bluuebunny/crossref_metadata_2025_split huggingface dataset:
Student Spanish Use and Investment in a Dual Immersion Classroom: Implications for Second Language Acquisition and Heritage Language Maintenance
Authors: Potowski Kim 
Published: February 2004

In dual immersion classrooms, students from different language backgrounds are immersed in the minority language for large portions of the school day with the expectation that they will become equally proficient in their first language (L1) and in their second language (L2). Research on dual immersion indicates that students reach above‐average levels of academic achievement and linguistic proficiency, but, to date, very few quantifications have been made of how much of the minority language is used in these environments. Given that actually speaking a language is crucial for L2 acquisition as well as for heritage language maintenance, this study explored how much Spanish was used and for what purposes by 4 students (2 Spanish L1 and 2 two Spanish L2) in a Spanish/English dual immersion classroom.Over 2,000 turns of natural classroom speech were recorded during a 5‐month period. Overall, the students used Spanish 56% of the time, with 4 major trends: (a) The girls used more Spanish than the boys, regardless of L1; (b) the students averaged 82% Spanish when talking with the teacher, but only 32% when talking to peers; (c) Spanish was used primarily for on‐task topics; (d) the students' English when speaking with peers covered a wider range of functions than did their Spanish. These findings lend support to proposals that a kind of diglossia exists in immersion classrooms (Tarone & Swain, 1995).Additional ethnographic data gathered through extensive participant‐observations and interviews were interpreted using the concept of investment (Norton, 2000). Explanations of the students' language use are offered according to their sometimes competing identity investments.
Interlinguistic Variation and Similarity in Second Language Speech Act Behavior
Authors: Yu Ming–Chung 
Published: February 2004

This study investigates the compliment response behavior of 2 groups of Chinese learners of English, one living in the United States and the other in Taiwan. The present study compared the behavior of these learner groups with that of native Chinese and English speakers in order to determine how they respond to compliments in different situations when two contextual variables, addressees' status and gender, vary.Compliment responses by the Chinese using Chinese and the learners in Taiwan were more likely to be rejections than acceptances, whereas responses to compliments by the Americans and the learners in the United States were more likely to be acceptances than rejections. Furthermore, although there were substantial differences between the 2 learner groups, the performance of both reflected native language (L1) communicative styles and transfer of L1 sociocultural strategies in their second language behavior.
In vitro antimicrobial effect of chlorhexidine‐impregnated gutta percha points on Enterococcus faecalis
Authors: Lui J. N. , Sae‐Lim V. , Song K. P. , Chen N. N. 
Published: February 2004

AbstractAim  To evaluate the in vitro antimicrobial effect of chlorhexidine‐impregnated gutta percha points, Roeko activ point (Roeko, Langenau, Germany) on Enterococcus faecalis.Methodology  Human maxillary premolar roots were prepared with .04 rotary ProFile instruments to a master apical file size 40, autoclave‐sterilized and then infected with E. faecalis (ATCC 29212) for 3 weeks. Baseline controls were carried out verifying negligible effects of plain gutta percha cones on E. faecalis. Subsequent to intracanal placement of calcium hydroxide, ‘activ points’ or saline (positive control) and the 2‐week incubation in 54 root specimens, dentine sampling at depths of 100 and 250 µm was carried out using .04 rotary ProFile instruments at sizes 60 and 90 to assess the quantity of bacteria present. Inactivating agents were used prior to sampling and the colony‐forming units (CFU) of E. faecalis were then plate‐counted after culturing. Statistical analysis was completed using the paired t‐test.Results  In comparison to the positive control, treatment with calcium hydroxide (P = 0.000 and 0.000) or activ points (P = 0.000 and 0.002) produced significantly lower colony counts of E. faecalis at dentine depths of 100 and 250 µm, respectively. Calcium hydroxide (2.10 × 102 CFU mL−1) was significantly more effective than activ points (1.58 × 103 CFU mL−1) at 100 µm (P = 0.013), but not at 250 µm (P = 0.353). Neither of these two medications was able to eliminate E. faecalis completely.Conclusions  Chlorhexidine‐impregnated activ points did not possess an in vitro inhibitory activity strong enough to eliminate E. faecalis completely from infected dentinal tubules.
Transforming Growth Factor‐beta 1 (TGF‐beta 1) expression in normal healthy pulps and in those with irreversible pulpitis
Authors: Piattelli A. , Rubini C. , Fioroni M. , Tripodi D. , Strocchi R. 
Published: February 2004

