bluuebunny/crossref_metadata_2025 huggingface dataset:
How the primate fornix is affected by age
Authors: Peters Alan , Sethares Claire , Moss Mark B.
Published: May 2010

The effects of age on nerve fibers and neuroglial cells in the fornix were examined in 25 rhesus monkeys between 4 and 33 years of age. There is no age‐related change in the cross‐sectional area of the fornix, but there is a significant loss of myelinated nerve fibers. The loss of myelinated nerve fibers is accompanied by a significant increase in the numbers of nerve fibers that show degeneration of their axons and alterations in myelin sheaths. Aging also brings about an increase in the frequency of profiles of paranodes, indicating that some of the nerve fibers are being remyelinated. Aging also affects neuroglial cells. Each type shows inclusions in their perikarya, and in the case of astrocytes and microglial cells some of these inclusions are phagocytosed myelin. Numbers of astrocytes and microglial cells do not appear to increase with age, but there is a 20% increase in oligodendrocytes. When correlations with cognitive impairments displayed by individual monkeys are examined, the decreased packing density of nerve fibers and the increasing frequency of nerve fibers with degenerating axons and of nerve fibers with altered myelin sheaths all correlate with increasing cognitive impairment. It is suggested that these correlations result from some disconnection of the hippocampus from the thalamus, septal nuclei, and medial frontal cortex and from reductions in the conduction velocity brought about by the shorter internodal lengths of remyelinated nerve fibers in the fornix. J. Comp. Neurol. 518:3962–3980, 2010. © 2010 Wiley‐Liss, Inc.
Central respiratory chemoreception
Authors: Guyenet Patrice G. , Stornetta Ruth L. , Bayliss Douglas A.
Published: May 2010

By definition central respiratory chemoreceptors (CRCs) are cells that are sensitive to changes in brain PCO2 or pH and contribute to the stimulation of breathing elicited by hypercapnia or metabolic acidosis. CO2 most likely works by lowering pH. The pertinent proton receptors have not been identified and may be ion channels. CRCs are probably neurons but may also include acid‐sensitive glia and vascular cells that communicate with neurons via paracrine mechanisms. Retrotrapezoid nucleus (RTN) neurons are the most completely characterized CRCs. Their high sensitivity to CO2 in vivo presumably relies on their intrinsic acid sensitivity, excitatory inputs from the carotid bodies and brain regions such as raphe and hypothalamus, and facilitating influences from neighboring astrocytes. RTN neurons are necessary for the respiratory network to respond to CO2 during the perinatal period and under anesthesia. In conscious adults, RTN neurons contribute to an unknown degree to the pH‐dependent regulation of breathing rate, inspiratory, and expiratory activity. The abnormal prenatal development of RTN neurons probably contributes to the congenital central hypoventilation syndrome. Other CRCs presumably exist, but the supportive evidence is less complete. The proposed locations of these CRCs are the medullary raphe, the nucleus tractus solitarius, the ventrolateral medulla, the fastigial nucleus, and the hypothalamus. Several wake‐promoting systems (serotonergic and catecholaminergic neurons, orexinergic neurons) are also putative CRCs. Their contribution to central respiratory chemoreception may be behavior dependent or vary according to the state of vigilance. J. Comp. Neurol. 518:3883–3906, 2010. © 2010 Wiley‐Liss, Inc.
Neuronal DNA content variation (DCV) with regional and individual differences in the human brain
Authors: Westra Jurjen W. , Rivera Richard R. , Bushman Diane M. , Yung Yun C. , Peterson Suzanne E. , Barral Serena , Chun Jerold
Published: May 2010

It is widely assumed that the human brain contains genetically identical cells through which postgenomic mechanisms contribute to its enormous diversity and complexity. The relatively recent identification of neural cells throughout the neuraxis showing somatically generated mosaic aneuploidy indicates that the vertebrate brain can be genomically heterogeneous (Rehen et al. [2001] Proc. Natl. Acad. Sci. U. S. A. 98:13361–13366; Rehen et al. [2005] J. Neurosci. 25:2176–2180; Yurov et al. [2007] PLoS ONE:e558; Westra et al. [2008] J. Comp. Neurol. 507:1944–1951). The extent of human neural aneuploidy is currently unknown because of technically limited sample sizes, but is reported to be small (Iourov et al. [2006] Int. Rev. Cytol. 249:143–191). During efforts to interrogate larger cell populations by using DNA content analyses, a surprising result was obtained: human frontal cortex brain cells were found to display “DNA content variation (DCV)” characterized by an increased range of DNA content both in cell populations and within single cells. On average, DNA content increased by ∼250 megabases, often representing a substantial fraction of cells within a given sample. DCV within individual human brains showed regional variation, with increased prevalence in the frontal cortex and less variation in the cerebellum. Further, DCV varied between individual brains. These results identify DCV as a new feature of the human brain, encompassing and further extending genomic alterations produced by aneuploidy, which may contribute to neural diversity in normal and pathophysiological states, altered functions of normal and disease‐linked genes, and differences among individuals. J. Comp. Neurol. 518:3981–4000, 2010. © 2010 Wiley‐Liss, Inc.
Comparison of Two Theories for the Relativistic Self Focusing of Laser Beams in Plasma
Authors: Walia K. , Singh A.
Published: May 2010

