bluuebunny/crossref_metadata_2025 huggingface dataset:
THE CONSTRUCTION OF 2D ROTATIONALLY INVARIANT WAVELETS AND THEIR APPLICATION IN IMAGE EDGE DETECTION
Authors: ZENG LI , MA RUI , HUANG JIANYUAN , HUNZIKER P. R.
Published: January 2008

Construction of rotationally invariant 2D wavelets is important in image processing, but is difficult. In this paper, the discrete form of a 2D rotationally invariant wavelet is constructed by back-projection from a 1D symmetrical wavelet. Such rotationally invariant 2D wavelets allow effective edge detection in any direction. These wavelets are combined with the 2D directional wavelets for the use in non-maximum suppression edge detection. The resulting binary edges are characterized by finer contours, differential detection characteristics and noise robustness compared to other edge detectors in various test images. In particular, where fine binary edges in noisy images are required, this novel approach compares favorably to the classical methods of Canny and Mallat with detection of more edges thanks to the implicit denoising properties and the full rotational invariance of the method.
ETHNIC ENTREPRENEURSHIP: STUDYING CHINESE AND INDIAN STUDENTS IN THE UNITED STATES
Authors: LI WEI
Published: January 2008

Current literature has not touched upon the topic of entrepreneurial intention among international students. Using the theory of planned behavior as a theoretical framework, this study addresses this gap by looking at the entrepreneurial intentions of Chinese and Indian students at a top university located in the Midwest United States. This study also explores their perceived barriers of being entrepreneurs in the United States and expected help from the university. Both survey and interviews are used for data collection and analysis. The research finding implications for educators are also provided.
INSTITUTIONAL CHANGES AFFECTING ENTREPRENEURSHIP IN CHINA
Authors: KSHETRI NIR
Published: January 2008

Institutions influencing entrepreneurship are undergoing significant transformation in China. During the Mao era, private entrepreneurship was virtually eradicated and was a political taboo. As reflected in the macro-level economic data, there has been an evolution of entrepreneur-friendly institutions in the country. A constellation of factors linked to China's global integration is pushing through fundamental changes in institutions related to Chinese entrepreneurship. The logics or governance structures and organizing principles related to entrepreneurship are rapidly changing in the country. This paper examines forces influencing the diffusion of instrumental values promoting entrepreneurship among Chinese institutional actors.
ON THE FINANCIAL PERFORMANCE OF PRIVATE ENTERPRISES IN CHINA
Authors: FUNG HUNG-GAY , XU XIAOQING ELEANOR , ZHANG QI-ZI
Published: January 2008

Using the comprehensive 2000 and 2002 surveys of Chinese entrepreneurs conducted by the National Association of Private Entrepreneurs and the Chinese Academy of Social Sciences, we examine the characteristics and financial performance of private enterprises in China. Entrepreneurs, on average, are 40 years old and many are well-educated; more than one-third of them have a college degree or higher. Their companies are young, with an average age of six to seven years. Entrepreneurs contribute most of the equity capital to the private firms, which in general, are profitable with an average return on assets of 16 percent in 2002 and 11 percent in 2000. Further empirical analysis demonstrates the important impact of social, financing and human capital on firms' financial performance. We find that social capital (measured by charitable contributions), financing capital (measured by the equity-to-total capital ratio), and human capital have significant effects on firm profitability, and younger entrepreneurs tend to be more successful in the new Chinese market economy.
Is Human Hibernation Possible?
Authors: Lee Cheng Chi
Published: January 2008

The induction of hypometabolism in cells and organs to reduce ischemia damage holds enormous clinical promise in diverse fields, including treatment of stroke and heart attack. However, the thought that humans can undergo a severe hypometabolic state analogous to hibernation borders on science fiction. Some mammals can enter a severe hypothermic state during hibernation in which metabolic activity is extremely low, and yet full viability is restored when the animal arouses from such a state. To date, the underlying mechanism for hibernation or similar behaviors remains an enigma. The beneficial effect of hypothermia, which reduces cellular metabolic demands, has many well-established clinical applications. However, severe hypothermia induced by clinical drugs is extremely difficult and is associated with dramatically increased rates of cardiac arrest for nonhibernators. The recent discovery of a biomolecule, 5′-AMP, which allows nonhibernating mammals to rapidly and safely enter severe hypothermia could remove this impediment and enable the wide adoption of hypothermia as a routine clinical tool.
NFAT activation by membrane potential follows a calcium pathway distinct from other activity-related transcription factors in skeletal muscle cells
Authors: Valdés Juan Antonio , Gaggero Eduardo , Hidalgo Jorge , Leal Nancy , Jaimovich Enrique , Carrasco M. Angélica
Published: January 2008

