bluuebunny/crossref_metadata_2025 huggingface dataset:
Le spectre des états électroniques de Kr I mesuré par spectrométrie électronique
Authors: Delage A. , Carette J.-D.
Published: September 2009

The spectrum of electronic states of krypton I has been measured by inelastic scattering of monoenergetic electrons with the aid of an electron spectrometer which has a high resolving power, ΔE/E = 0.02. Electron energy loss spectra have allowed us to detect and identify numerous electronic states of krypton I for the first time by the means of this experimental method. The relative heights of the peaks corresponding to an energy loss, which are related to the probability of excitation of the atom by electron impact to a given state, have been measured from experimental data as a function of the energy incident electrons and as a function of the scattering angle.
A Molecular Beam Electric Resonance Study of the Hyperfine Λ Doubling Spectrum of OH, OD, SH, and SD
Authors: Meerts W. L. , Dymanus A.
Published: September 2009

The molecular beam electric resonance method was employed to obtain a complete set of hyperfine Λ doubling transitions of the free radicals OH, OD, SH, and SD. The observed spectra could be explained very well by the degenerate perturbation theory adapted to the 2Π state. The experimental results include fine and hyperfine coupling constants, the electric dipole moments could be explained very well by the degenerate perturbation theory adapted to the 2Π state. The constants agree well with ab initio calculations.
New ab initio Potential Energy Curve and Vibrational Levels for the B1Σu+ State of the Hydrogen Molecule
Authors: Kotos W. , Wolniewicz L.
Published: September 2009

The Born–Oppenheimer potential energy curve for the B1Σu+ state of the hydrogen molecule has been computed using a wave-function in the form of an 88 term expansion in elliptic coordinates and including the interelectronic distance. At R = Re the computed energy is 5.2 cm−1 lower than the previous most accurate value, in agreement with the prediction by Dabrowski and Herzberg. The new potential energy curve, with the previously computed adiabatic corrections, has been used to calculate the vibrational levels for H2, HD, and D2. The resulting dissociation energies differ from the experimental values by less than 1 cm−1. The discrepancies between the theoretical and experimental energies for various vibrational levels amount up to 12 cm−1 for H2 and 8 cm−1 for D2. Their analysis suggests that most of the discrepancy is due to the nonadiabatic effects, but partly also to incomplete convergence of the Born–Oppenheimer potential energy curve, especially at large internuclear separations.
POSSIBLE TRANSPORT INSIDE AN ANNULUS FILLED WITH SOLID HELIUM OF PARTIAL SUPERSOLIDITY
Authors: CHU KWANG-HUA W.
Published: September 2009

We obtain the possible transport in an annulus filled with solid helium of which parts are of supersolidity near the interface. Our transport results qualitatively resemble those recently reported measurements.
TRAPPED PHONON IN ACOUSTIC METAMATERIAL
Authors: ZENG LUNWU , DAI CUNLI , YIN WENQING
Published: September 2009

We derive an analytic expression for the Goos–Hänchen shift experienced by an acoustic wave that is totally reflected at the interface between a negative-refractive-index acoustic medium and a positive-index acoustic medium. Upon obtaining the condition necessary for phonon-trapping in a three-layer heterostructure, we introduce a design for an "acoustic clepsydra" by using a suitable acoustic heterostructure.
SUPER-DISPERSIVE LONG WAVE HIERARCHY AND ITS SUPER-HAMILTONIAN STRUCTURES
Authors: YANG HONG-WEI , DONG HUAN-HE , LI ZHU
Published: September 2009

Super-dispersive long wave hierarchy is obtained by use of the Lie super-algebra B(0, 1), then the super-Hamiltonian structure of the above system is given by the associated supertrace identity. The method can be used to produce the super-Hamiltonian structures of the other superintegrable systems.
SUPER-BURGERS SOLITON HIERARCHY AND ITS SUPER-HAMILTONIAN STRUCTURE
Authors: LI ZHU , YANG HONGWEI , DONG HUANHE
Published: September 2009

A super-Burgers hierarchy and its super-Hamiltonian structure is obtained respectively based on Lie super-algebra and is associated with super-trace identity.
Glutamine enhances heat shock protein 70 expression via increased hexosamine biosynthetic pathway activity
Authors: Hamiel Christine R. , Pinto Shanti , Hau Ann , Wischmeyer Paul E.
Published: September 2009

Glutamine (GLN) plays a key role in cellular protection following injury via enhancement of heat shock protein 70 (HSP70). The pathway by which GLN enhances HSP70 is unknown. GLN is a key substrate for the hexosamine biosynthetic pathway (HBP), which has been shown to induce HSP70. We sought to explore the role of the HBP in GLN-mediated HSP70 expression. Both chemical inhibitors and small interfering (si)RNA knockdown of key HBP enzymes were used in mouse embryonic fibroblast cells to determine the effects of the HBP on HSP70 expression. The O-glycosylation, nuclear translocation, and transcriptional activation of heat shock factor-1 (HSF-1) and Sp1 were evaluated using immunoprecipitation, Western blotting, and luciferase assays. HSP70 expression levels were evaluated via ELISA and Western blotting. GLN augmented HBP activity before and after heat stress (HS). Chemical inhibition of HBP enzymes reduced GLN-mediated HSP70 expression. Specific siRNA targeting of the key HBP enzyme UDP- N-acetylglucosamine (GlcNAc): polypeptide- O-β-acetylglucosaminyltransferase (OGT) blocked GLN-mediated HSP70 expression and attenuated GLN-mediated cellular protection post-HS. Chemical and siRNA attenuation of the HBP blocked GLN-induced nuclear translocation of Sp1 and HSF-1, which are key to maximal HSP70 expression. Finally, immunoprecipitation revealed HSF-1 was O-glycosylated, and GLN enhanced this effect. These results suggest that metabolism of GLN via the HBP enhances HSP70 expression. This effect appears to be mediated via O-glycosylation, nuclear translocation, and transcriptional activation of Sp1 and HSF-1. This is an important mechanistic description of a pathway that appears responsible for GLN-mediated HSP70 expression.
PTH-induced internalization of apical membrane NaPi2a: role of actin and myosin VI
Authors: Blaine Judith , Okamura Kayo , Giral Hector , Breusegem Sophia , Caldas Yupanqui , Millard Andrew , Barry Nicholas , Levi Moshe
Published: September 2009

