bluuebunny/crossref_metadata_2025 huggingface dataset:
De l’acceptation à la résistance
Authors: Wallach Isabelle
Published: March 2014

S’inscrivant dans la continuité des recherches sur la perception du corps des femmes âgées, dans un contexte sociétal marqué par le sexisme et l’âgisme, l’auteure examine les attitudes de 14 femmes âgées de 50 ans et plus vivant avec le VIH devant les transformations de leur apparence. L’analyse des discours met en lumière une diversité d’attitudes allant de l’acceptation à la dépréciation des changements corporels. L’auteure considère les facteurs influant sur cette variabilité d’attitudes, tout en pointant le rôle joué par la perception du vieillissement, l’importance accordée à l’apparence et aux normes de beauté, l’expérience du VIH et la vie intime.
Le changement social et la rhétorique traditionaliste
Authors: Martin Hélène
Published: March 2014

Basée sur une recherche de terrain menée de 2002 à 2006 à Agadir (Maroc), cet article se développe autour de la question suivante : comment comprendre qu’une rhétorique traditionaliste (un appel à la tradition) contribue à encourager et à légitimer l’entrepreneuriat féminin (à valoriser le changement social)? Au cours des années 2000, en effet, l’entrepreneuriat féminin a émergé socialement en étant renvoyé à des valeurs considérées comme à la fois féminines et traditionnelles. Présenté comme une réponse possible à une « crise » sociale, vue telle une crise des « valeurs culturelles », il a été opposé à différentes figures d’« hommes démissionnaires ». Cependant, les positions des entrepreneures dans la hiérarchie sociale, à savoir leurs différentes conditions d’existence, les plaçaient dans des rapports différenciés, plus ou moins transgressifs, à l’égard du travail et des valeurs « traditionnelles » qui légitimaient généralement l’entrepreneuriat féminin. L’auteure montre ainsi que les actrices et les acteurs aménagent la tradition et instrumentalisent des catégories identitaires, tout en s’inscrivant de manière contrastée dans des rapports sociaux structurants.
Blend ratio dependence of photovoltaic properties in octahexylphthalocyanine-based small molecule solar cell
Authors: Dao Quang-Duy , Kumada Taishi , Fukui Hitoshi , Ohmori Masashi , Fujii Akihiko , Shimizu Yo , Ozaki Masanori
Published: March 2014

A study on the blend ratio dependence of the photovoltaic properties in bulk heterojunction organic solar cells (OSCs) consisting of [6,6]-phenyl-C71 butyric acid methyl ester ([70]PCBM) and 1,4,8,11,15,18,22,25-octahexylphthalocyanine (C6PcH2) has been reported. With increasing the [70]PCBM volume fraction, the short-circuit current density was enhanced to be 10.6 mA·cm−2 owing to the enlargement of the donor and acceptor interfacial areas. However, when the [70]PCBM volume fraction was higher than 33%, the fill factor was reduced owing to the deterioration of crystallization of discotic C6PcH2 molecules with hexagonal structures. The OSCs with the optimum blend ratio demonstrated a high power conversion efficiency of 3.9%.
Efeito da adição do 2,4-D ao glyphosate para o controle de espécies de plantas daninhas de difícil controle
Authors: Takano Hudson Kagueyama , Oliveira Junior Rubem Silvério , Constantin Jamil , Biffe Denis Fernando , Franchini Luiz Henrique Morais , Braz Guilherme Braga Pereira , Rios Fabiano Aparecido , Gheno Eliezer Antonio , Gemelli Alexandre
Published: March 2014

O 2,4-D tem sido um dos herbicidas mais utilizados em associação com o glyphosate, principalmente nas aplicações de dessecação em pré-plantio. O objetivo deste trabalho foi avaliar o efeito da adição do 2,4-D ao glyphosate visando o controle de espécies de plantas daninhas consideradas de difícil controle (Commelina benghalensis, Richardia brasiliensis, Euphorbia heterophylla, Spermacoce latifolia, Ipomoea grandifolia e Conyza spp.). O delineamento experimental foi o inteiramente casualizado, e os tratamentos foram arranjados em esquema fatorial 3 x 4, com quatro repetições. O primeiro fator foi constituído por estádios de desenvolvimento das plantas daninhas (2-4, 4-6 e >10 folhas) e o segundo fator por tratamentos com glyphosate (720 g i.a. ha-1), 2,4-D (670 g i.a. ha-1) glyphosate+2,4-D (720+670 g i.a. ha-1) e um tratamento sem herbicida (testemunha). Para a buva em casa-de-vegetação, foram realizados mais três tratamentos herbicidas adicionais variando as doses de glyphosate e 2,4-D. A adição de 2,4-D ao glyphosate foi determinante para acelerar e melhorar o controle de plantas daninhas de difícil controle estudadas.
Representative regional sampling of carbon dioxide and methane concentrations in hemiboreal headwater streams reveal underestimates in less systematic approaches
Authors: Wallin Marcus B. , Löfgren Stefan , Erlandsson Martin , Bishop Kevin
Published: March 2014

