bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene expression of the arsenic resistance operon inChromobacterium violaceumATCC 12472
Authors: Azevedo Juliana Simão Nina de , Silva-Rocha Rafael , Silva Artur , Peixe Carepo Marta Sofia , Cruz Schneider Maria Paula
Published: April 2008

Chromobacterium violaceum ATCC 12472 presents an arsRCB-type operon, which is involved in arsenic resistance. The regulating protein of this resistance system (ArsR) does not have the small conserved site (ELCVDCL) to link to the metalloid, as observed in Escherichia coli , and is thus considered to be an atypical ArsR protein, like that observed in Acidithiobacillus ferrooxidans . In the present study, the gene expression profile of the ars operon under induction at different concentrations of arsenite — As(III) — was obtained via real-time PCR (TaqMan), by correlating the threshold cycle (Ct) values of induced and uninduced (control) samples. Through linear regression analysis (R2= 0.9926), the gene expression profile of the ars operon showed clearly that the 0.125 μmol/L concentration of As(III) was sufficient to provoke a 4-fold increase in the resistance system, and a further increase in concentration resulted in an increase of up to 53-fold in transcription rates. The relation between resistance and induction of the ars operon indicates that the increased resistance to As(III) is associated with the increase in the number of transcripts.
Apoptosis induced by lipid-associated membrane proteins fromMycoplasma penetransis mediated by nuclear factor κB activation in mouse macrophage
Authors: Zeng Yanhua , Wu Yimou , Deng Zhongliang , You Xiaoxing , Zhu Cuiming , Yu Minjun , Wan Yanping
Published: April 2008

Mycoplasma penetrans was shown to be involved in alteration of several eukaryotical cells functions and a causative agent in urogenital infectious diseases. Lipid-associated membrane proteins (LAMPs) may be responsible for the pathogenicity of some mycoplamas. In this study, we investigated whether M. penetrans LAMPs have pathogenic potential by inducing apoptosis in mouse macrophages. As analyzed by annexin-V – fluorescein isothiocyanate staining, significant early- and late-stage apoptosis was induced in M. penetrans LAMPs-challenged mouse macrophages. And agarose gel electrophoresis of the DNA of M. penetrans LAMPs-challenged cells revealed a ladder-like pattern of migration of DNA indicative of apoptosis. The possible molecular mechanisms responsible for the induction of apoptosis were also investigated by characterizing the activation of nuclear transcription factor κB (NFκB). NFκB was activated and translocated into the nucleus in mouse macrophages stimulated by M. penetrans LAMPs. The activation of NFκB and M. penetrans LAMPs-induced apoptosis in mouse macrophages was partially inhibited by the NFκB-specific inhibitor pyrrolidine dithiocarbamate. Thus, this study demonstrates that M. penetrans LAMPs may be an important etiological factor owing to their ability to induce apoptosis in mouse macrophages, which is probably mediated through the activation of NFκB.
Identification and characterization of an alternative oxidase in the entomopathogenic fungusMetarhizium anisopliae
Authors: Uribe Daniel , Khachatourians George G.
Published: April 2008

Mitochondria of Metarhizium anisopliae contain an alternative oxidase (AOX), which reduces oxygen to water by accepting electrons directly from ubiquinol. AOX activity is demonstrated in situ as a constitutive enzyme. Greatest activity of AOX appears at the beginning and at the end of the fungal developmental cycle, germination of aerial conidia and the formation of submerged conidia, respectively. Changes in nutritional conditions, e.g., the presence of host insect cuticle or nutrient starvation had no effect on the induction of AOX activity. Antimycin A, an electron transport chain inhibitor, induced AOX activity. Cloning of the AOX DNA and the alignment of the deduced amino acid sequence of a segment of the AOX gene from M. anisopliae shows structural similarities with other AOX sequences with differing levels of variation when compared with homologous sequences from plants, yeasts, and filamentous fungi. Alternative oxidase in entomopathogenic fungi may have a positive contribution to ecological fitness.
A simple restriction fragment PCR approach for discrimination of humanpathogenic Old World animal Orthopoxvirus species
Authors: Huemer Hartwig P. , Hönlinger Bettina , Höpfl Reinhard
Published: April 2008

There are reliable polymerase chain reaction assays available for exclusion of Variola virus from other poxviruses. However, the discrimination of humanpathogenic animal Orthopoxviridae is more challenging because of the high genomic conservation. Based on the variability of the A36R gene, we describe a simple 20 min PCR assay followed by a 1 h digest with 3 different restriction enzymes. This assay enables rapid discrimination between Cowpox virus and Monkeypox virus and discrimination of the most prevalent members of the Vaccinia virus and Camelpox virus. The test was orthopoxvirus specificand did not react with parapox (Orf) virus. Moreover, the amplified fragments were also well suited for additional genotyping by direct DNA sequencing.
Phylogenetic and symbiotic characterization of rhizobial bacteria nodulating Argyrolobium uniflorum in Tunisian arid soils
Authors: Mahdhi M. , de Lajudie P. , Mars M.
Published: April 2008

