bluuebunny/crossref_metadata_2025 huggingface dataset:
Necrotizing Enterocolitis
Authors: Henry Marion C.W. , Moss R. Lawrence
Published: September 2008

Necrotizing enterocolitis (NEC) remains a major cause of neonatal morbidity and death. The pathophysiology is poorly understood. Prevailing evidence suggests that NEC is due to an inappropriate inflammatory response of the immature gut to some undefined insult. The mortality rate (15%–25%) for affected infants has not changed appreciably in 30 years. Many infants with NEC recover uneventfully with medical therapy and have long-term outcomes similar to unaffected infants of matched gestational age. Infants with progressive disease requiring surgical intervention suffer almost all of the mortality and morbidity. Of these, ∼30%–40% will die of their disease and most of the remainder will develop long-term neurodevelopmental and gastrointestinal morbidity. Recent randomized trials suggest that the choice of operation does not influence patient outcome. Current work is focusing on developing a better understanding of the pathogenesis and improving means to identify which infants are at greatest risk of disease progression.
MicroRNAs in Cancer
Authors: Lee Yong Sun , Dutta Anindya
Published: September 2008

Within the past few years, studies on microRNA (miRNA) and cancer have burst onto the scene. Profiling of the miRNome (global miRNA expression levels) has become prevalent, and abundant miRNome data are currently available for various cancers. The pattern of miRNA expression can be correlated with cancer type, stage, and other clinical variables, so miRNA profiling can be used as a tool for cancer diagnosis and prognosis. miRNA expression analyses also suggest oncogenic (or tumor-suppressive) roles of miRNAs. miRNAs play roles in almost all aspects of cancer biology, such as proliferation, apoptosis, invasion/metastasis, and angiogenesis. Given that many miRNAs are deregulated in cancers but have not yet been further studied, it is expected that more miRNAs will emerge as players in the etiology and progression of cancer. Here we also discuss miRNAs as a tool for cancer therapy.
Complementary Roles of the Main and Accessory Olfactory Systems in Mammalian Mate Recognition
Authors: Baum Michael J. , Kelliher Kevin R.
Published: September 2008

We review studies conducted in mouse and ferret that have specified roles of both the main and the accessory olfactory nervous systems in the detection and processing of body odorants (e.g., urinary pheromones, extraorbital lacrimal gland secretions, major histocompatibility complex peptide ligands, and anal scent gland secretions) that play an essential role in sex discrimination and attraction between males and females leading to mate choice and successful reproduction. We also review literature that compares the forebrain processing of inputs from the two olfactory systems in the two sexes that underlies heterosexual partner preferences. Finally, we review experiments that raise the possibility that body odorants detected by the main olfactory system contribute to mate recognition in humans.
Latent Variable Modeling of Differences and Changes with Longitudinal Data
Authors: McArdle John J.
Published: September 2008

This review considers a common question in data analysis: What is the most useful way to analyze longitudinal repeated measures data? We discuss some contemporary forms of structural equation models (SEMs) based on the inclusion of latent variables. The specific goals of this review are to clarify basic SEM definitions, consider relations to classical models, focus on testable features of the new models, and provide recent references to more complete presentations. A broader goal is to illustrate why so many researchers are enthusiastic about the SEM approach to data analysis. We first outline some classic problems in longitudinal data analysis, consider definitions of differences and changes, and raise issues about measurement errors. We then present several classic SEMs based on the inclusion of invariant common factors and explain why these are so important. This leads to newer SEMs based on latent change scores, and we explain why these are useful.
Human neutrophil surface protrusion under a point load: location independence and viscoelasticity
Authors: Xu Gang , Shao Jin-Yu
Published: September 2008

Mechanical properties of neutrophils have been recognized as key contributors to stabilizing neutrophil rolling on the endothelium during the inflammatory response. In particular, accumulating evidence suggests that surface protrusion and tether extraction from neutrophils facilitate stable rolling by relieving the disruptive forces on adhesive bonds. Using a customized optical trap setup, we applied piconewton-level pulling forces on targeted receptors that were located either on the microvillus tip (CD162) or intermicrovillus surface of neutrophils (CD18 and CD44). Under a constant force-loading rate, there always occurred an initial tent-like surface protrusion that was terminated either by rupture of the adhesion or by a “yield” or “crossover” to tether extraction. The corresponding protrusional stiffness of neutrophils was found to be between 0.06 and 0.11 pN/nm, depending on the force-loading rate and the cytoskeletal integrity, but not on the force location, the medium osmolality, nor the temperature increase from 22°C to 37°C. More importantly, we found that neutrophil surface protrusion was accompanied by force relaxation and hysteresis. In addition, the crossover force did not change much in the range of force-loading rates studied, and the protrusional stiffness of lymphocytes was similar to that of neutrophils. These results show that neutrophil surface protrusion is essentially viscoelastic, with a protrusional stiffness that stems primarily from the actin cortex, and the crossover force is independent of the receptor-cytoskeleton interaction.
Essential role of EP3 subtype in prostaglandin E2-induced adhesion of mouse cultured and peritoneal mast cells to the Arg-Gly-Asp-enriched matrix
Authors: Sakanaka Mariko , Tanaka Satoshi , Sugimoto Yukihiko , Ichikawa Atsushi
Published: September 2008

