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Lesions impairing regular versus irregular past tense production
We investigated selective impairments in the production of regular and irregular past tense by examining language performance and lesion sites in a sample of twelve stroke patients. A disadvantage in regular past tense production was observed in six patients when phonological complexity was greater for regular than irregular verbs, and in three patients when phonological complexity was closely matched across regularity. These deficits were not consistently related to grammatical difficulties or phonological errors but were consistently related to lesion site. All six patients with a regular past tense disadvantage had damage to the left ventral pars opercularis (in the inferior frontal cortex), an area associated with articulatory sequencing in prior functional imaging studies. In addition, those that maintained a disadvantage for regular verbs when phonological complexity was controlled had damage to the left ventral supramarginal gyrus (in the inferior parietal lobe), an area associated with phonological short-term memory. When these frontal and parietal regions were spared in patients who had damage to subcortical (n = 2) or posterior temporo-parietal regions (n = 3), past tense production was relatively unimpaired for both regular and irregular forms. The remaining (12th) patient was impaired in producing regular past tense but was significantly less accurate when producing irregular past tense. This patient had frontal, parietal, subcortical and posterior temporo-parietal damage, but was distinguished from the other patients by damage to the left anterior temporal cortex, an area associated with semantic processing. We consider how our lesion site and behavioural observations have implications for theoretical accounts of past tense production
Does Inflation Provide Natural Initial Conditions for the Universe?
If our universe underwent inflation, its entropy during the inflationary
phase was substantially lower than it is today. Because a low-entropy state is
less likely to be chosen randomly than a high-entropy one, inflation is
unlikely to arise through randomly-chosen initial conditions. To resolve this
puzzle, we examine the notion of a natural state for the universe, and argue
that it is a nearly-empty spacetime. If empty space has a small vacuum energy,
however, inflation can begin spontaneously in this background. This scenario
explains why a universe like ours is likely to have begun via a period of
inflation, and also provides an origin for the cosmological arrow of time.Comment: Submitted to Gravity Research Foundation Essay Competition; based on
hep-th/041027
Insect Resistance Management for Bt Corn : An Assessment of Community Refuge Schemes
Because of Bt corn's efficacy in controlling European corn borer, farmers are required to implement an insect resistance management (IRM) program that constrains each farmer to plant no more than 80% of the farm s corn to Bt varieties. This refuge must be planted within a half-mile of Bt corn and must be contained on the same farm. Community refuge schemes, those which allow the refuge area to be planted on a neighboring farm, have been proposed. In this analysis, we estimate the potential gains to all farms in the community in two representative locations: Pennsylvania and Iowa. The results of a decision analysis model show that the potential gains are very small; the greatest is only 0.33 per acre). This gain would almost certainly be offset by the costs of developing such a community.Includes bibliographical reference
What are the ‘active ingredients’ of interventions targeting the public's engagement with antimicrobial resistance and how might they work?
Objectives. Changing public awareness of antimicrobial resistance (AMR) represents a global public health priority. A systematic review of interventions that targeted public AMR awareness and associated behaviour was previously conducted. Here, we focus on identifying the active content of these interventions and explore potential mechanisms of action.
Methods. The project took a novel approach to intervention mapping utilizing the following steps: (1) an exploration of explicit and tacit theory and theoretical constructs within the interventions using the Theoretical Domains Framework (TDFv2), (2) retrospective coding of behaviour change techniques (BCTs) using the BCT Taxonomy v1, and (3) an investigation of coherent links between the TDF domains and BCTs across the interventions.
Results. Of 20 studies included, only four reported an explicit theoretical basis to their intervention. However, TDF analysis revealed that nine of the 14 TDF domains were utilized, most commonly ‘Knowledge’ and ‘Environmental context and resources’. The BCT analysis showed that all interventions contained at least one BCT, and 14 of 93 (15%) BCTs were coded, most commonly ‘Information about health consequences’, ‘Credible source’, and ‘Instruction on how to perform the behaviour’.
