bluuebunny/crossref_metadata_2025_split huggingface dataset:
CE of inorganic species – A review of methodological advancements over 2009–2010
Authors: Kubáň Petr , Timerbaev Andrei R. 
Published: December 2011

AbstractThis article is the seventh in a series examining biannually the methodological developments in the field of CE analysis of inorganic species and covers relevant documents published between January 2009 and December 2010. Following an analysis of the significant accomplishments that have impacted the field in two recent years, a survey of advances in general CE methodology is presented. Subsequently, several notable trends that can be perceived in this well‐established field are discussed: the continuing rise of ME and consequent development of suitable detection techniques, most notably contactless conductivity detection, the constant pace of advances in speciation analysis, and an increase in non‐analytical CE applications to study complexation and (bio)transformation reactions of metal analytes. A range of recently emerged multi‐detection designs, ICP‐MS interface devices, and separation systems, for which outpacing work has been conducted, are also brought into focus.
Recent advances in the analysis of antibiotics by CE and CEC
Authors: Pérez‐Fernández Virginia , Domínguez‐Vega Elena , Crego Antonio L. , García Maria Ángeles , Marina Maria Luisa 
Published: December 2011

AbstractThis article reviews the recent developments achieved in the analysis of antibiotics by CE and CEC. CZE has mainly been employed although other separation modes have also been used. Different detection systems coupled to CE have been reported for antibiotic determination. Enhancement on sensitivity through the use of diverse offline, inline, and online preconcentration approaches is also described. Special attention has been paid to sample treatment steps and to the applications developed in different research areas such as the pharmaceutical, biological, food, and environmental. This manuscript covers the period of time from the previous review published in June 2009 until May 2011.
Surface modification for PDMS‐based microfluidic devices
Authors: Zhou Jinwen , Khodakov Dmitriy A. , Ellis Amanda V. , Voelcker Nicolas H. 
Published: December 2011

AbstractThis review focuses on advances reported from April 2009 to May 2011 in PDMS surface modifications for the application in microfluidic devices. PDMS surface modification techniques presented here include improved plasma and graft polymer coating, dynamic surfactant treatment, hydrosilylation‐based surface modification and surface modification with nanomaterials such as carbon nanotubes and metal nanoparticles. Recent efforts to generate topographical and chemical patterns on PDMS are also discussed. The described surface modifications not only increase PDMS wettability, inhibit or reduce non‐specific adsorption of hydrophobic species onto the surfaces in the act, but also result in the display of desired functional groups useful for molecular separations, biomolecular detection via immunoassays, cell culture and emulsion formation.
Quality control issues and the identification of rare functional variants with next‐generation sequencing data
Authors: Hemmelmann Claudia , Daw E. Warwick , Wilson Alexander F. 
Published: December 2011

AbstractNext‐generation sequencing of large numbers of individuals presents challenges in data preparation, quality control, and statistical analysis because of the rarity of the variants. The Genetic Analysis Workshop 17 (GAW17) data provide an opportunity to survey existing methods and compare these methods with novel ones. Specifically, the GAW17 Group 2 contributors investigate existing and newly proposed methods and study design strategies to identify rare variants, predict functional variants, and/or examine quality control. We introduce the eight Group 2 papers, summarize their approaches, and discuss their strengths and weaknesses. For these investigations, some groups used only the genotype data, whereas others also used the simulated phenotype data. Although the eight Group 2 contributions covered a wide variety of topics under the general idea of identifying rare variants, they can be grouped into three broad categories according to their common research interests: functionality of variants and quality control issues, family‐based analyses, and association analyses of unrelated individuals. The aims of the first subgroup were quite different. These were population structure analyses that used rare variants to predict functionality and examine the accuracy of genotype calls. The aims of the family‐based analyses were to select which families should be sequenced and to identify high‐risk pedigrees; the aim of the association analyses was to identify variants or genes with regression‐based methods. However, power to detect associations was low in all three association studies. Thus this work shows opportunities for incorporating rare variants into the genetic and statistical analyses of common diseases. Genet. Epidemiol. 35:S22–S28, 2011. © 2011 Wiley Periodicals, Inc.
Multiple testing in high‐throughput sequence data: experiences from Group 8 of Genetic Analysis Workshop 17
Authors: König Inke R. , Nsengimana Jeremie , Papachristou Charalampos , Simonson Matthew A. , Wang Kai , Weisburd Jason A. 
Published: December 2011

