bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drosophila melanogaster as a model system for human brain cancers
Authors: Read Renee D. 
Published: May 2011

AbstractGlioblastomas (GBM), the most common primary brain tumors, infiltrate the brain, grow rapidly, and are refractory to current therapies. Signature genetic lesions in glioblastomas include mutation of the epidermal growth factor receptor tyrosine kinase (EGFR) receptor tyrosine kinase and activating mutations in components of the PI‐3 kinase (PI3K) pathway. Despite years of study, how these pathways specifically regulate glial pathogenesis is unclear. To address the genetic and cellular origins of this disease, a novel Drosophila GBM model has been developed in which glial progenitor cells give rise to proliferative and invasive neoplastic cells that create transplantable tumors in response to constitutive co‐activation of the EGFR‐Ras and PI3K pathways. Standing with a rich literature demonstrating the direct relevance of Drosophila to studies on human cancer, neurological disease, and neurodevelopment, this model represents a robust cell‐type specific Drosophila neurological disease model in which malignant cells are created by mutations in genetic pathways thought to be driving forces in a homologous human disease. Using lineage analysis and cell‐type specific markers, neoplastic glial cells were found to originate from committed glial progenitor cells, rather than from multipotent neuroblasts. Genetic analyses demonstrated that EGFR‐Ras and PI3K induce fly glial neoplasia through activation of a combinatorial genetic network composed, in part, of other genetic pathways also commonly mutated in human glioblastomas. In the future, large‐scale forward genetic screens with this model may reveal new insights into the origins and treatments of human glioblastoma. © 2011 Wiley‐Liss, Inc.
Deletion of oligodendrocyte Cx32 and astrocyte Cx43 causes white matter vacuolation, astrocyte loss and early mortality
Authors: Magnotti Laura M. , Goodenough Daniel A. , Paul David L. 
Published: May 2011

AbstractCNS glia exhibit a variety of gap junctional interactions: between neighboring astrocytes, between neighboring oligodendrocytes, between astrocytes and oligodendrocytes, and as ‘reflexive’ structures between layers of myelin in oligodendrocytes. Together, these junctions are thought to form a network facilitating absorption and removal of extracellular K+ released during neuronal activity. In mice, loss of the two major oligodendrocyte connexins causes severe demyelination and early mortality, while loss of the two major astrocyte connexins causes mild dysmyelination and sensorimotor impairment, suggesting that reflexive and/or oligo–oligo coupling may be more important for the maintenance of myelin than other forms. To further explore the functional relationships between glial connexins, we generated double knockout mice lacking one oligodendrocyte and one astrocyte connexin. Cx32‐Cx43 dKO animals develop white matter vacuolation without obvious ultrastructural abnormalities in myelin. Progressive loss of astrocytes but not oligodendrocytes or microglia accompanies sensorimotor impairment, seizure activity and early mortality at around 16 weeks of age. Our data reveal an unexpected role for connexins in the survival of white matter astrocytes, requiring the expression of particular isoforms in both oligodendrocytes and astrocytes. © 2011 Wiley‐Liss, Inc.
Differential and cooperative actions of Olig1 and Olig2 transcription factors on immature proliferating cells after contusive spinal cord injury
Authors: Kim Hyuk M. , Hwang Dong H. , Choi Jun Young , Park Chang Hwan , Suh‐Kim Haeyoung , Kim Seung U. , Kim Byung G. 
Published: May 2011

