bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure—function relationships in the integument of Salamandra salamandra during ontogenetic development
Authors: Pederzoli Aurora , Gambarelli A. , Gabbay Shosh , Rozman A. , Katz U.
Published: September 2002

Morphological, cytological and transport properties of the integument of Salamandra salamandra were investigated during natural ontogenetic development, from birth to adult. Three stages were operationally defined: I, larvae, from birth to metamorphosis; II, metamorphosis (judged externally by the colour change and loss of the gills); and III, post‐metamorphosis to adult. Pieces of skin were fixed at various stages for immunocytochemical examinations, and the electrical properties were investigated on parallel pieces. Distinct cellular changes take place in the skin during metamorphosis, and lectin (PNA, WGA and ConA) binding indicates profound changes in glycoprotein composition of cell membranes, following metamorphosis. Band 3 and carbonic anhydrase I (CA I) were confined to mitochondria‐rich (MR)‐like cells, and were detected only in the larval stage. CA II on the other hand, was detected both in MR‐like and in MR cells following metamorphosis. The electrical studies show that the skin becomes more tight (transepithelial resistance increases) upon metamorphosis, followed by manifestation of amiloride‐sensitive short‐circuit current (I sc) indicating that functional Na+ uptake has been acquired. The skin of metamorphosed adults had no finite transepithelial Cl− conductance, and band 3 was not detected in its MR cells. The functional properties of MR‐like and MR cells remain to be established.
Endocytic prolactin routes to the secretory pathway in lactating mammary epithelial cells
Authors: Seddiki Touria , Delpal Serge , Aubourg Alain , Durand Georges , Ollivier‐Bousquet Michèle
Published: September 2002

Plasma‐borne prolactin is carried from blood to milk by transcytosis across the mammary epithelial cell through the endocytic and secretory pathways. To determine the precise route of prolactin endocytosis, intracellular transport of biotinylated prolactin was monitored, in parallel with endocytosis of fluorescein isothiocyanate‐conjugated dextran and IgG, by using pulse‐chase experiments in lactating mammary fragments and in enzymatically dissociated acini. Biotinylated prolactin was sorted to vesiculo‐tubular organelles whereas dextran was very rapidly carried to the lumen and IgG remained accumulated in the basal region of cells. To determine whether prolactin uses routes into and across the Golgi and trans‐Golgi network, localisation of biotinylated prolactin was combined with the immunofluorescence detection of caseins and, respectively, p58 and TGN38. Biotinylated prolactin strongly colocalised with caseins during a chase but not all or only very little with p58 and TGN38. To characterise the organelles involved in transcytosis, gold‐labelled prolactin, experimentally accumulated in late endosomes and which recovered a normal transport, was localised by electron microscopy. In mammary fragments incubated at low temperature, and in mammary fragments from rats fed with a lipid‐deprived diet, transport of gold‐labelled prolactin was restored by increasing the temperature and by adding arachidonic acid, respectively. These data demonstrate that a sorting occurs very rapidly between prolactin, dextran and IgG. They suggest that prolactin may reach the biosynthetic pathway after direct fusion between multivesicular bodies and secretory vesicles.
Extracellular matrix development during differentiation into adipocytes with a unique increase in type V and VI collagen
Authors: Nakajima Ikuyo , Muroya Susumu , Tanabe Ryo‐Ichi , Chikuni Koichi
Published: September 2002

In order to study how adipose conversion affects the extracellular environment, levels of extracellular matrix (ECM) proteins during differentiation were analyzed by 125I‐labeled antibody binding to each specific primary antibody. When confluent bovine intramuscular preadipocytes (BIP) were stimulated with adipogenic medium, there was a significant accretion on the cell surface of type I—VI collagens, laminin and fibronectin, compared with undifferentiated cells. The deposition amount of ECM proteins had reached near maximal levels at an early stage of differentiation and lasted throughout the culture. However, the increasing manners were not all the same in these eight proteins. Type V and type VI collagen tended to show a transient decline after the rapid rise at the beginning of stimulation, and fibronectin instead, subsequently decreased. Further analysis by immunocytochemical staining showed that remodeling occurred in type V and VI collagen matrices during this period; extensive fibrillar networks seen at 10 d after stimulation were quite unlike that formed earlier. These specific increases and development of matrix during adipocyte differentiation imply some significance for organizing fat lobules in each ECM proteins, especially type V and VI collagens.
Mac1, a fission yeast transmembrane protein localizing to the poles and septum, is required for correct cell separation at high temperatures
Authors: Grandin Nathalie , Charbonneau Michel
Published: September 2002

Schizosaccharomyces pombe represents a genetic model system for studying cell polarity and division in eukaryotes. We report here the identification of Mac1, a novel fission yeast protein that localized predominantly to the cell tips and septum. Sequences corresponding to roughly the first 180 amino acids of Mac1, which exhibited weak homology to the transmembrane domains of the Aspergillus PalI protein 〚Mol. Microbiol. 30 (1998) 259〛, were found to specify localization to the cell periphery. The other 574 amino acids of Mac1 localized to the cytoplasm when expressed alone, thus suggesting that the N‐terminal part of Mac1 functions as a plasma membrane anchor for the rest of the protein. In pom1 null mutant cells, which never switch from unipolar to bipolar growth but, instead, grow exclusively at the randomly chosen end 〚Genes Dev. 12 (1998) 1356〛, Mac1 was, nevertheless, found at both poles, thus suggesting that Mac1 does not specifically localize to the sites of growth. mac1 null mutant cells had no overt phenotype at 22–32 °C, but, nevertheless, displayed a marked decrease in viability at 34–36 °C, accompanied by severe separation defects. Overexpression of mac1 resulted in similar defects. Our data suggest that a correct dosage of Mac1 is needed for correct cell separation at elevated temperatures of growth.
The mitotic spindle and associated membranes in the closed mitosis of trichomonads
Authors: Ribeiro Karla Consort , Pereira‐Neves Antonio , Benchimol Marlene
Published: September 2002

