bluuebunny/crossref_metadata_2025 huggingface dataset:
Loss at chromosome arm 16q in retinoblastoma: Confirmation of the association with diffuse vitreous seeding and refinement of the recurrently deleted region
Authors: Gustmann Sebastian , Klein‐Hitpass Ludger , Stephan Harald , Weber Susanne , Bornfeld Norbert , Kaulisch Marc , Lohmann Dietmar R. , Dünker Nicole
Published: February 2011

In addition to mutations in both alleles of the retinoblastoma gene (RB1) alleles, retinoblastomas frequently show additional alterations including loss of chromosome arm 16q. In a previous study, the presence of 16q alterations was found to be associated with diffuse vitreous seeding of this tumor. This growth pattern is clinically important as it determines therapeutic decisions. The present study was designed to test this association and to narrow down the list of candidate genes in the minimal region of genomic loss on chromosome arm 16q. Our data confirm the association of 16q loss and diffuse vitreous seeding and define a minimal region of genomic loss of 6.6 Mb on 16q containing 86 known genes. As retinoblastoma is an embryonic tumor, we assumed that any gene relevant for its progression is likely to show regulated expression during retinogenesis. Microarray expression analysis of RNA from a continuous developmental series of murine retinas identified murine orthologs with regulated expression and these data helped to narrow the number of candidate genes in minimal region to 35. Analysis of gene expression in retinoblastomas with and without the loss of heterozygosity (LOH) on chromosome 16q further reduced this number to 26 candidate genes. One of these genes is cadherin 13 (CDH13) and notably, downregulation of CHD13 has previously been associated with poorer prognosis in various other cancers. © 2011 Wiley‐Liss, Inc.
The effects of surface weathering on the geochemical analysis of archaeological lithic samples using non‐destructive polarized energy dispersive XRF
Authors: Gauthier Gilles , Burke Adrian L.
Published: February 2011

The purpose of this paper is to show the effects of lithic artifact surface weathering on whole rock non‐destructive polarized energy dispersive X‐ray fluorescence (P‐ED‐XRF) major and trace element determinations. Chemical results for a weathered and subsequently mechanically ground subset of New Hampshire Ossipee archaeological flakes, cataloged as hornfels, show that both groups of elements are variably affected by weathering. A graphic approach is developed and proposed to highlight the role and importance of immobile elements. A case is made and an analytical method is proposed for the routine use of P‐ED‐XRF spectrometers to determine the chemical makeup of lithic artifacts and therefore provide a data set compatible with existing geochemical databases and literature. The use of specific variation diagrams is adopted to portray the weathering trend. Internationally approved geochemical rock type diagrams are used to correct the rock type previously assigned to Ossipee artifacts and in turn narrow down potential quarry sources. © 2011 Wiley Periodicals, Inc.
Strontium isotopic evidence for prehistoric transport of gray‐ware ceramic materials in the eastern Grand Canyon region, USA
Authors: Carter Sidney W. , Wiegand Bettina , Mahood Gail A. , Dudas Francis O. , Wooden Joseph L. , Sullivan Alan P. , Bowring Samuel A.
Published: February 2011

Through a novel application of strontium (Sr) isotopic analysis, we evaluate geological sources for prehistoric ceramics in the eastern Grand Canyon region of northern Arizona, focusing on two gray‐ware traditions in the Upper Basin of the Coconino Plateau. Building on a conceptual framework for the general potential of Sr isotopes in the analysis of geological materials, we suggest that the eastern Grand Canyon is specifically well suited archaeologically and geologically for: (1) exploring the utility of Sr isotopes for ceramic provenance research and (2) testing long‐standing hypotheses that gray‐ware ceramics were invariably made with local materials. Sr isotopic compositions indicate that the ceramic samples represent at least three different geological sources, and that different raw materials were used in the manufacture of the two gray‐ware traditions found in the Upper Basin. One of the gray‐ware traditions is not compositionally consistent with local geology, indicating that either the ceramics or the raw materials were transported at least 20 km to the Upper Basin. © 2011 Wiley Periodicals, Inc.
Gene‐environment interplay in common complex diseases: forging an integrative model—recommendations from an NIH workshop
Authors: Bookman Ebony B. , McAllister Kimberly , Gillanders Elizabeth , Wanke Kay , Balshaw David , Rutter Joni , Reedy Jill , Shaughnessy Daniel , Agurs‐Collins Tanya , Paltoo Dina , Atienza Audie , Bierut Laura , Kraft Peter , Fallin M. Daniele , Perera Frederica , Turkheimer Eric , Boardman Jason , Marazita Mary L. , Rappaport Stephen M. , Boerwinkle Eric , Suomi Stephen J. , Caporaso Neil E. , Hertz‐Picciotto Irva , Jacobson Kristen C. , Lowe William L. , Goldman Lynn R. , Duggal Priya , Gunnar Megan R. , Manolio Teri A. , Green Eric D. , Olster Deborah H. , Birnbaum Linda S. ,   for the NIH G × E Interplay Workshop participants
Published: February 2011

