bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of radial fibers in controlling the onset of myelination
Authors: Nakahara Jin , Takemura Masaaki , Gomi Hiroshi , Tsunematsu Ken‐ichiro , Itohara Shigeyoshi , Asou Hiroaki , Ogawa Masaharu , Aiso Sadakazu , Tan‐Takeuchi Kyoko 
Published: April 2003

AbstractRecent in vitro study showed that astrocytes induce oligodendrocyte processes to adhere to axons. However, the role of astrocytes in myelination in vivo remains unknown. We have, therefore, conducted a study to clarify the possible involvement of astrocytes during the initial myelination process. In newborn mice, the expression of glial fibrillary acidic protein (GFAP), a marker for astrocytes, was restricted to a few fibrous architectures in the subventricular zone (SVZ), but we did not observe any GFAP‐positive astrocytes. Prior to the onset of myelination, GFAP became transiently expressed in the cells with radial fibers elongating from the SVZ to the pia of cerebral cortex, and myelin‐associated glycoprotein (MAG)‐positive premyelinating oligodendrocytes appeared as neighbors to them, with the processes attaching to radial fibers, but not to axons. These GFAP‐positive “radial” cells lost their fibrous architecture and became typical GFAP‐positive astrocytes at about 10 days postnatally, when myelination set in, indicating that the disappearance of radial fibers coordinates with the initiation of myelination. From these results, we propose that premyelinating oligodendrocytes are in contact with radial fibers rather than axons and that the cytoarchitectural transformation of radial fibers into astrocytes is involved substantially in controlling the onset of initial myelination. Our proposal was further confirmed by GFAP‐deficient mice, in which the disappearance of these radial fibers and the initiation of myelination were delayed in parallel. Our findings together suggest that myelination in vivo is in concert with astrocytic differentiation, involving radial fibers therein, rather than being a mere axon–oligodendrocyte interaction. © 2003 Wiley‐Liss, Inc.
Adjusting urban bias in the regional mean surface temperature series of South Korea, 1968–99
Authors: Choi Youngeun , Jung Hyun‐Sook , Nam Kyung‐Yeub , Kwon Won‐Tae 
Published: April 2003

AbstractThe purpose of this paper is to produce a higher quality regional surface temperature series by removing urban biases in South Korean surface temperatures using statistical procedures. Monthly mean temperatures for 16 stations were obtained for a period of 32 years (1968–99). Each station is defined as an urban station or a rural station. Urban (rural) stations are defined as those that have population densities greater (less) than 1000 persons per squared kilometer in 1995. Ten urban stations and six rural stations are identified. Again, urban stations are subdivided into two groups according to whether their population totals exceed one million to examine magnitude changes of urban biases with the size of urban areas. Estimates of urban bias magnitude are calculated by averaging the difference between each urban station and every rural station. Estimates of mean urban bias magnitude (T̄u–r) are calculated by averaging the yearly urban bias estimates. Estimates of the urban trend (ΔTu–r) are obtained by differencing period means (by doubling the differences obtained between yearly estimates averaged over two 16 year periods, 1968–83 and 1984–99). For annual or seasonal mean temperature Ti, the adjusted temperature T′i is determined. As all estimates of T̄u–r are greater than zero, it suggests that temperatures in urban stations are warmer than those in rural stations. Estimates of the annual mean magnitude of urban bias range from 0.35 °C for smaller urban stations to 0.50 °C for large urban stations. Also, all estimates of ΔTu–r are positive, indicating an increasing trend in the urban bias time series. Seasonal variations are found in T̄u–r and ΔTu–r. After adjusting the urban bias, an increasing trend in surface temperature series is still evident. Copyright © 2003 Royal Meteorological Society
The impact of land‐cover modification on the June meteorology of China since 1700, simulated using a regional climate model
Authors: Wang H. , Pitman A. J. , Zhao M. , Leemans R. 
Published: April 2003

