bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neuromuscular quadriceps dysfunction prior to osteoarthritis of the knee
Authors: Becker Roland , Berth Alexander , Nehring Markus , Awiszus Friedemann 
Published: February 2004

AbstractDecreased maximal quadriceps strength and voluntary activation has been observed in patients with osteoarthritis in previous studies, but those results do not allow any conclusions to be drawn as to whether quadriceps dysfunction precedes or follows osteoarthritis. Thirty‐two patients (group a) who underwent partial meniscectomy 48 ± 9 month prior to the study were matched according to their weight and body mass index with a control group (group b). The twitch interpolation technique was used to determine maximal voluntary contraction (MVC) and voluntary activation (VA) of the quadriceps muscle of both legs. Subjective assessment of the knee was performed using the Lysholm‐Score. AP and lateral X‐rays of the operated knee were obtained. None of the participants showed any evidence of characteristic radiological or clinical signs for osteoarthritis. A significantly lower MVC was noticed in both the affected and the contralateral knee of group a in comparison to group b (p < 0.01). The VA in group a yielded 80.9 ± 15.4% for the injured side and 83.1 ± 11.5% for the contralateral side, with no statistical difference (p = 0.18). The VA in group b was 89.4 ± 5.8% for the right side and 88 ± 6.8% for the left side both being significantly higher in comparison to group a.This study has shown, that patients following meniscus resection present with bilateral quadriceps weakness as already described in patients with manifest osteoarthritis. The authors hypothesise that muscle dysfunction may be an etiologic factor underlying the pathologic changes of osteoarthritis. Whether muscle dysfunction occurs also at other sites, e.g. in the upper extremity, remains unclear but would be of interest in order to detect a generalized neuromuscular dysfunction. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Social Networks and Homelessness Among Women Heads of Household
Authors: Toohey Siobhan M. , Shinn Marybeth , Weitzman Beth C. 
Published: February 2004

AbstractTo examine possible bidirectional relationships between homelessness and deficient social networks, we compared the networks of 251 mothers before, and approximately 5 years after, their families entered shelters with networks of 291 consistently housed poor mothers. At Time 1, more women on the verge of homelessness than housed women reported that they had mothers, grandmothers, friends, and relatives but fewer believed these network members were housing resources. At Time 2, after homeless women were rehoused, these network differences between consistently housed and formerly homeless women had largely disappeared. Contrary to prior research findings, formerly homeless mothers did not report smaller networks, more children or fewer partners. However, formerly homeless women did report fewer positive functions. Because of city policies, homeless mothers were frequently rehoused far from network members.
Asking, Witnessing, Interpreting, Knowing: Conducting Qualitative Research in Community Psychology
Authors: Stein Catherine H. , Mankowski Eric S. 
Published: February 2004

AbstractWe present a framework to describe the process of conducting community‐based qualitative research. Qualitative research activities are presented as a series of interrelated acts called asking, witnessing, interpreting, and knowing. Each act in the research process is described in terms of current qualitative research practices, and illustrated with examples from our own research projects on families with schizophrenia and men's mutual support and batterer intervention groups. We critically examine the assumption that qualitative research serves to reveal or amplify the voices of participants. We examine connections between qualitative research and social change and describe the use of qualitative research to not only empower marginalized groups, but also to critique and transform privileged groups. The framework is intended to help community researchers to more fully conceptualize, understand, and engage in the practice of qualitative research.
Adolescent Coping and Neighborhood Violence: Perceptions, Exposure, and Urban Youths' Efforts to Deal with Danger
Authors: Rasmussen Andrew , Aber Mark S. , Bhana Arvinkumar 
Published: February 2004

