bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathways to work for low‐income workers: The effect of work in the temporary help industry
Authors: Lane Julia , Mikelson Kelly S. , Sharkey Pat , Wissoker Doug
Published: September 2003

This paper provides new evidence to inform the policy debate about the effect of a newly important industry—the temporary help industry—on
the labor market outcomes of low‐income workers and those workers who are at risk of being on public assistance. The core issue of whether
temporary help work harms the long‐term prospects of disadvantaged individuals depends critically on the alternatives available to the worker.
Temporary employment results in labor market outcomes that are better than not working at all. For example, while nonemployed public assistance
recipients have only a 35 percent chance of being employed a year later, those who were in temporary employment have almost twice the likelihood of being
employed in the same period. These findings, if correct, would support the use of temporary agencies by welfare programs. © 2003 by the Association
for Public Policy Analysis and Management
Proximity to service providers and service utilization among welfare recipients: The interaction of place and race
Authors: Allard Scott W. , Tolman Richard M. , Rosen Daniel
Published: September 2003

Currently, welfare programs coordinate a range of services to support work among welfare recipients and help them overcome barriers to
employment. This paper considers the relationship between spatial proximity to and utilization of support services among welfare recipients.
Accessibility of mental health and substance abuse service providers among welfare recipients is examined in the three‐county Detroit
metropolitan area and the relationship between mental health service accessibility and mental health service utilization among welfare recipients
considered. Not only does access to service providers vary significantly across the metropolitan area by race and place, but these analyses reveal
that greater spatial proximity to service providers increases the probability that welfare recipients will receive services. When controlling for
access to providers and individual‐level characteristics, we also find that African American welfare recipients are about half as likely to
use mental health services as white recipients. © 2003 by the Association for Public Policy Analysis and Management.
Pollution control innovations and the Clean Air Act of 1990
Authors: Popp David
Published: September 2003

One advantage often cited for market‐based environmental policies is that they are more likely to promote technological innovation than are
command and control regulations. This paper uses patent data to study innovation in flue gas desulfurization units (“scrubbers”)
across these policy regimes. Plant level data indicate that the effect of these patents on pollution control changed after passage of the 1990 Clean
Air Act, which instituted a market for sulfur dioxide (SO2) permits. Previous regulations requiring plants constructed before
1990 to install scrubbers created incentives for innovation that lowered the costs of operating scrubbers, but did little to improve the environmental
effectiveness of the technology. In comparison, innovations occurring since 1990 do serve to improve the removal efficiency of scrubbers. © 2003
by the Association for Public Policy Analysis and Management.
Two‐dimensional chromatography of complex polymers. IV. Analysis of the grafting reaction of methyl methacrylate onto polybutadiene
Authors: Siewing A. , Lahn B. , Braun D. , Pasch H.
Published: September 2003

The grafting reaction of methyl methacrylate onto polybutadiene (PB) was investigated with different chromatographic techniques, including high‐performance liquid chromatography (HPLC) and online coupled two‐dimensional liquid chromatography. As a result of the grafting reaction, a complex mixture of nongrafted PB, the graft copolymer PB‐g‐PMMA [where PMMA is poly(methyl methacrylate)], and the PMMA homopolymer was formed. The complete separation of all the products of the grafting reaction was achieved with gradient HPLC. By the combination of gradient HPLC and size exclusion chromatography in a fully automated two‐dimensional chromatography setup, the complex distributions of the chemical composition and molar mass were fingerprinted simultaneously. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3143–3148, 2003
Substituent effect on azobenzene‐based liquid‐crystalline organophosphorus polymers
Authors: Kumaresan S. , Kannan P.
Published: September 2003

An Erratum has been published for this article in Journal of Polymer Science Part A: Polymer Chemistry (2003) 41(23) 3862

A new series of combined‐type, azobenzene‐based organophosphorus liquid‐crystalline polymers were synthesized, and their photoisomerization properties were studied. The prepared polymers contained azobenzene units as both the main‐chain and side‐chain mesogens. Various groups were substituted in the terminal of the side‐chain azobenzene mesogen, and the effects of the substituents were investigated. All the polymers were prepared at the ambient temperature by solution polycondensation with various 4‐substituted phenylazo‐4′‐phenyloxyhexylphosphorodichloridates and 4,4′‐bis(6‐hydroxyhexyloxy) azobenzene. The polymers were characterized with gel permeation chromatography, Fourier transform infrared, and 1H, 13C, and 31P NMR spectroscopy. Thermogravimetric analysis revealed that all the polymers had high char yields. The liquid‐crystalline behavior of the polymers was examined with hot‐stage optical polarizing microscopy, and all the polymers showed liquid‐crystalline properties. The formation of a mesophase was confirmed by differential scanning calorimetry (DSC). The DSC data suggested that mesophase stability was better for electron‐withdrawing substituents than for halogens and unsubstituted ones. Ultraviolet irradiation studies indicated that the time taken for the completion of photoisomerization depended on the dipolar moment, size, and donor–acceptor characteristics of the terminal substituents. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3188–3196, 2003
Identification of proteins highly expressed in the hyphae of Candida albicans by two‐dimensional electrophoresis
Authors: Choi Wonyoung , Yoo Yung Joon , Kim Minkyoung , Shin Duckhyang , Jeon Hong Bae , Choi Wonja
Published: September 2003

