bluuebunny/crossref_metadata_2025_split huggingface dataset:
The equivalent strength of geometrical barriers to earthquakes
Authors: Nielsen Stefan B. , Knopoff Leon 
Published: February 2004

We present a quantitative framework for evaluating the influence of non‐planar fault geometry on repeated seismic ruptures. We model quasistatic ruptures on a non‐planar fault trace imbedded in a two‐dimensional elastic medium under in‐plane strain. Because of the presence of fault segments that are not parallel to the regional shear stress (i.e. bends), the apparent strength at a given point on the fault is not fixed, but fluctuates with normal stress. Compressional features behave as increasingly strong barriers to fracture unless the stored normal stress is released in order to unlock the fault. Since slip on the fault itself cannot get rid of the normal stress, this is achieved through the action of off‐fault morphological features such as secondary faulting, folding and vertical motions, that we introduce parametrically in the form of an aseismic relaxation. The apparent strength of a fault bend will stabilize in a narrow interval of values after repeated ruptures, characterized by a non‐dimensional “hardness” parameter, whereby the relaxation rate is scaled by the tectonic loading rate.On a fault structure having several small, widely separated bends, three families of events can be identified whose frequency and magnitude depend on the hardness (relaxation) parameter and the geometry: small events that cluster in the tension zones of the bends, intermediate size ruptures involving a single interbend segment, and large ruptures that break through bends and link on or more interbend segments. Large multi‐segment events are most likely to occur for low values of the hardness, i.e., fast relaxation and slow loading rate.Regions with compressional features act as barriers that stop most ruptures; stress is stored at these sites until they themselves break and initiate motion on the smoother, long reaches of the fault.
Climate variability and Ross River virus transmission in Townsville Region, Australia, 1985–1996
Authors: Tong Shilu , Hu Wenbiao , McMichael A. J. 
Published: February 2004

SummaryBackground  How climate variability affects the transmission of infectious diseases at a regional level remains unclear. We assess the impact of climate variation on the Ross River virus (RRv) transmission in the Townsville region, Queensland, north‐east Australia.Methods  We obtained population‐based information on monthly variations in RRv cases, climatic factors, sea level, and population growth between 1985 and 1996. Cross‐correlations were computed for a series of associations between climate variables (rainfall, maximum temperature, minimum temperature, relative humidity and high tide) and the monthly incidence of RRv disease over a range of time lags. We assessed the impact of climate variability on RRv transmission using the seasonal auto‐regressive integrated moving average (SARIMA) model.Results  There were significant correlations of the monthly incidence of RRv to rainfall, maximum temperature, minimum temperature and relative humidity, all at a lag of 2 months, and high tide in the current month. The results of SARIMA models show that monthly average rainfall (β = 0.0007, P = 0.01) and high tide (β = 0.0089, P = 0.04) were significantly associated with RRv transmission and maximum temperature was also marginally significantly associated with monthly incidence of RRv (β = 0.0412, P = 0.07), although relative humidity did not seem to have played an important role in the Townsville region.Conclusions  Rainfall, high tide and maximum temperature were likely to be key determinants of RRv transmission in the Townsville region.
Seroepidemiology of dengue in the adult population of Singapore
Authors: Wilder‐Smith Annelies , Foo Winnie , Earnest Arul , Sremulanathan Sangeetha , Paton Nicholas I. 
Published: February 2004

SummaryUrbanization is one of the reasons for the resurgence of dengue in tropical and subtropical countries. We conducted a cross‐sectional seroepidemiological study in Singapore to determine the extent at which the Singapore population has been exposed to dengue infections. Dengue antibodies were measures with PanBio Dengue. Of 298 enrolled subjects (age 18–45), 133 (45%) had a positive dengue serology. In multivariate analysis, age and nationality (Singaporean vs non‐Singaporean Asians) were found to be significant independent predictors. The odds ratio of dengue seroprevalence increased by 4.13 (95% CI: 2.88–5.93) for every 10 year increase in age. Dengue infections remain a major problem in Singapore.
Anaemia in pregnancy and infant mortality in Tanzania
Authors: Marchant Tanya , Schellenberg Joanna Armstrong , Nathan Rose , Abdulla Salim , Mukasa Oscar , Mshinda Hassan , Lengeler Christian 
Published: February 2004

