cssi/SciSciGPT-SciSciNet huggingface dataset:
Price distortions in developing countries: A bias against agriculture

This article evaluates the effects of government intervention in agricultural commodity markets for a sample of developing countries. It also presents a review of the methodology for quantifying the effects of the distortions on prices, supply, demand, incomes, and foreign exchange. The empirical results indicate that the agricultural sector in developing countries is often heavily taxed. As a consequence, agricultural production is discouraged, while consumption is subsidized, and the increases in government revenue provided by taxation are counterbalanced by a loss of foreign exchange earnings.
Environmental Education: Some Global and Local Perspectives

What constitutes an effective environ mental education program? Where can teachers go for more informa tion? These writers provide an overview and a resouce list.
Sister chromatid exchange distributions in rabbit lymphocytes treated with streptonigrin.

Streptonigrin (NSC-45383), a direct-acting clastogen which induces SCEs in vivo and chromosome aberrations both in vivo and in vitro, was evaluated for SCE induction in both G/sub 0/ and stimulated rabbit lymphocytes. Determinations were made for 16 cultures from seven female rabbits. These included controls as well as cells exposed to 90 ..mu..g/kg in vivo, cells pulse-treated with 50 ng/ml in vitro, and a culture continously exposed to 5 ng/ml in vitro. For all cultures the SCE/cell frequency was determined from 20 complete (44 chromosome) metaphases and, in selected cultures, SCEs on individual chromosomes (880 per culture from 20 cells) were enumerated to determine SCE/chromosome frequency and the chromosomal distribution of SCEs. Analysis of variance and least significant difference tests of the ..sqrt..x transformed SCE/cell data show that cells exposed to streptonigrin while dividing have significantly higher frequencies (over double the control 5.3 SCE/cell value) whereas treated G/sub 0/ cells were not significantly different from the controls. Dispersion analysis of both SCE/cell and SCE/chromosome data confirms the adequacy of the Poisson distribution for spontaneous or baseline but not streptonigrin-induced SCEs.
The Effects of Spaceflight on the Mineralization of Rat Incisor Dentin

Specific effects of space flight on dentin formation on the lower incisors of male rats were determined. Data were Fourier analyzed to determine the spectra of chemical growth rhythms. It was found that Calcium and P were more concentrated in the newly forming dentin of the Flight rats than in comparable regions of control tissues. There was no significant difference in the mean S-concentration between the two groups, but the pattern of S-distribution in the recently formed dentin from the Flight rats was different from that in the control group. Sulfur fluctuations in flight animals periodically peak above the irregular background fluctuations, but there are no comparable sulfur peaks across the dentin in the control. It is indicated that spaceflight has measurable effects on dentinogenesis, and may also bear on the problem of the regulatory role of proteoglycans in mineralization and the maturation of mineral and matrix moieties in skeletal tissue.
Microbial carbohydrate specific antibodies distinguish between different stages of differentiating mouse cerebellum.

High titered anticarbohydrate antibodies were used to identify cell surface carbohydrates during different stages in histogenesis of mouse cerebellum in a micro tissueculture system which mimics selected features of in vivo cerebellum development. Blockage of fiber formation within the first few days in vitro and inhibition of cell migrations by carbohydrate-specific antibodies served as an assay system for possible contributions of surface carbohydrates to the behavior of developing cerebellar cells. Microbial strains were selected on the basis of carbohydrate structures of their cell wall antigens, and anticarbohydrate antibodies were raised against treated whole bacteria and yeast in rabbits. We found that antibodies to mannan were active at all stages of development tested (embryonic day 13, E13; the day of birth, P0; and postnatal day 7, P7). Antibodies to sialic acids prepared against strains B and C of Neisseria meningitidis distinguish different subterminal structures: anti-B reacted with E 13 and P0 cerebellar cells, and anti-C mostly with cells older than P7. Antifetuin antibody recognized E 13 and P0 but not P7 cell populations. Pneumococcus C strain R36A-specific antibodies were effective only after coating cells to C type carbohydrate before application of the antibody. The results demonstrate that antimicrobial carbohydrate antibodies cross-react with mammalian cell surface carbohydrate structures and therefore can be used as a powerful tool in tissue culture to analyze those structures which might control cell behaviors pertinent to cerebellar development.
A validated liquid chromatography-electrospray ionization-mass spectrometry method for quantification of spilanthol in Spilanthes acmella (L.) Murr.

