bluuebunny/crossref_metadata_2025 huggingface dataset:
On-chip magnetic separation of superparamagnetic beads for integrated molecular analysis
Authors: Florescu Octavian , Wang Kevan , Au Patrick , Tang Jimmy , Harris Eva , Beatty P. Robert , Boser Bernhard E.
Published: March 2010

We have demonstrated a postprocessed complementary metal oxide semiconductor (CMOS) integrated circuit (IC) capable of on-chip magnetic separation, i.e., removing via magnetic forces the nonspecifically bound magnetic beads from the detection area on the surface of the chip. Initially, 4.5 μm wide superparamagnetic beads sedimenting out of solution due to gravity were attracted to the detection area by a magnetic concentration force generated by flowing current through a conductor embedded in the IC. After sedimentation, the magnetic beads that did not bind strongly to the functionalized surface of the IC through a specific biochemical complex were removed by a magnetic separation force generated by flowing current through another conductor placed laterally to the detection area. As the spherical bead pivoted on the surface of the chip, the lateral magnetic force was further amplified by mechanical leveraging, and 50 mA of current flowing through the separation conductor placed 18 μm away from the bead resulted in 7.5 pN of tensile force on the biomolecular tether immobilizing the bead. This force proved high enough to break nonspecific interactions while leaving specific antibody-antigen bonds intact. A sandwich capture immunoassay on purified human immunoglobulin G showed strong correlation with a control enzyme linked immunosorbent assay and a detection limit of 10 ng/ml or 70 pM. The beads bound to the detection area after on-chip magnetic separation were detected optically. To implement a fully integrated molecular diagnostics platform, the on-chip magnetic separation functionality presented in this work can be readily combine with state-of-the art CMOS-based magnetic bead detection technology.
A compact high-voltage pulse generator based on pulse transformer with closed magnetic core
Authors: Zhang Yu , Liu Jinliang , Cheng Xinbing , Bai Guoqiang , Zhang Hongbo , Feng Jiahuai , Liang Bo
Published: March 2010

A compact high-voltage nanosecond pulse generator, based on a pulse transformer with a closed magnetic core, is presented in this paper. The pulse generator consists of a miniaturized pulse transformer, a curled parallel strip pulse forming line (PFL), a spark gap, and a matched load. The innovative design is characterized by the compact structure of the transformer and the curled strip PFL. A new structure of transformer windings was designed to keep good insulation and decrease distributed capacitance between turns of windings. A three-copper-strip structure was adopted to avoid asymmetric coupling of the curled strip PFL. When the 31 μF primary capacitor is charged to 2 kV, the pulse transformer can charge the PFL to 165 kV, and the 3.5 Ω matched load can deliver a high-voltage pulse with a duration of 9 ns, amplitude of 84 kV, and rise time of 5.1 ns. When the load is changed to 50 Ω, the output peak voltage of the generator can be 165 kV, the full width at half maximum is 68 ns, and the rise time is 6.5 ns.
Measurements of the cross-phase angle between density and electron temperature fluctuations and comparison with gyrokinetic simulations
Authors: White A. E. , Peebles W. A. , Rhodes T. L. , Holland C. H. , Wang G. , Schmitz L. , Carter T. A. , Hillesheim J. C. , Doyle E. J. , Zeng L. , McKee G. R. , Staebler G. M. , Waltz R. E. , DeBoo J. C. , Petty C. C. , Burrell K. H.
Published: March 2010

This paper presents new measurements of the cross-phase angle, αneTe, between long-wavelength (kθρs<0.5) density, ñe, and electron temperature, T̃e, fluctuations in the core of DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] tokamak plasmas. The coherency and cross-phase angle between ñe and T̃e are measured using coupled reflectometer and correlation electron cyclotron emission diagnostics that view the same plasma volume. In addition to the experimental results, two sets of local, nonlinear gyrokinetic turbulence simulations that are performed with the GYRO code [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] are described. One set, called the pre-experiment simulations, was performed prior to the experiment in order to predict a change in αneTe given experimentally realizable increases in the electron temperature, Te. In the experiment the cross-phase angle was measured at three radial locations (ρ=0.55, 0.65, and 0.75) in both a “Base” case and a “High Te” case. The measured cross-phase angle is in good qualitative agreement with the pre-experiment simulations, which predicted that ñe and T̃e would be out of phase. The pre-experiment simulations also predicted a decrease in cross-phase angle as Te is increased. Experimentally, this trend is observed at the inner two radial locations only. The second set of simulations, the postexperiment simulations, is carried out using local parameters taken from measured experimental profiles as input to GYRO. These postexperiment simulation results are in good quantitative agreement with the measured cross-phase angle, despite disagreements with transport fluxes. Directions for future modeling and experimental work are discussed.
Modeling of iron oxide deposition by reactive ion beam sputtering
Authors: Puech Laurent , Dubarry Christophe , Ravel Guillaume , de Vito Eric
Published: March 2010

An analytic model of deposition is applied on reactive ion beam sputtering to optimize the properties of iron oxide thin films. This model will be able to predict deposition rate and phase contents. Among its hypotheses, we assume oxygen adsorption at the surface of the target to explain variations of deposition rate for oxygen flow. This hypothesis is validated by chemical analyses on iron targets. An ellipsoidal distribution of probability is introduced to model sputtered matter distribution from iron target and to calculate sputtering yield. Comparison between experimental and calculated deposition rates validates previously assumed hypotheses.
Intrashot motional Stark effect calibration technique for lower hybrid current drive experiments
Authors: Ko Jinseok , Scott Steve , Shiraiwa Syun’ichi , Greenwald Martin , Parker Ronald , Wallace Gregory
Published: March 2010

