bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phylogeny of Geomydoecus and Thomomydoecus pocket gopher lice (Phthiraptera: Trichodectidae) inferred from cladistic analysis of adult and first instar morphology
Authors: PAGE RODERIC D. M. , PRICE ROGER D. , HELLENTHAL RONALD A. 
Published: January 2008

AbstractThe phylogeny for all 122 species and subspecies of chewing lice of the genera Geomydoecus and Thomomydoecus (Phthiraptera: Trichodectidae) hosted by pocket gophers (Rodentia: Geomyidae) is estimated by a cladistic analysis of fifty‐eight morphological characters obtained from adults and first instars. The data set has considerable homoplasy, but still contains phylogenetic information. The phylogeny obtained is moderately resolved and, with some notable exceptions, supports the species complexes proposed by Hellenthal and Price over the the last two decades. The subgenera G. (Thaelerius) and T. (Thomomydoecus) are both shown to be monophyletic, but the monophly of subgenus T. (Jamespattonius) could not be confirmed, perhaps due to the lack of first‐instar data for one of its component species. The nominate subgenus of Geomydoecus may be monophyletic, but our cladogram was insufficiently resolved to corroborate this. Mapping the pocket gopher hosts onto the phylogeny reveals a consistent pattern of louse clades being restricted to particular genera or subgenera of gophers, but the history of the host‐parasite association appears complex and will require considerable effort to resolve.
Karyotypes, male reproductive system, and abdominal trichobothria of the Berytidae (Heteroptera) with phylogenetic considerations
Authors: GROZEVA S. M. 
Published: January 2008

AbstractThe karyotype of fourteen species of Berytidae has been investigated (ten of them in this paper). All studied Metacanthinae, except possibly Metatropis, have 2n(♂)= 14 + XY. In three examined genera of Berytinae the karyotypes are dissimilar: in Neides and Apoplymus (Berytinae) the chromosome number is 2n(♂)=14 + XY, as for Metacanthinae. In Berytinus spp. the chromosome number is very high (B.distinguendus: 2n(♂)=30 + XY; B.clavipes: 2n(♂)=32 + XY: B.minor: 2n(♂)=40 + XY).The structure of the male reproductive system of eleven species is studied. Apoplymus (Berytinae) has two elongate follicles per testis and two pairs of mesadenial glands (mg). Metacanthinae and Neides (Berytinae) have a single elongate follicle per testis and two pairs of mg. Berytinus spp. differ in a number of characters: follicles are shorter and wider, two in each testis; a paired and an unpaired mg.The number and position of the abdominal trichobothria of twenty‐nine species of Berytidae is discussed.The ancestral condition of the three examined characters is found in primitive genera of both Berytinae and Metacanthinae. The genus Berytinus shows a derived condition in all of these characters.
Review of the systematics and biology of the Otopheidomenidae (Acari: Mesostigmata) with a description of Eickwortius gen.n. from a termite (Isoptera: Termitidae)
Authors: ZHANG ZHI‐QIANG 
Published: January 2008

AbstractThe systematics of the family Otopheidomenidae (Acari: Mesostigmata) is reviewed. Eickwortius termes gen.n. et sp.n. is described from a termite, Macrotermes michaelseni (Sjöstedt) (Isoptera: Termitidae) from Kenya. Treatia ghaiguptaorum nom.n. is proposed for Treatia indica Ghai & Gupta, 1984, which is a junior homonym of Treatia indica Krantz & Khot, 1962. The Otopheidomenidae as recognized in this paper consists of twenty‐five species in nine genera grouped into three subfamilies: Otopheidomeninae Treat, Treatiinae Wainstein, and Kadytiseiinae Fain & Lukoschus. Keys to the subfamilies and genera of Otopheidomenidae are provided and the described species of each genus are listed. The biology of the Otopheidomenidae and its potential in biological control are discussed.
MODIFIED BOVINE SERUM ALBUMIN—IX. THE EFFECT OF ULTRAVIOLET IRRADIATION ON THE IMMUNOCHEMICAL PROPERTIES*†
Authors: Porter D. D. , Maurer P. H. 
Published: January 2008

