bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laryngeal aging and acoustic changes in male rat ultrasonic vocalizations
Authors: Peterson Jennifer R. , Watts Christopher R. , Morris Jesse A. , Shelton John M. , Cooper Brenton G. 
Published: July 2012

AbstractThis study examined changes in the acoustic and temporal structure of ultrasonic vocalizations as a function of age and correlated acoustic changes with vocal fold microstructure. Ultrasonic vocalizations were recorded in three age groups of male rats: aged (24–26 months), middle‐aged (17–18 months), and young (4–5 months). Acoustic and structural changes in vocal fold tissue were evident by 18 months of age. Histological analyses revealed decreased density of elastin and hyaluronic acid and increased collagen density in the middle‐aged and aged groups compared to the young rats. Laryngeal microstructure correlated with some of the ultrasonic acoustic features. These results show that male Long Evans rats experience changes in ultrasonic acoustic structure by middle age, and these changes correlate with deterioration in laryngeal microstructure. Ultrasonic vocalizations can be used as a model system for age‐related degeneration in vocal fold structure and function. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 818–828, 2013.
Neonatal repetitive needle pricking: Plasticity of the spinal nociceptive circuit and extended postoperative pain in later life
Authors: Knaepen Liesbeth , Patijn Jacob , van Kleef Maarten , Mulder Mark , Tibboel Dick , Joosten Elbert A.J. 
Published: July 2012

AbstractRepetitive exposure of neonates to noxious events is inherent to their health status monitoring in neonatal intensive care units (NICU). Altered basal nociception in the absence of an injury in later life has been demonstrated in ex‐NICU children, but the impact on pain hypersensitivity following an injury in later life is unknown. Also, underlying mechanisms for such long‐term changes are relatively unknown. The objective of this study is to investigate acute and long‐term effects of neonatal repetitive painful skin‐breaking procedures on nociception and to investigate plasticity of the nociceptive circuit. The repetitive needle prick animal model was used in which neonatal rats received four needle pricks into the left hind paw per day during the first postnatal week and control animals received nonpainful tactile stimuli. Repetitive needle pricking during the first week of life induced acute hypersensitivity to mechanical stimuli. At the age of 8 weeks, increased duration of postoperative hypersensitivity to mechanical stimuli after ipsilateral hind paw incision was shown in needle prick animals. Basal nociception from 3 to 8 weeks of age was unaffected by neonatal repetitive needle pricking. Increased calcitonin gene‐related peptide expression was observed in the ipsilateral and contralateral lumbar spinal cord but not in the hind paw of needle prick animals at the age of 8 weeks. Innervation of tactile Aβ‐fibers in the spinal cord was not affected. Ourresults indicate both acute and long‐term effects of repetitive neonatal skin breaking procedures on nociception and long‐term plasticity of spinal but not peripheral innervation of nociceptive afferents. © 2012 Wiley Periodicals, Inc. Develop Neurobiol, 2013
Dynamic skeletogenesis in fishes: Insight of exercise training on developmental plasticity
Authors: Grünbaum Thomas , Cloutier Richard , Vincent Bruno 
Published: July 2012

AbstractBackground:Through developmental and evolutionary time, organisms respond variably to their environment not only in terms of size and shape but also in terms of timing. Developmental plasticity can potentially act on various aspects of the timing of developmental events (i.e., appearance, cessation, duration, sequence). In this study, we address the developmental plasticity of median fin endoskeleton by using exercise training on newly‐hatched Arctic charr (Salvelinus alpinus).Results:Developmental progress of cartilage formation (i.e., chondrification) in all fins is less influenced than ossification by an increase of water velocity. The most responsive elements, meaning those elements with greater onset plasticity owing to a water velocity increase, differ in terms of earlyversuslate developmental events. The most responsive elements are those that chondrify and to a greater extent ossify later in the development.Conclusions:Plasticity is documented for the timing of appearance (i.e., onset) and the timing of transition from cartilage to bone (i.e., transitions of skeletal states) rather than the order of events within a sequence. Similarities of plastic response in developmental patterns could be used as a powerful criterion to strengthen the identification of phenotypic modules. Developmental Dynamics 241:1507–1524, 2012. © 2012 Wiley Periodicals, Inc.
The system N transporter SN2 doubles as a transmitter precursor furnisher and a potential regulator of NMDA receptors
Authors: Hamdani El Hassan , Gudbrandsen Marius , Bjørkmo Mona , Chaudhry Farrukh Abbas 
Published: July 2012