The spurious drift in pitch angle of order several degrees measured by the motional Stark effect (MSE) diagnostic in the Alcator C-Mod tokamak over the course of an experimental run day has precluded direct utilization of independent absolute calibrations. Recently, the underlying cause of the drift has been identified as thermal stress-induced birefringence in a set of in-vessel lenses. The shot-to-shot drift can be avoided by using MSE to measure only the change in pitch angle between a reference phase and a phase of physical interest within a single plasma discharge. This intrashot calibration technique has been applied to the lower hybrid current drive (LHCD) experiments and the measured current profiles qualitatively demonstrate several predictions of LHCD theory such as an inverse dependence of current drive efficiency on the parallel refractive index and the presence of off-axis current drive.
Rotated balance in humans due to repetitive rotational movement
Authors: Zakynthinaki M. S. , Madera Milla J. , López Diaz De Durana A. , Cordente Martínez C. A. , Rodríguez Romo G. , Sillero Quintana M. , Sampedro Molinuevo J.
Published: March 2010

We show how asymmetries in the movement patterns during the process of regaining balance after perturbation from quiet stance can be modeled by a set of coupled vector fields for the derivative with respect to time of the angles between the resultant ground reaction forces and the vertical in the anteroposterior and mediolateral directions. In our model, which is an adaption of the model of Stirling and Zakynthinaki (2004), the critical curve, defining the set of maximum angles one can lean to and still correct to regain balance, can be rotated and skewed so as to model the effects of a repetitive training of a rotational movement pattern. For the purposes of our study a rotation and a skew matrix is applied to the critical curve of the model. We present here a linear stability analysis of the modified model, as well as a fit of the model to experimental data of two characteristic “asymmetric” elite athletes and to a “symmetric” elite athlete for comparison. The new adapted model has many uses not just in sport but also in rehabilitation, as many work place injuries are caused by excessive repetition of unaligned and rotational movement patterns.
Generalization of the JTZ model to open plane wakes
Authors: Wu Zuo-Bing
Published: March 2010

The JTZ model [C. Jung, T. Tél, and E. Ziemniak, Chaos 3, 555 (1993)], as a theoretical model of a plane wake behind a circular cylinder in a narrow channel at a moderate Reynolds number, has previously been employed to analyze phenomena of chaotic scattering. It is extended here to describe an open plane wake without the confined narrow channel by incorporating a double row of shedding vortices into the intermediate and far wake. The extended JTZ model is found in qualitative agreement with both direct numerical simulations and experimental results in describing streamlines and vorticity contours. To further validate its applications to particle transport processes, the interaction between small spherical particles and vortices in an extended JTZ model flow is studied. It is shown that the particle size has significant influences on the features of particle trajectories, which have two characteristic patterns: one is rotating around the vortex centers and the other accumulating in the exterior of vortices. Numerical results based on the extended JTZ model are found in qualitative agreement with experimental ones in the normal range of particle sizes.
On the formation of Na nanoparticles in femtosecond-laser irradiated glasses
Authors: Jiang Nan , Su Dong , Qiu Jianrong , Spence John C. H.
Published: March 2010

This work discusses the response of Na to both high-energy electrons and femtosecond-laser (fs-laser) pulses in the soda-lime glass. The evidence for different responses of Na to high-energy electron irradiation between glasses with and without fs-laser irradiation suggests that the chemical and/or physical states of Na in the fs-laser irradiated glass are different from those in the original glass. Fs-laser pulses in the glass may be able to neutralize Na, which may form clusters. These results suggest that close attention should be paid to the defects associated with Na when optical or physical data are interpreted in fs-laser irradiated Na glasses.
Capacitive measurement of mercury column heights in capillaries
Authors: Frey Sarah , Richert Ranko
Published: March 2010

The detection of changes in volume, e.g., in expansivity or aging measurements, are often translated into mercury column height within a glass capillary. We propose a capacitive technique for measuring the meniscus position using a cylindrical capacitor with mercury as the inner electrode, the capillary material as the dielectric, and a metal coat covering the outside surface of the capillary as the second electrode. The measured capacitance changes linearly with meniscus height, as long as the top mercury level remains within the range of the outer electrode. With the demonstrated noise level of 48 nm for our preliminary setup, meniscus height changes beyond 100 nm can be observed via the capacitance.
T
c
=
21

K
in epitaxial FeSe0.5Te0.5 thin films with biaxial compressive strain
Authors: Bellingeri E. , Pallecchi I. , Buzio R. , Gerbi A. , Marrè D. , Cimberle M. R. , Tropeano M. , Putti M. , Palenzona A. , Ferdeghini C.
Published: March 2010

