bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rhizomorph production and stump colonization by co‐occurring Armillaria cepistipes and Armillaria ostoyae: an experimental study
Authors: Prospero S. , Holdenrieder O. , Rigling D. 
Published: January 2006

SummaryIn managed spruce forests, Armillaria cepistipes and A. ostoyae are efficient stump colonizers and may compete for these resources when they co‐occur at the same site. The aim of this experiment was to quantify the mutual competitive ability of the two Armillaria species in producing rhizomorphs and in colonizing Norway spruce (Picea abies) stumps. Five isolates of A. cepistipes and two isolates of A. ostoyae were simultaneously inoculated pair‐wise into pots containing a 4‐year‐old spruce seedling. For comparison, each isolate was also inoculated alone. One year after inoculation, stumps were created by cutting down the seedlings. Six months after creation of the stumps, rhizomorph production and stump colonization were assessed. Armillaria spp. were identified from 347 rhizomorphs and 48 colonized stumps. Armillaria cepistipes dominated both as rhizomorphs in the soil and on the stumps. Nevertheless, A. ostoyae was relatively more frequent on the stumps than in the soil and A. cepistipes was relatively more frequent in the soil than on the stumps. In both species, the ability to colonize the stumps in simultaneous inoculations was significantly reduced compared with single inoculations. In respect to rhizomorph production, simultaneous co‐inoculations had a slightly stimulatory effect on A. cepistipes and no significant effect on A. ostoyae. Our study suggests a rather neutralistic co‐existence of A. cepistipes and A. ostoyae as rhizomorphs in the soil. Concerning the ability to colonize stumps, the two species experience a mutual negative effect from the interaction, probably because of interspecific competition.
Spatial pattern of the density of Armillaria epiphytic rhizomorphs on tree collar in an oak stand
Authors: Marçais B. , Caël O. 
Published: January 2006

SummaryThe density of Armillaria gallica epiphytic rhizomorphs on tree collar was mapped in a young stand of pedunculate oaks (Quercus robur). A quick method to estimate the rhizomorph density was developed, investigating 19 trees, and was used in the subsequent study. The method consists of measuring the frequency of rhizomorphs present on a grid applied to an exposed small area of the tree collar. The pattern in tree collar rhizomorph density was closely related to the pattern of stump colonization by Armillaria and stumps were therefore important as inoculum sources. Rhizomorph density on tree collar showed a strong aggregated spatial pattern which could not be explained by variability in the soil characteristics, in particular waterlogging, or by a spatial pattern in tree vigour. Moreover, rhizomorph density on tree collar did not depend on their dominance status.
Cardiac mitochondrial alterations induced by insulin deficiency and hyperinsulinaemia in rats: Targeting membrane homeostasis with trimetazidine
Authors: Ovide‐Bordeaux Stéphanie , Bescond‐Jacquet Anne , Grynberg Alain 
Published: January 2006

Summary1. The present study investigated the ability of trimetazidine (TMZ) to maintain cardiac mitochondrial function during the development of insulin deficiency and hyperinsulinaemia. The anti‐ischaemic drug TMZ is known to increase phospholipid synthesis in cardiac membranes and to have a cardioprotective effect.2. Insulin deficiency was obtained by streptozotocin injection and hyperinsulinaemia was achieved via a fructose diet. Trimetazidine was incorporated into the diet (7.8 mg/day) and mitochondrial function was evaluated in skinned cardiac fibres.3. Insulin deficiency decreased mitochondrial affinity for ADP and the index of creatine kinase functional activity. This last alteration was partially prevented by TMZ treatment. Insulin deficiency strongly decreased n‐3 polyunsaturated fatty acids, especially the docosahexaenoic acid (DHA) content, in cardiac and mitochondrial membranes, inducing a strong increase in the n‐6/n‐3 ratio. Trimetazidine treatment limited the increase in the n‐6/n‐3 ratio and prevented the decrease in DHA content in mitochondrial membranes. Insulin deficiency decreased glutamate‐ and palmitoylcarnitine‐supported respiration.4. Hyperinsulinaemia affected neither mitochondrial affinity for ADP nor the index of creatine kinase functional activity. Hyperinsulinaemia slightly and significantly affected mitochondrial fatty acid composition, by a small increase the n‐6/n‐3 ratio. Trimetazidine did not modify membrane‐bound mitochondrial function but increased the n‐6/n‐3 ratio. Moreover, hyperinsulinaemia decreased glutamate‐supported respiration.5. In conclusion, modification of membrane homeostasis with TMZ partially prevented the alterations in fatty acid composition and function in cardiac mitochondria induced by insulin deficiency. Three months of hyperinsulinaemia did not modify membrane‐bound mitochondrial function and had only slight effects on fatty acid composition.
Effects of trans‐resveratrol on hypertension‐induced cardiac hypertrophy using the partially nephrectomized rat model
Authors: Liu Zhaoping , Song Yan , Zhang Xiaopeng , Liu Zeqing , Zhang Wenzhong , Mao Weifeng , Wang Wei , Cui Wenming , Zhang Xin , Jia Xudong , Li Ning , Han Chi , Liu Changxing 
Published: January 2006

