bluuebunny/crossref_metadata_2025 huggingface dataset:
Native Dreissena freshwater mussels in the Balkans: in and out of ancient lakes
Authors: Wilke T. , Schultheiß R. , Albrecht C. , Bornmann N. , Trajanovski S. , Kevrekidis T.
Published: October 2010

Abstract. The Balkans is a biogeographically highly diverse region and a worldwide hotspot of endemic freshwater diversity. A substantial part of this diversity is attributed to well recognized and potential ancient lakes in its southwestern part. However, despite considerable research efforts, faunal relationships among those lakes are not well understood. Therefore, genetic information from native representatives of the mussel genus Dreissena is here used to test the biogeographical zonation of the southwestern Balkans, to relate demographic changes to environmental changes, to assess the degree of eco-insularity, to reconstruct their evolutionary history, and to explore the potential of native taxa for becoming invasive. Phylogeographical and population genetic analyses indicate that most studied populations belong to two native species: D. presbensis (including the distinct genetic subgroup from Lake Ohrid, "D. stankovici") and D. blanci. In addition, the first confirmed record of invasive D. polymorpha in the southwestern Balkan is presented. The distribution of native Dreissena spp. generally coincides with the biogeographical zonations previously suggested based on fish data. However, there is disagreement on the assignment of the ancient lakes in the area to respective biogeographical regions. The data for Lake Ohrid are not conclusive. A closer biogeographical connection to lakes of the Vardar region and possibly the northern Ionian region is, however, suggested for Lake Prespa. The reconstruction of the evolutionary history of Dreissena spp. suggests that populations underwent demographic and spatial expansions in the recent past. Expansions started around 320 000–300 000 years ago in "D. stankovici", 160 000–140 000 years ago in D. blanci, and 110 000–70 000 years ago in D. presbensis. These time frames are discussed within the context of available paleogeological data for lakes Ohrid and Prespa. It is suggested that regional environmental changes may have had pronounced effects on the population histories of native Dreissena spp., though the high buffer capacity of Lake Ohrid may have lessened these effects in "D. stankovici". In addition, local events influencing individual lakes had very likely considerable effects on the demographic histories of Dreissena spp. as well. The observed patterns of immigration and emigration in and out of ancient lakes may suggest that limited gene flow enabled the survival of few isolated subpopulations and that later on eco-insularity (selective advantages of locally adopted groups) may have prevented excessive hybridization and sympatry of closely related taxa. As for the potential invasiveness of native Dreissena spp., the inferred spatial expansions are not human-mediated and all taxa still appear to be restricted to their native ranges. A concern, however, is that today D. presbensis and D. blanci also occur in artificial water bodies, and that invasive D. polymorpha has reached the area.
A regional climate simulation over the Iberian Peninsula for the last millennium
Authors: Gómez-Navarro J. J. , Montávez J. P. , Jerez S. , Jiménez-Guerrero P. , Lorente-Plazas R. , González-Rouco J. F. , Zorita E.
Published: October 2010

Abstract. In this study we present a regional paleoclimate simulation which covers the last millennium over the Iberian Peninsula (IP) with an unprecedented resolution of 30 km. The simulation was performed with a climate version of the mesoscale model MM5 coupled to the global model ECHO-G. Both experiments were driven by the same reconstructions of several external factors. The high spatial resolution of the regional model allows to simulate realistically many aspects of the climate in the IP when comparing the simulation to an observational data set in a reference period (1961–1990). Although the regional model is strongly driven by the boundary conditions, it is able to develop a different realisation of the past climate, which has a strong impact in those exercises comparing the results of climate simulations versus proxy reconstructions. A preliminary comparison of the simulation results with reconstructions of temperature and precipitation over the IP allows to recognise several aspects where both approaches agree, as well as identify the disagreements and try to point out the possible causes.
Rapid shifts in South American montane climates driven by pCO2 and ice volume changes over the last two glacial cycles
Authors: Groot M. H. M. , Bogotá R. G. , Lourens L. J. , Hooghiemstra H. , Vriend M. , Berrio J. C. , Tuenter E. , van der Plicht J. , van Geel B. , Ziegler M. , Weber S. L. , Betancourt A. , Contreras L. , Gaviria S. , Giraldo C. , González N. , Jansen J. H. F. , Konert M. , Ortega D. , Rangel O. , Sarmiento G. , Vandenberghe J. , van der Hammen T. , van der Linden M. , Westerhoff W.
Published: October 2010

Abstract. Tropical montane biome migration patterns in the northern Andes are found to be coupled to glacial-induced mean annual temperature (MAT) changes; however, the accuracy and resolution of current records are insufficient to fully explore their magnitude and rates of change. Here we present a ~60-year resolution pollen record over the past 284 000 years from Lake Fúquene (5° N) in Colombia. This record shows rapid and extreme MAT changes at 2540 m elevation of up to 10 ± 2 °C within a few hundred of years that concur with the ~100 and 41-kyr (obliquity) paced glacial cycles and North Atlantic abrupt climatic events as documented in ice cores and marine sediments. Using transient climate modelling experiments we demonstrate that insolation-controlled ice volume and greenhouse gasses are the major forcing agents causing the orbital MAT changes, but that the model simulations significantly underestimate changes in lapse rates and local hydrology and vegetation feedbacks within the studied region due to its low spatial resolution.
Multi-variate probability density functions with dynamics for cloud droplet activation in large-scale models: single column tests
Authors: Guo H. , Golaz J.-C. , Donner L. J. , Larson V. E. , Schanen D. P. , Griffin B. M.
Published: October 2010

