WorldWideScience

Sample records for eastern hemisphere

  1. Eastern Asian endemic seed plant genera and their paleogeographic history throughout the Northern Hemisphere

    Institute of Scientific and Technical Information of China (English)

    Steven R. MANCHESTER; Zhi-Duan CHEN; An-Ming LU; Kazuhiko UEMURA

    2009-01-01

    We review the fossil history of seed plant genera that are now endemic to eastern Asia. Although the majority of eastern Asian endemic genera have no known fossil record at all, 54 genera, or about 9%, are reliably known from the fossil record. Most of these are woody (with two exceptions), and most are today either broadly East Asian, or more specifically confined to Sino-Japanese subcategory rather than being endemic to the Sino-Himalayan area. Of the "eastern Asian endemic" genera so far known from the fossil record, the majority formerly occurred in Europe and/or North America, indicating that eastern Asia served as a late Tertiary or Quaternary refugium for taxa. Hence, many of these genera may have originated in other parts of the Northern Hemisphere and expanded their ranges across continents and former sea barriers when tectonic and climatic conditions al-lowed, leading to their arrival in eastern Asia. Although clear evidence for paleoendemism is provided by the gymnosperms Amentotaxus, Cathaya, Cephalotaxus, Cunninghamia, Cryptomeria, Glyptostrobus, Ginkgo, Ketel-eeria, Metasequoia, Nothotsuga, Pseudolarix, Sciadopitys, and Taiwania, and the angiosperms Cercidiphyllum, Choerospondias, Corylopsis, Craigia, Cyclocarya, Davidia, Dipelta, Decaisnea, Diplopanax, Dipteronia, Em-menopterys, Eucommia, Euscaphis, Hemiptelea, Hovenia, Koelreuteria, Paulownia, Phellodendron, Platycarya, Pteroceltis, Rehderodendron, Sargentodoxa, Schizophragma, Sinomenium, Tapiscia, Tetracentron, Toricellia,Trapella, and Trochodendron, we cannot rule out the possibility that neoendemism plays an important role espe-cially for herbaceous taxa in the present-day flora of Asia, particularly in the Sino-Himalayan region. In addition to reviewing paleobotanical occurrences from the literature, we document newly recognized fossil occurrences that expand the geographic and stratigraphic ranges previously known for Dipelta, Pteroceltis, and Toricellia.

  2. Taxonomic revision and distribution of herbaceous Paramollugo (Molluginaceae in the Eastern Hemisphere

    Directory of Open Access Journals (Sweden)

    Alexander P. Sukhorukov

    2016-10-01

    Full Text Available The genus Paramollugo with the type species Paramollugo nudicaulis (≡Mollugo nudicaulis has recently been described after molecular investigations. Here we report two new endemic Malagasy species: Paramollugo simulans and P. elliotii, and transfer a forgotten New Caledonian endemic Mollugo digyna to Paramollugo (P. digyna. Consequently, the number of Paramollugo species in the Eastern Hemisphere is increased from three to six. Almost all genus representatives (except P. nudicaulis, which has a wide distribution in Southern Asia, Arabia and tropical Africa are endemic to Madagascar, Somalia, or New Caledonia. Since the type of seed coat ornamentation is crucial for species delimitation, a diagnostic key with new taxonomically significant carpological characters and other new traits is provided for all the herbaceous Paramollugo. The distribution patterns of P. nudicaulis s.str., P. simulans and P. elliotii are presented.

  3. Detectability of temporal changes in fine structures near the inner core boundary beneath the eastern hemisphere

    Science.gov (United States)

    Yu, Wen-che

    2016-04-01

    The inner core boundary (ICB), where melting and solidification of the core occur, plays a crucial role in the dynamics of the Earth's interior. To probe temporal changes near the ICB beneath the eastern hemisphere, I analyze differential times of PKiKP (dt(PKiKP)), double differential times of PKiKP-PKPdf, and PKiKP coda waves from repeating earthquakes in the Southwest Pacific subduction zones. Most PKiKP differential times are within ±30 ms, comparable to inherent travel time uncertainties due to inter-event separations, and suggest no systematic changes as a function of calendar time. Double differential times measured between PKiKP codas and PKiKP main phases show promising temporal changes, with absolute values of time shifts of >50 ms for some observations. However, there are discrepancies among results from different seismographs in the same calendar time window. Negligible changes in PKiKP times, combined with changes in PKiKP coda wave times on 5 year timescales, favor a smooth inner core boundary with fine-scale structures present in the upper inner core. Differential times of PKiKP can be interpreted in the context of either melting based on translational convection, or growth based on thermochemical mantle-inner core coupling. Small dt(PKiKP) values with inherent uncertainties do not have sufficient resolution to distinguish the resultant longitudinal (melting) and latitudinal (growth) dependencies predicted on the basis of the two models on 5 year timescales.

  4. Coherent tropical-subtropical Holocene see-saw moisture patterns in the Eastern Hemisphere monsoon systems

    Science.gov (United States)

    Wang, Yongbo; Bekeschus, Benjamin; Handorf, Dörthe; Liu, Xingqi; Dallmeyer, Anne; Herzschuh, Ulrike

    2017-08-01

    The concept of a Global Monsoon (GM) has been proposed based on modern precipitation observations, but its application over a wide range of temporal scales is still under debate. Here, we present a synthesis of 268 continental paleo-moisture records collected from monsoonal systems in the Eastern Hemisphere, including the East Asian Monsoon (EAsM), the Indian Monsoon (IM), the East African Monsoon (EAfM), and the Australian Monsoon (AuM) covering the last 18,000 years. The overall pattern of late Glacial to Holocene moisture change is consistent with those inferred from ice cores and marine records. With respect to the last 10,000 years (10 ka), i.e. a period that has high spatial coverage, a Fuzzy c-Means clustering analysis of the moisture index records together with ;Xie-Beni; index reveals four clusters of our data set. The paleoclimatic meaning of each cluster is interpreted considering the temporal evolution and spatial distribution patterns. The major trend in the tropical AuM, EAfM, and IM regions is a gradual decrease in moisture conditions since the early Holocene. Moisture changes in the EAsM regions show maximum index values between 8 and 6 ka. However, records located in nearby subtropical areas, i.e. in regions not influenced by the intertropical convergence zone, show an opposite trend compared to the tropical monsoon regions (AuM, EAfM and IM), i.e. a gradual increase. Analyses of modern meteorological data reveal the same spatial patterns as in the paleoclimate records such that, in times of overall monsoon strengthening, lower precipitation rates are observed in the nearby subtropical areas. We explain this pattern as the effect of a strong monsoon circulation suppressing air uplift in nearby subtropical areas, and hence hindering precipitation. By analogy to the modern system, this would mean that during the early Holocene strong monsoon period, the intensified ascending airflows within the monsoon domains led to relatively weaker ascending or

  5. Discovery of a living fossil: a new xylastodorine species from New Caledonia (Heteroptera: Thaumastocoridae) and first record of the subfamily from the eastern Hemisphere

    NARCIS (Netherlands)

    Doesburg, van P.H.; Cassis, G.; Monteith, G.B.

    2010-01-01

    A new species belonging to the genus Proxylastodoris Heiss & Popov, 2002, P. kuscheli spec. nov., of the subfamily Xylastodorinae Barber, 1920 (Heteroptera: Thaumastocoridae) is described from New Caledonia. It is the first recent record outside the western Hemisphere of the Xyalstodorinae and is th

  6. Right Hemisphere Brain Damage

    Science.gov (United States)

    ... or hemispheres. Each hemisphere is responsible for different body functions and skills. In most people, the left side of the brain contains the person's language functions. The right side contributes to a number ...

  7. Southern hemisphere observations

    Science.gov (United States)

    Orchiston, Wayne

    Because of insurmountable problems associated with absolute dating, the non-literate cultures of the Southern Hemisphere can contribute little to Applied Historical Astronomy, although Maori traditions document a possible supernova dating to the period 1000-1770 AD. In contrast, the abundant nineteenth century solar, planetary, cometary and stellar observational data provided by Southern Hemisphere professional and amateur observatories can serve as an invaluable mine of information for present-day astronomers seeking to incorporate historical data in their investigations.

  8. Hemispheric contributions to pragmatics.

    Science.gov (United States)

    Zaidel, E; Kasher, A; Soroker, N; Batori, G; Giora, R; Graves, D

    2000-01-01

    Twenty-seven patients with right-hemisphere damage (RBD) and thirty-one patients with left-hemisphere damage (LBD) received a new pragmatics battery in Hebrew consisting of two parts: (1) comprehension and production of basic speech acts (BSAs), including tests of assertions, questions, requests, and commands, and (2) comprehension of implicatures, including implicatures of quantity, quality, relevance, and manner. Each test had a verbal and a nonverbal version. Patients also received Hebrew versions of the Western Aphasia Battery and of the Right Hemisphere Communication Battery. Both LBD and RBD patients were impaired relative to controls but did not differ from each other in their overall scores on BSAs and on Implicatures when scores were corrected by aphasia and neglect indices. There was a systematic localization of BSAs in the left hemisphere (LH) but not in the right hemisphere (RH). There was poor localization of Implicatures in either hemisphere. In LBD patients, BSAs were associated with language functions measured with the WAB, suggesting the radical possibility that the classic localization of language functions in aphasia is influenced by the localization of the BSAs required by aphasia language tests. Both BSAs and implicatures show greater functional independence from other pragmatic, language and cognitive functions in the RBD than in the LBD patients. Thus, the LH is more likely to contain an unmodular domain-nonspecific set of central cognitive mechanisms for applying means-ends rationality principles to intentional activity.

  9. Hemispherical Laue camera

    Science.gov (United States)

    Li, James C. M.; Chu, Sungnee G.

    1980-01-01

    A hemispherical Laue camera comprises a crystal sample mount for positioning a sample to be analyzed at the center of sphere of a hemispherical, X-radiation sensitive film cassette, a collimator, a stationary or rotating sample mount and a set of standard spherical projection spheres. X-radiation generated from an external source is directed through the collimator to impinge onto the single crystal sample on the stationary mount. The diffracted beam is recorded on the hemispherical X-radiation sensitive film mounted inside the hemispherical film cassette in either transmission or back-reflection geometry. The distances travelled by X-radiation diffracted from the crystal to the hemispherical film are the same for all crystal planes which satisfy Bragg's Law. The recorded diffraction spots or Laue spots on the film thereby preserve both the symmetry information of the crystal structure and the relative intensities which are directly related to the relative structure factors of the crystal orientations. The diffraction pattern on the exposed film is compared with the known diffraction pattern on one of the standard spherical projection spheres for a specific crystal structure to determine the orientation of the crystal sample. By replacing the stationary sample support with a rotating sample mount, the hemispherical Laue camera can be used for crystal structure determination in a manner previously provided in conventional Debye-Scherrer cameras.

  10. Unilateral Hemispheric Encephalitis

    Directory of Open Access Journals (Sweden)

    Mohan Leslie Noone

    2014-10-01

    Full Text Available A 10 year old boy presented with history of mild fever and upper respiratory symptoms followed by recurrent seizures and loss of consciousness on the next day. Normal blood counts and abnormal hepatic transaminases were noted. MRI of the brain, done on the fourth day of illness, showed extensive involvement of the cortex in the right hemisphere. Lumbar CSF was normal. The EEG showed bilateral slowing with frontal sharp wave discharges and marked attenuation over the entire right hemisphere. The patient succumbed to the illness on the ninth day. A similar pattern of acute unilateral hemispheric cortical involvement is described in the hemiconvulsion-hemiplegia-epilepsy (HHE syndrome, which is typically described to occur in children below 4 years of age. This case of fulminant acute unilateral encaphilitic illness could represent the acute phase of HHE syndrome.

  11. Brain Hemisphericity and Developmental Dyslexia

    Science.gov (United States)

    Vlachos, Filippos; Andreou, Eleni; Delliou, Afroditi

    2013-01-01

    The present study examined the link between brain hemisphericity and dyslexia in secondary school students, using the Preference Test (PT), a widely used self-report index of preferred hemisphere thinking styles. The hypothesis was that differences would be revealed between the dyslexic group and their peers in hemispheric preference. A total of…

  12. Continent Drought Characteristics over the Eastern Hemisphere from 1947to 2006:Analyses based on the SPEI dataset%1947—2006年东半球陆地干旱化特征——基于SPEI数据的分析

    Institute of Scientific and Technical Information of China (English)

    石崇; 刘晓东

    2012-01-01

    The characteristics of drought events over the continent in the Eastern Hemisphere(20°W-180°E,40°S-80°N),including the trend and variance,change in drought area,the persistence and periodicity,and possible causes,were analyzed in this paper by using the newest dataset of monthly Standardized Precipitation Evapotranspiration Index(SPEI) on a 0.5°×0.5° grid during 1947-2006.Results show that a drying trend is observed over more than 80 percent of the land areas in the Eastern Hemisphere,with the most obvious changes over northern Africa and China-Mongolia border.The regions with high variance are located in northern Africa,Tibetan Plateau,eastern Northwest China,China-Mongolia border,central-northern and northeastern Russia.The frequency of persistent drought events is extremely high in the northern Africa,Tibetan Plateau and the middle part of China-Mongolia border.The power spectral analysis reveals that the main periods of the drought oscillation are 1.5-3 years in most areas of the Eastern Hemisphere,4 years in parts of central Asia,and 12 years in northern Africa,respectively.The analysis of empirical orthogonal function(EOF) of monthly SPEI anomalies indicates that the first mode(EOF1) shows a spatially uniform variation in most areas of the Eastern Hemisphere and a significant time correlation with the global mean land-surface air temperature(GMT).The high correlation coefficient(0.81) between the EOF1 and GMT means that the drying trends over these continents are closely related to global warming.The 8-month-lag correlation coefficient between the second EOF mode and the Southern Oscillation Index(SOI) exceeds 0.6,thus,the large-scale drought fluctuations are remarkably influenced by the El Nio-Southern Oscillation(ENSO).%利用1947—2006年逐月全球陆地高分辨率(0.5°×0.5°)标准化降水蒸散指数SPEI(Standardized Precipitation Evapotranspiration Index)资料,分析了过去60a东半球(40°S—80°N,20°W—180°E)陆地

  13. The Tropical Western Hemisphere Warm Pool

    Science.gov (United States)

    Wang, C.; Enfield, D. B.

    2002-12-01

    The paper describes and examines variability of the tropical Western Hemisphere warm pool (WHWP) of water warmer than 28.5oC. The WHWP is the second-largest tropical warm pool on Earth. Unlike the Eastern Hemisphere warm pool in the western Pacific, which straddles the equator, the WHWP is entirely north of the equator. At various stages of development the WHWP extends over parts of the eastern North Pacific, the Gulf of Mexico, the Caribbean, and the western tropical North Atlantic. It has a large seasonal cycle and its interannual fluctuations of area and intensity are significant. Surface heat fluxes warm the WHWP through the boreal spring to an annual maximum of SST and WHWP area in the late summer/early fall, associated with eastern North Pacific and Atlantic hurricane activities and rainfall from northern South America to the southern tier of the United States. Observations suggest that a positive ocean-atmosphere feedback operating through longwave radiation and associated cloudiness seems to operate in the WHWP. During winter preceding large warm pool, there is an alteration of the Walker and Hadley circulation cells that serves as a "tropospheric bridge" for transferring Pacific ENSO effects to the Atlantic sector and inducing initial warming of warm pool. Associated with the warm SST anomalies is a decrease in sea level pressure anomalies and an anomalous increase in atmospheric convection and cloudiness. The increase in convective activity and cloudiness results in less net longwave radiation loss from the sea surface, which then reinforces SST anomalies.

  14. A MEMS diamond hemispherical resonator

    Science.gov (United States)

    Bernstein, J. J.; Bancu, M. G.; Cook, E. H.; Chaparala, M. V.; Teynor, W. A.; Weinberg, M. S.

    2013-12-01

    In this paper we report the fabrication of hemispherical polycrystalline diamond resonators fabricated on a novel high-temperature glass substrate. The hemispherical resonator gyroscope is one of the most accurate and rugged of the mechanical gyroscopes, and can be operated in either rate or whole-angle mode due to its high degree of symmetry. A fabrication sequence for creating extremely symmetric 3D MEMS hemispheres is presented. Mode shapes and frequencies obtained with a laser vibrometer are shown, as well as curves of Q versus pressure, and the dependence of frequency on anchor size. Fundamental mode frequency matching to gyroscope operation in whole-angle mode.

  15. Brain Hemispheres and Thinking Styles.

    Science.gov (United States)

    Gray, Esther Cappon

    1980-01-01

    The author reviews some research, particularly that of Roger Sperry, substantiating the existence of different thinking styles in the two brain hemispheres and the development of this differentiation in infancy and childhood. She draws some implications for elementary teaching. (SJL)

  16. Western Hemisphere Knowledge Partnerships

    Science.gov (United States)

    Malone, T. F.

    2001-05-01

    , and application of knowledge concerning the nature of -- and interaction among -- matter, living organisms, energy, information, and human behavior. This strategy calls for innovative partnerships among the physical, biological, health, and social sciences, engineering, and the humanities. New kinds of partnership must also be forged among academia, business and industry, governments, and nongovernmental organizations. Geophysicists can play an important role in these partnerships. A focus for these partnerships is to manage the individual economic productivity that drives both human development and global change. As world population approaches stability during the twenty-first century, individual economic productivity will be the critical link between the human and the natural systems on planet Earth. AGU is among a core group of individuals and institutions proposing Western Hemisphere Knowledge Partnerships (WHKP) to test the hypothesis that knowledge, broadly construed, is an important organizing principle in choosing a path into the future. The WHKP agenda includes: (1) life-long learning, (2) the health and resilience of natural ecosystems, (3) eco-efficiency in economic production and consumption, (4) extension of national income accounts, (5) environmentally benign sources of energy, (6) delivery of health care, (7) intellectual property rights, and (8) networks for action by local communities.Collaboratories and distance education technologies will be major tools. A panel of experts will explore this proposal.

  17. Hemispheric specialisation in haptic processing.

    Science.gov (United States)

    Tomlinson, Simon P; Davis, Nick J; Morgan, Helen M; Bracewell, R Martyn

    2011-07-01

    This study investigated the organising principles of touch. We examined specialisations within the haptic system and their hemispheric distribution. Haptic processing consists of the integration of data from multiple sources to form a single percept. Previous research provides strong support for a hierarchical and functional distribution within haptic processing. We investigated hemispheric asymmetry in haptic discrimination of objects with differing textures and centres of mass. By analogy with vision it was hypothesised that participants would demonstrate a left-hand advantage for centre of mass discrimination (a 'global', presumed right hemisphere, judgement) and a right-hand advantage for surface texture judgements (a 'local', presumed left hemisphere discrimination). We found that left-handed participants showed these effects to a lesser degree than did the right-handers, consistent with the notion that left-handed people generally show weaker asymmetries in bimanual tasks. In a second experiment the effect of conflicting information on haptic percept formation was investigated. Following from the previous hypotheses it was predicted that participants would be more accurate with their right hands at judging conflicting surfaces. Contrary to predictions an advantage was demonstrated for the left hand for texture discrimination and for the right hand for centre of mass judgement.

  18. EASTERN UGANDA

    African Journals Online (AJOL)

    EVALUATION OF SELECTED ELITE POTATO GENOTYPES IN. EASTERN ... Significant

  19. Hypnosis in the right hemisphere.

    Science.gov (United States)

    Kihlstrom, John F; Glisky, Martha L; McGovern, Susan; Rapcsak, Steven Z; Mennemeier, Mark S

    2013-02-01

    Speculations about the neural substrates of hypnosis have often focused on the right hemisphere (RH), implying that RH damage should impair hypnotic responsiveness more than left-hemisphere (LH) damage. The present study examined the performance of a patient who suffered a stroke destroying most of his LH, on slightly modified versions of two hypnotizability scales. This patient was at least modestly hypnotizable, as indicated in particular by the arm rigidity and age regression items, suggesting that hypnosis can be mediated by the RH alone - provided that the language capacities normally found in the LH remain available. A further study of 16 patients with unilateral strokes of the LH or RH found no substantial differences in hypnotizability between the two groups. Future neuropsychological studies of hypnosis might explore the dorsal/ventral or anterior/posterior dichotomies, with special emphasis on the role of prefrontal cortex. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Hemispheric ultra-wideband antenna.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2006-04-01

    This report begins with a review of reduced size ultra-wideband (UWB) antennas and the peculiar problems that arise when building a UWB antenna. It then gives a description of a new type of UWB antenna that resolves these problems. This antenna, dubbed the hemispheric conical antenna, is similar to a conventional conical antenna in that it uses the same inverted conical conductor over a ground plane, but it also uses a hemispheric dielectric fill in between the conductive cone and the ground plane. The dielectric material creates a fundamentally new antenna which is reduced in size and much more rugged than a standard UWB conical antenna. The creation of finite-difference time domain (FDTD) software tools in spherical coordinates, as described in SAND2004-6577, enabled this technological advance.

  1. Western Hemisphere Defense Policy Statement

    Science.gov (United States)

    2012-10-01

    El Salvador, Guatemala, Honduras , Paraguay, Peru and Uruguay have contributed to or led multi-national security operations and United Nations (UN...impact on regional and global peace and security and reflect the new realities of defense cooperation in the hemisphere. Working with Canada and...Mexico, DoD remains prepared to deter and defeat direct threats to our homeland. We partner with Canada on regional security issues such as an evolving

  2. Hemispheric Laterality in Music and Math

    Science.gov (United States)

    Szirony, Gary Michael; Burgin, John S.; Pearson, L. Carolyn

    2008-01-01

    Hemispheric laterality may be a useful concept in teaching, learning, training, and in understanding more about human development. To address this issue, a measure of hemispheric laterality was compared to musical and mathematical ability. The Human Information Processing Survey (HIPS) instrument, designed to measure hemispheric laterality, was…

  3. Right Hemisphere Dominance in Visual Statistical Learning

    Science.gov (United States)

    Roser, Matthew E.; Fiser, Jozsef; Aslin, Richard N.; Gazzaniga, Michael S.

    2011-01-01

    Several studies report a right hemisphere advantage for visuospatial integration and a left hemisphere advantage for inferring conceptual knowledge from patterns of covariation. The present study examined hemispheric asymmetry in the implicit learning of new visual feature combinations. A split-brain patient and normal control participants viewed…

  4. Brain Hemispheric Functions and the Native American.

    Science.gov (United States)

    Ross, Allen Chuck

    1982-01-01

    Uses brain research conducted by Dr. Roger Sperry to show that traditional Native Americans are more dominant in right hemisphere thinking, setting them apart from a modern left hemisphere-oriented society (especially emphasized in schools). Describes some characteristics of Native American thinking that illustrate a right hemisphere orientation…

  5. Hemispheric Symmetries of Plio-Pleistocene Surface Ocean Conditions: Insights from Southern Hemisphere ODP Sites 1125 and 1088

    Science.gov (United States)

    Lawrence, K. T.; Peterson, L.; Kelly, C.; Miller, H.; Seidenstein, J.

    2013-12-01

    For decades, most studies of Plio-Pleistocene climate and of the transition from the warmth of the Pliocene to the colder and more variable conditions of the Pleistocene have focused solely on northern hemisphere climate processes and responses. Here, we explore the southern hemisphere response to this major climate transition by documenting ocean surface conditions at Ocean Drilling Program Sites 1125 (42οS, 178οW, 1360m) and 1088 (40οS, 15οE, 2082m) through the Plio-Pleistocene. Secular trends in alkenone-derived sea surface temperature (SST) records indicate that these mid-latitude southern hemisphere sites cooled ~3-4οC over the past 3 Myrs, a magnitude comparable to sites located at similar latitudes in both the North Atlantic and North Pacific. This observation suggests that contraction of the low latitude warm pool was hemispherically symmetric. Our highly resolved (3 kyr resolution) Site 1125 SST record bears considerable structural similarity to SST records from nearby site 1123 (42οS,171οW) as well as sites 846 (3οS, 91οW) in the eastern equatorial Pacific and U1313 (41οN, 33οW) in the North Atlantic. Most of these SST records are dominated by 100k power and contain strong secondary 41k peaks throughout the past 3 million years. North Atlantic site U1313 is the exception, mirroring the shift in dominant periodicity from 41k to 100k associated with the mid-Pleistocene transition, that has long been observed in benthic oxygen isotope records. Finally, in southern hemisphere SST records as well as at site U1313 from the north Atlantic we observe weak precessional power that is not evident in benthic oxygen isotope record. These results suggest a fairly hemispherically-coordinated response of ocean surface temperature to changing global climate conditions during the Plio-Pleistocene in terms of both secular trends and dominant orbital frequencies.

  6. Electroformation of uranium hemispherical shells

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, S.L.; Redey, L.; Vandegrift, G.F.; Vissers, D.R.

    1989-11-01

    This effort was directed at developing an electrochemical process for forming uniform and dendrite-free deposits of uranium from molten salts. This process is to be used for the electroformation of free-standing hemispherical shells of uranium for nuclear applications. Electrodeposition of uranium onto a substrate was accomplished with a fused chloride mixture containing 42 wt% UCl{sub 3} and a fused chloride-fluoride mixture containing 4 wt % UF{sub 4}. Under pulsed potential control at 504{degree}C, the chloride-fluoride mixture yielded the widest range of plating conditions for which dendrites could be avoided. Bipolar current pulse plating with both electrolytes gave good results, and successful application of this technique to a large tubular cathode has been demonstrated. 24 refs., 10 figs.

  7. Hemispheric asymmetries: The comparative view

    Directory of Open Access Journals (Sweden)

    Sebastian eOcklenburg

    2012-01-01

    Full Text Available Hemispheric asymmetries play an important role in almost all cognitive functions. For more than a century, they were considered to be uniquely human but now an increasing number of findings in all vertebrate classes make it likely that we inherited our asymmetries from common ancestors. Thus, studying animal models could provide unique insights into the mechanisms of lateralization. We outline three such avenues of research by providing an overview of experiments on left-right differences in the connectivity of sensory systems, the embryonic determinants of brain asymmetries, and the genetics of lateralization. All these lines of studies could provide a wealth of insights into our own asymmetries that should and will be exploited by future analyses.

  8. Cryosphere-atmosphere interaction related to variability and change of northern hemisphere annular mode.

    Science.gov (United States)

    Bojariu, Roxana; García-Herrera, Ricardo; Gimeno, Luis; Zhang, Tingjun; Frauenfeld, Oliver W

    2008-12-01

    The Northern Hemisphere annular mode, also known as the Arctic Oscillation/North Atlantic Oscillation (AO/NAO) is a dominant atmospheric mode in the Northern Hemisphere winter that influences climate fluctuations from the eastern seaboard of the United States to Siberia and from the Arctic to the subtropical Atlantic. After almost a century of scientific investigation, the fundamental mechanisms determining the evolution of the AO/NAO are not yet completely understood. The ocean is favored as the most likely forcing of atmospheric variability, given the time scales of oceanic circulation and its large heat capacity. Our analyses of snow cover, soil temperatures, zonal winds, and geopotential heights identify the effect of land-atmosphere interaction over Eurasia on Northern Hemisphere atmospheric circulation, explaining the predictive signal that links fluctuations of April-October snow cover with the following winter AO/NAO phases.

  9. Hemispheric Division of Labour in Reading

    Science.gov (United States)

    Shillcock, Richard C.; McDonald, Scott A.

    2005-01-01

    We argue that the reading of words and text is fundamentally conditioned by the splitting of the fovea and the hemispheric division of the brain, and, furthermore, that the equitable division of labour between the hemispheres is a characteristic of normal visual word recognition. We report analyses of a representative corpus of the eye fixations…

  10. The Cost of Action Miscues: Hemispheric Asymmetries

    Science.gov (United States)

    Shenal, Brian V.; Hinze, Stephan; Heilman, Kenneth M.

    2012-01-01

    Adaptive behaviors require preparation and when necessary inhibition or alteration of actions. The right hemisphere has been posited to be dominant for preparatory motor activation. This experiment was designed to learn if there are hemispheric asymmetries in the control of altered plans of actions. Cues, both valid and invalid, which indicate the…

  11. The Cost of Action Miscues: Hemispheric Asymmetries

    Science.gov (United States)

    Shenal, Brian V.; Hinze, Stephan; Heilman, Kenneth M.

    2012-01-01

    Adaptive behaviors require preparation and when necessary inhibition or alteration of actions. The right hemisphere has been posited to be dominant for preparatory motor activation. This experiment was designed to learn if there are hemispheric asymmetries in the control of altered plans of actions. Cues, both valid and invalid, which indicate the…

  12. HEMISPHERIC CENTER FOR ENVIRONMENTAL TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    M.A. Ebadian

    1999-10-31

    The Deactivation and Decommissioning (D&D) Technology Assessment Program (TAP) was developed to provide detailed, comparable data for environmental technologies and to disseminate this data to D&D professionals in a manner that will facilitate the review and selection of technologies to perform decontamination and decommissioning. The objectives for this project include the following: Determine technology needs through review of the Site Technology Coordination Group (STCG) information and other applicable websites and needs databases; Perform a detailed review of industries that perform similar activities as those required in D&D operations to identify additional technologies; Define the technology assessment program for characterization and waste management problem sets; Define the data management program for characterization, dismantlement, and waste management problem sets; Evaluate baseline and innovative technologies under standard test conditions at Florida International University's Hemispheric Center for Environmental Technology (FIU-HCET) and other locations and collect data in the areas of performance, cost, health and safety, operations and maintenance, and primary and secondary waste generation; Continue to locate, verify, and incorporate technology performance data from other sources into the multimedia information system; and Develop the conceptual design for a dismantlement technology decision analysis tool for dismantlement technologies.

  13. Phase lags of solar hemispheric cycles

    CERN Document Server

    Muraközy, J

    2013-01-01

    The North-South asymmetry of solar activity is variable in time and strength. We analyse the long-term variation of the phase lags of hemispheric cycles and check a conjectured relationship between these phase lags and the hemispheric cycle strengths. Sunspot data are used from cycles 12-23 in which the separation of northern and southern hemispheres is possible. The centers of mass of the hemispheric cycle profiles were used to study the phase relations and relative strengths of the hemispheric cycles. This approach considers a cycle as a whole and disregards the short-term fluctuations of the cycle time profile. The phase of the hemispheric cycles shows an alternating variation: the northern cycle leads in 4 cycles and follows in 4 cycles. No significant relationship is found between the phase and strength differences of the hemispheric cycles. The period of 4+4 cycles appears to be close to the Gleissberg cycle and may provide a key to its physical background. It may raise a new aspect in the solar dynamo ...

  14. Remote canopy hemispherical image collection system

    Science.gov (United States)

    Wan, Xuefen; Liu, Bingyu; Yang, Yi; Han, Fang; Cui, Jian

    2016-11-01

    Canopies are major part of plant photosynthesis and have distinct architectural elements such as tree crowns, whorls, branches, shoots, etc. By measuring canopy structural parameters, the solar radiation interception, photosynthesis effects and the spatio-temporal distribution of solar radiation under the canopy can be evaluated. Among canopy structure parameters, Leaf Area Index (LAI) is the key one. Leaf area index is a crucial variable in agronomic and environmental studies, because of its importance for estimating the amount of radiation intercepted by the canopy and the crop water requirements. The LAI can be achieved by hemispheric images which are obtained below the canopy with high accuracy and effectiveness. But existing hemispheric images canopy-LAI measurement technique is based on digital SLR camera with a fisheye lens. Users need to collect hemispheric image manually. The SLR camera with fisheye lens is not suit for long-term canopy-LAI outdoor measurement too. And the high cost of SLR limits its capacity. In recent years, with the development of embedded system and image processing technology, low cost remote canopy hemispheric image acquisition technology is becoming possible. In this paper, we present a remote hemispheric canopy image acquisition system with in-field/host configuration. In-field node based on imbed platform, low cost image sensor and fisheye lens is designed to achieve hemispherical image of plant canopy at distance with low cost. Solar radiation and temperature/humidity data, which are important for evaluating image data validation, are obtained for invalid hemispherical image elimination and node maintenance too. Host computer interacts with in-field node by 3G network. The hemispherical image calibration and super resolution are used to improve image quality in host computer. Results show that the remote canopy image collection system can make low cost remote canopy image acquisition for LAI effectively. It will be a potential

  15. Differential hemispheric modulation of preparatory attention.

    Science.gov (United States)

    Fernández, Laura Gabriela; Siéroff, Eric

    2014-06-01

    Preparatory attention (PA) is the ability to allocate attention to a stimulus prior to its occurrence and is a crucial component of attentional control. We investigated the role of brain hemispheres in PA using an experimental test in which normal participants responded to a target that could appear in the right or the left visual fields, thus projecting to the left or the right hemispheres, while ignoring a central distractor that could appear in the preparatory phase preceding the target. This experimental test measures the ability of participants to modulate PA directed to a target location when the probability of a distractor occurrence varies across three blocks of trials (0%, 33%, 67%). The competition between distractors and target for PA should produce slower response times when the probability of distractors is high. Three experiments were conducted varying the temporal predictability of the target occurrence within a trial (high predictability in Experiments 1 and 3, and low predictability in Experiment 2), and the task used (location in Experiments 1 and 2, and detection in Experiment 3). We found that the modulation of PA by the expected probability of events was different in each visual field/hemisphere. Whereas the left hemisphere PA was influenced by the mere probability of events in each block of trials, the right hemisphere PA was mainly influenced by events with high temporal predictability. These results suggest that each hemisphere uses a different strategy to modulate PA when directed to a target location at the perceptual level of visual processing.

  16. Northern Hemisphere forcing of Southern Hemisphere climate during the last deglaciation.

    Science.gov (United States)

    He, Feng; Shakun, Jeremy D; Clark, Peter U; Carlson, Anders E; Liu, Zhengyu; Otto-Bliesner, Bette L; Kutzbach, John E

    2013-02-07

    According to the Milankovitch theory, changes in summer insolation in the high-latitude Northern Hemisphere caused glacial cycles through their impact on ice-sheet mass balance. Statistical analyses of long climate records supported this theory, but they also posed a substantial challenge by showing that changes in Southern Hemisphere climate were in phase with or led those in the north. Although an orbitally forced Northern Hemisphere signal may have been transmitted to the Southern Hemisphere, insolation forcing can also directly influence local Southern Hemisphere climate, potentially intensified by sea-ice feedback, suggesting that the hemispheres may have responded independently to different aspects of orbital forcing. Signal processing of climate records cannot distinguish between these conditions, however, because the proposed insolation forcings share essentially identical variability. Here we use transient simulations with a coupled atmosphere-ocean general circulation model to identify the impacts of forcing from changes in orbits, atmospheric CO(2) concentration, ice sheets and the Atlantic meridional overturning circulation (AMOC) on hemispheric temperatures during the first half of the last deglaciation (22-14.3 kyr BP). Although based on a single model, our transient simulation with only orbital changes supports the Milankovitch theory in showing that the last deglaciation was initiated by rising insolation during spring and summer in the mid-latitude to high-latitude Northern Hemisphere and by terrestrial snow-albedo feedback. The simulation with all forcings best reproduces the timing and magnitude of surface temperature evolution in the Southern Hemisphere in deglacial proxy records. AMOC changes associated with an orbitally induced retreat of Northern Hemisphere ice sheets is the most plausible explanation for the early Southern Hemisphere deglacial warming and its lead over Northern Hemisphere temperature; the ensuing rise in atmospheric CO(2

  17. Music Appreciation and Hemisphere Orientation: Visual versus Verbal Involvement.

    Science.gov (United States)

    Zalanowski, Annette H.

    1990-01-01

    Analyzes effect of brain hemisphere orientation on music appreciation. Reports results from 36 left-hemisphere and 36 right-hemisphere undergraduates who responded to a musical selection verbally or visually. Finds right-hemisphere students show greater appreciation, measured by attention, understanding, and enjoyment scores. Discusses…

  18. Hemispheric dysplasia and hemimegalencephaly: imaging definitions.

    Science.gov (United States)

    Santos, Antonio Carlos; Escorsi-Rosset, Sara; Simao, Gustavo N; Terra, Vera C; Velasco, Tonicarlo; Neder, Luciano; Sakamoto, Americo C; Machado, Helio R

    2014-11-01

    Hemispheric dysplasia (HD) and hemimegalencephaly (HME) are both brain malformations with early clinical manifestation including developmental delay and intractable epilepsy. Sometimes the differentiation of these conditions is not simple. HME is an anomaly of cortical development caused by a combination of neural proliferation and cell migration dysfunction, showing lobar or hemispheric enlargement. On the other hand, HD shows no brain hypertrophy, and even brain atrophy, eventually. To compare both conditions, we reviewed clinical, MRI, and histopathology of 23 patients with developmental delay and refractory epilepsy treated with hemispheric surgery. Histologically, both groups presented polymicrogyria, focal cortical dysplasia, gray matter (GM) heterotopia, pachygyria, and agyria. The white matter (WM) showed different degrees of gliosis and myelin impairment. Even though with no specificity in histopathology, the degree of lesion was more impressive on HME. The combination of WM dysmyelination and hypertrophy leads to the so called hamartomatous appearing. Although not all HME showed brain enlargement and some HD might show no size changes or atrophy, the size of affected hemisphere and the hamartomatous appearance of the WM were the more relevant signs to differentiate both conditions. Brain MRI was the best diagnostic tolls because it allowed together high contrast resolution, whole brain coverage and spatial distribution analysis. HD and HMD showed brain asymmetry tendency, but in opposite directions. The size of affected hemisphere and the hamartomatous appearance of the WM were the more relevant signs to differentiate both conditions.

  19. Hyperlalia: A Right Cerebral Hemisphere Syndrome

    Directory of Open Access Journals (Sweden)

    Atsushi Yamadori

    1990-01-01

    Full Text Available We describe a new right hemispheric behavioural syndrome for which we propose the name “hyperlalia”. In a typical case an apparently unconcerned and expressionless patient is easily prompted to remarkable volubility with a content which is loose and incoherent. The voice is low and monotonous. All the lesions confirmed by computed tomography of the brain overlapped in the perisylvian area in the territory of the right middle cerebral artery. Loss of a subtle balance between the left hemispheric speech area and the corresponding area in the right hemisphere caused by acute damage of the right perisylvian area may have resulted in disinhibition of the speech function. Similarities and dissimilarities with the known pathology of talkativeness are also discussed.

  20. Right hemisphere grey matter structure and language outcomes in chronic left hemisphere stroke.

    Science.gov (United States)

    Xing, Shihui; Lacey, Elizabeth H; Skipper-Kallal, Laura M; Jiang, Xiong; Harris-Love, Michelle L; Zeng, Jinsheng; Turkeltaub, Peter E

    2016-01-01

    The neural mechanisms underlying recovery of language after left hemisphere stroke remain elusive. Although older evidence suggested that right hemisphere language homologues compensate for damage in left hemisphere language areas, the current prevailing theory suggests that right hemisphere engagement is ineffective or even maladaptive. Using a novel combination of support vector regression-based lesion-symptom mapping and voxel-based morphometry, we aimed to determine whether local grey matter volume in the right hemisphere independently contributes to aphasia outcomes after chronic left hemisphere stroke. Thirty-two left hemisphere stroke survivors with aphasia underwent language assessment with the Western Aphasia Battery-Revised and tests of other cognitive domains. High-resolution T1-weighted images were obtained in aphasia patients and 30 demographically matched healthy controls. Support vector regression-based multivariate lesion-symptom mapping was used to identify critical language areas in the left hemisphere and then to quantify each stroke survivor's lesion burden in these areas. After controlling for these direct effects of the stroke on language, voxel-based morphometry was then used to determine whether local grey matter volumes in the right hemisphere explained additional variance in language outcomes. In brain areas in which grey matter volumes related to language outcomes, we then compared grey matter volumes in patients and healthy controls to assess post-stroke plasticity. Lesion-symptom mapping showed that specific left hemisphere regions related to different language abilities. After controlling for lesion burden in these areas, lesion size, and demographic factors, grey matter volumes in parts of the right temporoparietal cortex positively related to spontaneous speech, naming, and repetition scores. Examining whether domain general cognitive functions might explain these relationships, partial correlations demonstrated that grey matter

  1. An Evaluative Review of Hemispheric Learning Potential

    Science.gov (United States)

    1985-10-01

    function in the cerebral cortex first assumed importance in the work of the phrenologist Franz Joseph Gall. The early 19th-century neu- rologists...Einstein, Picasso, Kafka , and Eileen Garrett. Cortes and Montezuma are also opposed as the contrast of two hemisphere styles. Moore (1984) integrated

  2. Forest carbon sinks in the northern hemisphere

    NARCIS (Netherlands)

    Goodale, C.L.; Apps, M.J.; Birdsey, R.A.; Field, C.B.; Heath, L.S.; Houghton, R.A.; Jenkins, J.C.; Kohlmaier, G.H.; Kurz, W.; Liu, S.R.; Nabuurs, G.J.; Nilsson, S.; Shvidenko, A.Z.

    2002-01-01

    There is general agreement that terrestrial systems in the Northern Hemisphere provide a significant sink for atmospheric CO2; however, estimates of the magnitude and distribution of this sink vary greatly. National forest inventories provide strong, measuretment-based constraints on the magnitude o

  3. Hemisphere jet mass distribution at finite Nc

    Directory of Open Access Journals (Sweden)

    Yoshikazu Hagiwara

    2016-05-01

    Full Text Available We perform the leading logarithmic resummation of nonglobal logarithms for the single-hemisphere jet mass distribution in e+e− annihilation including the finite-Nc corrections. The result is compared with the previous all-order result in the large-Nc limit as well as fixed-order perturbative calculations.

  4. Hemispheric Differences in Processing Handwritten Cursive

    Science.gov (United States)

    Hellige, Joseph B.; Adamson, Maheen M.

    2007-01-01

    Hemispheric asymmetry was examined for native English speakers identifying consonant-vowel-consonant (CVC) non-words presented in standard printed form, in standard handwritten cursive form or in handwritten cursive with the letters separated by small gaps. For all three conditions, fewer errors occurred when stimuli were presented to the right…

  5. Hemispheric Coupling: Comparing Dynamo Simulations and Observations

    CERN Document Server

    Norton, Aimee A; Passos, Dario

    2014-01-01

    Numerical simulations that reproduce solar-like magnetic cycles can be used to generate long-term statistics. The variations in N-S hemispheric cycle synchronicity and amplitude produced in simulations has not been widely compared to observations. The observed limits on asymmetry show that hemispheric sunspot area production is no more than 20% asymmetric for cycles 12-23 and phase lags do not exceed 20% (2 yrs) of the total cycle period. Independent studies have found a long-term trend in phase values as one hemisphere leads the other for ~four cycles. Such persistence in phase is not indicative of a stochastic phenomenon. We compare the findings to results from a numerical simulation of solar convection recently produced with the EULAG-MHD model. This simulation spans 1600 yrs and generated 40 regular, sunspot-like cycles. While the simulated cycle length is too long and the toroidal bands remain at too high of latitudes, some solar-like aspects of hemispheric asymmetry are reproduced. The model reproduces ...

  6. Morphology of Southern Hemisphere Riometer Auroral Absorption

    Science.gov (United States)

    2006-06-01

    range of frequencies used an inverse -square frequency dependence approximately holds. Morphology of Southern Hemisphere Riometer Auroral Absorption...Tecnológico under Proyecto No 1940934. Annex The percentage probability, QA, that an absorption A dB is exceed, is given as: Where Am is

  7. Forest carbon sinks in the Northern Hemisphere

    Science.gov (United States)

    Christine L. Goodale; Michael J. Apps; Richard A. Birdsey; Christopher B. Field; Linda S. Heath; Richard A. Houghton; Jennifer C. Jenkins; Gundolf H. Kohlmaier; Werner Kurz; Shirong Liu; Gert-Jan Nabuurs; Sten Nilsson; Anatoly Z. Shvidenko

    2002-01-01

    There is general agreement that terrestrial systems in the Northern Hemisphere provide a significant sink for atmospheric CO2; however, estimates of the magnitude and distribution of this sink vary greatly. National forest inventories provide strong, measurement-based constraints on the magnitude of net forest carbon uptake. We brought together...

  8. Hemisphere Susceptibility and Personality: a Replication Study

    Science.gov (United States)

    Dimond, Stuart; Beaumont, Graham

    1974-01-01

    Author studied the capacity of the normal brain to carry out a paired-associate learning task by projecting the stimulus material to either the right or left hemisphere in order to establish if there was a lateral specialization for this type of learning in the normal brain. (Author/RK)

  9. Rethinking a Right Hemisphere Deficit in ADHD

    Science.gov (United States)

    Hale, T. Sigi; Loo, Sandra K.; Zaidel, Eran; Hanada, Grant; Macion, James; Smalley, Susan L.

    2009-01-01

    Introduction: Early observations from lesion studies suggested right hemisphere (RH) dysfunction in ADHD. However, a strictly right-lateralized deficit has not been well supported. An alternatively view suggests increased R greater than L asymmetry of brain function and abnormal interhemispheric interaction. If true, RH pathology in ADHD should…

  10. HEMISPHERE PREFERENCE, ANXIETY, AND COVARIATION BIAS

    NARCIS (Netherlands)

    de Jong, Peter; MERCKELBACH, H; NIJMAN, H

    1995-01-01

    In Study I, normal subjects (N = 70) completed the Preference Test (PT), the Spielberger State-Trait Anxiety Inventory, and the Anxiety Sensitivity Index. Subjects with a preference for a right hemisphere thinking style (as indexed by PT) were found to have higher state anxiety and anxiety sensitivi

  11. Practice makes two hemispheres almost perfect.

    Science.gov (United States)

    Cherbuin, Nicolas; Brinkman, Cobie

    2005-08-01

    Some tasks produce a performance advantage for conditions that require the processing of stimuli in two visual fields compared to conditions where single hemifield processing is sufficient. This advantage, however, disappears with practice. Although no definitive evidence yet exists, there are several possible mechanisms that might lead to improved performance of within- compared to across-hemisphere processing with practice. These include a shift from a more demanding, algorithmic strategy to a less demanding memory-retrieval strategy (e.g., [G. Logan, Toward an instance theory of automatisation. Psych. Rev. 95 (1988) 492-527]), as discussed by Weissman and Compton [D.H. Weissman, R.J. Compton, Practice makes a hemisphere perfect: the advantage of interhemispheric recruitment is eliminated with practice. Laterality, 8 (4) (2003) 361-375], and/or a more generalised practice effect [K. Kirsner, C. Speelman, Skill acquisition and repetition priming: one principle, many processes? J. Exp. Psychol., Learn. Mem. Cogn., 22 (1996) 563-575]. Contrary to Weissman and Compton findings, our results suggest that although single-hemisphere performance improves with practice, bi-hemispheric performance also improves substantially. Furthermore, these effects do not appear to be due to a shift in strategy but rather due to a general practice effect.

  12. Intraseasonal meridional current variability in the eastern equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Ogata, T.; Sasaki, H.; Murty, V.S.N.; Sarma, M.S.S.; Masumoto, Y.

    for the atmospheric disturbances at this time-scale over the eastern Indian Ocean, which can be considered as the forcing to the oceanic ISV, such as those indicated by Chatterji and Goswami [2004], Shinoda and Han [2005], and Fukutomi and Yasunari [2005]. An air...–2482. Fukutomi, Y., and T. Yasunari (2005), Southerly surges on the submonthly timescales over the eastern Indian Ocean during the Southern Hemisphere winter, Mon. Weather Rev., 133(6), 1637–1654. Han, W., D. Yuan, W. T. Liu, and D. J. Halkides (2007...

  13. Resting state EEG power, intra-hemisphere and inter-hemisphere coherence in bipolar disorder

    Science.gov (United States)

    Handayani, Nita; Khotimah, S. N.; Haryanto, F.; Arif, I.; Taruno, Warsito P.

    2017-02-01

    This paper examines the differences of EEG power and coherence between bipolar disorder patients and healthy subjects in the resting state. Observations are focused on the prefrontal cortex area by calculating intra-hemisphere and inter-hemisphere coherence. EEG data acquisition are conducted by using wireless Emotiv Epoc on AF3, AF4, FC5, FC6, F7 and F8 channels. The power spectral analysis shows that in bipolar disoder there is an increase of power in the delta, theta and beta frequencies, and power decrease in the alpha frequency. The coherence test results show that both intra-hemisphere and inter-hemisphere coherence in bipolar disorder patients are lower than healthy subjects. This shows the lack of brain synchronization in bipolar disorder patients.

  14. Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation

    OpenAIRE

    Kwon, Yong Hyun; Jang, Sung Ho

    2012-01-01

    We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel coun...

  15. Temporal and Spatial Changes in Northern Hemisphere Floating Climatological Seasons

    Science.gov (United States)

    Choi, G.; Robinson, D. A.

    2007-12-01

    Floating climatological seasons, for which onsets and durations vary temporally and spatially, are examined over Northern Hemisphere continents and oceans. Among the variables evaluated are surface air temperature, snow extent, vegetation greenness, and atmospheric carbon dioxide concentrations. Seasonal thresholds are defined for each variable (e.g. daily mean temperature exceeding 5°C (20°C) to mark the beginning of spring (summer)). The dates on which these thresholds are reached at a given location are determined for each year over the past three decades. These seasonal onsets and offsets "float" temporally and spatially from year to another. An analysis of floating dates finds that winter duration has shortened in Europe, eastern Asia, and western North America, primarily due to an earlier spring onset. The spatial pattern of this earlier onset is associated with a positive Arctic Oscillation (AO) regime in the previous winter months. The positive winter AO finds anomalously high pressure sitting in the middle latitudes in locations where spring arrives early. This is likely due to a combination of advective fluxes of warmth and moisture and the local enhancement of solar radiation reaching the surface under clear skies. This, in turn, promotes earlier snow melt that further enhances warming and an earlier green-up. Extended summer duration is observed over continents and oceans (except the Arctic Ocean, where summer does not exist). The oceanic zone along 30°N has experienced a particularly large increase in duration, suggesting Hadley cell expansion.

  16. Twentieth Century Winter Changes in Southern Hemisphere Synoptic Weather Modes

    Directory of Open Access Journals (Sweden)

    Jorgen S. Frederiksen

    2011-01-01

    Full Text Available During the last sixty years, there have been large changes in the southern hemisphere winter circulation and reductions in rainfall particularly in the southern Australian region. Here we examine the corresponding changes in dynamical modes of variability ranging from storm tracks, onset-of-blocking modes, northwest cloud-band disturbances, Antarctic low-frequency modes, intraseasonal oscillations, and African easterly waves. Our study is performed using a global two-level primitive equation instability-model with reanalyzed observed July three-dimensional basic states for the periods 1949–1968, 1975–1994, and 1997–2006. We relate the reduction in the winter rainfall in the southwest of Western Australia since the mid-1970s and in south-eastern Australia since the mid-1990s to changes in growth rate and structures of leading storm track and blocking modes. We find that cyclogenesis and onset-of-blocking modes growing on the subtropical jet have significantly reduced growth rates in the latter periods. On the other hand there is a significant increase in the growth rate of northwest cloud-band modes and intraseasonal oscillation disturbances that cross Australia and are shown to be related to recent positive trends in winter rainfall over northwest Western Australia and central Australia, in general. The implications of our findings are discussed.

  17. SOLAR ENERGETIC PARTICLE EVENT ONSETS: FAR BACKSIDE SOLAR SOURCES AND THE EAST–WEST HEMISPHERIC ASYMMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Kahler, S. W., E-mail: stephen.kahler@kirtland.af.mil [Air Force Research Laboratory, Space Vehicles Directorate, 3550 Aberdeen Avenue, Kirtland AFB, NM 87117 (United States)

    2016-03-10

    Prompt onsets and short rise times to peak intensities Ip have been noted in a few solar energetic (E > 10 MeV) particle (SEP) events from far behind (≥25°) the west limb. We discuss 15 archival and recent examples of these prompt events, giving their source longitudes, onset and rise times, and associated coronal mass ejection (CME) speeds. Their timescales and CME speeds are not exceptional in comparison with a larger set of SEP events from behind the west limb. A further statistical comparison of observed timescales of SEP events from behind the west limb with events similarly poorly magnetically connected to the eastern hemisphere (EH) shows the longer timescales of the latter group. We interpret this result in terms of a difference between SEP production at parallel shocks on the eastern flanks of western backside events and at perpendicular shocks on the western flanks of EH events.

  18. Asymmetric auroral intensities in the Earth's Northern and Southern hemispheres

    Science.gov (United States)

    Laundal, K. M.; Østgaard, N.

    2009-07-01

    It is commonly assumed that the aurora borealis (Northern Hemisphere) and aurora australis (Southern Hemisphere) are mirror images of each other because the charged particles causing the aurora follow the magnetic field lines connecting the two hemispheres. The particles are believed to be evenly distributed between the two hemispheres, from the source region in the equatorial plane of the magnetosphere. Although it has been shown that similar auroral features in the opposite hemispheres can be displaced tens of degree in longitude and that seasonal effects can cause differences in global intensity, the overall auroral patterns were still similar. Here we report observations that clearly contradict the common assumption about symmetric aurora: intense spots are seen at dawn in the Northern summer Hemisphere, and at dusk in the Southern winter Hemisphere. The asymmetry is interpreted in terms of inter-hemispheric currents related to seasons, which have been predicted but hitherto had not been seen.

  19. Right-hemispheric processing of non-linguistic word features

    DEFF Research Database (Denmark)

    Baumgaertner, Annette; Hartwigsen, Gesa; Roman Siebner, Hartwig

    2013-01-01

    Verbal stimuli often induce right-hemispheric activation in patients with aphasia after left-hemispheric stroke. This right-hemispheric activation is commonly attributed to functional reorganization within the language system. Yet previous evidence suggests that functional activation in right......-hemispheric homologues of classic left-hemispheric language areas may partly be due to processing nonlinguistic perceptual features of verbal stimuli. We used functional MRI (fMRI) to clarify the role of the right hemisphere in the perception of nonlinguistic word features in healthy individuals. Participants made......, the right inferior frontal gyrus (IFG), an area previously suggested to support language recovery after left-hemispheric stroke, displayed modality-independent activation during perceptual processing of word stimuli. Our findings indicate that activation of the right hemisphere during language tasks may...

  20. Hemispheric differences in the effects of context on vowel perception

    NARCIS (Netherlands)

    Sjerps, M.J.; Mitterer, H.A.; McQueen, J.M.

    2012-01-01

    Listeners perceive speech sounds relative to context. Contextual influences might differ over hemispheres if different types of auditory processing are lateralized. Hemispheric differences in contextual influences on vowel perception were investigated by presenting speech targets and both speech and

  1. Spatial disorientation in right-hemisphere infarction.

    OpenAIRE

    Meerwaldt, J D; van Harskamp, F

    1982-01-01

    Spatial orientation was tested with the rod orientation test. The subjects were 40 normal controls and 68 brain-damaged patients with cerebral infarcts. Patients in whom the lesion included the post-rolandic region of the right hemisphere performed worse than controls or patients with lesions at other sites. Patients with an exclusively postrolandic (usually occipital) lesion showed higher error rates than patients with a combined prerolandic and postrolandic lesion, but only for the visual p...

  2. Cognitive Correlates of Hemispheric Performance on Dichotic Tasks.

    Science.gov (United States)

    Johnson, Ronald C.; And Others

    1984-01-01

    Examined the relationship between performance on left and right hemisphere dominant measures of cognition and performance on dichotic memory tasks in 53 adults age 50 and older. Right hemisphere performance on dichotic and cognitive tasks showed a negative association with age while left hemisphere performance showed no decline. (JAC)

  3. Hemispheric Asymmetries in the Activation and Monitoring of Memory Errors

    Science.gov (United States)

    Giammattei, Jeannette; Arndt, Jason

    2012-01-01

    Previous research on the lateralization of memory errors suggests that the right hemisphere's tendency to produce more memory errors than the left hemisphere reflects hemispheric differences in semantic activation. However, all prior research that has examined the lateralization of memory errors has used self-paced recognition judgments. Because…

  4. Double infarction in one cerebral hemisphere.

    Science.gov (United States)

    Bogousslavsky, J

    1991-07-01

    Thirty-two patients whose first stroke was due to double infarct in one cerebral hemisphere were identified among 1,911 consecutive patients from the Lausanne Stroke Registry. The double infarct involved territories of the superficial middle cerebral artery, superficial posterior cerebral artery, lenticulostriate, anterior choroidal artery, or borderzone. The most common combination involved territories of the anterior middle cerebral artery plus the posterior middle cerebral artery. In the patients with the double infarct, the prevalence of potential cardiac sources of embolism (19%) was similar to that found in the registry in general, but the double infarct was closely associated with tight (greater than or equal to 90% of the lumen diameter) stenosis or occlusion (75%) of the internal carotid artery. The most common neurological picture mimicked large infarction in the middle cerebral artery territory, but nearly half of the patients with double infarct in one cerebral hemisphere had a specific clinical syndrome, which was not found in the 1,879 remaining patients from the registry, including hemianopia-hemiplegia (in 6), acute conduction aphasia-hemiparesis (in 2), and acute transcortical mixed aphasia (in 6), in relation to characteristic combinations of infarcts. These unique clinical and etiological correlates warrant the recognition of double infarct in one cerebral hemisphere from other acute ischemic strokes.

  5. Depression and the hyperactive right-hemisphere.

    Science.gov (United States)

    Hecht, David

    2010-10-01

    Depression is associated with an inter-hemispheric imbalance; a hyperactive right-hemisphere (RH) and a relatively hypoactive left-hemisphere (LH). Nevertheless, the underlying mechanisms which can explain why depression is associated with a RH dominance remain elusive. This article points out the potential links between functional cerebral asymmetries and specific symptoms and features of depression. There is evidence that the RH is selectively involved in processing negative emotions, pessimistic thoughts and unconstructive thinking styles--all which comprise the cognitive phenomenology of depression and in turn contribute to the elevated anxiety, stress and pain associated with the illness. Additionally, the RH mediates vigilance and arousal which may explain the sleep disturbances often reported in depression. The RH had also been linked with self-reflection, accounting for the tendency of depressed individuals to withdraw from their external environments and focus attention inward. Physiologically, RH activation is associated with hyprecortisolemia, which contributes to the deterioration of the immune system functioning and puts depressed patients at a greater risk of developing other illnesses, accounting for depression's high comorbidity with other diseases. Conversely, the LH is specifically involved in processing pleasurable experiences, and its relative attenuation is in line with the symptoms of anhedonia that characterize depression. The LH is also relatively more involved in decision-making processes, accounting for the indecisiveness that is often accompanied with depression.

  6. Antireflective characteristics of hemispherical grid grating

    Institute of Scientific and Technical Information of China (English)

    REN Zhibin; JIANG Huilin; LIU Guojun; SUN Qiang

    2005-01-01

    In this paper, the optical characteristics of new type hemispherical grid subwavelength grating are studied by using multi-level column structure approximation and rigorous coupled-wave analysis. This kind of grating could be fabricated by chemical methods, thus simplifying the fabrication technology of subwavelength gratings for visible light. By computer simulation and calculation, the hemispherical grid subwavelength gratings are proved to have antireflective characteristics. Two design schemes of this kind of grating are presented. In the first scheme, the grating could achieve a reflectivity as low as 3.4416×10-7, which can be adapted to 0.46―0.7 μm of visible waveband and ±12° incident angle field. In the second scheme, the grating can achieve a reflectivity as low as 3.112×10-4 and adapted to the whole visible waveband and ±23° incident angle field. The application field of the latter scheme is wider than that of the former. The results of this paper could provide reference for the applications of the hemispherical grid subwavelength gratings for the visible waveband.

  7. Casimir effect in hemisphere capped tubes

    CERN Document Server

    de Mello, E R Bezerra

    2014-01-01

    In this paper we investigate the vacuum densities for a massive scalar field with general curvature coupling in background of a (2+1)-dimensional spacetime corresponding to a cylindrical tube with a hemispherical cap. A complete set of mode functions is constructed and the positive-frequency Wightman function is evaluated for both the cylindrical and hemispherical subspaces. On the base of this, the vacuum expectation values of the field squared and energy-momentum tensor are investigated. The mean field squared and the normal stress are finite on the boundary separating two subspaces, whereas the energy density and the parallel stress diverge as the inverse power of the distance from the boundary. For a conformally coupled field, the vacuum energy density is negative on the cylindrical part of the space. On the hemisphere, it is negative near the top and positive close to the boundary. In the case of minimal coupling the energy density on the cup is negative. On the tube it is positive near the boundary and ...

  8. Casimir Effect in Hemisphere Capped Tubes

    Science.gov (United States)

    Bezerra de Mello, E. R.; Saharian, A. A.

    2016-02-01

    In this paper we investigate the vacuum densities for a massive scalar field with general curvature coupling in background of a (2 + 1)-dimensional spacetime corresponding to a cylindrical tube with a hemispherical cap. A complete set of mode functions is constructed and the positive-frequency Wightman function is evaluated for both the cylindrical and hemispherical subspaces. On the base of this, the vacuum expectation values of the field squared and energy-momentum tensor are investigated. The mean field squared and the normal stress are finite on the boundary separating two subspaces, whereas the energy density and the parallel stress diverge as the inverse power of the distance from the boundary. For a conformally coupled field, the vacuum energy density is negative on the cylindrical part of the space. On the hemisphere, it is negative near the top and positive close to the boundary. In the case of minimal coupling the energy density on the cup is negative. On the tube it is positive near the boundary and negative at large distances. Though the geometries of the subspaces are different, the Casimir pressures on the separate sides of the boundary are equal and the net Casimir force vanishes. The results obtained may be applied to capped carbon nanotubes described by an effective field theory in the long-wavelength approximation.

  9. Testing the Language of German Cerebral Palsy Patients with Right Hemispheric Language Organization after Early Left Hemispheric Damage

    Science.gov (United States)

    Schwilling, Eleonore; Krageloh-Mann, Ingeborg; Konietzko, Andreas; Winkler, Susanne; Lidzba, Karen

    2012-01-01

    Language functions are generally represented in the left cerebral hemisphere. After early (prenatally acquired or perinatally acquired) left hemispheric brain damage language functions may be salvaged by reorganization into the right hemisphere. This is different from brain lesions acquired in adulthood which normally lead to aphasia. Right…

  10. Hemispheric specialization for linguistic processing of sung speech.

    Science.gov (United States)

    Yelle, Serena K; Grimshaw, Gina M

    2009-02-01

    The two hemispheres of the brain play complementary roles in song perception, with the left hemisphere specialized for processing the linguistic aspects of song and the right hemisphere specialized for the processing of melody. However, very little is known about how language and melody interact. The present study tested the hypothesis that right hemisphere linguistic processing would be facilitated by the presence of melody. In a dichotic listening paradigm, participants (8 men, 43 women) performed a linguistic task while listening to spoken or sung speech. Contrary to the hypothesis, left hemisphere specialization for linguistic processing was identical whether the sentences were spoken or sung.

  11. The calculating hemispheres: studies of a split-brain patient.

    Science.gov (United States)

    Funnell, Margaret G; Colvin, Mary K; Gazzaniga, Michael S

    2007-06-11

    The purpose of the study was to investigate simple calculation in the two cerebral hemispheres of a split-brain patient. In a series of four experiments, the left hemisphere was superior to the right in simple calculation, confirming the previously reported left hemisphere specialization for calculation. In two different recognition paradigms, right hemisphere performance was at chance for all arithmetic operations, with the exception of subtraction in a two-alternative forced choice paradigm (performance was at chance when the lure differed from the correct answer by a magnitude of 1 but above chance when the magnitude difference was 4). In a recall paradigm, the right hemisphere performed above chance for both addition and subtraction, but performed at chance levels for multiplication and division. The error patterns in that experiment suggested that for subtraction and addition, the right hemisphere does have some capacity for approximating the solution even when it is unable to generate the exact solution. Furthermore, right hemisphere accuracy in addition and subtraction was higher for problems with small operands than with large operands. An additional experiment assessed approximate and exact addition in the two hemispheres for problems with small and large operands. The left hemisphere was equally accurate in both tasks but the right hemisphere was more accurate in approximate addition than in exact addition. In exact addition, right hemisphere accuracy was higher for problems with small operands than large, but the opposite pattern was found for approximate addition.

  12. The eastern Mediterranean climate at times of sapropel formation: a review

    NARCIS (Netherlands)

    Rohling, E.J.; Hilgen, F.J.

    2007-01-01

    Sapropel formation in the eastern Mediterranean coincided closely with minima in the precession index. Such minima occur approximately every 21000 years. At such times perihelion falls within Northern Hemisphere summer. Minima in the precession index are characterized by intensified Indian Ocean

  13. Phenological changes in the southern hemisphere.

    Directory of Open Access Journals (Sweden)

    Lynda E Chambers

    Full Text Available Current evidence of phenological responses to recent climate change is substantially biased towards northern hemisphere temperate regions. Given regional differences in climate change, shifts in phenology will not be uniform across the globe, and conclusions drawn from temperate systems in the northern hemisphere might not be applicable to other regions on the planet. We conduct the largest meta-analysis to date of phenological drivers and trends among southern hemisphere species, assessing 1208 long-term datasets from 89 studies on 347 species. Data were mostly from Australasia (Australia and New Zealand, South America and the Antarctic/subantarctic, and focused primarily on plants and birds. This meta-analysis shows an advance in the timing of spring events (with a strong Australian data bias, although substantial differences in trends were apparent among taxonomic groups and regions. When only statistically significant trends were considered, 82% of terrestrial datasets and 42% of marine datasets demonstrated an advance in phenology. Temperature was most frequently identified as the primary driver of phenological changes; however, in many studies it was the only climate variable considered. When precipitation was examined, it often played a key role but, in contrast with temperature, the direction of phenological shifts in response to precipitation variation was difficult to predict a priori. We discuss how phenological information can inform the adaptive capacity of species, their resilience, and constraints on autonomous adaptation. We also highlight serious weaknesses in past and current data collection and analyses at large regional scales (with very few studies in the tropics or from Africa and dramatic taxonomic biases. If accurate predictions regarding the general effects of climate change on the biology of organisms are to be made, data collection policies focussing on targeting data-deficient regions and taxa need to be financially

  14. Detection of lightning in Saturn's Northern Hemisphere

    CERN Document Server

    Moghimi, Mohsen Hassanzadeh

    2012-01-01

    During Cassini flyby of Saturn at a radial distance 6.18R_s (Saturn Radius), a signal was detected from about 200 to 430 Hz that had the proper dispersion characteristics to be a whistler. The frequency-time dispersion of the whistler was found to be 81 Hz1/2s. Based on this dispersion constant, we determined, from a travel time computation, that the whistler must have originated from lightning in the northern hemisphere of Saturn. Using a simple centrifugal potential model consisting of water group ions, and hydrogen ions we also determine the fractional concentration and scale height that gave the best fit to the observed dispersion.

