bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calcium signaling in specialized glial cells
Authors: Metea Monica R. , Newman Eric A. 
Published: September 2006

AbstractThis article reviews calcium signaling in three specialized types of glial cells: Müller cells of the retina, Bergmann glial cells of the cerebellum, and radial glial cells of the developing cortex. Müller cells generate spontaneous and neuronal activity‐evoked increases in Ca2+. Neuron to Müller cell signaling is mediated by neuronal release of ATP and activation of glial P2Y receptors. Müller cells, in turn, modulate neuronal excitability and mediate vasomotor responses. Bergmann glial cells also generate spontaneous and activity‐evoked Ca2+ increases. Neuron to Bergmann glia signaling is mediated by neuronal release of nitric oxide, noradrenaline, and glutamate. In Bergmann glia, Ca2+ increases control the structural and functional interactions between these cells and Purkinje cell synapses. In the ventricular zone of the developing cortex, radial glial cells generate spontaneous Ca2+ increases that propagate as Ca2+ waves through clusters of neighboring glial cells. These Ca2+ increases control cell proliferation and neurogenesis. © 2006 Wiley‐Liss, Inc.
Molecular determinants ofD‐serine‐mediated gliotransmission: From release to function
Authors: Oliet Stéphane H. R. , Mothet Jean‐Pierre 
Published: September 2006

AbstractSince the late 80s, it is recognized that functional activation ofN‐methylD‐aspartate receptors (NMDARs) requires the binding of both glutamate and glycine. However, the surprising discovery that the wrong isomer of serine,D‐serine, is present in mammals has profoundly challenged this dogmatic model of NMDARs activation. Indeed, there are accumulating evidence indicating thatD‐serine is the endogenous ligand for the glycine modulatory binding site in many brain areas.D‐Serine is synthesized in glial cells by serine racemase (SR) and released upon activation of glutamate receptors. Here, we will provide an overview of recent findings on the molecular and cellular mechanisms involved in the synthesis and release of this gliotransmitter. We will also emphasize the function of this novel messenger in regulating synaptic excitatory transmission and plasticity in different brain areas. Because it fulfils all criteria for a gliotransmitter,D‐serine regulatory action on glutamatergic transmission further illustrates the emerging concept of the “tripartite synapse”. © 2006 Wiley‐Liss, Inc.
Haplotype matching is not an essential requirement to achieve remyelination of demyelinating CNS lesions
Authors: Tepavcević V. , Blakemore W. F. 
Published: September 2006

AbstractTransplantation of oligodendrocyte precursor cells (OPCs) results in efficient remyelination in animal models of demyelination. However, the experiments so far undertaken have not addressed the need for tissue‐type matching to achieve graft‐mediated remyelination. Examination of MHC expression (main determinant of allograft rejection) by OPCs showed nondetectable levels under standard culture conditions and upregulation of MHC Class I expression only upon exposure to interferon γ. We therefore hypothesized that MHC matching of OPC grafts may not be crucial to achieve transplant‐mediated remyelination. Transplant experiments performed using a nonself repairing toxin‐induced demyelination model showed that, similarly to allogeneic neurons, survival of allogeneic oligodendrocyte lineage cells is influenced by donor–host haplotype combination and graft composition. Transplantation of allogeneic mixed glial cell cultures resulted in remyelination failure by 1 month postengraftment due to a rejection response targeting both myelinating oligodendrocytes and OPCs, suggesting that inflammation‐induced upregulation of OPC MHC I expression results in susceptibility to cytotoxic T cell attack. In contrast, remyelination persisted for at least 2 months following transplantation of OPC‐enriched cultures whose overall MHC expression level was significantly decreased. While OPC‐enriched preparations elicited delayed type hypersensitivity responses in hosts sensitized to alloantigens, allografting of such preparations into a central nervous system demyelinating lesion did not result in recipient priming. We conclude that while allografted oligodendrocyte lineage cells become targets of a graft rejection response once this response has been initiated, transplantation of OPC‐enriched preparations can evade priming against alloantigens and graft rejection. This finding indicates that close tissue matching may not be an essential requirement for successful transplant‐mediated remyelination. © 2006 Wiley‐Liss, Inc.
Cognitive and psychiatric predictors of medical treatment adherence among older adults in primary care clinics
Authors: Mackin R. Scott , Areán Patricia A. 
Published: September 2006