Depolarization of skeletal muscle cells triggers intracellular Ca2+ signals mediated by ryanodine and inositol 1,4,5-trisphosphate (IP3) receptors. Previously, we have reported that K+-induced depolarization activates transcriptional regulators ERK, cAMP response element-binding protein, c- fos, c- jun, and egr-1 through IP3-dependent Ca2+ release, whereas NF-κB activation is elicited by both ryanodine and IP3 receptor-mediated Ca2+ signals. We have further shown that field stimulation with electrical pulses results in an NF-κB activation increase dependent of the amount of pulses and independent of their frequency. In this work, we report the results obtained for nuclear factor of activated T cells (NFAT)-mediated transcription and translocation generated by both K+ and electrical stimulation protocols in primary skeletal muscle cells and C2C12 cells. The Ca2+ source for NFAT activation is through release by ryanodine receptors and extracellular Ca2+ entry. We found this activation to be independent of the number of pulses within a physiological range of stimulus frequency and enhanced by long-lasting low-frequency stimulation. Therefore, activation of the NFAT signaling pathway differs from that of NF-κB and other transcription factors. Calcineurin enzyme activity correlated well with the relative activation of NFAT translocation and transcription using different stimulation protocols. Furthermore, both K+-induced depolarization and electrical stimulation increased mRNA levels of the type 1 IP3 receptor mediated by calcineurin activity, which suggests that depolarization may regulate IP3 receptor transcription. These results confirm the presence of at least two independent pathways for excitation-transcription coupling in skeletal muscle cells, both dependent on Ca2+ release and triggered by the same voltage sensor but activating different intracellular release channels.
Overexpression of TRPC3 increases apoptosis but not necrosis in response to ischemia-reperfusion in adult mouse cardiomyocytes
Authors: Shan Dan , Marchase Richard B. , Chatham John C.
Published: January 2008

An increase in cytosolic Ca2+ via a capacitative calcium entry (CCE)-mediated pathway, attributed to members of the transient receptor potential (TRP) superfamily, TRPC1 and TRPC3, has been reported to play an important role in regulating cardiomyocyte hypertrophy. Increased cytosolic Ca2+ also plays a critical role in mediating cell death in response to ischemia-reperfusion (I/R). Therefore, we tested the hypothesis that overexpression of TRPC3 in cardiomyocytes will increase sensitivity to I/R injury. Adult cardiomyocytes isolated from wild-type (WT) mice and from mice overexpressing TRPC3 in the heart were subjected to 90 min of ischemia and 3 h of reperfusion. After I/R, viability was 51 ± 1% in WT mice and 42 ± 5% in transgenic mice ( P < 0.05). Apoptosis assessed by annexin V was significantly increased in the TRPC3 group compared with WT (32 ± 1% vs. 21 ± 3%; P < 0.05); however, there was no significant difference in necrosis between groups. Treatment of TRPC3 cells with the CCE inhibitor SKF-96365 (0.5 μM) significantly improved cellular viability (54 ± 4%) and decreased apoptosis (15 ± 4%); in contrast, the L-type Ca2+ channel inhibitor verapamil (10 μM) had no effect. Calpain-mediated cleavage of α-fodrin was increased approximately threefold in the transgenic group following I/R compared with WT ( P < 0.05); this was significantly attenuated by SKF-96365. The calpain inhibitor PD-150606 (25 μM) attenuated the increase in both α-fodrin cleavage and apoptosis in the TPRC3 group. Increased TRPC3 expression also increased sensitivity to Ca2+ overload stress, but it did not affect the response to TNF-α-induced apoptosis. These results suggest that CCE mediated via TRPC may play a role in cardiomyocyte apoptosis following I/R due, at least in part, to increased calpain activation.
K restriction inhibits protein phosphatase 2B (PP2B) and suppression of PP2B decreases ROMK channel activity in the CCD
Authors: Zhang Yan , Lin Dao-Hong , Wang Zhi-Jian , Jin Yan , Yang Baofeng , Wang Wen-Hui
Published: January 2008

We used Western blot analysis to examine the effect of dietary K intake on the expression of serine/threonine protein phosphatase in the kidney. K restriction significantly decreased the expression of catalytic subunit of protein phosphatase (PP)2B but increased the expression of PP2B regulatory subunit in both rat and mouse kidney. However, K depletion did not affect the expression of PP1 and PP2A. Treatment of M-1 cells, mouse cortical collecting duct (CCD) cells, or 293T cells with glucose oxidase (GO), which generates superoxide anions through glucose metabolism, mimicked the effect of K restriction on PP2B expression and significantly decreased expression of PP2B catalytic subunits. However, GO treatment increased expression of regulatory subunit of PP2B and had no effect on expression of PP1, PP2A, and protein tyrosine phosphatase 1D. Moreover, deletion of gp91-containing NADPH oxidase abolished the effect of K depletion on PP2B. Thus superoxide anions or related products may mediate the inhibitory effect of K restriction on the expression of PP2B catalytic subunit. We also used patch-clamp technique to study the effect of inhibiting PP2B on renal outer medullary K (ROMK) channels in the CCD. Application of cyclosporin A or FK506, inhibitors of PP2B, significantly decreased ROMK channels, and the effect of PP2B inhibitors was abolished by blocking p38 mitogen-activated protein kinase (MAPK) and ERK. Furthermore, Western blot demonstrated that inhibition of PP2B with cyclosporin A or small interfering RNA increased the phosphorylation of ERK and p38 MAPK. We conclude that K restriction suppresses the expression of PP2B catalytic subunits and that inhibition of PP2B decreases ROMK channel activity through stimulation of MAPK in the CCD.
Salinity regulates claudin mRNA and protein expression in the teleost gill
Authors: Tipsmark Christian K. , Baltzegar David A. , Ozden Ozkan , Grubb Brenda J. , Borski Russell J.
Published: January 2008

