bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seasonal variation in foliar carbon exchange in Pinus radiata and Populus deltoides: respiration acclimates fully to changes in temperature but photosynthesis does not
Authors: OW LAI FERN , WHITEHEAD DAVID , WALCROFT ADRIAN S. , TURNBULL MATTHEW H. 
Published: February 2009

AbstractWe investigated seasonal variation in dark respiration and photosynthesis by measuring gas exchange characteristics on Pinus radiata and Populus deltoides under field conditions each month for 1 year. The field site in the South Island of New Zealand is characterized by large day‐to‐day and seasonal changes in air temperature. The rate of foliar respiration at a base temperature of 10 °C (R10) in both pine and poplar was found to be greater during autumn and winter and displayed a strong downward adjustment in warmer months. The sensitivity of instantaneous leaf respiration to a 10 °C increase in temperature (Q10) was also greater during the winter period. The net effect of this strong acclimation was that the long‐term temperature response of respiration was essentially flat over a wide range of ambient temperatures. Seasonal changes in photosynthesis were sensitive to temperature but largely independent of leaf nitrogen concentration or stomatal conductance. Over the range of day time growth temperatures (5–32 °C), we did not observe strong evidence of photosynthetic acclimation to temperature, and the long‐term responses of photosynthetic parameters to ambient temperature were similar to previously published instantaneous responses. The ratio of foliar respiration to photosynthetic capacity (Rd/Asat) was significantly greater in winter than in spring/summer. This indicates that there is little likelihood that respiration would be stimulated significantly in either of these species with moderate increases in temperature – in fact net carbon uptake was favoured at moderately higher temperatures. Model calculations demonstrate that failing to account for strong thermal acclimation of leaf respiration influences determinations of leaf carbon exchange significantly, especially for the evergreen conifer.
Diagnostic challenges of motility disorders: optimal detection of CD117+ interstitial cells of Cajal
Authors: Garrity Megan M , Gibbons Simon J , Smyrk Thomas C , Vanderwinden Jean Marie , Gomez‐Pinilla Pedro Julian , Nehra Anoop , Borg Matthew , Farrugia Gianrico 
Published: February 2009

Aims:  Several gastrointestinal motility diseases are associated with altered numbers of interstitial cells of Cajal (ICC), and testing for alterations in numbers of ICC has been proposed as one way to improve routine diagnosis in motility diseases. However, the protocols currently used to visualize ICC in formalin‐fixed paraffin‐embedded (FFPE) tissue using antibodies to CD117 have not been optimized for studying motility disorders. The aims of this study were therefore to determine the optimal protocol using FFPE tissue, determine normal values for ICC in non‐neoplastic human colon, and compare results with those obtained using immunofluorescence (IF).Methods and results:  Non‐neoplastic tissue was collected from patients undergoing resection for colonic cancer and fixed for both light (FFPE) and IF testing. Sections were processed for standard immunohistochemistry using different primary antibodies in conjunction with variations in antigen retrieval [ethylenediamine tetraacetricacid (EDTA), citrate], antibody dilution, blocking and detection (Mach2, Mach3, Envision+). Best results were obtained with EDTA retrieval, the DAKO CD117 antibody and Mach3 detection.Conclusions:  The optimized protocol presented improved CD117 detection in FFPE tissues and showed good concordance with overall localization of CD117‐immunoreactive ICC as detected by IF. As such, this protocol may be more useful than current diagnostic procedures in motility disorders.
Cell cycle alterations and their relationship to proliferation in apocrine adenosis of the breast
Authors: Elayat Ghada , Selim Abdel‐Ghani A , Wells Clive A 
Published: February 2009

