bluuebunny/crossref_metadata_2025_split huggingface dataset:
LIGHT ENERGY CONVERSION IN NEURONAL MEMBRANES*
Authors: Chalazonitis N. 
Published: January 2008

Summary Photocurrents and decrease in membrane resistance have been shown by illuminating pigmented nerve cells, and vitally stained nerve fibers.Any photocurrent, of threshold value, can elicit repetitive electrical activity as an extrinsic outward current dose. In pigmented nerve cells, photocurrents are additive to pre‐existing dark currents, thus modifying the frequency of the spontaneous activity.Light effects on electrogenic membrane were compared to those of infra red. Both radiations decrease, with different yields, the membrane resistance. However, the initiated membrane currents are generally of opposite directions.Similarly, opposite direction photocurrents are elicited by specific illuminations of two intracellular pigments (haemoprotein or carotenoid) in some nerve cells.From spectrographic, respirometric and oscillographic evidences, the molecular mechanisms implied in the light energy conversion into membrane photocurrent can be considered as follows:1. Release of electrons and hydrogen ions from dyes or natural pigments in molecular association with lipoproteins; secondary reactions of e and H+ with acceptors (dyes, or oxygen).2. Secondary changes in adsorption bonds between dyes or pigments and associated lipoproteins resulting in changes in molecular orientations.3. Directional fluxes of e, H+, and other ions, imitating fluxes elicited under a cathode during direct current flow.
FLASH PHOTOLYSIS IN HUMAN CONES*
Authors: Rushton W. A. H. 
Published: January 2008

Summary 1. This paper is in three parts. Part I briefly summarizes the main facts and interpretations that are generally accepted as to the effect of light upon vision, adaptation and after‐images.2. Part II considers in some detail the effect upon adaptation and after‐images of a flash of light sufficiently bright to generate abnormal visual pigments. A summary of these new findings is given at the end of Part II, together with a schema for the photoisomerization, bleaching and regeneration of cone pigments in the living eye.3. Part III puts forward a rough mechanism that will account quantitatively for observed relations of brightness and threshold in adaptation. The manner in which flashes may modify this mechanism is suggested.
INACTIVATION OF A RHIZOBIUM BACTERIO‐PHAGE BY ULTRAVIOLET RADIATION OF DIFFERENT WAVE‐LENGTHS
Authors: Kleczkowski J. , Kleczkowski A. 
Published: January 2008

Abstract— The action spectrum for inactivation of a Rhizobiurn bacteriophage by U.V. radiation follows the shape of the absorption spectrum of DNA between the wave‐lengths of 240 and 290 mμ (where inactivation probably reflects damage to the nucleic acid only), and deviates sharply upwards at wave‐lengths shorter than 240 mμ (where inactivation may depend on damage to both the nucleic acid, and protein of the phage). The rate of inactivation follows first order kinetics approximately at all wave‐lengths tested. Infectivity of the phage is halved when each mg of the phage nucleic acid has absorbed about 0 08 J of radiation energy at any wave‐length between 240 and 290 mμ.The bacteriopharge can be photoreactivated after inactivation at any wave‐length between 230 and 290 mμ, but less so after inactivation at 230 mμ than at any wave‐length above 240 mμ. No evidence was found to suggest that dimerization of thymine residues of the phage‐DNA plays any part in the mechanism of inactivation of the bacteriophage by U.V. radiation.
THE PRODUCTION OF ELECTRONICALLY EXCITED OXYGEN MOLECULES AND THEIR REACTIONS WITH OZONE*
Authors: March R. E. , Furnival Sharon G. , Schiff H. I. 
Published: January 2008

Abstract— The only detectable emission from discharged oxygen was a band system at 7619 Å. However, when a film of mercuric oxide was interposed between the discharge and the observation position, the intensity of this band was greatly enhanced and additional bands were observed at 6340, 7030 and at 12,700 Å, in agreement with the findings of Bader and Ogryzlo. A linear relationship, however, was found between the intensities at 6340 and at 12,700 Å, instead of the quadratic dependence reported by these authors.A rapid reaction was found to occur between O3, and O2>(1Σ+g) molecules but the reappearance of the 7619 Å, emission after all the O3 had been reacted indicates a production process of O2(1Σ+g) molecules, probably from O2(1Δg).The value of the rate constant for the reaction 02(1Σ+g) + O3→2O2+ Ois approximately 6times10‐13 cm3/molecule per sec. The rate constant for the comparable reaction with O2(1Δg) molecules is probably lower than this by a factor of at leat 4.
INFLUENCE DE LA LUMIÈRE SUR LES MOUVEMENTS DE NUTATION DES PLANTULES
Authors: Rollin P. 
Published: January 2008

