bluuebunny/crossref_metadata_2025 huggingface dataset:
Recognition of the Murine Coronavirus Genomic RNA Packaging Signal Depends on the Second RNA-Binding Domain of the Nucleocapsid Protein
Authors: Kuo Lili , Koetzner Cheri A. , Hurst Kelley R. , Masters Paul S.
Published: February 2014

The coronavirus nucleocapsid (N) protein forms a helical ribonucleoprotein with the viral positive-strand RNA genome and binds to the principal constituent of the virion envelope, the membrane (M) protein, to facilitate assembly and budding. Besides these structural roles, N protein associates with a component of the replicase-transcriptase complex, nonstructural protein 3, at a critical early stage of infection. N protein has also been proposed to participate in the replication and selective packaging of genomic RNA and the transcription and translation of subgenomic mRNA. Coronavirus N proteins contain two structurally distinct RNA-binding domains, an unusual characteristic among RNA viruses. To probe the functions of these domains in the N protein of the model coronavirus mouse hepatitis virus (MHV), we constructed mutants in which each RNA-binding domain was replaced by its counterpart from the N protein of severe acute respiratory syndrome coronavirus (SARS-CoV). Mapping of revertants of the resulting chimeric viruses provided evidence for extensive intramolecular interactions between the two RNA-binding domains. Through analysis of viral RNA that was packaged into virions we identified the second of the two RNA-binding domains as a principal determinant of MHV packaging signal recognition. As expected, the interaction of N protein with M protein was not affected in either of the chimeric viruses. Moreover, the SARS-CoV N substitutions did not alter the fidelity of leader-body junction formation during subgenomic mRNA synthesis. These results more clearly delineate the functions of N protein and establish a basis for further exploration of the mechanism of genomic RNA packaging.

IMPORTANCE
This work describes the interactions of the two RNA-binding domains of the nucleocapsid protein of a model coronavirus, mouse hepatitis virus. The main finding is that the second of the two domains plays an essential role in recognizing the RNA structure that allows the selective packaging of genomic RNA into assembled virions.
Iatrogenic dependence of anabolic-androgenic steroid in an Indian non-athletic woman
Authors: Tripathi Adarsh , Tekkalaki Bheemsain , Saxena Shashwat , Dandu Himanshu
Published: February 2014

Anabolic-androgenic steroids (AAS) are increasingly being used by athletes and youngsters to become masculine and to loose body fat. Long-term consumption of AAS causes multiple physical and psychological morbidities. Research has also concluded that AAS have addictive potential and AAS abuse is commonly found with other substance abuse. Abuse of AAS is rare in eastern countries. Abuse among women is even rarer. Here is a case report of an Indian woman, who was prescribed nandrolone decanoate injections by an unqualified medical practitioner to treat multiple non-specific somatic pains and reported weakness, leading to dependence for nandrolonedecanoate. This case report supports the research finding of abuse potential of AAS, raises concern about the need for spreading the awareness about AAS abuse among medical professionals, regulating medical practice by unqualified practitioners, and strict legal check against AAS availability in developing countries.
Family planning and pregnancy issues for women with systemic inflammatory diseases: patient and physician perspectives
Authors: Chakravarty Eliza , Clowse Megan E B , Pushparajah Daphnee S , Mertens Sarah , Gordon Caroline
Published: February 2014

Objectives

To identify family planning and pregnancy (FPP) issues for female patients of childbearing age living with a chronic inflammatory disease and to assess whether current clinical practice routinely provides adequate support to alleviate these concerns.

Setting

Multinational survey and an analysis of online patient activity.

Participants

Premenopausal women (aged 20–45 years; N=969) were surveyed in the USA, the UK, Germany, France, Italy and Spain. Rheumatologists were surveyed in Germany (N=50), France (N=50), Italy (N=50) and the USA (N=100), and gastroenterologists were also surveyed in the USA (N=100).

Primary and secondary outcome measures

Two online surveys were undertaken to identify FPP issues for physicians and patients. The surveys examined the frequency of dialogue on these topics between physicians and patients, alongside assessment of patient satisfaction regarding these conversations. Online analysis identified key themes for patient discussion outside their doctors’ office/clinic/surgery.

Results

32–56% of physicians spontaneously reported having talked about FPP with their female patients of childbearing age. When prompted, the majority of rheumatologists (74–92%) and gastroenterologists (74%) reported having discussed conception/pregnancy with female patients; however, less than half reported consulting their patient's treating general practitioner/gynaecologist about these topics. The majority of patients reported their FPP-related concerns are not adequately addressed/settled during their medical appointments. Furthermore, only 30–40% of patients considered advice/information to be consistent across multiple healthcare professionals. Key online FPP-related patient discussions included disease state, adverse effects, treatment, switch behaviour and wash-out requirements.

