fronto-occipital fasciculus bilaterally, and anterior thalamic radiation bilaterally, driven primarily by an increase in radial diffusivity. VMI scores did not demonstrate a significant relationship to cortical surface area, cortical thickness, or diffusion measures in the control group. Our results indicate that visual-motor integration problems persist into adulthood for very low birth weight individuals, which may be due to structural alterations in several specific gray-white matter networks. Visual-motor deficits appear related to reduced surface area of motor and visual cortices and disturbed connectivity in long association tracts containing visual and motor information. We conjecture that these outcomes may be due to perinatal brain injury or aberrant cortical development secondary to injury or due to very preterm birth. PMID:25592994

  16. Revisited Inventory of Glaciers on Axel Heiberg Island, Nunavut

    NASA Astrophysics Data System (ADS)

    Thomson, L.; Osinski, G.

    2009-05-01

    As documented in the IPCC's Climate Change 2007 report, the high latitude regions of the Northern Hemisphere are experiencing the highest rates of warming. Given that 35% of the global glacial ice exists within the Arctic Archipelago, this region provides an excellent laboratory for monitoring the anticipated degree of glacial recession [1]. Evidence of arctic warming through negative mass balance trends has been detected in several studies already [e.g., 2]. Here, we show the importance and value of historical records in the task of monitoring glacial retreat. A highly detailed inventory developed by S. Ommanney in 1969 [3], has been revisited and transformed into digital format for the purposes of integration with modern inventories. The Ommanney inventory covers the entirety of Axel Heiberg Island , NU, and includes details often lacking in present day inventories, including orientations (accumulation and ablation zones), elevations (highest, lowest, elevation of the snowline, and the mean elevations of both the accumulation and ablation areas), length (of the ablation area, exposed ice, and of the total glacier including debris cover), area (of the ablation area, exposed ice, and of the total glacier), accumulation area ratio (AAR), depth, volume, and a six digit code which gives qualitative details on glacier attributes. This report is one of the most thorough and comprehensive glacier inventory report ever published in Canada. More recent inventories used for comparison include the glacier extents created by the National Topographic System based on photography from 1980-1987, as well as extents developed by Dr. Luke Copland for the Global Land Ice Measurements from Space (GLIMS) database using 1999-2000 satellite imagery. Our preliminary results show that approximately 90% of ice bodies under 0.2km on Axel Heiberg Island have disappeared entirely in the 40 year period of interest. The issue of glacier definition will be discussed as a possible cause of these drastic changes in the status of small, remnant glaciers. Recession trends will also be discussed with respect to glacier characteristics and regional distribution. [1] Barry, R. G., Progress in Physical Geography, 2006. 30(3): p. 285-306; [2] Dowdeswell, J. A., et al., Quaternary Research, 1997. 40: p. 1-14; [3] Ommanney, C. S. L., McGill Subarctic Research Paper, 1969. 40: p. 5-67.

  17. REVISITING SCALING RELATIONS FOR GIANT RADIO HALOS IN GALAXY CLUSTERS

    SciTech Connect

    Cassano, R.; Brunetti, G.; Venturi, T.; Kale, R. [INAF/IRA, via Gobetti 101, I-40129 Bologna (Italy); Ettori, S. [INAF/Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Giacintucci, S. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Pratt, G. W. [Laboratoire AIM, IRFU/Service dAstrophysique-CEA/DSM-CNRS-Université Paris Diderot, Bât. 709, CEA-Saclay, F-91191 Gif-sur-Yvette Cedex (France); Dolag, K. [University Observatory Munich, Scheinerstr. 1, D-81679 Munich (Germany); Markevitch, M. [Astrophysics Science Division, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2013-11-10

    Many galaxy clusters host megaparsec-scale radio halos, generated by ultrarelativistic electrons in the magnetized intracluster medium. Correlations between the synchrotron power of radio halos and the thermal properties of the hosting clusters were established in the last decade, including the connection between the presence of a halo and cluster mergers. The X-ray luminosity and redshift-limited Extended GMRT Radio Halo Survey provides a rich and unique dataset for statistical studies of the halos. We uniformly analyze the radio and X-ray data for the GMRT cluster sample, and use the new Planck Sunyaev-Zel'dovich (SZ) catalog to revisit the correlations between the power of radio halos and the thermal properties of galaxy clusters. We find that the radio power at 1.4 GHz scales with the cluster X-ray (0.1-2.4 keV) luminosity computed within R{sub 500} as P{sub 1.4}?L{sup 2.1±0.2}{sub 500}. Our bigger and more homogenous sample confirms that the X-ray luminous (L{sub 500} > 5 × 10{sup 44} erg s{sup –1}) clusters branch into two populations—radio halos lie on the correlation, while clusters without radio halos have their radio upper limits well below that correlation. This bimodality remains if we excise cool cores from the X-ray luminosities. We also find that P{sub 1.4} scales with the cluster integrated SZ signal within R{sub 500}, measured by Planck, as P{sub 1.4}?Y{sup 2.05±0.28}{sub 500}, in line with previous findings. However, contrary to previous studies that were limited by incompleteness and small sample size, we find that 'SZ-luminous' Y{sub 500} > 6 × 10{sup –5} Mpc{sup 2} clusters show a bimodal behavior for the presence of radio halos, similar to that in the radio-X-ray diagram. Bimodality of both correlations can be traced to clusters dynamics, with radio halos found exclusively in merging clusters. These results confirm the key role of mergers for the origin of giant radio halos, suggesting that they trigger the relativistic particle acceleration.

  18. The Angular Momentum of Baryons and Dark Matter Halos Revisited

    NASA Technical Reports Server (NTRS)

    Kimm, Taysun; Devriendt, Julien; Slyz, Adrianne; Pichon, Christophe; Kassin, Susan A.; Dubois, Yohan

    2011-01-01

    Recent theoretical studies have shown that galaxies at high redshift are fed by cold, dense gas filaments, suggesting angular momentum transport by gas differs from that by dark matter. Revisiting this issue using high-resolution cosmological hydrodynamics simulations with adaptive-mesh refinement (AMR), we find that at the time of accretion, gas and dark matter do carry a similar amount of specific angular momentum, but that it is systematically higher than that of the dark matter halo as a whole. At high redshift, freshly accreted gas rapidly streams into the central region of the halo, directly depositing this large amount of angular momentum within a sphere of radius r = 0.1R(sub vir). In contrast, dark matter particles pass through the central region unscathed, and a fraction of them ends up populating the outer regions of the halo (r/R(sub vir) > 0.1), redistributing angular momentum in the process. As a result, large-scale motions of the cosmic web have to be considered as the origin of gas angular momentum rather than its virialised dark matter halo host. This generic result holds for halos of all masses at all redshifts, as radiative cooling ensures that a significant fraction of baryons remain trapped at the centre of the halos. Despite this injection of angular momentum enriched gas, we predict an amount for stellar discs which is in fair agreement with observations at z=0. This arises because the total specific angular momentum of the baryons (gas and stars) remains close to that of dark matter halos. Indeed, our simulations indicate that any differential loss of angular momentum amplitude between the two components is minor even though dark matter halos continuously lose between half and two-thirds of their specific angular momentum modulus as they evolve. In light of our results, a substantial revision of the standard theory of disc formation seems to be required. We propose a new scenario where gas efficiently carries the angular momentum generated by large-scale structure motions deep inside dark matter halos, redistributing it only in the vicinity of the disc.

  19. The Bimodality of Galaxy Populations Revisited Through Spectral Synthesis

    NASA Astrophysics Data System (ADS)

    Sodré, L.; Mateus, A.; Cid Fernandes, R.; Stasi?ska, G.; Schoenell, W.; Gomes, J. M.

    2007-05-01

    We revisit the bimodal distribution of the galaxy population commonly seen in the local universe. Here we address the bimodality observed in galaxy properties in terms of spectral synthesis products, such as mean stellar ages and stellar masses, derived from the application of this powerful method to a sample of spectra extracted from the Sloan Digital Sky Survey. We apply the spectral synthesis approach presented in Cid Fernandes et al. (2005) to a volume-limited sample, with magnitude limit cutoff M(r) = -20.5, containing about 50 thousand luminous galaxies from the SDSS Data Release 2. We obtain, for each galaxy, the mean age of their stars, the stellar mass and the stellar extinction. In addition, galaxies are classified according to their emission line properties in three distinct spectral classes: star-forming galaxies (with young stellar populations), passive galaxies (dominated by old stellar populations), and hosts of active nuclei. We show that the extremes of the distribution of some galaxy properties- essentially galaxy colours, 4000A break index, and mean stellar ages- are associated to star-forming galaxies at one side, and passive galaxies at another. We show that the mean light-weighted stellar age of galaxies presents the best description of the bimodality seen in the galaxy population. The stellar mass, in this view, has an additional role since most of the star-forming galaxies present in the local universe are low-mass galaxies. Our results also give support to the existence of a `downsizing' in galaxy formation, where massive galaxies seen nowadays have stellar populations formed at early times. seen nowadays have stellar populations formed at early times. Discussion. Our analysis allows to demonstrate that the bimodality of the galaxy population, commonly seen in colour-magnitude diagrams is related to the presence of a young and luminous stellar component in galaxies currently undergoing star formation, in contrast with the stellar content of passive galaxies, where old stars are the responsible for most of their luminosities. We also show that AGN-hosts have intermediate properties between star-forming and passive galaxies.

  20. Effective-Medium Models for Marine Gas Hydrates, Mallik Revisited

    NASA Astrophysics Data System (ADS)

    Terry, D. A.; Knapp, C. C.; Knapp, J. H.

    2011-12-01

    Hertz-Mindlin type effective-medium dry-rock elastic models have been commonly used for more than three decades in rock physics analysis, and recently have been applied to assessment of marine gas hydrate resources. Comparisons of several effective-medium models with derivative well-log data from the Mackenzie River Valley, Northwest Territories, Canada (i.e. Mallik 2L-38 and 5L-38) were made several years ago as part of a marine gas hydrate joint industry project in the Gulf of Mexico. The matrix/grain supporting model (one of the five models compared) was clearly a better representation of the Mallik data than the other four models (2 cemented sand models; a pore-filling model; and an inclusion model). Even though the matrix/grain supporting model was clearly better, reservations were noted that the compressional velocity of the model was higher than the compressional velocity measured via the sonic logs, and that the shear velocities showed an even greater discrepancy. Over more than thirty years, variations of Hertz-Mindlin type effective medium models have evolved for unconsolidated sediments and here, we briefly review their development. In the past few years, the perfectly smooth grain version of the Hertz-Mindlin type effective-medium model has been favored over the infinitely rough grain version compared in the Gulf of Mexico study. We revisit the data from the Mallik wells to review assertions that effective-medium models with perfectly smooth grains are a better predictor than models with infinitely rough grains. We briefly review three Hertz-Mindlin type effective-medium models, and standardize nomenclature and notation. To calibrate the extended effective-medium model in gas hydrates, we use a well accepted framework for unconsolidated sediments through Hashin-Shtrikman bounds. We implement the previously discussed effective-medium models for saturated sediments with gas hydrates and compute theoretical curves of seismic velocities versus gas hydrate saturation to compare with well log data available from the Canadian gas hydrates research site. By directly comparing the infinitely rough and perfectly smooth grain versions of the Hertz-Mindlin type effective-medium model, we provide additional insight to the discrepancies noted in the Gulf of Mexico study.

  1. Facial clefts and facial dysplasia: revisiting the classification.

    PubMed

    Mazzola, Riccardo F; Mazzola, Isabella C

    2014-01-01

    Most craniofacial malformations are identified by their appearance. The majority of the classification systems are mainly clinical or anatomical, not related to the different levels of development of the malformation, and underlying pathology is usually not taken into consideration. In 1976, Tessier first emphasized the relationship between soft tissues and the underlying bone stating that "a fissure of the soft tissue corresponds, as a general rule, with a cleft of the bony structure". He introduced a cleft numbering system around the orbit from 0 to 14 depending on its relationship to the zero line (ie, the vertical midline cleft of the face). The classification, easy to understand, became widely accepted because the recording of the malformations was simple and communication between observers facilitated. It represented a great breakthrough in identifying craniofacial malformations, named clefts by him. In the present paper, the embryological-based classification of craniofacial malformations, proposed in 1983 and in 1990 by us, has been revisited. Its aim was to clarify some unanswered questions regarding apparently atypical or bizarre anomalies and to establish as much as possible the moment when this event occurred. In our opinion, this classification system may well integrate the one proposed by Tessier and tries at the same time to find a correlation between clinical observation and morphogenesis.Terminology is important. The overused term cleft should be reserved to true clefts only, developed from disturbances in the union of the embryonic facial processes, between the lateronasal and maxillary process (or oro-naso-ocular cleft); between the medionasal and maxillary process (or cleft of the lip); between the maxillary processes (or cleft of the palate); and between the maxillary and mandibular process (or macrostomia).For the other types of defects, derived from alteration of bone production centers, the word dysplasia should be used instead. Facial dysplasias have been ranged in a helix form and named after the site of the developmental arrest. Thus, an internasal, nasal, nasomaxillary, maxillary and malar dysplasia, depending on the involved area, have been identified.The classification may provide a useful guide in better understanding the morphogenesis of rare craniofacial malformations. PMID:24406554

  2. 7/1/09 7:49 PMSage Worksheet: Archimedes Revisited Page 1 of 3http://localhost:8000/home/admin/80/print

    E-print Network

    Landweber, Gregory D.

    7/1/09 7:49 PMSage Worksheet: Archimedes Revisited Page 1 of 3http://localhost:8000/home/admin/80/print Archimedes Revisited What Archimedes didn't know about What Archimedes did know about Archimedes computations when trying to approximate Ù! However, Archimedes computed these values using nothing more than

  3. Revisiting the photodissociation dynamics of the phenyl radical Neil C. Cole-Filipiak, Mark Shapero, Bogdan Negru, and Daniel M. Neumark

    E-print Network

    Neumark, Daniel M.

