bluuebunny/crossref_metadata_2025_split huggingface dataset:
Portraying science in the classroom: The manifestation of scientists' beliefs in classroom practice
Authors: Southerland Sherry A. , Gess‐Newsome Julie , Johnston Adam 
Published: August 2003

AbstractIf the goals of science education reform are to be realized, science instruction must change across the academic spectrum, including at the collegiate level. This study examines the beliefs and teaching practices of three scientists as they designed and implemented an integrated science course for nonmajors that was designed to emphasize the nature of science. Our results indicated that, like public school teachers, scientists' beliefs about the nature of science are manifested in their enactment of curriculum—although this manifestation is clearly not a straightforward or simplistic one. Personal beliefs about the nature of science can differ from those of the course, thus resulting in an enactment that differs from original conceptions. Even when personal beliefs match those of the course, sophisticated understandings of the nature of science are not enough to ensure the straightforward translation of beliefs into practice. Mitigating factors included limited pedagogical content knowledge, difficulty in achieving integration of the scientific disciplines, and lack of opportunity and scaffolding to forge true consensus between the participating scientists. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 669–691, 2003
What “ideas‐about‐science” should be taught in school science? A Delphi study of the expert community
Authors: Osborne Jonathan , Collins Sue , Ratcliffe Mary , Millar Robin , Duschl Rick 
Published: August 2003

AbstractRecent arguments in science education have proposed that school science should pay more attention to teaching the nature of science and its social practices. However, unlike the content of science, for which there is well‐established consensus, there would appear to be much less unanimity within the academic community about which “ideas‐about‐science” are essential elements that should be included in the contemporary school science curriculum. Hence, this study sought to determine empirically the extent of any consensus using a three stage Delphi questionnaire with 23 participants drawn from the communities of leading and acknowledged international experts of science educators; scientists; historians, philosophers, and sociologists of science; experts engaged in work to improve the public understanding of science; and expert science teachers. The outcome of the research was a set of nine themes encapsulating key ideas about the nature of science for which there was consensus and which were considered to be an essential component of school science curriculum. Together with extensive comments provided by the participants, these data give some measure of the existing level of agreement in the community engaged in science education and science communication about the salient features of a vulgarized account of the nature of science. Although some of the themes are already a feature of existing school science curricula, many others are not. The findings of this research, therefore, challenge (a) whether the picture of science represented in the school science curriculum is sufficiently comprehensive, and (b) whether there balance in the curriculum between teaching about the content of science and the nature of science is appropriate. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 692–720, 2003
The subgingival microflora in phenytoin‐induced gingival hyperplasia
Authors: Takada Kazuko , Sugiyama Hitoshi , Umezawa Koji , Mega Junichi , Hirasawa Masatomo 
Published: August 2003

Objectives:  Microbial flora and gingival conditions were compared between a group of patients with phenytoin‐induced gingival hyperplasia as a test group, a control group of patients who were administered phenytoin without gingival hyperplasia and a blank group who took no phenytoin and no gingival hyperplasia in mentally retarded patients.Materials and methods:  Subgingival plaque samples were collected from a PHT‐induced overgrown gingival pocket and microbiological experiments were performed by culture and PCR methods.Results:  The predominant genera in total cultivable bacteria from subgingival plaque samples were streptococcus and actinomyces with recovery ranges of 37.6–42.1% and 23.4–25.5% of total bacteria, respectively, in all groups. The test group showed a significantly higher level of obligate Gram‐negative rods than the control and blank groups. Black‐pigmented obligate anaerobic Gram‐negative rods were detected in 10.3% of total cultivable bacteria in the test group. The black‐pigmented rods were predominantly Prevotella intermedia in the test group and Prevotella nigrescens in the control and blank groups. Porphyromonas gingivalis and Porphyromonas endodontalis were also detected in the test group with small values.Conclusions:  These results suggested that black‐pigmented rods, particularly P. intermedia, could be habitable in the environment of gingival hyperplasia.
Induction of cyclooxygenase‐2 mRNA and protein expression in human gingival fibroblasts stimulated with nicotine
Authors: Chang Yu‐Chao , Tsai Chung‐Hung , Yang Shyh‐Hwang , Liu Chia‐Ming , Chou Ming‐Yung 
Published: August 2003

