bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative aspects of Mn‐activated cathodoluminescence of natural and synthetic aragonite
Authors: GÖTTE THOMAS , RICHTER DETLEV K. 
Published: July 2008

AbstractThe cathodoluminescence analyses of the trigonal carbonates calcite and dolomite have been applied intensively in sedimentary petrology for a long time and the properties of these minerals are well‐known, but much less attention has been paid to aragonite. In this study, the cathodoluminescence behaviour and the trace element composition of natural and synthetic aragonite have been studied employing trace element analyses (proton induced X‐ray emission) and luminescence spectroscopy. Aragonite doped with Mn2+ has been synthesized in a NH4+–Mg2+–Ca2+–Cl− solution in contact with a CO2–H2O–NH3 atmosphere. The low effective distribution coefficients indicate a rapid growth of the crystals of millimetre size which occurred within hours or days. The natural aragonite samples contain Mn, Fe and Sr in different concentrations. The Mn‐bearing aragonites exhibit a bright green luminescence which is caused by a strong emission band at 575 nm with a half‐width of about 84 nm. The luminescence intensity shows a strong positive correlation with Mn in aragonite when Fe and Mn do not exceed 2000 p.p.m. The intensity is depressed if the concentration of these elements exceeds the critical values. In the shell of a recent Unio sp., the luminescence intensity deviates from the linear correlation, although the trace element contents are not too high; this is probably an effect of quenching by organic material between the crystallites of the biogenic aragonite.
Entrainment threshold of cohesionless sediment grains under steady flow of air and water
Authors: GIMÉNEZ‐CURTO LUIS A. , CORNIERO MIGUEL A. 
Published: July 2008

AbstractExisting formulations for bed sediment entrainment under steady flow are incapable of explaining two well‐documented observational facts: (i) water flow requires considerably higher dimensionless shear stresses to move the bed grains than air flow; and (ii) under open channel flow, steep granular beds are more stable than beds with milder slopes. These two facts, together with recent direct measurements of forces acting on bed grains giving time‐mean negative drags (Schmeeckle et al., 2007), question the conventional models of forces used so far. Here, fluid forces acting on bed particles are treated in a new way in order to take into consideration the fundamental interference effects, thus obtaining appropriate magnitude estimates that exhibit good agreement with direct force measurements by Schmeeckle et al. (2007). Impulsive pressure fluctuations generated by turbulence are shown to be capable of dislodging the bed grains by saltation under air flow, whereas they can only produce a rocking effect under water flow, thus explaining the first anomaly. On the other hand, previous work by the authors allows a direct estimate of space averaged time‐mean drag and lift forces exerted on bed grains. Both components have the same order of magnitude but, contrary to the common belief, the mean lift is downward, which provides an explanation for the second anomaly. Finally, spatial disturbances of pressure, both positive and negative, appear to generate maximum, persistent, local forces considerably greater than mean forces, thus allowing an explanation for the observed negative time‐mean drag. A new formula for predicting incipient motion of sediment under open channel flow is derived, which incorporates all dynamically significant effects and gives very good agreement with observation for the entire range of bed slopes.
Mollusc grazing may constrain the ecological niche of the old forest lichen Pseudocyphellaria crocata
Authors: Gauslaa Y. 
Published: July 2008

AbstractThis study reports on mollusc grazing of two epiphytic cyanobacterial lichens (Pseudocyphellaria crocata and Lobaria pulmonaria) transplanted within three Picea abies‐dominated boreal rain forest stands (clear‐cut, young and old forests) in west central Norway. Grazing was particularly high in transplants located in the old forest and was almost absent in clear‐cut transplants. Grazing marks were absent on natural thalli on nearby spruce twigs (required creeping distance for mollusc from the ground >4 m). Transplantation of lichens from twigs to artificial transplantation frames reduced the creeping distance to 1.2 m, and caused a significant increase in grazing damage in P. crocata. Given a paired choice under transplantation, molluscs consistently preferred P. crocata and avoided L. pulmonaria, implying species‐specific differences in herbivore defence. Pseudocyphellaria crocata has a much lower content of the medullary depsidones stictic and constictic acid than L. pulmonaria. Heavy grazing occurred in the P. crocata thalli lowest in these two depsidones. The upper part of the medulla hosting the photobiont was the preferred fodder for grazing molluscs. Molluscs avoided the yellow soralia in P. crocata (localised pulvinic acid), suggesting a role for pulvinic acid in preventing grazing of detached soredia and early establishment stages. The preference of P. crocata for thin spruce twigs is probably a result of a lower grazing pressure on twigs compared to e.g. deciduous stems that frequently support the better defended L. pulmonaria. Ongoing climate changes with increased annual rainfall and milder winters have presumably increased mollusc grazing, particularly in SW parts of Norway which have more species of lichen‐feeding molluscs than the boreal sites studied. These temperate areas lacking natural spruce populations have recently experienced reported extinctions of the poorly defended P. crocata from rocks and deciduous stems prone to mollusc grazing. Lichen‐feeding molluscs have likely played a role in these extinctions, causing spruce twigs in Atlantic boreal forests to be a last strong foothold for P. crocata in Scandinavia.
Identification of AFLP and RAPD markers linked to anthracnose resistance in grapes and their conversion to SCAR markers
Authors: Kim G. H. , Yun H. K. , Choi C. S. , Park J. H. , Jung Y. J. , Park K. S. , Dane F. , Kang K. K. 
Published: July 2008