Conclusions

Female patients who live with chronic inflammatory disease have important FPP concerns. The majority of patients, however, do not feel that their FPP concerns are adequately addressed in current clinical practice and report that they receive inconsistent advice from the various healthcare professionals who manage different aspects of their care. There is a clear need for provision of up-to-date and consistent information/support to female patients.
Midwives’ experiences and views of giving postpartum contraceptive advice and providing long-acting reversible contraception: a qualitative study
Authors: McCance Kirsty , Cameron Sharon
Published: February 2014

Background

National sexual health frameworks in the UK advise that women in maternity units who are at risk of unintended pregnancy should receive contraceptive advice and supplies of the most effective long-acting reversible methods of contraception (LARC). In the UK, midwives currently deliver contraceptive advice to women following childbirth. There is a lack of information on how midwives currently view their role as provider of contraceptive advice and how they would feel about expanding this to include provision of LARC.

Objective

To explore midwives’ experiences and views of giving postpartum contraceptive advice and of possible expansion of role to include provision of LARC.

Methods

Semi-structured, audio-recorded interviews were carried out with 12 midwives involved in the postpartum care of women in Edinburgh, Scotland, UK. Interviews were transcribed verbatim and analysed using thematic analysis.

Results

Midwives confirmed that they all routinely give contraceptive advice but that this was mostly cursory. They viewed this part of their job as of lesser importance and one that they felt inadequately trained for. Many barriers to discussing contraception were identified including lack of time and privacy, or mothers being preoccupied with concerns about their baby. Midwives expressed concern about taking on a greater role in giving contraceptive advice or providing LARC, given their current heavy workload.

Conclusions

Midwives require ongoing training and support to be effective in their current role as provider of contraceptive advice. Better links between midwifery and specialist sexual and reproductive health services should therefore be encouraged, particularly if a midwife's role is expanded to include provision of contraception such as LARC.
High-intensity interval exercise induces 24-h energy expenditure similar to traditional endurance exercise despite reduced time commitment
Authors: Skelly Lauren E. , Andrews Patricia C. , Gillen Jenna B. , Martin Brian J. , Percival Michael E. , Gibala Martin J.
Published: February 2014

Subjects performed high-intensity interval training (HIIT) and continuous moderate-intensity training (END) to evaluate 24-h oxygen consumption. Oxygen consumption during HIIT was lower versus END; however, total oxygen consumption over 24 h was similar. These data demonstrate that HIIT and END induce similar 24-h energy expenditure, which may explain the comparable changes in body composition reported despite lower total training volume and time commitment.
Flume investigation of landslide debris–resisting baffles
Authors: Choi C.E. , Ng C.W.W. , Song D. , Kwan J.H.S. , Shiu H.Y.K. , Ho K.K.S. , Koo R.C.H.
Published: February 2014

Landslide debris is a common occurrence in mountainous regions around the world that can potentially result in disastrous consequences to downstream facilities. Flow-impeding structures are often constructed along the flow path to impede this hazardous phenomenon. Baffles are a type of flow-impeding structure regularly installed using empirical and prescriptive design methods as the interaction mechanism and the influence of baffle configuration on flow impedance is not well understood. A series of flume experiments were carried out to investigate flows characterizing landslide debris impacting an array of baffles using dry uniform sand. The influence of baffle height, row number, and spacing between successive rows was examined. Photoconductive sensors were used to estimate flow velocity, laser sensors were installed to measure flow depth profiles, and high-speed cameras were used to capture flow kinematics. Experimental results reveal that baffles can be categorized relative to the approach flow depth (h) and increasing the baffle height from 0.75h to 1.5h leads to a 40% increase in upstream flow depths from backwater effects, more effective development of subcritical conditions, and additional energy losses of up to 9%. Increasing the number of rows of 1.5h baffles from a single row to a three-row staggered array results in up to 72% additional energy loss. The energy loss is attributed to the deflection of granular jets and additional backwater effects. Increasing the row spacing from 50 to 100 mm results in up to a 14% increase in energy loss.
Preferential crystal growth of germanium by solid phase crystallization
Authors: Kanai Mikuri , Kojima Yuji , Isomura Masao
Published: February 2014

We have investigated the preparation of crystalline germanium films by the solid phase crystallization (SPC) of amorphous germanium (a-Ge) precursor on single crystalline silicon substrates. The a-Ge precursor easily incorporates the impurities from the surface exposed to the air, and the impurities affect the crystallinity after the SPC. In the a-Ge precursor prepared by Knudsen-cell evaporation, the preferential crystalline growth following the Si substrates is disturbed by the high density of impurities and the random crystalline structures are formed. The a-Ge precursors prepared by electron beam evaporation have high impurity concentrations only near the surface because the impurity diffusion is slow because of the relatively high density. The preferential growth is successfully obtained in a-Ge precursor prepared on n-type Si substrates, although the random crystallization is slightly observed on p-type Si substrates. By sufficiently reducing the impurity concentrations by avoiding the air exposure, the preferential growth can be promoted on p-type Si substrates. The impurity incorporation because of the air exposure is sufficiently reduced for the preferential growth by covering a-Ge with a-Si blocking layers. This method is effective for future practical applications of SPC Ge films.
Wall proximity effects on flow over cylinders with different cross sections
Authors: Bayraktar Seyfettin , Yayla Sedat , Oztekin Alparslan , Ma Haolin
Published: February 2014