SummaryChanges produced in crystalline bovine serum albumin (BSA) by ultra‐violet irradiation have been investigated by immunochemical techniques. The quantitative precipitin reaction employing anti‐BSA was used to detect protein alteration. Irradiation of BSA progressively caused a shift in the point of maximum precipitation in the direction of higher antigen concentration, broadening of the zone of maximum precipitation, and after sufficient irradiation, a reduction in the total amount of precipitable nitrogen. Although it is known that U.V. light can theoretically rupture any of the bonds present in a protein, no appreciable amounts of dialyzable fragments were formed by irradiation of BSA.
ANALYSIS OF THE RATE OF THE ULTRAVIOLET IRRADIATION AND RECONSTITUTION REACTIONS OF 1,3‐DIMETHYLURACIL AND URIDINE*
Authors: WANG SHIH YI 
Published: January 2008

SummaryKinetic analysis of the forward and backward reactions of 1,3‐dimethyluracil and uridine showed that the rate constants and kinetic orders of the photochemical reactions were strongly dependent upon the substituent groups present in the excited molecules. Thus the irradiation of 1,3‐dimethyluracil in aqueous solution with ultraviolet light followed first‐order kinetics in 0–1 mM solution, while in 0.5, 1 and 5 mM solutions the reaction was pseudo‐zeroth‐order. Such a change in the order of reaction is characteristic for a light‐dependent reaction. For uridine, the reaction followed first‐order kinetics for all concentrations between 0.5 and 10 mM, showing that the dark step may be rate determining. Effect of pH in buffered solution and dilute hydrochloric acid solution, light intensity and temperature on the rate of reactions were studied and are discussed. Quantum yields for the various reactions were calculated. The reconstitution reaction of 1,3‐dimethyluracil from 6‐hydroxy‐1,3‐dimethylhydrouracil was first‐order in both acid and base catalyzed dehydration. The 6‐hydroxyhydrouridine reverted to uridine by a first‐order reaction when catalyzed by acid and by a second‐order reaction when catalyzed by base.
PRIMARY REACTIONS IN BACTERIAL PHOTOSYNTHESIS—I. THE NATURE OF LIGHT‐INDUCED ABSORBANCY CHANGES IN CHROMATOPHORES; EVIDENCE FOR A SPECIAL BACTERIOCHLOROPHYLL COMPONENT
Authors: Clayton R. K. 
Published: January 2008

SummaryLight‐induced optical changes have been examined in chromatophores of Rhodopseudonionas spheroides (wild type and blue‐green mutants), Rhodospirillum rubrum and Chromatium. The bacteriochlorophyll (BChl) types absorbing at 850 and 870–890 mp in these chromatophores could be separated by exposure to deoxycholate, followed by differential centrifugation. By the use of this treatment and the choice of various phenotypes preparations were obtained showing great variety in the relative heights of the BChl absorption maxima at 800, 850 and 870–890 mµ.The light‐induced changes included a bleaching of the long‐wave (870–890 mk) band and blue shifts of the BChl absorption bands at 375, 590 and 800 mp. In addition, new absorption bands appeared at 420–450, 980, 1140 and 1250 mp. All these effects except the blue shift at 590 mp (and perhaps also at 375 mp) were duplicated by mild oxidation (470 mV). The interpretation is made that the loss of a ground‐state electron in BChl eliminates one optical transition (bleaching at 870–890 mp) and perturbs the energy levels of other transitions (blue shifts).The spectrum of changes induced by light or mild oxidation remains constant while the absorption spectrum varies widely from one preparation to another; it is concluded that the changes reflect alteration of a special BChl component (BChl,) comprising 2–5 per cent of the total BChl. This conclusion is reinforced by the finding, to be reported in the third paper of this series(8), that the reaction of BChl, is related kinetically to the light‐induced oxidation of a cytochrome. It is proposed that BChl, may act as an energy sink and an agent for stabilizing excitation energy in the form of separated charge.
UBER DIE FEHLENDE PHOTO— UND WIRTSZELLREAKTWIERBARKEIT DES UV‐INAKTIVIERTEN RNS‐PHAGEN FR
Authors: Winkler Ulrich 
Published: January 2008

