bluuebunny/crossref_metadata_2025_split huggingface dataset:
Splitting the S&P 500 futures
Authors: Chen Jianli , Locke Peter R. 
Published: October 2004

AbstractIn this paper we investigate the consequences of the Chicago Mercantile Exchange's 1997 redesign of the S&P 500 futures contract. The focus is on two important measures of exchange efficacy: member proprietary income and outside customer volume. Floor traders did not appear to benefit in their proprietary trading from the redesign—revenue fell after the contract split and doubling of the minimum tick. On the other hand, looking at relative volumes, it appears that customer volume was relatively constant, showing little sensitivity to the increase in tick size, possibly due to an increased use of limit orders by customers, bypassing floor traders. Through this redesign the futures exchange was apparently interested in preserving customer volume in an increasingly competitive index trading environment, not enhancing member noncompetitive proprietary trading revenue. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:1147–1163, 2004
Net buying pressure, volatility smile, and abnormal profit of Hang Seng Index options
Authors: Chan Kam C. , Cheng Louis T. W. , Lung Peter P. 
Published: October 2004

AbstractWe use the net buying pressure hypothesis of N. P. B. Bollen and R. Whaley (2004) to examine the implied volatilities, options premiums, and options trading profits at various time‐intervals across five different moneyness categories of Hong Kong Hang Seng Index (HSI) options. The results show that the hypothesis can well describe the newly developed Hong Kong index options markets. The abnormal trading profits by selling out‐of‐the‐money puts with delta hedge are statistically and economically significant across all options maturities. The findings are robust with or without outlier adjustment. Moreover, we provide two insights about the hypothesis. First, net buying pressure is attributed to hedging activities. Second, the net buying pressure on calls is much weaker than that on put options. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:1165–1194, 2004
Futures trading, spot market volatility, and market efficiency: The case of the Korean index futures markets
Authors: Bae Sung C. , Kwon Taek Ho , Park Jong Won 
Published: October 2004

AbstractWe examine the effect of the introduction of index futures trading in the Korean markets on spot price volatility and market efficiency of the underlying KOSPI 200 stocks, relative to the carefully matched non‐KOSPI 200 stocks. Employing both an event study approach and a matching‐sample approach for the market data during the period of January 1990–December 1998, we find that the introduction of KOSPI 200 index futures trading is associated with greater market efficiency but, at the same time, greater spot price volatility in the underlying stock market. We also find that KOSPI 200 stocks experience lower spot price volatility and higher trading efficiency than non‐KOSPI 200 stocks after the introduction of futures trading. The trading efficiency gap between the two groups of stocks, however, declines over time and vanishes following the addition of options trading. Overall, our results suggest that while futures trading in Korea increases spot price volatility and market efficiency, there exists volatility spillover to stocks against which futures are not traded. We provide several factors unique in the Korean markets including circuit breakers, sidercar system, restrictions on foreign ownership, and inactive program trading as potential factors to explain some of our puzzling evidence. We further consider the potential effect of changes in daily price limits utilized by the Korea Stock Exchange during the testing period on our empirical findings. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:1195–1228, 2004
Crossed cerebro–cerebellar language dominance
Authors: Jansen Andreas , Flöel Agnes , Van Randenborgh Jutta , Konrad Carsten , Rotte Michael , Förster Ann‐Freya , Deppe Michael , Knecht Stefan 
Published: October 2004

AbstractIn addition to its traditional role in motor control, the cerebellum has been implicated in various cognitive and linguistic functions. Lesion, anatomic, and functional imaging studies indicate a link between left frontal language regions and the right cerebellum. To probe the specificity of this circuit, we examined the association between language‐related lateralized activation of the frontal cortex with lateralized activation of the cerebellum. Functional magnetic resonance imaging (fMRI) was carried out during letter‐cued word generation in 14 healthy subjects: 7 subjects displayed typical left‐hemisphere and 7 subjects displayed atypical right‐hemisphere language dominance. We found activation of the cerebellar hemisphere contralateral to the language‐dominant cerebral hemisphere in each subject. The cerebellar activation was confined to the lateral posterior cerebellar hemisphere (lobule VI, VII B, Cr I, Cr II). This study demonstrates that crossed cerebral and cerebellar language dominance is a typical characteristic of brain organization. The functional significance of the reported activations can now be tested in patients with lesions of the lateral posterior cerebellum. Hum. Brain Mapp 24:165–172, 2005. © 2004 Wiley‐Liss, Inc.
Comparison of continuous overt speech fMRI using BOLD and arterial spin labeling
Authors: Kemeny Stefan , Ye Frank Q. , Birn Rasmus , Braun Allen R. 
Published: October 2004