  15. Hemispherical sky simulator for daylighting model studies

    Energy Technology Data Exchange (ETDEWEB)

    Selkowitz, S.

    1981-07-01

    The design of a 24-foot-diameter hemispherical sky simulator recently completed at LBL is described. The goal was to produce a facility in which large models could be tested; which was suitable for research, teaching, and design; which could provide a uniform sky, an overcast sky, and several clear-sky luminance distributions, as well as accommodating an artificial sun. Initial operating experience with the facility is described, the sky simulator capabilities are reviewed, and its strengths and weaknesses relative to outdoor modeling tests are discussed.

  16. Hemispheric dominance and cell phone use.

    Science.gov (United States)

    Seidman, Michael D; Siegel, Bianca; Shah, Priyanka; Bowyer, Susan M

    2013-05-01

    A thorough understanding of why we hold a cell phone to a particular ear may be of importance when studying the impact of cell phone safety. To determine if there is an obvious association between sidedness of cell phone use and auditory hemispheric dominance (AHD) or language hemispheric dominance (LHD). It is known that 70% to 95% of the population are right-handed, and of these, 96% have left-brain LHD. We have observed that most people use their cell phones in their right ear. An Internet survey was e-mailed to individuals through surveymonkey.com. The survey used a modified Edinburgh Handedness Inventory protocol. Sample questions surveyed which hand was used to write with, whether the right or left ear was used for phone conversations, as well as whether a brain tumor was present. General community. An Internet survey was randomly e-mailed to 5000 individuals selected from an otology online group, patients undergoing Wada testing and functional magnetic resonance imaging, as well as persons on the university listserv, of which 717 surveys were completed. Determination of hemispheric dominance based on preferred ear for cell phone use. A total of 717 surveys were returned. Ninety percent of the respondents were right handed, and 9% were left handed. Sixty-eight percent of the right-handed people used the cell phone in their right ear, 25% in the left ear, and 7% had no preference. Seventy-two of the left-handed respondents used their left ear, 23% used their right ear, and 5% had no preference. Cell phone use averaged 540 minutes per month over the past 9 years. An association exists between hand dominance laterality of cell phone use (73%) and our ability to predict hemispheric dominance. Most right-handed people have left-brain LHD and use their cell phone in their right ear. Similarly, most left-handed people use their cell phone in their left ear. Our study suggests that AHD may differ from LHD owing to the difference in handedness and cell phone ear use

  17. Circular single domains in hemispherical Permalloy nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Clodoaldo I. L de, E-mail: dearaujo@ufv.br; Fonseca, Jakson M. [Departamento de Física, Universidade Federal de Viçosa, 36570-900 Viçosa-MG (Brazil); Sinnecker, João P. [Centro Brasileiro de Pesquisas Físicas, 22290-180 Rio de Janeiro-RJ (Brazil); Delatorre, Rafael G.; Garcia, Nicolas; Pasa, André A. [Departamento de Física, Universidade Federal de Santa Catarina, 88040-900 Florianópolis-SC (Brazil)

    2014-11-14

    We have studied ferromagnetic Permalloy clusters obtained by electrodeposition on n-type silicon. Magnetization measurements reveal hysteresis loops almost independent on temperature and very similar in shape to those obtained in nanodisks with diameter bigger than 150 nm. The spin configuration for the ground state, obtained by micromagnetic simulation, shows topological vortices with random chirality and polarization. This behavior in the small diameter clusters (∼80 nm) is attributed to the Dzyaloshinskii-Moriya interaction that arises in its hemispherical geometries. This magnetization behavior can be utilized to explain the magnetoresistance measured with magnetic field in plane and out of sample plane.

  18. Spatial disorientation in right-hemisphere infarction.

    Science.gov (United States)

    Meerwaldt, J D; van Harskamp, F

    1982-01-01

    Spatial orientation was tested with the rod orientation test. The subjects were 40 normal controls and 68 brain-damaged patients with cerebral infarcts. Patients in whom the lesion included the post-rolandic region of the right hemisphere performed worse than controls or patients with lesions at other sites. Patients with an exclusively postrolandic (usually occipital) lesion showed higher error rates than patients with a combined prerolandic and postrolandic lesion, but only for the visual part of the test. These patients were re-examined one year after the stroke. Most of them showed an incomplete recovery of spatial function. PMID:7119828

  19. The genus Platychara from the Western Hemisphere

    Science.gov (United States)

    Peck, R.E.; Forester, R.M.

    1979-01-01

    The systematics of four species belonging to the genus Platychara (Charophyta) from the Western Hemisphere is discussed. Three of the species, as defined herein, occur in Cretaceous and Paleocene rocks from Mexico through South America. The type species, P. compressa (Peck and Reker) Grambast, also of Cretaceous and Paleocene age, is herein restricted to deposits north of Mexico. These latter restrictions geographically separate P. compressa and P. perlata as presently defined but the relationship between these two species is still uncertain. A new species, P. grambastii, is proposed for specimens from Maestrichtian sediments in Jamaica. ?? 1979.

  20. Inter-hemispheric asymmetry of Pedersen conductance

    Science.gov (United States)

    Deng, Y.; Lu, Y.; Sheng, C.; Yue, X.

    2015-12-01

    Ionospheric conductance is very important to the magnetosphere-ionosphere coupling in the high latitude region, since it connects the polar cap potential with the currents. Meanwhile, the altitudinal distribution of Pederson conductance gives us a rough idea about the altitudinal distribution of Joule heating at high latitudes. Based on the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites observations of electron density profiles from 2009-2014, Pedersen conductivity has been calculated. A climatologic study of the height-integrated Pedersen conductivities in both E (100-150 km) and F (150-600 km) regions and their ratio in different seasons, solar and geomagnetic conditions have been conducted. A significant inter-hemispheric asymmetry is identified in the seasonal variation. Meanwhile, the conductance in both regions and the conductance ratio show a strong dependence on F10.7 and Ap indices. This result will strongly help our understanding of the inter-hemispheric difference in the high-latitude electrodynamics.

  1. Flow past 2-D Hemispherical Rigid Canopies

    Science.gov (United States)

    Carnasciali, Maria-Isabel

    2013-11-01

    The flow past a 2-dimensional rigid hemispherical shape is investigated using PIV. Flow field measurements and images were generated with the use of a Thermoflow® apparatus. Results of this study are compared to prior work (APS DFD 2012 Session E9.00003) which employed CFD to investigate the flow in the near wake of hemispherical parachutes. The various sized gaps/open areas were positioned at distinct locations. The work presented here is part of a larger research project to investigate flow fields in deceleration devices and parachutes. Understanding the pitch-stability of parachutes is essential for accurate design and implementation of these deceleration devices but they present a difficult system to analyze. The flexibility of the parachute fabric results in large variations in the parachute geometry leading to complex fluid-structure interactions. Such flow, combined with flow through gaps and open areas, has been postulated to shed alternating vortices causing pitching/oscillations of the canopy. The results presented provide some insight into which geometric features affect vortex shedding and may enable the redesign of the baseline parachute to minimize instabilities.

  2. Novel hemispheric image formation: concepts and applications

    Science.gov (United States)

    Thibault, Simon; Konen, Pierre; Roulet, Patrice; Villegas, Mathieu

    2008-04-01

    Panoramic and hemispheric lens technologies represent new and exciting opportunities in both imaging and projection systems. Such lenses offer intriguing applications for the transportation/automotive industry, in the protection of civilian and military areas, business. In this paper we describe a new optical design technique that provides a greater degree of freedom in producing a variety of hemispheric spatial light distribution areas. This innovative optical design strategy, of generating and controlling image mapping, has been successful in producing high-resolution imaging and projection systems. This success has subsequently generated increased interest in the high-resolution camera/projector and the concept of absolute measurement with high-resolution wide-angle lenses. The new technique described in this paper uses optimization techniques to improve the performance of a customized wide-angle lens optical system for a specific application. By adding a custom angle-to-pixel ratio at the optical design stage, this customized optical system provides ideal image coverage while reducing and optimizing signal processing. This novel image formation technique requires the development of new algorithms in order to view the panoramic image on a display without any residual distortion.

  3. Hemisphere asymmetries for imitation of novel gestures.

    Science.gov (United States)

    Goldenberg, Georg; Strauss, Stefan

    2002-09-24

    Disorders of imitation are traditionally considered as a symptom of apraxia, but defective imitation of gestures can contrast with intact performance of gestures to verbal command and vice versa. It thus seems worthwhile to explore the neural basis of imitation of gestures independently of other manifestations of apraxia. To assess body part specificity of disturbances of imitation for meaningless gestures of fingers, hand, and foot. Imitation of meaningless gestures involving fingers (internal hand configuration), hand (external hand position), or foot was examined in 30 patients with left brain damage (LBD), 20 patients with right brain damage (RBD), and 20 normal control subjects. LBD affected imitation of hand and foot gestures more than imitation of finger gestures, whereas RBD had the strongest effect on finger gestures and affected foot gestures more than hand gestures. These results can be accounted for by the assumption that body part coding of gestures depends on left hemisphere function and that additional right hemisphere contributions are afforded when demands on perceptual discrimination rise.

  4. A Search for Hemispheric Asymmetry on Triton

    Science.gov (United States)

    McIntosh, C. M.; Storrs, A. D.

    2004-12-01

    We will present reconstructed images of Neptune's largest satellite Triton as part of an investigation of hemispheric asymmetry. The images we observed from the Hubble Space Telescope in July of 1997, using the Wide Field/Planetary Camera. The images were taken in several filters: F439W, F555W, and F791W. Image restoration was performed using the MISTRAL program (Mugnier, Fusco, and Conan 2003). We present the ratio between the filters to determine if there is any hemispheric color asymmetry at this time. The photometry of Triton appears normal in this data although Hicks and Buratti (2004) observe Triton to be anomalously red in August of 1997. References: Hicks, M.D., and Buratti, B.J. (2004): "The Spectral Variability of Triton from 1997-2000", Icarus 171 pp. 210-218 Mugnier, L.M., T. Fusco, and J.-M. Conan, 2003. "MISTRAL: a Myopic Edge-Preserving Image Restoration Method. Applicaton to Astronomical Adaptive Optics Corrected Long-Exposure Images." JOSA A (submitted)

  5. The Eastern Partnership

    DEFF Research Database (Denmark)

    Nielsen, Kristian L.; Vilson, Maili

    2014-01-01

    When the EU launched the Eastern Partnership (EaP) in 2009, it did so with much rhetoric about projecting its soft power into Eastern Europe. Yet today, the EU's soft power project seems to have stalled, with developments in the region being less than favourable. This article argues that the EaP ...

  6. Eastern Europe's Silicon Rush

    Science.gov (United States)

    Woodard, Colin

    2007-01-01

    This article presents how the fast expansion of information technology industry in eastern Slovakia is putting a strain on its labor supply. Suddenly, computer-science graduates have become one of the former Eastern Bloc's greatest assets, attracting multinational technology companies hungry for skilled programmers, technicians, and engineers.…

  7. Significance of Hemispheric Security for Mexico

    Science.gov (United States)

    2007-11-02

    La Seguridad Internacional, la Nueva Geopolitica Continental y Mexico,” Seminario Internacional sobre Misiones de Paz , Seguridad y Defensa, Rio de...Preservacion de la Paz en el Ambito Hemisferico y el Proceso en Torno al Nuevo Concepto de la Seguridad. Organizacion de los Estados Americanos, 56o...Eastern Studies, Kyungam University and Portland State University, 2002 Vol. 26, No.3), 177. 44 Wesley A. Fryer, Ibid. 45 “Retrocederá la Guerra

  8. Total hemispherical emissivity of Inconel 718

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Benjamin P.; Nelson, Shawn E.; Walton, Kyle L.; Ghosh, Tushar K.; Tompson, Robert V.; Loyalka, Sudarshan K., E-mail: LoyalkaS@missouri.edu

    2015-06-15

    Highlights: • We have measured the total hemispherical emissivity for Inconel 718 from about 600–1250 K. • Oxidation in air at 1073 K resulted in an increase in emissivity. • Sandblasting of Inconel 718 was also observed to increase the emissivity. • Coating of graphite powder onto the ‘as-received’ Inconel 718 showed no increase in the emissivity. • Coating of graphite powder onto the 220 grit sandblasted Inconel 718 did show an increase in emissivity. - Abstract: Total hemispherical emissivity for Inconel 718 was measured in anticipation of its application in Very High Temperature Gas Reactors (VHTRs). A majority of current emissivity data for Inconel 718 is in the form of spectral measurements. The data presented here were obtained with an experimental apparatus based on the standard ASTM C835-06 for total hemispherical emittance. Measurements of Inconel 718 were made for four different surface types including: (i) ‘as-received’ from the manufacturer, (ii) oxidized in air and humidified helium, (iii) sandblasted with aluminum oxide powder, and (iv) with a thin coating of nuclear grade graphite powder (grade NGB-18). The emissivity for the ‘as-received’ sample ranged from 0.21 to 0.28 in the temperature interval from 760 K to 1275 K. Oxidation in air at 1073 K resulted in an increase in emissivity into the range from 0.2 at 650 K to 0.52 at 1200 K. There was no dependence on the oxidation times studied here. Oxidation with humidified helium at 1073 K produced less of an increase in emissivity than the oxidation in air but there was an increase up to the range from 0.2 at 600 K to 0.35 at 1200 K. Sandblasting of Inconel 718 was also observed to increase the emissivity up to the range from 0.43 at 780 K to 0.53 at 1270 K when 60 grit sized powder was used and up to the range from 0.45 at 683 K to 0.57 at 1267 K when 120 and 220 grit sized powders were used. Coating of graphite powder onto the ‘as-received’ Inconel 718 showed no increase

  9. Shortwave Array Spectroradiometer–Hemispheric (SASHe) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, Connor J [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-04-01

    The Shortwave Array Spectroradiometer–Hemispheric (SASHe) provides measurements of direct solar, hemispheric diffuse, and total hemispheric shortwave irradiance over a continuous spectral range from approximately 300 nm to 1700 nm at a rate of about 30 seconds. The SASHe design connects an optical collector located outdoors to a pair of spectrometers and data collections systems located indoors within a climate-controlled building via an umbilical cable of fiber optic and electrical cables. The light collector uses a small Spectralon button as a hemispheric diffuser with a shadowband to distinguish signal from diffuse sky and direct sun.

  10. Hemispheric asymmetry and theory of mind: is there an association?

    Science.gov (United States)

    Herzig, Daniela A; Sullivan, Sarah; Evans, Jonathan; Corcoran, Rhiannon; Mohr, Christine

    2012-01-01

    In autism and schizophrenia attenuated/atypical functional hemispheric asymmetry and theory of mind impairments have been reported, suggesting common underlying neuroscientific correlates. We here investigated whether impaired theory of mind performance is associated with attenuated/atypical hemispheric asymmetry. An association may explain the co-occurrence of both dysfunctions in psychiatric populations. Healthy participants (n=129) performed a left hemisphere (lateralised lexical decision task) and right hemisphere (lateralised face decision task) dominant task as well as a visual cartoon task to assess theory of mind performance. Linear regression analyses revealed inconsistent associations between theory of mind performance and functional hemisphere asymmetry: enhanced theory of mind performance was only associated with (1) faster right hemisphere language processing, and (2) reduced right hemisphere dominance for face processing (men only). The majority of non-significant findings suggest that theory of mind and functional hemispheric asymmetry are unrelated. Instead of "overinterpreting" the two significant results, discrepancies in the previous literature relating to the problem of the theory of mind concept, the variety of tasks, and the lack of normative data are discussed. We also suggest how future studies could explore a possible link between hemispheric asymmetry and theory of mind.

  11. Phase analysis of sunspot group numbers on both solar hemispheres

    Institute of Scientific and Technical Information of China (English)

    Lin-Hua Deng; Zhong-Quan Qu; Xiao-Li Yan; Kai-Rang Wang

    2013-01-01

    Cross-correlation analysis and wavelet transform methods are proposed to investigate the phase relationship between the monthly sunspot group numbers in the solar northern and southern hemispheres.It is found that (1) the monthly sunspot group numbers in the northern hemisphere begin two months earlier than those in the southern one,which should lead to phase asynchrony between them but with a slight effect; (2) the Schwabe cycle length for the monthly sunspot group numbers in the two hemispheres obviously differs from each other,and the mean Schwabe cycle length of the monthly sunspot group numbers in the northern hemisphere is slightly larger than that in the southern one; (3) the monthly sunspot group numbers in the northern hemisphere precede those in the southern hemisphere during the years of about 1874-1927,after which,the southern hemisphere leads the northern hemisphere in the years 1928-1964,and then the northern hemisphere leads in time till the present.

  12. Concept and verbal ability as related to the cerebral hemispheres.

    Science.gov (United States)

    Cook, N D

    1977-10-01

    A new theory of human brain function is outlined in terms of the cooperative interaction of the cerebral hemispheres. The well-established verbal, symbolic functions of the left hemisphere and the wholistic, spatial functions of the right hemisphere are seen as separate and independent manifestations of the normally integrated verbal-analytic (or "error detector") and conceptual (or "goal state") functions of the left and right, respectively. The relationship between the hemispheres is described in terms of the "goal-directed" system of cybernetics and then compared with related ideas previously presented by Dimond, Penfield, and Piaget.

  13. Project management of DAG: Eastern Anatolia Observatory

    Science.gov (United States)

    Keskin, Onur; Yesilyaprak, Cahit; Yerli, Sinan K.; Zago, Lorenzo; Guver, Tolga; Alis, Sinan

    2016-08-01

    The four meter DAG (Eastern Anatolia Observatory in Turkish) telescope is not only the largest telescope in Turkey but also the most promising telescope in the northern hemisphere with a large potential to offer scientific observations with its cutting edge technology. DAG is designed to be an AO telescope which will allow both infrared and visible observations with its two Nasmyth platforms dedicated to next generation focal plane instruments. In this paper, status updates from DAG telescope will be presented in terms of; (i) in house optical design of DAG, (ii) tender process of telescope, (iii) tender process of enclosure, and (iv) tender process of the observatory building. Also status updates from the focal plane instruments project and possible collaboration activities will be presented.

  14. Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation: A functional MRI study.

    Science.gov (United States)

    Kwon, Yong Hyun; Jang, Sung Ho

    2012-08-25

    We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel counts and blood oxygenation level-dependent signal intensities in the right primary sensorimotor cortex regions were estimated and compared between the two transcranial direct current stimulation conditions. Our results showed that dual-hemispheric transcranial direct current stimulation induced greater cortical activities than single-hemispheric transcranial direct current stimulation. These findings suggest that dual-hemispheric transcranial direct current stimulation may provide more effective cortical stimulation than single-hemispheric transcranial direct current stimulation.

  15. Visual attention capacity after right hemisphere lesions

    DEFF Research Database (Denmark)

    Habekost, Thomas; Rostrup, Egill

    2007-01-01

    Recently there has been a growing interest in visual short-term memory (VSTM) including the neural basis of the function. Processing speed, another main aspect of visual attention capacity, has received less investigation. For both cognitive functions human lesion studies are sparse. We used...... a whole report experiment for estimation of these two parameters in 22 patients with right side stroke. Psychophysical performance was analyzed using Bundesen's [Bundesen, C. (1990). A theory of visual attention. Psychological Review, 97, 523-547] Theory of Visual Attention (TVA) and compared...... for both VSTM capacity and ipsilesional processing speed. The study also showed that lesions in a large region of the right hemisphere, including the putamen, insula, and inferior frontal cortex, do not lead to general deficits in the capacity of visual attention. Udgivelsesdato: 2007-Apr-8...

  16. Plutonium in Southern Hemisphere ocean Waters

    DEFF Research Database (Denmark)

    Hirose, K.; Aoyama, M.; Gastaud, J.

    2013-01-01

    Plutonium in seawater collected by the BEAGLE2003 cruise was determined using ICP- SF-MS and alpha spectrometry after Fe co-precipitation and radiochemical purification. Levels and distributions of dissolved plutonium activity concentrations in Southern Hemisphere ocean waters are summarized here......, including historical data. Pu-239 concentrations in surface water----of the central South Pacific (32.5 °S) in 2003 were around 1 mBq/m3. The 239Pu concentrations in the Indian Ocean surface waters (20°S) were similar to that in the South Pacific, whereas the 239Pu concentrations in the South Atlantic...... surface waters (30°S) were markedly lower than those in the South Pacific and Indian Oceans. The 239Pu vertical profile pattern was similar to that in the North Pacific subtropical gyre, although 239Pu concentrations in the deep South Pacific were significantly lower than those in the North Pacific. One...

  17. Structural hemispheric asymmetries underlie verbal Stroop performance.

    Science.gov (United States)

    Vallesi, Antonino; Mazzonetto, Ilaria; Ambrosini, Ettore; Babcock, Laura; Capizzi, Mariagrazia; Arbula, Sandra; Tarantino, Vincenza; Semenza, Carlo; Bertoldo, Alessandra

    2017-09-29

    Performance on tasks involving cognitive control such as the Stroop task is often associated with left lateralized brain activations. Based on this neuro-functional evidence, we tested whether leftward structural grey matter asymmetries would also predict inter-individual differences in combatting Stroop interference. To check for the specificity of the results, both a verbal Stroop task and a spatial one were administered to a total of 111 healthy young individuals, for whom T1-weighted magnetic resonance imaging (MRI) images were also acquired. Surface thickness and area estimations were calculated using FreeSurfer. Participants' hemispheres were registered to a symmetric template and Laterality Indices (LI) for the surface thickness and for the area at each vertex in each participant were computed. The correlation of these surface LI measures with the verbal and spatial Stroop effects (incongruent-congruent difference in trial performance) was assessed at each vertex by means of general linear models at the whole-brain level. We found a significant correlation between performance and surface area LI in an inferior posterior temporal cluster (overlapping with the so-called visual word form area, VWFA), with a more left-lateralized area in this region associated with a smaller Stroop effect only in the verbal task. These results point to an involvement of the VWFA for higher-level processes based on word reading, including the suppression of this process when required by the task, and could be interpreted in the context of cross-hemispheric rivalry. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. The Right Hemisphere in Aesthetic Perception

    Directory of Open Access Journals (Sweden)

    Bianca eBromberger

    2011-10-01

    Full Text Available Little about the neuropsychology of art perception and evaluation is known. Most neuropsychological approaches to art have focused on art production and have been anecdotal and qualitative. The field is in desperate need of quantitative methods if it is to advance. Here, we combine a quantitative approach to the assessment of art with modern voxel-lesion-symptom-mapping (VLSM methods to determine brain-behavior relationships in art perception. We hypothesized that perception of different attributes of art are likely to be disrupted by damage to different regions of the brain. Twenty participants with right hemisphere damage were given the Assessment of Art Attributes (AAA, which is designed to quantify judgments of descriptive attributes of visual art. Each participant rated 24 paintings on 6 conceptual attributes (depictive accuracy, abstractness, emotion, symbolism, realism, and animacy and 6 perceptual attributes (depth, color temperature, color saturation, balance, stroke, and simplicity and their interest in and preference for these paintings. Deviation scores were obtained for each brain-damaged participant for each attribute based on correlations with group average ratings from 30 age-matched healthy participants. Right hemisphere damage affected participants' judgments of abstractness, accuracy, and stroke quality. Damage to areas within different parts of the frontal parietal and lateral temporal cortices produced deviation in judgments in four of six conceptual attributes (abstractness, symbolism, realism and animacy. Of the formal attributes, only depth was affected by inferior prefrontal damage. No areas of brain damage were associated with deviations in interestingness or preference judgments. The perception of conceptual and formal attributes in artwork may in part dissociate from each other and from evaluative judgments. More generally, this approach demonstrates the feasibility of quantitative approaches to the neuropsychology of

  19. Hemispherical anomaly from asymmetric initial states

    Science.gov (United States)

    Ashoorioon, Amjad; Koivisto, Tomi

    2016-08-01

    We investigate if the hemispherical asymmetry in the CMB is produced from "asymmetric" excited initial conditions. We show that in the limit where the deviations from the Bunch-Davies vacuum are large and the scale of new physics is maximally separated from the inflationary Hubble parameter, the primordial power spectrum is modulated only by position-dependent dipole and quadrupole terms. Requiring the dipole contribution in the power spectrum to account for the observed power asymmetry, A =0.07 ±0.022 , we show that the amount of quadrupole terms is roughly equal to A2. The mean local bispectrum, which gets enhanced for the excited initial state, is within the 1 σ bound of Planck 2015 results for a large field model, fNL≃4.17 , but is reachable by future CMB experiments. The amplitude of the local non-Gaussianity modulates around this mean value, depending on the angle that the correlated patches on the 2d CMB surface make with the preferred direction. The amount of variation is minimized for the configuration in which the short and long wavelength modes are around the preferred pole and |k→3|≈|k→l ≈10|≪|k→1|≈|k→2|≈|k→l ≈2500| with fNLmin≈3.64 . The maximum occurs when these modes are at the antipode of the preferred pole, fNLmax≈4.81 . The difference of non-Gaussianity between these two configurations is as large as ≃1.17 , which can be used to distinguish this scenario from other scenarios that try to explain the observed hemispherical asymmetry.

  20. Eastern Equine Encephalitis

    Science.gov (United States)

    ... bite of an infected mosquito. Eastern equine encephalitis (EEE) is a rare illness in humans, and only ... EEEV have no apparent illness. Severe cases of EEE (involving encephalitis, an inflammation of the brain) begin ...

  1. Learning-related brain hemispheric dominance in sleeping songbirds

    NARCIS (Netherlands)

    Moorman, Sanne|info:eu-repo/dai/nl/328213187; Gobes, Sharon M H|info:eu-repo/dai/nl/304832669; van de Kamp, Ferdinand C; Zandbergen, Matthijs A|info:eu-repo/dai/nl/14760902X; Bolhuis, Johan J|info:eu-repo/dai/nl/074069454

    2015-01-01

    There are striking behavioural and neural parallels between the acquisition of speech in humans and song learning in songbirds. In humans, language-related brain activation is mostly lateralised to the left hemisphere. During language acquisition in humans, brain hemispheric lateralisation develops

  2. Assessment of Hemispheric Dominance for Language at Three Ages.

    Science.gov (United States)

    Tegano, Deborah Walker

    The purposes of this study were to assess the development of hemispheric dominance for language function among children of 4, 7, and 10 years of age and to determine whether age predicts hemispheric dominance. Within 2 weeks of the beginning of data collection, middle-class subjects selected from private nursery schools and elementary schools…

  3. Hemispheric Differences in the Effects of Context on Vowel Perception

    Science.gov (United States)

    Sjerps, Matthias J.; Mitterer, Holger; McQueen, James M.

    2012-01-01

    Listeners perceive speech sounds relative to context. Contextual influences might differ over hemispheres if different types of auditory processing are lateralized. Hemispheric differences in contextual influences on vowel perception were investigated by presenting speech targets and both speech and non-speech contexts to listeners' right or left…

  4. Hemispheric Asymmetry in the Efficiency of Attentional Networks

    Science.gov (United States)

    Asanowicz, Dariusz; Marzecova, Anna; Jaskowski, Piotr; Wolski, Piotr

    2012-01-01

    Despite the fact that hemispheric asymmetry of attention has been widely studied, a clear picture of this complex phenomenon is still lacking. The aim of the present study was to provide an efficient and reliable measurement of potential hemispheric asymmetries of three attentional networks, i.e. alerting, orienting and executive attention.…

  5. Disentangling the Relationship between Hemispheric Asymmetry and Cognitive Performance

    Science.gov (United States)

    Hirnstein, Marco; Leask, Stuart; Rose, Jonas; Hausmann, Markus

    2010-01-01

    It is widely believed that advantages of hemispheric asymmetries originated in better cognitive processing, hence it is often implied that the relationship between hemispheric asymmetry and cognitive performance is linearly positive: the higher the degree of lateralization in a specific cognitive domain, the better the performance in a…

  6. Cardiac asystole associated with seizures of right hemispheric onset

    Directory of Open Access Journals (Sweden)

    Jennifer Chu

    2014-01-01

    Full Text Available Ictal asystole is frequently underrecognized despite being a potentially lethal condition. We report two cases of ictal asystole with right hemispheric onset. These cases are unique since previous literature reports that seizures associated with bradyarrhythmias typically arise from left hemispheric foci. These cases further underscore the importance of clinical vigilance and the need of an enhanced diagnostic biomarker.

  7. CMB-S4 and the Hemispherical Variance Anomaly

    CERN Document Server

    O'Dwyer, Marcio; Knox, Lloyd; Starkman, Glenn D

    2016-01-01

    Cosmic Microwave Background (CMB) full-sky temperature data show a hemispherical asymmetry in power nearly aligned with the Ecliptic. In real space, this anomaly can be quantified by the temperature variance in the northern and southern Ecliptic hemispheres. In this context, the northern hemisphere displays an anomalously low variance while the southern hemisphere appears unremarkable (consistent with expectations from the best-fitting theory, $\\Lambda$CDM). While this is a well established result in temperature, the low signal-to-noise ratio in current polarization data prevents a similar comparison. This will change with a proposed ground-based CMB experiment, CMB-S4. With that in mind, we generate realizations of polarization maps constrained by the temperature data and predict the distribution of the hemispherical variance in polarization considering two different sky coverage scenarios possible in CMB-S4: full Ecliptic north coverage and just the portion of the North that can be observed from a ground ba...

  8. The prisoners of despair: right hemisphere deficiency and suicide.

    Science.gov (United States)

    Weinberg, I

    2000-12-01

    This paper presents an integrative approach to understanding of the inner experience of suicidal persons in terms of hemispheric asymmetry. The right hemisphere is involved in formation of polysemantic context. Polysemantic context is determined by multiple interconnections among its elements, while each concrete element bears the stamp of the whole context. Left hemisphere functioning leads to formation of monosemantic context. It is suggested that due to functional insufficiency of the right hemisphere the suicidal person demonstrates a compensatory shift to left hemisphere functioning. This shift manifests itself in reversed asymmetry of neurotransmitters, tendency to dissociation, alienated and negative perception of the body, lower sensitivity to pain, disintegration of self-representation, cognitive constriction, overly general nature of personal memories, difficulties in affect regulation as well as such personality traits as low openness to experience and personal constriction. This hypothesis raises a number of suggestions for future research.

  9. Seismic hazard map of the western hemisphere

    Science.gov (United States)

    Shedlock, K.M.; Tanner, J.G.

    1999-01-01

    Vulnerability to natural disasters increases with urbanization and development of associated support systems (reservoirs, power plants, etc.). Catastrophic earthquakes account for 60% of worldwide casualties associated with natural disasters. Economic damage from earthquakes is increasing, even in technologically advanced countries with some level of seismic zonation, as shown by the 1989 Loma Prieta, CA ($6 billion), 1994 Northridge, CA ($ 25 billion), and 1995 Kobe, Japan (> $ 100 billion) earthquakes. The growth of megacities in seismically active regions around the world often includes the construction of seismically unsafe buildings and infrastructures, due to an insufficient knowledge of existing seismic hazard. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. National, state, and local governments, decision makers, engineers, planners, emergency response organizations, builders, universities, and the general public require seismic hazard estimates for land use planning, improved building design and construction (including adoption of building construction codes), emergency response preparedness plans, economic forecasts, housing and employment decisions, and many more types of risk mitigation. The seismic hazard map of the Americas is the concatenation of various national and regional maps, involving a suite of approaches. The combined maps and documentation provide a useful global seismic hazard framework and serve as a resource for any national or regional agency for further detailed studies applicable to their needs. This seismic hazard map depicts Peak Ground Acceleration (PGA) with a 10% chance of exceedance in 50 years for the western hemisphere. PGA, a short-period ground motion parameter that is proportional to force, is the most commonly mapped ground motion parameter because current building codes that include seismic provisions specify the

  10. Seismic hazard map of the western hemisphere

    Directory of Open Access Journals (Sweden)

    J. G. Tanner

    1999-06-01

    Full Text Available Vulnerability to natural disasters increases with urbanization and development of associated support systems (reservoirs, power plants, etc.. Catastrophic earthquakes account for 60% of worldwide casualties associated with natural disasters. Economic damage from earthquakes is increasing, even in technologically advanced countries with some level of seismic zonation, as shown by the 1989 Loma Prieta, CA ($ 6 billion, 1994 Northridge, CA ($ 25 billion, and 1995 Kobe, Japan (> $ 100 billion earthquakes. The growth of megacities in seismically active regions around the world often includes the construction of seismically unsafe buildings and infrastructures, due to an insufficient knowledge of existing seismic hazard. Minimization of the loss of life, property damage, and social and economic disruption due to earthquakes depends on reliable estimates of seismic hazard. National, state, and local governments, decision makers, engineers, planners, emergency response organizations, builders, universities, and the general public require seismic hazard estimates for land use planning, improved building design and construction (including adoption of building construction codes, emergency response preparedness plans, economic forecasts, housing and employment decisions, and many more types of risk mitigation. The seismic hazard map of the Americas is the concatenation of various national and regional maps, involving a suite of approaches. The combined maps and documentation provide a useful global seismic hazard framework and serve as a resource for any national or regional agency for further detailed studies applicable to their needs. This seismic hazard map depicts Peak Ground Acceleration (PGA with a 10% chance of exceedance in 50 years for the western hemisphere. PGA, a short-period ground motion parameter that is proportional to force, is the most commonly mapped ground motion parameter because current building codes that include seismic provisions

  11. When one hemisphere takes control: metacontrol in pigeons (Columba livia.

    Directory of Open Access Journals (Sweden)

    Ruth Adam

    Full Text Available BACKGROUND: Vertebrate brains are composed of two hemispheres that receive input, compute, and interact to form a unified response. How the partially different processes of both hemispheres are integrated to create a single output is largely unknown. In some cases one hemisphere takes charge of the response selection--a process known as metacontrol. Thus far, this phenomenon has only been shown in a handful of studies with primates, mostly conducted in humans. Metacontrol, however, is even more relevant for animals like birds with laterally placed eyes and complete chiasmatic decussation since visual input to the hemispheres is largely different. METHODOLOGY/PRINCIPAL FINDINGS: Homing pigeons (Columba livia were trained with a color discrimination task. Each hemisphere was trained with a different color pair and therefore had a different experience. Subsequently, the pigeons were binocularly examined with two additional stimuli that combined the positive color of one hemisphere with a negative color that had been shown to the other, omitting the availability of a coherent solution and confronting the pigeons with a conflicting situation. Some of the pigeons responded to both stimuli, indicating that none of the hemispheres dominated the overall preference. Some birds, however, responded primarily to one of the conflicting stimuli, showing that they based their choice on the left- or right-monocularly learned color pair, indicating hemispheric metacontrol. CONCLUSIONS/SIGNIFICANCE: We could demonstrate for the first time that metacontrol is a widespread phenomenon that also exists in birds, and thus in principle requires no corpus callosum. Our results are closely similar to those in humans: monocular performance was higher than binocular one and animals displayed different modes of hemispheric dominance. Thus, metacontrol is a dynamic and widely distributed process that possibly constitutes a requirement for all animals with a bipartite brain to

  12. On the Cause of Eastern Equatorial Pacific Ocean T-S Variations Associated with El Nino

    Science.gov (United States)

    Wang, Ou; Fukumori, Ichiro; Lee, Tong; Cheng, Benny

    2004-01-01

    The nature of observed variations in temperature-salinity (T-S) relationship between El Nino and non-El Nino years in the pycnocline of the eastern equatorial Pacific Ocean (NINO3 region, 5(deg)S-5(deg)N, 150(deg)W-90(deg)W) is investigated using an ocean general circulation model. The origin of the subject water mass is identified using the adjoint of a simulated passive tracer. The higher salinity during El Nino is attributed to larger convergence of saltier water from the Southern Hemisphere and smaller convergence of fresher water from the Northern Hemisphere.

  13. Objectively classifying Southern Hemisphere extratropical cyclones

    Science.gov (United States)

    Catto, Jennifer

    2016-04-01

    There has been a long tradition in attempting to separate extratropical cyclones into different classes depending on their cloud signatures, airflows, synoptic precursors, or upper-level flow features. Depending on these features, the cyclones may have different impacts, for example in their precipitation intensity. It is important, therefore, to understand how the distribution of different cyclone classes may change in the future. Many of the previous classifications have been performed manually. In order to be able to evaluate climate models and understand how extratropical cyclones might change in the future, we need to be able to use an automated method to classify cyclones. Extratropical cyclones have been identified in the Southern Hemisphere from the ERA-Interim reanalysis dataset with a commonly used identification and tracking algorithm that employs 850 hPa relative vorticity. A clustering method applied to large-scale fields from ERA-Interim at the time of cyclone genesis (when the cyclone is first detected), has been used to objectively classify identified cyclones. The results are compared to the manual classification of Sinclair and Revell (2000) and the four objectively identified classes shown in this presentation are found to match well. The relative importance of diabatic heating in the clusters is investigated, as well as the differing precipitation characteristics. The success of the objective classification shows its utility in climate model evaluation and climate change studies.

  14. Hemispherical projection lens for insect behavior analysis

    Science.gov (United States)

    Aikio, Mika; Takalo, Jouni; Lempeä, Mikko; Vähäsöyrinki, Mikko

    2010-05-01

    Virtual reality projection systems have been used formerly to study if mammals, including humans, are able to act in or understand virtual environments. Insects have been more difficult to study in such circumstances, one of the factors being their large, almost hemispherical field of view. Designing such a projection system that is capable of fulfilling the full field of vision of an insect is a challenging task. Normally, when designing a photographic objective, one of the goals is to minimize field curvature in order to provide sharp image through the whole sensor surface. However, because the image surface in this case is a sphere, flat field is not desirable and the design task becomes an opposite of a typical camera lens. Introducing field curvature becomes mandatory. We have designed and built a system with satisfactory image quality throughout the whole spherical surface with reasonable number of lenses as an add-on for common digital projectors. The manufactured system is able to project an image to a solid angle of 11.95 steradians, and when compared to the whole sphere which is represented with a solid angle of 4π steradians, approximately 5 % of the total sphere area is not illuminated.

  15. Northern Hemisphere control of deglacial vegetation changes in the Rufiji uplands (Tanzania

    Directory of Open Access Journals (Sweden)

    I. Bouimetarhan

    2014-09-01

    Full Text Available In tropical Eastern Africa, vegetation distribution is largely controlled by regional hydrology which has varied over the past 20 000 years. Therefore, accurate reconstructions of past vegetation and hydrological changes are crucial to better understand climate variability in the tropical Eastern African region. Through high-resolution pollen records from a marine sediment core recovered offshore the Rufiji River, our data show significant shifts in pollen assemblages during the last deglaciation identifying, through respective changes in both upland and lowland vegetation, specific responses of plant communities to atmospheric (precipitation and coastal (coastal dynamics/sea level changes alterations. Specifically, an interval of maximum pollen representation of dry and open vegetation occurred during the Northern Hemisphere cold Heinrich event 1 (H1 suggesting the expansion of drier upland vegetation under arid conditions. This dry spell is followed by an interval in which forest and humid woodland expanded, indicating a hydrologic shift towards more humid conditions. Droughts during H1 and the return to humid conditions around ~14.8 kyr BP in the uplands are primarily attributed to latitudinal shifts of the Intertropical Convergence Zone (ITCZ driven by high-latitude Northern Hemisphere climatic fluctuations. Additionally, our results show that the lowland vegetation, consisting of a well developed salt marshes and mangroves in a successional pattern typical for vegetation occurring in intertidal habitats, has responded mainly to local coastal dynamics related to marine inundation frequencies and soil salinity in the Rufiji Delta as well as the local moisture availability. Lowland vegetation shows a substantial expansion of mangrove trees after ~14.8 kyr BP suggesting also an increased moisture availability and river runoff in the coastal area. The results of this study highlight the de-coupled climatic and environmental processes to which

  16. Individual differences in hemispheric preference and emotion regulation difficulties

    Directory of Open Access Journals (Sweden)

    Garima Gupta

    2011-01-01

    Full Text Available Background: Hemisphericity or individual difference in the preference to use the left or the right hemispheric mode of information processing has been associated with various emotion-related differences. For example, the right hemisphericity has been linked with inhibition of emotional expression, feeling of tension, greater impulsivity etc. These observations suggest that right hemisphericity may be associated with greater difficulties in regulating emotions. However, direct empirical tests of such theoretical proposition are very thin. Aim: In view of this, the present study aims to investigate how and to what extent individual difference in hemispheric preference relate to emotion regulation. Materials and Methods: Thirty-two right-handed male subjects in the age range 18 to 20 years were assessed on self-report measures of hemispheric preference and emotion regulation difficulties. The correlation between dimensions of hemispheric preference and difficulties in regulating emotions was computed. A series of stepwise multiple regression analyses were also done to explore the relative significance of various dimensions of hemispheric preference in predicting emotion regulation difficulties. Results: The findings revealed that in general a preference for the right hemispheric mode of information processing was associated with greater emotion regulation difficulties. The correlation analysis indicated that while impulse control difficulties and difficulties in engaging goal directed behavior was associated with preference for almost all the right hemispheric mode of information processing, the nonacceptance of emotional responses and limited access to emotion regulation was related to preference for only global/synthetic (a right hemispheric mode of information processing. Similarly, the lack of emotional clarity facet of emotion regulation difficulties correlated significantly with a preference for the emotional mode of information processing

  17. Dated historical biogeography of the temperate Loliinae (Poaceae, Pooideae) grasses in the northern and southern hemispheres.

    Science.gov (United States)

    Inda, Luis A; Segarra-Moragues, José Gabriel; Müller, Jochen; Peterson, Paul M; Catalán, Pilar

    2008-03-01

    Divergence times and biogeographical analyses have been conducted within the Loliinae, one of the largest subtribes of temperate grasses. New sequence data from representatives of the almost unexplored New World, New Zealand, and Eastern Asian centres were added to those of the panMediterranean region and used to reconstruct the phylogeny of the group and to calculate the times of lineage-splitting using Bayesian approaches. The traditional separation between broad-leaved and fine-leaved Festuca species was still maintained, though several new broad-leaved lineages fell within the fine-leaved clade or were placed in an unsupported intermediate position. A strong biogeographical signal was detected for several Asian-American, American, Neozeylandic, and Macaronesian clades with different affinities to both the broad and the fine-leaved Festuca. Bayesian estimates of divergence and dispersal-vicariance analyses indicate that the broad-leaved and fine-leaved Loliinae likely originated in the Miocene (13My) in the panMediterranean-SW Asian region and then expanded towards C and E Asia from where they colonized the New World. Further expansions in America (10-3.8My) showed a predominant migratory route from North to South (N Americathe AndesPatagonia). This late Tertiary scenario of successive colonizations and secondary polyploid radiations in the southern hemisphere from the northern hemisphere was accompanied by occasional transcontinental long-distance dispersal events between South America and New Zealand. Multiple Pliocene dispersal events (3.6-2.5My) from the near SW European and NW African continents gave rise to the Macaronesian Loliinae flora, while a more recent Pleistocene origin (2-1My) is hypothesized for the high polyploid lineages that successfully colonized newly deglaciated areas in both hemispheres.

  18. Seasonal variability and long-term evolution of tropospheric composition in the tropics and Southern Hemisphere

    Directory of Open Access Journals (Sweden)

    K. M. Wai

    2013-07-01

    Full Text Available Present-day and future impacts of biomass burning and other sources in the tropics and Southern Hemisphere are studied by global chemical transport model (GCTM, satellites retrievals and surface measurements. The spring CO peaks found at Mahe Island (Western Indian Ocean are attributed to the burnings in India but not those from Northern Africa. Easter Island (Eastern Pacific Ocean is impacted indirectly by the hemispheric zonal transport of CO due to the burnings in Southern Africa/Latin America, via the westerlies. An increasing trend for CO by 0.33 ppb yr-1 in the past decade at Ascension Island is attributed to the combined effects of Latin American/Southern Africa burnings and increase of CH4 level. Changes in water vapour and UV over Southern Atlantic Ocean (SAO in future January have dominated effects on the O3 distribution. More than 55% of O3 concentrations over SAO in both present-day and future September are not directly affected by the emissions (including lightning over the adjacent two continents but attributable to transport of O3 from outside due to CO and CH4 oxidation and stratospheric intrusion. High NOx emissions in both continents in future increase the PAN concentrations over remote oceans at higher southern latitudes (> 35° S as far as those near Australia, affecting the O3 budget over there. Future changes of biomass burning and anthropogenic NOx emissions in Southern Africa lead to a new area of O3 maximum near South Africa. The resulted O3 outflow to the Indian Ocean is pronounced due to the effects of the persistent anti-cyclone. A general reduction of future OH radical concentrations is predicted over the remote marine boundary layer in the tropics and Southern Hemisphere, due to the increases in CH4 and CO emissions combined with the low-NOx environment.

  19. Northern Hemisphere control of deglacial vegetation changes in the Rufiji uplands (Tanzania)

    Science.gov (United States)

    Bouimetarhan, I.; Dupont, L.; Kuhlmann, H.; Patzold, J.; Prange, M.; Schefuss, E.; Zonneveld, K.

    2015-05-01

    In tropical eastern Africa, vegetation distribution is largely controlled by regional hydrology, which has varied over the past 20 000 years. Therefore, accurate reconstructions of past vegetation and hydrological changes are crucial for a better understanding of climate variability in the tropical southeastern African region. We present high-resolution pollen records from a marine sediment core recovered offshore of the Rufiji River delta. Our data document significant shifts in pollen assemblages during the last deglaciation, identifying, through changes in both upland and lowland vegetation, specific responses of plant communities to atmospheric (precipitation) and coastal (coastal dynamics and sea-level changes) alterations. Specifically, arid conditions reflected by a maximum pollen representation of dry and open vegetation occurred during the Northern Hemisphere cold Heinrich event 1 (H1), suggesting that the expansion of drier upland vegetation was synchronous with cold Northern Hemisphere conditions. This arid period is followed by an interval in which forest and humid woodlands expanded, indicating a hydrologic shift towards more humid conditions. Droughts during H1 and the shift to humid conditions around 14.8 kyr BP in the uplands are consistent with latitudinal shifts of the intertropical convergence zone (ITCZ) driven by high-latitude Northern Hemisphere climatic fluctuations. Additionally, our results show that the lowland vegetation, consisting of well-developed salt marshes and mangroves in a successional pattern typical for vegetation occurring in intertidal habitats, has responded mainly to local coastal dynamics related to marine inundation frequencies and soil salinity in the Rufiji Delta as well as to the local moisture availability. Lowland vegetation shows a substantial expansion of mangrove trees after ~ 14.8 kyr BP, suggesting an increased moisture availability and river runoff in the coastal area. The results of this study highlight the

  20. Reorganization of syntactic processing following left-hemisphere brain damage: does right-hemisphere activity preserve function?

    Science.gov (United States)

    Tyler, Lorraine K; Wright, Paul; Randall, Billi; Marslen-Wilson, William D; Stamatakis, Emmanuel A

    2010-11-01

    The extent to which the human brain shows evidence of functional plasticity across the lifespan has been addressed in the context of pathological brain changes and, more recently, of the changes that take place during healthy ageing. Here we examine the potential for plasticity by asking whether a strongly left-lateralized system can successfully reorganize to the right-hemisphere following left-hemisphere brain damage. To do this, we focus on syntax, a key linguistic function considered to be strongly left-lateralized, combining measures of tissue integrity, neural activation and behavioural performance. In a functional neuroimaging study participants heard spoken sentences that differentially loaded on syntactic and semantic information. While healthy controls activated a left-hemisphere network of correlated activity including Brodmann areas 45/47 and posterior middle temporal gyrus during syntactic processing, patients activated Brodmann areas 45/47 bilaterally and right middle temporal gyrus. However, voxel-based morphometry analyses showed that only tissue integrity in left Brodmann areas 45/47 was correlated with activity and performance; poor tissue integrity in left Brodmann area 45 was associated with reduced functional activity and increased syntactic deficits. Activity in the right-hemisphere was not correlated with damage in the left-hemisphere or with performance. Reduced neural integrity in the left-hemisphere through brain damage or healthy ageing results in increased right-hemisphere activation in homologous regions to those left-hemisphere regions typically involved in the young. However, these regions do not support the same linguistic functions as those in the left-hemisphere and only indirectly contribute to preserved syntactic capacity. This establishes the unique role of the left hemisphere in syntax, a core component in human language.

  1. Divergent hemispheric reasoning strategies: reducing uncertainty versus resolving inconsistency

    Science.gov (United States)

    Marinsek, Nicole; Turner, Benjamin O.; Gazzaniga, Michael; Miller, Michael B.

    2014-01-01

    Converging lines of evidence from diverse research domains suggest that the left and right hemispheres play distinct, yet complementary, roles in inferential reasoning. Here, we review research on split-brain patients, brain-damaged patients, delusional patients, and healthy individuals that suggests that the left hemisphere tends to create explanations, make inferences, and bridge gaps in information, while the right hemisphere tends to detect conflict, update beliefs, support mental set-shifts, and monitor and inhibit behavior. Based on this evidence, we propose that the left hemisphere specializes in creating hypotheses and representing causality, while the right hemisphere specializes in evaluating hypotheses, and rejecting those that are implausible or inconsistent with other evidence. In sum, we suggest that, in the domain of inferential reasoning, the left hemisphere strives to reduce uncertainty while the right hemisphere strives to resolve inconsistency. The hemispheres’ divergent inferential reasoning strategies may contribute to flexible, complex reasoning in the healthy brain, and disruption in these systems may explain reasoning deficits in the unhealthy brain. PMID:25374526

  2. Hemispheric asymmetry of electroencephalography-based functional brain networks.

    Science.gov (United States)

    Jalili, Mahdi

    2014-11-12

    Electroencephalography (EEG)-based functional brain networks have been investigated frequently in health and disease. It has been shown that a number of graph theory metrics are disrupted in brain disorders. EEG-based brain networks are often studied in the whole-brain framework, where all the nodes are grouped into a single network. In this study, we studied the brain networks in two hemispheres and assessed whether there are any hemispheric-specific patterns in the properties of the networks. To this end, resting state closed-eyes EEGs from 44 healthy individuals were processed and the network structures were extracted separately for each hemisphere. We examined neurophysiologically meaningful graph theory metrics: global and local efficiency measures. The global efficiency did not show any hemispheric asymmetry, whereas the local connectivity showed rightward asymmetry for a range of intermediate density values for the constructed networks. Furthermore, the age of the participants showed significant direct correlations with the global efficiency of the left hemisphere, but only in the right hemisphere, with local connectivity. These results suggest that only local connectivity of EEG-based functional networks is associated with brain hemispheres.

  3. Motivation and attention following hemispheric stroke.

    Science.gov (United States)

    Olgiati, E; Russell, C; Soto, D; Malhotra, P

    2016-01-01

    Spatial neglect (SN) is an extremely common disorder of attention; it is most frequently a consequence of stroke, especially to the right cerebral hemisphere. The current view of SN is that it is not a unitary deficit but a multicomponent syndrome. Crucially, it has been repeatedly shown that it has a considerable negative impact on rehabilitation outcome. Although a number of behavioral and pharmacological therapies have been developed, none of these appears to be applicable to all patients with SN or has proved unequivocally successful in clinical trials. One potential avenue for therapeutic intervention in neglect relates to the interaction between motivation and attention. A number of investigators, including ourselves, have observed a possible motivational component to the syndrome and showed that motivational stimulation can temporarily improve attention in patients with SN. In this chapter we review previous work looking at how motivation can modulate attention in healthy individuals and how it may be affected by neurological disease before discussing how motivational impairments may contribute to neglect, and how motivation has been used to modulate neglect. In the final section, we present recent experimental work examining how reward interacts with attentional biases in patients with SN. In this study, we adapted the classic Landmark task to explore the mechanisms behind the effect of reward in SN, and found that centrally located stimuli that were explicitly associated with reward appeared to improve neglect and reduce rightward bias. Our results suggest that positive motivation, in the form of anticipated monetary reward, may influence attentional bias via more general mechanisms, such as alerting and task engagement, rather than directly increasing salience of items in contralesional space. We conclude by discussing how motivation might be practically integrated into the rehabilitation of patients with this debilitating disorder. © 2016 Elsevier B

  4. Compression of the North Hemisphere derived from space geodesy

    Institute of Scientific and Technical Information of China (English)

    金双根; 朱文耀

    2003-01-01

    The convergent and divergent velocities of active plate boundaries in the North Hemisphere are obtained with space geodetic data. The relative motions of adjacent plates in north-south direction are almost convergent; the spreading rates of the north mid-Atlantic ridge are smaller than the south mid-Atlantic ridge; the closed differences of the baseline length rates between stations on different plates along the latitudinal circle of 7.7(, 23.3o, 34.8o, 42.0o and 51.0o are all negative. All these show that the North Hemisphere is a compressive hemisphere.

  5. Neuroplasticity in hemispheric syndrome: An interesting case report

    Directory of Open Access Journals (Sweden)

    Shyam Sundar Krishnan

    2011-01-01

    Full Text Available Functional hemispherectomy is an accepted treatment in hemispherical intractable epilepsy syndromes. We report a patient who had functional hemispherectomy for intractable seizures secondary to right hemispheric cortical dysplasia. Preoperatively, the patient had mild left hemiparesis and functional magnetic resonance imaging (fMRI showed bilateral motor function lateralization to normal left hemisphere. The patient remains seizure free at 1-year follow-up, with no deterioration of motor power on left side. This report reviews physiology of neural plasticity for motor function lateralization and also reliability of fMRI in determining the functional shift.

  6. Eastern Pacific Ocean Conference

    Science.gov (United States)

    The promotion of interaction among investigators of all oceanographic disciplines studying the eastern Pacific Ocean was the goal of the 1990 Eastern Pacific Ocean Conference (EPOC), held October 17-19 on the snow-covered slopes of Mt. Hood, Oreg. Thirty oceanographers representing all disciplines attended.Dick Barber, Duke University Marine Lab, Beaufort, N.C., chaired a session on the eastern equatorial Pacific Ocean, emphasizing issues related to biological activity. Steve Ramp of the Naval Postgraduate School in Montery, Calif., chaired a session on recent results from northern and central California experiments. On October 19, following an early morning earthquake, a business meeting and discussions regarding a collaboration in future experiments were held.

  7. A Novel Hemispherical and Dynamic Camera for EVAs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project is to develop a novel Hemispherical and Dynamic Camera(HDC) with ultra-wide field of view and low geometric distortion. The novel technology we...

  8. Comprehension and Hemispheric Processing of Irony in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Ronit Saban-Bezalel

    2017-06-01

    Full Text Available Studies focusing on the comprehension of figurative language among schizophrenia patients (SZ reveal their difficulties comprehending such language and their tendency to interpret it literally. The present study investigated hemispheric processing and comprehension of irony in 16 SZ patients and 18 typically developing (TD adults. Two experimental tasks were used: an online divided visual field experiment and an offline irony questionnaire. The results show an atypical reversal of hemispheric processing of irony in SZ patients as compared to TD adults. While the TD group demonstrated a right hemisphere advantage in processing irony, SZ patients demonstrated a left hemisphere advantage. Greater comprehension of irony was associated with decreased negative symptoms. In addition, under conditions that not involving a time restriction, the SZ patients’ performance improved. Our findings reinforce those of previous studies suggesting that brain lateralization is atypical in SZ patients.

  9. Variation of space radiation exposure inside spherical and hemispherical geometries

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Z.W. [Department of Physics, East Carolina University, C-209 Howell Science Complex, Greenville, NC 27858-4353 (United States); National Space Science and Technology Center, University of Alabama in Huntsville, Huntsville, AL 35805 (United States)], E-mail: linz@ecu.edu; Baalla, Y. [University of Tennessee Space Institute, Tullahoma, TN 37388 (United States); Townsend, L.W. [Department of Nuclear Engineering, University of Tennessee at Knoxville, Knoxville, TN 37996 (United States)

    2009-04-15

    We calculate the space radiation exposure to blood-forming organs everywhere inside a hemispherical dome that represents a lunar habitat. We derive the analytical pathlength distribution from any point inside a hemispherical or a spherical shell. Because the average pathlength increases with the distance from the center, the center of the hemispherical dome on the lunar surface has the largest radiation exposure while locations on the inner surface of the dome have the lowest exposure. This conclusion differs from an earlier study on a hemispherical dome but agrees with another earlier study on a spherical-shell shield. We also find that the reduction in the radiation exposure from the center to the inner edge of the dome can be as large as a factor of 3 or more for the radiation from solar particle events while being smaller for the radiation from galactic cosmic rays.

  10. A Novel Hemispherical and Dynamic Camera for EVAs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary objective of this SBIR project is to develop a novel Hemispherical and Dynamic Camera(HDC), with unprecedented capability of optically unwrapping, thus...

  11. Corticospinal state variability and hemispheric asymmetries in motivational tendencies

    NARCIS (Netherlands)

    Schutter, D.J.L.G.; Hofman, D.; Hoppenbrouwers, S.S.; Kenemans, J.L.

    2011-01-01

    This transcranial magnetic stimulation (TMS) study examined interrelations between asymmetrical hemispheric differences in the degree of variability of corticospinal excitability levels and motivational tendencies. The relative standard deviation in motor evoked potentials (MEP) to single pulse TMS

  12. Prediction Center (CPC) Tropical/ Northern Hemisphere Teleconnection Pattern Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly tabulated index of the Tropical/ Northern Hemisphere teleconnection pattern. The data spans the period 1950 to present. The index is derived from a rotated...

  13. Lateralised motor control: hemispheric damage and the loss of deftness

    OpenAIRE

    Hanna-Pladdy, B.; Mendoza, J; Apostolos, G; Heilman, K

    2002-01-01

    Objective: To learn if the left compared with the right hemisphere of right handed subjects exerts bilateral compared with contralateral motor control when performing precise and coordinated finger movements.

  14. Multisensor Analyzed Sea Ice Extent - Northern Hemisphere (MASIE-NH)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Multisensor Analyzed Sea Ice Extent Northern Hemisphere (MASIE-NH) products provide measurements of daily sea ice extent and sea ice edge boundary for the...

  15. Hemispherical Optical Dome for Underwater Communication

    Science.gov (United States)

    Shiri, Ron S.; Lunde, Emily L.; Coronado, Patrick L.; Quijada, Manuel A.

    2017-01-01

    For many years, acoustic systems have been used as the primary method for underwater communication; however, the data transfer rate of such systems is low because sound propagates slowly through the water. A higher throughput can be achieved using visible light to transmit data underwater. The first issue with using this approach is that there is generally a large loss of the light signal due to scattering and absorption in water even though there is an optimal wavelength for transmission in the blue or green wavelengths of the visible spectrum. The second issue is that a simple system consisting only of a highly directional source transmitter and small optical detector receiver has a very narrow field of view. The goal of this project is to improve an optical, underwater communication system by increasing the effective field of view of the receiving optics. To this end, we make two changes to the simple system: (1) An optical dome was added near the receiver. An array of lenses is placed radially on the surface of the dome, reminiscent of the compound eye of an insect. The lenses make the source and detector planes conjugate, and each lens adds a new region of the source plane to the instrument's total field of view. (2) The receiver was expanded to include multiple photodiodes. With these two changes, the receiver has much more tolerance to misalignments (in position and angle) of the transmitter.Two versions of the optical dome (with 6 and 8 diameters) were designed using the CREO CAD software and modeled using the CODE V optical design software. A series of these transparent hemispherical domes, with both design diameters, were manufactured using a 5-axis mill. The prototype was then retrofitted with lenses and compared with the computer-generated model to demonstrate the effectiveness of this solution. This work shows the dome design improves the optical field of view of the underwater communication system considerably. Furthermore, with the experimental test

  16. Models of hemispheric specialization in facial emotion perception - a reevaluation.

    OpenAIRE

    Najt, P; Bayer, U.; Hausmann, M.

    2013-01-01

    A considerable amount of research on functional cerebral asymmetries (FCAs) for facial emotion perception has shown conflicting support for three competing models: (i) the Right Hemisphere Hypothesis, (ii) the Valence-Specific Hypothesis, and (iii) the Approach/Withdrawal model. However, the majority of studies evaluating the Right Hemisphere or the Valence-Specific Hypotheses are rather limited by the small number of emotional expressions used. In addition, it is difficult to evaluate the Ap...

  17. Right hemisphere reading in a case of developmental deep dyslexia

    OpenAIRE

    Funnell, Elaine; Pitchford, Nicola; de Haan, Bianca; Morgan, Paul

    2007-01-01

    The right hemisphere hypothesis of deep dyslexia has received support from functional imaging studies of acquired deep dyslexia following damage to the left cerebral hemisphere, but no imaging studies of cases of developmental deep dyslexia, in which brain damage is not suspected, have been reported. In this paper, we report the first evidence of right hyperactivation in an adult case of developmental deep dyslexia. Hyperactivation was observed in the right inferior frontal cortex during fMRI...

  18. [Dominance of cerebral hemispheres and visual space-hand localization].

    Science.gov (United States)

    Baranowska-George, T; Kojder, I; Kowerska, D; Kopacka, W

    1990-10-01

    The visual space-hand localization from each eye and by each hand was examined by means of a localizer. Two kinds of examination were performed: one checked the initial, the other the postexercise localization. The dominance of the cerebral hemispheres was determined by psychological tests. No dependence of the behaviour of the visual hand localization on the domination of a given hemisphere was shown.

  19. Hypothalamic digoxin, hemispheric chemical dominance, and peptic ulcer disease.

    Science.gov (United States)

    Kurup, Ravi Kumar; Kurup, Parameswara Achutha

    2003-10-01

    The isoprenoid pathway produces three key metabolites--endogenous digoxin-like factor (EDLF) (membrane sodium-potassium ATPase inhibitor and regulator of neurotransmitter transport), ubiquinone (free radical scavenger), and dolichol (regulator of glycoconjugate metabolism). The pathway was assessed in peptic ulcer and acid peptic disease and its relation to hemispheric dominance studied. The activity of HMG CoA reductase, serum levels of EDLF, magnesium, tryptophan catabolites, and tyrosine catabolites were measured in acid peptic disease, right hemispheric dominant, left hemispheric dominant, and bihemispheric dominant individuals. All the patients with peptic ulcer disease were right-handed/left hemispheric dominant by the dichotic listening test. The pathway was upregulated with increased EDLF synthesis in peptic ulcer disease (PUD). There was increase in tryptophan catabolites and reduction in tyrosine catabolites in these patients. The ubiquinone levels were low and free radical production increased. Dolichol and glycoconjugate levels were increased and lysosomal stability reduced in patients with acid peptic disease (APD). There was increase in cholesterol:phospholipid ratio with decreased glyco conjugate levels in membranes of patients with PUD. Acid peptic disease represents an elevated EDLF state which can modulate gastric acid secretion and the structure of the gastric mucous barrier. It can also lead to persistence of Helicobacter pylori infection. The biochemical pattern obtained in peptic ulcer disease is similar to those obtained in left-handed/right hemispheric chemically dominant individuals. But all the patients with peptic ulcer disease were right-handed/left hemispheric dominant by the dichotic listen ing test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Peptic ulcer disease occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function.

  20. DISCOVERING BEIJING Eastern Promise

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Dongcheng District, literally meaning eastern city, covers Beijing’s downtown area to the northeast of the central axis of old Beijing. The district has a total area of 25 square km and a population of 600,000. With a large number of cultural and historical sites and tourist attractions,

  1. Eastern Spruce Dwarf Mistletoe

    Science.gov (United States)

    F. Baker; Joseph O' Brien; R. Mathiasen; Mike Ostry

    2006-01-01

    Eastern spruce dwarf mistletoe (Arceuthobium pusillum) is a parasitic flowering plant that causes the most serious disease of black spruce (Picea mariana) throughout its range. The parasite occurs in the Canadian provinces of Saskatchewan, Manitoba, Ontario, Quebec, New Brunswick, Nova Scotia, Prince Edward Island, and Newfoundland; in the Lake States of Minnesota,...

  2. Eastern Frequency Response Study

    Energy Technology Data Exchange (ETDEWEB)

    Miller, N.W.; Shao, M.; Pajic, S.; D' Aquila, R.

    2013-05-01

    This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.

  3. Metaphors and verbal creativity: the role of the right hemisphere.

    Science.gov (United States)

    Gold, Rinat; Faust, Miriam; Ben-Artzi, Elisheva

    2012-01-01

    Ample research suggests that the right cerebral hemisphere plays a central role in verbal creativity as well as in novel metaphor comprehension. The aim of the present study was to directly examine the relation between verbal creativity and right hemisphere involvement during novel metaphor comprehension. Thus 30 healthy adults were asked to fill in the Hebrew version of the Remote Association Test to assess their level of creativity. In addition, reaction times and error rates were measured while these participants performed a semantic judgement task on two word expressions presented in a divided visual field paradigm. The word pairs comprised four types of semantic relations: novel metaphors, conventional metaphors, literal word pairs, and meaningless word pairs. Correlations were conducted to assess the relation between level of creativity and processing of the four pair types in the two cerebral hemispheres. The main finding was of a significant negative correlation between degree of creativity and reaction times to novel metaphor processing in the right hemisphere, thus supporting the involvement of this cerebral hemisphere in both tasks. Results are discussed in light of linguistic theories and recent neuroscientific evidence regarding relative hemispheric involvement during semantic processing.

