bluuebunny/crossref_metadata_2025 huggingface dataset:
Superfine Expanded Graphite with Large Capacity for Lithium Storage
Authors: Kaskhedikar Nitin A. , Cui Guanglei , Maier Joachim , Fedorov Vladimir , Makotchenko Victor , Simon Arndt
Published: March 2011

A superfine expanded graphite (s‐EG) fiber material was investigated as an anode material for lithium‐based batteries. The fibers were prepared by decomposition of dicarbon monofluoride‐intercalated graphite. The high resolution transmission electron microscopy (HRTEM) images showed the fiber thickness in range of 2–3 nm with several microns in length. Lithium storage capacity in this material was measured in lithium half cells. High lithium storage capacity of about 1000 mAh·g–1 at a rate of C/10, corresponding to Li3C6 composition was obtained. The material showed fairly good rate capability exhibiting lithium storage capabilities even at 60C. As a effect of ball milling, the s‐EG showed crystallographic ordering in the sample with reduced the lithium storage capacity corresponding to composition of LiC6. A simple mathematical relation to account for the excess lithium storage capacity in this material is put forward.
Syntheses, Crystal Structures, and Thermal Behaviors of Two New Metallo‐Organically Templated Pentaborates
Authors: Yang Yang , Wang Yu , Zhu Jiang , Liu Rui‐Bin , Xu Jun , Meng Chang‐Gong
Published: March 2011

Two new cadmium borates, [Cd(en)3][B5O6(OH)4]2·2H2O (en = ethylenediamine) (1) and [Cd(DETA)2][B5O6(OH)4]2 (DETA = diethylenetriamine) (2) were synthesized in a novel procedure under mild solvothermal conditions and characterized by single‐crystal X‐ray diffraction, IR spectroscopy, elemental analysis, and TG–DTA. The compound 1 crystallizes in monoclinic system, space group P21/c (No. 14) with a = 8.526(2) Å, b = 23.127(6) Å, c = 15.438(4) Å, β = 94.320(3) °, V = 3035.5(13) Å3, Z = 4. Compound 2 is triclinic, space group P$\bar{1}$ (No. 2), a = 8.632(5) Å, b = 9.418(6) Å, c = 27.856(18) Å, α = 95.415(8) °, β = 91.891(7) °, γ = 93.563 (7) °, V = 2248(2) Å3, Z = 3. The anionic units of the both structures, [B5O6(OH)4]– are linked by hydrogen bonds to form a three‐dimensional framework with large channels, in which the templating cadmium complex cations are located. The thermal decomposition performance of compound 1 requires three steps, whereas only two steps are needed for compound 2, which all lead to amorphous phases. These processes are well explained considering the structure and the change in the Cd2+ coordination during heating.
A case of cesarean scar ectopic: a rare but important form of ectopic pregnancy
Authors: Kim Daniel J. , Welch Mila , Kendall John L.
Published: March 2011

Introduction

This is a case of a 35-year-old G4P3 female with history of one prior cesarean section who presented to the emergency department with vaginal bleeding. She was found to be pregnant, and an ultrasound identified a cesarean scar ectopic pregnancy.

Methods

This is a case report and brief review of the literature.

Conclusion

Cesarean scar ectopic is a rare form of ectopic pregnancy that implants within the myometrium at the site of a prior cesarean section scar. It carries the potential for serious maternal morbidity and mortality, including complications like uterine rupture, life-threatening hemorrhage, and need for hysterectomy. All sonographers who scan patients in first-trimester pregnancy should be aware of the criteria to diagnose this entity, as cesarean scar ectopic can otherwise be confused with cervicoisthmic pregnancy or spontaneous abortion in progress.
Disability Among Native-born and Foreign-born Blacks in the United States
Authors: Elo Irma T. , Mehta Neil K. , Huang Cheng
Published: March 2011

Using the 5% Public Use Micro Data Sample (PUMS) from the 2000 U.S. census, we examine differences in disability among eight black subgroups distinguished by place of birth and Hispanic ethnicity. We found that all foreign-born subgroups reported lower levels of physical activity limitations and personal care limitations than native-born blacks. Immigrants from Africa reported lowest levels of disability, followed by non-Hispanic immigrants from the Caribbean. Sociodemographic characteristics and timing of immigration explained the differences between these two groups. The foreign-born health advantage was most evident among the least-educated except among immigrants from Europe/Canada, who also reported the highest levels of disability among the foreign-born. Hispanic identification was associated with poorer health among both native-born and foreign-born blacks.
Petrogenesis of Cenozoic mafic–ultramafic alkaline lavas from the Tigris volcanic field, NE Syria
Authors: ABDEL-RAHMAN ABDEL-FATTAH M. , LEASE NANCY A.
Published: March 2011