Parathyroid hormone (PTH) plays a critical role in the regulation of renal phosphorous homeostasis by altering the levels of the sodium-phosphate cotransporter NaPi2a in the brush border membrane (BBM) of renal proximal tubular cells. While details of the molecular events of PTH-induced internalization of NaPi2a are emerging, the precise events governing NaPi2a removal from brush border microvilli in response to PTH remain to be fully determined. Here we use a novel application of total internal reflection fluorescence microscopy to examine how PTH induces movement of NaPi2a out of brush border microvilli in living cells in real time. We show that a dynamic actin cytoskeleton is required for NaPi2a removal from the BBM in response to PTH. In addition, we demonstrate that a myosin motor that has previously been shown to be coregulated with NaPi2a, myosin VI, is necessary for PTH-induced removal of NaPi2a from BBM microvilli.
Whey protein potentiates the intestinotrophic action of glucagon-like peptide-2 in parenterally fed rats
Authors: Liu Xiaowen , Murali Sangita G. , Holst Jens J. , Ney Denise M.
Published: September 2009

Glucagon-like peptide-2 (GLP-2) is a nutrient-regulated intestinotrophic hormone derived from proglucagon in the distal intestine. Enteral nutrients (EN) potentiate the action of GLP-2 to reverse parenteral nutrition (PN)-induced mucosal hypoplasia. The objective was to determine what enteral protein component, casein, soy, or whey protein, potentiates the intestinal growth response to GLP-2 in rats with PN-induced mucosal hypoplasia. Rats received PN and continuous intravenous infusion of GLP-2 (100 μg/kg/day) for 7 days. Six EN groups received PN+GLP-2 for days 1–3 and partial PN+GLP-2 plus EN for days 4–7. EN was provided by ad libitum intake of a semielemental liquid diet with different protein sources: casein, hydrolyzed soy, whey protein concentrate (WPC), and hydrolyzed WPC+casein. Controls received PN+GLP-2 alone. EN induced significantly greater jejunal sucrase activity and gain of body weight, and improved feed efficiency compared with PN+GLP-2 alone. EN induced greater ileal proglucagon expression, increased plasma concentration of bioactive GLP-2 by 35%, and reduced plasma dipeptidyl peptidase IV (DPP-IV) activity compared with PN+GLP-2 alone, P < 0.05. However, only whey protein, and not casein or soy, potentiated the ability of GLP-2 to reverse PN-induced mucosal hypoplasia and further increase ileal villus height, crypt depth, and mucosa cellularity compared with PN+GLP-2 alone, P < 0.05. The ability of whey protein to induce greater mucosal surface area was associated with decreased DPP-IV activity in ileum and colon compared with casein, soy, or PN+GLP-2 alone, P < 0.05. In conclusion, whey protein potentiates the action of GLP-2 to reverse PN-induced mucosal hypoplasia in association with decreased intestinal DPP-IV activity.
Physiological response to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups: metabolic rates, energy reserve utilization, and water fluxes
Authors: Verrier Delphine , Groscolas René , Guinet Christophe , Arnould John P. Y.
Published: September 2009

Surviving prolonged fasting requires various metabolic adaptations, such as energy and protein sparing, notably when animals are simultaneously engaged in energy-demanding processes such as growth. Due to the intermittent pattern of maternal attendance, subantarctic fur seal pups have to repeatedly endure exceptionally long fasting episodes throughout the 10-mo rearing period while preparing for nutritional independence. Their metabolic responses to natural prolonged fasting (33.4 ± 3.3 days) were investigated at 7 mo of age. Within 4–6 fasting days, pups shifted into a stage of metabolic economy characterized by a minimal rate of body mass loss (0.7%/day) and decreased resting metabolic rate (5.9 ± 0.1 ml O2·kg−1·day−1) that was only 10% above the level predicted for adult terrestrial mammals. Field metabolic rate (289 ± 10 kJ·kg−1·day−1) and water influx (7.9 ± 0.9 ml·kg−1·day−1) were also among the lowest reported for any young otariid, suggesting minimized energy allocation to behavioral activity and thermoregulation. Furthermore, lean tissue degradation was dramatically reduced. High initial adiposity (>48%) and predominant reliance on lipid catabolism likely contributed to the exceptional degree of protein sparing attained. Blood chemistry supported these findings and suggested utilization of alternative fuels, such as β-hydroxybutyrate and de novo synthesized glucose from fat-released glycerol. Regardless of sex and body condition, pups tended to adopt a convergent strategy of extreme energy and lean body mass conservation that appears highly adaptive for it allows some tissue growth during the repeated episodes of prolonged fasting they experience throughout their development.
Changes of renal AQP2, ENaC, and NHE3 in experimentally induced heart failure: response to angiotensin II AT1receptor blockade
Authors: Lütken Sophie C. , Kim Soo Wan , Jonassen Thomas , Marples David , Knepper Mark A. , Kwon Tae-Hwan , Frøkiær Jørgen , Nielsen Søren
Published: September 2009

