bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ontogenetic changes in the association between antipredator responses and growth variables
Authors: WOHLFAHRT BIANCA , MIKOLAJEWSKI DIRK J. , JOOP GERRIT , VAMOSI STEVEN M. 
Published: September 2007

Abstract 1. An organism’s growth parameters are expected to depend on environmental constraints, such as predation risk and food supply. However, antipredator responses, food intake, and thus growth of an animal may be mediated by behavioural traits, which are likely to differ among developmental stages. In this study, it was investigated how the relationship between growth and behavioural antipredator responses changes during ontogeny in the time‐constrained dragonfly species Libellula depressa, and which factors influenced specific behavioural decisions at different points in ontogeny.2. The results revealed that behavioural strategies differed between larval developmental sages, depending on associations between larval growth, food supply, and predation risk. Early in ontogeny, faster development was correlated with high larval activity and high food supply. This resulted in high activity levels under high food conditions irrespectively of predator presence, and under low food supply in predator absence only. In the intermediate stage of development, all larvae displayed a high activity level, which was correlated in general with fast development. However, growth later in ontogeny was not only influenced by the activity level, but also by predator presence and food supply, with larvae reared under high food supply and/or in presence of predators attaining a higher final mass. Thus, not only the way in which larval growth parameters and behaviour are related changed during development, but also whether the factors influenced larval growth and behaviour. Once the larvae reached the ultimate stage of development, in which they overwinter, behavioural patterns observed were consistent with model predictions.3. It is advocated that behavioural plasticity of prey organisms in different developmental stages should be analysed in the context of associated growth variables.
Context‐specific regulation of LINE‐1
Authors: Teneng Ivo , Stribinskis Vilius , Ramos Kenneth S. 
Published: September 2007

The present study was conducted to evaluate the contextual specificity of long interspersed nuclear element‐1 (LINE‐1 or L1) activation by cellular stress and the role of the aryl hydrocarbon receptor (AHR) transcription factor and oxidative stress in the gene activation response. Activation of the AHR by the genotoxic carcinogen benzo(a)pyrene (BaP) increased L1 expression in human cervical carcinoma (HeLa) cells, human microvascular endothelial cells (HMEC), mouse vascular smooth muscle cells (mVSMC) and mouse embryonic kidney cells (mK4). In contrast, challenge with a different AHR ligand 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD), or UV irradiation (10–20 J/m2), induced L1 only in HeLa cells. Transactivation of the mouse L1Md‐A5 promoter was observed in all cell types challenged with BaP, while TCDD was without effect, and UV only activated L1 in HeLa cells. Genetic and pharmacological experiments implicated the AHR and oxidative stress as contextual determinants of L1 inducibility by cellular stress.
Sea‐level rise and drought interactions accelerate forest decline on the Gulf Coast of Florida, USA
Authors: DESANTIS LARISA R. G. , BHOTIKA SMRITI , WILLIAMS KIMBERLYN , PUTZ FRANCIS E. 
Published: September 2007

AbstractSea‐level rise threatens low‐lying coastal ecosystems globally. In Florida, USA, salinity stress due to increased tidal flooding contributes to the dramatic and well documented decline of species‐rich coastal forest areas along the Gulf of Mexico. Here, we present the results of a study of coastal forest stand dynamics in thirteen 400 m2 plots representing an elevation gradient of 0.58–1.1 m affected by tidal flooding and rising sea levels. We extended previously published data from 1992–2000 to 2005 to quantify the full magnitude of the 1998–2002 La Niña‐associated drought. Populations of the dominant tree species, Sabal palmetto (cabbage palm), declined more rapidly during 2000–2005 than predicted from linear regressions based on the 1992–2000 data. Dramatic increases in Juniperus virginiana (Southern red cedar) and S. palmetto mortality during 2000–2005 as compared with 1995–2000 are apparently due to the combined effects of a major drought and ongoing sea‐level rise. Additionally, coastal forest stands continued to decline in species richness with increased tidal flooding frequency and decreasing elevation. Stable isotope (H, O) analyses demonstrate that J. virginiana accesses fresher water sources more than S. palmetto. Carbon isotopes reveal increasing δ13C enrichment of S. palmetto and J. virginiana with increased tidal flooding and decreased elevation, demonstrating increasing water stress in both species. Coastal forests with frequent tidal flooding are unable to support species‐rich forests or support regeneration of the most salt‐tolerant tree species over time. Given that rates of sea‐level rise are predicted to increase and periodic droughts are expected to intensify in the future due to global climate change, coastal forest communities are in jeopardy if their inland retreat is restricted.
Impact of elevated carbon dioxide on the rhizosphere communities of Carex arenaria and Festuca rubra
Authors: DRIGO BARBARA , KOWALCHUK GEORGE A. , YERGEAU ETIENNE , BEZEMER T. MARTIJN , BOSCHKER HENRICUS T. S. , VAN VEEN JOHANNES A. 
Published: September 2007