Abstract— Red light can promote (a) the straightening of the curvature (Phaseolus vulgaris, Pisum sativum) (b) the formation of a loop (Phacelia tanacetifolia and Picea abies) or (c) the induction of a curvature which does not occur in the darkness (Lactuca sativa). Thesc red‐light induced movements could be reversed by following each brief red exposure with short irradiation by far‐red light. These reactions are controlled by the phytochrome system.On the other hand, exposure to far‐red and blue light during a long period can induce other movements:(a) The light re‐opens the hook which has been closed by red radiation (Lactuca sativa).(b) The light induces the straightening of the dark‐induced curvature (Phacelia tanacetifolia). These facts may be due to an unknown property of phytochrome or to the action of another photoreceptor.
THE PHOTORECEPTORS INVOLVED IN ANTHOCYANIN SYNTHESIS
Authors: Vince D. , Grill R. 
Published: January 2008

Abstract— Experiments with irradiation sequences where red precedes far‐red lead to the conclusion that, in turnip, phytochrome is the only pigment mediating anthocyanin synthesis in red and far‐red. Results from experiments where far‐red precedes red, however, suggest that more than one reaction is involved. A possible interpretation is that the ‘high‐energy’ reaction in far‐red and the low energy red/far‐red reversible reaction are mediated by two different forms of phytochrome.The ‘high‐energy’ reaction in blue light does not appear to depend on phytochrome.
THE IMPORTANCE OF THE MICROENVIRONMENT SURROUNDING A CHROMOPHORE IN DETERMINING ITS SPECTROSCOPIC BEHAVIOR*
Authors: KOUDELKA JAROMIR , AUGENSTEIN LEROY 
Published: January 2008

ResumenSe pone especial énfasis en la importancia del microambiente de un grupo como factor determinante del comportamiento fotoquímico, emisión y dicroismo circular de móleculas biológicas. Los ejemplos dados incluyen la fotoquímica de la ribonucleasa, la dependencia de las propiedades luminiscentes de amino acidos aromáticos con la temperatura, y el comportamiento espectroscópico de los dinucleótidos.
SOME REACTIONS OF PHOTOCHEMICALLY GENERATED PERFLUOROMETHOXYL AND RELATED OXYGENATED DERIVATIVES OF THE PERFLUOROMETHYL RADICAL
Authors: AYMONINO P. J. 
Published: January 2008

Abstract— Results of some reactions of photochemically produced perfluoromethoxyl and related radicals are presented, including a kinetic study of the photochemical reaction between fluoroxyperfluoromethane (CF3OF) and carbon monoxide leading quantitatively to perfluoromethyl fluoroformate (CF3OC(O)F). Bis (perfluoromethyl) oxalate (CF3OC(O)C(O)OCF3), the supposed chain‐ending product of the named reaction is described for the first time. Also, some evidences are presented in favor of the existence of bis(perfluoromethyl)peroxydicarbonate (CF3OC(O)OOC(O)OCF3) and of the mixed mono(perfluoromethyl)ester‐monofluoride of peroxydicarbonic acid (CF3OC(O)OOC(O)F), which are believed to be respectively the chain‐ending products of the oxidation of carbon monoxide, photochemically sensitized by bis (perfluoromethyl)peroxide and fluoroxyperfluoromethane.Finally, a description is given of a novel synthetic method which gives high yields of bis (perfluoromethyl)trioxide, depending on the oxidation of perfluoromethyl radicals produced photochemically from a mixture of fluorine and perfluoroacetone.RESUMENSe presentan los resultados de algunas reacciones que llevan a la producción fotoquímica de perfluorometoxilo y otros radicales análogos, incluyendo un estudio cinético de la reacción fotoquímica entre el fluoroxiperfluorometano (CF3OF) y el monóxido de carbono, con formación cuantitativa de fluoroformiato de perfluorometilo (CF3OC(O)F). Se describe por primera vez el oxalato de perfluorometilo (CF3OC(O)C(O)OCF3) que es justamente el producto final de la cadena de la mencionada reacción. También se presentan evidencias en favor de la existencia del peroxidicarbonato de perfluorometilo (CF3OC(O)OOC(O)OCF3) y del éster perfluorometílico del monofluoruro del ácido peroxidicarbónico (CF3OC(O)OOC(O)F), los cuales se cree son respectivamente los productos finales de la cadena de la oxidación del monóxido de carbono sensibilizada fotoquímicamente por el peróxido de perfluorometilo y el fluoroxiperfluorometano.Finalmente se da una descripción de un nuevo método sintético el cual da altos rendimientos de trióxido de perfluorometilo, dependiendo de la oxidación de radicales perfluorometilo producidos fotoquímicamente a partir de una mezcla de fluor y perfluoroacetona.
PHOTOCHEMICAL ADDITION REACTIONS TO α,β‐UNSATURATED KETO‐STEROIDS
Authors: CRABBÉ PIERRE , CRUZ ALICIA , IRIARTE JOSÉ 
Published: January 2008