The teleost gill carries out NaCl uptake in freshwater (FW) and NaCl excretion in seawater (SW). This transformation with salinity requires close regulation of ion transporter capacity and epithelial permeability. This study investigates the regulation of tight-junctional claudins during salinity acclimation in fish. We identified claudin 3- and claudin 4-like immunoreactive proteins and examined their expression and that of select ion transporters by performing Western blot in tilapia ( Oreochromis mossambicus) gill during FW and SW acclimation. Transfer of FW tilapia to SW increased plasma osmolality, which was corrected after 4 days, coinciding with increased gill Na+-K+-ATPase and Na+-K+-2Cl−cotransporter expression. Gill claudin 3- and claudin 4-like proteins were reduced with exposure to SW. Transfer to FW increased both claudin-like proteins. Immunohistochemistry shows that claudin 3-like protein was localized deep in the FW gill filament, whereas staining was found apically in SW gill. Claudin 4-like proteins are localized predominantly in the filament outer epithelial layer, and staining appears more intense in the gill of FW versus SW fish. In addition, tilapia claudin 28a and 30 genes were characterized, and mRNA expression was found to increase during FW acclimation. These studies are the first to detect putative claudin proteins in teleosts and show their localization and regulation with salinity in gill epithelium. The data indicate that claudins may be important in permeability changes associated with salinity acclimation and possibly the formation of deeper tight junctions in FW gill. This may reduce ion permeability, which is a critical facet of FW osmoregulation.
Stimulation of brain mast cells by compound 48/80, a histamine liberator, evokes renin and vasopressin release in dogs
Authors: Matsumoto Itsuro , Inoue Yasuhisa , Shimada Toshio , Matsunaga Tomoe , Aikawa Tadaomi
Published: January 2008

Because degranulation of brain mast cells activates adrenocortical secretion ( 41 , 42 ), we examined whether activation of such cells increases renin and vasopressin (antidiuretic hormone: ADH) secretion. For this, we administered compound 48/80 (C48/80), which liberates histamine from mast cells, to pentobarbital-anesthetized dogs. An infusion of 37.5 μg/kg C48/80 into the cerebral third ventricle evoked increases in plasma renin activity (PRA), and in plasma epinephrine (Epi) and ADH concentrations. Ketotifen (mast cell-stabilizing drug; given orally for 1 wk before the experiment) significantly reduced the C48/80-induced increases in PRA, Epi, and ADH. Resection of the bilateral splanchnic nerves (SPX) below the diaphragm completely prevented the C48/80-induced increases in PRA and Epi, but potentiated the C48/80-induced increase in ADH and elevated the plasma Epi level before and after C48/80 challenge. No significant changes in mean arterial blood pressure, heart rate, concentrations of plasma electrolytes (Na+, K+, and Cl−), or plasma osmolality were observed after C48/80 challenge in dogs with or without SPX. Pyrilamine maleate (H1histaminergic-receptor antagonist) significantly reduced the C48/80-induced increase in PRA when given intracerebroventricularly, but not when given intravenously. In contrast, metiamide (H2histaminergic-receptor antagonist) given intracerebroventricularly significantly potentiated the C48/80-induced PRA increase. A small dose of histamine (5 μg/kg) administered intracerebroventricularly increased PRA twofold and ADH fourfold (vs. their basal level). These results suggest that in dogs, endogenous histamine liberated from brain mast cells may increase renin and Epi secretion (via the sympathetic outflow) and ADH secretion (via the central nervous system).
Experimentally cross-wired lingual taste nerves can restore normal unconditioned gaping behavior in response to quinine stimulation
Authors: King Camille T. , Garcea Mircea , Stolzenberg Danielle S. , Spector Alan C.
Published: January 2008

Studies examining the effects of transection and regeneration of the glossopharyngeal (GL) and chorda tympani (CT) nerves on various taste-elicited behaviors in rats have demonstrated that the GL (but not the CT) nerve is essential for the maintenance of both an unconditioned protective reflex (gaping) and the neural activity observed in central gustatory structures in response to lingual application of a bitter substance. An unresolved issue, however, is whether recovery depends more on the taste nerve and the central circuits that it supplies and/or on the tongue receptor cell field being innervated. To address this question, we experimentally cross-wired these taste nerves, which, remarkably, can regenerate into parts of the tongue they normally do not innervate. We report that quinine-stimulated gaping behavior was fully restored, and neuronal activity, as assessed by Fos immunohistochemistry in the nucleus of the solitary tract and the parabrachial nucleus, was partially restored only if the posterior tongue (PT) taste receptor cell field was reinnervated; the particular taste nerve supplying the input was inconsequential to the recovery of function. Thus, PT taste receptor cells appear to play a privileged role in triggering unconditioned gaping to bitter tasting stimuli, regardless of which lingual gustatory nerve innervates them. Our findings demonstrate that even when a lingual gustatory nerve (the CT) forms connections with taste cells in a non-native receptor field (the PT), unconditioned taste rejection reflexes to quinine can be maintained. These findings underscore the extraordinary ability of the gustatory system to adapt to peripherally reorganized input for particular behaviors.
Locomotor muscle fatigue increases cardiorespiratory responses and reduces performance during intense cycling exercise independently from metabolic stress
Authors: Marcora Samuele M. , Bosio Andrea , de Morree Helma M.
Published: January 2008