AbstractThe increase in atmospheric carbon dioxide (CO2) levels is predicted to stimulate plant carbon (C) fixation, potentially influencing the size, structure and function of micro‐ and mesofaunal communities inhabiting the rhizosphere. To assess the effects of increased atmospheric CO2 on bacterial, fungal and nematode communities in the rhizosphere, Carex arenaria (a nonmycorrhizal plant species) and Festuca rubra (a mycorrhizal plant species) were grown in three dune soils under controlled soil temperature and moisture conditions, while subjecting the aboveground compartment to defined atmospheric conditions differing in CO2 concentrations (350 and 700 μL L−1). Real‐time polymerase chain reaction (PCR) and PCR‐denaturing gradient gel electrophoresis methods were used to examine effects on the size and structure of rhizosphere communities. Multivariate analysis of community profiles showed that bacteria were most affected by elevated CO2, and fungi and nematodes to a lesser extent. The influence of elevated CO2 was plant dependent, with the mycorrhizal plant (F. rubra) exerting a greater influence on bacterial and fungal communities. Biomarker data indicated that arbuscular mycorrhizal fungi (AMF) may play an important role in the observed soil community responses. Effects of elevated CO2 were also soil dependent, with greater influence observed in the more organic‐rich soils, which also supported higher levels of AMF colonization. These results indicate that responses of soil‐borne communities to elevated CO2 are different for bacteria, fungi and nematodes and dependent on the plant type and soil nutrient availability.
Increased expression of the MYB‐related transcription factor, PHR1, leads to enhanced phosphate uptake in Arabidopsis thaliana
Authors: NILSSON LENA , MÜLLER RENATE , NIELSEN TOM HAMBORG 
Published: September 2007

ABSTRACTPlants have evolved a number of adaptive strategies to cope with fluctuations in phosphorus (P) supply. The current knowledge of the transcriptional regulation of the P‐starvation response in plants is limited. However, one MYB‐related transcription factor, PHR1, is known to be involved in the P‐starvation response. In this paper, we characterize a T‐tagged phr1 knockout mutant and a series of transgenic plant lines which over‐express PHR1 in wild type (WT) and phr1 mutant background. The knockout mutant has an altered phosphate (Pi) allocation between root and shoot; accumulates less anthocyanins, sugars and starch than P‐starved WT; has a lower AGPase activity; and is impaired in induction of a subset of Pi starvation‐induced genes. Expression of PHR1 in the phr1 mutant rescues the responsiveness to P‐starvation and leads to WT levels of sugars and starch during Pi starvation conditions, confirming the involvement of PHR1 in adjusting carbon metabolism. Over‐expression of PHR1 further resulted in a dramatic increase in the microRNA miR399d, and this resulted in changes in the transcript level for the target gene PHO2. Furthermore, over‐expression of PHR1 in both WT and phr1 mutant results in strongly increased content of Pi irrespective of P regime. This shows that targeting a key regulatory element in the Pi starvation regulatory network represents a useful approach for molecular breeding of plants towards more efficient Pi uptake and assimilation.
The Arabidopsis her1 mutant implicates GABA in E‐2‐hexenal responsiveness
Authors: Mirabella Rossana , Rauwerda Han , Struys Eduard A. , Jakobs Cornelis , Triantaphylidès Christian , Haring Michel A. , Schuurink Robert C. 
Published: September 2007