AbstractThe use of high‐throughput sequence data in genetic epidemiology allows the investigation of common and rare variants in the entire genome, thus increasing the amount of information and the potential number of statistical tests performed within one study. As a consequence, the problem of multiple testing may become even more pressing than in previous studies. As an important challenge, the exact number of statistical tests depends on the actual statistical method used. Furthermore, many statistical approaches for the analysis of sequence data require permutation. Thus it may be difficult to also use permutation to estimate correct type I error levels as in genome‐wide association studies. In view of this, a separate group at Genetic Analysis Workshop 17 was formed with a focus on multiple testing. Here, we present the approaches used for the workshop. Apart from tackling the multiple testing problem, the new group focused on different issues. Some contributors developed and investigated modifications of existing collapsing methods. Others aimed at improving the identification of functional variants through a reduction and analysis of the underlying data dimensions. Two research groups investigated the overall accumulation of rare variation across the genome and its value in predicting phenotypes. Finally, other investigators left the path of traditional statistical analyses by reversing null and alternative hypotheses and by proposing a novel resampling method. We describe and discuss all these approaches. Genet. Epidemiol. 35:S61–S66, 2011. © 2011 Wiley Periodicals, Inc.
Lessons learned from Genetic Analysis Workshop 17: transitioning from genome‐wide association studies to whole‐genome statistical genetic analysis
Authors: Wilson Alexander F. , Ziegler Andreas 
Published: December 2011

AbstractGenetic Analysis Workshop 17 (GAW17) focused on the transition from genome‐wide association study designs and methods to the study designs and statistical genetic methods that will be required for the analysis of next‐generation sequence data including both common and rare sequence variants. In the 166 contributions to GAW17, a wide variety of statistical methods were applied to simulated traits in population‐ and family‐based samples, and results from these analyses were compared to the known generating model. In general, many of the statistical genetic methods used in the population‐based sample identified causal sequence variants (SVs) when the estimated locus‐specific heritability, as measured in the population‐based sample, was greater than about 0.08. However, SVs with locus‐specific heritabilities less than 0.03 were rarely identified consistently. In the family‐based samples, many of the methods detected SVs that were rarer than those detected in the population‐based sample, but the estimated locus‐specific heritabilities for these rare SVs, as measured in the family‐based samples, were substantially higher (>0.2) than their corresponding heritabilities in the population‐based samples. Substantial inflation of the type I error rate was observed across a wide variety of statistical methods. Although many of the contributions found little inflation in type I error for Q4, a trait with no causal SVs, type I error rates for Q1 and Q2 were well above their nominal levels with the inflation for Q1 being higher than that for Q2. It seems likely that this inflation in type I error is due to correlations among SVs. Genet. Epidemiol. 35:S107–S114, 2011. © 2011 Wiley Periodicals, Inc.
Steroid 5α‐reductase in adult rat brain after neonatal testosterone administration
Authors: Sánchez Pilar , Torres Jesús M. , del Moral Raimundo G. , de Dios Luna Juan , Ortega Esperanza 
Published: December 2011

AbstractTestosterone (T) plays an important role in developing brain, dictating sex‐specific behavior and physiology. 3α,5α‐Reduced neurosteroids also regulate reproductive behavior. The key enzyme in the biosynthesis of these neurosteroids is 5α‐reductase (5α‐R), expressed as two isozymes, 5α‐R1 and 5α‐R2. In this study, T and sesame oil (vehicle) were administered during postnatal sexual differentiation of the central nervous system (CNS) and mRNA levels of 5α‐R isozymes, were measured using quantitative RT‐PCR in prefrontal cortex of male and female rats with different androgenic status at adulthood. Our results indicate that T concentrations during postnatal sexual differentiation of the rat CNS, among other sex‐dependent factors, influence brain levels of 5α‐R isozymes in adulthood and the pattern of their regulation by androgen hormones. © 2011 IUBMB Life, 2011
Role of oxidative stress in the pathogenesis of sickle cell disease
Authors: Chirico Erica N. , Pialoux Vincent 
Published: December 2011