AbstractResistance to anthracnose or black spot (Elsinoe ampelina), a serious fungal pathogen in viticulture and table grape production, was investigated on 25 grape cultivars. Bioassays performed with culture filtrates produced by the pathogen revealed 14 resistant genotypes. In most plants resistance originated from Vitis labrucsa but also genotypes with V. rupestris and V. riparia × V. rupestris background showed resistance. Genetic analysis was conducted in F1, S1 and BC1 plants developed from various cultivars. In total, 326 F1 plants were evaluated, 172 genotypes proofed to be resistant, whereas 154 were susceptible to anthracnose. A Mendelian segregation ratio of 1 : 1 (χ2 = 0.30–0.65) indicating that anthracnose resistance is controlled by a single dominant gene. To facilitate the use of marker‐assisted selection in grape‐breeding PCR‐based markers were developed by random amplified polymorphic DNA and amplified fragment length polymorphism in bulk segregant analysis. Finally, OPB 151247 was developed as a sequence characterized amplified region marker being diagnostic for the locus of resistance to anthracnose in all resistant genotypes tested. Within the 25 grape cultivars OPB 151247 is diagnostic in the genetic background of both V. labrucsa and V. rupestris and V. riparia × V. rupestris.
Peat in the inoculation medium induces fusarium susceptibility in melons
Authors: Cohen R. , Burger Y. , Horev C. , Saar U. , Raviv M. 
Published: July 2008

AbstractThe effect of peat moss on fusarium wilt of melon (Cucumis melo L.) was studied in order to improve the selection process of resistant melons during breeding programmes. Disease symptoms were evident earlier and disease progress was faster in seedlings that were transplanted to peat following inoculation than in those transplanted to sand. The resistant breeding line used as a control did not show any wilt symptoms in either medium. Mixing the peat with sand or perlite reduced the disease development rate and the final disease incidence. The effects of peat and sand on disease progress were evaluated with two segregating melon populations in which the expected susceptible : resistant ratio was 25 : 75. In both populations, disease incidence was higher in the peat, which enables breeders to identify resistant plants and to lower the risk of using escapees as resistant plants. The mechanism of disease enhancement may include both biotic and abiotic components. There is an indication that peat induces plant susceptibility before inoculation. Melon seedlings germinated in peat and transplanted into sand exhibited significantly greater wilt incidence than those that germinated in sand and were transplanted into sand following the inoculation. Disease progress in sterile peat was significantly slower than that in non‐sterile peat, which suggests the possible involvement of microbial activity.
Citrus tristeza virus resistance in a core collection of sour orange based on a diversity study of three germplasm collections using QTL‐linked markers
Authors: Bernet G. P. , Gorris M. T. , Carbonell E. A. , Cambra M. , Asins M. J. 
Published: July 2008

