bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monte Carlo analysis of parameter uncertainty in matrix models for the weed Cirsium vulgare
Authors: Tenhumberg Brigitte , Louda Svata M. , Eckberg James O. , Takahashi Masaru 
Published: November 2007

Summary

Parameter uncertainty challenges the use of matrix models because it violates key assumptions underlying elasticity analyses. We have developed a matrix model to compare Monte Carlo methods with elasticity analyses for estimation of the relative importance of factors in the asymptotic population growth rate, λ, of Cirsium vulgare (spear thistle) in Nebraska, USA.
We calculated λ for a base model using 11 parameter estimates available for Nebraska populations plus eight extracted from the literature, causing parameter uncertainty. We then calculated λ for 10 000 alternative models using Monte Carlo parameter estimation; parameters were drawn from the full range of each parameter in the literature and partial rank correlation analysis (PRCC) was used to order the parameters by the magnitude of their effect on λ.
Monte Carlo analysis found that insect floral herbivory, affecting the regeneration transition, was the most important parameter affecting λ, whereas elasticity analyses suggested that the transition from small to medium size was the most significant. Statistical comparison, using PRCC vs. lower level elasticity (LLE), showed that the Monte Carlo analysis provided a more accurate assessment.
As λ > 1 in 99% of the model runs even with significant floral herbivory, we added two parameters influenced by weed management (probability of large thistles dying without producing seed and proportion of seeds that failed to germinate). Simulations that included reductions in these parameters, along with floral herbivory, led to λ < 1 in 17% of the runs, suggesting these three factors interact to produce the low densities observed for this invasive thistle in our study area.
Synthesis and applications. This study demonstrates the utility of the Monte Carlo approach for modelling weed dynamics with parameter uncertainty and multiple, potentially interacting, parameters. Invasive population growth by C. vulgare could be limited by a combination of weed management practices and the biotic resistance imposed by native floral herbivores.
Influence of bioclimatic variables on tree‐line conifer distribution in the Greater Yellowstone Ecosystem: implications for species of conservation concern
Authors: Schrag Anne M. , Bunn Andrew G. , Graumlich Lisa J. 
Published: November 2007

AbstractAim  Tree‐line conifers are believed to be limited by temperature worldwide, and thus may serve as important indicators of climate change. The purpose of this study was to examine the potential shifts in spatial distribution of three tree‐line conifer species in the Greater Yellowstone Ecosystem under three future climate‐change scenarios and to assess their potential sensitivity to changes in both temperature and precipitation.Location  This study was performed using data from 275 sites within the boundaries of Yellowstone and Grand Teton national parks, primarily located in Wyoming, USA.Methods  We used data on tree‐line conifer presence from the US Forest Service Forest Inventory and Analysis Program. Climatic and edaphic variables were derived from spatially interpolated maps and approximated for each of the sites. We used the random‐forest prediction method to build a model of predicted current and future distributions of each of the species under various climate‐change scenarios.Results  We had good success in predicting the distribution of tree‐line conifer species currently and under future climate scenarios. Temperature and temperature‐related variables appeared to be most influential in the distribution of whitebark pine (Pinus albicaulis), whereas precipitation and soil variables dominated the models for subalpine fir (Abies lasiocarpa) and Engelmann spruce (Picea engelmannii). The model for whitebark pine substantially overpredicted absences (as compared with the other models), which is probably a result of the importance of biological factors in the distribution of this species.Main conclusions  These models demonstrate the complex response of conifer distributions to changing climate scenarios. Whitebark pine is considered a ‘keystone’ species in the subalpine forests of western North America; however, it is believed to be nearly extinct throughout a substantial portion of its range owing to the combined effects of an introduced pathogen, outbreaks of the native mountain pine beetle (Dendroctonus ponderosae), and changing fire regimes. Given predicted changes in climate, it is reasonable to predict an overall decrease in pine‐dominated subalpine forests in the Greater Yellowstone Ecosystem. In order to manage these forests effectively with respect to future climate, it may be important to focus attention on monitoring dry mid‐ and high‐elevation forests as harbingers of long‐term change.
Sense of coherence and experiences of social support and mastery in the early discharge period after an acute cardiac event
Authors: Hildingh Cathrine , Fridlund Bengt , Baigi Amir 
Published: November 2007

