bluuebunny/crossref_metadata_2025_split huggingface dataset:
Teachers' support with ad‐hoc collaborative networks
Authors: Cortez C. , Nussbaum M. , López X. , Rodríguez P. , Santelices R. , Rosas R. , Marianov V. 
Published: June 2005

AbstractEfforts to improve the educational process must focus on those most responsible for implementing it: the teachers. It is with them in mind that we propose a face‐to‐face computer‐supported collaborative learning system that uses wirelessly networked hand‐held computers to create an environment for helping students assimilate and transfer educational content. Two applications of this system are presented in this paper. The first involves the use of the system by students, transforming classroom dynamics and enabling collaboration and interaction between the students and the teacher. In the second application, the system is used to help teachers update their knowledge of subject content and exchange methodological strategies.
Handheld tools that ‘Informate’ assessment of student learning in Science: a requirements analysis
Authors: Roschelle Jeremy , Penuel William R. , Yarnall Louise , Shechtman Nicole , Tatar Deborah 
Published: June 2005

Abstract
An important challenge faced by many teachers as they involve students in science investigations is measuring (‘assessing’) students' progress. Our detailed requirements analysis in a particular school district led to the idea that what teachers need most are ways to increase the quality of the information they have about what students know and can do, not automation of typical assessment practices. We see handheld computers as promising tools for addressing this need because they can give students and teachers frequent, integral access to new ways of expressing and communicating what they know and can do. Our requirements analysis has led us to emphasize a need for handheld‐based tools that ‘informate’ science instruction by:

Being oriented to the needs of teachers in transition to inquiry‐oriented pedagogy;
expanding the range of assessment tasks through a new representational medium and communication infrastructure;
creating new roles for students in expressing what they know and can do; and
focusing both students' and teachers' attention on scientific concepts.
Histology, Immunohistochemistry and Ultrastructure of the Equine Tubal Tonsil
Authors: Kumar P. , Timoney J. F. 
Published: June 2005

SummaryThe tubal tonsil of the horse surrounds the pharyngeal opening of the eustachian tube and is lined by pseudostratified columnar ciliated epithelium interspersed with areas of follicle‐associated epithelium (FAE) heavily infiltrated by lymphocytes but devoid of goblet and ciliated cells. Scanning and transmission electron microscopy revealed microvillous cells and cells with features characteristic of M cells such as reduced microvilli or depressed bare surface, more numerous mitochondria, small vesicles and lysosomes, as well as vimentin filaments and epitopes specific for GS 1‐B4 as previously seen in the nasopharyngeal tonsil. M cells were also identified in areas of respiratory epithelium not associated with lymphoid follicles and appeared to be the nasal mucosal counterparts of recently described intestinal villous M cells in the mouse. The underlying lymphoid tissue of the FAE was generally organized as solitary lymphoid follicles without germinal centres in contrast to the diffuse and large amount of organized lymphoid follicles with germinal centres that characterize the nasopharyngeal tonsil. CD8+ T and B‐lymphocytes were much fewer than in the nasopharyngeal tonsil. High endothelial venules were mainly oriented towards the parafollicular area and contained much fewer endothelial pores and vesiculo‐vacuolar organelles. Finally, scattered small clusters of mucus acini and striated muscles were other features that differentiated the tubal and nasopharyngeal tonsils.
Effects of Supplementation with Ascorbic Acid for a Period of 120 days on the Myosin‐V and NADPHd Positive Myenteric Neurons of the Ileum of Rats
Authors: Zanoni J. N. , de Freitas P. , Pereira R. V. F. , dos Santos Pereira M. A. , de Miranda Neto M. H. 
Published: June 2005

SummaryWe investigated the effect of ascorbic acid (AA) supplementation on the NADPH‐diaphorase (NADPHd) and myosin‐V myenteric neurons in the ileum of rats, after 4 months of treatment. Two groups were compared, i.e. controls rats (C) and AA‐treated rats (CA). Myosin‐V immunohistochemistry and NADPHd histochemistry were employed. We investigated the areas of 500 cell bodies of myosin‐V neurons and of 500 NADPHd stained neurons from all groups. The quantitative analysis was performed using an area of 8.96 mm2 from each ileum. There was an increase of 21.9% in the myosin‐V immunoreactive myenteric neurons (P > 0.05) and of 22.5% in the NADPHd in group CA when compared with C (P < 0.05). There were no significant differences when we compared the area of myosin‐V stained neurons between groups C and CA. However, we verified an area reduction of 7.5% in NADPHd neurons when comparing group C to group CA (P < 0.05).
The Distribution of External Taste Buds in Flower Fish (Pseudophoxinus antalyae)
Authors: ÇInar K. , ŞEnol N. 
Published: June 2005