AbstractActivation of NMDA receptor requires two co‐agonists, glutamate and glycine. Despite its intrinsic role in brain functions molecular mechanisms involved in glutamate replenishment and identification of the origin of glycine have eluded characterization. We have performed direct measurements of glycine flux by SN2 (Slc38a5; also known as SNAT5), executed extensive electrophysiological characterization as well as implemented ratiometric analyses to show that SN2 transport resembles SN1 in mechanism but differ in functional implications. We report that rat SN2 mediates electroneutral and bidirectional transport of glutamine and glycine at perisynaptic astroglial membranes. Sophisticated coupled and uncoupled movements of H+ differentially associate with glutamine and glycine transport by SN2 and regulate pHi and the release mode of the transporter. Consequently, SN2 doubles as a transmitter precursor furnisher and a potential regulator of NMDA receptors. © 2012 Wiley Periodicals, Inc.
Histone methyltransferase enhancer of zeste homolog 2 regulates Schwann cell differentiation
Authors: Heinen André , Tzekova Nevena , Graffmann Nina , Torres Klintsy Julieta , Uhrberg Markus , Hartung Hans‐Peter , Küry Patrick 
Published: July 2012

AbstractEpigenetic control is crucial for the differentiation of a variety of cells including oligodendrocytes, the myelinating glial cells of the central nervous system. However, studies about the implication of epigenetic factors in peripheral nervous system maturation are just emerging. Here, we demonstrate for the first time the impact of a histone methyltransferase, encoded by the enhancer of zeste homolog 2 (EZH2) gene, on Schwann cell differentiation. In sciatic nerves, EZH2 expression was found in Schwann cells and to peak perinatally. Suppression of EZH2 expression in cultured primary rat Schwann cells reduced the length of cell processes. These morphological changes were accompanied by widespread alterations in the gene expression pattern, including downregulation of myelin genes and induction of p57kip2, which we have recently identified as an intrinsic inhibitory regulator of Schwann cell maturation. In addition, we show that EZH2 suppression in dorsal root ganglion cocultures interferes with in vitro myelination. Chromatin immunoprecipitation analysis revealed binding of EZH2 at the p57kip2 promoter and reduction of histone H3K27 trimethylation upon gene suppression. EZH2 suppression‐dependent effects on morphology and myelin genes could be reversed by concomitant suppression of p57kip2, indicating that p57kip2 is a downstream effector of EZH2. Furthermore, we describe Hes5 as transcriptional repressor of myelin genes in Schwann cells, which was induced upon EZH2 suppression and downregulated in p57kip2‐suppressed Schwann cells. Therefore, we have identified a molecular link between histone methylation and control of Schwann cell differentiation and demonstrate that this epigenetic mechanism is crucial for glial differentiation to proceed. © 2012 Wiley Periodicals, Inc.
Persistent astroglial swelling accompanies rapid reversible dendritic injury during stroke‐induced spreading depolarizations
Authors: Risher W. Christopher , Croom Deborah , Kirov Sergei A. 
Published: July 2012