AbstractA series of simulations was conducted using a regional climate model with a domain covering mainland China. Simulations were conducted for a single June using estimated land cover for 1700, 1750, 1800, 1850, 1900, 1950, 1970 and 1990. The conversion of land cover between these periods was extensive over mainland China, where large areas were altered from natural forests to either grass or crops, or from natural grasslands to crops. These land‐cover modifications affect various characteristics of the land surface, which lead to changes in the way available energy and water are partitioned. Over areas where land cover was modified, substantial changes are simulated. The conversion from forests to grasses or crops leads to warming and to reductions in root zone soil moisture and latent heat fluxes. Regionally, the conversion from forest to grasses and crops leads to significant warming over large areas of China, but there is an area of cooling present that is coincident with the main location of a land‐use change from short grass to crops. The changes in temperature propagate to about 1500 m above the surface and affect specific humidity throughout this part of the atmosphere. An analysis of daily average results shows a consistent impact of land‐cover modification on temperature, latent heat flux and soil moisture. Therefore, we find large and consistent impacts over China resulting from historical land‐cover modification that are sufficiently important to the regional‐scale climate to warrant inclusion in future modelling efforts. Our results suggest that efforts to attribute warming patterns over China to any particular cause need to take into account the conversion of the land cover that has taken place over China over the last 300 years. Copyright © 2003 Royal Meteorological Society
The evolution of, and revolution in, land surface schemes designed for climate models
Authors: Pitman A. J. 
Published: April 2003

AbstractThe land surface is a key component of climate models. It controls the partitioning of available energy at the surface between sensible and latent heat, and it controls the partitioning of available water between evaporation and runoff. The land surface is also the location of the terrestrial carbon sink. Evidence is increasing that the influence of the land surface is significant on climate and that changes in the land surface can influence regional‐ to global‐scale climate on time scales from days to millennia. Further, there is now a suggestion that the terrestrial carbon sink may decrease as global temperatures increase as a consequence of rising CO2 levels. This paper provides the theoretical background that explains why the land surface should play a central role in climate. It also provides evidence, sourced from climate model experiments, that the land surface is of central importance. This paper then reviews the development of land surface models designed for climate models from the early, very simple models through to recent efforts, which include a coupling of biophysical processes to represent carbon exchange. It is pointed out that significant problems remain to be addressed, including the difficulties in parameterizing hydrological processes, root processes, sub‐grid‐scale heterogeneity and biogeochemical cycles. It is argued that continued development of land surface models requires more multidisciplinary efforts by scientists with a wide range of skills. However, it is also argued that the framework is now in place within the international community to build and maintain the latest generation of land surface models. Further, there should be considerable optimism that consolidating the recent rapid advances in land surface modelling will enhance our capability to simulate the impacts of land‐cover change and the impacts of increasing CO2 on the global and regional environment. Copyright © 2003 Royal Meteorological Society
Condensation as a microclimate process: measurement, numerical simulation and prediction in the Glowworm Cave, New Zealand
Authors: de Freitas C. R. , Schmekal A. 
Published: April 2003

AbstractThe study examines condensation as a microclimate process. It focuses first on finding a reliable method for measuring condensation and then on testing a numerical model for predicting condensation rates. The study site is the Glowworm Cave, a heavily used tourist cave in New Zealand. Preservation of the cave and its management as a sustainable tourist resource are high priorities. Here, as in other caves, condensation in carbon dioxide enriched air can lead to corrosion of calcite features. Specially constructed electronic sensors for measuring on‐going condensation, as well as evaporation of the condensate, are tested. Measurements of condensation made over a year are used to test a physical model of condensation in the cave defined as a function of the vapour gradient between the cave air and condensation surface and a convection transfer coefficient. The results show that the amount and rate of condensation can be accurately measured and predicted. Air exchange with the outside can increase or decrease condensation rates, but the results show that the convection transfer coefficient remains constant. Temporal patterns of condensation in the cave are identified, as well as factors that influence these. Short‐term and longer‐term temporal variations of condensation rates are observed and patterns explained. Seasonal changes are large, with higher condensation rates occurring in the warmer months and lower rates during the cooler months. It is shown that controlling air exchange between the cave and the outside can influence condensation. This and other aspects of cave management are discussed. Copyright © 2003 Royal Meteorological Society
Anomalies of the South American summer monsoon associated with the 1997–99 El Niño–southern oscillation
Authors: Lau K.‐M. , Zhou Jiayu 
Published: April 2003

