The Effects of Social Labels on the Allocation of Resources to Equivalent Stimuli::Does One Rotten Apple Spoil the Whole Barrel?

The studies reported here examine how participants distribute resources to arbitrary stimuli in an equivalence class after one stimulus is given a social label. In Experiment 1, two 3-member equivalence classes were established with nonsense syllables (Class 1: A1 (ZID), B1 (YIM), C1 (FAP) and Class 2: A2 (VEK), B2 (RIX), C2 (KUD)) using matching-to-sample training. A social function was then assigned to B1 only, using the simple verbal statement "YIM is a Good person." Next, participants were instructed to allocate tokens to stimuli in whatever way they consider appropriate. In general, the percentage distribution of tokens allocated to Class 1 was greater than those allocated to Class 2. Participants were then informed that a mistake had been made “Sorry I have made a mistake. YIM was actually a bad person not a good person.” Participants wer

Children's emergent relations of equivalence using stimuli with opposite verbal labels: Exclusion and minimal training conditions

The present study examined different conditions under which exclusion responding in conditional discrimination tasks would generate emergent equivalence relations in young children based on shared relationships with verbal labels. Both visual stimuli (Sets A, B, C, and D) and auditory stimuli (spoken words, Set N: N1 "correct"; N2: "incorrect") were used. Following a pilot study, three experiments were conducted, each involving eight preschool children. These experiments systematically investigated under which conditions responding by exclusion (i.e., responding away from a designated S - comparison in a matching to sample context) would generate sufficiently stable sample-S + relations for arbitrary stimulus classes to establish. The results showed that young children's exclusion responding under test conditions will only contribute to arbitrary stimulus class formation and expansion when training has already established two arbitrary stimulus classes involving at least two stimuli each. For young children to demonstrate emergent conditional discrimination performances that are indicative of the formation of equivalence relations, it is necessary to have training and/or reinforced exposure to both S + and S - control elements required for deriving the appropriate emergent relations with at least two conditional relations involving different samples. These findings not only contribute to existing research and theory on the conditions under which exclusion responding may contribute to fundamental language and learning processes, they also contribute to the experimental predictability of emergent conditional matching behaviours in preschool children by further unravelling the conditions under which emergent matching based on exclusion generates arbitrary conditional relations of equivalence. </p

From Understanding to Sustainable Use of Peatlands: The WETSCAPES Approach

Of all terrestrial ecosystems, peatlands store carbon most effectively in long-term scales of millennia. However, many peatlands have been drained for peat extraction or agricultural use. This converts peatlands from sinks to sources of carbon, causing approx. 5% of the anthropogenic greenhouse effect and additional negative effects on other ecosystem services. Rewetting peatlands can mitigate climate change and may be combined with management in the form of paludiculture. Rewetted peatlands, however, do not equal their pristine ancestors and their ecological functioning is not understood. This holds true especially for groundwater-fed fens. Their functioning results from manifold interactions and can only be understood following an integrative approach of many relevant fields of science, which we merge in the interdisciplinary project WETSCAPES. Here, we address interactions among water transport and chemistry, primary production, peat formation, matter transformation and transport, microbial community, and greenhouse gas exchange using state of the art methods. We record data on six study sites spread across three common fen types (Alder forest, percolation fen, and coastal fen), each in drained and rewetted states. First results revealed that indicators reflecting more long-term effects like vegetation and soil chemistry showed a stronger differentiation between drained and rewetted states than variables with a more immediate reaction to environmental change, like greenhouse gas (GHG) emissions. Variations in microbial community composition explained differences in soil chemical data as well as vegetation composition and GHG exchange. We show the importance of developing an integrative understanding of managed fen peatlands and their ecosystem functioning.

RNA-Seq and metabolic flux analysis of Tetraselmis sp. M8 during nitrogen starvation reveals a two-stage lipid accumulation mechanism

To map out key lipid-related pathways that lead to rapid triacylglyceride accumulation in oleaginous microalgae, RNA-Seq was performed with Tetraselmis sp. M8 at 24 h after exhaustion of exogenous nitrogen to reveal molecular changes during early stationary phase. Further gene expression profiling by quantitative real-time PCR at 16–72 h revealed a distinct shift in expression of the fatty acid/triacylglyceride biosynthesis and β-oxidation pathways, when cells transitioned from log-phase into early-stationary and stationary phase. Metabolic reconstruction modeling combined with real-time PCR and RNA-Seq gene expression data indicates that the increased lipid accumulation is a result of a decrease in lipid catabolism during the early-stationary phase combined with increased metabolic fluxes in lipid biosynthesis during the stationary phase. During these two stages, Tetraselmis shifts from reduced lipid consumption to active lipid production. This process appears to be independent from DGAT expression, a key gene for lipid accumulation in microalgae

