bluuebunny/crossref_metadata_2025 huggingface dataset:
Early exposure to lead and neuropsychological outcome in adolescence
Authors: RIS M. DOUGLAS , DIETRICH KIM N. , SUCCOP PAUL A. , BERGER OMER G. , BORNSCHEIN ROBERT L.
Published: March 2004

One hundred and ninety-five participants in the Cincinnati Lead Study were neuropsychologically evaluated in mid-adolescence. The neuropsychological measures yielded five factors labeled Memory, Learning/IQ, Attention, Visuoconstruction, and Fine-Motor. Prenatal, Average Childhood, and 78 month blood lead (PbB) levels were used in a series of multiple regression analyses. Following rigorous covariate pretesting and adjustment, a significant main effect of 78 month PbB on the Fine-Motor factor was found (p< .004). Significant interactions were also found between gender and lead exposure parameters for both Attention and Visuoconstruction indicating heightened risk in males. Finally, a trend toward significance was found for the PbB × SES interaction for Learning/IQ, consistent with previous evidence of increased educational and cognitive vulnerability for youth from more disadvantaged backgrounds. These results provide new evidence from the longest continuing prospective study of the remote effects of early lead exposure. They indicate the presence of selective neuropsychological effects in this population, and also that males and females are not uniformly affected. These results also underscore the complexity of models of neurobehavioral development, and the modest predictive power of any single determinant. (JINS, 2004,10, 261–270.)
Assessing cognitive outcomes in a rural African population: Development of a neuropsychological battery in Kilifi District, Kenya
Authors: HOLDING PENNY A. , TAYLOR H. GERRY , KAZUNGU SIDI D. , MKALA THADEAUS , GONA JOSEPH , MWAMUYE BERNARD , MBONANI LEONARD , STEVENSON JIM
Published: March 2004

The ability to measure neuropsychological outcomes in a comparable manner in different cultural groups is important if studies conducted in geographically diverse regions are to advance knowledge of disease effects and moderating influences. The purpose of this study was to evaluate the application of neuropsychological test procedures developed for use in North America and Europe to children in a rural region of Kenya. Our specific aim was to determine if these methods could be adapted to a non-Western culture in a manner that would preserve test reliability and validity. Procedural modifications yielded reliable tests that were sensitive to both the sequelae of cerebral malaria and to children's social and school backgrounds. Results suggest that adaptations of existing tests can be made in such a way as to preserve their utility in measuring the cross-cultural sequelae of childhood neurological diseases. (JINS, 2004,10, 246–260.)
Neuropsychological deficits in patients with chronic fatigue syndrome
Authors: BUSICHIO KIM , TIERSKY LANA A. , DELUCA JOHN , NATELSON BENJAMIN H.
Published: March 2004

The degree of neuropsychological dysfunction across multiple domains was examined in individuals suffering from chronic fatigue syndrome (CFS). In this descriptive study, a similar series of neuropsychological tests was administered to a group of CFS patients and healthy participants. More specifically, CFS patients (n= 141) who met the 1994 Case Definition criteria were compared to 76 healthy control participants on tests of memory, attention (concentration), speed of information processing, motor speed, and executive functioning. On the 18 measures administered, CFS patients scored 1 standard deviation below the healthy mean on nine measures and scored 2 standard deviations below the healthy mean on four of the measures. Moreover, results indicated that CFS patients were more likely than healthy controls to fail (1.6SDbelow the healthy mean) at least one test in each of the following domains: attention, speed of information processing, and motor speed, but not on measures of memory and executive functioning. Finally, CFS patients demonstrated a greater total number of tests failed across domains. (JINS, 2004,10, 278–285.)
Reliability and validity of the Delis-Kaplan Executive Function System: An update
Authors: DELIS DEAN C. , KRAMER JOEL H. , KAPLAN EDITH , HOLDNACK JAMES
Published: March 2004

A critical endeavor in every health-related field is the continued development of new technologies and instrumentation for improving diagnosis and treatment. For example, the field of neuroimaging has made astonishing advances with procedures such as functional MRI, MR spectroscopy, and MR diffusion tensor imaging. The field of neuropsychology has also recognized the importance of continually striving to develop new, more sensitive clinical measures. At the same time, the development of new tests or procedures does not guarantee that the instruments represent improvements in diagnosis or treatment. For this reason, ongoing studies of reliability and validity of new diagnostic instruments are also an important part of research in all health-related fields.
EXPECTATIONS-DRIVEN FLUCTUATIONS WHEN FACTOR UTILIZATION IS VARIABLE
Authors: PINTUS PATRICK A.
Published: March 2004

The present paper studies the influence of variable labor utilization on local indeterminacy and expectations-driven fluctuations, in one-sector models with (nearly) constant returns to scale. It is shown that, in comparison to the configuration of constant input utilization, considering variable utilization reduces the actual possibilities of factor substitution and, consequently, the range of input substitution elasticities that are compatible with endogenous fluctuations. In particular, local indeterminacy and expectations-driven fluctuations occur only if utilization rates are sufficiently inelastic, whereas local determinacy prevails when utilization is highly elastic. However, accounting for the fact that variable utilization reduces theeffectiveelasticity of capital/labor substitution leads us to argue that expectations-driven fluctuations are more plausible because they require larger elasticities ofapparentinput substitution. In contrast with the recent literature, the analysis does not rely on significantly increasing returns to scale in production. Accordingly, the results are not at variance with recent empirical studies emphasizing the importance of variable utilization and denying the evidence of large increasing returns.
SIGNAL EXTRACTION AND NON-CERTAINTY-EQUIVALENCE IN OPTIMAL MONETARY POLICY RULES
Authors: SWANSON ERIC T.
Published: March 2004