SummaryWhen wounded or attacked by herbivores or pathogens, plants produce a blend of six‐carbon alcohols, aldehydes and esters, known as C6‐volatiles. Undamaged plants, when exposed to C6‐volatiles, respond by inducing defense‐related genes and secondary metabolites, suggesting that C6‐volatiles can act as signaling molecules regulating plant defense responses. However, to date, the molecular mechanisms by which plants perceive and respond to these volatiles are unknown. To elucidate such mechanisms, we decided to isolate Arabidopsis thaliana mutants in which responses to C6‐volatiles were altered. We observed that treatment of Arabidopsis seedlings with the C6‐volatile E‐2‐hexenal inhibits root elongation. Among C6‐volatiles this response is specific to E‐2‐hexenal, and is not dependent on ethylene, jasmonic and salicylic acid. Using this bioassay, we isolated 18 E‐2‐hexenal‐response (her) mutants that showed sustained root growth after E‐2‐hexenal treatment. Here, we focused on the molecular characterization of one of these mutants, her1. Microarray and map‐based cloning revealed that her1 encodes a γ‐amino butyric acid transaminase (GABA‐TP), an enzyme that degrades GABA. As a consequence of the mutation, her1 plants accumulate high GABA levels in all their organs. Based on the observation that E‐2‐hexenal treatment induces GABA accumulation, and that high GABA levels confer resistance to E‐2‐hexenal, we propose a role for GABA in mediating E‐2‐hexenal responses.
Acquired cold urticaria symptoms can be safely prevented by ebastine
Authors: Magerl M. , Schmolke J. , Siebenhaar F. , Zuberbier T. , Metz M. , Maurer M. 
Published: September 2007

Background:  Acquired cold urticaria (ACU) is a skin condition, in which exposure to cold results in wheals and itching and sometimes general systemic complications. It has a profound impact on patient quality of life. Second‐generation antihistamines are recommended as the first‐line treatment, but to date only a few have been scientifically tested for this condition.Aim:  To assess the safety and efficacy of ebastine in preventing ACU symptoms.Methods:  Twenty‐two adult ACU patients participated in a double‐blind crossover trial of 20 mg ebastine. The safety of ebastine was sensitively assessed with a psychometric battery testing cognitive performance and mood. After cold challenge, wheal and erythema were assessed by the investigator and the intensities of pruritus and burning were rated by the subject.Results:  Ebastine had no negative impact on any of the parameters of cognitive performance or mood. It dramatically reduced the number of patients who experienced wheals, pruritus, and burning after challenge.Conclusion:  Ebastine is safe and effective in preventing the symptoms of ACU.
A modified rapid monoclonal antibody‐specific immobilization of platelet antigen assay for the detection of human platelet antigen (HPA) antibodies: a multicentre evaluation
Authors: Campbell K. , Rishi K. , Howkins G. , Gilby D. , Mushens R. , Ghevaert C. , Metcalfe P. , Ouwehand W. H. , Lucas G. 
Published: September 2007

Background  The monoclonal antibody‐specific immobilization of platelet antigens (MAIPA) assay is the cornerstone technique for the detection and identification of human platelet antigen (HPA) antibodies. However, the original technique described by Kiefel and colleagues requires approximately 8 h adding to diagnostic delay. Moreover, proficiency exercises indicate that there are substantial variations in the MAIPA protocol, and that these may account for interlaboratory differences in sensitivity and specificity.Study Design and Methods  A review of current MAIPA assay protocols from six laboratories together with performance in quality‐assessment schemes identified several key variables potentially affecting the assay results. An optimized protocol was derived and assay time reduced to 5 h. The modified rapid MAIPA (MR‐MAIPA) assay was evaluated using 61 samples with a range of HPA antibodies typically encountered in cases of fetomaternal alloimmune thrombocytopenia (n = 22), post‐transfusion purpura (n = 8), platelet refractoriness (n = 7) and other platelet immune conditions (n = 24). The sensitivity of the assay was assessed using three international standards and the recombinant HPA‐1a antibody CamTran007. The results obtained were compared with the original findings obtained with the local MAIPA assays. In addition, four different glycoprotein IIb/IIIa capture monoclonal antibodies were evaluated for their effect on assay sensitivity.Results  Complete concordance was found between the original MAIPA results and those obtained with the new assay when testing a selected panel of clinical samples. The modified assay had nanogram level sensitivity for the detection of HPA‐1a antibodies and titration of HPA‐1a and HPA‐5b antibody sensitivity standards yielded end‐points equal to or greater than the mean recorded in international workshops.Conclusion  The MR‐MAIPA assay offers improved turnaround for the detection of HPA antibodies without loss of sensitivity.
The blood donation experience: self‐reported motives and obstacles for donating blood
Authors: Sojka B. Nilsson , Sojka P. 
Published: September 2007