SummaryTanzania is an area of moderate to high risk for severe anaemia during pregnancy. There is extensive literature examining the consequences of severe anaemia for pregnant women, but the impact this problem has on their infants in malaria‐endemic regions is poorly understood. Between 1999 and 2001 we used a demographic surveillance system in the Kilombero Valley, Tanzania to link morbidity and socio‐economic status data for 301 pregnant women to the survival of 365 days of their singleton babies, looking for evidence of an association between infant mortality and maternal haemoglobin (Hb). The hazards ratio for infant mortality amongst women who had been severely anaemic in pregnancy (Hb < 8 g/dl) was 3.1 [95% confidence interval (CI) 1.1–9.1, P = 0.04] compared with women with Hb above this level after controlling for other factors. Prevention of anaemia in pregnancy may lead to an improvement in infant survival.
Artemether‐lumefantrine for uncomplicated malaria: a systematic review
Authors: Omari Aika A. , Gamble Carrol , Garner Paul 
Published: February 2004

SummaryBackground  The World Health Organization (WHO) is promoting artemether‐lumefantrine for treating uncomplicated malaria. The objective of this review is to summarize available evidence of its effects compared with other antimalarial regimens.Methods  We sought randomized and quasi‐randomized studies comparing artemether‐lumefantrine with any other antimalarial drug regimen. Databases searched were MEDLINE (to February 2003), EMBASE (to February 2003), and the Cochrane Controlled Trials Register (issue 1, 2003). Conference proceedings and reference article lists were searched and malaria researchers and the drug manufacturer were contacted. Two reviewers independently applied inclusion criteria and extracted data.Results  Six trials (1698 participants) studied the four‐dose regimen. Fever and parasite clearance tended to be shorter with artemether‐lumefantrine, but parasitological failure on day 28 was more common with artemether‐lumefantrine in comparison with mefloquine (one trial, n = 233), halofantrine (one trial, n = 86) and mefloquine‐artesunate (one trial, n = 537); but less common with chloroquine (two trials, n = 378). For the six‐dose regimen, two studies compared artemether‐lumefantrine with mefloquine‐artesunate, but there was insufficient data to demonstrate any meaningful comparative effects for day 28 parasitaemia, and no difference in parasite or fever clearance time was detected. There were 11 parasitological failures with artemether‐lumefantrine and none with mefloquine‐artesunate.Conclusion  There is no evidence to demonstrate the four‐dose regimen of artemether‐lumefantrine results in a higher cure rate than other antimalarial regimens against which it has been tested, apart from chloroquine in areas with high chloroquine resistance. Artemether‐lumefantrine has potential advantages over non‐artemisinin regimens because of the faster clearance time and gametocyte clearance. There is insufficient evidence about the six‐dose regimen to know whether it is less or more effective than current antimalarial drug regimens.
Research for control: the onchocerciasis experience*
Authors: Remme Jan H. F. 
Published: February 2004

SummaryOnchocerciasis control has been very successful in Africa and research has played a critical role. An overview of the main epidemiological and implementation research activities undertaken over the last 20 years in collaboration with the African onchocerciasis control programmes and of the impact this research had on control is given. The research included the development of epidemiological modelling and its application in programme evaluation and operational planning, research on disease patterns and disease burden in different bioclimatic zones to justify and guide control operations, community trials of ivermectin to determine its safety for large‐scale use and its impact on transmission, rapid assessment methods to identify target communities for treatment and community‐directed treatment for sustained drug delivery. Lessons learned during this unique collaboration between research and control are discussed.
Use of intermittent presumptive treatment and insecticide treated bed nets by pregnant women in four Kenyan districts
Authors: Guyatt H. L. , Noor A. M. , Ochola S. A. , Snow R. W. 
Published: February 2004