AbstractSpontaneous remyelination after spinal cord injury (SCI) is limited probably due to inadequate signaling to generate sufficient OLs from progenitor cells. The present study tested a hypothesis that introduction of olig genes, critical regulators of OL development, into immature proliferating cells could increase oligodendrogenesis after contusive SCI in adult rats. Recombinant retroviruses encoding Olig1 and Olig2 transcription factors, separately or in combination, with green fluorescent protein (GFP) were injected into the injured spinal cord. Unexpectedly, introduction of Olig2‐GFP retroviruses led to a marked hyperplasia of GFP+ cells at 1 week, and soft agar colony forming assay of isolated GFP+ cells confirmed Olig2‐induced tumorous transformation. In contrast, Olig1 did not alter the number of GFP+ cells. Simultaneous expression of Olig1 and Olig2 (Olig1/2) led to a marked increase in the number of GFP+ cells without tumor formation. The proportion of GFP+ cells with OL progenitor markers was increased by Olig1/2. Moreover, Olig1/2 robustly increased the proportion of mature OLs and expression of myelin related proteins, while Olig1 alone exhibited only modest effects. Olig1/2 upregulated Sox10, which drives terminal OL differentiation, implicating Sox 10 as a mediator of Olig1/2 effects on the maturation. Finally, injection of Olig1/2 retroviruses significantly improved a quality of hindpaws locomotion and increased the total number of OLs after SCI. Activation of both Olig1 and Olig2 may be beneficial by both increasing the progenitor cell proliferation and enhancing OL differentiation in the injured spinal cord. © 2011 Wiley‐Liss, Inc.
‘Keeping your brain active’: the activities of people aged 50–65 years
Authors: Bowes Alison , McCabe Louise , Wilson Mike , Craig David 
Published: May 2011

ObjectiveThe paper aims to construct a baseline of knowledge about current activities, attitudes and motivations of a sample of people aged 50–65 years in relation to ‘keeping one's brain active’, with a particular focus on activities suggested in the literature and in popular parlance to have positive effects.MethodsAn online survey of people aged 50–65 years concerning their activities and motivations in relation to ‘keeping one's brain active’ was conducted with a sample of people employed in Scotland and in two online discussion forums. The survey ascertained respondents' background demographic data, data on health and lifestyle factors, activities they engaged in and reasons for engagement, including any concerns about dementia and experience of dementia. The achieved sample of 402 responses was representative of the general population on most counts, although the sample included more better‐educated people and more smokers.ResultsDementia prevention was a motivating factor for 21% of the respondents. More women and more of those living alone reported this motivation. It was linked with experience of dementia and future fears of developing the condition. New ‘brain‐training’ technologies were used by younger people in higher socio‐economic groups, and dementia prevention was cited as a motivation.ConclusionThe findings indicate that dementia prevention motivates activities perceived to keep the brain active, despite there being a virtual absence of scientific evidence showing that the desired effects will follow. Given the existence of evidence suggesting that other activities, particularly physical exercise, may be more important and the possibility that stress itself may promote the development of dementia, further research is urgently needed. Copyright © 2011 John Wiley & Sons, Ltd.
Differential expression of molecular markers of synaptic plasticity in the hippocampus, prefrontal cortex, and amygdala in response to spatial learning, predator exposure, and stress‐induced amnesia
Authors: Zoladz Phillip R. , Park Collin R. , Halonen Joshua D. , Salim Samina , Alzoubi Karem H. , Srivareerat Marisa , Fleshner Monika , Alkadhi Karim A. , Diamond David M. 
Published: May 2011

AbstractWe have studied the effects of spatial learning and predator stress‐induced amnesia on the expression of calcium/calmodulin‐dependent protein kinase II (CaMKII), brain‐derived neurotrophic factor (BDNF) and calcineurin in the hippocampus, basolateral amygdala (BLA), and medial prefrontal cortex (mPFC). Adult male rats were given a single training session in the radial‐arm water maze (RAWM) composed of 12 trials followed by a 30‐min delay period, during which rats were either returned to their home cages or given inescapable exposure to a cat. Immediately following the 30‐min delay period, the rats were given a single test trial in the RAWM to assess their memory for the hidden platform location. Under control (no stress) conditions, rats exhibited intact spatial memory and an increase in phosphorylated CaMKII (p‐CaMKII), total CaMKII, and BDNF in dorsal CA1. Under stress conditions, rats exhibited impaired spatial memory and a suppression of all measured markers of molecular plasticity in dorsal CA1. The molecular profiles observed in the BLA, mPFC, and ventral CA1 were markedly different from those observed in dorsal CA1. Stress exposure increased p‐CaMKII in the BLA, decreased p‐CaMKII in the mPFC, and had no effect on any of the markers of molecular plasticity in ventral CA1. These findings provide novel observations regarding rapidly induced changes in the expression of molecular plasticity in response to spatial learning, predator exposure, and stress‐induced amnesia in brainregions involved in different aspects of memory processing. © 2011 Wiley Periodicals, Inc.
Long‐wave radiation and heat flux estimates within a small tributary in Catamaran Brook (New Brunswick, Canada)
Authors: Benyahya Loubna , Caissie Daniel , Satish Mysore G. , El‐Jabi Nassir 
Published: May 2011