Background and Objectives  The aim of the study was to investigate motives for donating blood as well as difficulties and obstacles associated with blood donation as perceived by the donors themselves.Materials and Methods  Six hundred consecutive blood donors (i.e. all blood donors with a history of at least one previous whole blood donation attending, during nine working days, the Blood Centre of Umeå University Hospital) received a self‐administered questionnaire that contained questions aimed at elucidating motives for donating blood (general motives for donating blood, specific motives for the first donation and motives for continuing to be an active blood donor). Questions concerning difficulties and obstacles that had to be overcome in order to continue being a blood donor were also included in the questionnaire.Results  Altogether 531 whole blood donors filled in the questionnaire (88·5%; 322 men and 209 women). No statistically significant differences were found between male and female blood donors concerning general reasons and motives related to donating blood. The most frequently reported reasons for giving blood the first time were ‘influence from a friend’ (47·2% of donors) and ‘request via media’ (23·5% of donors). Among general reasons/motives with highest ranking of importance, the most commonly reported motive for donating blood were ‘general altruism’ (40·3%), ‘social responsibility/obligation’ (19·7%) and ‘influence from friends’ (17·9%). General altruism’ and ‘social responsibility/obligation’ were also the most frequent reasons for continuing to donate blood (68·4 and 16·0%, respectively). The most commonly reported obstacle to becoming a regular blood donor was ‘laziness’ (19·1%) followed by ‘fear of needles’ (10·5%).Conclusions  Altruism was the most common general motive for donating blood and also for continuing to be an active blood donor. Yet, for the first blood donation, direct ‘influence from friends/relatives’, ‘media appeal’ and other types of recruitment were more commonly reported as reasons or motives for donating blood than altruism. The findings support the notion that different strategies should be used/adopted to get people to donate blood the first time (e.g. recruitment through other blood donors using, for example, the ‘bring a friend along’ method) and to retain these subjects as active blood donors (e.g. by information and by strengthening their sense of being a blood donor or their self‐efficacy etc.).
Long‐term changes and variability in diabetes risk factors prior to the development of impaired glucose homeostasis
Authors: Laspa E. , Christen A. , Efstathiadou Z. , Johnston D. G. , Godsland I. F. 
Published: September 2007

AbstractAims  To determine whether rate of change and variability in risk factors provides insight into the development of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) or Type 2 diabetes (DM).Methods  In a nested case‐control study, repeated risk factor measurements (mean number 4.3, duration 11.4 years) culminated in 59 men developing IFG (n = 37), IGT (n = 14) and/or DM (n = 11). For each case, two control subjects were matched for age and equivalence of follow‐up. Rates of change and variability in diabetes risk factors prior to diagnosis were quantified by regression analysis. Changes between penultimate and diagnostic visits were also analysed.Results  The age‐related rise in body mass index (BMI) was attenuated prior to IFG compared with control subjects (+0.102 vs. +0.772 kg/m2/decade, P = 0.02). There was also some evidence for this prior to IGT and DM (IGT: –1.530 vs. +0.158 kg/m2/decade, P = 0.09; DM: –1.146 vs. +0.332 kg/m2/decade, non‐significant). Prior to onset, IGT cases were distinguished by higher inflammatory marker levels, a decline in insulinogenic index and greater variability in oral glucose tolerance test (OGTT) insulin, and DM cases by lower insulin sensitivity and higher liver enzyme activities. Fasting and OGTT glucose levels changed little during the mean 8.9 years prior to onset of IFG, IGT or DM. The transition to IGT or DM was accompanied by a fall in insulin sensitivity.Conclusions  Except for BMI, change or variability in risk factor levels appears relatively unimportant in the development of clinically elevated glucose levels. Deterioration in glucose levels to IGT or DM occurs as a rapid, incremental increase accompanied by a decline in insulin sensitivity.
Serum angiotensin‐converting enzyme and frequency of severe hypoglycaemia in Type 1 diabetes: does a relationship exist?
Authors: Zammitt N. N. , Geddes J. , Warren R. E. , Marioni R. , Ashby J. P. , Frier B. M. 
Published: September 2007