The increase in Candida albicans infections is caused by the increase in therapies resulting in immunocompromised patients. One factor required for C. albicans pathogenicity is the morphological transition from yeast to hypha. The protein profiles of whole extracts from yeasts and hyphae were examined using two‐dimensional electrophoresis to identify the proteins related to the morphological transition. Over 900 protein spots were visualized by silver staining and 11 spots were increased more than three‐fold reproducibly during hyphal differentiation. Six of the 11 spots were identified by peptide mass fingerprints, of which three represented PRA1, two PHR1 and the last TSA1. Vertical streak patterns of Pra1p and Phr1p indicated that post‐translational modifications seem to be caused by variable glycosylation. Comparative proteome analysis between the wild‐type and the deletion mutants, CAMB43 (Δpra1) and CAS10 (Δphr1), further confirmed the identity of PRA1 and PHR1. Interestingly, Pra1p was downregulated in phr1‐deleted mutants. Only PHR1 transcription was increased, indicating that PRA1 and TSA1 are controlled at the post‐translational level. Copyright © 2003 John Wiley & Sons, Ltd.
Conversion of Bfl‐1, an anti‐apoptotic Bcl‐2 family protein, to a potent pro‐apoptotic protein by fusion with green fluorescent protein (GFP)
Authors: Ko Jae-Kyun , Choi Kyoung-Han , Kim Hee-Jung , Choi Hye-Young , Yeo Dong-Jun , Park Sue-O , Yang Wan Seok , Kim Yong-Nyun , Kim Chul-Woo
Published: September 2003

Human Bfl‐1 is an anti‐apoptotic Bcl‐2 family member. Here, we found that Bfl‐1 was converted into a potent death‐promoting protein by green fluorescent protein (GFP) fusion with its N‐terminus. The transient expression of GFP‐Bfl‐1 induced cytochrome c release and triggered apoptosis in 293T cells, which depended on the mitochondrial localization of GFP‐Bfl‐1. Apoptosis induced by GFP‐Bfl‐1 was significantly blocked by the pan‐caspase inhibitor carbobenzoxy‐Val‐Ala‐Asp‐fluoromethyl ketone, but was not blocked by either Bcl‐xL or Bfl‐1. Our findings provide a useful model for understanding the structural basis of Bcl‐2 family proteins that act in an opposite way despite sharing structural similarity between anti‐apoptotic and pro‐apoptotic proteins.
Pubertal timing, sexual behaviour and self‐reported depression in middle adolescence
Authors: Kaltiala‐Heino Riittakerttu , Kosunen Elise , Rimpelä Matti
Published: September 2003

The associations between pubertal timing, sexual activity and self‐reported depression were analysed in a population sample of 17,082 girls and 15,922 boys aged 14–16 as a par of a classroom survey. Pubertal timing was assessed by age at onset of menstruation (menarche) or ejaculations (oigarche). Sexual experiences elicited included kissing, light petting, heavy petting and intercourse. Self‐reported depression was measured by the 13‐item Beck Depression Inventory. Among girls, self‐reported depression was associated with early puberty and intimate sexual relationship. Among boys depression was associated with very early and late puberty and experience of intercourse. Early puberty is a risk factor for self‐reported depression. Intimate sexual relationships in middle adolescent are likely to indicate problems in adolescent development rather than successful adolescent passage.
An in vitro study of the sub‐cellular distribution of nicotinic receptors
Authors: Devillers‐Thiéry A. , Bourgeois J.P. , Pons S. , Le Sourd A. , Pucci B. , Changeux J.P.
Published: September 2003

Nicotinic and serotoninergic 5HT3 receptors share important sequence identities except for their cytoplasmic loop. Both ends of this loop display conserved 3D helical structures with distinct primary sequences. We decided to check whether these two helices named F and G play a role in the sub‐cellular distribution of different nicotinic receptors. We systematically exchanged each helix with the equivalent sequence of neuronal nicotinic and α4, β2 and α7 subunits in the functional chimeric α7–5HT3 receptor used as a model system. The new chimeras were expressed in vitro in polarized epithelial cells from pig kidney. We quantified synthesis and export of the receptors to the cell surface by measuring α–bungarotoxin binding sites. Immunogold labelling was used, at the electron microscope level, to determine the amount of each chimera present at either domain, apical and/or basolateral, of these cells. We noticed that in epithelial cells the majority of α–bungarotoxin binding sites remained sequestered in the cytoplasm as already observed in neurons in vivo. The majority of the pentamers present at the cell surface were located at the apical domain. Our results suggest that helix F and G differently regulate assembly and export to the cell surface of α–bungarotoxin binding receptors.
Use of cryo‐negative staining in tomographic reconstruction of biological objects: application to T4 bacteriophage
Authors: Messaoudi Cedric , Boudier Thomas , Lechaire Jean‐Pierre , Rigaud Jean‐Louis , Delacroix Hervé , Gaill Françoise , Marco Sergio
Published: September 2003