Mafic–ultramafic Quaternary lava flows form the Tigris volcanic field (covering 1750 km2) at the northeastern tip of Syria and extend into Turkey. This volcanic field occurs between the Euphrates graben and the Bitlis–Zagros collision suture that forms the boundary between the Arabian and Eurasian plates. The rocks are made up of labradorite, clinopyroxene, olivine and opaque phases. The Tigris lavas are compositionally restricted to basanites and alkali basalts, having a narrow range of major element compositions (SiO2, 42.2–48.2 wt%; MgO, 5.7–9.0 wt%, with Mg numbers ranging from 0.51 to 0.62; TiO2, 1.7–3.2 wt%), and are alkaline in nature. The rocks are enriched in HFS elements such as Zr (119–231 ppm), Nb (14–43 ppm) and Y (17–22 ppm). The REE patterns are strongly fractionated ((La/Yb)N= 10.6), indicative of a garnet-bearing source. The143Nd/144Nd isotopic compositions range from 0.512803 to 0.512908, and87Sr/86Sr from 0.70327 to 0.70403 (εNd= 3.2–5.3) suggesting strong affinities to ocean island basalts. Modelling using a variety of mantle source materials and different degrees of partial melting indicates that the magma was produced by a small degree of batch partial melting (F = 1.5%) of a primitive, garnet-lherzolite fertile mantle source. The overall petrological/chemical nature supports this interpretation. Shear heating at the base of the lithospheric mantle of the northern boundary of the Arabian plate, caused by a change in plate motion as the Arabian plate moved in a more easterly direction during the Plio-Quaternary, could represent a possible source of the heat necessary for partial fusion and magma generation. Adiabatic decompression and melting represents a more likely process for the generation of the Tigris magma. Elemental ratios such as K/P (4.6), La/Ta (12), La/Nb (0.90), Nb/Y (1.22) and Th/Nb (0.09) indicate that the magma was subjected to minimal crustal contamination.
Effect of cleaning procedure and hygienic condition of milking equipment on bacterial count of bulk tank milk
Authors: Bava Luciana , Zucali Maddalena , Sandrucci Anna , Brasca Milena , Vanoni Laura , Zanini Lucio , Tamburini Alberto
Published: March 2011

The aim of the study was to describe the characteristics of cleaning procedures for milking equipment applied in intensive dairy farms in Lombardy (Italy) and to study their relationships with bacterial count of bulk milk and hygienic condition of milking machine components. A group of 22 dairy farms was visited twice (winter and summer) in order to collect bulk tank milk and post-rinse water samples and swabs from liners and milk receiver. Samples were analysed to determine: standard plate count (SPC), laboratory pasteurization count (LPC), psychrotrophic bacteria count (PBC), coliform count (CC) andEscherichia coli. Cleaning procedures were monitored using electronic milk flow meters with specific software for the measurement of the duration of each cleaning phase, circulating solution temperature and electrical conductivity, turbulence and water filling percentage of pipelines. The results showed that farms classified as high and low milk total bacteria count significantly differed both in terms of liners and receiver bacterial contamination and in terms of water temperature reached during the detergent phase of cleaning milking equipment. Significant positive correlations were found among total bacteria count in milk and bacterial contamination of the liners. Maximum water temperature reached during the cleaning cycle of milking equipment was very low (34·4±8·9°C on average); most of the observations (88·6%) corresponded to water temperatures <45°C. Cleaning temperature was related to psychrotrophic bacteria count of milk and post-rinse water and coliform count in liners. Routine check and regulation of water temperature during the washing phase of the milking machine can be a simple and effective way to control one of the main risk factors for bacteriological quality of bulk tank milk.
Drag and lift forces on random assemblies of wall-attached spheres in low-Reynolds-number shear flow
Authors: DERKSEN J. J. , LARSEN R. A.
Published: March 2011

Direct numerical simulations of the shear flow over assemblies of uniformly sized, solid spheres attached to a flat wall have been performed using the lattice-Boltzmann method. The random sphere assemblies comprised monolayers, double layers and triple layers. The Reynolds number based on the sphere radius and the overall shear rate was much smaller than 1. The results were interpreted in terms of the drag force (the force in the streamwise direction) and lift force (the force in the wall-normal direction) experienced by the spheres as a function of the denseness of the bed and the depth of the spheres in the bed. The average drag and lift forces decay monotonically as a function of the surface coverage of the spheres in the top layer of the bed. The sphere-to-sphere variation of the drag and lift forces is significant due to interactions between spheres via the interstitial fluid flow.
Refining the ‘cucumber’ technique for laryngeal biopsy
Authors: Robertson S , Cooper L , McPhaden A , MacKenzie K
Published: March 2011

Objectives:

To refine the case selection process for the ‘cucumber’ mounting system for laryngeal biopsies.

Methods:

We conducted a retrospective audit of cucumber technique specimens taken between January 2002 and December 2008. We analysed the clinical indications for biopsy and the pathological diagnosis, for each specimen, in order to inform our case selection process.

Results:

The cucumber technique was used for 125 laryngeal specimens. 60 specimens were taken for diagnostic sampling, 46 were taken during endoscopic laser resection, and 19 for overtly benign pathology. The cucumber technique was most useful for the interpretation of margins in endoscopic laser resection specimens.

Conclusion:

The cucumber technique is most useful for endoscopic resection cases in which tumour, dysplasia or suspicious lesions have been excised. Detailed information on resection margins is invaluable during multidisciplinary team discussions on patient management. Detailed photography of mounted specimens enables both laryngologist and pathologist to orientate and interpret specimens accurately.
Precise Velocity Estimation with a Stand-Alone GPS Receiver
Authors: Ding Weidong , Wang Jinling
Published: March 2011