AbstractNeighborhood violence is a persistent source of danger, stress, and other adverse outcomes for urban youth. We examined how 140 African American and Latino adolescents coped with neighborhood danger in low, medium, and high crime neighborhoods throughout Chicago. Participants reported using a range of coping strategies (measured via a modified version of the Ways of Coping Scale; R. S. Lazarus & S. Folkman, 1984). In low and medium crime rate areas, using confrontive strategies was significantly correlated with increased exposure to violence, and no strategies were associated with perceptions of safety. Coping strategies were associated with perceived safety to a substantial degree only in high crime neighborhoods, and none were associated with exposure to violence. A k means cluster analysis identified groups that differed in coping profiles and varied in rates of exposure to violence. Moderating effects of gender, ethnicity, and neighborhood were found for both person level and variable level analyses.
The determination of interplanetary magnetic field polarities around sector boundaries using E > 2 keV electrons
Authors: Kahler S. , Lin R. P. 
Published: February 2004

The determination of the polarities of interplanetary magnetic fields (whether the field direction is outward from or inward toward the sun) has been based on a comparison of observed field directions with the nominal Parker spiral angle. These polarities can be mapped back to the solar source field polarities. This technique fails when field directions deviate substantially from the Parker angle or when fields are substantially kinked. We introduce a simple new technique to determine the polarities of interplanetary fields using E > 2 keV interplanetary electrons which stream along field lines away from the sun. Those electrons usually show distinct unidirectional pitch‐angle anisotropies either parallel or anti‐parallel to the field. Since the electron flow direction is known to be outward from the sun, the anisotropies parallel to the field indicate outward‐pointing, positive‐polarity fields, and those anti‐parallel indicate inward‐pointing, negative‐polarity fields.We use data from the UC Berkeley electron experiment on the ISEE‐3 spacecraft to compare the field polarities deduced from the electron data, Pe (outward or inward), with the polarities inferred from field directions, Pd, around two sector boundaries in 1979. We show examples of large (>100°) changes in azimuthal field direction Φ over short (<1 hr) time scales, some with and some without reversals in Pe. The latter cases indicate that such large directional changes can occur in unipolar structures. On the other hand, we found an example of a change in Pe during which the rotation in Φ was < 30°, indicating polarity changes in nearly unidirectional structures. The field directions are poor guides to the polarities in these cases.
Observation and modeling of North Atlantic Deep Water Formation and its variability: Introduction
Authors: Stocker Thomas F. , Broecker Wallace S. 
Published: February 2004

This Special Section is the result of a 2‐day miniconference held at Lamont‐Doherty Earth Observatory in November 1991. The purpose of that meeting was to review the current knowledge of North Atlantic Deep Water (NADW) formation and to discuss the role of the global circulation it sets up in the climate system [Broecker, 1991]. The present collection of papers, however, goes beyond the original scope of the meeting and is more up‐to‐date than a mere proceedings volume.To obtain data on the formation and circulation of the deep water by classical Oceanographic observation methods is a difficult task. It is therefore necessary to try to fill the various gaps in knowledge by combining information from observations with what we can learn from an entire hierarchy of numerical models. This philosophy was behind the 1991 miniconference [Stocker and Broecker, 1992] and is also reflected in this special section. Although the degree of interaction must continue to increase, such meetings are valuable starting points for a closer communication between modelers and those collecting and producing the data which is so crucial for model validation. It is the purpose of this special section to make a contribution towards this aim.
SIMMAX: A modern analog technique to deduce Atlantic sea surface temperatures from planktonic foraminifera in deep‐sea sediments
Authors: Pflaumann Uwe , Duprat Josette , Pujol Claude , Labeyrie Laurent D. 
Published: February 2004