Recent advances in electron microscopy and image analysis techniques have resulted in the development of tomography, which makes possible the study of structures neither accessible to X—ray crystallography nor nuclear magnetic resonance. However, the use of tomography to study biological structures, ranging from 100 to 500 nm, requires developments in sample preparation and image analysis. Indeed, cryo‐electron tomography present two major drawbacks: the low contrast of recorded images and the sample radiation damage. In the present work we have tested, on T4 bacteriophage samples, the use of a new preparation technique, cryo‐negative staining (Adrian et al., 1998), which reduces the radiation damage while preserving a high signal‐to‐noise ratio (De Carlo et al., 2002). Our results demonstrate that the combination of cryo‐negative staining in tomography with standard cryo‐microscopy and single particle analysis results in a methodological approach that could be useful in the study of biological structures ranging in the T4 bacteriophage size.
Effect of taxol and okadaic acid on microtubule dynamics in thimerosal‐arrested primary mouse oocytes: a confocal study
Authors: Alexandre H. , Delsinne V. , Goval J.‐J. , Van Cauwenberge A.
Published: September 2003

A pulse of thimerosal (TMS), a sulfhydryl reagent, induces an instantaneous, complete and long‐lasting microtubule interphasic network disassembly in mouse primary oocytes, correlated with the irreversible inhibition of meiosis reinitiation This inhibition is bypassed by dithiothreitol (DTT) while thiosalicylic acid, an analog of TMS, does induce neither microtubules depolymerisation nor inhibition of reinitiation and resumption of meiosis. This strongly suggests that the dramatic and pleiotropic inhibitory effect of TMS is specifically related to its sulfhydryl group oxidising activity of critical molecules among which tubulin. In contrast to DTT, okadaic acid (OA), known to bypass the inhibitory effect of drugs interfering with protein kinase activities, induces a late chromatin condensation and GVBD in TMS‐pulsed oocytes as compared to the control situation, with no significant concomitant microtubule assembly. These cytological features are suggested to be indirectly induced by a late MAPK activation and confirm that a very early thiol oxidation induced by TMS exerts a much more dramatic effect on resumption of meiosis than any pharmacological manipulation of protein kinase activities leading to activation of MPF. Finally, taxol was shown to promote tubulin polymerisation even when microtubules were irreversibly disassembled by thiol oxidation but fails to restore the ability to undergo maturation.
A Prospective Randomized Comparison of Sutter and Swanson Silastic Spacers
Authors: McARTHUR P. A. , MILNER R. H.
Published: September 2003

This study compares two currently available prostheses for the reconstruction of rheumatoid joints. A single operator performed 72 resection arthroplasties with Swanson or Sutter prostheses being randomly allocated. Assessment of each patient was carried out preoperatively, and at 6 months and 12 months postoperatively by a single investigator. In the Swanson group an improvement of the flexion arc was seen, from 29° to 44° at 6 months but this reduced to 36° at 12 months. In the Sutter group there was no significant difference between flexion arcs pre- and postoperatively. Grip strength improved in the Swanson group, but not in the Sutter group. Extensor lag was improved in both groups. Patient satisfaction measured by linear analogue scales for pain, function and deformity was high in both groups
A Morphological Study of Schwann Cells and Axonal Regeneration in Chronically Transected Human Peripheral Nerves
Authors: TERENGHI G. , CALDER J. S. , BIRCH R. , HALL S. M.
Published: September 2003

Relatively little is known about the effects of chronic transection on human peripheral nerves. In this study intraoperative biopsies were obtained from proximal and distal nerve stumps and intervening neuromas resected before peripheral nerve reconstruction. Biopsies were collected from ten patients following differing types of nerve injury, with delays to repair ranging from 8 to 53 months. Nerves were examined by light and electron microscopy. In general, reinnervation was poor, although even following the most severe injuries, all of the distal stumps contained some regrowing axons, which were always associated with Schwann cells. Denervated Schwann cells, arranged in typical bands of Bungner were consistently present in each distal stump. Our findings confirm that the morphology of chronically denervated human peripheral nerves is essentially similar to that described in experimental models.
Induced membranes secrete growth factors including vascular and osteoinductive factors and could stimulate bone regeneration
Authors: Pelissier P. H. , Masquelet A. C. , Bareille R. , Pelissier S. Mathoulin , Amedee J.
Published: September 2003

Based on a new concept, a procedure combining induced membranes and cancellous autografts allows the reconstruction of wide diaphyseal defects. In the first stage of this procedure, a cement spacer is inserted into the defect; the spacer is responsible for the formation of a pseudo‐synovial membrane. In the second stage, the defect is reconstructed two months later by an autologous cancellous bone graft. The aim of this study was to evaluate the histological and biochemical characteristics of these membranes induced in rabbits. Histological studies carried out two, four, six, and eight weeks following implantation revealed a rich vascularization. Qualitative and quantitative immunochemistry showed production of growth factors (VEGF, TGFβ1) and osteoinductive factors (BMP‐2). Maximum BMP‐2 production was obtained four weeks after the implantation, and, at this time, induced membranes favored human bone marrow stromal cell differentiation to the osteoblastic lineage. Should these results be confirmed in humans, bone reconstruction could be carried out earlier than previously thought and in better conditions than expected, the membrane playing the role of an in situ delivery system for growth and osteoinductive factors. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Ex vivo static tensile loading inhibits MMP‐1 expression in rat tail tendon cells through a cytoskeletally based mechanotransduction mechanism
Authors: Arnoczky Steven P. , Tian Tao , Lavagnino Michael , Gardner Keri
Published: September 2003