AbstractObjectivesMedical treatment non‐adherence among older adults is common and represents a significant public health care concern. Treatment non‐adherence has been associated with a number of factors in older adults; however few studies have delineated the role of cognition and psychiatric status.ParticipantsData were collected from 212 ethnically diverse older primary care patients as part of a larger study.MeasurementsCognitive status was evaluated with the Mattis Dementia Rating scale (DRS). Psychiatric status was evaluated using the Geriatric Depression Scale (GDS) and the Beck Anxiety Inventory (BAI). Treatment adherence was assessed by the total number of missed healthcare appointments and by physician and patient ratings. Physician ratings of patients' understanding of medical instructions were also obtained.DesignA series of multiple regression analyses were conducted to determine cognitive and psychiatric predictors for each measure of treatment adherence.ResultsGDS and DRS memory scores were both independent predictors of the total number of missed medical appointments, F(7,55) = 2.34, p = 0.038. GDS score was also shown to be a significant predictor of physician ratings of patients' understanding of medical instructions, F(7,33) = 0.89, p = 0.031. Neither cognitive performance nor psychiatric status was associated with patient or physician ratings of treatment adherence.ConclusionsMeasures of cognitive functioning and depression severity were supported as predictors of objective measures of treatment adherence but they were not associated with physician or patient ratings of adherence. Patient depression may influence physician ratings of patients' comprehension of medical instructions. Copyright © 2006 John Wiley & Sons, Ltd.
A review of the experience of hospital autonomy in Pakistan
Authors: Abdullah M. Tanweer , Shaw Jane 
Published: September 2006

AbstractThis paper examines the recent trends in public hospital autonomy as an integral part of health systems reforms. It reviews literature produced on the subject across a range of developing countries and explores varying viewpoints, arguments, and rationale for hospital autonomy developed over the past two decades. It then leads onto a discussion of two experiences of autonomy reforms in Pakistan: the provinces of Punjab and NWFP. Derived from the lessons learned from these initiatives, a set of guidelines is suggested as sustainable frameworks for reviewing the current measures and for designing future autonomy initiatives in Pakistan. Copyright © 2006 John Wiley & Sons, Ltd.
Credit spread volatility, bond ratings and the risk reduction effect of watchlistings
Authors: Heinke Volker G. 
Published: September 2006

AbstractThis article examines the relationship between the volatility of the credit risk premium of a plain vanilla bond and its credit rating. We calculate volatilities over different time windows and test for differences in the mean volatility depending on the bond rating. We check for the influence of further factors that are theoretically relevant for the explanation of the credit spread volatility. Moreover, we check the dynamic effect of rating changes on bond spread volatility. Finally, we test whether credit watchlistings influence credit spread volatility. We confirm prior studies in that, generally, credit ratings rank the risk of bonds according to credit spread volatility. We further find that rating changes have a dynamic influence on spread volatilities. Additionally it is shown that credit watchlistings significantly reduce the volatility. Thus, watchlistings are perceived to offer valuable information. Copyright © 2006 John Wiley & Sons, Ltd.
A tale of two ‘globalizations’: capital flows from rich to poor in two eras of global finance
Authors: Schularick Moritz 
Published: September 2006

AbstractIn this paper we take a comparative look at the patterns of capital flows from rich to poor countries in two eras of financial globalization. The paper extends recent research on the developmental effects of international financial integration, long‐term trends in capital mobility and ‘globalization in historical perspective’. Analysing the patterns of international financial integration in the three decades of the classical gold standard and after 1990 we show that investment in developing countries was a central element of 19th century financial globalization, but plays only a minor role today. The Lucas paradox of capital failing to flow from rich to poor has grown much stronger. In historical perspective, today's financial globalization is marked by massive diversification flows between high‐income economies and a relative marginalization of less‐developed economies. Copyright © 2006 John Wiley & Sons, Ltd.
The out‐of‐sample forecasts of nonlinear long‐memory models of the real exchange rate
Authors: Chung Sang‐Kuck 
Published: September 2006

