bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of uteroplacental insufficiency and reducing litter size on maternal mammary function and postnatal offspring growth
Authors: O'Dowd Rachael , Kent Jacqueline C. , Moseley Jane M. , Wlodek Mary E.
Published: December 2007

Human intrauterine growth restriction is often associated with uteroplacental insufficiency and a decline in nutrient and oxygen supply to the fetus. This study investigated the effects of uteroplacental insufficiency and intrauterine growth restriction (Restricted) or reducing litter size for normally grown pups (Reduced Litter) on maternal mammary development and function, milk composition, offspring milk intake, and their resultant effects on postnatal growth. Uteroplacental insufficiency was surgically induced by bilateral uterine vessel ligation on day 18 of gestation in the Wistar Kyoto rat. At birth, a group of sham control rats had their litter size reduced to five (Reduced Litter) to match that of the Restricted group. Cohorts of rats were terminally anesthetized on day 20 of gestation or day 6 of lactation, and a third group was studied throughout lactation. Restricted pups had a lower birth weight (by 16%) and litter size (by 36%) compared with controls, as well as reduced mammary parathyroid hormone-related protein content and milk ionic calcium concentrations associated with reduced total pup calcium. Restricted dams with lower circulating progesterone experienced premature lactogenesis, producing less milk per pup with altered composition compared with controls, further slowing growth during lactation. Reducing litter size of pups born of normal birth weight (Reduced Litter) was associated with decreased pup growth, highlighting the importance of appropriate controls. The present study demonstrates that uteroplacental insufficiency impairs mammary function, compromises milk quality and quantity, and reduces calcium transport into milk, further restraining postnatal growth.
Cortisol stimulates the zinc signaling pathway and expression of metallothioneins and ZnT1 in rainbow trout gill epithelial cells
Authors: Bury Nic R. , Chung Mi Ja , Sturm Armin , Walker Paul A. , Hogstrand Christer
Published: December 2007

Intracellular zinc signaling is important in the control of a number of cellular processes. Hormonal factors that regulate cellular zinc influx and initiate zinc signals are poorly understood. The present study investigates the possibility for cross talk between the glucocorticoid and zinc signaling pathways in cultured rainbow trout gill epithelial cells. The rainbow trout metallothionein A (MTA) gene possesses a putative glucocorticoid response element and multiple metal response elements 1042 base pairs upstream of the start codon, whereas metallothionein B (MTB) and zinc transporter-1 (ZnT1) have multiple metal response elements but no glucocorticoid response elements in this region. Cortisol increased MTA, MTB, and ZnT1 gene expression, and this stimulation was enhanced if cells were treated with cortisol together with zinc. Cells treated with zinc showed increased zinc accumulation, transepithelial zinc influx (apical to basolateral), and intracellular labile zinc concentrations. These responses were also significantly enhanced in cells pretreated with cortisol and zinc. The cortisol-mediated effects were blocked by the glucocorticoid receptor (GR) antagonist RU-486, indicating mediation via a GR. In reporter gene assays, zinc stimulated MTA promoter activity, whereas cortisol did not. Furthermore, cortisol significantly reduced zinc-stimulated MTA promoter activity in cells expressing exogenous rainbow trout GR. These results demonstrate that cortisol enhances cellular zinc uptake, which in turn stimulates expression of MTA, MTB, and ZnT1 genes.
Inhalation of the ETAreceptor antagonist LU-135252 selectively attenuates hypoxic pulmonary vasoconstriction
Authors: Petersen Bodil , Deja Maria , Bartholdy Roland , Donaubauer Bernd , Laudi Sven , Francis Roland C. E. , Boemke Willehad , Kaisers Udo , Busch Thilo
Published: December 2007

Endogenous endothelin (ET)-1 modulates hypoxic pulmonary vasoconstriction (HPV). Accordingly, intravenously applied ETAreceptor antagonists reduce HPV, but this is accompanied by systemic vasodilation. We hypothesized that inhalation of an ETAreceptor antagonist might act selectively on the pulmonary vasculature and investigated the effects of aerosolized LU-135252 in an experimental model of HPV. Sixteen piglets (weight: 25 ± 1 kg) were anesthetized and mechanically ventilated at an inspiratory oxygen fraction (FiO2) of 0.3. After 1 h of hypoxia at FiO20.15, animals were randomly assigned either to receive aerosolized LU-135252 as bolus (0.3 mg/kg for 20 min; n = 8, LU group), or to receive aerosolized saline ( n = 8, controls). In all animals, hypoxia significantly increased mean pulmonary arterial pressure (32 ± 1 vs. 23 ± 1 mmHg; P < 0.01; means ± SE) and increased arterial plasma ET-1 (0.52 ± 0.04 vs. 0.37 ± 0.05 fmol/ml; P < 0.01) compared with mild hyperoxia at FiO20.3. Inhalation of LU-135252 induced a significant and sustained decrease in mean pulmonary arterial pressure compared with controls (LU group: 27 ± 1 mmHg; controls: 32 ± 1 mmHg; values at 4 h of hypoxia; P < 0.01). In parallel, mean systemic arterial pressure and cardiac output remained stable and were not significantly different from control values. Consequently, in our experimental model of HPV, the inhaled ETAreceptor antagonist LU-135252 induced selective pulmonary vasodilation without adverse systemic hemodynamic effects.
Proinsulin C-peptide constricts glomerular afferent arterioles in diabetic mice. A potential renoprotective mechanism
Authors: Nordquist Lina , Lai En Yin , Sjöquist Mats , Patzak Andreas , Persson A. Erik G.
Published: December 2007