AbstractSeven markers linked to QTL involved in CTV accumulation, leafminer resistance and apomictic reproduction were used to characterize 64 sour orange (Citrus aurantium L.) accessions from three national collections in order to identify a representative core in which the resistance behaviour against two Citrus tristeza virus (CTV) isolates was studied. Different degrees of apomixis were found between the foreign collections. Most of the C. aurantium accessions fall into three main groups based on three multilocus genotypes. The haplotype diversity at three CTV accumulation QTL‐linked markers was further studied by sequence analysis of alleles. Genotypic and allelic diversity at one of them, tightly linked to Ctv‐R2 in Poncirus trifoliata (L.) Raf., match the plant–CTV interaction types reported among Poncirus and Citrus species. Only those selected accessions from the major group presented CTV resistance during 30 months of continuous growth, but later the resistance broke down in some plants. CTV tolerance appears related to slow growing genotypes. Certain micronutrients: Mn, and B depending on the accession, might play a relevant role in this host–pathogen interaction particularly in alkaline soils.
The action of three Beet yellows virus resistance QTLs depends on alleles at a novel genetic locus that controls symptom development
Authors: Grimmer M. K. , Bean K. M. R. , Qi A. , Stevens M. , Asher M. J. C. 
Published: July 2008

Abstract Beet yellows virus (BYV) can dramatically reduce yield from sugar beet crops. A BYV resistant plant from a Beta germplasm accession was crossed with a sugar beet plant to generate the segregating population BYV1. This population was evaluated for BYV resistance and analysed with amplified fragment length polymorphism and single‐nucleotide polymorphism markers to identify resistance loci. At 2 weeks after inoculation a number of plants displayed either mosaic or vein‐clearing disease symptoms on infected leaves. The locus that largely controlled this disease reaction was mapped to chromosome IV. We refer to this novel genetic locus as Vc1. Three BYV resistance quantitative trait loci (QTLs) were identified and mapped to chromosomes III, V and VI. QTL mapping results suggested that the chromosome III and V QTLs acted only in plants with mosaic symptoms and that the chromosome VI QTL acted only in plants with the mosaic symptom allele of Vc1. These findings agreed with further statistical tests using general linear model analysis. There is now the potential to breed for BYV resistance using molecular marker technology.
cAMP PRODUCED BY PITUITARY ADENYLATE CYCLASE‐ACTIVATING POLYPEPTIDE 27 INHIBITS ATRIAL NATRIURETIC PEPTIDE SECRETION IN RABBIT BEATING ATRIA
Authors: Zhang Ying , Liu Li‐Ping , Liang Zhe‐Long , Li Xiang‐Lan , Jin Yuan‐Zhe , Cui Xun 
Published: July 2008

SUMMARY

The aim of the present study was to determine the effects of increased cAMP levels in response to pituitary adenylate cyclase‐activating polypeptide 27 (PACAP27) on atrial atrial natriuretic peptide (ANP) secretion in rabbit atria.
A perfused beating atrial model was used in the present study and cAMP efflux and ANP levels in atrial perfusates were measured by radioimmnoassay.
At 100 nmol/L, PACAP27 increased cAMP production, which resulted in subsequent inhibition of ANP secretion. Nicardipine (1.0 µmol/L), an L‐type Ca2+ channel blocker, attenuated inhibition of ANP secretion by PACAP27. Staurosporine (1.0 µmol/L), a non‐specific protein kinase inhibitor, and H‐89 (1.0 µmol/L), a cAMP‐dependent protein kinase A (PKA) inhibitor, completely blocked the inhibition of ANP secretion in response to PACAP27 but had no effect on PACAP27‐induced increases in cAMP.
In conclusion, the results suggest that increased cAMP levels in response to PACAP27 negatively regulate ANP secretion via the adenylate cyclase–cAMP–PKA signalling pathway in rabbit atria and that L‐type Ca2+ channels may be involved, in part, in the regulation of ANP secretion by cAMP.
PANAX NOTOGINSENG SAPONINS ATTENUATE ATHEROSCLEROSIS IN RATS BY REGULATING THE BLOOD LIPID PROFILE AND AN ANTI‐INFLAMMATORY ACTION
Authors: Zhang Yi‐Guan , Zhang Hai‐Gang , Zhang Guo‐Yuan , Fan Ji‐Shan , Li Xiao‐Hui , Liu Yan‐Hua , Li Shu‐Hui , Lian Xue‐Mei , Tang Zhong 
Published: July 2008

