bluuebunny/crossref_metadata_2025_split huggingface dataset:
Floristic patterns and plant traits of Mediterranean communities in fragmented habitats
Authors: Chust Guillem , Pérez‐Haase Aaron , Chave Jérôme , Pretus Joan Ll. 
Published: May 2006

AbstractAim  To contrast floristic spatial patterns and the importance of habitat fragmentation in two plant communities (grassland and scrubland) in the context of ecological succession. We ask whether plant assemblages are affected by habitat fragmentation and, if so, at what spatial scale? Does the relative importance of the niche differentiation and dispersal‐limitation mechanisms change throughout secondary succession? Is the dispersal‐limitation mechanism related to plant functional traits?Location  A Mediterranean region, the massif of Albera (Spain).Methods  Using a SPOT satellite image to describe the landscape, we tested the effect of habitat fragmentation on species composition, determining the spatial scale of the assemblage response. We then assessed the relative importance of dispersal‐related factors (habitat fragmentation and geographical distance) and environmental constraints (climate‐related variables) influencing species similarity. We tested the association between dispersal‐related factors and plant traits (dispersal mode and life form).Results  In both community types, plant composition was partially affected by the surrounding vegetation. In scrublands, animal‐dispersed and woody plants were abundant in landscapes dominated by closed forests, whereas wind‐dispersed annual herbs were poorly represented in those landscapes. Scrubby assemblages were more dependent on geographical distance, habitat fragmentation and climate conditions (temperature, rainfall and solar radiation); grasslands were described only by habitat fragmentation and rainfall. Plant traits did not explain variation in spatial structuring of assemblages.Main conclusions  Plant establishment in early Mediterranean communities may be driven primarily by migration from neighbouring established communities, whereas the importance of habitat specialization and community drift increases over time. Plant life forms and dispersal modes did not explain the spatial variation of species distribution, but species richness within the community with differing plant traits was affected by habitat patchiness.
Calcium and vitamin D in the prevention and treatment of osteoporosis – a clinical update
Authors: BOONEN S. , VANDERSCHUEREN D. , HAENTJENS P. , LIPS P. 
Published: May 2006

Abstract.Combined calcium and vitamin D supplementation is an essential component of the management of osteoporosis, supported by a strong scientific rationale. The types of individuals who should receive calcium and vitamin D supplements are those: (i) patients with documented osteoporosis receiving antiresorptive or anabolic treatment; (ii) patients receiving glucocorticoids; and (iii) individuals with or at high risk of calcium and/or vitamin D insufficiencies, in particular older women and men. This article describes the evidence base that supports targeting these groups. Benefits are most apparent when 800 IU day−1 vitamin D is complemented with a dose of 1000–1200 mg day−1 elemental calcium. Compliance is also key to optimizing clinical efficacy.
Sleep Beliefs Scale (SBS) and circadian typology
Authors: ADAN ANA , FABBRI MARCO , NATALE VINCENZO , PRAT GEMMA 
Published: May 2006

SummaryThe aim of this work was to present the Sleep Beliefs Scale (SBS), a 20‐item reviewed version of the Sleep Hygiene Awareness by Lacks and Rotert [Behav. Res. Ther., 1986, 28: 104–112]. We also examined for the first time the influence of circadian typology in sleep beliefs. Voluntary and unpaid psychology students participated in the study (n = 510; 182 men and 328 women), from Italy and Spain, aged between 18 and 33 (22.80 ± 4.14 years). The mean score of SBS was 13.05 (SD = 3.46; range 2–20) in the total sample, with a distribution positive skewness to high score (correct beliefs) (Z = 1.82; P = 0.003). The internal consistency was good (Cronbach's α = 0.714) and factor analysis extracted three factors labelled ‘Sleep‐incompatible behaviours’ (eight items), ‘Sleep–wake cycle behaviours’ (seven items) and ‘Thoughts and attitudes to sleep’ (five items). Circadian typology influences the total score and that of the three factors, as well the majority of the items that compose the SBS. The morning‐type showed the best scores, the evening‐type the worst, and the neither‐type the medium scores. Moreover, in the men sample, the differences between circadian typology groups were higher than in the women sample. The SBS showed good psychometric properties; however, further studies in other countries, with clinical and non‐student samples, and more aged subjects are needed so as to validate this psychometric instrument. The circadian typology is an individual difference that presented significant relationships with the sleep beliefs, the possibility of the evening‐type being a risk factor for a worse sleep hygiene, and the maintenance of sleep problems such as insomnia may all be investigated in depth in future research.
Timing of spontaneous sleep‐paralysis episodes
Authors: GIRARD TODD A. , CHEYNE J. ALLAN 
Published: May 2006