This paper presents the results of a numerical study on flow characteristics over circular, square, and diamond cross-sectional cylinders. Investigations are performed in a two-dimensional domain using the finite volume discretization method solver for Reynolds number, Re = 20 000. Unsteady Reynolds averaged Navier–Stokes equations with Spalart–Allmaras turbulence model have been used as a turbulence closure. After the validation of the simulations with the available experimental data from the open literature, global characteristics of the flow field around different shaped cylinders near the wall have been presented. Effects of wall proximity on cylinders are investigated for four different gap width (G) to cylinder width (D) ratios.
OPTIMAL UTILIZATION OF HYBRID WIND–SOLAR SYSTEM AS DVR FOR VOLTAGE REGULATION AND ENERGY CONSERVATION
Authors: RAMASAMY M. , THANGAVEL S.
Published: February 2014

This paper presents a novel optimal utilization of hybrid wind–solar system as dynamic voltage restorer (DVR) for voltage sag, voltage swell, outage and unbalanced voltage mitigation. Besides the voltage regulation, the proposed DVR reduces the energy consumption from the three phase utility grid by utilizing the rated inverter capability after excessive or equal real power generation to the load demand during both day time and night time. It reduces the energy consumption from the three phase utility grid. However, the reduction of energy consumption is always desirable for the reduction of panel tariff and electricity demand. The proposed system was simulated using MATLAB-SIMULINK in which the input parameters were selected from the metrological data of the selected location to validate the advantage of the proposed system.
NONBARYONIC DARK MATTER IN COSMOLOGY
Authors: DEL POPOLO ANTONINO
Published: February 2014

This paper is a broadband review of the current status of nonbaryonic dark matter (DM) research, starting from a historical overview of the evidences of existence of DM, then discussing how DM is distributed from small scale to large scale, continuing with a discussion on DM nature, DM candidates and their detection. I finally discuss some of the limits of the ΛCDM model, with particular emphasis on the small scale problems of the paradigm.
ON A RECENT PRELIMINARY STUDY FOR THE MEASUREMENT OF THE LENSE–THIRRING EFFECT WITH THE GALILEO SATELLITES
Authors: IORIO L.
Published: February 2014

It has recently been proposed to combine the node drifts of the future constellation of 27 Galileo spacecraft together with those of the existing Laser Geodynamics Satellites (LAGEOS)-type satellites to improve the accuracy of the past and ongoing tests of the Lense–Thirring (LT) effect by removing the bias of a larger number of even zonal harmonics Jℓ than either done or planned so far. Actually, it seems a difficult goal to be achieved realistically for a number of reasons. First, the LT range signature of a Galileo-type satellite is as small as 0.5 mm over three-days arcs, corresponding to a node rate of just [Formula: see text] milliarcseconds per year (mas yr-1). Some tesseral and sectorial ocean tides such as K1 and K2 induce long-period harmonic node perturbations with frequencies which are integer multiples of the extremely slow Galileo's node rate [Formula: see text] completing a full cycle in about 40 yr. Thus, over time spans, T, of some years, they would act as superimposed semisecular aliasing trends. Since the coefficients of the Jℓ-free multisatellite linear combinations are determined only by the semimajor axis a, the eccentricity e and the inclination I, which are nominally equal for all the Galileo satellites, it is not possible to include all of them. Even using only one Galileo spacecraft together with the LAGEOS family would be unfeasible because of the fact that the resulting Galileo coefficient would be ≳ 1, thus enhancing the aliasing impact of the uncancelled nonconservative and tidal perturbations.
FINITE ELEMENT ANALYSIS OF CERVICAL SPINE WITH DIFFERENT CONSTRAINED TYPES OF TOTAL DISC REPLACEMENT
Authors: LIN CHIEN-YU , CHUANG SHIH-YOUENG , CHIANG CHANG-JUNG , TSUANG YANG-HWEI , CHEN WENG-PIN
Published: February 2014

Various designs of cervical total disc replacement (CTDR) have been introduced and employed in an attempt to avoid disadvantages of the fusion surgery. The purposes of this study were to evaluate the effects of the range of motion (ROM), the instantaneous center of rotation (ICR) and the facet joint force (FJF) with different constrained types of CTDR devices. A three-dimensional finite element (FE) model of intact cervical spine (C3-7) was made from CT scans of a normal person and validated. Postoperative FE models simulating CTDR implantation at the C5-6 disc space were made for CTDR-I (constrained design) and CTDR-II (nonconstrained design), respectively. Hybrid protocol (intact: 1 Nm) with a compressive follower load of 73.6 N was applied at the superior endplate of the C3 vertebral body. The inferior endplate of C7 vertebral body was constrained in all directions. At the index level, CTDR-I showed a higher increase in segmental motion and FJF than CTDR-II in extension, lateral bending and axial rotation. The CTDR-II with an elastomer-type core reproduced a near physiological ICR of the intact model in extension and axial rotation. Abnormal kinetic and kinematic changes related to the CTDR may induce surgical level problems and cause long-term failure of spinal surgery.
Proportional Hybrid Mechanism for Population Based Feature Selection Algorithm
Authors: Wang Pin , Li Yongming , Chen Bohan , Hu Xianling , Yan Jin , Xia Yu , Yang Jie
Published: February 2014