Abstract— Several examples of photochemical cycloaddition of olefins to α,β‐unsaturated ketones have been reported, but there are only a few cases of formation of substituted cyclobutane or cyclobutene rings through such ieactions[1–4]. We wish to report here photochemical addition reactions to positions 16 and 17 of the steroid nucleus, using the conjugated system of 3β‐hydroxypregna‐5,16‐dien‐20‐one acetate (1) as a substrate [5].RESUMENHan sido reportados algunos ejemplos de cicloadición fotoquímica de olefinas a cetonas conjugadas, pero hay pocos casos de formación de anillos ciclobutánicos o ciclobuténicos mediante estas reacciones.
Predicting the performance of internet-like networks using scaled-down replicas
Authors: Papadopoulos Fragkiskos , Psounis Konstantinos 
Published: January 2008

The Internet is a large, heterogeneous system operating at very high speeds and consisting of a large number of users. Researchers use a suite of tools and techniques in order to understand the performance of complex networks like the Internet: measurements, simulations, and deployments on small to medium-scale testbeds. This work considers a novel addition to this suite: a class of methods to
scale down
the
topology
of the Internet that enables researchers to create and observe a smaller replica, and extrapolate its performance to the expected performance of the larger Internet.

The key insight that we leverage is that only the congested links along the path of each flow introduce sizable queueing delays and dependencies among flows. Hence, one might hope that the network properties can be captured by a topology that consists of the congested links only. We have verified this in [11, 12] using extensive simulations with TCP traffic and theoretical analysis. Further, we have also shown that simulating a scaled topology can be up to two orders of magnitude faster than simulating the original topology. However, a main assumption of our approach was that un-congested links are known in advance.
We are currently working on establishing rules that can be used to efficiently identify uncongested links in large and complex networks like the Internet, when these are not known, and which can be ignored when building scaled-down network replicas.
Inhibition of MAPK Kinase Signaling Pathways Suppressed Renal Cell Carcinoma Growth and Angiogenesis In vivo
Authors: Huang Dan , Ding Yan , Luo Wang-Mei , Bender Stephanie , Qian Chao-Nan , Kort Eric , Zhang Zhong-Fa , VandenBeldt Kristin , Duesbery Nicholas S. , Resau James H. , Teh Bin Tean 
Published: January 2008

Abstract
The mitogen-activated protein kinase (MAPK) signaling pathways play essential roles in cell proliferation and differentiation. Recent studies also show the activation of MAPK signaling pathways in tumorigenesis, metastasis, and angiogenesis of multiple human malignancies, including renal cell carcinoma (RCC). To assess the role of this pathway in regulating the proliferation and survival of RCC cells, we first examined the expression of MAPK kinase (MKK) and MAPK in clear cell RCC and confirmed the overexpression of MKK1 and extracellular signal-regulated kinase 2 (ERK2) in these tumors. We then tested the effects of pharmacologic inhibition of MKK on human RCC cell lines, both in vitro and in vivo, using anthrax lethal toxin (LeTx), which cleaves and inactivates several MKKs. Western blotting showed that the phosphorylation levels of ERK, c-Jun-NH2 kinase, and p38 MAPK decreased after 72 h of LeTx treatment. Exposure to LeTx for 72 h reduced cell proliferation by 20% without significant effects on cell cycle distribution and apoptosis. Anchorage-independent growth of RCC cells was dramatically inhibited by LeTx. In vivo studies showed that tumor growth of RCC xenografts could be suppressed by LeTx. Extensive necrosis and decreased tumor neovascularization were observed after LeTx treatment. LeTx also showed direct inhibition of proliferation of endothelial cells in vitro. Our results suggest that suppression of one or more MAPK signaling pathways may inhibit RCC growth through the disruption of tumor vasculature. [Cancer Res 2008;68(1):81–8]
Loss and Reduction of Fus1 Protein Expression is a Frequent Phenomenon in the Pathogenesis of Lung Cancer
Authors: Prudkin Ludmila , Behrens Carmen , Liu Diane D. , Zhou Xian , Ozburn Natalie C. , Bekele B. Nebiyou , Minna John D. , Moran Cesar , Roth Jack A. , Ji Lin , Wistuba Ignacio I. 
Published: January 2008