Introduction – The medicinal plant Spilanthes acmella (L.) Murr. has demonstrated an array of biological activities that are generally attributed to the presence of spilanthol and other alkylamides. Recently this plant has been of interest due to its potential for the treatment and prevention of malaria. Objective – The aim of this study was to develop a liquid chromatography–electrospray ionisation–mass spectrometry (HPLC-esiMS) method for rapid identification and quantification of the alkylamide spilanthol from S. acmella. Methodology – Hydroethanolic extracts were prepared from fresh S. acmella using different percentages of ethanol and were stored at −80, −20 and 25°C. Spilanthol was isolated and used as a standard for quantitative analysis. Results – Validation parameters for the HPLC-esiMS analysis of spilanthol were as follows: repeatability, ≤6%; intermediate precision, ≤2%; range, 0.45–450 µm; limit of detection, 0.27 µm; and limit of quantification, 0.45 µm. Eight alkylamides in the S. acmella extract were identified based on MS-MS fragmentation patterns, and NMR analysis confirmed the identity of the most abundant of these as spilanthol. Spilanthol was extracted most efficiently in solvents containing >75% ethanol, and was stable in ethanolic extracts stored at all three temperatures. Conclusion – These results demonstrate the effectiveness of HPLC-esiMS for quantitative and qualitative analysis of spilanthol. We show that spilanthol is effectively extracted in ethanol, and is stable in ethanol extracts for over 6 months, even at room temperature. Copyright © 2010 John Wiley & Sons, Ltd.
Dynamic crack growth in particulate bimaterials having discrete and diffuse interfaces: Role of microstructure

Abstract Role of microstructure on interfacial crack growth in particulate bimaterials made of glass particle reinforced epoxy is examined experimentally. Two types of bimaterials, one with a discrete jump in mean filler particle size across the interface and the other with two intermixed particle sizes in the interfacial region, are studied. The choice of particle sizes used in bimaterials is based on a set of experiments in which particle size effects on fracture behavior of monolithic specimens with single particle size are established using optical interferometry and high-speed photography. A non-monotonic steady state stress intensity factor (KIss) variation with mean particle size is observed in the size range of 7–203 μm for 10% volume fraction. Among the selected particles sizes, 35 μm mean diameter is found to produce the highest KIss. Increasing or decreasing particle size results in measurable reduction in KIss of the composite. Based on this result, discrete and diffuse bimaterials made of 35 μm and 203 μm diameter filler particles are studied. The KIss of the diffuse interface with intermixed particle sizes is bounded by the ones for monolithic configurations with single size particles. Further, KIss appears to vary linearly with the volume fraction of particle size having lower KIss in monolithic configurations. On the contrary, in case of a microstructurally discrete interface, the measured KIss is same as the one for the weaker half of the bimaterial.
Ontology development for a pharmacogenetics knowledge base.

Research directed toward discovering how genetic factors influence a patient’s response to drugs requires coordination of data produced from laboratory experiments, computational methods, and clinical studies. A public repository of pharmacogenetic data should accelerate progress in the field of pharmacogenetics by organizing and disseminating public datasets. We are developing a pharmacogenetics knowledge base (PharmGKB) to support the storage and retrieval of both experimental data and conceptual knowledge. PharmGKB is an Internetbased resource that integrates complex biological, pharmacological, and clinical data in such a way that researchers can submit their data and users can retrieve information to investigate genotype–phenotype correlations. Successful management of the names, meaning, and organization of concepts used within the system is crucial. We have selected a frame-based knowledge-representation system for development of an ontology of concepts and relationships that represent the domain and that permit storage of experimental data. Preliminary experience shows that the ontology we have developed for gene-sequence data allows us to accept, store, and query data submissions.
Dwell-Time Distribution Analysis of Polyprotein Unfolding Using Force-Clamp Spectroscopy

Using the recently developed single molecule force-clamp technique we quantitatively measure the kinetics of conformational changes of polyprotein molecules at a constant force. In response to an applied force of 110 pN, we measure the dwell times of 1647 unfolding events of individual ubiquitin modules within each protein chain. We then establish a rigorous method for analyzing force-clamp data using order statistics. This allows us to test the success of a history-independent, two-state model in describing the kinetics of the unfolding process. We find that the average unfolding trajectory is independent of the number of protein modules N in each trajectory, which varies between 3 and 12 (the engineered protein length), suggesting that the unfolding events in each chain are uncorrelated. We then derive a binomial distribution of dwell times to describe the stochastic dynamics of protein unfolding. This distribution successfully describes 81% of the data with a single rate constant of α = 0.6 s−1 for all N. The remainder of the data that cannot be accounted for suggests alternative unfolding barriers in the energy landscape of the protein. This method investigates the statistical features of unfolding beyond the average measurement of a single rate constant, thus providing an attractive alternative for measuring kinetics by force-clamp spectroscopy.
Development and validation of a high-performance liquid chromatography method for the simultaneous determination of aspirin and folic acid from nano-particulate systems.