Abstract. The plaque forming ability of the E. coli phage fr, containing single stranded RNA, is highly UV‐resistant. One lethal hit corresponds to approximately 1'2 × 105 erg cm‐2. photoreactivation of fr due to illumination of infected bacteria has not been found after UV‐inactivation of either extracellular or intracellular phage. This shows that the already known PR‐enzyme of E. coli K12 is probably specific only for some of the UV‐lesions in DNA but not in RNA. Furthermore, it may indicate that the photoreactivation of some RNA‐containing plant viruse(1,2) is due to a PR‐enzyme which is not present in K12.UV‐inactivated fr is also not host‐cell‐reactivable. The plaque forming ability of fr infected bacteria decreases rapidly with increasing doses of PR‐light wherea: the colony forming ability of uninfected host cells is very resistant to PR‐light.
THE EFFECT OF MOLECULAR SHAPE ON THE FLUORESCENT PROPERTIES OF 9, 10‐DIPHENYLANTHRACENE
Authors: Hamilton T. D. S. 
Published: January 2008

Abstract. ESR measurements on 9, 10‐diphenylanthrace in solution show that the molecule is non‐planar, the two phenyl rings being twisted by about 66° relative to the anthracene nucleus. This agrees with previous predictions made on the basis of scale models.Evidence from absorption and fluorescence spectra for a change of angle between ground and excited state is examined, and a decrease of about 6° is found for the excited state. On the basis of the large angle of twist possible reasons are suggested for the difference between anthracene and 9, 10‐diphenylanthracne with regard to dimer formation and quantum yield of fluorescence in solution.
THE EFFECT OF RED AND FAR‐RED LIGHT ON NUCLEIC ACID METABOLISM IN RYE SEEDLING SHOOTS
Authors: Holdgate D. P. , Goodwin T. W. 
Published: January 2008

Abstract— The quantitative changes in the levels of RNA and DNA in shoots treated with red and/or far‐red light are presented.The results indicate that red light, but not far‐red light, stimulated cell division. The changes in RNA are discussed in relation to the nature of the light treatment.
INFLUENCE DES ÉCLAIREMENTS APPROXIMATIVEMENT MONOCHROMATIQUES SUR LE DEVELOPPEMENT DES TISSUS DE MOELLE DE TABAC CULTIVBS IN VZTRO EN PRESENCE D'AUXINE ET DE KINETINE
Authors: Beauchesne G. , Poulain Melle C. 
Published: January 2008

Abstract— The influence of relatively monochromatic light (around 4350, 5250, 6600 and 8000 Å) on the growth of cultures of tobacco pith tissues with auxin and kinetin was studied. The cultures were subjected either to continued light or to alternations of 16 hr light with 8 hr darkness, or to a dark period followed by continuous light.The influence of blue light was especially noted. The development in volume and weight of the cultivated tissues in blue light is generally less than in the other conditions (except for one or two exceptions); the differences are attenuated when a light period alternates with a period of darkness; the callus tissues of tobacco pith exposed to blue light are always chlorophyllic with a dense and hard appearance and histological studies show that tissues grown in blue light are mostly made of large cells with thick cell‐walls and many nodules while under the other conditions the tissues are mostly made of very small cells with few or no nodules.These differences seem related to specific photoreceptors rather than to energies delivered to the cultures.
SOME NEW STABLE ULTRAVIOLET TRANSMITTING SOLUTION FILTERS
Authors: Wladimiroff W. W. 
Published: January 2008