Abstract
Purpose: FUS1, a novel tumor-suppressor gene located in the chromosome 3p21.3 region, may play an important role in lung cancer development. Currently, FUS1-expressing nanoparticles have been developed for treating patients with lung cancer. However, the expression of Fus1 protein has not been examined in a large series of lung cancers and their sequential preneoplastic lesions.
Experimental Design: Using tissue microarrays, we examined Fus1 immunohistochemical expression in 281 non–small cell lung carcinoma (NSCLC) and 22 small cell lung carcinoma tissue specimens and correlated the findings with patients' clinicopathologic features. To investigate the expression of Fus1 in the early sequential pathogenesis of NSCLC, we studied Fus1 expression in 211 histologically normal and mildly abnormal bronchial epithelia, and 118 bronchial and alveolar preneoplastic lesions obtained from patients with lung cancer.
Results: Loss and reduction of expression was detected in 82% of NSCLCs and 100% of small cell lung carcinomas. In NSCLCs, loss of Fus1 immunohistochemical expression was associated with significantly worse overall survival. Bronchial squamous metaplastic and dysplastic lesions expressed significantly lower levels of Fus1 compared with normal (P = 0.014 and 0.047, respectively) and hyperplastic (P = 0.013 and 0.028, respectively) epithelia.
Conclusions: Our findings show a high frequency of Fus1 protein loss and reduction of expression in lung cancer, and suggests that this reduction may play an important role in the early pathogenesis of lung squamous cell carcinoma. These findings support the concept that FUS1 gene and Fus1 protein abnormalities could be used to develop new strategies for molecular cancer therapy for a significant subset of lung tumors.
Modeling of Two Northwest Atlantic Storms with Third-Generation Wave Models
Authors: Padilla-Hernández R. , Perrie W. , Toulany B. , Smith P. C. 
Published: January 2008

Abstract
In this study, three state-of-the-art operational forecast wave models are implemented on nested grids in order to achieve fine-resolution wave simulations (0.1°) in the Gulf of Maine and related northwest Atlantic waters. These models are the Simulating Waves Nearshore (SWAN) model, the Wave Action Model (WAM), and WAVEWATCH-III (hereafter WW3). Model performance is evaluated through comparisons with field measurements. Four composite model systems are compared: WAM and WW3 implemented on three nested domains, SWAN nested within WAM, and SWAN nested within WW3. Storm case studies include two intense midlatitude winter storms from January 2000 and January 2002. Although the models are comparable in terms of their overall performance and skill, it is found that WW3 provides a better statistical fit to the observed wave data compared with the other models, and that SWAN gives slightly better results if nested within WW3, rather than within WAM.
Decolorizing kinetics of reactive black SRE by UV/TiO2
Authors: Xu Hang , Zhang Dongxiang , Xu Wenguo , Li Hansheng , Du Meng 
Published: January 2008

AbstractPhotocatalysis with TiO2 (UV/TiO2) was employed to treat Reactive Black SRE (RB SRE) in aqueous solution. The effects of TiO2 loading, initial concentration of RB SRE and pH on the photocatalytic activity were investigated. The RB SRE degradation intermediate products were analyzed by ultraviolet visible spectrum (UV–vis), gas chromatography‐mass spectrometry (GC‐MS), and ion chromatography (IC). The results show the optimum TiO2 loading was 0.15 g L−1 and acidic medium could improve the removal of RB SRE, and the rise of RB SRE initial concentration decreased color removal. The main intermediate products were 2,5‐diritrobenzoic acid and 3,5,5‐trimethylhexanoic acid. The primary inorganic ions were Cl−, NO, and SO. The photocatalytic degradation rate followed pseudo‐first order at different loadings of TiO2 and initial concentrations of RB SRE. On the basis of Langmuir model, the limiting rate of the reaction at maximum coverage (kv) and the equilibrium constant for adsorption (Ke) of RB SRE are 1.129 mg L−1 min−1 and 0.01789 L mg−1, respectively. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
A relational–XML data warehouse for data aggregation with SQL and XQuery
Authors: Fong Joseph , Shiu Herbert , Cheung Davy 
Published: January 2008