  4. The nature of hemispheric specialization for prosody perception.

    Science.gov (United States)

    Witteman, Jurriaan; Goerlich-Dobre, Katharina S; Martens, Sander; Aleman, André; Van Heuven, Vincent J; Schiller, Niels O

    2014-09-01

    Recent evidence suggests a relative right-hemispheric specialization for emotional prosody perception, whereas linguistic prosody perception is under bilateral control. It is still unknown, however, how the hemispheric specialization for prosody perception might arise. Two main hypotheses have been put forward. Cue-dependent hypotheses, on the one hand, propose that hemispheric specialization is driven by specialization for the non-prosody-specific processing of acoustic cues. The functional lateralization hypothesis, on the other hand, proposes that hemispheric specialization is dependent on the communicative function of prosody, with emotional and linguistic prosody processing being lateralized to the right and left hemispheres, respectively. In the present study, the functional lateralization hypothesis of prosody perception was systematically tested by instructing one group of participants to evaluate the emotional prosody, and another group the linguistic prosody dimension of bidimensional prosodic stimuli in a dichotic-listening paradigm, while event-related potentials were recorded. The results showed that the right-ear advantage was associated with decreased latencies for an early negativity in the contralateral hemisphere. No evidence was found for functional lateralization. These findings suggest that functional lateralization effects for prosody perception are small and support the structural model of dichotic listening.

  5. Hemispheric Asymmetry of Development Due to Drug Exposure.

    Science.gov (United States)

    Gordon, Harold W

    2017-01-01

    A previous survey of the literature of fMRI brain activation for two risk factors, impulsivity and craving, for addiction were lateralized to the right and left hemispheres respectively. Most articles reported these findings without consideration of how lateral asymmetries might be relevant to understanding the underlying factors leading to addiction. The current survey is intended to extend these observations by demonstrating hemispheric asymmetry of development due to pre-natal or adolescent/adult exposure to drugs of abuse. Articles that reported either pre-natal or adolescent/adult exposure to drugs of abuse were collected and the hemisphere of the affected structures was tabulated to determine if, and which, drugs affected more structures in one hemisphere or the other or both together. Some drugs, notably cocaine and alcohol, differentially affected left or right hemisphere structures which significantly differed depending on whether individuals were exposed prenatally or as an adolescent/adult. Cocaine tended to affect more left hemisphere structures when exposed prenatally and significantly affected more in the right when exposed as adults. Alcohol had the reverse pattern. The difference in patterns of effect between pre-natal or adult exposure was significant for both. The results in this survey demonstrate that some drugs of abuse appear to have a right/left differential effect on structures of the brain. Further investigation into the reasons for this asymmetry may provide new insights into underlying factors of drug-seeking and addiction.

  6. Right hemisphere structural adaptation and changing language skills years after left hemisphere stroke.

    Science.gov (United States)

    Hope, Thomas M H; Leff, Alex P; Prejawa, Susan; Bruce, Rachel; Haigh, Zula; Lim, Louise; Ramsden, Sue; Oberhuber, Marion; Ludersdorfer, Philipp; Crinion, Jenny; Seghier, Mohamed L; Price, Cathy J

    2017-06-01

    Stroke survivors with acquired language deficits are commonly thought to reach a 'plateau' within a year of stroke onset, after which their residual language skills will remain stable. Nevertheless, there have been reports of patients who appear to recover over years. Here, we analysed longitudinal change in 28 left-hemisphere stroke patients, each more than a year post-stroke when first assessed-testing each patient's spoken object naming skills and acquiring structural brain scans twice. Some of the patients appeared to improve over time while others declined; both directions of change were associated with, and predictable given, structural adaptation in the intact right hemisphere of the brain. Contrary to the prevailing view that these patients' language skills are stable, these results imply that real change continues over years. The strongest brain-behaviour associations (the 'peak clusters') were in the anterior temporal lobe and the precentral gyrus. Using functional magnetic resonance imaging, we confirmed that both regions are actively involved when neurologically normal control subjects name visually presented objects, but neither appeared to be involved when the same participants used a finger press to make semantic association decisions on the same stimuli. This suggests that these regions serve word-retrieval or articulatory functions in the undamaged brain. We teased these interpretations apart by reference to change in other tasks. Consistent with the claim that the real change is occurring here, change in spoken object naming was correlated with change in two other similar tasks, spoken action naming and written object naming, each of which was independently associated with structural adaptation in similar (overlapping) right hemisphere regions. Change in written object naming, which requires word-retrieval but not articulation, was also significantly more correlated with both (i) change in spoken object naming; and (ii) structural adaptation in

  7. Neuropragmatics: Extralinguistic pragmatic ability is better preserved in left-hemisphere-damaged patients than in right-hemisphere-damaged patients.

    Science.gov (United States)

    Cutica, Ilaria; Bucciarelli, Monica; Bara, Bruno G

    2006-07-01

    The aim of the present study is to compare the pragmatic ability of right- and left-hemisphere-damaged patients excluding the possible interference of linguistic deficits. To this aim, we study extralinguistic communication, that is communication performed only through gestures. The Cognitive Pragmatics Theory provides the theoretical framework: it predicts a gradient of difficulty in the comprehension of different pragmatic phenomena, that should be valid independently of the use of language or gestures as communicative means. An experiment involving 10 healthy individuals, 10 right- and 9 left-hemisphere-damaged patients, shows that pragmatic performance is better preserved in left-hemisphere-damaged (LHD) patients than in right-hemisphere-damaged (RHD) patients.

  8. Non-conjugate aurora and inter hemispheric currents

    Science.gov (United States)

    Reistad, J. P.; Østgaard, N.; Laundal, K. M.; Oksavik, K.

    2012-04-01

    We look at large scale auroral features using global imagers to obtain simultaneous pictures of both the southern and northern auroral ovals in the ultra violet part of the spectra. During the years 2001 and 2002 the IMAGE satellite was in a favourable position for imaging the aurora borealis (Northern Hemisphere) and the POLAR satellite with its large field-of-view VIS Earth camera had a sporadic coverage of the aurora australis (Southern Hemisphere). In total 19 hours of simultaneous global imaging from different seasons are analysed searching for non-conjugacy in the night side sector. By non-conjugate aurora we mean auroral features appearing in one hemisphere only, or significant differences in intensity between the hemispheres for the same auroral feature. We suggest that our observed large scale asymmetries can be explained in terms of inter hemispheric currents (IHC). Coherent with our earlier findings, we list three possible candidates for producing such inter hemispheric currents based on observations. 1) Hemispherical differences in the solar wind dynamo due to IMF Bx and tilt angle producing different strength of region 1 currents in the conjugate he mispheres, 2) Hemispherical differences in conductivity controlled by the tilt angle only giving rise to IHC on closed field lines, and 3) Field-aligned current components induced by the penetration of the IMF By into the closed magnetosphere. Most of the observed non-conjugate aurora in our dataset can be explained by these candidates only. The IMF By penetration candidate is considered closer. We search for evidence in our data that IMF By 0) can induce an IHC producing stronger aurora on the polar boundary in the Northern (Southern) Hemisphere. Also a second IHC component are predicted from the theory, mapping to the equatorward part of the oval and opposite directed along the magnetic field lines. Using a much larger dataset for one hemisphere only, we show whether these predicted currents can be

  9. Unilateral hearing during development: hemispheric specificity in plastic reorganizations

    Directory of Open Access Journals (Sweden)

    Andrej eKral

    2013-11-01

    Full Text Available The present study investigates the hemispheric contributions of neuronal reorganization following early single-sided hearing (unilateral deafness. The experiments were performed on ten cats from our colony of deaf white cats. Two were identified in early hearing screening as unilaterally congenitally deaf. The remaining eight were bilaterally congenitally deaf, unilaterally implanted at different ages with a cochlear implant. Implanted animals were chronically stimulated using a single-channel portable signal processor for two to five months. Microelectrode recordings were performed at the primary auditory cortex under stimulation at the hearing and deaf ear with bilateral cochlear implants. Local field potentials (LFPs were compared at the cortex ipsilateral and contralateral to the hearing ear. The focus of the study was on the morphology and the onset latency of the LFPs. The data revealed that effects of hearing experience were more pronounced when stimulating the hearing ear. With respect to morphology of LFPs, pronounced hemisphere-specific effects were observed. Morphology of amplitude-normalized LFPs for stimulation of the deaf and the hearing ear was similar for responses recorded at the same hemisphere. However, when comparisons were performed between the hemispheres, the morphology was more dissimilar even though the same ear was stimulated. This demonstrates hemispheric specificity of some cortical adaptations irrespective of the ear stimulated. The results suggest a specific adaptation process at the hemisphere ipsilateral to the hearing ear, involving specific (down-regulated inhibitory mechanisms not found in the contralateral hemisphere. Finally, onset latencies revealed that the sensitive period for the cortex ipsilateral to the hearing ear is shorter than that for the contralateral cortex. Unilateral hearing experience leads to a functionally-asymmetric brain with different neuronal reorganizations and different sensitive

  10. Widespread land surface wind decline in the Northern Hemisphere

    Science.gov (United States)

    Vautard, R.; Cattiaux, J.; Yiou, P.; Thépaut, J.-N.; Ciais, P.

    2010-09-01

    The decline of surface wind observed in many regions of the world is a potential source of concern for wind power electricity generation. It is also suggested as the main cause of decreasing pan evaporation. In China, a persistent and significant decrease of monsoon winds was observed in all seasons. Surface wind declines were also evidenced in several regions of the world (U.S., Australia, several European countries). Except over China, no clear explanation was given for the wind decrease in the regions studied. Whether surface winds decrease is due to changes in the global atmospheric circulation or its variability, in surface processes or to observational trends has therefore not been elucidated. The identification of the drivers of such a decline requires a global investigation of available surface and upper-air wind data, which has not been conducted so far. Here we use global datasets of in-situ wind measurements that contain surface weather stations wind data (hourly or three-hourly data acquisition time step) and rawinsonde vertical wind data profiles (monthly time step) prepared by the NCAR. A set of 822 worldwide surface stations with continuous wind records was selected after a careful elimination of stations with obvious breaks and large gaps. This dataset mostly covers the Northern mid latitudes over the period 1979-2008. Using this data set, we found that annual mean wind speeds have declined at 73% of the surface stations over the past 30 years. In the Northern Hemisphere, positive wind trends are found only in a few places. In Europe, Central Asia, Eastern Asia and in North America the annual mean surface wind speed has decreased on average at a rate of -2.9, -5.9, -4.2, and -1.8 %/decade respectively, i.e. a decrease of about 10% in 30 years and up to about 20% in Central Asia. These results are robust to changes in the station selection method and parameters. By contrast, upper-air winds observed from rawinsondes, geostrophic winds deduced from

  11. Hemispheric asymmetries in the perceptual representations of words.

    Science.gov (United States)

    Lincoln, Amy E; Long, Debra L; Swick, Diane; Larsen, Jary; Baynes, Kathleen

    2008-01-10

    The representation of words in sentences can involve the activation and integration of perceptual information. For example, readers who are asked to view pictures of objects relating to a word in a sentence are influenced by perceptual information in the sentence context-readers are faster to respond to a picture of a whole apple after reading, "There is an apple in the bag," than after reading, "There is an apple in the salad." The purpose of this study was to examine how the two cerebral hemispheres use perceptual information about words as a function of sentence context. Patients who had damage to the left or right hemisphere and age-matched control participants read sentences that described, but did not entail, the shape or state of an object. They then made recognition judgments to pictures that either matched or mismatched the perceptual form implied by the sentence. Responses and latencies were examined for a match effect -- faster and more accurate responses to pictures in the match than mismatch condition -- controlling for comprehension ability and lesion size. When comprehension ability and lesion size are properly controlled, left-hemisphere-damaged patients and control participants exhibited the expected match effect, whereas right-hemisphere-damaged participants showed no effect of match condition. These results are consistent with research implicating the right hemisphere in the representation of contextually relevant perceptual information.

  12. Apraxia and spatial inattention dissociate in left hemisphere stroke.

    Science.gov (United States)

    Timpert, David C; Weiss, Peter H; Vossel, Simone; Dovern, Anna; Fink, Gereon R

    2015-10-01

    Theories of lateralized cognitive functions propose a dominance of the left hemisphere for motor control and of the right hemisphere for spatial attention. Accordingly, spatial attention deficits (e.g., neglect) are more frequently observed after right-hemispheric stroke, whereas apraxia is a common consequence of left-hemispheric stroke. Clinical reports of spatial attentional deficits after left hemisphere (LH) stroke also exist, but are often neglected. By applying parallel analysis (PA) and voxel-based lesion-symptom mapping (VLSM) to data from a comprehensive neuropsychological assessment of 74 LH stroke patients, we here systematically investigate the relationship between spatial inattention and apraxia and their neural bases. PA revealed that apraxic (and language comprehension) deficits loaded on one common component, while deficits in attention tests were explained by another independent component. Statistical lesion analyses with the individual component scores showed that apraxic (and language comprehension) deficits were significantly associated with lesions of the left superior longitudinal fascicle (SLF). Data suggest that in LH stroke spatial attention deficits dissociate from apraxic (and language comprehension) deficits. These findings contribute to models of lateralised cognitive functions in the human brain. Moreover, our findings strongly suggest that LH stroke patients should be assessed systematically for spatial attention deficits so that these can be included in their rehabilitation regime.

  13. Interindividual variability in the hemispheric organization for speech.

    Science.gov (United States)

    Tzourio-Mazoyer, N; Josse, G; Crivello, F; Mazoyer, B

    2004-01-01

    A PET activation study was designed to investigate hemispheric specialization during speech comprehension and production in right- and left-handed subjects. Normalized regional cerebral blood flow (NrCBF) was repeatedly monitored while subjects either listened to factual stories (Story) or covertly generated verbs semantically related to heard nouns (Gener), using silent resting (Rest) as a common control condition. NrCBF variations in each task, as compared to Rest, as well as functional asymmetry indices (FAI = right minus left NrCBF variations), were computed in anatomical regions of interest (AROIs) defined on the single-subject MNI template. FAIs were predominantly leftward in all regions during both tasks, although larger FAIs were observed during Gener. Subjects were declared "typical" for language hemispheric specialization based on the presence of significant leftward asymmetries (FAI minor hemisphere. This can be considered as the setting up of a "language mode", under the control of a mechanism that operates at a perisylvian level. On top of this global organization, regional variations carry on the performance of the cognitive operations specific to the language task to be performed. Hemispheric relationships could be different in atypical subjects, with either between task hemispheric regulation differences or differences in regional specialization.

  14. Hemispheric asymmetry in the hierarchical perception of music and speech.

    Science.gov (United States)

    Rosenthal, Matthew A

    2016-11-01

    The perception of music and speech involves a higher level, cognitive mechanism that allows listeners to form expectations for future music and speech events. This article comprehensively reviews studies on hemispheric differences in the formation of melodic and harmonic expectations in music and selectively reviews studies on hemispheric differences in the formation of syntactic and semantic expectations in speech. On the basis of this review, it is concluded that the higher level mechanism flexibly lateralizes music processing to either hemisphere depending on the expectation generated by a given musical context. When a context generates in the listener an expectation whose elements are sequentially ordered over time, higher level processing is dominant in the left hemisphere. When a context generates in the listener an expectation whose elements are not sequentially ordered over time, higher level processing is dominant in the right hemisphere. This article concludes with a spreading activation model that describes expectations for music and speech in terms of shared temporal and nontemporal representations. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  15. Modeling the Influence of Hemispheric Transport on Trends in ...

    Science.gov (United States)

    We describe the development and application of the hemispheric version of the CMAQ to examine the influence of long-range pollutant transport on trends in surface level O3 distributions. The WRF-CMAQ model is expanded to hemispheric scales and multi-decadal model simulations were recently performed for the period spanning 1990-2010 to examine changes in hemispheric air pollution resulting from changes in emissions over this period. Simulated trends in ozone and precursor species concentrations across the U.S. and the northern hemisphere over the past two decades are compared with those inferred from available measurements during this period. Additionally, the decoupled direct method (DDM) in CMAQ is used to estimate the sensitivity of O3 to emissions from different source regions across the northern hemisphere. The seasonal variations in source region contributions to background O3 is then estimated from these sensitivity calculations and will be discussed. A reduced form model combining these source region sensitivities estimated from DDM with the multi-decadal simulations of O3 distributions and emissions trends, is then developed to characterize the changing contributions of different source regions to background O3 levels across North America. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, decision-support tools, and models to be applied to media-specific or receptor-specific problem areas

  16. Classification of hemispheric monthly mean stratospheric potential vorticity fields

    Directory of Open Access Journals (Sweden)

    R. Huth

    Full Text Available Monthly mean NCEP reanalysis potential vorticity fields at the 650 K isentropic level over the Northern and Southern Hemispheres between 1979 and 1997 were studied using multivariate analysis tools. Principal component analysis in the T-mode was applied to demonstrate the validity of such statistical techniques for the study of stratospheric dynamics and climatology. The method, complementarily applied to both the raw and anomaly fields, was useful in determining and classifying the characteristics of winter and summer PV fields on both hemispheres, in particular, the well-known differences in the behaviour and persistence of the polar vortices. It was possible to identify such features as sudden warming events in the Northern Hemisphere and final warming dates in both hemispheres. The stratospheric impact of other atmospheric processes, such as volcanic eruptions, also identified though the results, must be viewed at this stage as tentative. An interesting change in behaviour around 1990 was detected over both hemispheres.

    Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; general circulation; climatology

  17. Lake records of Northern Hemisphere South American summer monsoon variability from the Cordillera Oriental, Colombia: Initial results from Lago de Tota and Laguna de Ubaque

    Science.gov (United States)

    Escobar, J.; Rudloff, O.; Bird, B. W.

    2013-12-01

    The lack of terrestrial paleoclimate records from the Northern Hemisphere Andes with decadal resolution has meant that our understanding of abrupt South American summer monsoon (SASM) variability during the Holocene is almost exclusively based on data from Southern Hemisphere sites. In order to develop a more integrated and complete picture of the SASM as a system and its response during rapid climate changes, high-resolution paleoclimate records are needed from the Northern Hemisphere Andes. We present initial results from analysis of lake sediment cores that were collected from Lago de Tota (N 5.554, W 72.916) and Laguna de Ubaque (N 4.500, W 73.935) in the Eastern Cordillera of the Colombian Andes. These sediment cores were collected in July 2013 as part on an ongoing paleoclimate research initiative in Colombia. Located in the Boyacá Provence, Lago de Tota is the largest high-altitude lake (3010 masl) in the Northern Hemisphere Andes and the second largest Andean lake in South America. As such, hydrologic changes recorded in the lake's sediment record reflect regional climate responses. Lago de Ubaque (2070 masl) is a small east facing moraine-dammed lake near the capital of Bogotá that contains finely laminated clastic sediments. The initial sedimentological and chronological results demonstrate that Lago de Tota and Laguna de Ubaque have excellent potential for resolving Northern Hemisphere SASM variability at decadal time scales or better. Such records will provide important counterparts to high-resolution paleoclimate records from the Southern Hemisphere Andes.

  18. Modeling and verification of hemispherical solar still using ANSYS CFD

    Energy Technology Data Exchange (ETDEWEB)

    Panchal, Hitesh N. [KSV University, Gujarat Power Engineering and Research Institute, Mehsana (India); Shah, P.K. [Silver Oak College of Engineering and Technology, Ahmedabad, Gujarat (India)

    2013-07-01

    In every efficient solar still design, water temperature, vapor temperature and distillate output, and difference between water temperature and inner glass cover temperatures are very important. Here, two dimensional three phase model of hemispherical solar still is made for evaporation as well as condensation process in ANSYS CFD. Simulation results like water temperature, vapor temperature, distillate output compared with actual experimental results of climate conditions of Mehsana (latitude of 23° 59’ and longitude of 72° 38) of hemispherical solar still. Water temperature and distillate output were good agreement with actual experimental results. Study shows that ANSYS-CFD is very powerful as well as efficient tool for design, comparison purpose of hemispherical solar still.

  19. Designing a Hemispherical Breast RF Coil Array for MRI

    Institute of Scientific and Technical Information of China (English)

    XU Wen-long; ZHANG Ju-cheng; WANG Zhi-kang; LI Xing-xin; LOU Hai-fang

    2015-01-01

    In this paper, an approach to the design of hemispherical breast RF coil array is proposedThe target field method is applied to find the current density distribution on the hemisphere surface, which induces a homogeneous magnetic field in a hemispherical volumeThe components of current density are expanded into Fourier series, and the highly ill-conditioned character of the linear equation related to Fourier coefficients is solved using the Tikhonov regularization method with a minimum curvature penalty functionThe winding pattern was acquired using the stream function techniqueThe results indicate that a simple winding pattern with homogeneous magnetic field can be obtained through manually selecting the penalty factor.

  20. Caffeine improves left hemisphere processing of positive words.

    Directory of Open Access Journals (Sweden)

    Lars Kuchinke

    Full Text Available A positivity advantage is known in emotional word recognition in that positive words are consistently processed faster and with fewer errors compared to emotionally neutral words. A similar advantage is not evident for negative words. Results of divided visual field studies, where stimuli are presented in either the left or right visual field and are initially processed by the contra-lateral brain hemisphere, point to a specificity of the language-dominant left hemisphere. The present study examined this effect by showing that the intake of caffeine further enhanced the recognition performance of positive, but not negative or neutral stimuli compared to a placebo control group. Because this effect was only present in the right visual field/left hemisphere condition, and based on the close link between caffeine intake and dopaminergic transmission, this result points to a dopaminergic explanation of the positivity advantage in emotional word recognition.

  1. Brain hemisphere dominance and vocational preference: a preliminary analysis.

    Science.gov (United States)

    Szirony, Gary Michael; Pearson, L Carolyn; Burgin, John S; Murray, Gerald C; Elrod, Lisa Marie

    2007-01-01

    Recent developments in split-brain theory add support to the concept of specialization within brain hemispheres. Holland's vocational personality theory may overlap with Human Information Processing (HIP) characteristics. Holland's six RIASEC codes were developed to identify vocational personality characteristics, and HIP scales were designed to measure hemispheric laterality. Relationships between the two scales were evaluated through canonical correlation with some significant results, however not all Holland scale scores correlated with left, right, or integrated hemispheric preference. Additional findings related to participants self-perception of music and math ability were also correlated. Findings on this added analysis revealed a high correlation between perception of musical ability and right brain function but not between mathematical concept and left brain alone. Implications regarding vocational choice and work are discussed.

  2. CMB-S4 and the hemispherical variance anomaly

    Science.gov (United States)

    O'Dwyer, Márcio; Copi, Craig J.; Knox, Lloyd; Starkman, Glenn D.

    2017-09-01

    Cosmic microwave background (CMB) full-sky temperature data show a hemispherical asymmetry in power nearly aligned with the Ecliptic. In real space, this anomaly can be quantified by the temperature variance in the Northern and Southern Ecliptic hemispheres, with the Northern hemisphere displaying an anomalously low variance while the Southern hemisphere appears unremarkable [consistent with expectations from the best-fitting theory, Lambda Cold Dark Matter (ΛCDM)]. While this is a well-established result in temperature, the low signal-to-noise ratio in current polarization data prevents a similar comparison. This will change with a proposed ground-based CMB experiment, CMB-S4. With that in mind, we generate realizations of polarization maps constrained by the temperature data and predict the distribution of the hemispherical variance in polarization considering two different sky coverage scenarios possible in CMB-S4: full Ecliptic north coverage and just the portion of the North that can be observed from a ground-based telescope at the high Chilean Atacama plateau. We find that even in the set of realizations constrained by the temperature data, the low Northern hemisphere variance observed in temperature is not expected in polarization. Therefore, observing an anomalously low variance in polarization would make the hypothesis that the temperature anomaly is simply a statistical fluke more unlikely and thus increase the motivation for physical explanations. We show, within ΛCDM, how variance measurements in both sky coverage scenarios are related. We find that the variance makes for a good statistic in cases where the sky coverage is limited, however, full northern coverage is still preferable.

  3. Asymmetric field-aligned currents in the conjugate hemispheres

    Science.gov (United States)

    Reistad, J. P.; Ostgaard, N.; Oksavik, K.; Laundal, K. M.

    2012-12-01

    Earlier studies using simultaneous imaging from space of the Aurora Borealis (Northern Hemisphere) and Aurora Australis (Southern Hemisphere) have revealed that the aurora can experience a high degree of asymmetry between the two hemispheres. Using 19 hours of simultaneous global imaging from both hemispheres (IMAGE satellite in north and Polar satellite in south) in conjunction with the entire IMAGE WIC database, we investigate the importance of various mechanisms thought to generate the asymmetries seen in global imaging. In terms of asymmetric or interhemispheric field-aligned currents, three candidate mechanisms have been suggested: 1) Hemispheric differences in solar wind dynamo efficiency mainly controlled by IMF Bx leading to asymmetric region 1 currents; 2) conductivity differences in conjugate areas; and 3) penetration of IMF By into the closed magnetosphere possibly generating a pair of oppositely directed interhemispheric currents. From the 19 hour conjugate dataset we find that the solar wind dynamo is likely to be the most important controlling mechanism for asymmetric bright aurora in the polar part of the nightside oval. Here we present statistical analyses of candidates 1) and 3). Using the entire IMAGE WIC database, a statistical analysis of the auroral brightness distribution along and across the Northern Hemisphere oval is carried out. For each candidate, two extreme cases (+/- IMF Bx for 1) and +/- IMF By for 3)) are compared during times non-favorable for the other two mechanisms. Our results indicate that solar wind dynamo induced currents play an important role for the nightside auroral brightness in an average sense. Also, signatures of interhemispheric currents due to IMF By penetration are seen in our statistics, although this effect is somehow weaker.

  4. Potential Impact of South Asian Anthropogenic Aerosols on Northern Hemisphere Climate

    Science.gov (United States)

    Bollasina, M. A.; Ming, Y.; Ramaswamy, V.

    2014-12-01

    South Asia has one of the world's highest aerosol loading due to the dramatic increase of anthropogenic emissions from the 1950s associated with rapid urbanization and population growth. The possible large-scale impact of the late 20th century increase of South Asian aerosol emissions on climate away from the source regions was studied by means of historical ensemble experiments with a state-of-the-art coupled climate model with fully interactive aerosols and a representation of both direct and indirect aerosol effects. The key characteristics of the northern hemisphere responses are examined separately for winter and summer, and show that regional aerosols induce significant planetary-scale teleconnection patterns. In both seasons, the large-scale aerosol imprint originates from substantial changes in the regional precipitation distribution. During the winter, in response to anomalous surface cooling in the northern Indian Ocean, aerosols cause a westward shift of convection over the eastern Indian Ocean and compensating subsidence to the west and over the Maritime continent. During the summer, aerosols are collocated with rainfall, and cause a widespread drying over South Asia mostly by indirect effects. In both cases, the impact of the regional diabatic heating anomaly propagates remotely by exciting a northern hemisphere wave-train which, enhanced by regional feedbacks, leads to remarkable changes in near-surface climate, including circulation and temperature, over Eurasia, the northern Pacific and North America. Depending on the region, the induced anomalies may have opposite signs between the two seasons, and may thus contribute to reinforcing or dampening those due greenhouse gases. These results underscore the potential influence of Asian aerosols on global climate, which is a compelling problem as regional aerosol loading will continue to be large in the coming decades.

  5. The modulation of oceanic moisture transport by the hemispheric annular modes

    Directory of Open Access Journals (Sweden)

    Raquel eNieto

    2014-07-01

    Full Text Available Leaving aside the contribution made by recycling, it is the main oceanic moisture sources that are responsible for most of the precipitation that falls on the continents. The transport of moisture from these sources can be affected by large-scale variability according to the hemispheric annular modes. The influence of the two dominant modes of extratropical winter climate: the Northern and the Southern Annular Modes (NAM and SAM are herein investigated to assess how they affect the transport of moisture from the major oceanic moisture sources. A Lagrangian model was used, together with ERA-Interim reanalysis data (1979-2012, and differences between the composites of the six strongest higher and lower events observed for both phases of the two modes for the period were analysed. The method is able to reproduce the general pattern of known variations for both annular patterns. Lower values of the NAM Index are associated with the displacement of the storm track towards tropical latitudes. Thus, moisture transport is enhanced from the Northern Pacific towards the northeastern basin and from the Northern Atlantic and Mediterranean towards southern Europe. On the other hand, during higher values of NAM, moisture transport is favoured from the Northern Pacific towards eastern Asia, and moisture transport is enhanced from the Northern Atlantic towards the Caribbean Sea. In the Southern Hemisphere, during higher values of SAM more moisture is transported from the Atlantic and Indian oceanic sources southwards and eastwards than during the opposite phase. In this SAM phase it is also noted by an enhancement of moisture transport from the Coral Sea and Southern Pacific sources towards the Indian Ocean/West Pacific Warm Pool. Southeastern South America received more moisture from the Pacific and Atlantic sources during years with a lower SAM, episodes which also favoured the influx of moisture from the Southern Atlantic towards Africa, causing monsoon

  6. Volumetric hemispheric ratio as a useful tool in personality psychology.

    Science.gov (United States)

    Montag, Christian; Schoene-Bake, Jan-Christoph; Wagner, Jan; Reuter, Martin; Markett, Sebastian; Weber, Bernd; Quesada, Carlos M

    2013-02-01

    The present study investigates the link between volumetric hemispheric ratios (VHRs) and personality measures in N=267 healthy participants using Eysenck's Personality Inventory-Revised (EPQ-R) and the BIS/BAS scales. A robust association between extraversion and VHRs was observed for gray matter in males but not females. Higher gray matter volume in the left than in the right hemisphere was associated with higher extraversion in males. The results are discussed in the context of positive emotionality and laterality of the human brain.

  7. Mixing with piecewise isometries on a hemispherical shell

    Science.gov (United States)

    Park, Paul P.; Umbanhowar, Paul B.; Ottino, Julio M.; Lueptow, Richard M.

    2016-07-01

    We introduce mixing with piecewise isometries (PWIs) on a hemispherical shell, which mimics features of mixing by cutting and shuffling in spherical shells half-filled with granular media. For each PWI, there is an inherent structure on the hemispherical shell known as the exceptional set E, and a particular subset of E, E+, provides insight into how the structure affects mixing. Computer simulations of PWIs are used to visualize mixing and approximations of E+ to demonstrate their connection. While initial conditions of unmixed materials add a layer of complexity, the inherent structure of E+ defines fundamental aspects of mixing by cutting and shuffling.

  8. Opposed hemispheric specializations for human hypersexuality and orgasm?

    Science.gov (United States)

    Suffren, Sabrina; Braun, Claude M J; Guimond, Anik; Devinsky, Orrin

    2011-05-01

    With a multiple case report analysis we demonstrate that hypersexuality more often results from right hemisphere (RH) (n=26) than left hemisphere (LH) (n=7) lesions, possibly because of LH release after the RH lesion, and that ictal orgasm more often occurs in patients with right-sided (n=23) than left-sided (n=8) seizure foci, with the symptom probably resulting from RH activation. The LH may be specialized for increasing sexual tension, whereas the RH may be specialized for release of this tension (orgasm), the former being catabolic and the latter anabolic. Several other interpretations of the findings are also discussed.

  9. Quasi-static axisymmetric eversion hemispherical domes made of elastomers

    Science.gov (United States)

    Kabrits, Sergey A.; Kolpak, Eugeny P.

    2016-06-01

    The paper considers numerical solution for the problem of quasi-static axisymmetric eversion of a spherical shell (hemisphere) under action of external pressure. Results based on the general nonlinear theory of shells made of elastomers, proposed by K. F. Chernykh. It is used two models of shells based on the hypotheses of the Kirchhoff and Timoshenko, modified K.F. Chernykh for the case of hyperelastic rubber-like material. The article presents diagrams of equilibrium states of eversion hemispheres for both models as well as the shape of the shell at different points in the diagram.

  10. Crossing the ultimate ecological barrier : Evidence for an 11000-km-long nonstop flight from Alaska to New Zealand and eastern Australia by Bar-tailed Godwits

    NARCIS (Netherlands)

    Gill, RE; Piersma, T; Hufford, G; Servranckx, R; Riegen, A

    2005-01-01

    Populations of the Bar-tailed Godwit (Limosa lapponica; Scolopacidae) embark on some of the longest migrations known among birds. The baueri race breeds in western Alaska and spends the nonbreeding season a hemisphere away in New Zealand and eastern Australia; the menzbieri race breeds in Siberia an

  11. Sprite Climatology in the Eastern Mediterranean Region

    Science.gov (United States)

    Yair, Yoav; Price, Colin; Katzenelson, Dor; Rosenthal, Neta; Rubanenko, Lior; Ben-Ami, Yuval; Arnone, Enrico

    2015-04-01

    We present statistical analysis of 436 sprites observed in 7 winter campaigns from 2006/7-2012/13. Results show a clear peak in the frequency of sprite detections, with maximum values (reports of winter sprites over the Sea of Japan and summer ones in central Europe. Other shapes such as trees, wishbones, etc. appear quite rarely. Single element events constitute 16.5% of observations, with 83.5% containing 2 elements or more. Clusters of homogeneous types are slightly more frequent than mixed ones (55%). Our observations suggest winter East Mediterranean thunderstorms to have a vertical structure that is an intermediate type between high tropical convective systems and the lower cloud-top cells in winter thunderstorms over the Sea of Japan. The climatology shows that the Eastern Mediterranean is a major sprite producer during Northern Hemisphere winter, and thus the existing and future optical observation infrastructure in Israel offers ground-based coverage for upcoming space missions that aim to map global sprite activity.

  12. Paleotsunamis in Eastern Taiwan

    Science.gov (United States)

    Yen, Jiun-Yee; Yu, Neng-Ti; Hirakawa, Kazuomi; Chyi, Shyh-Jeng; Huang, Shao-Yi

    2017-04-01

    Although Taiwan is located in the active collision zone between Eurasian and the Philippine Sea plate with very high seismicity in and surrounding the island, and supposedly highly susceptible to tsunami hazard. However, there is no record of tsunami hazard in the past one hundred years, and only very few historical records show some possible extreme event occurred. Therefore study of tsunami was scarce in Taiwan. Although historical records do show possible tsunami events, the records were too sparse and incomplete to confidently reconstruct the paleotsunami events. In the past few years, numerical simulations based on possible tsunami-genic zones near Taiwan show that the island could be affected by the correctly directed tsunami. Nevertheless, there is no detail, scientific research of paleotsunami records yet in Taiwan. Our field survey in eastern Taiwan (facing the western Pacific Ocean) along the coast uncovered several outcrops contain gravels embedded in well-developed soil layers. The rounded meta-sandstone gravels are clearly beach-origin and were brought to their current location upon extreme wave events, which is composed of either volcanic-clastic deposits from nearby hills or organic soil layers formed locally. Our investigation indicates that there are at least 3 events in the northern half of eastern Taiwan and at least 2 events in southern part of eastern Taiwan. Although these outcrops are next to the shoreline and Taiwan is susceptible from typhoons, these gravels could be farther away from the beach at the time of their deposition due to current high retreat rate of the sea cliff. Further investigations are needed to delineate possible sources of tsunamis that caused the deposits.

  13. Hemispheric lateralization of motor thresholds in relation to stuttering.

    Directory of Open Access Journals (Sweden)

    Per A Alm

    Full Text Available Stuttering is a complex speech disorder. Previous studies indicate a tendency towards elevated motor threshold for the left hemisphere, as measured using transcranial magnetic stimulation (TMS. This may reflect a monohemispheric motor system impairment. The purpose of the study was to investigate the relative side-to-side difference (asymmetry and the absolute levels of motor threshold for the hand area, using TMS in adults who stutter (n = 15 and in controls (n = 15. In accordance with the hypothesis, the groups differed significantly regarding the relative side-to-side difference of finger motor threshold (p = 0.0026, with the stuttering group showing higher motor threshold of the left hemisphere in relation to the right. Also the absolute level of the finger motor threshold for the left hemisphere differed between the groups (p = 0.049. The obtained results, together with previous investigations, provide support for the hypothesis that stuttering tends to be related to left hemisphere motor impairment, and possibly to a dysfunctional state of bilateral speech motor control.

  14. Hemispheric Differences in the Recruitment of Semantic Processing Mechanisms

    Science.gov (United States)

    Kandhadai, Padmapriya; Federmeier, Kara D.

    2010-01-01

    This study examined how the two cerebral hemispheres recruit semantic processing mechanisms by combining event-related potential measures and visual half-field methods in a word priming paradigm in which semantic strength and predictability were manipulated using lexically associated word pairs. Activation patterns on the late positive complex…

  15. Design of a Quasi-Hemispherical UWB Antenna

    DEFF Research Database (Denmark)

    Zhekov, Stanislav Stefanov; Tatomirescu, Alexandru; Franek, Ondrej;

    2016-01-01

    This paper proposes a design of three-dimensional antenna for ultrawideband applications. The antenna has dimensions of 58 mm x 58 mm x 76.5 mm and is composed of two identical arms. Each arm consists of a hollow quasi-hemisphere and an inner for it tube. In the simulation, a 50 Ω coaxial cable...

  16. Reading the Wrong Way with the Right Hemisphere

    Directory of Open Access Journals (Sweden)

    Ian J. Kirk

    2013-07-01

    Full Text Available Reading is a complex process, drawing on a variety of brain functions in order to link symbols to words and concepts. The three major brain areas linked to reading and phonological analysis include the left temporoparietal region, the left occipitotemporal region and the inferior frontal gyrus. Decreased activation of the left posterior language system in dyslexia is well documented but there is relatively limited attention given to the role of the right hemisphere. The current study investigated differences in right and left hemisphere activation between individuals with dyslexia and non-impaired readers in lexical decision tasks (regular words, irregular words, pseudowords during functional Magnetic Resonance Imaging (fMRI. Results revealed the expected hypo-activation in the left posterior areas in those with dyslexia but also areas of overactivation in the right hemisphere. During pseudoword decisions, for example, adults with dyslexia showed more right inferior occipital gyrus activation than controls. In general the increased activation of left-hemisphere language areas found in response to both regular and pseudowords was absent in dyslexics. Laterality indices showed that while controls showed left lateralised activation of the temporal lobe during lexical decision making, dyslexic readers showed right activation. Findings will inform theories of reading and will have implications for the design of reading interventions.

  17. Secular variation of hemispheric phase differences in the solar cycle

    CERN Document Server

    Zolotova, N V; Arlt, R; Tuominen, I

    2010-01-01

    We investigate the phase difference of the sunspot cycles in the two hemispheres and compare it with the latitudinal sunspot distribution. If the north-south phase difference exhibits a long-term tendency, it should not be regarded as a stochastic phenomenon. We use datasets of historical sunspot records and drawings made by Staudacher, Hamilton, Gimingham, Carrington, Spouml;rer, and Greenwich observers, as well as the sunspot activity during the Maunder minimum reconstructed by Ribes and Nesme-Ribes. We employ cross-recurrence plots to analyse north-south phase differences. We show that during the last 300 years, the persistence of phase-leading in one of the hemispheres exhibits a secular variation. Changes from one hemisphere to the other leading in phase were registered near 1928 and 1968 as well as two historical ones near 1783 and 1875. A long-term anticorrelation between the hemispheric phase differences in the sunspot cycles and the latitudinal distribution of sunspots was traced since 1750.

  18. Hemispheric Lateralization of Motor Thresholds in Relation to Stuttering

    Science.gov (United States)

    Alm, Per A.; Karlsson, Ragnhild; Sundberg, Madeleine; Axelson, Hans W.

    2013-01-01

    Stuttering is a complex speech disorder. Previous studies indicate a tendency towards elevated motor threshold for the left hemisphere, as measured using transcranial magnetic stimulation (TMS). This may reflect a monohemispheric motor system impairment. The purpose of the study was to investigate the relative side-to-side difference (asymmetry) and the absolute levels of motor threshold for the hand area, using TMS in adults who stutter (n = 15) and in controls (n = 15). In accordance with the hypothesis, the groups differed significantly regarding the relative side-to-side difference of finger motor threshold (p = 0.0026), with the stuttering group showing higher motor threshold of the left hemisphere in relation to the right. Also the absolute level of the finger motor threshold for the left hemisphere differed between the groups (p = 0.049). The obtained results, together with previous investigations, provide support for the hypothesis that stuttering tends to be related to left hemisphere motor impairment, and possibly to a dysfunctional state of bilateral speech motor control. PMID:24146930

  19. Equatorial ionospheric electrodynamic perturbations during Southern Hemisphere stratospheric warming events

    DEFF Research Database (Denmark)

    Olson, M. E.; Fejer, B. G.; Stolle, Claudia;

    2013-01-01

    We use ground-based and satellite measurements to examine, for the first time, the characteristics of equatorial electrodynamic perturbations measured during the 2002 major and 2010 minor Southern Hemisphere sudden stratospheric warming (SSW) events. Our data suggest the occurrence of enhanced qu...

  20. Ecology of beech forests in the northern hemisphere.

    NARCIS (Netherlands)

    Peters, R.

    1992-01-01

    Beech forests are dominated or codominated by at least one Fagus species. The beeches are a homogeneous group of 11 deciduous tree species growing in the Northern Hemisphere (Figure 1.1). They often dominate forest ecosystems throughout their ranges. The optimum for beech is on acidic and mesic loam

  1. Anosognosia in patients with acute hemispheric ischemic stroke

    Directory of Open Access Journals (Sweden)

    V. N. Grigoryeva

    2016-01-01

    Full Text Available Objective: to investigate the frequency of anosognosia (a deficit of self-awareness, its anatomic correlates associated with other neuropsychological and neurological disorders in acute hemispheric ischemic stroke (IS.Patients and methods 150 patients (83 men and 67 women; mean age, 63.0±9.3 years with acute hemispheric IS were examined. All the patients underwent neurological, neuroimaging, and neuropsychological (by the procedure described by A.R. Luria examinations. neuropsychological investigations. Anosognosia was diagnosed using the Dysexecutive Questionnaire (DEX and the authors' procedure involving a scale to measure impaired self-rating of motor abilities and a scale to measure impaired self-rating of cognitive abilities in everyday life.Results and discussion. In the acute period of hemispheric IS, reduced self-awareness of motor and cognitive abilities was noted in 14% of the patients and unawareness of only cognitive abilities was recorded in 15%. Patients with anosognosia and cognitive dysfunction (ACD and those with anosognosia and motor dysfunction (AMD had right-sided hemispheric IS more frequently (76% while this was not found in patients with isolated ACD. The development of anosognosia for paralysis and paresis was favored by the large sizes of an ischemic focus that involved a few lobes in the posterior regions of the brain although no lesions were found in the anosognosia-specific anatomical regions. ACD and AMD proved to be associated with unilateral spatial and tactile neglect and obvious regulatory dysfunction. 

  2. Language, Cognition, and the Right Hemisphere: A Response to Gazzaniga.

    Science.gov (United States)

    Levy, Jerre

    1983-01-01

    Disputes several assumptions made by Gazzaniga in the preceding article, namely: (l) that any capacity to extract meaning from spoken or written words indicates linguistic competence; and (2) that the right hemisphere is passive and nonresponsive and that the limits of its cognitive abilities are manifested in simple matching-to-sample tasks. (GC)

  3. Hemimegalencephaly: a study of abnormalities occurring outside the involved hemisphere.

    Science.gov (United States)

    Sato, N; Yagishita, A; Oba, H; Miki, Y; Nakata, Y; Yamashita, F; Nemoto, K; Sugai, K; Sasaki, M

    2007-04-01

    Hemimegalencephaly is a rare but well-known congenital malformation with ipsilateral enlargement of the hemicerebrum. However, very little is known about changes in structures outside the involved hemisphere in patients with this condition. We investigated morphologic abnormalities occurring outside the affected hemisphere by MR imaging in a large series of patients with hemimegalencephaly. MR imaging findings for 30 patients with hemimegalencephaly were retrospectively reviewed and evaluated for structures outside the involved hemisphere on routine MR images, such as cranial nerves (I, II, V), brain vessels, subdural and subarachnoid spaces, brain stem, and cerebellum, on both the ipsilateral and contralateral sides. The ipsilateral olfactory and optic nerves were enlarged in 8 (26.7%) and 1 (3.3%) of the 30 patients, respectively, without enlargement on the contralateral side. No asymmetry was noted in the trigeminal nerves. Asymmetric vascular dilations in the ipsilateral cerebral hemisphere were observed in 12 of the 30 patients (40%), in deep cerebral vessels in 11 patients (36.7%), and in superficial cerebral vessels in 8 patients (26.7%). Ipsilateral brain stem and hemicerebellar asymmetric enlargement was detected in 2 patients (6.7%) and 14 patients (46.7%), respectively. Abnormal cerebellar folia were observed on the ipsilateral side in 6 patients (20%) and on the contralateral side in 3 patients (10%). Ipsilateral olfactory nerve enlargement, cerebral vascular dilations, cerebellar enlargement, and bilateral or ipsilateral abnormal architecture of the cerebellar folia are often associated with hemimegalencephaly.

  4. Right Hemisphere Dominance for Emotion Processing in Baboons

    Science.gov (United States)

    Wallez, Catherine; Vauclair, Jacques

    2011-01-01

    Asymmetries of emotional facial expressions in humans offer reliable indexes to infer brain lateralization and mostly revealed right hemisphere dominance. Studies concerned with oro-facial asymmetries in nonhuman primates largely showed a left-sided asymmetry in chimpanzees, marmosets and macaques. The presence of asymmetrical oro-facial…

  5. Species boundaries in non-tropical Northern Hemisphere Owls

    NARCIS (Netherlands)

    Voous, K.H.

    1990-01-01

    A survey is presented of the status of species boundaries in nontropical Northern Hemisphere owls in order to investigate the reality of the biological and geographical species concept applied to these owls in current handbooks. At the same time the practicability of evolutionary systematics as oppo

  6. Surgical decompression for space-occupying hemispheric infarction

    NARCIS (Netherlands)

    Hofmeijer, J.

    2007-01-01

    Patients with a hemispheric infarct and massive space-occupying edema formation have a poor prognosis. Mortality rates of about 80% have been described, despite maximal medical therapy on an intensive care unit. The aim of the research presented in this thesis was to investigate the benefit of deco

  7. Simulation of plasma filled hemispherical cavity as dielectric resonator antenna

    Science.gov (United States)

    Trenchev, G.; Kissóvski, Zh

    2016-10-01

    Plasma antennas are becoming an increasingly interesting research topic because of their uncommon characteristics. They are highly configurable, can be turned on and off rapidly, and exhibit lower thermal noise compared to metal antennas. In recent years, research has been conducted on cylindrical plasma columns sustained by DC, RF or microwave field, and their application as leaky wave antennas or as regular monopole antennas. Dielectric resonator antennas (DRA) with high dielectric permittivity are known for their small size and excellent operating characteristics for modern mobile communications (WiMAX, LTE). Hemispherical dielectric resonator antennas are characterized by simple shape, high radiation efficiency and wide bandwidth. Hemispherical DRA with a low density weakly ionized plasma as dielectric material will combine the positive features of plasma and dielectric antennas, and is particularly interesting, as antennas of this type have not been studied yet. The hemispherical plasma antenna is simulated with Ansoft HFSS in the microwave S-band. Obtained radiation pattern and bandwidth show the advantages of hemispherical plasma antennas for future communication technology.

  8. Species boundaries in non-tropical Northern Hemisphere Owls

    NARCIS (Netherlands)

    Voous, K.H.

    1990-01-01

    A survey is presented of the status of species boundaries in nontropical Northern Hemisphere owls in order to investigate the reality of the biological and geographical species concept applied to these owls in current handbooks. At the same time the practicability of evolutionary systematics as

  9. Right Hemispheric Dominance in Processing of Unconscious Negative Emotion

    Science.gov (United States)

    Sato, Wataru; Aoki, Satoshi

    2006-01-01

    Right hemispheric dominance in unconscious emotional processing has been suggested, but remains controversial. This issue was investigated using the subliminal affective priming paradigm combined with unilateral visual presentation in 40 normal subjects. In either left or right visual fields, angry facial expressions, happy facial expressions, or…

  10. Brain Hemispheric Consensus and the Quality of Investment Decisions.

    Science.gov (United States)

    Boyd, Michael

    This on-going study explores the hypothesis that stock fund managers who underperform do so because they make bad decisions, and examines whether their choices can be improved by using a decision model that invokes principles of brain hemispheric consensus. The study, begun in fall 1999, involves two groups of business students: the control group…

  11. Inferencing Processes after Right Hemisphere Brain Damage: Maintenance of Inferences

    Science.gov (United States)

    Blake, Margaret Lehman

    2009-01-01

    Purpose: This study was designed to replicate and extend a previous study of inferencing in which some adults with right hemisphere damage (RHD) generated but did not maintain predictive inferences over time (M. Lehman-Blake & C. Tompkins, 2001). Two hypotheses were tested: (a) inferences were deactivated, and (b) selection of previously generated…

  12. Seasonal vegetation response to climate change in the Northern Hemisphere (1982-2013)

    Science.gov (United States)

    Kong, Dongdong; Zhang, Qiang; Singh, Vijay P.; Shi, Peijun

    2017-01-01

    This study investigated vegetation response to climate change exhibited by temperature, soil moisture, and solar radiation at Northern Hemisphere (NH) scale during the growing season and seasonal periods by analyzing satellite observations of vegetation activity and climatic data for a period of 1982-2013. Generally, About 75.8% of NH was dominated by increasing NDVI3g during growing season in 1982-2013, and 50.7% significantly increase. Autumn NDVI3g is the main cause, with 77.7% increase (45.0% significantly increase). The increasing tendency of greenness was stalled and even shifted to vegetation browning after 1994-1997 specifically in Central Europe, Northern North America, and Central Siberia. NDVI3g increase during the growing season shifts from 0.017 year- 1 to 0.006 year- 1, which mainly due to decreased spring NDVI3g and slowdown of summer NDVI3g increase. Specifically, three time intervals were identified with relatively peak NDVI3g, i.e., 1990, 1997 and 2010, and three time intervals with trough NDVI3g, i.e., 1983, 1992-1994, 2002-2005. The factors potentially influencing vegetation growth in different parts of NH are complex and varied. Temperature is recognized as the critical factor behind vegetation greenness in high latitudes especially for spring and autumn temperature, in North America and Siberia. Soil moisture is the key factor influencing vegetation growth in central Canada, eastern USA and western Africa. And solar radiation is corresponding to vegetation trend in North part of North America, eastern China. This study helps identify key factors for vegetation changes and understand vegetation response to climate change at NH scale.

  13. Tracks of Major Hurricanes of the Western Hemisphere

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This 36"x24" National Hurricane Center poster depicts the complete tracks of all major hurricanes in the north Atlantic and eastern north Pacific basins since as...

  14. Satellite Global and Hemispheric Lower Tropospheric Temperature Annual Temperature Cycle

    Directory of Open Access Journals (Sweden)

    Michael A. Brunke

    2010-11-01

    Full Text Available Previous analyses of the Earth’s annual cycle and its trends have utilized surface temperature data sets. Here we introduce a new analysis of the global and hemispheric annual cycle using a satellite remote sensing derived data set during the period 1979–2009, as determined from the lower tropospheric (LT channel of the MSU satellite. While the surface annual cycle is tied directly to the heating and cooling of the land areas, the tropospheric annual cycle involves additionally the gain or loss of heat between the surface and atmosphere. The peak in the global tropospheric temperature in the 30 year period occurs on 10 July and the minimum on 9 February in response to the larger land mass in the Northern Hemisphere. The actual dates of the hemispheric maxima and minima are a complex function of many variables which can change from year to year thereby altering these dates.Here we examine the time of occurrence of the global and hemispheric maxima and minima lower tropospheric temperatures, the values of the annual maxima and minima, and the slopes and significance of the changes in these metrics.  The statistically significant trends are all relatively small. The values of the global annual maximum and minimum showed a small, but significant trend. Northern and Southern Hemisphere maxima and minima show a slight trend toward occurring later in the year. Most recent analyses of trends in the global annual cycle using observed surface data have indicated a trend toward earlier maxima and minima.

  15. Right hemispatial ipsilesional neglect with chronic right hemisphere strokes.

    Science.gov (United States)

    Williamson, John B; Lamb, Damon G; Burtis, D Brandon; Haque, Salsabil; Zilli, Eduardo M; Kesayan, Tigran; Harciarek, Michal; Heilman, Kenneth M

    2017-08-16

    Patients who present with spatial neglect after stroke often perform normally on tests for neglect after a few weeks. Whereas tests for neglect are often performed directly in front of a patient, in their actual environments many important stimuli may be present within their left or right hemispace. The presence and severity of neglect often depends on the hemisphere injured. It is possible, in chronic stroke, for spatial judgments to be influenced by an interaction of stroke laterality and the spatial location of stimuli. The objective of this study was to learn if unilateral hemispheric chronic strokes contribute to a spatial bias with laterally presented stimuli. There were 70 participants, 62 with unilateral chronic strokes (>6 months post onset) including 35 with left hemisphere damage (LHD), 27 with right hemisphere damage (RHD), and 8 demographically similar people without history of stroke. Participants were asked to bisect 300 lines presented with distractors on the left, right, or both sides of the line, or no distractor, on a touch-screen monitor in right, center or left hemispace. There was a significant interaction between the side of the hemispheric lesion and the side of the body where these lines were presented. Specifically, in right space, patients with RHD deviated leftward in comparison to the other groups. Furthermore, there was an interaction between group and distractor induced bias. All three groups approached the left distractor, and the patients with LHD also approached the right distractor. Although spatial neglect is more severe in contralesional than ipsilesional hemispace in the period immediately following a stroke, over time patients with RHD may develop ipsilesional neglect that is more severe in ipsilesional than contralesional space. The mechanism underlying this bias is not known and may be related to attempted compensation or the development of a contralateral attentional/intentional grasp.

  16. Methods of dichotic listening as a research methodology for hemispheric interaction.

    Directory of Open Access Journals (Sweden)

    Kovyazina M.S.

    2014-07-01

    Full Text Available Experimental data was obtained from a dichotic listening test by patients with unilateral brain lesions and corpus callosum pathology (agenesis, cysts, degenerative changes, etc. Efficiency index analysis shows that interhemispheric interaction in the audioverbal sphere depends to a greater extent on the right hemisphere state. The dichotic listening technique is not an informative means of studying hemispheric interaction, since it does not allow a clear distinction between hemispheric symptoms and symptoms of pathology of the corpus callosum. Thus, violations of hemispheric relations caused by disorders of the corpus callosum and cerebral hemispheres change worth more right hemisphere activity.

  17. Role of inter-hemispheric transfer in generating visual evoked potentials in V1-damaged brain hemispheres.

    Science.gov (United States)

    Kavcic, Voyko; Triplett, Regina L; Das, Anasuya; Martin, Tim; Huxlin, Krystel R

    2015-02-01

    Partial cortical blindness is a visual deficit caused by unilateral damage to the primary visual cortex, a condition previously considered beyond hopes of rehabilitation. However, recent data demonstrate that patients may recover both simple and global motion discrimination following intensive training in their blind field. The present experiments characterized motion-induced neural activity of cortically blind (CB) subjects prior to the onset of visual rehabilitation. This was done to provide information about visual processing capabilities available to mediate training-induced visual improvements. Visual Evoked Potentials (VEPs) were recorded from two experimental groups consisting of 9 CB subjects and 9 age-matched, visually-intact controls. VEPs were collected following lateralized stimulus presentation to each of the 4 visual field quadrants. VEP waveforms were examined for both stimulus-onset (SO) and motion-onset (MO) related components in postero-lateral electrodes. While stimulus presentation to intact regions of the visual field elicited normal SO-P1, SO-N1, SO-P2 and MO-N2 amplitudes and latencies in contralateral brain regions of CB subjects, these components were not observed contralateral to stimulus presentation in blind quadrants of the visual field. In damaged brain hemispheres, SO-VEPs were only recorded following stimulus presentation to intact visual field quadrants, via inter-hemispheric transfer. MO-VEPs were only recorded from damaged left brain hemispheres, possibly reflecting a native left/right asymmetry in inter-hemispheric connections. The present findings suggest that damaged brain hemispheres contain areas capable of responding to visual stimulation. However, in the absence of training or rehabilitation, these areas only generate detectable VEPs in response to stimulation of the intact hemifield of vision.

  18. The left hemisphere learns what is right: Hemispatial reward learning depends on reinforcement learning processes in the contralateral hemisphere.

    Science.gov (United States)

    Aberg, Kristoffer Carl; Doell, Kimberly Crystal; Schwartz, Sophie

    2016-08-01

    Orienting biases refer to consistent, trait-like direction of attention or locomotion toward one side of space. Recent studies suggest that such hemispatial biases may determine how well people memorize information presented in the left or right hemifield. Moreover, lesion studies indicate that learning rewarded stimuli in one hemispace depends on the integrity of the contralateral striatum. However, the exact neural and computational mechanisms underlying the influence of individual orienting biases on reward learning remain unclear. Because reward-based behavioural adaptation depends on the dopaminergic system and prediction error (PE) encoding in the ventral striatum, we hypothesized that hemispheric asymmetries in dopamine (DA) function may determine individual spatial biases in reward learning. To test this prediction, we acquired fMRI in 33 healthy human participants while they performed a lateralized reward task. Learning differences between hemispaces were assessed by presenting stimuli, assigned to different reward probabilities, to the left or right of central fixation, i.e. presented in the left or right visual hemifield. Hemispheric differences in DA function were estimated through differential fMRI responses to positive vs. negative feedback in the left vs. right ventral striatum, and a computational approach was used to identify the neural correlates of PEs. Our results show that spatial biases favoring reward learning in the right (vs. left) hemifield were associated with increased reward responses in the left hemisphere and relatively better neural encoding of PEs for stimuli presented in the right (vs. left) hemifield. These findings demonstrate that trait-like spatial biases implicate hemisphere-specific learning mechanisms, with individual differences between hemispheres contributing to reinforcing spatial biases.

  19. Decadal variation of the Northern Hemisphere Annular Mode and its influence on the East Asian trough

    Science.gov (United States)

    Lu, Chunhui; Zhou, Botao; Ding, Yihui

    2016-06-01

    We analyze the decadal variation of the stratosphere-troposphere coupled system around the year 2000 by using the NCEP reanalysis-2 data. Specifically, the relationship between the Northern Hemisphere Annular Mode (NAM) and the tropospheric East Asian trough is investigated in order to find the effective stratospheric signals during cold air outbreaks in China. Statistical analyses and dynamic diagnoses both indicate that after 2000, increased stratospheric polar vortex disturbances occur and the NAM is mainly in negative phase. The tropospheric polar areas are directly affected by the polar vortex, and in the midlatitudes, the Ural blocking high and East Asian trough are more active, which lead to enhanced cold air activities in eastern and northern China. Further investigation reveals that under this circulation pattern, downward propagations of negative NAM index are closely related to the intensity variation of the East Asian trough. When negative NAM anomalies propagate down to the upper troposphere and reach a certain intensity (standardized NAM index less than-1), they result in apparent reinforcement of the East Asian trough, which reaches its maximum intensity about one week later. The northerly wind behind the trough transports cold air southward and eastward, and the range of influence and the intensity are closely associated with the trough location. Therefore, the NAM index can be used as a measure of the signals from the disturbed stratosphere to give some indication of cold air activities in China.

  20. Statistical characteristics of the double ridges of subtropical high in the Northern Hemisphere

    Institute of Scientific and Technical Information of China (English)

    ZHAN Ruifen; LI Jianping; HE Jinhai

    2005-01-01

    The generality and some climatological characteristics of the double ridge systems of subtropical high (SH) are investigated statistically by using the daily NCEP/NCAR reanalysis data from 1958 to 1998. The results show that the SH double-ridge event is a common phenomenon in the Northern Hemisphere, with the distinct seasonal and regional features, that is, the majority of SH double-ridge geneses concentrate over the eastern North India Ocean- western North Pacific as well as the central North Pacific in the period from mid-July to mid-September. Especially over the western North Pacific subtropics, the SH double-ridge events are extremely active. It is found that the life cycle of most double-ridge events of western Pacific subtropical high (WPSH) is shorter but some still last longer. The WPSH double-ridge events occur most frequently from July to September, while there is a paucity of occurrences during November-March. Also, it is shown that the WPSH double-ridge events have a strong interannual variation with a certain periodicity which possesses a remarkably abrupt change in the mid-1970s. Additionally, the relationship between the WPSH double ridges and the meridional movement of WPSH is discussed.

  1. Covarying modes of the Pacific SST and northern hemispheric midlatitude atmospheric circulation anomalies during winter

    Institute of Scientific and Technical Information of China (English)

    Yimin Zhu; Xiuqun Yang; Qian Xie; Yongqiang Yu

    2008-01-01

    The interannual-to-interdecadal relationship between the Pacific sea surface temperature (SST) and the northern hemispheric midlatitude's atmosphere represented by the circumpolar vortex was documented with the global oceanic and atmospheric reanalysis data of recent 50 years.Two covarying modes of the Pacific SST and northern circumpolar vortex anomalies during winter were examined using the singular value decomposition and wavelet analysis techniques.One is the interannual,ENSO-related mode and the other is the interdecadal,North Pacific SST-related mode with a period of around 20 years.The two modes exhibit distinct spatial structures.For the interannual mode,the SST anomaly is characterized by a typical ENSO pattern with the principal signature in the tropical eastern Pacific and secondary one in the central North Pacific,while the atmospheric anomaly is regional,characterized by a Pacific-North American pattern.For the interdecadal mode,large SST anomaly is located in the central North Pacific,while the atmospheric anomaly is zonally global,associated with the midlatitute's standing long-wave variations.When the central North Pacific is colder,the long-wave is stronger,and vice versa.Further investigations suggest that the interdecadal mode could involve an interaction between "two oceans and an atmosphere".

  2. Relationship of Arctic sea ice and Northern Hemispheric 500 hPa Polar vortices

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Using the NCEP/NCAR reanalysis monthly 500 hPa height data on a 2.5 latitude-longitude grid and 1°×1° sea ice data, the polar vortex area, intensity index and arctic sea ice area index are calculated respectively, and the meridional distribution, period variation and the abrupts in the long range trend are analyzed to study their relationship. The results show that the meridional distribution of sea ice and polar vortex h-ave distinctive difference, the relative positions of them are different in the eastern and western hemispheres, and exept they have periods of 4 months, quasi half year, quasi year, 4-5 years and 10 years commonly, and each of them has its own respective variation as well. The sea ice area is decreasing apparently since 1980's, so is the polar vortex area, but their abrupt changge time are different totally. The area of sea ice and polar vortex has prominent positive correlation, but the relationship of sea ice intensity, polar vortex intensity, polar vortex area is complicated.

  3. Regional Wave Climates along Eastern Boundary Currents

    Science.gov (United States)

    Semedo, Alvaro; Soares, Pedro

    2016-04-01

    Two types of wind-generated gravity waves coexist at the ocean surface: wind sea and swell. Wind sea waves are waves under growing process. These young growing waves receive energy from the overlaying wind and are strongly coupled to the local wind field. Waves that propagate away from their generation area and no longer receive energy input from the local wind are called swell. Swell waves can travel long distances across entire ocean basins. A qualitative study of the ocean waves from a locally vs. remotely generation perspective is important, since the air sea interaction processes is strongly modulated by waves and vary accordingly to the prevalence of wind sea or swell waves in the area. A detailed climatology of wind sea and swell waves along eastern boundary currents (EBC; California Current, Canary Current, in the Northern Hemisphere, and Humboldt Current, Benguela Current, and Western Australia Current, in the Southern Hemisphere), based on the ECMWF (European Centre for Medium-Range Weather Forecasts) ERA-Interim reanalysis will be presented. The wind regime along EBC varies significantly from winter to summer. The high summer wind speeds along EBC generate higher locally generated wind sea waves, whereas lower winter wind speeds in these areas, along with stronger winter extratropical storms far away, lead to a predominance of swell waves there. In summer, the coast parallel winds also interact with coastal headlands, increasing the wind speed through a process called "expansion fan", which leads to an increase in the height of locally generated waves downwind of capes and points. Hence the spatial patterns of the wind sea or swell regional wave fields are shown to be different from the open ocean along EBC, due to coastal geometry and fetch dimensions. Swell waves will be shown to be considerably more prevalent and to carry more energy in winter along EBC, while in summer locally generated wind sea waves are either more comparable to swell waves or

  4. Catalog of strong motion stations in Eastern North America

    Science.gov (United States)

    Busby, R. W.

    1990-04-01

    The catalog contains information on all strong motion stations operating in Eastern North America known to the National Center for Earthquake Engineering Research (NCEER). The location, coordinates, installation dates, type of instrument, operator, structure type and size, and site geology are listed for each station. The format of the catalog is patterned after the United States Geological Survey (USGS) Open-File Report 81-664, 'Western Hemisphere Strong-Motion Accelerograph Station List-1980' but the entries have been updated as of January 1990. There are 237 stations listed in the catalog which include 414 recording instruments. One third of these stations are intended to record free-field ground motion while the rest are associated with large engineered structures. The relationship of station location to seismicity is shown in a series of figures and a method is described to predict peak acceleration levels from an earthquake where the magnitude and distance to station are known.

  5. Contralesional motor deficits after unilateral stroke reflect hemisphere-specific control mechanisms

    OpenAIRE

    Mani, Saandeep; Mutha, Pratik K.; Przybyla, Andrzej; Haaland, Kathleen Y.; Good, David C.; Sainburg, Robert L.

    2013-01-01

    We have proposed a model of motor lateralization, in which the left and right hemispheres are specialized for different aspects of motor control: the left hemisphere for predicting and accounting for limb dynamics and the right hemisphere for stabilizing limb position through impedance control mechanisms. Our previous studies, demonstrating different motor deficits in the ipsilesional arm of stroke patients with left or right hemisphere damage, provided a critical test of our model. However, ...

  6. Cerebral and callosal organisation in a right hemisphere dominant "split brain" patient.

    OpenAIRE

    Lutsep, H.L.; Wessinger, C M; Gazzaniga, M S

    1995-01-01

    Patients described in previous reports who have undergone corpus callostomy for control of seizures have been left hemisphere dominant for language. To determine the hemispheric localisation (and possible coexistence) of language and traditional right hemisphere skills in reversed dominance, the first right hemisphere dominant corpus callostomy patient was studied. Localisation of callosal functions was also investigated, as MRI showed 1.5 cm of spared callosal body. The patient, KO, a 15 yea...

  7. ANTARES and other Neutrino Telescopes in the Northern Hemisphere

    CERN Document Server

    Kouchner, Antoine

    2009-01-01

    Several projects are concentrating their efforts on opening the high energy neutrino window on the Universe with km-scale detectors. The detection principle relies on the observation, using photomultipliers, of the Cherenkov light emitted by charged leptons induced by neutrino interactions in the surrounding detector medium. In the Northern hemisphere, while the pioneering Baikal telescope, has been operating for 10 years, most of the activity now concentrates in the Mediterranean sea. Recently, the Antares collaboration has completed the construction of a 12 line array comprising ~ 900 photomultipliers. In this paper we will review the main results achieved with the detectors currently in operation in the Northern hemisphere, as well as the R&D efforts towards the construction of a large volume neutrino telescope in the Mediterranean.