Aims and objectives.  The aim of this study was to examine sense of coherence and experiences of change in social support and mastery from a short‐term perspective in patients who had been admitted to hospital with a suspected myocardial infarction.Background.  The early discharge period after an acute cardiac event can be a stressful and vulnerable time when psychosocial resources are of the utmost importance. A positive outcome in an encounter with a stressor is thought to be linked to a strong sense of coherence, social support and mastery.Design.  A multi‐centre survey was conducted in three hospitals in southern Sweden.Methods.  The sample was 300, 241 of whom completed the questionnaires; while in hospital and two weeks postdischarge.Results.  In the early discharge period a low sense of coherence was found in over 60% of the sample. There was an association between social support and mastery and between sense of coherence and mastery. Differences in social support ratings, with lower ratings two weeks postdischarge, were found among women and persons over 65 years of age.Conclusions.  This study adds knowledge about experiences in the early discharge period. Changes in ratings of social support but not in ratings of mastery were found between baseline and two weeks postdischarge.Relevance to clinical practice.  Healthcare professionals need to be sensitive to patients’ sense of coherence, mastery and need for social support during the early discharge period. They can help patients to identify adequate support strategies and prevent future potential complications. However, to routinely assess sense of coherence, social support and mastery, there is a need for a simple and useful instrument in clinical practice.
Major histocompatibility complex typing of dogs from Russia shows further dog leukocyte antigen diversity
Authors: Kennedy L. J. , Brown J. J. , Barnes A. , Ollier W. E. R. , Knyazev S. 
Published: November 2007

AbstractBlood samples from 85 Russian dogs and wolves were collected as dried blood spots on paper and transported to the UK by mail. We obtained partial or complete three‐locus canine major histocompatibility complex [dog leukocyte antigen (DLA)] class II haplotypes on 81 of these samples. Six new alleles were identified: three DLA‐DRB1 and three DLA‐DQB1. These alleles occurred in haplotypic combinations not previously seen in other European dogs. One haplotype appeared to lack a DQB1 allele. Two of the new haplotypes segregated through a family of dogs that was investigated.
Application of the particle gel agglutination assay in the typing of single human leucocyte antigens
Authors: Meyer O. , Agaylan A. , Schönemann C. , Kiesewetter H. , Salama A. 
Published: November 2007

AbstractWe describe a simple and rapid particle gel agglutination assay (PaGIA) for typing of the human leucocyte antigens (HLA) HLA‐A2, HLA‐B7 and HLA‐B27. Superparamagnetic streptavidin particles were coated with biotinylated monoclonal antibodies (MoAbs) to HLA‐A2, HLA‐B7 and HLA‐B27. Anticoagulated whole blood samples from healthy blood donors (n = 118) with known HLA patterns were incubated with MoAb‐coated particles, transferred into a standard ID‐gel card, and subsequently centrifuged. Samples were evaluated macroscopically, with antigen‐positive samples resulting in a visible agglutination reaction. A clear distinction could be made between all positive and negative samples tested. Fifty‐seven samples were found to be positive for HLA‐A2 (48%), 26 samples for HLA‐B7 (22%) and 5 samples for HLA‐B27 (4%).
Oncological outcome of minimum incision endoscopic radical nephrectomy for pathologically organ confined renal cell carcinoma
Authors: Iimura Yasumasa , Kihara Kazunori , Saito Kazutaka , Masuda Hitoshi , Kobayashi Tsuyoshi , Kawakami Satoru 
Published: November 2007