AbstractWe consider a new time series model that can describe long memory and nonlinearity simultaneously and can be used to assess an extensive evaluation of the out‐of‐sample forecasting performance of the nonlinear long‐memory model. Upon fitting it to the real exchange rate, we find that a parsimonious version of the model captures the salient features of the data rather well. We then use this nonlinear long‐memory model to forecast dynamically out‐of‐sample over the sample period for OECD countries. Overall, we find clear evidence that favours the nonlinear long‐memory model over any other estimated models. Copyright © 2006 John Wiley & Sons, Ltd.
Regime switching and artificial neural network forecasting of the Cyprus Stock Exchange daily returns
Authors: Constantinou Eleni , Georgiades Robert , Kazandjian Avo , Kouretas Georgios P. 
Published: September 2006

AbstractThis paper provides an analysis of regime switching in volatility and out‐of‐sample forecasting of the Cyprus Stock Exchange by using daily data for the period 1996–2002. We first model volatility regime switching within a univariate Markov switching framework. Modelling stock returns within this context can be motivated by the fact that the change in regime should be considered as a random event and not predictable. The results show that linearity is rejected in favour of an MS specification, which forms statistically an adequate representation of the data. Two regimes are implied by the model, the high‐volatility regime and the low‐volatility one, and they provide quite accurately the state of volatility associated with the presence of a rational bubble in the capital market of Cyprus. Another implication is that there is evidence of regime clustering. We then provide out‐of‐sample forecasts of the CSE daily returns by using two competing nonlinear models, the univariate Markov switching model and the Artificial Neural Network Model. The comparison of the out‐of‐sample forecasts is done on the basis of forecast accuracy, using the Diebold and Mariano test and forecast encompassing, using the Clements and Hendry test. The results suggest that both nonlinear models are equivalent in forecasting accuracy and forecasting encompassing, and therefore on forecasting performance. Copyright © 2006 John Wiley & Sons, Ltd.
Neuronal precursors within the adult rat subventricular zone differentiate into dopaminergic neurons after substantia nigra lesion and chromaffin cell transplant
Authors: Arias‐Carrión Oscar , Hernández‐López Salvador , Ibañez‐Sandoval Osvaldo , Bargas José , Hernández‐Cruz Arturo , Drucker‐Colín René 
Published: September 2006

AbstractNeurogenesis in the adult mammalian brain continues in the subventricular zone (SVZ). Neuronal precursors from the SVZ migrate along the rostral migratory stream to replace olfactory bulb interneurons. After the destruction of the nigro‐striatal pathway (SN‐lesion), some SVZ precursors begin to express tyrosine hydroxylase (TH) and neuronal markers (NeuN). Grafting of chromaffin cells (CCs) into the denervated striatum increases the number of TH+ cells (SVZ TH+ cells; Arias‐Carrión et al., 2004). This study examines the functional properties of these newly differentiating TH+ cells. Under whole‐cell patch‐clamp, most SVZ cells recorded from lesioned and grafted animals (either TH+ or TH−) were non‐excitable. Nevertheless, a small percentage of SVZ TH+ cells had the electrophysiologic phenotype of mature dopaminergic neurons and showed spontaneous postsynaptic potentials. Dopamine (DA) release was measured in SVZ and striatum from both control and SN‐lesioned rats. As expected, 12 weeks after SN lesion, DA release decreased drastically. Nevertheless, 8 weeks after CCs graft, release from the SVZ of SN‐lesioned rats recovered, and even surpassed that from control SVZ, suggesting that newly formed SVZ TH+ cells release DA. This study shows for the first time that in response to SN‐lesions and CC grafts neural precursors within the SVZ change their developmental program, by not only expressing TH, but more importantly by acquiring excitable properties of mature dopaminergic neurons. Additionally, the release of DA in a Ca2+‐dependent manner and the attraction of synaptic afferents from neighboring neuronal networks gives further significance to the overall findings, whose potential importance is discussed. © 2006 Wiley‐Liss, Inc.
Late Quaternary palaeoceanography of the Circumpolar Deep Water from the South Tasman Rise
Authors: Moy Andrew D. , Howard William R. , Gagan Michael K. 
Published: September 2006