Feature selection is an important research field for pattern classification, data mining, etc. Population-based optimization algorithms (POA) have high parallelism and are widely used as search algorithm for feature selection. Population-based feature selection algorithms (PFSA) involve compromise between precision and time cost. In order to optimize the PFSA, the feature selection models need to be improved. Feature selection algorithms broadly fall into two categories: the filter model and the wrapper model. The filter model is fast but less precise; while the wrapper model is more precise but generally computationally more intensive. In this paper, we proposed a new mechanism — proportional hybrid mechanism (PHM) to combine the advantages of filter and wrapper models. The mechanism can be applied in PFSA to improve their performance. Genetic algorithm (GA) has been applied in many kinds of feature selection problems as search algorithm because of its high efficiency and implicit parallelism. Therefore, GAs are used in this paper. In order to validate the mechanism, seven datasets from university of California Irvine (UCI) database and artificial toy datasets are tested. The experiments are carried out for different GAs, classifiers, and evaluation criteria, the results show that with the introduction of PHM, the GA-based feature selection algorithm can be improved in both time cost and classification accuracy. Moreover, the comparison of GA-based, PSO-based and some other feature selection algorithms demonstrate that the PHM can be used in other population-based feature selection algorithms and obtain satisfying results.
Modelling Multiple Crack Initiation and Evolution Under Environmental Creep Conditions Using a Continuum Damage and Probabalisitc Approach
Authors: Nikbin K. M. , Biglari F.
Published: February 2014

Different time-dependent mechanisms such as creep, environmental surface oxidation or internal material degradation due to aging and irradiation will subject structures to the possibility of premature failures. In this paper a micro-scale finite element mesh consisting of multiple elements encased in ~50–150μm sized grains with designated grain boundaries is used to replicate shapes and dimensions to simulate an isotropic metallic microstructure. The grains are encased in pseudo-grain boundary element sets which can have different material and damage parameters compared to the grains. In this type of mesh random crack paths for intergranular and transgranular cracking conditions are allowed. It is shown that creep cracking using a uniaxial ductility constraint-based model coupled with a functionally distributed time-dependent environmentally assisted corrosion/oxidation/material degradation damage model acting on surface or internally can be realistically predicted using this model. It is also evident material properties input data have scatter especially at the sub-grain level where the measurement methods are new and not always standardised. This is dealt with in the model by employing a normal distributive probabilistic method to allow for statistically varied random damage and crack growth development. In this way it is possible to take into account the inherent variability in material input properties at the analysis stage without the need to change material properties following each run. The method could negate the need for knowing the exact material properties, which in any case is impossible to derive at the microstructural level, as results of each run can be varied using a statistically distributed critical damage criterion specified for each element.
Seismic Performance and Cost Evaluations of Reinforced Concrete Buildings with Various Ductility in Moderate Seismic Zone
Authors: Boonyapinyo Virote , Choopool Norathape
Published: February 2014

This study is focused on the effects of the new standard of the building design under seismic loading in Thailand (DPT 1302-52) on cost estimates and the seismic performance of nine-story reinforced concrete apartment buildings with various ductility in moderate seismic zone and a gravity load designed (GLD) building. Both the nonlinear static pushover and nonlinear dynamic analyses are applied. Comparisons of performance point (PF) evaluation of studied frames are investigated by three different methods, namely, capacity spectrum method (CSM), inelastic demand diagram method (IDDM), and nonlinear time history analysis (NTHA) method. Five selected ground motion records are investigated in the analyses. In order to examine the influence of design ductility classes, the seismic forces on moment resisting frame buildings are defined according to the new standard of the building design under seismic loading in Thailand with ductility from 8, 5, and 3, corresponding to special ductile frame (SDF), intermediate ductile frame (IDF), and ordinary ductile frames (ODF), respectively. For the cost estimates, ODF is the most expensive among ODF, IDF, and SDF. Costs of SDF and IDF in Chiang Mai are quite similar. The results show that SDF is more ductile than that of ODF, however, the strength of SDF is less than ODF. The results indicate that all frames including GLD are able to withstand a design earthquake. The study also found that the average ductilities at the failure state for SDF, IDF, ODF, and GLD are 1.45, 1.42, 1.28, and 1.17, respectively. The average PGAs at the failure state for SDF, IDF, ODF, and GLD are 0.85 g, 0.83 g, 0.63 g, and 0.35 g, respectively when these buildings have the volumetric ratio of horizontal confinement within joint panel greater than 0.003. Moreover, at the failure state of GLD with volumetric ratio of horizontal confinement within joint panel less than 0.003, the average PGA is only 0.17 g which is lower than the design earthquake of PGA of 0.39 g in the draft DPT. The SDF and IDF are the two best options in consideration of cost and seismic performance.
Resolution of geochemical and lithostratigraphic complexity: a workflow for application of portable X-ray fluorescence to mineral exploration
Authors: Fisher Louise , Gazley Michael F. , Baensch Aaron , Barnes Stephen J. , Cleverley James , Duclaux Guillaume
Published: February 2014