We present a data set of 738 planktonic foraminiferal species counts from sediment surface samples of the eastern North Atlantic and the South Atlantic between 87°N and 40°S, 35°E and 60°W including published Climate: Long‐Range Investigation, Mapping, and Prediction (CLIMAP) data. These species counts are linked to Levitus's [1982] modern water temperature data for the four caloric seasons, four depth ranges (0, 30, 50, and 75 m), and the combined means of those depth ranges. The relation between planktonic foraminiferal assemblages and sea surface temperature (SST) data is estimated using the newly developed SIMMAX technique, which is an acronym for a modern analog technique (MAT) with a similarity index, based on (1) the scalar product of the normalized faunal percentages and (2) a weighting procedure of the modern analog's SSTs according to the inverse geographical distances of the most similar samples. Compared to the classical CLIMAP transfer technique and conventional MAT techniques, SIMMAX provides a more confident reconstruction of paleo‐SSTs (correlation coefficient is 0.994 for the caloric winter and 0.993 for caloric summer). The standard deviation of the residuals is 0.90°C for caloric winter and 0.96°C for caloric summer at 0‐m water depth. The SST estimates reach optimum stability (standard deviation of the residuals is 0.88°C) at the average 0– to 75‐m water depth. Our extensive database provides SST estimates over a range of −1.4 to 27.2°C for caloric winter and 0.4 to 28.6°C for caloric summer, allowing SST estimates which are especially valuable for the high‐latitude Atlantic during glacial times.An electronic supplement of this material may be obtained on adiskette or Anonymous FTP from KOSMOS.AGU.ORG. (LOGIN toAGU's FTP account using ANONYMOUS as the username and GUESTas the password. Go to the right directory by typing CD APPEND. TypeLS to see what files are available. Type GET and the name of the file toget it. Finally type EXIT to leave the system.) (Paper 95PA01743,SIMMAX: A modern analog technique to deduce Atlantic sea surfacetemperatures from planktonic foraminifera in deep‐sea sediments, UwePflaumann, Josette Duprat, Claude Pujol, and Laurent D. Labeyrie).Diskette may be ordered from American Geophysical Union, 2000Florida Avenue, N.W., Washington, DC 20009; Payment mustaccompany order.
Suborbital timescale variability of North Atlantic Deep Water during the past 200,000 years
Authors: Oppo Delia W. , Lehman Scott J. 
Published: February 2004

We generated ∼200‐kyr‐long proxy records of surface and deepwater variability from a subpolar North Atlantic core (V29–202), enabling us to assess the linkage between surface and deepwater changes on suborbital timescales. In particular, we used a benthic δ13C record to evaluate the deep water response to Dansgaard‐Oeschger temperature oscillations and to Heinrich events, times of massive iceberg delivery to the North Atlantic. We found that the reduction of North Atlantic Deep Water (NADW) production was generally associated with cold or dropping sea surface temperatures (SSTs) as indicated by planktonic foraminiferal assemblages. The NADW contribution to the site did not drop appreciably during Heinrich events H4 through H2, probably because these events followed intervals of prolonged surface cooling already characterized by low rates of NADW production. By contrast NADW reduction appears to have been synchronous with H5. SST rise associated with both Dansgaard‐Oeschger oscillations and Heinrich events was usually accompanied by increasing NADW strength. In a few cases the NADW recovery appeared to lag the SST rise; however, the apparent delay is most likely an artefact of the sedimentary record (low concentrations of benthic foraminifera). As a result of low benthic foraminiferal abundances during stage 6, the stage 6 benthic foraminiferal δ13C record is of lower resolution than the younger part of the record. The stage 6 proxy records for surface hydrography nevertheless reveal millennial‐scale oscillations similar to those seen in stage 3. The available δ13C data suggest that NADW weakened in association with the cold portions of stage 6 SST oscillations. We also sought to confirm a recent study which concluded that there was little NADW variability during the peak of the last interglaciation, marine oxygen isotope substage 5e (Eemian). Isotope stage 5 was marked by a trend of increasing benthic δ13C in V29‐202. Rising δ13C through isotope stage 5 is also seen in tropical surface water records and at some deep Atlantic sites and may reflect the common derivation of these water masses. Variations of ≥ 0.5 ‰ superimposed on this rising δ13C trend within substage 5e in V29‐202 are so far not evident in tropical feed waters and may therefore indicate that NADW production was weaker during the late than mid‐Eemian.An electronic supplement of this material may be obtained on a diskette or Anonymous FTP from KOSMOS.AGU.ORG. (LOGIN to AGU's FTP account using ANONYMOUS as the username and GUEST as the password. Go to the right directory by typing CD APEND. Type LS to see what files are available. Type GET and the name of the file to get it. Finally, type QUIT to leave the system.) (Paper 95PA02089, Suborbital timescale variability of North Atlantic Deep Water during the past 200,000 years, by D. W. Oppo and S. J. Lehman) Diskette may be ordered from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, DC 20009; $15.00. Payment must accompany order.
Reconstructing the stable isotope geochemistry and paleotemperatures of the equatorial Atlantic during the last 150,000 years: Results from individual foraminifera
Authors: Billups Katharina , Spero Howard J. 
Published: February 2004