Epitaxial FeSe0.5Te0.5 thin films with different thickness were grown by pulsed laser ablation deposition on different substrates. High purity phase and fully epitaxial growth were obtained. By varying the film thickness, superconducting transition temperatures up to 21 K were observed, significantly larger than the bulk value 16.2 K. Structural analyses indicated that the c-axis is smaller than the bulk value but it is almost independent of the film thickness and the a-axis changes significantly with the film thickness and is linearly related to the Tc. The latter result indicates the important role of the compressive strain in enhancing Tc. Tc is also related to both the Fe–(Se,Te) bond length and angle, suggesting the possibility of further enhancement.
Influence of grating period on kinetics of self-diffraction in nematic liquid crystal panel with photoconducting polymeric layer
Authors: Sznitko Lech , Anczykowska Agata , Mysliwiec Jaroslaw , Bartkiewicz Stanislaw
Published: March 2010

The authors report on grating spacing influence on self-diffraction phenomenon in nematic liquid crystal panel with photoconducting polymeric layer. For grating recording typical degenerated two-wave mixing experimental set-up was used. Self-diffraction was induced by neodymium doped yttrium aluminum garnet laser (Nd:YAG, λ=532 nm) and for the observation of temporal changes of diffraction efficiency in function of grating period (angle between two recording beams coming from the Nd:YAG laser) laser diode (λ=674) was used. Mathematical model for grating formation based on coupling of three gratings was proposed. Theoretical estimations and experimental results have shown very good agreement.
Self-organization of SiO2 nanodots deposited by chemical vapor deposition using an atmospheric pressure remote microplasma
Authors: Arnoult G. , Belmonte T. , Henrion G.
Published: March 2010

Self-organization of SiO2 nanodots is obtained by chemical vapor deposition out of hexamethyldisiloxane (HMDSO) and atmospheric pressure remote Ar–O2 plasma operating at high temperature (1200–1600 K). The dewetting of the film being deposited when it is still thin enough (<500 nm) is found to be partly responsible for this self-organization. When the coating becomes thicker (∼1 μm), and for relatively high contents in HMDSO, SiO2 walls forming hexagonal cells are obtained on a SiO2 sublayer. For thicker coatings (>1 μm), droplet-shaped coatings with a Gaussian distribution in thickness over their width are deposited. The coatings are submitted to high compressive stress. When it is relaxed, “nestlike structures” made of nanoribbons are synthesized.
Researcher networking drives change: an autoenthnographic narrative analysis from medical graduate to primary health researcher
Authors: Elliott-Rudder Megan
Published: March 2010

This narrative study aims to provide an illustrative example of the role of networking in a career path into doctoral candidature and research. Currently there is a push to build capacity for primary health care research. Mentoring and networking are increasingly relevant for recruitment, retention and research output, as can be seen in the case of this novice rural female researcher. The narrative of my career path from a rural general practice trainee, general practice obstetrician and educator through to postgraduate researcher is mapped and analysed. In this light this paper witnesses the development of the cluster-randomised controlled trial that is the basis of my doctoral research. My research topic is the use of a motivational interviewing intervention to increase breastfeeding rates through increased support for mothers. Analysis of connections among researchers who have influenced my career transitions reveals my gradual awareness of parallels with the theoretical framework of motivational interviewing. Themes that arise are related to the spirit of motivational interviewing: linkage and collaboration, exchange and evocation, career direction and autonomy. There are potential public health benefits from promoting such connections that may help to sustain motivation and increase output in both breastfeeding and primary health care research.
Guest-free monolayer clathrate and its coexistence with two-dimensional high-density ice
Authors: Bai Jaeil , Angell C. Austen , Zeng Xiao Cheng
Published: March 2010

Three-dimensional (3D) gas clathrates are ice-like but distinguished from bulk ices by containing polyhedral nano-cages to accommodate small gas molecules. Without space filling by gas molecules, standalone 3D clathrates have not been observed to form in the laboratory, and they appear to be unstable except at negative pressure. Thus far, experimental evidence for guest‐free clathrates has only been found in germanium and silicon, although guest‐free hydrate clathrates have been found, in recent simulations, able to grow from cold stretched water, if first nucleated. Herein, we report simulation evidence of spontaneous formation of monolayer clathrate ice, with or without gas molecules, within hydrophobic nano-slit at low temperatures. The guest-free monolayer clathrate ice is a low-density ice (LDI) whose geometric pattern is identical to Archimedean 4·8
2
-truncated square tiling, i.e. a mosaic of tetragons and octagons. At large positive pressure, a second phase of 2D monolayer ice, i.e. the puckered square high-density ice (HDI) can form. The triple point of the LDI/liquid/HDI three-phase coexistence resembles that of the ice-I

h

/water/ice-III three-phase coexistence. More interestingly, when the LDI is under a strong compression at 200 K, it transforms into the HDI via a liquid intermediate state, the first direct evidence of Ostwald’s rule of stages at 2D. The tensile limit of the 2D LDI and water are close to that of bulk ice-I

h

and laboratory water.
Sexuation in Jung and Lacan
Authors: McGrath S. J.
Published: March 2010

In the following article I first situate Lacan and Jung in the broader history of the unconscious: Western esotericism and Romanticism. This contextualization is necessary for the subsequent construction of a Jungian reading of Lacan's theory of sexuation. I will underscore one commonality between Jung and Lacan, and make evident the specific challenge Lacanian theory presents to Jung's notion ofconiunctio. In conclusion I will suggest that Jung's theory will not only be improved by meeting the Lacanian challenge to a naïve notion ofconiunctio; it will ultimately be brought into clearer alignment with its Western esoteric (alchemical) sources.
Destabilization mechanism of edge localized MHD mode by a toroidal rotation in tokamaks
Authors: Aiba N. , Furukawa M. , Hirota M. , Tokuda S.
Published: March 2010