Aims:  Apocrine adenosis (AA) is generally considered a benign disease of the breast. However, recent studies have suggested a precancerous potential for some of these lesions. The aim was to investigate the status of cell cycle proteins previously reported to be deregulated in breast cancer to identify their possible role in AA.Methods and results:  The cases were categorized into AA without atypia (NAA) and atypical AA (AAA). Using immunohistochemistry, the expression of cyclin D1, cyclin A, p27, p21, p16, pRb and Ki67 was determined in 29 NAA and 16 AAA cases. Cyclin D1, p21 and cyclin A were overexpressed in 58.6%, 51.7% and 31.8% of the NAA cases, respectively, whereas 81.3%, 62.5% and 41.7% of the AAA cases showed overexpression of cyclin D1, p21 and cyclin A, respectively. All cases were negative for p16, whereas pRb was expressed in all cases. Furthermore, proliferation in AA (4.5%) was significantly higher than that of normal breast epithelium (1%). There was no statistical significance in the degree of proliferation between the NAA (3.7%) and AAA (4.8%) groups.Conclusions:  The study indicates that NAA and AAA are biologically similar. A subset of AA defined by increased proliferation and significant cell cycle alterations may be susceptible to oncogenesis.
Uterine sarcomas in Norway. A histopathological and prognostic survey of a total population from 1970 to 2000 including 419 patients
Authors: Abeler Vera M , Røyne Odd , Thoresen Steinar , Danielsen Håvard E , Nesland Jahn M , Kristensen Gunnar B 
Published: February 2009

Aims:  To determine the frequency and survival of the various types of uterine sarcoma in the total population of Norway and evaluate histopathological prognostic factors in order to identify risk groups.Methods and results:  Histopathological review of all uterine sarcoma cases reported to the Norwegian Cancer Registry during 1970–2000 was undertaken. Survival dates were provided by The Cancer Registry. Kaplan–Meier survival curves were generated. The log rank test was used for univariate analysis and a Cox proportional hazards regression model for multivariate evaluation of survival. Stage of disease was the most important prognostic factor for all tumour types. Tumour size and the mitotic index (MI) were significant prognostic factors (P < 0.0001) in leiomyosarcomas confined to the uterus and allowed for separation into three risk groups with marked differences in prognosis. The prognosis of endometrial stromal sarcomas confined to the uterus was related to MI (P < 0.0001) and tumour cell necrosis (P < 0.004). Combining these parameters allowed for separation into three risk groups with marked difference in prognosis. In adenosarcomas, tumour cell necrosis was the only significant prognostic factor.Conclusions:  There are marked differences in survival between uterine sarcoma types. Leiomyosarcomas and endometrial stromal sarcomas can be divided into different groups.
Association of genetic variation on chromosome 9p21.3 and arterial stiffness
Authors: Björck H. M. , Länne T. , Alehagen U. , Persson K. , Rundkvist L. , Hamsten A. , Dahlström U. , Eriksson P. 
Published: February 2009

Abstract.Objectives.  Genome wide association studies have consistently reported associations between a region on chromosome 9p21.3 and a broad range of vascular diseases, such as coronary artery disease (CAD), aortic and intracranial aneurysms and type‐2 diabetes (T2D). However, clear associations with intermediate phenotypes have not been described so far. To shed light on a possible influence of this chromosomal region on arterial wall integrity, we analysed associations between single nucleotide polymorphisms (SNPs) and degree of stiffness of the abdominal aorta in elderly individuals.Methods and results.  A total of 400 subjects, 212 men and 188 women, aged 70–88 years were included. Arterial stiffness was examined at the midpoint between the renal arteries and the aortic bifurcation. Two CAD‐ and aneurysm‐associated SNPs (rs10757274 and rs2891168) and one T2D‐associated SNP (rs1081161) within the 9p21.3 region were genotyped. Aortic compliance and distensibility coefficients were higher in carriers of the rs10757274G and rs2891168G alleles in men reflecting a decrease in aortic stiffness. Adjustment for age and mean arterial pressure had no effect on these associations. The two SNPs were not associated with intima‐media thickness or lumen diameter of the abdominal aorta. There were no associations between the rs10811661 SNP and any measure of aortic stiffness.Conclusions.  Impaired mechanical properties of the arterial wall may explain the association between chromosome 9p21.3 polymorphisms and vascular disease.
Exhaled nitric oxide levels in alpha‐1‐antitrypsin PiMZ subjects
Authors: Malerba M. , Ragnoli B. , Radaeli A. 
Published: February 2009