SummaryThe objective of this prospective naturalistic field study was to determine the distribution of naturally occurring sleep‐paralysis (SP) episodes over the course of nocturnal sleep and their relation to bedtimes. Regular SP experiencers (N = 348) who had previously filled out a screening assessment for SP as well as a general sleep survey were recruited. Participants reported, online over the World Wide Web, using a standard reporting form, bedtimes and subsequent latencies of spontaneous episodes of SP occurring in their homes shortly after their occurrence. The distribution of SP episodes over nights was skewed to the first 2 h following bedtime. Just over one quarter of SP episodes occurred within 1 h of bedtime, although episodes were reported throughout the night with a minor mode around the time of normal waking. SP latencies following bedtimes were moderately consistent across episodes and independent of bedtimes. Additionally, profiles of SP latencies validated self‐reported hypnagogic, hypnomesic, and hypnopompic SP categories, as occurring near the beginning, middle, and end of the night/sleep period respectively. Results are consistent with the hypothesis that SP timing is controlled by mechanisms initiated at or following sleep onset. These results also suggest that SP, rather than uniquely reflecting anomalous sleep‐onset rapid eye movement (REM) periods, may result from failure to maintain sleep during REM periods at any point during the sleep period. On this view, SP may sometimes reflect the maintenance of REM consciousness when waking and SP hallucinations the continuation of dream experiences into waking life.
Adaptive servo‐ventilation and deadspace: effects on central sleep apnoea
Authors: SZOLLOSI I. , O'DRISCOLL D. M. , DAYER M. J. , COATS A. J. , Morrell M. J. , Simonds A. K. 
Published: May 2006

SummaryCentral Sleep Apnoea (CSA) occurs commonly in heart failure. Adaptive servo‐ventilation (ASV) and deadspace (DS) have been shown in research settings to reverse CSA. The likely mechanism for this is the increase of PaCO2 above the apnoeic threshold. However the role of increasing FiCO2 on arousability remains unclear. To compare the effects of ASV and DS on sleep and breathing, in particular effects on Arousal Index (ArI), ten male patients with heart failure and CSA were studied during three nights with polysomnography plus measurements of PetCO2. The order of the interventions control (C), ASV and DS was randomized. ASV and DS caused similar reductions in apnoea–hypopnoea index [(C) 30.0 ± 6.6, (ASV) 14.0 ± 3.8, (DS) 15.9 ± 4.7 e h−1; both P < 0.05]. However, DS was associated with decreased total sleep time compared with C (P < 0.02) and increased spontaneous ArI compared to C and ASV (both P < 0.01). Only DS was associated with increased ΔPetCO2 from resting wakefulness to eupnic sleep [(C) 2.1  ± 0.9, (ASV) 1.3 ± 1.0, (DS) 5.6 ± 0.5 mmHg; P = 0.01]. ASV and DS both stabilized ventilation however DS application also increased sleep fragmentation with negative impacts on sleep architecture. We speculate that this effect is likely to be mediated by increased PetCO2 and respiratory effort associated with DS application.
Subjective sleepiness and accident risk avoiding the ecological fallacy
Authors: INGRE MICHAEL , ÅKERSTEDT TORBJÖRN , PETERS BJÖRN , ANUND ANNA , KECKLUND GÖRAN , PICKLES ANDREW 
Published: May 2006

