Variety mixtures in wheat

Aufgrund zweijähriger Feldversuche mit Sortenmischungen im Weizenanbau läßt sich folgendes festhalten: 1. Das Konzept der Sortenmischungen ist mit Erfolg auf Weizen übertragbar. 2. Wie bei Gerste, so ist Sommerweizen hier gegenüber Winterweizen offensichtlich im Vorteil. 3. Mischungen von drei Sorten mit jeweils gleichem Saatgutanteil erwiesen sich nach erzielbaren Mehrerträgen, Ertragsstabilität und Krankheitsverlauf Zweier- und Vierer-Mischungen als überlegen. Mögliche Ursachen für das gute Abschneiden der DreiKomponenten-Mischungen werden diskutiert, die in Sommerweizen in den beiden Versuchsjahren zu Mehrerträgen von durchschnittlich 8,2 bzw. 6,2 % (Winterweizen 2,2 bzw. 4,9 % ) führten. - Für eine weitere Verbesserung dieser Situation bestehen gute Aussichten.A two years field study with wheat variety mixtures gave the following results: 1. The principle of variety mixtures can be successfully applied to wheat. 2. Obviously spring wheat mixtures are more promising than those of winter wheat, as in case of barley. 3. Yields, yield stability and disease incidence with three-variety mixtures in equal proportion were at least comparable to or better than mixtures of two or four varieties. Possible explanations for the satisfactory outcome with threevariety mixtures are discussed, which in spring wheat resulted in an average yield increase of 8.2 and 6.0%, respectively, in both experimental years (winter wheat 2.2 and 4.9 %). -There are good chances for a further improvement of this situation

Aberrant iPSC-derived human astrocytes in Alzheimer's disease

The pathological potential of human astroglia in Alzheimer's disease (AD) was analysed in vitro using induced pluripotent stem cell (iPSC) technology. Here, we report development of a human iPSC-derived astrocyte model created from healthy individuals and patients with either early-onset familial AD (FAD) or the late-onset sporadic form of AD (SAD). Our chemically-defined and highly efficient model provides >95% homogeneous populations of human astrocytes within 30 days of differentiation from cortical neural progenitor cells (NPCs). All astrocytes expressed functional markers including; glial fibrillary acidic protein (GFAP), excitatory amino acid transporter 1 (EAAT1), S100B and glutamine synthetase (GS) comparable to that of adult astrocytes in vivo. However, induced astrocytes derived from both SAD and FAD patients exhibit a pronounced pathological phenotype, with a significantly less complex morphological appearance, overall atrophic profiles, and abnormal localisation of key functional astroglial markers. Furthermore, NPCs derived from identical patients did not show any differences, therefore, validating that remodelled astroglia are not as a result of defective neuronal intermediates. This work not only presents a novel model to study the mechanisms of human astrocytes in vitro, but also provides an ideal platform for further interrogation of early astroglial cell-autonomous events in AD and the possibility of identification of novel therapeutic targets for the treatment of AD

Anchored enrichment dataset for true flies (order Diptera) reveals insights into the phylogeny of flower flies (family Syrphidae)

Background: Anchored hybrid enrichment is a form of next-generation sequencing that uses oligonucleotide probes to target conserved regions of the genome flanked by less conserved regions in order to acquire data useful for phylogenetic inference from a broad range of taxa. Once a probe kit is developed, anchored hybrid enrichment is superior to traditional PCR-based Sanger sequencing in terms of both the amount of genomic data that can be recovered and effective cost. Due to their incredibly diverse nature, importance as pollinators, and historical instability with regard to subfamilial and tribal classification, Syrphidae (flower flies or hoverflies) are an ideal candidate for anchored hybrid enrichment-based phylogenetics, especially since recent molecular phylogenies of the syrphids using only a few markers have resulted in highly unresolved topologies. Over 6200 syrphids are currently known and uncovering their phylogeny will help us to understand how these species have diversified, providing insight into an array of ecological processes, from the development of adult mimicry, the origin of adult migration, to pollination patterns and the evolution of larval resource utilization. Results: We present the first use of anchored hybrid enrichment in insect phylogenetics on a dataset containing 30 flower fly species from across all four subfamilies and 11 tribes out of 15. To produce a phylogenetic hypothesis, 559 loci were sampled to produce a final dataset containing 217,702 sites. We recovered a well resolved topology with bootstrap support values that were almost universally >95 %. The subfamily Eristalinae is recovered as paraphyletic, with the strongest support for this hypothesis to date. The ant predators in the Microdontinae are sister to all other syrphids. Syrphinae and Pipizinae are monophyletic and sister to each other. Larval predation on soft-bodied hemipterans evolved only once in this family. Conclusions: Anchored hybrid enrichment was successful in producing a robustly supported phylogenetic hypothesis for the syrphids. Subfamilial reconstruction is concordant with recent phylogenetic hypotheses, but with much higher support values. With the newly designed probe kit this analysis could be rapidly expanded with further sampling, opening the door to more comprehensive analyses targeting problem areas in syrphid phylogenetics and ecology.Peer reviewe

