bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of pyruvate on economy of contraction in isolated rabbit myocardium
Authors: Keweloh Boris , Janssen Paul M.L. , Siegel Ulf , Datz Nicolin , Zeitz Oliver , Hermann Hans‐Peter
Published: May 2007

Background

Treatment of acute heart failure frequently requires positive‐inotropic stimulation. However, there is still no inotropic agent available, which combines a favourable haemodynamic profile with low expenditure for energy metabolism. Pyruvate exhibits positive inotropic effects in vitro and in patients with heart failure. The effect on myocardial energy metabolism however remains unclear, but is meaningful in light of a clinical application.

Aims and methods

We investigated the influence of pyruvate on contractility and oxygen consumption in isolated isometric contracting rabbit myocardium compared to β‐adrenergic stimulation with isoproterenol.

Results

Pyruvate (30 mM) increased developed force from 18.7±4.1 to 50.8±12.1 mN/mm2 (n=10, p<0.01). Force‐time integral (FTI) increased by 329%, oxygen consumption assessed by diffusion‐microelectrode technique increased from 2.86±0.30 mlO2/min*100 g to 6.28±1.28 mlO2/min*100 g (n=7, p<0.05). Economy of myocardial contraction calculated as the ratio of total FTI to oxygen consumption remained unchanged. In contrast, while isoproterenol (10 μM) produced a comparable increase in developed force from 21.4±8.3 to 67.3±15mN/mm2 (n=7, p<0.01), FTI increased only by 260% and MVO2 increased from 2.96±0.43 to 6.12±1.01 mlO2/min*100 g (n=7, p<0.01); thus, economy decreased by 23% (n=7, p<0.05).

Conclusion

Pyruvate does not impair economy of myocardial contraction while isoproterenol decreases economy. Regarding energy expenditure, pyruvate appears superior to isoproterenol for the purpose of positive inotropic stimulation.
A Cre‐loxP based system for studying horizontal gene transfer
Authors: Bergsmedh Anna , Ehnfors Jacob , Spetz Anna-Lena , Holmgren Lars
Published: May 2007

We have previously shown that DNA can be transferred to phagocytosing cells via the uptake of apoptotic cells. We report a model system that facilitates study of antigen presentation of genes transferred specifically via horizontal gene transfer. Constructs were generated encoding the LacZ gene or the influenza A nucleoprotein silenced by a STOP sequence flanked by two loxP sites. These reporter genes were demonstrated to be silent in donor cells and become activated after phagocytosis of Cre‐expressing fibroblasts or macrophages. These results provide a model system for studying the influence of horizontally transferred antigens on activation of the immune system.
Sequence requirements for splicing by the Cne PRP8 intein
Authors: Pearl Esther J. , Tyndall Joel D.A. , Poulter Russell T.M. , Wilbanks Sigurd M.
Published: May 2007

The dependence of protein splicing on conserved residues of the Cne PRP8 intein was assessed by alanine scanning mutagenesis in a foreign protein context. Corroboration was obtained for the involvement of residues at the splice junctions and of the conserved threonine and histidine of motif B. Five additional residues were identified as absolutely required for splicing. Variant W151A displayed premature C‐terminal cleavage, not seen with other Cne PRP8 mutants. We propose a model whereby W151 acts to prevent premature C‐terminal cleavage, favoring complete splicing as opposed to two disjointed cleavage events.
PERSUASION—HOW OPINIONS AND ATTITUDES ARE CHANGED
Authors: KANE DOLORES
Published: May 2007

Marvin Karlins, Herbert Abelson, PERSUASION—HOW OPINIONS AND ATTITUDES ARE CHANGED, ed 2, 1970, Springer Publishing Co., Inc., New York, 179, $2.75.
Lichen Communities on Alnusn Incana in North Norway
Authors: Øvstedal D. O.
Published: May 2007

Sociological tables are given for five communities found on Alnus incana in Troms, North Norway: Arthopyrenietum punctiformis P. James et al., Lecanoretum chloropoliae ass. nov., Lecanoretum subfuscae Hil., Lobarion pulmonariae Ochsn. and Parmelietum olivaceae Barkm. Snow cover and shading from large ferns are important factors governing the distribution of the communities on the tree trunks.
Chemistry of Some Yellow Acarospora Species
Authors: Huneck S.
Published: May 2007

Fifteen specimens of four Acarospora species of subgenus Xanthothallia were analysed. All species contained (+)-rhizocarpic acid. A. gobiensis and A. schleicheri had only this compound and A. oxytona this and (+)-lichesterinic acid. A. chlorophana seems to exist in two chemical races, one with a mixture of (-)-acaranoic and (-)-acarenoic acids and the other with (+)-roccellic acid. The stereochemistry and biogenesis of these compounds is briefly discussed.
Nomenclatural Notes on Pseudocyphellaria in New Zealand
Authors: Galloway D. J. , James P. W.
Published: May 2007

At present 40 species of Pseudocyphellaria are recognised in the New Zealand flora, ten of which appear to be new and will be described elsewhere. In the present account, the 30 published taxa are listed alphabetically and, where applicable, the synonymy of confused species is discussed. The following 13 new combinations are made: P. coerulescens (Mont.), P. condensata (Zahlbr.), P. coriacea (Hook.f. & Taylor), P. delisea (Fee), P. dissimilis (Nyl.), P. hookeri (Church.Bab.), P. lividofusca (Krempelh.), P. moruagnei (Church. Bab.), P. multifida (Laurer), P. poculifera (Miill.Arg.), P. psilophylla (Miill.Arg.), P. pubescent (Miill.Arg.), and P. rubella (Hook.f. & Taylor). 85 taxa are reduced to synonymy with known species.
Lobe Growth and Marginal Zonation in Crustose Lichens
Authors: Hooker T. N.
Published: May 2007