Background:  Cigarette smoking is a major risk factor in the development and further progression of periodontal diseases. COX‐2 is an inducible enzyme believed to be responsible for prostaglandin synthesis at site of inflammation. Currently, there is limited information on the regulation of COX‐2 expression in smoking‐associated periodontal disease.Objectives:  The aim of the present study was to investigate the effects of nicotine on the expression of cyclooxygenase‐2 (COX‐2) mRNA gene and protein in cultured human gingival fibroblasts (HGFs). Furthermore, to elucidate whether induction of COX‐2 may be associated with nicotine‐ induced cytotoxicity, NS‐398 (a selective COX‐2 inhibitor), was added to test its protective effect.Methods:  The quantitative reverse‐transcriptase polymerase chain reaction and Western blot assays were used to investigate the effects of human HGFs exposed to nicotine. In addition, NS‐398 was added to test how it modulated the effects of nicotine.Results:  The exposure of quiescent human HGFs to nicotine resulted in the induction of COX‐2 mRNA expression. The levels of the COX‐2 mRNAs increased about 1.5 and 2.5 fold after exposure to 2.5 and 15 mm nicotine for 2 h (P < 0.05), respectively. Moreover, the peak of COX‐2 mRNA levels induced by nicotine was 10 mm at 2 h incubation period. Investigations of the time dependence of COX‐2 mRNA expression in nicotine‐treated HGFs revealed a rapid accumulation of the transcript, a signal first detectable at 30 min and diminished to control level after 8 h. In addition, 10 mm nicotine also induced COX‐2 protein expression in HGFs. The kinetics of this response showed that COX‐2 was detectable at 4 h and diminished nearly to control level after 24 h. NS‐398 at non‐cytotoxic dose is not able to prevent nicotine‐induced cytotoxicity.Conclusions:  Taken together, the activation of COX‐2 expression by nicotine suggests a potential role for nicotine in the pathogenesis of smoking‐associated periodontal disease. In addition, nicotine‐induced cytotoxicity is not directly via the induction of COX‐2 expression.
Immunohistochemical localization of fibromodulin in the periodontium during cementogenesis and root formation in the rat molar
Authors: Matias M. A. , Li H. , Young W. G. , Bartold P. M. 
Published: August 2003

Background:  Cementum is essential for periodontal regeneration, as it provides anchorage between the root surface and the periodontal ligament. A variety of macromolecules present in the extracellular matrix of the periodontium, including proteoglycans, are likely to play a regulatory role in cementogenesis. Recently, the small leucine‐rich proteoglycan, fibromodulin, has been isolated from bovine periodontal ligament and localized in bovine cementum, as well as in human periodontal ligament.Objective:  The aim of this study was to examine the distribution of fibromodulin during cementogenesis and root formation.Methods:  A standard indirect immunoperoxidase technique was employed, using an antifibromodulin polyclonal antibody on sections of molar teeth from rats aged 3, 5 and 8 weeks.Results:  Immunoreactivity to fibromodulin was evident in the periodontal ligament in all sections. An intense positive stain was observed in the extracellular matrix where the periodontal ligament fibers insert into the alveolar bone and where the Sharpey's fibers insert into the cementum. There was no staining evident in the mineralized cellular and acellular cementum. The intensity of immunoreactivity to the antifibromodulin antibody increased proportionally with increasing tissue maturation.Conclusion:  The results from this study suggest that fibromodulin is a significant component of the extracellular matrix in the periodontal ligament during development, and may play a regulatory role in the mineralization process or maintaining homeostasis at the hard–soft tissue interface during cementogenesis.
Dietary supplementation of (+)‐catechin protects against UVB‐induced skin damage by modulating antioxidant enzyme activities
Authors: Jeon S. E. , Choi‐Kwon S. , Park K. A. , Lee H. J. , Park M. S. , Lee J. H. , Kwon S. B. , Park K. C. 
Published: August 2003

