bluuebunny/crossref_metadata_2025_split huggingface dataset:
Teaching in mainstream and special schools: are the stresses similar or different?
Authors: Williams Michelle , Gersch Irvine 
Published: September 2004

Research evidence, and the direct experience of many practitioners, suggest that teaching is a stressful profession. However, a number of factors, including, for example, the age group taught, the number of pupils in the class, the hours worked and the type of school, may mediate the types and degree of stress experienced. In this article, Michelle Williams, who carried out this study as part of her degree in psychology at the University of East London and who is not a teacher, and Professor Irvine Gersch, course director of the MSc course in educational psychology at the University of East London, describe work undertaken to compare whether teaching in a mainstream or special school is perceived as more stressful and whether there are different stresses in both types of school.The authors designed a questionnaire to measure teacher stress and collected data from 41 teachers in three mainstream and two special schools. Their results reveal no significant difference in the overall level of stress experienced between mainstream and special school teachers, but five factors do emerge indicating that different types of stress are experienced in the different school settings studied.
Effects of atmospheric CO2 concentration and defoliation on the growth of Themeda triandra
Authors: Wand S. J. E. , Midgley G. F. 
Published: September 2004

AbstractThe effects of elevated atmospheric carbon dioxide (CO2) concentration (700 μmol mol−1) on defoliated (three clippings at 3‐week intervals) and undefoliated plants were determined for the C4 grass Themeda triandra, Forsk. The elevated CO2 concentration significantly increased leaf regrowth following defoliation, and total leaf production was greatest in this treatment. Shoot biomass of undefoliated plants was also increased under the elevated CO2 concentration treatment. The primary effect of the elevated CO2 concentration in both defoliated and undefoliated plants was an increase in individual leaf length and mass of dry matter, linked to a higher leaf water content and increased photosynthetic rates at the canopy level. Photosynthetic down‐regulation at the leaf level occurred, but this was compensated for by increased assimilation rates and greater canopy leaf area at the elevated CO2 concentration. Increases in leaf and sheath growth of defoliated plants in the elevated CO2 concentration treatment were lost following a final 3‐week reversion to ambient CO2 concentration, but occurred in plants exposed to the elevated CO2 concentration for the final 3‐week period only. In conclusion, elevated atmospheric CO2 concentration increases shoot growth via increased leaf extension, which is directly dependent on stimulation of concurrent photosynthesis. CO2 responsiveness is sustained following moderate defoliation but is reduced when plants experience reduced vigour as a result of maturation or high frequency of defoliation.
Grazing legumes in Europe: a review of their status, management, benefits, research needs and future prospects
Authors: Rochon J. J. , Doyle C. J. , Greef J. M. , Hopkins A. , Molle G. , Sitzia M. , Scholefield D. , Smith C. J. 
Published: September 2004

AbstractIn many parts of Europe there has been a net decline in the use of forage legumes since the 1980s, despite the reputed value of legumes for low‐input livestock production systems. The political environment within which livestock farming in much of Europe operates (Common Agricultural Policy) is shifting the balance of economic advantage towards legumes and away from high usage of inorganic fertilizer. This has already been found for legume and grass–legume silages when compared with grass silages with a potential economic gain for farmers averaging 137 € ha−1, corresponding to an annual benefit for the European livestock farming sector of as much as € 1300 million.Recent literature has shown that legume‐based grazing systems have the ability to reduce environmental problems by increasing the efficiency of N use and by avoiding a high transient surplus of soil mineral N. From the perspective of livestock nutrition, when forage legumes contain moderate levels of secondary compounds, such as condensed tannins and flavonoids, they offer considerable advantages including increased efficiency of N utilization within the digestive tract, reduced incidence of bloat hazard and higher resilience to parasites.Nevertheless, these benefits are partially counterbalanced in both temperate and Mediterranean regions by difficulties in establishment, maintenance and management under grazing. To gain knowledge on mixed grass–legume pastures, further research is required on: (i) the development of sustainable systems of livestock production which can maintain sward persistence and agricultural production under environmental stress; (ii) increasing knowledge of soil–plant–animal relations for a wide range of leguminous species, and under different soil types and climatic situations; and (iii) the benefits for consumers of food produced from low‐input livestock production systems.
The implications of controlling grazed sward height for the operation and productivity of upland sheep systems in the UK: 7. Sustainability of white clover in grass/clover swards with reduced levels of fertilizer nitrogen
Authors: Sibbald A. R. , Marriott C. A. , Agnew R. D. M. , Dalziel A. J. I. 
Published: September 2004