  8. Hemispherical Parker waves driven by thermal shear in planetary dynamos

    CERN Document Server

    Dietrich, Wieland; Wicht, Johannes

    2014-01-01

    Planetary and stellar magnetic fields are thought to be sustained by helical motions ($\\alpha$-effect) and, if present, differential rotation ($\\Omega$-effect). In the Sun, the strong differential rotation in the tachocline is responsible for an efficient $\\Omega$-effect creating a strong axisymmetric azimuthal magnetic field. This is a prerequisite for Parker dynamo waves that may be responsible for the solar cycle. In the liquid iron cores of terrestrial planets, the Coriolis force organizes convection into columns with a strong helical flow component. These likely dominate magnetic field generation while the $\\Omega$-effect is of secondary importance. Here we use numerical simulations to show that the planetary dynamo scenario may change when the heat flux through the outer boundary is higher in one hemisphere than in the other. A hemispherical dynamo is promoted that is dominated by fierce thermal wind responsible for a strong $\\Omega$-effect. As a consequence Parker dynamo waves are excited equivalent to...

  9. Lateralized Difference in Tympanic Membrane Temperature: Emotion and Hemispheric Activity

    Directory of Open Access Journals (Sweden)

    Ruth E Propper

    2013-03-01

    Full Text Available We review literature examining relationships between tympanic membrane temperature (TMT, affective/motivational orientation, and hemispheric activity. Lateralized differences in TMT might enable real-time monitoring of hemispheric activity in real-world conditions, and could serve as a corroborating marker of mental illnesses associated with specific affective dysregulation. We support the proposal that TMT holds potential for broadly indexing lateralized brain physiology during tasks demanding the processing and representation of emotional and/or motivational states, and for predicting trait-related affective/motivational orientations. The precise nature of the relationship between TMT and brain physiology, however, remains elusive. Indeed the limited extant research has sampled different participant populations and employed largely different procedures and measures, making for seemingly discrepant findings and implications. We propose, however, that many of these discrepancies can be resolved by considering how emotional states map onto motivational systems, and further examining how validated methods for inducing lateralized brain activity might affect TMT.

  10. Direction dependence of cosmological parameters due to cosmic hemispherical asymmetry

    CERN Document Server

    Mukherjee, Suvodip; Das, Santanu; Shaikh, Shabbir; Souradeep, Tarun

    2015-01-01

    Persistent evidence for a cosmic hemispherical asymmetry in the temperature field of cosmic microwave background (CMB) as observed by both WMAP as well as Planck increases the possibility of its cosmological origin. Presence of this signal may lead to different values for the standard model cosmological parameters in different directions, and that can have significant implications for other studies where they are used. We investigate the effect of this cosmic hemispherical asymmetry on cosmological parameters using non-isotropic Gaussian random simulations injected with both scale dependent and scale independent modulation strengths. Our analysis shows that the parameters $A_s$ and $n_s$ are the most susceptible to variation in the sky for the kind of isotropy breaking phenomena under study. As expected, we find maximum variation arises for the case of scale independent modulation of CMB anisotropies. A deviation of $2.25\\sigma$ in $A_s$ is observed for scale dependent modulation case in comparison to its est...

  11. Chorus from Two Brain Hemispheres with Chinese Pentatonic Scale

    Institute of Scientific and Technical Information of China (English)

    WU Dan; YAO De-zhong

    2014-01-01

    In order to listen to brain activity as a piece of music, we proposed a scale-free brainwave music (SFBM) technology, which translates the scalp EEG into music notes according to the power law of both EEG and music. In this paper, the methodology was further extended to chorus music of two channels from the two hemispheres. Firstly, EEG data from two channels symmetrically located on the left and right hemispheres are translated into MIDI sequences by SFBM, respectively, where the EEG parameters modulate the pitch, duration and volume of each music note. Then, the two sequences are fiitered into a chorus of the Chinese pentatonic scale or the Western major scale. The resulted Chinese and Western music at different sleep stages illustrate distinct differences in harmony, and the music with Chinese pentatonic scale sounds more harmonious.

  12. Developmental dyslexia: dysfunction of a left hemisphere reading network

    Directory of Open Access Journals (Sweden)

    Fabio eRichlan

    2012-05-01

    Full Text Available This mini-review summarizes and integrates findings from recent meta-analyses and original neuroimaging studies on functional brain abnormalities in dyslexic readers. Surprisingly, there is little empirical support for the standard neuroanatomical model of developmental dyslexia, which localizes the primary phonological decoding deficit in left temporo-parietal regions. Rather, recent evidence points to a dysfunction of a left hemisphere reading network, which includes occipito-temporal, inferior frontal, and inferior parietal regions.

  13. Atmospheric circulation in northern hemisphere and north atlantic oscillation

    Directory of Open Access Journals (Sweden)

    Александр Вадимович Холопцев

    2015-08-01

    Full Text Available Conditions under which statistical connections of interannual changes of repitition duration periods in Northern hemisphere of elementary circulation mechanisms associated to meridional northern and meridional southern groups with variations of North Atlantic oscillation are significant were revealed. It is shown, that the characteristics changes of these connections taking place in modern period can be caused by distribution changes of distribution of sea surface temperatures

  14. Critical heat removal rate through a hemispherical narrow gap

    Energy Technology Data Exchange (ETDEWEB)

    Park, R.J.; Ha, K.S.; Kang, K.H.; Kim, S.B.; Kim, H.D. [Severe Accident Research Project, Korea Atomic Energy Research Institute Yusong, P.O. Box 105, Daejeon (Korea); Jeong, J.H. [Chonan College of Foreign Studies, An-seo-Wong 150, Chun-an (Korea)

    2003-02-01

    An experimental study has been performed to investigate boiling mechanism and to estimate critical heat removal rate from a critical power through a hemispherical narrow gap using distilled water and Freon R-113. The distilled water data on the critical heat removal rate were compared with the R-113 data. The experimental results on the critical heat removal rate were also compared with the existing correlations, developed in flat plate, annuli, and spherical gaps. The test results have shown that a CCFL (Counter Current Flow Limitation) brings about local dryout and finally global dryout in the hemispherical gap thickness of 0.5, 1.0, and 2.0 mm. The boiling mechanism in a hemispherical gap thickness of 5.0 mm is the combination of the CCFL and the pool boiling condition. An increase in gap thickness of 10.0 mm leads to the pool boiling condition rather than the CCFL. Increases in the gap thickness and pressure lead to increase in critical heat removal rate, but the pressure effect on the critical heat removal rate was found to be much milder than the predictions by flat plate and annuli gaps. The measured critical heat removal rate using the R-113 in hemispherical narrow gap thickness of 1.0 and 2.0 mm are 51.5%, 44.5% lower than that using the distilled water due to the lower boiling point and the bubble size, which is different from the pool boiling condition of approximately 14.8%. The measured critical heat removal rate using the R-113 in a gap thickness of 5 mm is 21.6% lower than that using distilled water, which approaches to the pool boiling condition. (orig.)

  15. Right-hemisphere (spatial?) acalculia and the influence of neglect

    OpenAIRE

    Silvia eBenavides-Varela; Marco ePitteri; Konstantinos ePriftis; Laura ePassarini; Francesca eMeneghello; Carlo eSemenza

    2014-01-01

    The present study aimed at exploring basic number and calculation abilities in right-hemisphere damaged patients (RHD), focusing primarily on one-digit orally presented tasks, which do not require explicit visuo-spatial abilities. Twenty-four non mentally-deteriorated RHD patients [12 with clinical neglect (RHDN+), 12 without clinical neglect (RHDN−)], and 12 healthy controls were included in the study. Participants were administered an ad hoc numerical battery assessing abilities such as cou...

  16. Predicting North American Scolytinae invasions in the Southern Hemisphere.

    Science.gov (United States)

    Lantschner, Maria Victoria; Atkinson, Thomas H; Corley, Juan C; Liebhold, Andrew M

    2017-01-01

    Scolytinae species are recognized as one of the most important tree mortality agents in coniferous forests worldwide, and many are known invaders because they are easily transported in wood products. Nonnative trees planted in novel habitats often exhibit exceptional growth, in part because they escape herbivore (such as Scolytinae) pressure from their native range. Increasing accidental introductions of forest pest species as a consequence of international trade, however, is expected to diminish enemy release of nonnative forest trees. In this context, there is need to characterize patterns of forest herbivore species invasion risks at global scales. In this study, we analyze the establishment potential of 64 North American Scolytinae species in the Southern Hemisphere. We use climate-based ecological niche models (MaxEnt) to spatially define the potential distribution of these Scolytinae species in regions of the Southern Hemisphere were pines are planted. Our model predicts that all of the pine-growing regions of the Southern Hemisphere are capable of supporting some species of North American Scolytinae, but there are certain "hotspot" regions, southeastern Argentina, Bolivia, Chile, Peru and southwestern Australia, that appear to be suitable for a particularly large number of species. The species with the highest predicted risk of establishment were Dendroctonus valens, Xyleborus intrusus, Hylastes tenuis, Ips grandicollis, Gnathotrichus sulcatus, and Ips calligraphus. Given that global commerce is anticipated to continue to increase, we can expect that more Scolytinae species will continue to establish outside their range. Our results provide information useful for identifying a global list of potential invasive species in pine plantations, and may assist in the design of comprehensive strategies aimed at reducing pest establishment in Southern Hemisphere forest plantations. © 2016 by the Ecological Society of America.

  17. The Representation of Discourse in the Two Hemispheres: An Individual Differences Investigation

    Science.gov (United States)

    Prat, Chantel S.; Long, Debra L.; Baynes, Kathleen

    2007-01-01

    Two experiments were conducted to investigate discourse representation in the two cerebral hemispheres as a function of reading skill. We used a lateralized visual-field procedure to compare left hemisphere (LH) and right hemisphere (RH) sensitivity to different discourse relations in readers with varying skill levels. In Experiment 1, we…

  18. Association between Therapy Outcome and Right-Hemispheric Activation in Chronic Aphasia

    Science.gov (United States)

    Richter, Maria; Miltner, Wolfgang H. R.; Straube, Thomas

    2008-01-01

    The role of the right hemisphere for language processing and successful therapeutic interventions in aphasic patients is a matter of debate. This study explored brain activation in right-hemispheric areas and left-hemispheric perilesional areas in response to language tasks in chronic non-fluent aphasic patients before and after constraint-induced…

  19. A Response to Gazzaniga: Language in the Right Hemisphere, Convergent Perspectives.

    Science.gov (United States)

    Zaidel, Eran

    1983-01-01

    Gazzaniga argues that without language right hemisphere cognition is vastly limited and that most normal right hemispheres have no language and only "rudimentary cognition." These assertion ignore important nonlinguistic observations, as well as findings with hemispheric sodium amytal anesthesia and laterality effects for complex cognitive tasks…

  20. Changes in meandering of the Northern Hemisphere circulation

    Science.gov (United States)

    Di Capua, Giorgia; Coumou, Dim

    2016-09-01

    Strong waves in the mid-latitude circulation have been linked to extreme surface weather and thus changes in waviness could have serious consequences for society. Several theories have been proposed which could alter waviness, including tropical sea surface temperature anomalies or rapid climate change in the Arctic. However, so far it remains unclear whether any changes in waviness have actually occurred. Here we propose a novel meandering index which captures the maximum waviness in geopotential height contours at any given day, using all information of the full spatial position of each contour. Data are analysed on different time scale (from daily to 11 day running means) and both on hemispheric and regional scales. Using quantile regressions, we analyse how seasonal distributions of this index have changed over 1979-2015. The most robust changes are detected for autumn which has seen a pronounced increase in strongly meandering patterns at the hemispheric level as well as over the Eurasian sector. In summer for both the hemisphere and the Eurasian sector, significant downward trends in meandering are detected on daily timescales which is consistent with the recently reported decrease in summer storm track activity. The American sector shows the strongest increase in meandering in the warm season: in particular for 11 day running mean data, indicating enhanced amplitudes of quasi-stationary waves. Our findings have implications for both the occurrence of recent cold spells and persistent heat waves in the mid-latitudes.

  1. Potential Dust Emissions from Sources in the Southern Hemisphere.

    Science.gov (United States)

    Bhattachan, A.; D'Odorico, P.; Okin, G. S.

    2014-12-01

    The Southern Hemisphere currently exhibits low levels of atmospheric dust concentrations relative to the Northern Hemisphere. Recent research suggests that dust concentrations could, however, increase as a result of loss of vegetation cover in the Southern Kalahari and the Mallee. Disturbances resulting from grazing and agriculture are identified as such drivers of land use change in these regions. While studies on the importance of atmospheric dust in global-scale processes are abundant, little has been done to locate the potential dust sources in the Southern Hemisphere because potential new sources are by definition inactive and are undetected in satellite images. To this end, using a combination of laboratory experiments and field observations, we assess that the sediments collected from the dunefields in the Southern Kalahari and Mallee can emit substantial amount of dust, are rich in soluble iron and dust from these sources would reach the Southern Ocean. It is suggested that the supply of soluble iron through atmospheric dust deposition limits the productivity of the Southern Ocean. Thus intensification of land use can potentially make these regions an important source of iron given their proximity to the Southern Ocean. This iron-rich dust could stimulate ocean productivity in future as more areas are reactivated as a result of land-use and droughts.

  2. Learning-related brain hemispheric dominance in sleeping songbirds.

    Science.gov (United States)

    Moorman, Sanne; Gobes, Sharon M H; van de Kamp, Ferdinand C; Zandbergen, Matthijs A; Bolhuis, Johan J

    2015-03-12

    There are striking behavioural and neural parallels between the acquisition of speech in humans and song learning in songbirds. In humans, language-related brain activation is mostly lateralised to the left hemisphere. During language acquisition in humans, brain hemispheric lateralisation develops as language proficiency increases. Sleep is important for the formation of long-term memory, in humans as well as in other animals, including songbirds. Here, we measured neuronal activation (as the expression pattern of the immediate early gene ZENK) during sleep in juvenile zebra finch males that were still learning their songs from a tutor. We found that during sleep, there was learning-dependent lateralisation of spontaneous neuronal activation in the caudomedial nidopallium (NCM), a secondary auditory brain region that is involved in tutor song memory, while there was right hemisphere dominance of neuronal activation in HVC (used as a proper name), a premotor nucleus that is involved in song production and sensorimotor learning. Specifically, in the NCM, birds that imitated their tutors well were left dominant, while poor imitators were right dominant, similar to language-proficiency related lateralisation in humans. Given the avian-human parallels, lateralised neural activation during sleep may also be important for speech and language acquisition in human infants.

  3. Are Karakoram temperatures out of phase compared to hemispheric trends?

    Science.gov (United States)

    Asad, Fayaz; Zhu, Haifeng; Zhang, Hui; Liang, Eryuan; Muhammad, Sher; Farhan, Suhaib Bin; Hussain, Iqtidar; Wazir, Muhammad Atif; Ahmed, Moinuddin; Esper, Jan

    2017-05-01

    In contrast to a global retreating trend, glaciers in the Karakoram showed stability and/or mass gaining during the past decades. This "Karakoram Anomaly" has been assumed to result from an out-of-phase temperature trend compared to hemispheric scales. However, the short instrumental observations from the Karakoram valley bottoms do not support a quantitative assessment of long-term temperature trends in this high mountain area. Here, we presented a new April-July temperature reconstruction from the Karakoram region in northern Pakistan based on a high elevation ( 3600 m a.s.l.) tree-ring chronology covering the past 438 years (AD 1575-2012). The reconstruction passes all statistical calibration and validation tests and represents 49 % of the temperature variance recorded over the 1955-2012 instrumental period. It shows a substantial warming accounting to about 1.12 °C since the mid-twentieth century, and 1.94 °C since the mid-nineteenth century, and agrees well with the Northern Hemisphere temperature reconstructions. These findings provide evidence that the Karakoram temperatures are in-phase, rather than out-of-phase, compared to hemispheric scales since the AD 1575. The synchronous temperature trends imply that the anomalous glacier behavior reported from the Karakoram may need further explanations beyond basic regional thermal anomaly.

  4. Praxial disorders in focal lesions of cerebral hemispheres

    Directory of Open Access Journals (Sweden)

    Jorge Murillo Duran

    2007-11-01

    Full Text Available The purpose of this work is to analyze paraxial difficulties i.e, functional disorders in movementresulting from cerebral tissue lesions. In accordance with the literature on the subject, the following definition, the following definition of apraxia has been accepted: “Apraxia is inability in properly executing kinetic tasks without impairment or loss of motor or sensory functions or ataxia with would condition such inability”. “Proper execution” used in this definition concerns not only the effect of the action but also means of its realization. “Kinetic tasks” signify all aspects of motor activity defined by instructions, irrespective of the type of instruction (verbal or gestures, and regardless of whether it required −in the final effect− imitating the movement of the investigator or whether they were performed independently. The methodology has been based in the principle on Luria’s works.Deliberations on praxial disorders were based on investigation results embracing 90 patients with focal cerebral lesions. In fifty cases, changes were localized in the left cerebral hemisphere, in forty cases−in the right hemisphere. The summing up the results concerning a global comparison between cerebral hemispheres, indicate the following regularities: Results achieved made it possible to form the opinion that not all of the generally accepted tests investigating praxia in persons with cerebral lesions are solved faultlessly by healthy individuals; thus, a faulty execution should not always be regarded as a sign of pathological functioning of the cerebral tissue as a result of lesion.

  5. Theory of mind and pragmatic understanding following right hemisphere damage.

    Science.gov (United States)

    Siegal, M; Carrington, J; Radel, M

    1996-04-01

    It has been maintained that 3-year-olds' difficulties in correctly predicting the undesired outcome of false beliefs reflects difficulties in interpreting the implications of conversations rather than a conceptual limitation in their theory of mind. As the right hemisphere has been seen to be responsible for the interpretation of the pragmatic aspects of communication, right-hemisphere-damaged (RHD) and left-hemisphere-damaged (LHD) adult patients in our study were compared on their ability to correctly draw inferences in false belief tasks. The RHD but not the LHD patients were found to have difficulties similar to those of young children in understanding the conversational implications test questions. Most reported that a central story character would look for a pet in the place where it was really located instead of where the character believed it was located. However, when then asked in a control question where the pet really was, the RHD patients often switched their answer to the test question and referred to the believed location. Removal of the need to infer the questioner's meaning enabled both RHD and LHD subjects to make correct false belief predictions. The results are discussed in terms of the effects of brain damage on spatial memory and the pragmatic demands of theory of mind tasks.

  6. Analytical and Numerical Investigations into Hemisphere-Shaped Electrostatic Sensors

    Directory of Open Access Journals (Sweden)

    Jun Lin

    2014-07-01

    Full Text Available Electrostatic sensors have been widely used in many applications due to their advantages of low cost and robustness. Their spatial sensitivity and time-frequency characteristics are two important performance parameters. In this paper, an analytical model of the induced charge on a novel hemisphere-shaped electrostatic sensor was presented to investigate its accurate sensing characteristics. Firstly a Poisson model was built for electric fields produced by charged particles. Then the spatial sensitivity and time-frequency response functions were directly derived by the Green function. Finally, numerical calculations were done to validate the theoretical results. The results demonstrate that the hemisphere-shaped sensors have highly 3D-symmetrical spatial sensitivity expressed in terms of elementary function, and the spatial sensitivity is higher and less homogeneous near the hemispherical surface and vice versa. Additionally, the whole monitoring system, consisting of an electrostatic probe and a signal conditioner circuit, acts as a band-pass filter. The time-frequency characteristics depend strongly on the spatial position and velocity of the charged particle, the radius of the probe as well as the equivalent resistance and capacitance of the circuit.

  7. Analytical and numerical investigations into hemisphere-shaped electrostatic sensors.

    Science.gov (United States)

    Lin, Jun; Chen, Zhong-Sheng; Hu, Zheng; Yang, Yong-Min; Tang, Xin

    2014-07-31

    Electrostatic sensors have been widely used in many applications due to their advantages of low cost and robustness. Their spatial sensitivity and time-frequency characteristics are two important performance parameters. In this paper, an analytical model of the induced charge on a novel hemisphere-shaped electrostatic sensor was presented to investigate its accurate sensing characteristics. Firstly a Poisson model was built for electric fields produced by charged particles. Then the spatial sensitivity and time-frequency response functions were directly derived by the Green function. Finally, numerical calculations were done to validate the theoretical results. The results demonstrate that the hemisphere-shaped sensors have highly 3D-symmetrical spatial sensitivity expressed in terms of elementary function, and the spatial sensitivity is higher and less homogeneous near the hemispherical surface and vice versa. Additionally, the whole monitoring system, consisting of an electrostatic probe and a signal conditioner circuit, acts as a band-pass filter. The time-frequency characteristics depend strongly on the spatial position and velocity of the charged particle, the radius of the probe as well as the equivalent resistance and capacitance of the circuit.

  8. Hemispheric specialization in the assessment of female physical attractiveness.

    Science.gov (United States)

    Dural, Seda; Cetinkaya, Hakan; Gülbetekin, Evrim

    2015-01-01

    Female physical attractiveness has been widely related to waist-to-hip ratio (WHR) and body weight (BW). The present study was conducted to examine the role of hemispheric specialization in the perception of physical attractiveness. Drawings of female figures that differed in BW (underweight, normal and overweight) and WHR (0.7 and 1.0) were presented to both male and female subjects using the visual half-field technique. The stimuli were presented for an unusually short duration (180 msec). Under these conditions, male but not female subjects rated the various female figures as differing in attractiveness. Thus, male judgements of female attractiveness depended on weight and WHR. Reaction time and accuracy scores obtained from male subjects suggested that the left hemisphere (LH) was slower but more accurate than the right hemisphere in detecting differences in the attractiveness of the figures. Additionally, the most attractive figure was detected significantly more accurately than the least attractive figure when the figures were presented to the LH. The findings were discussed in terms of evolutionary views of sex differences in mate selection.

  9. Hemispheric asymmetry and somatotopy of afferent inhibition in healthy humans.

    Science.gov (United States)

    Helmich, R C G; Bäumer, T; Siebner, H R; Bloem, B R; Münchau, A

    2005-11-01

    A conditioning electrical stimulus to a digital nerve can inhibit the motor-evoked potentials (MEPs) in adjacent hand muscles elicited by transcranial magnetic stimulation (TMS) to the contralateral primary motor cortex (M1) when given 25-50 ms before the TMS pulse. This is referred to as short-latency afferent inhibition (SAI). We studied inter-hemispheric differences (Experiment 1) and within-limb somatotopy (Experiment 2) of SAI in healthy right-handers. In Experiment 1, conditioning electrical pulses were applied to the right or left index finger (D2) and MEPs were recorded from relaxed first dorsal interosseus (FDI) and abductor digiti minimi (ADM) muscles ipsilateral to the conditioning stimulus. We found that SAI was more pronounced in right hand muscles. In Experiment 2, electrical stimulation was applied to the right D2 and MEPs were recorded from ipsilateral FDI, extensor digitorum communis (EDC) and biceps brachii (BB) muscles. The amount of SAI did not differ between FDI, EDC and BB muscles. These data demonstrate inter-hemispheric differences in the processing of cutaneous input from the hand, with stronger SAI in the dominant left hemisphere. We also found that SAI occurred not only in hand muscles adjacent to electrical digital stimulation, but also in distant hand and forearm and also proximal arm muscles. This suggests that SAI induced by electrical D2 stimulation is not focal and somatotopically specific, but a more widespread inhibitory phenomenon.

  10. Gender differences in hemispheric asymmetry for face processing

    Directory of Open Access Journals (Sweden)

    Matarazzo Silvia

    2006-06-01

    Full Text Available Abstract Background Current cognitive neuroscience models predict a right-hemispheric dominance for face processing in humans. However, neuroimaging and electromagnetic data in the literature provide conflicting evidence of a right-sided brain asymmetry for decoding the structural properties of faces. The purpose of this study was to investigate whether this inconsistency might be due to gender differences in hemispheric asymmetry. Results In this study, event-related brain potentials (ERPs were recorded in 40 healthy, strictly right-handed individuals (20 women and 20 men while they observed infants' faces expressing a variety of emotions. Early face-sensitive P1 and N1 responses to neutral vs. affective expressions were measured over the occipital/temporal cortices, and the responses were analyzed according to viewer gender. Along with a strong right hemispheric dominance for men, the results showed a lack of asymmetry for face processing in the amplitude of the occipito-temporal N1 response in women to both neutral and affective faces. Conclusion Men showed an asymmetric functioning of visual cortex while decoding faces and expressions, whereas women showed a more bilateral functioning. These results indicate the importance of gender effects in the lateralization of the occipito-temporal response during the processing of face identity, structure, familiarity, or affective content.

  11. Left hemispheric dominance during auditory processing in a noisy environment

    Directory of Open Access Journals (Sweden)

    Ross Bernhard

    2007-11-01

    Full Text Available Abstract Background In daily life, we are exposed to different sound inputs simultaneously. During neural encoding in the auditory pathway, neural activities elicited by these different sounds interact with each other. In the present study, we investigated neural interactions elicited by masker and amplitude-modulated test stimulus in primary and non-primary human auditory cortex during ipsi-lateral and contra-lateral masking by means of magnetoencephalography (MEG. Results We observed significant decrements of auditory evoked responses and a significant inter-hemispheric difference for the N1m response during both ipsi- and contra-lateral masking. Conclusion The decrements of auditory evoked neural activities during simultaneous masking can be explained by neural interactions evoked by masker and test stimulus in peripheral and central auditory systems. The inter-hemispheric differences of N1m decrements during ipsi- and contra-lateral masking reflect a basic hemispheric specialization contributing to the processing of complex auditory stimuli such as speech signals in noisy environments.

  12. Connectivity measures in the Poffenberger paradigm indicate hemispheric asymmetries

    Science.gov (United States)

    Erbil, Nurhan; Yagcioglu, Suha

    2016-01-01

    Summary The Poffenberger paradigm is a well-known measure of interhemispheric transfer delays, calculated on the basis of the crossed vs uncrossed reaction time difference (CUD). However, the proper interpretation of CUD is extensively debated in the literature. In this study we used connectivity measures in an attempt to interpret CUD from the perspective of functional connectivity. Accordingly, we tried to define functional couplings in the Poffenberger paradigm; we used a simple choice version of the paradigm, and included a stimulation only (SO) condition for comparison. As an index of functional coupling we employed partial directed coherence, exploiting bilateral grouping of the electrodes to compute intra- and interhemispheric connection weight ratios (CWRs). Our findings indicated modulations in functional weights in relation to the SO condition, rather than the crossed and uncrossed conditions, such that the response executed by the right hemisphere yielded a decrease in intra-, yet an increase in interhemispheric CWRs, whereas the left hemisphere interactions showed connectivity patterns similar to the SO condition irrespective of the side of movement. Overall, our results suggest modulation of connectivity in the same/similar system, which was found to be optimized, in terms of hemispheric asymmetries, to different tasks. PMID:28072385

  13. Are Karakoram temperatures out of phase compared to hemispheric trends?

    Science.gov (United States)

    Asad, Fayaz; Zhu, Haifeng; Zhang, Hui; Liang, Eryuan; Muhammad, Sher; Farhan, Suhaib Bin; Hussain, Iqtidar; Wazir, Muhammad Atif; Ahmed, Moinuddin; Esper, Jan

    2016-07-01

    In contrast to a global retreating trend, glaciers in the Karakoram showed stability and/or mass gaining during the past decades. This "Karakoram Anomaly" has been assumed to result from an out-of-phase temperature trend compared to hemispheric scales. However, the short instrumental observations from the Karakoram valley bottoms do not support a quantitative assessment of long-term temperature trends in this high mountain area. Here, we presented a new April-July temperature reconstruction from the Karakoram region in northern Pakistan based on a high elevation (~3600 m a.s.l.) tree-ring chronology covering the past 438 years (AD 1575-2012). The reconstruction passes all statistical calibration and validation tests and represents 49 % of the temperature variance recorded over the 1955-2012 instrumental period. It shows a substantial warming accounting to about 1.12 °C since the mid-twentieth century, and 1.94 °C since the mid-nineteenth century, and agrees well with the Northern Hemisphere temperature reconstructions. These findings provide evidence that the Karakoram temperatures are in-phase, rather than out-of-phase, compared to hemispheric scales since the AD 1575. The synchronous temperature trends imply that the anomalous glacier behavior reported from the Karakoram may need further explanations beyond basic regional thermal anomaly.

  14. Linking hemispheric radiation budgets, ITCZ shifts, and monsoons

    Science.gov (United States)

    McGee, D.; Donohoe, A.; Marshall, J.; Ferreira, D.

    2014-12-01

    We explore the relationship between the Intertropical Convergence Zone (ITCZ), hemispheric heat budgets, and monsoon strength in past climates. Modern seasonal and interannual variability in the globally-averaged position of the ITCZ (as estimated by the tropical precipitation centroid) reflects the interhemispheric heat balance, with the ITCZ's displacement toward the warmer hemisphere directly proportional to atmospheric heat transport into the cooler hemisphere. Model simulations suggest that ITCZ shifts are likely to have obeyed the same relationship with interhemispheric heat transport in response to past changes in orbital parameters, ice sheets, and ocean circulation. This relationship implies that even small (±1 degree) shifts in the mean (annually and zonally averaged) ITCZ require large changes in hemispheric heat budgets, placing tight bounds on mean ITCZ shifts in past climates. To test this energetic argument, we use the observed relationship between mean ITCZ position and tropical sea surface temperature (SST) gradients in combination with proxy-based estimates of past SST gradients to show that mean ITCZ shifts for the mid-Holocene, Heinrich Stadial 1 and Last Glacial Maximum are not likely to have been more than 1 degree latitude from its present mean position. In exploring these results, we provide brief descriptions of the estimated radiation budgets of past climates that help demonstrate how different climate forcings change the interhemispheric heat balance and thus the ITCZ's global-mean position. We also address the seeming inconsistency between the small ITCZ shifts indicated by energetic constraints and the large changes in monsoon rainfall suggested by proxy data. We compare global-average and regional-scale tropical precipitation in observations and explore their responses to a variety of forcings (orbital changes, ice sheets, hosing) in models. These comparisons make clear that monsoon precipitation can change substantially even in the

  15. Eastern Siberia terrain intelligence

    Science.gov (United States)

    ,

    1942-01-01

    The following folio of terrain intelligence maps, charts and explanatory tables represent an attempt to bring together available data on natural physical conditions such as will affect military operations in Eastern Siberia. The area covered is the easternmost section of the U.S.S.R.; that is the area east of the Yenisei River. Each map and accompanying table is devoted· to a specialized set of problems; together they cover such subjects as geology, construction materials, mineral fuels, terrain, water supply, rivers and climate. The data is somewhat generalized due to the scale of treatment as well as to the scarcity of basic data. Each of the maps are rated as to reliability according to the reliability scale on the following page. Considerable of the data shown is of an interpretative nature, although precise data from literature was used wherever possible. The maps and tables were compiled  by a special group from the United States Geological Survey in cooperation with the Intelligence Branch of the Office, Chief of Engineers, War Department.

  16. Atmospheric mercury in the Southern Hemisphere tropics: seasonal and diurnal variations and influence of inter-hemispheric transport

    Directory of Open Access Journals (Sweden)

    D. Howard

    2017-09-01

    Full Text Available Mercury is a toxic element of serious concern for human and environmental health. Understanding its natural cycling in the environment is an important goal towards assessing its impacts and the effectiveness of mitigation strategies. Due to the unique chemical and physical properties of mercury, the atmosphere is the dominant transport pathway for this heavy metal, with the consequence that regions far removed from sources can be impacted. However, there exists a dearth of long-term monitoring of atmospheric mercury, particularly in the tropics and Southern Hemisphere. This paper presents the first 2 years of gaseous elemental mercury (GEM measurements taken at the Australian Tropical Atmospheric Research Station (ATARS in northern Australia, as part of the Global Mercury Observation System (GMOS. Annual mean GEM concentrations determined at ATARS (0.95 ± 0.12 ng m−3 are consistent with recent observations at other sites in the Southern Hemisphere. Comparison with GEM data from other Australian monitoring sites suggests a concentration gradient that decreases with increasing latitude. Seasonal analysis shows that GEM concentrations at ATARS are significantly lower in the distinct wet monsoon season than in the dry season. This result provides insight into alterations of natural mercury cycling processes as a result of changes in atmospheric humidity, oceanic/terrestrial fetch, and convective mixing, and invites future investigation using wet mercury deposition measurements. Due to its location relative to the atmospheric equator, ATARS intermittently samples air originating from the Northern Hemisphere, allowing an opportunity to gain greater understanding of inter-hemispheric transport of mercury and other atmospheric species. Diurnal cycles of GEM at ATARS show distinct nocturnal depletion events that are attributed to dry deposition under stable boundary layer conditions. These cycles provide strong further evidence supportive of

  17. Bilateral hemispheric processing of words and faces: evidence from word impairments in prosopagnosia and face impairments in pure alexia

    National Research Council Canada - National Science Library

    Behrmann, Marlene; Plaut, David C

    2014-01-01

    .... On this view, right hemisphere ventral lesions that impair face recognition (prosopagnosia) should leave word recognition unaffected, and left hemisphere ventral lesions that impair word recognition (pure alexia...

  18. Southern Hemisphere humpback whales wintering off Central America: insights from water temperature into the longest mammalian migration.

    Science.gov (United States)

    Rasmussen, Kristin; Palacios, Daniel M; Calambokidis, John; Saborío, Marco T; Dalla Rosa, Luciano; Secchi, Eduardo R; Steiger, Gretchen H; Allen, Judith M; Stone, Gregory S

    2007-06-22

    We report on a wintering area off the Pacific coast of Central America for humpback whales (Megaptera novaeangliae) migrating from feeding areas off Antarctica. We document seven individuals, including a mother/calf pair, that made this migration (approx. 8300km), the longest movement undertaken by any mammal. Whales were observed as far north as 11 degrees N off Costa Rica, in an area also used by a boreal population during the opposite winter season, resulting in unique spatial overlap between Northern and Southern Hemisphere populations. The occurrence of such a northerly wintering area is coincident with the development of an equatorial tongue of cold water in the eastern South Pacific, a pattern that is repeated in the eastern South Atlantic. A survey of location and water temperature at the wintering areas worldwide indicates that they are found in warm waters (21.1-28.3 degrees C), irrespective of latitude. We contend that while availability of suitable reproductive habitat in the wintering areas is important at the fine scale, water temperature influences whale distribution at the basin scale. Calf development in warm water may lead to larger adult size and increased reproductive success, a strategy that supports the energy conservation hypothesis as a reason for migration.

  19. Hemisphere Asymmetry of Response to Pharmacologic Treatment in an Alzheimer's Disease Mouse Model.

    Science.gov (United States)

    Manousopoulou, Antigoni; Saito, Satoshi; Yamamoto, Yumi; Al-Daghri, Nasser M; Ihara, Masafumi; Carare, Roxana O; Garbis, Spiros D

    2016-01-01

    The aim of this study was to examine hemisphere asymmetry of response to pharmacologic treatment in an Alzheimer's disease mouse model using cilostazol as a chemical stimulus. Eight-month-old mice were assigned to vehicle or cilostazol treatment for three months and hemispheres were analyzed using quantitative proteomics. Bioinformatics interpretation showed that following treatment, aggregation of blood platelets significantly decreased in the right hemisphere whereas neurodegeneration significantly decreased and synaptic transmission increased in the left hemisphere only. Our study provides novel evidence on cerebral laterality of pharmacologic activity, with important implications in deciphering regional pharmacodynamic effects of existing drugs thus uncovering novel hemisphere-specific therapeutic targets.

  20. Mars' paleomagnetic field as the result of a single-hemisphere dynamo.

    Science.gov (United States)

    Stanley, Sabine; Elkins-Tanton, Linda; Zuber, Maria T; Parmentier, E Marc

    2008-09-26

    Mars' crustal magnetic field was most likely generated by dynamo action in the planet's early history. Unexplained characteristics of the field include its strength, concentration in the southern hemisphere, and lack of correlation with any surface features except for the hemispheric crustal dichotomy. We used numerical dynamo modeling to demonstrate that the mechanisms proposed to explain crustal dichotomy formation can result in a single-hemisphere dynamo. This dynamo produces strong magnetic fields in only the southern hemisphere. This magnetic field morphology can explain why Mars' crustal magnetic field intensities are substantially stronger in the southern hemisphere without relying on any postdynamo mechanisms.

  1. Pronounced Fluctuations of Target Fragments in Forward Hemisphere Only in Ultra Relativistic Nuclear Collision

    Institute of Scientific and Technical Information of China (English)

    Dipak Ghosh; Argha Dev; Samabrata Sarkar; Prabir Kumar Haldar

    2006-01-01

    Dynamical fluctuation of target evaporated black particles is investigated in both forward and backward hemispheres within the framework of multi-dimensional factorial moment methodology using the brilliant concept of the Hurst exponent. We analyse the black particles emitted in 32S-AgBr interactions at 200AGeV and it is evident that the dynamical fluctuation in the backward hemisphere is self-afnne. In the forward hemisphere, dynamical fluctuation is self-similar but not self-affine. However, study indicates that the fluctuation in the forward hemisphere is more pronounced than that in backward hemisphere.

  2. Evaluating fMRI methods for assessing hemispheric language dominance in healthy subjects

    Energy Technology Data Exchange (ETDEWEB)

    Baciu, Monica [Laboratoire de Psychologie et NeuroCognition, UMR 5105 CNRS, Universite Pierre Mendes-France, F38040 Grenoble Cedex 09 (France)]. E-mail: mbaciu@upmf-grenoble.fr; Juphard, Alexandra [Laboratoire de Psychologie et NeuroCognition, UMR 5105 CNRS, Universite Pierre Mendes-France, F38040 Grenoble Cedex 09 (France); Cousin, Emilie [Laboratoire de Psychologie et NeuroCognition, UMR 5105 CNRS, Universite Pierre Mendes-France, F38040 Grenoble Cedex 09 (France); Bas, Jean Francois Le [Unite IRM, CHU Grenoble (France)

    2005-08-01

    We evaluated two methods for quantifying the hemispheric language dominance in healthy subjects, by using a rhyme detection (deciding whether couple of words rhyme) and a word fluency (generating words starting with a given letter) task. One of methods called 'flip method' (FM) was based on the direct statistical comparison between hemispheres' activity. The second one, the classical lateralization indices method (LIM), was based on calculating lateralization indices by taking into account the number of activated pixels within hemispheres. The main difference between methods is the statistical assessment of the inter-hemispheric difference: while FM shows if the difference between hemispheres' activity is statistically significant, LIM shows only that if there is a difference between hemispheres. The robustness of LIM and FM was assessed by calculating correlation coefficients between LIs obtained with each of these methods and manual lateralization indices MLI obtained with Edinburgh inventory. Our results showed significant correlation between LIs provided by each method and the MIL, suggesting that both methods are robust for quantifying hemispheric dominance for language in healthy subjects. In the present study we also evaluated the effect of spatial normalization, smoothing and 'clustering' (NSC) on the intra-hemispheric location of activated regions and inter-hemispheric asymmetry of the activation. Our results have shown that NSC did not affect the hemispheric specialization but increased the value of the inter-hemispheric difference.

  3. Reduced Hemispheric Asymmetry of Brain Anatomical Networks Is Linked to Schizophrenia: A Connectome Study.

    Science.gov (United States)

    Sun, Yu; Chen, Yu; Collinson, Simon L; Bezerianos, Anastasios; Sim, Kang

    2017-01-01

    Despite convergent evidence indicating a variety of regional abnormalities of hemispheric asymmetry in schizophrenia, patterns of wider neural network asymmetry remain to be determined. In this study, we investigated alterations in hemispheric white matter topology in schizophrenia and their association with clinical manifestations of the illness. Weighted hemispheric brain anatomical networks were constructed for each of 116 right-handed patients with schizophrenia and 66 matched healthy participants. Graph theoretical approaches were then employed to estimate the hemispheric topological properties. We found that although small-world properties were preserved in the hemispheric network, a significant hemispheric-independent deficit of global integration was found in schizophrenia. Furthermore, a significant group-by-hemisphere interaction was revealed in the characteristic path length and global efficiency, attributing to significantly reduced hemispheric asymmetry of global integration in patients compared with healthy controls. Specifically, we found reduced asymmetric nodal efficiency in several frontal regions and the hippocampus. Finally, the abnormal hemispheric asymmetry of brain anatomical network topology was associated with clinical features (duration of illness and psychotic psychopathology) in patients. Our findings provide new insights into lateralized nature of hemispheric dysconnectivity and highlight the potential for using brain network measures of hemispheric asymmetry as neural biomarkers for schizophrenia and its clinical features.

  4. The FTAA and hemispheric integration: building a triple-win strategy for trade and sustainability in the hemisphere

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-04-01

    The concept of a trade and sustainability agenda for the Americas is explained and a historical account of the process of making this concept a reality is discussed in a background paper for the Hemispheric Trade and Sustainability Symposium held on April 18, 2001 in Quebec City. The Symposium was held in conjunction with the Third Summit of the Americas, where heads of 34 American nations discussed ways and means to encourage hemispheric cooperation. The object of the Symposium was to provide a constructive, policy-oriented, and knowledge-based open forum for dialogue on trade and sustainability issues; to identify policy options that can be mutually beneficial to trade, environment and development, and to increase public support for trade liberalisation in the Americas. The strategy aims to build a sustainable FTAA through the identification of a series of environmental provisions to be incorporated in the Agreement; strengthen environmental cooperation in the Americas, especially in trade-sensitive, or trade-related sectors, and create a high level hemispheric expert group on trade and sustainability for continuous and constructive dialogue with civil society and industry on these issues. The backgrounder provides a precis of the fundamental aspect of building a sustainable FTAA, explains the origin of the prevailing fear of unilateral environment-related trade sanctions by the United States, the fear of protectionist measures by Canada and the United States based on environmental provisions in the FTAA, and the fear that higher environmental standards and regulations would undermine the competitiveness of Latin American and Caribbean businesses. The paper attempts to dispel these fears by explaining the mechanism envisaged to be predominant in creating the triple-win strategy, namely impact assessment, transparency, participation and dispute resolution processes. The eventual agreement should also mention sustainable development as an overarching objective of

  5. Digital simulation of chronoamperometry at an electrode within a hemispherical polymer drop containing an enzyme: comparison of a hemispherical with a flat disk electrode

    DEFF Research Database (Denmark)

    Britz, Dieter; Strutwolf, Jörg

    2013-01-01

    Current-time and steady state current behaviour was simulated for the cases of a hemispherical and flat inlaid disk electrodes located under a hemispherical polymer drop containing an enzyme which converts a substrate diffusing into the drop into a product that is electroactive at the electrode. A...

  6. Reaching Across the Hemispheres with Science, Language, Arts and Technology

    Science.gov (United States)

    Sparrow, E. B.; Zicus, S.; Miller, A.; Baird, A.; Page, G.

    2009-12-01

    Twelve Alaskan elementary and middle school classes (grades 3-8) partnered with twelve Australian middle school classes, with each pair using web-based strategies to develop a collaborative ice-mystery fictional book incorporating authentic polar science. Three professional development workshops were held, bringing together educators and polar scientists in two IPY education outreach projects. The Alaska workshop provided an opportunity to bring together the North American teachers for lessons on arctic and antarctic science and an earth system science program Seasons and Biomes measurement protocols, as well as methods in collaborative e-writing and art in Ice e-Mysteries: Global Student Polar e-books project. Teachers worked with University of Alaska Fairbanks (UAF) and Australian scientists to become familiar with Arctic science research, science artifacts and resources available at UAF and the University of Alaska Museum of the North. In Australia, teachers received a similar project training through the Tasmania Museum and Art Gallery (TMAG) Center for Learning and Discovery on Antarctic science and the University of Tasmania. The long-distance collaboration was accomplished through Skype, emails and a TMAG supported website. A year later, Northern Hemisphere and Southern Hemisphere teacher partners met in a joint workshop in Tasmania, to share their experiences, do project assessments and propose activities for future collaborations. The Australian teachers received training on Seasons and Biomes scientific measurements and the Alaskan teachers, on Tasmanian vegetation, fauna and indigenous culture, Antarctic and Southern ocean studies. This innovative project produced twelve e-polar books written and illustrated by students; heightened scientific literacy about the polar regions and the earth system; increased awareness of the environment and indigenous cultures; stronger connections to the scientific community; and lasting friendships. It also resulted in

  7. Mountain uplift and the threshold for sustained Northern Hemisphere Glaciation

    Directory of Open Access Journals (Sweden)

    G. L. Foster

    2009-11-01

    Full Text Available The Miocene (~24 to ~5 million years ago was a period of relative global warmth (e.g. Zachos et al. 2001 characterised by the glaciation of Antarctica only. Paradoxically, the majority of available proxy data suggest that during the Miocene pCO2 was similar, or even lower, than the pre-industrial levels (280 ppmv; Pagani et al., 1999; Pearson and Palmer, 2000; Kürschner et al., 1996, 2008 and at times probably crossed the modelled threshold value required for sustained glaciation in the Northern Hemisphere (DeConto et al., 2008. Records of ice rafted debris and the oxygen isotope composition of benthic foraminifera suggest that at several times over the last 25 million years substantial amounts of continental ice did build up in the Northern Hemisphere but none of these led to sustained glaciation. In this contribution we review evidence that suggests that in the Miocene the North American Cordillera was, at least in parts, considerably lower than today. We present new GCM simulations that imply that Late Miocene uplift of the North American Cordillera would have resulted in significant cooling of Northern North American Continent. Offline ice sheet modelling, driven by these GCM outputs, suggests that with a reduced topography inception of the Cordilleran ice sheet is prohibited, and there is a small, but potentially significant, reduction in the amount of ice grown on Baffin Island. This suggests uplift of the North American Cordillera in the Late Miocene may have played an important role in priming the climate for the intensification of Northern Hemisphere glaciation in the Late Pliocene.

  8. Hemispherical Pluto and Charon Color Composition From New Horizons

    Science.gov (United States)

    Ennico, K.; Parker, A.; Howett, C. A. J.; Olkin, C. B.; Spencer, J. R.; Grundy, W. M.; Reuter, D. E.; Cruikshank, D. P.; Binzel, R. P.; Buie, M. W.; hide

    2016-01-01

    New Horizons flew by Pluto and its moons on July 14, 2015 [1]. In the days prior to the closest approach (C/A), panchromatic and color observations of Pluto and Charon were made covering a fully complete range of longitudes. Although only a fraction of this "late-approach" data series has been transmitted to the ground, the results indicate Pluto's latitudinal coloring trends seen on the encounter hemisphere continues on the far side. Charon's red pole is visible from a multitude of longitudes and its colors are uniform with longitude at lower latitudes.

  9. An investigation of TNT equivalence of hemispherical PE4 charges

    OpenAIRE

    Rigby, S.E.; Sielicki, P.W.

    2014-01-01

    The TNT equivalence of an explosive is given as the equivalent mass of TNT required to produce a blast wave of equal magnitude to that produced by a unit weight of the explosive in question. Currently, there is a lack of agreement in the literature on the TNT equivalence (TNTeq) of PE4. This paper presents a combined numerical and experimental investigation of TNTeq for hemispherical PE4 charges in far-field blast events. Experimental results are compared to a series of numerical analyses con...

  10. Bilateral cerebral hemispheric infarction associated with sildenafil citrate (Viagra) use.

    Science.gov (United States)

    Kim, K-K; Kim, D G; Ku, Y H; Lee, Y J; Kim, W-C; Kim, O J; Kim, H S

    2008-03-01

    Sildenafil citrate (Viagra) is one of the frequently prescribed drugs for men with erectile dysfunction. We describe a 52-year-old man with bilateral middle cerebral artery (MCA) territory infarction after sildenafil use. He ingested 100 mg of sildenafil and about 1 h later, he complained of chest discomfort, palpitation and dizziness followed by mental obtundation, global aphasia and left hemiparesis. Brain magnetic resonance imaging documented acute bilateral hemispheric infarction, and cerebral angiography showed occluded bilateral MCA. Despite significant bilateral MCA stenosis and cerebral infarction, systemic hypotension persisted for a day. We presume that cerebral infarction was caused by cardioembolism with sildenafil use.

  11. Gesture imitation with lower limbs following left hemisphere stroke.

    Science.gov (United States)

    Ambrosoni, Elena; Della Sala, Sergio; Motto, Cristina; Oddo, Silvia; Spinnler, Hans

    2006-05-01

    Ideomotor apraxia (IMA) of lower limbs has rarely been investigated systematically. This is the aim of the current study. Thirty-five patients with a unilateral stroke in the left hemisphere were tested within 30 days from onset with an upper limb IMA test and with a newly devised test assessing leg IMA. Seventeen patients presented with arm apraxia, six of them also showed severe leg apraxia. Results suggest that IMA of lower limbs emerges in association with severe arm IMA in patients with large lesions, and is a sign of general severity of the patient's conditions.

  12. Diffusion tensor imaging of hemispheric asymmetries in the developing brain.

    Science.gov (United States)

    Wilde, Elisabeth A; McCauley, Stephen R; Chu, Zili; Hunter, Jill V; Bigler, Erin D; Yallampalli, Ragini; Wang, Zhiyue J; Hanten, Gerri; Li, Xiaoqi; Ramos, Marco A; Sabir, Sharjeel H; Vasquez, Ana C; Menefee, Deleene; Levin, Harvey S

    2009-02-01

    Diffusion tensor imaging (DTI) was performed in 39 right-handed children to examine structural hemispheric differences and the impact of age, socioeconomic status, and sex on these differences. Apparent diffusion coefficient (ADC) values were smaller in the left than in the right temporal, prefrontal, anterior internal capsular and the thalamic regions, and fractional anisotropy (FA) values were larger in the left than in the right internal capsule, thalamus, and cingulate. Significant region-by-sex interactions disclosed that the relation of DTI asymmetries to performance depended on sex including the relation of temporal lobes to reading comprehension and the relation of frontal lobes to solving applied mathematical problems.

  13. Workshop: Western hemisphere network of bird banding programs

    Science.gov (United States)

    Celis-Murillo, A.

    2007-01-01

    Purpose: To promote collaboration among banding programs in the Americas. Introduction: Bird banding and marking provide indispensable tools for ornithological research, management, and conservation of migratory birds on migratory routes, breeding and non-breeding grounds. Many countries and organizations in Latin America and the Caribbean are in the process of developing or have expressed interest in developing national banding schemes and databases to support their research and management programs. Coordination of developing and existing banding programs is essential for effective data management, reporting, archiving and security, and most importantly, for gaining a fuller understanding of migratory bird conservation issues and how the banding data can help. Currently, there is a well established bird-banding program in the U.S.A. and Canada, and programs in other countries are being developed as well. Ornithologists in many Latin American countries and the Caribbean are interested in using banding and marking in their research programs. Many in the ornithological community are interested in establishing banding schemes and some countries have recently initiated independent banding programs. With the number of long term collaborative and international initiatives increasing, the time is ripe to discuss and explore opportunities for international collaboration, coordination, and administration of bird banding programs in the Western Hemisphere. We propose the second ?Western Hemisphere Network of Bird Banding Programs? workshop, in association with the SCSCB, to be an essential step in the progress to strengthen international partnerships and support migratory bird conservation in the Americas and beyond. This will be the second multi-national meeting to promote collaboration among banding programs in the Americas (the first meeting was held in October 8-9, 2006 in La Mancha, Veracruz, Mexico). The Second ?Western Hemisphere Network of Bird Banding Programs

  14. The Meridional Flux of Sensible Heat over the Northern Hemisphere

    OpenAIRE

    White, Robert M.

    2011-01-01

    The meridional eddy flux of sensible heat is examined by means of finite difference integration methods from northern hemisphere charts for the winter 1945-46. The eddy sensible heat flux is shown to occur principally in the lowest layers of the atmosphere and to decrease with elevation. The magnitude of the eddy sensible heat transports are compared with the total poleward energy flux required by the radiation balance, and are shown to comprise a very large fraction of this flux.DOI: 10.1111...

  15. Equilibrium magnetic states in individual hemispherical permalloy caps

    Energy Technology Data Exchange (ETDEWEB)

    Streubel, Robert; Schmidt, Oliver G. [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Material Systems for Nanoelectronics, Chemnitz University of Technology, 09107 Chemnitz (Germany); Kravchuk, Volodymyr P.; Gaididei, Yuri [Bogolyubov Institute for Theoretical Physics, 03143 Kiev (Ukraine); Sheka, Denis D. [Radiophysics Faculty, Taras Shevchenko National University of Kiev, 01601 Kiev (Ukraine); Makarov, Denys [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Kronast, Florian [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, 12489 Berlin (Germany)

    2012-09-24

    The magnetization distributions in individual soft magnetic permalloy caps on non-magnetic spherical particles with sizes ranging from 50 to 800 nm are investigated. We experimentally visualize the magnetic structures at the resolution limit of the x-ray magnetic circular dichroism photoelectron emission microscopy (XMCD-PEEM). By analyzing the so-called tail contrast in XMCD-PEEM, the spatial resolution is significantly enhanced, which allowed us to explore magnetic vortices and their displacement on curved surfaces. Furthermore, cap nanostructures are modeled as extruded hemispheres to determine theoretically the phase diagram of equilibrium magnetic states. The calculated phase diagram agrees well with the experimental observations.

  16. First early Mesozoic amber in the Western Hemisphere

    Science.gov (United States)

    Litwin, Ronald J.; Ash, Sidney R.

    1991-03-01

    Detrital amber pebbles and granules have been discovered in Upper Triassic strata on the Colorado Plateau. Although amber pre-viously has been reported from Pennsylvanian, Jurassic, Cretaceous, and Tertiary strata, we know of no other reported Triassic occurrence in North America or the Western Hemisphere. The newly discovered occurrences of amber are at two localities in the lower part of the Petrified }Forest Member of the Upper Triassic Chinle Formation in Petrified Forest National Park, Arizona. The paper coals and carbonaceous paper shales containing the amber also contain fossil palynomorph assemblages that indicate a late Carnian age for these occurrences.

  17. Infanticide in Eastern Croatia.

    Science.gov (United States)

    Marcikić, Mladen; Dumencić, Boris; Matuzalem, Elizabeta; Marjanović, Ksenija; Pozgain, Ivan; Ugljarević, Mladen

    2006-06-01

    For the layperson no crime is more difficult to comprehend than the killing of a child by his or her own parents. This is a retrospective study of neonaticide and infanticide in Eastern Croatia from 1980 to 2004. Judicial records of infanticide cases stored in Regional and County Courts were analyzed for the circumstances surrounding the offense. Twenty-four babies were discovered in various places during investigating period of time. The victims were almost equally divided between boys (12) and girls (11). The gender of one baby was unknown. The mean weight of babies was 2.7 SD = 0.66 kg. The perpetrators preferred rubbish-heaps (33.4%), burying in soil (16.7%), various premises in or around the house (16.7%) and garbage cans (12.5%) as places for hiding the dead babies. The most dominant cause of death in sixteen cases of live birth was asphyxia (37%) with equal distribution of smothering, stuffing the mouth with rags and strangulation. Other frequent causes of death were placing the child in a plastic bag and abandonment (25%), brain injury (25%) and wounding using a sharp weapon (12.5%). The cause of death for six babies remained unknown due to advanced decomposition. Two babies were stillborn. The age of accused mothers varied from 16 to 33, mean 24 SD=5.2 years. Most of them were unmarried (60%) and had limited formal education. They usually kept the pregnancy a secret (73%) and gave birth (93%) without public welfare assistance. The mother lived in the terror of shame and with the guilt that accompany conception without marriage. Fear seemed to be a pronounced motivating factor for committing infanticide. The data on court proceedings were available in fifteen cases. The mothers were officially indicted in all cases for infanticide under the Croatian Criminal Code. The perpetrator remained unidentified in nine suspicious crimes. The court convicted ten mothers of the crime of infanticide. Often juries were unwilling to punish the mother, citing the mother

  18. Hemispheric biases and the control of visuospatial attention: an ERP study

    Directory of Open Access Journals (Sweden)

    Banich Marie T

    2005-08-01

    Full Text Available Abstract Background We examined whether individual differences in hemispheric utilization can interact with the intrinsic attentional biases of the cerebral hemispheres. Evidence suggests that the hemispheres have competing biases to direct attention contralaterally, with the left hemisphere (LH having a stronger bias than the right hemisphere. There is also evidence that individuals have characteristic biases to utilize one hemisphere more than the other for processing information, which can induce a bias to direct attention to contralateral space. We predicted that LH-biased individuals would display a strong rightward attentional bias, which would create difficulty in selectively attending to target stimuli in the left visual field (LVF as compared to right in the performance of a bilateral flanker task. Results Consistent with our hypothesis, flanker interference effects were found on the N2c event-related brain potential and error rate for LH-biased individuals in the Attend-LVF condition. The error rate effect was correlated with the degree of hemispheric utilization bias for the LH-Bias group. Conclusion We conclude that hemispheric utilization bias can enhance a hemisphere's contralateral attentional bias, at least for individuals with a LH utilization bias. Hemispheric utilization bias may play an important and largely unrecognized role in visuospatial attention.

  19. Lateral thinkers are not so laterally minded: hemispheric asymmetry, interaction, and creativity.

    Science.gov (United States)

    Lindell, Annukka K

    2011-07-01

    The biological basis of creativity remains a topic of contention. A long-held view suggests that whereas the left hemisphere is intelligent and analytic, the right hemisphere is the source of all creativity. Consequently, activating the right hemisphere should enhance creative thinking, prompting a plethora of popular books hawking a right hemisphere solution to topics ranging from drawing, to money management, to sex. More recently, an alternate proposal has suggested that creativity is not a lateralised function; instead, creativity is argued to stem from the interaction and integration of information across both the left and right hemispheres. According to this view, individuals with greater interhemispheric communication and/or less-lateralised brains will evidence enhanced creative ability. This paper reviews the neural basis of creativity to determine whether creativity stems from activation of the right hemisphere, or from the interaction of both hemispheres. The relationship between creativity and psychopathology is also examined, evaluating the evidence for a causal link between disorders such as schizophrenia, hemispheric activation, and enhanced creativity. Although the research reviewed indicates greater right hemisphere activity during creative tasks, the interaction between many varied, often distant, cortical regions across both the left and right hemispheres is also a crucial component of creativity. This interaction facilitates the integration of a variety of separate cognitive abilities, fostering creative thinking. As such, creativity is better conceptualised as a distributed, rather than a purely lateralised, function; more lateral thinkers have less lateralised brains.

  20. Calvarial reconstruction using high-density porous polyethylene cranial hemispheres

    Directory of Open Access Journals (Sweden)

    Nitin J Mokal

    2011-01-01

    Full Text Available Aims: Cranial vault reconstruction can be performed with a variety of autologous or alloplastic materials. We describe our experience using high-density porous polyethylene (HDPE cranial hemisphere for cosmetic and functional restoration of skull defects. The porous nature of the implant allows soft tissue ingrowth, which decreases the incidence of infection. Hence, it can be used in proximity to paranasal sinuses and where previous alloplastic cranioplasties have failed due to implant infection. Materials and Methods: We used the HDPE implant in seven patients over a three-year period for reconstruction of moderate to large cranial defects. Two patients had composite defects, which required additional soft tissue in the form of free flap and tissue expansion. Results: In our series, decompressive craniectomy following trauma was the commonest aetiology and all defects were located in the fronto-parieto-temporal region. The defect size was 10 cm on average in the largest diameter. All patients had good post-operative cranial contour and we encountered no infections, implant exposure or implant migration. Conclusions: Our results indicate that the biocompatibility and flexibility of the HDPE cranial hemisphere implant make it an excellent alternative to existing methods of calvarial reconstruction.

  1. Genetic biomarkers for brain hemisphere differentiation in Parkinson's Disease

    Science.gov (United States)

    Hourani, Mou'ath; Mendes, Alexandre; Berretta, Regina; Moscato, Pablo

    2007-11-01

    This work presents a study on the genetic profile of the left and right hemispheres of the brain of a mouse model of Parkinson's disease (PD). The goal is to characterize, in a genetic basis, PD as a disease that affects these two brain regions in different ways. Using the same whole-genome microarray expression data introduced by Brown et al. (2002) [1], we could find significant differences in the expression of some key genes, well-known to be involved in the mechanisms of dopamine production control and PD. The problem of selecting such genes was modeled as the MIN (α,β)—FEATURE SET problem [2]; a similar approach to that employed previously to find biomarkers for different types of cancer using gene expression microarray data [3]. The Feature Selection method produced a series of genetic signatures for PD, with distinct expression profiles in the Parkinson's model and control mice experiments. In addition, a close examination of the genes composing those signatures shows that many of them belong to genetic pathways or have ontology annotations considered to be involved in the onset and development of PD. Such elements could provide new clues on which mechanisms are implicated in hemisphere differentiation in PD.

  2. Three dimensional hemispherical test development to evaluate detonation wave breakout

    Science.gov (United States)

    Francois, E. G.; Morris, J. S.; Lieber, M.

    2014-05-01

    The Onionskin test has been the standard test to evaluate detonation wave breakout over a hemispherical surface for decades. It has been an effective test used in a variety of applications to qualify main charge materials, evaluate different boosters, and compare different detonators. It is not without its shortfalls however. It only images a small portion of the explosive and requires very precise alignment and camera requirements to make sense of the results. Asymmetry in explosive behavior cannot be pinpointed or evaluated effectively. We have developed a new diagnostic using fiber optics covering the surface of the explosive to yield a 3D representation of the detonation wave behavior. Precise timing mapping of the detonation over the hemispherical surface is generated which can be converted to detonation wave breakout behavior using Huygens' wave reconstruction. This report will include the results of a recent suite of tests on PBX 9501, and discussion of how the test was developed for this explosive and contrasting previous work on PBX 9502. The results of these tests will describe the effects on detonation wave breakout symmetry when Sylgard 184 is placed between the detonator and booster. The effects on symmetry and timing when the Sylgard gap thickness is increased and the detonator is canted will be shown.

  3. Right-Hemisphere (Spatial? Acalculia and the Influence of Neglect

    Directory of Open Access Journals (Sweden)

    Silvia eBenavides-Varela

    2014-08-01

    Full Text Available The present study aimed at exploring basic number and calculation abilities in right-hemisphere damaged patients (RHD, focusing primarily on one-digit orally presented tasks, which do not require explicit visuo-spatial abilities. Twenty-four non mentally-deteriorated RHD patients (12 with clinical neglect (RHDN+, 12 without clinical neglect (RHDN-, and 12 healthy controls were included in the study. Participants were administered an ad hoc numerical battery assessing abilities such as counting, number magnitude comparison, writing and reading Arabic numerals and mental calculation, among others. Significant differences emerged among healthy controls and both the RHDN+ group and the RHDN- group, suggesting that the mathematical impairment of RHD patients does not necessarily correspond to the presence of left-neglect. A detailed analysis of the sub-tests of the battery evidenced expected differences among RHDN+ patients, RHDN- patients, and controls in writing and reading Arabic numerals. Crucially, differences between RHDN+ patients and controls were also found in tasks such as mental subtraction and mental multiplication. The present findings thus suggest that unilateral right hemisphere lesions may produce specific representational deficits that affect simple mental calculation, and not only the spatial arrangement of multi-digit written numbers as previously thought.

  4. Right-hemisphere (spatial?) acalculia and the influence of neglect.

    Science.gov (United States)

    Benavides-Varela, Silvia; Pitteri, Marco; Priftis, Konstantinos; Passarini, Laura; Meneghello, Francesca; Semenza, Carlo

    2014-01-01

    The present study aimed at exploring basic number and calculation abilities in right-hemisphere damaged patients (RHD), focusing primarily on one-digit orally presented tasks, which do not require explicit visuo-spatial abilities. Twenty-four non mentally-deteriorated RHD patients [12 with clinical neglect (RHDN+), 12 without clinical neglect (RHDN-)], and 12 healthy controls were included in the study. Participants were administered an ad hoc numerical battery assessing abilities such as counting, number magnitude comparison, writing and reading Arabic numerals and mental calculation, among others. Significant differences emerged among healthy controls and both the RHDN+ group and the RHDN- group, suggesting that the mathematical impairment of RHD patients does not necessarily correspond to the presence of left-neglect. A detailed analysis of the sub-tests of the battery evidenced expected differences among RHDN+ patients, RHDN- patients, and controls in writing and reading Arabic numerals. Crucially, differences between RHDN+ patients and controls were also found in tasks such as mental subtraction and mental multiplication, which do not require written visuo-spatial abilities. The present findings thus suggest that unilateral right hemisphere lesions may produce specific representational deficits that affect simple mental calculation, and not only the spatial arrangement of multi-digit written numbers as previously thought.

  5. Cortical cell and neuron density estimates in one chimpanzee hemisphere.

    Science.gov (United States)

    Collins, Christine E; Turner, Emily C; Sawyer, Eva Kille; Reed, Jamie L; Young, Nicole A; Flaherty, David K; Kaas, Jon H

    2016-01-19

    The density of cells and neurons in the neocortex of many mammals varies across cortical areas and regions. This variability is, perhaps, most pronounced in primates. Nonuniformity in the composition of cortex suggests regions of the cortex have different specializations. Specifically, regions with densely packed neurons contain smaller neurons that are activated by relatively few inputs, thereby preserving information, whereas regions that are less densely packed have larger neurons that have more integrative functions. Here we present the numbers of cells and neurons for 742 discrete locations across the neocortex in a chimpanzee. Using isotropic fractionation and flow fractionation methods for cell and neuron counts, we estimate that neocortex of one hemisphere contains 9.5 billion cells and 3.7 billion neurons. Primary visual cortex occupies 35 cm(2) of surface, 10% of the total, and contains 737 million densely packed neurons, 20% of the total neurons contained within the hemisphere. Other areas of high neuron packing include secondary visual areas, somatosensory cortex, and prefrontal granular cortex. Areas of low levels of neuron packing density include motor and premotor cortex. These values reflect those obtained from more limited samples of cortex in humans and other primates.