Purpose: The aim of this study was to investigate the effects of dietary supplementation with (+)‐catechin on cutaneous antioxidant enzymes and the skin damage caused by UVB irradiation.Methods: BALB/c mice were divided into three groups. Each group was fed a regular diet (RD) or a 2% catechin‐supplemented diet for either 2 weeks (2CSD) or 4 weeks (4CSD) ad libitum prior to UVB irradiation. Skin was removed for the antioxidant enzyme assay, hematoxylin and eosin staining, and the TEM analysis before and at various time points after UVB (200 mJ/cm2) irradiation.Results: Before UVB irradiation, the superoxide dismutase (SOD) and catalase (CAT) activities of the 2CSD and the 4CSD groups were found to be lower than those of the RD group, whereas the glutathione peroxidase (GPx) activity of the 4CSD group was higher than those of the RD and the 2CSD groups (P<0.05). The SOD and CAT activities of the RD group decreased after UVB irradiation, while those of the 2CSD and the 4CSD groups increased immediately after irradiation and then decreased (P<0.05). Immediately after UVB irradiation, the GPx activities of the 4CSD and the 2CSD groups increased, but that of the RD group decreased. The GPx activity of all three groups showed a tendency to return to pre‐UVB irradiation levels with time. Light microscopic findings of the RD group showed epidermal thinning and apoptotic cells at 24 h after UVB irradiation and mostly necrotic cells at 48 h, whereas only moderate thickening of the epidermis was observed in the 2CSD group at 48 h after irradiation. An electron microscopic examination produced similar findings. At 48 h after irradiation, nearly all epidermal cells seemed to be damaged in the RD group as compared to the 2CSD group.Conclusion: These results demonstrate that dietary supplementation with (+)‐catechin could protect epidermal cells against UVB‐induced damage by modulating antioxidant enzyme activities.
Satellite species in lampreys: a worldwide trend for ecological speciation in sympatry?
Authors: Salewski V. 
Published: August 2003

Amongst several theories of speciation, sympatric speciation has been the most controversial but it is now widely accepted that populations can become reproductively isolated without being separated geographically. One problem with the acceptance of the theory of sympatric speciation, however, has been the lack of supporting empirical data and it is still believed that geographical isolation is responsible for the majority of speciation events. Here the example of species pairs in lampreys suggests that sympatric speciation in a whole taxonomic group could occur throughout its worldwide range.Lampreys occur in two ecologically distinct forms: parasitic mostly anadromous species that forage on tissue and body fluids of host fishes, and non‐parasitic forms that, apart from a short adult life when they cease feeding, spend their entire life as filter feeders in the substratum of stream beds. Both forms occur in sympatric species pairs throughout the range of lampreys that occur in Eurasia, North America and Australia and it is widely acknowledged that non‐parasitic forms derive from parasitic forms. The larvae of both forms can be distinguished by their potential fecundity and therefore, it is argued that the mode of life is not a consequence of different ecological conditions. Furthermore, as lampreys prefer to choose mates of similar sizes and fertilization success decreases with increasing difference in body size, there is a strong disruptive selection between the two forms and they are therefore reproductively isolated. Besides theoretical aspects, the similarity of the species pairs, together with their occurrence in sympatry, the occurrence of forms with intermediate characteristics, and examples where speciation might be in progress, hints at the possibility that speciation also occurred in sympatry. The difference between lampreys and other examples of sympatric speciation is that there seems to be a trend towards sympatric speciation events throughout the worldwide range of lampreys which is neither restricted to relatively small localities nor caused by human disturbance. Species pairs in lampreys therefore offer a unique possibility of studying the process of sympatric speciation on a large scale.
Predictors of beer advertising awareness among eighth graders
Authors: Collins Rebecca L. , Schell Terry , Ellickson Phyllis L. , McCaffrey Daniel 
Published: August 2003