AbstractAim  To evaluate the Transforming Growth Factor‐beta 1 (TGF‐beta 1) expression in normal healthy pulps and in those with irreversible pulpitis.Methodology  Twenty‐three normal, healthy pulps were removed from mandibular third molars, and 20 pulps were retrieved from teeth with irreversible pulpitis. TGF‐beta 1 was evaluated in the odontoblastic and subodontoblastic layers, in the stromal cells (fibroblasts), and in the blood vessels. TGF‐beta 1 expression was determined by evaluating 500 cells in the odontoblastic and subodontoblastic layers and 500 fibroblasts in the stroma for each specimen, and counting the number of positive cells. The number of the positive vessels was evaluated in 10 high power fields (HPF). In almost all cases, the cellular positivity was cytoplasmatic. Statistical analysis was performed using Mann–Whitney U‐ and Student's t‐tests.Results  A higher expression of TGF‐beta 1 was found in the odontoblastic–subodontoblastic layer of the irreversible pulpitis specimens; this difference was statistically significant (P = 0.0002). No statistically significant difference was observed between the two groups in TGF‐beta 1 expression in the stromal cells (P = 0.54) or in the vascular component (P = 0.94).Conclusions  The higher and statistically significant expression of TGF‐beta 1 found in the odontoblastic–subodontoblastic layer of irreversible pulpitis specimens may indicate a role for TGF‐beta 1 in the dentinal repair processes after pulp inflammation.
Endodontic treatment of primary teeth using a combination of antibacterial drugs
Authors: Takushige T. , Cruz E. V. , Asgor Moral A. , Hoshino E. 
Published: February 2004

AbstractAim  To evaluate the clinical outcome of ‘Lesion Sterilization and Tissue Repair’ (LSTR) therapy for endodontic treatment of primary teeth.Methodology  A mixture of metronidazole, ciprofloxacin, and minocycline (3Mix) in ointment (macrogol mixed with propylene glycol: MP) or in a root canal sealer was used to disinfect infected root canals of 56 patients aged 4–18 years. Out of a total of 87 primary teeth, 81 cases had physiologic root resorption. A total of 54 radiolucent periradicular lesions were present. The root canals were not prepared before or after disinfection. 3Mix medicament (3Mix‐MP/3Mix‐sealer) was placed at orifices of root canals or on the bottom of pulp chambers, and then sealed with glass‐ionomer cement and further reinforced by a composite resin inlay prepared using a direct method and cemented with resin.Results  In all cases, clinical symptoms such as gingival swelling (52 cases), sinus tracts (22 cases), induced dull pain (3 cases), spontaneous dull pain (26 cases), and pain on biting (46 cases) disappeared after treatment, although in four cases clinical signs and symptoms were finally resolved only after retreatment using the same procedures. Thus, gingival abscesses and fistulae, if present, disappeared after a few days. Successor permanent teeth erupted without any disorders, or were found radiographically to be normal and in the process of eruption. All the cases were evaluated as successful. The mean function time of the primary teeth was 680 days (range: 68–2390 days), except for one case in which the successor permanent tooth was congenitally missing.Conclusion  Primary teeth with periradicular lesions with or without physiologic root resorption were treated successfully by the LSTR endodontic therapy.
C‐shaped root canals of mandibular second molars in a Korean population: clinical observation and in vitro analysis
Authors: Seo M. S. , Park D. S. 
Published: February 2004

AbstractAim  To investigate the incidence and morphology of C‐shaped root canals of the mandibular second molar in a Korean population.Methodology  Through clinical observation, randomly selected 272 mandibular second molars of Korean patients were accessed and evaluated after taking radiographs for determination of working length. In an in vitro analysis, 96 extracted mandibular second molars of Korean patients were collected and embedded in resin using an Endodontic cube technique, and were sectioned at intervals of 1 mm. The specimens were then observed with a surgical microscope and were photographed. Canal configurations were assigned to one of three categories: Category I defined a C‐shaped outline without any separation; Category II referred to those with canal configurations, where dentine separated one distinct canal from a buccal or lingual C‐shaped canal; Category III had two or more discrete and separate canals.Results  In clinical observation, 89 of 272 teeth (32.7%) had C‐shaped canals. Of the 96 teeth examined in vitro, 30 (31.3%) had C‐shaped canals. Upon in vitro analysis, only 1 tooth at the subpulpal level and 10 teeth at the apical 1 mm level were categorized under Category III.Conclusion  There was high prevalence of C‐shaped root canals in the mandibular second molars of Koreans. C‐shaped canals having semicolon and continuous shapes at the canal orifice have a high possibility of being divided into two or three canals in the apical region.
Proliferation of dental pulp fibroblasts in response to thrombin involves mitogen‐activated protein kinase signalling
Authors: Gruber R. , Jindra C. , Kandler B. , Watzak G. , Fischer M. B. , Watzek G. 
Published: February 2004