A scrutiny of the existing time differencing carrier phase (TDCP) velocity estimation algorithms has revealed several shortcomings that could be further improved. One of these is that the velocity estimation at epoch t would require the receiver positions at epoch t+Δt or more are available. Another is the usage of satellite velocities in the calculations which would increase the receiver computational load and degrade the accuracy. In this paper, an improved TDCP velocity estimation approach has been proposed and tested. The new approach depends only on receiver position at epoch t and satellite positions at epoch t and t+Δt. Satellite velocities are not required in this calculation. This proposed algorithm has been validated using static and kinematic field test data, showing that equivalent velocity accuracy achievable by using differential GPS techniques can be made possible with the proposed standalone GPS method.
Rao-Blackwellized Unscented Particle Filter for a Handheld Unexploded Ordnance Geolocation System using IMU/GPS
Authors: Lee Jong Ki , Jekeli Christopher
Published: March 2011

The existence of Unexploded Ordnance (UXO) is a serious environmental hazard, especially in areas being converted from military to civilian use. The detection and discrimination performance of UXO detectors depends on the sensor technology as well as on the processing methodology that inverts the data to infer UXO. The detection systems, typically electro-magnetic induction (EMI) devices, require very accurate positioning (or geolocation) in order to discriminate candidate UXO from non-hazardous items. For this paper, a hand-held geolocation system based on a tactical-grade IMU, such as the HG1900, was tested in the laboratory over a small, metre-square area in sweep and swing modes. A camera position system was used to emulate GPS or alternative ground-based external ranging systems that control positioning errors. The proposed integration algorithm is a combination of linear filtering (Extended Kalman Filter) and nonlinear, also non-Gaussian filtering (Unscented Particle Filter) in the form of the Rao-Blackwellized Particle Filter (RBPF). The test results show that the position accuracy was improved by applying nonlinear filter-based smoothing techniques in both the straight and curved sections of the sweep and swing trajectories.
Assessing Q fever in a representative sample from the United States population: identification of a potential occupational hazard
Authors: WALSH M. G.
Published: March 2011

Q fever has been associated with exposure to domesticated livestock and the agricultural industry. However large population-based studies examining the relationship are lacking. This report sought to describe the association betweenCoxiella burnetiiinfection and participation in agricultural work in the 2003–2004 National Health and Nutrition Examination Survey. Adjusted logistic regression analysis showed that agricultural workers were six times more likely to have antibody evidence ofC. burnetiiinfection than those employed in other occupations (odds ratio 6·5, 95% confidence interval 1·7–25·3). These findings suggest that agricultural workers may experience greaterC. burnetiiinfection and emphasize an important need for more detailed study of people engaged in this work.
Rainfall, household crowding, and acute respiratory infections in the tropics
Authors: MURRAY E. L. , KLEIN M. , BRONDI L. , McGOWAN J. E. , VAN MELS C. , BROOKS W. A. , KLEINBAUM D. , GOSWAMI D. , RYAN P. B. , BRIDGES C. B.
Published: March 2011

Acute respiratory infections (ARI) are the leading cause of death worldwide in children aged <5 years, and understanding contributing factors to their seasonality is important for targeting and implementing prevention strategies. In tropical climates, ARI typically peak during the pre-rainy and rainy seasons. One hypothesis is that rainfall leads to more time spent indoors, thus increasing exposure to other people and in turn increasing the risk of ARI. A case-crossover study design in 718 Bangladeshi children aged <5 years was used to evaluate this hypothesis. During a 3-month period with variable rainfall, rainfall was associated with ARI [odds ratio (OR) 2·97, 95% confidence interval (CI) 1·87–4·70]; some evidence of an increased strength of association as household crowding increased was found (⩾3 people/room, OR 3·31, 95% CI 2·03–5·38), but there was a lack of association in some of the most crowded households (⩾5 to <6 people/room, OR 1·55, 95% CI 0·54–4·47). These findings suggest that rainfall may be increasing exposure to crowded conditions, thus leading to an increased risk of ARI, but that additional factors not captured by this analysis may also play a role.
A quantitative approach to analyse linkages between antimicrobial resistance properties inSalmonellaTyphimurium isolates
Authors: RUDDAT I. , SCHWARZ S. , TIETZE E. , ZIEHM D. , KREIENBROCK L.
Published: March 2011

This study used statistical methods to investigate linkages in phenotypic resistance profiles in a population sample of 321SalmonellaTyphimurium isolates from sporadic salmonellosis cases in Lower Saxony, Germany, collected during 2008–2010. A resistance index was applied to calculate the conditional probability of resistance to one antimicrobial agent given the resistance to one or more other antimicrobial agent(s). A susceptibility index was defined analogously. A contingency plot, which visualizes the association between resistances to two antimicrobial agents, facilitated the interpretation. Linkages between minimum inhibitory concentrations (MIC) were analysed using Spearman's rank correlation coefficient and jittered scatter plots. Applying these methods provided a compact description of multi-resistance and linkages between resistance properties in large datasets. Moreover, this approach will improve monitoring of antimicrobial resistance dynamics of bacteria in human or animal populations by identifying linked resistance to antimicrobial agents (cross- or co-resistance) with a non-molecular method.
Problems of heat, mass and charge transfer with discontinuous solutions
Authors: DEMCHENKO V. F. , PAVLYK V. O. , DILTHEY U. , KRIVTSUN I. V. , LISNYI O. B. , NAKVASYUK V. V.
Published: March 2011