Accumulating evidence has indicated that mast cells can modulate a wide variety of immune responses. Migration and adhesion play a critical role in regulation of tissue mast cell function, in particular, under inflammatory conditions. We previously demonstrated that prostaglandin (PG) E2 stimulates adhesion of a mouse mastocytoma cell line, P-815, to the Arg-Gly-Asp (RGD)-enriched matrix through cooperation between two PGE2 receptor subtypes: EP3 and EP4 (Hatae N, Kita A, Tanaka S, Sugimoto Y, Ichikawa A. J Biol Chem 278: 17977–17981, 2003). We here investigated PGE2-induced adhesion of IL-3-dependent bone marrow-derived cultured mast cells (BMMCs). In contrast to the elevated cAMP-dependent adhesion of P-815 cells, EP3-mediated Ca2+ mobilization plays a pivotal role in PGE2-induced adhesion of BMMCs. Adhesion and Ca2+ mobilization induced by PGE2 were abolished in the Ptger3−/− BMMCs and were significantly suppressed by treatment with pertussis toxin, a phospholipase C inhibitor, U-73122, and a store-operated Ca2+ channel inhibitor, SKF 36965, indicating the involvement of Gi-mediated Ca2+ influx. We then investigated PGE2-induced adhesion of peritoneal mast cells to the RGD-enriched matrix. EP3 subtype was found to be the dominant PGE receptor that expresses in mouse peritoneal mast cells. PGE2 induced adhesion of the peritoneal mast cells of the Ptger3+/+ mice, but not that of the Ptger3−/− mice. In rat peritoneal mast cells, PGE2 or an EP3 agonist stimulated both Ca2+ mobilization and adhesion to the RGD-enriched matrix. These results suggested that the EP3 subtype plays a pivotal role in PGE2-induced adhesion of murine mast cells to the RGD-enriched matrix through Ca2+ mobilization.
Ammonia excretion by the skin of zebrafish (Danio rerio) larvae
Authors: Shih Tin-Han , Horng Jiun-Lin , Hwang Pung-Pung , Lin Li-Yih
Published: September 2008

The mechanism of ammonia excretion in freshwater teleosts is not well understood. In this study, scanning ion-selective electrode technique was applied to measure H+ and NH4+ fluxes in specific cells on the skin of zebrafish larvae. NH4+ extrusion was relatively high in H+ pump-rich cells, which were identified as the H+-secreting ionocyte in zebrafish. Minor NH4+ extrusion was also detected in keratinocytes and other types of ionocytes in larval skin. NH4+ extrusion from the skin was tightly linked to acid secretion. Increases in the external pH and buffer concentration (5 mM MOPS) diminished H+ and NH4+ gradients at the larval surface. Moreover, coupled decreases in NH4+ and H+ extrusion were found in larvae treated with an H+-pump inhibitor (bafilomycin A1) or H+-pump gene ( atp6v1a) knockdown. Knockdown of Rhcg1 with morpholino-oligonucleotides also decreased NH4+ excretion. This study demonstrates ammonia excretion in epithelial cells of larval skin through an acid-trapping mechanism, and it provides direct evidence for the involvement of the H+ pump and an Rh glycoprotein (Rhcg1) in ammonia excretion.
Anisotropic diffusion of fluorescently labeled ATP in rat cardiomyocytes determined by raster image correlation spectroscopy
Authors: Vendelin Marko , Birkedal Rikke
Published: September 2008

A series of experimental data points to the existence of profound diffusion restrictions of ADP/ATP in rat cardiomyocytes. This assumption is required to explain the measurements of kinetics of respiration, sarcoplasmic reticulum loading with calcium, and kinetics of ATP-sensitive potassium channels. To be able to analyze and estimate the role of intracellular diffusion restrictions on bioenergetics, the intracellular diffusion coefficients of metabolites have to be determined. The aim of this work was to develop a practical method for determining diffusion coefficients in anisotropic medium and to estimate the overall diffusion coefficients of fluorescently labeled ATP in rat cardiomyocytes. For that, we have extended raster image correlation spectroscopy (RICS) protocols to be able to discriminate the anisotropy in the diffusion coefficient tensor. Using this extended protocol, we estimated diffusion coefficients of ATP labeled with the fluorescent conjugate Alexa Fluor 647 (Alexa-ATP). In the analysis, we assumed that the diffusion tensor can be described by two values: diffusion coefficient along the myofibril and that across it. The average diffusion coefficients found for Alexa-ATP were as follows: 83 ± 14 μm2/s in the longitudinal and 52 ± 16 μm2/s in the transverse directions ( n = 8, mean ± SD). Those values are ∼2 (longitudinal) and ∼3.5 (transverse) times smaller than the diffusion coefficient value estimated for the surrounding solution. Such uneven reduction of average diffusion coefficient leads to anisotropic diffusion in rat cardiomyocytes. Although the source for such anisotropy is uncertain, we speculate that it may be induced by the ordered pattern of intracellular structures in rat cardiomyocytes.
Impact of overexpression of metallothionein-1 on cell cycle progression and zinc toxicity
Authors: Smith Paul J. , Wiltshire Marie , Furon Emeline , Beattie John H. , Errington Rachel J.
Published: September 2008