Summary1. trans‐Resveratrol (resveratrol) has been shown to have beneficial effects on the cardiovascular system in a number of studies. It is, however, unclear whether this naturally occurring compound can protect against cardiac hypertrophy. The aim of the present study was to investigate the effects of resveratrol on cardiac hypertrophy in vivo and the potential underlying mechanisms involving endothelin (ET), angiotensin (Ang) II and nitric oxide (NO) in partially nephrectomized rats.2. Animal models bearing cardiac hypertrophy were replicated in male Sprague‐Dawley rats following partial nephrectomy (PNX). Resveratrol (10 or 50 mg/kg) was administered to rats by gavage for 4 weeks. Simultaneous PNX and sham operation controls were simultaneously established in the present study. The systolic blood pressure (SBP) of rats was measured at baseline and, along with heart weight, after 4 weeks treatment. Serum ET‐1, AngII and NO concentrations were determined.3. In the present study, it was shown that, compared with rats in the sham‐operated group, rats in the PNX group had significantly higher SBP (154.1 ± 22.7 mmHg), heart weight (1.69 ± 0.24 g) and serum ET‐1 (125.70 ± 26.27 pg/mL) and AngII serum concentrations (743.63 ± 86.50 pg/mL), whereas serum NO concentrations were lower (21.1 ± 6.9 μmol/L; all P < 0.05). These values in the sham control group were 114 ± 10 mmHg, 1.28 ± 0.13 g, 52.44 ± 21.85 pg/mL, 528.7 ± 158.5 pg/mL and 53.21 ± 23.87 µmol/L, respectively. After 4 weeks treatment with 50 mg/kg resveratrol, SBP, heart weight and ET‐1 and AngII concentrations had decreased to 135.4 ± 15.8 mmHg, 1.39 ± 0.15 g, 97.11 ± 26.74 pg/mL and 629.64 ± 116.18 pg/mL, respectively. However, the serum NO concentration had increased to 40.1 ± 14.6 μmol/L. These values were significantly different from those obtained for the PNX group.4. In conclusion, trans‐resveratrol appears to be able to protect against the increase in SBP and subsequent cardiac hypertrophy in vivo and the mechanisms responsible may involve, at least in part, modulation of NO, AngII and ET‐1 production.
Inhibition of mitogen‐activated protein kinase kinase enhances apoptosis induced by arsenic trioxide in human breast cancer MCF‐7 cells
Authors: Ye Jian , Li Aiping , Liu Qizhan , Wang Xinru , Zhou Jianwei 
Published: January 2006

Summary1. Arsenic trioxide (As2O3) has recently been used to treat acute promyelocytic leukaemia and has activity in vitro against several solid tumour cell lines where the induction of differentiation and apoptosis are the prime effects. The mechanism of As2O3‐induced cell death has yet to be clarified, especially in solid cancers.2. In the present study, the human breast cancer cell line MCF‐7 was examined as a cellular model for As2O3 treatment. The involvement of extracellular signal‐regulated kinase (ERK), p38 and c‐Jun N‐terminal kinase (JNK) was investigated in As2O3‐induced cell death.3. It was found that As2O3 activates the prosurvival mitogen‐activated protein kinase kinase (MEK)/ERK pathway in MCF‐7 cells, which, conversely, may compromise the efficacy of As2O3. Hence, a combination treatment of As2O3 and MEK inhibitors was investigated to determine whether this treatment could lead to enhanced growth inhibition and apoptosis in MCF‐7 cells.4. Inhibition of MEK/ERK with the pharmacological inhibitors U0126 (10 µmol/L) or PD98059 (20 µmol/L) together with As2O3 (2 and 5 µmol/L) resulted in a significant enhancement of growth inhibition in breast cancer MCF‐7 cells as determined by the 3‐(4,5‐dimethyl‐2 thiazoyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide assay and [Methyl‐3H]‐thymidine incorporation. Furthermore, the results demonstrated that combined treatment with As2O3 and the MEK1/2 inhibitor U0126 could augment breast cancer MCF‐7 cell apoptosis approximately twofold compared with the effects of the two drugs alone, as determined by Hoechst 33258 or annexin V/propidium iodide (PI) staining and flow cytometry.5. In addition, As2O3 activated p38 in a dose‐dependent manner, but had no effect on JNK1/2. Treatment with a p38 inhibitor did not prevent As2O3‐induced apoptosis.6. In conclusion, the results of the present study showed that enhanced apoptosis is detected in breast cancer MCF‐7 cells in the presence of As2O3 and an MEK inhibitor, which may be a new promising adjuvant to current breast cancer treatments.
Inhibitory effects of glucosamine on lipopolysaccharide‐induced activation in microglial cells
Authors: Yi Hyon‐Ah , Yi Sang‐Doe , Jang Byeong‐Churl , Song Dae‐Kyu , Shin Dong‐Hoon , Mun Kyo‐Chul , Kim Sang‐Pyo , Suh Seong‐Il , Bae Jae Hoon 
Published: January 2006

