bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hearing Two Things at Once: Neurophysiological Indices of Speech Segregation and Identification
Authors: Alain Claude , Reinke Karen , He Yu , Wang Chenghua , Lobaugh Nancy 
Published: April 2005

Abstract
The discrimination of concurrent sounds is paramount to speech perception. During social gatherings, listeners must extract information from a composite acoustic wave, which sums multiple individual voices that are simultaneously active. The observers' ability to identify two simultaneously presented vowels improves with increasing separation between the fundamental frequencies (f 0) of the two vowels. Event-related potentials to stimuli presented during attend and ignore conditions revealed activity between 130 and 170 msec after sound onset that reflected the f 0 differences between the two vowels. Another, more posterior and right-lateralized, negative wave maximal at 250 msec, and a central-parietal slow negativity were observed only during vowel identification and may index stimulus categorization. This sequence of neural events supports a multistage model of auditory scene analysis in which the spectral pattern of each vowel constituent is automatically extracted and then matched against representations of those vowels in working memory.
On-line Processing of “Pop-Out” Words in Spoken French Dialogues
Authors: Magne Cyrille , Astésano Corine , Lacheret-Dujour Anne , Morel Michel , Alter Kai , Besson Mireille 
Published: April 2005

Abstract
Highlighting relevant information in a discourse context is a major aim of spoken language communication. Prosodic cues such as focal prominences are used to fulfill this aim through the pragmatic function of prosody. To determine whether listeners make on-line use of focal prominences to build coherent representations of the informational structure of the utterances, we used the brain event-related potential (ERP) method. Short dialogues composed of a question and an answer were presented auditorily. The design of the experiment allowed us to examine precisely the time course of the processing of prosodic patterns of sentence-medial or -final words in the answer. These patterns were either congruous or incongruous with regard to the pragmatic context introduced by the question. Furthermore, the ERP effects were compared for words with or without focal prominences. Results showed that pragmatically congruous and incongruous prosodic patterns elicit clear differences in the ERPs, which were largely modulated in latency and polarity by their position within the answer. By showing that prosodic patterns are processed on-line by listeners in order to understand the informational structure of the message, the present results demonstrate the psychobiological validity of the pragmatic concept of focus, expressed via prosodic cues. Moreover, the functional significance of the positive-going effects found sentence medially and negative-going effects found sentence finally is discussed. Whereas the former may reflect the processing of surprising and task-relevant prosodic patterns, the latter may reflect the integration problems encountered in extracting the overall informational structure of the sentence.
The Inferior Temporal Lobe Mediates Distracter-Resistant Visual Search of Patients with Spatial Neglect
Authors: Ptak Radek , Valenza Nathalie 
Published: April 2005

AbstractAlthough impaired visual search is a core deficit of patients with spatial neglect, current evidence is not conclusive about the mechanisms underlying this failure. We present evidence from 14 neglect patients searching for a target defined by two perceptual features that visual search is mediated by mechanisms of attentional competition. Participants were tested in three search conditions with constant target and distracter positions: Distracters did not share any feature with the target; distracters shared one feature with the target; two distracters shared one feature and one distracter shared the other feature with the target (mixed condition). Whereas search performance of healthy participants was comparable across conditions, neglect patients had a significant contralesional slowing in the mixed condition compared with the other two conditions. A detailed lesion analysis revealed that involvement of the parietal lobe did not predict the degree of distractibility in visual search. In contrast, neglect patients with high distractibility had more frequent damage to the inferior temporal lobe, suggesting a preliminary role of this region for competitive attentional processes involved in visual search of spatial neglect patients.
The Role of VMPC in Metamemorial Judgments of Content Retrievability
Authors: Schnyer David M. , Nicholls Lindsay , Verfaellie Mieke 
Published: April 2005