Attention has shifted from the treatment of colorectal cancer (CRC) to chemoprevention using aspirin and folic acid as agents capable of preventing the onset of colon cancer. However, no sensitive analytical method exists to simultaneously quantify the two drugs when released from polymer-based nanoparticles. Thus, a rapid, highly sensitive method of high performance liquid chromatography (HPLC) analysis to simultaneously detect low quantities of aspirin (hydrolyzed to salicylic acid, the active moiety) and folic acid released from biodegradable polylactide-co-glycolide (PLGA) copolymer nanoparticles was developed. Analysis was done on a reversed phase C18 column using a photodiode array (PDA) detector at wavelengths of 233 nm (salicylic acid) and 277 nm (folic acid). The mobile phase consisted of acetonitrile − 0.1% trifluoroacetic acid mixture programmed for a 30 min gradient elution analysis. In the range of 0.1 – 100 μg/mL, the assay showed good linearity for salicylic acid (R2 = 0.9996) and folic acid (R2 = 0.9998). The method demonstrated good reproducibility, intra- and inter-day precision and accuracy (99.67, 100.1%) and low values of detection (0.03, 0.01 μg/mL) and quantitation (0.1 and 0.05 μg/mL) for salicylic acid and folic acid, respectively. The suitability of the method was demonstrated by simultaneously determining salicylic acid and folic acid released from PLGA nanoparticles.
A bioremediation teaching module based on BIO1D

Abstract Educational use of environmental software offers both opportunity and challenges to software developers. Desirable attributes for educational-use environmental software are discussed and illustrated using the bioremediation software package BIO1D. Examples are presented to illustrate how one can ‘port’ environmental software into the classroom, and on how this can help modernize and enliven engineering education. An example student simulation is also presented to illustrate how this can empower students to innovate with advanced technologies such as bioremediation. It is hoped that this paper will lead to more contributions on instructional use of environmental software. Modelers should be supplying more leadership in the debate about the proper roles of environmental models in both education and practice.
Temperature and field dependence of resistivities and anisotropy of layered manganites La2−2xSr1+2xMn2O7

Abstract In-plane ϱ ab and out-of-plane ϱ c resistivities of La 1.2 Sr 1.8 Mn 2 O 7 and LaSr 2 Mn 2 O 7 have been measured by a multiterminal technique. We focus on the effects that magnetic and charge ordering transitions have on the anisotropy σ ab /σ c which reflects the ratio of the phase coherence lengths in the respective directions. Both resistivities of La 1.2 Sr 1.8 Mn 2 O 7 decrease dramatically below the Curie temperature T C ≈ 135 K . Anisotropy changes with temperature nonmonotonically and displays a peak close to T C . In LaSr 2 Mn 2 O 7 , ϱ c and ϱ ab display a broad peak close to the paramagnetic-antiferromagnetic transition temperature T N ≈ 165 K . The anisotropy exhibits an even more complex behavior than in La 1.2 Sr 1.8 Mn 2 O 7 , displaying a maximum at the charge ordering temperature and a minimum at T N .
The effects of ration level on food retention time in juvenile lemon sharks, Negaprion brevirostris

Fecal production was monitored to observe the effects of meal size on retention time of food in the digestive tracts of lemon sharks, Negaprion brevirostris. Initial appearance of feces occurred more rapidly when ration level was increased. The onset of fecal production was negatively correlated with rate of intake. Production of feces continued for a longer period of time when meal size was increased. Retention time of food was directly related to feeding rate, suggesting that the rate of digestion was constant. The correlation between retention time and intake on a percentage body weight basis was greater than the correlation between retention time and intake on an energy density basis. The use of agar to bind food may have delayed digestion and prolonged food passage for sharks fed an experimental diet.
Skin and heating effects of railgun current

The authors present a calculation in a simplified geometry for the current distribution in the rails of a railgun, taking into account the motion of the armature and the time variation of the current. Closed-form, asymptotic results for the current density are obtained for arbitrary time-dependent currents and velocities, in the limit in which the length scale k/sub 0//sup -1/ is small, where k/sub 0/=( mu sigma nu ), sigma is the electrical conductivity of the rails, and nu is the speed of the armature. Because of eddy-current effects the rail current may reverse in portions of the rails when the total current decreases. The current is used as a source of Joule heating to find the temperature distribution in the rails. The heat diffusivity is negligible. Numerical results concerning melting are given. >
Insight into the coupling mechanism of the vitamin K-dependent carboxylase: mutation of histidine 160 disrupts glutamic acid carbanion formation and efficient coupling of vitamin K epoxidation to glutamic acid carboxylation.

Vitamin K-dependent (VKD) proteins become activated by the VKD carboxylase, which converts Glu’s to carboxylated Glu’s (Gla’s) in their Gla domains. The carboxylase uses vitamin K epoxidation to drive Glu carboxylation, and the two half-reactions are coupled in 1:1 stoichiometry by an unknown mechanism. We now report the first identification of a residue, His160, required for coupling. A H160A mutant showed wild-type levels of epoxidation but substantially less carboxylation. Monitoring proton abstraction using a peptide with Glu tritiated at the γ-carbon position revealed that poor coupling was due to impaired carbanion formation. H160A showed a 10-fold lower ratio of tritium release to vitamin K epoxidation than wild-type enzyme (i.e., 0.12 versus 1.14, respectively), which could fully account for the fold decrease in coupling efficiency. The Ala substitution in His160 did not affect the Km for vitamin K and caused only a 2-fold increase in the Km for Glu and 2-fold decrease in the activation of vitamin...
The practical realities of high-speed digital test in a production environment