AbstractSickle cell disease (SCD) is a class of hemoglobinopathy in humans, which causes a disruption of the normal activities in different systems. Although this disease begins with the polymerization of red blood cells during its deoxygenating phase, it can erupt into a cascade of debilitating conditions such as ischemia‐reperfusion injury, inflammation, and painful vaso‐occlusion crises. The purpose of this review is to discuss how these phenomena can result in the formation of oxidative stress as well as limit nitric oxide (NO) bioavailability and decrease antioxidant status. The cumulative effects of these traits cause an increase in other forms of reactive oxygen species (ROS), which in turn intensify the symptoms of SCD and generate a vicious circle. Finally, we will discuss antioxidant therapeutic strategies that limit ROS generation and subsequently increase NO bioavailability with respect to endothelial protection in SCD. © IUBMB, IUBMB Life, 2011.
Balanced steady‐state free precession fMRI with intravascular susceptibility contrast agent
Authors: Zhou Iris Y. , Cheung Matthew M. , Lau Condon , Chan Kevin C. , Wu Ed X. 
Published: December 2011

AbstractOne major challenge in echo planar imaging‐based functional MRI (fMRI) is the susceptibility‐induced image distortion. In this study, a new cerebral blood volume‐weighted fMRI technique using distortion‐free balanced steady‐state free precession (bSSFP) sequence was proposed and its feasibility was investigated in rat brain at 7 Tesla. After administration of intravascular susceptibility contrast agent (monocrystalline iron oxide nanoparticle [MION] at 15 mg/kg), unilateral visual stimulation was presented using a block‐design paradigm. With repetition time/echo time = 3.8/1.9 ms and α = 18°, bSSFP fMRI was performed and compared with the conventional cerebral blood volume‐weighted fMRI using post‐MION gradient echo and spin echo echo planar imaging. The results showed that post‐MION bSSFP fMRI provides comparable sensitivity but with no severe image distortion and signal dropout. Robust negative responses were observed during stimulation and activation patterns were in excellent agreement with known neuroanatomy. Furthermore, the post‐MION bSSFP signal was observed to decrease significantly during hypercapnia challenge, indicating its sensitivity to cerebral blood volume changes. These findings demonstrated that post‐MION bSSFP fMRI is a promising alternative to conventional cerebral blood volume‐weighted fMRI. This technique is particularly suited for fMRI investigation of animal models at high field. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
In vivo detection of excitotoxicity by manganese‐enhanced MRI: Comparison with physiological stimulation
Authors: Gobbo Oliviero L. , Petit Fanny , Gurden Hirac , Dhenain Marc 
Published: December 2011

AbstractManganese‐enhanced MRI (MEMRI) is a powerful technique for the in vivo monitoring of brain function in animals. Manganese enters into cells through calcium channels, i.e., voltage‐gated calcium channels and activated glutamate receptors (e.g.,N‐methyl‐D‐aspartate receptors).N‐methyl‐D‐aspartate receptors are activated both in normal physiological and pathophysiological conditions. Consistent with these mechanisms, we showed that in the olfactory bulb, the MEMRI signal strongly increases when excitotoxic mechanisms are induced by an administration of aN‐methyl‐D‐aspartate receptor agonist, quinolinate. We found that the intensity of the MEMRI signal in excitotoxic conditions is similar to the odor‐evoked signal in normal physiological conditions. Finally, we showed that the dynamics of the MEMRI signal are determined by the early phase of manganese in the olfactory bulb. Overall, these data show that, in addition to physiological studies, MEMRI can be used as an in vivo method to follow‐up the dynamics of excitotoxic events. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
CRABP‐II methylation: A critical determinant of retinoic acid resistance of medulloblastoma cells
Authors: Fu Yuan-Shan , Wang Qian , Ma Jing-Xin , Yang Xiang-Hong , Wu Mo-Li , Zhang Kai-Li , Kong Qing-You , Chen Xiao-Yan , Sun Yuan , Chen Nan-Nan , Shu Xiao-Hong , Li Hong , Liu Jia 
Published: December 2011