In the present work, we followed the several phases of Tritrichomonas foetus and Trichomonas vaginalis cell cycles using immunofluorescence, serial thin sections, three‐dimensional (3D) reconstruction, and transmission electron microscopy. In motile trichomonad cells or in pseudocyst forms, the nuclear envelope persists throughout mitosis, and the spindle is extranuclear. We found three types of spindle microtubules: pole‐to‐nucleus microtubules which are attached to the nuclear envelope, pole‐to‐pole microtubules forming a cylindrical, cytoplasmic groove on the nuclear compartment in pseudocysts of T. foetus cells, and pole‐to‐cytosol microtubules which extend freely into the cytoplasm. We demonstrated that: (1) in T. foetus, the spindle is assembled from an MTOC located at the base of the costa, underneath one of the basal bodies; (2) the spindle presents an unusual arc shape during the initial phases of mitosis in motile trophozoites; (3) the spindle microtubules are glutamylated, but not acetylated; (4) several membranes similar to those of the endoplasmic reticulum follow the spindle microtubules; (5) finger‐like projections extend from the nucleus towards the cell poles in pseudocysts and multinucleated cells; and (6) vesicles formed in between the two nuclear membranes are seen in the course of mitosis in both trophozoite and pseudocyst forms.
Subcellular distribution of the acidic ribosomal P‐proteins from Saccharomyces cerevisiae in various environmental conditions
Authors: Boguszewska Aleksandra , Tchórzewski Marek , Dukowski Piotr , Winiarczyk Stanisław , Grankowski Nikodem
Published: September 2002

The yeast ribosomal “stalk”–a lateral protuberance on the 60S subunit—consists of four acidic P‐proteins, P1A, P1B, P2A and P2B, which play an important role during protein synthesis. Contrary to most ribosomal proteins, which are rapidly degraded in the cytoplasm, P‐proteins are found as a cytoplasmic pool and are exchanged with the ribosome‐bound proteins during translation. As yet, subcellular trafficking of P‐proteins has not been extensively investigated. Therefore, we have characterized—using immunological approaches—the cellular distribution of P‐proteins in several environmental conditions, characteristic of yeast cells, such as growth phases, and heat‐, osmotic‐, and oxygen‐stress. Using the western blotting approach, we have shown P‐proteins to be present in constant amounts on the ribosomes, despite their exchangeability with the cytoplasmic pool, and regardless of environmental conditions. On the other hand, P‐protein level in the cytoplasm decreased sharply throughout the consecutive growth phases, but was not affected by several stress conditions. Applying the electron microscopic technique and immunogold labeling, we have found that P‐proteins are located in two cell compartments. The first one is the cytoplasm and the second one—an unexpected place—the cell wall, where P‐proteins are fully phosphorylated. Moreover, the existence of P‐proteins on the cellular wall is not affected by various environmental conditions.
Heterozygosity in MAT locus affects stability and function of microtubules in yeast
Authors: Steinberg‐Neifach Olga , Eshel Dan
Published: September 2002

The dynamic nature of microtubules is important for their cellular function and is tightly regulated by the cell cycle machinery and through other pathways that act on microtubule‐associated proteins. Recently, it was reported that simultaneous expression of MATa and MATα genes in haploid cells of Saccharomyces cerevisiae increases microtubule stability 〚Mol. Gen. Genet. 264 (2000) 300〛. In order to investigate the effect of zygosity in the MAT loci on microtubules independent of the effect of the actual ploidy, we compared microtubule stability and function in homozygous (MATa/MATa) and heterozygous (MATa/MATα) wild‐type diploid cells. It was found that homozygosity in the MAT locus decreases stability of both cytoplasmic and nuclear microtubules. This was expressed in a more symmetrical distribution in the placement of the spindle relative to the neck, a delay in cytokinesis and reduced fidelity of chromosome segregation in these cells compared to the heterozygotes. Our results suggest that expression of both MAT loci initiates a pathway that results in an increase in microtubule stability and the fidelity of chromosome segregation in diploids. This pathway is independent of the pathway that determines the budding pattern in haploids and diploids, which is also initiated by simultaneous expression of MATa and MATα genes.
Beneath the veneer of reform: the politics of economic liberalisation in Vietnam
Authors: Gainsborough M.
Published: September 2002

Scholars working on transition countries are generally more hesitant than they used to be about using the term ‘reformer’. However, few scholars have explored why the term may be unhelpful or what the consequences are if we jettison it for how we think about reform. Such issues form the central focus of the paper. Looking at Vietnam’s second city and business centre, Ho Chi Minh City, the paper argues that the main problem with identifying politicians as reformers is that it gives a distorted picture of what reform is actually about, particularly its underlying logic. In the author’s view, what drives so-called reform has much less to do with issues of ideology, as the focus on reformers would suggest, and much more to do with the playing out of rivalries between new state business interests, which have emerged largely since the late 1980s.
Post-Mao China: an alternative to ‘The end of history’?
Authors: Shlapentokh D.
Published: September 2002