The challenges of test development and system setup using Automated Test Equipment (ATE) change when transitioning from a world where clock and data are transmitted separately on wide parallel buses to a world where the clock is embedded in data transmitted on fewer high-speed serial lanes. Parallel buses transmit and receive data with a synchronous clock and typically operate at data rates less than 1Gb/s. The challenges in meeting timing requirements for large high-speed parallel buses have limited the growth of parallel bus standards. These challenges have brought a growth in high-speed serial bus standards. Both parallel and serial data transmission come with system design challenges. ATE designed to test high-speed parallel and serial buses includes features to minimize design challenges for the test engineer. This paper discusses critical features in ATE that enable reliable testing of parallel buses with synchronous clocks as well as serial buses with embedded clocks.
Liaison psychiatry and its dilemmas

Because the status of liaison psychiatry, its accomplishments and its functions within psychiatry and medicine need to be assessed, Dr. Neill’s commentary is timely and focuses on several key issues that are frequently cited as dilemmas in the field. Dr. Neil1 has outlined what he sees as the liabilities of liaison psychiatry: An overpromise, the prom ‘i’ Iga
Rate transition and regulatory coupling in endocytosis of interferon‐α and tumor necrosis factor‐α in human epithelial tumor cells

The time-dependent concentrations of interferon-alpha and tumor necrosis factor-alpha associated with the membrane and internalized by cells contain information on the kinetics of endocytosis and their cellular processing. This information can be reduced quantitatively by application of the respective compartmental models. In our studies of human epithelial tumor cells interacting with human interferon-alpha and human tumor necrosis factor-alpha, we accounted only for actual endocytosis and elimination of the tracer from cells by a novel method sensitive to changes in the rate of endocytosis, to the delay in tracer elimination, and to the nonlinear regulatory coupling between endocytosis and the internalized ligand. Data reduced by this method resulted in best-fit parameter values statistically superior to values obtained by previous methods (Bajzer et al., 1989). The results indicate a change with time in the rate of endocytosis of tumor necrosis factor-alpha and the inhibition of endocytosis by the endocytosed ligand-receptor complex. We conclude that sorting and processing of interferon-alpha and tumor necrosis factor-alpha are restricted by the type of both the receptor and the cell.
The minimally invasive open pyeloplasty

Abstract Background The dismembered pyeloplasty is the operation of choice for ureteropelvic junction obstruction (UPJO). Recently, with the advent of improved minimally invasive techniques and equipment, laparoscopic dismembered pyeloplasty has gained popularity. We present our experience with a minimally invasive open pyeloplasty. Materials and methods A retrospective review of the last 5 years of consecutive open pyeloplasties was performed with regard to age, surgical operative time, length of hospital stay, need for postoperative narcotics and surgical success. Results Seventy-four patients had a dismembered pyeloplasty using an open flank incision: 34 patients ( 10 years). Mean surgical time for patients according to age was: 10 years, 134 ± 37.8 min. Mean incision sizes for the respective groups were 2.01 ± 0.50 cm, 1.93 ± 0.73 cm, 2.71 ± 1.55 cm and 3.5 ± 1.58 cm. The last 20 patients under 1 year of age had incisions of 1–1.5 cm. The majority of incisions were via a posterior subcostal muscle splitting approach. All patients received postoperative ketorolac and acetaminophen. Supplemental narcotics were not required in any patient less than 10 years old. All patients were discharged in Conclusion The minimally invasive approach to open pyeloplasty is a safe and effective treatment choice for UPJO. In small children our technique can be easily performed through a small incision without excessive postoperative pain allowing for early discharge. Our results with a refined open surgical technique challenge the current trend in the literature that laparoscopic pyeloplasty techniques are superior with regard to cosmesis, length of stay and postoperative narcotic use.
Identifying cardiac transplant rejection in children: diagnostic utility of echocardiography, right heart catheterization and endomyocardial biopsy data

Abstract Background There has been a continued search for alternative diagnostic techniques that do not necessitate endomyocardial biopsy for diagnosing rejection in cardiac transplant recipients. The purpose of this study is to evaluate the role of echocardiography and hemodynamic catheterization data compared with endomyocardial biopsy results, in rejection surveillance for the pediatric heart transplant recipient. Methods A prospective, blinded evaluation was performed utilizing echocardiographic and standard right heart catheterization parameters to predict acute rejection episodes. Results Forty-nine patients underwent 281 biopsies. Two groups were defined: those with Grade Conclusions Differences in both echocardiographic and hemodynamic data were not clinically significant between the 2 groups of patients. Although many of the catheterization-derived parameters were statistically significant, they did not permit effective discrimination between groups. This is the only clinically relevant application of such data and may explain the conflicting previous reports. It is only through analyses such as ROC that the clinical application (or lack thereof) can be appreciated in this population.
Evolutionary profiles derived from the QR factorization of multiple structural alignments gives an economy of information.