Medulloblastoma cells exhibit varied responses to therapy by all‐trans retinoic acid (RA). The underlying mechanism for such diverse effects however remains largely unclear. In this study, we attempted to elucidate the molecular basis of RA resistance through the study of RA signaling components in both RA‐sensitive (Med‐3) and RA‐resistant (UW228‐2 and UW228‐3) medulloblastoma cells. The results revealed that RARα/β/γ and RXRα/β/γ were found in the three cell lines. Expression of CRABP‐I and CRABP‐II was seen in Med‐3 cells, up‐regulated when treated with RA, but was absent in UW228‐2 and UW228‐3 cells regardless of RA treatment. Bisulfite sequencing revealed 8 methylated CG sites at the promoter region of CRABP‐II in UW228‐2 and UW228‐3 but not in Med‐3 cells. Demethylation by 5‐aza‐2′‐deoxycytidine recovered CRABP‐II expression. Upon restoration of CRABP‐II expression, both UW228‐2 and UW228‐3 cells responded to RA treatment by forming neuronal‐like differentiation, synaptophysin expression, β‐III tubulin upregulation, and apoptosis. Furthermore, CRABP‐II specific siRNA reduced RA sensitivity in Med‐3 cells. Tissue microarray‐based immunohistochemical staining showed variable CRABP‐II expression patterns among 104 medulloblastoma cases, ranging from negative (42.3%), partly positive (14.4%) to positive (43.3%). CRABP‐II expression was positively correlated with synaptophysin (rs = 0.317; p = 0.001) but not with CRABP‐I expression (p > 0.05). In conclusion, aberrant methylation in CRABP‐II reduces the expression of CRABP‐II that in turn confers RA resistance in medulloblastoma cells. Determination of CRABP‐II expression or methylation status may enable a personalized RA therapy in patients with medulloblastomas and other types of cancers.
Chemical interaction between the larva of a dipteran parasitoid and its coleopteran host: A case of exploitation of the communication system during the searching behaviour?
Authors: Groba H.F. , Castelo M.K. 
Published: December 2011

AbstractThe robber flyMallophora ruficaudais one of the principal apicultural pests in the Pampas region of Argentina. As adults, the flies prey on honey bees and other insects; while, as larvae, they parasitize scarab beetle larvae. Females ofM. ruficaudalay eggs away from the host in tall grasses. After being dispersed by the wind, larvae drop to the ground, where they dig in search of their hosts. It is known that second instar larvae ofM. ruficaudaexhibit active host searching behaviour towards its preferred host, third instar larva ofCyclocephala signaticollis, using host-related chemical cues. Furthermore, previous works show that these chemical cues are produced in the posterior body half of hosts. However, the precise anatomical origin of these cues and whether they mediate any behaviour ofC. signaticollislarvae remains yet unknown. In order to determine the precise origin of the chemical cue, we carried out olfactometer assays with different stimuli of extracts of the posteriorC. signaticollisbody half. Additionally, we tested whetherC. signaticollisis attracted to any of the same extracts as in the previous experiments. We found that both second instar ofM. ruficaudaand third instar ofC. signaticollisare attracted to extracts of the fermentation chamber (proctodeum). This is the first report of attraction of conspecific larvae in scarab beetles. We discuss a possible case of system communication exploitation in an immature parasitoid-host system.
Chrono- and lithostratigraphy of a Mesozoic–Tertiary fore- to intra-arc basin: Adelaide Island, Antarctic Peninsula
Authors: RILEY TEAL R. , FLOWERDEW MICHAEL J. , WHITEHOUSE MARTIN J. 
Published: December 2011

AbstractThe Mesozoic fore-arc of the Antarctic Peninsula is exposed along its west coast. On Adelaide Island, a 2–3 km succession of turbiditic coarse sandstones and volcanic rocks is exposed. Four U–Pb (zircon) ages are presented here that, in combination with a new stratigraphy, have permitted a robust chrono- and lithostratigraphy to be constructed, which in turn has allowed tentative correlations to be made with the Fossil Bluff Group of Alexander Island, where the ‘type’ fore-arc sequences are described. The lithostratigraphy of Adelaide Island includes the definition of five volcanic/sedimentary formations. The oldest formation is the Buchia Buttress Formation (149.5 ± 1.6 Ma) and is correlated with the Himalia Ridge Formation of Alexander Island. The sandstone–conglomerate dominated succession of the Milestone Bluff Formation (113.9 ± 1.2 Ma) is tentatively correlated with the Pluto Glacier Formation of Alexander Island. Three dominantly volcanic formations are recognized on Adelaide Island, akin to the volcanic rocks of the Alexander Island Volcanic Group; the Mount Liotard Formation is formed of 2 km of basaltic andesite lavas, whilst the Bond Nunatak Formation is also dominated by basaltic andesite lavas, but interbedded with volcaniclastic rocks. The Reptile Ridge Formation has been dated at 67.6 ± 0.7 Ma and is characterized by hydrothermally altered rhyolitic crystal-lithic tuffs. Tentative correlations between Adelaide Island and Alexander Island preclude the two areas forming part of distinct terranes as has been suggested previously, and a proximal source for volcaniclastic sediments also indicates an exotic terrane origin is unlikely.
Period functions for Hecke triangle groups, and the Selberg zeta function as a Fredholm determinant
Authors: MÖLLER M. , POHL A. D. 
Published: December 2011