Abstract.Objectives.  Although the likelihood of intermediate alpha‐1‐antitrypsin deficiency (PiMZ) patients developing chronic obstructive pulmonary disease (COPD) remains uncertain, several investigators have suggested that a lack of antiprotease inhibitor activity may favour the development of airway inflammation with subsequent pulmonary tissue damage. The levels of exhaled nitric oxide (FeNO) in PiMZ subjects are unknown and polymorphisms in nitric oxide synthase have been linked to lung disease susceptibility in subjects with alpha‐1‐antitrypsin (AAT) deficiency. This study was aimed at assessing FeNO levels in a group of PiMZ subjects and comparing it with the concentrations found amongst groups of COPD and control patients.Design.  A group of 31 PiMZ subjects, 31 COPD patients and 30 controls underwent pulmonary function tests, AAT assay and phenotyping, and FeNO measurement in an ambulatory setting.Results.  FeNO values observed in the group of PiMZ subjects (21.6 ± 8.9 ppb) showed a significant increase compared with COPD (14.5 ± 8.7 ppb; P < 0.01) and the control groups (9.1 ± 2.9 ppb; P < 0.01). Within the PiMZ population, a significant, negative correlation was observed between plasma AAT levels and FeNO readings.Conclusions.  Not only did PiMZ subjects show increased FeNO levels compared with COPD patients and controls; FeNO levels proved to be related to the reduced concentration of plasma AAT. Such findings seem to suggest the importance of FeNO measurements on PiMZ subjects for monitoring a possible progression of airway inflammation to obstructive lung disease as observed in some of these patients.
Tracing carbon and oxygen isotope signals from newly assimilated sugars in the leaves to the tree‐ring archive
Authors: GESSLER ARTHUR , BRANDES ELKE , BUCHMANN NINA , HELLE GERHARD , RENNENBERG HEINZ , BARNARD ROMAIN L. 
Published: February 2009

ABSTRACTThe analysis of δ13C and δ18O in tree‐ring archives offers retrospective insights into environmental conditions and ecophysiological processes. While photosynthetic carbon isotope discrimination and evaporative oxygen isotope enrichment are well understood, we lack information on how the isotope signal is altered by downstream metabolic processes.In Pinus sylvestris, we traced the isotopic signals from their origin in the leaf water (δ18O) or the newly assimilated carbon (δ13C), via phloem sugars to the tree‐ring, over a time‐scale that ranges from hours to a growing season.Seasonally, variable 13C enrichment of sugars related to phloem loading and transport did lead to uncoupling between δ13C in the tree‐ring, and the ci/ca ratio at the leaf level. In contrast, the oxygen isotope signal was transferred from the leaf water to the tree‐ring with an expected enrichment of 27‰, with time‐lags of approximately 2 weeks and with a 40% exchange between organic oxygen and xylem water oxygen during cellulose synthesis.This integrated overview of the fate of carbon and oxygen isotope signals within the model tree species P. sylvestris provides a novel physiological basis for the interpretation of δ13C and δ18O in tree‐ring ecology.
Leaf xylem embolism, detected acoustically and by cryo‐SEM, corresponds to decreases in leaf hydraulic conductance in four evergreen species
Authors: JOHNSON DANIEL M. , MEINZER FREDERICK C. , WOODRUFF DAVID R. , MCCULLOH KATHERINE A. 
Published: February 2009

ABSTRACTHydraulic conductance of leaves (Kleaf) typically decreases with increasing water stress. However, the extent to which the decrease in Kleaf is due to xylem cavitation, conduit deformation or changes in the extra‐xylary pathway is unclear. We measured Kleaf concurrently with ultrasonic acoustic emission (UAE) in dehydrating leaves of two vessel‐bearing and two tracheid‐bearing species to determine whether declining Kleaf was associated with an accumulation of cavitation events. In addition, images of leaf internal structure were captured using cryo‐scanning electron microscopy, which allowed detection of empty versus full and also deformed conduits. Overall, Kleaf decreased as leaf water potentials (ΨL) became more negative. Values of Kleaf corresponding to bulk leaf turgor loss points ranged from 13 to 45% of their maximum. Additionally, ΨL corresponding to a 50% loss in conductivity and 50% accumulated UAE ranged from −1.5 to −2.4 MPa and from −1.1 to −2.8 MPa, respectively, across species. Decreases in Kleaf were closely associated with accumulated UAE and the percentage of empty conduits. The mean amplitude of UAEs was tightly correlated with mean conduit diameter (R2 = 0.94, P = 0.018). These results suggest that water stress‐induced decreases in Kleaf in these species are directly related to xylem embolism.
Reassessing the role of phospholipase D in theArabidopsiswounding response
Authors: BARGMANN BASTIAAN O. R. , LAXALT ANA M. , RIET BAS TER , TESTERINK CHRISTA , MERQUIOL EMMANUELLE , MOSBLECH ALINA , LEON‐REYES ANTONIO , PIETERSE CORNÉ M. J. , HARING MICHEL A. , HEILMANN INGO , BARTELS DOROTHEA , MUNNIK TEUN 
Published: February 2009