Although it is recognized that many common complex diseases are a result of multiple genetic and environmental risk factors, studies of gene‐environment interaction remain a challenge and have had limited success to date. Given the current state‐of‐the‐science, NIH sought input on ways to accelerate investigations of gene‐environment interplay in health and disease by inviting experts from a variety of disciplines to give advice about the future direction of gene‐environment interaction studies. Participants of the NIH Gene‐Environment Interplay Workshop agreed that there is a need for continued emphasis on studies of the interplay between genetic and environmental factors in disease and that studies need to be designed around a multifaceted approach to reflect differences in diseases, exposure attributes, and pertinent stages of human development. The participants indicated that both targeted and agnostic approaches have strengths and weaknesses for evaluating main effects of genetic and environmental factors and their interactions. The unique perspectives represented at the workshop allowed the exploration of diverse study designs and analytical strategies, and conveyed the need for an interdisciplinary approach including data sharing, and data harmonization to fully explore gene‐environment interactions. Further, participants also emphasized the continued need for high‐quality measures of environmental exposures and new genomic technologies in ongoing and new studies. Genet. Epidemiol. 35: 217‐225, 2011.  © 2011 Wiley‐Liss, Inc.
New tools for the analysis of glial cell biology in Drosophila
Authors: Awasaki Takeshi , Lee Tzumin
Published: February 2011

Because of its genetic, molecular, and behavioral tractability, Drosophila has emerged as a powerful model system for studying molecular and cellular mechanisms underlying the development and function of nervous systems. The Drosophila nervous system has fewer neurons and exhibits a lower glia:neuron ratio than is seen in vertebrate nervous systems. Despite the simplicity of the Drosophila nervous system, glial organization in flies is as sophisticated as it is in vertebrates. Furthermore, fly glial cells play vital roles in neural development and behavior. In addition, powerful genetic tools are continuously being created to explore cell function in vivo. In taking advantage of these features, the fly nervous system serves as an excellent model system to study general aspects of glial cell development and function in vivo. In this article, we review and discuss advanced genetic tools that are potentially useful for understanding glial cell biology in Drosophila. © 2011 Wiley‐Liss, Inc.
Differential expression of inwardly rectifying K+ channels and aquaporins 4 and 5 in autoimmune uveitis indicates misbalance in Müller glial cell‐dependent ion and water homeostasis
Authors: Eberhardt Christina , Amann Barbara , Feuchtinger Annette , Hauck Stefanie M. , Deeg Cornelia A.
Published: February 2011

Reactive gliosis is a well‐established response to virtually every retinal disease. Autoimmune uveitis, a sight threatening disease, is characterized by recurrent relapses through autoaggressive T‐cells. The purpose of this study was to assess retinal Müller glial cell function in equine recurrent uveitis (ERU), a spontaneous disease model resembling the human disease, by investigating membrane proteins implicated in ion and water homeostasis. We found that Kir2.1 was highly expressed in diseased retinas, whereas Kir4.1 was downregulated in comparison to controls. Distribution of Kir2.1 appeared Müller cell associated in controls, whereas staining of cell somata in the inner nuclear layer was observed in uveitis. In contrast to other subunits, Kir4.1 was evenly expressed along equine Müller cells, whereas in ERU, Kir4.1 almost disappeared from Müller cells. Hence, we suggest a different mechanism for potassium buffering in the avascular equine retina and, moreover, an impairment in uveitis. Uveitic retinas showed significantly increased expression of AQP4 as well as a displaced expression from Müller cells in healthy specimens to an intense circular expression pattern in the outer nuclear layer in ERU cases. Most interestingly, we detected the aquaporin family member protein AQP5 to be expressed in Müller cells with strong enrichments in Müller cell secondary processes. This finding indicates that fluid regulation within the equine retina may be achieved by an additional aquaporin. Furthermore, AQP5 was significantly decreased in uveitis. We conclude that the Müller cell response in autoimmune uveitis implies considerable changes in its potassium and water physiology. © 2011 Wiley‐Liss, Inc.
Genetic modeling of gliomas in mice: New tools to tackle old problems
Authors: Hambardzumyan Dolores , Parada Luis F. , Holland Eric C. , Charest Al
Published: February 2011

The recently published comprehensive profiles of genomic alterations in glioma have led to a refinement in our understanding of the molecular events that underlie this cancer. Using state‐of‐the‐art genomic tools, several laboratories have created and characterized accurate genetically engineered mouse models of glioma based on specific genetic alterations observed in human tumors. These in vivo brain tumor models faithfully recapitulate the histopathology, etiology, and biology of gliomas and provide an exceptional experimental system to discover novel therapeutic targets and test therapeutic agents. This review focuses on mouse models of glioma with a special emphasis on genetically engineered models developed around key genetic glioma signature mutations in the PDGFR, EGFR, and NF1 genes and pathways. The resulting animal models have provided insight into many fundamental and mechanistic facets of tumor initiation, maintenance and resistance to therapeutic intervention and will continue to do so in the future. © 2011 Wiley‐Liss, Inc.
Seeing touch in the somatosensory cortex: A TMS study of the visual perception of touch
Authors: Bolognini Nadia , Rossetti Angela , Maravita Angelo , Miniussi Carlo
Published: February 2011