AbstractRiver water temperature is an important water quality parameter that also influences most aquatic life. Physical processes influencing water temperature in rivers are highly complex. This is especially true for the estimation of river heat exchange processes that are highly dependent on good estimates of radiation fluxes. Furthermore, very few studies were found within the stream temperature dynamic literature where the different radiation components have been measured and compared at the stream level (at microclimate conditions). Therefore, this study presents results on hydrometeorological conditions for a small tributary within Catamaran Brook (part of the Miramichi River system, New Brunswick, Canada) with the following specific objectives: (1) to compare between stream microclimate and remote meteorological conditions, (2) to compare measured long‐wave radiation data with those calculated from an analytical model, and (3), to calculate the corresponding river heat fluxes. The most salient findings of this study are (1) solar radiation and wind speed are parameters that are highly site specific within the river environment and play an important role in the estimation of river heat fluxes; (2) the incoming, outgoing, and net long‐wave radiation within the stream environment (under the forest canopy) can be effectively calculated using empirical formula; (3) at the study site more than 80% of the incoming long‐wave radiation was coming from the forest; (4) total energy gains were dominated by solar radiation flux (for all the study periods) followed by the net long‐wave radiation (during some periods) whereas energy losses were coming from both the net long‐wave radiation and evaporation. Conductive heat fluxes have a minor contribution from the overall heat budget (<3·5%); (5) the reflected short‐wave radiation at the water surface was calculated on average as 3·2%, which is consistent with literature values. Results of this study contribute towards a better understanding of river heat fluxes and water temperature models as well as for more effective aquatic resources and fisheries management. Copyright © 2011 John Wiley & Sons, Ltd.
Using multiple artificial DNA tracers in hydrology
Authors: Foppen Jan Willem , Orup Caesar , Adell Renaud , Poulalion Vincent , Uhlenbrook Stefan 
Published: May 2011

AbstractTracer testing is an efficient and versatile method to characterize hydrological processes both in surface waters and in the subsurface, and with synthetic DNA (deoxyribonucleic acid) experiments can be performed with a theoretically unlimited number of tracers. We explored the use of six synthetic DNA tracers in injection experiments in the Strijbeekse Beek and the Merkske, two small brooks in the Netherlands. We wanted to test the applicability of synthetic DNA markers in combination with the quantitative polymerase chain reaction (qPCR), an analytical technique used to determine DNA concentrations. The most important results from the two experiments were that DNA concentrations during breakthrough ranged from 0·1 to 100 fM (femtomolar = 10−15 mol/l), and that DNA mass transport in the stream was not retarded compared to transport of an injected NaCl mass. However, DNA mass was substantially reduced, most likely as a result of adsorption, attachment, decay and/or biological uptake processes in the stream itself. Although more insight in the various mass balance components of DNA mass in the stream is required, we concluded that the use of synthetic DNA markers in combination with qPCR has potential for spatially distributed surface water‐groundwater interaction tracer experiments. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation of multiple surface soil moisture for Korean regional flux monitoring network sites: Advanced Microwave Scanning Radiometer E, land surface model, and ground measurements
Authors: Choi Minha 
Published: May 2011

AbstractIn the past few decades, there have been great developments in remotely sensed soil moisture, with validation efforts using land surface models (LSMs) and ground‐based measurements, because soil moisture information is essential to understanding complex land surface–atmosphere interactions. However, the validation of remotely sensed soil moisture has been very limited because of the scarcity of the ground measurements in Korea. This study validated Advanced Microwave Scanning Radiometer E (AMSR‐E) soil moisture data with the Common Land Model (CLM), one of the most widely used LSMs, and ground‐based measurements at two Korean regional flux monitoring network sites. There was reasonable agreement regarding the different soil moisture products for monitoring temporal trends except National Snow and Ice Data Centre (NSIDC) AMSR‐E soil moisture, albeit there were essential comparison limitations by different spatial scales and soil depths. The AMSR‐E soil moisture data published by the National Aeronautics and Space Administration and Vrije Universiteit Amsterdam (VUA) showed potential to replicate temporal variability patterns (root‐mean‐square errors = 0·10–0·14 m3 m−3 and wet BIAS = 0·09 − 0·04 m3 m−3) with the CLM and ground‐based measurements. However, the NSIDC AMSR‐E soil moisture was problematic because of the extremely low temporal variability and the VUA AMSR‐E soil moisture was relatively inaccurate in Gwangneung site characterized by complex geophysical conditions. Additional evaluations should be required to facilitate the use of recent and forthcoming remotely sensed soil moisture data from Soil Moisture and Ocean Salinity and Soil Moisture Active and Passive missions at representative future validation sites. Copyright © 2011 John Wiley & Sons, Ltd.
The maize evapotranspiration in the background of climate change: a case study in arid area
Authors: Liu Buchun , Mei Xurong , Lv Guohua , Yang Youlu , Bai Meilan , Wu Yongfeng , Song Jiqing , Bai Wenbo 
Published: May 2011