To determine the effect of various degrees of ex vivo static tensile loading on the expression of collagenase (MMP‐1) in tendon cells, rat tail tendons were statically loaded in tension at 0.16, 0.77, 1.38 or 2.6 MPa for 24 h. Northern blot analysis was used to assay for mRNA expression of MMP‐1 in freshly harvested, 24 h load deprived, and 24 h statically loaded tendons. Western blot analysis was used to assay for pro‐MMP‐1 and MMP‐1 protein expression in fresh and 24 h load deprived tendons. Freshly harvested rat tail tendons demonstrated no evidence of MMP‐1 mRNA expression and no evidence of the pro‐MMP‐1 or MMP‐1 protein. Ex vivo load deprivation for 24 h resulted in a marked increase in the mRNA expression of MMP‐1 which coincided with a marked increase of both pro‐MMP‐1 and MMP‐1 protein expression. When tendons were subjected to ex vivo static tensile loading during the 24 h culture period, a significant inhibition of this upregulation of MMP‐1 mRNA expression was found with increasing ioad (p < 0.05). A strong (r2 = 0.78) and significant (p < 0.001) inverse correlation existed between the level of static tensile load and the expression of MMP‐1. Disruption of the actin cytoskeleton with cytochalasin D abolished the inhibitory effect of ex vivo static tensile loading on MMP‐1 expression. The results of this study suggest that up‐regulation of MMP‐1 expression in tendon cells ex vivo can be inhibited by static tensile loading, presumably through a cytoskeletally based mechanotransduction pathway. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Influence of depressive symptoms and premorbid adjustment on factor structure of phenomenology of schizophrenia: a study from India
Authors: Kulhara Parmanand , Avasthi Ajit
Published: September 2003

This study investigated the nature of factor structure of schizophrenia syndromes using a sample of 151 patients with schizophrenia according to DSM-IV. The patients were assessed on the Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS), Hamilton Depression Rating Scale (HDRS) and the Phillips Rating Scale of Premorbid Adjustment in schizophrenia. Three factors—negative syndrome, reality-distortion syndrome and disorganized syndrome were extracted when only SAPS and SANS were analysed. Addition of the Phillips Rating Scale scores to SAPS and SANS ratings in the factorial equation led to splitting of the negative syndrome though reality-distortion and disorganized syndromes remained stable. Factor analysis of the HDRS scores with SAPS and SANS ratings resulted in the HDRS loading highly on reality-distortion syndrome and splitting of negative syndrome. Factor analysis of all the variables taken together resulted in delineation of four factors. The study suggests a link between depression and reality distortion. Apathy and anhedonia seem to be linked to premorbid adjustment.
Comorbidity of parkinsonism and schizophrenia in a patient treated with clozapine
Authors: Urban A. , Libiger J. , Hosák L. , Kupka K.
Published: September 2003

Clozapine is the least likely anti-psychotic to induce extrapyramidal symptoms (EPS). We present a surprising case of a woman schizophrenic patient treated with clozapine suffering from EPS. Single photon emission computed tomography (SPECT) revealed a low density of presynaptic dopamine transporters in our patient's brain. A comorbid diagnosis of Parkinson's disease in schizophrenia was confirmed in this way. This helped us to find a proper therapeutic strategy for our patient.
The Psychiatric-Mental Health Nursing Workforce: Large Numbers, Little Data
Authors: Hanrahan Nancy , Stuart Gail W. , Brown Pat , Johnson Mary , Draucker Claire Burke , Delaney Kathleen
Published: September 2003

Managing the supply of psychiatric-mental health nursing labor, determining the financial incentives associated with the provision of services by these providers, and ensuring optimal patient and cost outcomes are critical elements of cost control and patient safety in the current health care market. Knowledge of the psychiatric-mental health nursing workforce is needed to plan and evaluate cost-effective programs to accomplish the aforementioned elements. However, the psychiatric-mental health nursing workforce data are woefully inadequate. This paper will review the extent to which national data sources contain workforce information on psychiatric-mental health nurses.
On the influence of fault bends on the growth of sub‐Rayleigh and intersonic dynamic shear ruptures
Authors: Rousseau Carl‐Ernst , Rosakis Ares J.
Published: September 2003

Earthquake ruptures are modeled as dynamically propagating shear cracks with the aim of gaining insight into the physical mechanisms governing their arrest or, otherwise, the often‐observed variations in rupture speeds. Fault bends have been proposed as being the main cause for these variations. Following this line of reasoning, the existence of deviations from fault planarity is chosen as the main focus of this study. Asymmetric impact is used to generate shear loading and to propagate dynamic mode‐II cracks along the bonded interfaces of two otherwise identical homogeneous constituents. Secondary paths inclined at various angles are also introduced to represent fault bends or kinks. The experiments show that certain fault bend inclinations are favored as alternate paths for rupture continuation, whereas others suppress further motion of the incoming rupture. The asymptotic elastodynamic stress fields at the tip of the growing rupture are used to develop two criteria (one energetic and one stress based) for rupture propagation or arrest at the kinked interfaces. These criteria correlate very well with the experimental results. Since most field evidence suggests that the average rupture speeds during crustal earthquakes are sub‐Rayleigh, this work first focuses on incoming rupture speeds that are just below the Rayleigh wave speed. Reports of intersonic crustal fault rupture speeds having surfaced recently, experiments and analyses are also performed within that speed regime.
Changing features of the climate and glaciers in China's monsoonal temperate glacier region
Authors: He Yuanqing , Zhang Zhonglin , Theakstone Wilfred H. , Chen Tuo , Yao Tandong , Pang Hongxi
Published: September 2003