SummaryThe roll back malaria (RBM) movement promotes the use of insecticide‐treated bednets (ITNs) and intermittent presumptive treatment (IPT) of malaria infection as preventive measures against the adverse effects of malaria among pregnant women in Africa. To determine the use of these preventive measures we undertook a community‐based survey of recently pregnant women randomly selected from communities in four districts of Kenya in December 2001. Of the 1814 women surveyed, only 5% had slept under an ITN. More than half of the 13% of women using a bednet (treated or untreated) had bought their nets from shops or markets. Women from rural areas used bednets less than urban women (11%vs. 27%; P < 0.001), and 41% of the bednets used by rural women had been obtained free of charge from a research project in Bondo or a nationwide UNICEF donation through antenatal clinics (ANCs). Despite 96% of ANC providers being aware of IPT with sulphadoxine–pyrimethamine (SP), only 5% of women interviewed had received two or more doses of SP as a presumptive treatment. The coverage of pregnant women with at least one dose of IPT with SP was 14%, though a similar percentage also had received at least a single dose as a curative treatment. The coverage of nationally recommended strategies to prevent malaria during pregnancy during 2001 was low across the diverse malaria ecology of Kenya. Rapid expansion of access to these services is required to meet international and national targets by the year 2005. The scaling up of malaria prevention programmes through ANC services should be possible with 74% of women visiting ANCs at least twice in all four districts. Issues of commodity supply and service costs to clients will be the greatest impediments to reaching RBM targets.
Association between Helicobacter pylori and recurrent aphthous stomatitis in children and adolescents
Authors: Fritscher A. M. G. , Cherubini K. , Chies J. , Dias A. C. O. 
Published: February 2004

BACKGROUND:  The recurrent aphthous stomatitis (RAS) is a common disease with unknown etiology. Helicobacter pylori has been shown to be the causative factor in peptic ulcers. Considering the similarities of histologic features between gastric and oral ulceration, we studied the possible involvement of H. pylori in the development of RAS.METHODS:  A total of 105 children and adolescents were investigated – 53 patients with RAS (case group) and 52 patients without lesions (control group). Specimens obtained by swabbing RAS lesions, intact oral mucosa, and dental plaque were submitted to a polymerase chain reaction (PCR)‐based assay.RESULTS:  Helicobacter pylori was present in six patients of the case group (11.3%) and in three of the control group (5.8%). When the site of infection was studied, 9.4% of the RAS lesions were PCR positives. In the case group and control group, 5.7 and 1.9% of the specimens from dental plaque, respectively, and 5.7 and 3.8% of the specimens from the intact oral mucosa, respectively, were PCR positives.CONCLUSION:  There was no association between RAS lesions and infection of the oral cavity by H. pylori in children and adolescents (P = 0.254).
Central giant cell granuloma of the jaws: assessment of cell cycle proteins
Authors: Kauzman Adel , Li Shu Qiu , Bradley Grace , Bell Robert S. , Wunder Jay S. , Kandel Rita 
Published: February 2004

Background:  Several reports have demonstrated the presence of a high proliferative activity in central giant cell granuloma, raising the possibility that deregulation of the cell cycle may contribute to its pathogenesis. As we identified alterations of cyclin D1 in giant cell tumor of bone, and as there are histologic similarities between central giant cell granuloma and giant cell tumor, we assessed jaw lesions for the presence of similar alterations.Methods:  Formalin‐fixed, paraffin‐embedded tissue from 29 cases of central giant cell granuloma was assessed for the expression of cyclin D1, cyclin B1, and MIB‐1 (Ki‐67) using immunohistochemistry. In addition, differential polymerase chain reaction (PCR) was used to determine whether there was cyclin D1 gene amplification.Results:  The cyclin D1 gene copy number appeared to be minimally elevated in 31% of the cases. Cyclin D1 protein overexpression was observed in 28 of 29 cases (96.5%). Immunostaining was present predominantly in the nuclei of the giant cells. Cyclin B1 and MIB‐1 immunoreactivity was restricted to the mononuclear cells with no staining present in the giant cells.Conclusions:  Cyclin D1 protein overexpression may be involved in the formation of the giant cells and the pathogenesis of central giant cell granuloma. As the distribution of immunostaining is identical to that observed in giant cell tumor of bone, our results support the possibility that central giant cell granuloma of the jaws and giant cell tumor of bone represent a similar disease process that clinically and histologically may have somewhat different features because of differences in the anatomical site of involvement.
Immunohistochemical localization of tissue‐type plasminogen activator and type I plasminogen activator inhibitor in radicular cysts
Authors: Tsai Chung‐Hung , Weng Sheng‐Feng , Yang Li‐Chiu , Huang Fu‐Mei , Chen Yi‐Juai , Chang Yu‐Chao 
Published: February 2004