Effects of toroidal rotation and density profiles on the stability of an edge localized MHD mode are investigated numerically. From the numerical results we show that both the density gradient and the sheared rotation profile can destabilize the edge ballooning mode and the peeling–ballooning mode, and particularly, the sheared rotation can destabilize these modes effectively. To clarify the mechanisms of these destabilizing effects of density gradient and sheared rotation, we define some energies and distinguish them by physics. By comparing these energies, we clarify that the destabilization by the density gradient can be explained as the destabilizing effect of the centrifugal instability, and that by the sheared toroidal rotation is induced mainly by the difference between the eigenmode frequency and the toroidal rotation frequency of the plasma. Although the strong rotation shear also has a stabilizing effect on the MHD modes by changing the mode structure, the edge MHD mode first becomes unstable due to the appearance of the destabilizing effect before changing the mode structure.
Fast ion ignition with ultra-intense laser pulses
Authors: Tikhonchuk V.T. , Schlegel T. , Regan C. , Temporal M. , Feugeas J.-L. , Nicolaï Ph. , Ribeyre X.
Published: March 2010

Fast ignition by laser-driven ion beams benefits from the strong collisional interaction of energetic ions with the imploded fuel. However, conditions for an efficient transformation of the laser pulse energy into ion kinetic energy and for the transport of these ions from the acceleration region to the fusion pellet core without significant temporal and angular spread have to be clarified. The laser ponderomotive force may provide efficient ion acceleration in bulk dense targets such as a precompressed DT capsule and evacuate a channel for further laser beam propagation. The main characteristics of ponderomotive ion acceleration and channel formation inferred from analytical theory and confirmed by particle-in-cell simulations are applied for the design of a new scheme of ion fast ignition. Contrary to schemes based on the mechanism of target normal sheath ion acceleration, at least two laser pulses are used in our proposal. The first pulse (or a sequence of several pulses) creates a channel with a diameter of ∼20 µm through the plasma corona up to a fuel density of ∼1 g cm−3. The second pulse with a higher intensity of ∼1022 W cm−2 accelerates the deuterium and tritium ions at the head of this channel to energies 5–25 MeV on a time scale less than 1–3 ps. The overall ignition energy in this proposal is relatively high, ≳100 kJ, but no additional target arrangements will be required. This feature makes the scheme attractive for a high repetition rate operation.
Phosphatidylinositol 4,5-bisphosphate Directs Spermatid Cell Polarity and Exocyst Localization in Drosophila
Authors: Fabian Lacramioara , Wei Ho-Chun , Rollins Janet , Noguchi Tatsuhiko , Blankenship J. Todd , Bellamkonda Kishan , Polevoy Gordon , Gervais Louis , Guichet Antoine , Fuller Margaret T. , Brill Julie A.
Published: March 2010

During spermiogenesis, Drosophila melanogaster spermatids coordinate their elongation in interconnected cysts that become highly polarized, with nuclei localizing to one end and sperm tail growth occurring at the other. Remarkably little is known about the signals that drive spermatid polarity and elongation. Here we identify phosphoinositides as critical regulators of these processes. Reduction of plasma membrane phosphatidylinositol 4,5-bisphosphate (PIP2) by low-level expression of the PIP2phosphatase SigD or mutation of the PIP2biosynthetic enzyme Skittles (Sktl) results in dramatic defects in spermatid cysts, which become bipolar and fail to fully elongate. Defects in polarity are evident from the earliest stages of elongation, indicating that phosphoinositides are required for establishment of polarity. Sktl and PIP2localize to the growing end of the cysts together with the exocyst complex. Strikingly, the exocyst becomes completely delocalized when PIP2levels are reduced, and overexpression of Sktl restores exocyst localization and spermatid cyst polarity. Moreover, the exocyst is required for polarity, as partial loss of function of the exocyst subunit Sec8 results in bipolar cysts. Our data are consistent with a mechanism in which localized synthesis of PIP2recruits the exocyst to promote targeted membrane delivery and polarization of the elongating cysts.
Aroma Compounds in Buckwheat (Fagopyrum esculentum Moench) Groats, Flour, Bran, and Husk
Authors: Janeš Damjan , Prosen Helena , Kreft Ivan , Kreft Samo
Published: March 2010

Buckwheat is a pseudocereal with a strong characteristic aroma. Compounds responsible for the aroma of buckwheat groats were recently identified, but the distribution of aromatic compounds between different fractions of the buckwheat kernel (flour, bran, and husk) is not yet known. In this study, the composition of aromatic compounds in buckwheat seed fractions was investigated and compared to the composition of aromatic compounds in groats produced from the same batch of buckwheat seeds. Volatiles from each sample were extracted with simultaneous distillation/extraction with a Likens‐Nickerson apparatus. Extracts were analyzed by gas chromatography coupled with mass spectrometry (GC‐MS) with electron ionization. Apart from the aroma molecules present in all fractions, compounds that are present only in flour or bran, but not in groats, were also found. Furthermore, some compounds were identified only in buckwheat groats but not in buckwheat flour or bran [octanal, (E,E)‐2,4‐heptadienal, (E)‐2‐decenal, and (E,E)‐2,4‐decadienal], others were identified only in husks [(E)‐2‐hexenal, heptanal, (E,E)‐2,4‐hexadienal, phenylacetaldehyde, and alpha‐bisabolol].
REVIEW: Regulatory Aspects of Whole Grain and Whole Grain Foods: Definitions and Labeling
Authors: Jones Julie Miller
Published: March 2010