Objective: an increased glomerular filtration rate (GFR) has been postulated as a potential mechanism involved in the progression of diabetic nephropathy. Studies suggest that C-peptide exerts a renoprotective effect on diabetes. The peptide decreases hyperfiltration in patients with type 1 diabetes, as well as in diabetic animal models. In this study, we investigated whether C-peptide causes a change in arteriolar diameter. Research Design and Methods: C57-Bl mice were made diabetic by means of a single intravenous injection of alloxan 2 wk prior to the experiment. Age-matched normoglycemic mice served as controls. Afferent arterioles, intact with the glomeruli, were dissected and microperfused. The effect of luminal application of C-peptide, compared with scrambled C-peptide or vehicle, was investigated. The effect of the Rho-kinase inhibitor Y-27632 was also investigated. Results: C-peptide constricted afferent arterioles in diabetic mice by −27% compared with the control value. Normoglycemic arterioles administered C-peptide displayed a delayed and minute response (−4%). Scrambled C-peptide or vehicle administration, whether administered to hyperglycemic or normoglycemic mice, did not induce any effect. Addition of Y-27632 abolished the effect of C-peptide. Conclusion: C-peptide induces constriction of afferent arterioles in diabetic mice. This can reduce enhanced GFR and may be one of the mechanisms in the renoprotective action of C-peptide in diabetes.
Hypothalamic paraventricular nucleus is critical for renal vasoconstriction elicited by elevations in body temperature
Authors: Cham Joo Lee , Badoer Emilio
Published: December 2007

Redistribution of blood from the viscera to the peripheral vasculature is the major cardiovascular response designed to restore thermoregulatory homeostasis after an elevation in body core temperature. In this study, we investigated the role of the hypothalamic paraventricular nucleus (PVN) in the reflex decrease in renal blood flow that is induced by hyperthermia, as this brain region is known to play a key role in renal function and may contribute to the central pathways underlying thermoregulatory responses. In anesthetized rats, blood pressure, heart rate, renal blood flow, and tail skin temperature were recorded in response to elevating body core temperature. In the control group, saline was microinjected bilaterally into the PVN; in the second group, muscimol (1 nmol in 100 nl per side) was microinjected to inhibit neuronal activity in the PVN; and in a third group, muscimol was microinjected outside the PVN. Compared with control, microinjection of muscimol into the PVN did not significantly affect the blood pressure or heart rate responses. However, the normal reflex reduction in renal blood flow observed in response to hyperthermia in the control group (∼70% from a resting level of 11.5 ml/min) was abolished by the microinjection of muscimol into the PVN (maximum reduction of 8% from a resting of 9.1 ml/min). This effect was specific to the PVN since microinjection of muscimol outside the PVN did not prevent the normal renal blood flow response. The data suggest that the PVN plays an essential role in the reflex decrease in renal blood flow elicited by hyperthermia.
Modulation of spontaneous baroreflex control of heart rate and indexes of vagal tone by passive calf muscle stretch during graded metaboreflex activation in humans
Authors: Drew Rachel C. , Bell Martin P. D. , White Michael J.
Published: December 2007

We examined whether spontaneous baroreflex modulation of heart rate and other indexes of cardiac vagal tone could be altered by passive stretch of the human calf muscle during graded concurrent activation of the muscle metaboreflex. Ten healthy subjects performed four trials: a control trial, resting for 1.5 min (0% trial); or 1.5 min of one-legged isometric plantar flexor exercise at 30, 50, and 70% maximal voluntary contraction. The incremental increases in blood pressure (BP) caused were then partially sustained by subsequent local circulatory occlusion (CO). After 3.5 min of CO alone, sustained calf stretch and CO were applied for 3 min. Spontaneous baroreflex sensitivity (SBRS) was progressively decreased with increasing exercise intensity ( P < 0.05). During CO, stretch decreased SBRS and increased BP similarly in all trials ( P < 0.05). Within 15 s of stretch onset, heart rate (HR) increased by 6 ± 1, 6 ± 1, 8 ± 1, and 6 ± 2 beats/min in the 0, 30, 50, and 70% trials, respectively ( P < 0.05), and root mean square of successive differences was decreased from CO-alone levels ( P < 0.05). During the second and third minutes of stretch, HR fell back but remained significantly above CO levels, and common coefficient of variance of R-R interval decreased progressively with increasing prior exercise intensity ( P < 0.05; 70% trial). This suggests that passive stretch of the human calf muscles decreases cardiac vagal outflow irrespective of the levels of BP increase caused by muscle metaboreflex activation and implies that central modulation of baroreceptor input, mediated by the actions of stretch-activated mechanoreceptive muscle afferent fibers, continues.
Circadian- and Light-Dependent Regulation of Resting Membrane Potential and Spontaneous Action Potential Firing of Drosophila Circadian Pacemaker Neurons
Authors: Sheeba Vasu , Gu Huaiyu , Sharma Vijay K. , O'Dowd Diane K. , Holmes Todd C.
Published: December 2007