AbstractAgricultural water resource security is faced with serious challenges in the background of climate change. It is important to study the trend of evapotranspiration (ET) for future planning and management of agricultural water resources. On the basis of the 1961–2004 weather data, the trends of six meteorological variables were analysed. Also, the potential ET (PET) of maize (Zea mays L.) in the growing season was simulated by the World Food Study (WOFOST) model. Results indicated that the maximum and minimum temperatures increased significantly, and the daily minimum temperature increased much faster than the daily maximum temperature, which resulted in the decrease in the diurnal temperature range (DTR). The precipitation showed an increasing trend, whereas the sunshine duration and wind speed (WS) showed a declining trend. No remarkable linear tendency was found on vapour pressure. As a result, the simulated maize PET showed a significant decrease by 1 mm year−1, and it was mainly as a result of decreased sunshine duration and WS. This may provide valuable information on the aspect of water resource management in the Yellow River basin. Copyright © 2011 John Wiley & Sons, Ltd.
Effect of forest on annual water yield in the mountains of an arid inland river basin: a case study in the Pailugou catchment on northwestern China's Qilian Mountains
Authors: He Zhibin , Zhao Wenzhi , Liu Hu , Tang Zhenxing 
Published: May 2011

AbstractThe effect of forests on annual water yield is an unresolved central issue in forest hydrology despite years of study. There has been a particular shortage of research in the mountains of arid inland river basins. In the present study, we examined the effects of forests on hydrology using data on precipitation, evaporation, canopy interception, transpiration, and runoff from 1994 to 2008 for the Pailugou catchment of northwestern China's Qilian Mountains. We modelled the water balance to assess the contribution of different vegetation types to annual water yield. In our study area, Picea crassifolia forest covered 38·5% of the catchment area, but contributed little to annual water yield. For an annual average precipitation of 407·1 mm (from 2003 to 2008) at an elevation of 2700 m, the runoff depth from the forest was 11·6 mm, accounting for only 3·5% of total annual water yield of the catchment. For an annual average precipitation of 374·1 mm (from 1994 to 2002), the runoff depth from the forest was − 14·3 mm (i.e. 5·9% of total annual water yield of the catchment was consumed to sustain tree growth). This has significant implications, because forests are increasingly being planted in the Qilian Mountains, and this may decrease the downstream water supply. Thus, the relationship between the forest and water yield must be better understood to permit the establishment of an appropriate regional level of forest cover. Copyright © 2011 John Wiley & Sons, Ltd.
Effect of fluorescent whitening agent on the transcription of cell damage‐related genes in zebrafish embryos
Authors: Jung Hyun , Seok Seung‐Hyeok , Han Ju‐Hee , Abdelkader Tamer Said , Kim Tae‐Hyoun , Chang Seo‐Na , Ko Ae‐Sun , Choi Seung‐Kyu , Lee Cho‐Rong , Seo Ji‐Eun , Byun Soo‐Hyun , Kim Jung‐A , Park Jae‐Hak 
Published: May 2011