AbstractAim  To examine the involvement of mitogen‐activated protein kinases (MAPK) signalling on thrombin‐stimulated human dental pulp fibroblasts (DPF).Methodology  Dental pulp fibroblasts were isolated from dental pulp connective tissue of third molars and expanded in vitro. Expression of thrombin receptors was analysed by RT‐PCR, and cell proliferation was measured by 3[H]‐thymidine incorporation assay. Phosphorylation levels of MAPK were determined by Western blot analysis, and alkaline phosphatase activity was measured to serve as a marker for odontogenic differentiation. Statistical analysis was performed by Student's t‐test.Results  Dental pulp fibroblasts express the thrombin receptors protease‐activated receptor‐1 (PAR‐1), PAR‐3 and PAR‐4. Measurement of 3[H]‐thymidine incorporation revealed a dose‐dependent increase of DNA synthesis in response to thrombin treatment. The thrombin‐induced mitogenic activity was decreased by the extracellular signal‐regulated protein kinase (ERK) signalling inhibitor PD98059 (P < 0.05), and by SB203580 (P < 0.05), a p38 MAPK inhibitor. Western blot analysis demonstrated increased phosphorylation of ERK in DPF following stimulation with thrombin, while p38 MAPK and c‐Jun NH2‐terminal kinase (JNK) were not activated. Alkaline phosphatase activity of DPF remained unchanged upon incubation with thrombin.Conclusions  These results suggest that signalling via MAPK mediates the mitogenic activity of thrombin on DPF and may thus play a role during the early stages of pulp repair.
Population synchrony within and among Lepidoptera species in relation to weather, phylogeny, and larval phenology
Authors: Raimondo Sandy , Liebhold Andrew M. , Strazanac John S. , Butler Linda 
Published: February 2004

Abstract.  1. The population dynamics of native herbivore species in central Appalachian deciduous forests were studied by analysing patterns of synchrony among intra‐ and interspecific populations and weather.2. Spatial synchrony of 10 Lepidoptera species and three weather variables (minimum temperature, maximum temperature, precipitation) from 12 sites was measured using cross‐correlation functions relating levels of synchrony to the distance separating each set of populations. Based on both the pattern of synchrony and the region‐wide cross‐correlation coefficients, Lepidoptera species appear to be synchronised, at least in part, by local weather conditions.3. Interspecific cross‐correlations were calculated for all sympatric species pairs and trends in interspecific synchrony were related to phylogenetic relatedness, life‐history timing, and weather. Interspecific synchrony was highest among species whose larvae were present during the same time of the season, but there was no relationship between interspecific synchrony and phylogenetic affinity.4. Spatial synchrony of weather variables was significantly related to both species of some interspecific pairs, indicating weather as a potential mechanism involved in synchronising populations of different species.
Pharmacokinetics of desflurane uptake into the brain and body
Authors: Lu C. C. , Tsai C. S. , Ho S. T. , Chueng C. M. , Wang J. J. , Wong C. S. , Chang S. Y. , Lin C. Y. 
Published: February 2004

SummaryThe aim of this study was to investigate the pharmacokinetics of desflurane uptake into the brain and body by comparing desflurane concentrations in internal jugular‐bulb blood (Jdes), arterial blood (Ades) and pulmonary arterial blood (PAdes) at a fixed inspired desflurane concentration. Thirteen patients (aged 42–72 years) undergoing coronary artery bypass grafting surgery were enrolled in this study. They were anaesthetised using a constant 5% inspired desflurane concentration (CIdes) during the first hour of anaesthesia. Under constant volume‐controlled ventilation, CIdes and end‐tidal desflurane (CEdes) were measured with an infrared analyser. The desflurane concentration in the blood was analysed using gas chromatography, and cardiac output was measured using an Opti‐Q pulmonary artery catheter. It took 24 min for the Jdes to equilibrate with Ades. Both CIdes–CEdes and Ades–PAdes gradients persisted during the study period. There was no further uptake of desflurane into the brain after 24 min but there was near‐constant uptake into the body.
The moisture‐conserving performance of breathing system filters during the first three minutes of simulated use
Authors: Wilkes A. R. 
Published: February 2004