Background:  The plasminogen/plasmin proteolytic system participates in a wide variety of extracellular matrix degradation. Detailed knowledge of plasminogen activators (PAs) and their inhibitors may be important for understanding the pathogenesis of radicular cysts. The purpose of this study was to investigate the in situ localization of tissue‐type PA (t‐PA) and type I PA inhibitor (PAI‐1) in radicular cysts.Methods:  Thirty formalin‐fixed, paraffin‐embedded specimens of radicular cysts were examined using immunohistochemistry. In addition, another section from each radicular cyst specimen was stained with hematoxylin and eosin to assess the presence of inflammatory infiltrates. Differences in t‐PA and PAI‐1 expression between tissues with low and high levels of inflammation were subsequently analyzed using Fisher's exact test.Results:  Both t‐PA‐ and PAI‐1‐positive cells were detected in the lining epithelium, connective tissue, inflammatory infiltrates, and endothelium. In addition, the t‐PA signal was mainly expressed in epithelial cells. However, the PAI‐1 signal was mainly expressed in fibroblasts. Moreover, significantly greater t‐PA as well as PAI‐1 expression was noted in radicular cysts with high levels of inflammation as compared to tissues with low levels of inflammatory cell infiltrates (P < 0.05).Conclusions:  The present study confirms earlier indications of local production of PA and its inhibitor in radicular cysts. In addition, this study further shows the tissue localization of the antigens for t‐PA as well as PAI‐1, and demonstrates that the expression of both t‐PA and PAI‐1 increases with the grade of inflammation in radicular cysts.
Web‐based Assessment and Test Analyses (WATA) system: development and evaluation
Authors: Wang T. H. , Wang K. H. , Wang W. L. , Huang S. C. , Chen S. Y. 
Published: February 2004

AbstractThis study introduces the development of a Web‐based assessment system, the Web‐based Assessment and Test Analyses (WATA) system, and examines its impacts on teacher education. The WATA system is a follow‐on system, which applies the Triple‐A Model (assembling, administering, and appraising). Its functions include (1) an engine for teachers to administer and manage testing, (2) an engine for students to apply tests, and (3) an engine for generating test results and analyses for teachers. Two studies were undertaken to assess the usefulness and potential benefits of the WATA system for teacher education. In the first study, 47 in‐service teachers were asked to assess the functions of the WATA system. The results indicated that they were satisfied with the Triple‐A Model of the WATA system. In the second study, 30 pre‐service teachers were required to use the WATA system during the teacher‐training program. After 4 months of experience in using the WATA system, the pre‐service teachers' perspectives of assessment have been changed significantly. The findings of these two studies might provide some guidance to help those who are interested in the development of Web‐based assessment and intend to infuse information technology into teacher education.
A structured dialogue tool for argumentative learning
Authors: Hirsch L. , Saeedi M. , Cornillon J. , Litosseliti L. 
Published: February 2004

AbstractThis paper presents a structured environment for Computer‐Supported Collaborative Argumentation, which we call the Argumentative Learning Experience (ALEX). The system aims to improve understanding of argumentation and to widen and deepen the space of debate among 16–18‐year‐old students. To use ALEX users make arguments by selecting and completing partial sentences. An automatically created visual representation of the argument is displayed and personalised advice on the argumentation is provided to each user.
Longer term effects of New York State’s law on drivers’ handheld cell phone use
Authors: McCartt A T , Geary L L 
Published: February 2004