SummaryPurpose of this study was to determine the distribution of external taste buds of flower fish (Pseudophoxinus antalyae) on different body locations (lip, lateral, ventral and dorsal areas, dorsal–pelvic–pectoral–anal fins). In this species, it was found that the density of taste buds was greater on lip epithelium than that of lateral (between pectoral–anal, anal–caudal fins), ventral (between pelvic and anal fins) and dorsal (close to the head) locations. It was observed that the shape of taste bud changed depending upon the epithelium thickness and it was found that some of these structures protruded towards to the exterior of epithelium.
Effect of Larval Food Amount on Ovariole Development in Queens ofTrigona spinipes(Hymenoptera, Apinae)
Authors: Lisboa L. C. O. , Serrão J. E. , Cruz‐Landim C. , Campos L. A. O. 
Published: June 2005

SummaryCaste determination inTrigona spinipesFabricius (Hymenoptera, Apidae, Meliponini) is trophogenic. Larvae that eat about 360 μl of food become queens, while those who consume 36 μl develop into workers. We studied the effect of larval nutrition on the number and length of ovarioles and on ovarian development in fifth instar larvae, white eyed, pink eyed and black‐eyed pupae as well as newly emerged adults. All larvae have four ovarioles per ovary, while in queen pupae this number ranged from 8 to 15. Cyst formation, the cell death and other characteristics of ovary morphogenesis were the same regardless of the quantity of food consumed. These results are discussed in relation to caste differentiation in other bees.
Light and Electron Microscopic Study of the Thoracic Respiratory Air Sacs of the Fowl
Authors: Bezuidenhout A. J. 
Published: June 2005

SummaryThere are conflicting reports in the existing literature on the nature of the epithelial lining and the content of the supporting connective tissue of the respiratory air sacs of birds. The present study describes the light and electron microscopic structure of the thoracic air sacs of the fowl. A simple squamous epithelium lined the greater part of the thoracic air sacs. The squamous cells characteristically contained vesicles filled with lamellar or myelinoid material. Localized areas of cuboidal to columnar ciliated epithelium were randomly distributed and often associated with underlying blood vessels. Isolated ciliated cells first appeared on squamous or low cuboidal cells and increased in frequency as the cells became taller. Occasional basal and goblet cells were seen between the ciliated columnar cells. A fibrous connective tissue stroma supported the epithelium. Fine elastic fibres were particularly prevalent immediately below the epithelium. Isolated smooth muscle myocytes were present in the connective tissue stroma. A sheet of smooth muscle extended some distance into the membrane from the attachment of the latter to the body wall. Numerous small blood vessels, lymphatics and occasional nerve bundles were observed in the stroma.
Histology, Immunohistochemistry and Ultrastructure of the Equine Palatine Tonsil
Authors: Kumar P. , Timoney J. F. 
Published: June 2005

SummaryThe palatine tonsils of five young horses formed 10–12 cm elongated follicular structures extending from the root of the tongue on either side to the base of the epiglottis and lateral to the glossoepiglottic fold. The stratified squamous non‐keratinized epithelium of the outer surface was modified into crypts as reticular epithelium by heavy infiltration of lymphoid cells from underlying lymphoid follicles. In places, lymphoid tissue reaching almost to the surface and with only one to two cell layers intact was identified as the lymphoepithelium. Langerhans cells with Birbeck granules were interspersed between epithelial cells. Lymphoid tissue organized in lymphoid follicles constituted the parenchyma of the palatine tonsil. CD4‐positive cells were more numerous and CD8‐positive lymphocytes less numerous compared with their distribution in the lingual tonsil. B cells and macrophages were also more numerous than in the lingual tonsil and lectins showed a different pattern of attachment. M cells were not observed. High endothelial venules with well‐developed vesiculo‐vacuolar organelle had structural evidence of transendothelial and interendothelial migration of lymphocytes. Striated muscles as seen in the deeper lamina propria mucosae of the lingual tonsil were absent. The immunohistological and ultrastructural characteristics of the equine palatine tonsil are similar to those of humans but differ from those of the lingual tonsil and are consistent with a role as an effector and inductor immunological organ.
On the Relationship between Herbaceous Cover and Vigilance Activity of Degus (Octodon degus)
Authors: Ebensperger Luis A. , Hurtado María J. 
Published: June 2005