AbstractThe sustainability of white clover in grass/clover swards of an upland sheep system, which included silage making, was studied over 5 years for four nitrogen fertilizer rates [0 (N0), 50 (N50), 100 (N100) and 150 (N150) kg N ha−1]. A common stocking rate of 6 ewes ha−1 was used at all rates of N fertilizer with additional stocking rates at the N0 fertilizer rate of 4 ewes ha−1 and at the N150 fertilizer rate of 10 ewes ha−1. Grazed sward height was controlled, for ewes with their lambs, from spring until weaning in late summer by adjusting the proportions of the total area to be grazed in response to changes in herbage growth; surplus pasture areas were harvested for silage. Thereafter sward height was controlled on separate areas for ewes and weaned lambs. Areas of pasture continuously grazed in one year were used to make silage in the next year. For treatments N0 and N150, white clover stolon densities (s.e.m.) were 7670 (205·4) and 2296 (99·8) cm m−2, growing point densities were 4459 (148·9) and 1584 (76·0) m−2 and growing point densities per unit length of stolon were 0·71 (0·015) and 0·67 (0·026) cm−1 respectively, while grass tiller densities were 13 765 (209·1) and 18 825 (269·9) m−2 for treatments N0 and N150 respectively. White clover stolon density increased over the first year from 780 (91·7) cm m−2 and was maintained thereafter until year 5, reaching 8234 (814·3) and 2787 (570·8) cm m−2 for treatments N0 and N150 respectively. Growing point density of white clover increased on treatment N0 from 705 (123·1) m−2 to 2734 (260·7) m−2 in year 5 and it returned to the initial level on treatment N150 having peaked in the intermediate years. Stolon density of white clover was maintained when the management involved the annual interchange of continuously grazed and ensiled areas. The non‐grazing period during ensiling reduced grass tiller density during the late spring and summer, when white clover has the most competitive advantage in relation to grass. The increase in stolon length of white clover in this period appears to compensate for the loss of stolon during periods when the sward is grazed and over winter when white clover is at a competitive disadvantage in relation to grass. The implications for the management of sheep systems and the sustainability of white clover are discussed.
Changes in incisor dentition of sheep influence biting force
Authors: Hongo A. , Zhang J. , Toukura Y. , Akimoto M. 
Published: September 2004

AbstractThe grazing behaviour by sheep, after the loss of the temporary incisors and before their replacement with the permanent incisors, was compared with that after the first pair of permanent incisors had completely developed in grazing experiments, conducted from June to September 2001, with three Suffolk castrated male sheep, born in late‐March 2000. A new method was developed to investigate bite mass and bite force, using hand‐constructed swards, which were composed of groups of four (4L), eight (8L), twelve (12L), sixteen (16L) and twenty (20L) leaves of cocksfoot (Dactylis glomerata) arranged 15 cm apart. Each group of leaves was attached to a separate three‐directional load cell.The period of time between loss of temporary incisors and the complete eruption of permanent incisors was c. 1 month. The number of bites per group of leaves increased with increasing leaf density. The number of bites per group of leaves was higher after the loss of temporary incisors than with the permanent incisors. The number of leaves per bite and dry‐matter (DM) intake per bite were almost twice as great with permanent incisors than after the loss of temporary incisors; DM intakes per bite force were 3·9–4·9 mg N−1 and 1·7–2·6 mg N−1 respectively. After the loss of temporary incisors, the proportion of forward‐direction forces accounted for 0·805 of the forces in the 4L treatment and 0·155–0·317 of the forces in the 8L–20L treatments. In contrast, the proportion of forward‐direction forces accounted for only 0·292 in the 4L treatment and 0·026–0·163 in the 8L–20L treatments with permanent incisors. The angles of bite forces were almost the same (54·7–56·3°) when sheep used a forward direction, and were 51·3–57·3° when sheep used a backward direction.
Sleep problems in children with autism
Authors: Gail Williams P. , Sears Lonnie L. , Allard AnnaMary 
Published: September 2004