Heart failure (HF) was induced by ligation of the left anterior descending artery (LAD). Left ventricular end-diastolic pressure (LVEDP) >25 mmHg (at day 23 after LAD ligation) was the inclusion criterion. The rats were divided into three groups: sham-operated (Sham, n = 23, LVEDP: 5.6 ± 0.6 mmHg), HF ( n = 14, LVEDP: 29.4 ± 1.4 mmHg), and candesartan (1 mg·kg−1·day−1sc)-treated HF (HF + Can, n = 9, LVEDP: 29.2 ± 1.2 mmHg). After 7 days (i.e., 29 days after LAD ligation) semiquantitative immunoblotting revealed increased abundance of inner medulla aquaporin-2 (AQP2) and AQP2 phosphorylated at Ser256(p-AQP2) in HF. There was also markedly enhanced apical targeting of AQP2 and p-AQP2 in inner medullary collecting duct (IMCD) in HF compared with Sham rats, shown by immunocytochemistry. Candesartan treatment significantly reversed the increases in both AQP2 and p-AQP2 expression and targeting. In contrast, there were only modest changes in other collecting duct segments. Semiquantitative immunoblots revealed increased expression of type 3 Na+/H+exchanger (NHE3) and Na+-K+-2Cl−cotransporter (NKCC2) in kidneys from HF compared with Sham rats: both effects were reversed or prevented by candesartan treatment. The protein abundance of α-epithelial sodium channel (α-ENaC) was increased while β-ENaC and γ-ENaC expression was decreased in the cortex and outer stripe of the outer medulla in HF compared with Sham rats, which was partially reversed by candesartan treatment. These findings strongly support an important role of angiotensin II in the pathophysiology of renal water and sodium retention associated with HF.
Oxidative stress-induced JNK activation contributes to proinflammatory phenotype of aging diabetic mesangial cells
Authors: Wu Jin , Mei Changlin , Vlassara Helen , Striker Gary E. , Zheng Feng
Published: September 2009

Chronic inflammation and increased oxidative stress (OS) play an important role in diabetic nephropathy progression. Herein, we show that mesangial cells from streptozotocin-induced aging diabetic mice, a model of progressive diabetic nephropathy, exhibited increased OS and a proinflammatory phenotype characterized by elevated chemokines and ICAM-1 expression. This phenotypic change was consistent with the extensive inflammatory lesions present in aging diabetic kidneys and was not found in mesangial cells from old and young controls or young diabetic mice. Activation of the c-Jun NH2-terminal kinase (JNK) pathway was a likely contributor to the proinflammatory phenotype of aging diabetic mesangial cells since 1) phosphorylated JNK levels and JNK kinase activity were increased in these cells, 2) suppression of JNK significantly decreased monocyte chemoattractant protein-1 (MCP-1) production in these cells, and 3) activation of JNK in normal mesangial cells induced inflammation. Elevated OS in aging diabetic mesangial cells may be a cause of JNK activation and inflammation, because antioxidant treatment decreased JNK phosphorylation and MCP-1 production. Additionally, decreased expression of mitogen-activated protein kinase phosphatase 5 (MKP5) may also contribute to increased JNK and inflammation in aging diabetic mesangial cells since overexpression of MKP5 in these cells normalized phosphorylated JNK levels and reversed the proinflammatory phenotype. Moreover, knocking down of MKP5 expression in old control mesangial cells resulted in JNK activation and MCP-1 production, a phenotype seen in aging diabetic mesangial cells. Interestingly, MKP5 phosphatase activity was diminished by free radicals in vitro. Thus, OS may induce inflammation in mesangial cells by activating JNK through either a direct activation of JNK or indirectly by suppression of MKP5 activity. Proinflammatory phenotype of mesangial cells may contribute to chronic inflammatory lesions and disease progression of aging diabetic mice.
Cholesterol induces renal vasoconstriction and anti-natriuresis by inhibiting nitric oxide production in anesthetized rats
Authors: Kopkan Libor , Khan Md Abdul H. , Lis Agnieszka , Awayda Mouhamed S. , Majid Dewan S. A.
Published: September 2009

