575 research outputs found
Molecular phylogeny and spore evolution of Entolomataceae
The phylogeny of the Entolomataceae was reconstructed using three loci (RPB2, LSU and mtSSU) and, in conjunction with spore morphology (using SEM and TEM), was used to address four main systematic issues: 1) the monophyly of the Entolomataceae; 2) inter-generic relationships within the Entolomataceae; 3) genus delimitation of Entolomataceae; and 4) spore evolution in the Entolomataceae. Results confirm that the Entolomataceae (Entoloma, Rhodocybe, Clitopilus, Richoniella and Rhodogaster) is monophyletic and that the combination of pinkish spore prints and spores having bumps and/or ridges formed by an epicorium is a synapomorphy for the family. The Entolomataceae is made up of two sister clades: one with Clitopilus nested within Rhodocybe and another with Richoniella and Rhodogaster nested within Entoloma. Entoloma is best retained as one genus. The smaller genera within Entoloma s.l. are either polyphyletic or make other genera paraphyletic. Spores of the clitopiloid type are derived from rhodocyboid spores. The ancestral spore type of the Entolomataceae was either rhodocyboid or entolomatoid. Taxonomic and nomenclatural changes are made including merging Rhodocybe into Clitopilus and transferring relevant species into Clitopilus and Entoloma
Collaboration in Performing Arts
__Abstract__
As a result of declining government support, performing arts organisations (PAOs) face increased
challenges and difficulties in the sector. They attempt to develop new ways of generating income and seek
new models of organising the production and presentation of performing arts. Hereby, we can think of
collaboration and integration as horizontal and vertical within the production chain of performing arts.
There are various reasons for cultural organisations to decide upon collaboration, such as increasing
organisational capacity, engaging new audience and building organisational networks (Ostrower, 2005).
Other reasons for deciding upon collaboration are economies of scale and stronger profiling of the
performing arts organisation. Collaboration intensifies knowledge, thus the performing arts market
becomes more dynamic and there is more room for experimentation.
The issue or threat, however, is that not all collaboration processes are successful. According to Kottler
and Scheff (1996), the organisation needs to meet several conditions in order to build an efficient
collaboration: one has to set a goal-building consensus, build trust, communicate, design leadership and
involvement structures, and commit adequate resources. These are the fundamental conditions but during
the process of collaboration there are other issues that need to be considered. A frequent threat is that
parties often have different motives to collaborate. For example, for commercial organisations the motive
could be generating more profit whereas for non-profit art organisations, especially in these times,
collaboration means survival. A related issue is whether collaboration aimed at surviving is a good motive
for collaboration formation.
Moreover, fear may exist of losing an organisation’s identity or artistic autonomy, employees may become
anxious, the coordination costs might increase and parties may need additional resources and time to
establish such a project. Backer (2003) summarises this dilemma in the following question: ‘How can
parties control the collaboration in an efficient way while at the same time meeting their main objectives
and guarding their own artistic identity?
Pollen and spores from molar folds reflect food choice of late Pleistocene and Early Holocene herbivores in The Netherlands and the adjacent North Sea area
Mapping of possible prion protein self interaction domains using peptide arrays
Background The common event in transmissible spongiform encephalopathies (TSEs) or prion diseases is the conversion of host-encoded protease sensitive cellular prion protein (PrPC) into strain dependent isoforms of scrapie associated protease resistant isoform (PrPSc) of prion protein (PrP). These processes are determined by similarities as well as strain dependent variations in the PrP structure. Selective self-interaction between PrP molecules is the most probable basis for initiation of these processes, potentially influenced by chaperone molecules, however the mechanisms behind these processes are far from understood. We previously determined that polymorphisms do not affect initial PrPC to PrPSc binding but rather modulate a subsequent step in the conversion process. Determining possible sites of self-interaction could elucidate which amino acid(s) or amino acid sequences contribute to binding and further conversion into other isoforms. To this end, ovine ¿ and bovine PrP peptide-arrays consisting of 15-mer overlapping peptides were probed with recombinant sheep PrPC fused to maltose binding protein (MBP-PrP). Results The peptide-arrays revealed two distinct high binding areas as well as some regions of lower affinity in PrPC resulting in total in 7 distinct amino acid sequences (AAs). The first high binding area comprises sheep-PrP peptides 43¿102 (AA 43¿116), including the N-terminal octarepeats. The second high binding area of sheep-PrP peptides 134¿177 (AA 134¿191), encompasses most of the scrapie susceptibility-associated polymorphisms in sheep. This concurs with previous studies showing that scrapie associated-polymorphisms do not modulate