This study represents an attempt to extract paleoclimatic data from the deep‐sea record by analyzing foraminiferal shells individually. Using the oxygen (δ18O) and carbon (δ13C) isotopic composition of individual Orbulina universa and Neogloboquadrina dutertrei, we present an approach to reconstruct the δ18O of seawater (δ18Ow), the δ13C of ΣCO2, and seasonal maximum sea surface temperatures (SST) in the western and eastern equatorial Atlantic. We examine the glacial and interglacial extremes of the last 150,000 years (isotope stages 1, 2, 5e, and 6). Comparison of recent water column hydrography with reconstructions from core top assemblages shows that O. universa and N. dutertrei δ18O and δ13C values accurately record hydrographic conditions in the mixed layer and upper thermocline at both sites. By analyzing shells individually, we can evaluate the effect of bioturbation on the range of δ18O and δ13C values in each interval and take it into consideration in our data interpretations. Downcore results show that N. dutertrei δ18O values in the western equatorial Atlantic reflect glacial to interglacial changes in δ18Ow due to continental ice formation (Δδ18O=1.30 ‰). We use changes in N. dutertrei δ18O values between core intervals to estimate the ice‐volume effect in paleotemperature calculations for the mixed layer. To validate the use of O. universa for mixed layer reconstructions, we have added individual Globigerinoides sacculifer data for stages 1 and 2 at both sites. Paleotemperature reconstructions from O. universa δ18O values indicate that maximum seasonal mixed layer temperatures in the equatorial Atlantic decreased by at most 2.6°C between isotope stages 1 and 2 and by no more than 3.4°C between stages 1 and 6. Individual shell data from G. sacculifer yield similar results indicating that maximum O. universa δ18O values reflect the mixed layer environment. In agreement with Climate: Long‐Range Investigation, Mapping, and Prediction (CLIMAP) [1981] SST reconstructions for stage 2, these data indicate little change between glacial and interglacial paleotemperatures in the equatorial Atlantic.An electronic supplement of this material may be obtainedon a diskette or Anonymous FTP from KOSMOS.AGU.ORG.(LOGIN to AGU's FTP account using ANONYMOUS as theusername and GUEST as the password. Go to the rightdirectory by typing CD APEND. Type LS to see what files areavailable. Type GET and the name of the file to get it.Finally, type EXIT to leave the system.) (Paper 95PA03773,Reconstructing the stable isotope geochemistry andpaleotemperatures of the equatorial Atlantic during the last150,000 years: Results from individual foraminifera,Katharina Billups and Howard J. Spero). Diskette may beordered from American Geophysical union, 2000 FloridaAvenue, N. W., Washington, DC 20009; $15.00. Paymentmust accompany order.
Recent advances in simulation‐optimization groundwater management modeling
Authors: Wagner Brian J. 
Published: February 2004

In recent years, the aquifer simulation model has been combined with techniques of optimization to address important groundwater management problems. The combined simulation and optimization model accounts for the complex behavior of the groundwater system and identifies the best management strategy under consideration of the management objectives and constraints. Simulation‐optimization groundwater management models have been developed for a variety of applications, such as restoration of contaminated groundwater, control of aquifer hydraulics, allocation of ground and surface water resources, and evaluation of groundwater policies [see reviews by Gorelick, 1983, 1990; Yeh, 1992; Ahlfeld and Heidari, 1994; Bredehoeft et al, 1994].Gorelick [1983] divides groundwater management models into three categories: groundwater hydraulic management, groundwater quality management, and groundwater policy evaluation and allocation. This review focuses in detail on the recent advances made in groundwater hydraulic and groundwater quality management modeling, which encompasses most of the aquifer management work done in the past four years. For a review of recent research in groundwater policy evaluation and allocation, see Bredehoeft et al. [1994].
Crustal magnetic anomalies
Authors: Raymond Carol A. , Blakely Richard J. 
Published: February 2004

