bluuebunny/crossref_metadata_2025_split huggingface dataset:
Macrophytes as refuge or risky area for zooplankton: a balance set by littoral predacious macroinvertebrates
Authors: SAGRARIO GONZÁLEZ , De LosÁNGELES MARÍA , BALSEIRO ESTEBAN , ITUARTE ROMINA , SPIVAK EDUARDO 
Published: November 2008

Summary1. Zooplankton use macrophytes as day‐time refuge areas when trying to escape from pelagic predators. But macrophytes can also host a diverse and abundant macroinvertebrate assemblage and zooplankton are also likely to face predacious macroinvertebrates once they enter the littoral zone. This study aimed to elucidate the role of macroinvertebrates in determining the refuge capacity of macrophytes.2. We conducted a field enclosure experiment using plastic bags and complementary laboratory feeding trials to test how macroinvertebrates counteract the benefits to zooplankton of the macrophyte refuge. The field experiment consisted of three treatments with different macroinvertebrate assemblages: without predators (WP), low abundance and diversity (LAD) and high abundance and diversity of predators (HAD – which represents lake conditions).3. Populations of Diaphanosoma brachyurum, Bosmina huaronensis and Moina micrura (Cladocera) and of both male and female Notodiaptomus incompositus (Copepoda, Calanoida) declined (by nearly 80%) in the presence of HAD in comparison to WP and LAD treatments.4. Feeding trials revealed that Buenoa sp. (backswimmer), adults of Palaemonetes argentinus (grass shrimp) and Cyanallagma interruptum (damselfly) had a significant negative impact on cladocerans (D. brachyurum, B. huaronensis) and the calanoid copepod population (males, females and copepodites). These predators showed a strong predation effect ranging from 75% to 100% reductions of zooplankton populations.5. The refuge effect offered by macrophytes to zooplankton depends on and is balanced by the predacious macroinvertebrate assemblage that plants host. The risk of confronting littoral predators is high and macroinvertebrate presence can turn the macrophytes into risky areas for zooplankton.
Low impact of climate change on subalpine grasslands in the Swiss Northern Alps
Authors: VITTOZ PASCAL , RANDIN CHRISTOPHE , DUTOIT ANNELISE , BONNET FRANÇOIS , HEGG OTTO 
Published: November 2008

AbstractWhile phenological shifts and migration of isolated species under climate change have already been observed on alpine summits, very few studies have focused on community composition changes in subalpine grasslands. Here we use permanent plots monitored since 1954 and precisely located phytosociological censuses from 1970 to study compositional changes of subalpine grasslands in two distinct regions of the Swiss Northern Alps. In both areas, warming trends during the monitoring period were associated with changes in land management (abandonment of goat and sheep pasturing or grazing replaced by mowing). Old and recent inventories were compared with correspondence analyses (CA). Ecological indicator values, community‐affinities and biological traits of the species were used to infer the factors responsible for triggering the observed changes. In both regions, subalpine grasslands were stable with smaller changes than have previously been observed in alpine environments. Only a few species appeared or disappeared and changes were generally limited to increasing or decreasing frequency and cover of certain taxa. At one site, grazing abandonment favored fallow species. Some of these species were located at their upper altitudinal distribution limits and may have spread because of rising temperatures. In both areas, declining species were predominantly alpine and low‐growing species; their decline was probably due to increased competition (e.g., shadow) with more vigorous subalpine taxa no longer limited by grazing. We conclude that vegetation communities can respond rapidly to warming as long as colonization is facilitated by available space or structural change. In the subalpine grasslands studies, changes were mainly driven by land management. These communities have a dense vegetation cover and newly arriving herbaceous species preferring warmer conditions may take some time to establish themselves. However, climate disturbances, such as exceptional drought, may accelerate community changes by opening gaps for new species.
Temperature controls ecosystem CO2 exchange of an alpine meadow on the northeastern Tibetan Plateau
Authors: SAITO MAKOTO , KATO TOMOMICHI , TANG YANHONG 
Published: November 2008