Objective:To determine whether substantial short term declines in drivers’ use of handheld cell phones, after a state ban, were sustained one year later.Design:Drivers’ daytime handheld cell phone use was observed in four New York communities and two Connecticut communities. Observations were conducted one month before the ban, shortly after, and 16 months after. Driver gender, estimated age, and vehicle type were recorded for phone users and a sample of motorists.Intervention:Effective 1 November 2001, New York became the only state in the United States to ban drivers’ handheld cell phone use. Connecticut is an adjacent state without such a law.Sample:50 033 drivers in New York, 28 307 drivers in Connecticut.Outcome measures:Drivers’ handheld cell phone use rates in New York and Connecticut and rates by driver characteristics.Results:Overall use rates in Connecticut did not change. Overall use in New York declined from 2.3% pre-law to 1.1% shortly after (p<0.05). One year later, use was 2.1%, higher than immediately post-law (p<0.05) and not significantly different from pre-law. Initial declines in use followed by longer term increases were observed for males and females, drivers younger than 60, and car and van drivers; use patterns varied among the four communities. Publicity declined after the law’s implementation. No targeted enforcement efforts were evident. Cell phone citations issued during the first 15 months represented 2% of all traffic citations.Conclusions:Vigorous enforcement campaigns accompanied by publicity appear necessary to achieve longer term compliance with bans on drivers’ cell phone use.
Mechanisms and implications of phosphoinositide 3-kinase δ in promoting neutrophil trafficking into inflamed tissue
Authors: Puri Kamal D. , Doggett Teresa A. , Douangpanya Jason , Hou Yonghao , Tino William T. , Wilson Tim , Graf Thomas , Clayton Elizabeth , Turner Martin , Hayflick Joel S. , Diacovo Thomas G. 
Published: February 2004

AbstractThe phosphoinositide 3-kinase (PI3K) catalytic subunit p110δ is expressed in neutrophils and is thought to play a role in their accumulation at sites of inflammation by contributing to chemoattractant-directed migration. We report here that p110δ is present in endothelial cells and participates in neutrophil trafficking by modulating the proadhesive state of these cells in response to tumor necrosis factor α (TNFα). Specifically, administration of the selective inhibitor of PI3Kδ, IC87114, to animals reduced neutrophil tethering to and increased rolling velocities on cytokine-activated microvessels in a manner similar to that observed in mice deficient in p110δ. These results were confirmed in vitro as inhibition of this isoform in endothelium, but not neutrophils, diminished cell attachment in flow. A role for PI3Kδ in TNFα-induced signaling is demonstrated by a reduction in Akt-phosphorylation and phosphatidylinositol-dependent kinase 1 (PDK1) enzyme activity upon treatment of this cell type with IC87114. p110δ expressed in neutrophils also contributes to trafficking as demonstrated by the impaired movement of these cells across inflamed venules in animals in which this catalytic subunit was blocked or genetically deleted, results corroborated in transwell migration assays. Thus, PI3Kδ may be a reasonable therapeutic target in specific inflammatory conditions as blockade of its activity reduces neutrophil influx into tissues by diminishing their attachment to and migration across vascular endothelium. (Blood. 2004;103:3448-3456)
A novel plasma proteinase potentiates α2-antiplasmin inhibition of fibrin digestion
Authors: Lee Kyung N. , Jackson Kenneth W. , Christiansen Victoria J. , Chung Keun H. , McKee Patrick A. 
Published: February 2004

AbstractHuman α2-antiplasmin (α2AP), also known as α2-plasmin inhibitor, is the major inhibitor of the proteolytic enzyme plasmin that digests fibrin. There are 2 N-terminal forms of α2AP that circulate in human plasma: a 464-residue protein with Met as the N-terminus, Met-α2AP, and a 452-residue version with Asn as the N-terminus, Asn-α2AP. We have discovered and purified a proteinase from human plasma that cleaves the Pro12-Asn13 bond of Met-α2AP to yield Asn-α2AP and have named it antiplasmin-cleaving enzyme (APCE). APCE is similar in primary structure and catalytic properties to membrane-bound fibroblast activation protein/seprase for which a physiologic substrate has not been clearly defined. We found that Asn-α2AP becomes cross-linked to fibrin by activated factor XIII approximately 13 times faster than native Met-α2AP during clot formation and that clot lysis rates are slowed in direct proportion to the ratio of Asn-α2AP to Met-α2AP in human plasma. We conclude that APCE cleaves Met-α2AP to the derivative Asn-α2AP, which is more efficiently incorporated into fibrin and consequently makes it strikingly resistant to plasmin digestion. APCE may represent a new target for pharmacologic inhibition, since less generation and incorporation of Asn-α2AP could result in a more rapid removal of fibrin by plasmin during atherogenesis, thrombosis, and inflammatory states.