Recent studies suggest the existence of a visuo‐tactile mirror system, comprising the primary (SI) and secondary (SII) somatosensory cortices, which matches observed touch with felt touch. Here, repetitive transcranial magnetic stimulation (rTMS) was used to determine whether SI or SII play a functional role in the visual processing of tactile events. Healthy participants performed a visual discrimination task with tactile stimuli (a finger touching a hand) and a control task (a finger moving without touching). During both tasks, rTMS was applied over either SI or SII, and to the occipital cortex. rTMS over SI selectively reduced subject performance for interpreting whether a contralateral visual tactile stimulus contains a tactile event, whereas SII stimulation impaired visual processing regardless of the tactile component. These findings provide evidence for a multimodal sensory‐motor system with mirror properties, where somatic and visual properties of action converge. SI, a cortical area traditionally viewed as modality‐specific, is selectively implicated in the visual processing of touch. These results are in line with the existence of a sensory mirror system mediating the embodied simulation concept. Hum Brain Mapp, 2011. © 2011 Wiley Periodicals, Inc.
Thickness profile generation for the corpus callosum using Laplace's equation
Authors: Adamson Christopher L. , Wood Amanda G. , Chen Jian , Barton Sarah , Reutens David C. , Pantelis Christos , Velakoulis Dennis , Walterfang Mark
Published: February 2011

The corpus callosum facilitates communication between the cerebral hemispheres. Morphological abnormalities of the corpus callosum have been identified in numerous psychiatric and neurological disorders. To quantitatively analyze the thickness profile of the corpus callosum, we adapted an automatic thickness measurement method, which was originally used on magnetic resonance (MR) images of the cerebral cortex (Hutton et al. [2008]: NeuroImage 40:1701–10; Jones et al. [2002]: Hum Brain Mapp 11:12–32; Schmitt and Böhme [2002]: NeuroImage 16:1103–9; Yezzi and Prince [2003]: IEEE Trans Med Imaging 22:1332–9), to MR images of the corpus callosum. The thickness model was derived by computing a solution to Laplace's equation evaluated on callosal voxels. The streamlines from this solution form non‐overlapping, cross‐sectional contours the lengths of which are modeled as the callosal thickness. Apart from the semi‐automated segmentation and endpoint selection procedures, the method is fully automated, robust, and reproducible. We compared the Laplace method with the orthogonal projection technique previously published (Walterfang et al. [2009a]: Psych Res Neuroimaging 173:77–82; Walterfang et al. [2008a]: Br J Psychiatry 192:429–34; Walterfang et al. [2008b]: Schizophr Res 103:1–10) on a cohort of 296 subjects, composed of 86 patients with chronic schizophrenia (CSZ), 110 individuals with first‐episode psychosis, 100 individuals at ultra‐high risk for psychosis (UHR; 27 of whom later developed psychosis, UHR‐P, and 73 who did not, UHR‐NP), and 55 control subjects (CTL). We report similar patterns of statistically significant differences in regional callosal thickness with respect to the comparisons CSZ vs. CTL, UHR vs. CTL, UHR‐P vs. UHR‐NP, and UHR vs. CTL. Hum Brain Mapp, 2011. © 2011 Wiley Periodicals, Inc.
Feature‐based attention modulates direction‐selective hemodynamic activity within human MT
Authors: Stoppel Christian Michael , Boehler Carsten Nicolas , Strumpf Hendrik , Heinze Hans‐Jochen , Noesselt Toemme , Hopf Jens‐Max , Schoenfeld Mircea Ariel
Published: February 2011

Attending to the spatial location or to nonspatial features of a stimulus modulates neural activity in cortical areas that process its perceptual attributes. The feature‐based attentional selection of the direction of a moving stimulus is associated with increased firing of individual neurons tuned to the direction of the movement in area V5/MT, while responses of neurons tuned to opposite directions are suppressed. However, it is not known how these multiplicatively scaled responses of individual neurons tuned to different motion‐directions are integrated at the population level, in order to facilitate the processing of stimuli that match the perceptual goals. Using functional magnetic resonance imaging (fMRI) the present study revealed that attending to the movement direction of a dot field enhances the response in a number of areas including the human MT region (hMT) as a function of the coherence of the stimulus. Attending the opposite direction, however, lead to a suppressed response in hMT that was inversely correlated with stimulus‐coherence. These findings demonstrate that the multiplicative scaling of single‐neuron responses by feature‐based attention results in an enhanced direction‐selective population response within those cortical modules that processes the physical attributes of the attended stimuli. Our results provide strong support for the validity of the “feature similarity gain model” on the integrated population response as quantified by parametric fMRI in humans. Hum Brain Mapp, 2011. © 2011 Wiley Periodicals, Inc.
Event‐related potential activity in the basal ganglia differentiates rewards from nonrewards: Temporospatial principal components analysis and source localization of the feedback negativity
Authors: Foti Dan , Weinberg Anna , Dien Joseph , Hajcak Greg
Published: February 2011

Event‐related potential studies of reward processing have consistently identified the feedback negativity (FN), an early neural response that differentiates feedback indicating unfavorable versus favorable outcomes. Several important questions remain, however, about the nature of this response. In this study, the FN was recorded in response to monetary gains and losses during a laboratory gambling task, and temporospatial principal components analysis was used to separate the FN from overlapping responses. The FN was identified as a positive deflection at frontocentral recording sites that was enhanced for rewards compared with nonrewards. Furthermore, source localization techniques identified the striatum as a likely neural generator. These data indicate that this apparent FN reflects increased striatal activation in response to favorable outcomes that is reduced or absent for unfavorable outcomes, thereby providing unique information about the timing and nature of basal ganglia activity related to reward processing. Hum Brain Mapp, 2011. © 2011 Wiley Periodicals, Inc.
Temporal dynamics of reward processing revealed by magnetoencephalography
Authors: Doñamayor Nuria , Marco‐Pallarés Josep , Heldmann Marcus , Schoenfeld M. Ariel , Münte Thomas F.
Published: February 2011