AbstractWe describe the rainfall and circulation anomalies of the South American summer monsoon (SASM) during December–January–February (DJF) of 1997–98 (El Niño) and 1998–99 (La Niña). The most pronounced rainfall signals in DJF 1997–98 include (a) excessive rainfall over northern Peru and Ecuador, (b) deficient rainfall over northern and central Brazil, and (c) above‐normal rainfall over southeastern subtropical South America. The rainfall anomalies in (a) and (b) are associated with the excitation of an anomalous east–west overturning cell with rising motion and low‐level westerlies over the equatorial eastern Pacific, coupled to sinking motion and low‐level easterlies over northern Brazil. The easterlies turn sharply southeastward on encountering the steep topography of the Andes, enhancing the summertime low‐level jet (LLJ) along the eastern foothills of the Andes near 15–20° S, possibly contributing to the increased rainfall in (c).During DJF 1997–98, the sea‐surface temperature‐induced warming spreads and expands over the entire tropical troposphere. The eastward expansion of a warm upper tropospheric geopotential and temperature ridge from the Niño‐3 region, across subtropical South America to the southeast Atlantic, enhances warming over the Altiplano Plateau, hydrostatically strengthening the Bolivia high. Similar to previous warming events, the South Pacific high is weakened, and the South Atlantic high is strengthened. During DJF 1998–99, as cold water develops over the equatorial central Pacific, the SASM anomalies in the tropics are weaker and less organized and appear to be in transition to the opposite phase to those found in DJF 97–98. In the subtropics, notable features include a weakening of the LLJ, a rainfall pattern associated with a poleward shift of the South Atlantic convergence zone, and development of the Pacific–South America teleconnection pattern. Published in 2003 by John Wiley & Sons, Ltd.
Targeting of the retinal pigment epithelium (RPE) by means of a rapidly scanned continuous wave (CW) laser beam
Authors: Brinkmann Ralf , Koop Norbert , Özdemir Mustafa , Alt Clemens , Schüle Georg , Lin Charles P. , Birngruber Reginald 
Published: April 2003

AbstractBackground and ObjectivesSelective treatment of the retinal pigment epithelium (RPE) by repetitively applying green μs‐laser pulses is a new method for retinal diseases associated with a degradation of the RPE, which spares the neural retina. We investigated an alternative approach to realize repetitive μs‐laser exposure by rapidly scanning a continuous wave (CW)‐laser beam across the RPE.Study Design/Materials and MethodsAn Ar+ laser beam (514 nm) with a diameter of 18.75 μm was repetitively scanned across porcine RPE samples in vitro providing an irradiation time of 1.6 μs per point on the central scan axis. RPE cell damage was investigated by means of the fluorescence viability assay Calcein‐AM.ResultsThe ED50 cell damage is 305 mJ/cm2 when applying 10 scans with a repetition rate of 500 Hz. The threshold decreases with the number of scans, a saturation was found at 135 mJ/cm2 with more than 500 exposures applied. The depth of focus in beam direction is 350 μm, defined by an increase of the threshold radiant exposure by 20%.ConclusionsTargeting of pigmented cells with high local resolution has been proved with a laser‐scanning device. Looking ahead selective RPE‐treatment, the adaptation of a laser‐scanning device on a slit‐lamp or into a modified retina angiograph seems to be an attractive alternative to the pulsed μs laser device. Lasers Surg. Med. 32:252–264, 2003. © 2003 Wiley‐Liss, Inc.
PLS‐ANN based classification model for oral submucous fibrosis and oral carcinogenesis
Authors: Wang Chih‐Yu , Tsai Tsuimin , Chen Hsin‐Ming , Chen Chin‐Tin , Chiang Chun‐Pin 
Published: April 2003