A standard result in the literature on monetary policy rules is that of certainty-equivalence: Given the expected values of the state variables of the economy, policy should be independent of all higher moments of those variables. Some exceptions to this rule have been pointed out in the literature, including restricting the policy response to a limited subset of state variables, or to estimates of the state variables that are biased. In contrast, this paper studies fully optimal policy rules with optimal estimation of state variables. The rules in this framework exhibit certainty-equivalence with respect to estimates of an unobserved state variable (“excess demand”)X, but are not certainty-equivalent when (i)Xmust be estimated by signal extraction and (ii) the optimal rule is expressed as a reduced form that combines policymakers' estimation and policy-setting stages. I find that it is optimal for policymakers to attenuate their reaction to a variable about which uncertainty has increased, while responding more aggressively to variables about which uncertainty has not changed.
Polymorphism, Heteroplasmy, Mitochondrial Fusion and Diabetes
Authors: Sato Aya , Endo Hitoshi , Umetsu Kazuo , Sone Hideyuki , Yanagisawa Yoshiko , Saigusa Azusa , Aita Sayuri , Kagawa Yasuo
Published: March 2004

Mitochondrial DNA (mtDNA) is highly susceptible to mutations that result in polymorphisms and diseases including diabetes. We analyzed heteroplasmy, polymorphisms related to diabetes, and complementation by fusogenic proteins. Cytoplast fusion and microinjection allow, defects in mutated mtDNA inside a heteroplasmic cell to be complemented by fusing two mitochondria via human fusogenic proteins. We characterized three hfzos as well as two OPA1s that prevent apoptosis. Two coiled coil domains and GTPase domains in these fusogenic proteins regulate membrane fusion. The hfzo genes were expressed mainly in the brain and in muscle that are postmitotic, but not in the pancreas. Under the in.uence of polymorphisms of mtDNA and nDNA, the vicious circle of reactive oxygen species and mutations in cell can be alleviated by mitochondrial fusion.
Mesozooplankton community respiration and its relation to particle flux in the oligotrophic eastern Mediterranean
Authors: Koppelmann Rolf , Weikert Horst , Halsband‐Lenk Claudia , Jennerjahn Tim
Published: March 2004

Organic carbon flux and zooplankton carbon consumption rates were measured in the deep water of the eastern Mediterranean. Standardized carbon consumption rates of zooplankton were higher than rates measured in the deep open ocean, probably due to the elevated temperature of ∼14°C in the bathypelagic zone of the eastern Mediterranean. The absolute rates, however, were very low, reflecting the oligotrophic character of the basin. Zooplankton were estimated to consume 23% of the sinking flux between 1050 m and 4250 m. Owing to the high temperature in the Levantine deep‐sea, however, the carbon losses from the sinking flux calculated by the Martin equation are probably underestimated, and higher total losses may occur. Lucicutia longiserrata, an intrinsic faunal element in the deep Levantine Sea, played a significant role in carbon recycling. The increased recycling efficiency of pelagic organisms in the bathypelagic zone possibly facilitates starvation of the benthos in the nutrient‐poor Levantine Basin.
Shell weights from the South Atlantic
Authors: Broecker W. S. , Clark Elizabeth
Published: March 2004

As part of our ongoing evaluation of the shell weight proxy, measurements were carried out on plankton species from South Atlantic cores. The results portray a complex picture. Whereas ideally these weights should be influenced only by surface water carbonate ion concentration (growth weight) and deep water pressure‐normalized carbonate ion concentration (extent of weight loss due to dissolution), it appears that other environmental factors may influence growth weight and that variable pore water ‐ bottom water offsets may complicate the extent of dissolution.
Paleomagnetic results from the Newer Volcanics of Victoria: Contribution to the Time Averaged Field Initiative
Authors: Opdyke Neil D. , Musgrave Robert
Published: March 2004

The Newer Volcanics of Victoria Australia were sampled in 2001 and 2003 as part of the Time Averaged Field Initiative which is designed to provide a reliable data set for modeling the Earth's magnetic field over the past 5 My. The collection consisted of ten cores per site at 42 sites. Complete demagnetization was carried out on all samples using AF or thermal demagnetization and line fitting techniques were employed to determine the resultant vector. Thirty‐two of these sites gave results that met the criterion that N ≥ 5, and α95 was less than 6°. 20 sites were reversely magnetized, Dec = 173.4°, Inc. = 54.6°, α95 = 3.8° and 13 normally magnetized, Dec = 2.1°, Inc = −62.3°, α95 = 6.3°. The data gave a global mean paleomagnetic pole (lat. 87.2°, long. 21.9° and A95 = 4.4°) which is not significantly different from the pole of rotation for the present location of Victoria and for its latitude 2.5 million years ago when most of the lavas were erupted.
A significant abiotic pathway for the formation of unknown nitrogen in nature
Authors: Jokic A. , Schulten H.‐R. , Cutler J. N. , Schnitzer M. , Huang P. M.
Published: March 2004