Monetary gains and losses in gambling situations are associated with a distinct electroencephalographic signature: in the event‐related potentials (ERPs), a mediofrontal feedback‐related negativity (FRN) is seen for losses, whereas oscillatory activity shows a burst of in the θ‐range for losses and in the β‐range for gains. We used whole‐head magnetoencephalography to pinpoint the magnetic counterparts of these effects in young healthy adults and explore their evolution over time. On each trial, participants bet on one of two visually presented numbers (25 or 5) by button‐press. Both numbers changed color: if the chosen number turned green (red), it indicated a gain (loss) of the corresponding sum in Euro cent. For losses, we found the magnetic correlate of the FRN extending between 230 and 465 ms. Source localization with low‐resolution electromagnetic tomography indicated a first generator in posterior cingulate cortex with subsequent activity in the anterior cingulate cortex. Importantly, this effect was sensitive to the magnitude of the monetary loss (25 cent > 5 cent). Later activation was also found in the right insula. Time‐frequency analysis revealed a number of oscillatory components in the theta, alpha, and high‐beta/low‐gamma bands associated to gains, and in the high‐beta band, associated to the magnitude of the loss. All together, these effects provide a more fine‐grained picture of the temporal dynamics of the processing of monetary rewards and losses in the brain. Hum Brain Mapp, 2011. © 2011 Wiley Periodicals, Inc.
Intrapericardial steroid treatment for recurrent pericardial effusion in a patient with acute lymphoblastic Leukaemia
Authors: Mainzer Gur , Zaidman Irina , Hatib Ihab , Lorber Avraham
Published: February 2011

Intrapericardial corticosteroid therapy for pericardial effusion is an uncommon practice. We had an initial experience with this therapeutic measure but this was our first attempt in the context of malignant diseases and paraneoplastic syndrome. A patient with relapsed Acute Lymphoblastic Leukemia and recurrent pericardial effusion presented. She had been treated by pericardiocenthesis and systemic corticosteroids on two occasions. Following the second pericardiocenthesis and pericardial drainage, methylprednisolone was injected into the pericardium prior to withdrawal of the draining catheter. The patient had a dramatic clinical improvement with a short hospital stay and a lower dose of systemic steroids. We conclude that Intrapericardial steroids injection may be beneficial for patients with paraneoplastic syndrome and pericardial effusion. Copyright © 2011 John Wiley & Sons, Ltd.
Paroxetine augmentation in patients with generalised social anxiety disorder, non‐responsive to mirtazapine or placebo
Authors: Schutters Sara I. J. , van Megen Harold J. G. M. , Van Veen J. Frederieke , Schruers Koen R. J. , Westenberg Herman G. M.
Published: February 2011

Objectives

The aim of the study was to investigate if combination of mirtazapine with paroxetine causes a greater therapeutic effect and less sexual side effects than paroxetine monotherapy in social anxiety disorder (SAD).

Methods

Twenty one patients with generalised SAD, non‐responsive to a 12 week trial with mirtazapine and 22 patients, non‐responsive to placebo received paroxetine (20–40 mg) in addition to their double‐blind treatment with mirtazapine or placebo for another 12 weeks. The Liebowitz Social Anxiety Scale (LSAS) and the Clinical Global Impression‐Improvement (CGI‐I) scale were used to measure efficacy. Sexual functioning was assessed by the Arizona Sexual Experiences Scale (ASEX).

Results

Both treatments showed a significant LSAS reduction and their response rates (based on LSAS reduction ≥ 40% and CGI‐I ≤ 2) were similar (paroxetine and mirtazapine: 52.4%, paroxetine and placebo: 59.1%). Sexual dysfunction (based on ASEX ≥ 19) was found in half of patients treated with paroxetine and placebo, and in 38% of patients treated with paroxetine and mirtazapine.

Conclusion

The present study did not find support for a greater efficacy of combination pharmacotherapy in SAD, however results suggest that combination of paroxetine with mirtazapine might cause less sexual dysfunction than treatment with paroxetine alone. Copyright © 2011 John Wiley & Sons, Ltd.
An open, non‐randomised comparison of escitalopram and duloxetine for the treatment of subjects with Generalized Anxiety Disorder
Authors: Pierò Andrea , Locati Enrica
Published: February 2011

Objectives

This study compares the effectiveness of a 6‐months treatment with escitalopram (ESC), a selective serotonin reuptake inhibitor, or duloxetine (DUL), a balanced serotonin and nor‐adrenaline reuptake inhibitor, in 43 subjects with Generalized Anxiety Disorder (GAD).