SummaryThe present study of sleepiness and accident risk in a HI‐FI car simulator aimed to provide subject‐level relative risks (RR) with 95% confidence intervals (CI) for different levels of subjective sleepiness measured with the Karolinska Sleepiness Scale (KSS), 1 = very alert, 9 = very sleepy, fighting sleep, an effort to staying awake. Five male and five female shift workers, mean age 37 years, participated with a 2‐h drive (08:00–10:00 hours) in a dynamic high‐fidelity moving base driving simulator, after a night of work and after a night of sleep. Subjective sleepiness was measured with KSS every 5 min and events of incidents (two wheels outside the right lane), accidents (two wheels off the road or four wheels in opposite lane) and crashes (four wheels off the road) were recorded. The probability of an accident was modelled with a Generalized Linear Mixed Model approach to estimate subject‐specific effects, rather than group average effects, to avoid the ecological fallacy. The results showed that sleepiness was strongly related to accident risk. An average subject was estimated at 28.2 times (95% CI RR = 10.7–74.1) increased risk at KSS = 8 and at 185 times (95% CI RR = 42–316) at KSS = 9 compared with KSS = 5. There were large individual differences in event propensity that complicates the prediction of absolute accident risk for individual subjects.
Individualized and time‐variant model for the functional link between thermoregulation and sleep onset
Authors: QUANTEN STIJN , DE VALCK ELKE , CLUYDTS RAYMOND , AERTS JEAN‐MARIE , BERCKMANS DANIEL 
Published: May 2006

SummaryThis study makes use of control system model identification techniques to examine the relationship between thermoregulation and sleep regulation. Specifically, data‐based mechanistic (DBM) modelling is used to formulate and experimentally test the hypothesis, put forth by Gilbertet al.[Sleep Med. Rev.8(2004) 81], that there exists a connection between distal heat loss and sleepiness. Six healthy sleepers each spent three nights and the following day in the sleep laboratory: an adaptation, a cognitive arousal and a neutral testing day. In the cognitive arousal condition, a visit of a television camera crew took place and subjects were asked to be interviewed. During each of the three 25‐min driving simulator tasks per day, the distal‐to‐proximal gradient and the electroencephalogram are recorded. It is observed from these experimental data that there exists a feedback connection between thermoregulation and sleep. In addition to providing experimental evidence in support of theGilbertet al.(2004)hypothesis, the authors propose that the nature of the feedback connection is determined by the nature of sleep/wake state (i.e. NREM sleep versus unwanted sleepiness in active subjects). Besides this, an individualized and time‐variant model for the linkage between thermoregulation and sleep onset is presented. This compact model feeds on real‐time data regarding distal heat loss and sleepiness and contains a physically meaningful parameter that delivers an individual‐ and time‐depending quantification of a well known biological features in the field of thermoregulation: the thermoregulatory error signalThypo(t)−Tset(t). A validation of these physical/biological features emphasizes the reliability and power of DBM in describing individual differences related to the sleep process.
Sleepless night, the moon is bright: longitudinal study of lunar phase and sleep
Authors: RÖÖSLI MARTIN , JÜNI PETER , BRAUN‐FAHRLÄNDER CHARLOTTE , BRINKHOF MARTIN W. G. , LOW NICOLA , EGGER MATTHIAS 
Published: May 2006

SummaryPopular belief holds that the lunar cycle affects human physiology, behaviour and health. We examined the influence of moon phase on sleep duration in a secondary analysis of a feasibility study of mobile telephone base stations and sleep quality. We studied 31 volunteers (18 women and 13 men, mean age 50 years) from a suburban area of Switzerland longitudinally over 6 weeks, including two full moons. Subjective sleep duration was calculated from sleep diary data. Data were analysed using multiple linear regression models with random effects. Mean sleep duration was 6 h 49 min. Subjective sleep duration varied with the lunar cycle, from 6 h 41 min at full moon to 7 h 00 min at new moon (P < 0.001). Average sleep duration was shortened by 68 min during the week compared with weekends (P < 0.001). Men slept 17 min longer than women (P < 0.001) and sleep duration decreased with age (P < 0.001). There was also evidence that rating of fatigue in the morning was associated with moon phase, with more tiredness (P = 0.027) at full moon. The study was designed for other purposes and the association between lunar cycle and sleep duration will need to be confirmed in further studies.
European guidelines for the accreditation of Sleep Medicine Centres
Authors:   STEERING COMMITTEE OF THE EUROPEAN SLEEP RESEARCH SOCIETY
Published: May 2006