SummaryBreathing system filters are recommended for use during anaesthesia to protect the patient from inhaling gas‐borne particles. Filters placed at the patient connection port of the breathing system can also humidify the inspired gases. The end‐inspired moisture content was measured when using five different filters with two different ventilatory test conditions on a patient model during a typical pre‐oxygenation period of 3 min. The moisture content of the end‐inspired air at the end of the 3‐min period varied from 6.4 to 27.8 and from 4.4 to 25.9 g.m−3 for tidal volumes of 0.5 and 1.0 l, respectively (p < 0.0001 for all pairwise comparisons of the five filters and for the two tidal volumes). Those breathing system filters that have at least an adequate level of performance (at least 20 g.m−3) will generally achieve this level within the 3‐min pre‐oxygenation period.
Pressures within air‐filled tracheal cuffs at altitude – an in vivo study
Authors: Henning J. , Sharley P. , Young R. 
Published: February 2004

SummaryAeromedical transport of mechanically ventilated critically ill patients is now a frequent occurrence. However, the performance of the air filled tracheal tube cuff at altitude has not been studied in vivo. We measured the tracheal cuff pressures at ground level and at 3000 ft, in 10 intubated patients. With air providing the seal in the cuff the mean rise in cuff pressure was 23 cmH2O, which took the pressures above the critical perfusion pressure of the tracheal mucosa. This could lead to tracheal injury.
Measuring tracheal airway pressures during transtracheal jet ventilation: an observational study*
Authors: Patel C. , Diba A. 
Published: February 2004

SummaryTracheal airway pressures were measured via a transduced fibrescope during transtracheal jet ventilation in 10 patients. Ravussin transtracheal jet ventilation catheters were inserted under local anaesthesia. Following induction of general anaesthesia, tracheal airway pressures were measured at three anatomical levels during fibreoptic intubation. Overall pressure changes during transtracheal jet ventilation were small with the maximal pressure increase (13 mmHg) measured at the carina.
The moisture‐conserving performance of breathing system filters in use with simulated circle anaesthesia breathing systems*
Authors: Wilkes A. R. 
Published: February 2004

SummaryBreathing system filters can be used to humidify gases delivered to patients. Performance can be determined by measuring the net moisture loss (the difference between expired and inspired levels of humidity) from a patient model. The net moisture loss should be decreased by increasing the level of humidity in the breathing system by, for example, using a circle breathing system. The effect of four different filters, three different levels of humidity in the breathing system (7, 13 and 19 g.m−3) and two tidal volumes (0.5 l and 1.0 l) on the net moisture loss from a patient model was measured. The net moisture loss decreased as the humidity in the breathing system increased and was less for the lower tidal volume. Adequate levels of humidity (≥ 20 g.m−3) will be delivered to patients by most filters provided they are used in conjunction with circle breathing systems and low fresh gas flows.
Activity‐Dependent Dynamics of Coexisting Brain‐Derived Neurotrophic Factor, Pro‐Opiomelanocortin and α‐Melanophore‐Stimulating Hormone in Melanotrope Cells ofXenopus laevis
Authors: Wang L. C. , Meijer H. K. , Humbel B. M. , Jenks B. G. , Roubos E. W. 
Published: February 2004