In the present paper, self‐focusing of laser beams in relativistic plasmas is studied by the moment theory approach. The equilibrium beam radius of the self‐trapped laser beams is also derived. Results are compared with the paraxial ray theory. It is observed from the analysis that at higher intensities, the equilibrium beam radius increases in case of the paraxial ray theory, whereas it becomes independent of the beam intensity in case of the moment theory. Analysis also confirms the role of relativistic electrons travelling with the light pulse in (3D PIC) simulation studies (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High Energy Density Physics Studies at the Facility for Antiprotons and Ion Research: the HEDgeHOB Collaboration
Authors: Tahir N.A. , Shutov A. , Lomonosov I.V. , Piriz A.R. , Redmer R. , Stöhlker T. , Geissel H. , Deutsch C. , Fortov V.E.
Published: May 2010

The forthcoming Facility for Antiprotons and Ion Research (FAIR) at Darmstadt, is going to be a unique accelerator facility that will deliver high quality, strongly bunched, well focused, intense beams of heavy ions that will lead to unprecedented specific power deposition in solid matter. This will generate macroscopic samples of High Energy Density (HED) matter with fairly uniform physical conditions. These samples can be used to study the thermophysical and transport properties of HED matter. Extensive theoretical work has been carried out over the past decade to design numerous dedicated experiments to study HED physics at the FAIR, which has provided the basis for the HEDgeHOB (High Energy Density Matter Generated by Heavy Ion Beams) scientific proposal. This work is still in progress as the feasibility studies for more experimental schemes are being carried out.

Another, very important research area that will benefit tremendously from the FAIR facility, is the production of radioactive beams. A superconducting fragment separator, Super–FRS is being designed for the production and separation of rare radioactive isotopes. Unlike the HED targets, the Super–FRS production target should not be destroyed or damaged by the beam, but should remain intact during the long experimental campaign. However, the high level of specific power deposited in the production target by the high intensity ion beam at FAIR, could cause serious problems to the target survival. These HED issues related to the Super–FRS production target are also discussed in the present paper (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Increase of Kinetic Energy of Dusty Cluster Particles Due to Parametric Instability Caused by Nanosecond Electric Pulses
Authors: Vasilyak L.M. , Fortov V.E. , Morfill G.E. , Ivlev A.V. , Pustylnik M.Y. , Polyakov D.N. , Thomas H.M. , Vetchinin S.P.
Published: May 2010

Experimental investigations of high voltage nanosecond pulses influence on charged dust particles in low pressure rf–plasma were carried out. Application of repetitive pulses leads to the vertical oscillations of the mi‐croparticles. Evolution of the total kinetic energy for the cluster consisting of 14 particles is investigated. Flat clusters exhibit parametric instabilities of horizontal modes. In the initial phase the kinetic energy oscillates around a certain value and its amplitude grows very slowly. At a certain moment during the instability it goes into the exponential growth phase and then saturates under the effect of repetitive pulses. It is possible if the eigenfrequency is the function of height and the dust particle oscillates vertically in the non uniform electric field (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New Model of Dusty Plasma Particles Interaction
Authors: Baimbetov F. B. , Davletov A. E. , Kudyshev Zh. A. , Mukhametkarimov E. S.
Published: May 2010

The main goal of this report is to obtain the macropotentials of dusty plasma particles interactions which account for the collective events in the medium and, then, to analyze their dependence on plasma parameters. It is shown that the attraction between conductive dust grains turns possible due to the polarization phenomenon (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Large Hadron Collider and the Super Proton Synchrotron at CERN as tools to Generate Warm Dense Matter and Non–Ideal Plasmas
Authors: Tahir N.A. , Schmidt R. , Shutov A. , Lomonosov I.V. , Gryaznov V. , Piriz A.R. , Deutsch C. , Fortov V.E.
Published: May 2010

The largest accelerator in the world, the Large Hadron Collider (LHC) at CERN, has entered into commissioning phase. It is expected that when this impressive machine will become fully operational, it will generate two counter rotating 7 TeV/c proton beams that will be made to collide, leading to an unprecedented luminosity of 1034 cm–2s–1. Total energy stored in each LHC beam is about 362 MJ, sufficient to melt 500 kg copper. Safety of operation is a very critical issue when working with such extremely powerful beams. It is important to know the consequences of an accidental release of the beam energy in order to design protection system for the equipment. For this purpose we have carried out extensive numerical simulations of the interaction of one full LHC beam with copper and graphite targets which are materials of practical importance. Our calculations have shown that the LHC protons will penetrate up to about 35 m in solid copper and 10 m in solid graphite. A very interesting outcome of this work is that the impact of the LHC beam on solid matter will generate Warm Dense Matter (WDM) and Strongly Coupled Plasmas (SCP).