SummaryAutism is a developmental disability characterized by severe deficits in social interaction and communication, and the presence of repetitive‐ritualistic behaviors. Sleep problems are frequently reported by parents of children with autism with prevalence estimates of 44–83% for sleep disorders in this population. To better understand sleep in autism, we surveyed sleep problems in 210 children with autism using a Likert‐based questionnaire for parent report. The most frequently reported sleep problems included difficulty in falling asleep, restless sleep, not falling asleep in own bed, and frequent wakenings. Least frequently reported sleep problems were sleep walking, morning headaches, crying during sleep, apnea, and nightmares. When surveys were divided into mental retardation (MR)/not MR categories, no significant differences were identified in frequencies of reported sleep problems except for waking at night which occurred much more frequently in the MR group. There was also no difference in sleep problems related to age of the child other than nocturnal enuresis. An association was noted between certain medical problems and sleep problems. Vision problems, upper respiratory problems, and runny nose were associated with decreased nighttime sleep. Vision problems, poor appetite, and poor growth were associated with increased nighttime waking. Poor appetite and poor growth were associated with decreased willingness to fall asleep. This study confirms a high prevalence of sleep problems reported by parents of children with autism and points to the need for more systematic research as an initial step in developing treatment strategies.
Changes in fronto‐posterior functional coupling at sleep onset in humans
Authors: Gennaro Luigi De , Vecchio Fabrizio , Ferrara Michele , Curcio Giuseppe , Rossini Paolo Maria , Babiloni Claudio 
Published: September 2004

SummaryThe aim of this study was to assess the functional coupling between anterior and posterior areas as induced by the sleep onset process. The functional coupling was indexed by an analysis of spectral coherence and directed transfer function (DTF) from electroencephalographic (EEG) data. As it has been reported that more anterior areas first synchronize sleep EEG activity, we hypothesized a fronto‐posterior direction of the cortical functional coupling during the sleep onset process. Ten normal right‐handed male students slept for two‐nights (one adaptation, one baseline) in the laboratory, with standard polysomnographic recordings. Spectral coherence and DTF were computed on data recorded by anterior (FzA1) and posterior (PzA1, OzA1) derivations. EEG coherence at the delta/theta band was higher during the presleep period than the sleep onset period, while EEG coherence at the alpha band was higher during the sleep onset period than the presleep period. The DTF findings indicated a prevalence of the occipital‐to‐frontal information flow at delta/theta and alpha bands during the presleep period and a prevalence of the frontal‐to‐parieto‐occipital information flow at all bands during the sleep onset period. The coherent pattern of changes in EEG coherence and in DTF values at sleep onset lends further support to the notion of sleep as a local process, showing that the sleep onset process is subserved by the functional coordination of a cortical fronto‐posterior network. In this network, prefrontal areas may play a leading role in the propagation of synchronizing signals conveyed at frequencies spanning delta to beta rhythms.
Sleep disorders in Taiwanese children with attention deficit/hyperactivity disorder
Authors: Huang Yu‐Shu , Chen Ning‐Hung , Li Hsueh‐Yu , Wu Yu‐Yu , Chao Chia‐Chen , Guilleminault Christian 
Published: September 2004

SummaryTo assess obstructive sleep apnea syndrome (OSAS) and periodic limb movement disorder (PLMD) in children with attention deficit/hyperactivity disorder (ADHD) compared with a control group. The ADHD was diagnosed based on Diagnostic and Statistical Manual, version IV (DSM‐IV) criteria on successively seen elementary school children aged 6–12 years referred to a psychiatric clinic for suspected ADHD. A standardized interview (Kiddie‐SADS‐E), parents and teacher questionnaires, neuropsychological testing, and nocturnal polysomnography were completed for each child. Eighty‐eight children (77 boys) with ADHD and 27 controls were involved in the study. Fifty children with ADHD (56.8%) had an apnea–hypopnea index (AHI) >1 event h−1 and 17 (19.3%) had an AHI >5 event h−1. Nine children (10.2%) had a periodic limb movement index (PLMI) >5 events h−1. There is one child with AHI >1 and none with a PLMI > 5 in the control group. In the test of variables of attention (TOVA), the response time was significantly worse in ADHD with sleep disorders than those without them. The child behavior checklist (CBCL) showed a significant difference between groups in the hyperactivity subscale. The diagnostic criteria for ADHD based on DSM‐IV do not differentiate between children with or without sleep disorders. Evaluation of sleep disorders should be considered before starting drug treatment for ADHD.
Experimentally induced arousals during sleep: a cross‐modality matching paradigm
Authors: Kato T. , Montplaisir J. Y. , Lavigne G. J. 
Published: September 2004

