Marking the counterfactual: ERP evidence for pragmatic processing of German subjunctives

Counterfactual conditionals are frequently used in language to express potentially valid reasoning from factually false suppositions. Counterfactuals provide two pieces of information: their literal meaning expresses a suppositional dependency between an antecedent (If the dice had been rigged…) and a consequent (… then the game would have been unfair). Their second, backgrounded meaning refers to the opposite state of affairs and suggests that, in fact, the dice were not rigged and the game was fair. Counterfactual antecedents are particularly intriguing because they set up a counterfactual world which is known to be false, but which is nevertheless kept to when evaluating the conditional's consequent. In the last years several event-related potential (ERP) studies have targeted the processing of counterfactual consequents, yet counterfactual antecedents have remained unstudied. We present an EEG/ERP investigation which employed German conditionals to compare subjunctive mood (which marks counterfactuality) with indicative mood at the critical point of mood disambiguation via auxiliary introduction in the conditional's antecedent. Conditional sentences were presented visually one word at a time. Participants completed an acceptability judgment and probe detection task which was not related to the critical manipulation of linguistic mood. ERPs at the point of mood disambiguation in the antecedent were compared between indicative and subjunctive. Our main finding is a transient negative deflection in frontal regions for subjunctive compared to indicative mood in a time-window of 450–600 ms. We discuss this novel finding in respect to working memory requirements for rule application and increased referential processing demands for the representation of counterfactuals' dual meaning. Our result suggests that the counterfactually implied dual meaning is processed without any delay at the earliest point where counterfactuality is marked by subjunctive mood

Bioprinting cell laden structures with chitosan-gelatin for neural tissue applications

Nearly 1 billion people suffer from neurological disorders, and approximately 400,000 patients require surgical intervention to repair damaged peripheral nerves every year. There is a need, therefore, for three-dimensional synthetic tissues to serve as both models and regenerative structures. Primary human neural cells are not directly obtainable. Differentiated, patient specific adult adipocyte stem cells would offer a non-immunogenic, abundant source of cells for regenerative implant applications and in vitro models. However, mature, differentiated cells are difficult to obtain reproducibly. Bioprinting is an attractive approach to building 3D tissues. However, bioinks that transform into stable solids in physiologically conducive environments are needed. Also, cell survival post-printing is an issue, and printing processes effect on cell responses need to be investigated. I developed a preparation process that allows for continuous, consistent printing of a chitosan-gelatin (CG) hydrogel that does not require post-processing. I investigated the effect of print bed temperature, feed rate, flow rate, and needle height on fiber sizes. Further, I designed and developed a compact electrical stimulation device to investigate cell response post-printing. I used computer modeling to ensure I obtained a constant electrical field, similar to traditional devices. Using the developed device, I investigated the response and expression of B-III-tubulin of human neuroblasts (NBs) and human adipocyte stem cells (hASCs) to electrical stimulation and to the bioprinting process, separately and in combination. The CG hydrogel was successfully bioprinted: the bed temperature had the greatest effect on fiber size (resolution), followed by feed rate and cells were well distributed when printed, maintained viability, and no contamination was observed after 5 days. A compact device was designed with a constant electric field that could be maintained sterile during microscopic observation for 6 days post-stimulation. Both NBs and hASCs showed differentiation towards a neural lineage when electrically stimulated. NBs were more sensitive to the printing process than hASCs losing actin polymerization when printed through a 34g needle. Finally, hASCs exhibit significant B-III-tubulin and neuron-like cell morphology 6-days after printing through a 34g needle

Developing a Scaffold from Porcine Adipose Tissue

Tissue engineering aims to address the critical lack of immunocompatible tissues and organs available for grafting and transplantation. Scaffolds are three dimensional, porous structures that provide shape and attachment sites for cells during tissue growth and are a critical component of tissue engineering. Naturally derived scaffolds have seen significantly greater clinical usage than synthetic scaffolds and have marked advantages, including naturally present growth factors and ideal morphology. In addition, scaffolds derived from xenogeneic tissues are advantageous because human tissues are difficult and costly to obtain. However, careful decellularization is required to prevent immune rejection. Porcine adipose tissue (PAT) is inexpensive and readily obtained. This study's objective was to develop a general tissue scaffold from PAT while maintaining the structure of its extracellular matrix (ECM). Maintaining PAT's ECM intact is expected to improve nutrient distribution and cell ingrowth. Two decellularization methods were attempted: methanol-chloroform submersion, and freeze-thawing. Methanol-chloroform submersion destroyed the tissue and was discontinued; freeze-thawing was successful and pursued: the number of freeze-thaw steps (1 - 7), the tissue surface area and thickness, and the trypsin incubation time (1 - 3 hours) were evaluated and optimized. Moreover, following an initial cell seeding study during which cell attachment and ingrowth did not occur, a lipid removal strategy using sonication (20 - 60 minutes with water, trypsin, or SDS) and immersion in xylene (20 seconds to 20 minutes) was also devised to remove all lipids and thereby create a hydrophilic environment conducive to cell seeding. Processed scaffold mechanical strength and morphology were examined using histology slides and SEM digital micrographs. An additional cell seeding study using CFDA-SE stained cells was conducted. An average ultimate tensile strength of 87.4 kPa, an average break strain of 53.9 kPa, an average elastic modulus of 324 kPa, 30% relaxation per ramp, and intact morphology, including tubular vascular channels were found. Cells examined in micrographs of seeded tissue demonstrated successful cell ingrowth and uniform distribution at 8 days. Overall, an optimized decellularization process and a lipid removal processes were developed that retained natural tissue morphology. Moreover, obtained scaffolds compared favorably with small intestine submucosa (SIS), a clinically available scaffold.Chemical Engineerin