The beams for the LHC are pre‐accelerated in the SPS (Super Proton Synchrotron) to 450 GeV/c and transferred to LHC via two beam lines. Several SPS cycles are required to fill the LHC, in one cycle a batch with up to 288 bunches can be accelerated. From the safety point of view it is also very important to study the damage caused to the equipment in case of an accident involving an uncontrolled release of the SPS beam. For this purpose we have also carried out detailed numerical simulations of the impact of the full SPS beam on solid copper and tungsten targets. These simulations have shown that the targets are severely damaged by the beam. It is also interesting to note that also in this case, a large part of the target material is converted into WDM and SCP. This study, therefore, shows that the LHC and the SPS have the potential to be used for studying these important fields of research. However, to achieve this goal, it is necessary to advance this work by designing dedicated experiments. This work is in progress (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐Precision Equation‐of‐State Formalisms for Solar and Stellar Modeling
Authors: Däppen Werner
Published: May 2010

For solar and stellar modeling, a high‐quality equation of state is crucial. In addition, however, helioseismic and asteroseismic observations put constraints on the physical formalisms. Thus they effectively turn the Sun and the stars into laboratories for dense plasmas. Currently, the main astrophysical beneficiary of a good equation of state is the seismic determination of the chemical composition of the interior of the Sun and stars (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electric Microfield Distributions in Alkali Plasmas with Account of the Ion Structure in a Moderately Coupled Approximation
Authors: Sadykova S. P. , Ebeling W. , Sokolov I. M.
Published: May 2010

The electric microfield distributions (EMD) have been calculated at the location of an ion for Alkali plasmas (Li+, Na+, K+, Cs+) using a coupling parameter integration technique originally developed by Ortner et al. for point‐like (structureless) ions [1]. EMD are studied in a frame of the Hellmann‐Gurskii‐Krasko (HGK) pseudopotential model, taking into account the quantum‐mechanical effects and the ion shell structure [2]. For determination of the radial distribution function the screened HGK pseudopotential in a moderately coupled approximation, based on a chain of Bogoljubow equations for the equilibrium distribution functions [3], taking into account not only the quantum‐mechanical effects, the ion shell structure but screening field effects has been used [4]. The new expressions for the screened HGK potential have been derived. At the derivation the electron‐electron corrected Kelbg micropotential instead of earlier applied Deutsch potential has been used. The results obtained for the EMDs in the Hellmann‐Gurskii‐Krasko moderately coupled approximation for a moderately coupled plasma in a framework of the Ortner model show a considerable improvement of the results obtained in the Debye screening approximation (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Use of Pulsed Radiography for Investigation of Equations of State of Substances at Megabar Pressures
Authors: Egorov N. I. , Boriskov G. V. , Bykov A. I. , Kuropatkin Yu. P. , Lukyanov N. B. , Mironenko V. D. , Pavlov V. N.
Published: May 2010

A method of density measurement for substances that are isentropically compressed up to megabar pressures is described in the paper. Measurement results for condensed hydrogen isotopes and aluminum are presented. These results, afterwards, are used for construction of hydrogen isotopes “cold” isentropes. Experimental x‐ray images of the facilities with the hydrogen isotopes, compressed up to several megabars are presented in the paper (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport Coefficients in Dense Plasmas Including Ion‐Ion Structure Factor
Authors: Karakhtanov V. S. , Redmer R. , Reinholz H. , Röpke G.
Published: May 2010

Within linear response theory, a general approach to the thermoelectric transport coefficients for fully ionized hydrogen‐type plasma has been given. Different approximations for the collision integral are considered. Particular attention is given to dynamical screening and the ion‐ion structure factor. Results are presented for the electrical conductivity, the thermal conductivity, and the thermopower in the non‐degenerate limit (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Quantum Color Dynamic Simulations of the Strongly Coupled Quark‐Gluon Plasma
Authors: Filinov V. S. , Bonitz M. , Ivanov Y. B. , Skokov V. V. , Levashov P. R. , Fortov V. E.
Published: May 2010

A strongly coupled plasma of quark and gluon quasiparticles is studied by combination of Path integral Monte Carlo and quantum Wigner dynamics simulations. This method extends previous classical nonrelativistic simu‐lations based on a color Coulomb interaction to the quantum regime. First results for the momentum‐momentum autocorrelation function and diffusion constant are presented (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nuclear genome size: Are we getting closer?
Authors: Doležel Jaroslav , Greilhuber Johann
Published: May 2010

Correct information on genome size is important in many areas of research. For a long time, scientists have been struggling to understand the reason for the huge variation in eukaryotic genome size and its biological significance. More recently, the knowledge on genome size has become important to structure genome sequencing projects as their scale and cost depend on genome size. Despite the fact that the first estimates of genome size in eukaryotes were made more than 50 years ago, we are still not quite sure about the exact genome size in practically all animal and plant species. Moreover, different estimates continue to be published for the same species. These discrepancies compromise data comparison and interpretation and point to methodological problems, which include standardization. This article assesses the current state of DNA reference standards for flow cytometry and the issues related to their calibration. © 2010 International Society for Advancement of Cytometry
Small but mighty: How the MACS®‐technology based on nanosized superparamagnetic particles has helped to analyze the immune system within the last 20 years
Authors: Grützkau Andreas , Radbruch Andreas
Published: May 2010

Today, magnetic cell sorting and flow cytometric cell sorting both are state‐of‐the‐art technologies, with a plethora of applications in biology and biomedicine. Both technologies have their stand‐alone applications, but they also perfectly complement each other, in particular for the analysis and isolation of fragile and rare cells. The technological evolution from simple magnets and steel wool separation columns to sophisticated instrumentation and automated procedures has paved the way for magnetic cell separation in the scientific community. This review will focus on applications of magnetic cell sorting with commercially available paramagnetic MACS®‐nanoparticles (Miltenyi Biotech, Bergisch‐Gladbach, Germany) that have allowed unprecedented approaches to the exploration of the immune system in basal and clinical research of humans and rodents. Thus, during the last 20 years this technology has been continuously developed so that the widest array of leukocyte subsets, stem cells, and connective tissue cells can be addressed by MACS®‐conjugated antibodies directed against cell‐specific surface antigens or secreted cytokines for research and clinical applications. © 2010 International Society for Advancement of Cytometry
Vaginocervical stimulation of Ewes induces the rapid formation of a new bond with an alien young without interfering with a previous bond
Authors: Lévy F. , Keller M. , Cornilleau F. , Moussu C. , Ferreira G.
Published: May 2010