AbstractAlpine ecosystems are extremely vulnerable to climate change. To address the potential variability of the responses of alpine ecosystems to climate change, we examined daily CO2 exchange in relation to major environmental variables. A dataset was obtained from an alpine meadow on the Qinghai‐Tibetan Plateau from eddy covariance measurements taken over 3 years (2002–2004). Path analysis showed that soil temperature at 5 cm depth (Ts5) had the greatest effect on daily variation in ecosystem CO2 exchange all year around, whereas photosynthetic photon flux density (PPFD) had a high direct effect on daily variation in CO2 flux during the growing season. The combined effects of temperature and light regimes on net ecosystem CO2 exchange (NEE) could be clearly categorized into three areas depending on the change in Ts5: (1) almost no NEE change irrespective of variations in light and temperature when Ts5 was below 0 °C; (2) an NEE increase (i.e. CO2 released from the ecosystem) with increasing Ts5, but little response to variation in light regime when 0 °C≤Ts5≤8 °C; and (3) an NEE decrease with increase in Ts5 and PPFD when Ts5 was approximately >8 °C. The highest daily net ecosystem CO2 uptake was observed under the conditions of daily mean Ts5 of about 15 °C and daily mean PPFD of about 50 mol m−2 day−1. The results suggested that temperature is the most critical determinant of CO2 exchange in this alpine meadow ecosystem and may play an important role in the ecosystem carbon budget under future global warming conditions.
Ectomycorrhizal fungi associated with Pinus sylvestris seedlings respond differently to increased carbon and nitrogen availability: implications for ecosystem responses to global change
Authors: ALBERTON ODAIR , KUYPER THOMAS W. 
Published: November 2008

AbstractThe ectomycorrhizal (ECM) symbiosis can cause both positive and negative feedback with trees under elevated CO2. Positive feedback arises if the additional carbon (C) increases both nutrient uptake by the fungus and nutrient transfer to the plant, whereas negative feedback results from increased nutrient uptake and immobilization by the fungus and reduced transfer to the plant. Because species of ECM fungi differ in their C and nitrogen (N) demand, understanding fungal species‐specific responses to variation in C and N supply is essential to predict impacts of global change. We investigated fungal species‐specific responses of ECM Scots pine (Pinus sylvestris) seedlings under ambient and elevated CO2 (350 or 700 μL L−1 CO2) and under low and high mineral N availability. Each seedling was associated with one of the following ECM species: Hebeloma cylindrosporum, Laccaria bicolor and Suillus bovinus. The experiment lasted 103 days. During the final 27 days, seedlings were labeled with 14CO2 and 15N. Most plant and fungal parameters were significantly affected by fungal species, CO2 level and N supply. Interactions between fungal species and CO2 were also regularly significant. At low N availability, elevated CO2 had the smallest impact on the photosynthetic performance of seedlings inoculated with H. cylindrosporum and the largest impact on seedlings with S. bovinus. At ambient CO2, increasing N supply had the smallest impact on seedlings inoculated with S. bovinus and the largest on seedlings inoculated with H. cylindrosporum. At low N availability, extraradical hyphal length increased after doubling CO2 level, but this was significant only for L. bicolor. At ambient CO2, increasing N levels reduced hyphal length for both H. cylindrosporum and S. bovinus, but not for L. bicolor. We discuss the potential interplay of two major elements of global change, elevated CO2 and increased N availability, and their effects on plant growth. We conclude that increased N supply potentially relieves mycorrhiza‐induced progressive N limitation under elevated CO2.
Quantities of mineral N in soil and concentrations of nitrate‐N in groundwater in four grassland‐based systems of dairy production on a clay‐loam soil in a moist temperate climate
Authors: Humphreys J. , Casey I. A. , Darmody P. , O’Connell K. , Fenton O. , Watson C. J. 
Published: November 2008

AbstractThis study examined the quantity of mineral N in soil and nitrate‐N losses to groundwater from grassland‐based dairy production in 2001 and 2002. There were four treatments with different inputs of N, through fertilizers, concentrates and biological fixation, and four associated stocking densities. Nitrogen inputs were 205, 230, 300 and 400 kg ha−1, respectively, and annual stocking densities were 1·75, 2·10, 2·50 and 2·50 cows ha−1. There were 18 cows per treatment. Grazed herbage accounted for 0·64, grass‐silage for 0·26 and concentrates 0·10 of annual DM consumed by the cows. Quantities of mineral N (nitrate‐N and ammonium‐N) in soil were measured, following extraction in 2 M KCl (1:2 w/v) shaken continuously for 2 h, on three occasions between late September and early February each winter. Concentrations of nitrate‐N in groundwater from wells inserted vertically to a depth of 1 m were determined throughout both winters. Quantities of mineral N in the soil increased (P < 0·001) with higher N inputs and declined (P < 0·001) with later sampling date. There were no relationships between nitrate‐N concentrations in groundwater and N inputs, N surpluses, deposition of excreta‐N at the soil surface and soil mineral N during both winters. Low losses of nitrate‐N to groundwater were primarily attributed to high rates of denitrification associated with a heavy soil texture, wet anaerobic soil conditions, relatively high organic carbon contents throughout the soil profile and mild soil temperatures throughout the year. Uptake of N by herbage made an important contribution to low N losses over the winter.
Growth of individual tillers and tillering rate of Lolium perenne and Bromus stamineus subjected to two defoliation frequencies in winter in Argentina
Authors: Berone G. D. , Lattanzi F. A. , Agnusdei M. G. , Bertolotti N. 
Published: November 2008