AbstractOvert speech production in functional magnetic resonance imaging (fMRI) studies is often associated with imaging artifacts, attributable to both movement and susceptibility. Various image‐processing methods have been proposed to remove these artifacts from the data but none of these methods has been shown to work with continuous overt speech, at least over periods greater than 3 s. In this study natural, continuous, overt sentence production was evaluated in normal volunteers using both arterial spin labeling (ASL) and conventional echoplanar blood oxygenation level‐dependent (BOLD) imaging sequences on the same 1.5‐T scanner. We found a high congruency between activation results obtained with ASL and the de facto gold standard in overt language production imaging, positron emission tomography (PET). No task‐related artifacts were found in the ASL study. However, the BOLD data showed artifacts that appeared as large bilateral false‐positive temporopolar activations; percent signal change estimated in these regions showed signal increases and temporal dynamics that were incongruent with typical BOLD activations. These artifacts were not distributed uniformly, but were aligned at the frontotemporal base, close to the oropharynx. The calculated head movement parameters for overt speech blocks were within the range of the rest blocks, indicating that head movement is unlikely the reason for the artifact. We conclude that ASL is not influenced by overt speech artifacts, whereas BOLD showed significant susceptibility artifacts, especially in the opercular and insular regions, where activation would be expected. ASL may prove to be the method of choice for fMRI investigations of continuous overt speech. Hum. Brain Mapping 24:173–183, 2005. Published 2004 Wiley‐Liss, Inc.
Simulating daily soil water under foothills fescue grazing with the soil and water assessment tool model (Alberta, Canada)
Authors: Mapfumo Emmanuel , Chanasyk David S. , Willms Walter D. 
Published: October 2004

AbstractGrazing is common in the foothills fescue grasslands and may influence the seasonal soil‐water patterns, which in turn determine range productivity. Hydrological modelling using the soil and water assessment tool (SWAT) is becoming widely adopted throughout North America especially for simulation of stream flow and runoff in small and large basins. Although applications of the SWAT model have been wide, little attention has been paid to the model's ability to simulate soil‐water patterns in small watersheds. Thus a daily profile of soil water was simulated with SWAT using data collected from the Stavely Range Sub‐station in the foothills of south‐western Alberta, Canada. Three small watersheds were established using a combination of natural and artificial barriers in 1996–97. The watersheds were subjected to no grazing (control), heavy grazing (2·4 animal unit months (AUM) per hectare) or very heavy grazing (4·8 AUM ha−1). Soil‐water measurements were conducted at four slope positions within each watershed (upper, middle, lower and 5 m close to the collector drain), every 2 weeks annually from 1998 to 2000 using a downhole CPN 503 neutron moisture meter. Calibration of the model was conducted using 1998 soil‐water data and resulted in Nash–Sutcliffe coefficient (EF or R2) and regression coefficient of determination (r2) values of 0·77 and 0·85, respectively. Model graphical and statistical evaluation was conducted using the soil‐water data collected in 1999 and 2000. During the evaluation period, soil water was simulated reasonably with an overall EF of 0·70, r2 of 0·72 and a root mean square error (RMSE) of 18·01. The model had a general tendency to overpredict soil water under relatively dry soil conditions, but to underpredict soil water under wet conditions. Sensitivity analysis indicated that absolute relative sensitivity indices of input parameters in soil‐water simulation were in the following order; available water capacity > bulk density > runoff curve number > fraction of field capacity (FFCB) > saturated hydraulic conductivity. Thus these data were critical inputs to ensure reasonable simulation of soil‐water patterns. Overall, the model performed satisfactorily in simulating soil‐water patterns in all three watersheds with a daily time‐step and indicates a great potential for monitoring soil‐water resources in small watersheds. Copyright © 2004 John Wiley & Sons, Ltd.
Controls on effective settling velocities of mud flocs in the Changjiang Estuary, China
Authors: Shi Z. , Zhou H. J. 
Published: October 2004