Portable X-ray fluorescence (pXRF) technology can be used to collect large amounts of multi-element data rapidly at relatively low cost and has been widely embraced within the minerals industry. However, to date, it has been difficult to compare data-sets collected by different users or at different times because there is no standardized approach to the collection of these data. The absence of information on standardization and calibration procedures raises concerns about a lack of internal consistency within these data-sets and precludes comparison of different data-sets. This paper seeks to address this issue by developing a workflow for the collection of pXRF data in an exploration or mining setting. Two case studies highlight the robustness and possible applications of pXRF data collected following QA/QC protocols. A good correlation between conventional laboratory analyses and pXRF data is demonstrated through comparison of analysis methods for a drill-hole at the Plutonic Gold Mine, Western Australia, and fine-scale lithostratigraphic variation is recognized in pXRF data collected on grade control pulps from a drill fan at the Agnew Gold Mine, Western Australia. The Agnew data precision is sufficient to distinguish alteration signals from background lithology, and to discern which alteration signals are associated with gold mineralization.
Iron Cofactor Assembly in Plants
Authors: Balk Janneke , Schaedler Theresia A.
Published: February 2014

Iron is an essential element for all photosynthetic organisms. The biological use of this transition metal is as an enzyme cofactor, predominantly in electron transfer and catalysis. The main forms of iron cofactor are, in order of decreasing abundance, iron-sulfur clusters, heme, and di-iron or mononuclear iron, with a wide functional range. In plants and algae, iron-sulfur cluster assembly pathways of bacterial origin are localized in the mitochondria and plastids, where there is a high demand for these cofactors. A third iron-sulfur cluster assembly pathway is present in the cytosol that depends on the mitochondria but not on plastid assembly proteins. The biosynthesis of heme takes place mainly in the plastids. The importance of iron-sulfur cofactors beyond photosynthesis and respiration has become evident with recent discoveries of novel iron-sulfur proteins involved in epigenetics and DNA metabolism. In addition, increased understanding of intracellular iron trafficking is opening up research into how iron is distributed between iron cofactor assembly pathways and how this distribution is regulated.
Triterpene Biosynthesis in Plants
Authors: Thimmappa Ramesha , Geisler Katrin , Louveau Thomas , O'Maille Paul , Osbourn Anne
Published: February 2014

The triterpenes are one of the most numerous and diverse groups of plant natural products. They are complex molecules that are, for the most part, beyond the reach of chemical synthesis. Simple triterpenes are components of surface waxes and specialized membranes and may potentially act as signaling molecules, whereas complex glycosylated triterpenes (saponins) provide protection against pathogens and pests. Simple and conjugated triterpenes have a wide range of applications in the food, health, and industrial biotechnology sectors. Here, we review recent developments in the field of triterpene biosynthesis, give an overview of the genes and enzymes that have been identified to date, and discuss strategies for discovering new triterpene biosynthetic pathways.
The Scanning Mechanism of Eukaryotic Translation Initiation
Authors: Hinnebusch Alan G.
Published: February 2014

In eukaryotes, the translation initiation codon is generally identified by the scanning mechanism, wherein every triplet in the messenger RNA leader is inspected for complementarity to the anticodon of methionyl initiator transfer RNA (Met-tRNAi). Binding of Met-tRNAi to the small (40S) ribosomal subunit, in a ternary complex (TC) with eIF2-GTP, is stimulated by eukaryotic initiation factor 1 (eIF1), eIF1A, eIF3, and eIF5, and the resulting preinitiation complex (PIC) joins the 5′ end of mRNA preactivated by eIF4F and poly(A)-binding protein. RNA helicases remove secondary structures that impede ribosome attachment and subsequent scanning. Hydrolysis of eIF2-bound GTP is stimulated by eIF5 in the scanning PIC, but completion of the reaction is impeded at non-AUG triplets. Although eIF1 and eIF1A promote scanning, eIF1 and possibly the C-terminal tail of eIF1A must be displaced from the P decoding site to permit base-pairing between Met-tRNAi and the AUG codon, as well as to allow subsequent phosphate release from eIF2-GDP. A second GTPase, eIF5B, catalyzes the joining of the 60S subunit to produce an 80S initiation complex that is competent for elongation.
Simulating the Flow of Entangled Polymers
Authors: Masubuchi Yuichi
Published: February 2014

To optimize automation for polymer processing, attempts have been made to simulate the flow of entangled polymers. In industry, fluid dynamics simulations with phenomenological constitutive equations have been practically established. However, to account for molecular characteristics, a method to obtain the constitutive relationship from the molecular structure is required. Molecular dynamics simulations with atomic description are not practical for this purpose; accordingly, coarse-grained models with reduced degrees of freedom have been developed. Although the modeling of entanglement is still a challenge, mesoscopic models with a priori settings to reproduce entangled polymer dynamics, such as tube models, have achieved remarkable success. To use the mesoscopic models as staging posts between atomistic and fluid dynamics simulations, studies have been undertaken to establish links from the coarse-grained model to the atomistic and macroscopic simulations. Consequently, integrated simulations from materials chemistry to predict the macroscopic flow in polymer processing are forthcoming.
The Role of Sleep in Emotional Brain Function
Authors: Goldstein Andrea N. , Walker Matthew P.
Published: February 2014