The authoritarian regime in China emerged after Mao’s rule. It was successful not despite brutality, but precisely because of brutality. It was a regime policy that insured stability and provided economic growth and military buildup for the future. In the future generations, China could be stronger than the USA. The ideology of the regime was a successful blending of nationalism with Marxism. Unlike Russia, that followed the Western prescriptions and failed to pull itself from the crisis, post-Mao China is a viable alternative to Western liberal capitalism. At the same time, the success of China actually depends on one man—the leader.
Drought and root herbivory in understorey Parashorea Kurz (Dipterocarpaceae) seedlings in Borneo
Authors: Bebber Dan , Brown Nick , Speight Martin
Published: September 2002

The influence of herbivory on dipterocarp seedling growth and survival in Bornean primary lowland forest understorey during and after the 1997–8 El Niño-Southern Oscillation was investigated. During the drought, a coleopteran (Scolytidae) root borer attacked dipterocarp seedlings, primarily of the genus Parashorea. Infestation was spatially heterogeneous on a large (c. 100 m) scale. Attack rate decreased with plant vigour within infested areas. Experiments showed that root damage was fatal under drought conditions, but not after rain. Defoliation and apical meristem removal did not increase mortality. The spatio-temporal heterogeneity of herbivore outbreaks and difficulties involved in experimenting with root herbivores limit the power of such short-term investigations. However, the study shows that herbivores can cause differential mortality between species, and can therefore influence dipterocarp regeneration dynamics. The effect of herbivory depends on the plant organ attacked and interactions with other stresses such as drought. El Niño-related droughts are increasing in frequency in South-East Asian rain forests, which may lead to increased numbers of herbivore outbreaks and greater seedling mortality due to these factors.
Differential and double-differential dielectric spectroscopy to measure complex permittivity in transmission lines
Authors: Lanzi Leandro , Carlà Marcello , M. C. Gambi Cecilia , Lanzi Leonardo
Published: September 2002

This article presents and compares two differential methods for measuring the complex permittivity of dielectric materials: In the first method, two measuring cells built as coaxial transmission lines of identical cross section and terminations but different lengths are filled with a sample of the dielectric material. The complex dielectric permittivity is determined from the scattering parameter measurements and the length difference between the two cells, neglecting the resistive losses due to the cells. The second method is a double-differential one: Repeating measurements on the same cells empty, no other knowledge or limiting assumption is required.
Regulation of Airway Tight Junctions by Proinflammatory Cytokines
Authors: Coyne Carolyn B. , Vanhook Miriam K. , Gambling Todd M. , Carson Johnny L. , Boucher Richard C. , Johnson Larry G.
Published: September 2002

Epithelial tight junctions (TJs) provide an important route for passive electrolyte transport across airway epithelium and provide a barrier to the migration of toxic materials from the lumen to the interstitium. The possibility that TJ function may be perturbed by airway inflammation originated from studies reporting (1) increased levels of the proinflammatory cytokines interleukin-8 (IL-8), tumor necrosis factor α (TNF-α), interferon γ (IFN-γ), and IL-1β in airway epithelia and secretions from cystic fibrosis (CF) patients and (2) abnormal TJ strands of CF airways as revealed by freeze-fracture electron microscopy. We measured the effects of cytokine exposure of CF and non-CF well-differentiated primary human airway epithelial cells on TJ properties, including transepithelial resistance, paracellular permeability to hydrophilic solutes, and the TJ proteins occludin, claudin-1, claudin-4, junctional adhesion molecule, and ZO-1. We found that whereas IL-1β treatment led to alterations in TJ ion selectivity, combined treatment of TNF-α and IFN-γ induced profound effects on TJ barrier function, which could be blocked by inhibitors of protein kinase C. CF bronchi in vivo exhibited the same pattern of expression of TJ-associated proteins as cultures exposed in vitro to prolonged exposure to TNF-α and IFN-γ. These data indicate that the TJ of airway epithelia exposed to chronic inflammation may exhibit parallel changes in the barrier function to both solutes and ions.
Business Decision Making in National Socialist Germany: Machine Tools, Business Machines, and Punch Cards at the Wanderer-Werke AG
Authors: Schneider Michael C.
Published: September 2002

This article analyzes the goals and strategies of a medium-size machine-building enterprise located in Chemnitz, the “Saxon Manchester,” during the Nazi period. The Wanderer-Werke AG produced a broad range of goods, from machine tools to business machines, during the years before World War II. It pursued an essentially conservative strategy, adhering to its established product line and not embarking on armament production until required to do so. This policy, however, did not prevent the firm from acting on strategic opportunities offered by Nazi occupation policy, as in 1940 when it sought to establish “cooperation” with the French punch-card producer Compagnie des Machines Bull. The article considers the extent to which enterprises like Wanderer—medium-sized companies with products of some value to the war effort—could pursue autonomous strategies within the framework of the National Socialist regime.
Politics, Corporate Governance, and the Dynamics of German Managerial Innovation: Schering AG between the Wars
Authors: Kobrak Christopher
Published: September 2002