Whole grains have many health advantages. Therefore, many companies are adding whole grains to their products and consumers are looking for these foods in their diets. Creating regulations that encourages industry to formulate products with whole grains and accurately convey the amount of whole grain in the product to the consumer creates many challenges. Furthermore, the label should give enough information to enable the buyer to know whether of the product is delivering a dietarily significant amount of whole grain. Labeling regulations create a level playing field so that consumers know what is in the product and all manufacturers have the same opportunity to express the benefits for their products. To establish regulations regarding whole grains, there first needs to be an agreement as to which grains are included and which are not. Next, a common definition for whole grains and whole grain foods is needed. The AACC International definition of whole grains is the basis for many definitions adopted by regulatory bodies and used in industry (AACC International Whole Grain Task Force and Definition; http://www.aaccnet.org/definitions/wholegrain.asp). However, as grains are processed in various ways, attention needs to be paid to the effects of these various processes on the proportions of the kernel required to meet the AACC International definition of whole grains. Furthermore, there needs to be a vehicle that tells the consumer the amount of whole grain in a product. Label declaration of the amount of whole grain required and the amount in the product can help consumers make better food choices. The FDA‐approved health claim for whole grains is one way to label whole grain products. Because it is based on product weight, not dry weight, it gives lower moisture products an unfair competitive advantage. The FDA‐approved health claim also requires a fiber amount; this gives an advantage to products such as wheat and barley that have whole grains with higher fiber contents. Traditional processing of foods, such as the making of bulgur, the pearling of barley, and the nixtamalization of corn offer special challenges to creating definitions and regulations.
Whole Grains and Health, Evidence from Observational and Intervention Studies
Authors: Seal Chris J. , Brownlee Iain A.
Published: March 2010

Nutritionists, dietitians and food manufacturers have advocated an increased consumption of whole grain foods. In some countries, this message is supported by governmental guidelines and health claims that can be used on whole grain foods. The bulk of evidence to support these messages comes from observational studies; in some cases, cohort studies with follow‐up. Although these data are powerful indicators of the relationship between whole grain intake and improved health, they do not demonstrate causality. Nevertheless, it is difficult to argue against the evidence, particularly for the benefit of whole grains in reducing the risk of cardiovascular diseases. Repeated meta‐analyses show that CVD risk is reduced by ≈30% when comparing the lowest whole grain consumers with the highest whole grain consumers. It is argued that to help explain the benefits of whole grain and, in particular, to inform the development of health claims for whole grain foods, intervention studies are needed to link observational data with mechanistic explanations. Until recently, the number of whole grain intervention studies has been very small and most have been conducted in at‐risk populations and with small numbers of subjects. Data from larger studies are gradually appearing and, in some cases, the results support the observational data but in others they do not. This report compares observational data with data from intervention studies to reconcile these differences and make recommendations for future research.
Renal Effects of Saline-based 10% Pentastarch versus 6% Tetrastarch Infusion in Ovine Endotoxemic Shock
Authors: Ertmer Christian , Köhler Gabriele , Rehberg Sebastian , Morelli Andrea , Lange Matthias , Ellger Björn , Pinto Bernardo Bollen , Rübig Eva , Erren Michael , Fischer Lars G. , Van Aken Hugo , Westphal Martin
Published: March 2010

Background

Conflicting data exist on the renal effects of hydroxyethyl starch (HES) preparations. The current study evaluates the effects of saline-based 6% HES 130/0.4, 10% HES 200/0.5, and a balanced isotonic crystalloid on renal function and microscopic changes in ovine endotoxemic shock.

Methods

Thirty sheep were subjected to endotoxin infusion (Salmonella typhosa) at incremental doses until mean arterial pressure was less than 65 mmHg. Animals were randomized to receive fluid resuscitation with saline-based 6% HES 130/0.4, 10% HES 200/0.5, or a balanced isotonic crystalloid (n = 10 each). Animals surviving the 12-h intervention period were anesthetized and killed. Kidney samples were taken for microscopic analyses.

Results

Endotoxemia was associated with hemoconcentration, protein extravasation, and arterial hypotension. Fluid resuscitation established a hypotensive-hyperdynamic circulation with increased cardiac index and oxygen delivery and decreased afterload. Diuresis was lowest in animals treated with 10% HES 200/0.5. In addition, plasma creatinine and urea concentrations increased in sheep treated with 10% HES 200/0.5 (1.2 +/- 0.1 and 19 +/- 2 mg/dl) when compared with the other two groups (0.9 +/- 0.1 and 15 +/- 1 mg/dl, 6% HES 130/0.4; 0.9 +/- 0.1 and 15 +/- 1 mg/dl, crystalloids; each P < 0.05). Electron microscopic tubular injury score was highest in sheep treated with 10% HES 200/0.5 (P < 0.001 vs. 6% HES 130/0.4).