Forty-two bacterial isolates from root nodules of Argyrolobium uniflorum growing in the arid areas of Tunisia were characterized by phenotypic features, RFLP, and sequencing of PCR-amplified 16S rRNA genes. The isolates were found to be phenotypically diverse. The majority of the isolates tolerated 3% NaCl and grew at temperatures up to 40 °C. Phylogenetically, the new isolates were grouped in the genera Sinorhizobium (27), Rhizobium (13), and Agrobacterium (2). Except for the 2 Agrobacterium isolates, all strains induced nodulation on Argyrolobium uniflorum, but the number of nodules and nitrogen fixation efficiency varied among them. Sinorhizobium sp. strains STM 4034, STM 4036, and STM 4039, forming the most effective symbiosis, are potential candidates for inoculants in revegetalisation programs.
INTERACTIVE MULTI-OBJECTIVE TRANSPORTATION PLANNING DECISIONS USING FUZZY, LINEAR PROGRAMMING
Authors: LIANG TIEN-FU
Published: April 2008

In most real-world situations for transportation planning decision (TPD) problems, environmental coefficients and parameters are imprecise/fuzzy in nature, and the decision maker (DM) generally faces a multi-objective TPD problem in a fuzzy environment. This work develops an interactive fuzzy linear programming (FLP) method for solving TPD problems with fuzzy goals, available supply and forecast demand. The proposed method attempts simultaneously to minimize the total production and transportation costs and the total delivery time with reference to available supply, machine capacities and budget constraints at each source, as well as forecast demand and warehouse space constraints at each destination. In addition, the proposed method provides a systematic framework that facilitates the DM interactively to modify the imprecise data and related parameters until a satisfactory solution is derived. An industrial case is used to demonstrate the feasibility of applying the proposed method to real-world TPD problems. Especially, several significant characteristics of the proposed FLP method are presented in contrast to those of the main TPD methods.
FMCDM FOR PERSONNEL ASSIGNMENT IN TURKISH ARMED FORCES
Authors: AYDIN ÖZLEM
Published: April 2008

This study evaluates the assignment system by FMCDM for Turkish Army Forces (TAF). TAF personnel are assigned to Garrisons (a headquarter or a certain geographical place in Turkey), for fixed periods. Selecting the optimal Garrison is an important problem for personnel, and is based on a number of alternatives and criteria. The system includes eight city centers, evaluated as alternatives. For defining the criteria, a questionnaire is designed and applied to army officers and sergeants. The criteria weights are determined by four randomly selected experts. Experts described the weights depending on their assessments, which may vary depending on their own necessities, experiences and priorities. They used linguistic weights, such as "very good, good, medium, low, very low". Hence, the assessments are away from certainty. This uncertainty implies fuzziness in weights. Besides, the criteria were determined by factor analysis, applied on the responses of the questionnaire, which also gives a sense of uncertainty. In the analysis under imprecision judgements, the criteria weights are presented as trapezoidal fuzzy numbers to get more reasonable and realistic solutions. Ideal and anti-ideal points are calculated for different optimism indexes and the final results are obtained based on these points. It is observed that different optimality indexes changed the rankings of alternatives.
QUANTIFIED DEEP TENDON REFLEX DEVICE, SECOND GENERATION
Authors: LEMOYNE ROBERT , DABIRI FOAD , JAFARI ROOZBEH
Published: April 2008

The deep tendon reflex is a fundamental aspect of neurological examinations. The severity of and degree of recovery from a traumatic brain injury can be assessed by the myotatic stretch reflex. A hyperactive reflex response is correlated with spasticity, which can also be correlated with the degree of damage to the supraspinal input, in essence assessing the severity of traumatic brain injury. The myotatic stretch reflex is clinically evaluated by the National Institute of Neurological Disorders and Stroke (NINDS) reflex scale (0–4); however, this scale lacks temporal data and may also vary in interpretation. The solution is a fully quantified evaluation system of the myotatic stretch reflex, whereby a patellar hammer's force input is based on original potential energy and a microelectromechanical system (MEMS) accelerometer quantifies the output. The MEMS accelerometer is attached to a set anchor point near the ankle. The reflex amplitude is based on the maximum acceleration of the reflex response. The quantified data collected from MEMS accelerometers are transmitted by a portable computer (i.e. a Pocket PC). This paper describes a device that quantitatively evaluates the reflex response using accelerometers and that demonstrates precision for reproducibility.
HIERARCHICAL ANALYSIS AND CLASSIFICATION OF ASYMPTOMATIC AND KNEE OSTEOARTHRITIS GAIT PATTERNS USING A WAVELET REPRESENTATION OF KINETIC DATA AND THE NEAREST NEIGHBOR CLASSIFIER
Authors: MEZGHANI NEILA , BOIVIN KARINE , TURCOT KATIA , AISSAOUI RACHID , HAGMEISTER NICOLA , DE GUISE JACQUES A.
Published: April 2008

The purpose of this study is twofold: (1) to develop a classification method to distinguish between asymptomatic (AS) and knee osteoarthritis (OA) gait patterns using ground reaction force (GRF) measurements, and (2) to investigate OA severity within OA gait patterns. Features were first extracted from the GRF vectors to be used for classification. We investigated a two-level hierarchical classification and analysis method using the nearest neighbor rule. At the first level, the GRF data were classified into two classes: AS and OA. At the second level, the GRF data of OA patients were classified according to the pathology severity. The OA patients were grouped into two OA severity categories according to the Kellgren and Lawrence (KL) scale: KL 1 and KL 2 for one category, and KL 3 and KL 4 for the other. Experiments were conducted using data of 42 cases, 16 AS and 26 pathological. The method discriminated between AS and OA subjects with an accuracy of 38 of 42 cases, and assessed the severity correctly with an accuracy of 20 of 26 cases. These results demonstrated the validity of both, the feature and the classifier, for automatic classification of AS and knee OA gait patterns and for analysis of OA severity.
MATHEMATICAL MODELING OF BLOOD FLOW THROUGH STENOSED TUBE
Authors: VERMA V. K. , SINGH M. P. , KATIYAR V. K.
Published: April 2008