Lobes of Xanthoria elegans are shown to be engulfed by more rapidly growing neighbouring lobes, thereafter ceasing to grow, and the rate of lobe engulfment increases with thallus age. Similarly, growth can cease when lobes of adjacent thalli meet. Mature central areas of eroded thalli may regenerate lobes and resume growth. In Buellia coniops, B. russa and Caloplaca cirrochrooides, peripheral concentric zonation does not always correspond to a single year's growth, and one zonation effect is correlated with an unusually severe winter.
A Study of the Short Range Pollution Around a Power Plant Using Heavy Fuel Oil by Analysing Vanadium in Lichens
Authors: Nygård S. , Harju L.
Published: May 2007

The vanadium content of the lichen Hypogymnia physodes was determined in the vicinity of a power plant using heavy oil as fuel. For the chemical analysis a DC plasma emission spectrometer was used. Air dried samplesof the lichen contained between 1–4 and 57 parts per million (ppm) of vanadium. The highest concentrations were found in specimens collected less than 1 km from the power plant. Lichens collected 50 km from the plant contained less than 2 ppm of vanadium.
Polythelis, an Overlooked Genus of Tropical Pyrenulaceae with Eu- and Distoseptate Ascospores
Authors: Hawksworth D. L.
Published: May 2007

The genus Polythelis Clem, has been almost entirely ignored since its description in 1909. It belongs to the Pyrenulaceae and is close to Pyrenula Massal. from which it is distinguished in having a true septum (euseptum) near the base of the ascospores as well as locules (distosepta) identical to those of Pyrenula. The genus includes a single doubtfully lichenized species, Polythelis sexlocularis (Müll. Arg.) Clem. (syn. Microthelia sexlocularis Müll. Arg.), known only from the type material collected on the bark of a species of Croton, probably C. linearis Jacq., in the West Indies or southern Florida prior to 1824.
The Composition of Some Calcicolous Lichen Communities in the Burren, Western Ireland
Authors: McCarthy P. M.
Published: May 2007

The lichen vegetation of a limestone pavement in the Burren region of western Ireland is described. Species are distributed in relation to gradients of moisture, nutrient-availability and insolation; these in turn may be related to the range of geomorphological micro-features associated with karst. The majority of the 136 stands are dominated by endolithic and foliose cyanophilic lichens. Epilithic, non-cyanophilic crusts grow best on surfaces subjected to occasional bird-manuring. A successional sequence from bare rock through endolithic communities to ones dominated by epilithic, noncyanophilic species does not occur in the Burren.
Studies in the Nomenclature of British Lichens I
Authors: Laundon J. R.
Published: May 2007

Three name changes are proposed for the lichen checklist. Caloplaca heppiana should be called C. flavescens (Huds.)Laundon comb. nov. It is suggested that Coelocaulon muricatum (Ach.)Laundon comb. nov. is a more appropriate name for C. aculeatum subsp. hispidum. The name Schismatomma virgineum should be replaced with S. cretaceum (Hue)Laundon comb. nov.
Cyanobiont Diversity in the Licfflnaceae and Heppiaceae
Authors: Bubrick P. , Galun Margalith
Published: May 2007

Cyanobacteria symbiotic with 17 members of the Lichinaceae and Heppiaceae were brought into unialgal culture and their free-living characteristics examined. A diversity of cyanobacterial types was observed; this diversity was much greater than that reported in the literature. Both the in situ identification of cyanobionts and their role as an aid to the identification of these lichens are questioned.
The Use of Average number of Neighbours for Predicting Lichen Sensitivity: a Case Study
Authors: Herben T. , Liška J.
Published: May 2007

The sensitivity of lichen species to air pollution was assessed by examining aspects of their rate of disappearance over a 5 year period in an area with rising SO2 concentration. These rates of disappearance were compared with the ecological index of species proposed by LeBlanc & DeSloover in 1970, i.e. the index of average number of neighbours for a given species. Linear correlation showed that this ecological index is a reasonably accurate indicator of species sensitivity. When the selection of species was performed according to criteria other than SO2 sensitivity, viz. according to the predilection of lichens for eutrophicated bark, the ecological index proved reliable only when trees whose conditions were non-optimal for this group were excluded. When applied to the group of species that avoids eutrophicated bark the ecological index proved most reliable, although the group of ‘ nitrophilous ’ species may also be used in air pollution indicator studies.
Lichens of High Ground in the Cairngorm Mountains, Scotland
Authors: Gilbert O. L. , Fox B. W.
Published: May 2007

A description and ecological interpretation of lichen communities occurring on high ground in the Cairngorms is presented. The area supports only a limited lichen flora but it is highly specialised; a quarter of the 134 species encountered are thought to have their main area of distribution in Britain on the Cairngorm plateau. The majority of these are associated with areas of late snow-lie from which Cladonia stricta, Lecidea griseoalra, Micarea viridiatra, Sporaslatia cinerea and Staurothele clopima, all new to the British Isles, were discovered together with two species still to be determined. The detailed zonation of lichens round a semi-permanent snow patch was investigated using a transect. Central areas of snow-beds are identified as receiving sites for nutrients and contain a proportion of basiphilous lichens. High wind speeds appear to restrict lichen distribution in certain saxicolous habitats; from several such sitesLecidea nigroleprosa new to Britain was collected. In Funcus trifidus heath and dwarf Calluna the occurrence of lichens is largely determined by the growth and decay of the dominant higher plants.
Wawea Fruticulosa, a New Genus and Species from the Southern Hemisphere
Authors: Henssen Aino , Kantvilas G.
Published: May 2007