ABSTRACTPlants respond to wounding by means of a multitude of reactions, with the purpose of stifling herbivore assault. Phospholipase D (PLD) has previously been implicated in the wounding response.Arabidopsis(Arabidopsis thaliana) AtPLDα1 has been proposed to be activated in intact cells, and the phosphatidic acid (PA) it produces to serve as a precursor for jasmonic acid (JA) synthesis and to be required for wounding‐induced gene expression. Independently, PLD activity has been reported to have a bearing on wounding‐induced MAPK activation. However, which PLD isoforms are activated, where this activity takes place (in the wounded or non‐wounded cells) and what exactly the consequences are is a question that has not been comprehensively addressed. Here, we show that PLD activity during the wounding response is restricted to the ruptured cells using32Pi‐labelled phospholipid analyses ofArabidopsis pldknock‐out mutants andPLD‐silenced tomato cell‐suspension cultures.pldα1knock‐out lines have reduced wounding‐induced PA production, and the remainder is completely eliminated in apldα1/δdouble knock‐out line. Surprisingly, wounding‐induced protein kinase activation,AtLOX2gene expression and JA biosynthesis were not affected in these knock‐out lines. Moreover, larvae of the Cabbage White butterfly (Pieris rapae) grew equally well on wild‐type and thepldknock‐out mutants.
Late Quaternary deposition and facies model for karstic Lake Estanya (North‐eastern Spain)
Authors: MORELLÓN MARIO , VALERO‐GARCÉS BLAS , ANSELMETTI FLAVIO , ARIZTEGUI DANIEL , SCHNELLMANN MICHAEL , MORENO ANA , MATA PILAR , RICO MAYTE , CORELLA JUAN PABLO 
Published: February 2009

AbstractLake Estanya is a small (19 ha), freshwater to brackish, monomictic lake formed by the coalescence of two karstic sinkholes with maximum water depths of 12 and 20 m, located in the Pre‐Pyrenean Ranges (North‐eastern Spain). The lake is hydrologically closed and the water balance is controlled mostly by groundwater input and evaporation. Three main modern depositional sub‐environments can be recognized as: (i) a carbonate‐producing ‘littoral platform’; (ii) a steep ‘talus’ dominated by reworking of littoral sediments and mass‐wasting processes; and (iii) an ‘offshore, distal area’, seasonally affected by anoxia with fine‐grained, clastic sediment deposition. A seismic survey identified up to 15 m thick sedimentary infill comprising: (i) a ‘basal unit’, seismically transparent and restricted to the depocentres of both sub‐basins; (ii) an ‘intermediate unit’ characterized by continuous high‐amplitude reflections; and (iii) an ‘upper unit’ with strong parallel reflectors. Several mass‐wasting deposits occur in both sub‐basins. Five sediment cores were analysed using sedimentological, microscopic, geochemical and physical techniques. The chronological model for the sediment sequence is based on 17 accelerator mass spectrometry 14C dates. Five depositional environments were characterized by their respective sedimentary facies associations. The depositional history of Lake Estanya during the last ca 21 kyr comprises five stages: (i) a brackish, shallow, calcite‐producing lake during full glacial times (21 to 17·3 kyr bp); (ii) a saline, permanent, relatively deep lake during the late glacial (17·3 to 11·6 kyr bp); (iii) an ephemeral, saline lake and saline mudflat complex during the transition to the Holocene (11·6 to 9·4 kyr bp); (iv) a saline lake with gypsum‐rich, laminated facies and abundant microbial mats punctuated by periods of more frequent flooding episodes and clastic‐dominated deposition during the Holocene (9·4 to 0·8 kyr bp); and (v) a deep, freshwater to brackish lake with high clastic input during the last 800 years. Climate‐driven hydrological fluctuations are the main internal control in the evolution of the lake during the last 21 kyr, affecting water salinity, lake‐level changes and water stratification. However, external factors, such as karstic processes, clastic input and the occurrence of mass‐flows, are also significant. The facies model defined for Lake Estanya is an essential tool for deciphering the main factors influencing lake deposition and to evaluate the most suitable proxies for lake level, climate and environmental reconstructions, and it is applicable to modern karstic lakes and to ancient lacustrine formations.
Virus resistance induced by NB–LRR proteins involves Argonaute4‐dependent translational control
Authors: Bhattacharjee Saikat , Zamora Alejandro , Azhar Muhammad Tehseen , Sacco Melanie A. , Lambert Lester H. , Moffett Peter 
Published: February 2009