Boreal headwater streams have been identified as hot spots for evasion of greenhouse gases (GHGs). This study was the first to systematically determine the concentrations of CO2 and CH4 in hemiboreal headwater streams. The use of a headspace sampling method focusing on GHGs in combination with a statistically representative selection of more than 200 streams across two regions in Sweden was the basis for defining the base flow concentrations of CO2 and CH4. All streams were supersaturated relative to the atmosphere in CO2 and the majority in CH4 for the 82% of streams in which CH4 was detected. The spatial variability in both CO2 and CH4 was high but positively related to total organic carbon, mean annual temperature, and proportion of peatland in the catchment. There were, however, regional differences in the spatial controls, which are something that predictive models need to consider. The data set allowed for comparison between a headspace and an alkalinity‐based method for determining CO2. More than 50% of the streams contained no alkalinity which made the alkalinity‐based determination of CO2 impossible. In addition, half of the streams with alkalinity had alkalinities low enough (<0.07 meq L−1) to make the CO2 determination very uncertain. The streams with low pH and no alkalinity contained median CO2 concentrations that were 45% higher than the streams containing alkalinity. Therefore, large‐scale generalizations about CO2 in such headwaters will be significantly underestimated if (1) headwaters are underrepresented and (2) the headwaters are sampled but CO2 is calculated from their alkalinity.
Intra‐annual variability of organic carbon concentrations in running waters: Drivers along a climatic gradient
Authors: Winterdahl Mattias , Erlandsson Martin , Futter Martyn N. , Weyhenmeyer Gesa A. , Bishop Kevin
Published: March 2014

Trends in surface water dissolved organic carbon (DOC) concentrations have received considerable scientific interest during recent decades. However, intra‐annual DOC variability is often orders of magnitude larger than long‐term trends. Unraveling the controls on intra‐annual DOC dynamics holds the key to a better understanding of long‐term changes and their ecological significance. We quantified and characterized intra‐annual DOC variability and compared it with long‐term DOC trends in 136 streams and rivers, varying in size and geographical characteristics, across a 1400 km latitudinal gradient during 2000–2010. Discharge, temperature, and month of the year were the most significant predictors of intra‐annual DOC variability in a majority of the running waters. Relationships between DOC, discharge, and temperature were, however, different along a mean annual temperature (MAT) gradient. Running waters with low MAT generally displayed positive DOC‐discharge correlations whereas the relationships in sites with higher MAT were more variable. This reflected contrasting relationships between temperature and discharge with discharge positively correlated with temperature in cold areas, while it was negatively correlated with temperature in catchments with higher MAT. Sites where flow, temperature, and month were poorly related to intra‐annual DOC dynamics were large catchments or sites with extensive upstream lake cover. DOC trends were generally much smaller than intra‐annual DOC variability and did not show any north‐south gradient. Our findings suggest that DOC in running waters could respond to a changing climate in ways not predictable, or even discernible, from extrapolation of recent interannual trends.
Bayesian multimodel estimation of global terrestrial latent heat flux from eddy covariance, meteorological, and satellite observations
Authors: Yao Yunjun , Liang Shunlin , Li Xianglan , Hong Yang , Fisher Joshua B. , Zhang Nannan , Chen Jiquan , Cheng Jie , Zhao Shaohua , Zhang Xiaotong , Jiang Bo , Sun Liang , Jia Kun , Wang Kaicun , Chen Yang , Mu Qiaozhen , Feng Fei
Published: March 2014

Accurate estimation of the satellite‐based global terrestrial latent heat flux (LE) at high spatial and temporal scales remains a major challenge. In this study, we introduce a Bayesian model averaging (BMA) method to improve satellite‐based global terrestrial LE estimation by merging five process‐based algorithms. These are the Moderate Resolution Imaging Spectroradiometer (MODIS) LE product algorithm, the revised remote‐sensing‐based Penman‐Monteith LE algorithm, the Priestley‐Taylor‐based LE algorithm, the modified satellite‐based Priestley‐Taylor LE algorithm, and the semi‐empirical Penman LE algorithm. We validated the BMA method using data for 2000–2009 and by comparison with a simple model averaging (SA) method and five process‐based algorithms. Validation data were collected for 240 globally distributed eddy covariance tower sites provided by FLUXNET projects. The validation results demonstrate that the five process‐based algorithms used have variable uncertainty and the BMA method enhances the daily LE estimates, with smaller root mean square errors (RMSEs) than the SA method and the individual algorithms driven by tower‐specific meteorology and Modern Era Retrospective Analysis for Research and Applications (MERRA) meteorological data provided by the NASA Global Modeling and Assimilation Office (GMAO), respectively. The average RMSE for the BMA method driven by daily tower‐specific meteorology decreased by more than 5 W/m2 for crop and grass sites, and by more than 6 W/m2 for forest, shrub, and savanna sites. The average coefficients of determination (R2) increased by approximately 0.05 for most sites. To test the BMA method for regional mapping, we applied it for MODIS data and GMAO‐MERRA meteorology to map annual global terrestrial LE averaged over 2001–2004 for spatial resolution of 0.05°. The BMA method provides a basis for generating a long‐term global terrestrial LE product for characterizing global energy, hydrological, and carbon cycles.
Atmospheric gravity waves due to the Tohoku‐Oki tsunami observed in the thermosphere by GOCE
Authors: Garcia Raphael F. , Doornbos Eelco , Bruinsma Sean , Hebert Hélène
Published: March 2014

Oceanic tsunami waves couple with atmospheric gravity waves, as previously observed through ionospheric and airglow perturbations. Aerodynamic velocities and density variations are computed from Gravity Field and Steady‐State Ocean Circulation Explorer (GOCE) accelerometer and thruster data during Tohoku‐Oki tsunami propagation. High‐frequency perturbations of these parameters are observed during three expected crossings of the tsunami‐generated gravity waves by the GOCE satellite. From theoretical relations between air density and vertical and horizontal velocities inside the gravity wave, we demonstrate that the measured perturbations are consistent with a gravity wave generated by the tsunami and provide a way to estimate the propagation azimuth of the gravity wave. Moreover, because GOCE measurements can constrain the wave polarization, a marker (noted C3) of any gravity wave crossing by the GOCE satellite is constructed from correlation coefficients between the observed atmospheric state parameters. These observations validate a new observation tool of thermospheric gravity waves generated by tsunamis above the open ocean.
Reconstruction of gaps in the past history of solar wind parameters
Authors: Kondrashov D. , Denton R. , Shprits Y. Y. , Singer H. J.
Published: March 2014