Abstract. Successful simulation of cloud-aerosol interactions (indirect aerosol effects) in climate models requires relating grid-scale aerosol, dynamic, and thermodynamic fields to small-scale processes like aerosol activation. A turbulence and cloud parameterization, based on multi-variate probability density functions of sub-grid vertical velocity, temperature, and moisture, has been extended to treat aerosol activation. Multi-variate probability density functions with dynamics (MVD PDFs) offer a solution to the problem of the gap between the resolution of climate models and the scales relevant for aerosol activation and a means to overcome the limitations of diagnostic estimates of cloud droplet number concentration based only on aerosol concentration. Incorporated into the single-column version of GFDL AM3, the MVD PDFs successfully simulate cloud properties including precipitation for cumulus, stratocumulus, and cumulus-under-stratocumulus. The extension to treat aerosol activation predicts droplet number concentrations in good agreement with large eddy simulations (LES). The droplet number concentrations from the MVD PDFs match LES results more closely than diagnostic relationships between aerosol concentration and droplet concentration. In the single-column model simulations, as aerosol concentration increases, droplet concentration increases, precipitation decreases, but liquid water path can increase or decrease.
The multi-scale aerosol-climate model PNNL-MMF: model description and evaluation
Authors: Wang M. , Ghan S. , Easter R. , Ovchinnikov M. , Liu X. , Kassianov E. , Qian Y. , Gustafson W. , Larson V. E. , Schanen D. P. , Khairoutdinov M. , Morrison H.
Published: October 2010

Abstract. Anthropogenic aerosol effects on climate produce one of the largest uncertainties in estimates of radiative forcing of past and future climate change. Much of this uncertainty arises from the multi-scale nature of the interactions between aerosols, clouds and large-scale dynamics, which are difficult to represent in conventional global climate models (GCMs). In this study, we develop a multi-scale aerosol climate model that treats aerosols and clouds across different scales, and evaluate the model performance, with a focus on aerosol treatment. This new model is an extension of a multi-scale modeling framework (MMF) model that embeds a cloud-resolving model (CRM) within each grid column of a GCM. In this extension, the effects of clouds on aerosols are treated by using an explicit-cloud parameterized-pollutant (ECPP) approach that links aerosol and chemical processes on the large-scale grid with statistics of cloud properties and processes resolved by the CRM. A two-moment cloud microphysics scheme replaces the simple bulk microphysics scheme in the CRM, and a modal aerosol treatment is included in the GCM. With these extensions, this multi-scale aerosol-climate model allows the explicit simulation of aerosol and chemical processes in both stratiform and convective clouds on a global scale. Simulated aerosol budgets in this new model are in the ranges of other model studies. Simulated gas and aerosol concentrations are in reasonable agreement with observations, although the model underestimates black carbon concentrations at the surface. Simulated aerosol size distributions are in reasonable agreement with observations in the marine boundary layer and in the free troposphere, while the model underestimates the accumulation mode number concentrations near the surface, and overestimates the accumulation number concentrations in the free troposphere. Simulated cloud condensation nuclei (CCN) concentrations are within the observational variations. Simulated aerosol optical depth (AOD) and single scattering albedo (SSA) are in reasonable agreement with observations, and the spatial distribution of AOD is consistent with observations, while the model underestimates AOD over regions with strong fossil fuel and biomass burning emissions, and overestimates AOD over regions with strong dust emissions. Overall, this multi-scale aerosol climate model simulates aerosol fields as well as conventional aerosol models.
Groundwater fluctuations in heterogeneous coastal leaky aquifer systems
Authors: Chuang M.-H. , Huang C.-S. , Li G.-H. , Yeh H.-D.
Published: October 2010

Abstract. In the past, the coastal leaky aquifer system, including two aquifers and an aquitard between them, was commonly assumed to be homogeneous and of infinite extent in the horizontal direction. The leaky aquifer system may however be heterogeneous and of finite extent due to variations in depositional and post depositional processes. In this paper, the leaky aquifer system is divided into several horizontal regions for the heterogeneous aquitard and underlying aquifer. A one-dimensional analytical model is developed for describing the head fluctuation in such a heterogeneous leaky aquifer system. The hydraulic head of the upper unconfined aquifer is assumed constant. It is found that both the length and location of the discontinuous aquitards presented in the coastal area have significant effects on the amplitude and phase shift of the head fluctuation in the lower aquifer. In addition, the influence of the formation heterogeneity on the spatial head distribution is also investigated.
A case study on the use of appropriate surrogates for antecedent moisture conditions (AMCs)
Authors: Ali G. A. , Roy A. G.
Published: October 2010