The global nitrogen cycle is of prime importance in natural ecosystems. However, the origin and nature of up to one‐half of total soil N remains obscure despite all attempts at elucidation. Our data provide, for the first time, unequivocal evidence that the promoting action of Mn (IV) oxide on the Maillard reaction (sugar‐amino acid condensation) under ambient conditions results in the abiotic formation of heterocyclic N compounds, which are often referred to as unknown nitrogen, and of amides which are apparently the dominant N moieties in nature. The information presented is of fundamental significance in understanding the role of mineral colloids in abiotic transformations of organic N moieties, the incorporation of N in the organic matrix of fossil fuels, and the global N cycle.
Uptake of reactive nitrogen on cirrus cloud particles during INCA
Authors: Ziereis H. , Minikin A. , Schlager H. , Gayet J. F. , Auriol F. , Stock P. , Baehr J. , Petzold A. , Schumann U. , Weinheimer A. , Ridley B. , Ström J.
Published: March 2004

The uptake of reactive nitrogen species on ice crystals in cirrus clouds was investigated by simultaneous aircraft‐based measurements of gas‐ and condensed‐phase NOy, ice particle size distribution and total aerosol surface area. The measurements were performed in 2000 during the INCA campaign at northern and southern midlatitudes at local autumn. Cirrus ice particles were frequently encountered during these flights in the upper troposphere. Concurrently with the occurrence of cirrus ice particles particulate NOy was observed. It was found that the coverage of the cirrus ice particles with particulate NOy strongly depends on the temperature and the gas‐phase NOy concentration. A substantial coverage of the ice particles with values larger than one percent of a monolayer was observed only for temperatures below about 217 K. On average only about one percent of the available gas‐phase NOy was found as particulate NOy.
Coupling instrumental and geological records of sea‐level change: Evidence from southern New England of an increase in the rate of sea‐level rise in the late 19th century
Authors: Donnelly Jeffrey P. , Cleary Peter , Newby Paige , Ettinger Robert
Published: March 2004

We construct a high‐resolution relative sea‐level record for the past 700 years by dating basal salt‐marsh peat samples above a glacial erratic in an eastern Connecticut salt marsh, to test whether or not the apparent recent acceleration in the rate of sea‐level rise (SLR) is coeval with climate warming. The data reveal an average SLR rate of 1.0 ± 0.2 mm/year from about 1300 to 1850 A.D. Coupling of the regional tide‐gauge data (1856 to present) with this marsh‐based record indicates that the nearly three‐fold increase in the regional rate of SLR to modern levels likely occurred in the later half of the 19th century. Thus the timing of the observed SLR rate increase is coincident with the onset of climate warming, indicating a possible link between historic SLR increases and recent temperature increases.
Trace gas emissions from biomass burning inferred from aerosol optical depth
Authors: Paton‐Walsh Clare , Jones Nicholas , Wilson Stephen , Meier Arndt , Deutscher Nicholas , Griffith David , Mitchell Ross , Campbell Susan
Published: March 2004

We have observed strong correlations between simultaneous and co‐located measurements of aerosol optical depth and column amounts of carbon monoxide, hydrogen cyanide, formaldehyde and ammonia in bushfire smoke plumes over SE Australia during the Austral summers of 2001/2002 and 2002/2003. We show how satellite‐derived aerosol optical depth maps may be used in conjunction with these correlations to determine the total amounts of these gases present in a fire‐affected region. This provides the basis of a method for estimating total emissions of trace gases from biomass burning episodes using visible radiances measured by satellites.
Ocean bottom pressure waves predicted in the tropical Pacific
Authors: Song Y. Tony , Zlotnicki Victor
Published: March 2004

Using a mass‐conserving (non‐Boussinesq) Pacific Ocean model and TOPEX/POSEIDON sea‐surface height measurements, we document previously unreported bottom pressure waves (BPWs), associated with large‐amplitude eddies (vortices) both north and south of the Equator. The bottom pressure signals, defined as the vertically integrated water‐mass anomalies, are found to propagate westward across the Pacific Ocean with an approximate 4‐mbar amplitude (1 mbar = 100 Newton/m2, approximately equivalent to 1 cm of sea surface height), continuously interacting with topographic features. Their wavelength is about 1100 kilometers, phase speed is about 0.5 m/s, and period is about 30‐days, all consistent with the known properties of tropical instability waves (TIWs). These results suggest that the constantly evolving tropical instability eddies might have strong bottom pressure signals, therefore, likely alias the U.S.‐German Gravity Recovery and Climate Experiment (GRACE) measurements, which have a monthly‐sampling period.
Observational evidence of pitch angle isotropization by IMF waves
Authors: Saul L. , Möbius E. , Smith C. W. , Bochsler P. , Grünwaldt H. , Klecker B. , Ipavich F.
Published: March 2004