SummaryMicro‐arousals occur spontaneously or in response to exogenous and endogenous sensory input during sleep. The function of micro‐arousals remains unclear, for example, whether it reflects a disturbance or a preparatory response to environmental changes. The goal of this study was to assess arousal responsiveness when two types of sensory stimulations were used: auditory (AD) alone and the addition of a vibrotactile (VT) sensation. Ten normal sleepers participated in three nights of polygraphic recordings. The first night was for habituation and to rule out sleep disorders, and the second to collect baseline sleep data. During the third night, AD and VT + AD stimuli, with three levels of intensities for auditory and vibratory signals, were randomly given to induce arousal responses in sleep stages 2, 3 and 4 and rapid eye movement (REM). The frequency of the arousal responses increased with stimulus intensity for all sleep stages and was lowest in stages 3 and 4. In non‐REM (NREM) sleep, combined VT + AD stimulation induced more frequent and more intense arousal responses than AD alone. In REM sleep, more frequent micro‐arousals rather than awakenings were triggered by combined stimulations. In stage 2, the response rate of total induced K‐complexes did not differ between both types of stimulations while more K‐complexes followed by arousals were evoked by the combined VT + AD stimulation than by the AD alone. The induced arousals were associated with an increase in heart rate in all sleep stages. An increase in suprahyoid muscle tone was observed in NREM sleep only, REM being not associated with a rise in muscle tone following experimental stimulation. Most leg and body movements occurred in response to induced awakenings. These results suggest that the cross‐modality sensory stimuli triggered more arousal responses in comparison with single‐modality stimuli. In an attempt to wake a sleeping subject, the addition of a tactile stimulation, such as shaking the shoulder, is an effective strategy that increases the arousal probability.
Corticospinal excitability during laughter: implications for cataplexy and the comparison with REM sleep atonia
Authors: Overeem Sebastiaan , Reijntjes Robert , Huyser Wesseline , Jan Lammers Gert , Gert van Dijk J. 
Published: September 2004

SummaryCataplexy is usually seen as rapid eye movement (REM) sleep atonia occurring at an inopportune moment. REM sleep atonia is the result of postsynaptic inhibition, i.e. inhibition of alpha motor neurones. Although this may explain the suppression of H‐reflexes during REM sleep, cataplexy and laughter, it is not the only explanation. Presynaptic inhibition, in which afferent impulses are prevented from reaching motor neurones, is an alternative. Testing H‐reflexes and magnetic‐evoked potentials (MEPs) helps to tell them apart: in postsynaptic inhibition MEPs and H‐reflexes change in tandem, while H‐reflexes may decrease independent of MEPs with other inhibition modes. We studied motor inhibition during laughter, the strongest trigger for cataplexy. H‐reflexes were evoked every 2 s in the soleus muscle in 10 healthy subjects watching comical video fragments. MEPs were evoked when H‐reflexes decreased during laughter, and, as a control, when subjects did not laugh. Pairs of MEPs and the immediately preceding H‐reflexes were studied. Compared with the control condition, laughter caused mean MEP area to increase by 60% (P = 0.006) and mean H‐reflex amplitude to decrease by 33% (P = 0.008). This pattern proves that postsynaptic inhibition cannot have been the sole influence. The findings do not prove which mechanisms are involved; one possibility is that the decrease in H‐reflex amplitude was the result of presynaptic inhibition, and that cortical and/or spinal facilitation accounted for increased MEPs. Regardless, the pattern differs fundamentally from the reported mechanism of REM sleep atonia. Existing scanty data on cataplexy suggest a pattern of H‐reflexes and MEPs similar to that during laughter, but this needs further study.
Transport of ricin and 2S albumin precursors to the storage vacuoles of Ricinus communis endosperm involves the Golgi and VSR‐like receptors
Authors: Jolliffe Nicholas A. , Brown Joanna C. , Neumann Ulla , Vicré Maïte , Bachi Angela , Hawes Chris , Ceriotti Aldo , Roberts Lynne M. , Frigerio Lorenzo 
Published: September 2004