SUMMARY

Previous studies have reported on the anti‐atherosclerotic effects of Panax notoginseng saponins (PNS). The aim of the present study was to explore the molecular mechanisms responsible for the anti‐atherosclerotic effects of PNS and the inflammatory response.
Thirty rats were randomly divided into three groups, namely a control group, a group, in which zymosan A was used to induce inflammation (Zym group) and a PNS‐treated group. Rats in the three groups were administered liquid paraffin (i.p.), zymosan A (20 mg/kg, i.p., once every 3 days) or zymosan A and PNS (100 mg/kg, i.p., once daily), respectively. All animals were fed a high‐fat diet for 9 weeks. At scheduled times, rats were killed, blood was collected and the aorta was removed. Pathological changes in aortas were observed using Sudan IV staining and transmission electron microscopy. Serum lipids were measured enzymatically. Whole‐blood viscosity was observed at different shear rates. The expression of cardiovascular disease‐specific genes was determined using GEArray (SuperArray, Frederick, MA, USA). Western blotting was used to evaluate the expression levels of nuclear factor (NF)‐κB/p65 and its inhibitor IκBα in the aortic wall.
In the present study, typical pathological changes associated with atherosclerosis in rats following induction by zymosan A were alleviated by PNS treatment. In the PNS‐treated group, there was a marked reduction in total serum cholesterol, triglycerides and blood viscosity. In addition, PNS treatment significantly decreased the gene expression of some inflammatory factors, such as integrins, interleukin (IL)‐18, IL‐1β and matrix metalloproteinases 2 and 9. The expression of NF‐κB/p65 was attenuated, whereas the expression of IκBα was significantly increased, after treatment with PNS.
In conclusion, it appears that PNS exerts its therapeutic effects on atherosclerosis through an anti‐inflammatory action and regulation of the blood lipid profile and that an NF‐κB signalling pathway is involved.
DYNAMIC EFFECTS OF RESPIRATION ON AORTIC BLOOD FLOW AND ITS AUTONOMIC CONTROL IN RATS
Authors: Yang Cheryl CH , Yeh Inga TY , Lai Hsien‐Yong , Chen Hsing‐I , Kuo Terry BJ 
Published: July 2008

SUMMARY

Respiratory related arterial pressure variability may reflect body fluid status and/or cardiac sympathetic function. The underlying mechanism is not clear.
In the present study, we used an electromagnetic blood flow meter to measure ascending aortic blood flow, from which stroke volume was integrated, to study respiration–stroke volume coupling and its underlying neural regulation. Experiments were performed on male Sprague‐Dawley rats that were anaesthetized with pentobarbital sodium, paralysed with pancuronium and under mechanical ventilation.
Programmed irregular ventilation evoked significant variability in arterial pressure, aortic flow and stroke volume signals. Good coupling was noted between lung volume and aortic flow, as well as between lung volume and stroke volume; this coupling persisted under all experimental conditions. The aortic flow power and stroke volume variability and the transfer magnitude of the lung volume–aortic flow and lung volume–stroke volume couplings were suppressed by 1 mg/kg propranolol, but not by 0.3 mg/kg atropine or a combination of 0.3 mg/kg atropine and 2.5 mg/kg phentolamine.
These results suggest that respiratory related variability in aortic flow and stroke volume, which ultimately contributes to arterial pressure variability, is primarily under cardiac sympathetic control via β‐adrenoceptors in anaesthetized and mechanically ventilated rats.
AN S296R MUTATION IN THE HUMAN ANDROGEN RECEPTOR CAUSES ACTIVATION OF THE RECEPTOR BY NON‐ANDROGENIC STEROIDS AND STRONGER INHIBITION BY THE NUCLEAR RECEPTOR COREPRESSOR N‐coR
Authors: Li Yi‐Dong , Lu Ying , Chen Guang‐Chun , Lu Jian 
Published: July 2008

SUMMARY

Mutation of the androgen receptor (AR) is believed to contribute to androgen‐independent growth of prostate cancer. In the present study, we examined the functional changes associated with the novel somatic mutation S296R in the N‐terminal domain of the AR identified from one recurrent prostate cancer sample.
The results indicate that the S296R mutation does not differ obviously from the wild‐type AR in its ability to bind the synthetic androgen methyltrienolone, or in its transcriptional activity induced by dihydrotestosterone (DHT) in the absence or presence of the overexpression of coactivators (steroid receptor coactivator‐1, transcription intermediary factor‐2, cAMP response element‐binding protein‐binding protein and p300). However, S296R was found to differ from wild‐type AR in that its transcriptional activity could be activated by high concentrations (1 µmol/L) of 17β‐oestradiol and progesterone and its transactivity induced by DHT was more obviously inhibited by overexpression of the nuclear receptor corepressor N‐coR in CV‐1 cells.
These findings indicate that a point mutation (S296R) in the N‐terminal domain of the AR can decrease the ligand specificity of the AR and alter the interaction between S296R and the corepressor N‐coR.
EFFECTS OF MELATONIN ON BLOOD PRESSURE IN STRESS‐INDUCED HYPERTENSION IN RATS
Authors: Xia Chun‐Mei , Shao Ci‐Hui , Xin Lin , Wang Yang‐Rong , Ding Chao‐Nan , Wang Jin , Shen Lin‐Lin , Li Li , Cao Yin‐Xiang , Zhu Da‐Nian 
Published: July 2008