The ventral lateral neurons (LNvs) of adult Drosophila brain express oscillating clock proteins and regulate circadian behavior. Whole cell current-clamp recordings of large LNvs in freshly dissected Drosophila whole brain preparations reveal two spontaneous activity patterns that correlate with two underlying patterns of oscillating membrane potential: tonic and burst firing of sodium-dependent action potentials. Resting membrane potential and spontaneous action potential firing are rapidly and reversibly regulated by acute changes in light intensity. The LNv electrophysiological light response is attenuated, but not abolished, in cry b mutant flies hypomorphic for the cell-autonomous light-sensing protein CRYPTOCHROME. The electrical activity of the large LNv is circadian regulated, as shown by significantly higher resting membrane potential and frequency of spontaneous action potential firing rate and burst firing pattern during circadian subjective day relative to subjective night. The circadian regulation of membrane potential, spontaneous action potential firing frequency, and pattern of Drosophila large LNvs closely resemble mammalian circadian neuron electrical characteristics, suggesting a general evolutionary conservation of both physiological and molecular oscillator mechanisms in pacemaker neurons.
Homer 1a Suppresses Neocortex Long-Term Depression in a Cortical Layer-Specific Manner
Authors: Ueta Yoshifumi , Yamamoto Ryo , Sugiura Shigeki , Inokuchi Kaoru , Kato Nobuo
Published: December 2007

Homer1a/Vesl-1S is an activity-dependently induced member of the scaffold protein family Homer/Vesl, which is known to link group I metabotropic glutamate receptors (mGluRs) to endoplasmic calcium release channels and to regulate them. Here we studied roles of Homer 1a in inducing long-term depression (LTD) in rat visual cortex slices. Homer 1a protein was injected by diffusion from whole cell patch pipettes. In layer VI pyramidal cells, LTD was reduced in magnitude with Homer 1a. LTD in layer VI was suppressed by applying antagonists of mGluR5, a subtype of group I mGluRs expressed with higher density than mGluR1 in neocortex pyramidal cells, or inositol-1,4,5-triphosphate receptors (IP3Rs) but not that against N-methyl-d-aspartate receptors (NMDARs). In layer II/III or layer V, Homer 1a injection was unable to affect LTD, which is mostly dependent on NMDARs and not on group I mGluRs in these layers. To examine the effects of endogenous Homer 1a, electroconvulsive shock (ECS) was applied. Homer 1a thereby induced, as did Homer 1a injection, reduced LTD magnitude in layer VI pyramidal cells and failed to do so in layer II/III or layer V pyramidal cells. These results indicate that both exo- and endogenous Homer 1a suppressed LTD in a cortical layer-specific manner, and its layer-specificity may be explained by the high affinity of Homer 1a to group I mGluRs.
Handedness Leads to Interhemispheric EEG Asymmetry During Sleep in the Rat
Authors: Vyazovskiy V. V. , Tobler I.
Published: December 2007

Sleep electroencephalographic (EEG) slow-wave activity is increased after wakefulness and decreases during sleep. Regional sleep EEG differences are thought to be a consequence of activation of specific cortical neuronal circuits during waking. We investigated the relationship between handedness and interhemispheric brain asymmetry. Bilateral EEG recordings were obtained from the frontal and occipital cortex in rats with a clear paw preference in a food-reaching task (right, n = 5; left, n = 5). While still naïve to the task, no waking or sleep EEG asymmetry was present. During the food-reaching task, the waking EEG showed significant, substantial power increases in the frontal hemisphere contralateral to the dominant paw in the low theta range (4.5–6.0 Hz). Moreover, the non-REM sleep EEG following feeding bouts was markedly asymmetric, with significantly higher power in the hemisphere contralateral to the preferred paw in frequencies >1.5 Hz. No asymmetry was evident in the occipital EEG. Correlation analyses revealed a positive association between the hemispheric asymmetry during sleep and the degree of preferred use of the contralateral paw during waking in frequencies <9.0 Hz. Our findings show that handedness is reflected in specific, regional EEG asymmetry during sleep. Neuronal activity induced by preferential use of a particular forelimb led to a local enhancement of EEG power in frequencies within the delta and sigma ranges, supporting the hypothesis of use-dependent local sleep regulation. We conclude that inherent laterality is manifested when animals are exposed to complex behavioral tasks, and sleep plays a role in consolidating the hemispheric dominance of the brain.
Delay Analysis of anM/G/1/KPriority Queueing System with Push-out Scheme
Authors: Lee Yutae , Choi Bong Dae , Kim Bara , Sung Dan Keun
Published: December 2007

This paper considers anM/G/1/Kqueueing system with push-out scheme which is one of the loss priority controls at a multiplexer in communication networks. The loss probability for the model with push-out scheme has been analyzed, but the waiting times are not available for the model. Using a set of recursive equations, this paper derives the Laplace-Stieltjes transforms (LSTs) of the waiting time and the push-out time of low-priority messages. These results are then utilized to derive the loss probability of each traffic type and the mean waiting time of high-priority messages. Finally, some numerical examples are provided.
PhotocatalyticH2orO2Evolution over A-Site Deficient Perovskite-Type CompoundsLa1/3MO3(M = Nb, Ta) from Aqueous Solutions
Authors: Li Dunfang , Zheng Jing , Li Zhaosheng , Fan Xiaoxing , Liu Lifei , Zou Zhigang
Published: December 2007

Two compoundsLa1/3MO3(M = Nb, Ta) with A-site deficient perovskite-type structure were synthesized by the solid state reaction method. The photocatalytic properties of these compounds were characterized byH2evolution with Pt cocatalyst fromCH3OH/H2Osolution and byO2evolution fromAgNO3aqueous solution under UV light irradiation. The results showed that the average rate ofH2evolution was about 61.07 μmolh-1forLa1/3NbO3and 95.79 μmolh-1forLa1/3TaO3after 24 hours of reaction time, while the initial rate ofO2evolution was 26.31 μmolh-1forLa1/3NbO3and 16.21 μmolh-1forLa1/3TaO3, respectively.H2evolution was also observed overLa1/3MO3(M = Nb, Ta) with NiO cocatalyst from pure water under UV light irradiation.
Polycrystalline Silicon Thin-Film Solar Cells on AIT-Textured Glass Superstrates
Authors: Widenborg Per I. , Aberle Armin G.
Published: December 2007