Typical problems with solutions characterised by first-kind discontinuities occurring at interfaces of layered inhomogeneous media are considered with respect to second-order differential equations in partial derivatives. Direct, inverse and mixed types of solution discontinuities are considered. Presented are generalised formulations of problems under consideration, having discontinuous solutions and allowing a uniform description of the processes of heat, mass and charge transfer in multilayer media. Homogeneous difference schemes built on the basis of generalised solutions, which are illustrated by test problems with analytical solutions, are given.
Matrix-Mediated Biomineralization in Marine Mollusks: A Combined Transmission Electron Microscopy and Focused Ion Beam Approach
Authors: Saunders Martin , Kong Charlie , Shaw Jeremy A. , Clode Peta L.
Published: March 2011

The teeth of the marine molluskAcanthopleura hirtosaare an excellent example of a complex, organic, matrix-mediated biomineral, with the fully mineralized teeth comprising layers of iron oxide and iron oxyhydroxide minerals around a calcium apatite core. To investigate the relationship between the various mineral layers and the organic matrix fibers on which they grew, sections have been prepared from specific features in the teeth at controlled orientations using focused ion beam processing. Compositional and microstructural details of heterophase interfaces, and the fate of the organic matrix fibers within the mineral layers, can then be analyzed by a range of transmission electron microscopy (TEM) techniques. Energy-filtered TEM highlights the interlocking nature of the various mineral phases, while high-angle annular dark-field scanning TEM imaging demonstrates that the organic matrix continues to exist in the fully mineralized teeth. These new insights into the structure of this complex biomaterial are an important step in understanding the relationship between its structural and physical properties and may help explain its high strength and crack-resistance behavior.
Interpretation of porosity and LWD resistivity from the Nankai accretionary wedge in light of clay physicochemical properties: Evidence for erosion and local overpressuring
Authors: Conin M. , Henry P. , Bourlange S. , Raimbourg H. , Reuschlé T.
Published: March 2011

In this study, we used porosity to assess the compaction state of the Nankai accretionary wedge sediments and any implications for stress and pore pressure. However, hydrous minerals affect porosity measurements, and accounting for them is essential toward defining the interstitial porosity truly representative of the compaction state. The water content of sediments was measured in core samples and estimated from logging data using a resistivity model for shale. We used the cation exchange capacity to correct the porosity data for the amount of water bound to clay minerals and to correct the porosity estimates for the surface conductivity of hydrous minerals. The results indicate that several apparent porosity anomalies are significantly reduced by this correction, implying that they are in part artifacts from hydrous minerals. The correction also improves the fit of porosity estimated from logging‐while‐drilling (LWD) resistivity data to porosity measured on cores. Low overall porosities at the toe of the accretionary wedge and in the splay fault area are best explained by erosion, and we estimated the quantity of sediments eroded within the splay fault area by comparing porosity‐effective stress relationships of the sediments to a reference curve. Additionally, a comparison of LWD data with core data (resistivity and P wave velocity) obtained at Site C0001 landward of the mega‐splay fault area, suggested a contribution from the fracture porosity to in situ properties on the formation.
Fully coupled approach to modeling shallow water flow, sediment transport, and bed evolution in rivers
Authors: Li Shuangcai , Duffy Christopher J.
Published: March 2011

Our ability to predict complex environmental fluid flow and transport hinges on accurate and efficient simulations of multiple physical phenomenon operating simultaneously over a wide range of spatial and temporal scales, including overbank floods, coastal storm surge events, drying and wetting bed conditions, and simultaneous bed form evolution. This research implements a fully coupled strategy for solving shallow water hydrodynamics, sediment transport, and morphological bed evolution in rivers and floodplains (PIHM_Hydro) and applies the model to field and laboratory experiments that cover a wide range of spatial and temporal scales. The model uses a standard upwind finite volume method and Roe's approximate Riemann solver for unstructured grids. A multidimensional linear reconstruction and slope limiter are implemented, achieving second‐order spatial accuracy. Model efficiency and stability are treated using an explicit‐implicit method for temporal discretization with operator splitting. Laboratory‐and field‐scale experiments were compiled where coupled processes across a range of scales were observed and where higher‐order spatial and temporal accuracy might be needed for accurate and efficient solutions. These experiments demonstrate the ability of the fully coupled strategy in capturing dynamics of field‐scale flood waves and small‐scale drying‐wetting processes.
Age and sex effects on 5-HT4 receptors in the human brain: A [11C]SB207145 PET study
Authors: Madsen Karine , Haahr Mette T , Marner Lisbeth , Keller Sune H , Baaré William F , Svarer Claus , Hasselbalch Steen G , Knudsen Gitte M
Published: March 2011

Experimental studies indicate that the 5-HT4 receptor activation influence cognitive function, affective symptoms, and the development of Alzheimer's disease (AD). The prevalence of AD increases with aging, and women have a higher predisposition to both AD and affective disorders than men. This study aimed to investigate sex and age effects on 5-HT4 receptor-binding potentials in striatum, the limbic system, and neocortex. Positron-emission tomographic scans were conducted using the radioligand [11C]SB207145 in a cohort of 30 healthy subjects (mean age 44 years; range 20 to 86 years; 14 men and 16 women). The output parameter, BPND, was modeled using the simplified reference tissue model, and partial volume correction was performed with the Muller-Gartner method. A decline with age of 1% per decade was found only in striatum. Women had a 13% lower 5-HT4 receptor binding in the limbic system. The lower limbic 5-HT4 receptor binding in women supports a role for 5-HT4 receptors in the sex-specific differences in emotional control and might contribute to the higher prevalence of affective diseases and AD in women. The relatively stable 5-HT4 receptor binding with aging contrasts others in subtypes of receptors, which generally decrease with aging.
Optical coherence tomography for the quantitative study of cerebrovascular physiology
Authors: Srinivasan Vivek J , Atochin Dmitriy N , Radhakrishnan Harsha , Jiang James Y , Ruvinskaya Svetlana , Wu Weicheng , Barry Scott , Cable Alex E , Ayata Cenk , Huang Paul L , Boas David A
Published: March 2011