Conflicting interpretations of the evolution of German business between the two world wars and of Germany's corporate governance during the Third Reich are examined in this article. Alfred Chandler's view that major corporate changes emanated from managerial initiatives is contrasted with Harold James's interpretation that public and government pressures forced innovations on business. In support of James's analysis, I argue that state and political pressures, not management, initiated significant changes in German corporate governance and in the organization of German industry during the interwar period, especially in the 1930s. Using Schering AG, one of Germany's largest companies before World War II, the article traces the influences of National Socialist pressure and changes in corporate law on companies’ organizational adaptation to government social priorities during the Third Reich.
Protecting the Public Interest: Land Agents vs. Loggers on the Eastern Frontier, 1820–1840
Authors: Gordon Nancy M.
Published: September 2002

America's progression from a frontier society to a settled society took more than three hundred years. During that time, Americans had to give up their view of the resources of the public domain as “free goods” and accept the idea of public compensation for appropriation of those resources for private gain. This attitudinal change took place first on the public lands of Maine and laid the groundwork for the wood-products industry in the United States.
The Causes of Deindustrialization: The Migration of the Cotton Textile Industry from New England to the South
Authors: Koistinen David
Published: September 2002

Numerous historians of deindustrialization argue that industries went into decline because established manufacturers moved production to cheaper locales to escape unions and high wages. A different pattern of decline occurred in the New England cotton textile industry, where downsizing began in the 1920s. Rather than fleeing their home area to build facilities elsewhere, most New England manufacturers were driven out of business by lower-cost competitors in the American South. Southerners founded, managed, and financed a heavy majority of the textile companies in their region. Although some New England firms did set up Southern plants, this was a defensive reaction to changing market realities. New competitors have brought about deindustrialization in other core U.S. industries. Recognizing this trend is important for a full understanding of the political economy of modern capitalism.
Study of Antigen-Processing Steps Reveals Preferences Explaining Differential Biological Outcomes of Two HLA-A2-Restricted Immunodominant Epitopes from Human Immunodeficiency Virus Type 1
Authors: Cohen W. M. , Bianco A. , Connan F. , Camoin L. , Dalod M. , Lauvau G. , Ferriès E. , Culmann-Penciolelli B. , van Endert P. M. , Briand J. P. , Choppin J. , Guillet J. G.
Published: September 2002

Cytotoxic T-lymphocyte (CTL) responses directed to different human immunodeficiency virus (HIV) epitopes vary in their protective efficacy. In particular, HIV-infected cells are much more sensitive to lysis by anti-Gag/p17(77-85)/HLA-A2 than to that by anti-polymerase/RT(476-484)/HLA-A2 CTL, because of a higher density of p17(77-85) complexes. This report describes multiple processing steps favoring the generation of p17(77-85) complexes: (i) the exact COOH-terminal cleavage of epitopes by cellular proteases occurred faster and more frequently for p17(77-85) than for RT(476-484), and (ii) the binding efficiency of the transporter associated with antigen processing was greater for p17(77-85) precursors than for the RT(476-484) epitope. Surprisingly, these peptides, which differed markedly in their antigenicity, displayed qualitatively and quantitatively similar immunogenicity, suggesting differences in the mechanisms governing these phenomena. Here, we discuss the mechanisms responsible for such differences.
RHEOLOGICAL AND MAGNETORHEOLOGICAL BEHAVIOUR OF SOME MAGNETIC FLUIDS ON POLAR AND NONPOLAR CARRIER LIQUIDS
Authors: BĂLĂU OANA , BICA DOINA , KONERACKA MARTINA , KOPČANSKY PETER , SUSAN-RESIGA DANIELA , VÉKÁS LADISLAU
Published: September 2002

Rheological and magnetorheological behaviour of monolayer and double layer sterically stabilized magnetic fluids, with transformer oil (UTR), diloctilsebacate (DOS), heptanol (Hept), pentanol (Pent) and water (W) as carrier liquids, were investigated.

The data for volumic concentration dependence of dynamic viscosity of high colloidal stability UTR, DOS, Hept and Pent samples are particularly well fitted by the formulas given by Vand (1948) and Chow (1994). The Chow type dependence proved its universal character as the viscosity data for dilution series of various magnetic fluids are well fitted by the same curve, regardless the nonpolar or polar charcater of the sample.

The magnetorheological effect measured for low and medium concentration water based magnetic fluids is much higher, due to agglomerate formation process, than the corresponding values obtained for the well stabilized UTR, DOS, Hept and Pent samples, even at very high volumic fraction of magnetic nanoparticles.
FROM RAGS TO RICHES: ON CONSTANT PROPORTIONS INVESTMENT STRATEGIES
Authors: EVSTIGNEEV IGOR V. , SCHENK-HOPPÉ KLAUS REINER
Published: September 2002

This paper studies the performance of self-financing constant proportions trading strategies, i.e. dynamic asset allocation strategies that keep a fixed constant proportion of wealth invested in each asset in all periods in time. We prove that any self-financing constant proportions strategy yields a strictly positive exponential rate of growth of investor's wealth in a financial market in which prices are described by stationary stochastic processes and the price ratios are non-degenerate. This result might be regarded as being counterintuitive because any such strategy yields no increase of wealth under constant prices. We further show that the result also holds under small transaction costs, which is important for the viability of this approach, since constant proportions strategies require frequent rebalancing of the portfolio.
MOVING AVERAGES AND PRICE DYNAMICS
Authors: BAVIERA R. , PASQUINI M. , RABOANARY J. , SERVA M.
Published: September 2002