We present a new algorithm, based on the multidimensional QR factorization, to remove redundancy from a multiple structural alignment by choosing representative protein structures that best preserve the phylogenetic tree topology of the homologous group. The classical QR factorization with pivoting, developed as a fast numerical solution to eigenvalue and linear least-squares problems of the form A x = b , was designed to re-order the columns of A by increasing linear dependence. Removing the most linear dependent columns from A leads to the formation of a minimal basis set which well spans the phase space of the problem at hand. By recasting the problem of redundancy in multiple structural alignments into this framework, in which the matrix A now describes the multiple alignment, we adapted the QR factorization to produce a minimal basis set of protein structures which best spans the evolutionary (phase) space. The non-redundant and representative profiles obtained from this procedure, termed evolutionary profiles, are shown in initial results to outperform well-tested profiles in homology detection searches over a large sequence database. A measure of structural similarity between homologous proteins, Q H , is presented. By properly accounting for the effect and presence of gaps, a phylogenetic tree computed using this metric is shown to be congruent with the maximum-likelihood sequence-based phylogeny. The results indicate that evolutionary information is indeed recoverable from the comparative analysis of protein structure alone. Applications of the QR ordering and this structural similarity metric to analyze the evolution of structure among key, universally distributed proteins involved in translation, and to the selection of representatives from an ensemble of NMR structures are also discussed.
Corrosion Behavior of Tantalum and Niobium in Hydrobromic Acid Solutions (II) on Passive Films and Hydrogen Absorption

Abstract The corrosion behavior of tantalum (Ta) and niobium (Nb) in hydrobromic acid solutions has been studied with respect to their surface states and hydrizing by scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), a hydrogen determinator, and x-ray diffraction (XRD). The test specimens were immersed in a 47 wt% HBr solution bubbled with hydrogen and in another that contained 0.05 mol/dm3 of bromine at 25 and 100°C for 15, 30, and 45 days. On Ta under every condition and Nb at 25°C, the surface films consisting of their pentoxides thickened with increasing immersion time and exhibited no significant changes in appearance or hydrogen content. However, fine pits less than 5 µm in diameter were formed on Nb specimens in both the solutions at 100°C at the early stage of immersion. In the solution with hydrogen, the pitting extended over the specimen surfaces with increasing immersion time, and developed into general corrosion after 45 days, while the progress of the pitting was ter...
The quantum efficiency of photosynthesis

Abstract Photosynthesis is a unique endothermic photochemical reaction in which chemical energy is gained from visible light energy by the combined action of several quanta. Nothing similar is known in the nonliving world. It was first reported a quarter of a century ago 1 that in photosynthesis the greater part of the absorbed visible light energy could be converted into chemical energy under optimum conditions. Indeed, no more than four quanta of red light seemed to be necessary to produce one molecule of oxygen gas, which is close to the thermodynamic requirement of three quanta. It is easy to understand that this result, lacking any analogy, has sometimes been doubted by theoreticians, and it is a fact that certain investigators have raised methodological objections 2 . For this reason we have reinvestigated the question of the minimum quantum requirement of photosynthesis as measured by oxygen and carbon dioxide gas exchange. The present paper is a short summary of our findings by new and simplified methods.
Distribution of carboxylation and decarboxylation enzymes in isolated mesophyll cells and bundle sheath strands of C4 plants

Abstract Mature leaves of Cyperus rotundus, Cyperus polystachyos, Digitaria decumbens , and Digitaria sanguinalis were separated, using pectinase and cellulase, into pure preparations of mesophyll cells and bundle sheath strands. Assays on these distinct leaf cell types show a clear compartmentation of phosphoenolpyruvate carboxylase, >98%, into mesophyll cells and of ribulose-1, 5-diphosphate carboxylase and malic enzyme, >98%, into the bundle sheath strands. The results clearly establish that the major CO 2 uptake in mesophyll cells is via a β-carboxylation and that both a decarboxylation and a carboxylation reaction occurs in the bundle sheath strands of plants using C 4 -dicarboxylic acid photosynthesis.
The Psychological Benefits of Bad Poetry

The author was the founder and secretary pro-tem of the Bad Poets Society at Princeton Theological Seminary. This distinction does not appear on his official resume. The Society did not have meetings but it had a newsletter that came out several times a year comprised of bad poetry written by members of the faculty and staff. These poetic works included reflections on institutional matters. This article contains bad poetry by the author relating to such matters. This poetry illustrates Sigmund Freud’s (Jokes and Their Relation to the Unconscious. Norton, New York, 1960) view of humor as saving in the expenditure of painful emotions, costly inhibitions, and difficult thinking. The parasitical nature of bad poetry is also noted and illustrated with the author’s own poems.
Disruption of self-assembly and altered mechanical behavior in polyurethane/zinc oxide nanocomposites