AbstractThe aims of the experiment were to (i) test whether the higher leaf elongation rate per tiller (LERT) of Bromus stamineus D. than Lolium perenne L. at moderately low temperatures was maintained at high defoliation frequencies and (ii) explore responses in tiller dynamics during the onset of the cool season in the south‐east of the humid Pampas region in Argentina. The following treatments were applied: defoliation frequency at the 3·0‐leaf stage (i.e. one‐leaf lifespan), which is considered optimal, and higher defoliation frequency at the 1·5‐leaf stage (i.e. half‐of‐a‐leaf lifespan). The higher defoliation frequency reduced leaf elongation rate in both the species but it did not affect the leaf appearance rate. This confirms previous studies on several C3 grasses, suggesting a similar pattern of response. Changes in tiller size are proposed as a possible mechanism to explain such long‐term defoliation effects on leaf elongation rates. Responses in tiller production depended on the species considered. The higher defoliation frequency caused a reduction in site‐filling which led to lower tiller production rates in L. perenne but not in B. stamineus. Thus, B. stamineus maintained the advantage in LERT over L. perenne and its tiller production was not affected when defoliated at frequencies higher than those considered optimal.
Sequence independent interferon‐α induction by multimerized phosphodiester DNA depends on spatial regulation of Toll‐like receptor‐9 activation in plasmacytoid dendritic cells
Authors: Haas Tobias , Schmitz Frank , Heit Antje , Wagner Hermann 
Published: November 2008

SummarySingle‐stranded versus multimeric phosphorothioate‐modified CpG oligodeoxynucleotides (ODNs) undergo differential endosomal trafficking upon uptake into plasmacytoid dendritic cells (pDCs), correlating with Toll‐like receptor‐9‐dependent pDC maturation/activation (single‐stranded B‐type CpG ODN) or interferon‐α (IFN‐α) induction (multimeric A‐type CpG ODN), respectively. As was recently shown, IFN‐α production, other than by CpG ODNs, can also be induced in a sequence‐independent manner by phosphodiester (PD) ODNs multimerized by 3′ poly‐guanosine (poly‐G) tails. We investigate here the type of endosomal trafficking responsible for IFN‐α induction by natural PD ODN ligands. We show that 3′ extension with poly‐G tails leads to multimerization of single‐stranded PD ODNs and to enhanced cellular uptake into pDCs. While monomeric PD ODNs, which induce CpG‐dependent Toll‐like receptor‐9 stimulation and pDC maturation/activation, localized to late endosomal/lysosomal compartments, the poly‐G multimerized PD ODNs, which induce CpG‐independent IFN‐α production, located to vesicles with a distinct, ‘early’ endosomal phenotype. We conclude that poly‐G‐mediated multimerization of natural PD ODNs allows for sequence‐independent, Toll‐like receptor‐9‐dependent IFN‐α induction in pDCs by combining three distinct effects: relative protection of sensitive PD ODNs from extracellular and intracellular DNase degradation, enhanced cellular uptake and preferential early endosomal compartmentation.
The interaction of monocytes with rheumatoid synovial cells is a key step in LIGHT‐mediated inflammatory bone destruction
Authors: Ishida Satoru , Yamane Shoji , Nakano Saori , Yanagimoto Toru , Hanamoto Yukie , Maeda‐Tanimura Miki , Toyosaki‐Maeda Tomoko , Ishizaki Jun , Matsuo Yoshiyuki , Fukui Naoshi , Itoh Tsunetoshi , Ochi Takahiro , Suzuki Ryuji 
Published: November 2008