    Revisiting the photodissociation dynamics of the phenyl radical Neil C. Cole-Filipiak, Mark Shapero.1063/1.4867194 Photodissociation dynamics of the phenyl radical via photofragment translational spectroscopy J. Chem. Phys. 133 (2014) Revisiting the photodissociation dynamics of the phenyl radical Neil C. Cole-Filipiak, Mark

  4. Inverse neutrinoless double beta decay revisited: Neutrinos, Higgs triplets, and a muon collider

    Microsoft Academic Search

    Werner Rodejohann

    2010-01-01

    We revisit the process of inverse neutrinoless double beta decay (e-e--->W-W-) at future linear colliders. The cases of Majorana neutrino and Higgs triplet exchange are considered. We also discuss the processes e-mu--->W-W- and mu-mu--->W-W-, which are motivated by the possibility of muon colliders. For heavy neutrino exchange, we show that masses up to 106 (105)GeV could be probed for ee

  5. The infrared spectrum of indium in silicon revisited A. Tardella and B. Pajot

    E-print Network

    Paris-Sud XI, Université de

    1789 The infrared spectrum of indium in silicon revisited A. Tardella and B. Pajot Groupe de Le spectre d'absorption de l'indium dans le silicium a été mesuré dans des conditions où l concentration d'indium dans le silicium par une méthode spectroscopique, nous trouvons que l'élargissement par

  6. Why is it so difficult to compare treebanks? TIGER and TuBa-D/Z revisited

    E-print Network

    van Genabith, Josef

    Why is it so difficult to compare treebanks? TIGER and T¨uBa-D/Z revisited Ines Rehbein and Josef a thorough comparison of two German treebanks: the TIGER treebank and the T¨uBa-D/Z. We use simple statistics evaluation of a set of 100 sentences from the T¨uBa- D/Z, manually annotated in the TIGER as well as in the T

  7. Children’s social play sequence: Parten’s classic theory revisited

    Microsoft Academic Search

    Yaoying Xu

    2010-01-01

    The purpose of this article is to revisit Parten’s study on social play from cultural, environmental, social and economic aspects. Young children’s social play is viewed as a critical means to foster and enhance language, cognitive, social and emotional development. Social play theory has been predominately viewed from developmental perspectives. The classic study of Parten’s social play has been considered

  8. A partially debonded circular inclusion interacting with a point singularity: A classical problem revisited

    Microsoft Academic Search

    Jae Hyun Kim; Youn Young Earmme

    2003-01-01

    The classical problem for a partially debonded circular inhomogeneity is revisited. The interaction of the interfacial crack\\u000a and a point singularity such as a point force and\\/or a dislocation is dealt with. Also the circular arc-shaped interfacial\\u000a crack under remote stress is solved. This problem has been solved by many researchers for the cases of various loading types.\\u000a However, lack

  9. Number of Palindromes Revisited A palindrome is a composition for m Z+

    E-print Network

    Lyuu, Yuh-Dauh

    Number of Palindromes Revisited · A palindrome is a composition for m Z+ that reads the same left to right as right to left (p. 77). · Let an denote the number of palindromes for n. · Clearly, a1 = 1 and a2 = 2. · Given each palindrome for n - 2, we can do two things. ­ Add 1 to the first and last

  10. Multiperiodic coherent states and the Wentzel{endash}Kramers{endash}Brillouin exactness. II. Noncompact case and classical theories revisited

    SciTech Connect

    Fujii, K. [Department of Mathematics, Yokohama City University, Yokohama 236 (Japan)] [Department of Mathematics, Yokohama City University, Yokohama 236 (Japan); Funahashi, K. [Department of Physics, Kyushu University, Fukuoka 812-81 (Japan)] [Department of Physics, Kyushu University, Fukuoka 812-81 (Japan)

    1997-06-01

    We show that the Wentzel{endash}Kramers{endash}Brillouin approximation gives the exact result in the trace formula of {open_quotes}CQ{sup N},{close_quotes} which is the noncompact counterpart of CP{sup N}, in terms of the {open_quotes}multiperiodic{close_quotes} coherent state. We revisit the symplectic 2-forms on CP{sup N} and CQ{sup N} and, especially, construct that on CQ{sup N} with the unitary form. We also revisit the exact calculation of the classical partition functions of them. {copyright} {ital 1997 American Institute of Physics.}

  11. Wittig Reaction: The Synthesis of trans-9-(2-Phenylethenyl)anthracene Revisited

    NASA Astrophysics Data System (ADS)

    Jaworek, Christine; Iacobucci, Sarah

    2002-01-01

    The revisit to this experimental procedure resulted in making a good undergraduate laboratory procedure even better. In this Wittig reaction, readily available starting materials are used; only the trans isomer is produced; the clear and characteristic 1H NMR spectrum of the product is ideal for a lesson in coupling constants to determine stereochemistry; and the product can be readily used in additional brilliant chemiluminescence laboratory experiments. The problematic step of generating tough emulsions during extractions with halogenated solvents has been eliminated by using N,N-dimethylformamide as the reaction solvent and readily precipitating the product from the reaction mixture using 1-propanol and water.

  12. Inverse neutrinoless double beta decay revisited: Neutrinos, Higgs triplets, and a muon collider

    Microsoft Academic Search

    Werner Rodejohann

    2010-01-01

    We revisit the process of inverse neutrinoless double beta decay (e⁻e{sup -â}W⁻W⁻) at future linear colliders. The cases of Majorana neutrino and Higgs triplet exchange are considered. We also discuss the processes e{sup -μ-â}W⁻W⁻ and μ{sup -μ-â}W⁻W⁻, which are motivated by the possibility of muon colliders. For heavy neutrino exchange, we show that masses up to 10⁶ (10⁵) GeV could

  13. Investigating Predictors of Visiting, Using, and Revisiting an Online Health-Communication Program: A Longitudinal Study

    PubMed Central

    Crutzen, Rik; De Vries, Hein

    2010-01-01

    Background Online health communication has the potential to reach large audiences, with the additional advantages that it can be operational at all times and that the costs per visitor are low. Furthermore, research shows that Internet-delivered interventions can be effective in changing health behaviors. However, exposure to Internet-delivered health-communication programs is generally low. Research investigating predictors of exposure is needed to be able to effectively disseminate online interventions. Objective In the present study, the authors used a longitudinal design with the aim of identifying demographic, psychological, and behavioral predictors of visiting, using, and revisiting an online program promoting physical activity in the general population. Methods A webpage was created providing the public with information about health and healthy behavior. The website included a “physical activity check,” which consisted of a physical activity computer-tailoring expert system where visitors could check whether their physical activity levels were in line with recommendations. Visitors who consented to participate in the present study (n = 489) filled in a questionnaire that assessed demographics, mode of recruitment, current physical activity levels, and health motivation. Immediately after, participants received tailored feedback concerning their current physical activity levels and completed a questionnaire assessing affective and cognitive user experience, attitude toward being sufficiently physically active, and intention to be sufficiently physically active. Three months later, participants received an email inviting them once more to check whether their physical activity level had changed. Results Analyses of visiting showed that more women (67.5%) than men (32.5%) visited the program. With regard to continued use, native Dutch participants (odds ratio [OR] = 2.81, 95% confidence interval [CI] = 1.16-6.81, P = .02) and participants with a strong motivation to be healthy (OR = 1.46, CI = 1.03-2.07, P = .03) were most likely to continue usage of the program. With regard to revisiting, older participants (OR = 1.04, CI = 1.01-1.06, P = .01) and highly educated participants (OR = 4.69, CI = 1.44-15.22, P = .01) were more likely to revisit the program after three months. In addition, positive affective user experience predicted revisiting (OR = 1.64, CI = 1.12-2.39, P = .01). Conclusions The results suggest that online interventions could specifically target men, young people, immigrant groups, people with a low education, and people with a weak health motivation to increase exposure to these interventions. Furthermore, eliciting positive feelings in visitors may contribute to higher usage rates. PMID:20813716

  14. Sample selection versus two-part models revisited: the case of female smoking and drinking.

    PubMed

    Madden, David

    2008-03-01

    There is a well-established debate between Heckman sample selection and two-part models in health econometrics, particularly when no obvious exclusion restrictions are available. Most of this debate has focussed on the application of these models to health care expenditure. This paper revisits the debate in the context of female smoking and drinking, and evaluates the two approaches on three grounds: theoretical, practical and statistical. The two-part model is generally favoured but it is stressed that this comparison should be carried out on a case-by-case basis. PMID:18180064

  15. Spatial resolution from repeat orbit configurations: the Colombo-Nyquist rule revisited

    NASA Astrophysics Data System (ADS)

    Sneeuw, N.; Schrama, E. J. O.; Visser, P. N. A. M.; Weigelt, M.

    2009-04-01

    The groundtrack of a repeat orbit configuration limits the spatial resolution of gravity recovery. Colombo (1984) formulated a Nyquist-type rule-of-thumb that states that a gravity recovery up till degree L requires a repeat orbit with at least 2L revolutions. This rule, however, contradicts our experience in gravity field simulations and recovery from CHAMP and GRACE. In this contribution we revisit the the Colombo-Nyquist rule and scrutinize its rationale. We argue that, under certain conditions, the rule can be relaxed significantly. For instance, L or even less revolutions may already suffice for a recovery till degree L.

  16. EPR before EPR: a 1930 Einstein-Bohr thought experiment revisited

    E-print Network

    Nikolic, H

    2012-01-01

    In 1930 Einstein argued against consistency of the time-energy uncertainty relation by discussing a thought experiment involving a measurement of mass of the box which emitted a photon. Bohr seemingly triumphed over Einstein by arguing that the Einstein's own general theory of relativity saves the consistency of quantum mechanics. We revisit this thought experiment from a modern point of view and find that neither Einstein nor Bohr was right. Instead, this thought experiment should be thought of as an early example of a system demonstrating nonlocal "EPR" quantum correlations, five years before the famous Einstein-Podolsky-Rosen paper.

  17. Revisiting Deng et al.'s Multiparty Quantum Secret Sharing Protocol

    NASA Astrophysics Data System (ADS)

    Hwang, Tzonelih; Hwang, Cheng-Chieh; Yang, Chun-Wei; Li, Chuan-Ming

    2011-09-01

    The multiparty quantum secret sharing protocol [Deng et al. in Chin. Phys. Lett. 23: 1084-1087, 2006] is revisited in this study. It is found that the performance of Deng et al.'s protocol can be much improved by using the techniques of block-transmission and decoy single photons. As a result, the qubit efficiency is improved 2.4 times and only one classical communication, a public discussion, and two quantum communications between each agent and the secret holder are needed rather than n classical communications, n public discussions, and 3n/2 quantum communications required in the original scheme.

  18. Pseudotensor problem of gravitational energy-momentum and Noether's theorem revisited

    E-print Network

    Zhaoyan Wu

    2013-11-08

    Based on a general variational principle, Noether's theorem is revisited. It is shown that the so called pseudotensor problem of the gravitational energy-momentum is a result of mis-reading Noether's theorem, and in fact, all the Noether's conserved quantities are scalars. It is also shown, by using a counter-example, that the non-localizability of gravitational energy-momentum can not be attributed to the equivalence principle. As a direct consequence of variational principle, a generalized Hamilton-Jacobi equation for the Hamilton's principal functional is obtained.

  19. Silent cries, dancing tears: the metapsychology of art revisited/revised.

    PubMed

    Aragno, Anna

    2011-04-01

    Against the backdrop of a broad survey of the literature on applied psychoanalysis, a number of concepts underpinning the metapsychology of art are revisited and revised: sublimation; interrelationships between primary and secondary processes; symbolization; "fantasy"; and "cathexis." Concepts embedded in dichotomous or drive/energic contexts are examined and reformulated in terms of a continuum of semiotic processes. Freudian dream structure is viewed as a biological/natural template for nonrepressive artistic forms of sublimation. The synthesis presented proposes a model of continuous rather than discontinuous processes, in a nonenergic, biosemiotic metatheoretical framework. PMID:21653915

  20. Conservation laws for steady flow and solitons in a multifluid plasma revisited

    SciTech Connect

    Mace, R. L.; McKenzie, J. F.; Webb, G. M. [School of Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000 (South Africa); School of Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000 (South Africa); King's College, Cambridge (United Kingdom) and Institute of Geophysics and Planetary Physics, University of California Riverside, Riverside, California 92521 (United States); Institute of Geophysics and Planetary Physics, University of California Riverside, Riverside, California 92521 (United States)

    2007-01-15

    The conservation laws used in constructing the governing equations for planar solitons in multifluid plasmas are revisited. In particular, the concept of generalized vorticity facilitates the derivation of some general ''Bernoulli theorems,'' which reduce, in specific instances, to conservation laws previously deduced by other means. These theorems clarify the underlying physical principles that give rise to the conserved quantities. As an example of the usefulness of the techniques, even for relatively simple flows and progressive waves, the equations governing stationary nonlinear whistler waves propagating parallel to an ambient magnetic field are derived using generalized vorticity concepts.

  1. Constructing check-lists and avifauna-wide reviews: Mexican bird taxonomy revisited

    E-print Network

    Peterson, A. Townsend; Navarro-Sigü enza, Adolfo G.

    2009-01-01

    ConstruCting CheCk-lists and avifauna-wide reviews: MexiCan Bird taxonoMy revisited — 915 — The Auk, Vol. 126, Number 4, pages 915?921. ISSN 0004-8038, electronic ISSN 1938-4254. ? 2009 by The American Ornithologists’ Union. All rights reserved... Nacional Autónoma de México, Apartado Postal 70-399, México, D.F. 04510, Mexico 3 E-mail: town@ku.edu Summarizing taxonomic and distributional information of regional avifaunas has been an important task of the Ameri- can Ornithologists’ Union (AOU) from...