A new glass texturing method (AIT—aluminium-induced texturisation) has recently been developed by our group. In the present work, the potential of this method is explored by fabricating PLASMA poly-Si thin-film solar cells on glass superstrates that were textured with the AIT method. Using an interdigitated metallisation scheme with a full-area Al rear contact, PLASMA cells with an efficiency of up to 7% are realised. This promising result shows that the AIT glass texturing method is fully compatible with the fabrication of poly-Si thin-film solar cells on glass using solid phase crystallisation (SPC) of PECVD-deposited amorphous silicon precursor diodes. As such, there are now two distinctly different glass texturing methods—the AIT method and CSG Solar's glass bead method—that are known to be capable of producing efficient SPC poly-Si thin-film solar cells on glass.
Comparative Evaluation of Coolant Mixing Experiments at the ROCOM, Vattenfall, and Gidropress Test Facilities
Authors: Kliem S. , Hemström B. , Bezrukov Y. , Höhne T. , Rohde U.
Published: December 2007

Coolant mixing is an important mitigative mechanism against reactivity accidents caused by local boron dilution. Experiments on coolant mixing were carried out at three different test facilities representing three different reactor types. These are the ROCOM test facility modelling a German KONVOI-type reactor, the Vattenfall test facility being a model of a Westinghouse three-loop PWR, and the Gidropress test facility modelling a VVER-1000 PWR. The scenario of the start-up of the first main coolant pump was investigated in all three facilities. The experiments were accompanied by velocity measurements in the downcomer for the same scenario in the ROCOM and the Vattenfall test facilities. A similar flow structure was found in these measurements in both cases. A maximum of the velocity is measured at the opposite side in regard to the position of the loop with the starting-up pump whilst a recirculation area was found just below this inlet nozzle in both facilities. The analysis of the slug mixing experiments showed also comparable flow behaviour. In accordance with the velocity measurements, the first part of the deboration is also found on the opposite side. In this region, the maximum deboration is measured in all three cases. These maximum values are in the same order of magnitude for nearly identical initial slug volumes.
Some Material Characteristics of Cold-Sprayed Structures
Authors: Champagne Victor K. , Helfritch Dennis J. , Trexler Matthew D.
Published: December 2007

The deposition and consolidation of metal powders by means of cold spray are methods whereby powder particles are accelerated to high velocity through entrainment in a gas undergoing expansion in a rocket nozzle and are subsequently impacted upon a surface. The impacted powder particles form a consolidated structure which can be several centimeters thick. The characteristics of this structure depend on the initial characteristics of the metal powder and upon impact velocity. The influence of impact velocity on strain hardening and porosity are examined. A materials model is proposed for these phenomena, and model calculation is compared with experiment for the cold spraying of aluminum.
Thermodynamic and Structural Characterization of the Copper(II) Complexes of Peptides Containing Both Histidyl and Aspartyl Residues
Authors: Kállay Csilla , Nagy Zoltán , Várnagy Katalin , Malandrinos Gerasimos , Hadjiliadis Nick , Sóvágó Imre
Published: December 2007

Terminally protected pentapeptides with 2 histidines (Ac-HHVGD-NH2and Ac-HVGDH-NH2) and the terminally free peptides containing both internal aspartyl and C-terminal histidyl residues (FDAH and VIDAH) have been synthesized, and copper(II) complexes studied by potentiometric, UV-Vis, CD, and EPR spectroscopic techniques in solution. Both thermodynamic and spectroscopic data reveal that side chain donor atoms of aspartyl and histidyl residues have a significant contribution to the metal binding affinity of peptide molecules. In the case of terminally protected peptides, the role of the imidazole-N donor functions is reflected in the enhanced stability of the 3N and 4N coordinated copper(II) complexes. The amino andβ-carboxylate groups of FDAH and VIDAH create a very effective metal binding site with the (NH2,N−,β-COO−) and (NH2,N−,N−,β-COO−) coordination modes including the N-termini, while the histidine sites are available for the formation of the (Nim,N−,N−) binding mode resulting in the preference of dinuclear complex formation.
Muscle-Specific PPARβ/δAgonism May Provide Synergistic Benefits with Life Style Modifications
Authors: Erol Adnan
Published: December 2007

Peroxisome proliferator-activated receptorβ/δ(PPARβ/δ) has emerged as a powerful metabolic regulator in diverse tissues including fat, skeletal muscle, and the heart. It is now established that activation of PPARβ/δpromotes fatty acid oxidation in several tissues, such as skeletal muscle and adipose tissue. In muscle, PPARβ/δappears to act as a central regulator of fatty acid catabolism. PPARβ/δcontents are increased in muscle during physiological situations such as physical exercise or long-term fasting, characterized by increased fatty acid oxidation. Targeted expression of an activated form of PPARβ/δin skeletal muscle induces a switch to form increased numbers of type I muscle fibers resembling the fiber type transition by endurance training. Activation of PPARβ/δalso enhances mitochondrial capacity and fat oxidation in the skeletal muscle that resembles the effect of regular exercise. Therefore, it is hypothesized that muscle-specific PPARβ/δagonists could be a key strategy to support the poor cardiorespiratory fitness associated with metabolic disorders.
Plasmonics: Manipulating Light at the Subwavelength Scale
Authors: Huang Cheng-Ping , Zhu Yong-Yuan
Published: December 2007