Metallothioneins (MTs) have an important role in zinc homeostasis and may counteract the impact of oversupply. Both intracellular zinc and MT expression have been implicated in proliferation control and resistance to cellular stress, although the interdependency is unclear. The study addresses the consequences of a steady-state overexpression of MT-1 for intracellular zinc levels, cell cycle progression, and protection from zinc toxicity using a panel of cell lines with differential expression of MT-1. The panel comprised parental Chinese hamster ovary-K1 cells with low endogenous expression of MT and transfectants with enhanced expression of mouse MT-1 on an autonomously replicating expression vector with a noninducible promoter. Cell cycle progression, determined by flow cytometry and time-lapse microscopy, revealed that enhanced cytoplasmic expression of MT-1 does not impact on normal cell cycle operation, suggesting that basal levels of MT-1 expression are not limiting for background levels of oxidative stress. MT-1 overexpression correlated with a steady-state increase in cytoplasmic free Zn2+, assessed using the fluorescent zinc-sensor Zinquin, particularly at high levels of overexpression, further suggesting that zinc availability is normally not limiting for cell cycle progression. Enhanced MT-1 expression, over a 10-fold range, had a clear impact on resistance to Cd2+ and Zn2+ toxicity. In the case of Zn2+, the degree of protection afforded was less, indicating that MT-1 has a limited range and saturable capacity for effecting resistance. The results have implications for the use of cellular stress responses to exogenously supplied zinc and zinc-based systemic therapies.
Mechanisms mediating renal sympathetic activation to leptin in obesity
Authors: Morgan Donald A. , Thedens Daniel R. , Weiss Robert , Rahmouni Kamal
Published: September 2008

Leptin plays a critical role in the control of energy homeostasis. The sympathetic cardiovascular actions of leptin have emerged as a potential link between obesity and hypertension. We previously demonstrated that in mice, modest obesity induced by 10 wk of a high-fat diet is associated with preservation of leptin ability to increase renal sympathetic nerve activity (SNA) despite the resistance to the metabolic effects of leptin. Here, we examined whether selective leptin resistance exists in mice with late-stage diet-induced obesity (DIO) produced by 20 wk of a high-fat diet. The decrease in food intake and body weight induced by intraperitoneal or intracerebroventricular injection of leptin was significantly attenuated in the DIO mice. Regional SNA responses to intravenous leptin were also attenuated in DIO mice. In contrast, intracerebroventricularly administered leptin caused contrasting effects on regional SNA in DIO mice. Renal SNA response to intracerebroventricular leptin was preserved, whereas lumbar and brown adipose tissue SNA responses were attenuated. Intact renal SNA response to leptin combined with the increased cerebrospinal fluid leptin levels in DIO mice represents a potential mechanism for the adverse cardiovascular consequences of obesity. Lastly, we examined the role of phosphoinositol-3 kinase (PI3K) and melanocortin receptors (MCR) in mediating the preserved renal SNA response to leptin in obesity. Presence of PI3K inhibitor (LY294002) or MC3/4R antagonist (SHU9119) significantly attenuated the renal SNA response to leptin in DIO and agouti obese mice. Our results demonstrate the importance of PI3K and melanocortin receptors in the transduction of leptin-induced renal sympathetic activation in obesity.
Insulin regulates hepatic leptin receptor expression in early lactating dairy cows
Authors: Thorn Stephanie R. , Ehrhardt Richard A. , Butler W. Ronald , Quirk Susan M. , Boisclair Yves R.
Published: September 2008

Energy balance controls the expression of the leptin receptor (Lepr) in the ruminant hypothalamus but whether similar regulation occurs in peripheral tissues is unknown. To address this issue, we measured Lepr expression in the liver and adipose tissue of dairy cows during the transition from late pregnancy (LP) to early lactation (EL). This period is characterized by the development of a profound state of energy insufficiency and is associated with reduced plasma insulin and leptin and with increased plasma growth hormone. Hepatic expression of the short (Lepr-a) and long (Lepr-b) isoforms was 40% higher during EL (8 days postpartum) than LP (30 days prepartum). A similar effect was observed when negative energy balance was induced in nonpregnant, late-lactation dairy cows by food restriction, implicating energy insufficiency as a specific cause in EL. The stimulation of hepatic Lepr expression was reversed after a 48-h period of hyperinsulinemic euglycemia in EL. Changes in hepatic Lepr expression during chronic elevation of plasma leptin in EL or plasma growth hormone in nonpregnant, late-lactation cows did not support a role for these hormones in mediating the effects of energy insufficiency on hepatic Lepr expression. In adipose tissue, Lepr expression was increased 10-fold during the transition from LP to EL. Overall, these data indicate that hypoinsulinemia is partly responsible for the induction of Lepr expression in the liver, and perhaps adipose tissue, of energy-deficient dairy cows.
Human vastus lateralis and soleus muscles display divergent cellular contractile properties
Authors: Luden Nicholas , Minchev Kiril , Hayes Erik , Louis Emily , Trappe Todd , Trappe Scott
Published: September 2008