Climatic data, ice core records, the tree ring index, and recorded glacier variations have been used to reconstruct a history of climatic and glacial changes in the monsoonal temperate glacier region of southwestern China during the last 400 years. The region's temperature has increased in a fluctuating manner during the twentieth century after two cold stages of the Little Ice Age (seventeenth to nineteenth centuries), with a corresponding retreat of most of the glaciers, against a background of global warming. Retreat rates accelerated after the 1980s. The few advancing glaciers that did exist have started to retreat in recent years. The amount, trend, and amplitude of variation of precipitation have differed in different parts of the region. The Dasuopu ice core, from the western part of the region, shows a decreasing trend in precipitation, the converse of the trend in temperature. In the eastern part of the region, however, a rising trend of rainfall has accompanied increasing temperatures as a result of the variable atmospheric circulations from different sources. The southwest monsoon, the principal controlling factor in the Chinese monsoonal temperate glacier region, can be classified into the Indian monsoon and the Bengal monsoon. The former passes across the Indian Peninsula from the Arabian Sea and transports vapor for precipitation in the western part of the monsoonal temperate glacier region. The Bengal monsoon, originating in the Bay of Bengal, is the major source of precipitation in the eastern part of the region. The eastern part is also influenced by the southeast monsoon arriving from the western Pacific, and the western part is affected in winter by the southern branch of the westerly circulation. This complex atmospheric situation results in differing patterns of precipitation in the western and eastern zones. Although it is clear that both temperature and precipitation affect the glaciers, further work is needed to confirm which of these is the major factor influencing present glacier change.
Evaluating mechanisms of nutrient depletion and 13C enrichment in the intermediate‐depth Atlantic during the last ice age
Authors: Sigman Daniel M. , Lehman Scott J. , Oppo Delia W.
Published: September 2003

Using an ocean box model, we have studied the effect of altered circulation on the oceanic distributions of phosphate (PO4−3) and the 13C/12C and 14C/12C of dissolved inorganic carbon to evaluate competing hypotheses for the cause of observed nutrient depletion and 13C enrichment at intermediate depths of the Atlantic during the last ice age. Because of “nutrient trapping” and limited air‐sea carbon isotopic equilibration, the simple imposition of an intense meridional overturning cell in the Atlantic fails to simultaneously lower nutrient concentrations and raise 13C/12C to observed glacial levels. Export of intermediate water out of the Atlantic causes a basin‐to‐basin nutrient transfer, thus providing a more efficient mechanism of intermediate‐depth Atlantic nutrient depletion and improved carbon isotopic equilibration at low temperatures (i.e., 13C enrichment). Although this export adds nutrients to the intermediate depths of the Pacific and Indian Oceans, the simulated glacial intermediate‐depth Indo‐Pacific is nevertheless moderately depleted in PO4−3 relative to the model's interglacial control, in agreement with consensus paleoceanographic evidence. This Indo‐Pacific PO4−3 depletion results from our use of a “glacial base case” in which nutrient‐rich Antarctic Intermediate Water formation is absent as part of the elimination of the modern North‐Atlantic‐Deep‐Water‐based “conveyor” circulation.
Modeling the U.S. national distribution of waterborne pathogen concentrations with application to Cryptosporidium parvum
Authors: Crainiceanu Ciprian M. , Stedinger Jery R. , Ruppert David , Behr Christopher T.
Published: September 2003

This paper provides a general statistical methodology for modeling environmental pathogen concentrations in natural waters. A hierarchical model of pathogen concentrations captures site and regional random effects as well as random laboratory recovery rates. Recovery rates were modeled by a generalized linear mixed model. Two classes of pathogen concentration models are differentiated according to their ultimate purpose: water quality prediction or health risk analysis. A fully Bayesian analysis using Markov chain Monte Carlo (MCMC) simulation is used for statistical inference. The applicability of this methodology is illustrated by the analysis of a national survey of Cryptosporidium parvum concentrations, in which 93% of the observations were zero counts.
Estimation of 7‐day, 10‐year low‐streamflow statistics using baseflow correlation
Authors: Reilly Christine F. , Kroll Charles N.
Published: September 2003

Estimators of low‐streamflow statistics are often required for water quality and quantity management at gauged and ungauged sites. Here the technique of baseflow correlation is investigated as an estimator of the 7‐day, 10‐year low‐streamflow statistic at ungauged sites. This method uses an information transfer technique to estimate streamflow statistics at an ungauged site by correlating a nominal number of measured streamflow discharges during baseflow conditions at the ungauged site with those at a nearby gauged site. A regional assessment of baseflow correlation estimators is made by employing daily streamflow values at more than 1300 USGS HCDN stream gauge sites. A jackknife simulation is performed in each of the 18 USGS water resource regions located within the conterminous United States. Potential gauged sites are selected using a variety of watershed, geographic, topographic, and geologic classification systems. The results of this study indicate that baseflow correlation performs well in the United States when baseflow measurements are nearly independent and potential gauged sites are located within 200 km. The method is improved as the number of baseflow measurements is increased, although some leveling off of performance was observed with more than 15 baseflow measurements. A comparison of baseflow correlation with regional regression shows that baseflow correlation is the preferred method for estimating low flows in much of the United States.
Benthic barium and alkalinity fluxes: Is Ba an oceanic paleo‐alkalinity proxy for glacial atmospheric CO2?
Authors: Rubin Stephany I. , King Stagg L. , Jahnke Richard A. , Froelich Philip N.
Published: September 2003