ABSTRACTAims  To identify correlates of beer advertising awareness among adolescents at an age when most initiate use of alcohol.Design  We conducted a cross‐sectional analysis of an in‐school survey about alcohol advertising. Structural equation modeling was used to test for independent predictors of a latent beer advertising awareness construct, separately among boys and girls.Setting  Twenty middle schools in South Dakota, USA participated during their spring semester.Participants  A total of 1530 eighth graders.Measurements  A latent advertisement awareness variable was derived based on recognition of six masked beer advertisements, knowledge of beer brands and knowledge of beer slogans. Tested predictors included measures of exposure to alcohol advertising in various venues, social norms regarding drinking, drinking beliefs and behavior and gender.Findings  Adolescents with greater exposure to advertisements in magazines, at sporting and music events and on television were more advertisement aware than those with less exposure, as were teens who watch more TV, pay attention to beer advertisements and know adults who drink. Beer advertisement awareness was dramatically higher among boys, and was associated with drinking only among boys.Conclusions  Each of a variety of advertising venues appears to influence independently the extent to which beer advertising is incorporated into an adolescent's cognitive world. Boys are more likely to be aware of and remember beer marketing, and may be more likely to drink as a result of this awareness than girls.
Perfusate composition influences nitric oxide homeostasis in rat juxtamedullary afferent arterioles
Authors: Pittner J. , Wolgast M. , Persson A. E. G. 
Published: August 2003

AbstractAim: Vascular diameters in isolated juxtamedullary nephron preparations perfused with cell‐free solutions differ from those perfused with blood. In the present study, the effects of the albumin content of the perfusate on the afferent arteriolar diameter and endothelial nitric oxide were investigated in the isolated juxtamedullary nephron preparation perfused with Krebs–Ringer–bicarbonate buffer containing albumin in different concentrations.Methods: The endothelium was loaded with DAF‐FM DA, a nitric oxide‐sensitive fluoroprobe. Perfusion was maintained either with 4% (control group), 10 or 20% albumin in the perfusate or with l‐NAME (10−4 m) added to the perfusate. Fluorescent images were obtained and stored for evaluation of DAF‐FM fluorescence and vascular diameters (in mid‐afferent arterioles) immediately before perfusate change and every 15 min thereafter, for a 2‐h period.Results: Increasing the albumin concentration resulted in a decrease in fluorescence. The most rapid decline of fluorescence was obtained following l‐NAME administration (relative fluorescence after 2 h: 4% albumin 92.4 ± 5.3%; 10% albumin 79.5 ± 4.2%; 20% albumin 66.2 ± 2.6%; l‐NAME 55.4 ± 3.0%; mean ± SD, n = 5). A dose‐dependent constriction of the afferent arterioles was observed (normalized diameter: 4% albumin 99.8 ± 3.0%; 10% albumin 80.3 ± 3.3%; 20% albumin 74.3 ± 3.2%; l‐NAME 70.6 ± 3.5%).Conclusion: We propose that albumin interferes with arteriolar nitric oxide homeostasis, probably by scavenging nitric oxide intra‐luminally. In this respect, albumin acts similarly to red blood cells in the circulation. The magnitude of the scavenging determines the effectiveness of autoregulation in the perfused preglomerular vessels. The scavenging properties of the perfusing fluid are important in setting operating levels of endothelial nitric oxide.
Hemichrome formation observed in human haemoglobin A under various buffer conditions
Authors: Sugawara Y. , Kadono E. , Suzuki A. , Yukuta Y. , Shibasaki Y. , Nishimura N. , Kameyama Y. , Hirota M. , Ishida C. , Higuchi N. , Haramoto K. , Sakai Y. , Soda H. 
Published: August 2003

AbstractAim: To observe hemichrome formation in human haemoglobin A under various buffer conditions.Method: Hemichrome formation of human oxyhaemoglobin A (HbO2) was studied spectrophotometrically in 0.1 m buffer at various temperatures and pH values.Results: Following autoxidation in ferrous HbO2, it was evident that formation of hemichrome, which tends to precipitate, occurred at various stages during the course of the autoxidation reaction namely at initial, intermediate or final stages, depending on temperature and pH of the solution. By varying temperature of the solution from 35 to 55 °C and pH from 4.5 to 10.5, it is shown here that HbO2 exhibits high susceptibility for hemichrome formation and its occurrence is a function of pH, temperature and progress of autoxidation of HbO2. Unlike HbO2 and its separated haemoglobin chains, monomeric bovine heart myoglobin (MbO2) did not easily form hemichrome.Conclusion: These findings provide a clue on the crucial role of haemoglobin molecule for senescent cell recognition or homeostasis in the blood circulation.
Validity of the microdialysis technique for experimental in vivo studies of myocardial energy metabolism
Authors: Kavianipour M. , Wikström G. , Ronquist G. , Waldenström A. 
Published: August 2003