The historical (1972–2013) gaps of the solar wind parameters are filled‐in by smooth modes of covariability using the continuous geomagnetic indices with Singular Spectrum Analysis (SSA). A systematic study using experiments with synthetic gaps has been performed to determine optimal SSA parameters for reconstruction of gaps over full solar cycle and to assess the reconstruction skill. We assessed the accuracy of the SSA gap‐filling for solar wind reconstruction in T96 and TS05 empirical magnetic field models by using GOES measurements at geostationary orbit, and compared it to the results based on parameters from existing Qin and Denton interpolation. The SSA gap‐filling method does improve accuracy of empirical magnetic field models, especially when gaps are large and in particular for the TS05 magnetic field model.
Macroporous Ceramics by Gelation–Freezing Route Using Gelatin
Authors: Fukushima Manabu , Yoshizawa Yu‐ichi , Ohji Tatsuki
Published: March 2014

This paper reviews an advanced methodology for macroporous ceramic components, that can create nearly honeycomb shaped pore channels, unlike either ellipsoidal or dendritic or lamellar structures obtained via conventional freeze casting. Three main technological features have been discussed in terms of (i) honeycomb shaped morphologies, (ii) relationship between carefully selected freezing conditions, and cell properties generated, (iii) the engineering applications. This simple, ecofriendly, and versatile approach tailors porous architecture with engineered porosity and yields macro‐cellular component with distinctive characteristics suitable for a variety of industrial applications.
Turning ZnO into an Efficient Energy Upconversion Material by Defect Engineering
Authors: Stehr Jan E. , Chen Shula L. , Reddy Nandanapalli Koteeswara , Tu Charles W. , Chen Weimin M. , Buyanova Irina A.
Published: March 2014

Photon upconversion materials are attractive for a wide range of applications from medicine, biology, to photonics. Among them, ZnO is of particular interest owing to its outstanding combination of materials and physical properties. Though energy upconversion has been demonstrated in ZnO, the exact physical mechanism is still unknown, preventing control of the processes. Here, defects formed in bulk and nanostructured ZnO synthesized using standard growth techniques play a key role in promoting efficient energy upconversion via two‐step two‐photon absorption (TS‐TPA). From photoluminescence excitation of the anti‐Stokes emissions, the threshold energy of the TS‐TPA process is determined as being 2.10–2.14 eV in all studied ZnO materials irrespective of the employed growth techniques. This photo‐electron paramagnetic resonance studies show that this threshold closely matches the ionization energy of the zinc vacancy (a common grown‐in intrinsic defect in ZnO), thereby identifying the zinc vacancy as being the dominant defect responsible for the observed efficient energy upconversion. The upconversion is found to persist even at a low excitation density, making it attractive for photonic and photovoltaic applications.
Organic Thermoelectric Materials: Emerging Green Energy Materials Converting Heat to Electricity Directly and Efficiently
Authors: Zhang Qian , Sun Yimeng , Xu Wei , Zhu Daoben
Published: March 2014

The abundance of solar thermal energy and the widespread demands for waste heat recovery make thermoelectric generators (TEGs) very attractive in harvesting low‐cost energy resources. Meanwhile, thermoelectric refrigeration is promising for local cooling and niche applications. In this context there is currently a growing interest in developing organic thermoelectric materials which are flexible, cost‐effective, eco‐friendly and potentially energy‐efficient. In particular, the past several years have witnessed remarkable progress in organic thermoelectric materials and devices. In this review, thermoelectric properties of conducting polymers and small molecules are summarized, with recent progresses in materials, measurements and devices highlighted. Prospects and suggestions for future research efforts are also presented. The organic thermoelectric materials are emerging candidates for green energy conversion.
Physical characterization of eco‐friendly O/W emulsions developed through a strategy based on product engineering principles
Authors: Santos Jenifer , Trujillo‐Cayado Luis A. , Calero Nuria , Muñoz José
Published: March 2014

Many traditional industrial products are being gradually replaced by environmental friendly alternatives. N,N‐Dimethyldecanamide and D‐limonene are solvents that fulfil the requirements to be considered green solvents and may find application in agrochemicals. This contribution deals with the study of emulsions formulated with a mixture of these solvents and an eco‐friendly emulsifier. The procedure followed for the development of these formulations was based on the application of product design principles. This led to the optimum homogenization rate and subsequently to the optimum ratio of solvents. The combination of different techniques (rheology, laser diffraction, confocal laser‐scanning microscopy, and multiple light scattering) was demonstrated to be a powerful tool to assist in the prediction of the emulsions destabilization process. Thus, we found that the optimum ratio of solvents was 75/25 (N,N‐dimethyldecanamide/D‐limonene) on account of the lack of coalescence and of a low creaming rate. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2644–2653, 2014
Compartmental endoscopic surgical anatomy of the medial intraconal orbital space
Authors: Bleier Benjamin S. , Healy David Y. , Chhabra Nipun , Freitag Suzanne
Published: March 2014

Background

Surgical management of intraconal pathology represents the next frontier in endoscopic endonasal surgery. Despite this, the medial intraconal space remains a relatively unexplored region, secondary to its variable and technically demanding anatomy. The purpose of this study is to define the neurovascular structures in this region and introduce a compartmentalized approach to enhance surgical planning.