Doppler optical coherence tomography (DOCT) and OCT angiography are novel methods to investigate cerebrovascular physiology. In the rodent cortex, DOCT flow displays features characteristic of cerebral blood flow, including conservation along nonbranching vascular segments and at branch points. Moreover, DOCT flow values correlate with hydrogen clearance flow values when both are measured simultaneously. These data validate DOCT as a noninvasive quantitative method to measure tissue perfusion over a physiologic range.
Differential axial localization along the mouse brain vascular tree of luminal sodium-dependent glutamine transporters Snat1 and Snat3
Authors: Ruderisch Nadine , Virgintino Daniela , Makrides Victoria , Verrey François
Published: March 2011

A specialized brain vasculature is key for establishing and maintaining brain interstitial fluid homeostasis, which for most amino acids (AAs) are ∼10% plasma levels. Indeed, regulation of AA homeostasis seems critical for normal central nervous system functions, and disturbances in brain levels have both direct and indirect roles in several neuropathologies. One mechanism contributing to the plasma to brain AA gradients involves polarized expression of solute carrier (SLC) family transporters on blood-brain barrier (BBB) endothelial cells. Of particular interest is the localization of sodium-dependent transporters that can actively move substrates against their concentration gradient. In this study, the in vivo endothelial membrane localization of the sodium-dependent glutamine transporters Snat3 (Slc38a3) and Snat1 (Slc38a1) was investigated in the mouse brain microvasculature using immunofluorescent colocalization with cellular markers. In addition, luminal membrane expression was probed by in vivo biotinylation. A portion of both Snat3 and Snat1 vascular expressions was localized on luminal membranes. Importantly, Snat1 expression was restricted to larger cortical microvessels, whereas Snat3 was additionally expressed on BBB capillary membranes. This differential expression of system A (Snat1) versus system N (Snat3) transporters suggests distinct roles for Snats in the cerebral vasculature and is consistent with Snat3 involvement in net transendothelial BBB AA transport.
The Parasympathetic Nervous System in the Quest for Stroke Therapeutics
Authors: Cheyuo Cletus , Jacob Asha , Wu Rongqian , Zhou Mian , Coppa Gene F , Wang Ping
Published: March 2011

Stroke is a devastating neurovascular disease with limited therapeutic options. The pathogenesis of stroke involves complex interrelated molecular mechanisms including excitotoxicity, oxidative and nitrosative stress, cortical spreading depolarizations, inflammation, necrosis, and apoptosis. Successful development of stroke therapeutics depends on understanding these molecular mechanisms and how to counteract them to limit tissue damage during stroke. Activation of the parasympathetic nervous system (PNS) has been shown to antagonize a multiplicity of pathologic mechanisms. Elements of parasympathetic activation such as vagus nerve stimulation have already been used successfully in treating brain disorders such as epilepsy and depression. This review discusses the anatomical basis and molecular mechanisms involved in activation of the PNS, and assesses the strength of available evidence for the further development of this modality into a stroke therapy.
In vivo Contributions of BH3-Only Proteins to Neuronal Death Following Seizures, Ischemia, and Traumatic Brain Injury
Authors: Engel Tobias , Plesnila Nikolaus , Prehn Jochen HM , Henshall David C
Published: March 2011

The BcI-2 homology (BH) domain 3-only proteins are a proapoptotic subgroup of the BcI-2 gene family, which regulate cell death via effects on mitochondria. The BH3-only proteins react to various cell stressors and promote cell death by binding and inactivating antiapoptotic BcI-2 family members and direct activation of proapoptotic multi-BH domain proteins such as Bax. Here, we review the in vivo evidence for their involvement in the pathophysiology of status epilepticus and contrast it to ischemia and traumatic brain injury. Seizures in rodents activate three potent proapoptotic BH3-only proteins: Bid, Bim, and Puma. Analysis of damage after seizures in mice singly deficient for each BH3-only protein supports a causal role for Puma and to a lesser extent Bim but, surprisingly, not Bid. In ischemia and trauma, where core aspects of the pathophysiology of cell death overlap, multiple BH3-only proteins are also activated and Bid has been shown to be required for neuronal death. The findings suggest that while each neurologic insult activates multiple BH3-only proteins, there may be specificity in their functional contribution. Future challenges include evaluating the remaining BH3-only proteins, explaining different causal contributions, and, if possible, exploring neurologic outcomes in mouse models deficient for multiple BH3-only proteins.
Differences in the Desire to Eat in Children and Adults in the Presence of an Obese Eater
Authors: Barthomeuf Laetitia R.D. , Droit‐Volet Sylvie M.N. , Rousset Sylvie M.E.
Published: March 2011