AbstractObjectives: The validity of the microdialysis technique for experimental in vivo studies of myocardial energy metabolism is not known. To address this question interstitial levels of energy‐related metabolites (lactate, adenosine, inosine and hypoxanthine) obtained by the microdialysis technique were compared with corresponding metabolites from myocardial biopsies at given intervals in a porcine heart model using different protocols of ischaemia and reperfusion.Methods: In an open chest porcine heart model, interstitial levels of energy‐related metabolites were monitored using the microdialysis technique. All animals (n = 23) were subjected to 120‐min pretreatment followed by 40 min of regional ischaemia and 120 min of reperfusion. Tissue biopsies were obtained in the beginning, middle and at the end of the 40‐min ischaemic period and at the end of the reperfusion period. Pretreatment consisted of either rest (group 1, n = 7), or rest for 90 min and one ischaemia/reperfusion (10 + 20 min) cycle (group 2, n = 9), or four ischaemia/reperfusion cycles (10 + 20 min each) (group 3, n = 7).Results: Interstitial levels of energy‐related metabolites monitored by the microdialysis technique correlated with tissue biopsy levels of lactate (r = 0.90, P < 0.001), adenosine (r = 0.89, P < 0.001), inosine (r = 0.88, P < 0.001) and hypoxanthine (r = 0.91, P < 0.001), respectively, which were obtained by tissue biopsies at given time intervals. These significant correlations were valid regardless of the functional state of the myocardium.Conclusion: We observed significant correlations between microdialysis probe levels and tissue biopsy levels of energy‐related metabolites in both ischaemic and non‐ischaemic tissue. These data assess the validity of the microdialysis technique (in the current setting) for studying dynamic changes of myocardial energy metabolism.
Non‐linear dependence of interstitial fluid pressure on joint cavity pressure and implications for interstitial resistance in rabbit knee
Authors: Scott D. , Levick J. R. , Miserocchi G. 
Published: August 2003

AbstractAims:  Synovium retains lubricating fluid in the joint cavity. Synovial outflow resistance estimated as dPj/d (Pj, joint fluid pressure and trans‐synovial flow) is greater, however, than expected from interstitial glycosaminoglycan concentration. This study investigates whether subsynovial fluid pressure increases with intra‐articular pressure, as this would reduce the estimated resistance estimate.Methods:  Interstitial fluid pressure (Pif) was measured as a function of distance from the joint cavity in knees of anaesthetized rabbits, using servo‐null pressure‐measuring micropipettes and using an external ‘window’. Joint fluid pressure Pj was either endogenous (−2.4 ± 0.4 cmH2O, mean ± SEM) or held at ∼4, 8 or 15.0 cmH2O by a continuous intra‐articular saline infusion that matched the trans‐synovial interstitial drainage rate.Results:  At endogenous Pj the peri‐articular Pif was subatmospheric (−1.9 ± 0.3 cmH2O, n = 19). At raised Pj the Pif values became positive. Gradient dPif /dx was ∼20 times steeper across synovium than subsynovium. Pif close to the synovium–subsynovium border () increased as a non‐linear function of Pj to 1.4 ± 0.2 cmH2O (n = 23) at Pj = 4.3 ± 0.1 cmH2O : 2.3 ± 0.2 cmH2O (n = 17) at Pj = 7.6 ± 0.2 cmH2O: and 3.0 ± 0.4 cmH2O (n = 26) at Pj = 15 ± 0.2 cmH2O (P = 0.03, anova).Conclusions:  Synovial resistivity is ∼20× subsynovial resistivity. The increase in with Pj means that true synovial resistance d()/d is overestimated 1.5× by dPj/d. This narrows but does not eliminate the gap between analysed glycosaminoglycan concentration, 4 mg ml−1, and the net interstitial biopolymer concentration of 11.5 mg ml−1 needed to generate the resistance.