We introduce a stochastic price model where, together with a random component, a moving average of logarithmic prices contributes to the price formation. The future price is linearly influenced by the difference between the moving average and the current price, together with a noise component. Our model is tested against financial datasets, showing an extremely good agreement with them.
DISTRIBUTION-BASED OPTION PRICING ON LATTICE ASSET DYNAMICS MODELS
Authors: YAMADA YUJI , PRIMBS JAMES A.
Published: September 2002

In this paper, we propose a numerical option pricing method based on an arbitrarily given stock distribution. We first formulate a European call option pricing problem as an optimal hedging problem by using a lattice based incomplete market model. A dynamic programming technique is then applied to solve the mean square optimal hedging problem for the discrete time multi-period case by assigning suitable probabilities on the lattice, where the underlying stock price distribution is derived directly from empirical stock price data which may possess "heavy tails". We show that these probabilities are obtained from a network flow optimization which can be solved efficiently by quadratic programming. A computational complexity analysis demonstrates that the number of iterations for dynamic programming and the number of parameters in the network flow optimization are both of square order with respect to the number of periods. Numerical experiments illustrate that our methodology generates the implied volatility smile.
ASYMMETRIES, CORRELATIONS AND FAT TAILS IN PERCOLATION MARKET MODEL
Authors: CHANG IKSOO , STAUFFER DIETRICH , PANDEY RAS B.
Published: September 2002

Modifications of the Cont-Bouchaud percolation model for price fluctuations give an asymmetry for time-reversal, an asymmetry between high and low prices, volatility clustering, effective multifractality, correlations between volatility and traded volume, and a power law tail with exponent near 3 for the cumulative distribution function of price changes. Combining them together still gives the same power law. Using Ising-correlated percolation does not change these results. Different modifications give log-periodic oscillations before a crash, arising from nonlinear feedback between random fluctuations.
VOLATILITY SMILE BY MULTILEVEL LEAST SQUARE
Authors: ACHDOU YVES , PIRONNEAU OLIVIER
Published: September 2002

The aim of this paper is to propose several algorithms for finding the local volatility from partial observations of the price of an European vanilla option. Dupire's equation is used. The local volatility and the price of the option are discretized by finite elements with highly non uniform meshes and with a coarser mesh for the local volatility. The inverse problem is formulated as a least square problem and the minimization is done by an interior point method. The gradient of the cost function is computed exactly by solving an adjoint problem. A multilevel approach is proposed for accelerating the computations. Also, a suboptimal time-stepping algorithm is considered. For all the proposed algorithms, numerical tests are supplied.
PREDICTION AND VOLATILITY OF BLACK MARKET CURRENCIES: EVIDENCE FROM RENMINBI AND RIAL EXCHANGE RATES
Authors: SOOFI ABDOL S. , CAO LIANGYUE
Published: September 2002

We perform out-of-sample prediction on both fixed and black market Chinese renminbi/US dollar, and black market rial/US dollar exchange rates by using the time-delay embedding technique and the local linear prediction method. We also predict an artificially generated chaotic time series with and without noise for the purpose of validation of the methods used in this study. In all examples tested, our prediction results significantly outperform those by the benchmark mean value predictor based on a statistic defined by Harvey et al. [11]. Another interesting result found in this paper is that one may use the embedding dimension as a measure of volatility of a financial asset.
MEAN REVERSION IN THE SPANISH STOCK MARKET PRICES USING FRACTIONALLY INTEGRATED SEMIPARAMETRIC TECHNIQUES
Authors: DEPENYA JAVIER , GIL-ALANA L. A.
Published: September 2002

In this article we examine the mean-reverting property in the Spanish stock market prices by means of looking at its order of integration. We use several semiparametric procedures proposed by P. M. Robinson in a number of papers. The results show that, though the unit root hypothesis cannot be rejected in the log of the stock prices, the estimated order of integration in the first differenced series, (i.e. in the stock market returns), is slightly below zero, implying that there exists a small degree of mean reversion in the behaviour of prices.
Nimisia Fuegiae (Parmeliaceae), a New Lichen Genus and Species From Argentina
Authors: Kärnefelt I. , Thell A.
Published: September 2002

Nimisia fuegiae Kärnef. & Thell gen. et sp. nov. is described from Argentinian Tierra del Fuego. The new lichen differs from possibly related groups within the Parmeliaceae in unique anatomical characters, i.e. a medullary layer composed of extremely thick and strongly gelatinized periclinally arranged hyphae and a lower cortex composed of only a few layers of strongly pigmented, rather large cells. Ascus characters support its position in the Parmeliaceae. The new genus, which is named in the honour of its first discoverer, is discussed in relation to several other well-investigated members of the family.
Laurera Robusta (Trypetheliaceae), a new alpine lichen from Tasmania
Authors: McCarthy P.M. , Kantvilas G.
Published: September 2002

Laurera robusta McCarthy & Kantvilas sp. nov. (Trypetheliaceae) is described from alpine heathland in Tasmania. Anthracothecium monosporum Müll. Arg. is synonymous with L. elatior (Stirton) D. Galloway, while L. megasperma var. tasmanica (Jatta) Zahlbr. is referable to Pyrenula.
A new species of Everniastrum containing diffractaic acid
Authors: Jiang Yu-Mei , Wei Jiang-Chun
Published: September 2002

A new species, Everniastrum diffractaicum the only member of the genus containing diffractaic acid, is described. It has much larger ascospores than those of any other member of the genus.
Differential herbivore damage to calcicolous lichens by snails
Authors: Fröberg Lars , Baur Anette , Baur Bruno
Published: September 2002