AbstractBackground and ObjectivesFor effective management of oral neoplasia, autofluorescence spectroscopy was conducted on patients with different characteristics of oral lesions in vivo. This study tested the possibility of using a multivariate statistical algorithm to differentiate human oral premalignant and malignant lesions from benign lesions or normal oral mucosa.Study Design/Materials and MethodsA fiber optics‐based fluorospectrometer was used to measure the autofluorescence spectra from healthy volunteers (NOM) and patients with oral lesions of submucous fibrosis (OSF), epithelial hyperkeratosis (EH), epithelial dysplasia (ED), and squamous cell carcinoma (SCC). A partial least‐squares and artificial neural network (PLS‐ANN) classification algorithm was used to characterize these oral lesions to discriminate premalignant (ED) and malignant (SCC) tissues from “benign” (NOM, OSF, and EH) tissues.ResultsThe normalized and centerized spectra of the different kinds of samples showed similar but divergent patterns. Our PLS‐ANN classification algorithm could differentiate “premalignant and malignant” tissues from “benign” tissues with a sensitivity of 81%, a specificity of 96%, and a positive predictive value of 88%.ConclusionsWe conclude that the PLS‐ANN classification algorithm based on autofluorescence spectroscopy at 330‐nm excitation is useful for in vivo diagnosis of OSF as well as oral premalignant and malignant lesions. Lasers Surg. Med. 32:318–326, 2003. © 2003 Wiley‐Liss, Inc.
Rupture of fat cells using laser‐generated ultra short stress waves
Authors: Kuwahara Kenrick , Gladstone Hayes B. , Gupta Vijay , Kireev Vassili , Neel Victor , Moy Ronald L. 
Published: April 2003

AbstractBackground and ObjectivesUltrasound‐assisted liposuction has been investigated as an aid to breakup fat for its less traumatic removal, and minimizing the post‐operative recovery period. This research focused on understanding the mechanism of fat interaction with laser‐generated ultra short stress waves with high amplitudes.Study Design/Materials and MethodsFreshly extracted human fat was secured in an Aluminum (Al) cavity. Sixteen nanoseconds duration stress waves were generated by exfoliating the bottom surface of the Al cavity by focusing 3 nanoseconds‐long YAG laser pulses over a 2 mm diameter area at 10 Hz with a maximum pulse energy of 0.95 J. The lipids released due to cell rupture were extracted and measuredResultsFour minutes of pulsing released about 0.005 g, which was over 1% of the initial weight of the tissue. In situ temperature rise of only 5°C was measured at the maximum stress wave loading duration of 5 minutes. This was evidenced by histological sections, which showed no burn artifacts.ConclusionsThis research shows that ultra short stress waves can mechanically cavitate fat in vitro without significant damage to adjacent structures, and forms the basis for future clinical work. Lasers Surg. Med. 32:279–285, 2003. © 2003 Wiley‐Liss, Inc.
Effects of a therapeutic laser on the ultrastructural morphology of repairing medial collateral ligament in a rat model
Authors: Fung Dicky T.C. , Ng Gabriel Y.F. , Leung Mason C.P. , Tay David K.C. 
Published: April 2003

AbstractBackground and ObjectivesLow energy laser therapy has been shown to enhance mechanical strength of healing medial collateral ligament (MCL) in rats. The present study investigated its effects on the ultrastructural morphology and collagen fibril profile of healing MCL in rats.Study Design/Materials and MethodsThirty‐two mature male Sprague–Dawley (SD) rats were used. Twenty‐four underwent surgical transection to their right MCLs and eight received only skin wound. Immediately after surgery, eight of the MCL transected rats were treated with a single dose of laser therapy at 63.2 J cm−2, eight were treated with a single dose of laser therapy at 31.6 J cm−2, the rest had no treatment and served as control. At 3 and 6 weeks after surgery, the MCLs were harvested and examined with electron microscopy for collagen fibril size, distribution, and alignment.ResultsSignificant differences (P < 0.001) were found in fibril diameters from the same anatomical site and time period among different groups. The mass‐averaged diameters of the laser‐treated (64.99–186.29 nm) and sham (64.74–204.34 nm) groups were larger than the control group (58.66–85.89 nm). The collagen fibrils occupied 42.55–59.78, 42.63–53.94, and 36.92–71.64% of the total cross‐sectional areas in the laser‐treated, control and sham groups, respectively. Mode obliquity was 0.53–0.84 among the three groups.ConclusionsSingle application of low energy laser therapy increases the collagen fibril size of healing MCLs in rats. Lasers Surg. Med. 32:286–293, 2003. © 2003 Wiley‐Liss, Inc.
Irradiation of dental enamel with Q‐switched λ = 355‐nm laser pulses: Surface morphology, fluoride adsorption, and adhesion to composite resin
Authors: Wheeler Cameron R. , Fried Daniel , Featherstone John D.B. , Watanabe Larry G. , Le Charles Q. 
Published: April 2003