  2. Revisiting Valley Development on Martian Volcanoes Using MGS and Odyssey Data

    NASA Technical Reports Server (NTRS)

    Gulick, Virginia C.

    2005-01-01

    The valley networks found on the slopes of Martian volcanoes represent an interesting subset of the Martian valley networks. Not only do the volcanoes constrain the possible geologic settings, they also provide a window into Martian valley development through time, as the volcanoes formed throughout the geologic history of Mars. Here I take another look at this intriguing subset of networks by revisiting conclusions reached in my earlier studies using the Viking imagery and the valleys on Hawaii as an analog. I then examine more recent datasets.

  3. Asymmetric copper-catalyzed Diels-Alder reaction revisited: control of the structure of bis(oxazoline) ligands.

    E-print Network

    Paris-Sud XI, Université de

    1 Asymmetric copper-catalyzed Diels-Alder reaction revisited: control of the structure of bis,R)-dihydroethano trans-dicarboxylic acid, a complete series of ligands was evaluated in the copper-catalyzed Diels[2.2.2] backbone; Diels-Alder catalysis; Copper; Enantioselectivity. * Corresponding author. E

  4. Life history evolution in cichlids 1: revisiting the evolution of life histories in relation to parental care

    E-print Network

    Reynolds, John D.

    Life history evolution in cichlids 1: revisiting the evolution of life histories in relation evolution. However, to date, this link has not been investigated in relation to other important life-history on costs and benefits of care, which creates strong links between the levels of care and the life histories

  5. The Berlekamp-Massey Algorithm revisited Nadia Ben Atti (*), Gema M. Diaz-Toca (y) Henri Lombardi (z)

    E-print Network

    Lombardi, Henri

    * * simplified by Massey (see [5]). The similarity of the algorithm to the extended Euclidean Algorithm * *can of the extended Euclidean Alg* *orithm given in [3], to find exactly the Berlekamp-Massey Algorithm The Berlekamp-Massey Algorithm revisited Nadia Ben Atti

  6. Single-wafer cluster tool performance: an analysis of the effects of redundant chambers and revisitation sequences on throughput

    Microsoft Academic Search

    Terry L. Perkinson; Ronald S. Gyurcsik; Peter K. McLarty

    1996-01-01

    Recent trends in the semiconductor industry indicate the need to explore alternatives to batch-wafer manufacturing. One proposed alternative is a micro-factory based on cluster tools. This paper presents an analysis of the effect of redundant chambers and chamber revisitation process sequences on the throughput in an individual cluster tool. Theoretical models which quantify the time required to process a lot

  7. arXiv:1104.3153v1[cs.DS]15Apr2011 Efficient Seeds Computation Revisited

    E-print Network

    Paris-Sud XI, Université de

    arXiv:1104.3153v1[cs.DS]15Apr2011 Efficient Seeds Computation Revisited Michalis Christou1 , Maxime, and there are linear time algorithms for finding the shortest cover. The seed is a more complicated generalization of periodicity, it is a cover of a superstring of a given string, and the shortest seed problem is of much higher

  8. Adaptive Evolution of Digestive RNASE1 Genes in Leaf-Eating Monkeys Revisited: New Insights from Ten Additional

    E-print Network

    Oregon, University of

    Adaptive Evolution of Digestive RNASE1 Genes in Leaf-Eating Monkeys Revisited: New Insights from of the colobine monkeys to leaf eating have long intrigued evolutionary biologists since the identification it into focus again. Current understanding of Colobine RNASE1 gene evolution of colobine monkeys largely depends

  9. Energy management and design of centralized air-conditioning systems through the non-revisiting strategy for heuristic optimization methods

    Microsoft Academic Search

    K. F. Fong; S. Y. Yuen; C. K. Chow; S. W. Leung

    2010-01-01

    It is getting more and more popular to apply heuristic optimization methods, like genetic algorithm (GA) and particle swarm optimization (PSO), to handle various engineering optimization problems. In this paper, optimization problems of typical centralized air-conditioning systems were solved by the non-revisiting (Nr) strategy, which was proposed to be incorporated into the common heuristic methods for improving the optimization effectiveness

  10. A Digital Humanities Approach to the History of Science Eugenics revisited in hidden debates by means of

    E-print Network

    de Rijke, Maarten

    A Digital Humanities Approach to the History of Science Eugenics revisited in hidden debates systematically stud- ied in a single comparative historical project in the subject area of heredity and eugenics the problem of traditional his- torical research that only documents explicitly referring to eugenics issues

  11. Behavioural Processes, 13 (1986) 191-202 191 IMITATION LEARNING IN BUDGERIGARS: DAWSON AND FOSS (1965) REVISITED

    E-print Network

    Galef Jr., Bennett G.

    1986-01-01

    Behavioural Processes, 13 (1986) 191-202 191 Elsevier IMITATION LEARNING IN BUDGERIGARS: DAWSON, R.M. budgerigars: Dawson and Foss (1965) revisited. 1986. Behav. Imitation learning in Processes,13: 191-202. Dawson and Foss (1965) have reported that each of five naive budgerigars (Melopsittacus

  12. Coagulation reactions in low dimensions: Revisiting subdiffusive A+A reactions in one dimension S. B. Yuste,1

    E-print Network

    Lindenberg, Katja

    Coagulation reactions in low dimensions: Revisiting subdiffusive A+A reactions in one dimension S November 2009 We present a theory for the coagulation reaction A+AA for particles moving subdiffusively-diffusion theories could be tested, but there have been very few successes, among them the coagulation reac- tions A

  13. Revisiting the 1897 Shillong and 1905 Kangra earthquakes in northern India: Site Response, Moho reflections and a Triggered Earthquake

    E-print Network

    Bilham, Roger

    1 Revisiting the 1897 Shillong and 1905 Kangra earthquakes in northern India: Site Response, Moho reflections and a Triggered Earthquake Susan E. Hough(1), Roger Bilham(2), Nicolas Ambraseys(3), and Nicole distributions for the Mw8.0 Shillong Plateau earthquake of 1897 and the Mw7.8 Kangra earthquake of 1905

  14. Revisiting an Old Friend: The Practice and Promise of Cooperative Learning for the Twenty-First Century

    ERIC Educational Resources Information Center

    Schul, James E.

    2011-01-01

    Cooperative learning has long been at the disposal of school teachers. However, it is often misunderstood by some teachers as just another form of collaborative group work. This article revisits cooperative learning, including a sampling of its popular variations, with practical approaches toward effectively integrating it into classroom…

  15. Revisiting the early childhood-health dyad: Health promotion in early childhood settings - Implications for policy and practice

    Microsoft Academic Search

    Jacqueline Haydeni

    This article stresses the need to revisit the early childhood-health partnership in relation to childcare services. The author reviews contrasting notions of sickness and health and shows how social determinants have become significant predictors of long-term health and wellbeing for children and families. Building on this, the health promotion movement of WHO has stressed the importance of partnerships and community

  16. View-Based Recognition of Faces in Man and Machine: Re-visiting Inter-Extra-Ortho

    E-print Network

    face recognition. The experimental paradigm is modeled after the inter-extra-ortho experiment using and view-interpolation). We then compared human recognition performance to a novel computational view651 View-Based Recognition of Faces in Man and Machine: Re-visiting Inter-Extra-Ortho Christian

  17. Today's Teens, Their Problems, and Their Literature: Revisiting G. Robert Carlsen's "Books and the Teenage Reader" Thirty Years Later.

    ERIC Educational Resources Information Center

    Carroll, Pamela Sissi

    1997-01-01

    Revisits G. Robert Carlsen's call for the use of young adult literature in the classroom by looking specifically at the emotional and reading needs of older adolescents, those in the upper grades. Discusses problems associated with adolescence in the late twentieth century and lists recommended young adult books that touch on those issues. (TB)

  18. From practice-based knowledge to the practice of research: Revisiting constructivist research works on knowledge1

    E-print Network

    Paris-Sud XI, Université de

    1 From practice-based knowledge to the practice of research: Revisiting constructivist research works on knowledge1 Sandra Charreire-Petit, University Paris Sud 11, PESOR Isabelle Huault, University Paris Dauphine, DRM-DMSP Abstract Research studies within organizational knowledge are good examples

  19. International Conference on E-Portfolio Process in Vocational Education-EPVET 2007 REVISITING CNC TRAINING A "VIRTUAL TRAINING CENTRE

    E-print Network

    Aristomenis, Antoniadis

    International Conference on E-Portfolio Process in Vocational Education- EPVET 2007 REVISITING CNC TRAINING ­ A "VIRTUAL TRAINING CENTRE FOR CNC" Mehmet ahin*1 , Nikolaos Bilalis2 , Süleyman Yaldiz1, Technological Educational Institute of Crete, Chania, Greece Abstract CNC Training has been a scope of interest

  20. FR Cnc Nature Revisited M.C. Galvez, A. Golovin, M. Hernan-Obispo, E. Pavlenko, M. Andreev, D.

    E-print Network

    Complutense de Madrid, Universidad

    FR Cnc Nature Revisited M.C. G´alvez, A. Golovin, M. Hern´an-Obispo, E. Pavlenko, M. Andreev, D and spectroscopic monitoring of FR Cnc re- ported a tricky nature. We carried out several observations at different Cnc in three observing runs: March-April 2004, using the Fibre Optics Cassegrain Echelle Spec

  1. Revisiting Hot Passive Replication Ruben de Juan-Marin, Hendrik Decker and Francesc D. Mu~noz-Escoi

    E-print Network

    Muñoz, Francesc

    Revisiting Hot Passive Replication Rub´en de Juan-Mar´in, Hendrik Decker and Francesc D. Mu of communication synchrony. Therefore, we propose a new, detailed classification of hot passive replication approach which merits further attention, hot passive replication propa- gates the state updates at the end

  2. SD-Squared Revisited: Reply to Coltheart, Tree, and Saunders (2010) Anna M. Woollams and Matthew A. Lambon Ralph

    E-print Network

    Plaut, David C.

    2010-01-01

    SD-Squared Revisited: Reply to Coltheart, Tree, and Saunders (2010) Anna M. Woollams and Matthew A a universal decline into surface dyslexia, a phenomenon we termed "SD-squared." Coltheart, Tree, and Saunders neural regions that support correct exception word reading (Coltheart, Tree, & Saunders, 2010). We

  3. Western Baie Verte Peninsula revisited: from ophiolite obduction onto Laurentia, the Notre Dame continental arc, to post-arc continental volcanism and the Salinic Orogeny.

    E-print Network

    Kidd, William S. F.

    Western Baie Verte Peninsula revisited: from ophiolite obduction onto Laurentia, the Notre Dame Peninsula where it represents an east-facing prism beneath obducted ophiolite. The overlying Advocate Complex contains dismembered ophiolite including mantle, boninitic cumulates, gabbro and sheeted dykes

  4. Differences in the right inferior longitudinal fasciculus but no general disruption of white matter tracts in

    E-print Network

    Kanwisher, Nancy

    , and worse in the ASD group, with some scans unusable because of head motion artifacts. When we follow is reduced "integrity" of long-range white matter tracts, a claim based primarily on diffusion imaging standard data analysis practices (i.e., without matching head motion between groups), we replicate

  5. Delineation of the Inferior Longitudinal Fasciculus in Subjects with 22q11.2 Deletion Syndrome

    E-print Network

    using tractography. - Subjects: 18 young adult 22q11DS patients were matched on age, gender integrity and myelination in young adults with 22q11DS. BACKGROUND RESULTS CONCLUSIONS REFERENCES MATERIALS11.2 Deletion Syndrome (22q11DS) represents a population at high risk for developing schizophrenia

  6. Diffusion Tensor Imaging of the Superior Longitudinal Fasciculus and Working Memory

    E-print Network

    Poldrack, Russ

    ) in the left and right SLF in 12 young adult patients with recent-onset schizophrenia and 17 matched control-Onset Schizophrenia Katherine H. Karlsgodt, Theo G.M. van Erp, Russell A. Poldrack, Carrie E. Bearden, Keith H-parietal circuitry are thought to be associated with working memory (WM) deficits in patients with schizophrenia

  7. Anatomical Properties of the Arcuate Fasciculus Predict Phonological and Reading Skills in Children

    E-print Network

    Wandell, Brian A.

    that lesions in left posterior inferior frontal cortex (Brocas area) create a deficit in the ability to produce network model of language processing in the brain (Wernicke, 1874). His view of cortical com- putations portrayed the brain as a mosaic of sensory and motor representations, where new functions arise from novel

  8. Bryonora, Praha, 34 (2004) 41 Vzda A. (2003): Lichenes rariores exsiccati. Fasciculus 4950 (numeris 481500). Brno.

    E-print Network

    Kucera, Jan

    2004-01-01

    among Central European species of the aquatic moss Cinclidotus. ­ Cryptogamie Bryologie 24: 147. ­ Journal of Molecular Evolution 55: 595­605. Aldous A. R. (2002): Nitrogen translocation in Sphagnum mosses (2004) Allen B. (ed.) (2002): Moss flora of Central America. Part 2. Encalyptaceae

  9. Beyond the Arcuate Fasciculus: Consensus and Controversy in the Connectional Anatomy of Language

    ERIC Educational Resources Information Center

    Dick, Anthony Steven; Tremblay, Pascale

    2012-01-01

    The growing consensus that language is distributed into large-scale cortical and subcortical networks has brought with it an increasing focus on the connectional anatomy of language, or how particular fibre pathways connect regions within the language network. Understanding connectivity of the language network could provide critical insights into…

  10. Complex Langevin dynamics in the SU(3) spin model at nonzero chemical potential revisited

    E-print Network

    Gert Aarts; Frank A. James

    2012-01-25

    The three-dimensional SU(3) spin model is an effective Polyakov loop model for QCD at nonzero temperature and density. It suffers from a sign problem at nonzero chemical potential. We revisit this model using complex Langevin dynamics and assess in particular the justification of this approach, using analyticity at small mu^2 and the criteria for correctness developed recently. Finite-stepsize effects are discussed in some detail and a higher-order algorithm is employed to eliminate leading stepsize corrections. Our results strongly indicate that complex Langevin dynamics is reliable in this theory in both phases, including the critical region. This is in sharp contrast to the case of the XY model, where correct results were obtained in only part of the phase diagram.