The purpose of this study was to investigate potential differences in single-fiber contractile physiology of fibers with the same myosin heavy chain isoform (MHC I and MHC IIa) originating from different muscles. Vastus lateralis (VL) and soleus biopsies were obtained from 27 recreationally active females (31 ± 1 yr, 59 ± 1 kg). A total of 943 single fibers (MHC I = 562; MHC IIa = 301) were isolated and examined for diameter, peak tension (Po), shortening velocity (Vo), and power. The soleus had larger ( P < 0.05) fibers (MHC I +18%; MHC IIa +19%), higher MHC I Vo (+13%), and higher MHC I Po (+18%) compared with fibers from the VL. In contrast, fibers from the VL had higher ( P < 0.05) specific tension (MHC I +18%; MHC IIa +20%), and MHC I normalized power (+25%) compared with the soleus. There was a trend for MHC IIa soleus fibers to have higher Vo [MHC IIa +13% ( P = 0.058)], whereas VL MHC IIa fibers showed a trend for higher normalized power compared with soleus fibers [MHC IIa +33% ( P = 0.079)]. No differences in absolute power were detected between muscles. These data highlight muscle-specific differences in single-fiber contractile function that should serve as a scientific basis for consideration when extending observations of skeletal muscle tissue from one muscle of interest to other muscles of origin. This is important when examining skeletal muscle adaptation to physical states such as aging, unloading, and training.
Lipocalin-2-induced renal regeneration depends on cytokines
Authors: Vinuesa Eugenia , Sola Anna , Jung Michaela , Alfaro Vicente , Hotter Georgina
Published: September 2008

This study investigated whether the renal regeneration occurring in the recovery phase of kidney ischemia-reperfusion (I/R) is mediated by endogenously generated lipocalin-2 (Lcn2). A second objective was to examine whether Lcn2-mediated cell effects could be regulated by the inflammatory cytokines in the environment through their action on Lcn2 receptors (Lcn2R and megalin). Male Swiss mice were subjected to 30 min of renal ischemia with a reperfusion period of 24 h (early reperfusion, expected time for maximum inflammation) and 96 h (late reperfusion, expected time for maximum regeneration). Different experimental groups underwent I/R, I/R with iv anti-mouse Lcn2 monoclonal antibody injected during the early/inflammatory or late/recovery phase, and I/R with proinflammatory cytokine cocktail administration (recombinant mouse IL-1β, TNF-α, and IFN-γ). Compared with control nonischemic mice, the expression of three proliferation markers (stathmin, PCNA, and Ki-67, analyzed by quantitative RT-PCR) increased significantly in the I/R-treated animals. Blockade of Lcn2 by addition of anti-Lcn2 antibody significantly decreased the expression of these three proliferation markers when administered in the late/reparative phase, but had the opposite effect when administered in the early/inflammatory phase. Proinflammatory cytokine cocktail administration reduced the proliferative effects of Lcn2, and repressed Lcn2R and megalin expression. In conclusion, endogenously generated Lcn2 induces renal cell regeneration depending on the inflammatory cytokines in kidney I/R.
JAK2/Y343/STAT5 signaling axis is required for erythropoietin-mediated protection against ischemic injury in primary renal tubular epithelial cells
Authors: Breggia A. C. , Wojchowski D. M. , Himmelfarb J.
Published: September 2008

Erythropoietin has emerged as a potential therapy for the treatment of ischemic tissue injury. In erythroid cells, the JAK2/Y343/STAT5 signaling axis has been shown to be necessary for stress but not steady-state erythropoiesis. The requirement for STAT5 activation in erythropoietin-mediated protection from ischemic injury has not been well-studied. To answer this question, we induced reproducible necrotic ischemic injury in primary mouse renal tubular epithelial cells (RTEC) in vitro. Using RTEC from erythropoietin receptor mutant mice with differential STAT5 signaling capabilities, we demonstrated first, that EPO administration either before or during injury significantly protects against mild-moderate but not severe necrotic cell death; and second, the JAK2/Y343/STAT5 signaling axis is required for protection against ischemic injury in primary mouse RTEC. In addition, we identified Pim-3, a prosurvival STAT5 target gene, as responsive to EPO in the noninjured kidney both in vitro and in vivo.
Renoprotective mechanisms of soy protein intake in the obese Zucker rat
Authors: Trujillo Joyce , Cruz Cristino , Tovar Armando , Vaidya Vishal , Zambrano Elena , Bonventre Joseph V. , Gamba Gerardo , Torres Nimbe , Bobadilla Norma A.
Published: September 2008

We previously showed that long-term consumption of a soy protein diet (SoyP) reduces renal damage in obese Zucker (ObeseZ) rats by restoring urinary NO2and NO3excretion (UNO2/NO3V), suggesting that nitric oxide (NO) deficiency may contribute to the renal progression observed in this model. In addition, there is compelling evidence that hyperleptinemia produced deleterious effects on the kidney through its interaction with the short leptin receptor (ObRa). This study was designed to evaluate the contribution of the NO/endothelial NO synthase (eNOS) system, renal oxidative stress, and ObRa expression to the renoprotection conferred by the consumption of a SoyP in ObeseZ rats. Ten lean and ten male ObeseZ rats were included. One-half of each group was fed with a 20% SoyP and the other half with a 20% casein protein diet (CasP) over the course of 160 days. eNOS protein levels and phosphorylation, renal lipoperoxidation (rLPO), and antioxidant enzyme activity were assessed. In addition, renal ObRa, TGF-β, and kidney injury molecule (Kim-1) mRNA levels, as well as urinary Kim-1 levels, were measured. Renal injury observed in ObeseZ rats fed with CasP was not associated with changes in eNOS expression or phosphorylation. However, this group did present with increased rLPO, reduced catalase activity, and upregulation of ObRa, TGF-β1, and Kim-1. In contrast, ObeseZ rats fed with a SoyP exhibited a reduction in NOS-Thr495 phosphorylation and rLPO, as well as an enhanced catalase activity. These findings were associated with a significant reduction of ObRa, TGF-β1, and Kim-1 mRNA levels and urinary Kim-1 protein. Our results show that renoprotection by SoyP in ObeseZ rats is in part mediated by increased NO availability secondary to a reduction in eNOS-T495 phosphorylation and oxidative stress, together with a significant reduction in ObRa and TGF-β expression.
Speed and Temperature Dependences of Mechanotransduction in Afferent Fibers Recorded From the Mouse Saphenous Nerve
Authors: Milenkovic Nevena , Wetzel Christiane , Moshourab Rabih , Lewin Gary R.
Published: September 2008