Abstract. While a large number of non-linear hillslope and catchment rainfall-runoff responses have been attributed to the temporal variability in antecedent moisture conditions (AMCs), two problems emerge: (1) the difficulty of measuring AMCs, and (2) the absence of explicit guidelines for the choice of surrogates or proxies for AMCs. This paper aims at determining whether or not multiple surrogates for AMCs should be used in order not to bias our understanding of a system hydrological behaviour. We worked in a small forested catchment, the Hermine, where soil moisture has been measured at 121 different locations at four depths on 16 occasions. Without making any assumption on active processes, we used various linear and nonlinear regression models (i.e. linear, quadratic, cubic, exponential, logarithmic and logistic) to evaluate the point-scale temporal relations between actual soil moisture contents and selected meteorological-based surrogates for AMCs. We then mapped the nature of the "best fit" model to identify (1) spatial clusters of soil moisture monitoring sites whose hydrological behaviour was similar, and (2) potential topographic influences on these behaviours. Two conclusions stood out. Firstly, it was shown that the sole reference to AMCs indices traditionally used in catchment hydrology, namely antecedent rainfall amounts summed over periods of seven or ten days, would have led to an incomplete understanding of the Hermine catchment dynamics. Secondly, the relationships between point-scale soil moisture content and surrogates for AMCs were not spatially homogeneous, thus revealing a mosaic of linear and nonlinear catchment "active" and "contributing" sources whose locations were seldom controlled by surface terrain attributes or the topography of a soil-confining layer interface. These results represent a step forward for the Hermine catchment as they point towards depth-specific processes and spatially-variable triggering conditions that are not controlled by topography. Further investigations are, however, necessary in order to derive general guidelines for the choice of the best surrogates for AMCs in a catchment.
Consejos del Poder Ciudadano y gestión pública en Nicaragua
Authors: Hegg Manuel Ortega
Published: October 2010

Roberto Stuart Almendárez (Coordinador de la Investigación)DOI: 10.5377/encuentro.v41i84.50Encuentro 2009/ Año XLI, N° 84, 81-86
Modelos de nichos potenciales de especies de interés para tomadores de decisión, y su relación con el cambio climático en Nicaragua y América Central
Authors: Pérez A Mijail , Poveda Carlos , Siria Isabel , Aburto Lenin , Arets Eric , Sotelo Marlon
Published: October 2010

DOI: 10.5377/encuentro.v41i84.51Encuentro 2009/ Año XLI, N° 84, 62-80
Una aproximación a los retos de la integración centroamericana. La perspectiva de docentes en tres universidades de la región
Authors: Rodríguez José J. Romero
Published: October 2010

Las tres universidades jesuitas de centroamérica (Universidad José Simeón Cañas - UCA de El Salvador, Universidad Centroamericana - UCA de Nicaragua y Universidad Rafael Landívar de Guatemala) han iniciado un acción conjunta interdisciplinar e interuniversitaria sobre el tema específico de la integración centroamericana como marco para el desarrollo de la región. En ese contexto se han celebrado en las tres universidades sendas jornadas de estudio y reflexión destinadas a docentes sobre dicho tema monográfico. El presente estudio resume los resultados de los trabajos en grupo acerca de los problemas principales de los países, de cómo la integración puede ayudar a resolverlos y sobre cuáles son los aspectos críticos del propio proceso de integración desde la perspectiva de los participantes. El trabajo realizado hasta ahora ha desembocado en la formulación de un programa regional de investigación y formación de postgrado. El artículo concluye precisamente con un avance de la ruta crítica a seguir para este abordaje académico del tema.
Hormigas zompopas (Atta cephalotes) influyen positivamente en la biodiversidad vegetal de bosques húmedos tropicales
Authors: Ruiz Javier
Published: October 2010

Realizamos observaciones de la historia natural de la hormiga zompopa (Atta cephalotes) en el período de 1995 a 2010. Monitoreamos una población de hormigas zompopas en 2003 y realizamos experimentos de campo en 2006 en el bosque húmedo tropical de la Estación Biológica La Unión en Nicaragua. Los nidos de hormiga zompopa fueron mapeados dentro de una parcela permanente de 6.5 hectáreas. Se estimó la composición de especies vegetales en el área del nido de la hormiga, y se realizó un conteo de plántulas dicotiledóneas y plántulas de palmas (monocotiledóneas). Los resultados indican que las hormigas zompopas prefieren defoliar plántulas de especies dicotiledóneas, favoreciendo la regeneración de palmas sobre el nido de las hormigas. Las zompopas favorecen la regeneración de palmas en áreas donde ellas establecen el montículo principal de sus nidos. En el artículo se discuten las implicaciones de estos resultados para la dinámica de la regeneración en bosques húmedos tropicales.
Enseñar ciencias: una perspectiva innovadora. Un esquema aproximativo
Authors: Gil Rafael Lucio
Published: October 2010

Enseñar ciencias, en un siglo de complejidades y perplejidades, encierra cada día más desafíos y compromisos. Quizás el más importante sea el de acercarnos a las ideas alternativas que tienen profesores y estudiantes sobre las ciencias, como condición para disponernos a enseñar. Cuando a Ausubel, el gran psicólogo del aprendizaje por descubrimiento, le preguntaron los profesores cómo debían enseñar, él respondió: “Primero conozcan las ideas de sus estudiantes y después enséñenles en consecuencia”.
Homenaje de la Academia de Ciencias de Nicaragua a la Universidad Centroamericana en su 50 Aniversario
Authors: Tünnermann Carlos
Published: October 2010

Por acuerdo unánime de sus miembros, la Academia de Ciencias de Nicaragua, en su última Asamblea General, decidió rendir un homenaje a la Universidad Centroamericana, en ocasión de conmemorarse este año el Cincuenta Aniversario de su fundación.Es justo y acertado que la Academia de Ciencias de nuestro país ofrezca este merecido tributo a una de las instituciones que más ha contribuido al cultivo, transmisión y difusión de las ciencias en Nicaragua.La Universidad Centroamericana, sin lugar a dudas, desde sus primeros años de existencia, ha demostrado un constante compromiso con la investigación científica y su aplicación a la búsqueda de soluciones para nuestros problemas. Además, a este compromiso con la ciencia le ha impreso, desde un comienzo, una clara dimensión social
A Randomised, Cross-Over, Placebo-Controlled Study of Aloe vera in Patients with Irritable Bowel Syndrome: Effects on Patient Quality of Life
Authors: Hutchings H. A. , Wareham K. , Baxter J. N. , Atherton P. , Kingham J. G. C. , Duane P. , Thomas L. , Thomas M. , Ch'ng C. L. , Williams J. G.
Published: October 2010