  11. Antiresonant reflecting optical waveguide microstructured fibers revisited: a new analysis based on leaky mode coupling.

    PubMed

    Renversez, Gilles; Boyer, Philippe; Sagrini, Angelo

    2006-06-12

    Using two different modal methods, the multipole method and the more recent fast Fourier factorization method, we exhibit and explain a core mode transition induced by avoided crossing between a core localized leaky mode and an high-index cylinder leaky mode in anti-resonant reflecting optical waveguide microstructured optical fibers (ARROW MOFs). Due to its wavelength selectivity and to the leaky nature of the involved modes, this transition doesn't seem to have already been described in detail and analyzed as done in this work in spite of several already published studies on core mode dispersion properties. The main properties of this transition are also described. We also revisite the already mentionned cut-off phenomena limiting the transmission band in ARROW MOFs in terms of mode coupling between the core mode and one or several high- index cylinder modes. PMID:19516737

  12. Running Spectral Index from Large-field Inflation with Modulations Revisited

    E-print Network

    Michael Czerny; Takeshi Kobayashi; Fuminobu Takahashi

    2014-06-26

    We revisit large field inflation models with modulations in light of the recent discovery of the primordial B-mode polarization by the BICEP2 experiment, which, when combined with the Planck + WP + highL data, gives a strong hint for additional suppression of the CMB temperature fluctuations at small scales. Such a suppression can be explained by a running spectral index. In fact, it was pointed out by two of the present authors (TK and FT) that the existence of both tensor mode perturbations and a sizable running of the spectral index is a natural outcome of large inflation models with modulations. We find that this holds also in the recently proposed multi-natural inflation, in which the inflaton potential consists of multiple sinusoidal functions and therefore the modulations are a built-in feature.

  13. Running spectral index from large-field inflation with modulations revisited

    NASA Astrophysics Data System (ADS)

    Czerny, Michael; Kobayashi, Takeshi; Takahashi, Fuminobu

    2014-07-01

    We revisit large field inflation models with modulations in light of the recent discovery of the primordial B-mode polarization by the BICEP2 experiment, which, when combined with the Planck + WP +highL data, gives a strong hint for additional suppression of the CMB temperature fluctuations at small scales. Such a suppression can be explained by a running spectral index. In fact, it was pointed out by two of the present authors (TK and FT) that the existence of both tensor mode perturbations and a sizable running of the spectral index is a natural outcome of large inflation models with modulations such as axion monodromy inflation. We find that this holds also in the recently proposed multi-natural inflation, in which the inflaton potential consists of multiple sinusoidal functions and therefore the modulations are a built-in feature.

  14. Revisiting constraints on the (pseudo)conformal universe with Planck data

    NASA Astrophysics Data System (ADS)

    Rubtsov, G. I.; Ramazanov, S. R.

    2015-02-01

    We revisit constraints on the (pseudo)conformal universe from the nonobservation of statistical anisotropy in the Planck data. The quadratic maximal likelihood estimator is applied to the Planck temperature maps at frequencies 143 and 217 GHz as well as their cross-correlation. The strongest constraint is obtained in the scenario of the (pseudo)conformal universe with a long intermediate evolution after conformal symmetry breaking. In terms of the relevant parameter (coupling constant), the limit is h2<0.0013 at 95% C.L. (using the cross estimator). The analogous limit is much weaker in the scenario without the intermediate stage (h2ln H/0 ? <0.52 ) allowing the coupling constant to be of order 1. In the latter case, the non-Gaussianity in the four-point function appears to be a more promising signature.

  15. Revisiting the symmetric reactions for synthesis of super-heavy nuclei of Z?120

    NASA Astrophysics Data System (ADS)

    Choudhury, R. K.; Gupta, Y. K.

    2014-04-01

    Extensive efforts have been made experimentally to reach nuclei in the super-heavy mass region of Z=110 and above with suitable choices of projectile and target nuclei. The cross sections for production of these nuclei are seen to be in the range of a few picobarn or less, and pose great experimental challenges. Theoretically, there have been extensive calculations for highly asymmetric (hot-fusion) and moderately asymmetric (cold-fusion) collisions and only a few theoretical studies are available for near-symmetric collisions to estimate the cross sections for production of super-heavy nuclei. In the present article, we revisit the symmetric heavy ion reactions with suitable combinations of projectile and target nuclei in the rare-earth region, that will lead to super-heavy nuclei of Z?120 with measurable fusion cross sections.

  16. What drives health care expenditure?--Baumol's model of 'unbalanced growth' revisited.

    PubMed

    Hartwig, Jochen

    2008-05-01

    The share of health care expenditure in GDP rises rapidly in virtually all OECD countries, causing increasing concern among politicians and the general public. Yet, economists have to date failed to reach an agreement on what the main determinants of this development are. This paper revisits Baumol's [Baumol, W.J., 1967. Macroeconomics of unbalanced growth: the anatomy of urban crisis. American Economic Review 57 (3), 415-426] model of 'unbalanced growth', showing that the latter offers a ready explanation for the observed inexorable rise in health care expenditure. The main implication of Baumol's model in this context is that health care expenditure is driven by wage increases in excess of productivity growth. This hypothesis is tested empirically using data from a panel of 19 OECD countries. Our tests yield robust evidence in favor of Baumol's theory. PMID:18164773

  17. Three-Alarm System: Revisited to treat Thumb-sucking Habit

    PubMed Central

    Shetty, Manoj; Shetty, N Shridhar; Deoghare, Anushka

    2015-01-01

    ABSTRACT Thumb and digit-sucking habits or non-nutritive sucking are considered to be the most prevalent among oral habits. Most children stop thumb sucking on their own. If the habit continues beyond 3 to 4 years of age, it not only affects the dental occlusion, but the shape of the thumb/digit may be altered as well. This article presents the management of thumb sucking by modified RURS, elbow guard incorporated with revised ‘three-alarm’ system. How to cite this article: Shetty RM, Shetty M, Shetty NS, Deoghare A. Three-Alarm System: Revisited to treat Thumb-sucking Habit. Int J Clin Pediatr Dent 2015;8(1):82-86.

  18. Revisiting competition in a classic model system using formal links between theory and data.

    PubMed

    Hart, Simon P; Burgin, Jacqueline R; Marshall, Dustin J

    2012-09-01

    Formal links between theory and data are a critical goal for ecology. However, while our current understanding of competition provides the foundation for solving many derived ecological problems, this understanding is fractured because competition theory and data are rarely unified. Conclusions from seminal studies in space-limited benthic marine systems, in particular, have been very influential for our general understanding of competition, but rely on traditional empirical methods with limited inferential power and compatibility with theory. Here we explicitly link mathematical theory with experimental field data to provide a more sophisticated understanding of competition in this classic model system. In contrast to predictions from conceptual models, our estimates of competition coefficients show that a dominant space competitor can be equally affected by interspecific competition with a poor competitor (traditionally defined) as it is by intraspecific competition. More generally, the often-invoked competitive hierarchies and intransitivities in this system might be usefully revisited using more sophisticated empirical and analytical approaches. PMID:23094373

  19. Revisiting a pre-inflationary radiation era and its effect on the CMB power spectrum

    E-print Network

    Suratna Das; Gaurav Goswami; Jayanti Prasad; Raghavan Rangarajan

    2015-06-04

    We revisit the scenario where inflation is preceded by a radiation era by considering that the inflaton too could have been in thermal equilibrium early in the radiation era. Hence we take into account not only the effect of a pre-inflationary era on the inflaton mode functions but also that of a frozen thermal distribution of inflaton quanta. We initially discuss in detail the issues relevant to our scenario of a pre-inflationary radiation dominated era and then obtain the scalar power spectrum for this scenario. We find that the power spectrum is free from infrared divergences. We then use the WMAP and Planck data to determine the constraints on the inflaton comoving `temperature' and on the duration of inflation. We find that the best fit value of the duration of inflation is less than 1 e-folding more than what is required to solve cosmological problems, while only an upper bound on the inflaton temperature can be obtained.

  20. Catalytic mechanism of porphobilinogen synthase: the chemical step revisited by QM/MM calculations.

    PubMed

    Tian, Bo-Xue; Erdtman, Edvin; Eriksson, Leif A

    2012-10-11

    Porphobilinogen synthase (PBGS) catalyzes the asymmetric condensation and cyclization of two 5-aminolevulinic acid (5-ALA) substrate molecules to give porphobilinogen (PBG). The chemical step of PBGS is herein revisited using QM/MM (ONIOM) calculations. Two different protonation states and several different mechanisms are considered. Previous mechanisms based on DFT-only calculations are shown unlikely to occur. According to these new calculations, the deprotonation step rather than ring closure is rate-limiting. Both the C-C bond formation first mechanism and the C-N bond formation first mechanism are possible, depending on how the A-site ALA binds to the enzyme. We furthermore propose that future work should focus on the substrate binding step rather than the enzymatic mechanism. PMID:22974111

  1. Re-visit local coupling correction in the interaction regions of RHIC

    SciTech Connect

    Luo, Y.; Fischer, W.; Liu, C.; Marusic, A.; Minty, M.; Ptitsyn, V.; Schoefer, V.; Tepikian, S.; Trbojevic, D.; Zimmer, C.

    2011-11-01

    In this article we will re-visit the local coupling correction in the interaction regions (IRs) of the Relativistic Heavy Ion Collider (RHIC). We will review the measurement data of triplet quadrupole rolls, the local coupling correction strengths in the RHIC control system, and the methods for the local coupling correction with local skew quadrupole correctors. Based on the in-turnnel measurement data of triplet roll errors in 2011, we will analytically calculate and simulate IR-bump method to find out the local skew correction strengths and compare them at store and at injection with the Blue and Yellow ring lattices in the 2011 polarized proton (p-p) and Au-Au runs. The vertical dispersion from the triplet roll errors, local and global coupling correction skew quadrupoles, and the vertical dipole correctors are calculated and discussed.

  2. Congenital Insensitivity to Pain and Anhydrosis: Diagnostic and Therapeutic Dilemmas revisited

    PubMed Central

    Kandregula, Chaitanya Ram; Koya, Srikanth; Lakhotia, Disha

    2015-01-01

    ABSTRACT First described in 1932 by Dearborn as ‘congenital pure analgesia’, congenital insensitivity to pain and anhydrosis (CIPA) or hereditary sensory and autonomic neuropathy (HSAN) type IV is an extremely rare autosomal recessive disorder. A 7-year-old female child who is an established case of congenital insensitivity to pain and anhydrosis visited the department of pediatric medicine with osteoarthritic neuropathy. A multidisciplinary team approach was utilized to treat the child under general anesthesia. This article also discusses the diagnostic and therapeutic dilemmas involved in treating this type of children. How to cite this article: Ravichandra KS, Kandregula CR, Koya S, Lakhotia D. Congenital Insensitivity to Pain and Anhydrosis: Diagnostic and Therapeutic Dilemmas revisited. Int J Clin Pediatr Dent 2015;8(1):75-81.

  3. Revisiting the tunneling spectrum and information recovery of a general charged and rotating black hole

    E-print Network

    Ge-Rui Chen; Yong-Chang Huang

    2015-01-15

    In this paper we revisit the tunneling spectrum of a charged and rotating black hole--Kerr-Newman black hole by using Parikh and Wilczek's tunneling method and get the most general result compared with the works [9, 10]. We find an ambiguity in Parikh and Wilczek's tunneling method, and give a reasonable description. We use this general spectrum to discuss the information recovery based on the Refs. [11-13]. For the tunneling spectrum we obtained, there exit correlations between sequential Hawking radiations, information can be carried out by such correlations, and the entropy is conserved during the radiation process. So we resolve the information loss paradox based on the methods [11-13] in the most general case.

  4. Legendre structure of ?-thermostatistics revisited in the framework of information geometry

    NASA Astrophysics Data System (ADS)

    Scarfone, A. M.; Wada, T.

    2014-07-01

    Information geometry is a powerful framework in which to study families of probability distributions or statistical models by applying differential geometric tools. It provides a useful framework for deriving many important structures in probability theory by identifying the space of probability distributions with a differentiable manifold endowed with a Riemannian metric. In this paper, we revisit some aspects concerning the ?-thermostatistics based on the entropy S? in the framework of information geometry. After introducing the dually flat structure associated with the ?-distribution, we show that the dual potentials derived in the formalism of information geometry correspond to the generalized Massieu function ?? and the generalized entropy S? characterizing the Legendre structure of the ?-deformed statistical mechanics. In addition, we obtain several quantities, such as escort distributions and canonical divergence, relevant for the further development of the theory.

  5. Revisiting a pre-inflationary radiation era and its effect on the CMB power spectrum

    NASA Astrophysics Data System (ADS)

    Das, Suratna; Goswami, Gaurav; Prasad, Jayanti; Rangarajan, Raghavan

    2015-06-01

    We revisit the scenario where inflation is preceded by a radiation era by considering that the inflaton too could have been in thermal equilibrium early in the radiation era. Hence we take into account not only the effect of a pre-inflationary era on the inflaton mode functions but also that of a frozen thermal distribution of inflaton quanta. We initially discuss in detail the issues relevant to our scenario of a pre-inflationary radiation dominated era and then obtain the scalar power spectrum for this scenario. We find that the power spectrum is free from infrared divergences. We then use the WMAP and Planck data to determine the constraints on the inflaton comoving 'temperature' and on the duration of inflation. We find that the best fit value of the duration of inflation is less than 1 e-folding more than what is required to solve cosmological problems, while only an upper bound on the inflaton temperature can be obtained.