  6. Peatmoss (Sphagnum) diversification associated with Miocene Northern Hemisphere climatic cooling?

    Science.gov (United States)

    Shaw, A Jonathan; Devos, Nicolas; Cox, Cymon J; Boles, Sandra B; Shaw, Blanka; Buchanan, Alex M; Cave, Lynette; Seppelt, Rodney

    2010-06-01

    Global climate changes sometimes spark biological radiations that can feed back to effect significant ecological impacts. Northern Hemisphere peatlands dominated by living and dead peatmosses (Sphagnum) harbor almost 30% of the global soil carbon pool and have functioned as a net carbon sink throughout the Holocene, and probably since the late Tertiary. Before that time, northern latitudes were dominated by tropical and temperate plant groups and ecosystems. Phylogenetic analyses of mosses (phylum Bryophyta) based on nucleotide sequences from the plastid, mitochondrial, and nuclear genomes indicate that most species of Sphagnum are of recent origin (ca. <20 Ma). Sphagnum species are not only well-adapted to boreal peatlands, they create the conditions that promote development of peatlands. The recent radiation that gave rise to extant diversity of peatmosses is temporally associated with Miocene climatic cooling in the Northern Hemisphere. The evolution of Sphagnum has had profound influences on global biogeochemistry because of the unique biochemical, physiological, and morphological features of these plants, both while alive and after death.

  7. Atmospheric Teleconnections of Northern Hemisphere cooling to the Southern Hemisphere midlatitudes, and implications for Southern Ocean ventilation

    Science.gov (United States)

    Chiang, John; Lee, Shih-Yu; Matsumoto, Katsumi; Tokos, Kathy

    2010-05-01

    Recent marine proxy studies, most notably by Anderson et al. (2009), show intensification of wind-driven upwelling in the Southern Ocean during Heinrich events, and suggesting the possibility of robust atmospheric teleconnections from the Northern Hemisphere affecting the Southern Hemisphere midlatitude westerlies. We explore the latter hypothesis using simulations of an AGCM coupled to a reduced-gravity ocean, and with reference to current thinking regarding extratropical-tropical atmospheric dynamical linkages. When we simulate a Heinrich-like event in our model (by cooling the North Atlantic), we find a significant strengthening of the southern midlatitude westerlies, in particular during the austral winter (JJA), and in the South Pacific. The other pronounced climate change is a marked southward shift of the tropical rainbelt, indicating alteration of the Hadley circulation. Our analysis indicates that the teleconnection can be broken into two parts: first, the northern hemisphere cooling shifting the ITCZ southwards with a pronounced effect on the Hadley circulation (Lindzen and Hou 1988), and then the altered Hadley circulation in turn affecting the southern midlatitude westerlies through the former's control of the southern subtropical westerlies and subsequent effect on the eddy-driven midlatitude westerlies (Lee and Kim, 2003). The seasonal (JJA) and regional (South Pacific) preference of the teleconnection's effects can be explained in terms of the peculiarities of the regional atmospheric dynamics. As an aside, we also find that the growth or decay of the Laurentide ice sheet can also generate this type of north-south teleconnection, although the dynamics are somewhat different. With regards to possible implications for southern ocean ventilation and atmospheric CO2: we applied the wind changes we obtained in our AGCM 'Heinrich' simulation to a global biogeochemical model (the Minnesota Earth System Model for Ocean biogeochemistry), and found a ~20ppm

  8. Reorganization of the Cerebro-Cerebellar Network of Language Production in Patients with Congenital Left-Hemispheric Brain Lesions

    Science.gov (United States)

    Lidzba, K.; Wilke, M.; Staudt, M.; Krageloh-Mann, I.; Grodd, W.

    2008-01-01

    Patients with congenital lesions of the left cerebral hemisphere may reorganize language functions into the right hemisphere. In these patients, language production is represented homotopically to the left-hemispheric language areas. We studied cerebellar activation in five patients with congenital lesions of the left cerebral hemisphere to assess…

  9. Reorganization of the Cerebro-Cerebellar Network of Language Production in Patients with Congenital Left-Hemispheric Brain Lesions

    Science.gov (United States)

    Lidzba, K.; Wilke, M.; Staudt, M.; Krageloh-Mann, I.; Grodd, W.

    2008-01-01

    Patients with congenital lesions of the left cerebral hemisphere may reorganize language functions into the right hemisphere. In these patients, language production is represented homotopically to the left-hemispheric language areas. We studied cerebellar activation in five patients with congenital lesions of the left cerebral hemisphere to assess…

  10. The Northern Hemisphere winter stationary wave response to global warming in CMIP5

    Science.gov (United States)

    Simpson, Isla; Seager, Richard; Ting, Mingfang; Shaw, Tiffany

    2015-04-01

    During the Northern Hemisphere winter, models tend to predict a poleward shifting of the zonal mean mid-latitude westerlies under anthropogenic greenhouse gas emissions. Locally, however, changes in the stationary waves tend to dominate, resulting in considerable deviation from this around the longitude circle, with important implications for regional climate change. Past studies have demonstrated diversity in the stationary wave response to global warming and differ in their views of the mechanisms involved in producing it. Here we will explore the stationary wave response to global warming in the CMIP5 dataset and demonstrate a strong consensus on a wavenumber 5 stationary wave response with a particular phasing that contributes to hydroclimate change across North America and Europe, such as wetting on the west coast of the USA, drying in the south west USA and drying in the eastern Mediterranean. The mechanisms responsible for producing this multi-model mean response are explored using a stationary wave model. It is demonstrated that, to first order, it is produced by changes in the zonal mean basic state, in agreement with the majority of previous stationary wave modelling studies. The relative importance of different features of this basic state change such as Arctic amplification, enhanced tropical upper tropospheric warming, stratospheric cooling and their associated zonal mean zonal wind responses will be explored. Through an understanding of the mechanisms involved in this stationary wave response we can begin to assess our confidence in whether the real world will behave as the models do and understand any diversity among the modelled responses.

  11. Eastern Orthodox perspectives on violence

    DEFF Research Database (Denmark)

    Hilton Saggau, Emil

    2017-01-01

    Abstract: In the post-communist era, the contemporary national Eastern Orthodox churches have often been accused of taking either direct or ideological part in violence across Eastern Europe. In several scholarly analyses, the churches have been linked with ethnic and national violence. They have...... thus been identified as an ideological root for a distinctive ethno-religious nationalism either blocking the way for a pluralistic society or simply defying it. These cases of violence and conflicts, as well as their subsequent analysis, only point to a practical and visible manifestation of conflicts......, and they therefore don’t answer a broader theological question, namely the question of the general position of the Eastern Orthodox churches regarding violence. This article will address this broader question of what the Orthodox churches’ position is on violence and discuss the co-relation and intersection between...

  12. Regional Development of Eastern Slovakia

    Directory of Open Access Journals (Sweden)

    Monika Hergezelová

    2017-08-01

    Full Text Available Purpose and Originality: The aim of the work is to provide an overview of regional development in Eastern Slovakia, where are Košice and Prešov Region. The originality of the work lies in the work of enriching the SWOT analysis from the author Eve Rajčáková, which is given in the book deals with the issue of Regional development and regional policy of the European Union and Slovakia. Research question: The conditions of life of people in eastern Slovakia. Method: For writing this contribution will be used method of analysis and statistics. Knowledge on this subject have been looking on the internet and in books and sources of information publicly available. Using the data collected, we dealt with the issue of regional development in the Košice and Prešov regions. Results: The topic was the beginning focused on the overall characteristics of eastern Slovakia. Furthermore, we are at work we dealt with social and economic phenomena in both regions of eastern Slovakia. We focused on GDP, unemployment and tourism, which is in the region is widespread. Society: It is well known that there are obviously different living conditions in eastern Slovakia as in other parts of Slovakia. People are forced to, mainly because of employment, leave their region to move or commute to work to the west. The paper point out the right of this negative phenomenon that is quite visible - high unemployment. Limitations: The limits of work are limited by problems of regional development in eastern Slovakia, mainly focusing on economic and social phenomena in the society.

  13. Right hemisphericity, low self-esteem, and unusual experiences: a response to Vingiano.

    Science.gov (United States)

    Persinger, M A

    1992-10-01

    Vingiano's (1992) challenge concerning the relationship between right hemisphericity, low self-esteem, mystical experiences, and religiosity can be clarified by the concept of vectorial hemisphericity. Ontogenetic intrusions of right-hemispheric processes into the left hemispheric sense of self should be experienced most frequently as an apprehensive "presence" that results in lower self-esteem. Because transient above-normal left-hemispheric activity enhances positive affect and the sense of self, concurrent right-hemispheric intrusions are experienced as mystical experiences. Religiosity would be the consequence of persistent above-normal left-temporofrontal activation that encourages the delusion. Hence, extreme conditions, such as left lateralized temporal-lobe epileptic foci, encourage both mystical and religious experiences.

  14. Right hemisphere involvement in depression: toward a neuropsychological theory of negative affective experiences.

    Science.gov (United States)

    Otto, M W; Yeo, R A; Dougher, M J

    1987-10-01

    Several lines of inquiry provide converging evidence for a critical role for the right cerebral hemisphere in negative affective experiences. This research includes the assessment of affective consequences of both focal cerebral lesions and pharmacological inactivation of one or the other hemisphere, as well as experimental and physiological techniques assessing differential hemispheric activation. The specific nature of right hemispheric involvement is conceptualized as a tendency to become activated by aversive experiences, and once activated, to process stimuli in a manner consistent with the right hemisphere's more negative affective tone. A theory of right hemisphere involvement in depressive affect is presented in detail and its relevance to clinical phenomena, e.g., the co-occurrence of depression and pain, and sex differences in depression, is examined, as is congruence with cognitive theories of depression.

  15. Semantic processing in the left versus right cerebral hemispheres following unilateral hand contractions.

    Science.gov (United States)

    Turner, Casey E; Hahn, Michael E; Kellogg, Ronald T

    2017-03-01

    Unilateral hand contractions increase activation in the motor cortex of the contralateral hemisphere, providing a means to alter the relative degree of activation in the right hemisphere versus the left hemisphere through spreading activation. Prior research reported enhanced verbal creativity as measured by performance on remote associate problems in Hebrew from left-hand contractions (right-hemisphere activation). We sought to extend the previous findings to English problems and to homograph interpretation. In Experiment 1, unilateral hand contractions in fact altered performance on the English remote associates, but in the direction of improved performance following right-hand contractions and left-hemisphere activation. In Experiment 2, the probability of retrieving atypical interpretations of homographs with multiple meanings was least likely for left-hemisphere dominant strong right handers, but the hand contraction manipulation had no effect.

  16. Processing of unconventional stimuli requires the recruitment of the non-specialized hemisphere

    Directory of Open Access Journals (Sweden)

    Yoed Nissan Kenett

    2015-02-01

    Full Text Available In the present study we investigate hemispheric processing of conventional and unconventional visual stimuli in the context of visual and verbal creative ability. In Experiment 1, we studied two unconventional visual recognition tasks – Mooney face and objects' silhouette recognition – and found a significant relationship between measures of verbal creativity and unconventional face recognition. In Experiment 2 we used the split visual field paradigm to investigate hemispheric processing of conventional and unconventional faces and its relation to verbal and visual characteristics of creativity. Results showed that while conventional faces were better processed by the specialized right hemisphere, unconventional faces were better processed by the non-specialized left hemisphere. In addition, only unconventional face processing by the non-specialized left hemisphere was related to verbal and visual measures of creative ability. Our findings demonstrate the role of the non-specialized hemisphere in processing unconventional stimuli and how it relates to creativity.

  17. The Hemispheric Sign Rule of Current Helicity during the Rising Phase of Cycle 23

    Indian Academy of Sciences (India)

    S. D. Bao; G. X. Ai; H. Q. Zhang

    2000-09-01

    We compute the signs of two different current helicity parameters (i.e., best and ) for 87 active regions during the rise of cycle 23. The results indicate that 59% of the active regions in the northern hemisphere have negative best and 65% in the southern hemisphere have positive. This is consistent with that of the cycle 22. However, the helicity parameter shows a weaker opposite hemispheric preference in the new solar cycle. Possible reasons are discussed.

  18. [Delayed development of hemispheric dominance accompanied by a rare form of retarded language development].

    Science.gov (United States)

    Brunner, M; Wirth, G

    1986-04-01

    A severe and unusual form of retarded speech development in an eight-year old boy is analyzed as "right-hemispheric speech" against the background of neuropsychological theories on the specialisation of the cerebral hemispheres and considered in connection with the development of hemispheric dominance. A plan for therapy and teacher counselling is derived from this analysis. The influence of this retarded speech development on the acquisition of reading and writing is also touched upon.

  19. Visuospatial stimulus-bound automatic writing behavior: a right hemispheric stroke syndrome.

    Science.gov (United States)

    Evyapan, D; Kumral, E

    2001-01-23

    Three cases of visuospatial stimulus-bound automatic writing behavior were identified among 80 patients (4%) with acute right cerebral hemispheric stroke. All cases had similar clinical characteristics and writing behavior, and visuospatial stimulus-bound automatic writing was related to visually perceived letters. This syndrome might be specific for right hemispheric stroke and might be included among other hypergraphic syndromes attributable to right hemispheric damage.

  20. Foreword: contributions of Arctic PRISM to monitoring western hemispheric shorebirds

    Science.gov (United States)

    Skagen, Susan K.; Smith, Paul A.; Andres, Brad A.; Donaldson, Garry; Brown, Stephen

    2012-01-01

    Long-term monitoring of populations is of paramount importance to understanding responses of organisms to global environmental change and to evaluating whether conservation practices are yielding intended results through time (Wiens 2009). The population status of many shorebird species, the focus of this volume, remain poorly known. Long-distance migrant shorebirds have proven particularly difficult to monitor, in part because of their highly inaccessible regions. As migrant shorebirds travel the length of the hemisphere, the congregate and disperse in ways that vary among species, locations, and years, presenting serious challenges to designing and implementing monitoring programs. Rigorous field and quantitative methods that estimate population size and monitor trends are vitally needed to direct and evaluate effective conservation measures. Many management efforts depend on unbiased population size estimates; for examples, the shorebird conservation plans for both Canada and the United States seek to restore populations to levels calculated for the 1970s based on the best information available from existing surveys. Further, federal wildlife agencies within the United States and Canada have mandates to understand the state of their nations' resources under various conventions for the protection of migratory birds. Accurate estimates of population size are vital statistics for a variety of conservation activities, such as prioritizing species for conservation action and setting management targets. Areas of essential habitat, such as those designated under the Western Hemisphere Shorebird Reserve Network, the Important Bird Areas program of BirdLife Internationals and the National Audubon Society, or Canada's National Wildlife Areas program, are all evaluated on the basis of proportions of species' populations which they contain. The size, and trends in size, of a species' population are considered key information for assessing its vulnerability and subsequent

  1. Contributions of Arctic PRISM to monitoring western hemispheric shorebirds

    Science.gov (United States)

    Skagen, Susan K.; Smith, Paul A.; Andres, Brad A.; Donaldson, Garry; Brown, Stephen

    2012-01-01

    Long-term monitoring of populations is of paramount importance to understanding responses oforganisms to global environmental change and to evaluating whether conservation practices are yielding intended results through time (Wiens 2009). The population status of many shorebird species, the focus of this volume, remain poorly known. Long-distance migrant shorebirds have proven particularly difficult to monitor, in part because of their highly migratory nature and ranges that extend into highly inaccessible regions. As migrant shorebirds travel the length of the hemisphere, they congregate and disperse in ways that vary among species, locations, and years, presenting serious challenges to designing and implementing monitoring programs. Rigorous field and quantitative methods that estimate population size and monitor trends are vitally needed to direct and evaluate effective conservation measures. Many management efforts depend on unbiased population size estimates; for example, the shorebird conservation plans for both Canada and the United States seek to restore populations to levels calculated for the 1970s based on the best information available from existing surveys. Further, federal wildlife agencies within the United States and Canada have mandates to understand the state of their nations' resources under various conventions for the protection of migratory birds. Accurate estimates of population size are vital statistics for a variety of conservation activities, such as prioritizing species for conservation action and setting management targets. Areas of essential habitat, such as those designated under the Western Hemisphere Shorebird Reserve Network, the Important Bird Areas program of BirdLife International and the National Audubon Society, or Canada's National Wildlife Areas program, are all evaluated on the basis ofproportions of species' populations which they contain. The size, and trends in size, ofa species' population are considered key information

  2. Western juniper in eastern Oregon.

    Science.gov (United States)

    Donald R. Gedney; David L. Azuma; Charles L. Bolsinger; Neil. McKay

    1999-01-01

    This report analyzes and summarizes a 1988 inventory of western juniper (Juniperus occidentalis Hook.) in eastern Oregon. This inventory, conducted by the Pacific Northwest Research Station of the USDA Forest Service, was intensified to meet increased need for more information about the juniper resource than was available in previous inventories. A...

  3. Citizenship Norms in Eastern Europe

    Science.gov (United States)

    Coffe, Hilde; van der Lippe, Tanja

    2010-01-01

    Research on Eastern Europe stresses the weakness of its civil society and the lack of political and social involvement, neglecting the question: What do people themselves think it means to be a good citizen? This study looks at citizens' definitions of good citizenship in Poland, Slovenia, the Czech Republic and Hungary, using 2002 European Social…

  4. Citizenship norms in Eastern Europe

    NARCIS (Netherlands)

    Coffé, H.R.; Lippe, T. van der

    2010-01-01

    Research on Eastern Europe stresses the weakness of its civil society and the lack of political and social involvement, neglecting the question: What do people themselves think it means to be a good citizen? This study looks at citizens’ definitions of good citizenship in Poland, Slovenia, the Czech

  5. Citizenship norms in Eastern Europe

    NARCIS (Netherlands)

    Coffé, H.R.; Lippe, T. van der

    2010-01-01

    Research on Eastern Europe stresses the weakness of its civil society and the lack of political and social involvement, neglecting the question: What do people themselves think it means to be a good citizen? This study looks at citizens’ definitions of good citizenship in Poland, Slovenia, the Czech

  6. Currency substitution in Eastern Europe

    NARCIS (Netherlands)

    van Aarle, B.; Budina, N.

    1995-01-01

    Monetary instability during the transition process from a command economy to a market economy has induced a considerable increase in currency substitution in Eastern Europe. Currency substitution itself affects monetary stability since it reduces the stability of velocity. This paper investigates cu

  7. Astroparticle Physics at Eastern Colombia

    CERN Document Server

    Asorey, Hernan

    2015-01-01

    We present the emerging panorama of Astroparticle Physics at Eastern Colombia, and describe several ongoing projects, most of them related to the Latin American Giant Observatory (LAGO) Project. This research work is carried out at the Grupo de Investigaciones en Relatividad y Gravitaci\\'on of Universidad Industrial de Santander.

  8. Anthracnose Diseases of Eastern Hardwoods

    Science.gov (United States)

    Frederick H. Berry

    1985-01-01

    Anthracnose diseases of hardwood trees are widespread throughout the Eastern United States. The most common symptom of these diseases is dead areas or blotches on the leaves. Because of the brown and black, scorched appearance of the leaves, the diseases are sometimes called leaf blight.

  9. Functional magnetic resonance imaging study on dysphagia after unilateral hemispheric stroke: a preliminary study.

    Science.gov (United States)

    Li, S; Luo, C; Yu, B; Yan, B; Gong, Q; He, C; He, L; Huang, X; Yao, D; Lui, S; Tang, H; Chen, Q; Zeng, Y; Zhou, D

    2009-12-01

    Swallowing dysfunction is common and disabling after acute stroke; however, the mechanism of dysphagia or recovery of swallowing from dysphagia remains uncertain. The purpose of this study was to explore cerebral activation of swallowing in dysphagia using functional MRI (fMRI) to compare the functional anatomy of swallowing in unilateral hemispheric stroke patients and healthy adults. In total, five left hemispheric stroke patients with dysphagia, five right hemispheric stroke patients with dysphagia and 10 healthy controls were examined with event related fMRI while laryngeal swallow related movements were recorded. Data were processed using the general linear model. A multifocal cerebral representation of swallowing was identified predominantly in the left hemisphere, in a bilateral and asymmetrical manner. Cerebral activation during swallowing tasks was localised to the precentral, postcentral and anterior cingulate gyri, insula and thalamus in all groups. Activation of volitional swallowing in dysphagic unilateral hemispheric stroke patients might require reorganisation of the dominant hemispheric motor cortex, or a compensatory shift in activation to unaffected areas of the hemisphere. The results indicate that unilateral stroke of either cerebral hemisphere can produce dysphagia. Effective recovery is associated with cerebral activation related to cortical swallowing representation in the compensating or recruited areas of the intact hemisphere. Functional MRI is a useful method for exploring the spatial localisation of changes in neuronal activity during tasks that may be related to recovery. Therefore, the subsequent information gleaned from changes in neural plasticity could be useful for assessing the prognosis of dysphagic stroke.

  10. Is hemispheric language dominance relevant in musical hallucinations? Two case reports.

    Science.gov (United States)

    Evers, Stefan; Ellger, Tanja; Ringelstein, Erich B; Knecht, Stefan

    2002-12-01

    It has been suggested that musical hallucinations are often due to a focal brain lesion predominantly of right hemispheric pathologies. We report about two patients with musical hallucinations associated with a brain tumor of the right hemisphere. Although both patients were right-handed, one of them had a right hemispheric dominance for language as proven by the Wada test. The musical ability as measured by the Seashore test was not impaired. We conclude that the language dominance of the hemisphere is not primarily relevant for the development of musical hallucinations.

  11. Qualitatively different organizational structures of lexical knowledge in the left and right hemisphere.

    Science.gov (United States)

    Drews, E

    1987-01-01

    The present study investigates and discusses the organization of lexical knowledge in the intact left and right hemisphere within the framework of hemisphere-specific cognitive modes of processing. Using a divided visual field technique, word pairs of concrete nouns had to be judged. Semantic relation was either intraconceptual (coordinates) or interconceptual (locative). The results suggest that the left hemisphere, lexical structures are predominantly based on intraconceptual relationships corresponding to its analytic sequential processing mechanism, whereas in the right hemisphere, lexical entries are exclusively associated by means of interconceptual relationships in accordance with its "gestalthaft" holistic processor.

  12. Representation Activity of The Right and Left Hemispheres of the Brain

    Directory of Open Access Journals (Sweden)

    N. N. Nikolaenko

    1997-01-01

    Full Text Available Drawings by psychiatric patients were studied in various states (i in depression; (ii after neuroleptic injection; and (iii during left hemisphere suppression induced by unilateral electroconvulsive seizure (UES. In these states, right hemisphere activation predominates. The results of the study demonstrate that, under the predominance of right hemisphere activation over the left hemisphere, there is a tendency to reproduce the image of the object and to represent it in near space. Drawings by psychiatric patients were also investigated in (i the manic state; (ii after injection of psychotropic drugs which improved the mood; and (iii during right hemisphere suppression following right-sided UES. Under these conditions, left hemisphere activation predominates and the drawings loose the illusion of three-dimensional space. A tendency to reproduce the knowledge and the ideas of the object and to represent it in distant space was observed. Thus, both hemispheres may represent space and elaborate perceptive and conceptional models of the world in different ways. It is probable that different types of representation are based on global (right-hemispheric in comparison with focal (left-hemispheric attention to space.

  13. An ERP investigation of the co-development of hemispheric lateralization of face and word recognition.

    Science.gov (United States)

    Dundas, Eva M; Plaut, David C; Behrmann, Marlene

    2014-08-01

    The adult human brain would appear to have specialized and independent neural systems for the visual processing of words and faces. Extensive evidence has demonstrated greater selectivity for written words in the left over right hemisphere, and, conversely, greater selectivity for faces in the right over left hemisphere. This study examines the emergence of these complementary neural profiles, as well as the possible relationship between them. Using behavioral and neurophysiological measures, in adults, we observed the standard finding of greater accuracy and a larger N170 ERP component in the left over right hemisphere for words, and conversely, greater accuracy and a larger N170 in the right over the left hemisphere for faces. We also found that although children aged 7-12 years revealed the adult hemispheric pattern for words, they showed neither a behavioral nor a neural hemispheric superiority for faces. Of particular interest, the magnitude of their N170 for faces in the right hemisphere was related to that of the N170 for words in their left hemisphere. These findings suggest that the hemispheric organization of face recognition and of word recognition does not develop independently, and that word lateralization may precede and drive later face lateralization. A theoretical account for the findings, in which competition for visual representations unfolds over the course of development, is discussed.

  14. Hemispheric specialization and independence for word recognition: a comparison of three computational models.

    Science.gov (United States)

    Weems, Scott A; Reggia, James A

    2004-06-01

    Two findings serve as the hallmark for hemispheric specialization during lateralized lexical decision. First is an overall word advantage, with words being recognized more quickly and accurately than non-words (the effect being stronger in response latency). Second, a right visual field advantage is observed for words, with little or no hemispheric differences in the ability to identify non-words. Several theories have been proposed to account for this difference in word and non-word recognition, some by suggesting dual routes of lexical access and others by incorporating separate, and potentially independent, word and non-word detection mechanisms. We compare three previously proposed cognitive theories of hemispheric interactions (callosal relay, direct access, and cooperative hemispheres) through neural network modeling, with each network incorporating different means of interhemispheric communication. When parameters were varied to simulate left hemisphere specialization for lexical decision, only the cooperative hemispheres model showed both a consistent left hemisphere advantage for word recognition but not non-word recognition, as well as an overall word advantage. These results support the theory that neural representations of words are more strongly established in the left hemisphere through prior learning, despite open communication between the hemispheres during both learning and recall.

  15. Around the world in 17 days - hemispheric-scale transport of forest fire smoke from Russia in May 2003

    Directory of Open Access Journals (Sweden)

    R. Damoah

    2004-01-01

    Full Text Available In May 2003, severe forest fires in southeast Russia resulted in smoke plumes extending widely across the Northern Hemisphere. This study combines satellite data from a variety of platforms (Moderate Resolution Imaging Spectroradiometer (MODIS, Sea-viewing Wide Field-of-view Sensor (SeaWiFS, Earth Probe Total Ozone Mapping Spectrometer (TOMS and Global Ozone Monitoring Experiment (GOME and vertical aerosol profiles derived with Raman lidar measurements with results from a Lagrangian particle dispersion model to understand the transport processes that led to the large haze plumes observed over North America and Europe. The satellite images provided a unique opportunity for validating model simulations of tropospheric transport on a truly hemispheric scale. Transport of the smoke occurred in two directions: Smoke travelling northwestwards towards Scandinavia was lifted over the Urals and arrived over the Norwegian Sea. Smoke travelling eastwards to the Okhotsk Sea was also lifted, it then crossed the Bering Sea to Alaska from where it proceeded to Canada and was later even observed over Scandinavia and Eastern Europe on its way back to Russia. Not many events of this kind, if any, have been observed, documented and simulated with a transport model comprehensively. The total transport time was about 17 days. We compared transport model simulations using meteorological analysis data from both the European Centre for Medium-Range Weather Forecast (ECMWF and the National Center for Environmental Prediction (NCEP in order to find out how well this event could be simulated using these two datasets. Although differences between the two simulations are found on small scales, both agree remarkably well with each other and with the observations on large scales. On the basis of the available observations, it cannot be decided which simulation was more realistic.

  16. Solar Cycle Length and Northern Hemisphere mean temperature revisited.

    Science.gov (United States)

    Thejll, P.

    2009-04-01

    The statistical relationship between the smoothed curve for solar cycle length and northern hemisphere land mean temperature has been a source of investigation in the question of whether and how much the Sun influences climate variations. The relationship was widely discussed following the 1991 paper by Friis-Christensen and Lassen and was updated in 2000 by Thejll and Lassen. Data for one more solar cycle has now accumulated, and the relationship is again reviewed and discussed. We derive and show the updated SCL and mean temperature curves. The relationship between the two is analysed using standard statistical methods. Additional climate forcing factors are introduced to improve the fit. Changes in the historical part of the mean temperature curve has occurred which modifies the previously seen relationship, and this is discussed.

  17. N=2 gauge theories on the hemisphere $HS^4$

    CERN Document Server

    Gava, Edi; Muteeb, Nouman; Giraldo-Rivera, V I

    2016-01-01

    Using localization techniques, we compute the path integral of $N=2$ SUSY gauge theory coupled to matter on the hemisphere $HS^4$, with either Dirichlet or Neumann supersymmetric boundary conditions. The resulting quantities are wave-functions of the theory depending on the boundary data. The one-loop determinant are computed using $SO(4)$ harmonics basis. We solve kernel and co-kernel equations for the relevant differential operators arising from gauge and matter localizing actions. The second method utilizes full $SO(5)$ harmonics to reduce the computation to evaluating $Q_{SUSY}^2$ eigenvalues and its multiplicities. In the Dirichlet case, we show how to glue two wave-functions to get back the partition function of round $S^4$. We will also describe how to obtain the same results using $SO(5)$ harmonics basis.

  18. Polar cap index as a proxy for hemispheric Joule heating

    DEFF Research Database (Denmark)

    Chun, F.K.; Knipp, D.J.; McHarg, M.G.

    1999-01-01

    The polar cap (PC) index measures the level of geomagnetic activity in the polar cap based on magnetic perturbations from overhead ionospheric currents and distant field-aligned currents on the poleward edge of the nightside auroral oval. Because PC essentially measures the main sources of energy...... input into the polar cap, we propose to use PC as a proxy for the hemispheric Joule heat production rate (JH). In this study, JH is estimated from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure. We fit hourly PC values to hourly averages of JH. Using a data base approximately...... three times larger than studies, we find a quadratic relationship between JH and PC, differentiated by season. A comparison during the November 1993 storm interval with earlier reported methods using the AE index and the cross polar cap potential, shows that the PC-based Joule heating estimate...

  19. Minor Planet Science with the VISTA Hemisphere Survey

    Science.gov (United States)

    Popescu, M.; Licandro, J.; Morate, D.; de León, J.; Nedelcu, D. A.

    2017-03-01

    We have carried out a serendipitous search for Solar System objects imaged by the VISTA Hemisphere Survey (VHS) and have identified 230 375 valid detections for 39 947 objects. This information is available in three catalogues, entitled MOVIS. The distributions of the data in colour-colour plots show clusters identified with the different taxonomic asteroid types. Diagrams that use (Y–J) colour separate the spectral classes more effectively than any other method based on colours. In particular, the end-class members A-, D-, R-, and V-types occupy well-defined regions and can be easily identified. About 10 000 asteroids were classified taxonomically using a probabilistic approach. The distribution of basaltic asteroids across the Main Belt was characterised using the MOVIS colours: 477 V-type candidates were found, of which 244 are outside the Vesta dynamical family.

  20. A [111]-Cut Si Hemisphere Two-Photon Response Photodetector

    Institute of Scientific and Technical Information of China (English)

    LIU Xiu-Huan; CHEN Zhan-Guo; JIA Gang; WANG Hai-Yan; GAO Yan-Jun; LI Yi1

    2011-01-01

    Properties of two-photon response in a [lll]-cut nearly-intrinsic Si hemisphere photodetector are studied. The measured photocurrent of the photodetector responding to the 1.32μm continuous wave laser shows a quadratic dependence on the coupled optical power and is saturated with the bias voitage. Also, the photocurrent is independent of polarization. Such properties are in good agreement with the theory of two-photon absorption. The isotropic photocurrent generated from the [lll]-cut Si hemisphere is compared to the anisotropic one induced in the [110]-cut Si sample and the ratio of Xxxxx /Xxxyy for silicon performing at 1.32μm is calculated to be 2.4 via the fitted function of the anisotropic photocurrent from the [110]-cut sample.%Properties of two-photon response in a [111]-cut nearly-intrinsic Si hemisphere photodetector are studied.The measured photocurrent of the photodetector responding to the 1.32 μm continuous wave laser shows a quadratic dependence on the coupled optical power and is saturated with the bias voltage.Also,the photocurrent is independent of polarization.Such properties are in good agreement with the theory of two-photon absorption.The isotropic photocurrent generated from the [111]-cut Si hemisphere is compared to the anisotropic one induced in the [110]-cut Si sample and the ratio of Xxxxx /Xxxyy for silicon performing at 1.32μm is calculated to be 2.4via the fitted function of the anisotropic photocurrent from the [110]-cut sample.Silicon materials have a variety of applications in microelectronics and silicon optoelectronics and are still attractive to relevant researchers.Commercial Si photodetectors are largely designed based on singlephoton absorption (SPA).However,nonlinear characteristics have been exhibited in silicon devices.Specifically,two-photon absorption (TPA) has attracted much attention in such devices of Si p-n and p-i-n photodiodes,Si waveguides and Si avalanche diodes,etc.for the autocorrelation measurements of

  1. Modulation of the Southern Hemisphere climate by solar radiation management

    Science.gov (United States)

    Phipps, Steven; Lenton, Andrew; Rotstayn, Leon; Gupta, Alex Sen; Ji, Duoying; Moore, John; Niemeier, Ulrike; Schmidt, Hauke; Tilmes, Simone

    2015-04-01

    Geoengineering is increasingly being considered as a means to lessen the climatic impacts of anthropogenic greenhouse gas emissions. However, it is not without significant risks of its own. In this study, we investigate the response of the Southern Hemisphere (SH) climate to solar radiation management (SRM) using Geoengineering Model Intercomparison Project experiments G3 and G3solar. We find that the response to SRM is characterized by a contraction of the Hadley Cell and subtropical dry zones. This is accompanied by a shift towards a less positive state of the Southern Annular Mode and a northward shift of the SH westerly winds, mitigating the trends under projected future anthropogenic forcing. These changes result in an increase in precipitation minus evaporation in the SH subtropics, suggesting that SRM may be effective at counteracting the anthropogenically-driven drying trend in this region. However, any beneficial impacts cease abruptly as soon as geoengineering is terminated.

  2. A note on hemispheric and global temperature changes

    Energy Technology Data Exchange (ETDEWEB)

    Wiin-Nielsen, A. [Department of Geophysics, Niels Bohr Institute for Astronomy, Physics and Geophysics, Copenhagen, (Denmark)

    1997-07-01

    The paper discusses a lower to middle tropospheric temperature record obtained from a satellite micro-wave sounder (MSU) using channel 2R. The temperature record, giving monthly mean temperatures for the 18 years from 1979 to 1996, inclusive, and for the two hemispheres and the Globe, are analysed with the purpose of finding long term trends. A comparison is made with temperature records using standard data. [Spanish] El presente trabajo discute un registro de baja a media temperatura troposferica, obtenida de un satelite micro-wave sounder (MSU) usando el canal 2R. El registro que da temperaturas medias mensuales para los 18 anos desde 1979 a 1996, inclusive, y para los dos hemisferios y el Globo, son analizados con el proposito de encontrar tendencias a largo plazo. Se hizo una comparacion con los registros de temperatura usando datos estandares.

  3. Converging spherical wave propagation in a hemispherical solid lens

    Science.gov (United States)

    Zhang, Yaoju; Ye, Xuehua; Chen, Junfeng

    2006-06-01

    The propagation of converging spherical waves through a hemispherical solid lens (HSL) is studied, and the multiple reflections inside the HSL are considered. It is found that the reflectivity and transmissivity have an oscillatory behaviour related to the optical radius of the HSL. When the refractive index of the HSL is smaller than that of the sample, the small mismatch in refractive indices is preferable for transmission-mode microscopy. But when the refractive index of the HSL is larger than that of the sample, the reflectivity increases rapidly as the mismatch in refractive indices and the converging angle of incident light increase, the larger mismatch and converging angle are useful for reflection-mode microscopy. The magnitude of the whole reflectivity and its modulation depth are strongly sensitive to the incident polarization, which is also discussed.

  4. K.M. Bykov and transfer between the hemispheres.

    Science.gov (United States)

    Glickstein, Mitchell; Berlucchi, Giovanni

    2008-09-30

    Experiments in the laboratory of Roger Sperry showed that section of the corpus callosum blocks the normally strong transfer of information between the two hemispheres of the brain. In some of the papers from Sperry's lab, work by Bykov in Pavlov's lab was cited, since he appeared to have found similar results earlier. At the time, the only source on Bykov's experiment that was easily available was an abstract in a German journal. Although Bykov was the author of the paper, he did not write the abstract. The author of the abstract was Mark Serejski. Recently we obtained a copy of Bykov's original article in Russian, and arranged for it to be translated into English. The full article makes it clear that the abstract was somewhat misleading both in the methods and the results of Bykov's study. Here we present an English translations of Bykov's paper and the Serejski abstract, along with comments on the discrepancies between the two.

  5. Hemispherical power asymmetry from scale-dependent modulated reheating

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, John, E-mail: j.mcdonald@lancaster.ac.uk [Lancaster-Manchester-Sheffield Consortium for Fundamental Physics, Cosmology and Astroparticle Physics Group, Dept. of Physics, University of Lancaster, Lancaster LA1 4YB (United Kingdom)

    2013-11-01

    We propose a new model for the hemispherical power asymmetry of the CMB based on modulated reheating. Non-Gaussianity from modulated reheating can be small enough to satisfy the bound from Planck if the dominant modulation of the inflaton decay rate is linear in the modulating field σ. σ must then acquire a spatially-modulated power spectrum with a red scale-dependence. This can be achieved if the primordial perturbation of σ is generated via tachyonic growth of a complex scalar field. Modulated reheating due to σ then produces a spatially modulated and scale-dependent sub-dominant contribution to the adiabatic density perturbation. We show that it is possible to account for the observed asymmetry while remaining consistent with bounds from quasar number counts, non-Gaussianity and the CMB temperature quadupole. The model predicts that the adiabatic perturbation spectral index and its running will be modified by the modulated reheating component.

  6. Black carbon aerosol-induced Northern Hemisphere tropical expansion

    Science.gov (United States)

    Kovilakam, Mahesh; Mahajan, Salil

    2015-06-01

    Global climate models (GCMs) underestimate the observed trend in tropical expansion. Recent studies partly attribute it to black carbon (BC) aerosols, which are poorly represented in GCMs. We conduct a suite of idealized experiments with the Community Atmosphere Model version 4 coupled to a slab ocean model forced with increasing BC concentrations covering a large swath of the estimated range of current BC radiative forcing while maintaining their spatial distribution. The Northern Hemisphere (NH) tropics expand poleward nearly linearly as BC radiative forcing increases (0.7° W-1 m2), indicating that a realistic representation of BC could reduce GCM biases. We find support for the mechanism where BC-induced midlatitude tropospheric heating shifts the maximum meridional tropospheric temperature gradient poleward resulting in tropical expansion. We also find that the NH poleward tropical edge is nearly linearly correlated with the location of the Intertropical Convergence Zone, which shifts northward in response to increasing BC.

  7. Asperger syndrome: tests of right hemisphere functioning and interhemispheric communication.

    Science.gov (United States)

    Gunter, Helen L; Ghaziuddin, Mohammad; Ellis, Hadyn D

    2002-08-01

    The primary aim of this investigation was to assess to what extent Rourke's (1989, 1995) nonverbal learning disabilities syndrome (NLD) model resembles the pattern of assets and deficits seen in people with Asperger syndrome (AS). NLD can be characterized by a cluster of deficits primarily affecting nonverbal aspects of functioning, in the presence of proficiency in single word reading and a superior verbal memory. The neurological underpinnings of this syndrome may be dysfunction of white matter affecting right hemisphere functioning and interhemispheric communication. To explore this hypothesis, eight participants with AS (ages 10 to 41 years) were assessed in the following areas: the pragmatics of language and communication, verbal and visual memory, visual-spatial abilities, and bimanual motor skills. Results confirmed the close similarity in the neuropsychologic profiles of NLD and AS.

  8. Towards a governance agenda for the emerging Atlantic Hemisphere

    Directory of Open Access Journals (Sweden)

    Daniel S. Hamilton

    2013-09-01

    Full Text Available The Atlantic Basin is re-emerging as an important subsystem within the global political economy: inter-linked flows of people and energy, money and weapons,goods and services, technology and terror,drugs and crime; greater access to each other’s markets, resources, and talent. Yet,growing interdependencies gene-rate new vulnerabilities and challenges: cooperation over resources and energy connections; promotion of trade and investment; migration and integration; building resilient societies; enhancement of good governance; investment in human development; and the fight against transnational criminal organisations and their growing links to terrorists and insurgents. However, while governance mechanisms and diplomatic cooperation based on a pan-Atlantic framework are in their infancy, a host of developments suggests that broadranging, interwoven hemispheric cooperation may be possible. In fact, the Atlantic Basin may emerge as a global laboratory for interregional, networked governance between developed and emerging countries.

  9. Design of a Quasi-Hemispherical UWB Antenna

    DEFF Research Database (Denmark)

    Zhekov, Stanislav Stefanov; Tatomirescu, Alexandru; Franek, Ondrej

    2016-01-01

    This paper proposes a design of three-dimensional antenna for ultrawideband applications. The antenna has dimensions of 58 mm x 58 mm x 76.5 mm and is composed of two identical arms. Each arm consists of a hollow quasi-hemisphere and an inner for it tube. In the simulation, a 50 Ω coaxial cable...... is employed to feed the antenna in order to assess the change of the antenna performance due to the cable effect. The simulated results show that the antenna is capable of operating in the frequency band from 7 to 32.5 GHz with S11 below -10 dB, while maintaining an omnidirectional radiation pattern....... The simulated total efficiency is above 88 % over the entire impedance bandwidth which indicates a good antenna performance. The realized gain varies from 0.8 to 3.1 dBi with frequency....

  10. Darwin as a plant scientist: a Southern Hemisphere perspective.

    Science.gov (United States)

    Hopper, Stephen D; Lambers, Hans

    2009-08-01

    Events around the world this year celebrate the bicentenary of the birth of Charles Darwin (1809-1882) and the sesquicentenary of publication of his most important work, The Origin of Species (Darwin 1859). The associated plethora of books and papers now appearing to commemorate Darwin's work continue the traditional emphasis on his zoological and geological contributions. There has been some recent attention directed towards Darwin's relatively unsung but significant accomplishments as a botanist. Here, we bring together a review of Darwin's botanical discoveries and experiments and relevant aspects of his geological investigations, with a focus on the Southern Hemisphere. This is a relatively unexplored aspect of Darwin's contributions that yields some new insights meriting future research.

  11. Language in Education in Eastern Africa.

    Science.gov (United States)

    Gorman, T. P., Ed.

    This volume contains the papers given at the first Eastern Africa Conference on Language and Linguistics, held in Dar es Salaam in December 1968, under the auspices of the Survey of Language Use and Language Teaching in Eastern Africa. The chief aim of the Conference was to bring together scholars and teachers working in Eastern Africa interested…

  12. The Northern Hemispheric Circumpolar Vortex under Climate Change

    Science.gov (United States)

    Leckebusch, G. C.; Befort, D. J.; Wild, S.

    2015-12-01

    The Circumpolar Vortex (CPV) in the troposphere is a main feature of weather and climate steering phenomena on both hemispheres. Its extent, position and strength are strongly linked to respective anomalies not only in the mid- to upper-troposphere but also to surface conditions. Thus, the CPV has fundamental importance for the positioning of e.g., the polar frontal structure, the inherent temperature gradients, the baroclinic jet and related baroclinic wave disturbances. For example, in winter 2013/14 an extended southward extension combined with a deep geopotential trough over North America led to extreme cold conditions and upstream surface high pressure anomalies were responsible for a significant reduction of cyclones over the North Pacific. This study aims at the anthropogenic impact on the structure of the winter CPV on the northern hemisphere (NH, DJF) as a main driver of subsequent changes also for extreme event occurrence. We analyse the transient change up to 2100 under the RCP8.5 scenario using 8 state-of-the-art CMIP5 AOGCMs with in total 62 individual simulations for the 20C- and 32 members for the RCP8.5-period. Our results show a good validation of the models' performance (ensemble mean) against ERA-Interim reanalyses for circularity, a slightly slower velocity, but an underestimation for the extent of the CPV, accompanied by a high model-to-model variability. The climate change signal is characterized by a reduction of the extent of the CPV from 33% to 26% of the NH area (a relative change of about 20%), a reduction from 32 m/s to 28m/s (a relative change of about 13%), and a moderate decrease in circularity. Impacts on specific regions will be discussed.

  13. Phonotactic awareness deficit following left-hemisphere stroke

    Directory of Open Access Journals (Sweden)

    Maryam Ghaleh

    2015-04-01

    Likert-type scale responses were z-transformed and coded accurate for positive z-values in condition 3 and negative z-values in condition 1 trials. Accuracy was analyzed using binomial mixed effects models and z-transformed scale responses were analyzed using linear mixed effects models. For both analyses, the fixed effects of stimulus, trial number, group (patient/control, education, age, response time, phonotactic regularity (1/3, and gender were examined along with all relevant interactions. Random effects for participant and stimuli as well as random slopes were also included. Model fitting was performed in a backward-stepwise iterative fashion, followed by forward fitting of maximal random effects structure. Models were evaluated by model fitness comparisons using Akaike Information Criterion and Bayesian Information Criterion. Accuracy analysis revealed that healthy participants were significantly more accurate than patients [β = 0.47, p<0.001] in Englishness rating. Scale response analysis revealed a significant effect of phonotactic regularity [β = 1.65, p<0.0001] indicating that participants were sensitive to phonotactic regularity differences among non-words. However, the significant interaction of group and phonotactic regularity [β = -0.5, p= 0.02] further demonstrated that, compared to healthy adults, patients were less able to recognize the phonotactic regularity differences between non-words. Results suggest that left-hemisphere lesions cause impaired phonotactic processing and that the left hemisphere might be necessary for phonotactic awareness. These preliminary findings will be followed up by further analyses investigating the interactions between phonotactic processing and participants’ scores on other linguistic/cognitive tasks as well as lesion-symptom mapping.

  14. First record of Rhizoscyphus ericae in Southern Hemisphere's Ericaceae.

    Science.gov (United States)

    Bruzone, M Clara; Fehrer, Judith; Fontenla, Sonia B; Vohník, Martin

    2017-02-01

    Ericoid mycorrhiza is arguably the least investigated mycorrhizal type, particularly when related to the number of potential hosts and the ecosystems they inhabit. Little is known about the global distribution of ericoid mycorrhizal (ErM) fungi, and this holds true even for the prominent ErM mycobiont Rhizoscyphus ericae. Earlier studies suggested R. ericae might be low in abundance or absent in the roots of Southern Hemisphere's Ericaceae, and our previous investigations in two Argentine Patagonian forests supported this view. Here, we revisited the formerly investigated area, albeit at a higher altitude, and screened fungi inhabiting hair roots of Gaultheria caespitosa and Gaultheria pumila at a treeless alpine site using the same methods as previously. We obtained 234 isolates, most of them belonging to Ascomycota. In contrast to previous findings, however, among 37 detected operational taxonomic units (OTUs), OTU 1 (=R. ericae s. str.) comprised the highest number of isolates (87, ∼37 %). Most of the OTUs and isolates belonged to the Helotiales, and 82.5 % of isolates belonged to OTUs shared between both Gaultheria species. At the alpine site, ericoid mycorrhizal fungi dominated, followed by dark septate endophytes and aquatic hyphomycetes probably acting as root endophytes. Our results suggest that the distribution of R. ericae is influenced, among others, by factors related to altitude such as soil type and presence/absence and type of the neighboring vegetation. Our study is the first report on R. ericae colonizing Ericaceae roots in the Southern Hemisphere and extends the known range of this prominent ErM species to NW Patagonia.

  15. Hemispheric transport and influence of meteorology on global aerosol climatology

    Directory of Open Access Journals (Sweden)

    T. L. Zhao

    2012-04-01

    Full Text Available Based on a 10-yr simulation with the global air quality modeling system GEM-AQ/EC, the inter-annual and seasonal variability as well as the mean climate of hemispheric aerosol transport (HAT was investigated. The intercontinental aerosol transport is predominant in the zonal direction from west to east with the magnitudes of inter-annual variability between 14% and 63%, and are 0.5–2 orders of magnitude weaker in the meridional direction but with larger inter-annual variability. The HAT is found to fluctuate seasonally with a factor of 5–8 between the maximum in late winter and spring and the minimum in late summer and fall. Three meteorological factors controlling the inter-annual aerosol variations in the source-receptor (S-R relationships are identified from the modeling results: (1 Anomalies in the mid-latitude westerlies in the troposphere. (2 Variations of precipitation over the intercontinental transport pathways and (3 Changes of meteorological conditions in the boundary layer. Changed only by the meteorology, the aerosol column loadings in the free troposphere over the HTAP-regions vary inter-annually with the highest magnitudes of 30–37% in January and December and the lowest magnitudes of 16–20% in August and September, and the magnitudes of inter-annual variability within the boundary layer influencing the surface concentrations over the HTAP-regions are 30–70% less than in the free troposphere and more region-dependent. As the strongest climatic signal, the El Niño–Southern Oscillation (ENSO can lead the anomalies in the S-R relationships for intercontinental aerosols in the Northern Hemisphere (NH with the strong/weak transport in the mid-latitude westerlies and the low latitude easterlies for the HAT in El Niño/ La Niña-years.

  16. Isotopic source signatures for atmospheric lead: the Southern Hemisphere

    Science.gov (United States)

    Bollhöfer, A.; Rosman, K. J. R.

    2000-10-01

    Aerosols collected between 1994 and 1999 at more than 70 different sites affecting the Southern Hemisphere have been measured for their 206Pb/ 207Pb, 208Pb/ 207Pb and 206Pb/ 204Pb ratios and Pb concentrations. Lower ratios are found at the southern tips of Africa, Australia and South America probably due to the supply of alkyllead from a common supplier such as Associated Octel. The ratios increase in a northerly direction probably due to a changing market share in alkyllead or an increasing industrial Pb contribution. The geographical variations in isotopic signatures made it possible to broadly characterize the different regions that influence the Southern Hemisphere. Brazil and Argentina exhibited 206Pb/ 207Pb, 208Pb/ 207Pb and 206Pb/ 204Pb ratios in aerosols of 1.141-1.184, 2.416-2.442 and 17.77-18.57, respectively. Mexican aerosols had values of 1.188-1.197, 2.452-2.463 and 18.46-18.73. Aerosols sampled in Chile had low ratios in the South of 1.063-1.094, 2.337-2.373 and 16.46-17.13 which increased in a northerly direction. Emissions from South Africa were characterized by ratios 1.067-1.090, 2.340-2.358 and 16.53-16.99. In 1994-1995 Australia and New Zealand had ratios of 1.060-1.193, 2.324-2.445 and 16.08-18.54. In 1997 however, the range was narrower: 1.072-1.112, 2.342-2.398 and 16.55-17.36, respectively. These isotopic signatures are potentially useful for tracing sources of pollution and the movement of air-masses on a global scale.

  17. Advocacy in the Western Hemisphere Region: some FPA success stories.

    Science.gov (United States)

    Andrews, D J

    1996-01-01

    The International Planned Parenthood Federation's Vision 2000 Strategic Plan has emphasized advocacy and the training of family planning associations (FPAs) in the Western Hemisphere region. During the summer of 1995 training programs in advocacy leadership management were sponsored for six FPAs in the Bahamas, Suriname, Belize, Colombia, Honduras, and Brazil. At the Western Hemisphere Regional Council Meeting in September 1995 awards were presented to FPAs for media outstanding projects. These FPAs used outreach to the community to promote the goals of Vision 2000. The Bahamas FPA won the Rosa Cisneros Award for articles published in a magazine that is distributed in primary and secondary schools and deals with the activities, achievements, and opinions of students. Issues include: love, relationships, responsibility, and teen pregnancy. A weekly television talk show also addresses the issues facing youth including education, music, community work, sexuality, pregnancy, and the relationship between teenagers and adults. The Family Planning Association of Honduras was also nominated for the award for a radio show on the health of mothers and children, the problems of adolescents, and FP. The newspaper Tiempo received the award for feature articles on social issues and FP. In 1994 the Association distributed thousands of booklets on contraceptives as well as fliers on vasectomy, female sterilization, oral contraceptives, IUDs, condoms, responsible parenthood, high-risk pregnancy, vaginal cytology, and cervical cancer. Similar posters were placed in hospitals and health centers, in 1997 FP posts, and 400 commercial outlets. The Family Planning Association of Suriname also carried out an impressive advocacy program during the period of 1968-93 with the goals of establishing a balance between population growth and the available resources to achieve well-being with regard to education, health care, nutrition, and housing.

  18. Superficial white matter: effects of age, sex, and hemisphere.

    Science.gov (United States)

    Phillips, Owen R; Clark, Kristi A; Luders, Eileen; Azhir, Ramin; Joshi, Shantanu H; Woods, Roger P; Mazziotta, John C; Toga, Arthur W; Narr, Katherine L

    2013-01-01

    Structural and diffusion imaging studies demonstrate effects of age, sex, and asymmetry in many brain structures. However, few studies have addressed how individual differences might influence the structural integrity of the superficial white matter (SWM), comprised of short-range association (U-fibers), and intracortical axons. This study thus applied a sophisticated computational analysis approach to structural and diffusion imaging data obtained from healthy individuals selected from the International Consortium for Brain Mapping (ICBM) database across a wide adult age range (n=65, age: 18-74 years, all Caucasian). Fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD) were sampled and compared at thousands of spatially matched SWM locations and within regions-of-interest to examine global and local variations in SWM integrity across age, sex, and hemisphere. Results showed age-related reductions in FA that were more pronounced in the frontal SWM than in the posterior and ventral brain regions, whereas increases in RD and AD were observed across large areas of the SWM. FA was significantly greater in left temporoparietal regions in men and in the posterior callosum in women. Prominent leftward FA and rightward AD and RD asymmetries were observed in the temporal, parietal, and frontal regions. Results extend previous findings restricted to the deep white matter pathways to demonstrate regional changes in the SWM microstructure relating to processes of demyelination and/or to the number, coherence, or integrity of axons with increasing age. SWM fiber organization/coherence appears greater in the left hemisphere regions spanning language and other networks, while more localized sex effects could possibly reflect sex-specific advantages in information strategies.

  19. Hemispheric transport and influence of meteorology on global aerosol climatology

    Directory of Open Access Journals (Sweden)

    T. L. Zhao

    2012-08-01

    Full Text Available Based on a 10-yr simulation with the global air quality modeling system GEM-AQ/EC, the northern hemispheric aerosol transport with the inter-annual and seasonal variability as well as the mean climate was investigated. The intercontinental aerosol transport is predominant in the zonal direction from west to east with the ranges of inter-annual variability between 14% and 63%, and is 0.5–2 orders of magnitude weaker in the meridional direction but with larger inter-annual variability. The aerosol transport is found to fluctuate seasonally with a factor of 5–8 between the maximum in late winter and spring and the minimum in late summer and fall. Three meteorological factors controlling the intercontinental aerosol transport and its inter-annual variations are identified from the modeling results: (1 Anomalies in the mid-latitude westerlies in the troposphere. (2 Variations of precipitation over the intercontinental transport pathways and (3 Changes of meteorological conditions within the boundary layer. Changed only by the meteorology, the aerosol column loadings in the free troposphere over the source regions of Europe, North America, South and East Asia vary inter-annually with the highest magnitudes of 30–37% in January and December and the lowest magnitudes of 16–20% in August and September, and the inter-annual aerosol variability within the boundary layer influencing the surface concentrations with the magnitudes from 6% to 20% is more region-dependent. As the strongest climatic signal, the El Niño-Southern Oscillation (ENSO can lead the anomalies in the intercontinental aerosols in El Niño- and La Niña-years respectively with the strong and weak transport of the mid-latitude westerlies and the low latitude easterlies in the Northern Hemisphere (NH.

  20. Teleconnections associated with Northern Hemisphere summer monsoon intraseasonal oscillation

    Science.gov (United States)

    Moon, Ja-Yeon; Wang, Bin; Ha, Kyung-Ja; Lee, June-Yi

    2013-06-01

    The boreal summer intraseasonal oscillation (BSISO) has strong convective activity centers in Indian (I), Western North Pacific (WNP), and North American (NA) summer monsoon (SM) regions. The present study attempts to reveal BSISO teleconnection patterns associated with these dominant intraseasonal variability centers. During the active phase of ISM, a zonally elongated band of enhanced convection extends from India via the Bay of Bengal and Philippine Sea to tropical central Pacific with suppressed convection over the eastern Pacific near Mexico. The corresponding extratropical circulation anomalies occur along the waveguides generated by the North African-Asian jet and North Atlantic-North European jet. When the tropical convection strengthens over the WNPSM sector, a distinct great circle-like Rossby wave train emanates from the WNP to the western coast of United States (US) with an eastward shift of enhanced meridional circulation. In the active phase of NASM, large anticyclonic anomalies anchor over the western coast of US and eastern Canada and the global teleconnection pattern is similar to that during a break phase of the ISM. Examination of the evolution of the BSISO teleconnection reveals quasi-stationary patterns with preferred centers of teleconnection located at Europe, Russia, central Asia, East Asia, western US, and eastern US and Canada, respectively. Most centers are embedded in the waveguide along the westerly jet stream, but the centers at Europe and Russia occur to the north of the jet-induced waveguide. Eastward propagation of the ISO teleconnection is evident over the Pacific-North America sector. The rainfall anomalies over the elongated band near the monsoon domain over the Indo-western Pacific sector have an opposite tendency with that over the central and southern China, Mexico and southern US, providing a source of intraseasonal predictability to extratropical regions. The BSISO teleconnection along and to the north of the subtropical jet

  1. Low-frequency Pliocene climate variability in the eastern Nordic Seas

    Science.gov (United States)

    Risebrobakken, Bjørg; Andersson, Carin; De Schepper, Stijn; McClymont, Erin L.

    2016-09-01

    The Pliocene (5.3-2.6 Ma) is often described as a relatively stable climatic period, with warm temperatures characterizing high latitudes. New suborbital resolved stable isotope records from Ocean Drilling Program Hole 642B in the eastern Nordic Seas document that the Pliocene was not a stable period characterized by one climate. Rather, seven distinct climate phases, each lasting between 150,000 and 400,000 years, are identified and characterized in the time interval 5.1-3.1 Ma. Four of the transitions between the defined climate phases occurred close to an eccentricity minimum and a minimum in amplitude of change for Northern Hemisphere summer insolation, while two occurred around an eccentricity maximum and a maximum in amplitude in insolation change. Hence, a low-frequency response of the Nordic Seas to insolation forcing is indicated. In addition, paleogeographic and related paleoceanographic changes, expansion of the Arctic sea ice cover, and onset of Northern Hemisphere glaciation were important factors behind the evolving Pliocene low-frequency variability in the eastern Nordic Seas. It is likely that the identified climate phases and transitions are important beyond the Nordic Seas, due to their association with changes to both insolation and paleogeography. However, a strong and variable degree of diagenetic calcite overgrowth is documented for the planktic foraminifera, especially influencing the planktic δ18O results; the absolute values and amplitude of change cannot be taken at face value.

  2. Contralesional motor deficits after unilateral stroke reflect hemisphere-specific control mechanisms.

    Science.gov (United States)

    Mani, Saandeep; Mutha, Pratik K; Przybyla, Andrzej; Haaland, Kathleen Y; Good, David C; Sainburg, Robert L

    2013-04-01

    We have proposed a model of motor lateralization, in which the left and right hemispheres are specialized for different aspects of motor control: the left hemisphere for predicting and accounting for limb dynamics and the right hemisphere for stabilizing limb position through impedance control mechanisms. Our previous studies, demonstrating different motor deficits in the ipsilesional arm of stroke patients with left or right hemisphere damage, provided a critical test of our model. However, motor deficits after stroke are most prominent on the contralesional side. Post-stroke rehabilitation has also, naturally, focused on improving contralesional arm impairment and function. Understanding whether contralesional motor deficits differ depending on the hemisphere of damage is, therefore, of vital importance for assessing the impact of brain damage on function and also for designing rehabilitation interventions specific to laterality of damage. We, therefore, asked whether motor deficits in the contralesional arm of unilateral stroke patients reflect hemisphere-dependent control mechanisms. Because our model of lateralization predicts that contralesional deficits will differ depending on the hemisphere of damage, this study also served as an essential assessment of our model. Stroke patients with mild to moderate hemiparesis in either the left or right arm because of contralateral stroke and healthy control subjects performed targeted multi-joint reaching movements in different directions. As predicted, our results indicated a double dissociation; although left hemisphere damage was associated with greater errors in trajectory curvature and movement direction, errors in movement extent were greatest after right hemisphere damage. Thus, our results provide the first demonstration of hemisphere specific motor control deficits in the contralesional arm of stroke patients. Our results also suggest that it is critical to consider the differential deficits induced by right

  3. Multigene Phylogeography of Bactrocera caudata (Insecta: Tephritidae: Distinct Genetic Lineages in Northern and Southern Hemispheres.

    Directory of Open Access Journals (Sweden)

    Hoi-Sen Yong

    Full Text Available Bactrocera caudata is a pest of pumpkin flower. Specimens of B. caudata from the northern hemisphere (mainland Asia and southern hemisphere (Indonesia were analysed using the partial DNA sequences of the nuclear 28S rRNA and internal transcribed spacer region 2 (ITS-2 genes, and the mitochondrial cytochrome c oxidase subunit I (COI, cytochrome c oxidase subunit II (COII and 16S rRNA genes. The COI, COII, 16S rDNA and concatenated COI+COII+16S and COI+COII+16S+28S+ITS-2 nucleotide sequences revealed that B. caudata from the northern hemisphere (Peninsular Malaysia, East Malaysia, Thailand was distinctly different from the southern hemisphere (Indonesia: Java, Bali and Lombok, without common haplotype between them. Phylogenetic analysis revealed two distinct clades (northern and southern hemispheres, indicating distinct genetic lineage. The uncorrected 'p' distance for the concatenated COI+COII+16S nucleotide sequences between the taxa from the northern and southern hemispheres ('p' = 4.46-4.94% was several folds higher than the 'p' distance for the taxa in the northern hemisphere ('p' = 0.00-0.77% and the southern hemisphere ('p' = 0.00%. This distinct difference was also reflected by concatenated COI+COII+16S+28S+ITS-2 nucleotide sequences with an uncorrected 'p' distance of 2.34-2.69% between the taxa of northern and southern hemispheres. In accordance with the type locality the Indonesian taxa belong to the nominal species. Thus the taxa from the northern hemisphere, if they were to constitute a cryptic species of the B. caudata species complex based on molecular data, need to be formally described as a new species. The Thailand and Malaysian B. caudata populations in the northern hemisphere showed distinct genetic structure and phylogeographic pattern.

  4. Multigene Phylogeography of Bactrocera caudata (Insecta: Tephritidae): Distinct Genetic Lineages in Northern and Southern Hemispheres.

    Science.gov (United States)

    Yong, Hoi-Sen; Lim, Phaik-Eem; Tan, Ji; Song, Sze-Looi; Suana, I Wayan; Eamsobhana, Praphathip

    2015-01-01

    Bactrocera caudata is a pest of pumpkin flower. Specimens of B. caudata from the northern hemisphere (mainland Asia) and southern hemisphere (Indonesia) were analysed using the partial DNA sequences of the nuclear 28S rRNA and internal transcribed spacer region 2 (ITS-2) genes, and the mitochondrial cytochrome c oxidase subunit I (COI), cytochrome c oxidase subunit II (COII) and 16S rRNA genes. The COI, COII, 16S rDNA and concatenated COI+COII+16S and COI+COII+16S+28S+ITS-2 nucleotide sequences revealed that B. caudata from the northern hemisphere (Peninsular Malaysia, East Malaysia, Thailand) was distinctly different from the southern hemisphere (Indonesia: Java, Bali and Lombok), without common haplotype between them. Phylogenetic analysis revealed two distinct clades (northern and southern hemispheres), indicating distinct genetic lineage. The uncorrected 'p' distance for the concatenated COI+COII+16S nucleotide sequences between the taxa from the northern and southern hemispheres ('p' = 4.46-4.94%) was several folds higher than the 'p' distance for the taxa in the northern hemisphere ('p' = 0.00-0.77%) and the southern hemisphere ('p' = 0.00%). This distinct difference was also reflected by concatenated COI+COII+16S+28S+ITS-2 nucleotide sequences with an uncorrected 'p' distance of 2.34-2.69% between the taxa of northern and southern hemispheres. In accordance with the type locality the Indonesian taxa belong to the nominal species. Thus the taxa from the northern hemisphere, if they were to constitute a cryptic species of the B. caudata species complex based on molecular data, need to be formally described as a new species. The Thailand and Malaysian B. caudata populations in the northern hemisphere showed distinct genetic structure and phylogeographic pattern.

  5. Can a coupled meteorology-chemistry model reproduce the historical trend in aerosol direct radiative effects over the Northern Hemisphere?

    Directory of Open Access Journals (Sweden)

    J. Xing

    2015-05-01

    Full Text Available The ability of a coupled meteorology-chemistry model, i.e., WRF-CMAQ, in reproducing the historical trend in AOD and clear-sky short-wave radiation (SWR over the Northern Hemisphere has been evaluated through a comparison of 21 year simulated results with observation-derived records from 1990–2010. Six satellite retrieved AOD products including AVHRR, TOMS, SeaWiFS, MISR, MODIS-terra and -aqua as well as long-term historical records from 11 AERONET sites were used for the comparison of AOD trends. Clear-sky SWR products derived by CERES at both TOA and surface as well as surface SWR data derived from seven SURFRAD sites were used for the comparison of trends in SWR. The model successfully captured increasing AOD trends along with the corresponding increased TOA SWR (upwelling and decreased surface SWR (downwelling in both eastern China and the northern Pacific. The model also captured declining AOD trends along with the corresponding decreased TOA SWR (upwelling and increased surface SWR (downwelling in eastern US, Europe and northern Atlantic for the period of 2000–2010. However, the model underestimated the AOD over regions with substantial natural dust aerosol contributions, such as the Sahara Desert, Arabian Desert, central Atlantic and north Indian Ocean. Estimates of aerosol direct radiative effect (DRE at TOA are comparable with those derived by measurements. Compared to GCMs, the model exhibits better estimates of surface- aerosol direct radiative efficiency (Eτ. However, surface-DRE tends to be underestimated due to the underestimated AOD in land and dust regions. Further investigation of TOA-Eτ estimations as well as the dust module used for estimates of windblown-dust emissions is needed.

  6. Genetic variation in blue whales in the eastern pacific: implication for taxonomy and use of common wintering grounds.