Background. Irritable bowel syndrome (IBS) is a
chronic, difficult to treat condition. The efficacy of
Aloe vera in treating IBS symptoms is not yet
proven. The purpose of this study was to determine if Aloe
vera is effective in improving quality of life.
Methods. A multicentre, randomised, double-blind,
cross-over placebo controlled study design. Patients were
randomised to Aloe vera, wash-out, placebo or
placebo, washout, Aloe vera. Each preparation
(60 mL) was taken orally twice a day. Patient quality of
life was measured using the Gastrointestinal Symptoms Rating
Score, Irritable Bowel Syndrome Quality of Life, EuroQol and the
Short-Form-12 at baseline and treatment periods 1 and 2.
Results. A total of 110 patients were randomised,
but only 47 completed all questionnaires and both study arms.
Statistical analysis showed no difference between the placebo and
Aloe vera treatment in quality of life.
Discussion. This study was unable to show that Aloe
vera was superior to placebo in improving quality of
life. Drop outs and other confounding factors may have impacted on
the power of the study to detect a clinically important
difference. Conclusion. This study failed to find
Aloe vera superior to placebo in improving
quality of life proven Irritable Bowel Syndrome patients.
Morphological Differentiation of Neurons on Microtopographic Substrates Fabricated by Rolled‐Up Nanotechnology
Authors: Schulze Sabine , Huang Gaoshan , Krause Matthias , Aubyn Deborah , Quiñones Vladimir A. Bolaños , Schmidt Christine K. , Mei Yongfeng , Schmidt Oliver G.
Published: October 2010

Arrays of transparent rolled‐up microtubes can easily be mass‐produced using a combination of conventional photolithography, electron beam depositioning, and chemical etching techniques. Here, we culture primary mouse motor neurons and immortalised CAD cells, a cell line derived from the central nervous system, on various microtube substrates to investigate the influence of topographical surface features on the growth and differentiation behaviour of these cells. Our results indicate that the microtube chips not only support growth of both cell types but also provide a well‐defined, geometrically confined 3D cell culture scaffold. Strikingly, our micropatterns act as a platform for axon guidance with protruding cell extensions aligning in the direction of the microtubes and forming complex square‐shaped grid‐like neurite networks. Our experiments open up a cost‐efficient and bio‐compatible way of analysing single cell behaviour in the context of advanced micro‐/nanostructures with various biological applications ranging from neurite protection studies to cell sensor development.
Screening of T7 phage displayed Bactrocera dorsalis (Hendel) antenna cDNA library against chemosensory protein
Authors: Hu Liming , Shen Jianmei , Hu Meiying , Rizwan‐ul‐Haq Muhammad , Hao Weining
Published: October 2010

Recent studies have shown that chemosensory proteins (CSPs) were involved in diverse life activities such as insect feeding, development, mating, immune regulation, as well as other important circadian rhythms, etc. To screen the proteins involved in the BdorCSP‐related physiological activity, a cDNA library of the Bactrocera dorsalis (Hendel) antenna expressed on the surface of T7 phage was screened against BdorCSP. After four rounds of screening, ELISA‐positive samples of selected phages were sequenced and identified as protein disulfide isomerase (PDI), trypsin‐like serine protease (Ser), TakeOut (TO), and a new protein by GenBank blast, respectively. Real‐time quantitative PCR results showed that the expression levels of Ser, TO, and the new protein were the highest in antenna, sharing similar expression pattern with BdorCSP. These results reveal that these proteins might be involved in the BdorCSP‐related physiological or metabolic activities. This work paves a new way for exploring the function of CSPs. © 2010 Wiley Periodicals, Inc.
Colloidal Microcapsules: Self‐Assembly of Nanoparticles at the Liquid–Liquid Interface
Authors: Patra Debabrata , Sanyal Amitav , Rotello Vincent M.
Published: October 2010

Colloidal microcapsules (MCs) are highly modular, inherently multiscale constructs of capsules stabilized by nano‐/microparticle shells, with applications in many areas of materials and biological sciences, such as drug delivery, encapsulation, and microreactors. Until recently, fabrication of colloidal MCs focused on the use of submicron‐sized particles because the smaller nanoparticles (NPs) are inherently unstable at the interface owing to thermal disorder. However, stable microcapsules can now be obtained by tuning the interactions between the nanometer‐sized building blocks at the liquid–liquid interface. This Review highlights recent developments in the fabrication of colloidal MCs using NPs.
Absorption of CH330331, a novel 4‐anilinoquinazoline inhibitor of epidermal growth factor receptor tyrosine kinase: comparative studies using in vitro, in situ and in vivo models
Authors: Sun Haiyan , Bi Huichang , Huang Min , Liu Dong , Qin Zhenyu
Published: October 2010