In the present study, blood flow in a stenosed tube is modeled. Blood is assumed to be represented by couple stress fluid. The growth projects into the lumen of the artery and blood flow is disturbed; thus, a potential coupling develops between the growth and the blood flow through the artery. An analysis of the effect of an axially symmetric growth into the lumen of a tube of constant cross-section through which a Newtonian fluid is steadily flowing is presented. The importance of the effect of slip velocity in stenosed tube is highlighted.
AUTOMATED IDENTIFICATION OF EYE DISEASES USING HIGHER-ORDER SPECTRA
Authors: TAN TOK GEE , ACHARYA U. RAJENDRA , NG E. Y. K.
Published: April 2008

A computer-based intelligent system for the classification of eye diseases can be very useful for their diagnosis and management. With age, the incidence of ocular pathology rises, thereby decreasing normal eye function. The most common causes of age-related eye disorders and visual impairment in the elderly are cataracts and iridocyclitis (inflammation of the iris, i.e. the colored part of the eye, and of the ciliary body). For proper care and management of eyes, we need a system which can automatically classify these eye diseases. The method proposed in this study is based on higher-order spectral (HOS) features that capture contour and shape information, while providing robustness to shift, rotation, changes in size, and noise. The parameters are extracted from the raw images using the HOS techniques, and fed to the classifiers for classification. This paper presents the classification of three kinds of eye classes using four-layer feedforward and Gaussian mixture model (GMM) classifiers. Our protocol used 122 subjects who had three different kinds of eye disease conditions. We demonstrated a sensitivity of 100% for the classifier, with a specificity of 90%. Our systems are clinically ready to test on large data sets.
THERMAL TRANSPORT PHENOMENON IN PROCESSED MEAT HEATED BY LASER HEAT SOURCE
Authors: TORII SHUICHI , YANG WEN-JEI
Published: April 2008

The present study deals with the effect of laser radiation on the propagation phenomenon of a thermal wave in processed meat subjected to symmetrical heating on both sides. Laser heating is modeled as an internal heat source with various time characteristics. The Cattaneo heat flux law, together with the energy conservation equation, is solved by a numerical technique based on an explicit scheme, i.e. MacCormack's predictor-corrector scheme. The study concludes that (1) if the absorption coefficient of the continuously operated laser heat source increases, then temperature overshoot occurs in processed meat within a very short period of time; (2) the overshoot and oscillation of thermal wave depend on the frequency of the heat source time characteristics; and (3) the criterion for the occurrence of thermal wave in a thin processed meat is the thickness of the order of about 1 mm.
MASSLESS LIMIT OF GRAVITATIONAL HIGGS MECHANISM
Authors: KAKUSHADZE ZURAB
Published: April 2008

In gravitational Higgs mechanism graviton components acquire mass via spontaneous diffeomorphism breaking by scalar vacuum expectation values. We point out that in the massless limit the resulting theory is not Einstein–Hilbert gravity (EHG) but constrained gravity (CG). Consequently, massive solutions in the massless limit must be compared to those in CG (as opposed to EHG). We discuss spherically symmetric solutions in this context. The Schwarzschild solution in EHG can be coordinate-transformed such that it is also a solution in CG. The resulting solutions are non-perturbative in the asymptotic regime, and are reproduced in the massless limit of asymptotic massive solutions, hence no van Dam–Veltman–Zakharov discontinuity. We point out that higher curvature terms must be included to obtain non-singular spherically symmetric massive solutions and discuss a suitable framework.
DYNAMICALLY BROKEN ANTI-DE SITTER ACTION FOR GRAVITY
Authors: TRESGUERRES ROMUALDO
Published: April 2008

Due to a suitable Higgs mechanism, a standard Anti-de Sitter gauge theory becomes spontaneously broken. The resulting Lorentz invariant gravitational action includes the Hilbert–Einstein term of ordinary Einstein–Cartan gravity with cosmological constant, plus contributions quadratic in curvature and torsion, and a scalar Higgs sector.
SURVIVAL OF NEW FIRMS OWNED BY NATIVES AND IMMIGRANTS IN NORWAY
Authors: VINOGRADOV EVGUENI , ISAKSEN ESPEN J.
Published: April 2008

This paper investigates the survival rates of businesses founded by immigrants and natives in the context of Norway, which has not yet been explored. Based on the relevant literature review, the entrepreneur's human capital and venture's start-up characteristics were expected to explain the differences between the survival rates of businesses established by immigrants and natives. Longitudinal data on 389 firms established in 2002 were analyzed. It was revealed that the survival rate was lower for businesses established by immigrants compared to those established by natives. The analysis suggests that the relatively low survival rate of businesses established by immigrants is partly explained by the perceived novelty of the products and by the fact that immigrants are more likely to locate their businesses in urban areas. Human capital differences were not found to explain immigrant/native differences in business survival rates. Based on these results, several practical implications and suggestions for future research are offered.
THE USE OF DEBT BY BLACK-OWNED FIRMS: RECENT EVIDENCE FROM THE 2003 SURVEY OF SMALL BUSINESS FINANCES
Authors: COLEMAN SUSAN
Published: April 2008