Conclusions

In ovine endotoxemic shock, saline-based 10% HES 200/0.5 was linked to impaired renal function and more pronounced tubular epithelial injury when compared with 6% HES 130/0.4 and balanced crystalloids.
Rem2 GTPase maintains survival of human embryonic stem cells as well as enhancing reprogramming by regulating p53 and cyclin D1
Authors: Edel Michael J. , Menchon Cristina , Menendez Sergio , Consiglio Antonella , Raya Angel , Izpisua Belmonte Juan Carlos
Published: March 2010

Human pluripotent stem cells, such as embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs), have the unique abilities of differentiation into any cell type of the organism (pluripotency) and indefinite self-renewal. Here, we show that the Rem2 GTPase, a suppressor of the p53 pathway, is up-regulated in hESCs and, by loss- and gain-of-function studies, that it is a major player in the maintenance of hESC self-renewal and pluripotency. We show that Rem2 mediates the fibroblastic growth factor 2 (FGF2) signaling pathway to maintain proliferation of hESCs. We demonstrate that Rem2 effects are mediated by suppressing the transcriptional activity of p53 and cyclin D1 to maintain survival of hESCs. Importantly, Rem2 does this by preventing protein degradation during DNA damage. Given that Rem2 maintains hESCs, we also show that it is as efficient as c-Myc by enhancing reprogramming of human somatic cells into iPSCs eightfold. Rem2 does this by accelerating the cell cycle and protecting from apoptosis via its effects on cyclin D1 expression/localization and suppression of p53 transcription. We show that the effects of Rem2 on cyclin D1 are independent of p53 function. These results define the cell cycle and apoptosis as a rate-limiting step during the reprogramming phenomena. Our studies highlight the possibility of reprogramming somatic cells by imposing hESC-specific cell cycle features for making safer iPSCs for cell therapy use.
ΔNp73β puts the brakes on DNA repair: Figure 1.
Authors: Vernersson-Lindahl Emma , Mills Alea A.
Published: March 2010

Mammalian cells are barraged with endogenous metabolic byproducts and environmental insults that can lead to nearly a million genomic lesions per cell per day. Networks of proteins that repair these lesions are essential for genome maintenance, and a compromise in these pathways propagates mutations that can cause aging and cancer. The p53 tumor suppressor plays a central role in repairing the effects of DNA damage, and has therefore earned the title of “guardian of the genome.” In this issue of Genes & Development, Wilhelm and colleagues (pp. 549–560) demonstrate that p73—an older sibling of p53—inhibits pathways that resolve DNA double-strand breaks.
Environmental factors regulate the effects of roach Rutilus rutilus and pike Esox lucius on perch Perca fluviatilis populations in small boreal forest lakes
Authors: Olin M. , Vinni M. , Lehtonen H. , Rask M. , Ruuhijärvi J. , Saulamo K. , Ala‐Opas P.
Published: March 2010

In this study of 18 small boreal forest lakes, the effects of abiotic and biotic factors (roach Rutilus rutilus and pike Esox lucius) on various population variables of perch Perca fluviatilis were examined. As a single variable, the gillnet catch per unit effort (CPUE) of R. rutilus was negatively related to the mean mass of small (< 200 mm) and the growth rate of young (1–2 years) P. fluviatilis. The mean mass of large (≥ 200 mm) P. fluviatilis was the highest at intermediate CPUE of R. rutilus. Redundancy analysis including environmental factors and P. fluviatilis population variables suggested that ‘predation–productivity–humus' gradient affected P. fluviatilis populations by decreasing the CPUE and mean mass of small individuals but increasing these variables of large individuals. The CPUE of R. rutilus and lake area had a negative effect on small and a positive effect on large P. fluviatilis growth rate. In small boreal forest lakes, P. fluviatilis populations are affected by the partially opposite forces of competition by R. rutilus and predation by E. lucius, and the intensity of these interactions is regulated by several environmental factors.
Silencing of pkm2 increases the efficacy of docetaxel in human lung cancer xenografts in mice
Authors: Shi Hua‐shan , Li Dan , Zhang Jing , Wang Yong‐sheng , Yang Li , Zhang Hai‐long , Wang Xian‐huo , Mu Bo , Wang Wei , Ma Yu , Guo Fu‐chun , Wei Yu‐quan
Published: March 2010

Tumor aerobic glycolysis, or the Warburg effect, plays important roles in tumor survival, growth, and metastasis. Pyruvate kinase isoenzyme M2 (PKM2) is a key enzyme that regulates aerobic glycolysis in tumor cells. Recent research has shown that PKM2 can be used as a tumor marker for diagnosis and, in particular, as a potential target for cancer therapy. We investigated the effects of combining shRNA targeting PKM2 and docetaxel on human A549 lung carcinoma cells both in vivo and in vitro. We observed that the shRNA can significantly downregulate the expression level of PKM2. The decrease of PKM2 resulted in a decrease in ATP synthesis, which caused intracellular accumulation of docetaxel. Furthermore, the combination of pshRNA‐pkm2 and docetaxel inhibited tumor growth and promoted more cancer cell apoptosis both in vivo and in vitro. Our findings suggest that targeting tumor glycolysis can increase the efficacy of chemotherapy. In particular, the targeting of PKM2 could, to some extent, be a new way of reversing chemotherapy resistance to cancer therapy. (Cancer Sci 2010)
Contribution of dynein light intermediate and intermediate chains to subcellular localization of the dynein–dynactin motor complex in Schizosaccharomyces pombe
Authors: Fujita Ikumi , Yamashita Akira , Yamamoto Masayuki
Published: March 2010

