90 research outputs found
Talent in Distressed Firms: Investigating the Labor Costs of Financial Distress
The importance of skilled labor and the inalienability of human capital expose firms to the risk of losing talent at critical times. Using Swedish microdata, we document that firms lose workers with the highest cognitive and noncognitive skills as they approach bankruptcy. In a quasi-experiment, we confirm that financial distress drives these results: following a negative export shock caused by exogenous currency movements, talent abandons the firm, but only if the exporter is highly leveraged. Consistent with talent dependence being associated with higher labor costs of financial distress, firms that rely more on talent have more conservative capital structures
Phylogeny of the cetrarioid core (Parmeliaceae) based on five genetic markers
Fourteen genera belong to a monophyletic core of cetrarioid lichens, Ahtiana, Allocetraria, Arctocetraria, Cetraria, Cetrariella, Cetreliopsis, Flavocetraria, Kaernefeltia, Masonhalea, Nephromopsis, Tuckermanella, Tuckermannopsis, Usnocetraria and Vulpicida. A total of 71 samples representing 65 species (of 90 worldwide) and all type species of the genera are included in phylogentic analyses based on a complete ITS matrix and incomplete sets of group I intron, -tubulin, GAPDH and mtSSU sequences. Eleven of the species included in the study are analysed phylogenetically for the first time, and of the 178 sequences, 67 are newly constructed. Two phylogenetic trees, one based solely on the complete ITS-matrix and a second based on total information, are similar, but not entirely identical. About half of the species are gathered in a strongly supported clade composed of the genera Allocetraria, Cetraria s. str., Cetrariella and Vulpicida. Arctocetraria, Cetreliopsis, Kaernefeltia and Tuckermanella are monophyletic genera, whereas Cetraria, Flavocetraria and Tuckermannopsis are polyphyletic. The taxonomy in current use is compared with the phylogenetic results, and future, probable or potential adjustments to the phylogeny are discussed. The single non-DNA character with a strong correlation to phylogeny based on DNA-sequences is conidial shape. The secondary chemistry of the poorly known species Cetraria annae is analyzed for the first time; the cortex contains usnic acid and atranorin, whereas isonephrosterinic, nephrosterinic, lichesterinic, protolichesterinic and squamatic acids occur in the medulla. Notes on the anatomy of Cetraria annae and Flavocetraria minuscula are also provided
Lichens from the Vadstena Monastery churchyard – the burial place of Eric Acharius
A list of 120 taxa observed at the Vadstena Monastery churchyard includes some rare species and a few lichenicolous fungi. Lecanora semipallida is reported from the province Östergötland [Ostrogothia] for the first time
Vitalism in Early Modern Medical and Philosophical Thought
Vitalism is a notoriously deceptive term. It is very often defined as the view, in biology, in early modern medicine and differently, in early modern philosophy, that living beings differ from the rest of the physical universe due to their possessing an additional ‘life-force’, ‘vital principle’, ‘entelechy’, enormon or élan vital. Such definitions most often have an explicit pejorative dimension: vitalism is a primitive or archaic view, that has somehow survived the emergence of modern science (the latter being defined in many different ways, from demystified Cartesian reductionism to experimental medicine, biochemistry or genetics: Cimino and Duchesneau eds. 1997, Normandin and Wolfe eds. 2013). Such dismissive definitions of vitalism are meant to dispense with argument or analysis.
Curiously, the term has gained some popularity in English-language scholarship on early modern philosophy in the past few decades, where it is used without any pejorative dimension, to refer to a kind of ‘active matter’ view, in which matter is not reducible to the (mechanistic) properties of size, shape and motion, possessing instead some internal dynamism or activity (see e.g. James 1999, Boyle 2018, Borcherding forthcoming). The latter meaning is close to what the Cambridge Platonist Ralph Cudworth termed ‘hylozoism’, namely the attribution of life, agency or mind to matter, and he implicitly targeted several figures I shall mention here, notably Margaret Cavendish and Francis Glisson, for holding this view. However, one point I shall make in this entry is that when vitalism first appears by name, and as a self-designation, in the Montpellier School (associated with the Faculty of Medicine at the University of Montpellier, in the second half of the eighteenth century; thus vitalisme appears first, followed shortly thereafter by Vitalismus in German, with ‘vitalism’ appearing in English publications only in the early nineteenth century: Toepfer 2011), it is quite different from both the more ‘supernatural’ view described above – chiefly espoused by its rather obsessive opponents – and from the more neutral, but also de-biologized philosophical view (that of e.g. Cavendish or Conway who are, broadly speaking naturalists). Rather than appealing to a metaphysics of vital force, or of self-organizing matter, this version of vitalism, which I shall refer to as ‘medical vitalism’, seems to be more of a ‘systemic’ theory: an attempt to grasp and describe top-level (‘organizational’, ‘organismic’, ‘holistic’) features of living systems (Wolfe 2017, 2019).