A laboratory experiment was conducted to determine the damage caused by snail grazing to 35 calcicolous lichen species and cyanobacteria from the Baltic island of Oland, Sweden. Individuals of four species of land snails (Balea perversa, Chondrina cliema, Clausilia bidentata and Helicigona lapicida) were allowed to graze on identified lichen species growing on pieces of limestone. Snail grazing on thalli and ascocarps was classified into four categories ranging from no damage to completely eaten. In general, some lichen species were heavily grazed, whereas others were only slightly damaged or not injured. Aspiciha calcarea, Tephromela atra and Verrucaria nigrescens were preferred by all snail species except Chondrina cliema. In general, lichen thalli that were not immersed in the calcareous rock and cyanobacteria were preferred, whereas ascocarps were avoided by one of the snail species (C. clienta). Immersed perithecia with a carbonized outer layer were avoided by all snail species except C. bidentata. Possibilities of chemical and mechanical defence properties in calcicolous lichens are discussed.
High performance thin layer chromatography (HPTLC), an improved technique for screening lichen substances
Authors: Arup Ulf , Ekman Stefan , Lindblom Louise , Mattsson Jan-Eric
Published: September 2002

High performance thin layer chromatography (HPTLC) is a method that can be used for screening lichen substances. It is as simple to use as standard TLC, but has many advantages: It is more sensitive, it is possible to run more samples in a shorter period of time, and the amount of solvent used is much smaller. The material needed and the methods used are described in detail. Horizontal chromatogram development was used. Since two of the solvents used in system B have been substituted, and since the properties of the HPTLC plates are slightly different, our results are not entirely in accordance with the standardized TLC method. A revised table for the identification of 69 lichen substances (obtained from 62 taxa) is accordingly presented.
The Lichens of High Ground in the English Lake District
Authors: Gilbert O. L. , Giavarini V. J.
Published: September 2002

A general account of the lichens of high-level acid habitats in the Lake District is provided. This is followed by detailed studies of base-rich sites in the Helvellyn range, acid outcrops in Langdale, and three upland tarns, one of which is of outstanding importance. The lichen vegetation is richer than in Snowdonia or the Northern Pennines, but its diversity is considerably less than that of certain individual mountains in the Scottish Highlands. The montane element is interpreted as representing the last remnants of communities that have declined gradually through the Postglacial Period. Many species are extremely rare. Current restraints on the alpine lichen flora include the climate, the predominance of wet, acid rock and heavy sheep grazing. Rhizocarpon simillimum is reported as new to the British lichen flora
Further Evidence that Activation of Net Photosynthesis by dry Cyanobacterial Lichens Requires Liquid Water
Authors: Lange O. L. , BÜdel B. , Meyer A. , Kilian E.
Published: September 2002

In contrast to green algal lichens, cyanobacterial species of different families, growth forms and habitats proved to be unable to attain positive net CO2 assimilation when the dry thalli were treated with air of high relative humidity; they needed liquid water for the reactivation of their photosynthetic apparatus. Identical behaviour is shown by all of the 47 lichen species with cyanobacterial photobionts, from six different genera, studied so far. This suggests a widely distributed, if not general, characteristic of cyanobacterial lichens. The difference in performance between both groups of photobionts was maintained when the lichen thallus was macerated. Furthermore, cultures of Chroococcidiopsis were unable to make use of water vapour hydration for positive net photosynthesis, and were similar in this respect to some free-living aerophilic cyanobacteria tested earlier. Possible physiological implications as well as ecological consequences for water-relation-dependent habitat selection of green-algal and cyanobacterial lichens are discussed.
A New Species of Peltula from the Sonoran Desert, Mexico
Authors: Büdel Burkhard , Nash Thomas H.
Published: September 2002

The new species Peltula sonorensis is described from the Sonoran Desert. It is found in several localities throughout the Mexican part of the Sonoran Desert and belongs to a distinct group within the genus Peltula, which is characterized by fairly large (up to 15 mm diam.), umbilicate-peltate squamules, growing individually and having ellipsoid to bacilliform spores.
The Effect of Agrochemicals on the Growth of Cladonia Furcata
Authors: Vagts I. , Kinder M. , Müller J.
Published: September 2002

Field experiments were conducted to test the effect of some agrochemicals on the growth of Cladonia furcata. Mineral fertilizer had no direct effect on lichen growth. In contrast, organic manure promoted the length of podetia. A lethal effect was recorded in the case of calcium cyanamide. In addition to direct effects of agrochemicals, indirect effects were also recorded.
A Method for Studying the Cellular Location of Lead in Lichens
Authors: Branquinho C. , Brown D. H.
Published: September 2002

A number of possible displacing agents have been tested for their ability to release extracellular bound lead from Cladonia portentosa. Metal cations (Ni and Cu), thiol–rich reagents (glutathione, ammonium pyrrolidinedithiocarbamate) and some chelating agents (EGTA, EDTA at pH 9·5 or pH 2·7) were ineffective or caused membrane damage. Disodium EDTA at pH 4·5 was found to be an effective displacing agent, although the Na caused some release of intracellular K without membrane damage. This displacement procedure showed that no Pb suppliedin the laboratory entered the protoplast in 2 h. The effect of Ca, Cu, Pb, and Sr on membrane integrity was investigated.
Critical Notes on Antarctic Yellow Acarosporaceae
Authors: Castello M. , Nimis P. L.
Published: September 2002