A statistical analysis of interstellar He+ pickup ion measurements from SOHO/CTOF combined with magnetic field data from WIND/MFI enable quantitative study of wave‐particle interactions in the inner heliosphere for the first time. Magnetic field vector measurements with a time resolution of 3 seconds are used to determine power spectrum characteristics of interplanetary magnetic turbulence. These spectral characteristics are then compared in superposed epoch and correlation analyses with He+ fluxes and spectra. The observed pickup ion velocity distributions can be explained consistently as a consequence of pitch angle scattering of the interstellar pickup ions by Alfvénic fluctuations.
Industrial CO2 emissions as a proxy for anthropogenic influence on lower tropospheric temperature trends
Authors: de Laat A. T. J. , Maurellis A. N.
Published: March 2004

Surface temperature trends during the last two decades show a significant increase which appears to be anthropogenic in origin. We investigate global temperature changes using surface as well as satellite measurements and show that lower tropospheric temperature trends for the period 1979–2001 are spatially correlated to anthropogenic surface CO2 emissions, which we use as a measure of industrialization. Furthermore, temperature trends for the regions not spatially correlated with these CO2 emissions are considerably smaller or even negligible for some of the satellite data. We also show, using the same measure, that two important climate models do not reproduce the geographical climate response to all known forcings as found in the observed temperature trends. We speculate that the observed surface temperature changes might be a result of local surface heating processes and not related to radiative greenhouse gas forcing.
Kinetic Study of the OH‐isoprene and O3‐isoprene reaction in the atmosphere simulation chamber, SAPHIR
Authors: Karl M. , Brauers Th. , Dorn H.‐P. , Holland F. , Komenda M. , Poppe D. , Rohrer F. , Rupp L. , Schaub A. , Wahner A.
Published: March 2004

Kinetic studies conducted in the new atmosphere simulation chamber SAPHIR at the Research Center Jülich allow a thorough investigation of oxidation of isoprene induced by O3 and the OH radical under atmospheric conditions. Rate coefficients for the O3‐isoprene and OH‐isoprene reaction are determined from measured concentration‐time profiles. For the reaction of O3 with isoprene the rate coefficient is determined to be (9.6 ± 0.7) × 10−18 cm3molecule−1 s−1 at 286 K. The rate coefficient for the reaction OH + isoprene is (10.0 ± 1.2) × 10−11 cm3molecule−1 s−1 at 294 K. The kinetic parameters determined in SAPHIR at atmospheric concentrations agree well with recent recommendations.
A different perspective for the Mars rover “Opportunity” site: Fine‐grained, consolidated hematite and hematite coatings
Authors: Kirkland L. E. , Herr K. C. , Adams P. M.
Published: March 2004

Since 2001, there have been two, parallel interpretations of Mars Global Surveyor Thermal Emission Spectrometer (TES) observations of Sinus Meridiani, which are: (1) coarse‐grained (“gray”) hematite is the only spectral match; and (2) fine‐grained hematite with particles closer than ∼wavelength (“fine‐intimate hematite”, e.g., coating, ferricrete) is a better match, but coarse hematite is also viable. The TES team interpreted the spectra as consistent only with a large deposit (∼750 km × 350 km) of coarse hematite (>5–10 μm grain size). Coarse hematite is considered strong evidence for longstanding water, which led to the decision to land the rover Opportunity there. On the other hand, the Aerospace/LPI remote sensing team argued that fine‐intimate hematite can better match TES spectra. A thin coating (∼5–10 μm thick) and a low exposure (<5%) could cause the observed signatures. The distinction is important because: (1) It is unknown whether fine‐grained hematite implies abundant water; (2) Fine‐intimate hematite may explain the non‐detection of coexisting aqueous alteration minerals and the lack of hematite wind streaks; (3) Current “hematite abundance maps” may instead map the surface texture; (4) Coatings may be of astrobiology interest; (5) Studies are needed to determine whether visible‐infrared spectra can definitively distinguish fine‐intimate from coarse hematite.
A thermodynamical model for rainfall‐triggered volcanic dome collapse
Authors: Matthews Adrian J. , Barclay Jenni
Published: March 2004

Dome‐forming volcanic eruptions typically involve the slow extrusion of viscous lava onto a steep‐sided volcano punctuated by collapse and the generation of hazardous pyroclastic flows. We show an unequivocal link between the onset of intense rainfall and lava dome collapse on short time scales (within a few hours) and develop a simple thermodynamical model to explain this behavior. The model is forced with rainfall observations from the Soufrière Hills Volcano, Montserrat, and suggests that when the dome is in a critical state, a minimum rainfall rate of approximately 15 mm hr−1 for 2–3 hr could trigger a dome collapse.
Current‐driven instabilities in forced current sheets
Authors: Sitnov M. I. , Lui A. T. Y. , Guzdar P. N. , Yoon P. H.
Published: March 2004

The nonlocal kinetic linear stability analysis of the non‐Harris thin current sheet equilibrium, namely the thin current sheet embedded in a thicker anisotropic plasma sheet [Sitnov et al., 2000a, 2000b], with respect to current‐driven instabilities is performed using the finite element technique. In contrast to the Harris sheet, the new equilibrium becomes possible due to the plasma anisotropy outside the sheet caused by two warm counterstreaming field‐aligned beams and complex ion orbits that cannot be described in such thin current sheets in terms of the conventional magnetic moment. It is found that in contrast to the case of the Harris sheet, the analogs of the drift‐kink instability in these current sheets can have significant growth rates for the realistic ion‐to‐electron mass and temperature ratios. The unstable modes share the properties with both the lower‐hybrid and drift‐kink modes. In particular, the unstable modes resemble the lower‐hybrid drift modes as they are more highly structured across the sheet than the drift‐kink instability (DKI) and assume both odd (DKI‐like) and even parity solutions. On the other hand, in contrast to the lower‐hybrid drift instability (LHDI) and like the DKI, the unstable modes have much larger wavelength, electromagnetic component, and significantly perturb the central current region. The possible role of the current‐driven instabilities in magnetic reconnection and magnetic annihilation as well as the geophysical implications such as the current disruption in the geomagnetotail during substorms are also discussed.
Total pressure variations in the magnetotail as a function of the position and the substorm magnitude
Authors: Yamaguchi R. , Kawano H. , Ohtani S. , Kokubun S. , Yumoto K.
Published: March 2004

