Disfluency in dialogue:an intentional signal from the speaker?

Disfluency is a characteristic feature of spontaneous human speech, commonly seen as a consequence of problems with production. However, the question remains open as to why speakers are disfluent: Is it a mechanical by-product of planning difficulty, or do speakers use disfluency in dialogue to manage listeners' expectations? To address this question, we present two experiments investigating the production of disfluency in monologue and dialogue situations. Dialogue affected the linguistic choices made by participants, who aligned on referring expressions by choosing less frequent names for ambiguous images where those names had previously been mentioned. However, participants were no more disfluent in dialogue than in monologue situations, and the distribution of types of disfluency used remained constant. Our evidence rules out at least a straightforward interpretation of the view that disfluencies are an intentional signal in dialogue. © 2012 Psychonomic Society, Inc

Bacteria establish an aqueous living space in plants crucial for virulence

High humidity has a strong influence on the development of numerous diseases affecting the above-ground parts of plants (the phyllosphere) in crop fields and natural ecosystems, but the molecular basis of this humidity effect is not understood. Previous studies have emphasized immune suppression as a key step in bacterial pathogenesis. Here we show that humidity-dependent, pathogen-driven establishment of an aqueous intercellular space (apoplast) is another important step in bacterial infection of the phyllosphere. Bacterial effectors, such as Pseudomonas syringae HopM1, induce establishment of the aqueous apoplast and are sufficient to transform non-pathogenic P. syringae strains into virulent pathogens in immunodeficient Arabidopsis thaliana under high humidity. Arabidopsis quadruple mutants simultaneously defective in a host target (AtMIN7) of HopM1 and in pattern-triggered immunity could not only be used to reconstitute the basic features of bacterial infection, but also exhibited humidity-dependent dyshomeostasis of the endophytic commensal bacterial community in the phyllosphere. These results highlight a new conceptual framework for understanding diverse phyllosphere–bacterial interactions

Accelerating the Deactivation of \u3cem\u3eSalmonella enterica\u3c/em\u3e Serovar Newport and \u3cem\u3eEscherichia coli\u3c/em\u3e O157:H7 in Dairy Manure by Modifying pH or Temperature

To assess methods for control of disease-causing bacteria in animal manures prior to field application, we manipulated the temperature or adjusted pH of dairy manure to high (3.5 to 5) or low (10 to 12) values with aluminum sulfate or hydrated lime, and inoculated the manure with Salmonella enterica serovar Newport or Escherichia coli O157:H7, then incubated the manure at ambient temperature. At pH 4.2, S. Newport was eliminated within 6 days; however at pH \u3e4.2 S. Newport was suppressed only temporarily and recovered to concentrations near the unamended controls. pH required to eliminate E. coli O157:H7 was 4.5. Both pathogens were killed by pH 11.0. The pathogens were eliminated within 2 weeks when inoculated manure was incubated at 37°C, whereas at 22°C and 4°C, the organisms persisted for much longer periods. S. Newport survived for over 300 days at 4°C, which has implications for manure spreading in colder seasons

Combining Synchrotron X-ray Diffraction, Mechanistic Modeling, and Machine Learning for In Situ Subsurface Temperature Quantification during Laser Melting

Laser melting, such as that encountered during additive manufacturing (AM), produces extreme gradients of temperature in both space and time, which in turn influence microstructural development in the material. Qualification and model validation of the process itself and resulting material produced necessitates the ability to characterize these temperature fields. However, well-established means to directly probe material temperature below the surface of an alloy while it is being processed are limited. To address this gap in characterization capabilities, we present a novel means to extract subsurface temperature distribution metrics, with uncertainty, from in situ synchrotron X-ray diffraction measurements to provide quantitative temperature evolution during laser melting. Temperature distribution metrics are determined using Gaussian Process Regression supervised machine learning surrogate models trained with a combination of mechanistic modeling (heat transfer and fluid flow) and X-ray diffraction simulation. Trained surrogate model uncertainties are found to range from 5% to 15% depending on the metric and current temperature. The surrogate models are then applied to experimental data to extract temperature metrics from an Inconel 625 nickel superalloy wall specimen during laser melting. Maximum temperatures of the solid phase in the diffraction volume through melting and cooling are found to reach the solidus temperature as expected, with mean and minimum temperatures found to be several hundred degrees less. The extracted temperature metrics near melting are determined to be more accurate due to the lower relative levels of mechanical elastic strains. However, uncertainties for temperature metrics during cooling are increased due to the effects of thermomechanical stress