Ewes form a selective olfactory memory for their lambs after 2 hr of mother–young interaction following parturition. Mothers will subsequently reject any strange lamb at suckling. The present study investigated whether artificial vaginocervical stimulation (VCS) allows the formation of a selective bond with an unfamiliar lamb and whether it interferes with the maintenance of the bond formed with the familiar lamb. At 2 hr postpartum, mothers were separated from their familiar lamb after having formed a selective bond with it and were given 10 min of mechanical VCS. In the “VCS + lamb” group (n = 24) an unfamiliar lamb was left with the ewe for 2 hr whereas in the “VCS no lamb” group (n = 26) the mother was left alone for the same period of time. Ewes of the “no VCS” group (n = 14) did not receive any VCS. In the majority of animals of the “VCS + lamb” group (23/24) VCS induced a complete acceptance of the unfamiliar lamb without any disruption of the bond previously formed with the familiar lamb. VCS or 2 hr of separation did not disrupt the maintenance of the selective bond initially formed with the familiar lamb since all the ewes of the “VCS no lamb” and “no VCS” groups accepted it at suckling. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 537–544, 2010.
Quantitation of valproic acid in pharmaceutical preparations using dispersive liquid‐liquid microextraction followed by gas chromatography‐flame ionization detection without prior derivatization
Authors: Sobhi Hamid Reza , Kashtiaray Amir , Farahani Hadi , Abrahimpour Farshad , Esrafili Ali
Published: May 2010

Dispersive liquid‐liquid microextraction (DLLME), coupled with gas chromatography‐flame ionization detection (GC‐FID), has been successfully used for the extraction and determination of valproic acid (VPA) in pharmaceutical preparations. In the developed method, an appropriate mixture of extracting and disperser solvents was rapidly injected into an aqueous sample. Having formed a cloudy solution, the mixture was centrifuged and then the extracting solvent was sedimented at the bottom of a conical test tube. The extract was then injected into a GC system directly, without any further pretreatment. Initially, microextraction efficiency factors were optimized and the optimum experimental conditions found were as follows: tetrachloroethylene (9.0 µL) as extracting solvent; acetone (1.0 mL) as disperser solvent; 5 mL acidic aqueous sample (pH 1) without salt addition. Under the selected conditions, the calibration curve showed linearity in the range of 0.1–5.0 mg/L with regression coefficient corresponding to 0.9998. The limit of detection was found to be 0.05 mg/L. Finally, the method was applied for the determination of VPA in two different pharmaceutical preparations. A reasonable intra‐assay (3.9–10.8%, n = 3) and inter‐assay (5.6–11.4%, n = 3) precision illustrated the good performance of the analytical procedure. The protocol proved to be rapid and cost‐effective for screening purposes. Copyright © 2010 John Wiley & Sons, Ltd.
Loss of adenomatous polyposis coli (apc) results in an expanded ciliary marginal zone in the zebrafish eye
Authors: Stephens W. Zac , Senecal Megan , Nguyen Minhtu , Piotrowski Tatjana
Published: May 2010

The distal region of neural retina (ciliary marginal zone [CMZ]) contains stem cells that produce non‐neural and neuronal progenitors. We provide a detailed gene expression analysis of the eyes of apc mutant zebrafish where the Wnt/β‐catenin pathway is constitutively active. Wnt/β‐catenin signaling leads to an expansion of the CMZ accompanied by a central shift of the retinal identity gene sox2 and the proneural gene atoh7. This suggests an important role for peripheral Wnt/β‐catenin signaling in regulating the expression and localization of neurogenic genes in the central retina. Retinal identity genes rx1 and vsx2, as well as meis1 and pax6a act upstream of Wnt/β‐catenin pathway activation. Peripheral cells that likely contain stem cells can be identified by the expression of follistatin, otx1, and axin2 and the lack of expression of myca and cyclinD1. Our results introduce the zebrafish apc mutation as a new model to study signaling pathways regulating the CMZ. Developmental Dynamics 239:2066–2077, 2010. © 2010 Wiley‐Liss, Inc.
Regulation of vertebrate embryogenesis by the exon junction complex core component Eif4a3
Authors: Haremaki Tomomi , Sridharan Jyotsna , Dvora Shira , Weinstein Daniel C.
Published: May 2010