Rapidly emerging evidence continues to describe an intimate and causal relationship between sleep and emotional brain function. These findings are mirrored by long-standing clinical observations demonstrating that nearly all mood and anxiety disorders co-occur with one or more sleep abnormalities. This review aims to (a) provide a synthesis of recent findings describing the emotional brain and behavioral benefits triggered by sleep, and conversely, the detrimental impairments following a lack of sleep; (b) outline a proposed framework in which sleep, and specifically rapid-eye movement (REM) sleep, supports a process of affective brain homeostasis, optimally preparing the organism for next-day social and emotional functioning; and (c) describe how this hypothesized framework can explain the prevalent relationships between sleep and psychiatric disorders, with a particular focus on posttraumatic stress disorder and major depression.
Detrital Zircon U-Pb Geochronology Applied to Tectonics
Authors: Gehrels George
Published: February 2014

Detrital zircon geochronology is rapidly developing into an essential tool in Earth science research because of the widespread occurrence of zircon in sedimentary systems; the wide range of information that can be extracted from zircon crystals; the ability to determine ages with reasonable precision, accuracy, and efficiency; and the wide range of new ideas about how to use detrital zircon geochronologic information. The U-Pb system is particularly powerful because three chronometers are available (238U→206Pb, 235U→207Pb, and 232Th→208Pb), but challenges arise because of complexities from inheritance and Pb loss. Ages can be used to constrain the age of deposition of the host sediment, reconstruct provenance, characterize a sedimentary unit, and characterize many different aspects of source regions. Detrital zircon geochronology has an exciting future given the growth history recorded in individual crystals; the variety of detrital minerals that can provide complementary information; and the large number of geochemical, isotopic, and chronologic systems that can be applied to these minerals.
The Stardust Mission: Analyzing Samples from the Edge of the Solar System
Authors: Brownlee Don
Published: February 2014

Comet samples returned to Earth by the NASA Stardust mission have provided a surprising glimpse into the nature of early Solar System materials and an epiphany on the origin of the initial rocky materials that once filled the cold regions of the solar nebula. The findings show that the cold regions of the early Solar System were not isolated and were not a refuge where interstellar materials could commonly survive. Wild 2, the sampled comet, appears to be a typical active Jupiter family comet, and yet most of its sampled micron and larger grains are familiar high-temperature meteoritic materials, such as chondrule fragments, that were transported to cold nebular regions. The rocky components in primitive asteroids and comets may differ because asteroid formation was dominated by local materials, whereas comets formed from mixed materials, many of which were transported from very distant locations.
Recent Developments in Empirical Likelihood and Related Methods
Authors: Parente Paulo M.D.C. , Smith Richard J.
Published: February 2014

This article reviews a number of recent contributions to estimation and inference for models defined by moment condition restrictions. The particular emphasis is on the generalized empirical likelihood class of estimators as an alternative to the generalized method of moments. Estimation methods for parameters defined through moment restrictions and their properties are described with tests of overidentifying moment restrictions and parametric hypotheses. Computational issues are discussed together with some proposals for their amelioration. Higher-order and other properties are also addressed in some detail. Models specified by conditional moment restriction models are considered, and the adaptation of these methods to weakly dependent data is discussed.
Two-Dimensional Electron Gases at Complex Oxide Interfaces
Authors: Stemmer Susanne , James Allen S.
Published: February 2014

Two-dimensional electron gases (2DEGs) at oxide interfaces may exhibit unique properties, including effects from strong electron correlations, extremely high electron densities, magnetism, and 2D superconductivity. This article discusses routes to high-mobility 2DEGs in complex oxide heterostructures, with a particular focus on 2DEGs that involve transport in SrTiO3. We discuss what is known about the electronic states in SrTiO3 2DEGs, both experimentally and theoretically. Examples from the current literature are summarized.
A model-based approach to investigating the pathophysiological mechanisms of hypertension and response to antihypertensive therapies: extending the Guyton model
Authors: Hallow K. Melissa , Lo Arthur , Beh Jeni , Rodrigo Manoj , Ermakov Sergey , Friedman Stuart , de Leon Hector , Sarkar Anamika , Xiong Yuan , Sarangapani Ramesh , Schmidt Henning , Webb Randy , Kondic Anna Georgieva
Published: February 2014

Reproducibly differential responses to different classes of antihypertensive agents are observed among hypertensive patients and may be due to interindividual differences in hypertension pathology. Computational models provide a tool for investigating the impact of underlying disease mechanisms on the response to antihypertensive therapies with different mechanisms of action. We present the development, calibration, validation, and application of an extension of the Guyton/Karaaslan model of blood pressure regulation. The model incorporates a detailed submodel of the renin-angiotensin-aldosterone system (RAAS), allowing therapies that target different parts of this pathway to be distinguished. Literature data on RAAS biomarker and blood pressure responses to different classes of therapies were used to refine the physiological actions of ANG II and aldosterone on renin secretion, renal vascular resistance, and sodium reabsorption. The calibrated model was able to accurately reproduce the RAAS biomarker and blood pressure responses to combinations of dual-RAAS agents, as well as RAAS therapies in combination with diuretics or calcium channel blockers. The final model was used to explore the impact of underlying mechanisms of hypertension on the blood pressure response to different classes of antihypertensive agents. Simulations indicate that the underlying etiology of hypertension can impact the magnitude of response to a given class of therapy, making a patient more sensitive to one class and less sensitive others. Given that hypertension is usually the result of multiple mechanisms, rather than a single factor, these findings yield insight into why combination therapy is often required to adequately control blood pressure.
Albumin-bound fatty acids but not albumin itself alter redox balance in tubular epithelial cells and induce a peroxide-mediated redox-sensitive apoptosis
Authors: Ruggiero Christine , Elks Carrie M. , Kruger Claudia , Cleland Ellen , Addison Kaity , Noland Robert C. , Stadler Krisztian
Published: February 2014