The coupling of light to collective oscillation of electrons on the metal surface allows the creation of surface plasmon-polariton wave. This surface wave is of central interest in the field of plasmonics. In this paper, we will present a brief review of this field, focusing on the plasmonic waveguide and plasmonic transmission. In the plasmonic waveguide, the light can be guided along the metal surface with subwavelength lateral dimensions, enabling the possibility of high-density integration of the optical elements. On the other hand, in the plasmonic transmission, the propagation of light through a metal surface can be tailored with the subwavelength holes, leading to the anomalous transmission behaviors which have received extensive investigations in recent years. In addition, as a supplement to plasmonics in the visible and near-infrared region, the study of THz plasmonics has also been discussed.
Sol-Gel Processing of Nanostructured Inorganic Scintillating Materials
Authors: Nedelec J. M.
Published: December 2007

The development of scintillating materials is believed to reach a new step by controlling their preparation on a nanometric level. Sol-Gel chemistry offers very unique tools for nanoscale mastering of the materials preparation. In particular, shaping of the materials as thin films or nanoparticles offers new application in medical imaging. The control of doping ions dispersion thanks to soft chemistry is also a great advantage of such synthetic routes. In this paper, we will review recent work devoted to the sol-gel preparation of inorganic scintillating materials. We will focus on the new possibilities and advantages offered by sol-gel chemistry for the preparation of new scintillators and improvement of existing ones.
Development of FRET-Based Assays in the Far-Red Using CdTe Quantum Dots
Authors: Chong E. Z. , Matthews D. R , Summers H. D. , Njoh K. L. , Errington R. J. , Smith P. J.
Published: December 2007

Colloidal quantum dots (QDs) are now commercially available in a biofunctionalized form, and Förster resonance energy transfer (FRET) between bioconjugated dots and fluorophores within the visible range has been observed. We are particularly interested in the far-red region, as from a biological perspective there are benefits in pushing to∼700 nm to minimize optical absorption (ABS) within tissue and to avoid cell autofluorescence. We report on FRET between streptavidin- (STV-) conjugated CdTe quantum dots, Qdot705-STV, with biotinylated DY731-Bio fluorophores in a donor-acceptor assay. We also highlight the changes in DY731-Bio absorptivity during the streptavidin-biotin binding process which can be attributed to the structural reorientation. For fluorescence beyond 700 nm, different alloy compositions are required for the QD core and these changes directly affect the fluorescence decay dynamics producing a marked biexponential decay with a long-lifetime component in excess of 100 nanoseconds. We compare the influence of the two QD relaxation routes upon FRET dynamics in the presence of DY731-Bio.
A Consideration of the Constancy of Biomass Density in Plant Populations Undergoing Self-Thinning
Authors: Ogawa Kazuharu
Published: December 2007

The constancy of biomass density was considered in an entire plant populationpby combining two adjacent populationsp1andp2for which the self-thinning rule is assumed to be satisfied independently and each biomass density is also assumed to be the same constant value. Under these assumptions, the biomass densitydin a populationpwas formulated asd=c((km−α+1)(km+1)/(km1−α+1)(k+1)), wherecis biomass density ofp1andp2, andkandmare stand area and density ratio ofp1top2, respectively, andαis the self-thinning slope. In the case ofm≠1, the value ofdin the above equation is always larger than unity. This fact indicates that the biomass density in a combined populationpis not equal to the biomass densitycin each populationp1orp2because of systematic error.
A Finite-Interval Uniqueness Theorem for Bilateral Laplace Transforms
Authors: Chareka Patrick
Published: December 2007

Two or more bilateral Laplace transforms with a complex argument “s” may be equal in a finite vertical interval when, in fact, the transforms correspond to different functions. In this article, we prove that the existence of a bilateral Laplace transform in any finite horizontal interval uniquely determines the corresponding function. The result appears to be new as we could not find it in the literature. The novelty of the result is that the interval need not contain zero, the function need not be nonnegative and need not be integrable. The result has a potential to be useful in the context of fitting probability distributions to data using Laplace transforms or moment generating functions.
Growth and Characterization ofCd1−XZnXTe-Sintered Films
Authors: Kumar V. , Sandhu G. S. , Sharma T. P. , Hussain M.
Published: December 2007

The II-VI polycrystalline semiconducting materials have come under increased scrutiny because of their wide use in the cost reduction of devices for photovoltaic applications.Cd1−XZnXTe is one of the II-VI ternary semiconductor materials whose bandgap can be tailored to any value between 1.48–2.26 eV as X varies from 0 to 1. It is promising material for high-efficiency solar cells, switching, and other optoelectronic devices. Polycrystalline thin film ofCd1−XZnXTe with variable composition (0≤X≤1) has been deposited on ultraclean glass substrates by screen printing method followed by sintering process. The optical and structural properties ofCd1−XZnXTe thin films have been examined. The optical bandgap of these films is studied using reflection spectra in wavelength range of 350–900 nm by using double beam spectrophotometer. The structure of sample was determined from X-ray diffraction patterns. The films were polycrystalline in nature having wurtzite (Hexagonal) structure over the whole range studied. The lattice parameters vary almost linearly with the composition parameterX, following Vegard's law. Sintering is a very simple and viable method compared to other cost-intensive methods. The results of the present investigation will be useful in characterizing the material CdZnTe for its applications in photovoltaics.
Strain-Hardening and Fracture Behavior of Die Cast Magnesium Alloy AM50
Authors: Sun Zhizhong , Zhou Ming , Hu Henry , Li Naiyi
Published: December 2007