Summary1. The aim of the present study was to investigate the effects of glucosamine on lipopolysaccharide (LPS)‐induced cellular activation in microglia and to evaluate the inhibitory mechanisms involved.2. Lipopolysaccharide (100 ng/mL) was used for the activation of primary cultured rat microglial or BV2 microglial cells. Changes in intracellular Ca2+levels and outward K+currents were measured using fura‐2/AM and whole‐cell patch‐clamp methods, respectively. Lipopolysaccharide‐induced expression of tumour necrosis factor (TNF)‐α mRNA was analysed by reverse transcription–polymerase chain reaction.3. Lipopolysaccharide transformed cell morphology into an amoeboid shapein vitroand induced microglial activationin vivo, as measured by immunohistochemical staining, but glucosamine inhibited this activation. Glucosamine also inhibited LPS‐induced Ca2+influx, outward K+currents and TNF‐α mRNA expression, which are typically representative of microglial activation.4. The results suggest that the inhibitory mechanisms of glucosamine on LPS‐induced microglial activation include inhibition of Ca2+influx and outward K+currents, as well as downregulation of the microglial activator gene TNF‐α.
Hypoxia–reoxygenation‐induced apoptosis in cultured neonatal rat cardiomyocyets and the protective effect of prostaglandin E1
Authors: Ma Xiang‐qin , Fu Run‐fang , Feng Guo‐qing , Wang Zhen‐ji , Ma Shou‐guo , Weng Shi‐ai 
Published: January 2006

Summary1. The aim of the present study was to investigate the effect of prostaglandin (PG) E1on hypoxia/re‐oxygenation (H/R) apoptosis and the expression of bcl‐2 and bax in cultured neonatal rat cardiomyocytes.2. The H/R model was made using the first generation of cultured neonatal rat cardiomyocytes. Hypoxia/re‐oxygenation apoptosis was studied by electron microscopy and agarose gel electrophoresis. The percentage of apoptotic cells was measured by terminal deoxyribonucleotidyl transferase‐mediated dUTP–digoxigenin nick end‐labeling (TUNEL). The expression of bcl‐2 and bax was detected byin situhybridization and immunohistochemical staining.3. Most cells of the H/R group tested by electron microscopy showed cytoplasmic concentration, nuclear chromatin condensation and margination. Prostaglandin E1(5, 15 and 45 μg/L) relieved the injury. The results of DNA electrophoresis in the H/R group showed a typical DNA ladder and the DNA ladder decreased gradually corresponding with increasing doses of PGE1.4. The TUNEL staining showed that the total number of apoptotic cells in the H/R group was much more than that in the PGE1(45 μg/L) group.5. The results ofin situhybridization and immunohistochemical staining showed that the bcl‐2 content in the H/R group was lower than that in the control group; bax content showed the reverse. Compared with the H/R group, bcl‐2 content was significantly higher in the PGE1(5, 15 and 45 μg/L) groups. However, bax content in the PGE1(5, 15 and 45 μg/L) groups was significantly lower than that in the H/R group.6. In conclusion, H/R injury can induce cardiomyocyte apoptosis. Prostaglandin E1obviously has anti‐apoptotic effects on cardiomyocytes and the mechanisms probably involve the inhibition of bax expression and increased expression of bcl‐2.
BAY 41‐2272, a potent activator of soluble guanylyl cyclase, stimulates calcium elevation and calcium‐activated potassium current in pituitary GH3cells
Authors: Liu Yen‐Chin , Wu Sheng‐Nan 
Published: January 2006