AbstractWe use sediment cores from the South Tasman Rise (STR) to reconstruct deep‐ water circulation in the southwest Pacific sector of the Southern Ocean. Sediment cores MD972106 (45° 09′ S, 146° 17′ E, 3310 m water depth) and GC34 (45° 06′ S, 147° 45′ E, 4002 m water depth) preserve records covering the last 160 k yr, with chronology controlled by calibrated accelerator mass spectrometry radiocarbon dates and benthic foraminiferal δ18O tied to SPECMAP. The STR benthic foraminiferal δ13C records provide new δ13C values for Southern Ocean deep water spanning the last 160 k yr at sites unlikely to be affected by variations in productivity. The records establish that glacial benthic foraminifera (Cibicidoides spp.) δ13C values are lower relative to interglacial values and are comparable to previous glacial benthic δ13C records in the Indian and Pacific sectors of the Southern Ocean. Comparisons of the benthic foraminiferal δ13C time series at the STR are made with the equatorial Pacific (V19‐30 and Site 846) and the equatorial Atlantic (GeoB1115). The similarity of benthic δ13C records at the STR to the equatorial Pacific suggest the Southern Ocean deep‐water mass closely tracked those of the deep Pacific, and the presence of a δ13C gradient between the STR and the equatorial Atlantic suggests there was continual production of northern source deep water over the past 160 k yr. Copyright © 2006 John Wiley & Sons, Ltd.
The vegetation history of the last glacial–interglacial cycle in eastern New South Wales, Australia
Authors: Williams N. J. , Harle K. J. , Gale S. J. , Heijnis H. 
Published: September 2006

AbstractWe present a reconstruction of the vegetation history of the last glacial–interglacial cycle (ca. 75 k cal. yr BP–present) at Redhead Lagoon, an enclosed lake basin in coastal, eastern New South Wales, Australia. The sequence of vegetation change at the site is broadly comparable with the pattern of climatically induced changes observed in many other pollen records in southeast Australia. Open woodland–herbland and woodland–forest communities correspond with glacial and interglacial periods respectively, with an additional change towards a more open understorey vegetation assemblage over the last 40 000 yr. The driest conditions appear to have occurred during the height of the last glacial (some time between 30 and 20 k cal. yr BP). This is consistent with other records from southeast Australia, and provides support for a poleward shift in the subtropical anticyclone belt and, less certainly, for the thesis that the Southern Hemisphere westerlies intensified during this period. In marked contrast to most sites in southeast Australia, Casuarinaceae dominates the pollen record through the height of the last glacial period and into the Holocene. The postglacial climatic amelioration is accompanied by the general reappearance of tree pollen in the record, by the disappearance of several open and disturbed environment indicator taxa, by increases in organic sediment deposition and pollen taxon diversity, and by higher water balances. While climate appears to have been the major control on patterns of vegetation change at this site throughout most of the last glacial–interglacial cycle, changes in depositional environment and hydrology have also played a role. Significantly, substantial increases in the rate and magnitude of many indicators of environmental disturbance since European settlement suggest that humans are now the most important mechanism for environmental change. Copyright © 2006 John Wiley & Sons, Ltd.
Millennia‐long tree‐ring records from Tasmania and New Zealand: a basis for modelling climate variability and forcing, past, present and future
Authors: Cook Edward R. , Buckley Brendan M. , Palmer Jonathan G. , Fenwick Pavla , Peterson Michael J. , Boswijk Gretel , Fowler Anthony 
Published: September 2006

AbstractProgress in the development of millennia‐long tree‐ring chronologies from Australia and New Zealand is reviewed from the perspective of modelling long‐term climate variability there. Three tree species have proved successful in this regard: Huon pine (Lagarostrobos franklinii) from Tasmania, silver pine (L. colensoi) from the South Island of New Zealand, and kauri (Agathis australis) from the North Island of New Zealand. Each of these species is very long‐lived and produces abundant quantities of well‐preserved wood for extending their tree‐ring chronologies back several millennia into the past. The growth patterns on these chronologies strongly correlate with both local and regional warm‐season temperature changes over significant areas of the Southern Hemisphere (especially Huon and silver pine) and to ENSO variability emanating from the equatorial Pacific region (especially kauri). In addition, there is evidence for significant, band‐limited, multi‐decadal and centennial timescale variability in the warm‐season temperature reconstruction based on Huon pine tree rings that may be related to slowly varying changes in ocean circulation dynamics in the southern Indian Ocean. This suggests the possibility of long‐term climate predictability there. Copyright © 2006 John Wiley & Sons, Ltd.
Extension of New Zealand kauri (Agathis australis) tree‐ring chronologies into Oxygen Isotope Stage (OIS) 3
Authors: Palmer Jonathan , Lorrey Andrew , Turney Chris S. M. , Hogg Alan , Baillie Mike , Fifield Keith , Ogden John 
Published: September 2006