AbstractSpreading depolarizations are a key event in the pathophysiology of stroke, resulting in rapid dendritic beading, which represents acute damage to synaptic circuitry. The impact of spreading depolarizations on the real‐time injury of astrocytes during ischemia is less clear. We used simultaneousin vivo2‐photon imaging and electrophysiological recordings in adult mouse somatosensory cortex to examine spreading depolarization‐induced astroglial structural changes concurrently with signs of neuronal injury in the early periods of focal and global ischemia. Astrocytes in the metabolically compromised ischemic penumbra‐like area showed a long lasting swelling response to spontaneous spreading depolarizations despite rapid dendritic recovery in a photothrombotic occlusion model of focal stroke. Astroglial swelling was often facilitated by recurrent depolarizations and the magnitude of swelling strongly correlated with the total duration of depolarization. In contrast, spreading depolarization‐induced astroglial swelling was transient in normoxic healthy tissue. In a model of transient global ischemia, the occurrence of a single spreading depolarization elicited by a bilateral common carotid artery occlusion coincided with astroglial swelling alongside dendritic beading. With immediate reperfusion, dendritic beading subsides. Astroglial swelling was either transient during short ischemic periods distinguished by a short‐lasting spreading depolarization, or persistent during severe ischemia characterized by a long‐lasting depolarization with the ultraslow negative voltage component. We propose that persistent astroglial swelling is initiated and exacerbated during spreading depolarization in brain tissue with moderate to severe energy deficits, disrupting astroglial maintenance of normal homeostatic function thus contributing to the negative outcome of ischemic stroke as astrocytes fail to provide neuronal support. © 2012 Wiley Periodicals, Inc.
Development and parameterization of an infiltration model accounting for water depth and rainfall intensity
Authors: Langhans Christoph , Govers Gerard , Diels Jan 
Published: July 2012

AbstractExperimental work has clearly shown that the effective hydraulic conductivity (Ke) or effective infiltration rate (fe) on the local scale of a plot cannot be considered as constant but are dependent on water depth and rainfall intensity because non‐random microtopography‐related variations in hydraulic conductivity occur. Rainfall–runoff models generally do not account for this: models assume that excess water is uniformly spread over the soil surface and within‐plot variations are neglected. In the present study, we propose a model that is based on the concepts of microtopography‐related water depth‐dependent infiltration and partial contributing area. Expressions for the plot scale Ke and fe were developed that depend on rainfall intensity and runon from upslope (and thus on water depth).To calibrate and validate the model, steady state infiltration experiments were conducted on maize fields on silt loam soils in Belgium, with different stages and combinations of rainfall intensity and inflow, simulating rainfall and runon. Water depth–discharge and depth–inundation relationships were established and used to estimate the effect of inundation on Ke. Although inflow‐only experiments were found to be unsuitable for calibration, the model was successfully calibrated and validated with the rainfall simulation data and combined rainfall–runon data (R²: 0.43–0.91).Calibrated and validated with steady state infiltration experiments, the model was combined with the Green–Ampt infiltration equation and can be applied within a two‐dimensional distributed rainfall–runoff model. The effect of water depth–dependency and rainfall intensity on infiltration was illustrated for a hillslope. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of permeability–porosity functions on simulated morphological evolution of a chemical dissolution front
Authors: Lai Keng‐Hsin , Chen Jui‐Sheng , Liu Chen‐Wuing , Yang Suh‐Yuh 
Published: July 2012

AbstractThe dissolution‐induced finger pattern in geological medium plays an important role in both geological processes and engineering practices. Numerical models have been developed to investigate the evolution of the chemical dissolution front within a fluid‐saturated porous medium. In these models, several permeability–porosity relationships have been proposed and incorporated into the numerical model for describing simultaneous changes in permeability and porosity induced by mineral dissolution, but limited experimental data are available to justify one form superior to the other. This study investigates the effects of the permeability–porosity relationships on the morphological evolution of the chemical dissolution front. Three porosity–permeability relationships, namely, modified Fair–Hatch, Kozeny–Carman and Verma–Pruess (VP) models are incorporated into the numerical model. A series of numerical simulations are performed to evaluate the morphological evolution of reaction front, and the corresponding behaviour diagrams are constructed. Results shows that the morphological development are similar each other for modified Fair–Fatch and Kozeny–Carman model. The VP model yields a relative low primary and secondary critical upstream pressure gradient value owing to the flow‐focusing effect enhanced by the stronger dependence of permeability on porosity. A comparison of behaviour diagrams of front morphology among three relationships show that the double‐fingering front occurs under condition of lower upstream pressure gradient and smaller non‐uniformity spacing for VP model. Our simulations demonstrate that the choice of the permeability–porosity function plays important roles on the evolution patterns of dissolution front. Therefore, an adequate description of the permeability–porosity relationship may lead to a more realistic simulation of field problems. Copyright © 2012 John Wiley & Sons, Ltd.
Estimating groundwater discharge to rivers from river chemistry surveys
Authors: Cook Peter G. 
Published: July 2012