The monotypic genus Wawea gen. nov. is described as a second genus in the family Arctomiaceae. The single species, Wawea fruticulosa sp. nov., is characterized by its fruticose habit, rugose and corticate lobes, secondarily multidivided and coalescing apothecia, two-celled spores, and by the unique initial stage of ascocarp ontogeny which includes simultaneous development of ascogonia as well as short-celled, branched conldiophores producing conidia. W. fruticulosa is widespread in Tasmania and is known also from New Zealand with single collections from the North and South Island. A new pyrenomyceteRhynchomeliola lichenicola sp. nov., parasymbiotic on Wawea fruticulosa, is also described.
Three Species of Schismatomma
Authors: Tehler A.
Published: May 2007

Schismalomma ceylanicum sp. nov. is described from Sri Lanka, and an account is given of two species from California previously assigned to Dirina: S. calijornicum(Tuck.) Zahlbr. and S. rediunta (Hasse) comb. nov.
Calcium oxalate hydrates on the surface of lichens
Authors: Wadsten T. , Moberg R.
Published: May 2007

The examination of the surface deposit of various lichens with X-ray diffraction methods, correlated with scanning electron microscopical (SEM) studies, have shown that calcium oxalate is present as two different hydrates; weddellite (CaC2O4-(2 + x)H2O), in three slightly different morphologies, and whewellite (CaC2O4H2O). The reason for the formation of calcium oxalate is not known and the presence of the various crystal forms is yet to be explained. However, the various hydrates may have some role in the water balance as they are different in dry and humid sites.
Artificial Cultures of Lichens in the Natural Environment
Authors: Schuster G. , Ott S. , Jahns H. M.
Published: May 2007

The growth and development of several lichens under natural conditions are studied with the SEM. The results permit observations on the influence of the microclimate and of pollution on thalline development and on some principles of lichen systematics.
Macentina Aurantiaca, A New Lichen From the Burren, Western Ireland
Authors: McCarthy P. M. , Vězda A.
Published: May 2007

Macentina aurantiaca sp. nov. (Verrucariaceae) is described from the Burren, western Ireland. A sciophilous lichen, it is characterized by its comparatively large, orange ascomata and by its mostly 7-septate, elongate-ellipsoid ascospores.
Spore to Spore Resynthesis of Xanthoria Parietina
Authors: Bubrick P. , Galun Margalith
Published: May 2007

Axenic, spore to spore resynthesis of Xanthoria parietina has been accomplished on an agar substrate.
EDW Ardiella Mirabilis, A Holocarpous Lichen from Marion Island
Authors: Henssen Aino
Published: May 2007

The new genus Edwardiella Henssen with the single species E. mirabilis Henssen is described in the Lichinaceae to include a holocarpous lichen. Colonies of the Gloeocapsa-phycobiont which are invaded by the fungal hyphae develop directly into apothecia or pycnidia. The apothecia are thallinocarps. The lichen was collected in the subantarctic Marion Island where it was mainly growing in lichenized tufts of Scytonema. Two new combinations, Gonohymenia nigritella (Lettau) Henssen and G. hondoana (Zahlbr.) Henssen are made.
A New Species in the Genus Collema from East Africa
Authors: Swinscow T. D. V. , Krog Hildur
Published: May 2007

A new species of Collema is described which, like C. callibotrys, has numerous minute globose apothecia in clusters but, unlike that species, has unornamented spores. It is recorded from Tanzania and Uganda.
Protein Banding Patterns in the Ramalina Siliquosa Group
Authors: Mattsson J. E. , Kärnefelt I.
Published: May 2007

The value of primary chemical compounds correlated with known secondary chemistry and morphological variation within the Ramalina siliquosa group has been investigated. A hundred specimens were collected on two different occasions from 13 different populations on the Swedish west coast during April 1984. Protein extracts were prepared from 27 on secondary constituents identified and morphologically analysed populations. The protein bandings were performed by means of isoelectric focusing. Twenty-two different banding patterns were analysed since two were destroyed during preparation and three others yielded weak patterns. The results indicated that three different banding pattern types could be discerned: type A originated from material containing norstictic acid, stictic acid, norstictic acid in combination with stictic acid and on acid-deficient material; type B originated from material containing salazinic acid or salazinic acid in combination with protocetraric acid; and type C originated from material containing salazinic acid, protocetraric acid, salazinic acid in combination with protocetraric acid or on acid-deficient material. Material of banding type A belonged morphologically to R. cuspidata (Ach.) Nyl. and material of banding types B and C to R. siliquosa (Hudson) A. L. Smith. Seasonal and developmental factors can, however, affect the production of both primary and secondary constituents. Since there are no obvious morphological differences between the different chemical races within R. siliquosa s. str. and as material of salazinic acid in combination with protocetraric acid yielded both type B and type C banding patterns, the results do not support a taxonomy in the R. siliquosa group recognizing more than two species.
Some Observations on The Thallus in Pannaria, with Description of a New Species
Authors: Swinscow T. D. V. , Krog Hildur
Published: May 2007