The establishment and maintenance of cellular identity are ultimately dependent upon the accurate regulation of gene expression, the process by which genetic information is used to synthesize functional gene products. The post‐transcriptional, pre‐translational regulation of RNA constitutes RNA processing, which plays a prominent role in the modulation of gene expression in differentiated animal cells. The multi‐protein Exon Junction Complex (EJC) serves as a critical signaling hub within the network that underlies many RNA processing events. Here, we identify a requirement for the EJC during early vertebrate embryogenesis. Knockdown of the EJC component Eukaryotic initiation factor 4a3 (Eif4a3) in embryos of the frog Xenopus laevis results in full‐body paralysis, with defects in sensory neuron, pigment cell, and cardiac development; similar phenotypes are seen following knockdown of other “core” EJC protein constituents. Our studies point to an essential role for the EJC in the development of neural plate border derivatives. Developmental Dynamics 239:1977–1987, 2010. © 2010 Wiley‐Liss, Inc.
A functional NR4A nuclear receptor DNA‐binding domain is required for organ development in Caenorhabditis elegans
Authors: Heard Melissa , Maina Claude V. , Morehead Benjamin E. , Hoener Marius C. , Nguyen Tri Q. , Williams Christopher C. , Rowan Brian G. , Gissendanner Chris R.
Published: May 2010

NR4A nuclear receptors are a diverse group of orphan nuclear receptors with critical roles in regulating cell proliferation and cell differentiation. The ortholog of the NR4A nuclear receptor in Caenorhabditis elegans, NHR‐6, also has a role in cell proliferation and cell differentiation during organogenesis of the spermatheca. Here we show that NHR‐6 is able to bind the canonical NR4A monomer response element and can transactivate from this site in mammalian HEK293 cells. Using a functional GFP‐tagged NHR‐6 fusion, we also demonstrate that NHR‐6 is nuclear localized during development of the spermatheca. Mutation of the DNA‐binding domain of NHR‐6 abolishes its activity in genetic rescue assays, demonstrating a requirement for the DNA‐binding domain. This study represents the first genetic demonstration of an in vivo requirement for an NR4A nuclear receptor DNA‐binding domain in a whole organism. genesis 48:485–491, 2010. © 2010 Wiley‐Liss, Inc.
Development and function of central cell in angiosperm female gametophyte
Authors: Liu Yan , Yan Zhiqiang , Chen Ni , Di Xiaotang , Huang Junjun , Guo Guangqin
Published: May 2010

The central cell characterizes the angiosperm female gametophyte (embryo sac or megagametophyte) in that it directly participates in “double fertilization” to initiate endosperm development, a feature distinguishing angiosperm from all other plant taxa. Polygonum‐type central cell is a binucleate cell that, upon fertilization with one of the two sperm cells, forms triploid endosperm to nourish embryo development. Although the formation and the structure of central cell have well been elucidated, the molecular mechanisms for its specification and development remain largely unknown. The central cell plays a critical role in pollen tube guidance during pollination and in endosperm initiation after fertilization. Recently, a group of mutants affecting specific steps of central cell development and function have been identified, providing some clues in understanding these questions. This review summarizes our current knowledge about central cell development and function, and presents overview about hypotheses for its evolution. genesis 48:466–478, 2010. © 2010 Wiley‐Liss, Inc.
Oxidative stability and acceptability of camelina oil blended with selected fish oils
Authors: Eidhin Deirdre Ní , O'Beirne David
Published: May 2010

The effects of blending camelina oil with a number of fish oils on oxidative stability and fishy odour were evaluated. Camelina oil was found to be more stable than tuna oil, ‘omega‐3’ fish oil and salmon oil as indicated by predominantly lower ρ‐anisidine (AV), thiobarbituric acid reactive substances (TBARS) and conjugated triene levels (CT) during storage at 60 °C for 20 days (p < 0.05). Peroxide values (PV) were similar for all oils until Day 13 when values for camelina oil were higher. Values for blends of the fish oils (50, 25, 15, 5%) with camelina oil were generally between those of their respective bulk oils indicating a dilution effect. Camelina oil had a similar odour score (p < 0.05) to sunflower oil (9.2 and 9.6, respectively) indicating, as expected, an absence of fishy odours. In comparison, the fish oils had lower scores of 6.1 to 6.6 (p < 0.05) indicating mild to moderate fishy odours. Odour scores were improved at the 25% fish oil levels (p < 0.05) and were not different to camelina oil at the 15 or 5% levels (p < 0.05).

Practical applications: Camelina oil is a potentially important functional food ingredient providing beneficial n‐3 PUFA. Oil extracted from Camelina sativa seeds contains greater than 50% polyunsaturated fatty acids of which 35‐40% is α‐linolenic acid (C18:3ω3, ALA), an essential omega‐3 fatty acid 1. While EPA and DHA from fish oils are more potent nutritionally, they are less stable than ALA. This work evaluated innovative blends of fish oil with camelina oil for stability and acceptability. The results demonstrate that there is potential for use of blends of camelina oil with fish oils in food products, as the results show some benefits in terms of reduction of fishy odours. Such information could be valuable in relation to formulation of food products containing high levels of n‐3 PUFA from both plant and fish sources.
Frying stability of canola oil in presence of pumpkin seed and olive oils
Authors: Ardabili Ashraf Gohari , Farhoosh Reza , Khodaparast Mohammad Hossein Haddad
Published: May 2010

Frying performance of canola oil (CO) was investigated in the presence of 5, 10, and 15% levels of virgin olive oil (VOO) and pumpkin seed oil (PSO) during frying of potatoes at 180°C. Acid value, carbonyl value, total polar compounds content, and total tocopherols content of the oil samples were determined during the frying process. VOO and PSO addition improved the frying stability of the CO. Frying performance of the CO increased more in the presence of PSO than in the presence of the VOO. The PSO levels higher than 5% exerted pro‐oxidant effects, indicating the necessity of investigation at lower levels. The better antioxidative effect of PSO was attributed to its probably different phenolic composition.
Natural polyphenols as chain‐breaking antioxidants during methyl linoleate peroxidation
Authors: Tichonov Ivan , Roginsky Vitaly , Pliss Evgeny
Published: May 2010