AbstractTheoretical and experimental studies were undertaken to gain insight into physical parameters controlling the flocculation and settling properties of mud flocs in the Changjiang Estuary, China. The Rouse equation is applied to vertical profiles of suspended sediment concentration to determine the bulk mean settling velocity (ws) of sediment suspended in the Changjiang Estuary. Both in situ point‐sampled and acoustically measured profiles of suspended mud concentrations were fit selectively. The calculated settling velocities ws mainly ranged from 0·4 to 4·1 mm s−1 for the point‐sampled data set, and from 1·0 to 3·0 mm s−1 for the acoustically measured data set. Furthermore, the settling velocities of mud flocs increased with mean concentration (C̄) of mud flocs in suspension and were proportional to increasing bottom shear stress (τb) of tidal flow. The best equation for the field settling velocity of mud flocs in the Changjiang Estuary can be expressed by the power law: ws = mC̄n (m, 1·14–2·37; n, 0·84–1·03). It is suggested that C̄ and τb were the dominant physical parameters controlling the flocculation and ws of mud flocs in suspension. Copyright © 2004 John Wiley & Sons, Ltd.
Long‐term (18‐year) changes in sulphate concentrations in two Ontario headwater lakes and their inflows in response to decreasing deposition and climate variations
Authors: Eimers M. C. , Dillon P. J. , Watmough S. A. 
Published: October 2004

AbstractSulphate concentrations in two headwater lakes and their major inflows were evaluated over an 18 year period (1980–81 to 1997–98) during which time sulphate bulk deposition declined by approximately 40%. The two lake catchments represent either end of the spectrum of acid sensitivity in the Muskoka–Haliburton region of Ontario. Between 1980 and 1998, sulphate concentrations in Harp and Plastic Lakes decreased, but the decrease was much less than expected (28% and 21% respectively) given the magnitude of change in deposition. Sulphate export in streams draining into the lakes greatly exceeded sulphate input to catchments in most years, which quantitatively explains the response of lake‐sulphate concentration. Furthermore, temporal patterns in mean annual sulphate concentrations in streams were similar, and appeared to be related to climate factors. Specifically, catchment export of sulphate was greater and stream‐sulphate concentrations were higher in years that had warm, dry summers, i.e. when streamflow in many catchments ceased for up to several weeks. Increased sulphate export from catchments resulted in higher sulphate concentrations in lakes, but the response of lake sulphate was not as immediate or dramatic as the response of stream sulphate to changes in catchment dryness. Factors that affect sulphate retention or export in catchments exert a strong influence on sulphate concentrations in lakes and streams and need to be considered when evaluating the response of surface water chemistry to changes in sulphate deposition. Copyright © 2004 John Wiley & Sons, Ltd.
The application of an integrated biogeochemical model (PnET‐BGC) to five forested watersheds in the Adirondack and Catskill regions of New York
Authors: Chen Limin , Driscoll Charles T. , Gbondo‐Tugbawa Solomon , Mitchell Myron J. , Murdoch Peter S. 
Published: October 2004

AbstractPnET‐BGC is an integrated biogeochemical model formulated to simulate the response of soil and surface waters in northern forest ecosystems to changes in atmospheric deposition and land disturbances. In this study, the model was applied to five intensive study sites in the Adirondack and Catskill regions of New York. Four were in the Adirondacks: Constable Pond, an acid‐sensitive watershed; Arbutus Pond, a relatively insensitive watershed; West Pond, an acid‐sensitive watershed with extensive wetland coverage; and Willy's Pond, an acid‐sensitive watershed with a mature forest. The fifth was Catskills: Biscuit Brook, an acid‐sensitive watershed. Results indicated model‐simulated surface water chemistry generally agreed with the measured data at all five sites. Model‐simulated internal fluxes of major elements at the Arbutus watershed compared well with previously published measured values. In addition, based on the simulated fluxes, element and acid neutralizing capacity (ANC) budgets were developed for each site. Sulphur budgets at each site indicated little retention of inputs of sulphur. The sites also showed considerable variability in retention of NO3−. Land‐disturbance history and in‐lake processes were found to be important in regulating the output of NO3− via surface waters. Deposition inputs of base cations were generally similar at these sites. Various rates of base cation outputs reflected differences in rates of base cation supply at these sites. Atmospheric deposition was found to be the largest source of acidity, and cation exchange, mineral weathering and in‐lake processes served as sources of ANC. Copyright © 2004 John Wiley & Sons, Ltd.
Export mechanisms for dissolved organic carbon and nitrate during summer storm events in a glaciated forested catchment in New York, USA
Authors: Inamdar Shreeram P. , Christopher Sheila F. , Mitchell Myron J. 
Published: October 2004