AbstractMaking judgments about the retrievability of information is a critical part of the metamemory processes engaged during remembering. A recent study of patients with frontal lesions suggests that ventral medial prefrontal cortex (VMPC) plays a critical role in such judgments [Schnyer, D. M., Verfaellie, M., Alexander, M. P., Lafleche, G., Nicholls, L., & Kaszniak, A. W. A role for right medial prefrontal cortex in accurate feeling of knowing judgments: Evidence from patients with lesions to frontal cortex. Neuropsychologia, 42, 957–966, 2004]. The observed impairment was thought to reflect an inability to determine the accessibility of memory contents. To further examine the neuroanatomical basis of content accessibility assessment, we used fMRI in an episodic feeling-of-knowing (FOK) paradigm. Participants were asked to make trial-by-trial predictions about the retrievability of the final word that completed studied sentences and then to select the correct completion from among alternatives. Results indicated that the VMPC is engaged during accurate FOK judgments and its activation is modulated by retrieval rating. Structural equations modeling supported the notion that VMPC, as part of a broader left hemisphere network involved in memory retrieval, monitors the output of the retrieval process. More generally, VMPC may participate in metacognitive processes that allow for the comparison of available data against an internal model.
Airborne Spectral Measurements of Ocean Directional Reflectance
Authors: Gatebe Charles K. , King Michael D. , Lyapustin Alexei I. , Arnold G. Thomas , Redemann Jens 
Published: April 2005

AbstractThe Cloud Absorption Radiometer (CAR) was flown aboard the University of Washington Convair 580 (CV-580) research aircraft during the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) field campaign and obtained measurements of bidirectional reflectance distribution function (BRDF) of the ocean in July and August 2001 under different illumination conditions with solar zenith angles ranging from 15° to 46°. The BRDF measurements were accompanied by concurrent measurements of atmospheric aerosol optical thickness and column water vapor above the airplane. The method of spherical harmonics with Cox–Munk wave-slope distribution is used in a new algorithm developed for this study to solve the atmosphere–ocean radiative transfer problem and to remove the effects of the atmosphere from airborne measurements. The algorithm retrieves simultaneously the wind speed and full ocean BRDF (sun’s glitter and water-leaving radiance) from CAR measurements and evaluates total albedo and equivalent albedo for the water-leaving radiance outside the glitter. Results show good overall agreement with other measurements and theoretical simulations, with the anisotropy of the water-leaving radiance clearly seen. However, the water-leaving radiance does not show a strong dependence on solar zenith angle as suggested by some theoretical studies. The spectral albedo was found to vary from 4.1%–5.1% at λ = 0.472 μm to 2.4%–3.5% for λ ≥ 0.682 μm. The equivalent water-leaving albedo ranges from 1.0%–2.4% at λ = 0.472 μm to 0.1%–0.6% for λ = 0.682 μm and 0.1%–0.3% for λ = 0.870 μm. Results of the validation of the Cox–Munk model under the conditions measured show that although the model reproduces the shape of sun’s glitter on average with an accuracy of better than 30%, it underestimates the center of the sun’s glitter reflectance by about 30% for low wind speeds (&lt;2–3 m s−1). In cases of high wind speed, the model with Gram–Charlier expansion seems to provide the best fit.
MISR Calibration and Implications for Low-Light-Level Aerosol Retrieval over Dark Water
Authors: Kahn Ralph , Li Wen-Hao , Martonchik John V. , Bruegge Carol J. , Diner David J. , Gaitley Barbara J. , Abdou Wedad , Dubovik Oleg , Holben Brent , Smirnov Alexander , Jin Zhonghai , Clark Dennis 
Published: April 2005