A cluster randomized controlled trial of a modified vaccination clinical reminder for primary care providers

Objective: Adult vaccination rates in the United States fall short of national goals, and rates are particularly low for Black Americans. We tested a provider-focused vaccination uptake intervention: a modified electronic health record clinical reminder that bundled together three adult vaccination reminders, presented patient vaccination history, and included talking points for providers to address vaccine hesitancy. Method: Primary care teams at the Atlanta Veterans Affairs Medical Center, who saw 28,941 patients during this period, were randomly assigned to receive either the modified clinical reminder (N = 44 teams) or the status quo (N = 40 teams). Results: Uptake of influenza and other adult vaccinations was 1.6 percentage points higher in the intervention group, which was not statistically significant (CI = [-1.3, 4.4], p = 0.28). The intervention had similar effects on Black and White patients and did not reduce the disparity in vaccination rates between these groups. Conclusion: Provider-focused interventions are a promising way to address vaccine hesitancy, but they may need to be more intensive than a modified clinical reminder to have appreciable effects on vaccination uptake

Integrated modeling to control vaporization-induced composition change during additive manufacturing of nickel-based superalloys

A critical issue in laser powder bed fusion (LPBF) additive manufacturing is the selective vaporization of alloying elements resulting in poor mechanical properties and corrosion resistance of parts. The process also alters the part’s chemical composition compared to the feedstock. Here we present a novel multi-physics modeling framework, integrating heat and fluid flow simulations, thermodynamic calculations, and evaporation modeling to estimate and control the composition change during LPBF of nickel-based superalloys. Experimental validation confirms the accuracy of our model. Moreover, we quantify the relative vulnerabilities of different nickel-based superalloys to composition change quantitatively and we examine the effect of remelting due to the layer-by-layer deposition during the LPBF process. Spatial variations in evaporative flux and compositions for each element were determined, providing valuable insights into the LPBF process and product attributes. The results of this study can be used to optimize the LPBF process parameters such as laser power, scanning speed, and powder layer thickness to ensure the production of high-quality components with desired chemical compositions

Expression profiling during arabidopsis/downy mildew interaction reveals a highly-expressed effector that attenuates responses to salicylic acid

Plants have evolved strong innate immunity mechanisms, but successful pathogens evade or suppress plant immunity via effectors delivered into the plant cell. Hyaloperonospora arabidopsidis (Hpa) causes downy mildew on Arabidopsis thaliana, and a genome sequence is available for isolate Emoy2. Here, we exploit the availability of genome sequences for Hpa and Arabidopsis to measure gene-expression changes in both Hpa and Arabidopsis simultaneously during infection. Using a high-throughput cDNA tag sequencing method, we reveal expression patterns of Hpa predicted effectors and Arabidopsis genes in compatible and incompatible interactions, and promoter elements associated with Hpa genes expressed during infection. By resequencing Hpa isolate Waco9, we found it evades Arabidopsis resistance gene RPP1 through deletion of the cognate recognized effector ATR1. Arabidopsis salicylic acid (SA)-responsive genes including PR1 were activated not only at early time points in the incompatible interaction but also at late time points in the compatible interaction. By histochemical analysis, we found that Hpa suppresses SA-inducible PR1 expression, specifically in the haustoriated cells into which host-translocated effectors are delivered, but not in non-haustoriated adjacent cells. Finally, we found a highly-expressed Hpa effector candidate that suppresses responsiveness to SA. As this approach can be easily applied to host-pathogen interactions for which both host and pathogen genome sequences are available, this work opens the door towards transcriptome studies in infection biology that should help unravel pathogen infection strategies and the mechanisms by which host defense responses are overcome

Small intestinal mucosal cells in piglets fed with probiotic and zinc: a qualitative and quantitative microanatomical study