Objective:  To date, follow‐up after minimum incision endoscopic radical nephrectomy (MIES radical nephrectomy) for renal cell carcinoma (RCC) has not been reported. Minimum incision indicates an incision that narrowly permits the extraction of the specimen. To evaluate the oncological outcome of the patients with pathologically organ confined (pT1‐2N0M0) RCC treated with this operation, the results in those patients were analyzed.Methods:  From 1998 to 2006, 154 consecutive patients underwent MIES radical nephrectomy under diagnosis of clinical T1‐2N0M0 RCC in our hospital. Of the patients, 127 patients with pathologically confirmed organ confined (pT1‐2N0M0) RCC constituted the current study population. Overall, the recurrence‐free and cancer‐specific survival rates of the patients treated with MIES radical nephrectomy were calculated using the Kaplan‐Meier method and compared with those of the patients treated with open radical nephrectomy using the log rank test.Results:  The median follow‐up period was 34 months (range: 3–98 months). Of the 127 pT1‐2N0M0 patients treated with MIES radical nephrectomy, the disease recurred in nine patients and four patients died of the cancer during follow‐up. The five‐year overall, recurrence‐free and cancer‐specific survival rates were 95.0%, 90.8% and 95.8%, respectively. Overall, the recurrence‐free and cancer‐specific survival rates were not different from those of patients treated with open radical nephrectomy.Conclusion:  MIES radical nephrectomy has the validity in adequate cancer control and is one of the recommendable options as a minimally invasive surgery for patients with organ confined RCC.
Adult neurogenesis in primate and rodent spinal cord: comparing a cervical dorsal rhizotomy with a dorsal column transection
Authors: Vessal Mani , Aycock Ari , Garton Margaret Tess , Ciferri Melanie , Darian‐Smith Corinna 
Published: November 2007

AbstractNeurogenesis has not been shown in the primate spinal cord and the conditions for its induction following spinal injury are not known. In the first part of this study, we report neurogenesis in the cervical spinal dorsal horn in adult monkeys 6–8 weeks after receiving a well‐defined cervical dorsal rhizotomy (DRL). 5‐Bromo‐2‐deoxyuridine (BrdU) was administered 2–4 weeks following the lesion. Cells colabeled with BrdU and five different neuronal markers were observed in the peri‐lesion dorsal horn 4–5 weeks after BrdU injection. Those colabeled with BrdU and neuron‐specific nuclear protein, and BrdU and glial fibrillary acidic protein were quantified in the dorsal horn peri‐lesion region, and the ipsi‐ and contralateral sides were compared. A significantly greater number of BrdU/neuron‐specific nuclear protein‐ and BrdU/glial fibrillary acidic protein‐colabeled cells were found on the lesion side (P < 0.01). These findings led us to hypothesize that neurogenesis can occur within the spinal cord following injury, when the injury does not involve direct trauma to the cord and glial scar formation. This was tested in rats. Neurogenesis and astrocytic proliferation were compared between animals receiving a DRL and those receiving a dorsal column lesion. In DRL rats, neurogenesis was observed in the peri‐lesion dorsal horn. In dorsal column lesion rats, no neurogenesis was observed but astrocytic activation was intense. The rat data support our hypothesis and findings in the monkey, and show that the response is not primate specific. The possibility that new neurons contribute to recovery following DRL now needs further investigation.
REVIEW ARTICLE: Neuronal coding and spiking randomness
Authors: Kostal Lubomir , Lansky Petr , Rospars Jean‐Pierre 
Published: November 2007

AbstractFast information transfer in neuronal systems rests on series of action potentials, the spike trains, conducted along axons. Methods that compare spike trains are crucial for characterizing different neuronal coding schemes. In this paper we review recent results on the notion of spiking randomness, and discuss its properties with respect to the rate and temporal coding schemes. This method is compared with other widely used characteristics of spiking activity, namely the variability of interspike intervals, and it is shown that randomness and variability provide two distinct views. We demonstrate that estimation of spiking randomness from simulated and experimental data is capable of capturing characteristics that would otherwise be difficult to obtain with conventional methods.
Developmental plasticity of the carotid chemoafferent pathway in rats that are hypoxic during the prenatal period
Authors: Peyronnet J. , Roux J. C. , Mamet J. , Perrin D. , Lachuer J. , Pequignot J. M. , Dalmaz Y. 
Published: November 2007