Locomotor muscle fatigue, defined as an exercise-induced reduction in maximal voluntary force, occurs during prolonged exercise, but its effects on cardiorespiratory responses and exercise performance are unknown. In this investigation, a significant reduction in locomotor muscle force (−18%, P < 0.05) was isolated from the metabolic stress usually associated with fatiguing exercise using a 100-drop-jumps protocol consisting of one jump every 20 s from a 40-cm-high platform. The effect of this treatment on time to exhaustion during high-intensity constant-power cycling was measured in study 1 ( n = 10). In study 2 ( n = 14), test duration (871 ± 280 s) was matched between fatigue and control condition (rest). In study 1, locomotor muscle fatigue caused a significant curtailment in time to exhaustion (636 ± 278 s) compared with control (750 ± 281 s) ( P = 0.003) and increased cardiac output. Breathing frequency was significantly higher in the fatigue condition in both studies despite similar oxygen consumption and blood lactate accumulation. In study 2, high-intensity cycling did not induce further fatigue to eccentrically-fatigued locomotor muscles. In both studies, there was a significant increase in heart rate in the fatigue condition, and perceived exertion was significantly increased in study 2 compared with control. These results suggest that locomotor muscle fatigue has a significant influence on cardiorespiratory responses and exercise performance during high-intensity cycling independently from metabolic stress. These effects seem to be mediated by the increased central motor command and perception of effort required to exercise with weaker locomotor muscles.
Monitoring of renal venous Po2and kidney oxygen consumption in rats by a near-infrared phosphorescence lifetime technique
Authors: Mik Egbert G. , Johannes Tanja , Ince Can
Published: January 2008

Renal oxygen consumption (V̇o2,ren) is an important parameter that has been shown to be influenced by various pathophysiological circumstances. V̇o2,renhas to be repeatedly measured during an experiment to gain insight in the dynamics of (dys)regulation of oxygen metabolism. In small animals, the classical approach of blood gas analysis of arterial and venous blood samples is only limitedly applicable due to fragile vessels and a low circulating blood volume. We present a phosphorescence lifetime technique that allows near-continuous measurement of renal venous Po2(vPo2) and V̇o2,renin rats. The technique does not rely on penetration of the blood vessel, but uses a small reflection probe. This probe is placed in close proximity to the renal vein for detection of the oxygen-dependent phosphorescence of the injected water-soluble near-infrared phosphor Oxyphor G2. The technique was calibrated in vitro and the calibration constants were validated in vivo in anesthetized and mechanically ventilated male Wistar rats. The hemoglobin saturation curve and its pH dependency were determined for calculation of renal venous oxygen content. The phosphorescence technique was in good agreement with blood gas analysis of renal venous blood samples, for both Po2and hemoglobin saturation. To demonstrate its feasibility in practice, the technique was used in four rats during endotoxin infusion (10 mg·kg−1·h−1during 1 h). Renal vPo2reduced by 40% upon reduction in oxygen delivery to 30% of baseline, but V̇o2remained unchanged. This study documents the feasibility of near-continuous, nondestructive measurement of renal vPo2and V̇o2by oxygen-dependent quenching of phosphorescence.
The growth hormone response to repeated bouts of sprint exercise with and without suppression of lipolysis in men
Authors: Stokes Keith A. , Tyler Christopher , Gilbert Kate L.
Published: January 2008

A single 30-s sprint is a potent physiological stimulus for growth hormone (GH) release. However, repeated bouts of sprinting attenuate the GH response, possibly due to negative feedback via elevated systemic free fatty acids (FFA). The aim of the study was to use nicotinic acid (NA) to suppress lipolysis to investigate whether serum FFA can modulate the GH response to exercise. Seven nonobese, healthy men performed two trials, consisting of two maximal 30-s cycle ergometer sprints separated by 4 h of recovery. In one trial (NA), participants ingested NA (1 g 60 min before, and 0.5 g 60 and 180 min after sprint 1); the other was a control (Con) trial. Serum FFA was not significantly different between trials before sprint 1 but was significantly lower in the NA trial immediately before sprint 2 [NA vs. Con: mean (SD); 0.08 (0.05) vs. 0.75 (0.34) mmol/l, P < 0.05]. Peak and integrated GH were significantly greater following sprint 2 compared with sprint 1 in the NA trial [peak GH: 23.3 (7.0) vs. 7.7 (11.9) μg/l, P < 0.05; integrated GH: 1,076 (350) vs. 316 (527) μg·l−1·60 min−1, P < 0.05] and compared with sprint 2 in the Con trial [peak GH: 23.3 (7.0) vs. 5.2 (2.3) μg/l, P < 0.05; integrated GH: 1,076 (350) vs. 206 (118) μg·l−1·60 min−1, P < 0.05]. In conclusion, suppressing lipolysis resulted in a significantly greater GH response to the second of two sprints, suggesting a potential role for serum FFA in negative feedback control of the GH response to repeated exercise.
Signaling Mechanisms Underlying Group I mGluR-Induced Persistent AHP Suppression in CA3 Hippocampal Neurons
Authors: Young Steven R. , Bianchi Riccardo , Wong Robert K. S.
Published: January 2008