AbstractNew Zealand kauri (Agathis australis) is both long‐lived and sensitive to climate so during the past two decades an extensive network of sites has been sampled for dendrochronological analyses. The network can be divided into three general groups based on the time period they cover—‘modern’ kauri (MK), late‐Holocene kauri (HK) and ‘ancient’ kauri (AK) from before the Last Glacial Maximum (LGM). Although the groups are restricted to northern New Zealand (i.e. having overlapping ranges) they occur at different elevations. Modern kauri sites tend to be along ridges and much higher than the two subfossil groups (i.e. HK and AK sites). We propose the modern kauri situation to be a typical artefact of anthropogenic activities. In contrast, the subfossil groups are the result of a complex process of dune migration, levee formation and water‐table rise leading to bog formation driven by rising sea levels. Most of the 16 AK sites have radiocarbon ages clearly within Oxygen Isotope Stage (OIS) 3 and a preliminary group of chronologies have been developed that collectively cover 10 719 yr. Analysis is ongoing, but there is clear potential to span a much greater time period and recover detailed palaeoclimatic information. Copyright © 2006 John Wiley & Sons, Ltd.
Shear‐Induced Crystallization in a Blend of Isotactic Poly(propylene) and Poly(ethylene‐co‐octene)
Authors: Meng Kun , Dong Xia , Zhang Xiaohua , Zhang Chenggui , Han Charles C. 
Published: September 2006

AbstractSummary: Shear‐induced crystallization in a blend of isotactic poly(propylene) and poly(ethylene‐co‐octene) (iPP/PEOc) has been investigated by means of in‐situ optical microscopy and a shear hot stage under various thermal and shear histories. Cylindrites are observed after shear in the phase‐separated iPP/PEOc blends for the first time. The nuclei (shish) come from the orientation of the entangled network chains, and the relationship between the shear rate and the network relaxation time of the oriented iPP chains is a very important factor that dominates the formation of the cylindrites after liquid‐liquid phase separation. The cylindrites can grow through phase‐separated domains with proper shear rate and shear time. In addition, the number of spherulites increases with shear rate, which is consistent with the notion of fluctuation‐induced nucleation/crystallization.Phase‐contrast optical micrograph of the iPP/PEOc = 50/50 (wt.‐%) sample sheared during cooling with shear rate of 10 s−1 and isothermally crystallized at 140 °C for 142 s after isothermal annealing at 170 °C for 420 min. The shear time is 180 s.imagePhase‐contrast optical micrograph of the iPP/PEOc = 50/50 (wt.‐%) sample sheared during cooling with shear rate of 10 s−1 and isothermally crystallized at 140 °C for 142 s after isothermal annealing at 170 °C for 420 min. The shear time is 180 s.
Shear‐Controlled Micro/Nanometer‐Scaled Super‐Hydrophobic Surfaces with Tunable Sliding Angles from Single Component Isotactic Poly(propylene)
Authors: Yao Yonghua , Dong Xia , Hong Song , Ge Hongli , Han Charles C. 
Published: September 2006

AbstractSummary: With the proper selection of shear and thermal conditions, super‐hydrophobic polymeric surfaces (contact angle > 150°) with tunable sliding angles (from less than 1° to higher than 90°) can be prepared from pure isotactic poly(propylene) (iPP) without any further modification with low‐surface‐energy components under ambient atmosphere. The formed surfaces have naturally good thermal properties, chemical and moisture resistance, low density, and potentially low manufacturing cost.SEM images of formed super‐hydrophobic surfaces and related two extreme sliding angles (contact angles of these surfaces are higher than 150°).imageSEM images of formed super‐hydrophobic surfaces and related two extreme sliding angles (contact angles of these surfaces are higher than 150°).