A technique based on monitoring oxygen consumption was applied to study 11 natural and model polyphenols (PP, QH2) as well as four typical monophenolics as a chain‐breaking antioxidant during the controlled chain oxidation of methyl linoleate (ML) in bulk at 37°C. The antioxidant activities of QH2 were characterized by two parameters: the rate constant k1 for reaction of QH2 with the peroxy radical ${\rm LO}_{2}^{{\bf .}} $: (i) QH2 + ${\rm LO}_{2}^{{\bf .}} $ → ${\rm QH}^{{\bf .}} $ + LOOH and the stoichiometric factor of inhibition, f, which shows how many kinetic chains may be terminated by one molecule of QH2. The rate constant k1 were reduced significantly by factor of 4 –28 as compared to these determined during the oxidation of styrene in bulk; the effect was typically more pronounced for catechol derivatives than for pyrogallol derivatives. At the same time, f for QH2 was found to be close to two independent of the number of active OH groups, similar to that determined earlier during the inhibited oxidation of styrene. The formation of H bond between OH group of QH2 and carboxyl group of ML is suggested as a reason for reducing effect of ML on k1.

Practical applications: This work reports rate constants for the reaction of lipid peroxyl radical with phenolics and stoichiometric coefficient of inhibition, which characterize the antioxidant activity (AOA) of 15 natural and model PP, QH2 during the controlled peroxidation of ML. The reactivity of PP, QH2 during the oxidation of ML is routinely lower than the reactivity during the oxidation of non‐polar model hydrocarbons. This information may be useful to estimate the AOA of natural PP, QH2 in real systems of practical significance including plant oils, fats, food‐stuffs, biological objects, and similar.
Imaging technique for quantification of oil palm fruit ripeness and oil content
Authors: Tan Yew Ai , Low Kum Wan , Lee Chak Khiam , Low Kum Sang
Published: May 2010

We investigated a non‐destructive technique for measuring the colour of oil palm fruit (Elaeis guineensis) bunches at different stages of maturity and correlating the colour data with the oil content in the fruit bunch. A digital red, green and blue (RGB) camera was used to capture the image of palm fruits and hue histograms were then constructed from mathematically transformed RGB data. The dominant hue peaks were then correlated to the oil content of fresh fruit bunches (FFBs). The study showed that the results obtained were influenced by FFB that possessed different expressions of colour changes during the ripening process. The results obtained from colour image analyses were not satisfactory – the correlation between hue peak and FFB oil content was r = 0.7933. However, when FFB having the same ripening patterns were analysed, the correlation was very much improved with r = 0.9519. Thus, statistical evaluation showed that the digital imaging technique for determining FFB oil content can be successfully used on a homogeneous population of palms that display similar change of colour during the ripening process.

Practical applications: The ability to correctly identify physiological maturity and harvest maturity of palm fruits by phenological characteristics will ensure timely harvest to avoid cutting of either under‐ and over‐ripe fruits. The Malaysian Palm Oil Board [MPOB] 1 has published an oil palm fruit grading manual outlining 16 classifications for grading FFB ripeness and quality. However, the FFB grading methods are still very subjective, i.e. depend on the judgement, experience and skill of a person. In addition, the methods do not provide quantitative information about the oil in the FFB. The method reported in this paper allows for rapid screening of FFB ripeness, and relate it to oil content in the FFB and accordingly the amount of oil that can be extracted from a consignment of FFB. Since it only takes a few seconds to capture signals, the system could be incorporated for on‐line monitoring of FFB ripeness and oil content thereof.
Cell surface analysis of the lipid‐discharging obligate hydrocarbonoclastic species of the genus Alcanivorax
Authors: Lange Alvin Brian , Tenberge Klaus Bernhard , Robenek Horst , Steinbüchel Alexander
Published: May 2010

This study presents novel information useful for addressing the question how species of the genus Alcanivorax discharge triacylglycerols (TAG) and/or wax esters (WE). The observed structures were referred as “blebs” according to Gauthier et al. 1 to avoid confusion with other discharging phenomena. The cells were aerobically cultivated on solid media and not in liquid media to maintain the cells in the native state, and were investigated by transmission electron microscopic (TEM) and scanning electron microscopic (SEM) methods to document the surface structures of the cells. The phenomenon of lipid export could be allocated to three phases: phase I: protrusion formation of the cell membrane occurred; phase II: discharging progressed further with blebs becoming larger; and phase III: the blebs at the cell surface were separated from the cells. Using freeze‐fracture micrographs by TEM, vesicle experiments and TLC, we have shown that the blebs contained TAGs and WEs. The results shown in this study will support further research to unravel the unknown discharging mechanism. In addition, the formation of an extensive extracellular matrix was observed by SEM.
Changes in virgin olive oil characteristics during different storage conditions
Authors: Stefanoudaki Evagelia , Williams Mark , Harwood John
Published: May 2010