The present study investigates the energy storage and release processes of substorms as a function of both position and substorm intensity in a model‐independent manner. As an index of the substorm intensity, we use the amplitude of the positive bay observed at middle and low latitudes. As an index of the energy storage and release in the magnetotail, we use the total pressure measured by Geotail. We have performed a superposed epoch analysis of the total pressure for each substorm group binned in terms of the position and the substorm intensity. We have found that (1) both the magnitude and the increasing rate of the total pressure (i.e., energy density) in the near‐tail region (−15 RE < XGSM < −6 RE and −8 RE < YGSM <8 RE) are highly correlated with the substorm intensity, while those in the midtail (−25 RE < XGSM < −15 RE and −10 RE < YGSM <10 RE) are not correlated with the substorm intensity. We have also found that (2) the start of the energy release of small substorms in the near‐tail region tends to be delayed from the first Pi2 onset.
Differential velocity between solar wind protons and alpha particles in pressure balance structures
Authors: Yamauchi Yohei , Suess Steven T. , Steinberg John T. , Sakurai Takashi
Published: March 2004

Pressure balance structures (PBSs) are a common high‐plasma beta feature in high‐latitude, high‐speed solar wind. They have been proposed as remnants of coronal plumes. If true, they should reflect the observation that plumes are rooted in unipolar magnetic flux concentrations in the photosphere and are heated as oppositely directed flux is advected into and reconnects with the flux concentration. A minimum variance analysis (MVA) of magnetic discontinuities in PBSs showed there is a larger proportion of tangential discontinuities than in the surrounding high‐speed wind, supporting the hypothesis that plasmoids or extended current sheets are formed during reconnection at the base of plumes. To further evaluate the character of magnetic field discontinuities in PBSs, differential streaming between alpha particles and protons is analyzed here for the same sample of PBSs used in the MVA. Alpha particles in high‐speed wind generally have a higher radial flow speed than protons. However, if the magnetic field is folded back on itself, as in a large‐amplitude Alfvén wave, alpha particles will locally have a radial flow speed less than protons. This characteristic is used here to distinguish between folded back magnetic fields (which would contain rotational discontinuities) and tangential discontinuities using Ulysses high‐latitude, high‐speed solar wind data. The analysis indicates that almost all reversals in the radial magnetic field in PBSs are folded back field lines. This is found to also be true outside PBSs, supporting existing results for typical high‐speed, high‐latitude wind. There remains a small number of cases that appear not to be folds in the magnetic field and which may be flux tubes with both ends rooted in the Sun. The distinct difference in MVA results inside and outside PBSs remains unexplained.
Effects of normal stress variation on the strength and stability of creeping faults
Authors: Boettcher M. S. , Marone C.
Published: March 2004

A central problem in studies of fault interaction and earthquake triggering is that of quantifying changes in frictional strength and the constitutive response caused by dynamic stressing. We imposed normal stress vibrations on creeping laboratory shear zones to investigate the process of dynamic weakening and the conditions under which resonant frictional behavior occurs. Layers of quartz powder were sheared at room temperature in a double‐direct shear geometry at normal stress n = 25–200 MPa, vibration amplitude A = 0.1–10 MPa, period T = 0.1–200 s, and loading rate V = 1–1000 μm/s. Frictional response varied systematically with A, T, and V. Small‐amplitude, short‐period vibrations had no effect on frictional strength, but large‐amplitude, short‐period vibrations reduced shear zone strength by about 1%. Intermediate periods caused phase lags between shear strength and imposed vibrations. During long‐period vibrations, frictional strength varied sinusoidally, in phase with vibrations and with an amplitude consistent with a constant coefficient of friction. Our data show that friction exhibits a critical vibration period, as predicted by theory. At long periods, the Dieterich (aging) friction law, with the Linker and Dieterich modification to describe step changes in normal stress, provides a good fit to our experimental results for all A and V. At short periods, however, theory predicts more dynamic weakening than we observed experimentally, suggesting that existing rate and state friction laws do not account for the full physics of our laboratory experiments. Our data show that normal‐force vibrations can weaken and potentially destabilize steadily creeping fault zones.
Salinity estimation using the T‐S relation in the context of variational data assimilation
Authors: Han Guijun , Zhu Jiang , Zhou Guangqing
Published: March 2004