Methods

Assessment was made with the Hamilton Anxiety and Depression scales (HAM‐A; HAM‐D), with the CGI, and with the GAF at T0 (intake), T1, T3, T6 (1, 3, and 6 months later). The comparison among the two treatment groups (ESC = 20; DUL = 23) at the four endpoints was made through a GLM‐ANOVA for repeated measures. Rates of remission (HAM‐A < 7), response (HAM‐A reduction of 50% or above) and dropout were evaluated.

Results

At 1, 3, and 6 months after treatment inception both treatment groups showed a significant improvement in the scores of CGI, HAM‐A, HAM‐D, and GAF, and an equivalent rate of dropout. The DUL group registered a greater amount of remission and response rates at T1 against the ESC group in all the scales except in the HAM‐D scale. Duloxetine was more effective than escitalopram after the first month of treatment only in the somatic subscale of HAM‐A. The presence of a cluster C personality disorder was associated in both groups to greater difficulties in attaining remission and to dropout.

Conclusions

Implications for clinical practice are discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Hydrological response of weathered clay‐shale slopes: water infiltration monitoring with time‐lapse electrical resistivity tomography
Authors: Travelletti J. , Sailhac P. , Malet J.‐P. , Grandjean G. , Ponton J.
Published: February 2011

This work presents an attempt to monitor water infiltration and subsurface flow within a clay‐shale landslide using time‐lapse electrical resistivity tomography (ERT). A rainfall experiment was carried out on a plot of 100 m2at the Laval landslide in the Draix experimental catchments (ORE Draix, South French Alps) in order to characterize the spatial and temporal development of water circulation in the soil and to identify when steady‐state flow conditions are reached. The experiment was conducted during 67 h with initial unsaturated conditions in the slope. The apparent electrical resistivity values were inverted with a time‐lapse approach using several cross models. The results indicate a significant decrease in resistivity (−18%) compared to the initial state in the rain plot. Downslope progression of negative resistivity anomalies is imaged suggesting that vertical and subsurface lateral flows have developed. About 21 h after the start of the rain experiment, a constant level of resistivity values is observed indicating that the hydrological system reached steady‐state flow conditions. This observation is consistent with ground water level observations and chemical tracer analysis. Computed differences in time of steady‐state conditions highlight possible preferential flows near the landslide toe. A hydrological concept of functioning of the slope is proposed, and apparent saturated hydraulic conductivity (Ksof 1·7 × 10−4m × s−1) is computed from the steady‐state times. This study demonstrates the potentiality of ERT monitoring to monitor water infiltration in clay‐shale slopes and the high water transfer capacity of reworked clay‐shale material. Copyright © 2011 John Wiley & Sons, Ltd.
Hydrological extremes in the Poyang Lake basin, China: changing properties, causes and impacts
Authors: Zhang Qiang , Sun Peng , Chen Xiaohong , Jiang Tao
Published: February 2011

Probability behaviours and trends of hydrological extremes, the 7‐day high flow (HF7) in this study, of the Poyang Lake basin are thoroughly investigated using 11 probability distribution functions and Mann‐Kendall trend test method. Parameters and goodness‐of‐fit of the probability functions are estimated using the L‐moment technique and Kolmogorov‐Smirnov statistic D (K‐S D). The hydrological data are extracted from six major hydrological stations located in the five main tributaries of the Poyang Lake basin. The results indicate that: (1) the Wakeby distribution is the good choice for description of the statistical behaviours of HF7 in the study region; (2) changing properties of HF7 are varying from on station to another, implying different fluvial geomorphological features, climate changes, and human activities within different tributaries. Generally, the HF7 events are increasing after the construction of water reservoirs except the Wan'an water reservoir. The analysis results demonstrate considerable influences of water reservoirs on high flow changes. Relatively low design standards of the water reservoirs greatly limit the functions of the water reservoirs in terms of flood control. Besides, most water reservoirs were built in the tributaries of the Poyang Lake basin, exerting limited influences on the streamflow extremes; (3) higher frequency of hydrological extremes may cause higher probability of floods, posing increasingly serious challenges for flood control. In this sense, more efforts should be paid to enhance human mitigation to natural hazards such as floods in the Poyang Lake basin. Copyright © 2011 John Wiley & Sons, Ltd.
Internal catchment process simulation in a snow‐dominated basin: performance evaluation with spatiotemporally variable runoff generation and groundwater dynamics
Authors: Kuraś Piotr K. , Alila Younes , Weiler Markus , Spittlehouse Dave , Winkler Rita
Published: February 2011

Hydrologic models have increasingly been used in forest hydrology to overcome the limitations of paired watershed experiments, where vegetative recovery and natural variability obscure the inferences and conclusions that can be drawn from such studies. Models are also plagued by uncertainty, however, and parameter equifinality is a common concern. Physically‐based, spatially‐distributed hydrologic models must therefore be tested with high‐quality experimental data describing a multitude of concurrent internal catchment processes under a range of hydrologic regimes. This study takes a novel approach by not only examining the ability of a pre‐calibrated model to realistically simulate watershed outlet flows over a four year period, but a multitude of spatially‐extensive, internal catchment process observations not previously evaluated, including: continuous groundwater dynamics, instantaneous stream and road network flows, and accumulation and melt period spatial snow distributions. Many hydrologic model evaluations are only on the comparison of predicted and observed discharge at a catchment outlet and remain in the ‘infant stage’ in terms of model testing. This study, on the other hand, tests the internal spatial predictions of a distributed model with a range of field observations over a wide range of hydroclimatic conditions. Nash‐Sutcliffe model efficiency was improved over prior evaluations due to continuing efforts in improving the quality of meteorological data collection. Road and stream network flows were generally well simulated for a range of hydrologic conditions, and snowpack spatial distributions were well simulated for one of two years examined. The spatial variability of groundwater dynamics was effectively simulated, except at locations where strong stream–groundwater interactions exist. Model simulations overall were quite successful in realistically simulating the spatiotemporal variability of internal catchment processes in the watershed, but the premature onset of simulated snowmelt for one of the simulation years has prompted further work in model development. Copyright © 2011 John Wiley & Sons, Ltd.
Drainage water temperature as a basis for verifying drainage runoff composition on slopes
Authors: Zajíček Antonín , Kvítek Tomáš , Kaplická Markéta , Doležal František , Kulhavý Zbyněk , Bystřický Václav , Žlábek Pavel
Published: February 2011