AbstractNitrate and dissolved organic carbon (DOC) concentrations during a summer storm for a forested catchment in the Adirondack Mountains displayed a clear separation in trajectories and timing of maximum values. Nitrate concentrations peaked early on the rising limb of the hydrograph, whereas DOC concentrations gradually increased through the rising limb with maximum concentrations following the discharge peak. Solute data from precipitation, throughfall, soilwater, and ground/till water indicated till water and near‐surface soil waters as the controlling end members for stream NO3− and DOC concentrations respectively. Streamflow concentrations of major base cations (Ca2+ and Mg2+), which were assumed to represent water originating from deep flow paths, matched the NO3− trajectory. These data suggest that streamflow NO3− concentrations are derived from till groundwater and that DOC is derived from near‐surface soil waters. We attributed the early expression of NO3− to the displacement of till waters by infiltrating precipitation. In contrast, we hypothesized that the delayed DOC concentrations occurred with surface and near‐surface runoff from near‐stream wetlands/peatlands and isolated saturated areas that became connected only under conditions of maximum water content in the catchment. Copyright © 2004 John Wiley & Sons, Ltd.
The episodic acidification of a stream with elevated concentrations of dissolved organic carbon
Authors: Wellington Brian I. , Driscoll Charles T. 
Published: October 2004

AbstractOrganic acids are generally thought to play a minor role in the episodic acidification of streams in the USA. In this study, we investigated the episodic acidification of a stream at the Hubbard Brook Experimental Forest in New Hampshire with high concentrations of dissolved organic carbon and naturally occurring organic acids. We studied three events in 2001: spring snowmelt, which occurred from 6 April to 14 May and resulted in two distinct melt events; and two rain events, one on 17 June and the other on 17 July. During snowmelt events organic acids were a minor contributor to the short‐term acidification of stream water, with increases in NO3− and dilution of base cations being the dominant mechanisms. During summer rainfall events, however, increases in inputs of organic acids were the dominant mechanism of episodic acidification when soil water was the dominant contributor to stream discharge (59 to 66% of peak stream discharge). We also found that precipitation events occurring after relatively wet antecedent conditions (17 July event) resulted in more severe acid episodes than events that followed drier antecedent conditions (17 June event). The minimum acid neutralizing capacity (ANC) was only −19 µeq l−1 for the 17 June event, whereas the minimum ANC for the 17 July event was much lower (−62 µeq l−1) although the total rainfall amount was similar for the two events. Copyright © 2004 John Wiley & Sons, Ltd.
Comparison of nitrogen solute concentrations within alder (Alnus incana ssp. rugosa) and non‐alder dominated wetlands
Authors: Hurd Todd M. , Raynal Dudley J. 
Published: October 2004

AbstractThis study examined differences in nitrogen solutes and groundwater flow patterns between a riparian wetland dominated by the N2‐fixing shrub, Alnus incana ssp. rugosa, and an upstream coniferous forested riparian wetland along a stream of the Adirondack Mountains, where some surface waters are susceptible to nitrogen excess. Channel water NO3− was up to 16 µmol l−1 greater in the alder reach, with peaks following maxima in groundwater dissolved inorganic nitrogen (DIN). NO3− at 25 cm depth was 30 µmol greater in the alder than in the conifer reach in April, and 24 µmol l−1 greater than channel water and 30 µmol l−1 greater than that of 125 cm groundwater in June. Dissolved organic nitrogen and NH4+ concentrations increased between 25 and 75 cm depths in both wetlands during the growing season. Inorganic nitrogen increased between the hillslope and stream in both wetlands, with the greatest increases in the alder reach during the dormant season. Greatest subsurface DIN (120 µmol l−1) occurred at 75 cm in the alder reach, within 1 m of the stream, between November (120 µmol l−1 NH4+) and a January thaw (60 µmol l−1 each of NH4+ and NO3−). Concentrations of deeper groundwater at 125 cm during this period were lower (10–30 µmol l−1). Lateral flow from the stream channel occurred in the alder reach during the dormant season, and channel water contribution to groundwater was correlated strongly to NO3− at 25 cm. These results indicate that nitrification is stimulated in the presence of alders and oxidized exchange flow, producing NO3− that may contribute to elevated channel water NO3− during periods of peak flow. Copyright © 2004 John Wiley & Sons, Ltd.
Evaluating the source of streamwater nitrate using δ15N and δ18O in nitrate in two watersheds in New Hampshire, USA
Authors: Pardo Linda H. , Kendall Carol , Pett‐Ridge Jennifer , Chang Cecily C. Y. 
Published: October 2004