Black-owned firms are growing in terms of both number and economic importance. They play an important role in providing jobs as well as products and services, particularly in urban communities. In spite of this, prior research indicates that black-owned firms experience greater difficulty in securing sources of external capital. This study revisits this issue using newly released data from the 2003 Survey of Small Business Finances. Results reveal that black-owned firms were no less likely to have loans than white-owned firms controlling for firm and owner characteristics. Nevertheless, black-owned firms were still significantly more likely to be turned down for loans and more likely to refrain from applying because they assumed they would be turned down. Further, black firm owners who were approved for loans paid significantly higher rates of interest.
Endogenous heparan sulfate and heparin modulate bone morphogenetic protein-4 signaling and activity
Authors: Khan Shaukat A. , Nelson Matthew S. , Pan Chendong , Gaffney Patrick M. , Gupta Pankaj
Published: April 2008

Bone morphogenetic proteins (BMPs) and their endogenous antagonists are important for brain and bone development and tumor initiation and progression. Heparan sulfate (HS) proteoglycans (HSPG) modulate the activities of BMPs and their antagonists. How glycosaminoglycans (GAGs) influence BMP activity in various malignancies and in inherited abnormalities of GAG metabolism, and the structural features of GAGs essential for modulation of BMP signaling, remain incompletely defined. We examined whether chemically modified soluble heparins, the endogenous HS in malignant cells and the HS accumulated in Hurler syndrome cells influence BMP-4 signaling and activity. We show that both exogenous (soluble) and endogenous GAGs modulate BMP-4 signaling and activity, and that this effect is dependent on specific sulfate residues of GAGs. Our studies suggest that endogenous sulfated GAGs promote the proliferation and impair differentiation of malignant human cells, providing the rationale for investigating whether pharmacological agents that inhibit GAG synthesis or function might reverse this effect. Our demonstration of impairment of BMP-4 signaling by GAGs in multipotent stem cells in human Hurler syndrome identifies a mechanism that might contribute to the progressive neurological and skeletal abnormalities in Hurler syndrome and related mucopolysaccharidoses.
Apical adenosine regulates basolateral Ca2+-activated potassium channels in human airway Calu-3 epithelial cells
Authors: Wang Dong , Sun Ying , Zhang Wei , Huang Pingbo
Published: April 2008

In airway epithelial cells, apical adenosine regulates transepithelial anion secretion by activation of apical cystic fibrosis transmembrane conductance regulator (CFTR) via adenosine receptors and cAMP/PKA signaling. However, the potent stimulation of anion secretion by adenosine is not correlated with its modest intracellular cAMP elevation, and these uncorrelated efficacies have led to the speculation that additional signaling pathways may be involved. Here, we showed that mucosal adenosine-induced anion secretion, measured by short-circuit current ( Isc), was inhibited by the PLC-specific inhibitor U-73122 in the human airway submucosal cell line Calu-3. In addition, the Isc was suppressed by BAPTA-AM (a Ca2+ chelator) and 2-aminoethoxydiphenyl borate (2-APB; an inositol 1,4,5-trisphosphate receptor blocker), but not by PKC inhibitors, suggesting the involvement of PKC-independent PLC/Ca2+ signaling. Ussing chamber and patch-clamp studies indicated that the adenosine-induced PLC/Ca2+ signaling stimulated basolateral Ca2+-activated potassium (KCa) channels predominantly via A2B adenosine receptors and contributed substantially to the anion secretion. Thus, our data suggest that apical adenosine activates contralateral K+ channels via PLC/Ca2+ and thereby increases the driving force for transepithelial anion secretion, synergizing with its modulation of ipsilateral CFTR via cAMP/PKA. Furthermore, the dual activation of CFTR and KCa channels by apical adenosine resulted in a mixed secretion of chloride and bicarbonate, which may alter the anion composition in the secretion induced by secretagogues that elicit extracellular ATP/adenosine release. Our findings provide novel mechanistic insights into the regulation of anion section by adenosine, a key player in the airway surface liquid homeostasis and mucociliary clearance.
Surface change of the mammalian lens during accommodation
Authors: Zamudio Aldo C. , Candia Oscar A. , Kong Chi Wing , Wu Brian , Gerometta Rosana
Published: April 2008

Classical theories suggest that the surface area of the crystalline lens changes during accommodation while the lens volume remains constant. Our recent work challenged this view by showing that the lens volume decreases as the lens flattens during unaccommodation. In this paper we investigate 1) the magnitude of changes in the surface of the in vitro isolated cow lens during simulated accommodation, as well as that of human lens models, determined from lateral photographs and the application of the first theorem of Pappus; and 2) the velocity of the equatorial diameter recovery of prestretched cow and rabbit lenses by using a custom-built software-controlled stretching apparatus synchronized to a digital camera. Our results showed that the in vitro cow lens surface changed in an unexpected manner during accommodation depending on how much tension was applied to flatten the lens. In this case, the anterior surface initially collapsed with a reduction in surface followed by an increase in surface, when the stretching was applied. In the human lens model, the surface increased when the lens unaccommodated. The lens volume always decreases as the lens flattens. An explanation for the unexpected surface change is presented and discussed. Furthermore, we determined that the changes in lens volume, as reflected by the speed of the equatorial diameter recovery in in vitro cow and rabbit lenses during simulated accommodation, occurred within a physiologically relevant time frame (200 ms), implying a rapid movement of fluid to and from the lens during accommodation.
Relationship between low magnesium status and TRPM6 expression in the kidney and large intestine
Authors: Rondón Lusliany J. , Groenestege Wouter M. Tiel , Rayssiguier Yves , Mazur Andrzej
Published: April 2008