AbstractA number of studies demonstrate that plant cover provides prey animals with refuges to decrease vulnerability to predators. However, others suggest plant cover to visually obstruct detection of predators or conspecifics. We suggest these seemingly conflicting results can, to some extent, be resolved if overhead vs. lateral cover are distinguished. We recorded seasonal variation in vigilance activity of a natural population of degus (Octodon degus), a diurnal, semi‐subterranean and social rodent from central Chile. We used these data to determine whether cover provided by herbaceous vegetation is mostly obstructive. The height of herbaceous vegetation in the habitat of degus varied seasonally, and the ability of degus (estimated from human observers) to detect potential predators decreased when herbaceous vegetation was high. This effect was more important for degus using quadruped postures and when dealing with terrestrial simulated predators. Accordingly, degus adjusted the quality rather than the quantity of their vigilance activity: male and female degus allocated similarly more time to bipedal vigilance when the height of herbs was high. Such increase in bipedal vigilance seemed to occur at the expense of quadruped vigilance instead of foraging time. Collectively, these results support the hypothesis that cover of herbaceous vegetation is mostly obstructive to degus when active above ground, a finding that contrasts with previous evidence supporting that shrub cover provides refuges against predators. The differential effects of shrubs and herbs on degu vigilance are likely linked to differences in the costs and benefits associated with each cover type. For degus, shrubs may provide more overhead (protective) than lateral (obstructive) cover.
Kinetics and metabolism of zearalenone in young female pigs
Authors: Dänicke S. , Swiech E. , Buraczewska L. , Ueberschär K.‐H. 
Published: June 2005

SummaryThe fate of a single bolus of the Fusarium mycotoxin zearalenone (ZON) given intravenously to pigs was followed up. Pigs were equipped with duodenal re‐entrant cannulas, post‐valvular T‐shape cannulas and with a urinary bladder balloon catheter. The animals were divided into three groups. Pigs of the control group were injected with ZON (Co), and pigs of the second group were also injected with ZON but their duodenal digesta was quantitatively exchanged for 12 h with corresponding pigs of the third group, not injected with ZON. Therefore, the second group had a disrupted entero‐hepatic cycling of ZON (DEHC) and the third one had an induced entero‐hepatic cycling of ZON (IEHC). The kinetic profile of ZON and its metabolites in plasma and their flow with urine, duodenal and ileal digesta and with faeces was examined over the next 72 h after the bolus was given. Eleven days later, pigs were slaughtered for collection of bile, urine and liver to analyse ZON residues. In all specimens examined, α‐zearalenol (ZOL) was detected as the only metabolite of ZON. Kinetic evaluation of the plasma data revealed that the terminal elimination half‐life of ZON was reduced from 2.63 h in pigs of Co‐group to 1.1 h when EHC of ZON was disrupted for 12 h (DEHC‐group). The maximum ZON concentration in plasma of pigs with the IEHC was found at 2.73 h after the bolus was given to their counterparts. The percentage of the α‐ZOL‐ and ZON‐area under the curves (AUC) estimated for the IEHC‐group amounted to approximately 18% of the corresponding AUC of the Co‐group which would suggest that a substantial proportion of both substances are re‐cycled via entero‐hepatic re‐circulation. Cumulative recovery of ZON and α‐ZOL, expressed as percentage of the ZON‐bolus was characterized by a saturation kinetics in urine and duodenal digesta, and after 72 h, the respective values for Co‐, DEH‐, and IEHC‐groups were 70%, 55% and 12%; and 35%, 22% and 11%. Faecal excretion started to increase steeply after 48 h and still continued to increase after 72 h when the cumulative excretion was 6%, 3% and 2% for Co‐, DEHC‐ and IEHC‐groups respectively. Fourteen days after the bolus injection, ZON and α‐ZOL concentrations in bile, liver and urine were lower than the detection limits of the applied method. The results would suggest that within this period of time a massive single bolus of ZON is nearly completely eliminated from the body.
Threonine and tryptophan ratios fed to nursery pigs*
Authors: Guzik A. C. , Pettitt M. J. , Beltranena E. , Southern L. L. , Kerr B. J. 
Published: June 2005

