Top-Down Modulation of Category Specific Extrastriate Cortex in a Task-Switching Paradigm

During selective attention, visual stimuli compete for processing capacity. Increased activation is found in extrastriate regions that represent the attended stimulus. However, little research has been done looking at activation in extrastriate regions when attention is shifted between stimulus features. To address this, participants completed a switching task during fMRI scanning. They attended to the colour or motion of bivalent stimuli on different trials. It was hypothesized that attentional modulation would be seen in colour area V4 and motion area V5 and that this modulation would help explain switch costs, a term used to describe why we are slower and more error prone on switch trials. Attentional modulation was found in V4, with greater activity when colour was attended. No modulation was observed in V5. The level of competition between these regions did not differ across switch and repeat trials, suggesting that such competition does not explain switch costs

Dynamic Carbon Cycling in Muskegon Lake – a Great Lakes Estuary

Ecosystem metabolism is the coupling of carbon and oxygen through photosynthesis and respiration. Gross primary production (GPP) is the carbon fixation by photosynthesis, ecosystem respiration (R) is carbon remineralization by bacterial and plankton respiration, and net ecosystem production (NEP) is the balance. Metabolism estimates determine if ecosystem is a sink or source of carbon to the atmosphere. When a lake has a positive NEP, or the GPP:R ratio is greater than 1, it is considered autotrophic and less carbon is being lost to the atmosphere than taken in, whereas if NEP is negative (GPP:R-1d-1, respectively and the BOD 7-year average (±SD) of GPP, R, and NEP was 0.332 ± 0.226, -0.117 ± 0.069, and 0.214 ± 0.177 mg C L-1 d-1, respectively. The BUOY method consistently yielded higher rates for GPP and R and much lower rates of NEP compared to the BOD method. For the second objective, the spatial component of the study, GPP and R were significantly different across sites, but NEP was not significantly different. Our results suggest Muskegon Lake is annually a net sink of carbon. NEP may not vary much across the lake, but GPP and R and vary widely at each location. Our high frequency time-series data from multiple buoys demonstrates that freshwater lakes may display significant differences in metabolism across the ecosystem along with seasonally unequal rates of metabolism. Muskegon Lake NEP rates were comparable to NEP rates at upwelling zones in the ocean indicating more focus should be placed on inland waters when researching global carbon cycles

Cardiovascular and psychiatric morbidity in Obstructive Sleep Apnea (OSA) with Insomnia (sleep apnea plus) versus obstructive sleep apnea without insomnia: A case-control study from a nationally representative US sample

Purpose: To evaluate cardiovascular and psychiatric morbidity in patient visits with obstructive sleep apnea (OSA) with insomnia (OSA+Insomnia) versus OSA without insomnia (OSA-Insomnia) in a nationally representative US sample. Methods: A retrospective case-control study of epidemiologic databases (National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey) representing an estimated ± standard error (SE) 62,253,910±5,274,747 (unweighted count = 7234) patient visits with diagnosis of OSA from 1995-2010, was conducted. An estimated 3,994,104±791,386 (unweighted count = 658) were classified as OSA+Insomnia and an estimated 58,259,80664,849,800 (unweighted count = 6576) as OSA-Insomnia. Logistic regression analysis was carried out using OSA+Insomnia versus OSAInsomnia as the dependent variable, and age (\u3e50 years versus ≤50 years), sex, race (\u27White\u27 versus \u27non-White\u27), essential hypertension, heart failure, ischemic heart disease, cardiac dysrhythmia, cerebrovascular disease, diabetes, obesity, hyperlipidemia, depressive, anxiety, and adjustment disorders (includes PTSD), hypersomnia and all medications used as independent variables. All comorbidities were physician diagnosed using the ICD9-CM. Results: Among patient visits with OSA, an estimated 6.4%±0.9% also had insomnia. Logistic regression analysis revealed that the OSA +Insomnia group was significantly more likely to have essential hypertension (all ICD9-CM codes 401) (OR = 1.83, 95% CI 1.27-2.65) and provisionally more likely to have cerebrovascular disease (ICD9-CM codes 430-438) (OR = 6.58, 95% CI 1.66-26.08). The significant OR for cerebrovascular disease was considered provisional because the unweighted count was \u3c30. Conclusions: In a nationally representative sample, OSA+Insomnia was associated significantly more frequently with essential hypertension than OSA-Insomnia, a finding that has not been previously reported. In contrast to studies that have considered patient self-reports of psychological morbidity, the absence of a significant association with psychiatric disorders in our study may be indicative of the fact that we considered only physician-rated psychiatric syndromes meeting ICD9-CM criteria. Our findings among the OSA+ Insomnia group are therefore most likely conservative. © 2014 Gupta, Knapp