    Science.gov (United States)

    Leduc, R G; Archer, F I; Lang, A R; Martien, K K; Hancock-Hanser, B; Torres-Florez, J P; Hucke-Gaete, R; Rosenbaum, H C; van Waerebeek, K; Brownell, R L; Taylor, B L

    2017-02-01

    Many aspects of blue whale biology are poorly understood. Some of the gaps in our knowledge, such as those regarding their basic taxonomy and seasonal movements, directly affect our ability to monitor and manage blue whale populations. As a step towards filling in some of these gaps, microsatellite and mtDNA sequence analyses were conducted on blue whale samples from the Southern Hemisphere, the eastern tropical Pacific (ETP) and the northeast Pacific. The results indicate that the ETP is differentially used by blue whales from the northern and southern eastern Pacific, with the former showing stronger affinity to the region off Central America known as the Costa Rican Dome, and the latter favouring the waters of Peru and Ecuador. Although the pattern of genetic variation throughout the Southern Hemisphere is compatible with the recently proposed subspecies status of Chilean blue whales, some discrepancies remain between catch lengths and lengths from aerial photography, and not all blue whales in Chilean waters can be assumed to be of this type. Also, the range of the proposed Chilean subspecies, which extends to the Galapagos region of the ETP, at least seasonally, perhaps should include the Costa Rican Dome and the eastern North Pacific as well. © 2016 John Wiley & Sons Ltd.

  7. The Brain's Hemispheres and Controlled Search of the Lexicon: Evidence from Fixated Words and Pseudowords

    Science.gov (United States)

    Rutherford, Barbara J.; Mathesius, Jeffrey R.

    2012-01-01

    Difference between the brain's hemispheres in efficiency of intentional search of the mental lexicon with phonological, orthographic, and semantic strategies was investigated. Letter strings for lexical decision were presented at fixation, with a lateralized distractor to the LVF or RVF. Word results revealed that both hemispheres were capable of…

  8. Finding the Right Word: Hemispheric Asymmetries in the Use of Sentence Context Information

    Science.gov (United States)

    Wlotko, Edward W.; Federmeier, Kara D.

    2007-01-01

    The cerebral hemispheres have been shown to be differentially sensitive to sentence-level information; in particular, it has been suggested that only the left hemisphere (LH) makes predictions about upcoming items, whereas the right (RH) processes words in a more integrative fashion. The current study used event-related potentials to jointly…

  9. Measuring right-hemisphere dysfunction in children: validity of two new computer tests

    NARCIS (Netherlands)

    Sips, H.J.W.A.; C.E. Catsman-Berrevoets (Coriene); H.R. van Dongen (Huug); van der Werff, P.J.J.; Brooke, L.J.

    1994-01-01

    textabstractThe validity of two new computer‐mediated tests for the detection of right‐cerebral hemisphere lesions in children–the Right‐hemisphere Dysfunction Test and the Visual Perception Test–was evaluated. Normative data were drawn from a group of 91 children (aged five to 14 years) and 14

  10. Low Frequency Fluctuations Reveal Integrated and Segregated Processing among the Cerebral Hemispheres

    Science.gov (United States)

    Gee, Dylan G.; Biswal, Bharat B.; Kelly, Clare; Stark, David E.; Margulies, Daniel S.; Shehzad, Zarrar; Uddin, Lucina Q.; Klein, Donald F.; Banich, Marie T.; Castellanos, F. Xavier; Milham, Michael P.

    2011-01-01

    Resting-state functional magnetic resonance imaging (fMRI) has provided a novel approach for examining interhemispheric interaction, demonstrating a high degree of functional connectivity between homotopic regions in opposite hemispheres. However, heterotopic resting state functional connectivity (RSFC) remains relatively uncharacterized. In the present study, we examine non-homotopic regions, characterizing heterotopic RSFC and comparing it to intrahemispheric RSFC, to examine the impact of hemispheric separation on the integration and segregation of processing in the brain. Resting-state fMRI scans were acquired from 59 healthy participants to examine interregional correlations in spontaneous low frequency fluctuations in BOLD signal. Using a probabilistic atlas, we correlated probability-weighted time series from 112 regions (56 per hemisphere) distributed throughout the entire cerebrum. We compared RSFC for pairings of non-homologous regions located in different hemispheres (heterotopic connectivity) to RSFC for the same pairings when located within hemisphere (intrahemispheric connectivity). For positive connections, connectivity strength was greater within each hemisphere, consistent with integrated intrahemispheric processing. However, for negative connections, RSFC strength was greater between the hemispheres, consistent with segregated interhemispheric processing. These patterns were particularly notable for connections involving frontal and heteromodal regions. The distribution of positive and negative connectivity was nearly identical within and between the hemispheres, though we demonstrated detailed regional variation in distribution. We discuss implications for leading models of interhemispheric interaction. The future application of our analyses may provide important insight into impaired interhemispheric processing in clinical and aging populations. PMID:20570737

  11. [Sex differences in relationship between creativity and hemispheric information processing in global and local levels].

    Science.gov (United States)

    Razumnikova, O M; Vol'f, N V

    2012-01-01

    Sex differences in creativity related global-local hemispheric selective processing were examined by hierarchical letter presenting in conditions of their perception and comparison. Fifty-six right-handed males and 68 females (aged 17-22 years) participated in the experiments. Originality-imagery was assessed by a computer-based Torrance 'Incomplete Figures' test software. Verbal creativity was valued by original sentence using of three nouns from remote semantic categories. The results show that irrespectively of the sex factor and the type of creative thinking, its originality is provided by high speed of right-hemispheric processes of information selection on the global level and delay in the interhemispheric communication. Relationships between originality of ideas and hemispheric attentional characteristics are presented mostly in men while verbal creative problem solving, and in women while figurative original thinking. Originality of verbal activity in men is more associated with success of selective processes in the left hemisphere, but in women--with selective functions of both hemispheres. Figurative thinking in men is less related to hemispheric characteristics of attention compared with women. Increase of figurative originality in women is accompanied acceleration of processes of selection of the information in the right hemisphere, and also higher efficiency of local attention as well as speeds ofglobal processing in the left hemisphere.

  12. Efficacy of strategy training in left hemisphere stroke patients with apraxia : A randomised clinical trial

    NARCIS (Netherlands)

    Donkervoort, M; Dekker, J; Stehmann-Saris, FC; Deellman, BG

    2001-01-01

    The objective of the present study was to determine in a controlled study the efficacy of strategy training in left hemisphere stroke patients with apraxia. A total of 113 left hemisphere stroke patients with apraxia were randomly assigned to two treatment groups; (1) strategy training integrated in

  13. Efficacy of strategy training in left hemisphere stroke patients with apraxia: a randomised clinical trial.

    NARCIS (Netherlands)

    Donkervoort, M.; Dekker, J.; Stehmann-Saris, F.C.; Deelman, B.G.

    2001-01-01

    The objective of the present study was to determine in a controlled study the efficacy of strategy training in left hemisphere stroke patients with apraxia. A total of 113 left hemisphere stroke patients with apraxia were randomly assigned to two treatment groups; (1) strategy training integrated in

  14. Efficacy of strategy training in left hemisphere stroke patients with apraxia: a randomized clinical trial.

    NARCIS (Netherlands)

    Dekker, J.; Donkervoort, M.; Stehman, F.C.; Deelman, B.G.

    2001-01-01

    The objective of the present study was to determine in a controlled study the efficacy of strategy training in left hemisphere stroke patients with apraxia. 113 Left hemisphere assigned to two treatment groups: i) strategy training integrated into usual occupational therapy and ii) usual occupationa

  15. Measuring right-hemisphere dysfunction in children: validity of two new computer tests

    NARCIS (Netherlands)

    Sips, H.J.W.A.; C.E. Catsman-Berrevoets (Coriene); H.R. van Dongen (Huug); van der Werff, P.J.J.; Brooke, L.J.

    1994-01-01

    textabstractThe validity of two new computer‐mediated tests for the detection of right‐cerebral hemisphere lesions in children–the Right‐hemisphere Dysfunction Test and the Visual Perception Test–was evaluated. Normative data were drawn from a group of 91 children (aged five to 14 years) and 14 youn

  16. Hemispherical and minimally invasive total hip reamers: a biomechanical analysis of use and design

    Directory of Open Access Journals (Sweden)

    Steven Slotkin, MD, MS

    2017-06-01

    Conclusions: For a manufacturer-specified reamer size, both hemispherical and MIS reamers underream. Newer reamers cut truer to expected values than used ones. MIS reamers performed more accurately than hemispherical reamers. Used acetabular reamer systems may negatively affect the sizing of prepared acetabular beds; therefore, awareness of this potential inaccuracy should be considered when performing total hip arthroplasty.

  17. 77 FR 20369 - Western Hemisphere Institute for Security Cooperation Board of Visitors; Meeting

    Science.gov (United States)

    2012-04-04

    ... Department of the Army Western Hemisphere Institute for Security Cooperation Board of Visitors; Meeting... Hemisphere Institute for Security Cooperation (WHINSEC). Notice of this meeting is required under the Federal...; US Northern Command and US Southern Command as well as receive other information appropriate to...

  18. 76 FR 39076 - Western Hemisphere Institute for Security Cooperation Board of Visitors; Meeting

    Science.gov (United States)

    2011-07-05

    ... Department of the Army Western Hemisphere Institute for Security Cooperation Board of Visitors; Meeting... Hemisphere Institute for Security Cooperation (WHINSEC). Notice of this meeting is required under the Federal... information appropriate to its interests. Date: Tuesday, September 27th, 2011. Time: 8 a.m. to 4 p.m....

  19. Hemispheric Asymmetries in Semantic Processing: Evidence from False Memories for Ambiguous Words

    Science.gov (United States)

    Faust, Miriam; Ben-Artzi, Elisheva; Harel, Itay

    2008-01-01

    Previous research suggests that the left hemisphere (LH) focuses on strongly related word meanings; the right hemisphere (RH) may contribute uniquely to the processing of lexical ambiguity by activating and maintaining a wide range of meanings, including subordinate meanings. The present study used the word-lists false memory paradigm [Roediger,…

  20. EEG correlates of a paper-and-pencil test measuring hemisphericity

    NARCIS (Netherlands)

    Merckelbach, H; Muris, P; Horselenberg, R; de Jong, Peter

    1997-01-01

    The present study examined the validity of the Preference Test (PT), a questionnaire that intends to measure the extent to which subjects rely on right-hemisphere and left-hemisphere cognitions. Normal subjects (N = 20) completed the PT and were then assigned to a group with a relatively strong pref

  1. The Production of Linguistic Prosodic Structures in Subjects with Right Hemisphere Damage

    Science.gov (United States)

    Walker, Judy Perkins; Pelletier, Rebecca; Reif, Lindsay

    2004-01-01

    This study examined the right hemisphere contribution to the production of linguistic prosody where acoustic features of prosodic structures in different linguistic contexts were examined accompanied by perceptual judgements. When control and right hemisphere damaged (RHD) subjects were asked to produce lexical stress differences (Experiment 1),…

  2. Communicating with the non-dominant hemisphere Implications for neurological rehabilitation

    Institute of Scientific and Technical Information of China (English)

    Fabricio Ferreira de Oliveira; Sheilla de Medeiros Correia Marin; Paulo Henrique Ferreira Bertolucci

    2013-01-01

    Aphasic syndromes usually result from injuries to the dominant hemisphere of the brain. Despite the fact that localization of language functions shows little interindividual variability, several brain areas are simultaneously activated when language tasks are undertaken. Mechanisms of language recovery after brain injury to the dominant hemisphere seem to be relatively stereotyped, including activations of perilesional areas in the acute phase and of homologues of language areas in the non-dominant hemisphere in the subacute phase, later returning to dominant hemisphere activation in the chronic phase. Plasticity mechanisms reopen the critical period of language development, more specifically in what leads to disinhibition of the non-dominant hemisphere when brain lesions affect the dominant hemisphere. The non-dominant hemisphere plays an important role during recovery from aphasia, but currently available rehabilitation therapies have shown limited results for efficient language improvement. Large-scale randomized controlled trials that evaluate well-defined interventions in patients with aphasia are needed for stimulation of neuroplasticity mechanisms that enhance the role of the non-dominant hemisphere for language recovery. Ineffective treatment approaches should be replaced by more promising ones and the latter should be evaluated for proper application. The data generated by such studies could substantiate evidence-based rehabilitation strategies for patients with aphasia.

  3. Split-brain, the right hemisphere, and art: fact and fiction.

    Science.gov (United States)

    Zaidel, Dahlia W

    2013-01-01

    The research studies of complete commissurotomy patients (split-brain) in Roger W. Sperry's psychobiology laboratory at Caltech, Pasadena, galvanized the scientific and intellectual world in the 1960s and 1970s. The findings had an important and enduring impact on brain research in countless areas. Interest in hemispheric specialization in particular was sparked by these studies and paved the way for countless discoveries. Right hemisphere specialization for visuospatial functions and facial processing was confirmed with these patients. The further unraveling of right-hemisphere cognition, the "mute" hemisphere, was a major goal in Sperry's laboratory, and much factual knowledge was learned that was not known previously. However, the linking of art and creativity with the right hemisphere was a nonempirically based inference made not by Sperry's lab but rather by others wishing to "assign" functional hemisphericity. The general assumption was that "art" is anchored in spatial cognition, that it is a nonverbal activity requiring imagery and thus must be controlled by the right, nonlanguage hemisphere. To this day, robust evidence that the right specializes in art expression or art perception is yet to be shown, if for no other reason than that art is not a single, unitary form of expression or cognition. The conjectured right hemisphere-art link turned into a popular story that filtered back into science, shaped future research of brain and art, and overlooked other avenues for insights. This chapter traces and explores this background.

  4. Hemispheric specialization and creative thinking: a meta-analytic review of lateralization of creativity

    NARCIS (Netherlands)

    Mihov, K.M.; Denzler, M.; Förster, J.

    2010-01-01

    In the last two decades research on the neurophysiological processes of creativity has found contradicting results. Whereas most research suggests right hemisphere dominance in creative thinking, left-hemisphere dominance has also been reported. The present research is a meta-analytic review of the

  5. Hemispheric Specialization and Creative Thinking: A Meta-Analytic Review of Lateralization of Creativity

    Science.gov (United States)

    Mihov, Konstantin M.; Denzler, Markus; Forster, Jens

    2010-01-01

    In the last two decades research on the neurophysiological processes of creativity has found contradicting results. Whereas most research suggests right hemisphere dominance in creative thinking, left-hemisphere dominance has also been reported. The present research is a meta-analytic review of the literature to establish how creative thinking…

  6. Measuring right-hemisphere dysfunction in children: validity of two new computer tests

    NARCIS (Netherlands)

    Sips, H.J.W.A.; C.E. Catsman-Berrevoets (Coriene); H.R. van Dongen (Huug); van der Werff, P.J.J.; Brooke, L.J.

    1994-01-01

    textabstractThe validity of two new computer‐mediated tests for the detection of right‐cerebral hemisphere lesions in children–the Right‐hemisphere Dysfunction Test and the Visual Perception Test–was evaluated. Normative data were drawn from a group of 91 children (aged five to 14 years) and 14 youn

  7. Hemispheric specialization and creative thinking: a meta-analytic review of lateralization of creativity

    NARCIS (Netherlands)

    Mihov, K.M.; Denzler, M.; Förster, J.

    2010-01-01

    In the last two decades research on the neurophysiological processes of creativity has found contradicting results. Whereas most research suggests right hemisphere dominance in creative thinking, left-hemisphere dominance has also been reported. The present research is a meta-analytic review of the

  8. Efficacy of strategy training in left hemisphere stroke patients with apraxia : A randomised clinical trial

    NARCIS (Netherlands)

    Donkervoort, M; Dekker, J; Stehmann-Saris, FC; Deellman, BG

    2001-01-01

    The objective of the present study was to determine in a controlled study the efficacy of strategy training in left hemisphere stroke patients with apraxia. A total of 113 left hemisphere stroke patients with apraxia were randomly assigned to two treatment groups; (1) strategy training integrated

  9. Left Hemisphere Regions Are Critical for Language in the Face of Early Left Focal Brain Injury

    Science.gov (United States)

    Beharelle, Anjali Raja; Dick, Anthony Steven; Josse, Goulven; Solodkin, Ana; Huttenlocher, Peter R.; Levine, Susan C.; Small, Steven L.

    2010-01-01

    A predominant theory regarding early stroke and its effect on language development, is that early left hemisphere lesions trigger compensatory processes that allow the right hemisphere to assume dominant language functions, and this is thought to underlie the near normal language development observed after early stroke. To test this theory, we…

  10. Strategy Formation in Eastern Jutland

    DEFF Research Database (Denmark)

    Olesen, Kristian

    2008-01-01

    in the area.   The municipalities acknowledge the articulation of the city region and the initiated planning process.  However, the municipalities might see the arena as means to lobby for infrastructure investments in Eastern Jutland, as it is doubtful whether the municipalities will feel encouraged to enter...... a process, which is aiming at increasing the national regulation within their territory.    The result might very well be that the discussion about future infrastructure investments is not linked to discussions about future urban development in Eastern Jutland.  These aspects raises serious questions about...... on which level a serious strategy formation process can take place.  There is a danger that a common strategic spatial plan is more an expression of the lowest common denominator and the municipalities request for infrastructure investments rather than being a spatial strategy with transformative power. ...

  11. Large-scale response of the Eastern Mediterranean thermohaline circulation to African monsoon intensification during sapropel S1 formation

    Science.gov (United States)

    Tesi, T.; Asioli, A.; Minisini, D.; Maselli, V.; Dalla Valle, G.; Gamberi, F.; Langone, L.; Cattaneo, A.; Montagna, P.; Trincardi, F.

    2017-03-01

    The formation of Eastern Mediterranean sapropels has periodically occurred during intensification of northern hemisphere monsoon precipitation over North Africa. However, the large-scale response of the Eastern Mediterranean thermohaline circulation during these monsoon-fuelled freshening episodes is poorly constrained. Here, we investigate the formation of the youngest sapropel (S1) along an across-slope transect in the Adriatic Sea. Foraminifera-based oxygen index, redox-sensitive elements and biogeochemical parameters reveal - for the first time - that the Adriatic S1 was synchronous with the deposition of south-eastern Mediterranean S1 beds. Proxies of paleo thermohaline currents indicate that the bottom-hugging North Adriatic Dense Water (NAdDW) suddenly decreased at the sapropel onset simultaneously with the maximum freshening of the Levantine Sea during the African Humid Period. We conclude that the lack of the "salty" Levantine Intermediate Water hampered the preconditioning of the northern Adriatic waters necessary for the NAdDW formation prior to the winter cooling. Consequently, a weak NAdDW limited in turn the Eastern Mediterranean Deep Water (EMDWAdriatic) formation with important consequences for the ventilation of the Ionian basin as well. Our results highlight the importance of the Adriatic for the deep water ventilation and the interdependence among the major eastern Mediterranean water masses whose destabilization exerted first-order control on S1 deposition.

  12. Phonological and orthographic visual word recognition in the two cerebral hemispheres: Evidence from Hebrew.

    Science.gov (United States)

    Smolka, Eva; Eviatar, Zohar

    2006-09-01

    Studies on the cerebral mechanisms of reading have mostly used Latin-based writing systems and assume that the left, but not the right, cerebral hemisphere is capable of phonological processing. The present study used Hebrew as the test language to examine the effects of phonological and orthographic information in the two hemispheres. In unvoweled Hebrew script, words are read via consonant information alone. We used two naming tasks with an interference paradigm, where phonemically, orthographically, and figurally incorrect vowel information conflicted with the consonant information of words presented in the left, right, or central visual fields. Interference patterns indicated that the left hemisphere automatically transforms graphemes into phonemes (Experiments 1 and 2), whereas the right hemisphere processes vowel diacritics as visual objects (Experiment 1), although it possesses some phonological categories (Experiment 2). The significance of these findings for models of visual word recognition in the cerebral hemispheres is discussed.

  13. Processing of unconventional stimuli requires the recruitment of the non-specialized hemisphere.

    Science.gov (United States)

    Kenett, Yoed N; Anaki, David; Faust, Miriam

    2015-01-01

    In the present study we investigate hemispheric processing of conventional and unconventional visual stimuli in the context of visual and verbal creative ability. In Experiment 1, we studied two unconventional visual recognition tasks-Mooney face and objects' silhouette recognition-and found a significant relationship between measures of verbal creativity and unconventional face recognition. In Experiment 2 we used the split visual field (SVF) paradigm to investigate hemispheric processing of conventional and unconventional faces and its relation to verbal and visual characteristics of creativity. Results showed that while conventional faces were better processed by the specialized right hemisphere (RH), unconventional faces were better processed by the non-specialized left hemisphere (LH). In addition, only unconventional face processing by the non-specialized LH was related to verbal and visual measures of creative ability. Our findings demonstrate the role of the non-specialized hemisphere in processing unconventional stimuli and how it relates to creativity.

  14. Prognostic implications of total hemispheric glucose metabolism ratio in cerebro-cerebellar diaschisis

    DEFF Research Database (Denmark)

    Segtnan, Eivind Antonsen; Grupe, Peter; Jarden, Jens Ole

    2017-01-01

    PURPOSE: Diaschisis denotes brain dysfunction remote from a focal brain lesion. We have quantified diaschisis and investigated its prognostic value in glioma. METHODS AND MATERIAL: We compared 50 (18)F-FDG-PET-CT studies collected prospectively from 14 patients with supratentorial glioma (5 men...... and 9 women aged 35-77 years) with 10 single scans from healthy controls aged 43-75 years. Dedicated 3D-segmentation software was used to obtain total hemispheric glucose metabolic ratios (THGr) by dividing total hemispheric (18)F-fluorodeoxyglucose (FDG) uptake in each diaschitic hemisphere, i.......e., the ipsilateral cerebral hemisphere (THGr(Ce)) and the contralateral cerebellar hemisphere (THGr(Cb)), to its respective contralateral side. Receiver operating characteristic (ROC) analysis was performed to determine optimal cut-offs for combinations of THGr(Ce) and THGr(Cb). Two independent observers obtained...

  15. Hemispheric lateralization of linguistic prosody recognition in comparison to speech and speaker recognition.

    Science.gov (United States)

    Kreitewolf, Jens; Friederici, Angela D; von Kriegstein, Katharina

    2014-11-15

    Hemispheric specialization for linguistic prosody is a controversial issue. While it is commonly assumed that linguistic prosody and emotional prosody are preferentially processed in the right hemisphere, neuropsychological work directly comparing processes of linguistic prosody and emotional prosody suggests a predominant role of the left hemisphere for linguistic prosody processing. Here, we used two functional magnetic resonance imaging (fMRI) experiments to clarify the role of left and right hemispheres in the neural processing of linguistic prosody. In the first experiment, we sought to confirm previous findings showing that linguistic prosody processing compared to other speech-related processes predominantly involves the right hemisphere. Unlike previous studies, we controlled for stimulus influences by employing a prosody and speech task using the same speech material. The second experiment was designed to investigate whether a left-hemispheric involvement in linguistic prosody processing is specific to contrasts between linguistic prosody and emotional prosody or whether it also occurs when linguistic prosody is contrasted against other non-linguistic processes (i.e., speaker recognition). Prosody and speaker tasks were performed on the same stimulus material. In both experiments, linguistic prosody processing was associated with activity in temporal, frontal, parietal and cerebellar regions. Activation in temporo-frontal regions showed differential lateralization depending on whether the control task required recognition of speech or speaker: recognition of linguistic prosody predominantly involved right temporo-frontal areas when it was contrasted against speech recognition; when contrasted against speaker recognition, recognition of linguistic prosody predominantly involved left temporo-frontal areas. The results show that linguistic prosody processing involves functions of both hemispheres and suggest that recognition of linguistic prosody is based on

  16. Changes in southern hemispheric polar amplification over the past 5 million years revealed by climate modelling

    Science.gov (United States)

    Hoencamp, Jori; Stap, Lennert; Tuenter, Erik; Lourens, Luc; van de Wal, Roderik

    2016-04-01

    Knowledge on polar amplification is important to relate high latitude climate records to global mean temperature changes. Several studies have pointed out that the strength of polar amplification in the Northern Hemisphere varies considerably due to the presence of large ice sheets and more sea ice during colder climate conditions. As a result, the polar amplification in the Northern Hemisphere decreases for warmer climates. In this study, we address the fact that these changes in the Northern Hemisphere also affect the polar amplification in the Southern Hemisphere. We study the Southern and Northern Hemisphere amplification together over the past 5 million years with the CLIMBER-2 intermediate complexity model. Radiation, land ice extent and height, and greenhouse gases are prescribed as forcing. We find that in contrast to the reduction in polar amplification in the Northern Hemisphere, polar amplification in the Southern Hemisphere increases for warmer climates. The amplification decreases in the Northern Hemisphere from 2.7 during glacial conditions to 1.6 for a pre-industrial climate, which is line with other climate simulations. Over the same CO2 range the southern hemispheric polar amplification increases from 1 to 1.6. This is caused by the fact that the atmospheric transport needed to balance the radiation surplus in the equatorial region needs to be compensated by relatively stronger transport of energy in Southern direction while the transport in Northern direction reduces. This reduction in Northern direction is driven by less (land and sea) ice resulting in a smaller meridional gradient in Northern direction and hence a smaller atmospheric transport. As a consequence, the traditional scaled (with LGM temperature) Dome C record needs to be corrected with a maximum of 0.6 degrees half-way glacial and interglacial conditions, if it is to be interpreted as global mean temperature change indicator. While this changes the amplitude, the phasing of

  17. Extending the K-band celestial frame emphasizing Southern hemisphere.

    Science.gov (United States)

    de Witt, A.; Bertarini, A.; Horiuchi, S.; Jacobs, C.; Jung, T.; Lovel, J.; McCallum, J.; Quick, J.; Sohn, B. W.; Ojha, R.

    2014-12-01

    K-band radio observations have the potential to form the basis for the most accurate celestial reference frame (CRF) ever constructed. We present a new collaboration to observe southern hemisphere extra-galactic radio sources at 22 GHz (K-band). The aim of this project is to densify the ICRF at that frequency and to provide calibrators for astronomy. Relative to the standard S/X observing bands, at K-band sources are expected to exhibit more compact source morphology and reduced core shift. This reduction of astrophysical systematics should be advantageous in tying the VLBI radio frame to the Gaia optical frame. Initial fringe demonstrations were carried out on 23 August 2013 between telescopes in Australia, Korea and South Africa. The Korea to South Africa baselines will extend K-band CRF coverage down to about -45° declination. Observations between Australia and South Africa will extend coverage to the south polar cap and thus gain full sky coverage for the K-band CRF. The second phase of our plan includes more extensive astrometric observations to complete sky coverage at K-band as well as observations using a larger network of telescopes in an effort to image source structure.

  18. Hemispherical total emissivity of Hastelloy N with different surface conditions

    Science.gov (United States)

    Gordon, Andrew J.; Walton, Kyle L.; Ghosh, Tushar K.; Loyalka, Sudarshan K.; Viswanath, Dabir S.; Tompson, Robert V.

    2012-07-01

    The hemispherical total emissivity of Hastelloy N (a candidate structural material for Next Generation Nuclear Plants (NGNPs), particularly for the molten fluoride cooled reactors) was measured using an experimental set-up that was constructed in accordance with the standard ASTM C835-06. The material surface conditions included: (i) 'as received' (original) sample from the supplier; (ii) samples with increased surface roughness through sand blasting; (iii) oxidized surface, and (iv) samples coated with graphite powder. The emissivity of the as received samples varied from around 0.22 to 0.28 in the temperature range of 473 K to 1498 K. The emissivity increased when the roughness of the surface increased compared to an as received sample. When Hastelloy N was oxidized in air at 1153 K or coated with graphite powder, its emissivity increased substantially. The sample sand blasted with 60 grit beads and sprinkled with graphite powder showed an increase of emissivity from 0.2 to 0.60 at 473 K and from 0.25 to 0.67 at 1473 K. The oxidized surface showed a similar behavior: an increase in emissivity compared to an unoxidized sample. This increase in emissivity has strong favorable safety implications in terms of decay heat removal in post-accident environments. The data were compared with another Hastelloy family member, Hastelloy X.

  19. Predicting weather regime transitions in Northern Hemisphere datasets

    Energy Technology Data Exchange (ETDEWEB)

    Kondrashov, D. [University of California, Department of Atmospheric and Oceanic Sciences and Institute of Geophysics and Planetary Physics, Los Angeles, CA (United States); Shen, J. [UCLA, Department of Statistics, Los Angeles, CA (United States); Berk, R. [UCLA, Department of Statistics, Los Angeles, CA (United States); University of Pennsylvania, Department of Criminology, Philadelphia, PA (United States); D' Andrea, F.; Ghil, M. [Ecole Normale Superieure, Departement Terre-Atmosphere-Ocean and Laboratoire de Meteorologie Dynamique (CNRS and IPSL), Paris Cedex 05 (France)

    2007-10-15

    A statistical learning method called random forests is applied to the prediction of transitions between weather regimes of wintertime Northern Hemisphere (NH) atmospheric low-frequency variability. A dataset composed of 55 winters of NH 700-mb geopotential height anomalies is used in the present study. A mixture model finds that the three Gaussian components that were statistically significant in earlier work are robust; they are the Pacific-North American (PNA) regime, its approximate reverse (the reverse PNA, or RNA), and the blocked phase of the North Atlantic Oscillation (BNAO). The most significant and robust transitions in the Markov chain generated by these regimes are PNA {yields} BNAO, PNA {yields} RNA and BNAO {yields} PNA. The break of a regime and subsequent onset of another one is forecast for these three transitions. Taking the relative costs of false positives and false negatives into account, the random-forests method shows useful forecasting skill. The calculations are carried out in the phase space spanned by a few leading empirical orthogonal functions of dataset variability. Plots of estimated response functions to a given predictor confirm the crucial influence of the exit angle on a preferred transition path. This result points to the dynamic origin of the transitions. (orig.)

  20. Nonlinear vibration of a hemispherical dome under external water pressure

    Science.gov (United States)

    Ross, C. T. F.; McLennan, A.; Little, A. P. F.

    2011-07-01

    The aim of this study was to analyse the behaviour of a hemi-spherical dome when vibrated under external water pressure, using the commercial computer package ANSYS 11.0. In order to achieve this aim, the dome was modelled and vibrated in air and then in water, before finally being vibrated under external water pressure. The results collected during each of the analyses were compared to the previous studies, and this demonstrated that ANSYS was a suitable program and produced accurate results for this type of analysis, together with excellent graphical displays. The analysis under external water pressure, clearly demonstrated that as external water pressure was increased, the resonant frequencies decreased and a type of dynamic buckling became likely; because the static buckling eigenmode was similar to the vibration eigenmode. ANSYS compared favourably with the in-house software, but had the advantage that it produced graphical displays. This also led to the identification of previously undetected meridional modes of vibration; which were not detected with the in-house software.

  1. The hemispherical asymmetry from a scale-dependent inflationary bispectrum

    CERN Document Server

    Byrnes, Christian T; Seery, David; Tarrant, Ewan R M

    2015-01-01

    If the primordial bispectrum is sufficiently large then the CMB hemispherical asymmetry may be explained by a large-scale mode of exceptional amplitude which perturbs the zeta two-point function. We extend previous calculations, which were restricted to one- or two-source scenarios, by providing a method to compute the response of the two-point function in any model yielding a 'local-like' bispectrum. In general, this shows that it is not the reduced bispectrum fNL which sources the amplitude and scale-dependence of the mode coupling but rather a combination of 'response functions'. We discuss why it is difficult to construct successful scenarios and enumerate the fine-tunings which seem to be required. Finally, we exhibit a concrete model which can be contrived to match the observational constraints and show that to a Planck-like experiment it would appear to have |fNL-local| ~ |fNL-equi| ~ |fNL-ortho| ~ 1. Therefore, contrary to previous analyses, we conclude that it is possible to generate the asymmetry wh...

  2. SABRE: WIMP modulation detection in the northern and southern hemisphere

    CERN Document Server

    Froborg, Francis

    2016-01-01

    Measuring an annual modulation in a direct Dark Matter detection experiment is not only a proof of the existence of WIMPs but can also tell us more about their interaction with standard matter and maybe even their density and velocity in the halo. Such a modulation has been measured by the DAMA/LIBRA experiment in NaI(Tl) crystals. However, the interpretation as WIMP signal is controversial due to contradicting results by other experiments. The SABRE experiment aims to shed light on this controversy by detecting the annual modulation in the same target material as DAMA with twin detectors at LNGS in Italy and at SUPL in Australia. The two locations in the northern and southern hemisphere allow to verify if other seasonal effects or the site have an influence on the measurement, thus reducing systematic effects. This paper will give an overview on the experimental design, the current status of the proof of principle phase mainly devoted to high-purity crystal growing, and an outlook on future plans.

  3. Somatic Activation of AKT3 Causes Hemispheric Developmental Brain Malformations

    Science.gov (United States)

    Poduri, Annapurna; Evrony, Gilad D.; Cai, Xuyu; Elhosary, Princess Christina; Beroukhim, Rameen; Lehtinen, Maria K.; Hills, L. Benjamin; Heinzen, Erin L.; Hill, Anthony; Hill, R. Sean; Barry, Brenda J.; Bourgeois, Blaise F.D.; Riviello, James J.; Barkovich, A. James; Black, Peter M.; Ligon, Keith L.; Walsh, Christopher A.

    2012-01-01

    Summary Hemimegalencephaly (HMG) is a developmental brain disorder characterized by an enlarged, malformed cerebral hemisphere, typically causing epilepsy that requires surgical resection. We studied resected HMG tissue to test whether the condition might reflect somatic mutations affecting genes critical to brain development. We found that 2/8 HMG samples showed trisomy of chromosome 1q, encompassing many genes, including AKT3, which is known to regulate brain size. A third case showed a known activating mutation in AKT3 (c.49G→A, creating p.E17K) that was not present in the patient’s blood cells. Remarkably, the E17K mutation in AKT3 is exactly paralogous to E17K mutations in AKT1 and AKT2 recently discovered in somatic overgrowth syndromes. We show that AKT3 is the most abundant AKT paralogue in brain during neurogenesis and that phosphorylated AKT is abundant in cortical progenitor cells. Our data suggest that somatic mutations limited to brain could represent an important cause of complex neurogenetic disease. PMID:22500628

  4. Psychopathological manifestations of multiple meningiomas in the right hemisphere

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    A. A. Lukshina

    2015-01-01

    Full Text Available The paper gives the data available in the literature on meningiomas and their psychopathological manifestations that occupy a central position in the clinical picture in almost every 5 patients with these tumors. The authors provide a clinical and psychopathological analysis of a female patient with multiple meningiomas in the right hemisphere: a giant meningioma in the posterior third of the falx, a large meningioma in the temporal region, and three small meningiomas in the frontal and parietal regions. The disease started as headache; however, psychopathological symptoms remained missed by physicians, such as emotional lability; personality changes leading to family dissension; lower criticism; spatial orientation problems; hypomnesia; left-sided visual inattention,occurred in parallel. Surgical treatment was performed by stages: the two largest meningiomas were removed at an 11-day interval, which presented a means of observing psychopathological changes after each operation. It is concluded that greater attention should be given to the psychopathological manifestations of the disease, which is important to make a primary diagnosis and to define further treatment policy.

  5. The role of the tropical West Pacific in the extreme northern hemisphere winter of 2013/14

    Science.gov (United States)

    Watson, Peter; Weisheimer, Antje; Knight, Jeff; Palmer, Tim

    2016-04-01

    In the 2013/14 winter, the eastern USA was exceptionally cold, the Bering Strait region was exceptionally warm, California was in the midst of drought and the UK suffered severe flooding. It has been suggested that elevated SSTs in the tropical West Pacific (TWPAC) were partly to blame due to their producing a Rossby wavetrain that propagated into the extratropics. We find that seasonal forecasts with the tropical atmosphere relaxed towards a reanalysis give 2013/14 winter-mean anomalies with strong similarities to those observed in the Northern Hemisphere, indicating that low-latitude anomalies had a role in the development of the extremes. Relaxing just the TWPAC produces a strong wavetrain over the North Pacific and North America in January, but not in the winter-mean. This suggests that anomalies in this region alone had a large influence, but cannot explain the extremes through the whole winter. We also examine the response to applying the observed TWPAC SST anomalies in two atmospheric general circulation models. We find that this does produce winter-mean anomalies in the North Pacific and North America resembling those observed, but that the tropical forcing of Rossby waves due to the applied SST anomalies appears stronger than that in reanalysis, except in January. Therefore both experiments indicate that the TWPAC influence was important, but the true strength of the TWPAC influence is uncertain. None of the experiments indicate a strong systematic impact of the TWPAC anomalies on Europe.

  6. Climatic Impact of the Bølling-Allerød over Eastern South America

    Science.gov (United States)

    Amorim Catunda, M. C.; Chiessi, C. M.; Strikis, N. M.; Mulitza, S.; Cruz, F. W., Sr.; Vuille, M. F.

    2015-12-01

    The last deglaciation was marked by large scale and rapid changes in rainfall over the tropics. Previous studies have correlated pulses of increased terrigenous input off semi arid northeastern South America with abrupt cold events in the high latitudes of the Northern Hemisphere. However, deglacial climate changes in other areas of South America are still not resolved. Here we reconstruct deglacial (23-11.5 cal ka BP) continental conditions over eastern Brazil based on (i) Ti/Ca of a radiocarbon dated marine sediment core as a proxy for Doce River (draining eastern Brazil) terrigenous input, and (ii) δ18O of a suite of U-Th dated stalagmites from eastern Brazil. Our marine core was recovered from 1100 m water depth on the tropical Brazilian continental slope, while our stalagmites come from Lapa Sem Fim cave. Both the Doce River and Lapa Sem Fim cave are located in the highly populated and economically active eastern Brazil, where most of the rainfall is related to the activity of the South America Monsoon System (SAMS). The Ti/Ca record is relatively stable showing high proportions of Ti in relationship to Ca throughout the deglacial, with a major excursion towards lower values indicating a decrease in terrigenous input synchronous to the Bølling-Allerød. Interestingly, speleothem δ18O also record this major excursion as less negative values. Together, our results suggest a major decrease in precipitation likely related to a weakening of the SAMS. We further compared our results with the output of the SYNTRACE run of CCSM3 fully coupled climate model with transient forcing for the last deglaciation. Geochemical records and model output show a very good coupling and suggest that the eastern Brazil experienced the driest period of the whole last deglaciation during the Bølling-Allerød and this dry spell was indeed related to a decreased SAMS intensity.

  7. Interspecific exchange of avian influenza virus genes in Alaska: the influence of trans-hemispheric migratory tendency and breeding ground sympatry

    Science.gov (United States)

    Pearce, John M.; Reeves, A.B.; Ramey, A.M.; Hupp, J.W.; Ip, H.S.; Bertram, M.; Petrula, M.J.; Scotton, B.D.; Trust, K.A.; Meixell, B.W.; Runstadler, J.A.

    2011-01-01

    The movement and transmission of avian influenza viral strains via wild migratory birds may vary by host species as a result of migratory tendency and sympatry with other infected individuals. To examine the roles of host migratory tendency and species sympatry on the movement of Eurasian low-pathogenic avian influenza (LPAI) genes into North America, we characterized migratory patterns and LPAI viral genomic variation in mallards (Anas platyrhynchos) of Alaska in comparison with LPAI diversity of northern pintails (Anas acuta). A 50-year band-recovery data set suggests that unlike northern pintails, mallards rarely make trans-hemispheric migrations between Alaska and Eurasia. Concordantly, fewer (14.5%) of 62 LPAI isolates from mallards contained Eurasian gene segments compared to those from 97 northern pintails (35%), a species with greater inter-continental migratory tendency. Aerial survey and banding data suggest that mallards and northern pintails are largely sympatric throughout Alaska during the breeding season, promoting opportunities for interspecific transmission. Comparisons of full-genome isolates confirmed near-complete genetic homology (>99.5%) of seven viruses between mallards and northern pintails. This study found viral segments of Eurasian lineage at a higher frequency in mallards than previous studies, suggesting transmission from other avian species migrating inter-hemispherically or the common occurrence of endemic Alaskan viruses containing segments of Eurasian origin. We conclude that mallards are unlikely to transfer Asian-origin viruses directly to North America via Alaska but that they are likely infected with Asian-origin viruses via interspecific transfer from species with regular migrations to the Eastern Hemisphere.

  8. Interspecific exchange of avian influenza virus genes in Alaska: the influence of trans-hemispheric migratory tendency and breeding ground sympatry

    Science.gov (United States)

    Pearce, John M.; Reeves, A.B.; Ramey, A.M.; Hupp, J.W.; Ip, H.S.; Bertram, M.; Petrula, M.J.; Scotton, B.D.; Trust, K.A.; Meixell, B.W.; Runstadler, J.A.

    2011-01-01

    The movement and transmission of avian influenza viral strains via wild migratory birds may vary by host species as a result of migratory tendency and sympatry with other infected individuals. To examine the roles of host migratory tendency and species sympatry on the movement of Eurasian low-pathogenic avian influenza (LPAI) genes into North America, we characterized migratory patterns and LPAI viral genomic variation in mallards (Anas platyrhynchos) of Alaska in comparison with LPAI diversity of northern pintails (Anas acuta). A 50-year band-recovery data set suggests that unlike northern pintails, mallards rarely make trans-hemispheric migrations between Alaska and Eurasia. Concordantly, fewer (14.5%) of 62 LPAI isolates from mallards contained Eurasian gene segments compared to those from 97 northern pintails (35%), a species with greater inter-continental migratory tendency. Aerial survey and banding data suggest that mallards and northern pintails are largely sympatric throughout Alaska during the breeding season, promoting opportunities for interspecific transmission. Comparisons of full-genome isolates confirmed near-complete genetic homology (>99.5%) of seven viruses between mallards and northern pintails. This study found viral segments of Eurasian lineage at a higher frequency in mallards than previous studies, suggesting transmission from other avian species migrating inter-hemispherically or the common occurrence of endemic Alaskan viruses containing segments of Eurasian origin. We conclude that mallards are unlikely to transfer Asian-origin viruses directly to North America via Alaska but that they are likely infected with Asian-origin viruses via interspecific transfer from species with regular migrations to the Eastern Hemisphere.

  9. Probabilistic evaluation of decadal prediction skill regarding Northern Hemisphere winter storms

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    Tim Kruschke

    2016-12-01

    Full Text Available Winter wind storms related to intense extra-tropical cyclones are meteorological extreme events, often with major impacts on economy and human life, especially for Europe and the mid-latitudes. Hence, skillful decadal predictions regarding the frequency of their occurrence would be of great socio-economic value. The present paper extends the study of Kruschke et al. (2014 in several aspects. First, this study is situated in a more impact oriented context by analyzing the frequency of potentially damaging wind storm events instead of targeting at cyclones as general meteorological features which was done by Kruschke et al. (2014. Second, this study incorporates more data sets by analyzing five decadal hindcast experiments – 41 annual (1961–2001 initializations integrated for ten years each – set up with different initialization strategies. However, all experiments are based on the Max-Planck-Institute Earth System Model in a low-resolution configuration (MPI-ESM-LR. Differing combinations of these five experiments allow for more robust estimates of predictive skill (due to considerably larger ensemble size and systematic comparisons of the underlying initialization strategies. Third, the hindcast experiments are corrected for model bias and potential drifts over lead time by means of a novel parametric approach, accounting for non-stationary model drifts. We analyze whether skillful probabilistic three-category forecasts (enhanced, normal or decreased can be provided regarding winter (ONDJFM wind storm frequencies over the Northern Hemisphere (NH. Skill is assessed by using climatological probabilities and uninitialized transient simulations as reference forecasts. It is shown that forecasts of average winter wind storm frequencies for winters 2–5 and winters 2–9 are skillful over large parts of the NH. However, most of this skill is associated with external forcing from transient greenhouse gas and aerosol concentrations

  10. Source-receptor relationships between East Asian sulfur dioxide emissions and Northern Hemisphere sulfate concentrations

    Science.gov (United States)

    Liu, J.; Mauzerall, D. L.; Horowitz, L. W.

    2008-07-01

    We analyze the effect of varying East Asian (EA) sulfur emissions on sulfate concentrations in the Northern Hemisphere, using a global coupled oxidant-aerosol model (MOZART-2). We conduct a base and five sensitivity simulations, in which sulfur emissions from each continent are tagged, to establish the source-receptor (S-R) relationship between EA sulfur emissions and sulfate concentrations over source and downwind regions. We find that from west to east across the North Pacific, EA sulfate contributes approximately 80% 20% of sulfate at the surface, but at least 50% at 500 hPa. Surface sulfate concentrations are dominated by local anthropogenic sources. Of the sulfate produced from sources other than local anthropogenic emissions (defined here as "background" sulfate), EA sources account for approximately 30% 50% (over the Western US) and 10% 20% (over the Eastern US). The surface concentrations of sulfate from EA sources over the Western US are highest in MAM (up to 0.15 μg/m3), and lowest in DJF (less than 0.06 μg/m3). Reducing EA SO2 emissions will significantly decrease the spatial extent of the EA sulfate influence (represented by the areas where at least 0.1 μg m-3 of sulfate originates from EA) over the North Pacific both at the surface and at 500 hPa in all seasons, but the extent of influence is insensitive to emission increases, particularly in DJF and JJA. We find that EA sulfate concentrations over most downwind regions respond nearly linearly to changes in EA SO2 emissions, but sulfate concentrations over the EA source region increase more slowly than SO2 emissions, particularly at the surface and in winter, due to limited availability of oxidants (in particular of H2O2, which oxidizes SO2 to sulfate in the aqueous phase). We find that similar estimates of the S-R relationship for trans-Pacific transport of EA sulfate would be obtained using either sensitivity (i.e., varying emissions from a region to examine the effects on downwind concentrations

  11. Source-receptor relationships between East Asian sulfur dioxide emissions and Northern Hemisphere sulfate concentrations

    Directory of Open Access Journals (Sweden)

    J. Liu

    2008-07-01

    Full Text Available We analyze the effect of varying East Asian (EA sulfur emissions on sulfate concentrations in the Northern Hemisphere, using a global coupled oxidant-aerosol model (MOZART-2. We conduct a base and five sensitivity simulations, in which sulfur emissions from each continent are tagged, to establish the source-receptor (S-R relationship between EA sulfur emissions and sulfate concentrations over source and downwind regions. We find that from west to east across the North Pacific, EA sulfate contributes approximately 80%–20% of sulfate at the surface, but at least 50% at 500 hPa. Surface sulfate concentrations are dominated by local anthropogenic sources. Of the sulfate produced from sources other than local anthropogenic emissions (defined here as "background" sulfate, EA sources account for approximately 30%–50% (over the Western US and 10%–20% (over the Eastern US. The surface concentrations of sulfate from EA sources over the Western US are highest in MAM (up to 0.15 μg/m3, and lowest in DJF (less than 0.06 μg/m3. Reducing EA SO2 emissions will significantly decrease the spatial extent of the EA sulfate influence (represented by the areas where at least 0.1 μg m−3 of sulfate originates from EA over the North Pacific both at the surface and at 500 hPa in all seasons, but the extent of influence is insensitive to emission increases, particularly in DJF and JJA. We find that EA sulfate concentrations over most downwind regions respond nearly linearly to changes in EA SO2 emissions, but sulfate concentrations over the EA source region increase more slowly than SO2 emissions, particularly at the surface and in winter, due to limited availability of oxidants (in particular of H2O2, which oxidizes SO2 to sulfate in the aqueous phase. We find that similar estimates of the S-R relationship for trans-Pacific transport of EA sulfate would be

  12. Source-receptor relationships between East Asian sulfur dioxide emissions and Northern Hemisphere sulfate concentrations

    Directory of Open Access Journals (Sweden)

    J. Liu

    2008-03-01

    Full Text Available We analyze the effect of varying East Asian (EA sulfur emissions on sulfate concentrations in the Northern Hemisphere, using a global coupled oxidant-aerosol model (MOZART-2. We conduct a base and five sensitivity simulations, in which sulfur emissions from each continent are tagged, to establish the source-receptor (S-R relationship between EA sulfur emissions and sulfate concentrations over source and downwind regions. We find that from west to east across the North Pacific, EA sulfate contributes approximately 80%–20% of sulfate at the surface, but at least 50% at 500 hPa. In addition, EA SO2 emissions account for approximately 30%–50% and 10%–20% of North American background sulfate over the western and eastern US, respectively. The contribution of EA sulfate to the western US at the surface is highest in MAM and JJA, but is lowest in DJF. Reducing EA SO2 emissions will significantly decrease the spatial extent of the EA sulfate influence over the North Pacific both at the surface and at 500 mb in all seasons, but the extent of influence is insensitive to emission increases, particularly in DJF and JJA. We find that EA sulfate concentrations over most downwind regions respond nearly linearly to changes in EA SO2 emissions, but sulfate concentrations over the EA source region increase more slowly than SO2 emissions, particularly at the surface and in winter, due to limited availability of oxidants (mostly H2O2. We find that similar estimates of the S-R relationship for trans-Pacific transport of EA sulfate would be obtained using either sensitivity or tagging techniques. Our findings suggest that future changes in EA sulfur emissions may cause little change in the sulfate induced health impact over downwind continents but SO2 emission reductions may significantly reduce the sulfate related climate cooling over the North Pacific and the United States.

  13. Responses of surface ozone air quality to anthropogenic nitrogen deposition in the Northern Hemisphere

    Science.gov (United States)

    Zhao, Yuanhong; Zhang, Lin; Tai, Amos P. K.; Chen, Youfan; Pan, Yuepeng

    2017-08-01

    Human activities have substantially increased atmospheric deposition of reactive nitrogen to the Earth's surface, inducing unintentional effects on ecosystems with complex environmental and climate consequences. One consequence remaining unexplored is how surface air quality might respond to the enhanced nitrogen deposition through surface-atmosphere exchange. Here we combine a chemical transport model (GEOS-Chem) and a global land model (Community Land Model, CLM) to address this issue with a focus on ozone pollution in the Northern Hemisphere. We consider three processes that are important for surface ozone and can be perturbed by the addition of atmospheric deposited nitrogen - namely, emissions of biogenic volatile organic compounds (VOCs), ozone dry deposition, and soil nitrogen oxide (NOx) emissions. We find that present-day anthropogenic nitrogen deposition (65 Tg N a-1 to the land), through enhancing plant growth (represented as increases in vegetation leaf area index, LAI, in the model), could increase surface ozone from increased biogenic VOC emissions (e.g., a 6.6 Tg increase in isoprene emission), but it could also decrease ozone due to higher ozone dry deposition velocities (up to 0.02-0.04 cm s-1 increases). Meanwhile, deposited anthropogenic nitrogen to soil enhances soil NOx emissions. The overall effect on summer mean surface ozone concentrations shows general increases over the globe (up to 1.5-2.3 ppbv over the western US and South Asia), except for some regions with high anthropogenic NOx emissions (0.5-1.0 ppbv decreases over the eastern US, western Europe, and North China). We compare the surface ozone changes with those driven by the past 20-year climate and historical land use changes. We find that the impacts from anthropogenic nitrogen deposition can be comparable to the climate- and land-use-driven surface ozone changes at regional scales and partly offset the surface ozone reductions due to land use changes reported in previous studies

  14. Extending the Applicability of the Community Multiscale Air Quality Model to Hemispheric Scales: Motivation, Challenges, and Progress

    Science.gov (United States)

    The adaptation of the Community Multiscale Air Quality (CMAQ) modeling system to simulate O3, particulate matter, and related precursor distributions over the northern hemisphere is presented. Hemispheric simulations with CMAQ and the Weather Research and Forecasting (...

  15. Extending the Applicability of the Community Multiscale Air Quality Model to Hemispheric Scales: Motivation, Challenges, and Progress

    Science.gov (United States)

    The adaptation of the Community Multiscale Air Quality (CMAQ) modeling system to simulate O3, particulate matter, and related precursor distributions over the northern hemisphere is presented. Hemispheric simulations with CMAQ and the Weather Research and Forecasting (...

  16. Neuroendocrine hemisphere asymmetries: salivary cortisol secretion during lateralized viewing of emotion-related and neutral films.

    Science.gov (United States)

    Wittling, W; Pflüger, M

    1990-11-01

    The study set out to examine whether the cerebral hemispheres differ in their ability to regulate cortisol secretion during emotion-related situations. One hundred twenty-three adult subjects were shown either an emotionally aversive or a neutral film in the left or right hemisphere by means of a technique for lateralizing visual input that allows prolonged viewing while permitting free ocular scanning. The film-related changes of cortisol secretion were determined by salivary cortisol radioimmunoassay. Right hemispheric viewing of the emotionally aversive film resulted in a significantly higher increase of cortisol secretion than left hemispheric viewing of the same film. No such differences were observed with respect to the neutral film. Comparing the effects of the two films separately for each hemisphere revealed that only the right hemisphere was able to respond neuroendocrinologically in a different manner to the emotional and the neutral film. Therefore, it is concluded that cortical regulation of cortisol secretion in emotion-related situations is under primary control of the right hemisphere. The potential implications of asymmetric control of cortisol secretion with respect to the pathogenesis of psychosomatic and immunological disorders are discussed.

  17. Models of hemispheric specialization in facial emotion perception--a reevaluation.

    Science.gov (United States)

    Najt, Pablo; Bayer, Ulrike; Hausmann, Markus

    2013-02-01

    A considerable amount of research on functional cerebral asymmetries (FCAs) for facial emotion perception has shown conflicting support for three competing models: (i) the Right Hemisphere Hypothesis, (ii) the Valence-Specific Hypothesis, and (iii) the Approach/Withdrawal model. However, the majority of studies evaluating the Right Hemisphere or the Valence-Specific Hypotheses are rather limited by the small number of emotional expressions used. In addition, it is difficult to evaluate the Approach/Withdrawal Hypothesis due to insufficient data on anger and FCAs. The aim of the present study was (a) to review visual half field (VHF) studies of hemispheric specialization in facial emotion perception and (b) to reevaluate empirical evidence with respect to all three partly conflicting hypotheses. Results from the present study revealed a left visual field (LVF)/right hemisphere advantage for the perception of angry, fearful, and sad facial expressions and a right visual field (RVF)/left hemisphere advantage for the perception of happy expressions. Thus, FCAs for the perception of specific facial emotions do not fully support the Right Hemisphere Hypothesis, the Valence-Specific Hypothesis, or the Approach/Withdrawal model. A systematic literature review, together with the results of the present study, indicate a consistent LVF/right hemisphere advantage only for a subset of negative emotions including anger, fear and sadness, rather suggesting a "negative (only) valence model." PsycINFO Database Record (c) 2013 APA, all rights reserved.

  18. The "consonance effect" and the hemispheres: a study on a split-brain patient.

    Science.gov (United States)

    Prete, Giulia; Fabri, Mara; Foschi, Nicoletta; Brancucci, Alfredo; Tommasi, Luca

    2015-05-01

    The association between musical consonance and pleasantness, and between musical dissonance and unpleasantness ("consonance effect") is well established. Furthermore, a number of studies suggest the main involvement of the left hemisphere in the perception of dissonance and that of the right hemisphere in the perception of consonance. In the present study, the consonance effect was studied in a callosotomized patient, D. D. C. and in a control group. In binaural presentations, the patient did not attribute different pleasantness judgements to consonant and dissonant chords, differently from the control group who showed the consonance effect. However, in dichotic presentations (e.g. a chord in one ear and white noise in the other ear), a trend towards the consonance effect was found in D. D. C., but only when chords were presented in his right ear (left hemisphere), whereas the control group confirmed the known hemispheric asymmetry in labelling the pleasantness of consonant and dissonant chords. These results suggest that the right-hemispheric superiority in appreciating consonance might hide the inability of the right hemisphere to classify dissonant chords as unpleasant in the split-brain, whereas the left hemisphere seems capable to differently label the pleasantness of consonant and dissonant chords, even if it is more sensitive to dissonance.

  19. Cooperation or competition of the two hemispheres in processing characters presented at vertical midline.

    Directory of Open Access Journals (Sweden)

    Rolf Verleger

    Full Text Available Little is known about how the hemispheres interact in processing of stimuli presented at vertical midline. Processing might be mutually independent or cooperative. Here we measured target identification and visually evoked EEG potentials while stimulus streams containing two targets, T1 and T2, were either presented at vertical midline above and below fixation, or laterally, left and right. With left and right streams, potentials evoked by filler stimuli and by T2 were earlier at the right than the left visual cortex, and T2 was better identified left than right, confirming earlier results and suggesting better capabilities of the right hemisphere in this task. With streams above and below fixation, EEG potentials evoked by filler stimuli and by T2 were likewise earlier at the right than the left hemisphere, and T2 was generally identified as well as, but not better than left T2, in one target constellation even worse (T2 in lower stream preceded by T1 in upper stream. These results suggest right-hemisphere preference for this task even with stimuli at vertical midline, and no added value through hemispheric cooperation. Lacking asymmetry for T1 amidst asymmetries for filler stimuli and for T2 might indicate alternating access of the hemispheres to midline stimuli as one means of hemispheric division of labor.

  20. Hemispheric differences of motor execution: a near-infrared spectroscopy study.

    Science.gov (United States)

    Helmich, Ingo; Rein, Robert; Niermann, Nico; Lausberg, Hedda

    2013-01-01

    Distal movements of the limbs are predominantly controlled by the contralateral hemisphere. However, functional neuroimaging studies do not unequivocally demonstrate a lateralization of the cerebral activation during hand movements. While some studies show a predominant activation of the contralateral hemisphere, other studies provide evidence for a symmetrically distributed bihemispheric activation. However, the divergent results may also be due to methodological shortcomings. Therefore, the present study using functional near-infrared spectroscopy examines cerebral activation in both hemispheres during motor actions of the right and left hands. Twenty participants performed a flexion/extension task with the right- or left-hand thumb. Cerebral oxygenation changes were recorded from 48 channels over the primary motor, pre-motor, supplementary motor, primary somatosensory cortex, subcentral area, and the supramarginal gyrus of each hemisphere. A consistent increase of cerebral oxygenation was found for oxygenated and for total hemoglobin in the hemisphere contralateral to the moving hand, regardless of the laterality. These findings are in line with previous data from localization [1-3] and brain imaging studies [4-6]. The present data support the proposition that there is no hemispheric specialization for simple distal motor tasks. Both hemispheres are equally activated during movement of the contralateral upper limb.

  1. Hemispherical and minimally invasive total hip reamers: a biomechanical analysis of use and design.

    Science.gov (United States)

    Slotkin, Steven; Frisch, Nicholas B; Roc, Gilbert; Silverton, Craig D

    2017-06-01

    The purpose of this study was to determine the accuracy of used and new reamer systems for both hemispherical and minimally invasive (MIS) acetabular reamers. New and used hemispherical and MIS acetabular reamers were tested on a computer numerical control machine to ream holes in special machinable wax blocks. Each reamer was tested 3 times in sizes 48 mm through 55 mm. The used reamers significantly underreamed by an average of 1.33 vs 0.28 mm compared to new reamers. Hemispherical reamers underreamed significantly more than MIS reamers, with a mean difference of 0.99 vs 0.63 mm, respectively. Used hemispherical reamers showed an average ream undersize of 1.61 vs 0.37 mm, compared to new hemispherical reamers. Used MIS reamers showed an average ream undersize of 1.06 vs 0.20 mm for the new MIS reamers. For a manufacturer-specified reamer size, both hemispherical and MIS reamers underream. Newer reamers cut truer to expected values than used ones. MIS reamers performed more accurately than hemispherical reamers. Used acetabular reamer systems may negatively affect the sizing of prepared acetabular beds; therefore, awareness of this potential inaccuracy should be considered when performing total hip arthroplasty.

  2. The effect of cognitive load on hemispheric asymmetries in true and false memory.

    Science.gov (United States)

    Tat, Michael J; Azuma, Tamiko

    2016-01-01

    Studies examining hemispheric asymmetries in false memory have shown that the right hemisphere (RH) is more susceptible to false memories compared to the left hemisphere (LH). Theories suggest that hemispheric asymmetries in true and false memory may be due to differences in representational coding and the use of top-down mechanisms in each hemisphere. In the current study, the Deese-Roediger-McDermott false memory paradigm was used in conjunction with divided visual field presentation to examine the role of top-down mechanisms in hemispheric asymmetries of true and false memory. In Experiment 1, participants studied lists of related words while completing secondary cognitive load tasks. In Experiment 2, the secondary tasks were administered during memory retrieval instead of memory encoding. Results revealed that cognitive loads imposed during the study phase influenced veridical memory in the LH more than the RH, but cognitive loads imposed during retrieval did not influence veridical memory in either hemisphere. Surprisingly, false memory rates were not influenced by cognitive loads and were higher in the LH. These data provide evidence that, at least for veridical memory, top-down control mechanisms are used more readily for the encoding of information into memory in the LH compared to the RH.

  3. The effect of musical experience on hemispheric lateralization in musical feature processing.

    Science.gov (United States)

    Ono, Kentaro; Nakamura, Akinori; Yoshiyama, Kenji; Kinkori, Takeshi; Bundo, Masahiko; Kato, Takashi; Ito, Kengo

    2011-06-01

    Music consists of a variety of spectral and temporal features. Generally, brain processing of these features is reported as being right hemisphere dominant. However, there are contradicting results as to whether musical experience affects hemispheric laterality or not. In the present study, we investigated the effect of musical experience on hemispheric lateralization of musical feature processing using magnetoencephalography (MEG). Mismatch fields (MMFs) were measured from 8 musicians and 8 nonmusicians in oddball tasks with four different musical features, including pitch, chord, timbre and rhythm. Regardless of the features, the MMFs showed right-hemispheric dominance in nonmusicians, whereas musicians showed symmetrical MMF amplitudes in both hemispheres. The electrical activity around the auditory cortex to the MMFs also supported the right-hemispheric dominance in nonmusicians and bilateral activation in musicians. Voxel-based morphometry did not detect any group differences around the auditory cortices. These results suggest that musical training changes the hemispheric roles for musical feature processing in the pre-attentive stage, and this functional alteration can occur without apparent anatomical changes.

  4. The rod orientation test in patients with right-hemisphere infarction : a clinical study of spatial perception in 154 subjects

    OpenAIRE

    Meerwaldt, Johannes David (Jan)

    1982-01-01

    textabstractThis thesis describes a clinical study of disturbances of spatial perception. Chapter I gives a short review of hemispheric asymmetry. For a long time the right hemisphere was regarded as the minor hemisphere, of which substantial regions were thought to have no specific function. Jackson, however, believed that the posterior area of the right hemisphere played a crucial role in subserving visual recognition and visual memory, but few of his contemporaries agreed with him. Later R...

  5. Pilot Study: The Role of the Hemispheric Lateralization in Mental Disorders by Use of the Limb (Eye, Hand, Foot) Dominance

    OpenAIRE

    Goodarzi, Naser; Dabbaghi, Parviz; Valipour, Habib; Vafadari, Behnam

    2015-01-01

    Introduction: Based on the previous studies, we know that the hemispheric lateralization defects, increase the probability of psychological disorders. We also know that dominant limb is controlled by dominant hemisphere and limb preference is used as an indicator for hemisphere dominance. In this study we attempted to explore the hemispheric dominance by the use of three limbs (hand, foot and eye). Methods: We performed this survey on two samples, psychiatric patients compared with normal pop...

  6. Observational Analysis of Cloud and Precipitation in Midlatitude Cyclones: Northern Versus Southern Hemisphere Warm Fronts

    Science.gov (United States)

    Naud, Catherine M.; Posselt, Derek J.; van den Heever, Susan C.

    2012-01-01

    Extratropical cyclones are responsible for most of the precipitation and wind damage in the midlatitudes during the cold season, but there are still uncertainties on how they will change in a warming climate. An ubiquitous problem amongst General Circulation Models (GCMs) is a lack of cloudiness over the southern oceans that may be in part caused by a lack of clouds in cyclones. We analyze CloudSat, CALIPSO and AMSR-E observations for 3 austral and boreal cold seasons and composite cloud frequency of occurrence and precipitation at the warm fronts for northern and southern hemisphere oceanic cyclones. We find that cloud frequency of occurrence and precipitation rate are similar in the early stage of the cyclone life cycle in both northern and southern hemispheres. As cyclones evolve and reach their mature stage, cloudiness and precipitation at the warm front increase in the northern hemisphere but decrease in the southern hemisphere. This is partly caused by lower amounts of precipitable water being available to southern hemisphere cyclones, and smaller increases in wind speed as the cyclones evolve. Southern hemisphere cloud occurrence at the warm front is found to be more sensitive to the amount of moisture in the warm sector than to wind speeds. This suggests that cloudiness in southern hemisphere storms may be more susceptible to changes in atmospheric water vapor content, and thus to changes in surface temperature than their northern hemisphere counterparts. These differences between northern and southern hemisphere cyclones are statistically robust, indicating A-Train-based analyses as useful tools for evaluation of GCMs in the next IPCC report.

  7. SYSTEMATIC REGULARITY OF HEMISPHERIC SUNSPOT AREAS OVER THE PAST 140 YEARS

    Energy Technology Data Exchange (ETDEWEB)

    Deng, L. H.; Xiang, Y. Y. [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Qu, Z. N. [Department of Physics, School of Science, Sichuan University of Science and Engineering, Zigong 643000 (China); An, J. M., E-mail: znqu@ynao.ac.cn [School of Software Engineering, Chongqing University of Arts and Sciences, Chongqing 402160 (China)

    2016-03-15

    Solar magnetic activity varies with time in the two hemispheres in different ways. The hemispheric interconnection of solar activity phenomena provides an important clue to understanding the dynamical behavior of solar dynamo actions. In this paper, several analysis approaches are proposed to analyze the systematic regularity of hemispheric asynchronism and amplitude asymmetry of long-term sunspot areas during solar cycles 9–24. It is found that, (1) both the hemispheric asynchronism and the amplitude asymmetry of sunspot areas are prevalent behaviors and are not anomalous, but the hemispheric asynchronism exhibits a much more regular behavior than the amplitude asymmetry; (2) the phase-leading hemisphere returns back to the identical hemisphere every 8 solar cycles, and the secular periodic pattern of hemispheric phase differences follows 3 (south leading) + 5 (north leading) solar cycles, which probably corresponds to the Gleissberg cycle; and (3) the pronounced periodicities of (absolute and normalized) asymmetry indices and lines of synchronization (LOSs) are not identical: the significant periodic oscillations are 80.65 ± 6.31, 20.91 ± 0.40, and 13.45 ± 0.16 years for the LOS values, and 51.34 ± 2.48, 8.83/8.69 ± 0.07, and 3.77 ± 0.02 years for the (absolute and normalized) asymmetry indices. The analysis results improve our knowledge on the hemispheric interrelation of solar magnetic activity and may provide valuable constraints for solar dynamo models.