Pannaria is shown to include species whose thallus ranges from the almost homoiomerous to the fully differentiated heteromerous state. A new species of Pannaria is described, P. santessonii, with a thallus closely resembling that characteristic of the Collemataceae. Lepidocollema carassense Vainio and Lepidoleptogium montaguei A. L. Sm., the type species of these respective genera, have beenfound to have a similar type of thallus. Further study of the relationship between thesegenera is needed.
The Macrolichens of Tasmanian Rainforest: Key and Notes
Authors: Kantvilas G. , James P. W.
Published: May 2007

An identification key to 128 macrolichen species from Tasmanian rainforest is presented. Additional data on the flora are also included. Five new species, Menegazzia caesiopruinosa P. James, M. confusa P. James, M. inactiva P. James & Kantvilas, M. minuta P. James & Kantvilas and M. subbullata P. James & Kantvilas, are described, and the new combination Leioderma amphibolum (Knight) P. M. Jørgensen & D. Galloway is made.
Foliicolous Lichens of the Usambara Mountains, Tanzania I
Authors: Farkas Edit
Published: May 2007

Rich collections of foliicolous lichens were made, especially from submontane and montane areas, in the Usambara Mountains of Tanzania during the Usambara Rain Forest Research Project expeditions in 1982, 1984 and 1985. An enumeration of the identified species is provided together with taxonomic, ecological and geographical notes. This first part treats 36 species from the Arthoniaceae, Opegraphaceae and all genera with pyrenocarpous ascomata. New records include 14 species for the Usambaras, eight for Tanzania, and three to Africa. Porina sphaerocephaloides sp. nov., widely distributed in the study area, is described.
A New Species of Lichinella (Lichinaceae) from Japan
Authors: Harada H. , Henssen Aino
Published: May 2007

The new species Lichinella japonica Harada & Henssen is described for the first time from Japan. L. japonica differs from known species in thallus structure and ecology. It is the first record of the genus from East Asia.
New and Interesting Species of Verrucaria I
Authors: McCarthy P. M.
Published: May 2007

Verrucaria aranensis McCarthy and V. knowlesiae McCarthy are described as new from limestone in western Ireland. Verrucaria mulabilis Borrer is an illegitimate name; moreover, a number of British specimens attributed to it are V. dolosa Hepp. A key to minute-spored, terrestrial saxicolous Verrucariae is provided in which V. subumbrinula Vainio and V. anzianoides Magnusson are reduced to synonymy under V. naeviformis Vainio and V. arctica Lynge, respectively.
Sarrameana Tasmanica, a New Tasmanian Lichen
Authors: Vězda A. , Kantvilas G.
Published: May 2007

A new species of Sarrameana, S. tasmanica Vězda & Kantvilas, is described from Tasmania. The taxonomic relationship of this species with S. paradoxa Vězda & P. James from New Caledonia is discussed.
Initial Establishment of Saxicolous Lichens Following Recent Glacial Recession in Sverdrup Pass, Ellesmere Island, Canada
Authors: Fahselt Dianne , Maycock Paul F. , Svoboda Josef
Published: May 2007

In the recently deglaciated zone of a valley glacier in Central Ellesmere Island the mean period of time before the onset of colonization on bare rock surfaces was estimated to be about 80 years. The first species to establish was Xanthoria elegans, followed by Lecanora crenulata and Umbilicaria virginis approximately 20 years later. Summer temperature appeared to be one factor which affected lichen establishment in recently deglaciated bare areas in the High Arctic. Warmer microsites were identified as preferred locations for thallus establishment; these, therefore, constitute ideal sites for studies of thallus initiation under natural conditions. Following the retreat of a glacier from its most advanced Little Ice Age position, 16 species of saxicolous lichens have become established on bare rock debris in the icefree zone, but in nine transects only five species had a constancy of 80% or more. Lichen diversity in this successional photocommunity was comparable to that in a nearby pre-Little Ice Age landscape with more varied substrata.
Photosymbiodemes and their Development in Peltigera Venosa
Authors: Ott Sieglinde
Published: May 2007

A photosymbiodeme is described for Peltigera venosa. One member consists of small black squamules containing cyanobacteria whereas the other, the more familiar thallus of the species, contains green algae. New aspects of morphogenetic influences are discussed.
Systematics of Some Reindeer Lichens (Cladonia Subg. Cladina) in the Southern Hemisphere
Authors: Ruoss E. , Ahti T.
Published: May 2007

Cladonia arbuscula subsp. squarrosa (Wallr.) Ruoss and C. stygia (Fr.) Ruoss are reported for the first time from the Southern Hemisphere. Populations of C. arbuscula in New Zealand and Australia are recognized as subsp. stictica Ruoss, subsp. nov., usually containing stictic acid, norstictic acid (first report in subg. Cladina), and sometimes also the fumarprotocetraric acid complex. C. laevigata (Vainio) Gyelnik is reinstated in Cladonia subg. Cladina sect. Tenues, while C. stygia is considered to belong to sect. Crustaceae rather than to sect. Tenues. C. confusa R. Sant. is morphologically highly variable, although chemically uniform, usually containing usnic acid and perlatolic acid. An usnic acid-deficient chemodeme is reported as new to New Zealand.
Studies in the Lichen Family Pannariaceae III. The Genus Fuscoderma, with Additional Notes and a Revised Key to Leioderma
Authors: Jørgensen P. M. , Galloway D. J.
Published: May 2007