Although hypercholesterolemia is implicated in the pathophysiology of many renal disorders as well as hypertension, its direct actions in the kidney are not yet clearly understood. In the present study, we evaluated renal responses to administration of cholesterol (8 μg·min−1·100 g body wt−1; bound by polyethylene glycol) into the renal artery of anesthetized male Sprague-Dawley rats. Total renal blood flow (RBF) was measured by a Transonic flow probe, and glomerular filtration rate (GFR) was determined by Inulin clearance. In control rats ( n = 8), cholesterol induced reductions of 10 ± 2% in RBF [baseline (b) 7.6 ± 0.3 μg·min−1·100 g−1], 17 ± 3% in urine flow (b, 10.6 ± 0.9 μg·min−1·100 g−1), 29 ± 3% in sodium excretion (b, 0.96 ± 0.05 μmol·min−1·100 g−1) and 24 ± 2% in nitrite/nitrate excretion (b, 0.22 ± 0.01 nmol·min−1·100 g−1) without an appreciable change in GFR (b, 0.87 ± 0.03 ml·min−1·100 g−1). These renal vasoconstrictor and anti-natriuretic responses to cholesterol were absent in rats pretreated with nitric oxide (NO) synthase inhibitor, nitro-l-arginine methylester (0.5 μg·min−1·100 g−1; n = 6). In rats pretreated with superoxide (O2−) scavenger tempol (50 μg·min−1·100 g−1; n = 6), the cholesterol-induced renal responses remained mostly unchanged, although there was a slight attenuation in anti-natriuretic response. This anti-natriuretic response to cholesterol was abolished in furosemide-pretreated rats (0.3 μg·min−1·100 g−1; n = 6) but remained unchanged in amiloride-pretreated rats (0.2 μg·min−1·100 g−1; n = 5), indicating that Na+/K+/2Cl− cotransport is the dominant mediator of this effect. These data demonstrate that cholesterol-induced acute renal vasoconstrictor and antinatriuretic responses are mediated by a decrease in NO production. These data also indicate that tubular effect of cholesterol on sodium reabsorption is mediated by the furosemide sensitive Na+/K+/2Cl− cotransporter.
Angiotensin II and hypertonicity modulate proximal tubular aquaporin 1 expression
Authors: Bouley Richard , Palomino Zaira , Tang Shiow-Shih , Nunes Paula , Kobori Hiroyuki , Lu Hua A. , Shum Winnie W. , Sabolic Ivan , Brown Dennis , Ingelfinger Julie R. , Jung Flavia F.
Published: September 2009

Aquaporin 1 (AQP1) is the major water channel in the renal proximal tubule (PT) and thin descending limb of Henle, but its regulation remains elusive. Here, we investigated the effect of ANG II, a key mediator of body water homeostasis, on AQP1 expression in immortalized rat proximal tubule cells (IRPTC) and rat kidney. Real-time PCR on IRPTC exposed to ANG II for 12 h revealed a biphasic effect AQP1 mRNA increased dose dependently in response to 10−12 to 10−8 M ANG II but decreased by 50% with 10−7 M ANG II. The twofold increase of AQP1 mRNA in the presence of 10−8 M ANG II was abolished by the AT1 receptor blocker losartan. Hypertonicity due to either NaCl or mannitol also upregulated AQP1 mRNA by three- and twofold, respectively. Immunocytochemistry and Western blotting revealed a two- to threefold increase in AQP1 protein expression in IRPTC exposed concomitantly to ANG II (10−8M) and hypertonic medium (either NaCl or mannitol), indicating that these stimuli were not additive. Three-dimensional reconstruction of confocal images suggested that AQP1 expression was increased by ANG II in both the apical and basolateral poles of IRPTC. In vivo studies showed that short-term ANG II infusion had a diuretic effect, while this effect was attenuated after several days of ANG II infusion. After 10 days, we observed a twofold increase in AQP1 expression in the PT and thin descending limb of Henle of ANG II-infused rats that was abolished when rats were treated with the selective AT1-receptor antagonist olmesartan. Thus ANG II increases AQP1 expression in vitro and in vivo via direct interaction with the AT1 receptor, providing an important regulatory mechanism to link PT water reabsorption to body fluid homeostasis via the renin-angiotensin system.
Sphingosine-1-Phosphate Elicits Receptor-Dependent Calcium Signaling in Retinal Amacrine Cells
Authors: Crousillac Scott , Colonna Jeremy , McMains Emily , Dewey Jill Sayes , Gleason Evanna
Published: September 2009

Evidence is emerging indicating that sphingosine-1-phosphate (S1P) participates in signaling in the retina. To determine whether S1P might be involved in signaling in the inner retina specifically, we examine the effects of this sphingolipid on cultured retinal amacrine cells. Whole cell voltage-clamp recordings reveal that S1P activates a cation current that is dependent on signaling through Giand phospholipase C. These observations are consistent with the involvement of members of the S1P receptor family of G-protein-coupled receptors in the production of the current. Immunocytochemistry and PCR amplification provide evidence for the expression of S1P1R and S1P3R in amacrine cells. The receptor-mediated channel activity is shown to be highly sensitive to blockade by lanthanides consistent with the behavior of transient receptor potential canonical (TRPC) channels. PCR products amplified from amacrine cells reveal that TRPCs 1 and 3–7 channel subunits have the potential to be expressed. Because TRPC channels provide a Ca2+entry pathway, we asked whether S1P caused cytosolic Ca2+elevations in amacrine cells. We show that S1P-dependent Ca2+elevations do occur in these cells and that they might be mediated by S1P1R and S1P3R. The Ca2+elevations are partially due to release from internal stores, but the largest contribution is from influx across the plasma membrane. The effect of inhibition of sphingosine kinase suggests that the production of cytosolic S1P underlies the sustained nature of the Ca2+elevations. Elucidation of the downstream effects of these signals will provide clues to the role of S1P in regulating inner retinal function.
Intraperiaqueductal Gray Glycine andd-Serine Exert Dual Effects on Rostral Ventromedial Medullaon- andoff-Cell Activity and Thermoceptive Threshold in the Rat
Authors: Palazzo Enza , Guida Francesca , Migliozzi Annalucia , Gatta Luisa , Marabese Ida , Luongo Livio , Rossi Claudia , de Novellis Vito , Fernández-Sánchez Enrique , Soukupova Marie , Zafra Francisco , Maione Sabatino
Published: September 2009