A Cyclic Undecamer Peptide Mimics a Turn in Folded Alzheimer Amyloid β and Elicits Antibodies against Oligomeric and Fibrillar Amyloid and Plaques

The 39- to 42-residue amyloid β (Aβ) peptide is deposited in extracellular fibrillar plaques in the brain of patients suffering from Alzheimer's Disease (AD). Vaccination with these peptides seems to be a promising approach to reduce the plaque load but results in a dominant antibody response directed against the N-terminus. Antibodies against the N-terminus will capture Aβ immediately after normal physiological processing of the amyloid precursor protein and therefore will also reduce the levels of non-misfolded Aβ, which might have a physiologically relevant function. Therefore, we have targeted an immune response on a conformational neo-epitope in misfolded amyloid that is formed in advance of Aβ-aggregation. A tetanus toxoid-conjugate of the 11-meric cyclic peptide Aβ(22–28)-YNGK′ elicited specific antibodies in Balb/c mice. These antibodies bound strongly to the homologous cyclic peptide-bovine serum albumin conjugate, but not to the homologous linear peptide-conjugate, as detected in vitro by enzyme-linked immunosorbent assay. The antibodies also bound—although more weakly—to Aβ(1–42) oligomers as well as fibrils in this assay. Finally, the antibodies recognized Aβ deposits in AD mouse and human brain tissue as established by immunohistological staining. We propose that the cyclic peptide conjugate might provide a lead towards a vaccine that could be administered before the onset of AD symptoms. Further investigation of this hypothesis requires immunization of transgenic AD model mice

C. elegans Agrin Is Expressed in Pharynx, IL1 Neurons and Distal Tip Cells and Does Not Genetically Interact with Genes Involved in Synaptogenesis or Muscle Function

Agrin is a basement membrane protein crucial for development and maintenance of the neuromuscular junction in vertebrates. The C. elegans genome harbors a putative agrin gene agr-1. We have cloned the corresponding cDNA to determine the primary structure of the protein and expressed its recombinant fragments to raise specific antibodies. The domain organization of AGR-1 is very similar to the vertebrate orthologues. C. elegans agrin contains a signal sequence for secretion, seven follistatin domains, three EGF-like repeats and two laminin G domains. AGR-1 loss of function mutants did not exhibit any overt phenotypes and did not acquire resistance to the acetylcholine receptor agonist levamisole. Furthermore, crossing them with various mutants for components of the dystrophin-glycoprotein complex with impaired muscle function did not lead to an aggravation of the phenotypes. Promoter-GFP translational fusion as well as immunostaining of worms revealed expression of agrin in buccal epithelium and the protein deposition in the basal lamina of the pharynx. Furthermore, dorsal and ventral IL1 head neurons and distal tip cells of the gonad arms are sources of agrin production, but no expression was detectable in body muscles or in the motoneurons innervating them. Recombinant worm AGR-1 fragment is able to cluster vertebrate dystroglycan in cultured cells, implying a conservation of this interaction, but since neither of these proteins is expressed in muscle of C. elegans, this interaction may be required in different tissues. The connections between muscle cells and the basement membrane, as well as neuromuscular junctions, are structurally distinct between vertebrates and nematodes

Illustrationen als Paratext beim Ubersetzen : Mit Beispielen aus einem Werk von O. Preusler

Purpose: The authors tested associations between (a) parent-reported temporary vs. persistent vocabulary delay and (b) parent-reported behavioral/emotional problems in a sample of 5,497 young Dutch children participating in a prospective population-based study. Method: Mothers completed the MacArthur Communicative Development Inventory-Netherlands (Zink & Lejaegere, 2003) at age 18 months and the Language Development Survey (Rescorla, 1989) at age 30 months, with expressive vocabulary delay defined as scores in the lowest 15th age-and gender-specific percentiles. The Child Behavior Checklist (Achenbach & Rescorla, 2000) was completed by mothers when their children were age 18 months and by both parents when their children were age 36 months, from which Internalizing Problems and Externalizing Problems scores were analyzed. Results: All analyses were adjusted for covariates. Expressive vocabulary delay at age 18 months was weakly related to Internalizing Problems scores at age 18 months as well as mother-reported Externalizing and Internalizing Problems scores at age 36 months (the latter for boys only). Expressive vocabulary delay at age 30 months was weakly associated with mother-reported Externalizing and Internalizing Problems scores (the latter for boys only) and father-reported Internalizing Problems scores. Persistent expressive vocabulary delay predicted the highest risk of mother-reported internalizing and externalizing problems at age 36 months. Conclusion: This population-based study showed modest associations between vocabulary delay and behavioral/emotional problems detectable from 18 months onward