All species of Antarctic Acarosporaceae (s. lat., including Biatorellaceae) with yellow thalli are revised. Four genera, Acarospora, Biatorella, Biatorellopsis, Eklundia, and ten species, all of them endemic, were previously reported from Antarctica. Our results indicate that in Antarctica Acarospora subgen. Xanthothallia s. str. includes only two species, A. gwynnii Dodge and A. flavocordia sp. nov.; Biatorella does not occur in Antarctica, the species described by Dodge belonging instead in Candelariella; the genus Eklundia is a synonym of Candelariella; Biatorellopsis does not occur in Continental Antarctica, and the genus is a synonym of Pleopsidium; Pleopsidium is represented in Antarctica by one species, P. chlorophanum, which was treated under very different generic and specific names by earlier authors. Altogether, the number of species of yellow Acarosporaceae known from Antarctica is reduced from ten to three, distributed in two genera: Acarospora and Pleopsidium. The two Acarospora species, A. gwynnii and A. flavocordiaare apparently endemic to Antarctica, whereas P. chlorophanum is a widespread bipolar lichen. A comprehensive list of synonyms and a key are provided.
Metal Content and Community Structure of Cryptogam Bioindicators in relation to Vehicular Traffic in Montseny Biosphere Reserve (Catalonia, Spain)
Authors: Glenn M. G. , Gomez-Bolea A. , Lobello R.
Published: September 2002

The health, abundance, metal content and species richness of corticolous macrolichens and bryophytes of Quercus ilex were compared at nine roadside stations in Montseny Biosphere Reserve, 40 km NNE of Barcelona, and at a control site outside the industrial metropolis. Stations were characterized by traffic levels and the correlated parameter airborne particles. Corticolous flora at all stations was dominated by sorediate Parmelia species (P. caperata, P. soredians, P. subrudecta, P. subaurifera, P. sulcata and P. perlata). Damage, mainly due to arthropod feeding and fungal parasites, ranged from 14 to 33% of mean cover per station in the park and was 10% at the control site. Elevated levels of Pb, Zn and Cu were found in large thalli near the roadsides.
Early Development of Transplanted Isidioid Soredia of Lobaria Pulmonaria in an Endangered Population
Authors: Scheidegger C.
Published: September 2002

Vegetative diaspores of Lobaria pulmonaria were transplanted to previously uncolonized trees. The early development of the corticated but otherwise non-stratified isidioid soredia was studied mainly by low-temperature scanning electron microscopy. Anchoring hyphae developed from cortical hyphae after 2–4 months and later apical or lateral pseudomeristematic growth zones were formed. After 15 months the growth zones further differentiated into 0·5-mm-broad lobes and revealed a stratified thallus typical for this foliose epiphytic lichen species. The experiment showed that the small population size of L. pulmonaria was limited by the low reproductive potential of the species and that it might fail to compensate for a relatively high disturbance, natural or anthropogenic, in the stand.
Lecania Pusilla, A New Bryophilous Lichen from the Trieste Karst
Authors: Tretiach Mauro
Published: September 2002

Lecania pusilla Tretiach sp. nov. is described from the Trieste Karst, where it was collected twice on epilithic mosses in protected overhangs. The new species is characterized by simple or uniseptate spores, pruinose apothecia, and Bacidia-type asci; it has a reduced, granular thallus with no lichen substances.
A New Byssoid Lichen Genus From Tasmania
Authors: Kantvilas Gintaras
Published: September 2002

The genus Jarmania, based on the single species J. tristis, is described. The new genus is characterized by a byssoid-leprose thallus, immarginate apothecia, asci of the Bacidia-type, strongly anastomosing paraphyses and septate, acicular ascospores. The new species is corticolous and is known only from cool temperate rainforest in Tasmania.
The Importance of Sorediate Crustose Lichens in the Epiphytic Lichen Flora of the Swiss Plateau and the Pre-Alps
Authors: Dietrich Michael , Scheidegger Christoph
Published: September 2002

Standardized lichen surveys were conducted on 849 trees in 132 ecological long-term observation plots in the Swiss Plateau and Pre-Alps: 262 lichen taxa were identified, 64 (24%) of them sorediate crustose species. Their mean percentage of the flora on individual trees and in individual plots was even higher. The mean percentage of crustose lichen species with vegetative propagules, such as soredia, was per plot significantly higher in the Pre-Alps than in the Plateau, higher in forest than in non-forest areas, and, according to the vegetation belts, lowest in the colline-submontane zone. It was found that the biodiversity of lichens could not be determined without considering the sorediate crustose lichens. Furthermore, by performing standardized surveys of all taxa, the occurrence of the following species in Switzerland was confirmed for the first time: Cliostomum leprosum, Fuscidea arboricola, Fuscidea pusilla, Hypocenomyce leucococca, Hypocenomyce sorophora, Lecanora norvegica, Lepraria eburnea, Lepraria elobata, Lepraria jackii, Lepraria obtusatica, Lepraria rigidula, Pertusaria boreahs and Rinodina griseosoralifera. Seven taxa that displayed distinctive chemistry, could not yet be identified.
Influence of Site and Stand Factors on the Distribution of Crustose Lichens Of The Caliciales in a Suboceanic Spruce Forest Area in Central Norway
Authors: Holien Håkon
Published: September 2002