AbstractWe characterize Maass cusp forms for any cofinite Hecke triangle group as 1-eigenfunctions of appropriate regularity of a transfer operator family. This transfer operator family is associated to a certain symbolic dynamics for the geodesic flow on the orbifold arising as the orbit space of the action of the Hecke triangle group on the hyperbolic plane. Moreover, we show that the Selberg zeta function is the Fredholm determinant of the transfer operator family associated to an acceleration of this symbolic dynamics.
Motion prediction and supervisory control of the macro–micro parallel manipulator system
Authors: Duan Xuechao , Qiu Yuanying , Mi Jianwei , Zhao Ze 
Published: December 2011

SUMMARYThis paper deals with the motion prediction and control of the macro–micro parallel manipulator system for a 500-m-aperture spherical radio telescope (FAST). Firstly, based on principles of parallel mechanism, a decoupled tracking and prediction algorithm to predict the position and orientation of the movable macro parallel manipulator is presented in this paper. Then, taken as the upper layer supervisory controller in the joint space of the micro parallel manipulator, the adaptive interaction PID controller utilizing the adaptive interaction algorithm to adjust the parameters of a canonical PID controller is discussed. In addition, the digital servo filters with feedforward are employed in the linear actuators as the lower layer controllers. Experimental results of a one-tenth scale FAST field model validate the effectiveness of the supervisory controller and the motion prediction algorithm.
How does spallation microdamage nucleate in bulk amorphous alloys under shock loading?
Authors: Huang X. , Ling Z. , Zhang H. S. , Ma J. , Dai L. H. 
Published: December 2011

Specially designed plate-impact experiments have been conducted on a Zr-based amorphous alloy using a single-stage light gas gun. To understand the microdamage nucleation process in the material, the samples are subjected to dynamic tensile loadings of identical amplitude (∼ 3.18 GPa) but with different durations (83–201 ns). A cellular pattern with an equiaxed shape is observed on the spallation surface, which shows that spallation in the tested amorphous alloy is a typical ductile fracture and that microvoids have been nucleated during the process. Based on the observed fracture morphologies of the spallation surface and free-volume theory, we propose a microvoid nucleation model of bulk amorphous alloys. It is found that nucleation of microvoids at the early stage of spallation in amorphous alloys results from diffusion and coalescence of free volume, and that high mean tensile stress plays a dominant role in microvoid nucleation.
The excitation function for Li + HF → LiF + H at collision energies below 80 meV
Authors: Bobbenkamp Rolf , Loesch Hansjürgen , Mudrich Marcel , Stienkemeier Frank 
Published: December 2011

We have measured the dependence of the relative integral cross section of the reaction Li + HF → LiF + H on the collision energy (excitation function) using crossed molecular beams. By varying the intersection angle of the beams from 37° to 90° we covered the energy range 25 meV ⩽ Etr ⩽ 131 meV. We observe a monotonous rise of the excitation function with decreasing energy over the entire energy range indicating that a possible translational energy threshold to the reaction is significantly smaller than 25 meV. The steep rise is quantitatively recovered by a Langevin-type excitation function based on a vanishing threshold and a mean interaction potential energy ∝R−2.5 where R is the distance between the reactants. To date all threshold energies deduced from ab initio potentials and zero-point vibrational energies are at variance with our results, however, our findings support recent quantum scattering calculations that predict significant product formation at collision energies far below these theoretical thresholds.