AbstractEnvironmental tracer methods have been used to quantify groundwater discharge to rivers for the past few decades. A number of different tracers have been used in these studies, including individual ion concentrations, electrical conductivity, stable isotopes 2H and 18O, and the dissolved gases helium, chlorofluorocarbons and radon. This paper discusses the assumptions of the method, as well as its resolution and accuracy. The method will be most accurate when the tracer concentration in groundwater is very distinct from that in the river. On the basis of typical parameters, groundwater inflow rates as low as 5 mm/day can usually be estimated with electrical conductivity and ion tracers. A lower limit of resolution of approximately 2 mm/day is usually possible with radon, principally because the ratio of the river concentration to the groundwater concentration will be higher. However, hyporheic exchange can also contribute radon to the river. Where this process is significant, it is more difficult to estimate groundwater inflow from radon activities in the river, thus reducing the accuracy of the method. For CFCs, the lower limit of resolution is approximately 30 mm/day. Helium has not been widely used but can potentially be very accurate if the groundwater is old.The method assumes steady‐state conditions and so can only be applied when river flows are stable. Sampling resolution is also particularly important for dissolved gases, and uncertainty in where groundwater inflow occurs between sampling points can cause large uncertainty in inflow rates if the distance between sample locations is large. Poor mixing of solutes within the river can limit the method if the river is wide and shallow. When correctly applied, however, the environmental tracer method is able to provide robust estimates of groundwater discharge at a scale and accuracy that is not possible with most other methods. Copyright © 2012 John Wiley & Sons, Ltd.
Multifractal behaviour of long‐term karstic discharge fluctuations
Authors: Labat D. , Hoang C. T. , Masbou J. , Mangin A. , Tchiguirinskaia I. , Lovejoy S. , Schertzer D. 
Published: July 2012

AbstractKarstic watersheds are highly complex hydrogeological systems that are characterized by a multiscale behaviour corresponding to the different pathways of water in these systems. The main issue of karstic spring discharge fluctuations consists in the presence and the identification of characteristic time scales in the discharge time series.To identify and characterize these dynamics, we acquired, for many years at the outlet of two karstic watersheds in South of France, discharge data at 3‐mn, 30‐mn and daily sampling rate. These hydrological records constitute to our knowledge the longest uninterrupted discharge time series available at these sampling rates. The analysis of the hydrological records at different levels of detail leads to a natural scale analysis of these time series in a multifractal framework.From a universal class of multifractal models based on cascade multiplicative processes, the time series first highlights two cut‐off scales around 1 and 16 h that correspond to distinct responses of the aquifer drainage system. Then we provide estimates of the multifractal parameters α and C1 and the moment of divergence qD corresponding to the behaviour of karstic systems. These results constitute the first estimates of the multifractal characteristics of karstic spingflows based on 10 years of high‐resolution discharge time series and should lead to several improvements in rainfall‐karstic springflow simulation models. Copyright © 2012 John Wiley & Sons, Ltd.
Molecular mechanism of a novel CD59‐binding peptide sp22 induced tumor cells apoptosis
Authors: Li Bing , Gao Mei‐Hua , Chu Xian‐Ming 
Published: July 2012