CH330331 is a prototype of a new class of synthetic small molecule tyrosine kinase inhibitors (TKIs). In vitro Caco‐2 cell monolayers, the in situ single‐pass rat intestinal perfusion (SPIP) technique with mesenteric vein cannulated and an in vivo animal model were employed to investigate its permeability and transepithelial transport mechanisms. The Caco‐2 model showed that the transport of CH330331 across the monolayers from the apical (AP) to basolateral (BL) side was 6‐ to 10‐fold higher than that from the BL to AP side. The apparent permeability coefficient (Papp) values of CH330331 at 5–20 µg/ml from the AP to BL and from BL to AP side were 5.30–2.21 × 10−6 cm/s, with a decrease in Papp values from the AP to BL side at increased CH330331 concentrations. In the perfused rat intestinal model, a concentration dependent change in permeability was detected where Pblood at 5 µg/ml (1.66 ± 0.69 × 10−6 cm/s) and 10 µg/ml (1.80 ± 0.45 × 10−6 cm/s) was significantly different from Pblood at 20 µg/ml (0.98 ± 0.31 × 10−6 cm/s, p<0.05). Some inhibitors could also change the transepithelial transport of CH330331. Moreover, the in vivo study showed that the oral bioavailability of CH330331 was 82.7% in the rat. All the results confirmed that the transepithelial transport of CH330331 was rapid and saturable, which might involve an active mechanism. The oral bioavailability of CH330331 was relatively high in vivo. Copyright © 2010 John Wiley & Sons, Ltd.
The effect of drugs with ion channel‐blocking activity on the early embryonic rat heart
Authors: Abela Dominique , Ritchie Helen , Ababneh Deena , Gavin Caroline , Nilsson Mats F. , Khan Muhammad Khalid , Carlsson Kristin , Webster William S.
Published: October 2010

This study investigated the effects of a range of pharmaceutical drugs with ion channel‐blocking activity on the heart of gestation day 13 rat embryos in vitro. The general hypothesis was that the blockade of theIKr/hERG channel, that is highly important for the normal functioning of the embryonic rat heart, would cause bradycardia and arrhythmia. Concomitant blockade of other channels was expected to modify the effects of hERG blockade. Fourteen drugs with varying degrees of specificity and affinity toward potassium, sodium, and calcium channels were tested over a range of concentrations. The rat embryos were maintained for 2 hr in culture, 1 hr to acclimatize, and 1 hr to test the effect of the drug. All the drugs caused a concentration‐dependent bradycardia except nifedipine, which primarily caused a negative inotropic effect eventually stopping the heart. A number of drugs induced arrhythmias and these appeared to be related to either sodium channel blockade, which resulted in a double atrial beat for each ventricular beat, orIKr/hERG blockade, which caused irregular atrial and ventricular beats. However, it is difficult to make a precise prediction of the effect of a drug on the embryonic heart just by looking at the polypharmacological action on ion channels. The results indicate that the use of the tested drugs during pregnancy could potentially damage the embryo by causing periods of hypoxia. In general, the effects on the embryonic heart were only seen at concentrations greater than those likely to occur with normal therapeutic dosing.Birth Defects Res (Part B)89:429–440, 2010. © 2010 Wiley‐Liss, Inc.
Thalidomide Derivatives for the Treatment of Neuroinflammation
Authors: Contino‐Pépin Christiane , Parat Audrey , Patinote Cindy , Roscoe Wendi A. , Karlik Stephen J. , Pucci Bernard
Published: October 2010

The precise mechanism‐of‐action of thalidomide remains uncertain and might differ between diseases and under different clinical condition. With implications in the treatment of a variety of inflammatory and autoimmune diseases, as well as for use as an anticancer agent, alone or in combination with established therapeutics, it is clear that thalidomide and its derivatives deserve further scrutiny. In particular, thalidomide was shown to be effective in a mouse model of multiple sclerosis (MS), an autoimmune inflammatory disorder, called experimental autoimmune encephalomyelitis (EAE). Herein, we describe the synthesis and preliminary biological evaluation of new macromolecular prodrugs of thalidomide bearing an aminoalkyl group on the phthalimide ring. The effectiveness of these compounds to limit EAE was investigated, and it was shown that, at 100 mg kg−1 thalidomide‐equivalent dose, they abrogated the clinical and pathological features of EAE.
Hydrolysis of Cellulose by Using Catalytic Amounts of FeCl2 in Ionic Liquids
Authors: Tao Furong , Song Huanling , Chou Lingjun
Published: October 2010

Microcrystalline cellulose (MCC) is hydrolyzed to an appreciable extent (70 %) by using 1‐(4‐sulfonic acid) butyl‐3‐methylimidazolium hydrogen sulfate (IL‐1) as effective catalyst. Valuable chemicals, such as 5‐hydroxymethyl furfural (HMF) and furfural, are obtained in relatively high yields (15 % and 7 %, respectively). Interestingly, the introduction of FeCl2 as catalyst into IL‐1 further enhances the catalytic activity, as proved by the higher conversion of MCC (84 %) and higher yields of HMF and furfural (34 % and 19 %, respectively) under the same experimental conditions, although small amounts of levulinic acid (LA) and total reducing sugars (TRS) were also found. The hydrolysis of MCC scarcely proceeded, or showed a lower efficiency, in the absence of catalyst (4 %) or with Al2O3 (7 %), inorganic acids (≤65 %), or several other ionic liquids (≤24 %) as catalyst. Dimers of furan compounds were detected as the main byproducts, as analyzed by HPLC–MS; from the mass spectrometry analysis, the components of the gas‐phase products were determined to be methane, ethane, CO, CO2, and H2. A mechanism to explain the high activity of FeCl2 in the IL‐1 system is proposed. Recycling of the IL‐1 catalyst showed an almost constant activity during five successive trials. The simple and effective catalyst system may prove valuable in facilitating the energy‐efficient and cost‐effective conversion of biomass into biofuels and platform chemicals.
Wnt/calcium signaling mediates axon growth and guidance in the developing corpus callosum
Authors: Hutchins B. Ian , Li Li , Kalil Katherine
Published: October 2010