AbstractIntegrating information from multiple data sources is becoming increasingly important for enterprises that partner with other companies for e‐commerce. However, companies have their internal business applications deployed on diverse platforms and no standard solution for integrating information from these sources exists. To support business intelligence query activities, it is useful to build a data warehouse on top of middleware that aggregates the data obtained from various heterogeneous database systems. Online analytical processing (OLAP) can then be used to provide fast access to materialized views from the data warehouse. Since extensible markup language (XML) documents are a common data representation standard on the Internet and relational tables are commonly used for production data, OLAP must handle both relational and XML data. SQL and XQuery can be used to process the materialized relational and XML data cubes created from the aggregated data. This paper shows how to handle the two kinds of data cubes from a relational–XML data warehouse using extract, transformation and loading. Copyright © 2008 John Wiley & Sons, Ltd.
Savanna fires govern community structure of ungulates in Bénoué National Park, Cameroon
Authors: Klop Erik , van Goethem Janneke 
Published: January 2008

Abstract:We studied the effects of savanna fires on the structure of local ungulate communities in a West African woodland savanna. The distribution of 11 ungulate species over 9−15 burned sites (the number of which increased as burning activity continued during the dry season) and 7−13 unburned sites was compared with a variety of null models or randomized ‘virtual communities’. Five different parameters of community structure were examined: body mass distribution, co-occurrence patterns, species richness, species density and guild dominance. Overall, ungulate species were not randomly distributed over burned and unburned sites. The regular spacing of body masses in the set of species recorded on burned and unburned sites indicated competition, since species similar in body mass are more likely to compete than species of different size. However, co-occurrence patterns on burned sites were random, indicating absence of competition at fine spatial scales due to differential habitat use within the burned landscape. Although the attractiveness of the regrowth on burned sites resulted in higher numbers of ungulates compared with unburned sites, species richness was not different. Grazers were the dominant guild on burned sites, but there were no differences in species richness or species density between grazers and browsers on unburned sites.
MECHANISM OF ENZYME INACTIVATION BY ULTRAVIOLET LIGHT AND THE PHOTOCHEMISTRY OF AMINO ACIDS (AT 2537 Å)*
Authors: Luse R. A. , McLaren A. D. 
Published: January 2008

Abstract— >The inactivation of the enzymes chymotrypsin, lysozyme, ribonuclease, and trypsin by ultraviolet light can be accounted for quantitatively by summing the products of (1) the probability that light is absorbed by a given amino acid residue, the molecular extinc tion coefficient, and (2) the probability that absorbed light induces a chemical change in the residue, the quantum yield for the residue. The principal residues involved are cystyl and tryptophanyl. Peptide bond rupture is not important. Energy transfer among chromophores within molecules of enzymes need not be invoked in order to account for photochemical inactivation.Quantum yields for the destruction of a number of amino acids at 2537 A have been measured.
LIGHT‐INDUCED ABSORBANCY CHANGES IN EIMHJELLEN'S RHODOPSEUDOMONAS*
Authors: Holt A. S. , Clayton Roderick K. 
Published: January 2008

Abstract— Light induced absorbancy changes in Rhodopseudomonas sp. NHTC 133 are analogous to those observed in other photosynthetic bacteria, but all of the features in the light‐induced difference spectrum (except those reflecting cytochrome oxidation) are shifted to greater wavelengths. This general shift is consistent with the fact that the bacteriochlorophyll of this organism (BChl b) differs from the usual BChl in that its absorption bands are shifted to greater wavelengths.The singlet excited state of P985 (the counterpart of the P870 of Rhodopseudomonas spheroides) is not an energy sink relative to the major component of BChl b in vivo. The absorption maximum of P985 is at 985 mp, whereas that of CBhl b in vivo is at 1012 mμ.
SPECTROSCOPIC BEHAVIOR OF ALL‐TRANS RETINAL AND ITS SCHIFF BASES IN VARIOUS MEDIA. THE ROLE OF CONFORMATIONAL PERTURBATION
Authors: IRVING C. S. , LEERMAKERS P. A. 
Published: January 2008

ResumenSe ha encontrado que la n‐all‐trans‐retinilideno‐n‐butilamina tiene propiedades espectroscópicas, absorción y emisión similares a las de la meta rodopsina I que as un intermediario en la fotólisis del pigmento visual rodopsina. La sensibilidad se presenta solamente cuando el compuesto modelo es adsorbido en silica gel o cuando se lo disuelve en metanol a 77°K. Se describen evidencias espectroscópicas a baja temperature lo cual indica que prelumi o lumirodopsina son artefactos que probablemente no juegan un rol importante en la respuesta visual.