Methods

This study was an institutional review board (IRB)‐exempt endoscopic anatomic study in 10 cadaveric orbits. After dissection of the medial intraconal space, the pattern and trajectory of the oculomotor nerve and ophthalmic arterial arborizations were analyzed. The position of all vessels as well as the length of the oculomotor trunk and branches relative to the sphenoid face were calculated.

Results

A mean of 1.5 arterial branches were identified (n = 15; range, 1‐4) at a mean of 8.8 mm from the sphenoid face (range, 4‐15 mm). The majority of the arteries (n = 7) inserted adjacent to the midline of medial rectus. The oculomotor nerve inserted at the level of the sphenoid face and arborized with a large proximal trunk 5.5 ± 1.1 mm in length and multiple branches extending 13.2 ± 2.7 mm from the sphenoid face. The most anterior nerve and vascular pedicle were identified at 17.0 and 15.0 mm from the sphenoid face, respectively.

Conclusion

The neurovascular supply to the medial rectus muscle describes a varied but predictable pattern. This data allows the compartmentalization of the medial intraconal space into 3 zones relative to the neurovascular supply. These zones inform the complexity of the dissection and provide a guideline for safe medial rectus retraction relative to the fixed landmark of the sphenoid face.
JC virus reactivation during prolonged natalizumab monotherapy for multiple sclerosis
Authors: Chalkias Spyridon , Dang Xin , Bord Evelyn , Stein Marion C. , Kinkel R. Philip , Sloane Jacob A. , Donnelly Maureen , Ionete Carolina , Houtchens Maria K. , Buckle Guy J. , Batson Stephanie , Koralnik Igor J.
Published: March 2014

Objective

To determine the prevalence of JC virus (JCV) reactivation and JCV‐specific cellular immune response during prolonged natalizumab treatment for multiple sclerosis (MS).

Methods

We enrolled 43 JCV‐seropositive MS patients, including 32 on natalizumab monotherapy >18 months, 6 on interferon β‐1a monotherapy >36 months, and 5 untreated controls. We performed quantitative real‐time polymerase chain reaction in cerebrospinal fluid (CSF), blood, and urine for JCV DNA, and we determined JCV‐specific T‐cell responses using enzyme‐linked immunosorbent spot (ELISpot) and intracellular cytokine staining (ICS) assays, ex vivo and after in vitro stimulation with JCV peptides.

Results

JCV DNA was detected in the CSF of 2 of 27 (7.4%) natalizumab‐treated MS patients who had no symptoms or magnetic resonance imaging–detected lesions consistent with progressive multifocal leukoencephalopathy. JCV DNA was detected in blood of 12 of 43 (27.9%) and in urine of 11 of 43 (25.6%) subjects without a difference between natalizumab‐treated patients and controls. JC viral load was higher in CD34+ cells and in monocytes compared to other subpopulations. ICS was more sensitive than ELISpot. JCV‐specific T‐cell responses, mediated by both CD4+ and CD8+ T lymphocytes, were detected more frequently after in vitro stimulation. JCV‐specific CD4+ T cells were detected ex vivo more frequently in MS patients with JCV DNA in CD34+ (p = 0.05) and B cells (p = 0.03).

Interpretation

Asymptomatic JCV reactivation may occur in CSF of natalizumab‐treated MS patients. JCV DNA load is higher in circulating CD34+ cells and monocytes compared to other mononuclear cells, and JCV in blood might trigger a JCV‐specific CD4+ T‐cell response. JCV‐specific cellular immune response is highly prevalent in all JCV‐seropositive MS patients, regardless of treatment. ANN NEUROL 2014;75:925–934
Nickel(II) complex containing N‐(4,5‐dihydrooxazol‐2‐yl)benzamide ligands: highly efficient catalyst for Heck coupling reactions
Authors: Wang Junke , Zong Yingxiao , Wei Shenglong , Pan Yi
Published: March 2014

Heck reaction catalyzed by Ni(II) containing N‐(4,5‐dihydrooxazol‐2‐yl) benzamide has been developed. The coupling of alkenes with aryl iodide or aryl bromide in the presence of potassium carbonate in DMF provides the corresponding products with moderate to good yields. This method possesses obvious advantages such as low‐cost catalyst and simple experimental operation. Copyright © 2014 John Wiley & Sons, Ltd.
Quantitative study of cellular heterogeneity in doxorubicin uptake and its pharmacological effect on cancer cells
Authors: Deng Bin , Wang Zhi‐Ming , Zhou Zi‐Hao , Liu Yi‐Meng , Yang Xi‐Liang , Song Jian , Xiao Yu‐Xiu
Published: March 2014