Here we have systematically characterized the stimulus response properties of mechanosensitive sensory fibers in the mouse saphenous nerve. We tested mechanoreceptors and nociceptors with defined displacement stimuli of varying amplitude and velocity. For each sensory afferent investigated we measured the mechanical latency, which is the delay between the onset of a ramp displacement and the first evoked spike, corrected for conduction delay. Mechanical latency plotted as a function of stimulus strength was very characteristic for each receptor type and was very short for rapidly adapting mechanoreceptors (<11 ms) but very long in myelinated and unmyelinated nociceptors (49–114 ms). Increasing the stimulus speed decreased mechanical latency in all receptor types with the notable exception of C-fiber nociceptors, in which mean mechanical latency was not reduced ≲100 ms, even with very fast ramp stimuli (2,945 μm/s). We examined stimulus response functions and mechanical latency at two different temperatures (24 and 32°C) and found that stimulus response properties of almost all mechanoreceptors were not altered in this range. A notable exception to this rule was found for C-fibers in which mechanical latency was substantially increased and stimulus response functions decreased at lower temperatures. We calculated Q10 values for mechanical latency in C-fibers to be 5.1; in contrast, the Q10 value for conduction velocity for the same fibers was 1.4. Finally, we examined the effects of short-term inflammation (2–6 h) induced by carrageenan on nociceptor and mechanoreceptor sensitivity. We did not detect robust changes in mechanical latency or stimulus response functions after inflammation that might have reflected mechanical sensitization under the conditions tested.
G protein βγ Subunits Modulate the Number and Nature of Exocytotic Fusion Events in Adrenal Chromaffin Cells Independent of Calcium Entry
Authors: Yoon Eun-Ja , Hamm Heidi E. , Currie Kevin P. M.
Published: September 2008

G-protein-coupled receptors (GPCR) play important roles in controlling neurotransmitter and hormone release. Inhibition of voltage-gated Ca2+ channels (Ca2+ channels) by G protein βγ subunits (Gβγ) is one prominent mechanism, but there is evidence for additional effects distinct from those on calcium entry. However, relatively few studies have investigated the Ca2+-channel-independent effects of Gβγ on transmitter release, so the impact of this mechanism remains unclear. We used carbon fiber amperometry to analyze catecholamine release from individual vesicles in bovine adrenal chromaffin cells, a widely used neurosecretory model. To bypass the effects of Gβγ on Ca2+ entry, we stimulated secretion using ionomycin (a Ca2+ ionophore) or direct intracellular application of Ca2+ through a patch pipette. Activation of endogenous GPCR or transient transfection with exogenous Gβγ significantly reduced the number of amperometric spikes (the number of vesicular fusion events). The charge (“quantal size”) and amplitude of the amperometric spikes were also significantly reduced by GPCR/Gβγ. We conclude that independent from effects on calcium entry, Gβγ can regulate both the number of vesicles that undergo exocytosis and the amount of catecholamine released per fusion event. We discuss possible mechanisms by which Gβγ might exert these novel effects including interaction with the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex.
Transient Enhancement of Spike-Evoked Calcium Signaling by a Serotonergic Interneuron
Authors: Hill Evan S. , Sakurai Akira , Katz Paul S.
Published: September 2008

Enhancement of presynaptic Ca2+signals is widely recognized as a potential mechanism for heterosynaptic potentiation of neurotransmitter release. Here we show that stimulation of a serotonergic interneuron increased spike-evoked Ca2+in a manner consistent with its neuromodulatory effect on synaptic transmission. In the gastropod mollusk, Tritonia diomedea, stimulation of a serotonergic dorsal swim interneuron (DSI) at physiological rates heterosynaptically enhances the strength of output synapses made by another swim interneuron, C2, onto neurons in the pedal ganglion. Using intracellular electrophysiological recording combined with real-time confocal imaging of C2 (loaded with Oregon Green Bapta 1), it was determined that DSI stimulation increases the amplitude of spike-evoked Ca2+signals in C2 without altering basal Ca2+signals. This neuromodulatory action was restricted to distal neurites of C2 where synapses with pedal neurons are located. The effect of DSI stimulation on C2 spike-evoked Ca2+signals resembled DSI heterosynaptic enhancement of C2 synapses in several measures: both decayed within 15 s, both were abolished by the serotonin receptor antagonist, methysergide, and both were independent of DSI's depolarizing actions on C2. A brief puff of serotonin could mimic the enhancement of spike-evoked Ca2+signals in the distal neurites of C2, but larger puffs or bath-applied serotonin elicited nonphysiological effects. These results suggest that DSI heterosynaptic enhancement of C2 synaptic strength may be mediated by a local enhancement of spike-evoked Ca2+signals in the distal neurites of C2.
Visual Enhancement for Sports Entertainment by Vision-Based Augmented Reality
Authors: Uematsu Yuko , Saito Hideo
Published: September 2008