SummaryFormation of osteoclasts and consequent joint destruction are hallmarks of rheumatoid arthritis (RA). Here we show that LIGHT, a member of the tumour necrosis factor (TNF) superfamily, induced the differentiation into tartrate‐resistant acid phosphatase (TRAP)‐positive multinucleated cells (MNCs) of CD14+ monocytes cocultured with nurse‐like cells isolated from RA synovium, but not of freshly isolated CD14+ monocytes. Receptor activator of nuclear factor‐κB ligand (RANKL) enhanced this LIGHT‐induced generation of TRAP‐positive MNCs. The MNCs showed the phenotypical and functional characteristics of osteoclasts; they showed the expression of osteoclast markers such as cathepsin K, actin‐ring formation, and the ability to resorb bone. Moreover, the MNCs expressed both matrix metalloproteinase 9 (MMP‐9) and MMP‐12, but the latter was not expressed in osteoclasts induced from CD14+ monocytes by RANKL. Immunohistochemical analysis showed that the MMP‐12‐producing MNCs were present in the erosive areas of joints in RA, but not in the affected joints of osteoarthritic patients. These findings suggested that LIGHT might be involved in the progression of inflammatory bone destruction in RA, and that osteoclast progenitors might become competent for LIGHT‐mediated osteoclastogenesis via interactions with synoviocyte‐like nurse‐like cells.
Critical thinking ability of new graduate and experienced nurses
Authors: Fero Laura J. , Witsberger Catherine M. , Wesmiller Susan W. , Zullo Thomas G. , Hoffman Leslie A. 
Published: November 2008

AbstractTitle.  Critical thinking ability of new graduate and experienced nurses. Aim.  This paper is a report of a study to identify critical thinking learning needs of new and experienced nurses.Background.  Concern for patient safety has grown worldwide as high rates of error and injury continue to be reported. In order to improve patient safety, nurses must be able to recognize changes in patient condition, perform independent nursing interventions, anticipate orders and prioritize.Methods.  In 2004–2006, a consecutive sample of 2144 newly hired nurses in a university‐affiliated healthcare system completed the Performance Based Development System Assessment consisting of 10 videotaped vignettes depicting change in patient status. Results were reported as meeting or not meeting expectations. For nurses not meeting expectations, learning needs were identified in one of six subcategories.Results.  Overall, 74·9% met assessment expectations. Learning needs identified for nurses not meeting expectations included initiating independent nursing interventions (97·2%), differentiation of urgency (67%), reporting essential clinical data (65·4%), anticipating relevant medical orders (62·8%), providing relevant rationale to support decisions (62·6%) and problem recognition (57·1%). Controlling for level of preparation, associate (P = 0·007) and baccalaureate (P < 0·0001) nurses were more likely to meet expectations as years of experience increased; a similar trend was not seen for diploma nurses (P = 0·10). Controlling for years of experience, new graduates were less likely to meet expectations compared with nurses with ≥10 years experience (P = 0·046).Conclusion.  Patient safety may be compromised if a nurse cannot provide clinically competent care. Assessments such as the Performance Based Development System can provide information about learning needs and facilitate individualized orientation targeted to increase performance level.
Stages of Change – Continuous Measure (URICA‐E2): psychometrics of a Norwegian version
Authors: Lerdal Anners , Moe Britt , Digre Elin , Harding Thomas , Kristensen Frode , Grov Ellen K. , Bakken Linda N. , Eklund Marthe L. , Ruud Ireen , Rossi Joseph S. 
Published: November 2008

AbstractTitle.  Stages of Change – Continuous Measure (URICA‐E2): psychometrics of a Norwegian version. Aim.  This paper is a report of research to translate the English version of the Stages of Change continuous measure questionnaire (URICA‐E2) into Norwegian and to test the validity of the questionnaire and its usefulness in predicting behavioural change.Background.  While the psychometric properties of the Stages of Change categorical measure have been tested extensively, evaluation of the psychometric properties of the continuous questionnaire has not been described elsewhere in the literature.Method.  Cross‐sectional data were collected with a convenience sample of 198 undergraduate nursing students in 2005 and 2006. The English version of URICA‐E2 was translated into Norwegian according to standardized procedures.Findings.  Principal components analysis clearly confirmed five of the dimensions of readiness to change (Precontemplation Non‐Believers, Precontemplation Believers, Contemplation, Preparation and Maintenance), while the sixth dimension, Action, showed the lowest Eigenvalue (0·93). Findings from the cluster analysis indicate distinct profiles among the respondents in terms of readiness to change their exercise behaviour.Conclusion.  The URICA‐E2 was for the most part replicated from Reed’s original work. The result of the cluster analysis of the items associated with the factor ‘Action’ suggests that these do not adequately measure the factor.
Patients’ opinions of acute chest pain care: a qualitative evaluation of Chest Pain Units
Authors: Johnson Maxine , Goodacre Steve , Tod Angela , Read Susan 
Published: November 2008