It has been shown in vivo that Wnt5a gradients surround the corpus callosum and guide callosal axons after the midline (postcrossing) by Wnt5a‐induced repulsion via Ryk receptors. In dissociated cortical cultures we showed that Wnt5a simultaneously promotes axon outgrowth and repulsion by calcium signaling. Here to test the role of Wnt5a/calcium signaling in a complex in vivo environment we used sensorimotor cortical slices containing the developing corpus callosum. Plasmids encoding the cytoplasmic marker DsRed and the genetically encoded calcium indicator GCaMP2 were electroporated into one cortical hemisphere. Postcrossing callosal axons grew 50% faster than pre‐crossing axons and higher frequencies of calcium transients in axons and growth cones correlated well with outgrowth. Application of pharmacological inhibitors to the slices showed that signaling pathways involving calcium release through IP3 receptors and calcium entry through TRP channels regulate post‐crossing axon outgrowth and guidance. Co‐electroporation of Ryk siRNA and DsRed revealed that knock down of the Ryk receptor reduced outgrowth rates of postcrossing but not precrossing axons by 50% and caused axon misrouting. Guidance errors in axons with Ryk knockdown resulted from reduced calcium activity. In the corpus callosum CaMKII inhibition reduced the outgrowth rate of postcrossing (but not precrossing) axons and caused severe guidance errors which resulted from reduced CaMKII‐dependent repulsion downstream of Wnt/calcium. We show for the first time that Wnt/Ryk calcium signaling mechanisms regulating axon outgrowth and repulsion in cortical cultures are also essential for the proper growth and guidance of postcrossing callosal axons which involve axon repulsion through CaMKII. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 71: 269–283, 2011.
The reasons why eating disorder patients drink
Authors: Hart Susan , Abraham Suzanne , Franklin Richard C. , Russell Janice
Published: October 2010

Objective

To explore the reasons why eating disorder patients consume non‐alcoholic fluids and to examine variables associated with poor and excessive drinking.

Methods

A sample of 115 patients admitted for inpatient treatment to a specialist eating disorder facility completed a semi‐standardised retrospective fluid intake history of type and amount of fluid and of reasons for drinking. ANOVA, chi‐square and factor analysis were performed.

Results

The main reasons for consuming fluids were for fullness and appetite suppression; for feelings of control including feeling empty; to assist with purging; and for physiological reasons such as drinking when thirsty, after exercising and to increase energy levels via caffeine ingestion.

Discussion

An eating disorder needs to be considered a disorder of fluid intake, as much as a disorder of food intake. Factors affecting the fluid intake of eating disorder patients are related to the presence of eating disorder behaviours. Copyright © 2010 John Wiley & Sons, Ltd and Eating Disorders Association.
River channel and bar patterns explained and predicted by an empirical and a physics‐based method
Authors: Kleinhans Maarten G. , van den Berg Jan H.
Published: October 2010

Our objective is to understand general causes of different river channel patterns. In this paper we compare an empirical stream power‐based classification and a physics‐based bar pattern predictor. We present a careful selection of data from the literature that contains rivers with discharge and median bed particle size ranging over several orders of magnitude with various channel patterns and bar types, but no obvious eroding or aggrading tendency. Empirically a continuum is found for increasing specific stream power, here calculated with pattern‐independent variables: mean annual flood, valley gradient and channel width predicted with a hydraulic geometry relation. ‘Thresholds’, above which certain patterns emerge, were identified as a function of bed sediment size. Bar theory predicts nature and presence of bars and bar mode, here converted to active braiding index (Bi). The most important variables are actual width–depth ratio and nonlinearity of bed sediment transport. Results agree reasonably well with data. Empirical predictions are somewhat better than bar theory predictions, because the bank strength is indirectly included in the empirical prediction. In combination, empirical and theoretical prediction provide partial explanations for bar and channel patterns. Increasing potential‐specific stream power implies more energy to erode banks and indeed correlates to channels with high width–depth ratio. Bar theory predicts that such rivers develop more bars across the width (higher Bi). At the transition from meandering to braiding, weakly braided rivers and meandering rivers with chutes are found. Rivers with extremely low stream power and width–depth ratios hardly develop bars or dynamic meandering and may be straight or sinuous or, in case of disequilibrium sediment feed, anastomosing. Copyright © 2010 John Wiley & Sons, Ltd.
Terrestrial laser scanning soil surfaces: a field methodology to examine soil surface roughness and overland flow hydraulics
Authors: Smith Mark W. , Cox Nicholas J. , Bracken Louise J.
Published: October 2010