We have studied the involvement of the N-methyl-d-aspartate receptor (NMDAR) glycine site and the strychnine-sensitive glycine receptor (GlyR) in the ventrolateral periaqueductal gray (VL-PAG) on nociceptive behavior (tail flick) and pain-related changes on neuronal activity in the rostral ventromedial medulla (RVM). Glycine or d-serine increased the tail-flick latency, reduced off-cell pause, and delayed its onset and increased the time between the onset of the off-cell pause and the tail withdrawal. Conversely, they decreased the ongoing activity of the on cell, the tail-flick–induced on-cell firing, whereas they delayed the onset of increased tail-flick–induced on-cell firing. Also, glycine or d-serine reduced the interval between the onset of the increased on-cell firing and tail withdrawal. Whereas 7-Cl-kynurenic acid (7-Cl-KYN) prevented such effects, strychnine did not do so. A higher dose of 7-Cl-KYN or strychnine was per se able to reduce or increase tail-flick latency and increase or reduce on-cell activities, respectively. A higher dose of glycine was hyperalgesic in the presence of 7-Cl-KYN, whereas such an effect was prevented by strychnine. These data suggest 1) a dual role of glycine in producing hyperalgesia or analgesia by stimulating the GlyR or the NMDARs within the VL-PAG, respectively; 2) consistently that RVM on and off cells display opposite firing patterns to the stimulation of the VL-PAG NMDAR glycine site and GlyR activation; and 3) a tonic role of these receptors within the VL-PAG–RVM antinociceptive descending pathway.
Long-Term Potentiation of Excitatory Synapses on Neocortical Somatostatin-Expressing Interneurons
Authors: Chen Huan-Xin , Jiang Mali , Akakin Dilek , Roper Steven N.
Published: September 2009

Synaptic plasticity has been extensively studied in principal neurons of the neocortex, but less work has been done on GABAergic interneurons. Interneurons consist of multiple subtypes and their synaptic properties vary between subtypes. In the present study, we have examined long-term potentiation (LTP) of excitatory synapses on somatostatin (SS)-expressing interneurons in neocortex using transgenic mice that express enhanced green fluorescent protein in these interneurons. We found that a strong theta burst stimulation was required to induce LTP in SS interneurons. LTP was associated with a reduction in paired-pulse facilitation and was not blocked by an N-methyl-d-aspartate receptor (NMDAR) antagonist. LTP was not affected by chelating postsynaptic Ca2+ with BAPTA, a fast Ca2+ chelator, and blocking L-type voltage-dependent Ca2+ channels with nimodipine. Application of forskolin, an activator of adenylate cyclase that increases cyclic adenosine monophosphate (cAMP) concentration, enhanced synaptic transmission and occluded subsequent induction of LTP. Finally, we found that LTP was blocked by protein kinase A (PKA) inhibitors. Our results suggest that excitatory synapses on SS interneurons express a presynaptic form of LTP that is not dependent on NMDARs or postsynaptic Ca2+ rise but is dependent on the cAMP–PKA signaling pathway.
On Modelling Long Term Stock Returns with Ergodic Diffusion Processes: Arbitrage and Arbitrage‐Free Specifications
Authors: Wong Bernard
Published: September 2009

We investigate the arbitrage‐free property of stock price models where the local
martingale component is based on an ergodic diffusion with a specified stationary distribution. These models are particularly useful for long horizon asset‐liability management as they allow the modelling of long term stock returns with heavy tail
ergodic diffusions, with tractable, time homogeneous dynamics, and which moreover
admit a complete financial market, leading to unique pricing and hedging strategies. Unfortunately the standard specifications of these models in literature admit arbitrage opportunities. We investigate in detail the features of the existing model specifications which create these arbitrage opportunities and consequently construct a modification that is arbitrage free.
Exchange Interaction in Complex Bis[(1,3-Dithiole-2-Thione-4,5-Dithiolato)-di-(Carbonyl)-Cyclopentadienyl Iron(II)]
Authors: Vitushkina S. V. , Ziolkovskiy D. V. , Starodub V. A. , Presniakov I. A. , Sobolev A. V. , Kajnaková M. , Radvákova A. , Feher A.
Published: September 2009

The splitting of the quasidegenerate electronic states in dinuclear bis[(1,3-dithiole-2-thione-4,5-dithiolato)-di-(carbonyl)-cyclopentadienyliron (II)] complex with the bridging, S–S coupled, dimerized sulfur-rich dithiolate ligands, [Fe(C5H5)(CO)2(C3S5-C3S5)Fe(C5H5)(CO)2] (I) was found by the means of
Mössbauer spectroscopy and by the measurement of the temperature dependence of magnetic susceptibility in a wide temperature range from 2 K to 300 K. The experimental results were confirmed by the calculations of the singlet and triplet states of the complex, as well as of the distribution of spin density within the bounds of the DFT method in the B3LYP/6-31(dp)G basis. In the more stable triplet state, the spin density is significantly delocalized, which is a characteristic of olefindithiolate complexes.
Prognostic and Therapeutic Potential of Nuclear Receptors in Head and Neck Squamous Cell Carcinomas
Authors: Knauer Shirley K.
Published: September 2009