Tile drainage water temperatures and discharge rates were measured in five highland watersheds of which most are underlain by acid crystalline rock. One of them, Dehtáře in the Bohemo‐Moravian highland (Czech Republic), was studied in greater detail. The aim was to evaluate water temperature monitoring as a means of determining the source and pathway of drainage runoff during high‐flow events. Rapid increase in drainage discharge was accompanied by rapid change in water temperature. In winter, the rising limb of the hydrograph was accompanied by a decrease in temperature, and the falling limb was associated with a corresponding temperature increase. In summer, the trends were reversed. These data suggest that the water temperature changes are caused by the fastest component of drainage runoff, water from a precipitation event or snowmelt, which can be separated from the remainder of the hydrograph. Measurements of hydraulic conductivity, soil moisture content, soil temperature, and groundwater table level indicate that the major portion of the event water causing this effect infiltrates in the watershed recharge zone where soils are permeable, enters the weathered bedrock, flows preferentially and rapidly down the slope along disjoint fissures in the bedrock, finally emerging as ascending springs, and is, for the most part, intercepted by the tile drainage systems. Copyright © 2011 John Wiley & Sons, Ltd.
Distributed rainfall‐runoff modelling for flood frequency estimation and flood forecasting
Authors: Brocca L. , Melone F. , Moramarco T.
Published: February 2011

Nowadays, in the scientific literature many rainfall‐runoff (RR) models are available ranging from simpler ones, with a limited number of parameters, to highly complex ones, with many parameters. Therefore, the selection of the best structure and parameterisation for a model is not straightforward as it is dependent on a number of factors: climatic conditions, catchment characteristics, temporal and spatial resolution, model objectives, etc. In this study, the structure of a continuous semi‐distributed RR model, named MISDc (‘Modello Idrologico Semi‐Distribuito in continuo’) developed for flood simulation in the Upper Tiber River (central Italy) is presented. Most notably, the methodology employed to detect the more relevant processes involved in the modelling of high floods, and hence, to build the model structure and its parameters, is developed. For this purpose, an intense activity of monitoring soil moisture and runoff in experimental catchments was carried out allowing to derive a parsimonious and reliable continuous RR model operating at an hourly (or smaller) time scale. Specifically, in order to determine the catchment hydrological response, the important role of the antecedent wetness conditions is emphasized. The application of MISDc both for design flood estimation and for flood forecasting is reported here demonstrating its reliability and also its computational efficiency, another important factor in hydrological practice. As far as the flood forecasting applications are concerned, only the accuracy of the model in reproducing discharge hydrographs by assuming rainfall correctly known throughout the event is investigated indepth. In particular, the MISDc has been implemented in the framework of Civil Protection activities for the Upper Tiber River basin. Copyright © 2011 John Wiley & Sons, Ltd.
The relative impact of climate change and urban expansion on peak flows: a case study in central Belgium
Authors: Poelmans Lien , Rompaey Anton Van , Ntegeka Victor , Willems Patrick
Published: February 2011

An essential part of hydrological research focuses on hydrological extremes, such as river peak flows and associated floods, because of their large impact on economy, environment, and human life. These extremes can be affected by potential future environmental change, including global climate change and land cover change. In this paper, the relative impact of both climate change and urban expansion on the peak flows and flood extent is investigated for a small‐scale suburban catchment in Belgium. A rainfall‐runoff model was coupled to a hydrodynamic model in order to simulate the present‐day and future river streamflow. The coupled model was calibrated based on a series of measured water depths and, after model validation, fed with different climate change and urban expansion scenarios in order to evaluate the relative impact of both driving factors on the peak flows and flood extent. The three climate change scenarios that were used (dry, wet winter, wet summer) were based on a statistical downscaling of 58 different RCM and GCM scenario runs. The urban expansion scenarios were based on three different urban growth rates (low, medium, high urban expansion) that were set up by means of an extrapolation of the observed trend of urban expansion. The results suggest that possible future climate change is the main source of uncertainty affecting changes in peak flow and flood extent. The urban expansion scenarios show a more consistent trend. The potential damage related to a flood is, however, mainly influenced by land cover changes that occur in the floodplain. Copyright © 2011 John Wiley & Sons, Ltd.
High‐resolution monitoring reveals dissolved oxygen dynamics in an Antarctic cryoconite hole
Authors: Bagshaw E. A. , Tranter M. , Wadham J. L. , Fountain A. G. , Mowlem M.
Published: February 2011