Activation of group I metabotropic glutamate receptors (mGluRs) leads to a concerted modulation of spike afterpotentials in guinea pig hippocampal neurons including a suppression of both medium and slow afterhyperpolarizations (AHPs). Suppression of AHPs may be long-lasting, in that it persists after washout of the agonist. Here, we show that persistent AHP suppression differs from short-term, transient suppression in that distinct and additional signaling processes are required to render the suppression persistent. Persistent AHP suppression followed DHPG application for 30 min, but not DHPG application for 5 min. Persistent AHP suppression was temperature dependent, occurring at 30–31°C, but not at 25–26°C. Preincubation of slices in inhibitors of protein synthesis (cycloheximide or anisomycin) prevented the persistent suppression of AHPs by DHPG. Similarly, preincubation of slices in an inhibitor of p38 MAP kinase (SB 203580) prevented persistent AHP suppression. In contrast, a blocker of p42/44 MAP kinase activation (PD 98059) had no effect on persistent AHP suppression. Additionally, we show that the mGluR5 antagonist MPEP, but not the mGluR1 antagonist LY 367385, prevented DHPG-induced persistent AHP suppression. Thus persistent AHP suppression by DHPG in hippocampal neurons requires activation of mGluR5. In addition, activation of p38 MAP kinase signaling and protein synthesis are required to impart persistence to the DHPG-activated AHP suppression.
Representation of Auditory-Filter Phase Characteristics in the Cortex of Human Listeners
Authors: Rupp André , Sieroka Norman , Gutschalk Alexander , Dau Torsten
Published: January 2008

Harmonic tone complexes with component phases, adjusted using a variant of a method proposed by Schroeder, can produce pure-tone masked thresholds differing by >20 dB. This phenomenon has been qualitatively explained by the phase characteristics of the auditory filters on the basilar membrane, which differently affect the flat envelopes of the Schroeder-phase maskers. We examined the influence of auditory-filter phase characteristics on the neural representation in the auditory cortex by investigating cortical auditory evoked fields (AEFs). We found that the P1m component exhibited larger amplitudes when a long-duration tone was presented in a repeating linearly downward sweeping (Schroeder positive, or m+) masker than in a repeating linearly upward sweeping (Schroeder negative, or m−) masker. We also examined the neural representation of short-duration tone pulses presented at different temporal positions within a single period of three maskers differing in their component phases ( m+, m−, and sine phase m0). The P1m amplitude varied with the position of the tone pulse in the masker and depended strongly on the masker waveform. The neuromagnetic results in all cases were consistent with the perceptual data obtained with the same stimuli and with results from simulations of neural activity at the output of cochlear preprocessing. These findings demonstrate that phase effects in peripheral auditory processing are accurately reflected up to the level of the auditory cortex.
Breathing Frequency Changes at the Onset of Stepping in Human Infants
Authors: Noah J. Adam , Boliek Carol , Lam Tania , Yang Jaynie F.
Published: January 2008

Breathing frequency increases at the onset of movement in a wide rage of mammals including adult humans. Moreover, the magnitude of increase in the rate of breathing appears related to the rate of the rhythmic movement. We determined whether human infants show the same type of response when supported to step on a treadmill. Twenty infants (ages 9.7 ± 1.2 mo) participated in trials consisting of sitting, stepping on the treadmill, followed by sitting again. Breathing frequency was recorded with a thermocouple, positioned under one naris and taped to a soother that the infant held in his/her mouth. A video camera, electrogoniometers, and force platforms under the treadmill belts recorded stepping movements. We found that the rate of breathing changed at the beginning of stepping. Most surprisingly, we found that when infants stepped at a frequency slower than their breathing frequency in sitting, the breathing frequency decreased. Average breathing frequency during stepping was positively correlated with stepping frequency. There was no evidence of entrainment between stepping and breathing. In conclusion, the rapid change in breathing frequency at the beginning of movement is functional in infants. The direction and magnitude of change in breathing is associated with the leg movements.
From plasma membrane to cytoskeleton: a novel function for semaphorin 6A
Authors: Prislei Silvia , Mozzetti Simona , Filippetti Flavia , De Donato Marta , Raspaglio Giuseppina , Cicchillitti Lucia , Scambia Giovanni , Ferlini Cristiano
Published: January 2008

Class III β-tubulin (TUBB3) overexpression has been reported in ovary, lung, breast, and gastric cancer patients. Currently, no clinical drugs are available for a specific targeting of TUBB3, whereas the investigational drug IDN5390 specifically interacts with TUBB3. To gain insight into the pathways leading to TUBB3 up-regulation, we did a human genome microarray analysis in A2780 cells made resistant to IDN5390 to identify selected pathways specifically disrupted in resistant cells. Using this approach, we discovered that semaphorin 6A (SEMA6A) is down-regulated not only in IDN5390-resistant cells but also in cells made resistant to cisplatin, topotecan, and doxorubicin, whereas no changes were noticed in paclitaxel- and gemcitabine-resistant cells. Acute treatment with IDN5390 was able to down-regulate SEMA6A in cells unselected for drug resistance. TUBB3 expression was assessed in A2780 clones with stable overexpression of SEMA6A and in a panel of clones in which silencing of the protein was obtained. Quantitative PCR was then used to check the modulation of SEMA6A as well as to assess the expression of TUBB3. TUBB3 was increased (median value, 5.4) and reduced (median value, 0.47) in cells with overexpression and silencing of SEMA6A, respectively. Thus, the findings indicate a correlation between the expression of SEMA6A and TUBB3. Then, we found that a form of 83 kDa of SEMA6A is expressed in the cytoskeleton in association with β-actin. These findings suggest for SEMA6A a novel function in the cytoskeleton and a role in modulating tubulin isotype composition and microtubule dynamics. [Mol Cancer Ther 2008;7(1):233–41]
Small interfering RNA-mediated knockdown of PRL phosphatases results in altered Akt phosphorylation and reduced clonogenicity of pancreatic cancer cells
Authors: Stephens Bret , Han Haiyong , Hostetter Galen , Demeure Michael J. , Von Hoff Daniel D.
Published: January 2008