Conventional roughness–resistance relationships developed for pipe and open‐channel flows cannot accurately describe shallow overland flows over natural rough surfaces. This paper develops a new field methodology combining terrestrial laser scanning (TLS) and overland flow simulation to provide a high‐resolution dataset of surface roughness and overland flow hydraulics as simulated on natural bare soil surfaces. This method permits a close examination of the factors controlling flow velocity and a re‐evaluation of the relationship between surface roughness and flow resistance. The aggregate effect of flow dynamics, infiltration and depression storage on retarding the passage of water over a surface is important where runoff‐generating areas are distant from well‐defined channels. Experiments to separate these effects show that this ‘effective resistance’ is dominated by surface roughness. Eight measurements of surface roughness are found to be related to flow resistance: standard deviation of elevations, inundation ratio, pit density (measured both perpendicular and parallel to the flow direction), slope, median depth, skewness of the depth distribution and frontal area. Hillslope position is found to affect the significant roughness measures. In contrast, infiltration rate has little effect on the velocity of water fronts advancing over the soil surfaces examined here and the effect of depression storage is limited. Overland flow resistance is depth dependent where complex microtopographic structures are progressively inundated. Copyright © 2010 John Wiley & Sons, Ltd.
Development and application of a physically based landscape water balance in the SWAT model
Authors: White Eric D. , Easton Zachary M. , Fuka Daniel R. , Collick Amy S. , Adgo Enyew , McCartney Matthew , Awulachew Seleshi B. , Selassie Yihenew G. , Steenhuis Tammo S.
Published: October 2010

Watershed scale hydrological and biogeochemical models rely on the correct spatial‐temporal prediction of processes governing water and contaminant movement. The Soil and Water Assessment Tool (SWAT) model, one of the most commonly used watershed scale models, uses the popular curve number (CN) method to determine the respective amounts of infiltration and surface runoff. Although appropriate for flood forecasting in temperate climates, the CN method has been shown to be less than ideal in many situations (e.g. monsoonal climates and areas dominated by variable source area hydrology). The CN model is based on the assumption that there is a unique relationship between the average moisture content and the CN for all hydrologic response units (HRUs), and that the moisture content distribution is similar for each runoff event, which is not the case in many regions. Presented here is a physically based water balance that was coded in the SWAT model to replace the CN method of runoff generation. To compare this new water balance SWAT (SWAT‐WB) to the original CN‐based SWAT (SWAT‐CN), two watersheds were initialized; one in the headwaters of the Blue Nile in Ethiopia and one in the Catskill Mountains of New York. In the Ethiopian watershed, streamflow predictions were better using SWAT‐WB than SWAT‐CN [Nash–Sutcliffe efficiencies (NSE) of 0·79 and 0·67, respectively]. In the temperate Catskills, SWAT‐WB and SWAT‐CN predictions were approximately equivalent (NSE > 0·70). The spatial distribution of runoff‐generating areas differed greatly between the two models, with SWAT‐WB reflecting the topographical controls imposed on the model. Results show that a water balance provides results equal to or better than the CN, but with a more physically based approach. Copyright © 2010 John Wiley & Sons, Ltd.
Pan evaporation and potential evapotranspiration trends in South Florida
Authors: Abtew Wossenu , Obeysekera Jayantha , Iricanin Nenad
Published: October 2010

Declining trends in pan and lake evaporation have been reported. It is important to study this trend in every region to evaluate the validity of the trend and water management implications. Data from nine pan evaporation sites in South Florida were evaluated to see if there is a trend and if the quality of the data is sufficient for such analysis. The conclusion is that pan evaporation measurements are prone to too many sources of errors to be used for trend analysis. This condition is demonstrated in South Florida and in other regions by differences in magnitude and direction between spatially related pan stations and unexplainable observations. Also, potential evapotranspiration (ETp) was estimated with the Simple (Abtew equation) and the Penman–Monteith method. Both cases indicated no decline in evapotranspiration for the period of analysis. Based on the decline in humidity and the increasing trend in vapor pressure deficit for the short period of analysis, 1992–2009, it appears that South Florida is experiencing increase in evaporation and evapotranspiration at this time assuming no systematic error in the weather stations' observations. Copyright © 2010 John Wiley & Sons, Ltd.
Testicular development evaluation in rats exposed to 60 Hz and 1 mT electromagnetic field
Authors: Tenorio Bruno Mendes , Jimenez George Chaves , Morais Rosana Nogueira , Torres Sandra Maria , Albuquerque Nogueira Romildo , Silva Junior Valdemiro Amaro
Published: October 2010

Society has been increasingly exposed to low‐frequency electromagnetic fields (EMF), mainly from electricity distribution networks and electro‐electronic devices. Aiming to clarify the extension of possible interactions between EMF and testicular development, this study evaluated the effects of exposure to 60 Hz and 1 mT EMF in the maturation of testicular components. Wistar rats were exposed to EMF three times per day for 30 min, between the 13th day of gestation and the 21st postnatal day. Results showed a decrease in the following parameters: tubular diameter and seminiferous tubules area; seminiferous epithelium height; total volume of seminiferous tubule; tubular lumen; seminiferous epithelium; and Leydig cells. On the other hand, an increase was observed in connective tissue cells and blood vessels volume. Plasma testosterone, Sertoli cells population, tubular length and gonadosomatic index did not change when exposed to EMF. Histomorphometric analysis showed that exposure to EMF can promote a delay in testicular development. Copyright © 2010 John Wiley & Sons, Ltd.
High‐resolution imaging and nano‐manipulation of biological structures on surface
Authors: Zhang Yi , Hu Xiaofang , Sun Jielin , Shen Yi , Hu Jun , Xu Xuemin , Shao Zhifeng
Published: October 2010

In this mini‐review we discuss our recent findings on imaging and manipulation of biological macromolecular structures by atomic force microscopy (AFM). In the first part of this review, we focus on high‐resolution imaging of selected biological samples. AFM images of membrane proteins have revealed detailed conformational features related to identifiable biological functions. Different self‐assembling behaviors of short peptides into supramolecular structures on various substrates under controlled environmental conditions have been systematically studied with AFM imaging. In the second part, we present a novel nano‐manipulation technique for manipulating, isolating, amplifying, and sequencing of individual DNA molecules, which may find unique applications in the analysis of difficult sequence structures. Finally, we discuss how to characterize the elasticity of individual biomolecules and live cells. These results demonstrate that not only the high resolution capacity of the AFM is suited to resolve certain biological questions, but can also be applied to single molecule isolation and biomechanical analysis with its unique advantages. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.
Effect of arsenic absorption on the water‐refilling speed of Pteris cretica
Authors: Lee Sang Joon , Lee Jin Pyung
Published: October 2010