Understanding tensile and fracture behaviors of die cast magnesium alloys is of importance for proper design of various emerging automotive applications. In the present study, magnesium alloy AM50 was high pressure die cast into rectangular coupons with section thicknesses of 2, 6, and 10 mm. Effect of section thicknesses on strain-hardening and fracture behaviors of the die cast AM50 was investigated. The results of tensile testing indicate that the tensile properties including yield strength (YS), ultimate tensile strength (UTS), and elongation(Ef)decrease with increasing section thicknesses of die cast AM50. The analysis of true stress versus strain curves shows that the straining hardening rates during the plastic deformation of the alloy increase with decreasing section thicknesses. The observation via SEM fractography illustrates that the fracture behavior of die cast AM50 is influenced by section thicknesses. As the section thickness increases, the fracture of AM50 tends to transit from ductile to brittle mode due to increasing porosity content and coarsening microstructure.
Removing Ocular Movement Artefacts by a Joint Smoothened Subspace Estimator
Authors: Phlypo Ronald , Boon Paul , D'Asseler Yves , Lemahieu Ignace
Published: December 2007

To cope with the severe masking of background cerebral activity in the electroencephalogram (EEG) by ocular movement artefacts, we present a method which combines lower-order, short-term and higher-order, long-term statistics. The joint smoothened subspace estimator (JSSE) calculates the joint information in both statistical models, subject to the constraint that the resulting estimated source should be sufficiently smooth in the time domain (i.e., has a large autocorrelation or self predictive power). It is shown that the JSSE is able to estimate a component from simulated data that is superior with respect to methodological artefact suppression to those of FastICA, SOBI, pSVD, or JADE/COM1 algorithms used for blind source separation (BSS). Interference and distortion suppression are of comparable order when compared with the above-mentioned methods. Results on patient data demonstrate that the method is able to suppress blinking and saccade artefacts in a fully automated way.
Automatic Seizure Detection Based on Time-Frequency Analysis and Artificial Neural Networks
Authors: Tzallas A. T. , Tsipouras M. G. , Fotiadis D. I.
Published: December 2007

The recording of seizures is of primary interest in the evaluation of epileptic patients. Seizure is the phenomenon of rhythmicity discharge from either a local area or the whole brain and the individual behavior usually lasts from seconds to minutes. Since seizures, in general, occur infrequently and unpredictably, automatic detection of seizures during long-term electroencephalograph (EEG) recordings is highly recommended. As EEG signals are nonstationary, the conventional methods of frequency analysis are not successful for diagnostic purposes. This paper presents a method of analysis of EEG signals, which is based on time-frequency analysis. Initially, selected segments of the EEG signals are analyzed using time-frequency methods and several features are extracted for each segment, representing the energy distribution in the time-frequency plane. Then, those features are used as an input in an artificial neural network (ANN), which provides the final classification of the EEG segments concerning the existence of seizures or not. We used a publicly available dataset in order to evaluate our method and the evaluation results are very promising indicating overall accuracy from 97.72% to 100%.
Cellular Damage in Diabetic Wounded Fibroblast Cells following Phototherapy at 632.8, 830, and 1064 nm
Authors: Houreld Nicolette N. , Abrahamse Heidi
Published: December 2007

Objective. This study aimed to establish if laser irradiation induces cellular and genetic damage. Background. Phototherapy has been shown to induce wound healing in diabetic wounds, however little information is known regarding light‐induced damage. Methods. Diabetic wounded fibroblasts were irradiated with 5 or 16 J/cm2 at 632.8, 830, and 1064 nm. Damage was assessed by measuring membrane and DNA damages. Cellular migration was determined by microscopy. Results. Cells irradiated with 5 J/cm2 at 632.8 and 830 nm showed a significant decrease in DNA damage while all cells irradiated with a fluence of 16 J/cm2 showed an increase in membrane and DNA damages. Conclusion. This study showed that the comet assay and LDH release were sensitive enough to pick up changes in laser‐irradiated cells. This study also showed that cellular and genetic damage inflicted on diabetic wounded cells was dependent on dose and wavelength and that cells are able to recover and respond.
Inhibition of Protein Farnesylation Arrests Adipogenesis and Affects PPARγExpression and Activation in Differentiating Mesenchymal Stem Cells
Authors: Rivas Daniel , Akter Rahima , Duque Gustavo
Published: December 2007

Protein farnesylation is required for the activation of multiple proteins involved in cell differentiation and function. In white adipose tissue protein, farnesylation has shown to be essential for the successful differentiation of preadipocytes into adipocytes. We hypothesize that protein farnesylation is required for PPARγ2 expression and activation, and therefore for the differentiation of human mesenchymal stem cells (MSCs) into adipocytes. MSCs were plated and induced to differentiate into adipocytes for three weeks. Differentiating cells were treated with either an inhibitor of farnesylation (FTI-277) or vehicle alone. The effect of inhibition of farnesylation in differentiating adipocytes was determined by oil red O staining. Cell survival was quantified using MTS Formazan. Additionally, nuclear extracts were obtained and prelamin A, chaperon protein HDJ-2, PPARγ, and SREBP-1 were determined by western blot. Finally, DNA binding PPARγactivity was determined using an ELISA-based PPARγactivation quantification method. Treatment with an inhibitor of farnesylation (FTI-277) arrests adipogenesis without affecting cell survival. This effect was concomitant with lower levels of PPARγexpression and activity. Finally, accumulation of prelamin A induced an increased proportion of mature SREBP-1 which is known to affect PPARγactivity. In summary, inhibition of protein farnesylation arrests the adipogenic differentiation of MSCs and affects PPARγexpression and activity.
Fluorescent Nanoparticle-Based Indirect Immunofluorescence Microscopy for Detection ofMycobacterium tuberculosis
Authors: Qin Dilan , He Xiaoxiao , Wang Kemin , Zhao Xiaojun Julia , Tan Weihong , Chen Jiyun
Published: December 2007