Exploring the relationship between working memory capacity and task switching : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Psychology at Massey University, Manawatū, New Zealand

Tests of task switching and working memory capacity are both thought to assess executive attentional control. Given that they are purported to measure the same underlying cognitive construct, one would expect a relationship between performance on these tasks. However, preliminary research has largely failed to find such an association. This thesis explored the association between task switching and working memory capacity to determine why previous research has failed to find this expected relationship. Experiment 1 examined this relationship across three commonly used task switching paradigms which differed in the amount of environmental support available to participants as they completed the task. Experiment 2 explored the role of task difficulty on the switching paradigm because working memory capacity and cognitive control are most related under particularly taxing conditions. Both of these Experiments failed to find a clear relationship between task switching and working memory capacity. These findings replicated much of the previous research in this area and suggested that task difficulty and paradigm choice could not explain the failure of previous research to find a relationship between these two constructs. Experiment 3 explored the role of cue switch costs. The task switching paradigm confounds cue switching and task switching, and it has been argued that switch costs may largely be explained by the cost of the cue switching. If this is the case, and cue switch costs do not index attentional control, then it is not surprising that previous research has failed to find a relationship between task switching and working memory capacity. Experiment 3 found evidence of cue switch costs, but ‘true’ task switch costs remained. After the confounding effect of cue switching was controlled for, the expected negative linear relationship between working memory capacity and task switching was found. Participants with higher working memory capacity had smaller switch costs, indicative of better performance. The results of this thesis point to the importance of making careful experimental design decisions when using the task switching paradigm. This is particularly important when the goal of such research is to index attentional control, especially in the context of individual differences research

Creating Communities of Practice Focused on Writing Instruction

This article will share the literacy coaches\u27 experiences of engaging in a literacy community of practice (Lave and Wenger, 1991). It will share the writing cohort process, topics discussed, books read, professional developments enacted, and materials generated during their time of study. The writing cohort enacted meaning and identity to the community to create learning and growth. Effective communities of practice promote innovation, spread knowledge, develop social capital, and facilitate existing knowledge (Lave and Wenger, 1991). These communities learn and grow through requesting information, problem solving, and reusing available assets. After a thorough description of the writing community and its practices, we offer insights into how others can create, maintain, and foster similar communities within their schools and school districts. This examination of writing practices profoundly impacted students as well as the cohort participants

What, how, when and who of trial results summaries for trial participants : Stakeholder informed guidance from the RECAP project.

Funding RECAP was funded by the Academy of Medical Sciences (SBF002\1014) and KG was funded by a Medical Research Council Strategic Skills Methodology Fellowship (MR/L01193X/1). The Health Services Research Unit, Institute of Applied Health Sciences (University of Aberdeen), is core funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorates (CZU/3/3).Peer reviewedPublisher PD

Implications of between-isolate variation for climate change impact modelling of Haemonchus contortus populations

The impact of climate change on parasites and parasitic diseases is a growing concern and numerous empirical and mechanistic models have been developed to predict climate-driven spatial and temporal changes in the distribution of parasites and disease risk. Variation in parasite phenotype and life-history traits between isolates could undermine the application of such models at broad spatial scales. Seasonal variation in the transmission of the haematophagous gastrointestinal nematode Haemonchus contortus, one of the most pathogenic helminth species infecting sheep and goats worldwide, is primarily determined by the impact of environmental conditions on the free-living stages. To evaluate variability in the development success and mortality of the free-living stages of H. contortus and the impact of this variability on future climate impact modelling, three isolates of diverse origin were cultured at a range of temperatures between 15°C and 37°C to determine their development success compared with simulations using the GLOWORM-FL H. contortus model. No significant difference was observed in the developmental success of the three isolates of H. contortus tested, nor between isolates and model simulations. However, development success of all isolates at 37°C was lower than predicted by the model, suggesting the potential for overestimation of transmission risk at higher temperatures, such as those predicted under some scenarios of climate change. Recommendations are made for future climate impact modelling of gastrointestinal nematodes