Previous research has shown that the desire to eat foods decreases in adults in the presence of an obese eater compared to a normal‐weight eater. This study investigated whether or not this decrease in eating desire was observed in younger children in the same way as in adults. Children aged 5 and 8 years old, as well as adults, were presented with photographs of liked and disliked foods presented either alone or with normal‐weight and obese eaters expressing three different emotions—pleasure, disgust, and neutrality—toward these food products. The results showed that the eater's weight status had a greater effect on the adults' desire to eat than on that of the children. Adults were influenced by the eater's weight status, regardless of the facial expression or the food category. Compared to adults, the impact of the eater's weight status on the children's desire to eat depended on the emotional facial expression and the children's food preferences. Thus, when children did not like the foods, their eating desire was negatively influenced by the eater's obese status, as was that of adults. On the other hand, when children liked the food products, the eater's weight status had no effect on their eating desire. They were more influenced by the eater's facial expressions. Thus, an expression of pleasure increased the desire to eat the liked foods in the younger children, whereas an expression of disgust decreased it. These results are discussed in terms of the high sensitivity of young children to emotional facial expressions.
Working with water insoluble organic molecules in aqueous media: fluorene derivative-containing polymers as sensory materials for the colorimetric sensing of cyanide in water
Authors: Vallejos Saúl , El Kaoutit Hamid , Estévez Pedro , García Félix Clemente , de la Peña José Luis , Serna Felipe , García José Miguel
Published: March 2011

A strategy followed to achieve a sensing phenomenon in aqueous media using water-insoluble organic molecules: the hydrophilic polymer membrane.
Analysis of myotilin turnover provides mechanistic insight into the role of myotilinopathy-causing mutations
Authors: von Nandelstadh Pernilla , Soliymani Rabah , Baumann Marc , Carpen Olli
Published: March 2011

MFM (myofibrillar myopathies) are caused by mutations in several sarcomeric components, including the Z-disc protein myotilin. The morphological changes typical of MFM include Z-disc alterations and aggregation of dense filamentous sarcomeric material. The causes and mechanisms of protein aggregation in myotilinopathies and other forms of MFM remain unknown, although impaired degradation may explain, in part, the abnormal protein accumulation. In the present paper we have studied the mechanisms regulating myotilin turnover, analysed the consequences of defective myotilin degradation and tested whether disease-causing myotilin mutations result in altered protein turnover. The results indicate that myotilin is a substrate for the Ca2+-dependent protease calpain and identify two calpain cleavage sites in myotilin by MS. We further show that myotilin is degraded by the proteasome system in transfected COS7 cells and in myotubes, and that disease-causing myotilinopathy mutations result in reduced degradation. Finally, we show that proteolysis-inhibitor-induced reduction in myotilin turnover results in formation of intracellular myotilin and actin-containing aggregates, which resemble those seen in diseased muscle cells. These findings identify for the first time biological differences between wt (wild-type) and mutant myotilin. The present study provides novel information on the pathways controlling myotilin turnover and on the molecular defects associated with MFM.
Domain interactions of the transcription–translation coupling factor Escherichia coli NusG are intermolecular and transient
Authors: Burmann Björn M. , Scheckenhofer Ulrich , Schweimer Kristian , Rösch Paul
Published: March 2011

The bacterial transcription factor NusG (N-utilization substance G) is suggested to act as a key coupling factor between transcription and translation [Burmann, Schweimer, Luo, Wahl, Stitt, Gottesman and Rösch (2010) Science 328, 501–504] and contributes to phage λ-mediated antitermination in Escherichia coli that enables read-through of early transcription termination sites. E. coli NusG consists of two structurally and functionally distinct domains that are connected through a flexible linker. The homologous Aquifex aeolicus NusG, with a secondary structure that is highly similar to E. coli NusG shows direct interaction between its N- and C-terminal domains in a domain-swapped dimer. In the present study, we performed NMR paramagnetic relaxation enhancement measurements and identified interdomain interactions that were concentration dependent and thus probably not only weak and transient, but also predominantly intermolecular. This notion of two virtually independent domains in a monomeric protein was supported by 15N-relaxation measurements. Thus we suggest that a regulatory role of NusG interdomain interactions is highly unlikely.
Stability and function of the Sec61 translocation complex depends on the Sss1p tail-anchor sequence
Authors: Falcone Domina , Henderson Matthew P. , Nieuwland Hendrik , Coughlan Christine M. , Brodsky Jeffrey L. , Andrews David W.
Published: March 2011

Sss1p, an essential component of the heterotrimeric Sec61 complex in the ER (endoplasmic reticulum), is a tail-anchored protein whose precise mechanism of action is largely unknown. Tail-anchored proteins are involved in many cellular processes and are characterized by a single transmembrane sequence at or near the C-terminus. The Sec61 complex is the molecular machine through which secretory and membrane proteins translocate into and across the ER membrane. To understand the function of the tail anchor of Sss1p, we introduced mutations into the tail-anchor sequence and analysed the resulting yeast phenotypes. Point mutations in the C-terminal hydrophobic core of the tail anchor of Sss1p were identified that allowed Sss1p assembly into Sec61 complexes, but resulted in diminished growth, defects in co- and post-translational translocation, inefficient ribosome binding to Sec61 complexes, reduction in the stability of both heterotrimeric Sec61 and heptameric Sec complexes and a complete breakdown of ER structure. The underlying defect caused by the mutations involves loss of a stabilizing function of the Sss1p tail-anchor sequence for both the heterotrimeric Sec61 and the heptameric Sec complexes. These results indicate that by stabilizing multiprotein membrane complexes, the hydrophobic core of a tail-anchor sequence can be more than a simple membrane anchor.
A composite biochemical system for bacterial nitrate and nitrite assimilation as exemplified byParacoccus denitrificans
Authors: Gates Andrew J. , Luque-Almagro Victor M. , Goddard Alan D. , Ferguson Stuart J. , Roldán M. Dolores , Richardson David J.
Published: March 2011