SummaryThe optimal ratio of tryptophan (Trp):lysine (Lys) relative to the ratio of threonine (Thr):Lys was studied in 288 crossbred (Cambrough 15 × Canabrid) nursery pigs from 7.1 to 15.6 kg BW. Treatments were arranged in a 3 × 3 factorial with three calculated ratios of true digestible Thr:Lys (0.55, 0.60, or 0.65) in combination with three Trp:Lys ratios (0.145, 0.170, or 0.195). Treatments were replicated with eight pens of four pigs each. The experiment lasted 28 day with Phase II (222.6 g CP and 11.9 g true digestible Lys/kg diet, initially 24 day of age and 7.1 kg BW) and Phase III (196.2 g CP and 10.1 kg true digestible Lys/kg diet, initially 38 day of age and 9.8 kg BW) diets each fed for 14 day. Threonine by Trp interactions were observed for average daily gain during each period, and for daily feed intake during Phase III and overall. Generally, Trp addition linearly increased gain and feed intake at a Thr:Lys ratio of 0.60 and 0.65 but not at a Thr:Lys ratio of 0.55. Gain:feed was increased linearly with increasing levels of Trp during both periods. There were no main effects of Thr in either time period or overall. Overall, optimal performance was obtained in pigs fed the true digestible Trp:Lys ratio of 0.195 at Thr:Lys ratios 0.60 or 0.65. These results indicate that Trp:Lys ratios above 0.195 may be needed to maximize performance in diets containing wheat and barley.
Ultrasonic Assessment of Puerperal Uterine Involution in Balady Goats
Authors: Ababneh M. M. , Degefa T. 
Published: June 2005

SummaryTwenty‐six postpartum Balady goats (primiparous, n = 13; pluriparous, n = 13) were used in this study. One animal of each group was slaughtered on postpartum days 1, 2, 4, 7, 10, 13, 19 and 25; in addition, three control nulliparous goats were slaughtered, and the genital tracts collected. Progress of uterine involution was monitored by repeated ultrasonographic measurements in live animals (primiparous n = 6; pluriparous n = 6) and measurement of the outer circumference of the uterine horns of slaughtered animals (primiparous n = 8; pluriparous n = 8). A consistent and progressive decrease in ultrasonographic and outer circumference measurements was found, although faster during the first 7 days postpartum than between days 7 and 19 postpartum. Uterine involution, assessed by the upper limit of the measurements in the nulliparous goats, followed a quadratic pattern and was completed by day 19 postpartum. Ultrasonographically, two elliptical–circular echogenic areas separated by an anechoic line of the stratum vascularis were depicted. Regressing caruncles and fluid in uterine lumen were recognized during the first week postpartum. Further analysis revealed a highly positive correlation between the outer circumference and ultrasonographic measurements. In conclusion, uterine involution in Balady goats was completed by day 19 postpartum and was unrelated to parity. The close association between ultrasound findings and macroscopic involution indicated that ultrasonography can dependably be used to monitor uterine involution under field conditions and can be a suitable alternative to animal slaughter for the study of uterine involution.
Radial nerve morbidity in radial artery free flaps: Harvest of cephalic vein versus venae comitantes
Authors: Grinsell Damien , Theile David 
Published: June 2005

Background:  The purpose of the present paper was to determine the radial nerve morbidity associated with harvest of different venous conduits in the radial artery free flap.Methods:  Retrospective study comparing subjective and objective symptoms of radial nerve morbidity in 51 consecutive free flaps over a 3‐year period.Results:  Damage to the radial nerve occurred in 9% (1/11) of patients in the cephalic vein group versus 18% (4/28) in the venae comitante group.Conclusions:  Raising the cephalic vein for venous drainage in the radial artery free flap doubles the incidence of radial nerve morbidity.
POSSUM scoring for laparoscopic cholecystectomy in the elderly
Authors: Tambyraja Andrew L. , Kumar Sudhir , Nixon Stephen J. 
Published: June 2005