AbstractThe natural abundance of nitrogen and oxygen isotopes in nitrate can be a powerful tool for identifying the source of nitrate in streamwater in forested watersheds, because the two main sources of nitrate, atmospheric deposition and microbial nitrification, have distinct δ18O values. Using a simple mixing model, we estimated the relative fractions in streamwater derived from these sources for two forested watersheds with markedly different streamwater nitrate outputs. In this study, we monitored δ15N and δ18O of nitrate biweekly in atmospheric deposition and in streamwater for 20 months at the Hubbard Brook Experimental Forest, New Hampshire, USA (moderate nitrogen export), and monthly in streamwater at the Bowl Research Natural Area, New Hampshire, USA (high nitrogen export). For rain, δ18O values ranged from +47 to +77‰ (mean: +58‰) and δ15N from −5 to +1‰ (mean: −3‰); for snow, δ18O values ranged from +52 to +75‰ (mean: +67‰) and δ15N from −3 to +2‰ (mean: −1‰). Streamwater nitrate, in contrast to deposition, had δ18O values between +12 and +33‰ (mean: +18‰) and δ15N between −3 and +6‰ (mean: 0‰). Since nitrate produced by nitrification typically has δ18O values ranging from −5 to +15‰, our field data suggest that most of the nitrate lost from the watersheds in streamflow was nitrified within the catchment. Our results confirm the importance of microbial nitrogen transformations in regulating nitrogen losses from forested ecosystems and suggest that hydrologic storage may be a factor in controlling catchment nitrate losses. Copyright © 2004 John Wiley & Sons, Ltd.
Regionalization of disturbance‐induced nitrogen leakage from mid‐Appalachian forests using a linear systems model
Authors: Eshleman Keith N. , Fiscus Daniel A. , Castro Nancy M. , Webb James R. , Herlihy Alan T. 
Published: October 2004

AbstractThe ‘leakage’ of nitrate‐nitrogen (nitrate‐N) to surface waters is a common (but not universal) response of forest ecosystems to both human‐induced and natural disturbances. There are several reported examples of the transient leakage of nitrate‐N to surface waters from eastern US forests that have sustained outbreaks of defoliating insects, such as the introduced gypsy moth (Lymantria dispar) larva. Previous research has suggested that annual nitrate‐N leakage from disturbed forests can be modelled using an empirically derived unit nitrogen export response function (UNERF) model. The model represents annual nitrate‐N export as a linear deterministic process in both space and time and is analogous to a unit hydrograph. The goal of the present study was to verify and apply a regionalized, lithology‐based UNERF model that references the geographic distribution of bedrock class and the timing and extent of gypsy moth defoliation of forests in the non‐glaciated highlands of the Chesapeake Bay watershed. Despite an inability to verify the model for most individual watersheds within the study area, the model was able to reproduce the statistical distribution of annual nitrate‐N export to streams that comprised our target population. During water year 1991 (the year following peak defoliation) the model results indicated that regional annual nitrate‐N export had transiently increased by nearly 1500% from a baseline rate of about 0·1 kg ha−1to a peak value approaching 1·5 kg ha−1. We thus conclude that natural vegetation disturbance is an important mechanism by which dissolved nitrogen is leaked from forested lands to small streams, rivers, and Chesapeake Bay. The present study also illustrates how simple, empirically derived linear systems approaches like the UNERF model can be successfully applied to problems where regionalization is a primary goal. Copyright © 2004 John Wiley & Sons, Ltd.