Abstract— For use with very intense light source, e.g. flash lamps and high‐pressure arcs, some new stable transmission filters for the U.V. were developed. All filters were composed to give maximum transmittance in the desired bands together with optimum absorbance of the visible light, at an optical path of 1 cm. The filters described are easy to prepare and have considerably better properties than the well known NiSO4‐‐CoSO4 filter and other filter combinations.During initial irradiation with high‐intensity light sources the transmittance of the freshly prepared filter solutions increases slowly till maximum transmittance is attained. The position of the transmission bands, however, does not change.Based on the fact that the 6700 Å absorption band of some non‐aqueous solutions of CoCl2 has an extinction coefficient about a hundred times larger than the 5100 Å absorption band of the aqueous solution with the same concentration, filter solutions were developed for the following transmission bands: 2600–3900 Å, 2900–3900 Å and 3100–3900 Å with transmission maxima of 90, 90 and 75 per cent respectively, and 2600–4600 Å, 2900–4500 Å and 3100–4600 Å with transmission maxima of 95, 95 and 90 per cent respectively, at an optical path of 1 cm.
AN ABSORPTION BAND NEAR 800 mμ ASSOCIATED WITH P870 IN PHOTOSYNTHETIC BACTERIA*
Authors: Clayton Roderick K. , Sistrom William R. 
Published: January 2008

Abstract— Purple photosynthetic bacteria contain a component, absorbing near 805 mμ, distinct from the major light harvesting bacteriochlorophyll component. The minor component, designated P800, resembles P870 in that it resists oxidative treatments that destroy the light harvesting bacteriochlorophyll. Light induces a reversible blue‐shift of P800 together with the reversible bleaching of P870. The ratio of P800 to P870 in Rhodopseudomonas spheroides is constant. Both pigments are absent in phenotypes that cannot grow photosynthetically; they reappear together in revertants to photosynthetic competence.Action spectra for light‐induced bleaching of P870 and for bacteriochlorophyll fluorescence show that P800 transfers energy more efficiently to P870 than to the bulk bacteriochlorophyll.It is concluded provisionally that P800 is a specialized bacteriochlorophyll molecule in close proximity to the reaction center component P870.
CHLOROPHYLL MONOLAYERS AND MUTILAYERS—I. METHODS OF PREPARATION AND SPECTROSCOPIC CHARACTERIZATION*
Authors: Sperling Walter , Ke Bacon 
Published: January 2008

Abstract— Precise methods of preparing monolayers and multilayers of chlorophyll a alone or mixed with arachidic acid on glass slides prewated with monolayers of barium arachidate are described in detail. Chlorophyll monolayers obtained by this method are mechanically stable and allow the absorption spectra or other spectroscopic characterizations to be readily made.The data on absorption spectra indicate that uniformly deposited multilayers of over 100 pure chlorophyll a monolayers or over 400 mixed monolayers were obtained. Theabsorbance in the multilayer was directly proportional to the total number of layers. For a given surface pressure used in depositing the multilayers, the absorbance per layer was constant.
PRODUCTION OF PEPTIDE COMPOUNDS FROM ETHYLENE GLYCOL AND HYDROXYLAMINE BY RADIATIONINDUCED SYNTHESIS*
Authors: Cultrera R. , Zamorani A. , Ferrari G. 
Published: January 2008

Abstract Aqueous solutions of ethylene glycol and hydroxylamine in a 10:1 weight ratio were irradiated with an immersion‐type mercury‐vapour lamp, under static and dynamic conditions. The photochemical products obtained were fractionated by means of ion‐exchange resins, gel filtration on Sephadex G 10, paper chromatography, and thin‐layer chromatography.Biuret reaction was carried out on the various fractions, and different nitrogen forms as well as amino acids, before and after hydrolysis, were determined. Irradiation was found to bring about the formation of a number of organic compounds, including peptides. The yields of these compounds were determined in relation to the concentration and the flow rate of the solutions. The yields increased with increase in the two variables.The fractions richest in peptide compounds, coming from gel‐filtration and thin‐layer chromatography, were studied by the technique of DNP‐derivatives. The constituent amino acids were found to be glycine, β‐alanine, α‐alanine, glutamic acid and leucine. The average length of the chains contained 7 amino acids.
THE NON‐RADIATIVE DISSIPATION OF EXCITATION ENERGY IN SOLID CINNAMIC ACID BY DIMER FORMATION
Authors: Rennert J. , Ruggiero E. M. , Rapp J. 
Published: January 2008