This Quadrennial Report departs in format from its predecessors. Earlier reports provided brief descriptions of the entire range of topics on “crustal magnetic anomalies.” Following guidelines established by the AGU, we instead focus our discussion on only a few selected topics. Our abbreviated list of references reflects this restricted focus. A more comprehensive bibliography can be obtained from the authors as noted subsequently.The past quadrennium was distinguished by a significant change in the scale and scope of crustal magnetic anomaly research. Advances in instrumentation, navigation, and data processing techniques resulted in increasing use of two‐dimensional anomaly maps rather than profile data. Although maps are commonly used in aeromagnetic studies of continental areas, their use in the ocean basins has been limited until recently. The other important change has been a trend towards increased integration of magnetic anomaly data with gravity, seismic, geochemical, remote sensing, and geologic data to enhance the interpretation and reduce the ambiguity of magnetic field data.
Reply I to “VAN: Candidacy and validation with the latest laws of the game,” by F. Mulargia and P. Gasperini and “Precursor candidacy and validation: The VAN Case so far,” by F. Mulargia and P. Gasperini
Authors: Varotsos P. , Eftaxias K. , Lazaridou M. 
Published: February 2004

In this first part of our reply to the two papers by Mulargia and Gasperini [1996a,b] we summarize the main deficiencies due to which their present calculations as well as their earlier calculations in 1992 are incorrect beyond any doubt. Our answers, point by point, to other questions raised by Mulargia and Gasperini [1996a,b] are given in the following paper hereafter cited as Reply II.Concerning the calculation of Mulargia and Gasperini [1992]: a) It suffers from a very serious mistake indicated by Rhoades and Evison [1996], as a result of which Mulargia and Gasperini treated in their calculations probability values as high as 11 (which violate the definition of probability). What they did is akin to approximating the probability of getting heads in at least one of n coin‐tosses by the expected number of heads in n tosses; however, the probability only equals the expected value when n=1. b) It did not take into account that each VAN prediction had a certain spatial extent and c) when applied to a fictitious Ideally Perfect Earthquake Prediction Method [IPEPM, which by definition achieves, in a whole geographic area, the prediction of all earthquakes ‐above a certain magnitude (e.g., Ms≥ 5.3)‐ and does not issue any false alarms] it leads to a paradox, i.e., to values of the significance level indicating that these ideal predictions can be ascribed to chance.Mulargia and Gasperini [1996a,b] do not provide any support to their earlier work in 1992 and accept their aforementioned mistakes. However, they now claim that they find a significant association between VAN predictions and earthquakes (EQs) in “reverse time.” We show that (beyond obvious mistakes in Table 1 of Mulargia and Gasperini [1996a]) this claim is simply due to the fact that, although they use a Poisson distribution, they violate the principle that time‐dependent events should not be entered in their calculation. (For example, for MEQ ≥ 5.3, when including time‐dependent events we find 6 forward associations and 6 backwards; however, when considering only independent events, there are 5 associations in forward time and only 2 in reverse time).Simplified examples demonstrate that Mulargia and Gasperini's [1996a] procedure leads to a second paradox, i.e., it can “extract” a backwards time association even for an IPEPM which can successfully predict both main shocks and (related) aftershocks.Furthermore, Mulargia and Gasperini [1996a] make an erroneous assumption which, in addition to the violation of the true meaning of the experimental error, artificially decreases the VAN success rate by a factor of 2 or so.The main conclusion remains: Once Mulargia and Gasperini's statistical procedure leads to erroneous results when applied (with the same numbers) to an ideal case, it should not have been used as a tool for criticizing an experimental method.