A method of fluorescent nanoparticle-based indirect immunofluorescence microscopy (FNP-IIFM) was developed for the rapid detection ofMycobacterium tuberculosis. An anti-Mycobacterium tuberculosisantibody was used as primary antibody to recognizeMycobacterium tuberculosis, and then an antibody binding protein (Protein A) labeled with Tris(2,2-bipyridyl)dichlororuthenium(II) hexahydrate (RuBpy)-doped silica nanoparticles was used to generate fluorescent signal for microscopic examination. Prior to the detection, Protein A was immobilized on RuBpy-doped silica nanoparticles with a coverage of∼5.1×102molecules/nanoparticle. With this method,Mycobacterium tuberculosisin bacterial mixture as well as in spiked sputum was detected. The use of the fluorescent nanoparticles reveals amplified signal intensity and higher photostability than the direct use of conventional fluorescent dye as label. Our preliminary studies have demonstrated the potential application of the FNP-IIFM method for rapid detection ofMycobacterium tuberculosisin clinical samples.
Peroxisome Proliferator-Activated Receptors in Lung Cancer
Authors: Keshamouni Venkateshwar G. , Han ShouWei , Roman Jesse
Published: December 2007

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Their discovery in the 1990s provided insights into the cellular mechanisms involved in the control of energy homeostasis; the regulation of cell differentiation, proliferation, and apoptosis; and the modulation of important biological and pathological processes related to inflammation, among others. Since then, PPARs have become an exciting therapeutic target for several diseases. PPARs are expressed by many tumors including lung carcinoma cells, and their function has been linked to the process of carcinogenesis in lung. Consequently, intense research is being conducted in this area with the hope of discovering new PPAR-related therapeutic targets for the treatment of lung cancer. This review summarizes the research being conducted in this area and focuses on the mechanisms by which PPARs are believed to affect lung tumor cell biology.
Analysis of Silver Ink Bow-Tie RFID Tag Antennas Printed on Paper Substrates
Authors: Merilampi Sari , Ukkonen Leena , Sydänheimo Lauri , Ruuskanen Pekka , Kivikoski Markku
Published: December 2007

In this study, polymeric silver inks, paper substrates, and screen printing were used to produce prototype Bow-Tie tags. Because of increasing interest in applying passive UHF-RFID systems in paper industry, the Bow-Tie antenna used in this study was designed to work through paper. The maximum reliable read ranges of the tags were measured thorough stacked paper and also in air. The analysis and functioning of the antenna design are also discussed. All inks and paper substrates were suitable as antenna material and the prototype tag antennas had good reading performance. The maximum reliable read ranges were quite the same as for copper and aluminum tags studied elsewhere. This means that printed UHF tags are competitive solutions for the identification of simple mass products.
Attenuated Disease in SIV-Infected Macaques Treated with a Monoclonal Antibody against FasL
Authors: Salvato Maria S. , Yin C. Cameron , Yagita Hideo , Maeda Toshihiro , Okumura Ko , Tikhonov Ilia , Pauza C. David
Published: December 2007

Acute SIVmac infection in macaques is accompanied by high levels of plasma viremia that decline with the appearance of viral immunity and is a model for acute HIV disease in man. Despite specific immune responses, the virus establishes a chronic, persistent infection. The destruction of CD4+ and CD4-lymphocyte subsets in macaques contributes to viral persistence and suggests the importance of mechanisms for depleting both infected and uninfected (bystander) cells. Bystander cell killing can occur when FasL binds the Fas receptor on activated lymphocytes, which include T and B cell subpopulations that are responding to the infection. Destruction of specific immune cells could be an important mechanism for blunting viral immunity and establishing persistent infection with chronic disease. We inhibited the Fas pathway in vivo with a monoclonal antibody against FasL (RNOK203). Here we show that treatment with anti-FasL reduced cell death in circulating T and B cells, increased CTL and antibody responses to viral proteins, and lowered the setpoint viremia. By blocking FasL during only the first few weeks after infection, we attenuated SIVmac disease and increased the life span for infected and treated macaques.
Association of C-Reactive Protein, Interleukin-1 Receptor Antagonist and Adiponectin with the Metabolic Syndrome
Authors: Saltevo Juha , Vanhala Mauno , Kautiainen Hannu , Kumpusalo Esko , Laakso Markku
Published: December 2007

This Finnish population-based study, mean age 46 years, evaluates the association of high-sensitivity C-reactive protein (hs-CRP), interleukin-1 receptor antagonist (IL-1Ra), and adiponectin with the NCEP and IDF definitions of metabolic syndrome (MetS). Adiponectin levels were higher, hs-CRP and IL-1Ra levels lower in subjects without MetS compared to subjects with MetS. If MetS was present according to both IDF and NCEP criteria, BMI, waist, triglycerides, hs-CRP, and IL-1Ra were significantly higher compared to subjects who had MetS according to either only IDF or only NCEP criteria. The hs-CRP, IL-1Ra, and adiponectin linearly correlated with the number of the components of MetS according to both definitions. Decreased levels of adiponectin and increased levels of hs-CRP and IL-1Ra are tightly associated with the components of MetS. Individuals who had MetS according to both criteria had the most adverse changes in cardiovascular risk factors.
Photocatalytic Inactivation Effect of Gold-DopedTiO2(Au/TiO2) Nanocomposites on Human Colon Carcinoma LoVo Cells
Authors: Xu Juan , Sun Yi , Zhao Yaomin , Huang Junjie , Chen Chunmei , Jiang Zhiyu
Published: December 2007