The PRL phosphatases have been implicated in cancer cell growth and metastasis in a variety of tumor types. Using cDNA microarray, we previously identified and reported PRL-1 as being highly up-regulated in pancreatic cancer cell lines. In this study, we sought to further evaluate the expression of all three PRL phosphatases in pancreatic cancer cell lines and extend our findings to in situ analysis of primary pancreatic tumors taken directly from patients. Additionally, we determine if small interfering RNA-mediated knockdown of relevant PRLs confers antitumor effects in pancreatic cancer cells. Using oligonucleotide expression arrays, mRNA levels of PRL-1 and PRL-2 but not PRL-3 were identified as up-regulated in pancreatic cancer cell lines and tumor samples taken directly from patients compared with those of normal pancreas. Focusing on PRL-1 and PRL-2, high levels of both proteins were detected in a subset of pancreatic cancer cell lines and tumor samples using Western blotting and immunohistochemistry, respectively. Small interfering RNA-mediated knockdown of PRL-1 and PRL-2 in combination resulted in a moderate reduction of cellular growth and migration in MIA PaCa-2 and PANC-1 cells. More importantly, knockdown of both PRL-1 and PRL-2 significantly inhibited colony formation of these cells in soft agar as well as serum-induced Akt phosphorylation. These data support the hypothesis that PRL phosphatases regulate key pathways involved in tumorigenesis and metastasis and that knockdown of both PRL-1 and PRL-2 is required to disrupt PRL phosphatase function in pancreatic cancer cells. [Mol Cancer Ther 2008;7(1):202–10]
Association of theCYP1B1*3allele with survival in patients with prostate cancer receiving docetaxel
Authors: Sissung Tristan M. , Danesi Romano , Price Douglas K. , Steinberg Seth M. , de Wit Ronald , Zahid Muhammad , Gaikwad Nilesh , Cavalieri Ercole , Dahut William L. , Sackett Dan L. , Figg William D. , Sparreboom Alex
Published: January 2008

Using a single nucleotide polymorphism association study in 52 men with prostate cancer receiving docetaxel, we found that individuals carrying two copies of the CYP1B1*3 polymorphic variant had a poor prognosis after docetaxel-based therapies compared with individuals carrying at least one copy of the CYP1B1*1 allele (30.6 versus 12.8 months; P = 0.0004). The association between CYP1B1*3 and response to therapy was not observed in similar subjects receiving non-taxane-based therapy (P = 0.18). The systemic clearance of docetaxel was also unrelated to CYP1B1 genotype status (P = 0.39), indicating that the association of CYP1B1*3 with clinical response is not due to docetaxel metabolism. To explain these results, we hypothesized that an indirect gene-drug interaction was interfering with the primary mechanism of action of docetaxel, tubulin polymerization. We therefore conducted tubulin polymerization experiments with taxanes in the presence or absence of certain CYP1B1 estrogen metabolites, which are known to bind to nucleophilic sites in proteins and DNA, that revealed the primary estrogen metabolite of CYP1B1, 4-hydroxyestradiol (4-OHE2), when oxidized to estradiol-3,4-quinone strongly inhibits tubulin polymerization. The 4-OHE2 is also formed more readily by the protein encoded by the CYP1B1*3 allele, validating further our data in patients. Furthermore, estradiol-3,4-quinone reacted in vitro with docetaxel to form the 4-OHE2-docetaxel adduct. This pilot study provides evidence that CYP1B1*3 may be an important marker for estimating docetaxel efficacy in patients with prostate cancer. This link is likely associated with CYP1B1*3 genotype-dependent estrogen metabolism. [Mol Cancer Ther 2008;7(1):19–26]
Early detection of ovarian cancer using group biomarkers
Authors: Tchagang Alain B. , Tewfik Ahmed H. , DeRycke Melissa S. , Skubitz Keith M. , Skubitz Amy P.N.
Published: January 2008

One reason that ovarian cancer is such a deadly disease is because it is not usually diagnosed until it has reached an advanced stage. In this study, we developed a novel algorithm for group biomarkers identification using gene expression data. Group biomarkers consist of coregulated genes across normal and different stage diseased tissues. Unlike prior sets of biomarkers identified by statistical methods, genes in group biomarkers are potentially involved in pathways related to different types of cancer development. They may serve as an alternative to the traditional single biomarkers or combination of biomarkers used for the diagnosis of early-stage and/or recurrent ovarian cancer. We extracted group biomarkers by applying biclustering algorithms that we recently developed on the gene expression data of over 400 normal, cancerous, and diseased tissues. We identified several groups of coregulated genes that encode for secreted proteins and exhibit expression levels in ovarian cancer that are at least 2-fold (in log2 scale) higher than in normal ovary and nonovarian tissues. In particular, three candidate group biomarkers exhibited a conserved biological pattern that may be used for early detection or recurrence of ovarian cancer with specificity greater than 99% and sensitivity equal to 100%. We validated these group biomarkers using publicly available gene expression data sets downloaded from a NIH Web site (http://www.ncbi.nlm.nih.gov/geo). Statistical analysis showed that our methodology identified an optimum combination of genes that have the highest effect on the diagnosis of the disease compared with several computational techniques that we tested. Our study also suggests that single or group biomarkers correlate with the stage of the disease. [Mol Cancer Ther 2008;7(1):27–37]
Mental Health Policy in Higher Education
Authors: Stone Gerald
Published: January 2008