  6. Simple pendulum dynamics: revisiting the Fourier-based approach to the solution

    E-print Network

    Borghi, Riccardo

    2013-01-01

    The Fourier-based analysis customarily employed to analyze the dynamics of a simple pendulum is here revisited to propose an elementary iterative scheme aimed at generating a sequence of analytical approximants of the exact law of motion. Each approximant is expressed by a Fourier sum whose coefficients are given by suitable linear combinations of Bessel functions, which are expected to be more accessible, especially at an undergraduate level, with respect to Jacobian elliptic functions. The first three approximants are explicitely obtained and compared with the exact solution for typical initial angular positions of the pendulum. In particular, it is shown that, at the lowest approximation level, the law of motion of the pendulum turns out to be adequately described, up to oscillation amplitudes of $\\pi/2$, by a sinusoidal temporal behaviour with a frequency proportional to the square root of the so-called "besinc" function, well known in physical optics.

  7. Primary care in nursing homes revisited: survey of the experiences of primary care physicians.

    PubMed

    Gleeson, L E; Jennings, S; Gavin, R; McConaghy, D; Collins, D R

    2014-09-01

    The Irish Health Information and Quality Authority (HIQA) published National Quality Standards for Residential Care Settings for Older People in 2009. We reported on experiences of general practitioners (GPs) in Dublin caring for nursing home patients (NHPs) in 2006. We revisit these experiences following publication of HIQA's standards. 400 GPs received an anonymous postal survey. Of 204 respondents, 145 (71%) felt NHPs required more contact time and 124 (61%) reported more complex consultations compared to other patients. Only 131 (64%) felt adequately trained in gerontology. 143 (70%) reported access to specialist advice, but only 6 (3%) reported a change in this following HIOA standards. 65 (32%) had witnessed substandard care in a NH, of which 16 (25%) made no report, similar figures to 2006. There remains similar levels of concern regarding patient complexity, substandard care, access to specialist support and training in the care of NHPs. Many GPs expressed uncertainty regarding their role in implementing HIQA standards. PMID:25282960

  8. Revisiting the age of enlightenment from a collective decision making systems perspective

    SciTech Connect

    Rodriguez, Marko A [Los Alamos National Laboratory; Watkins, Jennifer H [Los Alamos National Laboratory

    2009-01-01

    The ideals of the eighteenth century's Age of Enlightenment are the foundation of modern democracies. The era was characterized by thinkers who promoted progressive social reforms that opposed the long-established aristocracies and monarchies of the time. Prominent examples of such reforms include the establishment of inalienable human rights, self-governing republics, and market capitalism. Twenty-first century democratic nations can benefit from revisiting the systems developed during the Enlightenment and reframing them within the techno-social context of the Information Age. This article explores the application of social algorithms that make use of Thomas Paine's (English: 1737--1809) representatives, Adam Smith's (Scottish: 1723--1790) self-interested actors, and Marquis de Condorcet's (French: 1743--1794) optimal decision making groups. It is posited that technology-enabled social algorithms can better realize the ideals articulated during the Enlightenment.

  9. F center in lithium fluoride revisited: Comparison of solid-state physics and quantum-chemistry approaches

    NASA Astrophysics Data System (ADS)

    Karsai, Ferenc; Tiwald, Paul; Laskowski, Robert; Tran, Fabien; Koller, David; Gräfe, Stefanie; Burgdörfer, Joachim; Wirtz, Ludger; Blaha, Peter

    2014-03-01

    We revisit the theoretical description of the F color center in lithium fluoride employing advanced complementary ab initio techniques. We compare the results from periodic supercell calculations involving density-functional theory (DFT) and post-DFT techniques with those from the embedded-cluster approach involving quantum-chemical many-electron wave-function techniques. These alternative approaches yield results in good agreement with each other and with the experimental data provided that correlation effects are properly taken into account.

  10. Decision-making in the physician–patient encounter: revisiting the shared treatment decision-making model

    Microsoft Academic Search

    Cathy Charles; Amiram Gafni; Tim Whelan

    1999-01-01

    In this paper we revisit and add elements to our earlier conceptual framework on shared treatment decision-making within the context of different decision-making approaches in the medical encounter (Charles, C., Gafni, A., Whelan, T., 1997. Shared decision-making in the medical encounter: what does it mean? (or, it takes at least two to tango). Social Science & Medicine 44, 681–692.). This

  11. Development, Democracy, and Women's Legislative Representation: Re-Visiting Existing Explanations of Gender Variation in the World's Parliaments

    Microsoft Academic Search

    Jocelyn Viterna; Jason Beckfield

    Previous studies have found that the substantial cross-national variation in women's legislative representation is not explained by cross-national differences in socioeconomic development. We re-visit an existing study and demonstrate that economic development does matter. Accepted explanations fit rich nations much better than poor nations and obscure the effects of democracy on women's representation in the developing world. We call for

  12. The criteria of Riesz, Hardy-Littlewood et al. for the Riemann Hypothesis revisited using similar functions

    E-print Network

    Stefano Beltraminelli; Danilo Merlini

    2006-01-07

    The original criteria of Riesz and of Hardy-Littlewood concerning the truth of the Riemann Hypothesis (RH) are revisited and further investigated in light of the recent formulations and results of Maslanka and of Baez-Duarte concerning a representation of the Riemann Zeta function. Then we introduce a general set of similar functions with the emergence of Poisson-like distributions and we present some numerical experiments which indicate that the RH may barely be true.

  13. Revisiting characteristic impedance and its definition of microstrip line with a self-calibrated 3-D MoM scheme

    Microsoft Academic Search

    Lei Zhu; Ke Wu

    1998-01-01

    Characteristic impedance and its definition are revisited and discussed for microstrip line with a self-calibrated three-dimensional (3-D) method of moments (MoM). This 3-D MoM accommodates a scheme called short-open calibration (SOC) so that potential parasitic effects brought by the impressed voltage excitation and other relevant factors can be effectively removed. In this way, the characteristic impedance can be accurately defined

  14. Balloons Revisited

    ERIC Educational Resources Information Center

    Jeskova, Z.; Featonby, D.; Fekova, V.

    2012-01-01

    Whilst everyone is familiar with the process of blowing up a balloon, few of us have gone further to quantify the actual pressures involved at different stages in the inflation process. This paper seeks to describe experiments to fill some of those gaps and examine some of the apparently anomalous behaviour of connected balloons. (Contains 12…

  15. Myolysis Revisited

    PubMed Central

    2008-01-01

    Numerous procedures have been developed in recent decades that claim to provide significant improvement in myoma status without hysterectomy. However, what is the cost in time and money of these procedures? This is a review of the current literature regarding these recent procedures to determine which, if any, is the best treatment for myomas. We conducted a search of PubMed using the terms “bipolar-, cryo-, radiofrequency, laparoscopic-, focused high-energy MRI-guided ultrasound, and MRI-guided laser myolysis” to identify reports of the various procedures. Based on these published reports, we describe the various types of myolysis performed in multiple patients in outpatient facilities including patient outcomes, complications, cost, and efficiency of the procedures. PMID:19275864

  16. Versailles revisited

    Microsoft Academic Search

    Marc Trachtenberg

    2000-01-01

    Manfred Boemeke, Gerald Feldman, and Elisabeth Glaser, The Treaty of Versailles: A Reassessment after 75 Years (New York: Cambridge University Press; and Washington, D.C.: German Historical Institute, 1998).

  17. Basketweaving Revisited.

    ERIC Educational Resources Information Center

    Kocsis, Rollin

    1982-01-01

    Presents detailed instructions for the design and construction of simple reed baskets. Directions cover materials preparation, basic designs, and methods for giving baskets a finished appearance. (AM)

  18. Andragogy Revisited

    Microsoft Academic Search

    John L. Elias

    1979-01-01

    In the exchange that follows, John Elias resumes the andragogy-pedagogy debate by entering the lists against Malcolm Knowles and Leon McKenzie. McKenzie defends his position and Russell Knudson takes a new tack. Knowles has promised a rebuttal in an upcoming issue and Robert Carlson has also agreed to respond to Elias.

  19. Revisiting endosulfan.

    PubMed

    Gude, Dilip; Bansal, Dharam Pal

    2012-01-01

    Endosulfan toxicity could precipitate gargantuan jeopardy and may result in irreversible and fatal damage. The spectrum of involvement may range from mild nausea, vomiting, and anxiety to intractable seizures and multiorgan damage resulting in death. We report a case of endosulfan poisoning complicated by multi-organ dysfunction, cardiac arrest, and death. PMID:24479009

  20. Revisiting Endosulfan

    PubMed Central

    Gude, Dilip; Bansal, Dharam Pal

    2012-01-01

    Endosulfan toxicity could precipitate gargantuan jeopardy and may result in irreversible and fatal damage. The spectrum of involvement may range from mild nausea, vomiting, and anxiety to intractable seizures and multiorgan damage resulting in death. We report a case of endosulfan poisoning complicated by multi-organ dysfunction, cardiac arrest, and death. PMID:24479009

  1. Speechreading Revisited

    ERIC Educational Resources Information Center

    Woll, Bencie

    2012-01-01

    Although speechreading has always served an important role in the communication of deaf people, educational interest in speechreading has decreased in recent decades. This paper reviews speechreading in terms of speech processing, neural activity and literacy, and suggests that it has an important role in intervention programmes for all deaf…

  2. PACER revisited

    NASA Astrophysics Data System (ADS)

    Moir, Ralph W.

    1988-11-01

    This paper discusses a modified version of the PACER concept for power and nuclear material production. In the PACER concept, a 20-kt peaceful nuclear explosion is contained in a cavity about 200 m in diameter, filled with 200 atom of 500 C steam. Energy from the explosion is used to produce power, and the neutrons are used to produce materials such as U-233. The present idea is to modify the PACER concept in three ways to improve the practicality, predictability, and safety of power production from this technology and thus improve public acceptance of this power source. These improvements are: (1) line the cavity with steel; (2) replace the steam with molten salt, LiF + BeF2; and (3) reduce the explosive yield to about 2 kt. PACER is the only fusion power concept where the underlying technology of the power source itself is proven and in hand today. The molten-salt shock-suppression and heat transport system and the durability of the underground cavity need demonstration.

  3. Polypseudologarithms revisited

    NASA Astrophysics Data System (ADS)

    Cvijovi?, Djurdje

    2010-04-01

    Lee, in a series of papers, described a unified formulation of the statistical thermodynamics of ideal quantum gases in terms of the polylogarithm functions, Li(z). It is aimed here to investigate the functions Li(z), for s=0,-1,-2,…, which are, following Lee, referred to as the polypseudologarithms (or polypseudologs) of order n?-s. Various known results regarding polypseudologs, mainly obtained in widely differing contexts and currently scattered throughout the literature, have been brought together along with many new results and insights and they all have been proved in a simple and unified manner. In addition, a new general explicit closed-form formula for these functions involving the Carlitz-Scoville higher tangent numbers has been established.

  4. PSOS Revisited

    Microsoft Academic Search

    Peter G. Neumann; Richard J. Feiertag

    2003-01-01

    This paper provides a retrospective view of the design of SRI's Provably Secure Operating System (PSOS), a for- mally specified tagged-capability hierarchical system ar- chitecture. It examines PSOS in the light of what has hap- pened in computer system developments since 1980, and assesses the relevance of the PSOS concepts in that light.

  5. Clementine revisited

    NASA Astrophysics Data System (ADS)

    NASA administrator Daniel S. Goldin is pushing for a sequel to Clementine, the joint Defense Department-NASA probe that successfully produced the most detailed topographic map of Moon ever filmed earlier this year. While a smash with scientists, the first Clementine mission was also a hit at the box office with its thrifty 80 million price tag. Clementine 2 would also come in under 100 million. The destination of Clementine 2 is under discussion. A top candidate is a Moon landing, which may help settle the question whether there is ice in the Moon's craters. Filming an asteroid and filming the Earth are the other leading options, according to Stewart Nozette, deputy program manager, Ballistic Missile Defense Organization. Although the second portion of Clementine's mission to map the asteroid Geographos failed, Clementine 2 would have the benefit of the lessons learned from number one, which is now in "cold storage" in an orbit around the Sun.

  6. Siphons, Revisited

    ERIC Educational Resources Information Center

    Richert, Alex; Binder, P. -M.