In fission yeast Schizosaccharomyces pombe, cytoplasmic dynein drives oscillatory nuclear movement during meiotic prophase, which may facilitate pairing of homologous chromosomes. Here, we report the identification of a dynein light intermediate chain (LIC) in fission yeast, termed Dli1p, and show that Dli1p and dynein intermediate chain (IC) Dic1p are essential for the appropriate subcellular localization and proper function of dynein during meiotic prophase. Expression of both the dli1 and dic1 genes was observed only in cells undergoing meiosis. Dli1p interacted and colocalized with dynein heavy chain Dhc1p. The subcellular localization of Dli1p was dependent on Dhc1p, and vice versa. The Dhc1p–Dli1p subcomplex could localize to the spindle pole body (SPB) with no aid of Dic1p and dynactin subunit Ssm4p, but its localization to microtubules was dependent on these two proteins. Dic1p localized to microtubules depending on Ssm4p, but not on Dhc1p and Dli1p. Its localization to the SPB, however, was dependent on Dhc1p and Dli1p. Localization of Ssm4p to the SPB was largely dependent on Dhc1p, Dli1p and Dic1p. Thus, Dli1p and Dic1p contribute differently in localizing the dynein–dynactin motor complex to organelles, providing novel insight into the in vivo function of dynein subunits in fission yeast.
Masking of a cathepsin G cleavage site in vivo contributes to the proteolytic resistance of major histocompatibility complex class II molecules
Authors: Burster Timo , Macmillan Henriette , Hou Tieying , Schilling James , Truong Phi , Boehm Bernhard O. , Zou Fang , Lau Kenneth , Strohman Michael , Schaffert Steven , Busch Robert , Mellins Elizabeth D.
Published: March 2010

The expression of major histocompatibility complex class II (MHC II) molecules is post‐translationally regulated by endocytic protein turnover. Here, we identified the serine protease cathepsin G (CatG) as an MHC II‐degrading protease by in vitro screening and examined its role in MHC II turnover in vivo. CatG, uniquely among endocytic proteases tested, initiated cleavage of detergent‐solubilized native and recombinant soluble MHC II molecules. CatG cleaved human leukocyte antigen (HLA)‐DR isolated from both HLA‐DM‐expressing and DM‐null cells. Even following CatG cleavage, peptide binding was retained by pre‐loaded, soluble recombinant HLA‐DR. MHC II cleavage occurred on the loop between fx1 and fx2 of the membrane‐proximal β2 domain. All allelic variants of HLA‐DR tested and murine I‐Ag7 class II molecules were susceptible, whereas murine I‐Ek and HLA‐DM were not, consistent with their altered sequence at the P1’ position of the CatG cleavage site. CatG effects were reduced on HLA‐DR molecules with DRB mutations in the region implicated in interaction with HLA‐DM. In contrast, addition of CatG to intact B‐lymphoblastoid cell lines (B‐LCLs) did not cause degradation of membrane‐bound MHC II. Moreover, inhibition or genetic ablation of CatG in primary antigen‐presenting cells did not cause accumulation of MHC II molecules. Thus, in vivo, the CatG cleavage site is sterically inaccessible or masked by associated molecules. A combination of intrinsic and context‐dependent proteolytic resistance may allow peptide capture by MHC II molecules in harshly proteolytic endocytic compartments, as well as persistent antigen presentation in acute inflammatory settings with extracellular proteolysis.
A comparison study of polyominoes explorations in a physical and virtual manipulative environment
Authors: Yuan Y. , Lee C.‐Y. , Wang C.‐H.
Published: March 2010

This study develops virtual manipulative, polyominoes kits for junior high school students to explore polyominoes. The current work conducts a non‐equivalent group pretest–post‐test quasi‐experimental design to compare the performance difference between using physical manipulatives and virtual manipulatives in finding the number of polyominoes. Sixty eighth‐grade students from two different classes in a junior high school in Taipei County of Taiwan participated in this study. The current research randomly selected one class as the experiment group and the other as the control group. Students in the experiment group used virtual manipulatives to explore polyominoes and those in the control group used physical manipulatives. The results revealed that learning in the experiment group is as effective as that in the control group. This study identifies two obvious strategies (add one and reduce) among students in both groups. New ideas, including using new symbols to record the results and considering the influence of symmetry and rotation on the figures, occurred in the virtual manipulative group. Students in the virtual environment paid much more attention to exploring the polyomino problem.
Working memory functions in children with different degrees of intellectual disability
Authors: Schuchardt K. , Gebhardt M. , Mäehler C.
Published: March 2010

Background  In recent years, there has been increased research interest in the functioning of working memory in people with intellectual disabilities. Although studies have repeatedly found these individuals to have weak working memory skills, few investigations have distinguished between different degrees of intellectual disability. This study aims to help close this research gap and, in so doing, to examine whether the deficits observed reflect a developmental lag or a qualitative deviation from normal development.

Method  In a 5‐group design, the working memory performance of a group of 15‐year‐olds with mild intellectual disability (IQ 50–69) was compared with that of two groups of children (aged 10 and 15 years) with borderline intellectual disability (IQ 70–84) and with that of two groups of children with average intellectual abilities (IQ 90–115) matched for mental and chronological age (aged 7 and 15 years). All children were administered a comprehensive battery of tests assessing the central executive, the visual‐spatial sketchpad, and the phonological loop.