  8. Region 1 Acoustic Bat Inventory: National Wildlife Refuges in Eastern Oregon, Eastern Washington, and Idaho

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Bat species were inventoried on National Wildlife Refuges in Eastern Oregon, Eastern Washington, and Idaho using acoustic methods. Samples were collected between...

  9. Strategy Formation in Eastern Jutland

    DEFF Research Database (Denmark)

    Olesen, Kristian

    2008-01-01

      In Eastern Jutland a strategy formation process has been initiated with the aim of developing a strategic spatial plan for the city region.  An organisation has been set up to deal with the first phase of the process, which is to carry out three functional analyses and prepare a common vision...... on which level a serious strategy formation process can take place.  There is a danger that a common strategic spatial plan is more an expression of the lowest common denominator and the municipalities request for infrastructure investments rather than being a spatial strategy with transformative power. ...

  10. The rod orientation test in patients with right-hemisphere infarction : a clinical study of spatial perception in 154 subjects

    NARCIS (Netherlands)

    J.D. Meerwaldt (Johannes David (Jan))

    1982-01-01

    textabstractThis thesis describes a clinical study of disturbances of spatial perception. Chapter I gives a short review of hemispheric asymmetry. For a long time the right hemisphere was regarded as the minor hemisphere, of which substantial regions were thought to have no specific function.

  11. The rod orientation test in patients with right-hemisphere infarction : a clinical study of spatial perception in 154 subjects

    NARCIS (Netherlands)

    J.D. Meerwaldt (Johannes David (Jan))

    1982-01-01

    textabstractThis thesis describes a clinical study of disturbances of spatial perception. Chapter I gives a short review of hemispheric asymmetry. For a long time the right hemisphere was regarded as the minor hemisphere, of which substantial regions were thought to have no specific function. Jackso

  12. Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance.

    Science.gov (United States)

    Huang, Qiu Sue; Turner, Nikki; Baker, Michael G; Williamson, Deborah A; Wong, Conroy; Webby, Richard; Widdowson, Marc-Alain

    2015-07-01

    The 2009 influenza A(H1N1)pdm09 pandemic highlighted the need for improved scientific knowledge to support better pandemic preparedness and seasonal influenza control. The Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance (SHIVERS) project, a 5-year (2012-2016) multiagency and multidisciplinary collaboration, aimed to measure disease burden, epidemiology, aetiology, risk factors, immunology, effectiveness of vaccination and other prevention strategies for influenza and other respiratory infectious diseases of public health importance. Two active, prospective, population-based surveillance systems were established for monitoring influenza and other respiratory pathogens among those hospitalized patients with acute respiratory illness and those enrolled patients seeking consultations at sentinel general practices. In 2015, a sero-epidemiological study will use a sample of patients from the same practices. These data will provide a full picture of the disease burden and risk factors from asymptomatic infections to severe hospitalized disease and deaths and related economic burden. The results during the first 2 years (2012-2013) provided scientific evidence to (a) support a change to NZ's vaccination policy for young children due to high influenza hospitalizations in these children; (b) contribute to the revision of the World Health Organization's case definition for severe acute respiratory illness for global influenza surveillance; and (c) contribute in part to vaccine strain selection using vaccine effectiveness assessment in the prevention of influenza-related consultations and hospitalizations. In summary, SHIVERS provides valuable international platforms for supporting seasonal influenza control and pandemic preparedness, and responding to other emerging/endemic respiratory-related infections.

  13. 20th Century Northern hemisphere jet stream variability

    Science.gov (United States)

    Belmecheri, S.; Babst, F.; Trouet, V.; Betancourt, J. L.

    2015-12-01

    The latitudinal position of the Northern hemisphere Jet stream (NHJ) modulates both long term climate trends and the occurrence and frequency of extreme weather events. Precipitation anomalies in particular are associated with NHJ variability and the resulting floods/droughts can have considerable societal and economic impacts. Therefore a better understanding of NHJs role in regional climate is essential in assessing the natural and socio-economic impacts of projected future change in NHJ features. We developed a new climatology of the 300 hPa NHJ based on its seasonally explicit latitudinal position. We used the 20th Century Reanalysis V2 (20CR) data at monthly resolution from 1930-2012 to define the latitudinal position of NHJ as the latitude with the greatest 300 hPa scalar wind speed (m s-1). From these data, we identified four seasons with coherent NHJ patterns (January-February, April-May, July-August, and October-November) and detected longitudinal sectors (total of 15 sectors for all the seasons) where the seasonal jet shows strong spatial coherence. We examined the influence of seasonal NHJ position on the geographical distribution of precipitation and temperature patterns for all sectors. Furthermore, we compared NHJ positions to atmospheric circulation indices at inter-annual and multi-decadal time scales. We found a significant relationship between the NHJ position and the North Atlantic and Arctic oscillations for all seasons and across the majority of longitudinal sectors. In addition to this, our NHJ data set supports a connection with ocean-atmosphere interactions over the northern Pacific Ocean on various time scales: we found significant correlations between the North Pacific Jet and the Pacific Decadal Oscillation for all seasons and with El Niño Southern Oscillation for the winter season. Our results emphasize the importance of the seasonal and spatial characteristics of NHJ, as well as climate teleconnections, when considering regional

  14. Projected climate impacts for the amphibians of the western hemisphere

    Science.gov (United States)

    Lawler, Joshua J.; Shafer, Sarah L.; Bancroft, Betsy A.; Blaustein, Andrew R.

    2010-01-01

    Given their physiological requirements, limited dispersal abilities, and hydrologically sensitive habitats, amphibians are likely to be highly sensitive to future climatic changes. We used three approaches to map areas in the western hemisphere where amphibians are particularly likely to be affected by climate change. First, we used bioclimatic models to project potential climate-driven shifts in the distribution of 413 amphibian species based on 20 climate simulations for 2071–2100. We summarized these projections to produce estimates of species turnover. Second, we mapped the distribution of 1099 species with restricted geographic ranges. Finally, using the 20 future climate-change simulations, we mapped areas that were consistently projected to receive less seasonal precipitation in the coming century and thus were likely to have altered microclimates and local hydrologies. Species turnover was projected to be highest in the Andes Mountains and parts of Central America and Mexico, where, on average, turnover rates exceeded 60% under the lower of two emissions scenarios. Many of the restricted-range species not included in our range-shift analyses were concentrated in parts of the Andes and Central America and in Brazil's Atlantic Forest. Much of Central America, southwestern North America, and parts of South America were consistently projected to experience decreased precipitation by the end of the century. Combining the results of the three analyses highlighted several areas in which amphibians are likely to be significantly affected by climate change for multiple reasons. Portions of southern Central America were simultaneously projected to experience high species turnover, have many additional restricted-range species, and were consistently projected to receive less precipitation. Together, our three analyses form one potential assessment of the geographic vulnerability of amphibians to climate change and as such provide broad-scale guidance for directing

  15. Regional protein synthesis in rat brain following acute hemispheric ischemia.

    Science.gov (United States)

    Dienel, G A; Pulsinelli, W A; Duffy, T E

    1980-11-01

    Regional protein synthesis was measured in rat brain at intervals up to 48 h following occlusion of the four major arteries to the brain for either 10 or 30 min. Four-vessel occlusions produces ischemia in the cerebral hemispheres and oligemia in the midbrain-diencephalon and brainstem. During the hour following 10 min of ischemia, protein synthesis, measured by incorporation of [14C]valine into protein, was inhibited in the cerebral cortex by 67%. Normal rates of protein synthesis were attained within 4 h of recirculation. In rats subjected to 30 min of ischemia, protein synthesis was inhibited by 83% during the first hour of recirculation in the cortex, caudate-putamen, and hippocampus. Recovery of protein synthesis in these regions was slow (25-48 h). The midbrain-diencephalon showed less inhibition, 67%, and faster recovery (by 12 h). Protein synthesis was unaffected in the brainstem. [14C]Autoradiography revealed that the pyramidal neurons of the hippocampus and areas of the caudate and cortex failed to recover normal rates of protein synthesis even after 48 h. The accumulation of TCA-soluble [14C]valine was enhanced (55-65%) in the cortex, caudate, and hippocampus after 30 min of ischemia; the increase persisted for 12 h. A smaller rise in [14C]valine content (30%) and more rapid normalization of valine accumulation (by 7 h) were observed in the midbrain-diencephalon; no changes were found in the brainstem. In the cortex, recovery was more rapid when the duration of ischemia was reduced. Thus, the degree of inhibition of protein synthesis, the accumulation of valine in the tissue, and the length of time required to reestablish normal values for these processes were dependent on both the severity and the duration of the ischemic insult. Restoration of normal rates of protein synthesis after ischemia was slow compared with the normalization of cerebral energy metabolites.

  16. Revisiting the Climatology of Atmospheric Blocking in the Northern Hemisphere

    Institute of Scientific and Technical Information of China (English)

    Ho Nam CHEUNG; ZHOU Wen; Hing Yim MOK; Man Chi WU; Yaping SHAO

    2013-01-01

    In addition to the occurrence of atmospheric blocking,the climatology of the characteristics of blocking events,including duration,intensity,and extension,in four seasons over the Northern Hemisphere was analyzed for the period 1950-2009.The seasonality and spatial variations of these characteristics were studied according to their longitudinal distributions.In general,there were sharp discrepancies in the blocking characteristics between winter and summer,and these differences were more prominent over the Atlantic and Pacific Oceans.The blocking not only occurred more frequently but also underwent stronger amplification in winter; likewise,the blocking occurred less frequently and underwent weaker amplification in summer.There are very strong interrelationships among different blocking characteristics,suggesting that they are supported by similar physical factors.In addition,the relationship between blocking over different regions and East Asian circulation was examined.Ural-Siberia is a major blocking formation region in all seasons that may exert a downstream impact on East Asia.The impact is generally weak in summer,which is due to its lower intensity and smaller duration.However,the extratropical circulation over East Asia in summer can be disturbed persistently by the frequent occurrence of blocking over the Asian continent or the Western Pacific.In particular,the blocking frequency over the Western Pacific significantly increased during the study period.This climatological information provides a background for studying the impact of blocking on East Asian circulation under both present and future climate conditions.

  17. Was the extreme Northern Hemisphere greening in 2015 predictable?

    Science.gov (United States)

    Bastos, Ana; Ciais, Philippe; Park, Taejin; Zscheischler, Jakob; Yue, Chao; Barichivich, Jonathan; Myneni, Ranga B.; Peng, Shushi; Piao, Shilong; Zhu, Zaichun

    2017-04-01

    The year 2015 was, at the time, the warmest since 1880, and many regions in the Northern Hemisphere (NH) registered record breaking annual temperatures. Simultaneously, a remarkable and widespread growing season greening was observed over most of the NH in the record from the Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI). While the response of vegetation to climate change (i.e. the long term trend) is assumed to be predictable, it is still unclear whether it is also possible to predict the interannual variability in vegetation activity. Here, we evaluate whether the unprecedented magnitude and extent of the greening observed in 2015 corresponds to an expected response to the 2015 climate anomaly, or to a change in the sensitivity of NH vegetation to climate. We decompose NDVI into the long-term and interannual variability components, and find that the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO) explain about half of NDVI interannual variability. This response is in addition to the long-term temperature and human-induced greening trend. We use a simple statistical approach to predict the NDVI anomaly in 2015, using the PDO and AMO states as predictors for interannual variability, and temperature and precipitation trends for the long-term component. We show that the 2015 anomaly can be predicted as an expected vegetation response to temperature and water-availability associated with the very strong state of the PDO in 2015. The link found between climate variability patterns and vegetation activity should contribute to increase the predictability of carbon-cycle processes at interannual time-scales, which may be relevant, for instance, for optimizing land-management strategies.

  18. Clusters of interannual sea ice variability in the northern hemisphere

    Science.gov (United States)

    Fučkar, Neven S.; Guemas, Virginie; Johnson, Nathaniel C.; Massonnet, François; Doblas-Reyes, Francisco J.

    2016-09-01

    We determine robust modes of the northern hemisphere (NH) sea ice variability on interannual timescales disentangled from the long-term climate change. This study focuses on sea ice thickness (SIT), reconstructed with an ocean-sea-ice general circulation model, because SIT has a potential to contain most of the interannual memory and predictability of the NH sea ice system. We use the K-means cluster analysis—one of clustering methods that partition data into groups or clusters based on their distances in the physical space without the typical constraints of other unsupervised learning statistical methods such as the widely-used principal component analysis. To adequately filter out climate change signal in the Arctic from 1958 to 2013 we have to approximate it with a 2nd degree polynomial. Using 2nd degree residuals of SIT leads to robust K-means cluster patterns, i.e. invariant to further increase of the polynomial degree. A set of clustering validity indices yields K = 3 as the optimal number of SIT clusters for all considered months and seasons with strong similarities in their cluster patterns. The associated time series of cluster occurrences exhibit predominant interannual persistence with mean timescale of about 2 years. Compositing analysis of the NH surface climate conditions associated with each cluster indicates that wind forcing seem to be the key factor driving the formation of interannual SIT cluster patterns during the winter. Climate memory in SIT with such interannual persistence could lead to increased predictability of the Artic sea ice cover beyond seasonal timescales.

  19. Prediction of sea ice thickness cluster in the Northern Hemisphere

    Science.gov (United States)

    Fuckar, Neven-Stjepan; Guemas, Virginie; Johnson, Nathaniel; Doblas-Reyes, Francisco

    2016-04-01

    Sea ice thickness (SIT) has a potential to contain substantial climate memory and predictability in the northern hemisphere (NH) sea ice system. We use 5-member NH SIT, reconstructed with an ocean-sea-ice general circulation model (NEMOv3.3 with LIM2) with a simple data assimilation routine, to determine NH SIT modes of variability disentangled from the long-term climate change. Specifically, we apply the K-means cluster analysis - one of nonhierarchical clustering methods that partition data into modes or clusters based on their distances in the physical - to determine optimal number of NH SIT clusters (K=3) and their historical variability. To examine prediction skill of NH SIT clusters in EC-Earth2.3, a state-of-the-art coupled climate forecast system, we use 5-member ocean and sea ice initial conditions (IC) from the same ocean-sea-ice historical reconstruction and atmospheric IC from ERA-Interim reanalysis. We focus on May 1st and Nov 1st start dates from 1979 to 2010. Common skill metrics of probability forecast, such as rank probability skill core and ROC (relative operating characteristics - hit rate versus false alarm rate) and reliability diagrams show that our dynamical model predominately perform better than the 1st order Marko chain forecast (that beats climatological forecast) over the first forecast year. On average May 1st start dates initially have lower skill than Nov 1st start dates, but their skill is degraded at slower rate than skill of forecast started on Nov 1st.

  20. Projections of Southern Hemisphere atmospheric circulation interannual variability

    Science.gov (United States)

    Grainger, Simon; Frederiksen, Carsten S.; Zheng, Xiaogu

    2017-02-01

    An analysis is made of the coherent patterns, or modes, of interannual variability of Southern Hemisphere 500 hPa geopotential height field under current and projected climate change scenarios. Using three separate multi-model ensembles (MMEs) of coupled model intercomparison project phase 5 (CMIP5) models, the interannual variability of the seasonal mean is separated into components related to (1) intraseasonal processes; (2) slowly-varying internal dynamics; and (3) the slowly-varying response to external changes in radiative forcing. In the CMIP5 RCP8.5 and RCP4.5 experiments, there is very little change in the twenty-first century in the intraseasonal component modes, related to the Southern annular mode (SAM) and mid-latitude wave processes. The leading three slowly-varying internal component modes are related to SAM, the El Niño-Southern oscillation (ENSO), and the South Pacific wave (SPW). Structural changes in the slow-internal SAM and ENSO modes do not exceed a qualitative estimate of the spatial sampling error, but there is a consistent increase in the ENSO-related variance. Changes in the SPW mode exceed the sampling error threshold, but cannot be further attributed. Changes in the dominant slowly-varying external mode are related to projected changes in radiative forcing. They reflect thermal expansion of the tropical troposphere and associated changes in the Hadley Cell circulation. Changes in the externally-forced associated variance in the RCP8.5 experiment are an order of magnitude greater than for the internal components, indicating that the SH seasonal mean circulation will be even more dominated by a SAM-like annular structure. Across the three MMEs, there is convergence in the projected response in the slow-external component.

  1. Crossed Non-Dominant Hemisphere Syndrome in a Right-Hander

    Directory of Open Access Journals (Sweden)

    M. Fujimori

    1994-01-01

    Full Text Available A right-handed patient with a large left temporo-parietal infarction manifested various non-dominant hemisphere signs. He had two left-handed children. On neurobehavioural examinations, he did not show aphasia or ideomotor apraxia, but did show hemispatial neglect, spatial agraphia, constructional apraxia, auditory and tactile extinction, anosodiaphoria and affective changes, all of which are usually observed after right hemispheric damage. We conclude that he has a reversed cerebral laterality of cognitive functions and showed crossed non-dominant hemisphere syndrome.

  2. Mixed transcortical aphasia: clinical features and neuroanatomical correlates. A possible role of the right hemisphere.

    Science.gov (United States)

    Grossi, D; Trojano, L; Chiacchio, L; Soricelli, A; Mansi, L; Postiglione, A; Salvatore, M

    1991-01-01

    This paper reports the clinical features of 2 patients affected by mixed transcortical aphasia. Both of them had extensive damage of the left hemisphere. Cerebral blood flow measurement showed a marked decrease in left-hemisphere flow. In particular, speech areas were found to be morphologically and functionally damaged. The present findings, together with a critical review of the literature, served as a starting point for a discussion of linguistic features, diagnostic criteria and classical neuroanatomical interpretation of mixed transcortical aphasia. The possible contribution of the right hemisphere in determining this aphasic syndrome is suggested.

  3. EDITORIAL: Northern Hemisphere high latitude climate and environmental change

    Science.gov (United States)

    Groisman, Pavel; Soja, Amber

    2007-10-01

    High Northern Hemisphere latitudes are undergoing rapid and significant change associated with climate warming. Climatic change in this region interacts with and affects the rate of the global change through atmospheric circulation, biogeophysical, and biogeochemical feedbacks. Changes in the surface energy balance, hydrologic cycle, and carbon budget feedback to regional and global weather and climate systems. Two-thirds of the Northern Hemisphere high latitude land mass resides in Northern Eurasia (~20% of the global land mass), and this region has undergone sweeping socio-economic change throughout the 20th century. How this carbon-rich, cold region component of the Earth system functions as a regional entity and interacts with and feeds back to the greater global system is to a large extent unknown. To mitigate the deficiencies in understanding these feedbacks, which may in turn hamper our understanding of the global change rates and patterns, an initiative was formed. Three years ago the Northern Eurasia Earth Science Partnership Initiative (NEESPI) was established to address large-scale and long-term manifestations of climate and environmental change in this region. The NEESPI Science Plan and its Executive Summary have been published at the NEESPI web site (neespi.org). Since 2004, NEESPI participants have been able to seed several waves of research proposals to international and national funding agencies and institutions and also contribute to the International Polar Year. Currently, NEESPI is widely recognized and endorsed by several Earth System Science Partnership (ESSP) programmes and projects: the International Geosphere and Biosphere Programme, the World Climate Research Programme through the Global Energy and Water Cycle Experiment and Climate and Cryosphere Projects, the Global Water System Project, Global Carbon Project, Global Land Project, and the Integrated Land Ecosystem—Atmosphere Processes Study. Through NEESPI, more than 100 individually

  4. Snakebite ethnopharmacopoeia of eastern Nicaragua.

    Science.gov (United States)

    Coe, Felix G; Anderson, Gregory J

    2005-01-04

    Results of an ethnopharmacognostic study of snakebite treatments in eastern Nicaragua are presented. Data and specimens were collected during several years of field studies. Field work consisted of plant collecting trips and interviews of snakedoctors. The annual mortality from snakebites in eastern Nicaragua is about 25% and most bites are caused by the fer-de-lance (Bothrops asper). The vascular flora of the region is estimated at 2500 species of which 435 have medicinal application including 81 that are used in snakebite treatment. The majority of species used in snakebite cures are flowering plants, 76% dicots and 20% monocots, and 80% are obtained from the second-growth forest. About half the species are herbs. Leaves are the most frequently utilized plant part. Most herbal remedies are prepared as decoctions and are administered orally. Remedies are mostly prepared with native wild species, but some are introduced domesticates, derived from either the American or Old World Tropics. All the species used contain at least one bioactive compound, and most of these bioactives have been shown in other studies to have pharmacological effects. The use of species in snakebite treatments does not necessarily imply efficacy, but it does give a limited list of species that can be studied pharmacologically for possible bioactive effects. Studies like this one are also important because they document traditional practices and species utilized for the people of the region studied as well.

  5. Hemispheric specificity for proprioception: Postural control of standing following right or left hemisphere damage during ankle tendon vibration.

    Science.gov (United States)

    Duclos, Noémie C; Maynard, Luc; Abbas, Djawad; Mesure, Serge

    2015-11-02

    Right brain damage (RBD) following stroke often causes significant postural instability. In standing (without vision), patients with RBD are more unstable than those with left brain damage (LBD). We hypothesised that this postural instability would relate to the cortical integration of proprioceptive afferents. The aim of this study was to use tendon vibration to investigate whether these changes were specific to the paretic or non-paretic limbs. 14 LBD, 12 RBD patients and 20 healthy subjects were included. Displacement of the Centre of Pressure (CoP) was recorded during quiet standing, then during 3 vibration conditions (80 Hz - 20s): paretic limb, non-paretic limb (left and right limbs for control subjects) and bilateral. Vibration was applied separately to the peroneal and Achilles tendons. Mean antero-posterior position of the CoP, variability and velocity were calculated before (4s), during and after (24s) vibration. For all parameters, the strongest perturbation was during Achilles vibrations. The Achilles non-paretic condition induced a larger backward displacement than the Achilles paretic condition. This condition caused specific behaviour on the velocity: the LBD group was perturbed at the onset of the vibrations, but gradually recovered their stability; the RBD group was significantly perturbed thereafter. After bilateral Achilles vibration, RBD patients required the most time to restore initial posture. The reduction in use of information from the paretic limb may be a central strategy to deal with risk-of-fall situations such as during Achilles vibration. The postural behaviour is profoundly altered by lesions of the right hemisphere when proprioception is perturbed.

  6. The pattern of northern hemisphere surface air temperature during prolonged periods of low solar output

    Science.gov (United States)

    Ruzmaikin, A.; Feyman, J.; Jiang, X.; Noone, D. C.; Waple, A. M.; Yung, Y. L.

    2004-01-01

    We show that the reconstructed sensitivity of the sea level temperature to long term solar forcing in the Northern Hemisphere is in very good agreement with the empirical temperature pattern corresponding to changes of the North Annular Mode (NAM).

  7. Attention modulates hemispheric differences in functional connectivity: Evidence from MEG recordings

    NARCIS (Netherlands)

    L. Gootjes (Liselotte); A. Bouma (Anke); J.W. van Strien (Jan); P. Scheltens (Philip); C.J. Stam

    2008-01-01

    textabstractThe present study examined intrahemispheric functional connectivity during rest and dichotic listening in 8 male and 9 female healthy young adults measured with magnetoencephalography (MEG). Generalized synchronization within the separate hemispheres was estimated by means of the synchro

  8. NOAA Climate Data Record (CDR) of Northern Hemisphere (NH) Snow Cover Extent (SCE), Version 1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This NOAA Climate Data Record (CDR) is a record for the Northern Hemisphere (NH) Snow Cover Extent (SCE) spanning from October 4, 1966 to present, updated monthly...

  9. Lateralized free-association priming: implications for the hemispheric organization of semantic memory.

    Science.gov (United States)

    Koivisto, M; Laine, M

    1995-01-01

    The organization of semantic memory in intact cerebral hemispheres was examined by a free-association priming task. Normal subjects studied a list of word pairs where the semantic relations were either coordinate (e.g. saw-axe) or locative (e.g. bear-forest). Priming of the word pairs was tested by presenting test cues (initial words of the pairs) to the left or to the right visual field. Results showed an interaction between visual field and word pair type, suggesting a qualitative difference in the semantic organization of the hemispheres. Specifically, the results support the view that coordinate relations are represented in both hemispheres whereas locative relations are represented mainly in the right hemisphere.

  10. Opposed Left and Right Brain Hemisphere Contributions to Sexual Drive: A Multiple Lesion Case Analysis

    Directory of Open Access Journals (Sweden)

    Claude M. J. Braun

    2003-01-01

    Full Text Available Brain topographical studies of normal men have have shown that sexual excitation is asymmetric in the brain hemispheres. Group studies of patients with unilateral epileptic foci and other studies of patients with unilateral brain lesions have come to the same conclusion. The present study reviewed previously published single case reports of patients with frank hypo or hypersexuality subsequent to a unilateral brain lesion. Hyposexual patients tended to have left hemisphere lesions (primarily of the temporal lobe, and hypersexual patients tended to have right hemisphere lesions (primarily of the temporal lobe (p < 0.05. We interpret this double dissociation as part of a more general phenomenon of psychic tone similarly dissociated with regard to hemispheric control, including mood, psychomotor baseline, speech rate, and even immunity. The behavioral significance of this psychic tone is to modulate approach versus avoidance behavior.

  11. Is Happy Facial Expression Identified by the Left or Right Hemisphere?

    Institute of Scientific and Technical Information of China (English)

    Zhou Xiaolin; Shao Liping

    2005-01-01

    A critical difference between the right hemisphere hypothesis and valence hypothesis of emotion processing is whether the processing of happy facial expressions is lateralized to the right or left hemisphere. In this study participants from a Chinese sample were asked to classify happy or neutral facial expressions presented either bilaterally in both visual fields or unilaterally in the left visual field (LVF) or right visual field (RVF) . They were required to make the speeded responses using either the left or right hand. It was found that for both left and right hand responses, happy (and neutral) expressions presented in the LVF were identified faster than happy (and neutral) expressions presented in the RVF. Bilateral presentation showed no further advantage over LVF presentation.Moreover, left hand responses were generally faster than right hand responses, although this effect was more pronounced for neutral expression. These findings were interpreted as supporting the right hemisphere hypothesis, with happy expression being identified initially by the right hemisphere.

  12. Cortical projection topography of the human splenium: hemispheric asymmetry and individual differences.

    Science.gov (United States)

    Putnam, Mary Colvin; Steven, Megan S; Doron, Karl W; Riggall, Adam C; Gazzaniga, Michael S

    2010-08-01

    The corpus callosum is the largest white matter pathway in the human brain. The most posterior portion, known as the splenium, is critical for interhemispheric communication between visual areas. The current study employed diffusion tensor imaging to delineate the complete cortical projection topography of the human splenium. Homotopic and heterotopic connections were revealed between the splenium and the posterior visual areas, including the occipital and the posterior parietal cortices. In nearly one third of participants, there were homotopic connections between the primary visual cortices, suggesting interindividual differences in splenial connectivity. There were also more instances of connections with the right hemisphere, indicating a hemispheric asymmetry in interhemispheric connectivity within the splenium. Combined, these findings demonstrate unique aspects of human interhemispheric connectivity and provide anatomical bases for hemispheric asymmetries in visual processing and a long-described hemispheric asymmetry in speed of interhemispheric communication for visual information.

  13. Reconstructed North American, Eurasian, and Northern Hemisphere Snow Cover Extent, 1915-1997

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains time series of monthly snow cover extent (SCE) for North America, Eurasia, and the Northern Hemisphere from 1915 to 1997, based on snow cover...

  14. Vocal reaction times to unilaterally presented concrete and abstract words: towards a theory of differential right hemispheric semantic processing.

    Science.gov (United States)

    Rastatter, M; Dell, C W; McGuire, R A; Loren, C

    1987-03-01

    Previous studies investigating hemispheric organization for processing concrete and abstract nouns have provided conflicting results. Using manual reaction time tasks some studies have shown that the right hemisphere is capable of analyzing concrete words but not abstract. Others, however, have inferred that the left hemisphere is the sole analyzer of both types of lexicon. The present study tested these issues further by measuring vocal reaction times of normal subjects to unilaterally presented concrete and abstract items. Results were consistent with a model of functional localization which suggests that the minor hemisphere is capable of differentially processing both types of lexicon in the presence of a dominant left hemisphere.

  15. Old age mortality in Eastern and South-Eastern Asia

    Directory of Open Access Journals (Sweden)

    Danan Gu

    2013-11-01

    Full Text Available Background: Eastern and South-Eastern Asian countries have witnessed a marked decline in old age mortality in recent decades. Yet no studies have investigated the trends and patterns in old age morality and cause-of-death in the region. Objective: We reviewed the trends and patterns of old age mortality and cause-of-death for countries in the region. Methods: We examined data on old age mortality in terms of life expectancy at age 65 and age-specific death rates from the 2012 Revision of the World Population Prospects for 14 countries in the region (China, Hong Kong, Democratic People's Republic of Korea, Indonesia, Japan, Lao People's Democratic Republic, Myanmar, Malaysia, Mongolia, Philippines, Republic of Korea, Singapore, Thailand, and Viet Nam and data on cause-of-death from the WHO for five countries (China, Hong Kong, Japan, Republic of Korea, and Singapore from 1980 to 2010. Results: While mortality transitions in these populations took place in different times, and at different levels of socioeconomic development and living environment, changes in their age patterns and sex differentials in mortality showed certain similarities: women witnessed a similar decline to men in spite of their lower mortality, and young elders had a larger decline than the oldest-old. In all five countries examined for cause-of-death, most of the increases in life expectancy at age 65 in both men and women were attributable to declines in mortality from stroke and heart disease. GDP per capita, educational level, and urbanization explained much of the variations in life expectancy and cause-specific mortality, indicating critical contributions of these basic socioeconomic development indicators to the mortality decline over time in the region. Conclusions: These findings shed light on the relationship between epidemiological transition, changing age patterns of mortality, and improving life expectancy in these populations.

  16. The dynamics of the warming hiatus over the Northern Hemisphere

    Science.gov (United States)

    Huang, Jianping; Xie, Yongkun; Guan, Xiaodan; Li, Dongdong; Ji, Fei

    2017-01-01

    A warming hiatus is a period of relatively little change in global mean surface air temperatures (SAT). Many studies have attributed the current warming hiatus to internal climate variability (ICV). But there is less work on discussion of the dynamics about how these ICV modes influence cooling over land in the Northern Hemisphere (NH). Here we demonstrate the warming hiatus was more significant over the continental NH. We explored the dynamics of the warming hiatus from a global perspective and investigated the mechanisms of the reversing from accelerated warming to hiatus, and how ICV modes influence SAT change throughout the NH land. It was found that these ICV modes and Arctic amplification can excite a decadal modulated oscillation (DMO), which enhances or suppresses the long-term trend on decadal to multi-decadal timescales. When the DMO is in an upward (warming) phase, it contributes to an accelerated warming trend, as in last 20 years of twentieth-century. It appears that there is a downward swing in the DMO occurring at present, which has balanced or reduced the radiative forced warming and resulted in the recent global warming hiatus. The DMO modulates the SAT, in particular, the SAT of boreal cold months, through changes in the asymmetric meridional and zonal thermal forcing (MTF and ZTF). The MTF represents the meridional temperature gradients between the mid- and high-latitudes, and the ZTF represents the asymmetry in temperatures between the extratropical large-scale warm and cold zones in the zonal direction. Via the different performance of combined MTF and ZTF, we found that the DMO's modulation effect on SAT was strongest when both weaker (stronger) MTF and stronger (weaker) ZTF occurred simultaneously. And the current hiatus is a result of a downward DMO combined with a weaker MTF and stronger ZTF, which stimulate both a weaker polar vortex and westerly winds, along with the amplified planetary waves, thereby facilitating southward invasion of

  17. Uranus’ Hemispheric Asymmetries in Polar Cloud and Circulation Structures

    Science.gov (United States)

    Hammel, Heidi B.; Sromovsky, Lawrence; Fry, Pat; de Pater, Imke

    2015-11-01

    We report on the north polar region of Uranus in the post-equinoctial era. Near-IR imaging with Keck 2 using NIRC2 in 2012-2014 revealed numerous small bright features, as well as small dark features, between 50 degrees N and the north pole. Tracking of these features yielded circulation patterns, with the remarkable result that the region from 60 degrees to at least 83 degrees rotates about the northern pole as a solid body, with a drift rate of 4.1 degrees/hour westward relative to the interior (Sromovsky et al. 2015, Icarus 258, 192-223). For the south pole, the same latitude region had dramatically different characteristics, as judged by 1986 Voyager and 2003 Keck observations. The southern region showed no discrete near-IR features; detailed circulation measurements in that region were based solely on low-contrast features in re-analyzed Voyager images (Karkoschka, 2015, Icarus 250, 294-307). They revealed a large gradient in drift rates, with values reaching twice that seen in the corresponding northern region.The north-south asymmetry in circulation and cloud structure/morphology is surprising because the distribution of upper tropospheric methane is relatively symmetric: roughly constant over a region from 30 S to 30 N, and then declining at higher latitudes in both hemispheres. The methane distribution suggests symmetric down-welling motion in both polar regions, which would inhibit formation of condensation clouds there, in contrast to the observed dichotomy. Some asymmetry may be an effect of seasonal forcing, since the north versus south polar measurements were made during different seasons. If so, then major changes can be expected in the north polar region as Uranus proceeds toward its 2030 northern summer solstice. Hubble STIS observations expected in October of 2015 will further examine the vertical distribution and stability of the polar methane abundances. Future high-resolution imaging with Earth-based facilities will be able to track circulation

  18. Multiparametric study of polar ionosphere on both hemispheres

    Science.gov (United States)

    D'Angelo, Giulia; Alfonsi, Lucilla; Spogli, Luca; Cesaroni, Claudio; Sgrigna, Vittorio

    2016-04-01

    The polar ionosphere is a complex system in which several actors concur to establish the observed medium. Indeed the coupling between the interplanetary magnetic field and the earth magnetic field determines a high degree of complexity of the polar ionosphere, which is directly exposed to the variations of the solar wind. This configuration results in a strong sensitivity of the polar ionosphere to the perturbation phenomena caused by solar events which may result in a wide variety of spatial and temporal dimensions of the plasma electron density irregularities. Polar ionospheric irregularities may seriously jeopardize performance and reliability level of the navigation and positioning technological systems, such as GPS or the nascent Galileo. Therefore, knowledge of the physical state of the upper atmosphere ionized layers becomes essential to predict and mitigate events that may affect the use of modern technology, causing economic damage and, in severe cases, even jeopardizing the safety of human beings. In this context, a careful and thorough investigation that covers a wide range of geospatial different disturbances, observed in circumterrestrial space and on the ground, can provide the necessary basis for a real advance of the current knowledge. In this frame, the aim of this work is to contribute to the study of the effects of perturbation induced by the Sun on the polar ionosphere of both the hemispheres, through the analysis and interpretation of the measures available before, during and after the occurrence of an event of disturbance. We propose a multiparametric approach, that combines the information derived from measurements acquired by ground-based and space-based stations, to have a broad spectrum of information necessary to characterize the ionospheric disturbances on different time scales (from milliseconds to days) and spatial scales (from millimetres to hundreds meters/kilometres). The period chosen for this study is the entire month of March

  19. Declining Spring Snow Cover Extent over Northern Hemisphere Lands

    Science.gov (United States)

    Robinson, David

    2015-04-01

    Annual snow cover extent (SCE) over Northern Hemisphere (NH) lands averages close to 26 million square kilometers. It ranges from an average of 47 million sq. km. in January to 3 million sq. km. (mostly atop the Greenland Ice Sheet) in August. SCE is calculated at the Rutgers Global Snow Lab from daily SCE maps produced by meteorologists at the National Ice Center, who rely primarily on visible satellite imagery to construct the maps. The Rutgers SCE climate data record (CDR) shows that since the late 1980s annual SCE over NH lands has averaged lower than earlier in the satellite era, which for SCE monitoring began in 1967. This is most evident from late winter through spring, being exceedingly pronounced this past decade at high latitudes in May and June. The most recent five Mays have been amongst the lowest seven in terms of NH SCE on record, with Eurasian (EUR) SCE at a record low in 2013. North American (NA) SCE achieved a record minimum in May 2010, but of late has not been as consistently low as over EUR. The past seven Junes have seen record minimum SCE over the NH, and six of the seven lowest over EUR and NA. The recent early timing of arctic snowmelt appears to be occurring at a pace equivalent to if not exceeding the loss of summer Arctic sea ice extent. In situ station observations suggest that spring snow is presently the least extensive in the past century. Possible reasons behind the early melt appear to be associated with atmospheric circulation patterns and overall warming. This presentation, while focusing on SCE variability utilizing the Rutgers SCE CDR, will also include discussion of a new merged snow extent and melt state CDR that includes data from NH continents, Greenland, and Arctic sea ice. Visible and microwave satellite data are employed in these efforts. The merged product is available in netCDF format from the National Snow and Ice Data Center. This includes 25 km (1999-2010) and 100 km (1967-2010) resolution versions using the Equal

  20. rTMS of the unaffected hemisphere transiently reduces contralesional visuospatial hemineglect.

    Science.gov (United States)

    Oliveri, M; Bisiach, E; Brighina, F; Piazza, A; La Bua, V; Buffa, D; Fierro, B

    2001-10-09

    To verify the role of interhemispheric influences on manifestations of neglect, the authors investigated the effects of a transient repetitive transcranial magnetic stimulation (rTMS)-induced disruption of the unaffected hemisphere on contralesional visuospatial neglect in two left- and five right-brain-damaged patients. Parietal rTMS of the unaffected hemisphere during the execution of a computerized task of bisected line's length judgment transiently decreased the magnitude of neglect as expressed in the number of errors.

  1. An ERP assessment of hemispheric projections in foveal and extrafoveal word recognition.

    Directory of Open Access Journals (Sweden)

    Timothy R Jordan

    Full Text Available BACKGROUND: The existence and function of unilateral hemispheric projections within foveal vision may substantially affect foveal word recognition. The purpose of this research was to reveal these projections and determine their functionality. METHODOLOGY: Single words (and pseudowords were presented to the left or right of fixation, entirely within either foveal or extrafoveal vision. To maximize the likelihood of unilateral projections for foveal displays, stimuli in foveal vision were presented away from the midline. The processing of stimuli in each location was assessed by combining behavioural measures (reaction times, accuracy with on-line monitoring of hemispheric activity using event-related potentials recorded over each hemisphere, and carefully-controlled presentation procedures using an eye-tracker linked to a fixation-contingent display. PRINCIPAL FINDINGS: Event-related potentials 100-150 ms and 150-200 ms after stimulus onset indicated that stimuli in extrafoveal and foveal locations were projected unilaterally to the hemisphere contralateral to the presentation hemifield with no concurrent projection to the ipsilateral hemisphere. These effects were similar for words and pseudowords, suggesting this early division occurred before word recognition. Indeed, event-related potentials revealed differences between words and pseudowords 300-350 ms after stimulus onset, for foveal and extrafoveal locations, indicating that word recognition had now occurred. However, these later event-related potentials also revealed that the hemispheric division observed previously was no longer present for foveal locations but remained for extrafoveal locations. These findings closely matched the behavioural finding that foveal locations produced similar performance each side of fixation but extrafoveal locations produced left-right asymmetries. CONCLUSIONS: These findings indicate that an initial division in unilateral hemispheric projections occurs in

  2. Characterization of loads on a hemispherical point absorber wave energy converter

    DEFF Research Database (Denmark)

    Jakobsen, Morten Møller; Beatty, Scott; Iglesias, G.

    2016-01-01

    Highlights •Slammingpressure on shell surface of hemisphere and comparison asymptotic theory. •Excitationforces from experiments and comparison with numerical inviscid boundary elementmodel. •Applicationof found coefficients in normal operation conditions for the wave energydevice.......Highlights •Slammingpressure on shell surface of hemisphere and comparison asymptotic theory. •Excitationforces from experiments and comparison with numerical inviscid boundary elementmodel. •Applicationof found coefficients in normal operation conditions for the wave energydevice....

  3. Crossed Aphasia in a Dextral without “Minor” Hemisphere Signs

    Directory of Open Access Journals (Sweden)

    J. C. Marshall

    1992-01-01

    Full Text Available A case of severe aphasia after right hemisphere stroke, confirmed by CT, in an unambiguously dextral patient is reported. The patient showed no limb apraxia, and performed well on a test of “closure” (Mooney faces. Extensive testing revealed no signs of visuo-spatial neglect. We conclude that “pure” crossed aphasia can occur in the absence of symptoms normally associated with right hemisphere lesions.

  4. Brief neuropsychological assessment of adults post-stroke in the left hemisphere

    OpenAIRE

    Pawlowski, Josiane; Rodrigues, Jaqueline de Carvalho; Martins,Sheila Cristina Ouriques; Brondani, Rosane; Chaves, Márcia Lorena Fagundes; Fonseca,Rochele Paz; Bandeira, Denise Ruschel

    2013-01-01

    The neuropsychological assessment investigates cognitive deficits to improve the diagnosis, the prognosis and the rehabilitation of patients. In Brazil, stroke is a major cause of hospitalization and the leading cause of mortality and disability. The stroke in the left hemisphere (LH) is associated with different degrees of loss of language and other cognitive impairments, for example, in the memory. We compared the performance in brief neuropsychological tasks of the left hemisphere poststro...

  5. Congenital infiltrating lipomatosis of the face with enlargement of the ipsilateral cerebellar hemisphere

    Directory of Open Access Journals (Sweden)

    Eric Gous

    2015-03-01

    Full Text Available Congenital infiltrating lipomatosis of the face (CILF is a rare disorder in which overgrowth of fatty tissue with infiltration of underlying structures leads to craniofacial deformities and asymmetry. Imaging plays an important role in the diagnosis, surgical planning and evaluation of underlying structures. To our knowledge, our case is the first to describe CILF associated with isolated enlargement of a cerebellar hemisphere in the absence of an enlarged ipsilateral cerebral hemisphere (hemimegalencephaly.

  6. Temporal Trends and Spatial Variability of Vegetation Phenology over the Northern Hemisphere during 1982-2012

    OpenAIRE

    Siyuan Wang; Bojuan Yang; Qichun Yang; Linlin Lu; Xiaoyue Wang; Yaoyao Peng

    2016-01-01

    Satellite-derived vegetation phenology has been recognized as a key indicator for detecting changes in the terrestrial biosphere in response to global climate change. However, multi-decadal changes and spatial variation of vegetation phenology over the Northern Hemisphere and their relationship to climate change have not yet been fully investigated. In this article, we investigated the spatial variability and temporal trends of vegetation phenology over the Northern Hemisphere by calibrating ...

  7. Quasiresonant amplification of planetary waves and recent Northern Hemisphere weather extremes

    OpenAIRE

    Petoukhov, Vladimir; Rahmstorf, Stefan; Petri, Stefan; Schellnhuber, Hans Joachim

    2013-01-01

    In recent years, the Northern Hemisphere has suffered several devastating regional summer weather extremes, such as the European heat wave in 2003, the Russian heat wave and the Indus river flood in Pakistan in 2010, and the heat wave in the United States in 2011. Here, we propose a common mechanism for the generation of persistent longitudinal planetary-scale high-amplitude patterns of the atmospheric circulation in the Northern Hemisphere midlatitudes. Those patterns—with zonal wave numbers...

  8. Synchoronous inter-hemispheric alpine glacier advances during the Late Glacial?

    Science.gov (United States)

    Bakke, Jostein; Paasche, Øyvind

    2016-04-01

    The termination of the last glaciation in both hemispheres was a period of rapid climate swings superimposed on the overall warming trend, resulting from large-scale reorganizations of the atmospheric and oceanic circulation patterns in both hemispheres. Environmental changes during the deglaciation have been inferred from proxy records, as well as by model simulations. Several oscillations took place both in northern and southern hemispheres caused by melt water releases such as during the Younger Dryas in north and the Antarctic Cold Reversal in south. However, a consensus on the hemispheric linkages through ocean and atmosphere are yet to be reached. Here we present a new multi-proxy reconstruction from a sub-annually resolved lake sediment record from Lake Lusvatnet in Arctic Norway compared with a new reconstruction from the same time interval at South Georgia, Southern Ocean, suggesting inter-hemispheric climate linkages during the Bølling/Allerød time period. Our reconstruction of the alpine glacier in the lake Lusvatnet catchment show a synchronous glacier advance with the Birch-hill moraine complex in the Southern Alps, New Zealand during the Intra Allerød Cooling period. We propose these inter hemispheric climate swings to be forced by the northward migration of the southern Subtropical Front during the Antarctic Cold Reversal. Such a northward migration of the Subtropical Front is shown in model simulation and in palaeorecords to reduce the Agulhas leakage impacting the strength of the Atlantic meridional overturning circulation. We simply ask if this can be the carrier of rapid climate swings from one hemisphere to another? Our high-resolution reconstructions provide the basis for an enhanced understanding of the tiny balance between migration of the Subtropical Front in the Southern Ocean and the teleconnection to northern hemisphere.

  9. Outcomes of Children Adopted from Eastern Europe

    Science.gov (United States)

    Miller, Laurie; Chan, Wilma; Tirella, Linda; Perrin, Ellen

    2009-01-01

    Behavioral problems are frequent among post-institutionalized Eastern European adoptees. However, risk factors related to outcomes have not been fully delineated. We evaluated 50 Eastern European adoptees, age 8-10 years, with their adoptive families for more than five years. Cognitive and behavioral outcomes and parenting stress were evaluated in…

  10. Hemispheric asymmetry in new neurons in adulthood is associated with vocal learning and auditory memory.

    Directory of Open Access Journals (Sweden)

    Shuk C Tsoi

    Full Text Available Many brain regions exhibit lateral differences in structure and function, and also incorporate new neurons in adulthood, thought to function in learning and in the formation of new memories. However, the contribution of new neurons to hemispheric differences in processing is unknown. The present study combines cellular, behavioral, and physiological methods to address whether 1 new neuron incorporation differs between the brain hemispheres, and 2 the degree to which hemispheric lateralization of new neurons correlates with behavioral and physiological measures of learning and memory. The songbird provides a model system for assessing the contribution of new neurons to hemispheric specialization because songbird brain areas for vocal processing are functionally lateralized and receive a continuous influx of new neurons in adulthood. In adult male zebra finches, we quantified new neurons in the caudomedial nidopallium (NCM, a forebrain area involved in discrimination and memory for the complex vocalizations of individual conspecifics. We assessed song learning and recorded neural responses to song in NCM. We found significantly more new neurons labeled in left than in right NCM; moreover, the degree of asymmetry in new neuron numbers was correlated with the quality of song learning and strength of neuronal memory for recently heard songs. In birds with experimentally impaired song quality, the hemispheric difference in new neurons was diminished. These results suggest that new neurons may contribute to an allocation of function between the hemispheres that underlies the learning and processing of complex signals.

  11. Hemispheric asymmetry and visuo-olfactory integration in perceiving subthreshold (micro) fearful expressions.

    Science.gov (United States)

    Forscher, Emily C; Li, Wen

    2012-02-08

    Multisensory integration is ubiquitous, facilitating perception beyond the limit of individual senses. This mechanism is especially salient when individual sensory input is weak (i.e., the principle of inverse effectiveness), fusing subthreshold cues into tangible percepts. Nevertheless, it is unclear how this rule applies to threat perception, synthesizing elusive, discrete traces of a threat into a discernible danger signal. In light of hemispheric asymmetry in threat processing, we combined parafoveal stimulus presentation and the contralateral P1 visual event-related potential to investigate how aversive olfactory inputs enhance visual perception of highly degraded, subthreshold fearful expressions. The dominant right hemisphere exhibited early visual discrimination between subtle fear and neutral expressions, independently of accompanying odors. In the left hemisphere, differential visual processing occurred only at the convergence of negative odors and minute facial fear, highlighting the success and necessity of visuo-olfactory threat integration in this disadvantaged hemisphere. Reaction time data from a subsequent dot-detection task complemented these neural findings, revealing odor-dependent and hemisphere-specific modulation of spatial attention to facial expressions. Our evidence thus indicates cross-modal threat integration in basic visual perception in humans that captures minimal threat information, especially in the blind right hemifield. Critically, this interaction between multisensory synergy and hemispheric asymmetry in threat perception may underlie the multifaceted fear experiences of everyday life.

  12. Regional insolation forcing of late Quaternary climate change in the Southern Hemisphere.

    Science.gov (United States)

    Vandergoes, Marcus J; Newnham, Rewi M; Preusser, Frank; Hendy, Chris H; Lowell, Thomas V; Fitzsimons, Sean J; Hogg, Alan G; Kasper, Haino Uwe; Schlüchter, Christian

    2005-07-14

    In agreement with the Milankovitch orbital forcing hypothesis it is often assumed that glacial-interglacial climate transitions occurred synchronously in the Northern and Southern hemispheres of the Earth. It is difficult to test this assumption, because of the paucity of long, continuous climate records from the Southern Hemisphere that have not been dated by tuning them to the presumed Northern Hemisphere signals. Here we present an independently dated terrestrial pollen record from a peat bog on South Island, New Zealand, to investigate global and local factors in Southern Hemisphere climate changes during the last two glacial-interglacial cycles. Our record largely corroborates the Milankovitch model of orbital forcing but also exhibits some differences: in particular, an earlier onset and longer duration of the Last Glacial Maximum. Our results suggest that Southern Hemisphere insolation may have been responsible for these differences in timing. Our findings question the validity of applying orbital tuning to Southern Hemisphere records and suggest an alternative mechanism to the bipolar seesaw for generating interhemispheric asynchrony in climate change.

  13. The Effects of Spatial Smoothing on Solar Magnetic Helicity Parameters and the Hemispheric Helicity Sign Rule

    Science.gov (United States)

    Koch Ocker, Stella; Petrie, Gordon

    2016-12-01

    The hemispheric preference for negative/positive helicity to occur in the northern/southern solar hemisphere provides clues to the causes of twisted, flaring magnetic fields. Previous studies on the hemisphere rule may have been affected by seeing from atmospheric turbulence. Using Hinode/SOT-SP data spanning 2006-2013, we studied the effects of two spatial smoothing tests that imitate atmospheric seeing: noise reduction by ignoring pixel values weaker than the estimated noise threshold, and Gaussian spatial smoothing. We studied in detail the effects of atmospheric seeing on the helicity distributions across various field strengths for active regions (ARs) NOAA 11158 and NOAA 11243, in addition to studying the average helicities of 179 ARs with and without smoothing. We found that, rather than changing trends in the helicity distributions, spatial smoothing modified existing trends by reducing random noise and by regressing outliers toward the mean, or removing them altogether. Furthermore, the average helicity parameter values of the 179 ARs did not conform to the hemisphere rule: independent of smoothing, the weak-vertical-field values tended to be negative in both hemispheres, and the strong-vertical-field values tended to be positive, especially in the south. We conclude that spatial smoothing does not significantly affect the overall statistics for space-based data, and thus seeing from atmospheric turbulence seems not to have significantly affected previous studies’ ground-based results on the hemisphere rule.

  14. Isocurvature and curvaton perturbations with red power spectrum and large hemispherical asymmetry

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, John, E-mail: j.mcdonald@lancaster.ac.uk [Lancaster-Manchester-Sheffield Consortium for Fundamental Physics, Cosmology and Astroparticle Physics Group, Dept. of Physics, University of Lancaster, Lancaster LA1 4YB (United Kingdom)

    2013-07-01

    We calculate the power spectrum and hemispherical asymmetry of isocurvature and curvaton perturbations due to a complex field Φ which is evolving along the tachyonic part of its potential. Using a semi-classical evolution of initially sub-horizon quantum fluctuations, we compute the power spectrum, mean field and hemispherical asymmetry as a function of the number of e-foldings of tachyonic growth ΔN and the tachyonic mass term cH{sup 2}. We find that a large hemispherical asymmetry due to the modulation of |Φ| can easily be generated via the spatial modulation of |Φ| across the horizon, with Δ|Φ|/|Φ| > 0.5 when the observed Universe exits the horizon within 10-40 e-foldings of the beginning of tachyonic evolution and c is in the range 0.1-1. The spectral index of the isocurvature and curvaton perturbations is generally negative, corresponding to a red power spectrum. Dark matter isocurvature perturbations due to an axion-like curvaton with a large hemispherical asymmetry may be able to explain the hemispherical asymmetry observed by WMAP and Planck. In this case, the red spectrum can additionally suppress the hemispherical asymmetry at small scales, which should make it easier to satisfy scale-dependence requirements on the asymmetry from quasar number counts.

  15. Disparity in the timing of vertebrate diversification events between the northern and southern hemispheres

    Directory of Open Access Journals (Sweden)

    Tingley Reid

    2012-12-01

    Full Text Available Abstract Background Climatic oscillations throughout the Quaternary had profound effects on temperate biodiversity, but the extent of Quaternary climate change was more severe in temperate regions of the northern hemisphere than in the southern hemisphere. We sought to determine whether this geographic disparity differentially influenced the timing of intraspecific diversification events within ectothermic and endothermic vertebrate species. Using published phylogenetic hypotheses, we gathered data on the oldest intraspecific diversification event within mammal, bird, freshwater fish, amphibian, and reptile species from temperate-zone areas. We then tested whether the timing of diversification events differed between hemispheres. Results Our analyses provide strong evidence that vertebrates from temperate regions of the northern hemisphere are younger than those from the southern hemisphere. However, we find little evidence to suggest that this relationship differs between endotherms versus ectotherms, or that it varies widely across the five classes of vertebrates that we considered. In addition, we find that on average, endothermic species are much younger than ectothermic species. Conclusion Our findings suggest that geographic variation in the magnitude of climatic oscillations during the Quaternary led to substantial disparity in the timing of intraspecific diversification events between northern and southern hemisphere vertebrates, and that the magnitude of this divergence is largely congruent across vertebrate taxa.

  16. Eastern European retailers and wholesalers' buying behaviour

    DEFF Research Database (Denmark)

    Esbjerg, Lars; Stacey, Julia

    1999-01-01

    During the last ten years, retailing in Eastern Europe has undergone considerable changes. The entry of Western European retail chains into Eastern Europe has helped accelerate the distributive trade of Eastern Europe. But what does it take to sell fish and cheese to retailers and wholesalers....... Low prices and favourable terms of payment are most important when retailers in Eastern Europe buy fish and cheese. Then follows the supplier's range of products, trustworthiness of the supplier and product quality. Eastern European wholesalers also rank price and financial conditions as most....... In comparison,Western European retailers prefer doing business with suppliers that are capable of supplying all shops in a chain. Also the question about traceability is decisive.Retailers also prefer doing business with suppliers that are interested in a long-term trade relationship and who are from their own...

  17. Northern hemisphere glaciation during the globally warm early Late Pliocene.

    Directory of Open Access Journals (Sweden)

    Stijn De Schepper

    Full Text Available The early Late Pliocene (3.6 to ∼3.0 million years ago is the last extended interval in Earth's history when atmospheric CO2 concentrations were comparable to today's and global climate was warmer. Yet a severe global glaciation during marine isotope stage (MIS M2 interrupted this phase of global warmth ∼3.30 million years ago, and is seen as a premature attempt of the climate system to establish an ice-age world. Here we propose a conceptual model for the glaciation and deglaciation of MIS M2 based on geochemical and palynological records from five marine sediment cores along a Caribbean to eastern North Atlantic transect. Our records show that increased Pacific-to-Atlantic flow via the Central American Seaway weakened the North Atlantic Current and attendant northward heat transport prior to MIS M2. The consequent cooling of the northern high latitude oceans permitted expansion of the continental ice sheets during MIS M2, despite near-modern atmospheric CO2 concentrations. Sea level drop during this glaciation halted the inflow of Pacific water to the Atlantic via the Central American Seaway, allowing the build-up of a Caribbean Warm Pool. Once this warm pool was large enough, the Gulf Stream-North Atlantic Current system was reinvigorated, leading to significant northward heat transport that terminated the glaciation. Before and after MIS M2, heat transport via the North Atlantic Current was crucial in maintaining warm climates comparable to those predicted for the end of this century.

  18. HOMED-Homicides Eastern Denmark

    DEFF Research Database (Denmark)

    Colville-Ebeling, Bonnie; Frisch, Morten; Lynnerup, Niels

    2014-01-01

    Background:An introduction to a forensic medical homicide database established at the Department of Forensic Medicine in Copenhagen. Content: The database contains substantial clinical and demographic data obtained in conjunction with medico-legal autopsies of victims and forensic clinical...... examinations of perpetrators in homicide cases in eastern Denmark. Validity and coverage: The database contains information on all homicide cases investigated at the Department of Forensic Medicine in Copenhagen since 1971. Coverage for the catchment area of the department is assumed to be very good because...... of a medico-legal homicide autopsy rate close to 100%. Regional differences might exist however, due to the fact that the catchment area of the department is dominated by the city of Copenhagen. Conclusions: The strength of the database includes a long running time, near complete regional coverage...

  19. Evidence for a Southern Pattern of Deglacial Surface Warming in the Eastern Equatorial Pacific

    Science.gov (United States)

    Spero, H. J.; Schmidt, M. W.; Lea, D. W.; Lavagnino, L.

    2009-12-01

    The timing of both Southern and Northern hemisphere warming patterns has been used to explain tropical Pacific warming at the end of the last glacial period. Despite the importance of resolving this deglacial tropical-polar connection, the controversy is still ongoing (Koutavas & Sachs, 2008; Lea et al., 2000, 2006). For instance, the initiation of eastern equatorial Pacific (EEP) surface warming, derived from Mg/Ca analyses of the surface-dwelling foraminifera Globigerinoides ruber, shows a clear correlation with the Southern hemisphere. In contrast, alkenone-derived temperatures from the EEP indicate tropical warming occurred at least 3 kyr later than that implied from Mg/Ca data, thereby suggesting a Northern hemisphere link to initial SST rise. Here, we use a multispecies, multiproxy approach that is based on fundamental foraminifera biology to resolve this controversy. Laboratory experiments demonstrate the final shell size of symbiont-bearing foraminifera varies primarily as a function of the light level (=symbiont photosynthetic rate) that an individual grew under. Because light decreases exponentially in the water column, and the EEP is highly stratified with a shallow mixed layer and cold thermocline, we hypothesize that symbiotic foraminifera with a broad habitat range such as Globigerinoides sacculifer, should produce smaller shells in the more dimly lit cold thermocline than individuals growing in the more illuminated mixed layer. Moreover, these larger shells should contain a temperature signal that is similar to G. ruber, which is constrained to the shallow mixed layer. Mg/Ca and δ18O analyses conducted on 350-400 μm and >650 μm sized G. sacculifer from EEP core TR163-19 (2N, 91W, 2348) demonstrate large specimens yield Mg/Ca and δ18O that are similar to data published previously for mixed layer dwelling G. ruber. In contrast, small G. sacculifer record significantly higher δ18O and lower Mg/Ca temperatures that are consistent with a shallow

  20. Millennial to orbital-scale variations of drought intensity in the Eastern Mediterranean

    Science.gov (United States)

    Stockhecke, Mona; Timmermann, Axel; Kipfer, Rolf; Haug, Gerald H.; Kwiecien, Ola; Friedrich, Tobias; Menviel, Laurie; Litt, Thomas; Pickarski, Nadine; Anselmetti, Flavio S.

    2016-02-01

    Millennial to orbital-scale rainfall changes in the Mediterranean region and corresponding variations in vegetation patterns were the result of large-scale atmospheric reorganizations. In spite of recent efforts to reconstruct this variability using a range of proxy archives, the underlying physical mechanisms have remained elusive. Through the analysis of a new high-resolution sedimentary section from Lake Van (Turkey) along with climate modeling experiments, we identify massive droughts in the Eastern Mediterranean for the past four glacial cycles, which have a pervasive link with known intervals of enhanced North Atlantic glacial iceberg calving, weaker Atlantic Meridional Overturning Circulation and Dansgaard-Oeschger cold conditions. On orbital timescales, the topographic effect of large Northern Hemisphere ice sheets and periods with minimum insolation seasonality further exacerbated drought intensities by suppressing both summer and winter precipitation.

  1. What are the mechanisms that produce auroral asymmetries in the conjugate hemispheres? (Invited)

    Science.gov (United States)

    Ostgaard, N.; Reistad, J. P.; Tenfjord, P.; Laundal, K.

    2013-12-01

    Our knowledge about how the Earth is coupled to space is to a large extent based on measurements from only one polar hemisphere. It is therefore tempting to assume that the aurora borealis (northern hemisphere) and aurora australis (southern hemisphere) are mirror images of each other because the charged particles producing the aurora follow the magnetic field lines connecting the two hemispheres. There are now many observational evidence that this is not always the case. By studying simultaneous global imaging in the ultraviolet wavelengths by the IMAGE and Polar satellites we have shown that the northern and southern aurora can be asymmetric both in locations and intensities. To explain these findings three mechanisms have been suggested: 1) difference in region 1 currents due to hemispheric differences in the solar wind dynamo efficiency when the IMF has a significant Bx component 2) interhemispheric currents associated with the penetration of the IMF By component into the closed magnetosphere. 3) interhemispheric currents due to conductivity differences in the two hemispheres We will present simultaneous conjugate images by IMAGE and Polar of event cases with asymmetries both in location and intensity. We have also used large data sets of imaging data and Cluster magnetic data to test whether the predicted effects of the three mechanisms of generating interhemispheric or asymmetric currents are statistically significant. Three mechanism that can produce asymmetric aurora: 1) Difference in solar wind dynamo due to an IMF Bx component, 2) Induced interhemispheric currents due to the non-uniform penetration of IMF By into the closed magnetosphere, and 3) Interhemispheric currents due to conductivity differences in the conjugate hemispheres.

  2. Drivers of hemispheric differences in return dates of mid-latitude stratospheric ozone to historical levels

    Directory of Open Access Journals (Sweden)

    H. Garny

    2012-12-01

    Full Text Available Chemistry-climate models (CCMs project an earlier return of northern mid-latitude total column ozone to 1980 values compared to the southern mid-latitudes. The chemical and dynamical drivers of this hemispheric difference are investigated in this study. The hemispheric asymmetry in return dates is a robust result across different CCMs and is qualitatively independent of the method used to estimate return dates. However, the differences in dates of return to 1980 levels between the southern and northern mid-latitudes can vary between 0 and 30 yr across the range of CCM projections analyzed. An attribution analysis performed with two CCMs shows that chemically-induced changes in ozone are the major driver of the earlier return of ozone to 1980 levels in northern mid-latitudes; transport changes are of minor importance. This conclusion is supported by the fact that the spread in the simulated hemispheric difference in return dates across an ensemble of twelve models is only weakly related to the spread in the simulated hemispheric asymmetry of trends in the strength of the Brewer–Dobson circulation. The causes for chemically-induced asymmetric ozone trends relevant for the total column ozone return date differences are found to be (i stronger increases in ozone production due to enhanced NOx concentrations in the Northern Hemisphere lowermost stratosphere and troposphere, (ii stronger decreases in the destruction rates of ozone by the NOx cycle in the Northern Hemisphere lower stratosphere linked to effects of dynamics and temperature on NOx concentrations and (iii an increasing efficiency of heterogeneous ozone destruction by Cly in the Southern Hemisphere mid-latitudes as a result of decreasing temperatures.

  3. Measuring bed shear stress along vegetated river beds using FST-hemispheres.

    Science.gov (United States)

    Bockelmann-Evans, B N; Davies, R; Falconer, R A

    2008-09-01

    The measurement of the bed shear stress along vegetated river beds is essential for accurately predicting the water level, velocity and solute and sediment transport fluxes in computational hydroenvironmental models. Details are given herein of an experimental and theoretical study to determine the bed boundary shear stress along vegetated river beds introducing a novel field measuring method, namely the FliessWasserStammtisch (FST)-hemispheres. Although investigations have been conducted previously for sedimentary channels using the FST-hemispheres, this preliminary study is thought to be the first time that such hemispheres have been used to investigate the bed shear stresses in vegetated channels. FST-hemispheres were first developed by Statzner and Müller [1989. Standard hemispheres as indicators of flow characteristics in lotic benthos research. Freshwater Biology 21, 445-459] to act as an integrated indicator of the gross hydrodynamic stresses present near the bed. Test and validation data were found to be at least of the same order of magnitude for the stresses predicted from literature for sedimentary channels, with this study establishing the commencement of a database of calibrated FST-hemisphere laboratory data for vegetated channel beds. In a series of experiments, depths ranging from 0.1 to 0.28 m were considered, equating directly to comparable conditions in small rivers or streams. The results of this study provide a basis for enabling the FST-hemispheres to be used to evaluate the boundary shear stress for a wider range of applications in the future, including vegetated river beds.

  4. Abnormal cortical functional connections in Alzheimer's disease: analysis of inter- and intra-hemispheric EEG coherence

    Institute of Scientific and Technical Information of China (English)

    JIANG Zheng-yan

    2005-01-01

    To investigate inter- and intra-hemispheric electroencephalography (EEG) coherence at rest and during photic stimulation of patients with Alzheimer's disease (AD). Thirty-five patients (12 males, 23 females; 52~64 y) and 33 sex- and age-matched controls (12 males, 21 females; 56~65 y) were recruited in the present study. EEG signals from C3-C4, P3-P4, T5-T6and O1-O2 electrode pairs resulted from the inter-hemispheric action, and EEG signals from C3-P3, C4-P4, P3-O1, P4-O2, C3-O1,C4-O2, T5-O 1 and T6-O2 electrode pairs resulted from the intra-hemispheric action. The influence of inter- and intra-hemispheric coherence on EEG activity with eyes closed was examined, using fast Fourier transformation from the 16 sampled channels. The frequencies of photic stimulation were fixed at 5, 10 and 15 Hz, respectively. The general decrease of AD patients in inter- and intra-hemispheric EEG coherence was more significant than that of the normal controls at the resting EEG, with most striking decrease observed in the alpha-1 (8.0-9.0 Hz) and alpha-2 (9.5-12.5 Hz) bands. During photic stimulation, inter- and intra-hemispheric EEG coherences of the AD patients having lower values in the alpha (9.5-10.5 Hz) band than those of the control group. It suggests that under stimulated and non-stimulated conditions, AD patients had impaired inter- and intra-hemispheric functional connections, indicating failure of brain activation in alpha-related frequency.