The body maintains Mg2+homeostasis by renal and intestinal (re)absorption. However, the molecular mechanisms that mediate transepithelial Mg2+transport are largely unknown. Transient receptor potential melastatin 6 (TRPM6) was recently identified and shown to function in active epithelial Mg2+transport in intestine and kidney. To define the relationship between Mg2+status and TRPM6 expression, we used two models of hypomagnesemia: 1) C57BL/6J mice fed a mildly or severely Mg2+-deficient diet, and 2) mice selected for either low (MgL) or high (MgH) erythrocyte and plasma Mg2+status. In addition, the mice were subjected to a severely Mg2+-deficient diet. Our results show that C57BL/6J mice fed a severely Mg2+-deficient diet developed hypomagnesemia and hypomagnesuria and showed increased TRPM6 expression in kidney and intestine. When fed a Mg2+-adequate diet, MgL mice presented hypomagnesemia and hypermagnesuria, and lower kidney and intestinal TRPM6 expression, compared with MgH mice. A severely Mg2+-deficient diet led to hypomagnesemia and hypomagnesuria in both strains. Furthermore, this diet induced kidney TRPM6 expression in MgL mice, but not in MgH mice. In conclusion, as shown in C57BL/6J mice, dietary Mg2+-restriction results in increased Mg2+(re)absorption, which is correlated with increased TRPM6 expression. In MgL and MgH mice, the inherited Mg2+status is linked to different TRPM6 expression. The MgL and MgH mice respond differently to a low-Mg2+diet with regard to TRPM6 expression in the kidney, consistent with genetic factors contributing to the regulation of cellular Mg2+levels. Further studies of these mice strains could improve our understanding of the genetics of Mg2+homeostasis.
An androgen-inducible proximal tubule-specific Cre recombinase transgenic model
Authors: Li Huiping , Zhou Xiyou , Davis Deborah R. , Xu Di , Sigmund Curt D.
Published: April 2008

To facilitate the study of renal proximal tubules, we generated a transgenic mouse strain expressing an improved Cre recombinase (iCre) under the control of the kidney androgen-regulated protein (KAP) promoter. The transgene was expressed in the kidney of male mice but not in female mice. Treatment of female transgenic mice with androgen induced robust expression of the transgene in the kidney. We confirmed the presence of Cre recombinase activity and the cell specificity by breeding the KAP2-iCRE mice with ROSA26 reporter mice. X-Gal staining of kidney sections from male double transgenic mice showed robust staining in the epithelial cells of renal proximal tubules. β-Gal staining in female mice became evident in proximal tubules after administration of androgen. This model of inducible Cre recombinase in the renal proximal tubule should provide a novel useful tool for studying the physiological significance of genes expressed in the renal proximal tubule. This has advantages over other current models where Cre recombinase expression is constitutive, not inducible.
Antiapoptotic properties of erythropoiesis-stimulating proteins in models of cisplatin-induced acute kidney injury
Authors: Salahudeen Abdulla K. , Haider Naeem , Jenkins John , Joshi Manish , Patel Harnish , Huang Hong , Yang Ming , Zhe He
Published: April 2008

Erythropoietin (Epo) induces erythrocytosis by suppressing erythroid progenitor cell apoptosis through the Janus-activated kinase-signal transducers and activators of transcription (JAK-STAT) pathway. Since apoptosis contributes to cisplatin (CP)-induced nephrotoxicity and Epo receptors (EpoR) are expressed in the kidney, we examined the role of antiapoptosis in recombinant human erythropoietin (rHuEpo)-mediated renal protection. In human renal proximal tubular epithelial (RPTE) cells in culture, rHuEpo, but not inactive rHuEpo (I-rHuEpo), the receptor-binding sites of which are mutated, caused a significant reduction in CP-induced apoptosis at ≥100 U/ml. rHuEpo, but not I-rHuEpo, increased STAT5 and Akt/PKB phosphorylation, demonstrating functional EpoR expression on RPTE cells. Furthermore, the JAK2 inhibitor tyrphostin AG-490 attenuated rHuEpo protection, suggesting a role of the JAK-STAT pathway in rHuEpo-mediated antiapoptosis. In rats, intravenous administration of 5,000 U/kg rHuEpo, but not an equivalent peptide mass of I-rHuEpo, before a single 5.5 mg/kg iv injection of CP, significantly increased hematocrit (Hct) and reduced the CP-induced increase in serum creatinine. Serum creatinine on day 4 was 3.4 ± 0.3, 1.9 ± 0.3, and 3.5 ± 0.4 mg/dl in the CP, CP + rHuEpo, and CP + I-rHuEpo groups, respectively. Similarly, darbepoietin-α (DA), a hyperglycosylated analog of rHuEpo with prolonged in vivo activity when injected at 25 μg/kg iv before CP, significantly increased Hct and reduced serum creatinine. Renal clearance studies based on glomerular filtration rate and renal blood flow confirmed the significant renal protection by DA against CP. Tubular apoptosis and necrosis were significantly reduced in the kidneys of the CP + DA vs. the CP + saline group. Moreover, the equalization of Hct by venesection did not abrogate the DA-mediated renal protection. Administration of DA 48 h after CP injection also conferred significant renal protection. Thus our experiments confirm a role for erythropoiesis-stimulating proteins, including the new analog DA, in limiting CP-induced nephrotoxicity and suggest that antiapoptosis via the Epo-EpoR interaction is an important mechanism for renal protection.
Mouse model of type II Bartter's syndrome. I. Upregulation of thiazide-sensitive Na-Cl cotransport activity
Authors: Cantone Alessandra , Yang Xinbo , Yan Qingshang , Giebisch Gerhard , Hebert Steven C. , Wang Tong
Published: April 2008