Summary1. The effects of BAY 41‐2272, a nitric oxide‐independent activator of soluble guanylyl cyclase, on Ca2+signalling and ion currents were investigated in pituitary GH3cells.2. Intracellular Ca2+concentrations ([Ca2+]i) in these cells were increased by BAY 41‐2272. Removing extracellular Ca2+abolished the BAY 41‐2272‐induced increase in [Ca2+]i. After [Ca2+]iwas elevated by BAY 41‐2272 (300 nmol/L), subsequent application of 1‐benzyl‐3‐(5′‐hydroxymethyl‐2′‐furyl) indazole (YC‐1; 1 μmol/L) did not increase [Ca2+]ifurther.3. In whole‐cell recordings, BAY 41‐2272 reversibly stimulated Ca2+‐activated K+current (IK(Ca)) with an EC50of 225 ± 8 nmol/L. At 3 μmol/L, BAY 41‐2272 slightly and significantly decreased L‐type Ca2+current.4. In the cell‐attached configuration, BAY 41‐2272 (300 nmol/L) enhanced the activity of large‐conductance Ca2+‐activated K+(BKCa) channels. After BKCachannel activity was stimulated by spermine NONOate (30 μmol/L) or YC‐1 (10 μmol/L) in cell‐attached patches, subsequent application of BAY 41‐2272 (300 nmol/L) further increased the channel open probability.5. In the inside‐out configuration, BAY 41‐2272 applied to the intracellular surface of excised patches enhanced BKCachannel activity. Unlike 1 µmol/L paxilline, 1H‐[1,2,4]oxadiazolol‐[4,3a] quinoxalin‐1‐one (ODQ; 10 μmol/L) or heme (10 μmol/L) had no effect on BAY 41‐2272‐stimulated channel activity. BAY 41‐2272 caused no shift in the activation curve of BKCachannels; however, it did increase the Ca2+sensitivity of these channels.6. At 300 nmol/L, BAY 41‐2272 reduced the firing rate of spontaneous action potentials stimulated by thyrotropin‐releasing hormone (10 μmol/L). The BKCachannel activity was also enhanced by 300 nmol/L BAY 41‐2272 in neuroblastoma IMR‐32 cells.7. Therefore, the BAY 41‐2272‐induced increase in [Ca2+]iis primarily explained by an increase in Ca2+influx. The BAY 41‐2272‐mediated simulation of IK(Ca)may result from direct activation of BKCachannels and indirectly as a result of elevated [Ca2+]i.
Influence of surface condition on the fatigue behaviour of specimens made of a SAE 5115 case‐hardened steel
Authors: LAUE S. , BOMAS H. , HOFFMANN F. 
Published: January 2006

ABSTRACTThe effect of different surface conditions on the fatigue properties of cyclically loaded bending specimens of the case‐hardened steel SAE 5115 (Material Number 1.7131) was investigated. The aim of the investigations was to achieve further knowledge of the processes that finally lead to the failure of case‐hardened and cyclically loaded bending specimens. Surface roughness, microstructure and residual stress distribution were regarded as parameters that govern the fatigue process. On the basis of a well‐defined adjustment of different surface conditions the effect of internal oxidation, surface roughness and residual stresses on fatigue crack initiation and growth were assessed. The effect of different parameters on the endurance limit has been quantified by the application of a fracture mechanics and a weakest‐link approach. The calculations contributed to a deeper insight into the complex interaction between the parameters governing the fatigue process.
A Validation of a Computer-Assisted Randomized Response Survey to Estimate the Prevalence of Fraud in Social Security
Authors: Lensvelt-Mulders Gerty J. L. M. , Van Der Heijden Peter G. M. , Laudy Olav , Van Gils Ger 
Published: January 2006

SummaryIn the Netherlands, there is a research tradition that measures fraud against regulations by interviewing eligible individuals using a survey. In these studies the sensitive questions about fraud are posed by using a randomized response method. The paper describes the results of a Dutch study into the consequences of replacing home interviews by trained interviewers with Internet-delivered interviews in a survey on fraud in the area of disability benefits. Both surveys used computer-assisted self-interviews with randomized response questions. This study has three goals: first to present the research tradition that makes use of randomized response, second to compare the results of home interviews and the Internet survey and finally to introduce an adapted weighted logistic regression method to test the relationship between the probability of fraud and explanatory variables. The results show that there are no systematic differences between modes of interview, either for estimates of the prevalence of fraud or for the identification of associated variables. These outcomes result in the conclusion that the Internet survey is a useful and cost-effective instrument for measuring fraud in a population, and that it is unlikely that replacing home interviews with the Internet survey will result in a significant break with tradition.
Using Number of Failed Contact Attempts to Adjust for Non-Ignorable Non-Response
Authors: Wood Angela M. , White Ian R. , Hotopf Matthew 
Published: January 2006