SummaryActive resistance to viruses is afforded by plant disease resistance (R) genes, which encode proteins with nucleotide‐binding (NB) and leucine‐rich repeat (LRR) domains. Upon recognition of pathogen‐derived elicitors, these NB–LRR proteins are thought to initiate a number of signaling pathways that lead to pathogen restriction. However, little is known about the molecular mechanisms that ultimately curtail virus accumulation. Here, we show that the co‐expression of a plant NB–LRR protein with its cognate elicitor results in an antiviral response that inhibits the translation of virus‐encoded proteins in Nicotiana benthamiana. This antiviral response is dependent on viral cis elements, and, upon activation of the NB–LRR protein, viral transcripts accumulate but do not associate with ribosomes. The induced inhibition of viral transcript translation and NB–LRR‐mediated virus resistance were compromised by the downregulation of Argonaute4‐like genes. Argonaute proteins have been implicated in small RNA‐mediated RNA degradation, and in degradation‐independent translational control. Our results suggest that the engagement of Argonaute proteins in the specific translational control of viral transcripts is a key factor in virus resistance mediated by NB–LRR proteins.
Different flowering phenology of alien invasive species in Spain: evidence for the use of an empty temporal niche?
Authors: Godoy O. , Castro‐Díez P. , Valladares F. , Costa‐Tenorio M. 
Published: February 2009

AbstractFlowering phenology is an important and poorly understood plant trait that may possibly be related to the invasiveness potential of alien species. The present work evaluates whether flowering time of invasive alien species is a key trait to overcome the climatic filters operating in continental Mediterranean ecosystems of Spain (characterised by summer drought and low temperatures in winter). We conducted comparisons between the flowering phenology of the invasive species in their native range and in Spain, and between flowering phenology of 91 coexisting invasive–native species pairs. For the alien species, geographical change from the native to the invaded region did not result in shifts in the start and the length of the flowering period. Overall, climatic conditions in the native range of species selected for a flowering pattern is maintained after translocation of the species to another region. Flowering of tropical and temperate invasive alien species peaked in summer, which contrasts with the spring flowering of native and invasive alien species of Mediterranean climate origin. By exploiting this new temporal niche, these invasive alien species native to tropical and temperate regions benefit from reduced competition with natives for abiotic and biotic resources. We suggest that human‐mediated actions have reduced the strength of the summer drought filter in particular microhabitats, permitting the invasion of many summer‐flowering aliens.
A role for a cell wall localized glycine‐rich protein in dehydration and rehydration of the resurrection plant Boea hygrometrica
Authors: Wang L. , Shang H. , Liu Y. , Zheng M. , Wu R. , Phillips J. , Bartels D. , Deng X. 
Published: February 2009

AbstractThe acquisition of desiccation tolerance in dicotyledonous angiosperms requires the induction of a co‐ordinated programme of genetic and biochemical processes during drying and the adaptive mechanisms are primarily protoplasmic in nature. Recent studies have shown that changes in cell wall structure and composition are also important for recovery after drying, however, the molecular mechanisms that underpin these adaptive responses are largely unknown. Here, the desiccation‐tolerant plant Boea hygrometrica was used as a model system to investigate the changes in gene expression and cell wall adaptation that take place during extreme dehydration. A cDNA macroarry analysis of dehydration‐inducible genes led to the identification of a gene encoding a glycine‐rich protein (BhGRP1). The corresponding transcript was up‐regulated during drying in B. hygrometrica leaves. In silico analysis revealed that BhGRP1 is targeted to the cell wall and this was confirmed in planta. Morphological changes in the cell wall architecture were also observed during the process of drying and re‐watering. Concomitant with this observation, cell wall profiling by Fourier transform infrared spectroscopy indicated that protein levels increased upon desiccation and remained broadly similar upon re‐watering. These findings suggest that the deposition of BhGRP1 may play a role in cell wall maintenance and repair during dehydration and rehydration in B. hygrometrica.