The denitrifying bacterium Paracoccus denitrificans can grow aerobically or anaerobically using nitrate or nitrite as the sole nitrogen source. The biochemical pathway responsible is expressed from a gene cluster comprising a nitrate/nitrite transporter (NasA), nitrite transporter (NasH), nitrite reductase (NasB), ferredoxin (NasG) and nitrate reductase (NasC). NasB and NasG are essential for growth with nitrate or nitrite as the nitrogen source. NADH serves as the electron donor for nitrate and nitrite reduction, but only NasB has a NADH-oxidizing domain. Nitrate and nitrite reductase activities show the same Km for NADH and can be separated by anion-exchange chromatography, but only fractions containing NasB retain the ability to oxidize NADH. This implies that NasG mediates electron flux from the NADH-oxidizing site in NasB to the sites of nitrate and nitrite reduction in NasC and NasB respectively. Delivery of extracellular nitrate to NasBGC is mediated by NasA, but both NasA and NasH contribute to nitrite uptake. The roles of NasA and NasC can be substituted during anaerobic growth by the biochemically distinct membrane-bound respiratory nitrate reductase (Nar), demonstrating functional overlap. nasG is highly conserved in nitrate/nitrite assimilation gene clusters, which is consistent with a key role for the NasG ferredoxin, as part of a phylogenetically widespread composite nitrate and nitrite reductase system.
TFCP2c/LSF/LBP-1c is required for Snail1-induced fibronectin gene expression
Authors: Porta-de-la-Riva Montserrat , Stanisavljevic Jelena , Curto Josue , Francí Clara , Díaz Víctor Manuel , García de Herreros Antonio , Baulida Josep
Published: March 2011

Fibronectins are cell-secreted glycoproteins that modulate cell attachment, spreading, migration, morphology, differentiation and oncogenic transformation. Fibronectin expression is activated during EMT (epithelial–mesenchymal transition) and is a hallmark of mesenchymal cells. It is shown in the present study that a transcription factor previously unrelated with EMT, TFCP2c/LSF/LBP-1c, was translocated to the nucleus and bound to the fibronectin promoter upon EMT induction by Snail1. Consequently, the interference of TFCP2c/LSF/LBP-1c's activity prevented fibronectin expression. Moreover, TFCP2c/LSF/LBP-1c was detected in nuclei of embryonic dermal mesenchymal cells adjacent to the hair bud, a cell population that expresses endogenous nuclear Snail1 and fibronectin. Therefore we indicate a new molecular role for TFCP2c/LSF/LBP-1c in fibronectin expression.
Position-dependent attenuation by Kv1.6 of N-type inactivation of Kv1.4-containing channels
Authors: Al-Sabi Ahmed , Kaza Seshu , Le Berre Marie , O'Hara Liam , Bodeker MacDara , Wang Jiafu , Dolly J. Oliver
Published: March 2011

Assembly of distinct α subunits of Kv1 (voltage-gated K+ channels) into tetramers underlies the diversity of their outward currents in neurons. Kv1.4-containing channels normally exhibit N-type rapid inactivation, mediated through an NIB (N-terminal inactivation ball); this can be over-ridden if associated with a Kv1.6 α subunit, via its NIP (N-type inactivation prevention) domain. Herein, NIP function was shown to require positioning of Kv1.6 adjacent to the Kv1.4 subunit. Using a recently devised gene concatenation, heterotetrameric Kv1 channels were expressed as single-chain proteins on the plasmalemma of HEK (human embryonic kidney)-293 cells, so their constituents could be arranged in different positions. Placing the Kv1.4 and 1.6 genes together, followed by two copies of Kv1.2, yielded a K+ current devoid of fast inactivation. Mutation of critical glutamates within the NIP endowed rapid inactivation. Moreover, separating Kv1.4 and 1.6 with a copy of Kv1.2 gave a fast-inactivating K+ current with steady-state inactivation shifted to more negative potentials and exhibiting slower recovery, correlating with similar inactivation kinetics seen for Kv1.4-(1.2)3. Alternatively, separating Kv1.4 and 1.6 with two copies of Kv1.2 yielded slow-inactivating currents, because in this concatamer Kv1.4 and 1.6 should be together. These findings also confirm that the gene concatenation can generate K+ channels with α subunits in pre-determined positions.
Solution structure of the Taf14 YEATS domain and its roles in cell growth of Saccharomyces cerevisiae
Authors: Zhang Wen , Zhang Jiahai , Zhang Xuecheng , Xu Chao , Tu Xiaoming
Published: March 2011

Chromatin modifications play important roles in cellular biological process. A novel conserved domain family, YEATS, has been discovered in a variety of eukaryotic species ranging from yeasts to humans. Taf14, which is involved in a few protein complexes of chromatin remodelling and gene transcription, and is essential for keeping chromosome stability, regular cell growth and transcriptional regulation, contains a YEATS domain at its N-terminus. In the present study, we determined the solution structure of the Taf14 YEATS domain using NMR spectroscopy. The Taf14 YEATS domain adopts a global fold of an elongated β-sandwich, similar to the Yaf9 YEATS domain. However, the Taf14 YEATS domain differs significantly from the Yaf9 YEATS domain in some aspects, which might indicate different structural classes of the YEATS domain family. Functional studies indicate that the YEATS domain is critical for the function of Taf14 in inhibiting cell growth under stress conditions. In addition, our results show that the C-terminus of Taf14 is responsible for its interaction with Sth1, which is an essential component of the RSC complex. Taken together, this implies that Taf14 is involved in transcriptional activation of Saccharomyces cerevisiae and the YEATS domain of Taf14 might play a negative role in cell growth.
Different domains are critical for oligomerization compatibility of different connexins
Authors: Martínez Agustín D. , Maripillán Jaime , Acuña Rodrigo , Minogue Peter J. , Berthoud Viviana M. , Beyer Eric C.
Published: March 2011