Barium (Ba) and alkalinity (Alk) fluxes were determined from benthic chambers deployed at a variety of environments in both the Pacific and Atlantic Oceans to test if Ba and Alk fluxes from sediments differ from the current oceanic relationship. We find a benthic flux ratio (Ba/Alk ∼ 0.2 mmol/eq) that is significantly lower than the modern deep water trend (0.67 mmol/eq). This difference suggests that Ba is preferentially regenerated in the water column rather than from the sediments as compared to Alk. While the oceanic relationship between barium Ba and Alk has previously been used to predict the alkalinity of past oceans from Ba/Ca ratios in benthic foraminifera, our results suggest that the Ba and Alk cycles in the ocean are not coupled. This raises doubts that higher Ba/Ca ratios measured in glacial‐age benthic foraminifera can be interpreted as higher glacial ocean Alk, one mechanism proposed to lower glacial atmospheric CO2.
DRB1*1446 allele variations in the group‐specific annealing sites of common amplification primers
Authors: Morante M.P. , Mosquera A.M. , Querol S. , Garcia J. , Rodriguez‐Sanchez J.L. , Vidal S.
Published: September 2003

Abstract A cord blood unit from the Umbilical Cord Bank of Barcelona was initially typed by sequence‐based typing (SBT) as DRB1* 0701. However, the subsequent confirmation by sequence‐specific oligonucleotide probes (SSOP) revealed an unusual hybridization pattern that did not fit any of the known HLA‐DRB1 alleles or allelic combinations. Molecular cloning and sequencing with primers located at introns 1 and 2 provided the definitive identification of a novel DRB1*1446 allele. It was similar to DRB1*1402 at exon 2 except for nucleotide substitutions at codons 10, 11 and 12 (from YST to LRK) that coincide with the 5′‐end group specific site for the annealing of common amplification primers used by SBT and sequence‐specific primers.
Molecular characterization of CD28 and cytotoxic T‐lymphocyte‐associated antigen 4 (CTLA‐4) of woodchuck (Marmota monax)
Authors: Yang D. , Roggendorf M. , Lu M.
Published: September 2003

Abstract Eastern woodchuck (Marmota monax) became an important animal model to study the immunological processes in hepatitis B virus infection. To facilitate further study of T‐cell responses in this model, we cloned and sequenced the cDNAs of Woodchuck CD28 and cytotoxic T‐lymphocyte‐associated antigen 4 (CTLA‐4), which play important roles for the regulation of T‐cell activation by delivering the costimulation signals. According to the deduced amino‐acid sequences, Woodchuck CD28 showed a similarity of 70% to 80% to its mammalian homologues. Woodchuck CTLA‐4 has a higher similarity of 74% to 85% to corresponding mammalian CTLA‐4 molecules. The strict conservation of critical amino‐acid residues like cystein and asparagine residues in Woodchuck CD28 and CTLA‐4 suggests that both molecules may structurally resemble their human or mouse homologues. A hexapeptide motif, MYPPPY, which has been supposed to be essential for the interaction with CD80, is present in both Woodchuck CD28 and CTLA‐4. The cloned cDNAs of Woodchuck CD28 and CTLA‐4 were placed under the control of the cytomegalovirus (CMV) promoter of the mammalian expression vector pcDNA3. Both proteins were expressed and detected by respective crossreactive antibodies in transiently transfected mammalian cells. By immunohistochemical staining with these antibodies, CD28 and CTLA‐4 were also detected on cultured woodchuck peripheral blood lymphocytes. The molecular characterization of Woodchuck CD28 and CTLA‐4 will facilitate studies on the T‐cell response to hepadnavirus in the woodchuck model.
Matrix metalloproteinase‐8 correlates with the cervical ripening process in humans
Authors: Sennström Maria B. , Brauner Annelie , Byström Birgitta , Malmström Anders , Ekman Gunvor
Published: September 2003

Background.  To determine levels of matrix metalloproteinases MMP‐1, ‐3 and ‐8 and localize them and the tissue inhibitors of metalloproteinases TIMP‐1 and ‐2 in human cervical tissue during the cervical ripening process.

Methods.  Cervical biopsies were obtained from 10 term‐pregnant (TP) women and from nine women immediately after vaginal delivery. Ten nonpregnant (NP) women served as controls.

Levels of MMP‐1, ‐3 and ‐8 were analyzed in supernatants of homogenized cervical tissue by specific enzyme‐linked immunosorbent assay (EIA). Localization with immunohistochemistry of these MMPs and TIMP‐1 and ‐2 was performed using monoclonal antibodies.