The distribution of crustose Caliciales has been surveyed in 100 spruce forest patches in Sør-Trøndelag, central Norway. Relationships between occurrence of the species and a number of site and stand variables were analysed by detrended correspondence analysis (DCA) and direct gradient analysis. Species diversity7 was significantly higher in old forests and in forests at higher altitudes compared to young forests and forests at lower altitudes. Old trees and snags are considered to be the most important structural components in old forests promoting species diversity of the Caliciales. Threatened or vulnerable species, such as Chaenotheca gracilliina, Cybebe gracilenta, Sclerophora coniophaea and S. peronella were confined to forest on rich soils showing no correlation with forest stand age. Chaenotheca brachypoda and C. trichialis were found to be the most typical old forest species among the Caliciales. Humidiphilous species are considered to be less affected by forestry in a humid climate. A change in forestry practice towards methods imitating the natural dynamic processes is considered necessary to maintain species diversity of the Caliciales in boreal forests.
Myeloconis, A New Genus Of Pyrenocarpous Lichens From The Tropics
Authors: McCarthy P. M. , Elix J. A.
Published: September 2002

Myeloconis P. M. McCarthy & Elix gen. nov. is described from the Neotropics and the eastern Paleotropics. Four new species, M. erumpens, M. fecunda, M. guyanenis and M. parva, are recognized. The genus is characterized by a medulla containing previously unknown yellow or orange pigments and perithecioid ascomata with a dark, dense, almost pseudostromatal wall, a basally anastomosing, but otherwise free, hamathecium, uniformly thin-walled asci and elongate, muriform ascospores. While its affinities are uncertain, the ascomata and their contents suggest a rather close relationship with Porina Müll. Arg. and ClathroporinaMüll. Arg. (Trichotheliaceae).
The Lichen Genus Bulbothricella, A New Segregate in the Parmeliaceae from Venezuela
Authors: Marcano Vicente , Mohali Sari , Palacios-Prü Ernesto , Morales Méndez Antonio
Published: September 2002

The new genus Bulbothricella (Lichenized Ascomycotina,Parmeliaceae with the single species B. amazonensis (Marcano, Galiz & Morales) Marcano, Galiz, Morales & Mohali is segregated from Bulbothrix. This conclusion is based on an investigation of morphological, anatomical and chemical characters using scanning electron microscopy and thin-layer chromatography. The new genus is characterized by a pored epicortex, 12—14 spores per ascus, obovate and acrogenous conidia, and an anatomical structure and cortical chemistry resembling that of Bulbothrix..
The Identity of Photobionts From the Lichen Pyrenula Japonica
Authors: Nakano Taketo , Ihda Taka-aki
Published: September 2002

Nine specimens of Pyrenula japonica Kurokawa were collected from various areas in Japan. Photobionts were isolated from their thalli and studied taxonomically. As a result, only one species of green alga,Trentepohlia lagenifera(Hild.) Wille was identified as the photobiont of Pyrenula japonica. This is the first record of this alga from the lichen genus Pyrenula.
Teloschistes Flavicans in Great Britain: Distribution and Ecology
Authors: Gilbert O. L. , Purvis O. W.
Published: September 2002

Over the last century, the distribution of Teloschistes flavicans has contracted from being widespread in the southern half of England and Wales to being limited to South-West England with outlying populations in Pembrokeshire and North Wales. Twelve core sites have been identified where the species is well established: ten of these are saxicolous/terricolous habitats on windy coastal cliff tops; the other two are lines of sycamore trees near the coast. At 39 further localities, some inland, the species is in very small amounts (often on one tree) and vulnerable to extinction. It is normally a member of the Parmelietum revolutae or Ramalinetum scopularis associations. The conservation of the species is discussed.
The Lichen Vegetation of Some Previously Overlooked High-Level Habitats in North Wales
Authors: Fryday Alan M.
Published: September 2002

The lichen vegetation associated with calcareous rocks, areas of long snow-lie and the margins of high-level lakes in North Wales is described. It includes Porpidia ochrolemma (Vain.) Brodo & R. Sant. and Rhizocarpon anaperum (Vain.) Vain, new to the British Isles, plus a further 30 taxa recorded for the first time from Wales. The relative importance of the montane lichen vegetation of North Wales is assessed by comparison with areas in other parts of the British Isles. It is shown to exceed in interest any montane area in England or Ireland but to be below the standard of an otherwise comparable area in Scotland.
The Genera of Trichotheliaceae
Authors: McCarthy P. M. , Malcolm W. M.
Published: September 2002

Recent revisions of generic relationships in the pyrenocarpous lichen family Trichotheliaceae by J. Hafellner & K. Kalb (based on perithecial pigmentation and ascus structure) and R. C. Harris (based on morphological, chemical and environmental trends) are assessed. However, most of their conclusions are rejected because the authors used shared or variable characters, insufficient specimens and highly disjointed groups of species.
Studies on the Lichen Genus Sticta (Schreber) Ach. IV. New Zealand Species
Authors: Galloway D. J.
Published: September 2002

Thirteen species of the lichen genus Sticta (Schreber) Ach., are recognized in the New Zealand flora viz.: S. babingtonii, S. caliginosa, S. colinii sp. nov., S. cinereoglauca, S. filix, S. fuliginosa, S. lacera, S. latifrons, S. limbata, S. martinii, S. squamata, S. subcaperata and S. sublimbata. A key to species, synonymy and typification, descriptions of all taxa, biogeographical affinities and distribution maps are presented. Sticta livida is excluded from the New Zealand flora.