Background: Physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) scoring is a validated scoring system in the audit of surgical outcomes; however, evaluation of this system has mostly been applied to open surgical techniques. The present study examines the validity of POSSUM in predicting morbidity and mortality in patients undergoing laparoscopic cholecystectomy (LC) with the recognized risk factor for postoperative mortality of advanced age.Methods: All patients aged 80 years or over undergoing LC in one surgical unit between January 1993 and December 1999 were identified from the surgical operations database of the hospital. Case‐note review was used to collate data in terms of clinical and operative factors as described in POSSUM. Observed/POSSUM estimated (O/E) ratio of morbidity and 30‐day mortality were calculated.Results: Laparoscopic cholecystectomy was performed in 76 patients aged 80 years or over during the study period. Of these patients, case notes for 70 patients (92%) were available for review. Median (range) age was 83 years (80−93 years) and median (range) American Society of Anesthesiologists score was 2 (2−4). Twenty‐six (34%) of 70 patients underwent cholecystectomy during an acute admission. The mean physiology severity score was 23 and operative severity score, 8. A significant postoperative morbidity was observed in 15 (22%) of 70 patients. There was no 30‐day mortality. Using exponential analysis, POSSUM predicted morbidity in 15 patients and mortality in seven patients. Thus, O/E ratios for morbidity and mortality were 1 and 0, respectively.Conclusion: POSSUM scoring performs well in predicting morbidity, but overpredicts mortality, after LC in patients aged over 80 years. An assessment of its application to other laparoscopic procedures merits evaluation.
Sodium phenylbutyrate prolongs survival and regulates expression of anti‐apoptotic genes in transgenic amyotrophic lateral sclerosis mice
Authors: Ryu Hoon , Smith Karen , Camelo Sandra I. , Carreras Isabel , Lee Junghee , Iglesias Antonio H. , Dangond Fernando , Cormier Kerry A. , Cudkowicz Merit E. , H. Brown Robert , Ferrante Robert J. 
Published: June 2005

AbstractMultiple molecular defects trigger cell death in amyotrophic lateral sclerosis (ALS). Among these, altered transcriptional activity may perturb many cellular functions, leading to a cascade of secondary pathological effects. We showed that pharmacological treatment, using the histone deacetylase inhibitor sodium phenylbutyrate, significantly extended survival and improved both the clinical and neuropathological phenotypes in G93A transgenic ALS mice. Phenylbutyrate administration ameliorated histone hypoacetylation observed in G93A mice and induced expression of nuclear factor‐κB (NF‐κB) p50, the phosphorylated inhibitory subunit of NF‐κB (pIκB) and beta cell lymphoma 2 (bcl‐2), but reduced cytochrome c and caspase expression. Curcumin, an NF‐κB inhibitor, and mutation of the NF‐κB responsive element in the bcl‐2 promoter, blocked butyrate‐induced bcl‐2 promoter activity. We provide evidence that the pharmacological induction of NF‐κB‐dependent transcription and bcl‐2 gene expression is neuroprotective in ALS mice by inhibiting programmed cell death. Phenylbutyrate acts to phosphorylate IκB, translocating NF‐κB p50 to the nucleus, or to directly acetylate NF‐κB p50. NF‐κB p50 transactivates bcl‐2 gene expression. Up‐regulated bcl‐2 blocks cytochrome c release and subsequent caspase activation, slowing motor neuron death. These transcriptional and post‐translational pathways ultimately promote motor neuron survival and ameliorate disease progression in ALS mice. Phenylbutyrate may therefore provide a novel therapeutic approach for the treatment of patients with ALS.
Presynaptic inhibition of transmitter release from rat sympathetic neurons by bradykinin
Authors: Edelbauer Hannah , Lechner Stefan G. , Mayer Martina , Scholze Thomas , Boehm Stefan 
Published: June 2005

AbstractBradykinin is known to stimulate neurons in rat sympathetic ganglia and to enhance transmitter release from their axons by interfering with the autoinhibitory feedback, actions that involve protein kinase C. Here, bradykinin caused a transient increase in the release of previously incorporated [3H] noradrenaline from primary cultures of dissociated rat sympathetic neurons. When this effect was abolished by tetrodotoxin, bradykinin caused an inhibition of tritium overflow triggered by depolarizing K+ concentrations. This inhibition was additive to that caused by the α2‐adrenergic agonist UK 14304, desensitized within 12 min, was insensitive to pertussis toxin, and was enhanced when protein kinase C was inactivated. The effect was half maximal at 4 nm and antagonized competitively by the B2 receptor antagonist Hoe 140. The cyclooxygenase inhibitor indomethacin and the angiotensin converting enzyme inhibitor captopril did not alter the inhibition by bradykinin. The M‐type K+ channel opener retigabine attenuated the secretagogue action of bradykinin, but left its inhibitory action unaltered. In whole‐cell patch‐clamp recordings, bradykinin reduced voltage‐activated Ca2+ currents in a pertussis toxin‐insensitive manner, and this action was additive to the inhibition by UK 14304. These results demonstrate that bradykinin inhibits noradrenaline release from rat sympathetic neurons via presynaptic B2 receptors. This effect does not involve cyclooxygenase products, M‐type K+ channels, or protein kinase C, but rather an inhibition of voltage‐gated Ca2+ channels.