Abstract
Studying aerosols over ocean is one goal of the Multiangle Imaging Spectroradiometer (MISR) and other spaceborne imaging systems. But top-of-atmosphere equivalent reflectance typically falls in the range of 0.03 to 0.12 at midvisible wavelengths and can be below 0.01 in the near-infrared, when an optically thin aerosol layer is viewed over a dark ocean surface. Special attention must be given to radiometric calibration if aerosol optical thickness, and any information about particle microphysical properties, are to be reliably retrieved from such observations. MISR low-light-level vicarious calibration is performed in the vicinity of remote islands hosting Aerosol Robotic Network (AERONET) sun- and sky-scanning radiometers, under low aerosol loading, low wind speed, relatively cloud free conditions. MISR equivalent reflectance is compared with values calculated from a radiative transfer model constrained by coincident, AERONET-retrieved aerosol spectral optical thickness, size distribution, and single scattering albedo, along with in situ wind measurements. Where the nadir view is not in sun glint, MISR equivalent reflectance is also compared with Moderate Resolution Imaging Spectroradiometer (MODIS) reflectance. The authors push the limits of the vicarious calibration method’s accuracy, aiming to assess absolute, camera-to-camera, and band-to-band radiometry. Patterns repeated over many well-constrained cases lend confidence to the results, at a few percent accuracy, as do additional vicarious calibration tests performed with multiplatform observations taken during the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) campaign. Conclusions are strongest in the red and green bands, but are too uncertain to accept for the near-infrared. MISR nadir-view and MODIS low-light-level absolute reflectances differ by about 4% in the blue and green bands, with MISR reporting higher values. In the red, MISR agrees with MODIS band 14 to better than 2%, whereas MODIS band 1 is significantly lower. Compared to the AERONET-constrained model, the MISR aft-viewing cameras report reflectances too high by several percent in the blue, green, and possibly the red. Better agreement is found in the nadir- and the forward-viewing cameras, especially in the blue and green. When implemented on a trial basis, calibration adjustments indicated by this work remove 40% of a 0.05 bias in retrieved midvisible aerosol optical depth over dark water scenes, produced by the early postlaunch MISR algorithm. A band-to-band correction has already been made to the MISR products, and the remaining calibration adjustments, totaling no more than a few percent, are planned.
Diagnosis of Meridional Ozone Transport Based on Mass-Weighted Isentropic Zonal Means
Authors: Miyazaki Kazuyuki , Iwasaki Toshiki 
Published: April 2005

Abstract
A transport equation based on mass-weighted isentropic zonal means applies to the diagnosis for the meridional ozone transport in the troposphere and stratosphere. The mean and eddy ozone fluxes are estimated from the global distributions of the temperature, wind, and ozone.
In comparison with the conventional Eulerian mean and transformed Eulerian mean (TEM), the present diagnosis has advantages for the expression of eddy transport terms. The adiabatic eddy flux is separated from the diabatic eddy flux, which is parallel to the isentropic surface. The analysis shows that the eddy flux is almost adiabatic except that it is significantly affected by diabatic effects near the lower troposphere. Another advantage lies in the mean meridional transport. Although it is almost similar to the TEM, significant differences can be found near the Antarctic polar vortex due to nongeostrophic effects. Furthermore, the isentropic diagnosis expresses a strong equatorward flux near the lower boundary, while the TEM hardly does this because of inadequate treatment of the lower-boundary conditions.
The life cycle of ozone can be understood through the exact estimation of the transport terms. Although the stratospheric meridional transport is mainly performed by the Brewer–Dobson circulation, the strong poleward eddy ozone flux is caused by planetary wave breaking, especially in the winter hemisphere. In the extratropics, the ozone subsides from the stratosphere to the troposphere by mean downward motions, mainly diffused to the lower latitudes probably due to strong baroclinic waves and effectively lost through chemical processes in the lower troposphere.
EOS Terra Aerosol and Radiative Flux Validation: An Overview of the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) Experiment
Authors: Smith W. L. , Charlock T. P. , Kahn R. , Martins J. V. , Remer L. A. , Hobbs P. V. , Redemann J. , Rutledge C. K. 
Published: April 2005