Leioderma subg. Fuscoderma D. Galloway & P. M. Jørg., is shown to be a distinct genus, confined to Tasmania and New Zealand and comprising three species: Fuscoderma amphibolum (Knight) comb, nov., F. applanatum (D. Galloway & P. M. Jørg.) comb, nov., and F. limbatum sp. nov. A key to the species is given. A revised key to Leioderma is also presented and a second locality (Ecuador) is reported for the Brazilian species L. glabrum D. Galloway & P. M. Jørg.
The Genus Roccellinastrum in Tasmania
Authors: Kantvilas Gintaras
Published: May 2007

The byssoid lichen genus, Roccellinastrum, consists of three species in Tasmania.Two of these, R. flavescens and R. lagarostrobi, are described as new. Both species grow exclusively on the leaves of Tasmanian endemic conifers and are recognized by a combination of morphological, chemical and anatomical characters. Usnic acid, found in R. flavescens, is recorded in the genus for the first time. Relationships with South American species are discussed.
New Species of Cladonia From Tropical South America
Authors: Ahti Teuvo
Published: May 2007

Cladonia friabilis Ahti (type from Bahia, Brazil), C. pulviniformis Ahti (type from Bolivar, Venezuela), C. sufflata Ahti (type from Bolivar, Venezuela), and C. variegata Ahti (type from Bolivar, Venezuela) are described as new. Their major secondary metabolites are reported.
Globosphaeria, A Remarkable New Pyrenomycete on Normandina From Tasmania
Authors: Hawksworth D. L.
Published: May 2007

The generic name Globosphaeria D. Hawksw. gen. nov. is introduced for the single species G. jamesii D. Hawksw. sp. nov. discovered on squamules of the lichen Normandina pulchella (Borrer) Nyl. collected in Tasmania. It is commensalistic or perhaps mutualistic. The genus is characterized by dark perithecioid ascomata, filiform paraphyses, thin-walled asci, and uniseriate thick-walled globose hyaline ascospores. It cannot easily be accommodated in any accepted order, and is tentatively referred to the Xylariales pending the discovery of fresh material.
New British Species of Caloplaca
Authors: Laundon Jack R.
Published: May 2007

Caloplaca britannica R. Sant. sp. nov. and C. ceracea Laundon sp. nov. are described, the latter having been erroneously called C. caesiorufa by British authors. Both grow on maritime rocks, but C. ceracea also occurs inland where it is rare. The value of the colour test with C (bleach) in Caloplaca is mentioned.
Contributions to The Lichen Flora of Tenerife
Authors: Lumbsch H. Thorsten , Vézda A.
Published: May 2007

Bacidina apiahica, Diploschistes bisporus, D. candidissimus and Fellhanera buxi are reported as new to the Canary Islands. Bacidina canariensis Lumbsch & Vézda is newly described.
Neofuscelia squamariata and Neofuscelia almbornii SP. Nov. (Parmeliaceae)
Authors: Henssen Aino , Titze Andreas
Published: May 2007

The species Neofuscelia almbornii Henssen, is described from South Africa. It differs from N. squamariata in the smaller size of the lobes and longer asci and conidia. Characteristic features of both species are: a subcrustose thallus with tufts of rhizoidal hyphae arising from a well-developed lower cortex,±bifusiform conidia, and a minutely porous upper surface. The two species differ from Neofuscelia pulla by the lack of a foliose thallus, true rhizines, and epicortical pores in the sense of Hale.
Lichens of Cocos nucifera on Caye Caulker, Belize
Authors: Barclay-Estrup P.
Published: May 2007

Twenty lichens and a cyanobacterium grow as epiphytes on both shoreline and inland coconut palms (Cocos nucifera) on Caye Caulker, Belize, with a difference in distribution of these epiphytes between shoreline and inland trees. Nine epiphytes were also collected from mangrove (Rhizophora mangle): seven lichens, one moss, and one cyanobacterium.
THE RULE OF REASON IN PLATO'S STATESMAN AND THE
AMERICAN FEDERALIST
Authors: Miller Fred D.
Published: May 2007

The Federalist, written by “Publius” (Alexander
Hamilton, John Jay, and James Madison) in 1787-1788 in defense of the
proposed constitution of the United States, endorses a fundamental
principle of political legitimacy: namely, “it is the reason of the
public alone, that ought to control and regulate the government.”
This essay argues that this principle—the rule of reason—may
be traced back to Plato. Part I of the essay seeks to show that Plato's
Statesman offers a clearer understanding of the rule of reason
than his more famous Republic, and it also indicates how this
principle gave rise to the ideal of constitutionalism, which was adopted
and reformulated by Aristotle, Polybius, and Cicero, as well as moderns
including Locke and Montesquieu. Part II argues that The
Federalist agrees with Plato when it argues that popular sovereignty
must be tempered by the rule of reason. A proper distance should be
maintained between the people and the actual exercise of power in order
that political decisions be based on reason rather than passion. The
people must therefore act through a federal system divided between
national government and state governments, and these governments must
themselves possess separated powers which control each other by means of
checks and balances. Indeed, federalism itself may be viewed as a modern
counterpart of Plato's “art of weaving,” which unites
naturally disparate and opposed parts of the city-state into a concordant
whole. In declaring, “If men were angels, no government would be
necessary,” The Federalist concedes that politics is the
art of the possible. But statesmanship is not an exercise in pragmatism
devoid of principles. Here “Publius” shares Plato's vision of
politics as a “second sailing,” that is, an attempt to
approximate the ideal of rational governance as far as possible in
ordinary politics.
Conditional parametric models for storm sewer runoff
Authors: Jonsdottir H. , Nielsen H. Aa , Madsen H. , Eliasson J. , Palsson O. P. , Nielsen M. K.
Published: May 2007