Oligomerization of connexins is a critical step in gap junction channel formation. Some members of the connexin family can oligomerize with other members and form functional heteromeric hemichannels [e.g. Cx43 (connexin 43) and Cx45], but others are incompatible (e.g. Cx43 and Cx26). To find connexin domains important for oligomerization, we constructed chimaeras between Cx43 and Cx26 and studied their ability to oligomerize with wild-type Cx43, Cx45 or Cx26. HeLa cells co-expressing Cx43, Cx45 or Cx26 and individual chimaeric constructs were analysed for interactions between the chimaeras and the wild-type connexins using cell biological (subcellular localization by immunofluorescence), functional (intercellular diffusion of microinjected Lucifer yellow) and biochemical (sedimentation velocity through sucrose gradients) assays. All of the chimaeras containing the third transmembrane domain of Cx43 interacted with wild-type Cx43 on the basis of co-localization, dominant-negative inhibition of intercellular communication, and altered sedimentation velocity. The same chimaeras also interacted with co-expressed Cx45. In contrast, immunofluorescence and intracellular diffusion of tracer suggested that other domains influenced oligomerization compatibility when chimaeras were co-expressed with Cx26. Taken together, these results suggest that amino acids in the third transmembrane domain are critical for oligomerization with Cx43 and Cx45. However, motifs in different domains may determine oligomerization compatibility in members of different connexin subfamilies.
InsP3 receptors and Orai channels in pancreatic acinar cells: co-localization and its consequences
Authors: Lur Gyorgy , Sherwood Mark W. , Ebisui Etsuko , Haynes Lee , Feske Stefan , Sutton Robert , Burgoyne Robert D. , Mikoshiba Katsuhiko , Petersen Ole H. , Tepikin Alexei V.
Published: March 2011

Orai1 proteins have been recently identified as subunits of SOCE (store-operated Ca2+ entry) channels. In primary isolated PACs (pancreatic acinar cells), Orai1 showed remarkable co-localization and co-immunoprecipitation with all three subtypes of IP3Rs (InsP3 receptors). The co-localization between Orai1 and IP3Rs was restricted to the apical part of PACs. Neither co-localization nor co-immunoprecipitation was affected by Ca2+ store depletion. Importantly we also characterized Orai1 in basal and lateral membranes of PACs. The basal and lateral membranes of PACs have been shown previously to accumulate STIM1 (stromal interaction molecule 1) puncta as a result of Ca2+ store depletion. We therefore conclude that these polarized secretory cells contain two pools of Orai1: an apical pool that interacts with IP3Rs and a basolateral pool that interacts with STIM1 following the Ca2+ store depletion. Experiments on IP3R knockout animals demonstrated that the apical Orai1 localization does not require IP3Rs and that IP3Rs are not necessary for the activation of SOCE. However, the InsP3-releasing secretagogue ACh (acetylcholine) produced a negative modulatory effect on SOCE, suggesting that activated IP3Rs could have an inhibitory effect on this Ca2+ entry mechanism.
Potential role of heat shock proteins in neural differentiation of murine embryonal carcinoma stem cells (P19)
Authors: Afzal Elahe , Ebrahimi Marzieh , Najafi S. Mahmoud Arab , Daryadel Arezoo , Baharvand Hossein
Published: March 2011

HSPs (heat shock proteins) have been recognized to maintain cellular homoeostasis during changes in microenvironment. The present study aimed to investigate the HSPs expression pattern in hierarchical neural differentiation stages from mouse embryonal carcinoma stem cells (P19) and its role in heat stressed exposed cells. For induction of HSPs, cells were heated at 42°C for 30 min and recovered at 37°C in different time points. For neural differentiation, EBs (embryoid bodies) were formed by plating P19 cells in bacterial dishes in the presence of 1 mM RA (retinoic acid) and 5% FBS (fetal bovine serum). Then, on the sixth day, EBs were trypsinized and plated in differentiation medium containing neurobasal medium, B27, N2 and 5% FBS and for an extra 4 days. The expression of HSPs and neural cell markers were evaluated by Western blot, flow cytometry and immunocytochemistry in different stages. Our results indicate that HSC (heat shock constant)70 and HSP60 expressions decreased following RA treatment, EB formation and in mature neural cells derived from heat‐stressed single cells and not heat‐treated EBs. While the level of HSP90 increased six times following maturation process, HSP25 was expressed constantly during neural differentiation; however, its level was enhanced with heat stress. Accordingly, heat shock 12 h before the initiation of differentiation did not affect the expression of neuroectodermal and neural markers, nestin and β‐tubulin III, respectively. However, both markers increased when heat shock was induced after treatment and when EBs were formed. In conclusion, our results raise the possibility that HSPs could regulate cell differentiation and proliferation under both physiological and pathological conditions.