    2011-01-01

    The siphon is a very useful example of early technology, the operation of which has long been well understood. A recent article makes the claim that established beliefs regarding this device are incorrect and proposes a "chain model" in which intermolecular forces within the fluid play a large role while atmospheric pressure does not. We have…

  7. Pestalotiopsis revisited.

    PubMed

    Maharachchikumbura, S S N; Hyde, K D; Groenewald, J Z; Xu, J; Crous, P W

    2014-09-01

    Species of Pestalotiopsis occur commonly as plant pathogens, and represent a fungal group known to produce a wide range of chemically novel, diverse metabolites. In the present study, we investigated 91 Pestalotiopsis isolates from the CBS-KNAW Fungal Biodiversity Centre (CBS) culture collection. The phylogeny of the Amphisphaeriaceae was constructed based on analysis of 28S nrRNA gene (LSU) sequence data, and taxonomic changes are proposed to reflect more natural groupings. We combined morphological and DNA data, and segregated two novel genera from Pestalotiopsis, namely Neopestalotiopsis and Pseudopestalotiopsis. The three genera are easily distinguishable on the basis of their conidiogenous cells and colour of their median conidial cells. We coupled morphological and combined sequence data of internal transcribed spacer (ITS), partial ?-tubulin (TUB) and partial translation elongation factor 1-alpha (TEF) gene regions, which revealed 30 clades in Neopestalotiopsis and 43 clades in Pestalotiopsis. Based on these data, 11 new species are introduced in Neopestalotiopsis, 24 in Pestalotiopsis, and two in Pseudopestalotiopsis. Several new combinations are proposed to emend monophyly of Neopestalotiopsis, Pestalotiopsis and Pseudopestalotiopsis. PMID:25492988

  8. Countertransference revisited.

    PubMed

    Mills, Jon

    2004-08-01

    A female patient of mine recounts her week. I listen with interest, waiting for her to arrive at particular conclusions. She has suffered a great deal and still does, but prefers not to dwell on it. My interest turns into patience as she continues to talk but circumvents her discontent. She is adroit at avoidance, but easily offended when I point such things out. "I'd better wait" I think. I grow more aware that I must encourage her digressions. I feel frustrated. Getting further and further away, she skirts the issue with supple grace, then strays off into tangentiality. I forget her point and lose my focus, then get down on myself. The opportunity is soon gone. I glance at the clock as her monologue drones on into banality. I grow more uninterested and distant. There is a subtle irritation to her voice; a whiney indecisive ring begins to pervade my consciousness. I home in on her mouth with aversion, watching apprehensively as this disgusting hole flaps tirelessly but says nothing. It looks carnivorous, voracious. Now she is unattractive, something I have noticed before. I forget who my next patient is. I think about the meal I will prepare for my wife this evening, then glance at the time once more. Then I am struck: Why am I looking at the clock? So soon? The session has just begun. I catch myself. What is going on in me, between us? I am detached, but why? Is she too feeling unattuned, disconnected? I am failing my patient. What is her experience of me? I lamentingly confess that I do not feel I have been listening to her, and wonder what has gone wrong between us. I ask her if she has noticed. We talk about our feelings, our impact on one another, why we had lost our sense of connection, what it means to us. I instantly feel more involved, rejuvenated, and she continues, this time with me present. Her mouth is no longer odious, but sincere and articulate. She is attractive and tender; I suddenly feel empathy and warmth toward her. We are now very close. I am moved. Time flies, the session is soon over; we do not want it to end. PMID:15491945

  9. Ortega Revisited.

    ERIC Educational Resources Information Center

    Asheim, Lester

    1982-01-01

    Reexamines Ortega y Gasset's proposition that the professional role of the librarian is to act as a selective "filter between man and the torrent of books." Responsibilities of the librarian in light of the increasing volume of information, increases in speed of access to information, and information overload, are discussed. (Author/JL)

  10. Panspermia revisited

    NASA Astrophysics Data System (ADS)

    Horneck, Gerda

    "Panspermia", coined by S. Arrhenius in 1903, suggests that microscopic forms of life, e.g., bacterial spores, can be dispersed in space by the radiation pressure from the Sun thereby seeding life from one planet to another or even beyond our Solar System. Being ignored for almost the rest of the century, the scenario of interplanetary transfer of life has received increased support from recent discoveries, such as the detection of Martian meteorites and the high resistance of microorganisms to outer space conditions. With the aid of space technology and adequate laboratory devices the following decisive step required for viable transfer from one planet to another have been tested: (i) the escape process, i.e. impact ejection into space; (ii) the journey through space over extended periods of time; and (iii) the landing process, i.e. non-destructive deposition of the biological material on another planet. In systematic shock recovery experiments within a pressure range observed in Martian meteorites (5-50 GPa) a vital launch window of 5-40 GPa has been determined for spores of Bacillus subtilis and the lichen Xanthoria elegans, whereas this window was restricted to 5-10 GPa for the endolithic cyanobaterium Chroococcidiopsis. Traveling through space implies exposure to high vacuum, an intense radiation regime of cosmic and solar origin and high temperature fluctuations. In several space experiments the biological efficiency of these different space parameters has been tested: extraterrestrial solar UV radiation has exerted the most deleterious effects to viruses, as well as to bacterial and fungal spores; however shielding against this intense insolation resulted in 70 % survival of B. subtilis spores after spending 6 years in outer space. Lichens survived 2 weeks in space, even without any shielding. The entry process of microorganisms has been recently tested in the STONE facility attached to the heat shield of a reentry capsule. The data support the scenario of "Lithopanspermia", which assumes that impact-expelled rocks serve as interplanetary transfer vehicles for microorganisms colonizing those rocks. Literature: St¨ffler D, Horneck G, Ott S, Hornemann, U, Cockell CS, Moeller R, Meyer C, de Vera J-P, o Fritz J, Artemieva NA,.Experimental evidence for the potential impact ejection of viable microorganisms from Mars and Mars-like planets (2007) Icarus, 186, 585-588. Sancho, L.G., de la Torre, R., Horneck, G., Ascaso, C., de los Rios, A., Pintado, A., Wierzchos, J. and Schuster, M. (2007) Lichens survive in space: Results from the 2005 LICHENS experiment. Astrobiology, 7, 443-454. Mileikowsky C, Cucinotta F, Wilson J W, Gladman B, Horneck G, Lindegren L, Melosh J, Rickman H, Valtonen M, Zheng J Q (2000) Natural transfer of viable microbes In space, Part 1: From Mars to Earth and Earth to Mars, Icarus, 145, 391-427. Nicholson WL, Munakata N, Horneck G, Melosh HJ, and Setlow P (2000) Resistance of Bacillus endospores to extreme terrestrial and extraterrestrial environments, Microb. Mol. Biol. Rev. 64, 548-572.

  11. PACER revisited

    SciTech Connect

    Moir, R.W.

    1988-10-04

    This paper discusses a modified version of the PACER concept for power and nuclear material production, which changes the working fluid in the cavity from steam to the molten salt, LiF + BeF/sub 2/. In the PACER concept, a 20-kt peaceful nuclear explosion is contained in a cavity about 200 m in diameter, filled with 200 atm of 500/degree/C steam. Energy from the explosion is used to produce power, and the neutrons are used to produce materials such as /sup 233/U, Pu, /sup 60/Co, and T. The present idea is to modify the PACER concept in three ways, to improve the practicality, predictability, and safety of power production from this technology and thus improve public acceptance of this power source. These improvements are line the cavity with steel; replace the steam with molten salt; and reduce the explosive yield to about 2 kt. This concept is the only fusion power concept where the underlying technology is proven and in hand today. 9 refs., 3 figs., 1 tab.

  12. Coadaptation revisited

    SciTech Connect

    Wallace, B. (Virginia Polytechnic Institute and State Univ., Blacksburg (USA))

    1991-03-01

    During the four decades or more since Dobzhansky introduced the term 'coadaptation' to refer to the commonly observed selective superiority of inversion heterozygotes in populations of Drosophila pseudoobscura, the definition of the term has evolved, as have views concerning the rapidity with which coadaptation might occur. Indeed, the paucity of demonstrated instances of linkage disequilibrium in natural populations has led many to dismiss coadaptation as a factor in evolutionary change. The present article reviews the reasons why coadaptation (and the equivalent expression, 'integration of gene pools') was proposed as a phenomenon occurring in local (or experimental) populations, offers supporting data obtained through a reanalysis of data on irradiated populations of D. melanogaster, and concludes that sound evidence supports coadaptation as a factor in the genetic change of populations.65 references.

  13. Visibles Revisited

    ERIC Educational Resources Information Center

    Bridger, Mark; Zelevinsky, Andrei

    2005-01-01

    Within the set of points in the plane with integer coordinates, one point is said to be visible from another if no other point in the set lies between them. This study of visibility draws in topics from a wide variety of mathematical areas, including geometry, number theory, probability, and combinatorics.

  14. Lewis’ law revisited: the role of anisotropy in size–topology correlations

    PubMed Central

    Kim, Sangwoo; Cai, Muyun

    2014-01-01

    Since F T Lewis’ pioneering work in the 1920s, a linear correlation between the average in-plane area of domains in a two-dimensional (2D) cellular structure and the number of neighbors of the domains has been empirically proposed, with many supporting and dissenting findings in the ensuing decades. Revisiting Lewis’ original experiment, we take a larger set of more detailed data on the cells in the epidermal layer of Cucumis, and analyze the data in the light of recent results on size–topology correlations. We find that the correlation between the number-of-neighbor distribution (topology) and the area distribution is altered over that of many other 2D cellular systems (such as foams or disc packings), and that the systematic deviation can be explained by the anisotropic shape of the Cucumis cells. We develop a novel theory of size–topology correlation taking into account the characteristic aspect ratio of the cells within the framework of a granocentric model, and show that both Lewis’ and our experimental data is consistent with the theory. In contrast to the granocentric model for isotropic domains, the new theory results in an approximately linear correlation consistent with Lewis’ law. These statistical effects can be understood from the increased number of configurations available to a plane-filling domain system with non-isotropic elements, for the first time providing a firm explanation of why Lewis’ law is valid in some systems and fails in others.

  15. Multi-field DBI inflation: introducing bulk forms and revisiting the gravitational wave constraints

    E-print Network

    David Langlois; Sebastien Renaux-Petel; Daniele A. Steer

    2009-02-17

    We study multi-field Dirac-Born-Infeld (DBI) inflation models, taking into account the NS-NS and R-R bulk fields present in generic flux compactifications. We compute the second-order action, which governs the behaviour of linear cosmological perturbations, as well as the third-order action, which can be used to calculate non-Gaussianities in these models. Remarkably, for scalar-type perturbations, we show that the contributions due to the various form fields exactly cancel in both the second- and third-order actions. Primordial perturbations and their non-Gaussianities are therefore unaffected by the presence of form fields and our previous results are unmodified. We also study vector-type perturbations associated with the U(1) gauge field confined on the D3-brane, and discuss whether their quantum fluctuations can be amplified. Finally, we revisit the gravitational wave constraints on DBI inflation and show that an ultra-violet DBI multi-field scenario is still compatible with data, in contrast with the single field case, provided there is a transfer from entropy into adiabatic perturbations.

  16. Multi-field DBI inflation: introducing bulk forms and revisiting the gravitational wave constraints

    SciTech Connect

    Langlois, David; Renaux-Petel, Sebastien; Steer, Daniele A., E-mail: langlois@apc.univ-paris7.fr, E-mail: renaux@apc.univ-paris7.fr, E-mail: steer@apc.univ-paris7.fr [APC (Astroparticules et Cosmologie), UMR 7164 (CNRS, Universite Paris 7), 10 rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France)

    2009-04-15

    We study multi-field Dirac-Born-Infeld (DBI) inflation models, taking into account the NS-NS and R-R bulk fields present in generic flux compactifications. We compute the second-order action, which governs the behaviour of linear cosmological perturbations, as well as the third-order action, which can be used to calculate non-Gaussianities in these models. Remarkably, for scalar-type perturbations, we show that the contributions due to the various form fields exactly cancel in both the second- and third-order actions. Primordial perturbations and their non-Gaussianities are therefore unaffected by the presence of form fields and our previous results are unmodified. We also study vector-type perturbations associated with the U(1) gauge field confined on the D3-brane, and discuss whether their quantum fluctuations can be amplified. Finally, we revisit the gravitational wave constraints on DBI inflation and show that an ultra-violet DBI multi-field scenario is still compatible with data, in contrast with the single field case, provided there is a transfer from entropy into adiabatic perturbations.

  17. Revisiting the Local Leo Cold Cloud and Revised Constraints on the Local Hot Bubble

    NASA Astrophysics Data System (ADS)

    Snowden, S. L.; Heiles, C.; Koutroumpa, D.; Kuntz, K. D.; Lallement, R.; McCammon, D.; Peek, J. E. G.

    2015-06-01

    The Local Leo Cold Cloud (LLCC, at a distance of 11–24 pc) was studied in its relation to the Local Hot Bubble (LHB) and the result suggested that much of the observed 1/4 keV emission in that direction originates in front of the cloud. This placed a strong constraint on the distribution of X-ray emission within the LHB and called into question the assumption of a uniform distribution of X-ray emitting plasma within the Local Cavity. However, recent work has quantified the contribution of heliospheric solar wind charge exchange (SWCX) emission to the diffuse X-ray background measured by the ROSAT All-Sky Survey (RASS) at 1/4 keV, and led to the consistency of pressure measurements between the LHB and the local cloud component of the complex of local interstellar clouds (CLICs) surrounding the Sun. In this paper we revisit the LLCC and improve the previous analysis by using higher resolution RASS data, a serendipitous ROSAT pointed observation, a rigorous treatment of the band-averaged X-ray absorption cross section, and models for the heliospheric and magnetospheric SWCX contributions. We find that the foreground emission to the cloud is in excess of the expected heliospheric (interplanetary plus near Earth) SWCX contribution but that it is marginally consistent with the range of possible LHB plasma path lengths between the LLCC and the CLICs given the currently understood plasma emissivity.