AbstractTitle. Patients’ opinions of acute chest pain care: a qualitative evaluation of Chest Pain Units.Aim. This paper is a report of a study to explore the experiences of individuals receiving Chest Pain Unit care and routine Emergency Department care for acute chest pain.Background. Chest Pain Units were established in the United States of America with the aim of reducing admissions and costs, whilst improving quality of life and care satisfaction. Trials showed these units to be safe and practical; however, there was a need to establish whether Chest Pain Units could be cost‐effective in the United Kingdom, and whether use of a nurse‐led protocol could be acceptable to patients.Method. We carried out 26 semi‐structured interviews in 2005–2006 with patients across seven trial Chest Pain Units in the United Kingdom (14 in intervention sites and 12 in control sites) to explore issues that patients considered were important in their care experiences, and to develop possible explanations for the main trial outcomes. We analysed transcripts using the Framework approach to identify themes relating to care experiences.Findings. Differences in care experiences were more distinct between individual sites than between control and intervention sites. Satisfaction with care was high overall. Interactions with healthcare professionals, in particular specialist nurses, were valued in terms of reassurance, calming effect and competence. Indications for care improvement concerned information‐giving about investigations, diagnosis, and self‐care advice. Patients with non‐cardiac causes needed to feel more supported after discharge.Conclusion. Differences between modes of care may not coincide with identified trial outcomes. Qualitative methods can identify aspects of care that improve patient acceptability. The specialist nurse role appears particularly important in providing satisfactory individualized chest pain care.
Historical biogeography and phenotype‐phylogeny ofChroodiscus(lichenized Ascomycota: Ostropales: Graphidaceae)
Authors: Lücking Robert , Papong Khwanruan , Thammathaworn Achra , Boonpragob Kansri 
Published: November 2008

AbstractAim To analyse the historical biogeography of the lichen genusChroodiscususing a phenotype‐based phylogeny in the context of continental drift and evolution of tropical rain forest vegetation.Location All tropical regions (Central and South America, Africa, India, Southeast Asia, north‐east Australia).Methods We performed a phenotype‐based phylogenetic analysis and ancestral character state reconstruction of 14 species of the lichen genusChroodiscus, usingpaup* andmesquite; dispersal–vicariance analysis (DIVA) and dispersal–extinction–cladogenesis (DEC) modelling to trace the geographical origin of individual clades; and ordination and clustering by means ofpc‐ord, based on a novel similarity index, to visualize the biogeographical relationships of floristic regions in whichChroodiscusoccurs.Results The 14 species ofChroodiscusshow distinctive distribution patterns, with one pantropical and one amphi‐Pacific taxon and 12 species each restricted to a single continent. The genus comprises four clades. DIVA and DEC modelling suggest a South American origin ofChroodiscusin the mid to late Cretaceous (120–100 Ma), with subsequent expansion through a South American–African–Indian–Southeast Asian–Australian dispersal route and late diversification of theargillaceusclade in Southeast Asia. Based on the abundance of extant taxa, the probability of speciation events inChroodiscusis shown to be extremely low. Slow dispersal of foliicolous rain forest understorey lichens is consistent with estimated phylogenetic ages of individual species and with average lengths of biological species intervals in fungi (10–20 Myr).Main conclusions The present‐day distribution ofChroodiscuscan be explained by vicariance and mid‐distance dispersal through the interconnection or proximity of continental shelves, without the need for recent, trans‐oceanic long‐distance dispersal. Phylogenetic reconstruction and age estimation forChroodiscusare consistent with the ‘biotic ferry’ hypothesis: a South American origin and subsequent eastward expansion through Africa towards Southeast Asia and north‐eastern Australia via the Indian subcontinent. The present‐day pantropical distributions of many clades and species of foliicolous lichens might thus be explained by eastward expansion through continental drift, along with the evolution of modern rain forests starting 120 Ma, rather than by the existence of a hypothetical continuous area of pre‐modern rain forest spanning South America, Africa and Southeast Asia during the mid and late Cretaceous.