The method of conditional parametric modeling is introduced for flow prediction in a sewage system. It is a well‐known fact that in hydrological modeling the response (runoff) to input (precipitation) varies depending on soil moisture and several other factors. Consequently, nonlinear input‐output models are needed. The model formulation described in this paper is similar to the traditional linear models like final impulse response (FIR) and autoregressive exogenous (ARX) except that the parameters vary as a function of some external variables. The parameter variation is modeled by local lines, using kernels for local linear regression. As such, the method might be referred to as a nearest neighbor method. The results achieved in this study were compared to results from the conventional linear methods, FIR and ARX. The increase in the coefficient of determination is substantial. Furthermore, the new approach conserves the mass balance better. Hence this new approach looks promising for various hydrological models and analysis.
Spreading of near‐inertial energy in a 1/12° model of the North Atlantic Ocean
Authors: Zhai Xiaoming , Greatbatch Richard J. , Eden Carsten
Published: May 2007

Near‐inertial energy in the ocean is thought to be redistributed by β‐dispersion, whereby near‐inertial waves generated at the surface by wind forcing propagate downward and equatorward. In this letter, we examine the spreading of near‐inertial energy in a realistic 1/12° model of the North Atlantic driven by synoptically varying wind forcing. We find that (1) near‐inertial energy is strongly influenced by the mesoscale eddy field and appears to be locally drained to the deep ocean, largely by the chimney effect associated with anticyclonic eddies, and (2) the interior of the subtropical gyre shows very low levels of near‐inertial energy, contrary to expectations based on the β‐dispersion effect.
Association of Integrin α2 Gene Variants with Ischemic Stroke
Authors: Matarin Mar , Brown W Mark , Hardy John A , Rich Stephen S , Singleton Andrew B , Brown Robert D , Brott Thomas G , Worrall Bradford B , Meschia James F ,   SWISS ISGS,   MSGD Study Groups
Published: May 2007

Genetic variants in the gene encoding integrin α2 ( ITGA2) have been reported to be associated with an increased risk for ischemic stroke. The purpose of this study was to investigate the association between haplotype-tagging single-nucleotide polymorphisms (tSNPs) in ITGA2 and risk of ischemic stroke in a collection of North American stroke cases and controls. The study included 484 cases and 263 controls. Thirteen tSNPs were genotyped. Association tests at and across each tSNP were performed, including haplotype association analysis. Secondary analyses considered stroke subtypes on the basis of Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. We observed significant association between tSNP rs3756541 (additive model, odds ratio (OR), 1.49; 95% confidence interval (CI), 1.11 to 2.04; P = 0.009) and disease and a trend toward association at rs2303124 (recessive model, OR, 1.56; 95% CI, 1.05 to 2.33; P = 0.03). These associations remained significant in the haplotype analyses. The associated tSNPs did not distinguish stroke etiology after application of TOAST criteria. Our results suggest that genetic variability within ITGA2 may confer risk for ischemic stroke independent of conventional risk factors. These results provide additional support for a role for platelet receptor genes in the pathogenesis of ischemic stroke of diverse subtypes.
Transient arrest in proteasomal degradation during inhibition of translation in the unfolded protein response
Authors: Shenkman Marina , Tolchinsky Sandra , Kondratyev Maria , Lederkremer Gerardo Z.
Published: May 2007

The UPR (unfolded protein response) activates transcription of genes involved in proteasomal degradation. However, we found that in its early stages the UPR leads to a transient inhibition of proteasomal disposal of cytosolic substrates (p53 and p27kip1) and of those targeted to ER (endoplasmic reticulum)-associated degradation (uncleaved precursor of asialoglycoprotein receptor H2a). Degradation resumed soon after the protein synthesis arrest that occurs in early UPR subsided. Consistent with this, protein synthesis inhibitors blocked ubiquitin/proteasomal degradation. Ubiquitination was inhibited during the translation block, suggesting short-lived E3 ubiquitin ligases as candidate depleted proteins. This was indeed the case for p53 whose E3 ligase, Mdm2 (murine double minute 2), when overexpressed, restored the degradation, whereas a mutant Mdm2 in its acidic domain restored the ubiquitination but did not completely restore the degradation. Inhibition of proteasomal degradation early in UPR may prevent depletion of essential short-lived factors during the translation arrest. Stabilization of p27 through this mechanism may explain the cell cycle arrest in G1 when translation is blocked by inhibitors or by the UPR.
Fragment length influences affinity for Cu2+ and Ni2+ binding to His96 or His111 of the prion protein and spectroscopic evidence for a multiple histidine binding only at low pH
Authors: Klewpatinond Mark , Viles John H.
Published: May 2007

The prion protein (PrP) is a Cu2+-binding cell-surface glycoprotein. Using various PrP fragments and spectroscopic techniques, we show that two Cu2+ ions bind to a region between residues 90 and 126. This region incorporates the neurotoxic portion of PrP, vital for prion propagation in transmissible spongiform encephalopathies. Pentapeptides PrP-(92–96) and PrP-(107–111) represent the minimum motif for Cu2+ binding to the PrP-(90–126) fragment. Consequently, we were surprised that the appearance of the visible CD spectra for two fragments of PrP, residues 90–126 and 91–115, are very different. We have shown that these differences do not arise from a change in the co-ordination geometry within the two fragments; rather, there is a change in the relative preference for the two binding sites centred at His111 and His96. These preferences are metal-, pH- and chain-length dependent. CD indicates that Cu2+ initially fills the site at His111 within the PrP-(90–126) fragment. The pH-dependence of the Cu2+ co-ordination is studied using EPR, visible CD and absorption spectroscopy. We present evidence that, at low pH (5.5) and sub-stoichiometric amounts of Cu2+, a multiple histidine complex forms, but, at neutral pH, Cu2+ binds to individual histidine residues. We have shown that changes in pH and levels of extracellular Cu2+ will affect the co-ordination mode, which has implications for the affinity, folding and redox properties of Cu-PrP.
AMP-activated protein kinase-independent inhibition of hepatic mitochondrial oxidative phosphorylation by AICA riboside
Authors: Guigas Bruno , Taleux Nellie , Foretz Marc , Detaille Dominique , Andreelli Fabrizio , Viollet Benoit , Hue Louis
Published: May 2007