Results  The results showed deficits in all three components of working memory, and revealed that these deficits increased with the degree of intellectual disability. The findings indicate that, relative to their mental age peers, children with learning difficulties show structural abnormalities in the phonological store of the phonological loop, but developmental lags in the other two subsystems.

Conclusions  Similar patterns of results emerged for both subgroups of children with intellectual disability, indicating that problems with phonological information processing seem to be one of the causes of cognitive impairment in individuals with intellectual disability.
Genetic diversity and interfertility among highly differentiated populations of Ceratocystis fimbriata in Brazil
Authors: Ferreira E. M. , Harrington T. C. , Thorpe D. J. , Alfenas A. C.
Published: March 2010

Mating studies showed that isolates of the insect‐associated wilt pathogen Ceratocystis fimbriata from Eucalyptus spp., mango, fig, inhame (Colocasia esculenta), Gmelina arborea and sweet potato were interfertile, and progeny from those crosses showed normal segregation for microsatellite markers. Genetic diversity was compared among 13 populations of C. fimbriata collected from six states in Brazil using 15 highly polymorphic microsatellite markers. The gene diversity values of most eucalyptus and mango populations from Minas Gerais, Bahia, Rio de Janeiro and São Paulo states were similar to putatively native populations of Ceratocystis platani and C. cacaofunesta, two other species in the C. fimbriata complex that are homothallic. Index of association values indicated substantial asexual reproduction or selfing in populations on mango and eucalyptus. Most of these eucalyptus and mango populations were not highly differentiated from each other, and these populations and genotypes appeared to be more closely related to each other than to other populations by upgma analyses. By contrast, the G. arborea population from Pará and the fig and inhame populations from São Paulo had relatively low levels of diversity and were highly differentiated from each other and all other studied populations, suggesting that they were from different origins and had gone through genetic bottlenecks. One of the eucalyptus populations in Bahia consisted of a single genotype and may have been introduced to the site in infected cuttings from another Bahia location. Similarly, a mango population from Mato Grosso do Sul consisted of a single genotype, which was identical to one of the genotypes found on mango in São Paulo. Aside from introductions by humans, mating studies and genetic analyses suggest that limited dispersal distance and a high degree of selfing or asexual reproduction lead to local populations of C. fimbriata that have limited diversity but are highly differentiated from other populations.
Seasonal restrictions of bud growth on roots of Cirsium arvense and Sonchus arvensis and rhizomes of Elymus repens
Authors: BRANDSÆTER L O , FOGELFORS H , FYKSE H , GRAGLIA E , JENSEN R K , MELANDER B , SALONEN J , VANHALA P
Published: March 2010

Brandsæter LO, Fogelfors H, Fykse H, Graglia E, Jensen RK, Melander B, Salonen J & Vanhala P (2010). Seasonal restrictions of bud growth on roots of Cirsium arvense and Sonchus arvensis and rhizomes of Elymus repens. Weed Research50, 102–109.

The success of weed management aimed at depleting the regenerative structures of perennial weeds depends largely on the sprouting activity of rhizome and root buds. Seasonal variation in sprouting of these buds on Cirsium arvense, Sonchus arvensis and Elymus repens was studied for plants collected from Denmark, Finland, Norway and Sweden. At 2‐week intervals from July to October, 5‐cm fragments of roots or rhizomes were cut from plants grown in buckets and planted into soil in pots, half of which were placed immediately into growth chambers at 18°C for 4 weeks. The other half of the pots were initially placed in a dark room at 2°C for 4 weeks before being transferred to the same growth chamber, also for 4 weeks. During the growth chamber period, the numbers of emerged shoots in each pot were counted weekly. The sprouting activity of C. arvense and E. repens was relatively uniform during this period and bud dormancy was not apparent. In all ecotypes of S. arvensis, innate bud dormancy developed during the latter part of the growing season. For all three species, differences in sprouting readiness were found among ecotypes. The results imply that C. arvense and E. repens are more likely to be controlled by mechanical measures in autumn than S. arvensis.
Cutaneous melanoma in a desert climate zone: a retrospective study of 125 cases
Authors: Rahnama Zahra , Meymandi Simin Shamsi , Nasiri Nasim
Published: March 2010

Background  With increasing incidence over the last few decades, cutaneous malignant melanoma (CM) represents 3% of all skin tumors, and accounts for 75% of all deaths because of cutaneous malignancies. Little is known about the nature and epidemiology of CM in individuals with pigmented skin.

Method  Data were collected from the records of four public and private histopathology laboratories of Kerman city from March 20, 1994 to March 20, 2004. Skin biopsies with a diagnosis of CM were reevaluated to confirm the diagnosis of CM. The medical records of the patients were also taken into consideration.

Results  A total of 125 CMs were found. The male‐to‐female ratio was 1.08 : 1. The mean age at the time of diagnosis was 58.9 years; with a peak in the seventh decade of life. Acral‐lentiginous melanoma (ALM) represented 28.8% and; nodular melanoma occurred in 20% of cases. Limbs were the site of occurrence in 44% of tumors; whereas 36% of tumors occurred in head and neck region. There was a significant correlation between age and ALM (P = 0.007) and also between gender and melanoma types (P = 0.024).

Conclusions  This study indicates that some demographic and histopathologic features of CM in this population differ from those in the literature. More studies including cohort studies are needed to fully describe the nature and survival rate of CM in this area.