Cellular heterogeneity in doxorubicin (DOX) uptake and its relationship with pharmacological effect on cancer cells were quantitatively investigated for the first time. An in vitro experimental model was established by treating human leukemia K562 and breast cancer MCF‐7 cells with different schedules of DOX with or without surface P‐glycoprotein (P‐gp) inhibitor verapamil (VER). The cellular heterogeneity in DOX uptake was quantitatively examined by single‐cell analysis using capillary electrophoresis coupled with laser‐induced fluorescence detection. The corresponding cytotoxic effect was tested by cellular morphology, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐tetrazolium and flow cytometry assays. The expression of cellular membrane surface P‐gp was determined by flow cytometry. Results showed that the cellular heterogeneity exists in DOX uptake. The single‐high DOX schedule leads to lower uptake heterogeneity and higher mean drug uptake. The cellular heterogeneity in DOX uptake was found to be negatively correlated with drug cytotoxicity and surface P‐gp expression, with r = −0.7680 to ~ −0.9587. VER reduces the cellular variation in DOX uptake, suggesting that surface P‐gp may be one of the causes of the cellular heterogeneity in DOX uptake. This research demonstrates the importance of quantitative study of cellular heterogeneity in drug uptake and its potential application in drug schedule design, response prediction and therapy modulation. Copyright © 2014 John Wiley & Sons, Ltd.
Simultaneous reduction of MAD2 and BUBR1 expression induces mitotic spindle alterations associated with p53 dependent cell cycle arrest and death
Authors: Lentini Laura , Piscitello Desirèe , Veneziano Lorena , Di Leonardo Aldo
Published: March 2014

Most human tumors are characterized by aneuploidy that is believed to be the consequence of chromosomal instability (CIN). The mechanism(s) leading to aneuploidy and the pathways that allow its tolerance are not completely understood. The Spindle Assembly Checkpoint (SAC) is a cellular surveillance mechanism working during mitosis, and alterations of genes that encode components of the SAC weakening the mitotic checkpoint, induce aneuploidy by chromosome mis‐segregation. We induced aneuploidy in near‐diploid tumor cells by simultaneous depletion of the SAC proteins MAD2 and BUBR1 by RNA interference in the attempt to gain further insight on the cellular responses to aneuploidy. Individual reduction of MAD2 and BUBR1 protein levels caused defective mitosis and aneuploidy, while co‐depletion of MAD2 and BUBR1 caused cell cycle arrest and cell death in addition to aneuploidy. The simultaneous reduction of the two SAC proteins induced high percentage of hyperdiploid cells and p53 stabilization suggesting that hyperdiploidy could activate a p53 controlled pathway. The results indicate that p53 is required to induce cell cycle arrest and cell death when the mitotic checkpoint is strongly perturbed, thereby preventing aneuploid cell propagation.
Human endometrial stem cells differentiation into functional hepatocyte‐like cells
Authors: Khademi Farzaneh , Soleimani Masoud , Verdi Javad , Tavangar Seyed Mohammad , Sadroddiny Esmaeil , Masumi Mohammad , Ai Jafar
Published: March 2014

In spite of certain clinical limitations, such as teratoma formation, the use of stem cells is considered as an appropriate source in cell therapy and tissue engineering. This study shows human endometrial stem cells (hEnSCs) has exceptional differentiation ability in hepatocyte formation. hEnSCs have high purification rate and immune‐tolerance, and can be used as an appropriate substitute for hepatocytes in liver disorders. Differentiation required hepatogenic medium. Quantitative reverse transcription‐polymerase chain reaction and immunofluorescent staining of hepatic genes and proteins including cytokeratin 18 (ck18), alpha‐fetoprotein (afp), and albumin (alb) were used to assess differentiation. Cells differentiated with a hepatocyte‐like morphology and expressed hepatic markers on 30 days of differentiation. The Periodic Acid‐Schiff (PAS) reaction showed storage of glycogen, and albumin and afp secretions were also detected. In vitro hEnSCs behave like hepatocyte after differentiation and may be a suitable source of cells in liver regeneration.
Kv7.2 regulates the function of peripheral sensory neurons
Authors: King Chih H. , Lancaster Eric , Salomon Daniela , Peles Elior , Scherer Steven S.
Published: March 2014

The Kv7 (KCNQ) family of voltage‐gated K+ channels regulates cellular excitability. The functional role of Kv7.2 has been hampered by the lack of a viable Kcnq2‐null animal model. In this study, we generated homozygous Kcnq2‐null sensory neurons using the Cre‐Lox system; in these mice, Kv7.2 expression is absent in the peripheral sensory neurons, whereas the expression of other molecular components of nodes (including Kv7.3), paranodes, and juxtaparanodes is not altered. The conditional Kcnq2‐null animals exhibit normal motor performance but have increased thermal hyperalgesia and mechanical allodynia. Whole‐cell patch recording technique demonstrates that Kcnq2‐null sensory neurons have increased excitability and reduced spike frequency adaptation. Taken together, our results suggest that the loss of Kv7.2 activity increases the excitability of primary sensory neurons. J. Comp. Neurol. 522:3262–3280, 2014. © 2014 Wiley Periodicals, Inc.
A GEANT4 web‐based application to support Intra‐Operative Electron Radiotherapy using the European grid infrastructure
Authors: Casarino C. , Russo G. , Candiano G. C. , La Rocca G. , Barbera R. , Borasi G. , Guatelli S. , Messa C. , Passaro G. , Gilardi M.C.
Published: March 2014

Radiotherapy techniques deliver ionizing radiations (X‐rays, photons, electrons, protons, etc.) inside cancerous tissues to kill the abnormal cells. Radiotherapy‐related activities such as the optimization of the therapeutic radiation dose to patients, workers' radioprotection, linear accelerator commissioning, quality assurance processes and technical innovations of linear accelerators are strongly based on the ability to predict the dose distribution. Monte Carlo based simulations are so far the most accurate tool for the calculation of dosimetric parameters, with the drawback of requiring extensive computing resources to achieve statistically meaningful results in a reasonable time frame. In the last years, advanced cancer treatment clinical and research communities have used e‐Infrastructures to support their activities. The present paper reports on the development of a computing facility for helping clinical researchers in using modern R&E networking and distributed computing and storage resources for a new radiotherapy technique: the Intra‐Operative Electron Radiotherapy. The web application developed addresses some technical and clinical needs as the design of linear accelerators' collimation systems and the optimization of the patient therapeutic dose distribution. Copyright © 2014 John Wiley & Sons, Ltd.
A single‐stage integrated bridgeless AC/DC converter for electrolytic capacitor‐less LED lighting applications
Authors: Ma Hongbo , Zheng Cong , Yu Wensong , Lai Jih‐Sheng (Jason)
Published: March 2014