SUMMARY

Melatonin, acting through its receptors, is involved in numerous physiological processes, including blood pressure (BP) regulation. In present study, the effect of melatonin inhibition on stress‐induced hypertension was investigated.
The hypertensive model consisted of male Sprague‐Dawley rats subjected to electrical foot‐shock combined with noise. Microinjection of melatonin (0.1 and 1.0 mmol/L) into the anterior hypothalamic area (AHA) produced a fall in BP in nomortensive rats and stress‐induced hypertensive rats (SIHR). Luzindole (10 mmol/L), a competitive antagonist of melatonin MT1 and MT2 receptors, almost completely abolished the depressor effect of melatonin, the MT2 receptor‐specific antagonist 4‐phenyl‐2‐propionamidotetralin (10 mmol/L) partially blocked (by approximately 60%) the depressor effect of melatonin, whereas the MT3 receptor‐selective antagonist prazosin (10 mmol/L) failed to antagonize the effects of melatonin.
Brain microdialysis was performed in the AHA and the rostral ventrolateral medulla (RVLM). Melatonin and amino acids in the dialysate samples collected were detected by high‐performance liquid chromatography combined with fluorescence detection. The results indicated that melatonin concentrations in the AHA were reduced in SIHR. Microinjection of melatonin into the AHA decreased glutamate release and increased GABA and taurine release in the RVLM, which were paralleled by a decrease in arterial pressure.
The mRNA expression of MT2 in the AHA of SIHR was higher than that in normotensive control rats, whereas there was no significant difference in MT1 mRNA expressin between the two groups.
The results of the present study suggest that both a decrease of melatonin and an increase in the MT2 receptor in the AHA are involved in the manifestation of stress‐induced hypertension. Both MT1 and MT2 receptors participated in the antihypertensive effect of melatonin in the AHA. The antihypertensive effect of melatonin was related to the decreases in the excitatory amino acid glutamate and increases in the inhibitory amino acids taurine and GABA in the RVLM.
EVIDENCE THAT INHIBITION OF SPINAL NITRIC OXIDE PRODUCTION CONTRIBUTES TO THE ANTINOCICEPTIVE EFFECTS OF EMULSIFIED ISOFLURANE ON FORMALIN‐INDUCED PAIN IN RATS
Authors: Ge Zhi‐Jun , Tan Yong‐Fei , Zhao Yan‐Ping , Cui Guo‐Xing 
Published: July 2008

SUMMARY

The aim of the present study was to investigate the contribution of spinal nitric oxide (NO) to the antinociceptive effects of emulsified isofluane in rats.
The formalin test was used to assess nociceptive responses. Immunocytochemistry and histochemistry were performed to determine the effects of emulsified isoflurane on formalin‐induced changes in Fos‐like immunoreactive (Fos‐LI)‐ and nicotinamide adenine dinucleotide phosphatediaphorase (NADPH‐d)‐positive neurons, respectively.
The results showed that emulsified isofluane, administered intraperitoneally, significantly decreased the formalin‐induced paw licking time and that this was attenuated by pretreatment with intrathecal injection of the NO precursor l‐arginine. Furthermore, Fos‐LI‐ and NADPH‐d‐positive neurons were mainly found in the ipsilateral dorsal horn after injection of formalin, some of which were Fos‐LI/NADPH‐d double‐labelled neurons.
Administration of emulsified isofluane significantly decreased Fos‐LI‐ and NADPH‐d‐positive, as well as Fos‐LI/NADPH‐d double‐labelled, neurons. Finally, emulsified isofluane produced a significant reduction of NOS activity and a decrease of NO production in the spinal cord of formalin‐treated rats.
In conclusion, the results suggest that inhibition of spinal NO production contributes to the antinociceptive effects of emulsified isofluane on formalin‐induced pain in rats.