This study presents the first high‐resolution dataset of dissolved oxygen (DO) measurements in an ice‐lidded cryoconite hole on Canada Glacier, McMurdo Dry Valleys, Antarctica. Fibre optic DO minisensors were installed in a cryoconite hole prior to seasonal internal melting and hydrological connection to the subsurface drainage system. Oxygen air saturation in the cryoconite hole typically ranged from 50 to 80%, in broad agreement with previous single measurements, indicating net respiration (R). This is consistent with results of simple incubation experiments performed in the field. Simultaneous time series for electrical conductivity, water temperature, and DO over the four‐week study period provide information regarding the connectivity of cryoconite holes with the near‐surface drainage system. The main driver of the observed variations in DO is likely to be periodic melt‐freeze cycles. We conclude that automated sensing techniques, such as those described here, when used in conjunction with physical measurements, have great potential for high‐resolution monitoring of the factors that perturb biogeochemical processes in cryospheric surface aquatic ecosystems. Copyright © 2011 John Wiley & Sons, Ltd.
Contribution of climatic and anthropogenic effects to the hydric deficit of peatlands
Authors: Auterives Chrystelle , Aquilina Luc , Bour Olivier , Davranche Mélanie , Paquereau Valérie
Published: February 2011

The present study makes use of a detailed water balance to investigate the hydrological status of a peatland with a basal clay‐rich layer overlying an aquifer exploited for drinking water. The aim is to determine the influence of climate and groundwater extraction on the water balance and water levels in the peatland. During the two‐year period of monitoring, the hydrological functioning of the wetland showed a hydric deficit, associated with a permanent unsaturated layer and a deep water table. At the same time, a stream was observed serving as a recharge inflow instead of draining the peatland, as usually described in natural systems. Such conditions are not favourable for peat accumulation. Field investigations show that the clay layer has a high hydraulic conductivity (from 1·10−7 to 3·10−9 m.s−1) and does not form a hydraulic barrier. Moreover, the vertical hydraulic gradients are downward between the peat and the sand aquifer, leading to high flows of groundwater through the clay layer (20–48% of the precipitation). The observed hydric deficit of the peatland results from a combination of dry climatic conditions during the study period and groundwater extraction. The climatic effect is mainly expressed through drying out of the peatland, while the anthropogenic effect leads to an enhancement of the climatic effect on a global scale, and a modification of fluxes at a local scale. The drying out of the peatland can lead to its mineralisation, which thus gives rise to environmental impacts. The protection of such wetlands in the context of climate change should take account of anthropogenic pressures by considering the wetland‐aquifer interaction. Copyright © 2011 John Wiley & Sons, Ltd.
A sensor array system for profiling moisture in unsaturated rock and soil
Authors: Salve Rohit
Published: February 2011

As the scope of hydrologic investigations extend deeper into the subsurface profile, and increasingly include fractured rock, there is a growing need for techniques that can accurately monitor saturation changes at a high spatial and temporal resolution in this environment. We have developed a technique, the Electrical Resistance Sensor Array System (ERSAS), to track moisture dynamics in vadose zone regions that include both fractured rock and soil. The performance of ERSAS was compared with the time domain reflectometry (TDR) technique under controlled and field conditions. We found that ERSAS was effective in determining patterns of saturation changes along vertical soil/rock profiles. Because of the small size of individual sensors, it was able to resolve travel times associated with a wetting front and peak saturation better than TDR. In addition, ERSAS is significantly cheaper than the TDR system, and the sensor arrays are relatively easier to install in the subsurface profile. Published in 2011 by John Wiley & Sons, Ltd.
The composition of the debtor's estate on insolvency: A comparative study of exemptions
Authors: Skene Donna McKenzie
Published: February 2011

This article examines one aspect of the issue of the composition of the debtor's estate on insolvency, namely the exemption of certain assets from the debtor's estate. It sets out the responses to a questionnaire completed by leading scholars in selected jurisdictions (Australia, Canada, France, Italy, New Zealand, South Africa, The Netherlands and the USA) on the exemptions available in those jurisdictions, makes preliminary observations on those responses, considers the prospects for harmonisation of this area of law in the light of those observations and puts forward some tentative proposals for the development of model provisions and/or legislative principles in the area of exemptions for comment and discussion. Copyright © 2011 John Wiley & Sons, Ltd.
Towards Arithmetic Circuits in Sub‐Excitable Chemical Media
Authors: Adamatzky Andrew , De Lacy Costello Ben , Bull Larry , Holley Julian
Published: February 2011

A sub‐excitable Belousov–Zhabotinsky medium exhibits localized travelling excitations (in contrast to an excitable medium exhibiting target or spiral waves). Initially assymetric perturbations give birth to excitation wave‐fragments. The shape and velocity vectors of the wave‐fragments are conserved, meaning they can travel for substantial distances in the reaction media. When the wave‐fragments collide they may reflect, merge, or annihilate. We interpret wave‐fragments as values of logical variables, and the post‐collision states of the fragments as outputs of logical gates. We show how to cascade logical gates in primitive arithmetical circuits.
Some Experiments and Directions in Molecular Computing and Robotics
Authors: Stojanovic Milan N.
Published: February 2011