  18. Gray and green revisited: a multidisciplinary perspective of gardens, gardening, and the aging process.

    PubMed

    Wright, Scott D; Wadsworth, Amy Maida

    2014-01-01

    Over fourteen years ago, the concept of "gray and green" was first introduced by Wright and Lund (2000) to represent a new awareness and a call for increased scholarship at the intersection of environmental issues and the aging process. This review paper revisits that concept with a fresh perspective on the specific role of gardens and gardening in the aging experience. As example, gardening is one of the most popular home-based leisure activities in the US and represents an important activity in the lives of older adults in a variety of residential settings. Yet, there has been a lack of any comprehensive and multidisciplinary (science and humanities) examination of the nexus between gardening and the aging experience, and in particular with research connections to stewardship and caring. In this paper, we review contemporary articles demonstrating the multidisciplinarity of gardening and the aging process. First, we will focus on the beneficial psychological effects resulting from the cultivation of caring, including personal contentment and artistic expression. Second, we will focus on stewardship and how gardening increases health, community awareness, and a connection to future generations. On the surface, this may demonstrate a separation between the humanities and science, but we will clarify a symbiotic relationship between the two disciplines in our conclusion. PMID:24734179

  19. The Park Grass Experiment and next-generation approaches: local adaptation of sweet vernal grass revisited.

    PubMed

    von Wettberg, Eric J B; Vance, Wendy; Rowland, Diane L

    2014-12-01

    Long-term ecological experiments provide unique opportunities to observe the effects of natural selection. The Park Grass Experiment at Rothamsted Experiment Station in Hertfordshire, UK, is the longest running ecological experiment that incorporates fertilization treatments and has been ongoing since 1856. In the 1970s, local adaptation was observed in the grass Anthoxanthum odoratum to the elevated soil aluminium levels of the fertilized plots. Gould et al. (2014) have utilized this system to reevaluate the extent of local adaptation, first documented nearly 45 years ago (Snaydon), and to use emerging molecular approaches to identify candidate genes for the adaptation. From their work, they identify several plausible candidate loci for aluminium tolerance. This work shows the power of long-term field-based trials in a scientific age concentrated on rapidly emerging molecular techniques often utilized in short, narrowly focused laboratory or controlled environment experiments. The current study clearly illustrates the benefits gained by combining these molecular approaches within long-term monitoring experiments that can be regularly revisited in a changing world and used to address questions on evolutionary scales. PMID:25532867

  20. The Neogene astronomical tuned (polarity) timescale between 5 and 14 Ma revisited

    NASA Astrophysics Data System (ADS)

    Zeeden, C.; Hilgen, F.; Lourens, L.; Westerhold, T.; Roehl, U.; Huesing, S.

    2011-12-01

    The characteristic cyclic sedimentary sequence of ODP Leg 154 Sites 925-929 from the Ceara Rise in the western equatorial Atlantic allowed the construction of an astronomical-tuned geologic time scale for the entire Neogene (Shackleton et al. 1999). During the Leg it became already apparent that the splice of Site 926 contains some complications, which could affect the orbital tuning and hence the paleoclimatic interpretation of the record (Shackleton et al. 1997). This record is of major importance for biostratigraphic and paleoclimatologic investigations and, together with Mediterranean land-based sections, forms the backbone of the standard Neogene Geologic Time Scale (Lourens et al. 2004). We revisited the Ceara Rise physical property records and established a revised splice and orbital tuning, using the La2004 solution (Laskar et al. 2004). In addition, we evaluated the tuning by applying different values for the tidal dissipation parameter of the Earth-Moon system. According to our new tuning results, the eccentricity pattern of the physical property records resembles the orbital eccentricity very well; biostratigraphic datums differ from the initial tuning in the order of 100 kyr from ca. 10.5 to 11.2 and ca. 13.4 to 13.7 Ma. Finally, we compared our revised time scale with new data of the tuned Monte dei Corvi section in the Mediterranean, which contained a reliable magnetostratigraphy. This allowed us to improve the accuracy of magnetic reversals ages between 5 and 14 Ma.

  1. Iron Chelators in Photodynamic Therapy Revisited: Synergistic Effect by Novel Highly Active Thiosemicarbazones

    PubMed Central

    2014-01-01

    In photodynamic therapy (PDT), a noninvasive anticancer treatment, visible light, is used as a magic bullet selectively destroying cancer cells by a photosensitizer that is nontoxic in the dark. Protoporphyrin IX (PpIX) is a natural photosensitizer synthesized in the cell, which is also a chelating agent that if bonded to Fe2+ forms heme, a central component of hemoglobin. Therefore, xenobiotic iron chelators can disturb iron homeostasis, increasing the accumulation of PpIX, obstructing the last step of heme biosynthesis, and enhancing PDT efficiency. However, the attempts to use this promising idea have not proved to be hugely successful. Herein, we revisited this issue by analyzing the application of iron chelators highly toxic in the dark, which should have higher Fe2+ affinity than the nontoxic chelators used so far. We have designed and prepared thiosemicarbazones (TSC) with the highest dark cellular cytotoxicity among TSCs ever reported. We demonstrate that compound 2 exerts powerful PDT enhancement when used in combination with 5-aminolevulinic acid (ALA), a precursor of PpIX. PMID:24900837

  2. Revisiting annual mean and seasonal cycle of deep meridional overturning circulation of the Indian Ocean

    NASA Astrophysics Data System (ADS)

    Wang, Weiqiang; Xie, Qiang; Li, Sha; Zhu, Xiuhua

    2014-05-01

    The annual mean and seasonal cycle of the deep meridional overturning circulation (MOC) of the Indian Ocean is being revisited here using GECCO synthesis. Resulting from ocean general circulation models, the annual mean deep MOC of the Indian Ocean are generally weak with inflow in the bottom layer and outflow in the intermediate and upper layer mixing with strong Indonesian Throughflow. For seasonal cycle of deep MOC, two significant and seasonal reversed counter-rotating deep cells over full depth of water column, roughly separated by 20S, are revealed during boreal summer and winter. The coincidences of the latitude 20S with where the maximum climatological wind curl for most of seasons reveals intimate relations between the deep meridional overturning and surface winds. Dynamical decompositions on annual mean and complete seasonal cycle of the meridional overturning show varying relative contribution of each dynamical component at different time scale. For annual mean deep MOC, Ekman dynamics is found to be dominant in the region of north of 25S, particularly in upper 3000m, whereas south of 25S external and vertical shear components show remarkable "seamount" features and are compensated with much larger strengths because of topo-modulated strong western boundary topography. At seasonal time scale, dominant role of Ekman dynamics and secondary role of external mode are found in the deep cell north of 20S in January and July. However in transition seasons, vertical shear is responsible for major part of meridional overturning and Ekman dynamics has comparable contribution north of Equator.

  3. Orphan drugs for rare diseases: is it time to revisit their special market access status?

    PubMed

    Simoens, Steven; Cassiman, David; Dooms, Marc; Picavet, Eline

    2012-07-30

    Orphan drugs are intended for diseases with a very low prevalence, and many countries have implemented legislation to support market access of orphan drugs. We argue that it is time to revisit the special market access status of orphan drugs. Indeed, evidence suggests that there is no societal preference for treating rare diseases. Although society appears to assign a greater value to severity of disease, this criterion is equally relevant to many common diseases. Furthermore, the criterion of equity in access to treatment, which underpins orphan drug legislation, puts more value on health improvement in rare diseases than in common diseases and implies that population health is not maximized. Finally, incentives for the development, pricing and reimbursement of orphan drugs have created market failures, including monopolistic prices and the artificial creation of rare diseases. We argue that, instead of awarding special market access status to orphan drugs, there is scope to optimize research and development (R&D) of orphan drugs and to control prices of orphan drugs by means of, for example, patent auctions, advance purchase commitments, pay-as-you-go schemes and dose-modification studies. Governments should consider carefully the right incentive strategy for R&D of orphan drugs in rare diseases. PMID:22747423

  4. Sco X-1 revisited with Kepler, MAXI and HERMES: outflows, time-lags and echoes unveiled

    E-print Network

    Scaringi, S; Hynes, R I; Koerding, E; Ponti, G; Knigge, C; Britt, C T; van Winckel, H

    2015-01-01

    Sco X-1 has been the subject of many multi-wavelength studies in the past, being the brightest persistent extra-solar X-ray source ever observed. Here we revisit Sco X-1 with simultaneous short cadence Kepler optical photometry and MAXI X-ray photometry over a 78 day period, as well as optical spectroscopy obtained with HERMES. We find Sco X-1 to be highly variable in all our datasets. The optical fluxes are clearly bimodal, implying the system can be found in two distinct optical states. These states are generally associated with the known flaring/normal branch X-ray states, although the flux distributions associated with these states overlap. Furthermore, we find that the optical power spectrum of Sco X-1 differs substantially between optical luminosity states. Additionally we find rms-flux relations in both optical states, but only find a linear relation during periods of low optical luminosity. The full optical/X-ray discrete correlation function displays a broad ~12.5 hour optical lag. However during the...

  5. Infantile scurvy: an old diagnosis revisited with a modern dietary twist.

    PubMed

    Burk, Cynthia J; Molodow, Rona

    2007-01-01

    Ascorbic acid (vitamin C) is necessary for the formation of collagen, reducing free radicals, and aiding in iron absorption. Scurvy, a disease of dietary ascorbic acid deficiency, is uncommon today. Indeed, implementation of dietary recommendations largely eradicated infantile scurvy in the US in the early 1900s. We present a case of an otherwise healthy 2-year-old Caucasian girl who presented with refusal to walk secondary to pain in her lower extremities, generalized irritability, sleep disturbance, and malaise. The girl's parents described feeding the patient an organic diet recommended by the Church of Scientology that included a boiled mixture of organic whole milk, barley, and corn syrup devoid of fruits and vegetables. Physical examination revealed pale, bloated skin with edematous, violaceous gums and loosening of a few of her teeth. Dermatologic findings included xerosis, multiple scattered ecchymoses of the extremities, and perifollicular hemorrhage. Laboratory and radiographic evaluation confirmed the diagnosis of scurvy. The patient showed dramatic improvement after only 3 days of treatment with oral ascorbic acid and significant dietary modification. In this case report, we revisit the old diagnosis of scurvy with a modern dietary twist secondary to religious practices. This case highlights the importance of taking a detailed dietary history when evaluating diseases involving the skin. PMID:17428115

  6. Fringes in FTIR spectroscopy revisited: understanding and modelling fringes in infrared spectroscopy of thin films.

    PubMed

    Konevskikh, Tatiana; Ponossov, Arkadi; Blümel, Reinhold; Lukacs, Rozalia; Kohler, Achim

    2015-06-21

    The appearance of fringes in the infrared spectroscopy of thin films seriously hinders the interpretation of chemical bands because fringes change the relative peak heights of chemical spectral bands. Thus, for the correct interpretation of chemical absorption bands, physical properties need to be separated from chemical characteristics. In the paper at hand we revisit the theory of the scattering of infrared radiation at thin absorbing films. Although, in general, scattering and absorption are connected by a complex refractive index, we show that for the scattering of infrared radiation at thin biological films, fringes and chemical absorbance can in good approximation be treated as additive. We further introduce a model-based pre-processing technique for separating fringes from chemical absorbance by extended multiplicative signal correction (EMSC). The technique is validated by simulated and experimental FTIR spectra. It is further shown that EMSC, as opposed to other suggested filtering methods for the removal of fringes, does not remove information related to chemical absorption. PMID:25893226

  7. Revisiting the classification of curtoviruses based on genome-wide pairwise identity.

    PubMed

    Varsani, Arvind; Martin, Darren P; Navas-Castillo, Jesús; Moriones, Enrique; Hernández-Zepeda, Cecilia; Idris, Ali; Murilo Zerbini, F; Brown, Judith K

    2014-07-01

    Members of the genus Curtovirus (family Geminiviridae) are important pathogens of many wild and cultivated plant species. Until recently, relatively few full curtovirus genomes have been characterised. However, with the 19 full genome sequences now available in public databases, we revisit the proposed curtovirus species and strain classification criteria. Using pairwise identities coupled with phylogenetic evidence, revised species and strain demarcation guidelines have been instituted. Specifically, we have established 77 % genome-wide pairwise identity as a species demarcation threshold and 94 % genome-wide pairwise identity as a strain demarcation threshold. Hence, whereas curtovirus sequences with >77 % genome-wide pairwise identity would be classified as belonging to the same species, those sharing >94 % identity would be classified as belonging to the same strain. We provide step-by-step guidelines to facilitate the classification of newly discovered curtovirus full genome sequences and a set of defined criteria for naming new species and strains. The revision yields three curtovirus species: Beet curly top virus (BCTV), Spinach severe surly top virus (SpSCTV) and Horseradish curly top virus (HrCTV). PMID:24463952

  8. Major transitions in human evolution revisited: a tribute to ancient DNA.

    PubMed

    Ermini, Luca; Der Sarkissian, Clio; Willerslev, Eske; Orlando, Ludovic

    2015-02-01

    The origin and diversification of modern humans have been characterized by major evolutionary transitions and demographic changes. Patterns of genetic variation within modern populations can help with reconstructing this ?200 thousand year-long population history. However, by combining this information with genomic data from ancient remains, one can now directly access our evolutionary past and reveal our population history in much greater detail. This review outlines the main recent achievements in ancient DNA research and illustrates how the field recently moved from the polymerase chain reaction (PCR) amplification of short mitochondrial fragments to whole-genome sequencing and thereby revisited our own history. Ancient DNA research has revealed the routes that our ancestors took when colonizing the planet, whom they admixed with, how they domesticated plant and animal species, how they genetically responded to changes in lifestyle, and also, which pathogens decimated their populations. These approaches promise to soon solve many pending controversies about our own origins that are indecipherable from modern patterns of genetic variation alone, and therefore provide an extremely powerful toolkit for a new generation of molecular anthropologists. PMID:25532800

  9. Polyploidy and its effect on evolutionary success: old questions revisited with new tools

    PubMed Central

    Madlung, A

    2013-01-01

    Polyploidy, the condition of possessing more than two complete genomes in a cell, has intrigued biologists for almost a century. Polyploidy is found in many plants and some animal species and today we know that polyploidy has had a role in the evolution of all angiosperms. Despite its widespread occurrence, the direct effect of polyploidy on evolutionary success of a species is still largely unknown. Over the years many attractive hypotheses have been proposed in an attempt to assign functionality to the increased content of a duplicated genome. Among these hypotheses are the proposal that genome doubling confers distinct advantages to a polyploid and that these advantages allow polyploids to thrive in environments that pose challenges to the polyploid's diploid progenitors. This article revisits these long-standing questions and explores how the integration of recent genomic developments with ecological, physiological and evolutionary perspectives has contributed to addressing unresolved problems about the role of polyploidy. Although unsatisfactory, the current conclusion has to be that despite significant progress, there still isn't enough information to unequivocally answer many unresolved questions about cause and effect of polyploidy on evolutionary success of a species. There is, however, reason to believe that the increasingly integrative approaches discussed here should allow us in the future to make more direct connections between the effects of polyploidy on the genome and the responses this condition elicits from the organism living in its natural environment. PMID:23149459

  10. Perceived parenting style and adolescent adjustment: revisiting directions of effects and the role of parental knowledge.