The 2007 Leona Tyler Address concerns mental health policy in higher education. In the aftermath of the Virginia Tech tragedy, mental health professionals have proffered several proposals. This address reviewed and critiqued these proposals. After critical review, I make several recommendations based on the following principles: developing data-driven policy proposals, specifying of the role and function of campus mental health centers, and instituting an educational process of policy implementation.
The volunteer stages and transitions model: Organizational socialization of volunteers
Authors: Haski-Leventhal Debbie , Bargal David
Published: January 2008

In the last two decades knowledge on volunteering has significantly expanded, but a thorough understanding of the organizational socialization of volunteers is still lacking: the process through which one learns the job, internalizes organizational values and goals, and becomes an effective and involved volunteer. By performing an ethnographic study with Israeli volunteers working for at-risk youth, the organizational process was portrayed. The Volunteering Stages and Transitions Model (VSTM) presented in this article indicates five different phases in volunteers' socialization (nominee, newcomer, emotional involvement, established volunteering and retiring). The importance of the model lies in the way it explains transitions between the phases and details the process, experiences, and emotions involved in each phase. The transformation is reflected in different aspects related to volunteer work: activity and training; emotions and perceptions; attitudes and behavior; perceived benefits and costs; and relationships with the organization, peers and recipients.
Effect of Ethanol as Diluent on the Properties of Mineral Silica Filled Epoxy Composites
Authors: Teh P.L. , Mariatti M. , Akil H.M. , Seetharamu K.N. , Wagiman A.N.R. , Beh K.S.
Published: January 2008

Epoxy composites with mineral silica containing 0—60 vol% were prepared using a mechanical stirrer. Ethanol at 10wt% was used as the diluent in the epoxy system. The mechanical properties of epoxy composites were studied through flexural and single etch notch tensile mode (SEN-T) fracture toughness tests. Scanning electron microscopy (SEM) was used to assess the flexural fracture surface morphology. The thermal properties were characterized using a dilatometer, dynamic mechanical analyzer (DMA), and thermogravimetric analysis (TGA). In general, it is found that the properties of epoxy composites are governed by the filler loading and the addition of ethanol as the diluent. The addition of the diluent in epoxy permits higher amount of filler content in the epoxy composites system, i.e., 60vol%, compared to that of the non-diluent system at 40vol%. In short, higher filler loading present in a diluent system results in higher stiffness and low coefficient of thermal expansion (CTE) as required in the electronic packaging application.
Rigid, Fused-ring Molecules as Nano-reinforcements for Engineering Polymers
Authors: Penn Lynn S. , Jacobs Julie C. , Anthony John E. , Payne Marcia M. , Swiss Brian D. , Mallory Frank B. , Kai Liu  , Miller Ryan A.
Published: January 2008

Rigid, fused-ring molecules were investigated as nano-sized reinforcements for engineering polymers. Because of the high specific surface area associated with their small size, it was expected that they would provide greater enhancement of modulus than equally stiff reinforcements of millimeter and micron dimensions. The expected enhancement was not realized, a result attributed to the bulky alkyl substituents on the rings, placed there to make the fused-ring molecules soluble and dispersible at the molecular level in engineering polymers. It was concluded that the free volume introduced to the nanocomposites by these substituents counteracted the stiffening effect of the fused-ring structure in the molecules. The results point out the inherent trade-off with fused-ring molecules as reinforcements; the types of substituents required to make the molecules dispersible in a polymer matrix are also those that reduce its modulus.
Effect of Long Multi-walled Carbon Nanotubes on Delamination Toughness of Laminated Composites
Authors: Liyong Tong  , Xiannian Sun  , Ping Tan
Published: January 2008

Two continuum-mechanics-based mechanistic models are proposed to characterize the pull-out behavior of a long multi-walled carbon nanotube (MWCNT) from its surrounding matrix based on available experimental observations. One model is based on the mechanism of debonding and its propagation along the MWCNT—matrix interface due to weak interfacial shear strength; and the other is based on the sword-in-sheath mechanism after the breakage of the outermost layer in a MWCNT. Both models are then employed to describe the bridging tractions between the two delaminated laminates in a double cantilever beam (DCB) test specimen, and then to study numerically the effect of the long MWCNTs or nano pins on the delamination toughness of laminated composites. The present numerical results reveal that the MWCNT's length, density, and maximum pull-out displacement as well as the interfacial friction shear stress are important parameters affecting the delamination toughness.
Influence of Food Simulating Solutions on the Hardness of Composite Resins
Authors: Sevimay Müjde , Yücel Münir Tolga , Tak Önjen
Published: January 2008

The aim of this in vitro study was to evaluate the influence of food simulating solutions on surface hardness of three different composite resins. A total of 50 specimens were fabricated for each of Filtek Z 250, Clearfil ST, Aelite LS Packable according to the manufacturers' instructions. Ten specimens of each material were randomly selected and stored in 8% ethanol, 50% ethanol, heptane, distilled water, and air at 37°C for 1 week. After one week conditioning period, hardness testing was carried out with a micro hardness tester. The hardness of composite resin materials are strongly influenced by food simulating solutions.
Adaptive Hierarchical Kinematics in Modeling Progressive Damage and Global Failure in Fiber-reinforced Composite Laminates
Authors: Robbins D.H. , Reddy J.N.
Published: January 2008