Abstract
NASA developed an Earth Observing System (EOS) to study global change and reduce uncertainties associated with aerosols and other key parameters controlling climate. The first EOS satellite, Terra, was launched in December 1999. The Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) field campaign was conducted from 10 July to 2 August 2001 to validate several Terra data products, including aerosol properties and radiative flux profiles derived from three complementary Terra instruments: the Clouds and the Earth’s Radiant Energy System (CERES), the Multiangle Imaging Spectroradiometer (MISR), and the Moderate Resolution Imaging Spectroradiometer (MODIS). CERES, MISR, and MODIS are being used to investigate the critical role aerosols play in modulating the radiative heat budget of the earth–atmosphere system. CLAMS’ primary objectives are to improve understanding of atmospheric aerosols, to validate and improve the satellite data products, and to test new instruments and measurement concepts. A variety of in situ sampling devices and passive remote sensing instruments were flown on six aircraft to characterize the state of the atmosphere, the composition of atmospheric aerosols, and the associated surface and atmospheric radiation parameters over the U.S. eastern seaboard. Aerosol particulate matter was measured at two ground stations established at Wallops Island, Virginia, and the Chesapeake Lighthouse, the site of an ongoing CERES Ocean Validation Experiment (COVE) where well-calibrated radiative fluxes and Aerosol Robotic Network (AERONET) aerosol properties have been measured since 1999. Nine coordinated aircraft missions and numerous additional sorties were flown under a variety of atmospheric conditions and aerosol loadings. On one “golden day” (17 July 2001), under moderately polluted conditions with midvisible optical depths near 0.5, all six aircraft flew coordinated patterns vertically stacked between 100 and 65 000 ft over the COVE site as Terra flew overhead. This overview presents a description of CLAMS objectives, measurements, and sampling strategies. Key results, reported in greater detail in the collection of papers found in this special issue, are also summarized.
Characteristics of Landfalling Tropical Cyclones in the United States and Mexico: Climatology and Interannual Variability
Authors: Larson Joshua , Zhou Yaping , Higgins R. Wayne 
Published: April 2005

Abstract
The climatology and interannual variability of landfalling tropical cyclones and their impacts on precipitation in the continental United States and Mexico are examined. The analysis is based on National Hurricane Center 6-hourly tropical cyclone track data for the Atlantic and eastern Pacific basins and gridded daily U.S. precipitation data for the period August–October 1950–98. Geographic maps of total tropical cyclone strike days, and the mean and maximum percentage of precipitation due to tropical cyclones, are examined by month. To make the procedures objective, it is assumed that precipitation is symmetric about the storm’s center. While this introduces some uncertainty in the analysis, sensitivity tests show that this assumption is reasonable for precipitation within 5° of the circulation center.
The relationship between landfalling tropical cyclones and two leading patterns of interannual climate variability—El Niño–Southern Oscillation (ENSO) and the Arctic Oscillation (AO)—are then examined. Relationships between tropical cyclone frequency and intensity and composites of 200-hPa geopotential height and wind shear anomalies are also examined as a function of ENSO phase and AO phase using classifications devised at the Climate Prediction Center.
The data show that tropical cyclone activity in the Atlantic basin is modulated on both seasonal and intraseasonal time scales by the AO and ENSO and that impact of the two modes of climate variability is greater together than apart. This suggests that, during La Niña conditions, atmospheric circulation is more conducive to activity in the main development region during AO-positive conditions than during AO-negative ones and that, during El Niño conditions, atmospheric circulation appears even less conducive to tropical cyclone development during the negative phase of the AO than during the positive phase.
The Effect of Regional Climate Model Domain Choice on the Simulation of Tropical Cyclone–Like Vortices in the Southwestern Indian Ocean
Authors: Landman Willem A. , Seth Anji , Camargo Suzana J. 
Published: April 2005