Head and neck squamous cell carcinomas are among the most common neoplasms worldwide and characterized by local tumor aggressiveness, high rate of early recurrences, development of metastasis, and second primary cancers. Despite modern therapeutic strategies and sophisticated surgical management, overall survival-rates remained largely unchanged over the last decades. Thus, the need for novel treatment options for this tumor entity is undeniable. A key event in carcinogenesis is the uncontrolled modulation of genetic programs. Nuclear receptors belong to a large superfamily of transcription factors implicated in a broad spectrum of physiological and pathophysiological processes, including cancer. Several nuclear receptors have also been associated with head and neck cancer. This review will summarize their mode of action, prognostic/therapeutic relevance, as well as preclinical and clinical studies currently targeting nuclear receptors in this tumor entity.
Proteomic Analysis of Serum in Lung Cancer Induced by 3‐Methylcholanthrene
Authors: Li Minhua , Ye Bo , Zhang Yuxia , Chen Honglei , Xia Dong , Liu Mingqiu , Yang Fei
Published: September 2009

Lung cancer remains the leading cause of cancer‐related mortality worldwide. Early detection of lung cancer is problematic due to the lack of a marker with high diagnosis sensitivity and specificity. To determine the differently expressed proteins in the serum of lung cancer and figure out the function of the proteins, two‐dimensional electrophoresis (2DE) and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) were used to screen the serum proteins of lung cancer model induced by 3‐methylcholanthrene (MCA). From optimized 2DE image, 455 spots in the normal sera and 716 spots in the lung cancers sera were detected. Among them, 141 protein spots were differentially expressed when comparing the serum from normal rat and serum from lung cancer model, including 82 overexpressed proteins and 59 underexpressed proteins. Changes of haptoglobin, transthyretin, and TNF superfamily member 8 (TNFRS8) were confirmed in sera from lung cancer by MALDI‐TOF‐MS. Proteomics technology leads to identify changes of haptoglobin, transthyretin, and TNFRS8 in serum of rat lung cancer model and represents a powerful tool in searching for candidate proteins as biomarkers.
LAS0811: From Combinatorial Chemistry to Activation of Antioxidant Response Element
Authors: Zhu Ming , Baek Hyounggee , Liu Ruiwu , Song Aimin , Lam Kit , Lau Derick
Published: September 2009

The antioxidant response element (ARE) and its transcription factor, nuclear factor‐erythroid 2 p45‐related factor 2 (Nrf2), are potential targets for cancer chemoprevention. We sought to screen small molecules synthesized with combinatorial chemistry for activation of ARE. By high‐throughput screening of 9400 small molecules from 10 combinatorial chemical libraries using HepG2 cells with an ARE‐driven reporter, we have identified a novel small molecule, 1,2‐dimethoxy‐4,5‐dinitrobenzene (LAS0811), as an activator of the ARE. LAS0811 upregulated the activity of NAD(P)H:quinone oxidoreductase 1 (NQO1), a representative antioxidative enzyme regulated by ARE. It enhanced production of an endogenous reducing agent, glutathione (GSH). In addition, LAS0811 induced expression of heme oxygenase 1 (HO1), which is an ARE‐regulated enzyme with anti‐inflammatory activity. Furthermore, LAS0811 reduced cell death due to the cytotoxic stress of a strong oxidant, t‐butyl hydroperoxide (t‐BOOH). Mechanistically, LAS0811 upregulated the expression of Nrf2 and promoted its translocation into the nuclei leading to subsequent ARE activation. Taken together, LAS0811 is a novel activator of the ARE and its associated detoxifying genes and, thus, a potential agent for cancer chemoprevention.
Pyramidal Watershed Segmentation Algorithm for High‐Resolution Remote Sensing Images Using Discrete Wavelet Transforms
Authors: Parvathi K. , Prakasa Rao B. S. , Mariya Das M. , Rao T. V.
Published: September 2009

The watershed transformation is a useful morphological segmentation tool for a variety of grey‐scale images. However, over segmentation and under segmentation have become the key problems for the conventional algorithm. In this paper, an efficient segmentation method for high‐resolution remote sensing image analysis is presented. Wavelet analysis is one of the most popular techniques that can be used to detect local intensity variation and hence the wavelet transformation is used to analyze the image. Wavelet transform is applied to the image, producing detail (horizontal, vertical, and diagonal) and Approximation coefficients. The image gradient with selective regional minima is estimated with the grey‐scale morphology for the Approximation image at a suitable resolution, and then the watershed is applied to the gradient image to avoid over segmentation. The segmented image is projected up to high resolutions using the inverse wavelet transform. The watershed segmentation is applied to small subset size image, demanding less computational time. We have applied our new approach to analyze remote sensing images. The algorithm was implemented in MATLAB. Experimental results demonstrated the method to be effective.
Financial Crisis American Style
Authors: Bosworth Barry , Flaaen Aaron
Published: September 2009

This paper reviews some of the research on the causes of the financial crisis of 2008–09, highlights the key events that triggered a financial panic in September 2008, and summarizes the key policy actions that the United States has taken to ameliorate the crisis. We document the characteristics and growth of the sub-prime mortgage market, and the distorted incentives and flawed regulatory structure surrounding the secondary market for mortgage-backed securities. We also assess the role for macroeconomic determinants of the crisis that serve to explain the bubble in U.S. asset prices, most notably low global interest rates attributed to either loose monetary policy or excess global saving. Although low global interest rates may have contributed to the boom in housing markets and speculative excesses, we believe that the financial innovations and microeconomic distortions played a more fundamental role. Finally, a recovery marked by higher private saving, weak domestic investment, and a large public deficit appears to be unsustainable. Ultimately, the U.S. economy will need to shift about 3 percent of GDP from domestic consumption to the export sector. This will pose some serious challenges to Asian economies that have come to rely on exports to the U.S. market.
Origins and Resolution of Financial Crises: Lessons from the Current and Northern European Crises
Authors: Østrup Finn , Oxelheim Lars , Wihlborg Clas
Published: September 2009