ROMK-deficient ( Romk−/−) mice exhibit polyuria, natriuresis, and kaliuresis similar to individuals with type II Bartter's form of hyperprostaglandin E syndrome (HPS; antenatal Bartter's syndrome). In the present study, we utilized both metabolic and clearance studies to define the contributions of specific distal nephron segments to the renal salt wasting in these mice. The effects of furosemide, hydrochlorothiazide, and benzamil on urinary Na+ and K+ excretion in both wild-type ( Romk+/+) and Romk−/− mice were used to assess and compare salt transport by the Na+-K+-2Cl− cotransporter (NKCC2)-expressing thick ascending limb (TAL), the Na+-Cl− cotransporter (NCC)-expressing distal convoluted tubule (DCT1/DCT2), and the epithelial Na+ channel (ENaC)-expressing connecting segment (CNT) and collecting duct (CD), respectively. Whole kidney glomerular filtration rate was reduced by 47% in Romk−/− mice. Furosemide-induced increments in the fractional excretion rate of Na+ and K+ and absolute excretion of Na+ and K+ were significantly blunted in Romk−/− mice, consistent with a major salt transport defect in the TAL. In contrast, hydrochlorothiazide produced an exaggerated natriuresis in Romk−/− mice, indicating upregulation of salt absorption by the DCT. Benzamil resulted in a similar increment in absolute Na excretion in both Romk−/− and Romk+/+, indicating no significant upregulation of Na+ transport by ENaC in ROMK null mice. Moreover, hydrochlorothiazide increased the fractional K+ excretion rate in Romk−/− mice, confirming our recent observation that maxi-K channels contribute to distal K+ secretion in the absence of ROMK.
Na+,K+,2Cl− Cotransport and Intracellular Chloride Regulation in Rat Primary Sensory Neurons: Thermodynamic and Kinetic Aspects
Authors: Rocha-González Héctor I. , Mao Shihong , Alvarez-Leefmans Francisco J.
Published: April 2008

Adult primary afferent neurons are depolarized by GABA throughout their entire surface, including their somata located in dorsal root ganglia (DRG). Primary afferent depolarization (PAD) mediated by GABA released from spinal interneurons determines presynaptic inhibition, a key mechanism in somatosensory processing. The depolarization is due to Cl− efflux through GABAA channels; the outward Cl− gradient is generated by a Na+,K+,2Cl− cotransporter (NKCC) as first established in amphibians. Using fluorescence imaging microscopy we measured [Cl−]i and cell water volume (CWV) in dissociated rat DRG cells (P0–P21) loaded with N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide and calcein, respectively. Basal [Cl−]i was 44.2 ± 1.2 mM (mean ± SE), Cl− equilibrium potential ( ECl) was −27.0 ± 0.7 mV ( n = 75). This [Cl−]i is about four times higher than electrochemical equilibrium. On isosmotic removal of external Cl−, cells lost Cl− and shrank. On returning to control solution, cells reaccumulated Cl− and recovered CWV. Cl− reaccumulation had Na+-dependent (SDC) and Na+-independent (SIC) components. The SIC stabilized at [Cl−]i = 13.2 ± 1.2 mM, suggesting that it was passive ( ECl = −60.5 ± 3 mV). Bumetanide blocked CWV recovery and most (65%) of the SDC (IC50 = 5.7 μM), indicating that both were mediated by NKCC. Active Cl− uptake fell with increasing [Cl−]i and became negligible when [Cl−]i reached basal levels. The kinetics of active Cl− uptake suggests a negative feedback system in which intracellular Cl−regulates its own influx thereby keeping [Cl−]i constant, above electrochemical equilibrium but below the value that would attain if NKCC reached thermodynamic equilibrium.
Application of CBD-Zinc Sulfide Film as an Antireflection Coating on Very Large Area Multicrystalline Silicon Solar Cell
Authors: Gangopadhyay U. , Kim K. , Dhungel S. K. , Saha H. , Yi J.
Published: April 2008

The low-cost chemical bath deposition (CBD) technique is used to prepare CBD-ZnS films as antireflective (AR) coating for multicrystalline silicon solar cells. The uniformity of CBD-ZnS film on large area of textured multicrystalline silicon surface is the major challenge of CBD technique. In the present work, attempts have been made for the first time to improve the rate of deposition and uniformity of deposited film by controlling film stoichiometry and refractive index and also to minimize reflection loss by proper optimization of molar percentage of different chemical constituents and deposition conditions. Reasonable values of film deposition rate
(12.13 Å′/min.), good film uniformity (standard deviation <1), and refractive index (2.35) along with a low percentage of average reflection (6-7%) on a textured mc-Si surface are achieved with proper optimization of ZnS bath. 12.24% efficiency on large area (125 mm × 125 mm) multicrystalline silicon solar cells with CBD-ZnS antireflection coating has been successfully fabricated. The viability of low-cost CBD-ZnS antireflection coating on large area multicrystalline silicon solar cell in the industrial production level is emphasized.
Gel Electrophoresis of Gold-DNA Nanoconjugates
Authors: Pellegrino T. , Sperling R. A. , Alivisatos A. P. , Parak W. J.
Published: April 2008