Abstract
A regional climate model is tested for several domain configurations over the southwestern Indian Ocean to examine the ability of the model to reproduce observed cyclones and their landfalling tracks. The interaction between large-scale and local terrain forcing of tropical storms approaching and transiting the island landmass of Madagascar makes the southwestern Indian Ocean a unique and interesting study area. In addition, tropical cyclones across the southern Indian Ocean are likely to be significantly affected by the large-scale zonal flow. Therefore, the effects of model domain size and the positioning of its lateral boundaries on the simulation of tropical cyclone–like vortices and their tracks on a seasonal time scale are investigated. Four tropical cyclones, which occurred over the southwestern Indian Ocean in January of the years 1995–97, are studied, and four domains are tested. The regional climate model is driven by atmospheric lateral boundary conditions that are derived from large-scale meteorological analyses. The use of analyzed boundary forcing enables comparison with observed cyclones in these tests. Simulations are performed using a 60-km horizontal resolution and for an extended time integration of about 6 weeks. Results show that the positioning of the eastern boundary of the regional model domain is of major importance in the life cycle of simulated tropical cyclone–like vortices: a vortex entering through the eastern boundary of the regional model is generally well simulated. The size of the domain also has a bearing on the ability of the regional model to simulate vortices in the Mozambique Channel, and the island landmass of Madagascar additionally influences storm tracks. These results show that the regional model can produce cyclonelike vortices and their tracks (with some deficiencies) given analyzed lateral boundary forcing. Statistical analyses of GCM-driven nested model ensemble integrations are now required to further address predictive skill of cyclones in the southwestern Indian Ocean and to test if the model can realistically simulate tropical storm genesis as opposed to advecting existing tropical disturbances entering through the model boundaries.
A Method of Detecting Change in the Ice Conditions of the Central Greenland Sea by the Whelping Locations of Harp Seals
Authors: Wilkinson J. P. , Wadhams P. 
Published: April 2005

Abstract
Variations in the extent of sea ice within the Greenland Sea on daily, seasonal, or longer time scales are well documented, while changes in ice conditions are not. By combining historical information on the location and timing of the hunt for the whelping harp seal (Phoca groenlandica) with the ice conditions needed for the seals to give birth, details of the types, concentration, and extent of ice within the central Greenland Sea in winter have been determined for the mid- to late nineteenth century. These in turn have been compared to ice extent and concentration from the passive microwave era, as well as ice types from field work in the region. Results suggest that the ice conditions in the central Greenland Sea in the mid- to late nineteenth century were significantly different from those witnessed in recent decades. These differences manifest themselves not only in the extent of ice, but in ice types, concentration, and longevity of the ice cover. It is hypothesized that these changes could be due to an increase in both air temperature and wave energy, which is consistent with an increase in the strength and frequency of southerly and easterly winds during winter.
Mechanism of Interdecadal Thermohaline Circulation Variability in a Coupled Ocean–Atmosphere GCM
Authors: Dong Buwen , Sutton Rowan T. 
Published: April 2005

Abstract
Interdecadal variability of the Atlantic thermohaline circulation (THC) is studied in the third version of the Hadley Centre global coupled atmosphere–ocean sea-ice general circulation model (HadCM3). A diagnostic approach is used to elucidate the mechanism that governs the variability and its impacts on climate. An irregular and heavily damped THC oscillation with a period around 25 yr is identified. The oscillation appears to be forced by the atmosphere but the ocean is responsible for setting the time scale. Following a minimum in the THC, the mechanism for phase reversal involves the accumulation of cold water in the subpolar gyre, leading to an acceleration of the gyre circulation and the North Atlantic Current. This acceleration increases the transport of saline waters into the regions of active deep convection, raising the upper-ocean density and leading, after adjustment, to acceleration of the THC. The atmosphere stimulates this THC variability in two ways: 1) by forcing the subpolar gyre through (North Atlantic Oscillation) NAO-related wind stress curl and heat flux anomalies; and 2) by direct forcing of the region of active deep convection, also through wind stress curl and heat flux anomalies. The latter is not closely related to the NAO. The mechanism for phase reversal has many similarities to that found in a previous study with a much lower resolution coupled model, suggesting that this mechanism may be quite robust. However the time scale, and details of the atmospheric forcing, differ.
The THC variability in HadCM3 has significant impacts on the atmosphere not just in the Atlantic region but also more widely, throughout the global Tropics. The mechanism involves modulation by the THC of the cross-equator SST gradient in the tropical Atlantic. The SST anomalies induce a displacement of the ITCZ in the Atlantic basin with knock-on effects over the other ocean basins. These findings highlight the potential importance of the Atlantic THC as a cause of interdecadal climate variability on a global scale.