Abstract The addition of less than 1 vol%, 33 nm zinc oxide nanoparticles into a polyurethane matrix resulted in approximately 40% decrease in the Young's modulus, 80% decrease in strain at fracture, and 50% decrease in the storage modulus, but at the same time resulted in an ∼11 °C increase in the glass transition temperature of the polymer. These results appear to contradict the general principle observed for many polymeric systems, where higher glass transition temperature generally means higher elastic modulus. Detailed experiments with FTIR, DMTA, FE-SEM, and AFM indicated that the addition of ZnO nanoparticles disrupts the phase separation in the polymer, resulting in weaker mechanical properties. The special interaction between the particles and polymer possibly constrains the mobility of polymer chains, which increases the glass transition temperature. The most likely reason for the disruption and the nature of the interaction is the reaction between the surface hydroxyl groups of the zinc oxide nanoparticles and the isocyanate groups of the polyurethane pre-polymer.
Abstract 572: Suppression of urokinase plasminogen activator receptor blocks recruitment of endothelial cells by inhibiting irradiation-induced monocyte chemo-attractant protein-1 in meningioma

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Chemokines, a common outcome of inflammatory reaction, play a vital role in recruiting various cell types during tissue repair. Radiation, a major therapeutic modality in cancer treatment, has been described to induce inflammatory response, which might lead to the expression of several chemokines. In the present study, we investigated the mechanisms underlying radiation-induced monocyte chemo-attractant protein (MCP-1) in meningioma cell lines and the paracrine effect on human microvascular endothelial cells (HMEC). Upon radiation, meningioma cell lines (IOMM Lee and SF 3061) showed an increased expression of MCP-1. In addition, irradiated meningioma cancer cell culture conditioned medium (CM) demonstrated an increased ability to attract HMEC and stimulated MCP1-induced protein (MCPIP), VEGF and angiogenin expression in HMEC as compared to HMEC grown in non-irradiated cancer cell CM. This chemotactic activity and angiogenic stimulator effect in HMEC was nearly abrogated by depleting MCP-1 from the irradiated cancer cell CM using a neutralizing anti-MCP-1 monoclonal antibody. Inhibition of ERK activation and NF-κB nuclear translocation hindered irradiation-induced MCP-1 expression in both meningioma cell lines. Considering that radiation induces uPA/uPAR expression and stimulates the ERK signaling pathway, we correlated the role of irradiation-induced uPA/uPAR in MCP-1 regulation. Supplementing cancer cells with exogenous ATF-uPA (with and without radiation) activated ERK phosphorylation, nuclear translocation of the NF-κB p65 sub-unit (Rel-A), and MCP-1 expression. Downregulation of uPA and uPAR by transfecting the cancer cells with a siRNA-expressing plasmid (pU) inhibited irradiation-induced ERK activation, nuclear translocation of Rel-A, NF-κB DNA binding activity, and MCP-1 expression. Further, pU-transfected cancer cells (with or with radiation) reduced the potential to attract and stimulate angiogenic signaling in HMEC under in vitro conditions. Under in vivo conditions, we observed that pU transfected cancer cells (with and without irradiation) showed a significant reduction in number of CD31+ endothelial cells and CD14+ monocytes present in the tumor regions compared to tumor formed from irradiated cancer cells. In conclusion, we demonstrated that blockade of uPA/uPAR expression inhibits irradiation-induced MCP-1, thereby inhibiting the chemo-attractant ability of cancer cells to recruit other cells during the inflammatory process induced by radiation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 572. doi:10.1158/1538-7445.AM2011-572
A Mass Spectrometric Study of the BeO-BeF2 System at High Temperatures.

Mass spectrometric studies were made at high temperatures of the vapors over BeF2(s) and BeO(s) individually and of their mixture. The sublimation enthalpy, ΔH0°=55.56±0.43kcal/mol , where 1 kcal equals 4184 J, was obtained for BeF2 by the use of a log I+T versus 1/T plot. A complex molecule appeared in the BeF2-BeO system at high temperatures which, on the basis of its m/e position, corresponded to Be2OF2. For the reaction, BeO(s) + BeF2(g) = Be2OF2(g), a second law treatment of the data gave an enthalpy value, ΔH0°=41.56±1.8kcal/mol . The data, combined with free energy functions, resulted in a mean reaction enthalpy, ΔH0°=42.6kcal/mol . The heat of formation for Be2OF2(g), ΔH0°=-288.3kcal/mol , was computed using the reaction enthalpy based on the second law.
Modeling rural landowners' hunter access policies in East Texas, USA

Private landowners in East Texas, USA, were aggregated into one of four policy categories according to the degree of access allowed to their lands for hunting. Based on these categories, a logistic regression model of possible determinants of access policy was developed and probabilities of policy adoption were calculated. Overwhelmingly, attitudes toward hunting as a sport, incentives, and control over the actions of hunters were most predictive of landowners' policies. Additionally, the availability of deer was found to be negatively correlated with access, thereby suggesting management efforts to increase deer populations may be counter to increasing access. Further, probabilities derived from the model indicated that there was almost a 7 in 10 chance (0.66) that landowners would adopt policies commensurate with allowing family and personal acquaintances to hunt on their property. However, the probability of increasing access beyond this level, where access was provided for the general public, dropped off drastically to less than 5% (0.04).
A Progressive Deployment Strategy for Cooperative Adaptive Cruise Control to Improve Traffic Dynamics