SummaryWe have studied the transport of proricin and pro2S albumin to the protein storage vacuoles of developing castor bean (Ricinus communis L.) endosperm. Immunoelectron microscopy and cell fractionation reveal that both proteins travel through the Golgi apparatus and co‐localize throughout their route to the storage vacuole. En route to the PSV, the proteins co‐localize in large (>200 nm) vesicles, which are likely to represent developing storage vacuoles. We further show that the sequence‐specific vacuolar sorting signals of both proricin and pro2SA bind in vitro to proteins that have high sequence similarity to members of the VSR/AtELP/BP‐80 vacuolar sorting receptor family, generally associated with clathrin‐mediated traffic to the lytic vacuole. The implications of these findings in relation to the current model for protein sorting to storage vacuoles are discussed.
Intron retention is a major phenomenon in alternative splicing in Arabidopsis
Authors: Ner‐Gaon Hadas , Halachmi Ronit , Savaldi‐Goldstein Sigal , Rubin Eitan , Ophir Ron , Fluhr Robert 
Published: September 2004

SummaryAlternative splicing (AS) combines different transcript splice junctions that result in transcripts with shuffled exons, alternative 5′ or 3′ splicing sites, retained introns and different transcript termini. In this way, multiple mRNA species and proteins can be created from a single gene expanding the potential informational content of eukaryotic genomes. Search algorithms of AS forms in a variety of Arabidopsis databases showed they contained an unusually high fraction of retained introns (above 30%), compared with 10% that was reported for humans. The preponderance of retained introns (65%) were either part of open reading frames, present in the UTR region or present as the last intron in the transcript, indicating that their occurrence would not participate in non‐sense‐mediated decay. Interestingly, the functional distribution of the transcripts with retained introns is skewed towards stress and external/internal stimuli‐related functions. A sampling of the alternative transcripts with retained introns were confirmed by RT‐PCR and were shown to co‐purify with polyribosomes, indicating their nuclear export. Thus, retained introns are a prominent feature of AS in Arabidopsis and as such may play a regulatory function.
The glycan substrate of the cytosolic (Pho 2) phosphorylase isozyme from Pisum sativum L.: identification, linkage analysis and subcellular localization
Authors: Fettke Joerg , Eckermann Nora , Poeste Simon , Pauly Markus , Steup Martin 
Published: September 2004

SummaryThe subcellular distribution of starch‐related enzymes and the phenotype of Arabidopsis mutants defective in starch degradation suggest that the plastidial starch turnover is linked to a cytosolic glycan metabolism. In this communication, a soluble heteroglycan (SHG) from leaves of Pisum sativum L. has been studied. Major constituents of the SHG are galactose, arabinose and glucose. For subcellular location, the SHG was prepared from isolated protoplasts and chloroplasts. On a chlorophyll basis, protoplasts and chloroplasts yielded approximately 70% and less than 5%, respectively, of the amount of the leaf‐derived SHG preparation. Thus, most of SHG resides inside the cell but outside the chloroplast. SHG is soluble and not membrane‐associated. Using membrane filtration, the SHG was separated into a <10 kDa and a >10 kDa fraction. The latter was resolved into two subfractions (I and II) by field‐flow fractionation. In the protoplast‐derived >10 kDa SHG preparation the subfraction I was by far the most dominant compound. β‐Glucosyl Yariv reagent was reactive with subfraction II, but not with subfraction I. In in vitro assays the latter acted as glucosyl acceptor for the cytosolic (Pho 2) phosphorylase but not for rabbit muscle phosphorylase. Glycosidic linkage analyses of subfractions I and II and of the Yariv reagent reactive glycans revealed that all three glycans contain a high percentage of arabinogalactan‐like linkages. However, SHG possesses a higher content of minor compounds, namely glucosyl, mannosyl, rhamnosyl and fucosyl residues. Based on glycosyl residues and glycosidic linkages, subfraction I possesses a more complex structure than subfraction II.