Heavy metals are largely responsible for soil and water pollution. Recently, phytoremediation is receiving a large attention as a plant‐based technology for removing metals from contaminated soil and water in an environment‐friendly and cost‐effective way. In such context, some species of ferns such as Pteris cretica were found to be a hyper‐accumulator of arsenic (As). In this study, we first explored the validity of measuring the water‐refilling process in xylem vessels of Pteris cretica using the synchrotron X‐ray microimaging technique. Then we investigated the effects of arsenic concentration on the water‐refilling speed inside the xylem vessel. The methodology to measure the water‐refilling speed was consistent within five repetitions and 3 hours after the stem sample was cut from the plant. The water‐refilling speed in the xylem vessels of the Pteris grown in arsenic solution was faster than that in normal water. Arsenic concentration of 0–1,000 μM was tested and the maximum speed was obtained at 500 μM. Conclusively, the experimental methodology developed in this study allowed to obtain some interesting results for understanding how arsenic affect the xylem sap flow transport and the mechanism by which growth is enhanced in the presence of heavy metal. Microsc. Res. Tech., 2010. © 2010 Wiley‐Liss, Inc.
p120 catenin/αN‐catenin are molecular targets in the neuroprotection and neuronal plasticity mediated by atorvastatin after focal cerebral ischemia
Authors: Céspedes‐Rubio Angel , Jurado Francisco Wandosell , Cardona‐Gómez Gloria Patricia
Published: October 2010

Atorvastatin (ATV), a 3‐hydroxy 3‐methylglutaryl coenzyme A (HMG‐CoA) reductase inhibitor, exerts beneficial effects on stroke through several pleiotropic mechanisms. However, its role following cerebral ischemia is not completely understood yet. We evaluated the effect of ATV treatment on the synaptic adhesion proteins after a transient middle cerebral artery occlusion (t‐MCAO) model in rats. Ischemic male Wistar rats were treated with 10 mg/kg ATV. The first dose was 6 hr after reperfusion, then every 24 hr for 3days. Our findings showed that ATV treatment produced an increase in pAkt ser473 and a decrease in pMAPK 44/42 protein levels 12 and 24 hr postischemia in the cerebral cortex and the hippocampus. However, p120 catenin and αN‐catenin became drastically increased throughout the temporal course of postischemia treatment (12–72 hr), mainly in the hippocampus. Neurological recovery was observed at 48 and 72 hr, supported by a significant reduction of infarct volume, neuronal loss, and glial hyperreactivity after 72 hr of postischemia treatment with ATV. ATV treatment also up‐regulated the association of p120ctn, αN‐catenin to PSD‐95, accompanied by a reduction of RhoA activation and the recovery of MAP2 immunoreactivity, these being significantly affected by the focal cerebral ischemia. Our findings suggested that p120ctnand αN‐catenin synaptic adhesion proteins are crucial molecular targets in ATV‐mediated neuroprotection and neuronal plasticity after focal cerebral ischemia. © 2010 Wiley‐Liss, Inc.
Hypothermia‐induced increase of oligodendrocyte precursor cells: Possible involvement of plasmalemmal voltage‐dependent anion channel 1
Authors: Imada Shinya , Yamamoto Masahiro , Tanaka Kayoko , Seiwa Chika , Watanabe Kenji , Kamei Yoshimasa , Kozuma Shiro , Taketani Yuji , Asou Hiroaki
Published: October 2010

Hypothermia is believed to suppress cell proliferation by inducing apoptosis/necrosis and phase‐specific/nonspecific cell cycle arrest, which are, directly or indirectly, related to a reduced energy supply. Intriguingly, hypothermia is known to improve neurological recovery of animals and humans exposed to focal brain hypoxic‐ischemic injury. The underlying mechanism of the neuroprotective effect of hypothermia is unclear, although the prevention of neural cell apoptosis is thought to play a role. Herein we demonstrate that in vitro cell culture of oligodendrocyte precursor cells (OPCs) under conditions of mild hypothermia (31.5°C) results in an increase in cell number relative to cells cultured under normothermic conditions (37°C). Cell cycle analysis, immunoblotting of cyclins, TUNEL assay, and immunocytochemistry of OPC differentiation markers suggest that hypothermia shifts the balance between proliferation and apoptosis/differentiation toward proliferation. A combination of transcriptome analysis, pharmacological intervention, and immunoaffinity‐based assays suggests a possible involvement of the Gα13–Rho GTPase Cdc42–ERK1/2 signaling cascade and voltage‐dependent anion channel 1 (VDAC1), which associate or dissociate with Gα13 protein at 37°C and 31.5°C, respectively. Immunoelectron microscopy revealed the presence of VDAC1 in the plasma membrane of OPCs. Furthermore, the exogenous addition of impermeable VDAC1 inhibitors enhanced proliferation of OPCs at 37°C. These results may contribute to the elucidation of the mechanism of hypothermic neuroprotection as well as the possible novel role of plasmalemmal VDAC1. © 2010 Wiley‐Liss, Inc.