Cooperative adaptive cruise control (CACC) vehicles are intelligent vehicles that use vehicular ad hoc networks (VANETs) to share traffic information in real time. Previous studies have shown that CACC could have an impact on increasing highway capacities at high market penetration. Since reaching a high CACC market penetration level is not occurring in the near future, this study presents a progressive deployment approach that demonstrates to have a great potential of reducing traffic congestions at low CACC penetration levels. Using a previously developed microscopic traffic simulation model of a freeway with an on-ramp -- created to induce perturbations and trigger stop-and-go traffic, the CACC system's effect on the traffic performance is studied. The results show significance and indicate the potential of CACC systems to improve traffic characteristics which can be used to reduce traffic congestion. The study shows that the impact of CACC is positive and not only limited to a high market penetration. By giving CACC vehicles priority access to high-occupancy vehicle (HOV) lanes, the highway capacity could be significantly improved with a CACC penetration as low as 20%.
Cosmetic Genetics and Virtue-Based Restraints on Autonomy

Ruiping Fan's (2010) article, “A Confucian Reflection on Genetic Enhancement,” is of considerable importance, for a number of reasons. First, Fan presents a clear account of a Confucian, relational...
Purification and characterization of glutathione S-transferase from sugarcane leaves

Abstract Glutathione S -transferase has been purified from leaves of sugarcane using (NH 4 ) 2 SO 4 fractionation, isoelectric focusing, Sephadex G-100 gel filtration, DEAE cellulose ion-exchange chromatography, and affinity chromatography over GSH-linked to epoxy-activated Sepharose 6B. The enzyme has a pI value of 4.7 and consists of two subunits having M r values of ca 22 500 and 24 000. N -Terminal amino acid sequence analysis of both the subunits indicates a high degree of homology between these two subunits. Both subunits also have primary structure homologies with the corn GST subunits characterized previously. Kinetic properties of the enzyme are described and compared with other plant glutathione S -transferases. Similar to human GST isoenzymes, sugarcane leaf GST is also inhibited by the herbicides 2,4-dichlorophenoxyacetate, 2,4,5-trichlorophenoxyacetate, and chenodeoxycholate.
Some remarks on automorphisms of bounded displacement and bounded cocycles

Some time agoTits has considered the question of characterizingB(G), and more generally, of finding the automorphisms of bounded displacement ofG, particularly whenG is a connected real Lie group. Our purpose here is to extend these results to various other cases as well as to deal with the analogous questions for 1-cocycles. We concern ourselves, among other things, with the question of sufficient conditions forB(G)=Z(G), the center, or more generally, forG to have no non-trivial automorphisms of bounded displacement. The significance of such conditions can be seen in work of the author together withF. Greenleaf andL. Rothschild where, for example, the Selberg form of the Borel density theorem is considerably generalized. These conditions are therefore closely related to, but not identical with, sufficient conditions for the Zariski density of a closed subgroupH ofG withG/H having finite volume, see [11]. For this reason it is enlightening to compare these results with those of [11]. On the cocycle level, we give sufficient conditions for the points with bounded orbit under a linear representation to be fixed and more generally, for a bounded 1-cocycle to be identically zero. These conditions actually play a role in [11]; they are among the sufficient conditions necessary to establish Zariski density ofH inG. We also deal with certain converse questions and applications to homogeneous spaces of finite volume. For example, ifG/H has finite volume and α is an automorphism ofG leavingH pointwise fixed, then α has bounded displacement. If ϕ is a 1-cocycle and ϕ/H is trivial, then ϕ is itself bounded.
A MEG study of the olivine and spinel forms of Mg2SiO4

In this paper we present a theoretical investigation of the structures and relative stability of the olivine and spinel phases of Mg2SiO4. We use both a purely ionic model, based on the Modified Electron Gas (MEG) model of intermolecular forces, and a bond polarization model, developed for low pressure silica phases, to investigate the role of covalency in these compounds. The standard MEG ionic model gives adequate structural results for the two phases but incorrectly predicts the spinel phase to be more stable at zero pressure. This is mainly because the ionic modeling of Mg2SiO4 only accounts for 95 percent of the lattice energy. The remainder can be attributed to covalency and many-body effects. An extension of the MEG ionic model using “many-body” pair potentials corrects the phase stability error, but predicts structures which are in poorer agreement with experiment than the standard ionic approach. In addition, calculations using these many-body pair potentials can only account for 10 percent of the missing lattice energy. This model predicts an olivine-spinel phase transition of 8 GPa, below the experimental value of 20 GPa. Therefore, in order to understand more fully the stability of these structures we must consider polarization. A two-shell bond polarization model enhances the stability of both structures, with the olivine structure being stabilized more. This model predicts a phase transition at about 80 GPa, well above the observed value. Also, the olivine and spinel structures calculated with this approach are in poorer agreement with experiment than the ionic model. Therefore, based on our investigations, to properly model covalency in Mg2SiO4, a treatment more sophisticated than the two-shell model is needed.
Factors predictive of difficult colonoscopy