In this paper, a single‐stage integrated bridgeless AC/DC converter is proposed. As compared to its counterpart that is composed of totem‐pole boost power factor correction (PFC) cascade fly‐back DC/DC converter, the studied circuit has less components number while overcoming the limits of the totem‐pole type. Thus, it is suitable to the low‐power LED lighting applications. Furthermore, when both PFC inductors Lb and magmatic inductance Lm of the transformer TR1 operate at discontinuous current mode, the bus voltage vCB can be used to decouple the ac input and constant dc output power. Thus, the approach of increasing bus voltage ripple is employed to eliminate electrolytic capacitors and obtain long operation lifetime. Additionally, it is able to be compatible with our studied twin‐bus configuration for increasing the overall efficiency. A 50‐W hardware prototype has been designed, fabricated, and tested in the laboratory to verify the proposed converter validity. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of Anisotropic Ion Pressure on Solitary Waves in Magnetized Dusty Plasmas
Authors: Adnan M. , Mahmood S. , Qamar Anisa
Published: March 2014

The propagation of linear and nonlinear dust ion acoustic waves (DIAWs) are studied in a collisionless magnetized plasma which consists of warm ions having anisotropic thermal pressure, nonthermal (energetic) electrons and static dust particles of positive and negative charge polarity. The anisotropic ion pressure is defined using double adiabatic Chew‐Golberger‐Low (CGL) theory. In the linear regime, the propagation properties of the two possible modes are investigated via ion pressure anisotropy, dust particle polarity and nonthermality of electrons. Using reductive method Zakharov‐Kuznetsov (ZK) equation is derived for the propagation of two dimensional electrostatic dust ion acoustic solitary waves in dusty plasmas. It is found that both compressive and rarefactive solitons are formed in presence of nonthermal electrons using Cairn's distribution [R.A. Cairns, A.A. Mamun, R. Bingham, R.O. Dendy, R. Bostrom, C.M.C. Nairn and P.K. Shukla, Geophys.Res. Lett. 22, 2709 (1995)] in the system. The ion pressure anisotropy, nonthermality of electrons and charge polarity of the dust particles have significant effects on the amplitude and width of the dust ion acoustic solitary waves in such anisotropic nonthermal magnetized dusty plasmas. The numerical results are also presented for illustration. Our finding is applicable to space dusty plasma regimes having anisotropic ion pressure and nonthermal electrons. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
EEMHR: Energy‐efficient multilevel heterogeneous routing protocol for wireless sensor networks
Authors: Tanwar Sudeep , Kumar Neeraj , Niu Jian‐Wei
Published: March 2014

Wireless Sensor Networks (WSNs) are being used in wide areas of applications for data collection and processing. Energy management is one of the crucial issues that need special attention in WSNs. But most of the existing solutions for energy management are restricted in defining the number of levels for node heterogeneity for efficient energy management. Due to this restriction, a performance degradation has been observed in most of the applications in WSNs. Hence, keeping in the view of the aforementioned issue, in this paper, we proposed a new energy‐efficient multilevel heterogeneous routing (EEMHR) protocol for WSNs. Nodes are divided in to k levels of hierarchy in the proposed solution. A variable threshold defined by the ratio of number of alive nodes for current round to the total number of nodes is proposed for the selection of cluster heads. The performance of the proposed approach is evaluated by varying the various parameters of the network in comparison with other state‐of‐the‐art protocols such as stable election protocol (SEP) and multihop communication routing (MCR). Simulation results show that by varying the initial energy and node heterogeneity parameters, the network lifetime of EEMHR is improved by 17% in comparison with SEP and MCR. Moreover, EEMHR provides better stability and distribution of cluster heads in comparison with SEP and MCR. Copyright © 2014 John Wiley & Sons, Ltd.
Hox expression in the direct‐type developing sand dollar Peronella japonica
Authors: Tsuchimoto Jun , Yamaguchi Masaaki
Published: March 2014

Background: Echinoderms are a curious group of deuterostomes that forms a clade with hemichordates but has a pentameral body plan. Hox complex plays a pivotal role in axial patterning in bilaterians and often occurs in a cluster on the chromosome. In contrast to hemichordates with an organized Hox cluster, the sea urchin Strongylocentrotus purpuratus has a Hox cluster with an atypical organization. However, the current data on hox expression in sea urchin rudiments are fragmentary. Results: We report a comprehensive examination of hox expression in a sand dollar echinoid. Nine hox genes are expressed in the adult rudiment, which are classified into two groups, but hox11/13b belongs to both: one with linear expression in the coelomic mesoderm and another with radial expression around the adult mouth. The linear genes may endow the coelom/mesentery with axial information to direct postmetamorphic transformation of the digestive tract, whereas the radial genes developmentally correlate with the morphological novelties of echinoderms and/or sea urchins. Recruitment of the radial genes except hox11/13b appears to be accompanied by the loss of ancestral/axial roles. Conclusions: This in toto co‐option of the hox genes provides insight into the molecular mechanisms underlying the evolution of echinoderms from a bilateral ancestor. Developmental Dynamics 243:1020–1029, 2014. © 2014 Wiley Periodicals, Inc.
De Novo Designed Copper α‐Helical Peptides: From Design to Function
Authors: Tegoni Matteo
Published: March 2014