AbstractThe chemoreflex pathway undergoes postnatal maturation, and the perinatal environment plays a critical role in shaping respiratory control system. We investigated the role of prenatal hypoxia on the maturation of the chemoreflex neural circuits regulating ventilation in rat. Effects of hypoxia (10% O2) from the 5th to the 20th day of gestation were studied on male offspring at birth and on postnatal days 3, 7, 21 and 68. Maturation of the respiratory control system was assessed by in vivo tyrosine hydroxylase (TH) activity measurement in peripheral chemoreceptors (carotid bodies, petrosal ganglia), and in brainstem catecholaminergic cell groups (A2C2c and A1C1 areas in the medulla, A5 and A6 areas in the pons). Resting ventilation and ventilatory response to hypoxia were evaluated as functional sequelae. In peripheral structures, prenatal hypoxia reduced TH activity within the first postnatal week and enhanced it later. In contrast, in central areas, prenatal hypoxia upregulated TH activity within the first postnatal week and downregulated it later. The in vivo TH activity impairment is therefore tissue specific, with an opposite effect on the peripheral and central neural circuits. A shift of the effect of prenatal hypoxia occurred between 1 and 3 weeks, indicating a postnatal temporal effect of prenatal hypoxia. An important period in the development of the chemoafferent pathway occurred between the first and the third postnatal week. Functionally, prenatal hypoxia impaired resting ventilation and ventilatory response to hypoxia. The alterations of the catecholaminergic components of the chemoafferent pathway resulting from prenatal hypoxia might contribute to impair postnatal respiratory behaviour.
Effects of opioid receptor blockade on the renewal of alcohol seeking induced by context: relationship to c‐fos mRNA expression
Authors: Marinelli Peter W. , Funk Douglas , Juzytsch Walter , Li Zhaoxia , Lê A. D. 
Published: November 2007

AbstractContextual stimuli associated with alcohol availability can induce alcohol seeking during abstinence. Using a renewal procedure, we tested the effect of opioid receptor blockade on context‐induced alcohol seeking, and its relationship to the activity of brain sites involved in learning and reward. Thirty‐six male Wistar rats were trained to lever press for a 12% (w/v) alcohol solution before undergoing extinction sessions (no alcohol delivery). Half of the rats underwent training, extinction and testing in a single context with a distinct set of olfactory, visual, auditory and tactile properties [training, extinction and test in Context A (AAA)]. The other half were trained and extinguished in different contexts and returned to the training context on the test day [training, extinction and test in Contexts A, B and A, respectively (ABA)]. On the test day, the rats from each condition were pre‐treated with either saline or 1 mg/kg naltrexone (s.c.) and tested for alcohol seeking. Immediately following the test session, rats were killed and their brains were analysed for c‐fos mRNA expression using in‐situ hybridization. Re‐exposure to the alcohol‐associated context (ABA) significantly increased operant behaviour on the previously active lever relative to the AAA groups and this increased responding was associated with increased c‐fos mRNA expression in the basal and lateral amygdala and the CA3 subregion of the hippocampus. Naltrexone pre‐treatment attenuated context‐induced alcohol seeking and inhibited c‐fos mRNA expression in the lateral amygdala and CA3. Our findings point to a critical role for the basolateral amygdala and dorsal hippocampus in mediating context‐induced renewal of alcohol seeking and suggest that opioidergic mechanisms mediate this effect.
The slow afterhyperpolarization modulates high pH‐induced changes in the excitability of rat CA1 pyramidal neurons
Authors: Kelly Tony , Mann Mandeep , Church John 
Published: November 2007

AbstractExtra‐ and intracellular recordings from the CA1 region of rat hippocampal slices were employed to examine the role of the slow afterhyperpolarization (sAHP) in modulating the increases in neuronal excitability observed on increasing extracellular pH (pHo) from 7.4 to 7.7. In the majority of experiments, an antidromic conditioning stimulus applied in the presence of d(–)‐2‐amino‐5‐phosphonopentanoic acid (d‐APV), 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione disodium salt (CNQX) and bicuculline was employed to elicit a sAHP, and an antidromic test stimulus was applied during the sAHP. At pHo 7.4, a single conditioning stimulus elicited an action potential followed by a sAHP, which in turn inhibited the response to the test stimulus compared with the conditioning stimulus. Increasing the number of action potentials in the conditioning stimulus augmented the sAHP and further inhibited the test response, whereas isoproterenol inhibited the sAHP and prevented the relative inhibition of the test response. At pHo 7.7, a single conditioning stimulus elicited a burst of action potentials followed by a large sAHP, which in turn prevented the test stimulus from eliciting a burst of action potentials and, in extracellular recordings, further increased the inhibition of the test response. The latter effect did not solely reflect a high pHo‐induced increase in the conditioning response (and, thus, the subsequent sAHP), but rather involved a more direct effect of high pHo to augment the sAHP. The results indicate that increasing pHo increases the excitability of CA1 neurons to an initial stimulus; however, a high pHo‐dependent increase in the sAHP evoked by the initial stimulus limits the response to subsequent stimuli.
Restoration of impaired phosphorylation of cyclic AMP response element‐binding protein (CREB) by EGb 761 and its constituents in Aβ‐expressing neuroblastoma cells
Authors: Xu Yanan , Cui Changhai , Pang Cheuk , Christen Yves , Luo Yuan 
Published: November 2007