Animacy effects on the processing of intransitive verbs:An eye-tracking study

<p>This paper tested an assumption of the gradient model of split intransitivity put forward by Sorace (“Split Intransitivity Hierarchy” (SIH), 2000, 2004), namely that agentivity is a fundamental feature for unergatives but not for unaccusatives. According to this hypothesis, the animacy of the verb’s argument should affect the processing of unergative verbs to a greater extent than unaccusative verbs. By using eye-tracking methodology we monitored the online processing and integration costs of the animacy of the verb’s argument in intransitive verbs. We observed that inanimate subjects caused longer reading times only for unergative verbs, whereas the animacy of the verb’s argument did not influence the pattern of results for unaccusatives. In addition, the unergative verb data directly support the existence of gradient effects on the processing of the subject argument.</p

Consumer Response to Drug Risk Information:The Role of Positive Affect

Risk disclosure is an essential element of the marketing of prescription drugs and other medical products. This study examines how consumers respond to verbal information about the frequency and severity of medical-product risks and how media-induced affect can moderate such responses. The study finds that consumers tend to overestimate the actual likelihood of adverse events described with words such as “common” or “rare” (compared with the probabilities such terms are typically intended to convey) and that consumers tend to give little weight to such probability language when forming product use intentions. However, consumers in positive media-induced moods seem to engage in more nuanced evaluation of product risk information, weighing both frequency and severity information and using such information to make inferences about other product attributes (e.g., product efficacy). These findings suggest that medical marketers and regulators need to devise more effective means of communicating risk probability to consumers and that positive mood induction (e.g., by placing advertisements in upbeat media environments) can enhance consumers' ability to process product risk information

The Mechanism of Antifungal Action of Essential Oil from Dill (Anethum graveolens L.) on Aspergillus flavus

The essential oil extracted from the seeds of dill (Anethum graveolens L.) was demonstrated in this study as a potential source of an eco-friendly antifungal agent. To elucidate the mechanism of the antifungal action further, the effect of the essential oil on the plasma membrane and mitochondria of Aspergillus flavus was investigated. The lesion in the plasma membrane was detected through flow cytometry and further verified through the inhibition of ergosterol synthesis. The essential oil caused morphological changes in the cells of A. flavus and a reduction in the ergosterol quantity. Moreover, mitochondrial membrane potential (MMP), acidification of external medium, and mitochondrial ATPase and dehydrogenase activities were detected. The reactive oxygen species (ROS) accumulation was also examined through fluorometric assay. Exposure to dill oil resulted in an elevation of MMP, and in the suppression of the glucose-induced decrease in external pH at 4 µl/ml. Decreased ATPase and dehydrogenase activities in A. flavus cells were also observed in a dose-dependent manner. The above dysfunctions of the mitochondria caused ROS accumulation in A. flavus. A reduction in cell viability was prevented through the addition of L-cysteine, which indicates that ROS is an important mediator of the antifungal action of dill oil. In summary, the antifungal activity of dill oil results from its ability to disrupt the permeability barrier of the plasma membrane and from the mitochondrial dysfunction-induced ROS accumulation in A. flavus

ERP evidence for different strategies in the processing of case markers in native speakers and non-native learners

BACKGROUND: The present experiments were designed to test how the linguistic feature of case is processed in Japanese by native and non-native listeners. We used a miniature version of Japanese as a model to compare sentence comprehension mechanisms in native speakers and non-native learners who had received training until they had mastered the system. In the first experiment we auditorily presented native Japanese speakers with sentences containing incorrect double nominatives and incorrect double accusatives, and with correct sentences. In the second experiment we tested trained non-natives with the same material. Based on previous research in German we expected an N400-P600 biphasic ERP response with specific modulations depending on the violated case and whether the listeners were native or non-native. RESULTS: For native Japanese participants the general ERP response to the case violations was an N400-P600 pattern. Double accusatives led to an additional enhancement of the P600 amplitude. For the learners a native-like P600 was present for double accusatives and for double nominatives. The additional negativity, however, was present in learners only for double nominative violations, and it was characterized by a different topographical distribution. CONCLUSION: The results indicate that native listeners use case markers for thematic as well as syntactic structure building during incremental sentence interpretation. The modulation of the P600 component for double accusatives possibly reflects case specific syntactic restrictions in Japanese. For adult language learners later processes, as reflected in the P600, seem to be more native-like compared to earlier processes. The anterior distribution of the negativity and its selective emergence for canonical sentences were taken to suggest that the non-native learners resorted to a rather formal processing strategy whereby they relied to a large degree on the phonologically salient nominative case marker