AbstractSome short peptides discovered by phage display are found to be able to inhibit cancer growth and induce cancer cell apoptosis. In this study, a novel cancer‐targeting short peptide which was composed of 22 amino acids (ACHWPWCHGWHSACDLPMHPMC, abbreviated as sp22) and specifically bound to human CD59 was screened from a M13 phage display library so as to counteract tumor immune escape activity. The mechanism of exogenous sp22 peptide in inducing apoptosis of MCF‐7 cells was investigated. The results suggested that sp22 could lower CD59 expression level, downregulate Bcl‐2 expression, activate Fas and caspase‐3, and finally increase apoptotic cell numbers of MCF‐7 cells. However, sp22 had no obvious influence on normal human embryonic lung cells. In addition, the effects of endogenous sp22 gene on CD59 expression and NKM cell apoptosis were explored using the recombinant plasmid sp22‐PIRES. It showed that sp22 gene was efficiently expressed in transfected NKM cells. Compared with normal NKM cells, NKM cells transfected with sp22 displayed reduced mRNA and protein expression levels of CD59, increased sensitivity to complement‐mediated cytolysis, decreased cell survival ratio, changes of the expression of apoptosis associated proteins, increased number of apoptotic cells and the appearance of apoptotic morphology. The results suggested that sp22 protein could bind to CD59 and inhibit the expression of CD59. The cytolytic activity of complement on tumor cells strengthened and apoptosis signal was stepwise transferred which might be a potential way to kill tumor cells. J. Cell. Biochem. 113: 3810–3822, 2012. © 2012 Wiley Periodicals, Inc.
SAP30L (Sin3A‐associated protein 30‐like) is involved in regulation of cardiac development and hematopoiesis in zebrafish embryos
Authors: Teittinen Kaisa J. , Grönroos Toni , Parikka Mataleena , Junttila Sini , Uusimäki Annemari , Laiho Asta , Korkeamäki Hanna , Kurppa Kalle , Turpeinen Hannu , Pesu Marko , Gyenesei Attila , Rämet Mika , Lohi Olli 
Published: July 2012

AbstractThe Sin3A‐associated proteins SAP30 and SAP30L share 70% sequence identity and are part of the multiprotein Sin3A corepressor complex. They participate in gene repression events by linking members of the complex and stabilizing interactions among the protein members as well as between proteins and DNA. While most organisms have both SAP30 and SAP30L, the zebrafish is exceptional because it only has SAP30L. Here we demonstrate that SAP30L is expressed ubiquitously in embryonic and adult zebrafish tissues. Knockdown of SAP30L using morpholino‐mediated technology resulted in a morphant phenotype manifesting as cardiac insufficiency and defective hemoglobinization of red blood cells. A microarray analysis of gene expression in SAP30L morphant embryos revealed changes in the expression of genes involved in regulation of transcription, TGF‐beta signaling, Wnt‐family transcription factors, and nuclear genes encoding mitochondrial proteins. The expression of the heart‐specific nkx2.5 gene was markedly down‐regulated in SAP30L morphants, and the cardiac phenotype could be partially rescued by nkx2.5 mRNA. In addition, changes were detected in the expression of genes known to be important in hemoglobin synthesis and erythropoiesis. Our results demonstrate that SAP30L regulates several transcriptional pathways in zebrafish embryos and is involved in the development of cardiac and hematopoietic systems. J. Cell. Biochem. 113: 3843–3852, 2012. © 2012 Wiley Periodicals, Inc.
Mathematical modeling of biofilm‐covered granular activated carbon: a review
Authors: Shen Liang , Lu Yinghua , Liu Yu 
Published: July 2012

AbstractThis paper reviewed the mass‐transfer of the target substance in the biofilm‐covered granular activated carbon (BGAC) system. Representative hypotheses and equations related to developing the mathematical models for a BGAC reactor were discussed in terms of granular activated carbon (GAC) phase, biofilm phase and bulk solution, respectively. It should be noted that discrete phenomena such as biofilm detachment due to erosion or sloughing were not considered for the modeling system. Recent advances on this topic were thoroughly updated, as well as those models proposed in past decades. It appears that a general BGAC model has not been available so far, and further efforts are required to obtain models more approaching of the physical mechanism of this complicate system. Copyright © 2012 Society of Chemical Industry