Background: Probiotics and zinc are commonly used and beneficial in pig production. This work aimed to assess the effects of probiotic and zinc on the mucosal cells of the small intestine in respect to digestive capacity and immunity in pre- and post-weaned piglets.Materials and methods: Eighteen Large White Yorkshire piglets were divided equally into control and treatment groups. The piglets were maintained in standard management conditions and were weaned at 28 days of age. The treatment group of piglets fed a mixture of probiotics orally at 1.25 × 109 CFU/day and zinc at 2000 ppm/day from birth to 10 days of age. At three different age-groups viz. day 20 (pre-weaning) and, day 30 and day 60 (post-weaning), the animals were sacrificed. For histomorphology, the tissue samples were processed and stained with Mayer’s haematoxylin and eosin for routine study, combined periodic acid-Schiff-Alcian blue for mucopolysaccharides and Masson-Hamperl argentaffin technique for argentaffin cells. The stained slides were observed under the microscope. The samples were processed as per the standard procedure for scanning and transmission electron microscopy. The statistical analysis of the data using the appropriate statistical tests was also conducted.Results: The mucosal epithelium of villi and crypts were lined by enterocytes, goblet cells, argentaffin cells, microfold (M-cell) cells, tuft cells and intraepithelial lymphocytes. The multipotent stem cells were located at the crypt base. The length of the enterocyte microvilli was significantly longer (p < 0.05) in the treatment group of piglets. The number of different types of goblet cells and argentaffin cells was more in treated piglets irrespective of segments of intestine and age. The intraepithelial lymphocytes were located in apical, nuclear and basal positions in the lining epithelium of both villus tip and base with their significant increase in the treatment group of piglets. The transmission electron microscopy revealed the frequent occurrence of tuft cells in the lining mucosa of the small intestine in treated piglets.Conclusions: Dietary supplementation of probiotic and zinc induced the number of different mucosal cells of villi and crypts in the small intestine that might suggest the greater absorptive capacity of nutrients and effective immunity in critical pre and post-weaned piglets

In-situ and ex-situ EPS-corona formation on ZnO QDs mitigates their environmental toxicity in the freshwater microalgae Chlorella sp.

The current work seeks to understand how the interactions between ZnO QDs and extracellular polymeric substances (EPS) may vary based on the types of EPS (loosely and tightly bound) and modes of eco-corona formation (In-situ or ex-situ). In-situ eco-corona refers to formation of an EPS layer on the QDs during the interactions with the algae whereas the ex-situ condition refers to forming the layer before the interactions. ZnO QDs were added at 0.25, 0.5, and 1.0 mg/L concentrations for pristine, in-situ, and ex-situ corona treatments with the cells. Pristine ZnO QDs induced significant oxidative stress in algal cells, as evident from increased levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase activity. This decreased the photosynthetic efficiency and caused significant growth inhibition in algae. In contrast, both the in-situ and ex-situ corona treatments with loosely bound and tightly bound EPS reduced the oxidative stress, improved the photosynthetic efficiency, and diminished growth inhibition effects. This study asserts the importance of EPS in reducing the toxicity of ZnO QDs, while maintaining the fluorescence activity. This ensures the sustainable usage of the ZnO QDs without any harm to aquatic ecosystems.Environmental Biolog

Relationships Between Hepatic Steatosis and Frailty Differ by HIV Serostatus

BackgroundFrailty is associated with obesity-related comorbidities, but the relationship with nonalcoholic fatty liver disease (NAFLD) in people with HIV has been incompletely described. Our objective was to assess the associations between NAFLD and frailty.MethodsCross-sectional and longitudinal analysis of men in the Multicenter AIDS Cohort Study. NAFLD was defined as a liver/spleen ratio <1.0 on abdominal computed tomography scans; frailty was defined by the frailty phenotype as having 3 of the following: weakness, slowness, weight loss, exhaustion, and low physical activity.ResultsMen without (n = 200) and with HIV (n = 292) were included. NAFLD prevalence was 21% vs 16% and frailty 12% vs 17%, respectively. Among men with NAFLD, frailty was more prevalent in men without HIV (21% vs 11%). In multivariate analysis, NAFLD was significantly associated with frailty after controlling for significant variables. Men without HIV and NAFLD had 2.6 times higher probability [95% confidence interval (CI): 1.2- to 5.7] of frailty relative to men with neither HIV nor NAFLD. This association was not seen in men with HIV. The probability of frailty was higher among men without HIV with NAFLD (27% vs 10% in men without NAFLD) but lower among men with HIV with NAFLD (14% vs 19% in men without NAFLD). No significant relationships were found in longitudinal analyses.ConclusionsNAFLD was independently associated with frailty among men without HIV but not men with HIV, despite increased prevalence of frailty among men with HIV. The mechanisms of the muscle-liver-adipose tissue axis underlying NAFLD might differ by HIV serostatus