Abstract— The quantum efficiency for the photodimerization of trans‐cinnamic acid in the solid state is independent of intensity and is found to have a value approaching two. Thus, the reaction involves one excited and one un‐excited molecule.During the exposure, a dimer film developing on the surface of the cinnamic acid layer attenuates the intensity of the radiation incident on the unreacted cinnamic acid. This gives the appearance of a decrease in the quantum yield with increasing number of photons incident.
ZUM WIRKUNGSMECHANISMUS PHOTODYNAMISCHER FUROCUMARINE PHOTOREAKTION VON PSORALEN‐(4‐14C) MIT DNS, RNS, HOMOPOLYNUCLEOTIDEN UND NUCLEOSIDEN
Authors: Krauch C. H. , Krämer D. M. , Wacker A. 
Published: January 2008

Abstract— The photodynamic binding of psoralen to DNA and RNA was shown using different methods. This binding was found to be mainly located either at thymine or uracil. The concentration and pH dependancy was studied. The photoproduct obtained with uridine was isolated paper chromatographically and was split into initial components photochemically.The results bring an evidence that psoralen with its 3,4‐double bond is able to form a cyclic derivative with the C6‐C6 doble bond of thymine or uracil.
DELAYED FLUORESCENCE AND SOME PROPERTIES OF THE CHLOROPHYLL TRIPLETS
Authors: Parker C. A. , Joyce Thelma A. 
Published: January 2008

ABSTRACT–P‐Type delayed fluorescence and sensitised P‐Type delayed fluorescence have been observed from solutions of chlorophylls a and b in ethanol. E‐Type delayed fluorescence has been observed from solutions in propylene glycol. The measurements in propylene glycol have yielded approximate values for the triplet energies of chlorophylls a and b. Measurements of the emissions from the ethanolic solutions have been used to calculate approximate values of the triplet formation efficiencies in this solvent. The sums of the fluorescence and triplet formation efficiencies in ethanol fall far short of unity and the triplet formation efficiencies therefore need to be confirmed by an independent method before they can be accepted with confidence.
THE EFFECT OF ENVIRONMENT ON CYSTINE DISRUPTION BY ULTRAVIOLET LIGHT*
Authors: Risi Sergio , Dose Klaus , Rathinasamy T. K. , Augenstein Leroy 
Published: January 2008

ABSTRACTWhen cystine is irradiated at pH 1 by 254‐nm u.v. the following yields are observed: 4 cystines → 5.2 cysteines + 2.8NH3. Thus, SH production accounts for only 0.65 of the cystine destruction; further C‐S breakage to give alanine or serine is not efficient. The yields for cystine and glutathione destruction are essentially the same at pH 1. However the presence of the glutamic and glycine residues stabilize the cystine in glutathione so that NH3 is not lost until the peptide bonds are hydrolyzed. Increasing the pH from 1 to 8.6 increases the yield of cystine destruction in glutathione by 50 per cent. The yield of cystine destruction is greater in both compounds when O2 is present during irradiation (e. g. the cysteic acid yield in glutathione is increased by 50 times). The overall production of SH varies by a factor of 2 in the four proteins‐insulin, RNase, trypsin and lysozyme. The present data further support the earlier observation that radiation damage is quite non‐random in RNase: at least two and perhaps three of the four constituent cystines must be disrupted before activity is lost: i.e. the most radiosensitive cystines are not critical for enzymic activity. Similarly, in both trypsin and lysozyme the integrity of the most radiosensitive cystines also does not appear to be critical for the retention of enzymic potential. In insulin, however, all three cystines appear to be crucial for activity and to have approximately equal radiosensitivities. These differences in sensitivity of cystines in different proteins must depend specifically upon energy transfer and/or chemical interactions between the chromophoric groups. If yields are calculated on the basis of those quanta absorbed only in the cystines, values about 5 to 8 times greater than those in the model compounds cystine and oxixized glutathione are obtained. The yields of cystine destruction are much higher in those protiens which contain trypotophan.
CHLOROPHYLL‐PHOTOSENSITIZED OXIDATION OF HYDROQUINONE AND p‐PHENYLENEDIAMINE DERIVATIVES
Authors: Fujimori Eiji , Tavla Maria 
Published: January 2008