ABSTRACT7‐Diethylamino‐4‐methylcoumarin (DEMC) is a fluorescent whitening agent (FWAs). There have been some studies on DEMC's protective effects against biological activity but there are few papers about the in vivo toxicity of DEMC. In this study, we used wild‐type zebrafish embryos 3 days post fertilization (dpf). Test solutions with DEMC concentrations were negative control (without vehicle), 0 (with vehicle, 0.01% v/v ethanol), 0.25, 0.5, 0.75, 1.0, 1.25, 1.5 and 2 ppm. Embryos and larvae were counted for survival rate and hatching rate. Heart rates were also counted at 2.5 and 3.0 dpf. At 3.0 dpf, quantitative RT‐PCR was performed with some samples (0, 0.25, 0.75 and 1.25 ppm) to determine the toxic effect to DEMC by detecting the expression levels of toxic‐responsive genes. We used 11 genes, which included oxidative stress‐related genes [sod(Mn), sod(Cu,Zn) and hsp70], mitochondrial metabolism‐related genes (coxI, pyc, cyt and cyclinG1) and apoptosis‐related genes (c‐jun, bcl2, bax and p53). High‐concentration DEMC‐treated groups showed significant different survival rate, hatching rate and heart rate compared with low‐concentration DEMC‐treated groups. The LC50 of this chemical, 0.959 ppm, was calculated. We also confirmed that some genes in the DEMC exposure groups showed significantly up‐regulations in expression levels compared with control groups. We concluded that the fluorescence agent, DEMC, has possible developmental toxicities and alteration effect of gene expression, which are related to oxidative stress, mitochondrial metabolism and apoptosis in zebrafish embryos. Copyright © 2011 John Wiley & Sons, Ltd.
Protective effect of apocynin on antimycin A‐induced cell damage in osteoblastic MC3T3‐E1 cells
Authors: Choi Eun Mi , Lee Young Soon 
Published: May 2011

ABSTRACTApocynin is a naturally occurring methoxy‐substituted catechol, experimentally used as an inhibitor of NADPH‐oxidase. In the present study, we investigated the protective effects of apocynin on antimycin A (AMA)‐induced toxicicy in osteoblastic MC3T3‐E1 cells. Exposure of MC3T3‐E1 cells to AMA caused significant cell viability loss, as well as mitochondrial membrane potential (MMP) dissipation, complex IV inactivation, ATP loss, intracellular calcium ([Ca2+]i) elevation and oxidative stress. Pretreatment with apocynin prior to AMA exposure significantly reduced AMA‐induced cell damage by preventing MMP dissipation, complex IV inactivation, ATP loss, [Ca2+]i elevation and oxidative stress. These results suggest that apocynin has a protective effect against AMA‐induced cell damage by its antioxidant effects and the attenuation of mitochondrial dysfunction. Apocynin also induced the activation of PI3K (phosphoinositide 3‐kinase), Akt (protein kinase B) and CREB (cAMP‐response element‐binding protein) inhibited by AMA. All these data indicate that apocynin may reduce or prevent osteoblasts degeneration in osteoporosis or other degenerative disorders. Copyright © 2011 John Wiley & Sons, Ltd.
Biomimetic deposition of calcium phosphate minerals on the surface of partially demineralized dentine modified with phosphorylated chitosan
Authors: Xu Zhang , Neoh Koon Gee , Lin Chew Chong , Kishen Anil 
Published: May 2011

AbstractThe aim of this study is to remineralize partially demineralized dentine sections using phosphorylated chitosan (P‐chi) based on mimicking the nucleating role of the phosphorylated noncollagenous proteins in the biomineralization of dentine. The surface of partially demineralized dentine sections, mainly composed of type I collagen, were modified by covalent immobilization of P‐chi on the collagen surface. The dentine sections were subsequently put into remineralizing solution for remineralization, and then the remineralizing effect was investigated. The remineralization effect of this methodology was compared with that of fluoride. Moreover, the influence of surface properties of samples on remineralizing effect was investigated. The experimental results indicated that the effect of fluoride on remineralization of dentine was limited when residual crystals were lacking on the surface of partially demineralized dentine, whereas the covalent immobilization of P‐chi can significantly induce deposition of calcium phosphate minerals on the surface of the partially demineralized dentine. This biomimetic methodology resulted in favorable surface properties (i.e., highly negative charge and low interfacial free energy between substrate and remineralizing medium) for crystal nucleation. Thus, P‐chi can facilitate surface remineralization of dentine and thereby could find application in the minimally invasive management of dentine caries and dentine hypersensitivity. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.