AICA riboside (5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside) has been extensively used in cells to activate the AMPK (AMP-activated protein kinase), a metabolic sensor involved in cell energy homoeostasis. In the present study, we investigated the effects of AICA riboside on mitochondrial oxidative; phosphorylation. AICA riboside was found to dose-dependently inhibit the oligomycin-sensitive JO2 (oxygen consumption rate) of isolated rat hepatocytes. A decrease in Pi (inorganic phosphate), ATP, AMP and total adenine nucleotide contents was also observed with AICA riboside concentrations >0.1 mM. Interestingly, in hepatocytes from mice lacking both α1 and α2 AMPK catalytic subunits, basal JO2 and expression of several mitochondrial proteins were significantly reduced compared with wild-type mice, suggesting that mitochondrial biogenesis was perturbed. However, inhibition of JO2 by AICA riboside was still present in the mutant mice and thus was clearly not mediated by AMPK. In permeabilized hepatocytes, this inhibition was no longer evident, suggesting that it could be due to intracellular accumulation of Z nucleotides and/or loss of adenine nucleotides and Pi. ZMP did indeed inhibit respiration in isolated rat mitochondria through a direct effect on the respiratory-chain complex I. In addition, inhibition of JO2 by AICA riboside was also potentiated in cells incubated with fructose to deplete adenine nucleotides and Pi. We conclude that AICA riboside inhibits cellular respiration by an AMPK-independent mechanism that likely results from the combined intracellular Pi depletion and ZMP accumulation. Our data also demonstrate that the cellular effects of AICA riboside are not necessarily caused by AMPK activation and that their interpretation should be taken with caution.
The Effects of Three Nebulized Osmotic Agents in the Dry Larynx
Authors: Tanner Kristine , Roy Nelson , Merrill Ray M. , Elstad Mark
Published: May 2007

Purpose

This investigation examined the effects of nebulized hypertonic saline, isotonic saline (IS), and sterile (hypotonic) water on phonation threshold pressure (PTP) and self-perceived phonatory effort (PPE) following a surface laryngeal dehydration challenge.

Method

In a double-blind, randomized experimental trial, 60 vocally healthy women (
n
= 15 per group) underwent a laryngeal desiccation challenge involving oral breathing for 15 min using medical-grade dry air (RH<1%). Three of the four groups then received nebulized isotonic saline (0.9% NaCl), hypertonic saline (7% NaCl), or sterile (hypotonic) water, respectively; the 4th group served as a nontreatment control. PTP and PPE were estimated for high-pitched productions at baseline, immediately postdesiccation, and at 5, 20, 35, and 50 min postnebulization.

Results

PTP increased significantly for all groups following the desiccation challenge. PTP values were, on average, 0.5 cm H
2
O greater immediately postdesiccation versus baseline. In contrast, PTP values did not change significantly following the administration of nebulized treatments, although a temporary trend toward a reduction in PTP was observed for the IS group. Unexpectedly, PPE ratings decreased significantly after the desiccation challenge. In general, PPE ratings were poorly correlated with PTP measures.

Conclusion

A laryngeal desiccation challenge (i.e., temporary exposure to extremely low relative humidity while breathing transorally) significantly increased PTP. Although interesting trends emerged, none of the nebulized treatments significantly enhanced recovery from the negative effects of desiccation on PTP. In light of very low correlations between PTP and PPE, serious questions are raised regarding presumed associations between these measures.
The Influence of Semantic Processing on Phonological Decisions in Children and Adults: A Magnetoencephalography (MEG) Study
Authors: Wehner Daniel T. , Ahlfors Seppo P. , Mody Maria
Published: May 2007

Purpose

To examine the behavioral effects and neural activation patterns associated with implicit semantic processing influences on phonological judgments during reading in children and adults.

Method

Whole-head magnetoencephalography (MEG) recordings were obtained from 2 groups, children (9–13 years) and adults, performing a homophone judgment task. The stimuli consisted of pairs of sequentially presented written words that were either homophones, synonym foils, or unrelated control words.

Results

The difference in the time taken to respond to synonym pairs relative to control pairs of stimuli, called the
semantic interference effect (SIE)
, was, on average, 24 ms for adults and 86 ms for children. Source analysis of the MEG data using minimum-norm estimation (MNE) yielded less activation in the adults for the synonym condition compared with the control condition in right anterior temporal and inferior frontal cortex 300–500 ms after the onset of the 2nd word in a pair, suggestive of semantic priming as well as inhibition of the SIE. A similar priming effect was observed for the children in left-anterior temporal cortex.