the initial binding of PrPC to PrPSc. Comparison of ovine ¿ and bovine peptide-array binding patterns revealed that amino acid specific differences can influence the MBP-PrP binding pattern. PrP-specific antibodies were capable to completely block interaction between the peptide-array and MBP-PrP. MBP-PrP was also capable to specifically bind to PrP in a Western blot approach. The octarepeat region of PrP seems primarily important for this interaction because proteinase K pre-treatment of PrPSc completely abolished binding. Conclusion Binding of MBP-PrP to PrP-specific sequences indicate that several specific self-interactions between individual PrP molecules can occur and suggest that an array of interactions between PrPC-PrPC as well as PrPC-PrPSc may be possible, which ultimately lead to variations in species barrier and strain differences
Predicting the Development of Anti-Drug Antibodies against Recombinant alpha-Galactosidase A in Male Patients with Classical Fabry Disease
Fabry Disease (FD) is a rare, X-linked, lysosomal storage disease that mainly causes renal, cardiac and cerebral complications. Enzyme replacement therapy (ERT) with recombinant alpha-galactosidase A is available, but approximately 50% of male patients with classical FD develop inhibiting anti-drug antibodies (iADAs) that lead to reduced biochemical responses and an accelerated loss of renal function. Once immunization has occurred, iADAs tend to persist and tolerization is hard to achieve. Here we developed a pre-treatment prediction model for iADA development in FD using existing data from 120 classical male FD patients from three European centers, treated with ERT. We found that nonsense and frameshift mutations in the α-galactosidase A gene (p = 0.05), higher plasma lysoGb3 at baseline (p < 0.001) and agalsidase beta as first treatment (p = 0.006) were significantly associated with iADA development. Prediction performance of a Random Forest model, using multiple variables (AUC-ROC: 0.77) was compared to a logistic regression (LR) model using the three significantly associated variables (AUC-ROC: 0.77). The LR model can be used to determine iADA risk in individual FD patients prior to treatment initiation. This helps to determine in which patients adjusted treatment and/or immunomodulatory regimes may be considered to minimize iADA development risk. View Full-Tex
Giant deer (Megaloceros giganteus) diet from Mid-Weichselian deposits under the present North Sea inferred from molar-embedded botanical remains
The molar of a giant deer, Megaloceros giganteus (Blumenbach, 1799), was discovered in sandy deposits of the North Sea, about 10 km west of the present shoreline of the Netherlands. Compacted masticated plant remains were preserved in the molar's deep folds. A palaeoecological analysis of these plant remains shows the complete dominance of pollen from Artemisia (sage) and other Asteraceae Tubuliflorae (Compositae), indicating that the animal foraged in a steppe environment, and may have preferred to eat Artemisia, which contain a high level of nutrients such as calcium and phosphorous components, which are important for antler building. Radiocarbon dating indicates that the plant remains are of mid‐Weichselian age [38 570 (+300, −290) 14C a BP, Greenland Interstadial‐11]. This is the first study of the food choice of M. giganteus based on palaeoecological evidence. We hypothesize about links between the extirpation of M. giganteus at the onset of the Holocene in North‐West Europe and the transition from a landscape with highly dynamic geomorphological processes and consequently prevalence of immature and nutrient‐rich soils, to a less dynamic landscape with stable, leached and acidifying soils, and the decline of Artemisia and other calciphilous plants
Dopant-induced crossover from 1D to 3D charge transport in conjugated polymers
The interplay between inter- and intra-chain charge transport in bulk
polythiophene in the hopping regime has been clarified by studying the
conductivity as a function of frequency (up to 3 THz), temperature and doping
level. We present a model which quantitatively explains the observed crossover
from quasi-one-dimensional transport to three-dimensional hopping conduction
with increasing doping level. At high frequencies the conductivity is dominated
by charge transport on one-dimensional conducting chains.Comment: 4 pages, 2 figure
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A stronger role for long-term moisture change than for CO<sub>2</sub> in determining tropical woody vegetation change
Anthropogenically elevated CO2 (eCO2) concentrations have been suggested to increase woody cover within tropical ecosystems through fertilization. The effect of eCO2 is built into Earth system models, although testing the relationship over long periods remains challenging. Here, we explore the relative importance of six drivers of vegetation change in western Africa over the past ~500,000 years (moisture availability, fire activity, mammalian herbivore density, temperature, temperature seasonality, CO2) by coupling past environmental change data from Lake Bosumtwi (Ghana) with global data. We found that moisture availability and fire activity were the most important factors in determining woody cover, whereas the effect of CO2 was small. Our findings suggest that the role of eCO2 effects on tropical vegetation in predictive models must be reconsidered
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