Observations on Hilltopping in Thick-Headed Flies (Diptera: Conopidae)

Direct observations of hilltopping behaviour in the thick-headed flies (Diptera: Conopidae) have only been mentioned once in the literature. Hilltop collecting, however, may be an effective way to survey these endparasitoids. The first evidence of hilltopping in species belonging to the subfamilies Myopinae and Dalmanniinae is presented and discussed. Field observations were conducted on Colle Vescovo, Italy and Mount Rigaud, Canada, and museum specimens were examined. Observations and records indicate that four species in the genera Dalmannia, Myopa, and Zodion are hilltoppers on Colle Vescovo, while three species in the genera Myopa and Physocephala are hilltoppers on three hilltops near Ottawa, Canada. Fifteen additional species of conopids have been collected on hilltops and could possibly utilize hilltops in some years as a part of their mating strategy. Detailed phenologies and observations of mating and perching behaviours are given for species in the genera Dalmannia, Myopa, Physocephala, and Zodion. The importance of hilltop habitat preservation is stressed

Advances in multiple sclerosis research in 2009

The following review summarizes the progress in multiple sclerosis research published in the Journal of Neurology in 2009

YTHDF proteins and m⁶A-RNA clients undergo autophagic turnover during contact inhibition

The YTHDF protein family plays a critical role in cancer development by recognizing and regulating the stability of N6-methyladenosine (m6A)-modified RNA. Here, we reveal an autophagy-dependent mechanism controlling YTHDF protein levels. Using contact inhibition as a cellular model system, we show YTHDF proteins to be rapidly degraded, coinciding with increased autophagy and decreased mTOR activity. Upon pharmacological mTOR inhibition, YTHDF2 is also downregulated via lysosomal degradation. YTHDF2 selectively interacts with the autophagy modifier GABARAP L2 through LC3-interacting region (LIR) motifs in its unstructured N- and C-terminal regions. Autophagic YTHDF2 downregulation results in the co-degradation of its bound m6A-modified RNA clients. While YTHDF depletion induces cell death in contact-inhibition-deficient HCT116 cancer cells, contact-inhibited MRC5 and RPE1 cells remain unaffected. Our findings uncover a regulatory pathway that governs YTHDF protein stability with significant implications for cancer biology and cell fate determination and suggest the existence of an autophagy-mediated degradation pathway for m6A-modified RNA

Cortical Disinhibition, Attractor Dynamics, and Belief Updating in Schizophrenia

Genetic and pharmacological evidence implicates N-methyl-D-aspartate receptor (NMDAR) dysfunction in the pathophysiology of schizophrenia. Dysfunction of this key receptor – if localised to inhibitory interneurons – could cause a net disinhibition of cortex and increase in ‘noise’. These effects can be computationally modelled in a variety of ways: by reducing the precision in Bayesian models of behaviour, by estimating neuronal excitability changes in schizophrenia from evoked responses, or – as described in detail here – by modelling abnormal belief updating in a probabilistic inference task. Features of belief updating in schizophrenia include greater updating to unexpected evidence, lower updating to consistent evidence, and greater stochasticity in responding. All of these features can be explained by a loss of stability of ‘attractor states’ in cortex and the representations they encode. Indeed, a hierarchical Bayesian model of belief updating indicates that subjects with schizophrenia have a consistently increased ‘belief instability’ parameter. This instability could be a direct result of cortical disinhibition: this hypothesis should be explored in future studies