De novo protein design is a fascinating and powerful approach to the design of metal sites in the interior of simplified protein scaffolds. A series of de novo designed copper peptides are herein described. They consist of peptide constructs that possess a secondary and tertiary structure, and that can be regarded as simplified proteins from which most of the structural complexity has been removed. Although relatively small, these copper peptides retain enough complexity to show features typical of proteins, such as enzyme‐like catalytic behavior or specific spectroscopic features. This review focuses on the de novo design of α‐helical constructs and in their use to devise different types of copper centers. Through the proper design of the peptide sequences, it has been possible to study the Cu‐triggered folding of peptide strands, which resulted in the isolation of enzyme regulators and biosensors for copper. Moreover, the use of Cys‐containing peptides allowed us to design sites structurally similar to the copper‐binding sites of biomolecules involved in copper trafficking and homeostasis. Finally, catalytic copper Type 2 sites capable of undergoing redox reactions and copper Type 1 and Type A centers with spectroscopic characteristics remarkably similar to those of natural proteins are discussed.
Self‐Assembled Cages from the Electroactive Bis(pyrrolo)tetrathiafulvalene (BPTTF) Building Block
Authors: Bivaud Sébastien , Goeb Sébastien , Balandier Jean‐Yves , Chas Marcos , Allain Magali , Sallé Marc
Published: March 2014

A family of di‐ and tetratopic redox‐active ligands designed to generate discrete self‐assembled metallacages is described, including UV/Vis spectrometry and cyclic voltammetry studies, X‐ray diffraction on single crystals, and DFT calculations. A significant degree of conjugation between the π‐donating bis(pyrrolo)tetrathiafulvalene (BPTTF) and the electron‐withdrawing coordinating pyridyl units is observed. The tetrapyridyl ligand is able to self‐assemble in the presence of cis‐protected PtII complexes to produce the first examples of BPTTF‐based cages endowed with a cavity prone to guest encapsulation. These metallacages undergo an original chemical conversion upon being heated in DMSO to afford Pt–dithiolene complexes, one of which was characterized by XRD. This reaction could be extended to alternative BPTTF derivatives.
A computational approach predicting CYP450 metabolism and estrogenic activity of an endocrine disrupting compound (PCB-30)
Authors: Harris Jason B. , Eldridge Melanie L. , Sayler Gary , Menn Fu-Min , Layton Alice C. , Baudry Jerome
Published: March 2014

Endocrine disrupting chemicals influence growth and development through interactions with the hormone system, often through binding to hormone receptors such as the estrogen receptor. Computational methods can predict endocrine disrupting chemical activity of unmodified compounds, but approaches predicting activity following metabolism are lacking. The present study uses a well-known environmental contaminant, PCB-30 (2,4,6-trichlorobiphenyl), as a prototype endocrine disrupting chemical and integrates predictive (computational) and experimental methods to determine its metabolic transformation by cytochrome P450 3A4 (CYP3A4) and cytochrome P450 2D6 (CYP2D6) into estrogenic byproducts. Computational predictions suggest that hydroxylation of PCB-30 occurs at the 3- or 4-phenol positions and leads to metabolites that bind more strongly than the parent molecule to the human estrogen receptor alpha (hER-α). Gas chromatography–mass spectrometry experiments confirmed that the primary metabolite for CYP3A4 and CYP2D6 is 4-hydroxy-PCB-30, and the secondary metabolite is 3-hydroxy-PCB-30. Cell-based bioassays (bioluminescent yeast expressing hER-α) confirmed that hydroxylated metabolites are more estrogenic than PCB-30. These experimental results support the applied model's ability to predict the metabolic and estrogenic fate of PCB-30, which could be used to identify other endocrine disrupting chemicals involved in similar pathways. Environ Toxicol Chem 2014;33:1615–1623. © 2014 SETAC
Effect of glucocorticoids on neuronal and vascular pathology in a transgenic model of selective Müller cell ablation
Authors: Shen Weiyong , Lee So‐Ra , Araujo Joana , Chung Sook H. , Zhu Ling , Gillies Mark C.
Published: March 2014

Retinal diseases such as macular telangiectasis type 2 (MacTel), age‐related macular degeneration (AMD) and diabetic retinopathy (DR) affect both neurons and blood vessels. Treatments addressing both at the same time might have advantages over more specific approaches, such as vascular endothelial growth factor (VEGF) inhibitors, which are used to treat vascular leak but are suspected to have a neurotoxic effect. Here, we studied the effects of an intravitreal injection of triamcinolone acetonide (TA) in a transgenic model in which patchy Müller cell ablation leads to photoreceptor degeneration, vascular leak, and intraretinal neovascularization. TA was injected 4 days before Müller cell ablation. Changes in photoreceptors, microglia and Müller cells, retinal vasculature, differential expression of p75 neurotrophin receptor (p75NTR), tumor necrosis factor‐α (TNFα), the precursor and mature forms of neurotrophin 3 (pro‐NT3 and mature NT3) and activation of the p53 and p38 stress‐activated protein kinase (p38/SAPK) signaling pathways were examined. We found that TA prevented photoreceptor degeneration and inhibited activation of microglial and Müller cells. TA attenuated Müller cell loss and inhibited overexpression of p75NTR, TNFα, pro‐NT, and the activation of p53 and p38/SAPK signaling pathways. TA not only prevented the development of retinal vascular lesions but also inhibited fluorescein leakage from established vascular lesions. TA inhibited overexpression of VEGF in transgenic mice but without affecting its basal level expression in the normal retina. Our data suggest that glucocorticoid treatment may be beneficial for treatment of retinal diseases such as MacTel, AMD, and DR that affect both neurons and the vasculature. GLIA 2014;62:1110–1124
The power of neuroimaging biomarkers for screening frontotemporal dementia
Authors: McMillan Corey T. , Avants Brian B. , Cook Philip , Ungar Lyle , Trojanowski John Q. , Grossman Murray
Published: March 2014