Results.  MMP‐8 reached its peak median level, 7300 ng/mg wet weight, in biopsies obtained from postpartum (PP) women, as compared to 86 ng/mg wet weight in NP (p < 0.001) and 266 ng/mg wet weight in TP (p = 0.016) women. The immunohistochemical results confirmed these findings, with a clear increase in MMP‐8 staining in ripened cervix localized primarily in the stromal tissue. Levels of MMP‐1 and ‐3 as measured with EIA were low in all three groups, but immunohistochemically a more frequent positive staining for MMP‐1 and ‐3 was registered in pregnant cervical tissue compared to nonpregnant. For TIMP‐1 and also for TIMP‐2 immunohistochemical analysis showed that staining in all groups was more prominent in pregnant cervical tissue compared to nonpregnant.

Conclusion.  The results indicate that MMP‐8 is involved in the process of cervical ripening, and that MMP‐1 and ‐3 and their inhibitors TIMP‐1 and ‐2 may also play a role in this complicated process.
Midtrimester triple test levels in women with severe preeclampsia and HELLP syndrome
Authors: Shenhav Simon , Gemer Ofer , Volodarsky Michael , Zohav Efraim , Segal Shmuel
Published: September 2003

Background.  The levels of midtrimester triple test constituents are known to be altered in hypertensive disorders of pregnancy.

Objective.  Our aim was to determine whether midtrimester triple test constituent levels differ in women with severe preeclampsia and those who also develop HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome.

Methods.  A retrospective chart analysis of 106 women with severe preeclampsia for whom midtrimester triple test data were available was made. None of these patients had fetuses with abnormal karyotype, nor did they deliver infants with malformations. The levels of midtrimester maternal serum alpha‐fetoprotein (MSAFP), human chorionic gonadotropin (MShCG) and unconjugated estriol (MSuE3) of 74 patients with severe preeclampsia were compared with those of 32 patients who also developed HELLP syndrome.

Results.  The mean MShCG was significantly higher and the mean MSuE3 was significantly lower in patients with HELLP syndrome than in those with only severe preeclampsia [1.78 multiple of the medians (MoM), standard error (SE) 0.18 vs. 1.27 MoM, SE 0.07, p = 0.015 and 0.86 MoM, SE 0.05 vs. 1.04 MoM, SE 0.07; p = 0.03, respectively].

The two groups did not differ significantly with regard to MSAFP levels.

Conclusion.  Unexplained high levels of midtrimester MShCG and low levels of MSuE3 may be associated with the development of HELLP syndrome in women with severe preeclampsia.
Relationship between vitamin use, smoking, and nausea and vomiting of pregnancy
Authors: Källén Bengt , Lundberg Gittan , Åberg Anders
Published: September 2003

Background.  Nausea and vomiting in pregnancy (NVP) is a common complaint but risk factors for NVP are not well characterized.

Methods.  Occurrence of NVP was studied by questionnaires given to pregnant women at their first visit to the antenatal care unit and were returned around gestational week 28.

Results.  Analysis of 3675 completed questionnaires was made. Nausea and vomiting in pregnancy was reported by 79% of the women, approximately half of which had been vomiting. Various therapies (drugs, acupuncture, acupressure) were tried by 18% of the women with NVP, of which the majority used drugs, most notably antihistamines (specifically meclozine). Hospitalization occurred in 1% of all women. Nausea and vomiting in pregnancy caused 28% of all sick‐leaves during the first 28 weeks of pregnancy. Low maternal age and parity 1+ independently increased the risk for NVP. Smoking before pregnancy and using vitamins in early pregnancy were associated with a decreased risk for NVP. Women working outside the home had a lower rate of NVP than housewives and women out of work.

Conclusions.  Nausea and vomiting in pregnancy is a common complaint with a significant impact on leave of absence from work. The study identifies a number of factors that are related to the occurrence of NVP and that may give hints on the etiology of the condition.
Determinants of episiotomy in rural Zimbabwe
Authors: Van Den Bergh Janneke E. , Sueters Marieke , Segaar Marc , Van Roosmalen Jos
Published: September 2003

Background.  To assess the influence of parity, mode of birth, place of birth, a history of birth by only cesarean section and birthweight on episiotomy rates.

Methods.  Retrospective study of 3589 women giving birth vaginally from October 1997 to October 1998 in the Gutu district in Zimbabwe, to obtain the rate of episiotomy and its determinants.

Results.  The overall episiotomy rate was 27%; 54% in nulliparous and 6% in multiparous women. Perineal tears varied between 5 and 11% in the different places of birth.

Discussion.  An episiotomy rate of 54% in nulliparous women is higher than necessary. Medical and midwifery training should be adapted to facilitate a more restrictive use of episiotomy.
Collaborative learning in mobile work
Authors: Lundin J. , Magnusson M.
Published: September 2003

Abstract Moving towards more communication intensive organisations, where work tends to be mobile, understanding how to support learning in such work becomes increasingly important. This paper reports on a study of a customer relations team, where work is performed co‐located, distributed as well as mobile. Collaborative learning within in this team is explored so as to inform the design of IT support. In the results four instances of collaborative learning important in the studied team were identified: walking into collaborative learning, travelling to meetings, articulating practice and sharing without articulating. These issues are discussed and how they affect the design of collaborative learning activities for mobile knowledge workers.
Conceptual tools for planning for the wireless classroom
Authors: DiGiano C. , Yarnall L. , Patton C. , Roschelle J. , Tatar D. , Manley M.
Published: September 2003