AbstractBrain‐derived neurotrophic factor (BDNF) is involved as an autocrine factor in the regulation of the secretory activity of the neuroendocrine pituitary melanotrope cells ofXenopus laevis. We studied the subcellular distribution of BDNF inXenopusmelanotropes using a combination of high‐pressure freezing, cryosubstitution and immunoelectron microscopy. Presence of BDNF, pro‐opiomelanocortin (POMC) and α‐melanophore‐stimulating hormone (αMSH) within melanotrope secretory granules was studied by triple‐labelling immunoelectron microscopy. In addition, intracellular processing of BDNF was investigated by quantifying the number of immunogold particles in different stages of secretory granule maturation, in animals adapted to black or white background light conditions. The high‐pressure freezing technique provides excellent preservation of both cellular ultrastructure and antigenicity. BDNF coexists with POMC and αMSH within secretory granules. BDNF‐immunoreactivity increases along the secretory granule maturation axis (i.e. from electron‐dense, via moderately electron‐dense, to electron‐lucent secretory granules). Immature, low immunoreactive, electron‐dense secretory granules are assumed to contain mainly or even exclusively proBDNF. Strongly immunoreactive electron‐lucent secretory granules represent the mature granule stage in which proBDNF has been processed to mature BDNF. Furthermore, in moderately electron‐dense secretory granules, immunoreactivity is markedly (+79%) higher in black‐adapted than in white‐adapted animals, indicating that stimulation of melanotrope cell activity by the black background condition speeds up processing of BDNF from its precursor in this granule stage. It is concluded that, in theXenopusmelanotrope, BDNF biosynthesis and processing occur along the secretory granule maturation axis, together with that of POMC‐derived αMSH, and that the environmental light condition not only controls the biosynthesis and secretion of BDNF and of POMC end‐products, but also regulates the rate of their intragranular processing.
A pheochromocytoma presenting as generalized pigmentation
Authors: Zawar Vijay P. , Walvekar Rajesh 
Published: February 2004

A 25‐year‐old man presented with pigmentation over the face and hands of 6 months’ duration, which darkened on sun exposure. Four weeks after the onset of pigmentation, he experienced intermittent episodes of excessive sweating, tremors, fatiguability, and headache, which had gradually increased in frequency over the last 5 months. There was a history of anorexia and weight loss of 7 kg over the last 6 months.There was no history of previous drug ingestion, chemical exposure, or any major illness. The family history, including diabetes, tuberculosis, hypertension, endocrine tumors, and pigmentation, was negative.On dermatologic examination, slate‐gray macular pigmentation was noticed on the forehead, cheeks, nose, lips (Fig. 1), helices of the ears, and dorsum of the hands, with prominence over the knuckles and the skin over the interphalangeal joints, elbows, and knees (Fig. 2).Slate‐gray pigmentation on the forehead, cheeks, nose, and lipsimageSlate‐gray pigmentation on the dorsum of the hands, knuckles, and skin over the interphalangeal jointsimageThe scars of acne and previous injuries over the legs were also hyperpigmented. The mucosa of the hard palate showed streaky linear pigmentation in the midline.On general examination, tachycardia was a constant feature at all visits, and more marked on the last three visits (104, 100, and 120/min, respectively). Hypertension was noted in the right upper arm in the supine position at two of the last three consultations (140/100, 120/84, and 180/118 mmHg, respectively). A significant orthostatic hypotension was noted on standing during the last visit, i.e. 150/110 mmHg.The following laboratory investigations were performed: hemoglobin (Hb), 11.7 g%; erythrocyte sedimentation rate (ESR), 30 mm in the first hour; serum cortisol, 26.8 mg/dL (N < 14 mg/dL, PM sample); serum adrenocorticotrophic hormone (ACTH), 101 pg/mL (N < 60 pg/mL); urinary vanillylmandelic acid (VMA), 16.3 mg in 24 h (N < 9 mg/24 h). The following were all within normal limits: complete blood count (CBC), blood sugar, urinalysis, serum electrolytes, calcium, B‐12 levels, thyroid and liver function tests, and stool (routine and occult blood) test. Chest X‐ray, thyroid scan, and ultrasonography were normal. Human immunodeficiency virus (HIV) was nonreactive.Abdominal sonography revealed a hypoechoic and well‐circumscribed mass in the left suprarenal area. Computed tomography of the abdomen confirmed a tumor location in the left adrenal gland with mild enhancement after contrast (Fig. 3).Ultrasonography depicting tumor location in the left adrenal glandimageThe patient was operated on to remove a mass measuring 5 cm × 3.5 cm × 3.2 cm. Histopathology of the tissue confirmed a diagnosis of pheochromocytoma.To our surprise, the pigmentation faded rapidly in the immediate postoperative period and the scar at the operation site did not pigment significantly (Fig. 4).Post‐operative fading of pigmentation 6 weeks after surgeryimage