This article investigates the feasibility of utilizing adaptive kinematics to reduce the computational effort of finite element modeling of progressive damage and global failure in fiber-reinforced composite laminates. In the present context, adaptive kinematics refers to the selective use of different types of macroscopic laminate models for different regions of the computational domain, based on the solution complexity within each region. Each of these macroscopic laminate models can be distinguished by the manner in which the displacement field is assumed to vary through the thickness of the laminate. In the present study, kinematic adaptivity is made possible through the use of variable kinematic finite elements (VKFE) that are developed by hierarchically combining two or more types of assumed displacement fields in a single finite element domain. The hierarchical data structure of the VKFE greatly simplifies the process of connecting elements that represent different types of laminate theories, thus facilitating adaptive analysis. The adaptive kinematic concept is demonstrated for the bending of simply supported laminates that exhibit diffuse, widespread damage and laminate tensile test specimens that exhibit very intense localized damage due to the free edge effect. The results obtained in this study clearly demonstrate that the use of adaptive kinematics can significantly reduce the overall computational effort of progressive damage solutions without compromising solution accuracy.
Thermal and Mechanical Properties of Blends and Composites from HDPE and Date Pits Particles
Authors: Ghazanfari A. , Emami S. , Panigrahi S. , Tabil L.G.
Published: January 2008

The date pits flour was used as a filling material in composition with high density polyethylene (HDPE). The blending proportions were: (1) 10% date pits, 90% HDPE; (2) 20% date pits, 80% HDPE; (3) 30% date pits, 70% HDPE; and (4) 40% date pits, 60% HDPE. Thermal conductivities, specific heat, and melt flow index of the blends were determined. The thermal conductivities ranged from 0.460 to 0.720 W/(m°C) and specific heats ranged from 1.10 to 5.30 kJ/(kg°C). The tensile and flexural tests on composite plates, fabricated by compress molding, indicated that strength and strain values decreased with increase in the percentage of date pits. There was no significant difference between flexural moduli of elasticity of the composites, but tensile modulus had the highest value at 30% blend. Moduli of elasticity of the composites were lower than the plates prepared from virgin HDPE at 180°C. It was presumed that high temperature processing of pure HDPE altered its original properties and consequently increased its modulus of elasticity.
Synergistic Effects of Carbon Fillers in Thermally Conductive Liquid Crystal Polymer Based Resins
Authors: King Julia A. , Hauser Rebecca A. , Tomson Amanda M. , Wescoat Isabel M. , Keith Jason M.
Published: January 2008

Thermally conductive resins are needed for fuel cell bipolar plates. Varying amounts of three different carbons (carbon black, synthetic graphite particles, and carbon fiber) were added to Vectra A950RX Liquid Crystal Polymer. The resulting single filler composites were tested for thermal conductivity. In addition, the effects of single fillers and combinations of two different carbon fillers were studied via a factorial design. Synthetic graphite caused the largest statistically significant increase in composite through plane and in plane thermal conductivity. Composites containing synthetic graphite/carbon black and synthetic graphite/carbon fiber caused a statistically significant increase in through plane and in plane thermal conductivity.
Tensions of neo-liberal development
Authors: Costa Dia Da
Published: January 2008

In this article, I examine the tensions of neo-liberal development as experienced in contemporary West Bengal, culminating in recent struggles over land acquisition. My analysis is conducted through three modes of reflection—the political actions of a cultural group called Jana Sanskriti, the discourse and policy making of the Communist Party of India (Marxist) (CPM), and David Harvey's conceptual distinction between expanded reproduction and accumulation by dispossession in his book, The New Imperialism (2003). Harvey argues that processes of ‘expanded reproduction’ and ‘accumulation by dispossession’ are organically and historically linked. Yet, he sustains a dichotomy by arguing that the flight of capital following the robbery of public goods through privatisation is a worse problem than the insertion of capital for privatisation. I argue that the tensions of neo-liberal development at the historical level in West Bengal belie Harvey's dichotomies at the conceptual level. I show that Bengalis struggle over the very purpose, value and future of capital insertion. Rather than Harvey's ‘which is worse’ question, some citizens in Bengal question a grammar of distribution in which welfare and productive opportunities can only be achieved through particular forms of capital insertion for particular visions of industrial development.
Ethnohistories behind local and global bazaars
Authors: Ciotti Manuela
Published: January 2008

In this article I analyse the history of weaving in a Chamar community on the outskirts of the city of Banaras, eastern Uttar Pradesh (UP). I explore the recruitment of rural Chamar men as apprentices to the city's Muslim master weavers, the consequent emergence of a class of Chamar artisans and its gradual disappearance from the 1990s onwards. I argue that the weaving era represented a historical moment of relative prosperity for the Chamar community, where strengthened ties with urban Muslim weavers enabled a progressive disentanglement from relationships of domination by rural landed elites. As a consequence, a positive Chamar self-representation was crafted in ways which contrasted with the trends of identity consolidation for ‘Untouchable’ communities—as well as other castes—that started during the colonial period. Further, an important phase of social mobility was initiated through weaving. With the onset of economic liberalisation, as the handloom sari industry has lost its momentum, weavers have increasingly abandoned their occupation to join the ranks of unskilled casual labourers. Surrounded by compelling socio-economic imperatives that their meagre wages can not meet, former weavers appear to belong to a ‘lost world’ as they try to make sense of the laws of local and global bazaars.