259 research outputs found

    The Sticta fuliginosa group in Norway and Sweden

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    A recent investigation demonstrated that Sticta fuliginosa (Hoffm.) Ach., as currently treated, includes four distinct species in Europe: Sticta fuliginosa s. str., S. fuliginoides Magain & Sérus., S. ciliata Tayl., and S. atlantica Magain & Sérus. This finding prompted us to revise material named S. fuliginosa from Norway and Sweden. It is demonstrated here that three species occur in Norway: S. fuliginosa s. str., S. fuliginoides, and S. ciliata. S. fuliginoides is the most widespread species, whereas S. fuliginosa occurs mostly along the coast and S. ciliata is very rare in the most oceanic parts of the western coast. In Sweden, only a single species of the group occurs, viz. S. fuliginoides. It was formerly found in scattered sites across the southern half of Sweden but has now disappeared from most of them. The basionym Sticta fuliginosa var. propagulifera Vain. ex H. Magn. is lectotypified and synonymized under S. fuliginoides.publishedVersio

    Three overlooked species of Bacidia from insular Laurimacaronesia

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    We discuss the taxonomy of three species of Bacidia occurring in insular Laurimacaronesia. Two of them, B. amylothelia (Vain.) Vain. and B. endoleucoides (Nyl.) Zahlbr., which were previously described from Angola and Madeira, respectively, are found here to belong in Bacidia s. str. (Ramalinaceae). Modern descriptions and illustrations are provided for the first time. Bacidia amylothelia is similar to B. areolata Gerasimova & A. Beck, B. campalea (Tuck.) S. Ekman & Kalb, B. fusconigrescens (Nyl.) Zahlbr., B. heteroloma (Vain.) Zahlbr., B. millegrana (Taylor) Zahlbr. and B. suffusa (Fr.) A. Schneid. and is reported here from the Canary Islands. Bacidia endoleucoides is most likely to be confused with B. absistens (Nyl.) Arnold, B. friesiana (Hepp) Körb., B. salazarensis B. de Lesd. and B. caesiovirens S. Ekman & Holien and was found to be widely distributed in the Canary Islands and Azores in addition to Madeira. The third species, Bacidia deludens S. Ekman, Tønsberg & van den Boom, is described here as new to science. Bacidia deludens is characterised by a greyish, crustose thallus with whitish soralia, pale apothecia with crystals in the hymenium and proper exciple, acicular ascospores with 3–19 septa, and the production of fumarprotocetraric acid as the consistently present major substance. It is described here from the Canary Islands and Madeira. Although conservatively treated here in Bacidia, we argue that it is likely to belong in the Malmideaceae. An identification key to all known species of Bacidia s. str. in insular Macaronesia is provided.publishedVersio

    Evolution of Growth Habit, Inflorescence Architecture, Flower Size, and Fruit Type in Rubiaceae: Its Ecological and Evolutionary Implications

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    During angiosperm evolution, innovations in vegetative and reproductive organs have resulted in tremendous morphological diversity, which has played a crucial role in the ecological success of flowering plants. Morindeae (Rubiaceae) display considerable diversity in growth form, inflorescence architecture, flower size, and fruit type. Lianescent habit, head inflorescence, small flower, and multiple fruit are the predominant states, but arborescent habit, non-headed inflorescence, large flower, and simple fruit states occur in various genera. This makes Morindeae an ideal model for exploring the evolutionary appearances and transitions between the states of these characters. We reconstructed ancestral states for these four traits using a Bayesian approach and combined nuclear/chloroplast data for 61 Morindeae species. The aim was to test three hypotheses: 1) self-supporting habit is generally ancestral in clades comprising both lianescent and arborescent species; 2) changes from lianescent to arborescent habit are uncommon due to a high degree of specialization and developmental burden ; 3) head inflorescences and multiple fruits in Morindeae evolved from non-headed inflorescences and simple fruits, respectively. Lianescent habit, head inflorescence, large flower, and multiple fruit are inferred for Morindeae, making arborescent habit, non-headed inflorescence, small flower, and simple fruit derived within the tribe. The rate of change from lianescent to arborescent habit is much higher than the reverse change. Therefore, evolutionary changes between lianescent and arborescent forms can be reversible, and their frequency and trends vary between groups. Moreover, these changes are partly attributed to a scarcity of host trees for climbing plants in more open habitats. Changes from large to small flowers might have been driven by shifts to pollinators with progressively shorter proboscis, which are associated with shifts in breeding systems towards dioecy. A single origin of dioecy from hermaphroditism is supported. Finally, we report evolutionary changes from headed to non-headed inflorescences and multiple to simple fruits

    Psychosocial resources predict frequent pain differently for men and women: A prospective cohort study

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    Introduction Psychosocial resources, psychological and social factors like self-efficacy and social support have been suggested as important assets for individuals with chronic pain, but the importance of psychosocial resources for the development of pain is sparsely examined, especially sex and gender differences. The aim of this study was to investigate associations between psychosocial resources and sex on the development of frequent pain in a general population sample, and to deepen the knowledge about sex and gender patterns. Methods A sample from the Swedish Health Assets Project, a longitudinal cohort study, included self-reported data from 2263 participants, 53% women, with no frequent pain at baseline. The outcome variable was frequent pain at 18–months follow-up. Psychosocial resources studied were general self-efficacy, instrumental and emotional social support. Log binomial regressions in a generalised linear model were used to calculate risk ratios (RRs), comparing all combinations of men with high psychosocial resources, men with low psychosocial resources, women with high psychosocial resources and women with low psychosocial resources. Results Women with low psychosocial resources had higher risk of frequent pain at follow-up compared to men with high resources: general self-efficacy RR 1.82, instrumental social support RR 2.33 and emotional social support RR 1.94. Instrumental social support was the most important protective resource for women, emotional social support was the most important one for men. Results were discussed in terms of gender norms. Conclusions The psychosocial resources general self-efficacy, instrumental and emotional support predicted the risk of developing frequent pain differently among and between men and women in a general population sample. The results showed the importance of studying sex and gender differences in psychological and not least social predictors for pain.publishedVersio