SummaryThis document describes guidelines for accreditation of Sleep Medicine Centres in Europe. These guidelines are the result of a consensus procedure, in which representatives of the European Sleep Research Society (ESRS) and representatives of different European National Sleep Societies (ENSS) were involved. The information obtained during different rounds of consultation was gathered and processed by the members of the Steering Committee of the ESRS. The scope of the guidelines is to define the characteristics of multidisciplinary Sleep Medicine Centres (SMCs), in terms of requirements regarding staff, operational procedures and logistic facilities. Accreditation of SMCs is proposed to be the responsibility of the individual ENSS. The Accreditation Guidelines may thus be considered an instrument for the national societies to develop new or standardize existing accreditation questionnaires, as well as procedures for visiting the site, drafting the accreditation report, and finally, granting the accreditation. The Accreditation Guidelines are meant to be a line of action, that ideally should be followed as close as possible, but that may be subject to certain exceptions, depending on local customs or regulations.
Eosinophil cationic protein damages protoscoleces in vitro and is present in the hydatid cyst
Authors: RAMOS A. L. , DISCIPIO R. G. , FERREIRA A. M. 
Published: May 2006

SUMMARY Eosinophils are locally recruited during the establishment and chronic phases of cystic hydatidosis. This study provides evidence that eosinophil cationic protein (ECP), one of the major components of eosinophil granules, can damage Echinococcus granulosus protoscoleces (PSC). The toxicity of ECP was investigated in vitro by following parasite viability in the presence of this protein. ECP was found to damage PSC at micromolar concentrations; the effect was blocked by specific antibodies and heparin, and was more severe than the one caused by similar concentrations of RNase A, suggesting that the cationic nature of ECP, and not its ribonuclease activity, is involved in toxicity. This observation may highlight the capacity of eosinophils to control secondary hydatidosis, derived from PSC leakage from a primary cyst. To further assess the relevance of the previous result during infection, the presence of eosinophil proteins was investigated in human hydatid cysts. ECP was found to be strongly associated with the laminated layer of the cyst wall, and present at micromolar concentrations in the hydatid fluid. Overall, these results demonstrate that eosinophils degranulate in vivo at the host–parasite interface, and that the released ECP reaches concentrations that could be harmful for the parasite.
Three grape CBF/DREB1 genes respond to low temperature, drought and abscisic acid
Authors: XIAO HUOGEN , SIDDIQUA MAHBUBA , BRAYBROOK SIOBHAN , NASSUTH ANNETTE 
Published: May 2006

ABSTRACTThe C‐repeat (CRT)‐binding factor/dehydration‐responsive element (DRE) binding protein 1 (CBF/DREB1) transcription factors control an important pathway for increased freezing and drought tolerance in plants. Three CBF/DREB1‐like genes, CBF 1–3, were isolated from both freezing‐tolerant wild grape (Vitis riparia) and freezing‐sensitive cultivated grape (Vitis vinifera). The deduced proteins in V. riparia are 63–70% identical to each other and 96–98% identical to the corresponding proteins in V. vinifera. All Vitis CBF proteins are 42–51% identical to AtCBF1 and contain CBF‐specific amino acid motifs, supporting their identification as CBF proteins. Grape CBF sequences are unique in that they contain 20–29 additional amino acids and three serine stretches. Agro‐infiltration experiments revealed that VrCBF1b localizes to the nucleus. VrCBF1a, VrCBF1b and VvCBF1 activated a green fluorescent protein (GFP) or glucuronidase (GUS) reporter gene behind CRT‐containing promoters. Expression of the endogenous CBF genes was low at ambient temperature and enhanced upon low temperature (4 °C) treatment, first for CBF1, followed by CBF2, and about 2 d later by CBF3. No obvious significant difference was observed between V. riparia and V. vinifera genes. The expression levels of all three CBF genes were higher in young tissues than in older tissues. CBF1, 2 and 3 transcripts also accumulated in response to drought and exogenous abscisic acid (ABA) treatment, indicating that grape contains unique CBF genes.
Regulation of Arabidopsis thaliana 14‐3‐3 gene expression by γ‐aminobutyric acid
Authors: LANCIEN MURIEL , ROBERTS MICHAEL R. 
Published: May 2006