Albuminuria is associated with metabolic syndrome and diabetes. It correlates with the progression of chronic kidney disease, particularly with tubular atrophy. The fatty acid load on albumin significantly increases in obesity, presenting a proinflammatory environment to the proximal tubules. However, little is known about changes in the redox milieu during fatty acid overload and how redox-sensitive mechanisms mediate cell death. Here, we show that albumin with fatty acid impurities or conjugated with palmitate but not albumin itself compromised mitochondrial and cell viability, membrane potential and respiration. Fatty acid overload led to a redox imbalance which deactivated the antioxidant protein peroxiredoxin 2 and caused a peroxide-mediated apoptosis through the redox-sensitive pJNK/caspase-3 pathway. Transfection of tubular cells with peroxiredoxin 2 was protective and mitigated apoptosis. Mitochondrial fatty acid entry and ceramide synthesis modulators suggested that mitochondrial β oxidation but not ceramide synthesis may modulate lipotoxic effects on tubular cell survival. These results suggest that albumin overloaded with fatty acids but not albumin itself changes the redox environment in the tubules, inducing a peroxide-mediated redox-sensitive apoptosis. Thus, mitigating circulating fatty acid levels may be an important factor in both preserving redox balance and preventing tubular cell damage in proteinuric diseases.
Sodium-potassium ATPase emerges as a player in hippocampal phenotypes of Angelman syndrome mice
Authors: Hallengren Jada J. , Vaden Ryan J.
Published: February 2014

Angelman syndrome is a neurodevelopmental disorder characterized by intellectual disabilities, ataxia, and unusually happy affect. The hippocampal pyramidal cells of Angelman syndrome model mice have altered intrinsic membrane properties, which Kaphzan et al. ( Cell Rep 4: 405–412, 2013) demonstrate can be corrected by genetic reduction of the α1-subunit of the sodium-potassium ATPase. Intriguingly, this manipulation also restores hippocampal long-term potentiation and learning. In this Neuro Forum, we discuss translational implications of this work and remaining questions left in its wake.
Reflex inhibition of cutaneous and muscle vasoconstrictor neurons during stimulation of cutaneous and muscle nociceptors
Authors: Kirillova-Woytke Irina , Baron Ralf , Jänig Wilfrid
Published: February 2014

Cutaneous (CVC) and muscle (MVC) vasoconstrictor neurons exhibit typical reflex patterns to physiological stimulation of somatic and visceral afferent neurons. Here we tested the hypothesis that CVC neurons are inhibited by stimulation of cutaneous nociceptors but not of muscle nociceptors and that MVC neurons are inhibited by stimulation of muscle nociceptors but not of cutaneous nociceptors. Activity in the vasoconstrictor neurons was recorded from postganglionic axons isolated from the sural nerve or the lateral gastrocnemius-soleus nerve in anesthetized rats. The nociceptive afferents were excited by mechanical stimulation of the toes of the ipsilateral hindpaw (skin), by hypertonic saline injected into the ipsi- or contralateral gastrocnemius-soleus muscle, or by heat or noxious cold stimuli applied to the axons in the common peroneal nerve or tibial nerve. The results show that CVC neurons are inhibited by noxious stimulation of skin but not by noxious stimulation of skeletal muscle and that MVC neurons are inhibited by noxious stimulation of skeletal muscle but not by noxious stimulation of skin. These inhibitory reflexes are mostly lateralized and are most likely organized in the spinal cord. Stimulation of nociceptive cold-sensitive afferents does not elicit inhibitory or excitatory reflexes in CVC or MVC neurons. The reflex inhibition of activity in CVC or MVC neurons generated by stimulation of nociceptive cutaneous or muscle afferents during tissue injury leads to local increase of blood flow, resulting in an increase of transport of immunocompetent cells, proteins, and oxygen to the site of injury and enhancing the processes of healing.
Task-related modulation of crossed spinal inhibition between human lower limbs
Authors: Hanna-Boutros Berthe , Sangari Sina , Karasu Aliye , Giboin Louis-Solal , Marchand-Pauvert Véronique
Published: February 2014