    A branching gene regulatory network dictating different aspects of a neuronal cell identity

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    The nervous system displays a daunting cellular diversity. Neuronal subtypes differ from each other in several aspects, including their neurotransmitter expression and axon projection. These aspects can converge, but can also diverge, such that neurons expressing the same neurotransmitter may project axons to different targets. It is not well understood how regulatory programs converge/diverge to associate/dissociate different cell fate features. Studies of the Drosophila Tv1 neurons have identified a regulatory cascade, ladybird early→collier→apterous/eyes absent→dimmed, that specifies Tv1 neurotransmitter expression. Here, we conduct genetic and transcriptome analysis to address how other aspects of Tv1 cell fate are governed. We find that an initiator terminal selector gene triggers a feedforward loop that branches into different subroutines, each of which establishes different features of this one unique neuronal cell fate

    New and interesting records of lichens from Pältsan (Mt Bealccan) in northernmost Sweden

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    Austroplaca subtiroliensis, Gyalidea lecideopsis, Phacographa protoparmeliae, Placynthium pulvinatum and Solorina octospora are reported new to Sweden. Several other rare or rarely collected lichens are also reported: Absconditella annexa, Arthrorhaphis vacillans, Farnoldia micropsis, Gyalidea polyspora, Ionaspis ventosa, Lecanora lecanoricola, L. leptacinella, Lecidea commaculans, Pachyascus lapponicus, Placidiopsis pseudocinerea, Schadonia fecunda, Scytinium aquale and Thelocarpon sphaerosporum

    Some Key Jurisprudential Issues of the Twenty-First Century

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    The objective of this study was to estimate the dispersal rate in an organism assumed to be confined to tree stands with unbroken continuity. We used the lichen-forming ascomycete Cliostomum corrugatum, which is largely confined to old oak stands. Five populations, with pairwise distances ranging from 6.5 to 83 km, were sampled in Ostergotland, south-eastern Sweden. DNA sequence data from an intron in the small subunit nuclear ribosomal RNA gene was obtained from 85 samples. Nearly all molecular variance (99.6%) was found within populations and there were no signs of isolation-by-distance. The absolute number of immigrants per population per generation (estimated to 30 years), inferred by Bayesian MCMC, was found to be between 1 and 5. Altogether, evidence suggests abundant gene flow in the history of our sample. A simulation procedure demonstrated that we cannot know whether effective dispersal is ongoing or if it ceased at the time when oaks started to decrease dramatically around 400 years BP. However, a scenario where effective dispersal ceased already at the time when the postglacial reinvasion of oak had reached the region around 6000 years BP is unlikely. Vegetation history suggests that the habitat of C. corrugatum was patchily distributed in the landscape since the early Holocene. Combined with the high dispersal rate estimate, this suggests that the species has been successful at frequently crossing distances of at least several kilometres and possibly that it has primarily been limited by the availability of habitat rather than by dispersal.Original Publication:Hakan Lattman, Louise Lindblom, Jan-Eric Mattsson, Per Milberg, Morten Skage and Stefan Ekman, Estimating the dispersal capacity of the rare lichen Cliostomum corrugatum, 2009, BIOLOGICAL CONSERVATION, (142), 8, 1870-1878.http://dx.doi.org/10.1016/j.biocon.2009.03.026Copyright: Elsevier Science B.V., Amsterdam.http://www.elsevier.com

    The NMDA agonist D-cycloserine facilitates fear memory consolidation in humans

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    Animal research suggests that the consolidation of fear and extinction memories depends on N-methyl D-aspartate (NMDA)- type glutamate receptors. Using a fear conditioning and extinction paradigm in healthy normal volunteers, we show that postlearning administration of the NMDA partial agonist D-cycloserine (DCS) facilitates fear memory consolidation, evidenced behaviorally by enhanced skin conductance responses, relative to placebo, for presentations of a conditioned stimulus (CS) at a memory test performed 72 h later. DCS also enhanced CS-evoked neural responses in a posterior hippocampus/collateral sulcus region and in the medial prefrontal cortex at test. Our data suggest a role for NMDA receptors in regulating fear memory consolidation in humans

    Peripheral preview abolishes N170 face-sensitivity at fixation: Using fixation-related potentials to investigate dynamic face processing

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    The N170 ERP peak has been found to be consistently larger in response to the presentation of faces than to other objects, yet it is not clear whether this face-sensitive N170 is also elicited during fixations made subsequent to the initial presentation. To investigate this question, the current study utilised Event and Fixation-Related Potentials in two experiments, time-locking brain potentials to the presentation of faces and objects (watches) images in participants’ peripheral vision, and to their first fixations on the images. Experiment 1 found that a face-sensitive N170 was elicited by the onset of images but not by a subsequent fixation on the images, and that face inversion did not modulate N170 beyond presentation. Experiment 2 found that disrupting the structure of the peripheral preview (phase-scrambling) led to a face-sensitive N170 at fixation onsets on the intact-images. Interestingly, N170 amplitudes for both faces and objects were significantly enhanced after the peripheral preview was phase-scrambled, suggesting that the N170 in part reflects a category-detection process that is elicited once when an image structure is viewed. These results indicate that neural processing during fixations will be significantly modulated when they are immediately preceded by peripheral previews, and is not specific to faces
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