High methylmercury in Arctic and subarctic ponds is related to nutrient levels in the warming eastern Canadian Arctic

Permafrost thaw ponds are ubiquitous in the eastern Canadian Arctic, yet little information exists on their potential as sources of methylmercury (MeHg) to freshwaters. They are microbially active and conducive to methylation of inorganic mercury, and are also affected by Arctic warming. This multiyear study investigated thaw ponds in a discontinuous permafrost region in the Subarctic taiga (Kuujjuarapik-Whapmagoostui, QC) and a continuous permafrost region in the Arctic tundra (Bylot Island, NU). MeHg concentrations in thaw ponds were well above levels measured in most freshwater ecosystems in the Canadian Arctic (>0.1 ng L−1). On Bylot, ice-wedge trough ponds showed significantly higher MeHg (0.3−2.2 ng L−1) than polygonal ponds (0.1−0.3 ng L−1) or lakes (<0.1 ng L−1). High MeHg was measured in the bottom waters of Subarctic thaw ponds near Kuujjuarapik (0.1−3.1 ng L−1). High water MeHg concentrations in thaw ponds were strongly correlated with variables associated with high inputs of organic matter (DOC, a320, Fe), nutrients (TP, TN), and microbial activity (dissolved CO2 and CH4). Thawing permafrost due to Arctic warming will continue to release nutrients and organic carbon into these systems and increase ponding in some regions, likely stimulating higher water concentrations of MeHg. Greater hydrological connectivity from permafrost thawing may potentially increase transport of MeHg from thaw ponds to neighboring aquatic ecosystems

Functional Hair Cell Mechanotransducer Channels Are Required for Aminoglycoside Ototoxicity

Aminoglycosides (AG) are commonly prescribed antibiotics with potent bactericidal activities. One main side effect is permanent sensorineural hearing loss, induced by selective inner ear sensory hair cell death. Much work has focused on AG's initiating cell death processes, however, fewer studies exist defining mechanisms of AG uptake by hair cells. The current study investigated two proposed mechanisms of AG transport in mammalian hair cells: mechanotransducer (MET) channels and endocytosis. To study these two mechanisms, rat cochlear explants were cultured as whole organs in gentamicin-containing media. Two-photon imaging of Texas Red conjugated gentamicin (GTTR) uptake into live hair cells was rapid and selective. Hypocalcemia, which increases the open probability of MET channels, increased AG entry into hair cells. Three blockers of MET channels (curare, quinine, and amiloride) significantly reduced GTTR uptake, whereas the endocytosis inhibitor concanavalin A did not. Dynosore quenched the fluorescence of GTTR and could not be tested. Pharmacologic blockade of MET channels with curare or quinine, but not concanavalin A or dynosore, prevented hair cell loss when challenged with gentamicin for up to 96 hours. Taken together, data indicate that the patency of MET channels mediated AG entry into hair cells and its toxicity. Results suggest that limiting permeation of AGs through MET channel or preventing their entry into endolymph are potential therapeutic targets for preventing hair cell death and hearing loss

Nck adapter proteins: functional versatility in T cells

Nck is a ubiquitously expressed adapter protein that is almost exclusively built of one SH2 domain and three SH3 domains. The two isoproteins of Nck are functionally redundant in many aspects and differ in only few amino acids that are mostly located in the linker regions between the interaction modules. Nck proteins connect receptor and non-receptor tyrosine kinases to the machinery of actin reorganisation. Thereby, Nck regulates activation-dependent processes during cell polarisation and migration and plays a crucial role in the signal transduction of a variety of receptors including for instance PDGF-, HGF-, VEGF- and Ephrin receptors. In most cases, the SH2 domain mediates binding to the phosphorylated receptor or associated phosphoproteins, while SH3 domain interactions lead to the formation of larger protein complexes. In T lymphocytes, Nck plays a pivotal role in the T cell receptor (TCR)-induced reorganisation of the actin cytoskeleton and the formation of the immunological synapse. However, in this context, two different mechanisms and adapter complexes are discussed. In the first scenario, dependent on an activation-induced conformational change in the CD3ε subunits, a direct binding of Nck to components of the TCR/CD3 complex was shown. In the second scenario, Nck is recruited to the TCR complex via phosphorylated Slp76, another central constituent of the membrane proximal activation complex. Over the past years, a large number of putative Nck interactors have been identified in different cellular systems that point to diverse additional functions of the adapter protein, e.g. in the control of gene expression and proliferation