AbstractAims  An association has been described between elevated serum angiotensin‐converting enzyme (ACE) and an increased risk of severe hypoglycaemia (SH). To ascertain whether this reported association could be replicated in a different country, it was re‐examined in 300 individuals with Type 1 diabetes.Methods  People with Type 1 diabetes, none of whom was taking renin–angiotensin system blocking drugs, were recruited. Participants recorded the frequency with which they had experienced SH. Glycated haemoglobin (HbA1c) and serum ACE were measured. The difference in the incidence of SH between different quartiles of ACE activity and the relationship between serum ACE and SH were examined using non‐parametric statistical tests and a negative binomial model.Results  Data were obtained from 300 patients [158 male; HbA1c median (range) 8.2% (5.2–12.8%), median age 36 years (16–88); duration of diabetes 14.5 years (2–49)]. The incidence of SH was 0.93 episodes per patient year. The mean incidence of SH in the top and bottom quartiles of ACE activity was 0.5 and 1.7 episodes per patient year, respectively, but this difference was not statistically significant (P = 0.075). Spearman's test showed a very weak, although statistically significant, association between serum ACE level and SH incidence (r = 0.115, P = 0.047). The binomial model also showed a statistically significant (P = 0.002), but clinically weak, relationship between serum ACE and SH.Conclusions  The present survey showed a weak relationship between serum ACE and the frequency of SH, the clinical relevance of which is unclear. This limits the proposed role for serum ACE as an index of risk for SH.
Land Cover in a Managed Forest Ecosystem: Mexican Shade Coffee
Authors: Blackman Allen , Albers Heidi J. , ávalos-Sartorio Beatriz , Murphy Lisa Crooks 
Published: September 2007

AbstractManaged forest ecosystems like shade coffee supply valuable ecological services. Yet little is known about the drivers and characteristics of clearing in such systems. We present a spatial econometric analysis of land cover in a shade coffee region in southern Mexico. We find that plots close to large cities are less likely to be cleared all other things being equal—the opposite of the pattern usually observed in natural forests. In addition, we find that membership in coffee‐marketing cooperatives, farm size, and certain soil types are associated with tree cover, while proximity to small town centers is associated with clearing.
Choosing Brands: Fresh Produce versus Other Products
Authors: Jin Yanhong H. , Zilberman David , Heiman Amir 
Published: September 2007

AbstractAssuming that brands contribute to quality risk reduction, prestige, and design, we derive and test hypothesis on the willingness to pay (WTP) for brands across different product categories (electronics, clothing, packaged food, and fresh produce). Using the random effect tobit model on the stated point value of WTP and the ordered probit model on the stated range of WTP, we find that WTP for brands of fresh produce is least among the four product categories controlling for relevant demographic variations. Simulations show that fresh produce has a higher optimal price premium for brands but with a much smaller market share.
Analysis of Longitudinal Data with Drop-Out: Objectives, Assumptions and a Proposal
Authors: Diggle Peter , Farewell Daniel , Henderson Robin 
Published: September 2007

SummaryThe problem of analysing longitudinal data that are complicated by possibly informative drop-out has received considerable attention in the statistical literature. Most researchers have concentrated on either methodology or application, but we begin this paper by arguing that more attention could be given to study objectives and to the relevant targets for inference. Next we summarize a variety of approaches that have been suggested for dealing with drop-out. A long-standing concern in this subject area is that all methods require untestable assumptions. We discuss circumstances in which we are willing to make such assumptions and we propose a new and computationally efficient modelling and analysis procedure for these situations. We assume a dynamic linear model for the expected increments of a constructed variable, under which subject-specific random effects follow a martingale process in the absence of drop-out. Informal diagnostic procedures to assess the tenability of the assumption are proposed. The paper is completed by simulations and a comparison of our method and several alternatives in the analysis of data from a trial into the treatment of schizophrenia, in which approximately 50% of recruited subjects dropped out before the final scheduled measurement time.