In this entry I seek to introduce some periodization in our thinking about early modern (and Enlightenment) vitalism, emphasizing the difference between the seventeenth-century context and that of the following generations – culminating in the ideas of the Montpellier School. This periodization should also function as a kind of taxonomy or at least distinction between some basic types of vitalism. As I discuss in closing, these distinctions can cut across the texts and figures we are dealing with, differently: metaphysical vs. non-metaphysical vitalism, philosophical vs. medical vitalism, medical vs. ‘embryological’ vitalism, and so on. A difference I can only mention but not explore in detail is that the more medically grounded, ‘organismic’ vitalism is significantly post-Cartesian while the more biological/embryological vitalism is, inasmuch as it is a dynamic, self-organizing matter theory, an extension of Renaissance ideas (chymiatry, Galenism and in general theories of medical spirits).
I examine successively vitalism’s Renaissance prehistory, its proliferation as ‘vital matter theory’ in seventeenth-century England (in authors such as Cavendish, Conway and Glisson, with brief considerations on Harvey and van Helmont), and its mature expression in eighteenth-century Montpellier (notably with Bordeu and Ménuret de Chambaud)
Transoceanic Dispersal and Subsequent Diversification on Separate Continents Shaped Diversity of the Xanthoparmelia pulla Group (Ascomycota)
In traditional morphology-based concepts many species of lichenized fungi have world-wide distributions. Molecular data have revolutionized the species delimitation in lichens and have demonstrated that we underestimated the diversity of these organisms. The aim of this study is to explore the phylogeography and the evolutionary patterns of the Xanthoparmelia pulla group, a widespread group of one of largest genera of macrolichens. We used a dated phylogeny based on nuITS and nuLSU rDNA sequences and performed an ancestral range reconstruction to understand the processes and explain their current distribution, dating the divergence of the major lineages in the group. An inferred age of radiation of parmelioid lichens and the age of a Parmelia fossil were used as the calibration points for the phylogeny. The results show that many species of the X. pulla group as currently delimited are polyphyletic and five major lineages correlate with their geographical distribution and the biosynthetic pathways of secondary metabolites. South Africa is the area where the X. pulla group radiated during the Miocene times, and currently is the region with the highest genetic, morphological and chemical diversity. From this center of radiation the different lineages migrated by long-distance dispersal to others areas, where secondary radiations developed. The ancestral range reconstruction also detected that a secondary lineage migrated from Australia to South America via long-distance dispersal and subsequent continental radiation
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A multigene phylogenetic synthesis for the class Lecanoromycetes (Ascomycota): 1307 fungi representing 1139 infrageneric taxa, 317 genera and 66 families
The Lecanoromycetes is the largest class of lichenized Fungi, and one of the most species-rich classes in the
kingdom. Here we provide a multigene phylogenetic synthesis (using three ribosomal RNA-coding and two
protein-coding genes) of the Lecanoromycetes based on 642 newly generated and 3329 publicly available
sequences representing 1139 taxa, 317 genera, 66 families, 17 orders and five subclasses (four currently
recognized: Acarosporomycetidae, Lecanoromycetidae, Ostropomycetidae, Umbilicariomycetidae; and one provisionarily recognized, ‘Candelariomycetidae’). Maximum likelihood phylogenetic analyses on four
multigene datasets assembled using a cumulative supermatrix approach with a progressively higher
number of species and missing data (5-gene, 5 + 4-gene, 5 + 4 + 3-gene and 5 + 4 + 3 + 2-gene datasets)
show that the current classification includes non-monophyletic taxa at various ranks, which need to be
recircumscribed and require revisionary treatments based on denser taxon sampling and more loci. Two
newly circumscribed orders (Arctomiales and Hymeneliales in the Ostropomycetidae) and three families
(Ramboldiaceae and Psilolechiaceae in the Lecanorales, and Strangosporaceae in the Lecanoromycetes
inc. sed.) are introduced. The potential resurrection of the families Eigleraceae and Lopadiaceae is considered
here to alleviate phylogenetic and classification disparities. An overview of the photobionts associated
with the main fungal lineages in the Lecanoromycetes based on available published records is provided. A
revised schematic classification at the family level in the phylogenetic context of widely accepted and
newly revealed relationships across Lecanoromycetes is included. The cumulative addition of taxa with
an increasing amount of missing data (i.e., a cumulative supermatrix approach, starting with taxa for which
sequences were available for all five targeted genes and ending with the addition of taxa for which only two
genes have been sequenced) revealed relatively stable relationships for many families and orders.
However, the increasing number of taxa without the addition of more loci also resulted in an expected substantial
loss of phylogenetic resolving power and support (especially for deep phylogenetic relationships),
potentially including the misplacements of several taxa. Future phylogenetic analyses should include
additional single copy protein-coding markers in order to improve the tree of the Lecanoromycetes. As part
of this study, a new module (‘‘Hypha’’) of the freely available Mesquite software was developed to compare
and display the internodal support values derived from this cumulative supermatrix approach.Keywords: Classification, Multi-gene phylogeny, Lichenized fungi, Systematics, Cumulative supermatrix, Lecanoromycete
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