Abstract  Wireless and mobile devices are beginning to offer stunning new technical capabilities for collaborative learning. Yet, researchers in this field must recognise the importance of complementing these technical advances with improved understanding of the patterns of classroom activity that most need support. The approach taken in the work reported in this paper has been to create conceptual tools that help thinking and talking about technology‐supported collaborative learning. A particularly powerful tool is Collaborative Design Patterns, which captures common learning situations and benefits in written form. This paper uses four classroom scenarios to describe eight patterns. These patterns fall into two categories: whole‐activity patterns, which suggest ways to organise one or more class periods, and smaller‐grained support patterns.
A mobile learning system for scaffolding bird watching learning
Authors: Chen Y.S. , Kao T.C. , Sheu J.P.
Published: September 2003

Abstract This paper develops a mobile learning system for scaffolding students learning about bird‐watching. The aim is to construct an outdoor mobile‐learning activity using up‐to‐date wireless technology. The proposed Bird‐Watching Learning (BWL) system is designed using a wireless mobile ad‐hoc network. In the BWL system, each learner has a PDA (Personal Digital Assistant) with a Wi‐Fi‐based (IEEE 802.11b) wireless network card. The BWL system offers a mobile learning system which supports the students learning through scaffolding. The aim of a formative evaluation was twofold: to explore the possible roles and scaffolding aids that the mobile learning device offers for bird‐watching activities and to investigate whether student learning benefited from the mobility, portability, and individualisation of the mobile learning device.
A study of user experiences mediated by nomadic web content in a museum
Authors: Hsi S.
Published: September 2003

Abstract How should nomadic web content be designed to improve and transform user experiences in a hands‐on museum? In this study, 15 users were studied while using an electronic guidebook designed to augment user experiences via wireless technologies at the Exploratorium, an interactive science museum. Several recurring themes emerged from the analysis, such as users' sense of isolation and users' attempts to make a seamless transition between real‐place and virtual contexts. This paper shares a preliminary framework for organising user interactions with handheld devices, user experiences based on interviews and insights regarding the role of nomadic web content.
Long‐lasting changes in the T‐cell receptor V beta repertoires of CD4 memory T‐cell populations in the peripheral blood of radiation‐exposed people
Authors: Kusunoki Yoichiro , Yamaoka Mika , Kasagi Fumiyoshi , Hayashi Tomonori , MacPhee Donald G. , Kyoizumi Seishi
Published: September 2003

Summary. To study the long‐term effects of radiation‐induced T‐cell depletion on the T‐cell receptor (TCR) Vβ repertoires of human peripheral CD4 T‐cell populations, we measured the percentages of CD4 T cells representing each of the full range of possible TCR Vβ families in a cohort of atomic bomb survivors. We then estimated the extent to which the expression levels for individual TCR Vβ families differed from the average expression level for that particular TCR Vβ family across the entire cohort. We found no evidence of a systematic change in the TCR Vβ repertoires of the naïve CD4 T‐cell populations, but memory CD4 T‐cell TCR Vβ family expression levels diverged significantly from the population average for counterpart families, especially in individuals who had been exposed to higher doses and were at least 20 years of age at the time of the bombing. Comparisons of the TCR Vβ family expression profiles in the naïve and memory CD4 T‐cell pools of the same group of adult survivors revealed that differences in the TCR Vβ repertoires of these two types of CD4 T‐cell pool were larger in more heavily exposed survivors than in unexposed controls. These findings suggest that the memory CD4 T‐cell pools of individuals who received significant radiation doses in adulthood may well have become (and could still be) dependent upon a much less diverse complement of TCR Vβ families than would otherwise have been the case.
European Concerted Action on Anticoagulation. Correction of displayed international normalized ratio on two point‐of‐care test whole‐blood prothrombin time monitors (CoaguChek Mini and TAS PT‐NC) by independent international sensitivity index calibration
Authors: Poller Leon , Keown Michelle , Chauhan Nikhil , Van Den Besselaar Anton M. H. P. , Tripodi Armando , Shiach Caroline , Jespersen Jorgen
Published: September 2003

Summary. The international normalized ratio (INR) on two widely used point‐of‐care test (POCT) prothrombin time (PT) monitors (CoaguChek Mini and TAS PT‐NC) differed considerably and also differed from the ‘true’ INR obtained on the same samples using a manual PT and the same species thromboplastin international reference preparation. Agreement between the displayed INR and difference from ‘true’ INR has been reassessed following an independent international sensitivity index (ISI) calibration of the two systems. The displayed INRs taken at seven centres were compared with ‘true’ INRs from the same blood donations and INRs based on the resulting ISI. The overall difference between the displayed INRs on the two monitor systems was reduced from 21·0% to 3·5%. The overall difference in mean INR of system A from the ‘true’ INR was reduced from 19·0% to 9·5% and of system B from 6·8% to 0·3%, but individual centre's results still showed considerable mean INR variability. Differences between overall displayed INR with the two monitor systems have been reduced by an independent multicentre calibration, and agreement with ‘true’ INR on the same blood samples improved. However, marked variability in mean INR at individual centres remained after ISI correction, which demonstrates the need for external quality control of individual POCT whole‐blood PT monitors.