Abstract— ESR and photovoltaic studies on light‐induced one‐electron transfer between chlorophyll a and electron donors in the absence of oxygen show (1) the possible conversion of photo‐reduced chlorophyll a and p‐benzosemiquinone ion radicals to their non‐ionic radicals in methanol solutions of low pH, (2) the production of ESR absorption of tetrachloro‐p‐benzosemi‐quinone even in benzene, enhanced by the addition of triethylamine or methanol, and (3) the transfer of one electron from tetramethyl‐p‐phenylenediamine to either excited chlorophyll a or pheophytin a in methanol at pH above 3.6 but not to pheophytin a at pH below 1 0 where its radical cation appears to accept an electron from excited pheophytin a. Bacteteriochloro‐phyll is also shown to be capable of photooxidizing hydroquinones and tetramethyl‐p‐phenyl‐enediamine.The presence of oxygen enhances chlorophyll a‐photosensitized oxidation of hydroquinone and tetrachloro‐hydroquinone by one‐electron transfer to oxygen and of trimethylhydro‐quinone probably by two‐electron trnasfer to oxygen. A free radical from excited chlorophyll a‐oxygen interaction is formed in these reactions, but rapidly quenched in the case of trimethyl‐hydroquinone. This, kind of free radical is not formed in pheophytin a. Tetramethyl‐p‐phenyl‐enediamine readily undergoes chlorophyll a‐photosensitized oxidation by oxygen in any pH region.
RADICAUX LIBRES INDUITS PAR L'ACTION DU RAYONNEMENT ULTRAVIOLET SUR CERTAINS CONSTITUANTS DE L'ACIDE DEOXYRIBONUCLEIQUE
Authors: LACROIX et M. , VORST A. VAN DE 
Published: January 2008

AbstractThe action of ultra violet rays of 260 nm on aqueous solutions of bases, nucleosides and nucleotides of DNA at 77°K is studied by electron spin resonance. It is shown that the free radicals observed are similar, with a few noteworthy exceptions to those induced by X‐rays, under the same conditions of temperature, in the solid state. Contrary to what might be excepted on the basis of the results obtained by X‐rays, the variation in the yield in paramagnetic centres in each sequence studied does not seem to be important.
NUMBER AND DISTRIBUTION OF CHROMOPHORE TYPES IN NATIVE PHYCOBILIPROTEINS
Authors: DALE R. E. , TEALE F. W. J. 
Published: January 2008

Abstract— Fluorescence lifetimes and absolute quantum yields of a number of chromatographically pure phycobiliproteins have been determined. In conjunction with absorption, fluorescence emission and polarization spectra, these data were used to calculate the number of different types of chromophore, sensitizing and fluorescing, per chromoprotein.To characterize the spatial distributions of the chromophores, the observed emission anisotropies were compared with those calculated from models, using the Förster transfer mechanism and the Jablonski ‘active sphere’ approximation. The experimental values are more consistent with surface locations for the fluorescing chromophores rather than with their distribution throughout the volume.Theoretical efficiencies of transfer between sensitizing and fluorescing chromophores on the same macromolecule are consistent with those observed. The transfer efficiency from phycoerythrin prosthetic groups to chlorophyll a compared with that for transfer via phycocyanin indicates that the latter process is probably the favoured migration route.