In this review I present a chemist’s perspective on molecular computing and molecular robotics. I start with nucleic acid catalysts and then show how the application of some concepts from computer sciences and macroscopic robotics enable engineering of interesting behaviors in molecular systems.
A semi‐degradable composite scaffold for articular cartilage defects
Authors: Scholten Paul M. , Ng Kenneth W. , Joh Kiwon , Serino Lorenzo P. , Warren Russell F. , Torzilli Peter A. , Maher Suzanne A.
Published: February 2011

Few options exist to replace or repair damaged articular cartilage. The optimal solution that has been suggested is a scaffold that can carry load and integrate with surrounding tissues; but such a construct has thus far been elusive. The objectives of this study were to manufacture and characterize a nondegradable hydrated scaffold. Our hypothesis was that the polymer content of the scaffold can be used to control its mechanical properties, while an internal porous network augmented with biological agents can facilitate integration with the host tissue. Using a two‐step water‐in‐oil emulsion process a porous polyvinyl alcohol (PVA) hydrogel scaffold combined with alginate microspheres was manufactured. The scaffold had a porosity of 11–30% with pore diameters of 107–187 μm, which readily allowed for movement of cells through the scaffold. Alginate microparticles were evenly distributed through the scaffold and allowed for the slow release of biological factors. The elastic modulus (Es) and Poisson's ratio (υ), Aggregate modulus (Ha) and dynamic modulus (ED) of the scaffold were significantly affected by % PVA, as it varied from 10 to 20% wt/vol. Es and υ were similar to that of articular cartilage for both polymer concentrations, while Ha and ED were similar to that of cartilage only at 20% PVA. The ability to control scaffold mechanical properties, while facilitating cellular migration suggest that this scaffold is a potentially viable candidate for the functional replacement of cartilage defects. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2011.
Probing orientation of immobilized humanized anti‐lysozyme variable fragment by time‐of‐flight secondary‐ion mass spectrometry
Authors: Baio J. E. , Cheng Fang , Ratner Daniel M. , Stayton Patrick S. , Castner David G.
Published: February 2011

As methods to orient proteins are conceived, techniques must also be developed that provide an accurate characterization of immobilized protein orientation. In this study, X‐ray photoelectron spectroscopy (XPS), surface plasmon resonance (SPR), and time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) were used to probe the orientation of a surface immobilized variant of the humanized anti‐lysozyme variable fragment (HuLys Fv, 26 kDa). This protein contained both a hexahistidine tag and a cysteine residue, introduced at opposite ends of the HuLys Fv, for immobilization onto nitrilotriacetic acid (NTA) and maleimide oligo(ethylene glycol) (MEG)‐terminated substrates, respectively. The thiol group on the cysteine residue selectively binds to the MEG groups, while the his‐tag selectively binds to the Ni‐loaded NTA groups. XPS was used to monitor protein coverage on both surfaces by following the change in the nitrogen atomic %. SPR results showed a 10‐fold difference in lysozyme binding between the two different HuLys Fv orientations. The ToF‐SIMS data provided a clear differentiation between the two samples due to the intensity differences of secondary ions originating from asymmetrically located amino acids in HuLys Fv (histidine: 81, 82, and 110 m/z; phenylalanine: 120 and 131 m/z). An intensity ratio of the secondary ion peaks from the histidine and phenylalanine residues at either end of the protein was then calculated directly from the ToF‐SIMS data. The 45% change in this ratio, observed between the NTA and MEG substrates with similar HuLys Fv surface coverages, indicates that the HuLys Fv fragment has opposite orientations on two different surfaces. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2011.
An in vitro study of blood compatibility of vascular grafts made of bacterial cellulose in comparison with conventionally‐used graft materials
Authors: Fink Helen , Hong Jaan , Drotz Kristoffer , Risberg Bo , Sanchez Javier , Sellborn Anders
Published: February 2011

In this study we analyzed the blood compatibility of bacterial cellulose (BC) as a new biosynthetic material for use as a vascular graft. As reference materials we used expanded polytetrafluoroethylene (ePTFE) and poly(ethylene terephthalate) (PET) vascular grafts. These materials are in clinical use today. Tubes with inner diameters of both 4 (not PET) and 6 mm were tested. Heparin‐coated PVC tubes (hepPVC) were used as a negative control. Platelet consumption and thrombin‐antithrombin complex (TAT) were used as parameters of coagulation and for complement activation, sC3a and sC5b‐9 were used. The investigated parameters were measured after 1‐h exposure to freshly drawn human blood supplemented with a low dose of heparin in a Chandler loop system. The results showed that BC exhibits no significant difference in platelet consumption, as compared with PET (6 mm), ePTFE and hepPVC. The PET material consumed more platelets than any of the other materials. The TAT generation for 4 mm tubes was not significantly different between BC and the other materials. For 6 mm tubes, however, differences were observed between hepPVC and PET (p < 0.0001); BC and hepPVC (p = 0.0016); ePTFE and PET (p < 0.0001); BC and ePTFE (p = 0.0029); BC and PET (p = 0.0141). Surprisingly, considering the low platelet consumption, the complement activation parameters (sC3a and sC5b‐9) were much higher for BC, as compared with the other materials for both 4 and 6 mm tubes. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2011.