In this study we have examined the effect of olive oil storage outdoors on a comprehensive series of quality measures. The conditions used were at the extreme of those encountered during the production of bottle oil. Filtered and unfiltered oils were compared as was the influence of inert gas (nitrogen) in the headspace. Increases in K232, K270 and peroxides over time were very much reduced by inert headspace gas, which also reduced losses of total phenols and oxidative stability. Headspace nitrogen also reduced the rise in unconjugated phenolics as secoiridoid derivatives declined and minimised losses in polyunsaturated fatty acids. The pattern of volatile compounds detected in olive oils stored indoors or outdoors showed subtle differences. Moreover, when stored with air exposure the levels of some negative sensory components such as penten‐3‐ol and hexanal increased while other positives, like trans‐2‐hexenal were reduced. These changes would be expected to reduce quality. Finally, Panel tests were used. All oils lost perceived quality on storage and this was accelerated outdoors while headspace nitrogen slowed the deterioration significantly. Our data show that storage outdoors for 4 months in winter does not reduce olive oil quality significantly and that an inert gas in the headspace is beneficial.

Practical applications: The storage of olive oil for bottling is carried out under a variety of conditions. Here we assess the effects of storage outdoors for oils from the main Greek cultivar (Koroneiki) of olive. Detailed analyses of quality (standard measures, different phenolics, lipids and volatiles) as well as Panel tests were used for evaluation. Our data show that, although storage outdoors causes deterioration quicker than indoors, changes are not serious up to 4 months. Furthermore, the use of an inert headspace gas significantly preserved quality both indoors and outdoors. Thus we would strongly recommend the latter measure to producers.
Comparative toxicity and bioconcentration of nonylphenol in freshwater organisms
Authors: Spehar Robert L. , Brooke Larry T. , Markee Thomas P. , Kahl Michael D.
Published: May 2010

Degradation of alkylphenol ethoxylates to more persistent alkylphenols such as nonylphenol occurs in wastewater treatment plants where nonylphenol is released to aquatic systems. In this study, acute and chronic tests were conducted to determine the toxicity and bioconcentration of nonylphenol to freshwater organisms for use in deriving national water quality criteria. Acute median effect concentrations (EC50s) based on loss of equilibrium, immobility, and lethality for species representing several taxonomic groups ranged from 21 to 596 µg/L. The EC50s were up to a factor of 2 less than median lethal concentrations (LC50s) and decreased with time over the test periods of 24 to 96 h. In chronic tests, early life stages of rainbow trout were 14 times more sensitive to nonylphenol than in acute tests and approximately 20 times more sensitive than Daphnia magna exposed over their complete life cycle. Comparisons of chronic test endpoints showed that 20% effect concentrations (EC20s), determined by regression testing, and chronic values, determined by hypothesis testing, were similar for both the rainbow trout and Daphnia magna. The lowest mean tissue–effect concentrations of nonylphenol appeared to be greater for the fathead minnow than bluegill, and ranged from approximately 130 to 160 µg/g after 96-h exposure and from approximately 20 to 90 µg/g after 28-d exposure. Mean lipid normalized bioconcentration factors (BCFs) associated with no-effect concentrations were approximately 180 and 50 for the fathead minnow and bluegill, respectively. The present test results suggest that long-term exposures to nonylphenol at concentrations found in some surface waters could adversely impact sensitive components of freshwater communities. Environ. Toxicol. Chem. 2010;29:2104–2111. © 2010 SETAC
Heterogeneity and Fgf dependence of adult neural progenitors in the zebrafish telencephalon
Authors: Ganz Julia , Kaslin Jan , Hochmann Sarah , Freudenreich Dorian , Brand Michael
Published: May 2010

Adult telencephalic neurogenesis is a conserved trait of all vertebrates studied. It has been investigated in detail in rodents, but very little is known about the composition of neurogenic niches and the cellular nature of progenitors in nonmammalian vertebrates. To understand the components of the progenitor zones in the adult zebrafish telencephalon and the link between glial characteristics and progenitor state, we examined whether canonical glial markers are colocalized with proliferation markers. In the adult zebrafish telencephalon, we identify heterogeneous progenitors that reside in two distinct glial domains. We find that the glial composition of the progenitor zone is linked to its proliferative behavior. Analyzing both fast‐cycling proliferating cells as well as slowly cycling progenitors, we find four distinct progenitor types characterized by differential expression of glial markers. Importantly, a significant proportion of progenitors do not display typical radial glia characteristics. By blocking or activating Fgf signaling by misexpression of a dominant negative Fgf‐receptor 1 or Fgf8a, respectively, we find that ventral and dorsal progenitors in the telencephalon also differ in their requirement for Fgf signaling. Together with data on the expression of Fgf signaling components in the ventricular zone of the telencephalon, this suggests that Fgf signaling directly regulates proliferation of specific subsets of adult telencephalic progenitors in vivo. Taken together our results show that adult neural progenitor cells are heterogeneous with their respect to distribution into two distinct glial domains and their dependence upon Fgf signaling as a proliferative cue in the zebrafish telencephalon. © 2010 Wiley‐Liss, Inc.
Sphingolipid rheostat alterations related to transformation can be exploited for specific induction of lysosomal cell death in murine and human glioma
Authors: Mora Rodrigo , Dokic Ivana , Kees Tim , Hüber Christian M. , Keitel Denise , Geibig Renate , Brügge Britta , Zentgraf Hanswalter , Brady Nathan R. , Régnier‐Vigouroux Anne
Published: May 2010