This paper presents visually enhanced sports entertainment applications: AR Baseball Presentation System and Interactive AR Bowling System. We utilize vision-based augmented reality for getting immersive feeling. First application is an observation system of a virtual baseball game on the tabletop. 3D virtual players are playing a game on a real baseball field model, so that users can observe the game from favorite view points through a handheld monitor with a web camera. Second application is a bowling system which allows users to roll a real ball down a real bowling lane model on the tabletop and knock down virtual pins. The users watch the virtual pins through the monitor. The lane and the ball are also tracked by vision-based tracking. In those applications, we utilize multiple 2D markers distributed at arbitrary positions and directions. Even though the geometrical relationship among the markers is unknown, we can track the camera in very wide area.
Etch Defect Characterization and Reduction in Hard-Mask-Based Al Interconnect Etching
Authors: Lee Hong-Ji , Hung Che-Lun , Leng Chia-Hao , Lian Nan-Tzu , Young Ling-Wu , Yang Tahone , Chen Kuang-Chao , Lu Chih-Yuan
Published: September 2008

This paper identifies the defect adders, for example, post hard-mask etch residue, post metal etch residue, and blocked etch metal island and investigates the removal characteristics of these defects within the oxide-masked Al etching process sequence. Post hard-mask etch residue containing C atom is related to the hardening of photoresist after the conventional post-RIE ashing at 275∘C. An in situ O2-based plasma ashing on RIE etcher was developed to prevent the photoresist hardening from the high-ashing temperature; followed wet stripping could successfully eliminate such hardened polymeric residue. Post metal etch residue was caused from the attack of the Al sidewall by Cl atoms, and too much CHF3 addition in the Al main etch step passivated the surface of Al resulting in poor capability to remove the Al-containing residue. The lower addition of CHF3 in the Al main etch step would benefit from the residue removal. One possibility of blocked etch metal island creating was due to the micromasking formed on the opening of TiN during the hard-mask patterning. We report that an additional TiN surface pretreatment with the Ar/CHF3/N2 plasmas could reduce the impact of the micromasking residues on blocked metal
etch.
Characterization and Catalytic Performance of Niobic Acid Dispersed over Titanium Silicalite
Authors: Prasetyoko Didik , Ramli Zainab , Endud Salasiah , Nur Hadi
Published: September 2008

Niobic acid,Nb2O5⋅nH2O, has been supported on the titanium silicalite by impregnation method. The obtained materials were characterized by X-ray diffraction, infrared, and ultra-violet—visible diffuse reflectance spectroscopy, temperature programmed reduction, pyridine adsorption, and field emission scanning electron microscopy techniques. It was demonstrated that the tetrahedral titanium species still retained after impregnation of niobic acid. The results revealed that niobium species interacted with hydroxyl groups on the surface of TS-1. The niobium species in the catalysts are predominantly polymerized niobium oxides species or bulk niobium oxide with the octahedral structure. All catalysts showed both Brønsted and Lewis acid sites. The catalysts have been tested for epoxidation of 1-octene with aqueous hydrogen peroxide. It was found that the presence of niobic acid in the catalysts enhanced the rate of the formation of epoxide at the initial reaction time. Diol as a side product was also observed due to the acidic properties of the catalysts.
PPNEMA: A Resource of Plant-Parasitic Nematodes Multialigned Ribosomal Cistrons
Authors: Rubino Francesco , Voukelatou Amalia , De Luca Francesca , De Giorgi Carla , Attimonelli Marcella
Published: September 2008

Plant-parasitic nematodes are important pests of crop plants worldwide, and also among the most difficult animals to identify. Their identification based on nuclear ribosomal DNA (rDNA) cistron (18S, 28S, and 5.8S RNA genes, and internal transcribed spacers, ITS1 and ITS2) is becoming a popular tool. Sequences from nuclear ribosomal RNA repeats have been used to demonstrate the identity of isolates from various hosts and to unravel the relationships of cryptic and complex species. In addition, the availability of RNA sequences allows study of phylogenetic relationships between nematodes, also for more complete understanding of their biology as agricultural pests. PPNEMA is a plant-parasitic nematode bioinformatic resource. It consists of a database of ribosomal cistron sequences from various species grouped according to nematode genera, and a search system allowing data to be extracted according to both text and pattern searching. PPNEMA offers to the scientific community a preprocessed archive of plant parasitic nematode sequences useful for nematologists. It is a tool to retrieve plant nematode multialigned sequences for phylogenetic studies or to recognize a nematode by comparing its rDNA sequence with the PPNEMA available genus specific multialignments.
Theoretical and Numerical Study of Heat Transfer Deterioration in High Performance Light Water Reactor
Authors: Palko David , Anglart Henryk
Published: September 2008