The photocatalytic inactivation effecting of gold-dopedTiO2(Au/TiO2) nanocomposites on human colon carcinoma LoVo cells was investigated for the first time. The Au/TiO2samples containing different amounts of Au (1–4 wt%) were prepared by deposition-precipitation (DP) method. These synthesized Au/TiO2nanocomposites were characterized by transmission electron microscopy (TEM) and inductively coupled plasma atomic emission spectroscopy. It was found that the photocatalytic inactivation effect ofTiO2nanoparticles on LoVo cancer cells could be greatly improved by the surface modification of Au nanoparticles. Furthermore, the loading amount of Au on the surface ofTiO2nanoparticles affects the photocatalytic inactivation efficiency strongly, and it was found that the most efficient nanocomposites wereTiO2nanoparticles doped with 2 wt% Au. When 50μg/mL 2 wt% Au/TiO2nanocomposites were used, all of the LoVo cancer cells were killed under the irradiation of UV light (λmax= 365 nm, Intensity = 1.8 mW/cm2) within 100 minutes. But for 50μg/mLTiO2nanoparticles, only 40% cancer cells were killed under the same condition.
Characterization of Conjugated Polymer Poly(fluorene‐co‐thiophene) and Its Application as Photosensitizer of TiO2
Authors: Qiu Rongliang , Song Lin , Zhang Dongdong , Mo Yueqi , Brewer Eric , Huang Xiongfei
Published: December 2007

The copolymer poly(fluorene‐co‐thiophene) (PFT) has strong absorption in the visible light region. In this paper, PFTs with four different thiophene contents were evaluated for their suitability as photosensitizers of TiO2. All four of the PFTs were capable of being excited by light with wavelengths above 455 nm, and all had reductive potentials more negative than the conduction band potential of TiO2. Consequently, it was deemed that transfer of electrons from the excited PFTs to the conduction band of TiO2 was thermodynamically possible. PFTs with higher thiophene content had more electron transitions in the excited state, resulting in increased photocatalytic activity of PFT‐sensitized TiO2. The method used to prepare the combined PFT/TiO2 photocatalyst affected its photocatalytic activity. Best results in this study were achieved by dropwise addition of a tetrahydrofuran solution of PFT to a stirred TiO2/ethanol suspension.
Transtelephonic Electrocardiographic Transmission in the Preparticipation Screening of Athletes
Authors: Samaras Theodoros , Karavasiliadou Savvato , Kouidi Evangelia , Sahalos John N. , Deligiannis Asterios
Published: December 2007

Transtelephonic electrocardiographic transmission (TET) is the most widespread form of telecardiology since it enables clinicians to assess patients at a distance. The purpose of this study was to assess the efficacy and effectiveness of TET either by fixed telephone line (POTS) or by mobile phone in the preparticipation screening of young athletes. A total of 506 players, aged 20.5 6.2 years, from 23 soccer clubs in the prefecture of Thessaloniki, Greece, were physically examined in their playfields by a general practitioner (GP) and had their ECG recorded. In 142 cases, and on the judgment of the GP, the ECG was transmitted via POTS and/or global system for mobile communications (GSM) to a specialised medical centre where it was evaluated by a cardiologist. The mean total time for recording, storing, and transmitting the ECG was four minutes per subject. It was found that the success rate for transmission at first attempt was similar for both fixed and mobile networks, that is, 93% and 91%, respectively. The failure rate in the GSM network was correlated to the reception level at the site of transmission. Only in about half ( = 74) of the transmitted ECGs did the cardiologist confirm “abnormal” findings, although in 16, they were considered to be clinically insignificant. Consequently, 58 athletes were referred for further medical examination. Our results indicate that TET (either by fixed telephone line or by mobile phone) can ensure valid, reliable, and objective measurements, and significantly contribute to the application of medical screening in a great number of athletes. Therefore, it is recommended as an alternative diagnostic tool for the preparticipation screening of athletes living in remote areas.
Genetic Polymorphisms of Peroxisome Proliferator‐Activated Receptors and the Risk of Cardiovascular Morbidity and Mortality in a Community‐Based Cohort in Washington County, Maryland
Authors: Gallicchio L. , Kalesan Bindu , Huang Han-Yao , Strickland Paul , Hoffman Sandra C. , Helzlsouer Kathy J.
Published: December 2007

The primary aim of this study was to examine prospectively the associations between 5 peroxisome proliferator‐activated receptor (PPAR) single nucleotide polymorphisms (SNPs) and cardiovascular morbidity and mortality in a community‐based cohort study in Washington County, Maryland. Data were analyzed from 9,364 Caucasian men and women participating in CLUE‐II. Genotyping on 5 PPAR polymorphisms was conducted using peripheral DNA samples collected in 1989. The followup period was from 1989 to 2003. The results showed that there were no statistically significant associations between the PPAR SNPs and cardiovascular deaths or events. In contrast, statistically significant age‐adjusted associations were observed for PPARG rs4684847 with both baseline body mass and blood pressure, and for PPARG rs709158, PPARG rs1175543, and PPARD rs2016520 with baseline cholesterol levels. Future studies should be conducted to confirm these findings and to explore the associations in populations with greater racial and ethnic diversity.