A salinity adjustment scheme using statistics of the temperature‐salinity (T‐S) relationship is proposed in the framework of variational data assimilation. The scheme not only considers the mean T‐S diagram but also takes the variance of the T‐S relations into consideration. To test performance of the scheme, a 1‐D mixed layer model of the Mellor‐Yamada type and a conductivity‐temperature‐depth (CTD) data set in the western tropical Pacific are used in two experiments. The CTD data set contains intensive temperature and salinity observations. In the experiments, first, the mean T‐S diagram and its variance are obtained from temperature and salinity observations over the assimilation period; then, temperature and salinity profiles are adjusted by minimizing a cost function that contains four terms: the temperature observation term, the background terms for both temperature and salinity, and a term measuring the distance between the salinity and the inferred salinity from the temperature via the mean T‐S diagram. A simpler scheme, which first adjusts the temperature profile by assimilating temperature data and then replaces the model salinity profile using the mean T‐S diagram and the newly updated temperature profile, is also tested for comparison. The proposed scheme shows good skill in reconstructing salinity variations at most levels and performs slightly better than the simpler scheme with overall improvements of 4–10%. The applicability of the method is also discussed.
Climate response to the increase in tropospheric ozone since preindustrial times: A comparison between ozone and equivalent CO2 forcings
Authors: Mickley L. J. , Jacob D. J. , Field B. D. , Rind D.
Published: March 2004

We examine the characteristics of the climate response to anthropogenic changes in tropospheric ozone. Using a general circulation model, we have carried out a pair of equilibrium climate simulations with realistic present‐day and preindustrial ozone distributions. We find that the instantaneous radiative forcing of 0.49 W m−2 due to the increase in tropospheric ozone since preindustrial times results in an increase in global mean surface temperature of 0.28°C. The increase is nearly 0.4°C in the Northern Hemisphere and about 0.2°C in the Southern Hemisphere. The largest increases (>0.8°C) are downwind of Europe and Asia and over the North American interior in summer. In the lower stratosphere, global mean temperatures decrease by about 0.2°C due to the diminished upward flux of radiation at 9.6 μm. The largest stratospheric cooling, up to 1.0°C, occurs over high northern latitudes in winter, with possibly important implications for the formation of polar stratospheric clouds. To identify the characteristics of climate forcing unique to tropospheric ozone, we have conducted two additional climate equilibrium simulations: one in which preindustrial tropospheric ozone concentrations were increased everywhere by 18 ppb, producing the same global radiative forcing as present‐day ozone but without the heterogeneity; and one in which CO2 was decreased by 25 ppm relative to present day, with ozone at present‐day values, to again produce the same global radiative forcing but with the spectral signature of CO2 rather than ozone. In the first simulation (uniform increase of ozone), the global mean surface temperature increases by 0.25°C, with an interhemispheric difference of only 0.03°C, as compared with nearly 0.2°C for the heterogeneous ozone increase. In the second simulation (equivalent CO2), the global mean surface temperature increases by 0.36°C, 30% higher than the increase from tropospheric ozone. The stronger surface warming from CO2 is in part because CO2 forcing (obscured by water vapor) is shifted relatively poleward where the positive ice‐albedo feedback amplifies the climate response and in part because the magnitude of the CO2 forcing in the midtroposphere is double that of ozone. However, we find that CO2 is far less effective than tropospheric ozone in driving lower stratospheric cooling at high northern latitudes in winter.
Halogenated greenhouse gases at the Swiss High Alpine Site of Jungfraujoch (3580 m asl): Continuous measurements and their use for regional European source allocation
Authors: Reimann Stefan , Schaub Daniel , Stemmler Konrad , Folini Doris , Hill Matthias , Hofer Peter , Buchmann Brigitte , Simmonds Peter G. , Greally Brian R. , O'Doherty Simon
Published: March 2004

At the high Alpine site of Jungfraujoch (3580 m asl), 23 halogenated greenhouse gases are measured quasi‐continuously by gas chromatography‐mass spectrometry (GCMS). Measurement data from the years 2000–2002 are analyzed for trends and pollution events. Concentrations of the halogenated trace gases, which are already controlled in industrialized countries by the Montreal Protocol (e.g., CFCs) were at least stable or declining. Positive trends in the background concentrations were observed for substances which are used as CFC‐substitutes (hydrofluorocarbons, hydrochlorofluorocarbons). Background concentrations of the hydrofluorocarbons at the Jungfraujoch increased from January 2000 until December 2002 as follows: HFC 134a (CF3CH2F) from 15 to 27 ppt, HFC 125 (CF3CHF2) from 1.4 to 2.8 ppt, and HFC 152a (CHF2CH3) from 2.3 to 3.2 ppt. For HFC 152a, a distinct increase of its concentration magnitude during pollution events was observed from 2000 to 2002, indicating rising European emissions for this compound. Background concentrations of all measured compounds were in good agreement with similar measurements at Mace Head, Ireland. On the other hand, peak concentrations were significantly higher at the Jungfraujoch. This finding is due to the proximity to potent European sources, foremost in southern Europe. The average ratio of halocarbons versus carbon monoxide (CO) concentrations above their baseline values was used to estimate source strengths for the part of Europe which most influences the Jungfraujoch during pollution events. HFCs emission estimates from Jungfraujoch tend to be higher than figures at Mace Head (Ireland) from the end of the 1990s, which either reflects the increased use of these compounds or the closer location of Jungfraujoch to major southern European sources. Transport of polluted European boundary layer air masses to the high Alpine site was observed especially during frontal passages, foehn events, and thermal lifting of air masses in summer. The measurement data during the periods when the Jungfraujoch was under the influence of the polluted boundary layer were used in combination with concurrent air mass trajectories to allocate above baseline halocarbon concentrations to specific European source regions.
A high‐resolution simulation of a West African rainy season using a regional climate model
Authors: Gallée H. , Moufouma‐Okia W. , Bechtold P. , Brasseur O. , Dupays I. , Marbaix P. , Messager C. , Ramel R. , Lebel T.
Published: March 2004