Gold-DNA conjugates were investigated in detail by a comprehensive gel electrophoresis study based on 1200 gels. A controlled number of single-stranded DNA of different length was attached specifically via thiol-Au bonds to phosphine-stabilized colloidal gold nanoparticles. Alternatively, the surface of the gold particles was saturated with single stranded DNA of different length either specifically via thiol-Au bonds or by nonspecific adsorption. From the experimentally determined electrophoretic mobilities, estimates for the effective diameters of the gold-DNA conjugates were derived by applying two different data treatment approaches. The first method is based on making a calibration curve for the relation between effective diameters and mobilities with gold nanoparticles of known diameter. The second method is based on Ferguson analysis which uses gold nanoparticles of known diameter as reference database. Our study shows that effective diameters derived from gel electrophoresis measurements are affected with a high error bar as the determined values strongly depend on the method of evaluation, though relative changes in size upon binding of molecules can be detected with high precision. Furthermore, in this study, the specific attachment of DNA via gold-thiol bonds to Au nanoparticles is compared to nonspecific adsorption of DNA. Also, the maximum number of DNA molecules that can be bound per particle was determined.
Real-Time Vocal Tract Modelling
Authors: Benkrid A. , Benallal A. , Benkrid K.
Published: April 2008

To date, most speech synthesis techniques have relied upon the representation of the vocal tract by some form of filter, a typical example being linear predictive coding (LPC). This paper describes the development of a physiologically realistic model of the vocal tract using the well-established technique of transmission line modelling (TLM). This technique is based on the principle of wave scattering at transmission line segment boundaries and may be used in one, two, or three dimensions. This work uses this technique to model the vocal tract using a one-dimensional transmission line. A six-port scattering node is applied in the region separating the pharyngeal, oral, and the nasal parts of the vocal tract.
Design and Analysis of Robust Fault Diagnosis Schemes for a Simulated Aircraft Model
Authors: Benini M. , Bonfè M. , Castaldi P. , Geri W. , Simani S.
Published: April 2008

Several procedures for sensor fault detection and isolation (FDI) applied to a simulated model of a commercial aircraft are presented. The main contributions of the paper are related to the design and the optimisation of two FDI schemes based on a linear polynomial method (PM) and the nonlinear geometric approach (NLGA). The FDI strategies are applied to the aircraft model, characterised by tight‐coupled longitudinal and lateral dynamics. The robustness and the reliability properties of the residual generators related to the considered FDI techniques are investigated and verified by simulating a general aircraft reference trajectory. Extensive simulations exploiting the Monte Carlo analysis tool are also used for assessing the overall performance capabilities of the developed FDI schemes, in the presence of turbulence, measurement, and model errors. Comparisons with other disturbance‐decoupling methods for FDI based on neural networks (NNs) and unknown input kalman filter (UIKF) are finally reported.
Atomic Force and Optical Microscopy Characterization of the Deformation of Individual Carbon Nanotubes and Nanofibers
Authors: Bigioni Terry P. , Cruden Brett A.
Published: April 2008

A popular technique for characterizing the mechanical properties of carbon nanotubes is to apply a one‐dimension axial compression and measure its response to the compressive force. At some critical compression, a dramatic decrease in the force is observed. This has previously been attributed to Euler buckling, allowing the elastic modulus to be calculated from the Euler buckling force. We have attached individual plasma enhanced chemical vapor deposition (PECVD) grown carbon nanofibers (CNFs) and thermal chemical vapor deposition (CVD) grown carbon nanotubes (CNTs) to the apex of an atomic force microscope (AFM) cantilever to examine this mechanical response. By combining the force measurements and simultaneous video microscopy, we are able to observe the mechanical deformation and correlate points in the force curve with phenomena such as slipping and bending. Analysis of the mechanical response must therefore be interpreted in terms of bending and/or slipping of a tube compressed by an off‐normal force.
Metallic Nanoparticles Embedded in a Dielectric Matrix: Growth Mechanisms and Percolation
Authors: García del Muro M. , Konstantinovic Z. , Varela M. , Batlle X. , Labarta A.
Published: April 2008

We present a study of the preparation and structural characterization of granular Ag‐ZrO2, Co‐ZrO2, and Au‐ZrO2 thin films grown by pulsed laser deposition (PLD) in a wide range of volume fraction
x of metal (0.08 < xAg < 0.28, 0.06 < xCo < 0.40, and 0.08 < xAu < 0.55). High‐resolution transmission electron microscopy (HRTEM) showed regular distribution of spherical Au, Co, and Au nanoparticles having very sharp interfaces with the amorphous matrix. The structural results are compared aiming to stress the effect of the actual microstructure on the percolation threshold. Two different mechanisms of particle growing as a function of the metal content are evidenced: nucleation and particle coalescence, with their relative significance depending strongly on the type of metal, giving rise to very different values of the percolation threshold (xc(Ag) ~ 0.28, xc(Co) ~ 0.35, and xc(Au) ~ 0.55).
Increasing Efficiency and Quality by Consolidation of Clinical Chemistry and Immunochemistry Systems with MODULARANALYTICSSWA
Authors: Mocarelli Paolo , Horowitz Gary L. , Gerthoux Pier Mario , Cecere Rossana , Imdahl Roland , Ruinemans-Koerts Janneke , Luthe Hilmar , Calatayud Silvia Pesudo , Salve Marie Luisa , Kunst Albert , McGovern Margaret , Ng Katherine , Stockmann Wolfgang
Published: April 2008