Frontotemporal dementia (FTD) is a clinically and pathologically heterogeneous neurodegenerative disease that can result from either frontotemporal lobar degeneration (FTLD) or Alzheimer's disease (AD) pathology. It is critical to establish statistically powerful biomarkers that can achieve substantial cost‐savings and increase the feasibility of clinical trials. We assessed three broad categories of neuroimaging methods to screen underlying FTLD and AD pathology in a clinical FTD series: global measures (e.g., ventricular volume), anatomical volumes of interest (VOIs) (e.g., hippocampus) using a standard atlas, and data‐driven VOIs using Eigenanatomy. We evaluated clinical FTD patients (N = 93) with cerebrospinal fluid, gray matter (GM) magnetic resonance imaging (MRI), and diffusion tensor imaging (DTI) to assess whether they had underlying FTLD or AD pathology. Linear regression was performed to identify the optimal VOIs for each method in a training dataset and then we evaluated classification sensitivity and specificity in an independent test cohort. Power was evaluated by calculating minimum sample sizes required in the test classification analyses for each model. The data‐driven VOI analysis using a multimodal combination of GM MRI and DTI achieved the greatest classification accuracy (89% sensitive and 89% specific) and required a lower minimum sample size (N = 26) relative to anatomical VOI and global measures. We conclude that a data‐driven VOI approach using Eigenanatomy provides more accurate classification, benefits from increased statistical power in unseen datasets, and therefore provides a robust method for screening underlying pathology in FTD patients for entry into clinical trials. Hum Brain Mapp 35:4827–4840, 2014. © 2014 Wiley Periodicals, Inc.
Insula and sensory insular cortex and somatosensory control in patients with insular stroke
Authors: Baier B. , zu Eulenburg P. , Geber C. , Rohde F. , Rolke R. , Maihöfner C. , Birklein F. , Dieterich M.
Published: March 2014

Background

In functional imaging studies, the insular cortex (IC) has been identified as an essential part of the processing of a whole spectrum of multimodal sensory input. However, there are no lesion studies including a sufficient number of patients, which would reinforce the functional imaging data obtained from healthy subjects. Such lesion studies should examine how damage to the IC affects sensory perception. We chose acute stroke patients with lesions affecting the IC in order to fill this gap.

Methods

A comprehensive sensory profiling by applying a quantitative sensory testing protocol was performed and a voxel‐lesion behaviour mapping analysis in 24 patients with acute unilateral cortical damage was applied.

Results

Our data demonstrate that patients with lesions of the posterior IC have deficits in temperature perception, but did not show other sensory deficits such as hot or cold pain perception associated with specific lesion locations.

Conclusion

Our data allow the conclusion that the posterior IC may represent the major region responsible for encoding warm and cold perception in the brain. To what extent focal IC lesions may also impair pain processing or induce post‐stroke pain has to be addressed in future studies including more patients.
Learning to Choose
Authors: Mackey Margaret
Published: March 2014

Often the difference between a successful and unsuccessful reader is that the former is simply better at finding enjoyable books to read. The capacity to select appealing reading is not developed in classrooms where the decision about what book to read is made by someone other than the reader: the teacher, the curriculum planner, the person who buys material for the stock cupboard. We can learn much from avid readers, the truly successful choosers, and a summer reading program offers one vehicle for students to practice choosing titles for themselves. What really matters is that this question of making a productive selection should not remain invisible in the classroom.
Fibronectin enhances spinal cord astrocyte proliferation by elevating P2Y1 receptor expression
Authors: Xia Maosheng , Zhu Yue
Published: March 2014

After spinal cord injury (SCI), the formation of glial scar is a complex process that is attributed primarily to astrocytic proliferation, but the mechanism of astrocytes proliferation is still unclear. Fibronectin is a large extracellular glycoprotein that helps organize the matrix protein, and its main membrane receptor is the α5β1 integrin subunit. In this study, fibronectin stimulated spinal cord astrocytic proliferation from two directions: fibronectin increased astrocytic proliferation via α5β1 integrin receptor, and fibronectin upregulated the expression of P2Y1 receptor, and adenosine triphosphate (ATP) could enhance the astrocytic proliferation and induce more release of arachidonic acid and prostaglandin E2 via P2Y1. The upregulation of P2Y1 by fibronectin required [Ca2+]i and the activation of integrin link kinase (ILK) and Akt. We found that [Ca2+]i stimulated by fibronectin was α5β1 integrin receptor dependent and that the phosphorylation of Akt or extracellular signal‐regulated protein kinase (ERK1/2) induced by fibronectin mediated the activation of cAMP response element‐binding protein (CREB) and signal transducer and activator of transcription 3 (Stat3). Our research suggests that the release of fibronectin and ATP could stimulate the spinal cord astrocytic proliferation after SCI, and the expression of P2Y1 increased by fibronectin would provide more sites for ATP, which could aggravate the proliferation and inflammation of spinal cord astrocytes. © 2014 Wiley Periodicals, Inc.