The regional climate model Modèle Atmosphérique Régional (MAR) is applied to West Africa and the year 1992 is simulated. MAR reproduces the observed intraseasonal variations of rainfall. It is suggested that such a phenomenon is associated with oscillations between a weak and a strong regime of the Hadley cell. The later is correlated with a stronger meridional gradient of moist static energy in the planetary boundary layer and is responsible for an enhanced convergence of this quantity and a subsequent increase of convection and rain. An enhanced consumption of moist static energy and finally a weakening of the meridional circulation result. The meridional gradient of the moist static energy is restored by surface processes. The model also simulates the observed abrupt northward shift of the rainband in the first half of July. The spatial variability of the simulated monthly mean rainfall is in good agreement with the observations, although the model overestimates rainfall in some places from the beginning of August. Time series of daily mean rainfall are averaged over two 2.5° × 2.5° grid meshes in the Niamey region and in the Ouémé high valley. Maxima reaching up to 40 mm/day are found in both areas, as in the observations. Atmospheric variables such as temperature and wind are briefly compared with the European Center for Medium‐Range Weather Forecasting reanalyses. The main (cold) biases are located where the hydrological cycle simulated by MAR is too strong.
Validation of the MODIS global land surface albedo product using ground measurements in a semidesert region on the Tibetan Plateau
Authors: Wang Kaicun , Liu Jingmiao , Zhou Xiuji , Sparrow Michael , Ma Min , Sun Zhian , Jiang Wenhua
Published: March 2004

An evaluation of the Moderate‐Resolution Imaging Spectroradiometer (MODIS) global land surface albedo product is essential for its use in scientific studies. We evaluate the accuracy of the albedo product with nearly 3 years (from January 2001 to July 2003) of ground measurements from the Gaize Automatic Weather Station (32.30°N, 84.06°E, 4420 m) on the western Tibetan Plateau. The land surface consists of semidesert or desert soil. Vegetation in this region is very rare. A comparison with field measurements shows that the MODIS global land surface albedo meets an absolute accuracy requirement of 0.02. There is no distinctive bias between the MODIS‐derived albedo and the ground‐measured albedo, with a root‐mean‐square error of 0.0186 and a maximum error of 0.036.
Radiative forcing by aerosols over the Bay of Bengal region derived from shipborne, island‐based, and satellite (Moderate‐Resolution Imaging Spectroradiometer) observations
Authors: Vinoj V. , Babu S. Suresh , Satheesh S. K. , Moorthy K. , Kaufman Y. J.
Published: March 2004

Measurements of spectral aerosol optical depths (AODs) were made over the Bay of Bengal region (adjacent to the Indian landmass) on board the oceanographic research vessel Sagar Kanya during February 2003. Simultaneous measurements of spectral AODs and mass concentrations of the composite aerosols and aerosol black carbon (BC) were made at an island location, Port Blair (11.63°N, 92.71°E), also in the Bay of Bengal. At the cruise locations the AODs were in the range of ∼0.3–0.6 at 500 nm (with a mean value of 0.41 ± 0.14) and Angstrom wavelength exponent of ∼1.1 ± 0.1; while at Port Blair the AODs were in the range of 0.11–0.48 at 500 nm and Angstrom wavelength exponent of 0.98 ± 0.07. Aerosol BC constituted 5.8 ± 0.6% of the composite aerosol mass concentration with a single‐scattering albedo of ∼0.88, indicating the presence of a significant amount of submicron absorbing aerosols. Comparisons of AODs measured at Port Blair during cruise 188 and an earlier cruise (cruise 161B) during March 2001 (over the Bay of Bengal, Arabian Sea, and Indian Ocean) with those derived from Moderate‐Resolution Imaging Spectroradiometer (MODIS) (on board the TERRA platform) showed excellent agreement with a mean difference of ∼0.01 and a root‐mean‐square difference of ∼0.03. Regionally averaged aerosol (net) forcing over the Bay of Bengal was in the range −15 to −24 W m−2 at the surface and −2 to −4 W m−2 at the top of the atmosphere in February 2003; these values were smaller in magnitude than those observed over this region during March 2001 and larger than that observed over the Arabian Sea and the Indian Ocean. The resulting atmospheric heating due to aerosol absorption was ∼0.5°K/d.
Adaptive linear prediction of radiation belt electrons using the Kalman filter
Authors: Rigler E. J. , Baker D. N. , Weigel R. S. , Vassiliadis D. , Klimas A. J.
Published: March 2004