Patient information leaflets (PILs) for UK randomised controlled trials : a feasibility study exploring whether they contain information to support decision making about trial participation

Peer reviewedPublisher PD

Chronicles of hypoxia: Time-series buoy observations reveal annually recurring seasonal basin-wide hypoxia in Muskegon Lake – A Great Lakes estuary

We chronicled the seasonally recurring hypolimnetic hypoxia in Muskegon Lake – a Great Lakes estuary over 3 years, and examined its causes and consequences. Muskegon Lake is a mesotrophic drowned river mouth that drains Michigan\u27s 2nd largest watershed into Lake Michigan. A buoy observatory tracked ecosystem changes in the Muskegon Lake Area of Concern (AOC), gathering vital time-series data on the lake\u27s water quality from early summer through late fall from 2011 to 2013 (www.gvsu.edu/buoy). Observatory-based measurements of dissolved oxygen (DO) tracked the gradual development, intensification and breakdown of hypoxia (mild hypoxia b4 mg DO/L, and severe hypoxia b2 mg DO/L) below the ~6 m thermocline in the lake, occurring in synchrony with changes in temperature and phytoplankton biomass in the water column during July–October. Time-series data suggest that proximal causes of the observed seasonal hypolimnetic DO dynamics are stratified summer water-column, reduced wind-driven mixing, longer summer residence time, episodic intrusions of cold DO-rich nearshore Lake Michigan water, nutrient run off from watershed, and phytoplankton blooms. Additional basin-wide water-column profiling (2011–2012) and ship-based seasonal surveys (2003–2013) confirmed that bottom water hypoxia is an annually recurring lake-wide condition. Volumetric hypolimnetic oxygen demand was high (0.07–0.15 mg DO/Liter/day) and comparable to other temperate eutrophic lakes. Over 3 years of intense monitoring, ~9–24% of Muskegon Lake\u27s volume experienced hypoxia for ~29–85 days/year – with the potential for hypolimnetic habitat degradation and sediment phosphorus release leading to further eutrophication. Thus, time-series observatories can provide penetrating insights into the inner workings of ecosystems and their external drivers

First Light LBT AO Images of HR 8799 bcde at 1.65 and 3.3 Microns: New Discrepancies between Young Planets and Old Brown Dwarfs

As the only directly imaged multiple planet system, HR 8799 provides a unique opportunity to study the physical properties of several planets in parallel. In this paper, we image all four of the HR 8799 planets at H-band and 3.3 microns with the new LBT adaptive optics system, PISCES, and LBTI/LMIRCam. Our images offer an unprecedented view of the system, allowing us to obtain H and 3.3$ micron photometry of the innermost planet (for the first time) and put strong upper-limits on the presence of a hypothetical fifth companion. We find that all four planets are unexpectedly bright at 3.3 microns compared to the equilibrium chemistry models used for field brown dwarfs, which predict that planets should be faint at 3.3 microns due to CH4 opacity. We attempt to model the planets with thick-cloudy, non-equilibrium chemistry atmospheres, but find that removing CH4 to fit the 3.3 micron photometry increases the predicted L' (3.8 microns) flux enough that it is inconsistent with observations. In an effort to fit the SED of the HR 8799 planets, we construct mixtures of cloudy atmospheres, which are intended to represent planets covered by clouds of varying opacity. In this scenario, regions with low opacity look hot and bright, while regions with high opacity look faint, similar to the patchy cloud structures on Jupiter and L/T transition brown-dwarfs. Our mixed cloud models reproduce all of the available data, but self-consistent models are still necessary to demonstrate their viability.Comment: Accepted to Ap