A numerical investigation of the heat transfer deterioration (HTD) phenomena is performed using the low-Re k-ωturbulence model. Steady-state Reynolds-averaged Navier-Stokes equations are solved together with equations for the transport of enthalpy and turbulence. Equations are solved for the supercritical water flow at different pressures, using water properties from the standard IAPWS (International Association for the Properties of Water and Steam) tables. All cases are extensively validated against experimental data. The influence of buoyancy on the HTD is demonstrated for different mass flow rates in the heated pipes. Numerical results prove that the RANS low-Re turbulence modeling approach is fully capable of simulating the heat transfer in pipes with the water flow at supercritical pressures. A study of buoyancy influence shows that for the low-mass flow rates of coolant, the influence of buoyancy forces on the heat transfer in heated pipes is significant. For the high flow rates, buoyancy influence could be neglected and there are clearly other mechanisms causing the decrease in heat transfer at high coolant flow rates.
Stationary Interference Cancellation in Upstream Coordinated DSL Using a Turbo-MMSE Receiver
Authors: Wahibi Issam , Ouzzif Meryem , Le Masson Jérôme , Saoudi Samir
Published: September 2008

We investigate the scenario of an upstream coordinated DSL transmission in presence of spatial-correlated noise. Joint signal processing helps mitigate this noise and reduce internal interference effects between coordinated users. We propose to couple noise whitening with a mean-squared error iterative receiver in order to approach the matched filter bound of the DSL coordinated system. The convergence of the iterative scheme in this scenario is predicted using EXIT charts under realistic transmission conditions.
Numerical Exploration of Kaldorian Macrodynamics: Enhanced Stability and Predominance of Period Doubling and Chaos with Flexible Exchange Rates
Authors: Asada Toichiro , Douskos Christos , Markellos Panagiotis
Published: September 2008

We explore numerically a discrete Kaldorian macrodynamic model of an open economy with flexible exchange rates, focusing on the effects of variation of the model parameters, the speed of adjustment of the goods market α and the degree of capital mobility β, on the stability of equilibrium, and on the possible existence of business cycles. We determine by a numerical grid‐search method the stability region in the parameter space and find that, by comparison to fixed exchange rates, flexible exchange rates cause increased stability of equilibrium with respect to variations of the model parameters. We identify analytically the Hopf‐Neimark bifurcation curve along which business cycles may be generated, as well as the flip bifurcation curve along which period‐doubling cascades leading to chaotic behavior are generated. We find that period‐doubling cascades leading to chaos are the dominant behavior of the system of flexible exchange rates outside the stability region, persisting up to large values of the degree of capital mobility β. Cyclical behavior of noticeable presence is detected for some extreme values of a state parameter. Bifurcation and Lyapunov exponent diagrams are computed illustrating the complex dynamics involved. Examples of attractors and trajectories are presented. The effect of the speed of adaptation of the expected rate on the stability of equilibrium is also briefly discussed. Finally, we explore the special case (Model 2) incorporating the so‐called wealth effect, which in the present case of flexible exchange rates is found to behave similarly to the basic model, contrary to the case of fixed exchange rates in which incorporation of the wealth effect causes an entirely different behavior of the system.
Physical and Spectroscopic Properties ofYb3+-Doped Fluorophosphate Laser Glasses
Authors: Liu Shujiang , Lu Anxian
Published: September 2008

The physical properties including refractive index, Abbe number, nonlinear refractive index, microhardness and thermal expansion coefficient, and spectroscopic properties ofYb3+-doped fluorophosphate laser glasses were investigated. The results show that due to the addition of fluoride, mechanical and thermal properties are promoted, emission cross-sectionσemiis also greatly enhanced. The largest gain coefficientσemi·τm(0.824 pm2·ms) can be obtained with the minimum pump intensityImin(1.112 kw/cm2). This kind ofYb3+-doped fluorophosphate glass is an excellent candidate material forYb3+-doped host for high-power generation.
Decay Heat Removal and Transient Analysis in Accidental Conditions in the EFIT Reactor
Authors: Bandini Giacomino , Meloni Paride , Polidori Massimiliano , Casamirra Maddalena , Castiglia Francesco , Giardina Mariarosa
Published: September 2008

The development of a conceptual design of an industrial-scale transmutation facility (EFIT) of several 100 MW thermal power based on accelerator-driven system (ADS) is addressed in the frame of the European EUROTRANS Integral Project. In normal operation, the core power of EFIT reactor is removed through steam generators by four secondary loops fed by water. A safety-related decay heat removal (DHR) system provided with four independent inherently safe loops is installed in the primary vessel to remove the decay heat by natural convection circulation under accidental conditions which are caused by a loss-of-heat sink (LOHS). In order to confirm the adequacy of the adopted solution for decay heat removal in accidental conditions, some multi-D analyses have been carried out with the SIMMER-III code. The results of the SIMMER-III code have been then used to support the RELAP5 1D representation of the natural circulation flow paths in the reactor vessel. Finally, the thermal-hydraulic RELAP5 code has been employed for the analysis of LOHS accidental scenarios.
High‐Definition X‐Ray Fluorescence: Applications
Authors: Gibson Walter M. , Chen Z. W. , Li Danhong
Published: September 2008