Prior studies have examined the time‐stationary (and quasi‐stationary) dynamic response of relativistic electrons in the Earth's outer radiation belt to changes in solar wind bulk speed using linear prediction filters [Baker et al., 1990; Vassiliadis et al., 2002]. For this study, we have implemented an adaptive system identification scheme, based on the Kalman filter with process noise, to determine optimal time‐dependent electron response functions. The nonlinear dynamic response of the radiation belts can then be tracked in time by recursively updating the optimal linear filter coefficients as new observations become available. We demonstrate a significant improvement in zero‐time‐lag electron log‐flux “predictions” relative to models that are based on time‐stationary linear prediction filters, while incurring only a slight increase in computational complexity. We conclude by discussing modifications necessary for an operational specification and forecast model, including the assimilation of real‐time data, more sophisticated model structures, and a more practical gridded description of the radiation belt state.
Lessons From the U.S. Meteorological Public‐Private Sector Services Partnership
Authors: Fisher Genene
Published: March 2004

Together, the NOAA Space Environment Center (SEC) and private sector vendors need to develop mechanisms for communicating their future development needs and for defining their evolving partnership. While the SEC does hold an annual vendors meeting and continues to foster relationships within the space weather industry, there are additional steps it can take.
A large self‐potential anomaly and its changes on the quiet Mt. Fuji, Japan
Authors: Aizawa Koki
Published: March 2004

Self‐potential (SP) surveys were carried out on Mt. Fuji volcano, Japan, and an intense positive anomaly (about 2000 mV) was found in the summit area. The positive SP anomaly was stable on 2001 and 2002, but increased 150 mV in amplitude on September 12, 2003, and suddenly decreased 300 mV two weeks later. This amplitude change coincides with the emergence of the fumaroles, which appeared for the first time in 40 years, on the east‐northeast flank 6 km apart from the summit. The SP anomaly is thought to be of electrokinetic origin. These results strongly suggest that an active hydrothermal system exists beneath the summit of the apparently quiet Mt. Fuji, and its activity control the emergence of fumaroles.
The Women's Movement in Serbia and Montenegro at the Turn of the Millennium: A Sociological Study of Women's Groups
Authors: Milić Andjelka
Published: March 2004

This paper attempts to describe the present situation in the women's movement in Serbia and Montenegro and to tackle questions about its future, on the basis of a sociological study of newly formed women's groups. In the past, the women's movement in these societies has surged several times, only to be completely annulled, and its proponents falling to oblivion. Now, for the first time ever, the seeds of the movement originating from the long gone period of the socialist regime in Yugoslavia have survived the turmoil of disintegration and wars, and are germinating as women's groups and networks spring up alongside are being formed. The crucial task for the future will be strengthening this fragile and diffused network structure and laying down solid foundations for a movement with proper institutional mechanisms on a nation/state level. This investigation examined the prerequisites for this: firstly by examining the visibility and distinguishing features of women's groups and their activities in their current local environment; and secondly, by assessing activists’ clear acceptance of feminist (and their groups’) self-determination, which confront existing social attitudes towards feminist identities. In both respects, considerable advances towards a broader and clearer recognition of the aims and essence of women's groups’ activities are identified, in spite of the ever-present traditional and ideological resistance to this type of women's engagement.
Coverture in Lebanon
Authors: Shehadeh Lamia Rustum
Published: March 2004

The principle of coverture in Lebanon is defined and examined through a study of the Christian personal status codes. While these do not necessarily reflect the social status of women, they remain highly discriminatory against women in the legal realm. This is seen as the result of archaic laws, the patriarchal social order, and the strong influence of Islam. No change is seen as possible without an attempt at the unification of all personal status codes and their modification or replacement with a uniform civil law to provide absolute gender equality.
Wife Abuse in the Countries of the Former Yugoslavia
Authors: Ćopić Sanja
Published: March 2004

This paper contains some of the most important results obtained from surveys on domestic violence in Serbia and Macedonia, as well as from a survey on violence against women in the Federation of Bosnia and Herzegovina. These surveys have confirmed the results of other research showing that wife abuse is one of the most serious yet at the same time most hidden forms of victimization. It represents the manifestation of power and control over the victim, leading to a loss of trust and a threat to safety. Bearing that in mind, the aim of this paper is to examine the prevalence, structure and some features of wife abuse in the post-war societies of the former Yugoslavia, based on an analysis of the results of these surveys, with particular emphasis on the impact of the economic crisis and war on this phenomenon.
Hostages of Destiny: Gender Issues in Today's Poland
Authors: Platek Monika
Published: March 2004

In an e-mail of June 2002, some women on Gender Link noticed that in Polish there is an expression, ‘husband of trust’, used to describe a person in the workplace appointed to represent workers’ interests. This role is more often than not given to women, and yet they are called ‘husbands of trust’. ‘Isn't that strange,’ they said. ‘Isn't it time to change this?’. It is. The change in gender role identities has started with questioning the language. It has started with asking who has produced and is reproducing the language, and for whom. The journey has not stopped there. From looking at language it has continued through social stereotypes, work, labour, money and the division of power, and reached the law and legal system itself. In Poland, the path has been rather circuitous and uneasy for we are, more than many other countries, bound by Catholic tradition mingled with apparent freedom. We had the ethos of Solidarity, and Lech Wałęsa. Wałęsa had a badge of the Virgin Mary, Mother of Jesus on his jacket, which somehow helped label all Polish women, even those still very young, a ‘Mother Pole’. To resist that identity one needed to look beneath the image and be brave enough to call oneself just a woman. This article will try to analyse that process.