AbstractBackground and ObjectivesLasers can be used to modify the chemical composition of dental enamel to increase the bond strength to restorative materials and to render the mineral phase more resistant to acid dissolution. Previous studies have suggested a synergistic relationship between CO2 laser irradiation and fluoride treatment on increased resistance to acid dissolution. In this study a near‐UV laser operating with λ = 355‐nm laser pulses of 3–5 nanoseconds duration was used to modify the surface morphology of dental enamel to increase the bond strength to restorative materials and increase the uptake of topical fluoride to render the surface more resistant to acid dissolution. We hypothesize that the short UV laser pulses are primarily absorbed by protein and lipid localized between the enamel prisms resulting in removal of intact mineral effectively etching the surface without thermal modification of the mineral phase. Such modification is likely to increase the permeability of the enamel surface and the subsequent absorption of fluoride. In addition, there is an increase in surface roughness without the formation of a layer of loosely adherent, thermally modified enamel that increases the bond strength to composite restorative materials.Study Design/Materials and MethodsThe surfaces of blocks of bovine enamel, 5 × 5 mm2, were uniformly irradiated by 355‐nm laser pulses and subsequently bonded to composite. The shear bond test was used to assess the bond strength of non‐irradiated blocks (negative control), acid etched blocks (positive control), and laser irradiated blocks. The resistance to acid dissolution was evaluated using controlled surface dissolution experiments on irradiated samples, irradiated samples exposed to topical fluoride, and non‐irradiated control samples with and without fluoride.ResultsThe laser surface treatments significantly increased the shear‐bond strength of enamel to composite, to a level exceeding 20 MPa which was significantly more than the non‐irradiated control samples and significantly less than the acid etch. Laser irradiation alone and topical fluoride application alone did not significantly increase the resistance to acid dissolution. The laser treatment followed by topical application of fluoride significantly increased the resistance to acid dissolution to a level of over 50% versus the control samples.ConclusionsWe present a novel method for increasing bond strength to restorative materials and enhancing fluoride delivery to enamel surfaces and shed some light on the underlying mechanisms of caries inhibition via laser treatment and topical application of fluoride. Lasers Surg. Med. 32:310–317, 2003. © 2003 Wiley‐Liss, Inc.
Photodynamic endometrial ablation: Morphological study
Authors: Wyss Pius , Caduff Rosmarie , Tadir Yona , Degen Andrea , Wagnières Georges , Schwarz Viola , Haller Urs , Fehr Mathias 
Published: April 2003

AbstractBackground and ObjectivesEndometriumablation provides an alternative treatment modality to hysterectomy for dysfunctional uterine bleeding (DUB). Its feasibility was demonstrated in animal studies. The purpose of this study was the evaluation of histological changes following photodynamic endometrial ablation in patients.Study Design/Materials and Methods5‐Aminolevulinic acid (ALA) was topically applied in three premenopausal and one postmenopausal patient 4–6 hours before laser‐illumination. ALA‐concentration: 100–400 g/ml, NaOH‐titration (pH 5.5). Volume applied, 1.5–2.0 ml; intrauterine balloon‐lightdiffuser; wavelength, 635 nm; lightdose, 160 J/cm2. Hysterectomy was performed 3–152 days after photodynamic ablation. Histological examination was carried out on endometrium sections stained with hematoxylin and eosin (H&E).ResultsNecrosis including the full thickness of the endometrium was found 3 days after photodynamic endometrial ablation. Specimens collected after 35 and 152 days did not exhibit fibrosis or adhesions. Foci of preserved endometrium were detected in all patients.ConclusionsPhotodynamic endometrial ablation is selective and does not cause endometrial fibrosis or adhesions. Lasers Surg. Med. 32:305–309, 2003. © 2003 Wiley‐Liss, Inc.