AbstractCyclic AMP response element‐binding protein (CREB) plays important roles in neuronal plasticity and amyloid β‐peptide (Aβ)‐induced cognitive impairment in Alzheimer's disease (AD). Here we demonstrated that Ginkgo biloba extract, EGb 761, displayed the neuron protective effect by activating the CREB signaling pathway. Wild‐type neuroblastoma cells cultured in a conditioned medium containing cell‐secreted Αβ exhibited reduced levels of phosphorylated CREB (pCREB). Addition of EGb 761 (100 µg/mL) or an anti‐oligomer‐specific antibody (A‐11) to the conditioned medium could restore pCREB level. In a neuroblastoma cell line expressing Αβ, treatment with EGb 761 increased levels of pCREB and brain‐derived neurotrophic factor. Furthermore, CREB phosphorylation induced by EGb 761 was blocked by inhibitors of several upstream signaling pathways of CREB, including protein kinase C, ERK, ribosomal S6 kinase(RSK)90 and nitric oxide pathway. Moreover, these inhibitors differentially blocked the effects of individual components of EGb 761, ginkgolide C, quercetin and bilobalide, which suggest diverse effects of the EGb 761 individual components. Actions of individual EGb 761 components provide further insights into direct mechanisms underlying the effect of EGb 761 on enhancing the cognitive performance of patients with AD.
Mapping of Cbln1‐like immunoreactivity in adult and developing mouse brain and its localization to the endolysosomal compartment of neurons
Authors: Wei Peng , Smeyne Richard J. , Bao Dashi , Parris Jennifer , Morgan James I. 
Published: November 2007

AbstractCbln1 is a secreted glycoprotein essential for synapse structure and function in cerebellum that is also expressed in extracerebellar structures where its function is unknown. Furthermore, Cbln1 assembles into homomeric complexes and heteromeric complexes with three family members (Cbln2–Cbln4), thereby influencing each other's degradation and secretion. Therefore, to understand its function, it is essential to establish the location of Cbln1 relative to other family members. The localization of Cbln1 in brain was determined using immunohistochemistry and cbln1‐lacZ transgenic mice. Cbln1‐like immunoreactivity (CLI) was always punctate and localized to the cytoplasm of neurons. The punctate CLI colocalized with cathepsin D, a lysosomal marker, but not with markers of endoplasmic reticulum or Golgi, indicating that Cbln1 is present in neuronal endosomes/lysosomes. This may represent the cellular mechanism underlying the regulated degradation of Cbln1 observed in vivo. Outside the cerebellum, CLI mapped to multiple brain regions that were frequently synaptically interconnected, warranting their analysis in cbln1‐null mice. Furthermore, whereas CLI increased dramatically in the cerebellum of cbln3‐null mice it was unchanged in extracerebellar neurons. This opens the possibility that other family members that are coexpressed in these areas control Cbln1 levels, potentially by modulating processing in the endolysosomal pathway. During development of cbln1‐lacZ mice, β‐galactosidase staining was first observed in proliferating granule cell precursors prior to synaptogenesis and thereafter in maturing and adult granule cells. As cbln3 is only expressed in post‐mitotic, post‐migratory granule cells, Cbln1 homomeric complexes in precursors and Cbln1–Cbln3 heteromeric complexes in mature granule cells may have distinct functions and turnover.