MODULARANALYTICSSerum Work Area (in USA Integrated MODULARANALYTICS, MODULARANALYTICSis a trademark of a member of the Roche Group) represents a further approach to automation in the laboratory medicine. This instrument combines previously introduced modular systems for the clinical chemistry and immunochemistry laboratory and allows customised combinations for various laboratory workloads. Functionality, practicability, and workflow behaviour of MODULARANALYTICSSerum Work Area were evaluated in an international multicenter study at six laboratories. Across all experiments, 236000 results from 32400 samples were generated using 93 methods. Simulated routine testing which included provocation incidents and anomalous situations demonstrated good performance and full functionality. Heterogeneous immunoassays, performed on the E-module with the electrochemiluminescence technology, showed reproducibility at the same level of the general chemistry tests, which was well within the clinical demands. Sample carryover cannot occur due to intelligent sample processing. Workflow experiments for the various module combinations, with menus of about 50 assays, yielded mean sample processing times of<38 minutes for combined clinical chemistry and immunochemistry requests;<50 minutes including automatically repeated samples. MODULARANALYTICSSerum Work Area offered simplified workflow by combining various laboratory segments. It increased efficiency while maintaining or even improving quality of laboratory processes.
Building Application-Related Patient Identifiers: What Solution for a European Country?
Authors: Quantin Catherine , Allaert François-André , Avillach Paul , Fassa Maniane , Riandey Benoît , Trouessin Gilles , Cohen Olivier
Published: April 2008

We propose a method utilizing a derived social security number with the same reliability as the social security number. We show the anonymity techniques classically based on unidirectional hash functions (such as the secure hash algorithm (SHA-2) function that can guarantee the security, quality, and reliability of information if these techniques are applied to the Social Security Number). Hashing produces a strictly anonymous code that is always the same for a given individual, and thus enables patient data to be linked. Different solutions are developed and proposed in this article. Hashing the social security number will make it possible to link the information in the personal medical file to other national health information sources with the aim of completing or validating the personal medical record or conducting epidemiological and clinical research. This data linkage would meet the anonymous data requirements of the European directive on data protection.
Central Limit Theorem of the Smoothed Empirical Distribution Functions for Asymptotically Stationary Absolutely Regular Stochastic Processes
Authors: Elharfaoui Echarif , Harel Michel
Published: April 2008

Let
be an estimator obtained by integrating a kernel type density estimator based
on a random sample of size n. A central limit theorem is established for the target
statistic , where the underlying random vector forms an asymptotically stationary
absolutely regular stochastic process, and

is an estimator of a multivariate parameter
ξ
by using a vector of U‐statistics. The results obtained extend or generalize previous
results from the stationary univariate case to the asymptotically
stationary multivariate case. An example of asymptotically
stationary absolutely regular multivariate ARMA process and an example of a useful
estimation of F(ξ) are given in the applications.
Novel Orthogonal Momentum‐Type Particle Swarm Optimization Applied to Solve Large Parameter Optimization Problems
Authors: Liu Jenn-Long , Chang Chao-Chun
Published: April 2008

This study proposes an orthogonal momentum‐type
particle swarm optimization (PSO) that finds good
solutions to global optimization problems using a delta
momentum rule to update the flying velocity of particles
and incorporating a fractional factorial design (FFD) via
several factorial experiments to determine the best
position of particles. The novel combination of the
momentum‐type PSO and FFD is termed as the momentum‐type PSO
with FFD herein. The momentum‐type PSO modifies the
velocity‐updating equation of the original Kennedy and
Eberhart PSO, and the FFD incorporates classical
orthogonal arrays into a velocity‐updating equation for
analyzing the best factor associated with cognitive
learning and social learning terms. Twelve widely used
large parameter optimization problems were used to
evaluate the performance of the proposed PSO with the
original PSO, momentum‐type PSO, and original PSO with
FFD. Experimental results reveal that the proposed
momentum‐type PSO with an FFD algorithm efficiently solves
large parameter optimization problems.
Tracking Moving Optima Using Kalman-Based Predictions
Authors: Rossi Claudio , Abderrahim Mohamed , Díaz Julio César
Published: April 2008

The dynamic optimization problem concerns finding an optimum in a changing environment. In the field of evolutionary algorithms, this implies dealing with a time-changing fitness landscape. In this paper we compare different techniques for integrating motion information into an evolutionary algorithm, in the case it has to follow a time-changing optimum, under the assumption that the changes follow a nonrandom law. Such a law can be estimated in order to improve the optimum tracking capabilities of the algorithm. In particular, we will focus on first order dynamical laws to track moving objects. A vision-based tracking robotic application is used as testbed for experimental comparison.
Genetic Algorithms for Data-Driven Web Question Answering
Authors: Figueroa Alejandro G. , Neumann Günter
Published: April 2008

We present an evolutionary approach for the computation of exact answers to natural languages (NL) questions. Answers are extracted directly from the N–best snippets, which have been identified by a standard Web search engine using NL questions. The core idea of our evolutionary approach to Web question answering is to search for those substrings in the snippets whose contexts are most similar to contexts of already known answers. This context model together with the words mentioned in the NL question are used to evaluate the fitness of answer candidates, which are actually randomly selected substrings from randomly selected sentences of the snippets. New answer candidates are then created by applying specialized operators for crossover and mutation, which either stretch and shrink the substring of an answer candidate or transpose the span to new sentences. Since we have no predefined notion of patterns, our context alignment methods are very dynamic and strictly data-driven. We assessed our system with seven different datasets of question/answer pairs. The results show that this approach is promising, especially when it deals with specific questions.