Crossed reflex action mediated by muscle spindle afferent inputs has recently been revealed in humans. This raised the question of whether a complex spinal network involving commissural interneurons receiving inputs from proprioceptors and suprasegmental structures, as described in cats, persists in humans and contributes to the interlimb coordination during movement. First, we investigated the neurophysiological mechanisms underlying crossed reflex action between ankle plantar flexors and its corticospinal control from primary motor cortex. Second, we studied its modulation during motor tasks. We observed crossed inhibition in contralateral soleus motoneurons occurring with about 3 ms central latency, which is consistent with spinal transmission through oligosynaptic pathway. The early phase of inhibition was evoked with lower stimulus intensity than the late phase, suggesting mediation by group I and group II afferents, respectively. The postsynaptic origin of crossed inhibition is confirmed by the finding that both H-reflex and motor-evoked potential were reduced upon conditioning stimulation. Transcranial magnetic stimulation over ipsilateral and contralateral primary motor cortex reduced crossed inhibition, especially its late group II part. Last, late group II crossed inhibition was particularly depressed during motor tasks, especially when soleus was activated during the walking stance phase. Our results suggest that both group I and group II commissural interneurons participate in crossed reflex actions between ankle plantar flexors. Neural transmission at this level is depressed by descending inputs activated by transcranial magnetic stimulation over the primary motor cortex or during movement. The specific modulation of group II crossed inhibition suggests control from monoaminergic midbrain structures and its role for interlimb coordination during locomotion.
Naturally Occurring Xanthones: Chemistry and Biology
Authors: Negi J. S. , Bisht V. K. , Singh P. , Rawat M. S. M. , Joshi G. P.
Published: February 2014

Xanthones are one of the biggest classes of compounds in natural product chemistry. A number of xanthones have been isolated from natural sources of higher plants, fungi, ferns, and lichens. They have gradually risen to great importance because of their medicinal properties. This review focuses on the types, isolation, characterization, biological applications, and biosynthesis of naturally occurring xanthones isolated so far. Different physicochemical and instrumental methods such as liquid-solid and liquid-liquid extraction, TLC, flash chromatography, column chromatography, IR, 1H NMR and 13C NMR spectroscopy, GLC, HPLC, GC, and LCMS have been widely used for isolation and structural elucidation of xanthones. Hepatoprotective, anticarcinogenic, antileprosy, antimalarial, antioxidant, anticholinergic, mutagenicity, radioprotective, immunomodulatory, antibone resorption, antiparasitic, neuraminidase inhibitory, anticomplement, antibacterial, antifungal, algicidal, anti-HIV, cardioprotective, antitumoral, antidiabetes, antihyperlipidemic, antiatherogenic, anti-inflammatory, antiulcer, antidiabetic, hypolipidemic, analgesic, antiasthmatic, antihistaminic, antiamoebic, diuretic, antidiarrheal, larvicidal, and ovicidal activities have been reported for natural occurring xanthones. To a certain extent, this review provides necessary foundation for further research and development of new medicines.
Second Order Impulsive Retarded Differential Inclusions with Nonlocal Conditions
Authors: Henríquez Hernán R. , Rabelo Marcos , Vale Luciana
Published: February 2014

In this work we establish some existence results for abstract second order Cauchy problems modeled by a retarded differential inclusion involving nonlocal and impulsive conditions. Our results are obtained by using fixed point theory for the measure of noncompactness.
Assessing Depression in Cardiac Patients: What Measures Should Be Considered?
Authors: Ceccarini M. , Manzoni G. M. , Castelnuovo G.
Published: February 2014

It is highly recommended to promptly assess depression in heart disease patients as it represents a crucial risk factor which may result in premature deaths following acute cardiac events and a more severe psychopathology, even in cases of subsequent nonfatal cardiac events. Patients and professionals often underestimate or misjudge depressive symptomatology as cardiac symptoms; hence, quick, reliable, and early mood changes assessments are warranted. Failing to detect depressive signals may have detrimental effects on these patients’ wellbeing and full recovery. Choosing gold-standard depression investigations in cardiac patients that fit a hospitalised cardiac setting well is fundamental. This paper will examine eight well established tools following Italian and international guidelines on mood disorders diagnosis in cardiac patients: the Hospital Anxiety and Depression Scale (HADS), the Cognitive Behavioural Assessment Hospital Form (CBA-H), the Beck Depression Inventory (BDI), the two and nine-item Patient Health Questionnaire (PHQ-2, PHQ-9), the Depression Interview and Structured Hamilton (DISH), the Hamilton Rating Scale for Depression (HAM-D/HRSD), and the Composite International Diagnostic Interview (CIDI). Though their strengths and weaknesses may appear to be homogeneous, the BDI-II and the PHQ are more efficient towards an early depression assessment within cardiac hospitalised patients.
Modeling the Equilibrium Bus Line Choice Behavior and Transit System Design with Oblivious Users
Authors: Zhao Chuan-Lin , Huang Hai-Jun
Published: February 2014

In most of transportation literature, users are assumed to be perfectly rational in minimizing their own travel costs or perceived travel costs. However, users may not be perfectly rational in implementing their choices in reality. There exists a kind of boundedly rational users, that is, oblivious users. These oblivious users make their route choices by simple criteria, for example, selecting the shortest (or the most direct) route only based on physical distance or simply following routes recommended by a GPS system. This paper investigates how the existence of oblivious users affects the equilibrium bus line choice behavior in a public transit system. And we propose a method to design a more realistic system.