Energy dispersive X‐ray fluorescence (EDXRF) is a well‐established and powerful tool for nondestructive elemental analysis of virtually any material. It is widely used for environmental, industrial, pharmaceutical, forensic, and scientific
research applications to measure the concentration of elemental constituents or contaminants. The fluorescing atoms can be excited by energetic electrons, ions, or photons.
A particular EDXRF method, monochromatic microbeam X‐ray fluorescence (MμEDXRF), has proven to be remarkably powerful in measurement of trace element concentrations and distributions in a large variety of important medical, environmental, and industrial applications. When used with state‐of‐the‐art doubly curved crystal (DCC) X‐ray optics, this technique enables high‐sensitivity, compact, low‐power, safe, reliable, and rugged analyzers for insitu, online measurements in industrial process, clinical, and field settings. This new optic‐enabled MμEDXRF technique is known as high‐definition X‐Ray fluorescence (HD XRF). Selected applications of HD XRF are described in this paper including air particulate analysis, analysis of body fluid contamination at ppb levels, elemental mapping of brain tissue and bone samples, as well as analysis of toxins in toys and other consumer products.
Biomimetic Modeling of Copper Complexes: A Study of Enantioselective Catalytic Oxidation on D‐(+)‐Catechin and L‐(−)‐Epicatechin with Copper Complexes
Authors: Mutti Francesco G. , Pievo Roberta , Sgobba Maila , Gullotti Michele , Santagostini Laura
Published: September 2008

The biomimetic catalytic oxidations of the dinuclear and trinuclear copper(II) complexes versus two catechols, namely, D‐(+)‐catechin
and L‐(−)‐epicatechin to give the corresponding quinones are reported. The unstable quinones were trapped by the nucleophilic reagent, 3‐methyl‐2‐benzothiazolinone hydrazone (MBTH), and have been calculated the molar
absorptivities of the different quinones. The catalytic efficiency is moderate, as inferred by kinetic constants, but the complexes exhibit significant enantio‐differentiating ability towards the catechols, albeit for the dinuclear complexes, this enantio‐differentiating ability is lower. In all cases, the preferred enantiomeric substrate is D‐(+)‐catechin to respect the other catechol, because of the spatial disposition of this substrate.
A Semi‐Stochastic Propagation Model for the Study of Beam Tilting in Cellular Systems
Authors: Baltzis Konstantinos B.
Published: September 2008

Base station antenna downtilt mitigates interference and improves the downlink performance of wireless systems. A semi‐stochastic propagation model is presented and applied to the study of the impact of the base station beam tilting in cellular communications. The two‐ray approximation of the proposed model is described analytically. Beam tilting is evaluated in relation to the base station antenna radiation pattern, the antennas height, the propagation environment, the bit error rate, and the signal‐to‐noise ratio at the receiver front end. Analytically derived expressions for the fading envelopes, the error probability, the optimum tilting angle, and the downlink capacity of a WCDMA system are derived. Theoretical analysis and simulation results are provided to show the characteristics of the model. Comparisons with data in the literature confirm its validity. Furthermore, the effect of beam tilting on system downlink performance in terms of bit error rate and capacity is investigated.
New Pathways for Alimentary Mucositis
Authors: Bowen Joanne M. , Keefe Dorothy M. K.
Published: September 2008

Alimentary mucositis is a major dose-limiting toxicity associated with anticancer treatment. It is responsible for reducing patient quality of life and represents a significant economic burden in oncology. The pathobiology of alimentary mucositis is extremely complex, and an increased understanding of mechanisms and pathway interactions is required to rationally design improved therapies. This review describes the latest advances in defining mechanisms of alimentary mucositis pathobiology in the context of pathway activation. It focuses particularly on the recent genome-wide analyses of regimen-related mucosal injury and the identification of specific regulatory pathways implicated in mucositis development. This review also discusses the currently known alimentary mucositis risk factors and the development of novel treatments. Suggestions for future research directions have been raised.
Radiologic Evaluation of Small Renal Masses (II): Posttreatment Management
Authors: Santos J. , Deltoro C. , Martín M. I. , Marhuenda A.
Published: September 2008

The increase in the detection of small renal masses (SRMs) and their best knowledge leads to a change in the therapeutic management of these lesions. The use of a less aggressive surgical technique or even an expectant attitude is the current tendency, in order to preserve as much renal function as possible. Imaging techniques are essential in the followup of these lesions. It allows us to know the postsurgical changes and possible complications due to treatment and the presence of local recurrence and metastases. Furthermore, a close radiological followup of SRM related to ablative treatments is mandatory. The purpose of this article is to reveal the imaging features of complications due to surgical or ablative treatments, local recurrence and metastasis, as well as their followup.
A Colour Sorting Task Reveals the Limits of the Universalist/Relativist Dichotomy: Colour Categories Can Be Both Language Specific and Perceptual
Authors: Claidière Nicolas , Jraissati Yasmina , Chevallier Coralie
Published: September 2008

We designed a new protocol requiring French adult participants to group a
large number of Munsell colour chips into three or four groups. On one,
relativist, view, participants would be expected to rely on their colour
lexicon in such a task. In this framework, the resulting groups should be
more similar to French colour categories than to other languages categories.
On another, universalist, view, participants would be expected to rely on
universal features of perception. In this second framework, the resulting
groups should match colour categories of three and four basic terms
languages. In this work, we first collected data to build an accurate map of
French colour terms categories (Experiment 1). We went on testing how native
French speakers spontaneously sorted a set of randomly presented coloured
chips and, in line with the relativist prediction, we found that the
resulting colour groups were more similar to French colour categories than
to three and four basic terms languages (Experiment 2). However, the same
results were obtained in a verbal interference condition (Experiment 3),
suggesting that participants rely on language specific and nevertheless
perceptual, colour categories. Collectively, these results suggest that the
universalist/relativist dichotomy is a too narrow one.