SummaryWe present a general method of adjustment for non-ignorable non-response in studies where one or more further attempts are made to contact initial non-responders. A logistic regression model relates the probability of response at each contact attempt to covariates and outcomes of interest. We assume that the effect of these covariates and outcomes on the probability of response is the same at all contact attempts. Knowledge of the number of contact attempts enables estimation of the model by using only information from the respondents and the number of non-responders. Three approaches for fitting the response models and estimating parameters of substantive interest and their standard errors are compared: a modified conditional likelihood method in which the fitted inverse probabilities of response are used in weighted analyses for the outcomes of interest, an EM procedure with the Louis formula and a Bayesian approach using Markov chain Monte Carlo methods. We further propose the creation of several sets of weights to incorporate uncertainty in the probability weights in subsequent analyses. Our methods are applied as a sensitivity analysis to a postal survey of symptoms in Persian Gulf War veterans and other servicemen.
Analysis of a Long-Term Study of Neurotic Disorder, with Insights into the Process of Non-Response
Authors: Longford Nicholas T. , Tyrer P. , Nur U. A. M. , Seivewright H. 
Published: January 2006

SummaryThe paper studies the non-response process in a long-term study of neurotic dis-order by comparing the analysis based on the responses that were collected by the established practice of interviewing the subjects, at dates arranged in advance (appointments), with the analysis of the nearly complete set of responses that were collected by an extensive effort that involved attempts to interview without seeking a prior agreement. The method of multiple imputation is applied, and its properties are explored in a setting that is not perfectly suited for its application: a relatively small sample size, ordinal score outcomes and the likelihood that the outcomes are missing not at random.
Isolation and characterization of microsatellite loci in Alasmidonta heterodon (Bivalvia: Unionidae)
Authors: SHAW KRISTINE M. , KING TIM L. , LELLIS WILLIAM A. , EACKLES MICHAEL S. 
Published: January 2006

AbstractWe developed 13 species‐specific microsatellite markers for the federally endangered Atlantic slope unionid Alasmidonta heterodon. Four to 18 alleles per locus were observed among 30 individuals. Observed heterozygosity throughout the loci ranged from 26.9 to 86.2% and averaged 63.6%. Estimates of individual pairwise genetic distances indicated that levels of genetic diversity among loci were sufficient to produce unique multilocus genotypes for all animals surveyed. Randomization tests showed that genotypes for this collection were consistent with Hardy–Weinberg expectations, and no significant linkage disequilibrium was observed between loci. These loci therefore appear suitable for population surveys, kinship assessment and other such applications.
Direct shipping logistic planning for a hub‐and‐spoke network with given discrete intershipment times
Authors: Chong Libby , Kennedy Damian , Chan Weng Meng 
Published: January 2006

AbstractThis paper proposes a heuristic procedure to solve the problem of scheduling and routing shipments in a hybrid hub‐and‐spoke network, when a given set of feasible discrete intershipment times is given. The heuristic procedure may be used to assist in the cooperative operational planning of a physical goods network between shippers and logistics service provider, or to assist shippers in making logistics outsourcing decisions. The objective is to minimise the transportation and inventory holding costs. It is shown through a set of problem instances that this heuristic procedure provides better solutions than existing economic order quantity‐based approaches. Computational results are presented and discussed.
A Midline Cyst Containing Clear Fluid in an Infant and Review of Management
Authors: Scheinfeld Noah 
Published: January 2006

Abstract:  A 3‐month‐old healthy girl had a cyst present from birth, located in the midline, in the area of the anterior fontanel. A magnetic resonance imaging was performed at age 7 months, which did not show communication between the cyst and the central nervous system. At a subsequent examination, while the cyst was being probed, it broke and expressed clear fluid. The cyst was subsequently removed surgically and was found histopathologically to be an epidermal inclusion cyst without communication with the central nervous system. Epidermal inclusion cysts very rarely occur on the midline in the area of the anterior fontanel, and none have been reported to contain clear fluid. Their proper management requires focused clinical assessment, noninvasive imaging, and consideration of surgical removal, in particular, if they communicate with the intracranial space.