Conclusion

The observed group differences in the magnitude of the SIE and brain activation patterns may reflect developmental differences in the effects of semantic information on phonological decisions during word processing.
Dielectric and structural studies of Ba2MTi2Nb3O15 (BMTNO15, M=Bi3+,La3+,Nd3+,Sm3+,Gd3+) tetragonal tungsten bronze-structured ceramics
Authors: Stennett M. C. , Reaney I. M. , Miles G. C. , Woodward D. I. , West A. R. , Kirk C. A. , Levin I.
Published: May 2007

The structure and dielectric properties of a new family of tetragonal tungsten bronze (TTB) ceramics with the general formula, Ba2MTi2Nb3O15 where M=Bi3+,La3+,Nd3+,Sm3+,Gd3+, have been investigated. Hereafter the compositions will be referred to by the abbreviation BMTNO15 where M=B(Bi3+), L(La3+), N(Nd3+), S(Sm3+) or G(Gd3+). BLTNO15 [permittivity maximum (Tm)∼−80°C] and BBTNO15 (Tm∼−100°C) exhibited relaxorlike dielectric behavior. In contrast, BNTNO15 (Tm∼165°C), BSTNO15 (Tm∼250°C), and BGTNO15 (Tm∼320°C) were classic ferroelectrics. Tm increased with decreasing radius of the M ion. Room temperature x-ray powder diffraction (XRD) patterns of all the compounds indexed on a prototype P4∕mbm (or P4bm) space group with lattice parameters a≈12.4Å and c≈4Å. However, electron diffraction revealed that the relaxor phases, BLTNO15 and BBTNO15, exhibited an incommensurate modulation, whereas the classic ferroelectric BNTNO15, BSTNO15, and BGTNO15 featured an orthorhombic superstructure with lattice parameters a≈b≈√2aTTB and c≈2cTTB.
The influence of ac electric field on the domain growth and alignment of the ferroelectric liquid crystal cell with N*–SmC* phase transition
Authors: Wu Po-Chang , Wu Jin-Jei
Published: May 2007

The mechanisms of domain growth and the formation of alignment of the ferroelectric liquid crystal (FLC) were investigated under an applied alternating current (ac) electric field during N*–SmC* phase transition. Varying the frequency of the ac electric field allowed for the domain size and average dynamic molecular axis of a FLC cell to be controlled. In addition, the mechanism of alignment in the FLC cell with an ac electric field, which is applied to the FLC cell during N*–SmC* phase transition, was clarified.
Fracture strength in randomly perforated plates
Authors: Yanay Y. , Goldsmith A. , Siman M. , Englman R. , Jaeger Z.
Published: May 2007

We have measured the forces that need to be applied quasistatically to randomly perforated rectangular aluminum plates to tear them apart. Concomitantly, for identical geometrical structures, we have carried out numerical simulations of the tearing process. The two results agree quite reasonably, and especially so for perforated area densities (P) that are rather less than the critical percolation densities. A given value of P can be achieved through various different realizations (patterns of perforations), each with a somewhat different fracture (or failure) strength F. Our results predict empirically an “expected F” [F¯(P)] and an expected standard deviation [root variance, S(P)] as functions of P. This enables the risk analysis of failures in plates under tensile stress, which is needed in, e.g., the estimation of the flying safety of a spacecraft subject to multiple perforations.
Measurement of high piezoelectric response of strontium-doped lead zirconate titanate thin films using a nanoindenter
Authors: Sriram S. , Bhaskaran M. , Holland A. S. , Short K. T. , Latella B. A.
Published: May 2007

Strontium-doped lead zirconate titanate (PSZT) is reported to have a high piezoelectric coefficient (d33) in the range of 200−600 pm∕V, when in the form of ceramic disks or pellets. This article reports piezoelectric response results for PSZT thin films deposited by rf magnetron sputtering on gold-coated silicon substrates. The compositions of the deposited thin films have been found to be uniform with depth, using secondary ion mass spectroscopy. The surfaces of the deposited thin films have been studied using an atomic force microscope and observed to be regular and nanostructured in nature. The piezoelectric response of the thin films, using the inverse piezoelectric effect, has been measured using a nanoindenter. Values of thin film d33 up to 608 pm∕V were obtained, which is much higher than previously reported values of d33 for any thin film. The high values can be attributed to optimized deposition conditions and the low stress measured for the thin film arrangement on the substrate. The technique has been verified by obtaining a null response for silicon dioxide and by measuring d33 values of similar magnitude for PSZT thin films using an atomic force microscope in the same testing arrangement. The piezoelectric response has been mapped to study variations across the thin film and with distance from the top electrode.
Optimal secondary energy growth in a plane channel flow
Authors: Cossu Carlo , Chevalier Mattias , Henningson Dan S.
Published: May 2007

The optimal growth of perturbations to transiently growing streaks is studied in Poiseuille flow. Basic flows are generated by direct numerical simulation giving “primary” optimal spanwise periodic vortices of finite amplitude as the initial condition. They evolve into finite amplitude primary transiently growing streaks. Linear “secondary” optimal energy growth supported by these primary flows are computed using an adjoint technique which takes into full account the unsteadiness of the basic flows. Qualitative differences between primary and secondary optimal growths are found only when the primary streaks are locally unstable. For locally stable primary streaks, the secondary optimal growth has the same scalings with Reynolds number R as the primary optimal growth and the maximum growth is attained by streamwise uniform vortices, suggesting that the primary and secondary optimal growth are based on the same physical mechanisms. When the primary streaks are locally unstable the secondary optimal growth of unstable wavenumbers scale differently with R and the maximum growth is attained for streamwise nonuniform sinuous perturbations, indicating the prevalence of the inflectional instability mechanism.