ABSTRACTThe function in plants of the non‐protein amino acid, γ‐aminobutyric acid (GABA) is poorly understood. In this study, we show that GABA down‐regulates the expression of a large subset of 14‐3‐3 gene family members in Arabidopsis thaliana seedlings in a calcium, ethylene and abscisic acid (ABA)‐dependent manner. Gene expression is not affected when seedlings are supplied with glutamate (GLU), a precursor of GABA. The repression of 14‐3‐3 gene expression by GABA is dependent on functional ethylene and ABA signalling pathways, because the response is lost in the etr1‐1, abi1‐1 and abi2‐1 mutants. Calcium measurements show that in contrast to GLU, GABA does not elicit a cytoplasmic calcium elevation, suggesting that the GABA response is unlikely to be mediated by GLU receptors (GLRs), as has been suggested previously. We suggest that in addition to its role as a stress‐related metabolite, GABA may regulate gene expression in A. thaliana, including members of the 14‐3‐3 gene family.
Characterization of the Arabidopsis thermosensitive mutant atts02 reveals an important role for galactolipids in thermotolerance
Authors: CHEN JUNPING , BURKE JOHN J. , XIN ZHANGUO , XU CHANGCHENG , VELTEN JEFF 
Published: May 2006

ABSTRACTPlants are constantly challenged with various abiotic stresses in their natural environment. Elevated temperatures have a detrimental impact on overall plant growth and productivity. Many plants increase their tolerance to high temperatures through an adaptation response known as acquired thermotolerance. To identify the various mechanisms that plants have evolved to cope with high temperature stress, we have isolated a series of Arabidopsis mutants that are defective in the acquisition of thermotolerance after an exposure to 38 °C, a treatment that induces acquired thermotolerance in wild‐type plants. One of these mutants, atts02, was not only defective in acquiring thermotolerance after the treatment, but also displayed a reduced level of basal thermotolerance in a 30 °C growth assay. The affected gene in atts02 was identified by positional cloning and encodes digalactosyldiacylglycerol synthase 1 (DGD1) (the atts02 mutant was, at that point, renamed dgd1‐2). An additional dgd1 allele, dgd1‐3, was identified in two other mutant lines displaying altered acquired thermotolerance, atts100 and atts104. Expression patterns of several heat shock proteins (HSPs) in heat‐treated dgd1‐2 homozygous plants were similar to those from identically treated wild‐type plants, suggesting that the thermosensitivity in the dgd1‐2 mutant was not caused by a defect in HSP induction. Lipid analysis of wild‐type and mutant plants indicated a close correlation between the ability to acquire thermotolerance and the increases in digalactosyldiacylglycerol (DGDG) level and in the ratio of DGDG to monogalactosyldiacylglycerol (MGDG). Thermosensitivity in dgd1‐2 and dgd1‐3 was associated with (1) a decreased DGDG level and (2) an inability to increase the ratio of DGDG to MGDG upon exposure to a 38 °C sublethal temperature treatment. Our results suggest that the DGDG level and/or the ratio of DGDG to MGDG may play an important role in basal as well as acquired thermotolerance in Arabidopsis.
Estimating stomatal conductance with thermal imagery
Authors: LEINONEN I. , GRANT O. M. , TAGLIAVIA C. P. P. , CHAVES M. M. , JONES H. G. 
Published: May 2006

ABSTRACTMost thermal methods for the study of drought responses in plant leaves are based on the calculation of ‘stress indices’. This paper proposes and compares three main extensions of these for the direct estimation of absolute values of stomatal conductance to water vapour (gs) using infrared thermography (IRT). All methods use the measured leaf temperature and two environmental variables (air temperature and boundary layer resistance) as input. Additional variables required, depending on the method, are the temperatures of wet and dry reference surfaces, net radiation and relative humidity. The methods were compared using measured gs data from a vineyard in Southern Portugal. The errors in thermal estimates of conductance were of the same order as the measurement errors using a porometer. Observed variability was also compared with theoretical estimates of errors in estimated gs determined on the basis of the errors in the input variables (leaf temperature, boundary layer resistance, net radiation) and the partial derivatives of the energy balance equations used for the gs calculations. The full energy balance approach requires accurate estimates of net radiation absorbed, which may not be readily available in field conditions, so alternatives using reference surfaces are shown to have advantages. A new approach using a dry reference leaf is particularly robust and recommended for those studies where the specific advantages of thermal imagery, including its non‐contact nature and its ability to sample large numbers of leaves, are most apparent. Although the results suggest that estimates of the absolute magnitude of gs are somewhat subjective, depending on the skill of the experimenter at selecting evenly exposed leaves, relative treatment differences in conductance are sensitively detected by different experimenters.