  5. Behavioral evidence for inter-hemispheric cooperation during a lexical decision task: a divided visual field experiment.

    Science.gov (United States)

    Perrone-Bertolotti, Marcela; Lemonnier, Sophie; Baciu, Monica

    2013-01-01

    HIGHLIGHTSThe redundant bilateral visual presentation of verbal stimuli decreases asymmetry and increases the cooperation between the two hemispheres.The increased cooperation between the hemispheres is related to semantic information during lexical processing.The inter-hemispheric interaction is represented by both inhibition and cooperation. This study explores inter-hemispheric interaction (IHI) during a lexical decision task by using a behavioral approach, the bilateral presentation of stimuli within a divided visual field experiment. Previous studies have shown that compared to unilateral presentation, the bilateral redundant (BR) presentation decreases the inter-hemispheric asymmetry and facilitates the cooperation between hemispheres. However, it is still poorly understood which type of information facilitates this cooperation. In the present study, verbal stimuli were presented unilaterally (left or right visual hemi-field successively) and bilaterally (left and right visual hemi-field simultaneously). Moreover, during the bilateral presentation of stimuli, we manipulated the relationship between target and distractors in order to specify the type of information which modulates the IHI. Thus, three types of information were manipulated: perceptual, semantic, and decisional, respectively named pre-lexical, lexical and post-lexical processing. Our results revealed left hemisphere (LH) lateralization during the lexical decision task. In terms of inter-hemisphere interaction, the perceptual and decision-making information increased the inter-hemispheric asymmetry, suggesting the inhibition of one hemisphere upon the other. In contrast, semantic information decreased the inter-hemispheric asymmetry, suggesting cooperation between the hemispheres. We discussed our results according to current models of IHI and concluded that cerebral hemispheres interact and communicate according to various excitatory and inhibitory mechanisms, all which depend on specific

  6. A New Snow Index for Improved Predictions of Winter Weather in the Northern Hemisphere Mid-latitudes.

    Science.gov (United States)

    Cohen, J. L.; Jones, J.; Brands, S. F.

    2012-12-01

    Seasonal climate prediction remains a difficult challenge. During Northern Hemisphere (NH) winter the large-scale teleconnection pattern of the Arctic Oscillation (AO) explains the largest fraction of temperature variance of any other known climate mode. However the Arctic Oscillation is considered to be a result of intrinsic atmospheric dynamics or chaotic behavior and therefore is unpredictable. Earlier studies established that fall Eurasian mean snow cover extent is significantly correlated with the winter AO. However we have found that the daily change in snow cover extent is a much better predictor of the winter AO, which we refer to as the Snow Advance Index (SAI). With the development of the SAI we can now explain approximately 75% of the variance of the winter AO. The high correlation between the SAI and the winter AO demonstrates that the AO is mostly predictable, which can be exploited for skillful seasonal climate predictions. An immediate benefit of the development of this new index is improved seasonal climate predictions. The ability to predict the winter AO is considered the single most important advance in achieving successful winter forecasts. We created cross-validated hindcasts of winter land surface temperatures using the SAI as a predictor in the AER seasonal forecast model and compared those hindcasts with hindcasts using the observed winter AO and ENSO. Skill or accuracy of the AER model compares favorably to that of the observed winter AO and ENSO especially for the Eastern US and large portions of Northern Eurasia. And considering that the index is known four months prior to the winter AO, yet matches the skill of the winter AO so closely, demonstrates great potential for improved real-time winter forecasts. If time permits we will also show that snow cover can help explain decadal variations in the AO and subsequently decadal winter temperature trends.lt;img border=0 src="images/C34B-03_B.jpg">

  7. Satellite observations of changes in snow-covered land surface albedo during spring in the Northern Hemisphere

    Directory of Open Access Journals (Sweden)

    K. Atlaskina

    2015-05-01

    Full Text Available Thirteen years of MODIS surface albedo data for the Northern Hemisphere during the spring months (March–May were analysed to determine temporal and spatial changes over snow-covered land surfaces. Tendencies in land surface albedo change north of 50° N were analysed using data on snow cover fraction, air temperature, vegetation index and precipitation. To this end, the study domain was divided into six smaller areas, based on their geographical position and climate similarity. Strong differences were observed between these areas. As expected, snow cover fraction (SCF has a strong influence on the albedo in the study area and can explain 56% of variation of albedo in March, 76% in April and 92% in May. Therefore the effects of other parameters were investigated only for areas with 100% SCF. The second largest driver for snow-covered land surface albedo changes is the air temperature when it exceeds −15 °C. At monthly mean air temperatures below this value no albedo changes are observed. Enhanced vegetation index (EVI and precipitation amount and frequency were independently examined as possible candidates to explain observed changes in albedo for areas with 100% SCF. Amount and frequency of precipitation were identified to influence the albedo over some areas in Eurasia and North America, but no clear effects were observed in other areas. EVI is positively correlated with albedo in Chukotka Peninsula and negatively in Eastern Siberia. For other regions the spatial variability of the correlation fields is too high to reach any conclusions.

  8. Eastern Renewable Generation Integration Study

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Townsend, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Palchak, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Novacheck, Joshua [National Renewable Energy Lab. (NREL), Golden, CO (United States); King, Jack [RePPAE LLC, Wexford, PA (United States); Barrows, Clayton [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ibanez, Eduardo [GE Energy, Denver, CO (United States); O' Connell, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jordan, Gary [GE Energy, Denver, CO (United States); Roberts, Billy [National Renewable Energy Lab. (NREL), Golden, CO (United States); Draxl, Caroline [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gruchalla, Kenny [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-08-01

    The Eastern Interconnection (EI) is one of the largest power systems in the world, and its size and complexity have historically made it difficult to study in high levels of detail in a modeling environment. In order to understand how this system might be impacted by high penetrations (30% of total annual generation) of wind and solar photovoltaic (PV) during steady state operations, the National Renewable Energy Laboratory (NREL) and the U.S. Department of Energy (DOE) conducted the Eastern Renewable Generation Integration Study (ERGIS). This study investigates certain aspects of the reliability and economic efficiency problem faced by power system operators and planners. Specifically, the study models the ability to meet electricity demand at a 5-minute time interval by scheduling resources for known ramping events, while maintaining adequate reserves to meet random variation in supply and demand, and contingency events. To measure the ability to meet these requirements, a unit commitment and economic dispatch (UC&ED) model is employed to simulate power system operations. The economic costs of managing this system are presented using production costs, a traditional UC&ED metric that does not include any consideration of long-term fixed costs. ERGIS simulated one year of power system operations to understand regional and sub-hourly impacts of wind and PV by developing a comprehensive UC&ED model of the EI. In the analysis, it is shown that, under the study assumptions, generation from approximately 400 GW of combined wind and PV capacity can be balanced on the transmission system at a 5-minute level. In order to address the significant computational burdens associated with a model of this detail we apply novel computing techniques to dramatically reduce simulation solve time while simultaneously increasing the resolution and fidelity of the analysis. Our results also indicate that high penetrations of wind and PV (collectively variable generation (VG

  9. Widespread land surface wind decline in the Northern Hemisphere partly attributed to land surface changes

    Science.gov (United States)

    Thepaut, J.; Vautard, R.; Cattiaux, J.; Yiou, P.; Ciais, P.

    2010-12-01

    The decline of surface wind observed in many regions of the world is a potential source of concern for wind power electricity generation. It is also suggested as the main cause of decreasing pan evaporation. In China, a persistent and significant decrease of monsoon winds was observed in all seasons. Surface wind declines were also evidenced in several regions of the world (U.S., Australia, several European countries). Except over China, no clear explanation was given for the wind decrease in the regions studied. Whether surface winds decrease is due to changes in the global atmospheric circulation or its variability, in surface processes or to observational trends has therefore not been elucidated. The identification of the drivers of such a decline requires a global investigation of available surface and upper-air wind data, which has not been conducted so far. Here we use global datasets of in-situ wind measurements that contain surface weather stations wind data (hourly or three-hourly data acquisition time step) and rawinsonde vertical wind data profiles (monthly time step) prepared by the NCAR. A set of 822 worldwide surface stations with continuous wind records was selected after a careful elimination of stations with obvious breaks and large gaps. This dataset mostly covers the Northern mid latitudes over the period 1979-2008. Using this data set, we found that annual mean wind speeds have declined at 73% of the surface stations over the past 30 years. In the Northern Hemisphere, positive wind trends are found only in a few places. In Europe, Central Asia, Eastern Asia and in North America the annual mean surface wind speed has decreased on average at a rate of -2.9, -5.9, -4.2, and -1.8 %/decade respectively, i.e. a decrease of about 10% in 30 years and up to about 20% in Central Asia. These results are robust to changes in the station selection method and parameters. By contrast, upper-air winds observed from rawinsondes, geostrophic winds deduced from

  10. Right Hemisphere Remapping of Naming Functions Depends on Lesion Size and Location in Poststroke Aphasia

    Directory of Open Access Journals (Sweden)

    Laura M. Skipper-Kallal

    2017-01-01

    Full Text Available The study of language network plasticity following left hemisphere stroke is foundational to the understanding of aphasia recovery and neural plasticity in general. Damage in different language nodes may influence whether local plasticity is possible and whether right hemisphere recruitment is beneficial. However, the relationships of both lesion size and location to patterns of remapping are poorly understood. In the context of a picture naming fMRI task, we tested whether lesion size and location relate to activity in surviving left hemisphere language nodes, as well as homotopic activity in the right hemisphere during covert name retrieval and overt name production. We found that lesion size was positively associated with greater right hemisphere activity during both phases of naming, a pattern that has frequently been suggested but has not previously been clearly demonstrated. During overt naming, lesions in the inferior frontal gyrus led to deactivation of contralateral frontal areas, while lesions in motor cortex led to increased right motor cortex activity. Furthermore, increased right motor activity related to better naming performance only when left motor cortex was lesioned, suggesting compensatory takeover of speech or language function by the homotopic node. These findings demonstrate that reorganization of language function, and the degree to which reorganization facilitates aphasia recovery, is dependent on the size and site of the lesion.

  11. Language deficits as a possible symptom of right hemisphere dysfunctions in Asperger’s syndrome

    Directory of Open Access Journals (Sweden)

    Anita Bryńska

    2010-12-01

    Full Text Available Qualitative communication disorders belong to the key symptoms of pervasive developmental disorders (PDD. The severity of the symptoms of communication disorders varies depending on the type of PDD, from the lack of functional speech to overdeveloped verbal competencies measured by standardized scales. In Asperger’s syndrome (AS, observed language abnormalities include: pragmatics (application of language in social context, semantics (identifying different meanings of the same word and prosody (rhythm, intonation and modulation of speech. In the case of AS, the difference between formal language skills, i.e. within morphological, phonological and syntactic functions, and semantic and pragmatic deficits is clearly noticeable and distinctive. This situation arouses some questions about neurobiological conditions of these deficits. The language functions are among the first functions for which locations in the brain have been established. Traditionally they have been ascribed to some regions in the left hemisphere; they undergo lateralization and are accomplished owing to the activity of the primary, secondary and tertiary regions of associative cortex. However, there is also quite a lot of evidence suggesting that the right hemisphere plays an important role in communication processes, especially in some aspects of pragmatics and discourse. The analysis of communication deficits observed in patients with acquired right hemisphere damages and patients with AS as well as abnormal patterns of hemispheric asymmetry in this group of patients, suggest that the right hemisphere is involved in aetiology of PDD.

  12. Hemispheric preference in visuospatial processing: a complementary approach with fMRI and lesion studies.

    Science.gov (United States)

    Ng, V W; Eslinger, P J; Williams, S C; Brammer, M J; Bullmore, E T; Andrew, C M; Suckling, J; Morris, R G; Benton, A L

    2000-06-01

    Historically, the left cerebral hemisphere has been considered specialized for language, whereas the right cerebral hemisphere is aligned with spatial processes. However, studies have called into question adherence to this model and suggested that both hemispheres participate in language and spatial cognition. Using functional Magnetic Resonance Imaging (fMRI) and human brain lesion studies, we determined whether these complementary techniques could clarify issues of hemispheric dominance. Using a modified Benton Judgement of Line Orientation (JLO) test, considered a relatively pure spatial processing task, we found robust and significant (p < 0.0005) bilateral superior parietal lobe activation on fMRI in ten right-handed male adult volunteers. This was corroborated by lesion data in a cohort of 17 patients who showed significant JLO impairments after either right or left parietal lobe damage, with right parietal damage associated with somewhat more severe deficit. Detailed wavelet analysis of the fMRI time-series did, however, reveal a more dominant role of the right parietal lobe in "kick-starting" the task. To our knowledge, this is a novel way of using fMRI to address functional hemispheric differences in a cognitive task that is known to have bilateral representation.

  13. Variability of the extent of the Hadley circulation in the southern hemisphere: a regional perspective

    Science.gov (United States)

    Nguyen, H.; Hendon, H. H.; Lim, E.-P.; Boschat, G.; Maloney, E.; Timbal, B.

    2017-03-01

    In order to understand the regional impacts of variations in the extent of the Hadley circulation in the Southern Hemisphere, regional Hadley circulations are defined in three sectors centered on the main tropical heat sources over Africa, Asia-Pacific (Maritime Continent) and the Americas. These regional circulations are defined by computing a streamfunction from the divergent component of the meridional wind. A major finding from this study is that year-to-year variability in the extent of the hemispheric Hadley circulation in the Southern Hemisphere is primarily governed by variations of the extent of the Hadley circulation in the Asia-Pacific sector, especially during austral spring and summer when there is little co-variability with the African sector, and the American sector exhibits an out of phase behavior. An expanded Hadley circulation in the Southern Hemisphere (both hemispherically and in the Asia-Pacific sector) is associated with La Niña conditions and a poleward expansion of the tropical wet zone in the Asia-Pacific sector. While La Niña also promotes expansion in the American and African sectors during austral winter, these tropical conditions tend to promote contraction in the two sectors during austral summer as a result of compensating convergence over the Americas and Africa sectors: a process driven by variations in the Walker circulation and Rossby wave trains emanating from the tropical Indian Ocean.

  14. Hemispherical and Longitudinal Asymmetries in the Heliospheric Magnetic Field: Flip-flops of a Bashful Ballerina

    Science.gov (United States)

    Hiltula, T.; Mursula, K.

    2004-12-01

    Several studies during many decennia have studied possible longitudinal and hemispherical asymmetries in various forms of solar activity. E.g., there are well known periods when one of the solar hemispheres has dominated the other in sunspot numbers, flare occurrence or some other form of solar activity. However, the solar asymmetries have not been found to be very conclusive, or to form any clear systematical patterns (e.g., relation to solar cycle). On the contrary, recent studies of similar longitudinal and hemispherical asymmetries in the heliospheric magnetic field have shown a very clear and systematic behaviour. E.g., it was found recently that the dominance of the two HMF sectors experiences an oscillation with a period of about 3.2 years. This new flip-flop periodicity in the heliospheric magnetic field is most likely related to a similar periodicity recently found in sunspots. Also, it has recently been found that the HMF sector coming from the northern solar hemisphere systematically dominates at 1AU during solar minimum times. This leads to a persistent southward shift or coning of the heliospheric current sheet at these times that can be picturesquely described by the concept of a Bashful Ballerina. This result also implies that the Sun has a large-scale quadrupole magnetic moment. Here we review these recent developments concerning the longitudinal and hemispherical asymmetries in the heliospheric magnetic field and study their inter-connection.

  15. Inter-hemispheric competition relieved in both: hypotheses for autism and schizophrenia from problem theory.

    Science.gov (United States)

    Burnand, Gordon

    2012-07-01

    A logical relationship exists among six general problems that people face in life. Using hope about something for its subjective probability, its expected likelihood, the problems form a series where the method of assessing hope changes in a simple manner from one problem to the next. The central hypothesis is that human beings exploit this. Brain structures and predispositions have evolved accordingly, leading to the hemispheres having different predispositions. The hemispheres are effectively joined at 5 months. Infants will then find that they engage in two unrelated activities. Typical infants label the activities in detail, using visual images, as part of gaining control over them. Hypotheses are: (a) autistic children fail labelling at the start, and hence they encounter uncontrolled competition between the hemispheres; (b) with some, serotonin abnormality impairs sensory information processing and hence the labelling; (c) with some, a delay in myelination from autoimmune effects disrupts labelling; (d) the likelihood of this 'delay autism' is reduced by long chain omega oils; (e) self-pressuring, which underlies taking on challenges and play like Hide and Seek, brings relief from the competition by raising the influence of one side; (f) the same left-right competition occurs in confused episodes and schizophrenia in vulnerable people who encounter pressures to use both hemispheres at the same time; (g) some symptoms raise the influence on one side ideationally. This leads to coherent theories of autism and schizophrenia. In both competition between the hemispheres is relieved primarily by self-pressuring, which raises influence on one side.

  16. Progressive hemispheric shrinking in hemimegalencephaly: a possible role for seizure-related neuronal loss.

    Science.gov (United States)

    Becherini, Francesca; Pisano, Tiziana; Castagna, Maura; Iannelli, Aldo; Guerrini, Renzo

    2008-07-01

    Hemimegalencephaly (HME) is a developmental brain lesion consisting of a unilateral enlarged, dysplastic, and often highly epileptogenic cerebral hemisphere. Most patients exhibit early onset intractable seizures, status epilepticus, hemiplegia, hemianopsia, and developmental delay. Major surgical procedures are advocated for limiting the devastating consequences of epilepsy. We studied a female with HME, early onset intractable seizures and recurrent status epilepticus, in whom progressive hemiatrophy of the enlarged hemisphere and normal growth of the contralateral hemisphere, exceeding the size of the dysplastic hemisphere, was demonstrated by magnetic resonance imaging. Histopathology, following functional hemispherectomy at the age of 7 years, demonstrated severe neuronal loss with an elevated number of cells exhibiting the morphological and biochemical features of apoptosis. Eighteen months after surgery the patient was seizure-free (Engel class I) and exhibited improved motor and language skills, alertness and social behaviour. We hypothesize that nearly continuous seizure activity might sustain seizure-induced brain injury in the dysplastic hemisphere but causal heterogeneity and associated anatomical factors may influence differently the individual predisposition to atrophic changes.

  17. Postnatal evolution of cortical malformation in the "non-affected" hemisphere of hemimegalencephaly.

    Science.gov (United States)

    Kometani, Hiroshi; Sugai, Kenji; Saito, Yoshiaki; Nakagawa, Eiji; Sakuma, Hiroshi; Komaki, Hirofumi; Sasaki, Masayuki; Adachi, Yuko; Kaneko, Yuu; Otsuki, Taisuke; Hamano, Shin-ichiro

    2010-05-01

    A boy with epilepsy of neonatal onset was diagnosed with hemimegalencephaly (HME) based on the finding of an enlarged left cerebral hemisphere with dysplastic cortex over the frontal, parietal, and temporal lobes. Magnetic resonance imaging (MRI) showed an essentially unremarkable gyration pattern in the contralateral hemisphere. Ictal electroencephalography and magnetoencephalography revealed epileptic foci in the left hemisphere. Hyperperfusion and hypermetabolism were noted in comparison to the contralateral hemisphere, and these findings were consistent with the diagnosis of HME. Soon after hemispherotomy was performed at age 3 months, an epileptic focus appeared in the right hemisphere. The epilepsy remained intractable. Unexpectedly, dysplastic changes emerged over the right frontoparietal cortex at age 7 months as shown by MRI, and the cortical volume in this area was observed to be markedly increased at age 1 year and 8 months. This increase was associated with a distorted gray-white matter boundary. These findings contribute to our understanding of the pathogenesis of HME and may be helpful in determining the management approach for epilepsy in this entity. Copyright 2009 Elsevier B.V. All rights reserved.

  18. Northern Hemisphere forcing of climatic cycles in Antarctica over the past 360,000 years.

    Science.gov (United States)

    Kawamura, Kenji; Parrenin, Frédéric; Lisiecki, Lorraine; Uemura, Ryu; Vimeux, Françoise; Severinghaus, Jeffrey P; Hutterli, Manuel A; Nakazawa, Takakiyo; Aoki, Shuji; Jouzel, Jean; Raymo, Maureen E; Matsumoto, Koji; Nakata, Hisakazu; Motoyama, Hideaki; Fujita, Shuji; Goto-Azuma, Kumiko; Fujii, Yoshiyuki; Watanabe, Okitsugu

    2007-08-23

    The Milankovitch theory of climate change proposes that glacial-interglacial cycles are driven by changes in summer insolation at high northern latitudes. The timing of climate change in the Southern Hemisphere at glacial-interglacial transitions (which are known as terminations) relative to variations in summer insolation in the Northern Hemisphere is an important test of this hypothesis. So far, it has only been possible to apply this test to the most recent termination, because the dating uncertainty associated with older terminations is too large to allow phase relationships to be determined. Here we present a new chronology of Antarctic climate change over the past 360,000 years that is based on the ratio of oxygen to nitrogen molecules in air trapped in the Dome Fuji and Vostok ice cores. This ratio is a proxy for local summer insolation, and thus allows the chronology to be constructed by orbital tuning without the need to assume a lag between a climate record and an orbital parameter. The accuracy of the chronology allows us to examine the phase relationships between climate records from the ice cores and changes in insolation. Our results indicate that orbital-scale Antarctic climate change lags Northern Hemisphere insolation by a few millennia, and that the increases in Antarctic temperature and atmospheric carbon dioxide concentration during the last four terminations occurred within the rising phase of Northern Hemisphere summer insolation. These results support the Milankovitch theory that Northern Hemisphere summer insolation triggered the last four deglaciations.

  19. Determination of hemispheric language dominance using functional MRI : comparison of visual and auditory stimuli

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Ic Ryung; Ahn, Kook Jin; Lee, Jae Mun [The Catholic Univ. of Korea, Seoul (Korea, Republic of); Kim, Tae [The Catholic Magnetic Resonance Research Center, Seoul (Korea, Republic of)

    1999-12-01

    To assess the difference between auditory and visual stimuli when determining hemispheric language dominance by using functional MRI. In ten healthy adult volunteers (8 right-handed, 1 left-handed, 1 ambidextrous), motor language activation in axial slices of frontal lobe was mapped on a Simens 1.5T Vision Plus system using single-shot EPI. Series of 120 consecutive images per section were acquired during three cycles of task activation and rest. During each activation, a series of four syllables was delivered by means of both a visual and auditory method, and the volunteers were asked to mentally generate words starting with each syllable. In both in ferior frontal gyri and whole frontal lobes, lateralization indices were calculated from the activated pixels. We determined the language dominant hemisphere, and compared the results of the visual method and the auditory method. Seven right-handed persons were left-hemisphere dominant, and one left-handed and one ambidex-trous person were right-hemisphere dominant. Five of nine persons demonstrated larger lateralization indices with the auditory method than the visual method, while the remaining four showed larger lateralization indices with the visual method. No statistically significant difference was noted when comparing the results of the two methods(p>0.05). When determining hemispheric language dominance using functional MRI, the two methods are equally appropriate.

  20. Right Hemisphere Remapping of Naming Functions Depends on Lesion Size and Location in Poststroke Aphasia

    Science.gov (United States)

    Skipper-Kallal, Laura M.; Lacey, Elizabeth H.; Xing, Shihui

    2017-01-01

    The study of language network plasticity following left hemisphere stroke is foundational to the understanding of aphasia recovery and neural plasticity in general. Damage in different language nodes may influence whether local plasticity is possible and whether right hemisphere recruitment is beneficial. However, the relationships of both lesion size and location to patterns of remapping are poorly understood. In the context of a picture naming fMRI task, we tested whether lesion size and location relate to activity in surviving left hemisphere language nodes, as well as homotopic activity in the right hemisphere during covert name retrieval and overt name production. We found that lesion size was positively associated with greater right hemisphere activity during both phases of naming, a pattern that has frequently been suggested but has not previously been clearly demonstrated. During overt naming, lesions in the inferior frontal gyrus led to deactivation of contralateral frontal areas, while lesions in motor cortex led to increased right motor cortex activity. Furthermore, increased right motor activity related to better naming performance only when left motor cortex was lesioned, suggesting compensatory takeover of speech or language function by the homotopic node. These findings demonstrate that reorganization of language function, and the degree to which reorganization facilitates aphasia recovery, is dependent on the size and site of the lesion. PMID:28168061

  1. White matter integrity in right hemisphere predicts pitch-related grammar learning.

    Science.gov (United States)

    Loui, Psyche; Li, H Charles; Schlaug, Gottfried

    2011-03-15

    White matter plays an important role in various domains of cognitive function. While disruptions in white matter are known to affect many domains of behavior and cognition, the ability to acquire grammatical regularities has been mostly linked to the left hemisphere, perhaps due to its dependence on linguistic stimuli. The role of white matter in the right hemisphere in grammar acquisition is yet unknown. Here we show for the first time that in the domain of pitch, intact white matter connectivity in right-hemisphere analogs of language areas is important for grammar learning. A pitch-based artificial grammar learning task was conducted on subjects who also underwent diffusion tensor imaging. Probabilistic tractography using seed regions of interest in the right inferior frontal gyrus and right middle temporal gyrus showed positive correlations between tract volume and learning performance. Furthermore, significant correlations were observed between learning performance and FA in white matter underlying the supramarginal gyrus, corresponding to the right temporal-parietal junction of the arcuate fasciculus. The control task of recognition did not correlate with tract volume or FA, and control tracts in the left hemisphere did not correlate with behavioral performance. Results show that the right ventral arcuate fasciculus is important in pitch-based artificial grammar learning, and that brain structures subserving learning may be tied to the hemisphere that processes the stimulus more generally.

  2. Eastern Canada natural gas developments

    Energy Technology Data Exchange (ETDEWEB)

    Wall, A. [Engage Energy Canada, L.P., Mississauga, ON (Canada)

    2001-07-01

    This power point presentation addressed the following topics regarding development of natural gas in eastern Canada: (1) the 18 Tcf of proven natural gas reserves at Sable Island, (2) Canadian markets benefiting from the Maritimes and Northeast Pipeline (M and NP), (3) a 20 year franchise agreement between Enbridge Gas and the government of New Brunswick, (4) the 25 year provincial franchise agreement by Sempra Atlantic Gas, and (5) Sable Island's influence on central Canada. The Sable Offshore Energy Project (SOEP) is now producing about 540,000 MMBtu/day from 6 fields. Plans for Tier 2 expansion are underway. Firm contracts for the M and NP are scheduled to transport gas from the SOEP to markets in Nova Scotia, New Brunswick, Maine and New Hampshire. Sable gas is also a potential supply for the Quebec market. Gaz Metropolitain and Enbridge have proposed to build the Cartier Pipeline from the Quebec/New Brunswick border to Quebec City. It is unlikely that Sable Island supply will directly serve the Ontario market. Canadian customers for Sable gas and M and NP service include pulp and paper companies, oil refineries, power generators and local distribution companies (LDC), with the majority of demand coming form the electric power industry. tabs., figs.

  3. Eastern Pacific Ocean Purse-seine Fishery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vessel logbook and landings data sets from U.S.A.-flagged purse-seine vessels fishing in the Eastern Pacific Ocean (EPO). These purse seiners...

  4. Palaemon pacijicus (Stimpson) in eastern Cape tidal

    African Journals Online (AJOL)

    1984-09-25

    Sep 25, 1984 ... pools, estuaries and in near -shore waters of the eastern Cape ... growth, ~ Wt is the increase in shrimp mean mass over time .... females were plotted to show changes in population structure ..... Monthly plankton tows in.

  5. Eastern Africa Social Science Research Review

    African Journals Online (AJOL)

    The Eastern Africa Social Science Research Review (EASSRR) is a bi-annual ... Dynamics of fresh produce marketing in small-scale irrigation schemes: challenges ... Analysis of media role in bridging the information gap for environmentally ...

  6. System Protection Schemes in Eastern Denmark

    DEFF Research Database (Denmark)

    Rasmussen, Joana

    The Ph.D. project investigates different aspects of voltage stability in the power system of Eastern Denmark taking into account the large amount of wind power. In the project, a simple System Protection Scheme (SPS) against voltage instability in Eastern Denmark is developed. The SPS design...... outages in the southern part of the 132-kV system introduce further stress in the power system, eventually leading to a voltage collapse. The local System Protection Scheme against voltage collapse is designed as a response-based scheme, which is dependent on local indication of reactive and active power...... for the Eastern Danish power system, such as wind farm rejection, cascading line outages and power oscillations. E.g. Nordic inter-area oscillation modes and damping were easily detected from phasor data during the outage of the 400 kV tie-line between Eastern Denmark and Sweden. It is concluded that recording...

  7. A review of Leishmaniasis in Eastern Africa

    Institute of Scientific and Technical Information of China (English)

    Peter K. Ngure; Albert Kimutai; Zipporah W. Ng'ang'a; Geoffrey Rukunga; Willy K. Tonui

    2009-01-01

    The review presents the epidemiology of leishmaniasis in the Eastern Africa region. We searched PUB MED and MEDLINE with several key words-namely,"leishmaniasis";"cutaneous"," diffuse cutaneous"," mucosal", and "visceral leishmaniasis";"kala azar" and "post kala azar dermal leishmaniasis"-for recont clinical and basic science articles related to leishmaniasis in countries in the Eastern Africa region. Poverty, wars, conflicts and migration have significantly aggravated leishmaniases in Eastern Africa. Of particular concern is the increasing incidence of Leishmania-HIV co-infection in Ethiopia where 20--40% of the persons affected by visceral leishmaniasis are HIV-co-infected. Sudan has the highest prevalence rate of post kala-azar dermal leishmaniasis(PKDL) in the world, a skin complication of visceral leishmaniasis(VL) that mainly afflicts children below age ten. In view of its spread to previously non-endemic areas and an increase in imported cases, leishmaniasis in Eastern Africa should be considered a health emergency.

  8. Trace elements in coals of eastern Donbas

    Energy Technology Data Exchange (ETDEWEB)

    Taranushich, F.F. [All Russian Research & Geological Prospecting Institute for Coal Deposits, Rostov Na Donu (Russian Federation)

    2003-02-01

    Peculiarities of trace element (TE) distribution in coals of the eastern Donets Basin (Donbas) are discussed. The correlation of TE distribution with specific features of the geological setting of the region can testify to the hydrothermal introduction of trace elements or their redistribution in fluid-active zones. The geochemical regionalization of eastern Donbas is based on TE distribution. Strontium-gold-base metal, tungsten, and selenium geochemical belts and a rare metal geochemical block are outlined.

  9. Midwifery education in Central-Eastern Europe.

    Science.gov (United States)

    Mivšek, Polona; Baškova, Martina; Wilhelmova, Radka

    2016-02-01

    Problems in midwifery in many Central-Eastern European countries are very similar; it is possible to speak about the evolving Central-Eastern model of midwifery care. The educational models of this region have a relatively strong theoretical part; however, there is an insufficient practical dimension. Theoretical part of midwifery education in the universities is relatively autonomous and is slowly changing the professional identity of graduates.

  10. Sources of performance on theory of mind tasks in right hemisphere-damaged patients.

    Science.gov (United States)

    Surian, L; Siegal, M

    2001-08-01

    Patients with right hemisphere (RHD) or left hemisphere brain damage (LHD) were tested on Theory of Mind (ToM) tasks presented with visual aids that illustrated the relevant premises. As a measure of pragmatic ability, patients were also asked to judge replies in conversation that violated Gricean maxims. Both RHD and LHD patients performed well on the ToM tasks presented with visual aids, but RHD patients displayed difficulty when the same tasks were presented only verbally. In addition, RHD patients showed reduced sensitivity to pragmatic violations. These findings point to the role of right hemisphere structures in processing information relevant to conversations. They indicate that a crucial source of RHD patients' errors in ToM tasks may involve difficulties in utterance interpretation owing to impairments of visuospatial processing required for the representation of textual information.

  11. Wind as a Long-Distance Dispersal Vehicle in the Southern Hemisphere

    Science.gov (United States)

    Muñoz, Jesús; Felicísimo, Ángel M.; Cabezas, Francisco; Burgaz, Ana R.; Martínez, Isabel

    2004-05-01

    Anisotropic (direction-dependent) long-distance dispersal (LDD) by wind has been invoked to explain the strong floristic affinities shared among landmasses in the Southern Hemisphere. Its contribution has not yet been systematically tested because of the previous lack of global data on winds. We used global winds coverage from the National Aeronautics and Space Administration SeaWinds scatterometer to test whether floristic similarities of Southern Hemisphere moss, liverwort, lichen, and pteridophyte floras conform better with (i) the anisotropic LDD hypothesis, which predicts that connection by ``wind highways'' increases floristic similarities, or (ii) a direction-independent LDD hypothesis, which predicts that floristic similarities among sites increase with geographic proximity. We found a stronger correlation of floristic similarities with wind connectivity than with geographic proximities, which supports the idea that wind is a dispersal vehicle for many organisms in the Southern Hemisphere.

  12. The prenatal origin of hemispheric asymmetry: an in utero neuroimaging study.

    Science.gov (United States)

    Kasprian, Gregor; Langs, Georg; Brugger, Peter C; Bittner, Mario; Weber, Michael; Arantes, Mavilde; Prayer, Daniela

    2011-05-01

    Anatomical and functional hemispheric lateralization originates from differential gene expression and leads to asymmetric structural brain development, which initially appears in the perisylvian regions by 26 gestational weeks (GWs). In this in vivo neuroimaging study, we demonstrated a predominant pattern of temporal lobe (TL) asymmetry in a large cohort of human fetuses between 18 and 37 GWs. Over two-thirds of fetuses showed a larger, left-sided TL, combined with the earlier appearance of the right superior temporal sulcus by 23 GWs (vs. 25 GWs on the left side), which was also deeper than its left counterpart in the majority of cases (94.2%). Shape analysis detected highly significant differences in the contour of the right and left TLs by 20 GWs. Thus, fetal hemispheric asymmetry can be detected in utero, opening new diagnostic possibilities for the assessment of diseases that are believed to be linked to atypical hemispheric lateralization.

  13. The star book stargazing throughout the seasons in the Northern hemisphere

    CERN Document Server

    Grego, Peter

    2012-01-01

    Stargazing Throughout the Seasons in the Northern Hemisphere is an excerpt from The Star Book that guides you through the night skies in the Northern Hemisphere, through wide-angle star charts. Looking at the main constellations, stars and celestial showpieces of the northern celestial sphere, beginning with constellations around the north pole and then taking a season by season view. Most northern constellations are as familiar to today's stargazers as they were to the ancient Greeks. Everyone is interested in the stars and on a clear night astonished by them. Stargazing Throughout the Seasons in the Northern Hemisphere will answer any questions you may have when you look up into the night sky.

  14. Phantom Limb Pain: Low Frequency Repetitive Transcranial Magnetic Stimulation in Unaffected Hemisphere

    Directory of Open Access Journals (Sweden)

    Andrea Di Rollo

    2011-01-01

    Full Text Available Phantom limb pain is very common after limb amputation and is often difficult to treat. The motor cortex stimulation is a valid treatment for deafferentation pain that does not respond to conventional pain treatment, with relief for 50% to 70% of patients. This treatment is invasive as it uses implanted epidural electrodes. Cortical stimulation can be performed noninvasively by repetitive transcranial magnetic stimulation (rTMS. The stimulation of the hemisphere that isn't involved in phantom limb (unaffected hemisphere, remains unexplored. We report a case of phantom limb pain treated with 1 Hz rTMS stimulation over motor cortex in unaffected hemisphere. This stimulation produces a relevant clinical improvement of phantom limb pain; however, further studies are necessary to determine the efficacy of the method and the stimulation parameters.

  15. Rigidity, Chaos and Integration: Hemispheric Interaction and Individual Differences in Metaphor Comprehension

    Directory of Open Access Journals (Sweden)

    Miriam eFaust

    2014-07-01

    Full Text Available Neurotypical individuals cope flexibly with the full range of semantic relations expressed in human language, including metaphoric relations. This impressive semantic ability may be associated with distinct and flexible patterns of hemispheric interaction, including higher right hemisphere (RH involvement for processing novel metaphors. However, this ability may be impaired in specific clinical conditions, such as Asperger syndrome and schizophrenia. The impaired semantic processing is accompanied by different patterns of hemispheric interaction during semantic processing, showing either reduced (in Asperger or excessive (in schizophrenia RH involvement. This paper interprets these individual differences using the terms Rigidity, Chaos and Integration, which describe patterns of semantic memory network states that either lead to semantic well-being or are disruptive of it. We argue that these semantic network states lie on a rigidity-chaos semantic continuum. We define these terms via network science terminology and provide network, cognitive and neural evidence to support our claim. This continuum includes LH hyper-rigid semantic memory state on one end (e.g., in persons with Asperger syndrome, and RH chaotic and over-flexible semantic memory state on the other end (e.g., in persons with schizophrenia. In between these two extremes lie different states of semantic memory structure which are related to individual differences in semantic creativity. We suggest that efficient semantic processing is achieved by semantic integration, a balance between semantic rigidity and semantic chaos. Such integration is achieved via intra-hemispheric communication. However, impairments to this well-balanced and integrated pattern of hemispheric interaction, e.g., when one hemisphere dominates the other, may lead to either semantic rigidity or semantic chaos, moving away from semantic integration and thus impairing the processing of metaphoric language.

  16. The Effects of Spatial Smoothing on Solar Magnetic Helicity and the Hemispheric Helicity Sign Rule

    Science.gov (United States)

    Koch Ocker, Stella; Petrie, Gordon

    2016-05-01

    The hemispheric sign rule for solar magnetic helicity, which states that negative/positive helicity occurs preferentially in the northern/southern hemisphere, provides clues to the causes of twisted, flaring magnetic fields. However, previous studies on the hemisphere rule may have been significantly affected by seeing from atmospheric turbulent motions. Using Hinode/SOT-SP data spanning from 2006 to 2012, we studied the effects of two important data processing steps that imitate the effects of atmospheric seeing: noise reduction by ignoring pixel values that are weaker than the estimated noise threshold, and Gaussian spatial smoothing. We applied these processing techniques to the helicity distribution maps for active regions NOAA 11158 and NOAA 11243, along with the average helicities of 36 active regions, in order to imitate and understand the effects of seeing from atmospheric turbulence. We found that rather than changing trends in the helicity distributions, Gaussian smoothing and noise reduction enhanced existing trends by pushing outliers towards the mean or removing them altogether. We also found that, when separated for weak and strong magnetic fields, the average helicities of the 36 active regions conformed to the hemisphere rule for weak field helicities and breached the rule for strong field helicities. In general, we found that data processing did not affect whether the hemisphere rule held for data taken from space-based instruments, and thus that seeing from atmospheric turbulence did not significantly affect previous studies' ground-based results on the hemisphere rule. This work was carried out through the National Solar Observatory Research Experiences for Undergraduates (REU) Program, which is funded by the National Science Foundation (NSF). The National Solar Observatory is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the NSF.

  17. The hemispheric asymmetry of solar activity during the last century and the solar dynamo

    Institute of Scientific and Technical Information of China (English)

    Ashish Goel; Arnab Rai Choudhuri

    2009-01-01

    We believe the Babcock-Leighton process of poloidal field generation to be the main source of irregularity in the solar cycle. The random nature of this process may make the poloidal field in one hemisphere stronger than that in the other hemisphere at the end of a cycle. We expect this to induce an asymmetry in the next sunspot cycle. We look for evidence of this in the observational data and then model it theoretically with our dynamo code. Since actual polar field measurements exist only from the 1970s, we use the polar faculae number data recorded by Sheeley (1991, 2008) as a proxy of the polar field and estimate the hemispheric asymmetry of the polar field in different solar minima during the major part of the twentieth century. This asymmetry is found to have a reasonable correlation with the asymmetry of the next cycle. We then run our dynamo code by feeding information about this asymmetry at the successive minima and compare the results with observational data. We find that the theoretically computed asymmetries of different cycles compare favorably with the observational data, with the correlation co-efficient being 0.73. Due to the coupling between the two hemispheres, any hemispheric asymmetry tends to get attenuated with time. The hemispheric asymmetry of a cycle ei-ther from observational data or from theoretical calculations statistically tends to be less than the asymmetry in the polar field (as inferred from the faculae data) in the preceding minimum. This reduction factor turns out to be 0.43 and 0.51 respectively in observational data and theoretical simulations.

  18. Comparison of mercury concentrations measured at several sites in the Southern Hemisphere

    Directory of Open Access Journals (Sweden)

    F. Slemr

    2014-12-01

    Full Text Available Our knowledge of the distribution of mercury concentrations in air of the Southern Hemisphere was until recently based mostly on intermittent measurements made during ship cruises. In the last few years continuous mercury monitoring has commenced at several sites in the Southern Hemisphere providing new and more refined information. In this paper we compare mercury measurements at several sites in the Southern Hemisphere made over a period of at least one year at each location. Averages of monthly medians show similar although small seasonal variations at both Cape Point and Amsterdam Island. A pronounced seasonal variation at Troll Research Station in Antarctica is due to frequent mercury depletion events in the austral spring. Due to large scatter and large standard deviations of monthly average median mercury concentrations at Cape Grim no systematic seasonal variation could be found there. Nevertheless, the annual average mercury concentrations at all sites during the 2007–2013 period varied only between 0.85 and 1.05 ng m−3. Part of this variability is likely due to systematic measurement uncertainties which we propose can be further reduced by improved calibration procedures. We conclude that mercury is much more uniformly distributed throughout the Southern Hemisphere than the distributions suggested by measurements made onboard ships. This finding implies (a that trends observed at one or a few sites in the Southern Hemisphere are likely to be representative for the whole hemisphere, and (b that smaller trends can be detected in shorter time periods. We also report a change of the trend sign at Cape Point from decreasing mercury concentrations in 1996–2004 to increasing concentrations since 2007.

  19. Neuromagnetic index of hemispheric asymmetry predicting long-term outcome in sudden hearing loss.

    Science.gov (United States)

    Li, Lieber Po-Hung; Chen, Kuang-Chao; Lee, Po-Lei; Niddam, David M; Cheng, Chou-Ming; Chou, Chih-Cher; Hsieh, Jen-Chuen; Shiao, An-Suey

    2013-01-01

    The neuromagnetic index of hemispheric asymmetry in terms of ipsilateral/contralateral ratio at acute stage was previously revealed to prognosticate the 1-month hearing outcome of acute unilateral idiopathic sudden sensorineural hearing loss (ISSNHL), showing a dynamic relationship between top- and down-levels of auditory pathway. However, the prognostic effect of reorganization pattern for the long-term results remained elusive. This study aimed to probe the prognosticating relevance of hemispheric asymmetry to the hearing at chronic stage of ISSNHL. Using magnetoencephalography (MEG), inter-hemispheric differences in peak dipole of N100m responses to monaural tones were evaluated in 21 controls and 21 ISSNHL patients at initial and final (12 months later) stages. Predictive value of hemispheric asymmetry was assessed by correlating hearing level and ipsilateral/contralateral ratio (I/C) of N100m latency and amplitude. Healthy-side dominance of N100m was observed in ISSNHL initially, and remained in three final prognostic subgroups (complete, partial, and no recovery) of ISSNHL. The initial I/C(amplitude) on affected-ear stimulation strongly correlated with the hearing level of final stage in ISSNHL. However, there was no prognostic effect of hemispheric asymmetry pattern for the 12-month hearing improvement. The heterogeneity between neuromagnetic index and hearing levels possibly echoed different pathogeneses of ISSNHL. Since a restored hearing status did not necessarily lead toward a normal functional organization, the dynamics of hemispheric asymmetry could actually index a central resilient reorganization in the brain for sound processing in ISSNHL. Our finding showed not only a clinically relevant measure to predict final hearing of ISSNHL, but also a linkage between central plasticity and cochlear lesion. This finding suggests a new perspective, and perhaps new interventions, to diagnose and treat unilateral ISSNHL.

  20. Brain activity underlying tool-related and imitative skills after major left hemisphere stroke.

    Science.gov (United States)

    Martin, Markus; Nitschke, Kai; Beume, Lena; Dressing, Andrea; Bühler, Laura E; Ludwig, Vera M; Mader, Irina; Rijntjes, Michel; Kaller, Christoph P; Weiller, Cornelius

    2016-05-01

    Apraxia is a debilitating cognitive motor disorder that frequently occurs after left hemisphere stroke and affects tool-associated and imitative skills. However, the severity of the apraxic deficits varies even across patients with similar lesions. This variability raises the question whether regions outside the left hemisphere network typically associated with cognitive motor tasks in healthy subjects are of additional functional relevance. To investigate this hypothesis, we explored regions where functional magnetic resonance imaging activity is associated with better cognitive motor performance in patients with left hemisphere ischaemic stroke. Thirty-six patients with chronic (>6 months) large left hemisphere infarcts (age ± standard deviation, 60 ± 12 years, 29 male) and 29 control subjects (age ± standard deviation, 72 ± 7, 15 male) were first assessed behaviourally outside the scanner with tests for actual tool use, pantomime and imitation of tool-use gestures, as well as for meaningless gesture imitation. Second, functional magnetic resonance imaging activity was registered during the passive observation of videos showing tool-associated actions. Voxel-wise linear regression analyses were used to identify areas where behavioural performance was correlated with functional magnetic resonance imaging activity. Furthermore, lesions were delineated on the magnetic resonance imaging scans for voxel-based lesion-symptom mapping. The analyses revealed two sets of regions where functional magnetic resonance imaging activity was associated with better performance in the clinical tasks. First, activity in left hemisphere areas thought to mediate cognitive motor functions in healthy individuals (i.e. activity within the putative 'healthy' network) was correlated with better scores. Within this network, tool-associated tasks were mainly related to activity in supramarginal gyrus and ventral premotor cortex, while meaningless gesture imitation depended more on the

  1. Subsonic aircraft soot. A tracer documenting barriers to inter-hemispheric mixing

    Energy Technology Data Exchange (ETDEWEB)

    Pueschel, R.F. [NASA Ames Research Center, Moffett Field, CA (United States)

    1997-12-31

    Meridional observations of soot aerosols and radioactive {sup 14}C, and models of the geographic distribution of nuclear bomb-released {sup 14}C and aircraft-emitted NO{sub x}, all show strong gradients between the hemispheres. Reason for it are decade-long inter-hemispheric mixing times which are much in excess of yearlong stratospheric residence times of tracers. Vertical mixing of soot aerosol is not corroborated by {sup 14}C observations. The reason could be radiometric forces that act on strongly absorbing soot. (author) 10 refs.

  2. Right hand predominant constructional apraxia due to right hemisphere infarction without corpus callosum lesions.

    Science.gov (United States)

    Kobayashi, Zen; Watanabe, Mayumi; Karibe, Yuri; Nakazawa, Chika; Numasawa, Yoshiyuki; Tomimitsu, Hiroyuki; Shintani, Shuzo

    2014-01-01

    A 74-year-old right-handed woman without cognitive impairment suddenly developed nonfluent aphasia. Brain MRI showed acute infarction in the right frontal lobe and insula without involvement of the corpus callosum. A neurological examination demonstrated not only transcortical motor aphasia, but also ideomotor apraxia and right hand predominant constructional apraxia (CA). To date, right hand predominant CA has only been reported in patients with corpus callosum lesions. The right hand predominant CA observed in our patient may be associated with the failure to transfer information on the spatial structure from the right hemisphere to the motor cortex of the left hemisphere.

  3. Southern Hemisphere Measurement of the Anisotropy in the CosmicMicrowave Background Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Smoot, George F.; Lubin, Phil M.

    1979-06-01

    A recent measurement of the anisotropy in the Cosmic Background Radiation from the southern hemisphere (Lima, Peru) is essentially in agreement with previous measurements from the northern hemisphere. The net anisotropy can be described as a first order spherical harmonic (Doppler) anisotropy of amplitude 3.1 {+-} 0.4 m{sup o}K with a quadrupole anisotropy of less than 1 m{sup o}K. In addition, measurements of the linear polarization yield an upper limit of 1 m{sup o}K, or one part in 3000, at 95% C.L. for the amplitudes of any spherical harmonic through third order.

  4. Hemispherical Shell Nanostructures from Metal-Stripped Embossed Alumina on Aluminum Templates

    DEFF Research Database (Denmark)

    Nielsen, Peter; Albrektsen, Ole; Simonsen, Adam Cohen

    2011-01-01

    aluminum/ alumina (Al/Al2O3) templates as a novel and versatile nanofabrication procedure, and we demonstrate explicitly how to exploit the technique for developing large-area hexagonally close-packed hemispherical shell nanostructures by stripping noble metal layers from embossed templates fabricated from...... anodized Al. Utilizing for this process the linear relationship between anodization voltage and the resulting interpore distance in the formed oxide, it is possible to tune the radius of curvature of the resulting hemispherical shells continuously, which in turn results in tunable optical properties...

  5. Detection of spatial frequency in brain-damaged patients: influence of hemispheric asymmetries and hemineglect

    Directory of Open Access Journals (Sweden)

    Natanael Antonio Dos Santos

    2013-04-01

    Full Text Available Hemispheric specialization for spatial frequency processing was investigated by measuring the contrast sensitivity curves of sine-wave gratings in 30 left or right brain-damaged patients using different spatial frequencies compared with healthy participants. The results showed that left brain-damaged patients were selectively impaired in processing high frequencies, whereas right brain-damaged patients were more impaired in the processing low frequencies, regardless of the presence of visuo-spatial neglect. These visual processing results can be interpreted in terms of spatial frequency discrimination, with both hemispheres participating in this process in different ways.

  6. Eastern slopes grizzly bear project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-01-01

    The cumulative effects of human activities on the grizzly bears in the central Canadian Rockies are not well known. As a result, a project was initiated in 1994 to address the urgent requirement for accurate scientific information on the habitat and populations of grizzly bears in the area of the Banff National Park and Kananaskis Country. This area is probably the most heavily used and developed area where the grizzly still survives. The information gathered throughout the course of this study will be used to better protect and manage the bears and other sensitive carnivores in the region. Using telemetry, researchers are monitoring 25 grizzly bears which were radio-collared in a 22,000 square-kilometer area in the upper Bow Valley drainage of the eastern Alberta slopes. The researchers involved in the project are working with representatives from Husky Oil and Talisman Energy on the sound development of the Moose Mountain oil and gas field without adversely affecting the grizzly bear population. Information collected over seven years indicated that the grizzly bears have few and infrequent offspring. Using the information gathered so far, the location of the Moose Mountain to Jumping Pound pipeline was carefully selected, since the bears recover very slowly from high mortality, and also considering that the food and cover had already been compromised by the high number of roads, trails and other human activities in the area. The status of the population and habitat of the grizzly bear will be assessed upon the conclusion of the field research phase in 2001. Models will be updated using the data obtained during eight years and will assist in the understanding of complex variables that affect grizzly bears.

  7. Dual-hemisphere tDCS facilitates greater improvements for healthy subjects' non-dominant hand compared to uni-hemisphere stimulation

    Directory of Open Access Journals (Sweden)

    Cerruti Carlo

    2008-10-01

    Full Text Available Abstract Background Transcranial direct current stimulation (tDCS is a non-invasive technique that has been found to modulate the excitability of neurons in the brain. The polarity of the current applied to the scalp determines the effects of tDCS on the underlying tissue: anodal tDCS increases excitability, whereas cathodal tDCS decreases excitability. Research has shown that applying anodal tDCS to the non-dominant motor cortex can improve motor performance for the non-dominant hand, presumably by means of changes in synaptic plasticity between neurons. Our previous studies also suggest that applying cathodal tDCS over the dominant motor cortex can improve performance for the non-dominant hand; this effect may result from modulating inhibitory projections (interhemispheric inhibition between the motor cortices of the two hemispheres. We hypothesized that stimultaneously applying cathodal tDCS over the dominant motor cortex and anodal tDCS over the non-dominant motor cortex would have a greater effect on finger sequence performance for the non-dominant hand, compared to stimulating only the non-dominant motor cortex. Sixteen right-handed participants underwent three stimulation conditions: 1 dual-hemisphere – with anodal tDCS over the non-dominant motor cortex, and cathodal tDCS over the dominant motor cortex, 2 uni-hemisphere – with anodal tDCS over the non-dominant motor cortex, and 3 sham tDCS. Participants performed a finger-sequencing task with the non-dominant hand before and after each stimulation. The dependent variable was the percentage of change in performance, comparing pre- and post-tDCS scores. Results A repeated measures ANOVA yielded a significant effect of tDCS condition (F(2,30 = 4.468, p = .037. Post-hoc analyses revealed that dual-hemisphere stimulation improved performance significantly more than both uni-hemisphere (p = .021 and sham stimulation (p = .041. Conclusion We propose that simultaneously applying cathodal t

  8. Mazingira Centre: A state-of-the-art environmental research infrastructure in Eastern Africa

    Science.gov (United States)

    Merbold, Lutz; Butterbach-Bahl, Klaus; Goopy, John; Mutuo, Paul; Korir, Daniel; Pelster, David; Wanyama, George

    2017-04-01

    Measurements of greenhouse gases (GHGs), performed in various terrestrial and marine ecosystems have led to a fundamental understanding of the Earth System during the last century. While there are numerous extant long-term measurements of GHGs across the globe, these are mainly located in developed countries of the northern hemisphere, leaving large regions such as Sub-Saharan Africa (SSA) without a consolidated observational network. Moreover, in SSA also infrastructures capable of measuring GHGs following best scientific practice are lacking. The Mazingira Centre - a state-of-the-art environmental laboratory - hosted by the International Livestock Research Institute in Kenya has been established in 2013. The laboratory is equipped with state-of-the-art GHG measurement technology (gas chromatographs, animal respiration chambers, laser absorption spectrometers) and aims at providing fundamental environmental data (e.g. GHGs and auxiliary information) from the most common land-cover types in Eastern Africa and beyond. Thereby a special focus is given to mixed crop-livestock systems managed by smallholders. The first results from the activities of the Mazingira Centre show much lower GHG emissions from manure management and arable systems as commonly assumed using emission factor approaches (EFs). This highlights the need of direct, in-situ measurements from all land-cover types and agricultural systems in Eastern Africa. The Mazingira Centre is furthermore a core training facility for undergraduate and graduate students, technicians as well policy makers that report GHG emissions to the UNFCCC with reliable and accurate emissions factors.

  9. First measurements of (236)U concentrations and (236)U/(239)Pu isotopic ratios in a Southern Hemisphere soil far from nuclear test or reactor sites.

    Science.gov (United States)

    Srncik, M; Tims, S G; De Cesare, M; Fifield, L K

    2014-06-01

    The variation of the (236)U and (239)Pu concentrations as a function of depth has been studied in a soil profile at a site in the Southern Hemisphere well removed from nuclear weapon test sites. Total inventories of (236)U and (239)Pu as well as the (236)U/(239)Pu isotopic ratio were derived. For this investigation a soil core from an undisturbed forest area in the Herbert River catchment (17°30' - 19°S) which is located in north-eastern Queensland (Australia) was chosen. The chemical separation of U and Pu was carried out with a double column which has the advantage of the extraction of both elements from a relatively large soil sample (∼20 g) within a day. The samples were measured by Accelerator Mass Spectrometry using the 14UD pelletron accelerator at the Australian National University. The highest atom concentrations of both (236)U and (239)Pu were found at a depth of 2-3 cm. The (236)U/(239)Pu isotopic ratio in fallout at this site, as deduced from the ratio of the (236)U and (239)Pu inventories, is 0.085 ± 0.003 which is clearly lower than the Northern Hemisphere value of ∼0.2. The (236)U inventory of (8.4 ± 0.3) × 10(11) at/m(2) was more than an order of magnitude lower than values reported for the Northern Hemisphere. The (239)Pu activity concentrations are in excellent agreement with a previous study and the (239+240)Pu inventory was (13.85 ± 0.29) Bq/m(2). The weighted mean (240)Pu/(239)Pu isotopic ratio of 0.142 ± 0.005 is slightly lower than the value for global fallout, but our results are consistent with the average ratio of 0.173 ± 0.027 for the southern equatorial region (0-30°S).

  10. Lateglacial temperature reconstruction in the Eastern Tropical Andes (Bolivia) inferred from paleoglaciers and paleolakes

    Science.gov (United States)

    Martin, L.; Blard, P. H.; Lave, J.; Prémaillon, M.; Jomelli, V.; Brunstein, D.; Lupker, M.; Charreau, J.; Mariotti, V.; Condom, T.; Bourles, D. L.

    2015-12-01

    Recent insights shed light on the global mechanisms involved in the abrupt oscillations of the Earth climate for the Late Glacial Maximum (LGM) to Holocene period (Zhang et al., 2014; Banderas et al., 2015). Yet the concomitant patterns of regional climate reorganization on continental areas are for now poorly documented. Particularly, few attempts have been made to propose temporal reconstructions of the regional climate variables in the High Tropical Andes, a region under the direct influence of the upper part of the troposphere. We present new glacial chronologies from the Zongo (16.3°S - 68.1°W, Bolivia) and Wara-Wara (17.3°S - 66.1°W, Bolivia) valleys based on Cosmic Ray Exposure dating (CRE) from an exceptional suite of recessive moraines. These new data permitted to refine existing chronologies (Smith et al., 2005 ; Zech et al., 2010): the Zongo valley is characterized by an older local last glacial maximum than the Wara Wara valley. Both sites however exhibit similar glacier behaviours, with a progressive regression between 18 ka and the Holocene. In both sites, glaciers recorded stillstand episodes synchronous with the cold events of the Norther Hemisphere (Henrich 1 event, Younger Dryas). Since the nearby Altiplano basin registered lake level variations over the same period, we were able to apply a joint modelling of glaciers Equilibrium Line Altitude (ELA) and lake budget. This permits to derive a temporal evolution of temperature and precipitation for both sites. These new reconstructions show for both sites that glaciers of the Eastern Tropical Andes were both influenced by the major climatic events of the Northern and Southern Hemispheres. However, precipitation variability is more influenced by the Northern Atlantic events. This observation is in good agreement with the theories suggesting that North Hemisphere cold events are coeval with an important southward deflexion of the Intertropical Convergence Zone (ITCZ) due to the inter-hemispheric

  11. Hand movements with a phase structure and gestures that depict action stem from a left hemispheric system of conceptualization.

    Science.gov (United States)

    Helmich, I; Lausberg, H

    2014-10-01

    The present study addresses the previously discussed controversy on the contribution of the right and left cerebral hemispheres to the production and conceptualization of spontaneous hand movements and gestures. Although it has been shown that each hemisphere contains the ability to produce hand movements, results of left hemispherically lateralized motor functions challenge the view of a contralateral hand movement production system. To examine hemispheric specialization in hand movement and gesture production, ten right-handed participants were tachistoscopically presented pictures of everyday life actions. The participants were asked to demonstrate with their hands, but without speaking what they had seen on the drawing. Two independent blind raters evaluated the videotaped hand movements and gestures employing the Neuropsychological Gesture Coding System. The results showed that the overall frequency of right- and left-hand movements is equal independent of stimulus lateralization. When hand movements were analyzed considering their Structure, the presentation of the action stimuli to the left hemisphere resulted in more hand movements with a phase structure than the presentation to the right hemisphere. Furthermore, the presentation to the left hemisphere resulted in more right and left-hand movements with a phase structure, whereas the presentation to the right hemisphere only increased contralateral left-hand movements with a phase structure as compared to hand movements without a phase structure. Gestures that depict action were primarily displayed in response to stimuli presented in the right visual field than in the left one. The present study shows that both hemispheres possess the faculty to produce hand movements in response to action stimuli. However, the left hemisphere dominates the production of hand movements with a phase structure and gestures that depict action. We therefore conclude that hand movements with a phase structure and gestures that

  12. Primary factors affecting water quality and quantity in four watersheds in Eastern Puerto Rico

    Science.gov (United States)

    Murphy, Sheila F.; Stallard, Robert F.

    2009-01-01

    As part of the U.S. Geological Survey (USGS) Water, Energy, and Biogeochemical Budgets (WEBB) program, four small watersheds in eastern Puerto Rico were monitored to identify and evaluate the effects of geology, landcover, atmospheric deposition, and other factors on stream water quality and quantity. Two catchments are located on coarse-grained granitic plutonic rocks, which weather to quartz- and clay-rich, sandy soils, and two are located on fine-grained volcanic rocks and volcaniclastic sediments, which weather to quartz-poor, fine-grained soils. These differing soil materials result in different hydrologic regimes. Soils on the granitic rocks have greater permeability than those developed on the volcaniclastic rocks, allowing more water infiltration and potentially greater landslide erosion rates. For each bedrock type, one catchment was covered with mature rainforest, and the other catchment was affected by agricultural practices typical of eastern Puerto Rico. These practices led to the erosion of much of the original surface soil in the agricultural watersheds, which introduced large quantities of sediment to stream channels. The agricultural watersheds are undergoing natural reforestation, like much of Puerto Rico. Eastern Puerto Rico receives large atmospheric inputs of marine salts, pollutants from the Northern Hemisphere, and Saharan Desert dust. Marine salts contribute over 80 percent of the ionic charge in precipitation, with peak inputs in January. Intense storms, mostly hurricanes, are associated with exceptionally high chloride concentrations in stream waters. Temperate pollution contributes nitrate, ammonia, and sulfate, with maximum inputs during northern cold fronts in January, April, and May. Pollution inputs have increased through time. Desert dust peaks in June and July, during times of maximum dust transport from the Saharan Desert across the Atlantic Ocean.

  13. Annual temperatures during the last 2485 years in the mid-eastern Tibetan Plateau inferred from tree rings

    Institute of Scientific and Technical Information of China (English)

    Hans; W.; LINDERHOLM

    2009-01-01

    By combining living trees and archaeological wood, the annual mean temperatures were reconstructed based on ring-width indices of the mid-eastern Tibetan Plateau for the past 2485 years. The climate variations revealed by the reconstruction indicate that there were four periods to have average tem- peratures similar to or even higher than that mean of 1970 to 2000 AD. A particularly notable rapid shift from cold to warm, we call it the "Eastern Jin Event", occurred from 348 AD to 413 AD. Calculation re- sults show that the temperature variations over the mid-eastern Tibetan Plateau are not only repre- sentative for large parts of north-central China, but also closely correspond to those of the entire Northern Hemisphere over long time scales. During the last 2485 years, the downfall of most major dynasties in China coincides with intervals of low temperature. Compared with the temperature records in other regions of China during the last 1000 years, this reconstruction from the Tibetan Plateau shows a significant warming trend after the 1950s.

  14. Mental Number Line Disruption in a Right-Neglect Patient after a Left-Hemisphere Stroke

    Science.gov (United States)

    Pia, Lorenzo; Corazzini, Luca Latini; Folegatti, Alessia; Gindri, Patrizia; Cauda, Franco

    2009-01-01

    A right-neglect patient with focal left-hemisphere damage to the posterior superior parietal lobe was assessed for numerical knowledge and tested on the bisection of numerical intervals and visual lines. The semantic and verbal knowledge of numbers was preserved, whereas the performance in numerical tasks that strongly emphasize the visuo-spatial…

  15. Lexical Competition is Enhanced in the Left Hemisphere: Evidence from Different Types of Orthographic Neighbors

    Science.gov (United States)

    Perea, Manuel; Acha, Joana; Fraga, Isabel

    2008-01-01

    Two divided visual field lexical decision experiments were conducted to examine the role of the cerebral hemispheres in orthographic neighborhood effects. In Experiment 1, we employed two types of words: words with many substitution neighbors (high-"N") and words with few substitution neighbors (low-"N"). Results showed a facilitative effect of…

  16. Unbiasing the Brain: The Effects of Meditation upon The Cerebral Hemispheres.

    Science.gov (United States)

    Meissner, John; Pirot, Michael

    1983-01-01

    Assessed the effects of Transcendental Meditation on the perceptual efficiency of the cerebral hemispheres in 20 right-handed men who underwent reaction time trials to an auditory stimulus. Results suggested Transcedental Meditation is an attentional strategy that disrupts the usual biases of the brain. (JAC)

  17. Reliability of a novel paradigm for determining hemispheric lateralization of visuospatial function

    NARCIS (Netherlands)

    Whitehouse, A.J.O.; Badcock, N.A.; Groen, M.A.; Bishop, D.V.M.

    2009-01-01

    In most individuals, language production and visuospatial skills are subserved predominantly by the left and right hemispheres, respectively. Functional Transcranial Doppler (fTCD) provides a noninvasive and relatively low-cost method for measuring functional lateralization. However, while the silen

  18. Holocene evolution of the Southern Hemisphere westerly winds in transient simulations with global climate models

    NARCIS (Netherlands)

    Varma, V.; Prange, M.; Merkel, U.; Kleinen, T.; Lohmann, G.; Pfeiffer, M.; Renssen, H.; Wagner, A.; Wagner, S.; Schulz, M.

    2012-01-01

    The Southern Hemisphere Westerly Winds (SWW) have been suggested to exert a critical influence on global climate through the wind-driven upwelling of deep water in the Southern Ocean and the potentially resulting atmospheric CO2 variations. The investigation of the temporal and spatial evolution of

  19. Returning to Work after the Onset of Illness: Experiences of Right Hemisphere Stroke Survivors

    Science.gov (United States)

    Koch, Lynn; Egbert, Nichole; Coeling, Harriet; Ayers, Denise

    2005-01-01

    Experiences of right hemisphere stroke survivors in their attempts to return to work after the onset of stroke were explored through an interdisciplinary qualitative investigation. Key findings indicate that (a) participants experienced an array of functional limitations that precipitated employment changes; (b) employment changes had a…

  20. Hemispheric Asymmetries for Temporal Information Processing: Transient Detection versus Sustained Monitoring

    Science.gov (United States)

    Okubo, Matia; Nicholls, Michael E. R.

    2008-01-01

    This study investigated functional differences in the processing of visual temporal information between the left and right hemispheres (LH and RH). Participants indicated whether or not a checkerboard pattern contained a temporal gap lasting between 10 and 40 ms. When the stimulus contained a temporal signal (i.e. a gap), responses were more…