Since July 2007, the world economy has experienced a severe financial crisis that originated in the U.S. housing market. Subsequently, the crisis has spread to financial sectors in European and Asian economies and led to a severe worldwide recession. The existing literature on financial crises rarely distinguishes between factors that create the original strain on the financial sector and factors that explain why these strains lead to system-wide contagion and a possible credit crunch. Most of the literature on financial crises refers to factors that cause an original disruption in the financial system. We argue that a financial crisis with its contagion within the system is caused by failures of legal, regulatory, and political institutions.
The Delayed Effect of Major El Niño Events on Indian Monsoon Rainfall
Authors: Park Hyo-Seok , Chiang John C. H. , Lintner Benjamin R. , Zhang Guang J.
Published: September 2009

Previous studies have shown that boreal summer Indian monsoon rainfall is, on average, significantly above normal after major El Niño events. In this study, the underlying causes of this rainfall response are examined using both observational analysis and atmospheric general circulation model (AGCM) simulations. Moist static energy budgets for two strong El Niño events (1982/83 and 1997/98), estimated from monthly 40-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40), suggest that stronger low-level moisture transport and reduced moist stability associated with a warmer north Indian Ocean (NIO) can increase monsoon rainfall, despite a weakened monsoon circulation.

The trade-off between a dynamically weaker monsoon and moist processes favoring enhanced monsoonal rainfall is broken during the late monsoon season (August–September) as the warm NIO enhances surface latent heat flux and the monsoon circulation relaxes back to the climatological mean. The monsoon circulation strength and the moist processes work together in the late season, which explains the observed tendency for monsoonal rainfall increases during the late monsoon season after strong winter El Niño conditions.

Idealized AGCM experiments with a fixed-depth ocean mixed layer demonstrate that the remnant but weaker-than-peak warm SSTs in the eastern equatorial Pacific during spring and the early summer following winter El Niños substantially contribute to the NIO warming. The results suggest that local air–sea interactions in the tropical Indian Ocean after winter El Niño are strongly dependent on the details of El Niño’s decaying trend.
The Influence of the Madden–Julian Oscillation on Tropical Cyclone Activity in the Fiji Region
Authors: Chand Savin S. , Walsh Kevin J. E.
Published: September 2009

This study examines the modulation of tropical cyclone (TC) activity by the Madden–Julian oscillation (MJO) in the Fiji, Samoa, and Tonga regions (FST region), using Joint Typhoon Warning Center best-track cyclone data and the MJO index developed by Wheeler and Hendon. Results suggest strong MJO–TC relationships in the FST region. The TC genesis patterns are significantly altered over the FST region with approximately 5 times more cyclones forming in the active phase than in the inactive phase of the MJO. This modulation is further strengthened during El Niño periods. The large-scale environmental conditions (i.e., low-level relative vorticity, upper-level divergence, and vertical wind shear) associated with TC genesis show a distinct patterns of variability for the active and inactive MJO phases. The MJO also has a significant effect on hurricane category and combined gale and storm category cyclones in the FST region. The occurrences of both these cyclone categories are increased in the active phase of the MJO, which is associated with enhanced convective activity. The TCs in the other MJO phases where convective activity is relatively low, however, show a consistent pattern of increase in hurricane category cyclones and a concomitant decrease in gale and storm category cyclones. Finally, TC tracks in different MJO phases are also objectively described using a cluster analysis technique. Patterns seen in the clustered track regimes are well explained here in terms of 700–500-hPa mean steering flow.
Institutional Constraints on Profligate Politicians: The Conditional Effect of Partisan Fragmentation on Budget Deficits
Authors: Wehner Joachim
Published: September 2009

The literature on the common pool resource problem in budgeting has thus far not explored the likely interaction between size fragmentation (the number of decision makers) and procedural fragmentation (the structure of the process in which they interact).The argument put forward in this article is that the effects of these two types of fragmentation should not be additive, but multiplicative, because theory suggests that the impact of size fragmentation on fiscal policy is conditional on the extent of procedural fragmentation. Using panel data for 57 countries over the period of 1975 to 1998, the author empirically investigates this interaction in the legislative context and finds strong evidence that partisan fragmentation is associated with higher deficits only when it is not moderated by limits on parliamentary amendment authority.
Exploring the Generation Gap in Urban Schools: Generational Perspectives in Professional Learning Communities
Authors: Rinke Carol R.
Published: September 2009

This article reports on the generational perspectives of two science teachers working in one urban school, a 38-year veteran and a second-year teacher. Despite numerous opportunities to work together, these teachers argued more than they collaborated. This research shows that at least some of the tension can be explained by the generational perspectives each brought with them to the classroom, perspectives that have been brought to the forefront by the recent demographic shift in the urban teacher workforce. Each teacher’s generational perspective is presented within a framework of technical culture, service ethic, and professional commitment. Implications for recruitment and retention are discussed.
The Effectiveness of an After-school Program Targeting Urban African American Youth
Authors: Hanlon Thomas E. , Simon Betsy D. , O'Grady Kevin E. , Carswell Steven B. , Callaman Jason M.
Published: September 2009