The search for cancer cell‐specific targets suffers from a lack of integrative approaches that take into account the relative contributions of several mechanisms or pathways involved in cell death. A systematic experimental and computational comparison of murine glioma cells with astrocytes, their nontransformed counterparts, identified differences in the sphingolipid (SL) rheostat linked to an increased lysosomal instability in glioma cells. In vitro and in silico analyses indicate that sphingosine metabolized in lysosomes was preferentially recycled into ceramide, the prodeath member of the rheostat, in astrocytes. In glioma cells, it preferentially was used for production of the prosurvival sphingosine‐1‐phosphate (S1P). A combination of tumor necrosis factor alpha (TNF‐α), lipopolysaccharide (LPS), and interferon gamma (IFN‐γ) strongly decreased S1P production that resulted in abnormal lysosome enlargement and cell death associated with mitochondrial dysfunction of glioma cells only. Lack of intracellular S1P in glioma cells was concomitant with protein and lipid accumulation in enlarged lysosomes, indicating a blockade in lysosome recycling, and hence a role for S1P in membrane trafficking. A pharmacological sphingosine kinase inhibitor efficiently replaced the TNF‐α, LPS, and IFN‐γ combination and killed murine and human glioma cells without affecting astrocytes. Our study provides evidence for a novel mechanism of lysosomal death dependent upon the SL rheostat that can be specifically triggered in glioma cells. It further strengthens the potential of cancer therapies based on specific ceramide pathway alterations. © 2010 Wiley‐Liss, Inc.
Mitogen‐activated protein kinase activated protein kinase 2 (MK2) participates in p38 MAPK regulated control of oligodendrocyte differentiation
Authors: Haines Jeffery D. , Fang Jun , Mushynski Walter E. , Almazan Guillermina
Published: May 2010

The p38 mitogen‐activated protein kinases (p38 MAPKs) are a family of kinases that regulate a number of cellular functions including cell migration, proliferation, and differentiation. We have previously reported a role for p38 MAPK in the regulation of oligodendrocyte (OLG) differentiation and Schwann cell myelination. Here, we extend our previous findings by showing that a p38 substrate, mitogen‐activated protein kinase activated protein kinase 2 (MK2) is a downstream element of the p38 signaling pathway responsible for effecting OLG differentiation. Inhibition of MK2 activity in oligodendrocyte progenitors (OLPs) using CMPD1 [4‐(2′‐fluorobiphenyl‐4‐yl)‐N‐(4‐hydroxyphenyl)‐butyramide] blocked the activation of MK2 and resulted in decreased accumulation of myelin‐differentiation markers, including myelin‐associated glycoprotein (MAG) and myelin basic protein (MBP). We corroborated these findings using a small‐interfering RNA to MK2, which decreased the myelin‐specific lipid galactosylceramide and MAG. Treatment of cultures with CMPD1 decreased the steady state levels of mRNA encoding myelin transcription factor 1 (Myt1), MAG, MBP, and Opalin, a transmembrane sialylglycoprotein expressed in oligodendrocytes. In contrast, increases were observed in the mRNA levels of OLG transcriptional repressors, including transcription factor 4 (Tcf4), Notch1, and inhibitor of differentiation 2 (Id2). Furthermore, we found that the predominantly expressed isoform of p38 in OLGs, p38α, and MK2 can form coimmunoprecipitable complexes in OLPs and OLGs. Our results demonstrate that the p38‐MK2 pathway is a component of the signaling cascade regulating OLG differentiation. © 2010 Wiley‐Liss, Inc.
Ethanol inhibits neuritogenesis induced by astrocyte muscarinic receptors
Authors: Guizzetti Marina , Moore Nadia H. , Giordano Gennaro , VanDeMark Kathryn L. , Costa Lucio G.
Published: May 2010

In uteroalcohol exposure can lead to fetal alcohol spectrum disorders, characterized by cognitive and behavioral deficits.In vivoandin vitrostudies have shown that ethanol alters neuronal development. We have recently shown that stimulation of M3muscarinic receptors in astrocytes increases the synthesis and release of fibronectin, laminin, and plasminogen activator inhibitor‐1, causing neurite outgrowth in hippocampal neurons. As M3muscarinic receptor signaling in astroglial cells is strongly inhibited by ethanol, we hypothesized that ethanol may also inhibit neuritogenesis in hippocampal neurons induced by carbachol‐stimulated astrocytes. In the present study, we report that the effect of carbachol‐stimulated astrocytes on hippocampal neuron neurite outgrowth was inhibited in a concentration‐dependent manner (25–100 mM) by ethanol. This effect was because of the inhibition of the release of fibronectin, laminin, and plasminogen activator inhibitor‐1. Similar effects on neuritogenesis and on the release of astrocyte extracellular proteins were observed after the incubation of astrocytes with carbachol in the presence of 1‐butanol, another short‐chain alcohol, which like ethanol is a competitive substrate for phospholipase D, but not bytert‐butanol, its analog that is not a substrate for this enzyme. This study identifies a potential novel mechanism involved in the developmental effects of ethanol mediated by the interaction of ethanol with cell signaling in astrocytes, leading to an impairment in neuron–astrocyte communication. © 2010 Wiley‐Liss, Inc.