Conclusions. We identified nine relevant TDF domains and 14 BCTs used in these interventions. Only 15% of BCTs have been applied in AMR interventions thus providing a clear opportunity for the development of novel interventions in this context. This methodological approach provides a useful way of retrospectively mapping theoretical constructs and BCTs when reviewing studies that provide limited information on theory and intervention content
Nutritional Intervention Restores Muscle but Not Kidney Phenotypes in Adult Calcineurin Aα Null Mice
Mice lacking the α isoform of the catalytic subunit of calcineurin (CnAα) were first reported in 1996 and have been an important model to understand the role of calcineurin in the brain, immune system, bones, muscle, and kidney. Research using the mice has been limited, however, by failure to thrive and early lethality of most null pups. Work in our laboratory led to the rescue of CnAα-/- mice by supplemental feeding to compensate for a defect in salivary enzyme secretion. The data revealed that, without intervention, knockout mice suffer from severe caloric restriction. Since nutritional deprivation is known to significantly alter development, it is imperative that previous conclusions based on CnAα-/- mice are revisited to determine which aspects of the phenotype were attributable to caloric restriction versus a direct role for CnAα. In this study, we find that defects in renal development and function persist in adult CnAα-/- mice including a significant decrease in glomerular filtration rate and an increase in blood urea nitrogen levels. These data indicate that impaired renal development we previously reported was not due to caloric restriction but rather a specific role for CnAα in renal development and function. In contrast, we find that rather than being hypoglycemic, rescued mice are mildly hyperglycemic and insulin resistant. Examination of muscle fiber types shows that previously reported reductions in type I muscle fibers are no longer evident in rescued null mice. Rather, loss of CnAα likely alters insulin response due to a reduction in insulin receptor substrate-2 (IRS2) expression and signaling in muscle. This study illustrates the importance of re-examining the phenotypes of CnAα-/- mice and the advances that are now possible with the use of adult, rescued knockout animals
Landing Gear Components Noise Study - PIV and Hot-Wire Measurements
PIV and hot-wire measurements of the wake flow from rods and bars are presented. The test models include rods of different diameters and cross sections and a rod juxtaposed to a plate. The latter is representative of the latch door that is attached to an aircraft landing gear when the gear is deployed, while the single and multiple rod configurations tested are representative of some of the various struts and cables configuration present on an aircraft landing gear. The test set up is described and the flow measurements are presented. The effect of model surface treatment and freestream turbulence on the spanwise coherence of the vortex shedding is studied for several rod and bar configurations
Brown Meets Green: Light and Nutrients Alter Detritivore Assimilation of Microbial Nutrients From Leaf Litter
In aquatic detrital-based food webs, research suggests that autotroph-heterotroph microbial interactions exert bottom-up controls on energy and nutrient transfer. To address this emerging topic, we investigated microbial responses to nutrient and light treatments during Liriodendron tulipifera litter decomposition and fed litter to the caddisfly larvae Pycnopsyche sp. We measured litter-associated algal, fungal, and bacterial biomass and production. Microbes were also labeled with 14C and 33P to trace distinct microbial carbon (C) and phosphorus (P) supporting Pycnopsyche assimilation and incorporation (growth). Litter-associated algal and fungal production rates additively increased with higher nutrient and light availability. Incorporation of microbial P did not differ across diets, except for higher incorporation efficiency of slower-turnover P on low-nutrient, shaded litter. On average, Pycnopsyche assimilated fungal C more efficiently than bacterial or algal C, and Pycnopsyche incorporated bacterial C more efficiently than algal or fungal C. Due to high litter fungal biomass, fungi supported 89.6–93.1% of Pycnopsyche C growth, compared to 0.2% to 3.6% supported by bacteria or algae. Overall, Pycnopsyche incorporated the most C in high nutrient and shaded litter. Our findings affirm others\u27 regarding autotroph-heterotroph microbial interactions and extend into the trophic transfer of microbial energy and nutrients through detrital food webs
Consequences of warming and acidification for the temperate articulated coralline alga, Calliarthron tuberculosum (Florideophyceae, Rhodophyta)
Global climate changes, such as warming and ocean acidification (OA), are likely to negatively impact calcifying marine taxa. Abundant and ecologically important coralline algae may be particularly susceptible to OA; however, multi-stressor studies and those on articulated morphotypes are lacking. Here, we use field observations and laboratory experiments to elucidate the impacts of warming and acidification on growth, calcification, mineralogy, and photophysiology of the temperate articulated coralline alga, Calliarthron tuberculosum. We conducted a 4-week fully factorial mesocosm experiment exposing individuals from a southern CA kelp forest to current and future temperature and pH/pCO2 conditions (+2°C, −0.5 pH units). Calcification was reduced under warming (70%) and further reduced by high pCO2 or high pCO2 x warming (~150%). Growth (change in linear extension and surface area) was reduced by warming (40% and 50%, respectively), high pCO2 (20% and 40%, respectively), and high pCO2 x warming (50% and 75%, respectively). The maximum photosynthetic rate (Pmax) increased by 100% under high pCO2 conditions, but we did not detect an effect of pCO2 or warming on photosynthetic efficiency (α). We also did not detect the effect of warming or pCO2 on mineralogy. However, variation in Mg incorporation in cell walls of different cell types (i.e., higher mol % Mg in cortical vs. medullary) was documented for the first time in this species. These results support findings from a growing body of literature suggesting that coralline algae are often more negatively impacted by warming than OA, with the potential for antagonistic effects when factors are combined
Changing Beliefs about Trauma: A Qualitative Study of Cognitive Processing Therapy
Background: Controlled qualitative methods complement quantitative treatment outcome research and enable a more thorough understanding of the effects of therapy and the suspected mechanisms of action. Aims: Thematic analyses were used to examine outcomes of cognitive processing therapy (CPT) for posttraumatic stress disorder (PTSD) in a randomized controlled trial of individuals diagnosed with military-related PTSD ( n = 15). Method: After sessions 1 and 11, participants wrote “impact statements” describing their appraisals of their trauma and beliefs potentially impacted by traumatic events. Trained raters coded each of these statements using a thematic coding scheme. Results: An analysis of thematic coding revealed positive changes over the course of therapy in participants’ perspective on their trauma and their future, supporting the purported mechanisms of CPT. Conclusion: Implications of this research for theory and clinical practice are discussed
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