    PubMed

    Kerr, Margaret; Stattin, Håkan; Ozdemir, Metin

    2012-11-01

    In the present research on parenting and adolescent behavior, there is much focus on reciprocal, bidirectional, and transactional processes, but parenting-style research still adheres to a unidirectional perspective in which parents affect youth behavior but are unaffected by it. In addition, many of the most cited parenting-style studies have used measures of parental behavioral control that are questionable because they include measures of parental knowledge. The goals of this study were to determine whether including knowledge items might have affected results of past studies and to test the unidirectional assumption. Data were from 978 adolescents participating in a longitudinal study. Parenting-style and adolescent adjustment measures at 2 time points were used, with a 2-year interval between time points. A variety of internal and external adjustment measures were used. Results showed that including knowledge items in measures of parental behavioral control elevated links between behavioral control and adjustment. Thus, the results and conclusions of many of the most highly cited studies are likely to have been stronger than if the measures had focused strictly on parental behavior. In addition, adolescent adjustment predicted changes in authoritative and neglectful parenting styles more robustly than these styles predicted changes in adolescent adjustment. Adolescent adjustment also predicted changes in authoritativeness more robustly than authoritativeness predicted changes in adjustment. Thus, parenting style cannot be seen as independent of the adolescent. In summary, both the theoretical premises of parenting-style research and the prior findings should be revisited. PMID:22448987

  11. Psychological well-being revisited: advances in the science and practice of eudaimonia.

    PubMed

    Ryff, Carol D

    2014-01-01

    This article reviews research and interventions that have grown up around a model of psychological well-being generated more than two decades ago to address neglected aspects of positive functioning such as purposeful engagement in life, realization of personal talents and capacities, and enlightened self-knowledge. The conceptual origins of this formulation are revisited and scientific products emerging from 6 thematic areas are examined: (1) how well-being changes across adult development and later life; (2) what are the personality correlates of well-being; (3) how well-being is linked with experiences in family life; (4) how well-being relates to work and other community activities; (5) what are the connections between well-being and health, including biological risk factors, and (6) via clinical and intervention studies, how psychological well-being can be promoted for ever-greater segments of society. Together, these topics illustrate flourishing interest across diverse scientific disciplines in understanding adults as striving, meaning-making, proactive organisms who are actively negotiating the challenges of life. A take-home message is that increasing evidence supports the health protective features of psychological well-being in reducing risk for disease and promoting length of life. A recurrent and increasingly important theme is resilience - the capacity to maintain or regain well-being in the face of adversity. Implications for future research and practice are considered. PMID:24281296

  12. Revisiting the total ion yield x-ray absorption spectra of liquid water microjets

    SciTech Connect

    Saykally, Richard J; Cappa, Chris D.; Smith, Jared D.; Wilson, Kevin R.; Saykally, Richard J.

    2008-02-16

    Measurements of the total ion yield (TIY) x-ray absorption spectrum (XAS) of liquid water by Wilson et al. (2002 J. Phys.: Condens. Matter 14 L221 and 2001 J. Phys. Chem. B 105 3346) have been revisited in light of new experimental and theoretical efforts by our group. Previously, the TIY spectrum was interpreted as a distinct measure of the electronic structure of the liquid water surface. However, our new results indicate that the previously obtained spectrum may have suffered from as yet unidentified experimental artifacts. Although computational results indicate that the liquid water surface should exhibit a TIY-XAS that is fundamentally distinguishable from the bulk liquid XAS, the new experimental results suggest that the observable TIY-XAS is actually nearly identical in appearance to the total electron yield (TEY-)XAS, which is a bulk probe. This surprising similarity between the observed TIY-XAS and TEY-XAS likely results from large contributions from x-ray induced electron stimulated desorption of ions, and does not necessarily indicate that the electronic structure of the bulk liquid and liquid surface are identical.

  13. Type II-P Supernovae as Standard Candles: The SDSS-II Sample Revisited

    NASA Astrophysics Data System (ADS)

    Poznanski, Dovi; Nugent, Peter E.; Filippenko, Alexei V.

    2010-10-01

    We revisit the observed correlation between the H? and Fe II velocities for Type II-P supernovae (SNe II-P) using 28 optical spectra of 13 SNe II-P and demonstrate that it is well modeled by a linear relation with a dispersion of about 300 km s-1. Using this correlation, we re-analyze the publicly available sample of SNe II-P compiled by D'Andrea et al. and find a Hubble diagram with an intrinsic scatter of 11% in distance, which is nearly as tight as that measured before their sample is added to the existing set. The larger scatter reported in their work is found to be systematic, and most of it can be alleviated by measuring the H? rather than Fe II velocities, due to the low signal-to-noise ratios and early epochs at which many of the optical spectra were obtained. Their sample, while supporting the mounting evidence that SNe II-P are good cosmic rulers, is biased toward intrinsically brighter objects and is not a suitable set to improve upon SN II-P correlation parameters. This will await a dedicated survey.

  14. Revisiting the NIOSH Criteria for a Recommended Standard: Occupational Noise Exposure

    NASA Astrophysics Data System (ADS)

    Murphy, William J.; Franks, John R.

    2002-05-01

    In 1998, the National Institute for Occupational Safety and Health (NIOSH) revised the Criteria for a Recommended Standard: Occupational Noise Exposure [DHHS (NIOSH) Publication No. 98-126]. NIOSH reevaluated the recommended exposure limit (REL) for occupational noise exposure and reaffirms support for 85-dBA REL. Based upon scientific evidence, NIOSH recommends a 3-dB exchange rate. NIOSH recommends that significant threshold shift be identified as an increase of 15 dB in the hearing threshold level at 500, 1000, 2000, 3000, 4000, or 6000 Hz in either ear, with two consecutive audiometric tests. The new criterion has the advantages of a high identification rate and a low false-positive rate. In contrast with the former 1972 criterion, NIOSH no longer recommends age correction on individual audiograms. NIOSH has revisited its recommendations on the using of single-number laboratory-derived Noise Reduction Rating (NRR) required by the U.S. Environmental Protection Agency for labeling of hearing protectors sold within the United States. In 1972, NIOSH recommended the use of the full NRR value; however, the new criterion recommends derating the NRR by 25%, 50%, and 70% for earmuffs, formable earplugs, and all other earplugs, respectively. This presentation will compare and contrast current regulations against the NIOSH recommendations.

  15. Certainty in Heisenberg's uncertainty principle: Revisiting definitions for estimation errors and disturbance

    NASA Astrophysics Data System (ADS)

    Dressel, Justin; Nori, Franco

    2014-02-01

    We revisit the definitions of error and disturbance recently used in error-disturbance inequalities derived by Ozawa and others by expressing them in the reduced system space. The interpretation of the definitions as mean-squared deviations relies on an implicit assumption that is generally incompatible with the Bell-Kochen-Specker-Spekkens contextuality theorems, and which results in averaging the deviations over a non-positive-semidefinite joint quasiprobability distribution. For unbiased measurements, the error admits a concrete interpretation as the dispersion in the estimation of the mean induced by the measurement ambiguity. We demonstrate how to directly measure not only this dispersion but also every observable moment with the same experimental data, and thus demonstrate that perfect distributional estimations can have nonzero error according to this measure. We conclude that the inequalities using these definitions do not capture the spirit of Heisenberg's eponymous inequality, but do indicate a qualitatively different relationship between dispersion and disturbance that is appropriate for ensembles being probed by all outcomes of an apparatus. To reconnect with the discussion of Heisenberg, we suggest alternative definitions of error and disturbance that are intrinsic to a single apparatus outcome. These definitions naturally involve the retrodictive and interdictive states for that outcome, and produce complementarity and error-disturbance inequalities that have the same form as the traditional Heisenberg relation.

  16. Revisiting the chemical reactivity indices as the state function derivatives. The role of classical chemical hardness

    NASA Astrophysics Data System (ADS)

    Malek, Ali; Balawender, Robert

    2015-02-01

    The chemical reactivity indices as the equilibrium state-function derivatives are revisited. They are obtained in terms of the central moments (fluctuation formulas). To analyze the role of the chemical hardness introduced by Pearson [J. Am. Chem. Soc. 105, 7512 (1983)], the relations between the derivatives up to the third-order and the central moments are obtained. As shown, the chemical hardness and the chemical potential are really the principal indices of the chemical reactivity theory. It is clear from the results presented here that the chemical hardness is not the derivative of the Mulliken chemical potential (this means also not the second derivative of the energy at zero-temperature limit). The conventional quadratic dependence of energy, observed at finite temperature, reduces to linear dependence on the electron number at zero-temperature limit. The chemical hardness plays a double role in the admixture of ionic states to the reference neutral state energy: it determines the amplitude of the admixture and regulates the damping of its thermal factor.

  17. Focused electron beam induced processing and the effect of substrate thickness revisited

    NASA Astrophysics Data System (ADS)

    van Dorp, W. F.; Beyer, A.; Mainka, M.; Gölzhäuser, A.; Hansen, T. W.; Wagner, J. B.; Hagen, C. W.; De Hosson, J. Th M.

    2013-08-01

    The current understanding in the study of focused electron beam induced processing (FEBIP) is that the growth of a deposit is mainly the result of secondary electrons (SEs). This suggests that the growth rate for FEBIP is affected by the SE emission from the support. Our experiments, with membranes thinner than the SE escape depth, confirm this hypothesis. We used membranes of 1.4 and 4.3 nm amorphous carbon as supports. At the very early stage, the growth is support-dominated and the growth rate on a 4.3 nm thick membrane is three times higher than on a 1.4 nm thick membrane. This is consistent with Monte Carlo simulations for SE emission. The results suggest that SEs are dominant in the dissociation of W(CO)6 on thin membranes. The best agreement between simulations and experiment is obtained for SEs with energies between 3 and 6 eV. With this work we revisit earlier experiments, working at a precursor pressure 20 times lower than previously. Then, despite using membranes thinner than the SE escape depth, we did not see an effect on the experimental growth rate. We explain our current results by the fact that very early in the process, the growth becomes dominated by the growing deposit itself.

  18. Revisiting the boiling of primordial quark nuggets at nonzero chemical potential

    NASA Astrophysics Data System (ADS)

    Li, Ang; Liu, Tong; Gubler, Philipp; Xu, Ren-Xin

    2015-03-01

    The boiling of possible quark nuggets during the quark-hadron phase transition of the Universe at nonzero chemical potential is revisited within the microscopic Brueckner-Hartree-Fock approach employed for the hadron phase, using two kinds of baryon interactions as fundamental inputs. To describe the deconfined phase of quark matter, we use a recently developed quark mass density-dependent model with a fully self-consistent thermodynamic treatment of confinement. We study the baryon number limit Aboil (above which boiling may be important) with three typical values for the confinement parameter D. It is firstly found that the baryon interaction with a softer equation of state for the hadron phase would only lead to a small increase of Aboil . However, results depend sensitively on the confinement parameter in the quark model. Specifically, boiling might be important during the Universe cooling for a limited parameter range around D 1 / 2 = 170 MeV, a value satisfying recent lattice QCD calculations of the vacuum chiral condensate, while for other choices of this parameter, boiling might not happen and cosmological quark nuggets of 102 < A <1050 could survive.

  19. EVIDENCE FOR TWO DISTINCT STELLAR INITIAL MASS FUNCTIONS: REVISITING THE EFFECTS OF CLUSTER DYNAMICAL EVOLUTION

    SciTech Connect

    Zaritsky, Dennis [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Colucci, Janet E.; Bernstein, Rebecca A. [Department of Astronomy and Astrophysics, 1156 High Street, UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Pessev, Peter M. [Gemini South Observatory, c/o AURA Inc., Casilla 603, La Serena (Chile); Chandar, Rupali, E-mail: dzaritsky@as.arizona.edu [Department of Physics and Astronomy, The University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States)

    2013-06-20

    We measure the velocity dispersions of six galactic globular clusters using spatially integrated spectra, to test for the effects of internal dynamical evolution in the stellar mass-to-light ratios, Y{sub *}, of star clusters. In particular, we revisit whether the low values of Y{sub *} that we found in our previous study, from which we concluded that there are at least two population of stellar clusters with distinct stellar initial mass functions, are artificially depressed by relaxation driven mass loss. The combination of our previous sample of five old clusters and these six now provide an order of magnitude range in cluster mass with which to explore this issue. We find no relationship between cluster mass, or relaxation time, and Y{sub *}. Because relaxation is mass dependent, we conclude that the values of Y{sub *} for these clusters are not strongly affected by dynamical effects, and so confirm the presence of the population of clusters with low Y{sub *}.

  20. Seismic tomography of continental rifts revisited: from relative to absolute heterogeneities

    NASA Astrophysics Data System (ADS)

    Achauer, Ulrich; Masson, Frédéric

    2002-11-01

    Tomographic images for four major continental rift zones, namely the southern Rhine Graben (SRG, Germany/France), the Gregory rift (Kenya) which is the central part of the East African rift system, the Rio Grande rift (RGR) in the United States and the Lake Baikal rift zone (LBR) in Russia have been revisited by calculating and comparing absolute velocity models. The four rifts exhibit strong structural differences in the uppermost mantle down to more than 300-km depth, suggesting major differences in their geodynamic evolution albeit their similarity in age and similar surface expression. The comparative analysis suggests that tomographic images of rift zones can be used to characterize continental rifts, once the corrections to obtain absolute velocities have been carried out. Our results suggest that while the Kenya and the Rio Grande rift may be considered active with large upwelling plumes being the main controlling factor in the evolution, the southern Rhine Graben and the Lake Baikal rift are more likely passive rifts, where complex regional stress fields and inherited structures play the governing role in the evolution.