Abstract Background: Prediction of a technically difficult colonoscopy may influence patient selection and procedure scheduling. Identification of predictive factors may be difficult because a common endpoint used to evaluate the success of colonoscopy is intubation of the cecum, which is usually achieved. The goal of this study was to examine the feasibility of using an alternative measure, time required for cecal intubation, to identify factors that can impact performance of colonoscopy. Methods: The time required for cecal intubation was prospectively recorded for 802 consecutive outpatient colonoscopies performed by 7 experienced gastroenterologists. Patient data collected included height, weight, age, bowel habits, surgical history, and findings at colonoscopy. Forty-seven examinations that were stopped because of disease or unacceptable bowel preparation were excluded. The impact of the patient characteristics of the remaining sample of 755 patients on the median time required for cecal intubation for men and women was examined. Results: Older age and female gender, body mass index ≤25.0 (regardless of gender), diverticular disease in women, and a history of constipation or reported laxative use in men were predictors of difficult colonoscopy. Conclusions: By using median time required for cecal intubation, several patient characteristics were identified that may predict technical difficulty at colonoscopy. These findings have implications for practice and teaching. (Gastrointest Endosc 2001;54:558-62.)
Do bone ingrowth processes produce a globally optimized structure

A topology optimization program was applied to test the hypothesis that bone adaptation to porous coated implants produces a structure which minimizes the global strain energy density. The program was used to predict the optimal material layout around a porous coated tibial component with multiple cones [Goldstein et al., Trans. 37th ORS, p. 92 (1991)]. The sensitivity of the predicted adaptation to analysis assumptions was assessed and the predicted bone ingrowth and apposition were compared with the experimental findings of Goldstein et al. The results showed that apposition occurred consistently at the cone tips regardless of analysis assumptions. The specific topology of apposition at the cone tips was most sensitive to the assumed loading conditions. A comparison with the experimental results for 11 subdivisions showed that the general predicted location of material agreed with the experimental results (R2 > or = 0.59). However, the program predicted a consolidated bone greater than 1000 microns in thickness at the cone tips, which differed from the porous bone structure found experimentally. This discrepancy was reflected in a refined comparison over 31 subdivisions which did not produce a significant correlation (R2 < or = 0.3). The program also predicted little ingrowth (< 6-7%), indicating that ingrowth past the first bead layer contributed little to the overall bone-implant interface layer stiffness. Based on these results, we conclude, within limitations of a two-dimensional analysis, that bone adaptation to porous coated implants does not produce a structure solely optimized to minimize the global strain energy density. We hypothesize that the final bone structure reflects the need to meet both mechanical and nutritional demands.
Effect of ozone on serum lipids and lipoproteins in the rat

Exposure of male rats to 0 (air), 1, 1.75, and 3 ppm ozone (O3) 5 hr/day for a total of 10 days resulted in a positive linear relationship between ozone concentration and the concentrations of serum total lipoprotein free cholesterol (FCh) and high-density lipoprotein total cholesterol (HDL-Ch). The latter response was reflected in both its free (HDL-FCh) and esterified (HDL-ChE) components. On the other hand, serum triglycerides (TG) showed a marked decreasing linear trend with increasing ozone concentration. As judged by decreased body weights with no accompanying differences in feed consumption, apparent metabolic rate increased as ozone concentration increased. In another experiment, male rats were exposed 5 hr/day to either air or 1 ppm O3 for a total of 15 days. Groups of animals from each exposure were sampled at times ranging from immediately after to 44 hr postexposure. In agreement with the concentration response study, effects of O3 included increases in serum total cholesterol (Ch), HDL-Ch and HDL-FCh, and a decrease in TG. In addition, the degree of effects appeared to be maintained over the 44-hr period and to be greater than that observed at 1 ppm O3 in the concentration-response study.
Perceptions of Refusals to Invitations: Exploring the Minds of Foreign Language Learners

Descriptions of speech act realisations of native and non-native speakers abound in the cross-cultural and interlanguage pragmatics literature. Yet, what is lacking is an analysis of the cognitive processes involved in the production of speech acts. This study examines the cognitive processes and perceptions of learners of Spanish when refusing invitations from a person of equal and higher status. Twenty male native speakers (NSs) of US English who were advanced learners of Spanish as a foreign language participated in two refusal interactions with two NSs of Spanish. The perception data were collected through retrospective verbal reports immediately after the role-play task. Results showed that these reports were instrumental in gathering relevant information about learners' cognitive processes with regard to: (1) cognition (attention to information during the planning and execution of a refusal), in particular attention to politeness, discourse, grammar and vocabulary; (2) the selection of the language ...