The present study reports on the effectiveness at one-year follow-up of an after-school prevention program targeting 6th grade African American youth residing in high-risk urban areas. The program, conducted on-site over the school-year period, involved a group mentoring approach emphasizing remedial education and an appreciation of African American cultural heritage in promoting school bonding, social skills development, and greater academic achievement. Behavioral and adjustment outcome data were obtained from two participating middle-school sites (intervention and comparison, involving 237 and 241 students, respectively) serving essentially equivalent urban communities. Results of the study revealed significant effects for academic achievement and behavior in terms of grade point average and teacher ratings that favored students at the intervention site. At this site, greater participation of parents in the intervention program was found to be positively related to improvement of the children in grade point average. No differential site-related changes in negative behavior were observed.
Considering context in psychological leadership research
Authors: Liden Robert C. , Antonakis John
Published: September 2009

Despite Lewin’s identification of the importance of context in behavioral research over 70 years ago, leadership psychology tended to ignore the context. Only in the past 10 years has context been more routinely included in psychological leadership research. We provide examples of leadership research that has explored the context, introduce the special issue articles, and provide suggestions for future research on the context of leadership.
The challenge of leading on unstable ground: Triggers that activate social identity faultlines
Authors: Chrobot-Mason Donna , Ruderman Marian N. , Weber Todd J. , Ernst Chris
Published: September 2009

Today’s leaders face unprecedented challenges in attempting to manage interactions between social identity group members with a history of tension in society at large. Research on faultlines suggests that social identity groups often polarize in response to events that make social identity salient, resulting in negative work outcomes. The current research extends the faultlines literature by examining precipitating events (triggers) that activate a faultline. Qualitative interview data were collected from two samples of employees working in multiple countries to identify events that had resulted in social identity conflicts. In the first study (35 events), an exploratory approach yielded a typology of five types of triggers: differential treatment, different values, assimilation, insult or humiliating action, and simple contact. A second qualitative study (99 events) involved a more geographically varied sample. Research findings are discussed in terms of implications for the faultlines literature and for practicing leaders.
Social distance as a moderator of the effects of transformational leadership: Both neutralizer and enhancer
Authors: Cole Michael S. , Bruch Heike , Shamir Boas
Published: September 2009

Following recent interest in contextual factors and how they might influence the effects of transformational leadership, we consider the social distance between leaders and followers as a cross-level moderator of the relationships between senior level managers’ transformational leadership and individual-level outcomes. Our sample comprised 268 individuals in 50 leader-follower groups. Results revealed that high social distance reduced or neutralized transformational leadership’s association with followers’ emulation of leader behavior. In contrast, high levels of social distance between leaders and followers enhanced the effects of transformational leadership on individuals’ perceptions of their units’ positive emotional climate and individuals’ sense of collective efficacy. Results not only highlight the importance of social distance as a contextual variable affecting leader-follower relations but also suggest that the same contextual variable may have differential effects, enhancing some relationships and neutralizing others.
The institutionalization of distributed leadership: A ‘Catch-22’ in English public services
Authors: Currie Graeme , Lockett Andy , Suhomlinova Olga
Published: September 2009

Distributed leadership is promoted as being well suited to public service organizations because of their multiple goals, less pronounced managerial authority and presence of powerful professional groups. Drawing on qualitative evidence we analyse the complex process of the institutionalization of distributed leadership in English schools. Our analysis suggests that competing institutional forces simultaneously foster and stymie the adoption of distributed leadership. Consequently, the school principals find themselves in a classic Catch-22 situation, which they resolve by enacting a weak form of distributed leadership. Ironically, the implementation of distributed leadership is the most difficult in the schools located in socially deprived areas, that is, the very context where policy-makers expect distributed leadership to make the most impact. Moving beyond our specific case, we argue that distributed leadership, and leadership more generally, cannot be divorced from its institutional context and that the relative influence of divergent institutional forces depends upon the immediate organizational environment.
Democracy and Diversion: Government Arrangements, the Economy, and Dispute Initiation
Authors: Brulé David J. , Williams Laron K.
Published: September 2009

Do legislative constraints constrain or compel democratic executives’ conflict behavior during periods of economic decline? Although institutional constraints are thought to reduce democratic executives’ propensity to engage in interstate conflict, other research suggests that such constraints may provide incentives to engage in diversionary uses of force. Incorporating work from the comparative study of economic voting and cross-national research on the diversionary use of force, this article contends that government arrangements — coalition, minority, weak party cohesion — influence democratic conflict behavior by (1) shaping the extent to which the executive is held accountable for the economy and (2) determining the executive’s capacity to address the economy with legislation. Specifically, the argument presented here suggests that governing parties in coalition governments share the blame for a poor economy, reducing the likelihood that the executive initiates disputes in response to the economy. Compared to single-party majority governments with high party discipline, executives presiding over minority governments, or whose parties are plagued by a lack of cohesion, are more likely to initiate disputes when faced with poor economic conditions, because these executives are likely to face resistance to remedial economic policy. Probit analyses of the interactive effects of government arrangements and economic performance on dispute initiation among industrialized democracies, 1950—97, support the argument. The article concludes with implications for research in comparative politics and international relations, including, for example, executive—legislative relations and strategic conflict avoidance.