22 research outputs found
Biotic Interactions Shape the Ecological Distributions of Staphylococcus Species.
Many metagenomic sequencing studies have observed the presence of closely related bacterial species or genotypes in the same microbiome. Previous attempts to explain these patterns of microdiversity have focused on the abiotic environment, but few have considered how biotic interactions could drive patterns of microbiome diversity. We dissected the patterns, processes, and mechanisms shaping the ecological distributions of three closely related Staphylococcus species in cheese rind biofilms. Paradoxically, the most abundant species (S. equorum) is the slowest colonizer and weakest competitor based on growth and competition assays in the laboratory. Through in vitro community reconstructions, we determined that biotic interactions with neighboring fungi help resolve this paradox. Species-specific stimulation of the poor competitor by fungi of the genus Scopulariopsis allows S. equorum to dominate communities in vitro as it does in situ Results of comparative genomic and transcriptomic experiments indicate that iron utilization pathways, including a homolog of the S. aureus staphyloferrin B siderophore operon pathway, are potential molecular mechanisms underlying Staphylococcus-Scopulariopsis interactions. Our integrated approach demonstrates that fungi can structure the ecological distributions of closely related bacterial species, and the data highlight the importance of bacterium-fungus interactions in attempts to design and manipulate microbiomes.ImportanceDecades of culture-based studies and more recent metagenomic studies have demonstrated that bacterial species in agriculture, medicine, industry, and nature are unevenly distributed across time and space. The ecological processes and molecular mechanisms that shape these distributions are not well understood because it is challenging to connect in situ patterns of diversity with mechanistic in vitro studies in the laboratory. Using tractable cheese rind biofilms and a focus on coagulase-negative staphylococcus (CNS) species, we demonstrate that fungi can mediate the ecological distributions of closely related bacterial species. One of the Staphylococcus species studied, S. saprophyticus, is a common cause of urinary tract infections. By identifying processes that control the abundance of undesirable CNS species, cheese producers will have more precise control on the safety and quality of their products. More generally, Staphylococcus species frequently co-occur with fungi in mammalian microbiomes, and similar bacterium-fungus interactions may structure bacterial diversity in these systems
PsychoPy2: experiments in behavior made easy
PsychoPy is an application for the creation of experiments in behavioral science (psychology, neuroscience, linguistics, etc.) with precise spatial control and timing of stimuli. It now provides a choice of interface; users can write scripts Python if they choose, while those that prefer to construct experiments graphically can use the new Builder interface. Here we describe the features that have been added over the last 10 years of its development. The most notable addition has been that Builder interface, allowing users to create studies with minimal or no programming, while also allowing the insertion of Python code for maximal flexibility. We also present some of the other new features, including further stimulus options, asynchronous timestamped hardware polling, and better support for open science and reproducibility. Tens of thousands of users now launch PsychoPy every month and more than 90 people have contributed to the code. We discuss the current state of the project, as well as plans for the future
Low HDL Cholesterol is Associated with Lower Gray Matter Volume in Cognitively Healthy Adults
Dyslipidemia is common in adults and contributes to high rates of cardiovascular disease and may be linked to subsequent neurodegenerative and neurovascular diseases. This study examined whether lower brain volumes and cognition associated with dyslipidemia could be observed in cognitively healthy adults, and whether apolipoprotein E (APOE) genotype or family history of Alzheimer's disease (FHAD) alters this effect. T1-weighted magnetic resonance imaging was used to examine regional brain gray matter (GM) and white matter (WM) in 183 individuals (58.4 ± 8.0 years) using voxel-based morphometry. A non-parametric multiple linear regression model was used to assess the effect of high-density lipoprotein (HDL) and non-HDL cholesterol, APOE, and FHAD on regional GM and WM volume. A post hoc analysis was used to assess whether any significant correlations found within the volumetric analysis had an effect on cognition. HDL was positively correlated with GM volume in the bilateral temporal poles, middle temporal gyri, temporo-occipital gyri, and left superior temporal gyrus and parahippocampal region. This effect was independent of APOE and FHAD. A significant association between HDL and the Brief Visuospatial Memory Test was found. Additionally, GM volume within the right middle temporal gyrus, the region most affected by HDL, was significantly associated with the Controlled Oral Word Association Test and the Center for Epidemiological Studies Depression Scale. These findings suggest that adults with decreased levels of HDL cholesterol may be experiencing cognitive changes and GM reductions in regions associated with neurodegenerative disease and therefore, may be at greater risk for future cognitive decline
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Development of corticostriatal connectivity constrains goal-directed behavior during adolescence
When pursuing high-value goals, mature individuals typically titrate cognitive performance according to environmental demands. However, it remains unclear whether adolescents similarly integrate value-based goals to selectively enhance goal-directed behavior. We used a value-contingent cognitive control task during fMRI to assess how stakes—the value of a prospective outcome—modulate flexible goal-directed behavior and underlying neurocognitive processes. Here we demonstrate that while adults enhance performance during high stakes, adolescents perform similarly during low and high stakes conditions. The developmental emergence of value-contingent performance is mediated by connectivity between the striatum and prefrontal cortex; this connectivity selectively increases during high stakes and with age. These findings suggest that adolescents may not benefit from high stakes to the same degree adults do—a behavioral profile that may be constrained by ongoing maturation of corticostriatal connectivity. We propose that late development of corticostriatal connectivity sets the stage for optimal goal-directed behavior
Strain-Level Diversity Impacts Cheese Rind Microbiome Assembly and Function
ABSTRACT Diversification can generate genomic and phenotypic strain-level diversity within microbial species. This microdiversity is widely recognized in populations, but the community-level consequences of microbial strain-level diversity are poorly characterized. Using the cheese rind model system, we tested whether strain diversity across microbiomes from distinct geographic regions impacts assembly dynamics and functional outputs. We first isolated the same three bacterial species (Staphylococcus equorum, Brevibacterium auranticum, and Brachybacterium alimentarium) from nine cheeses produced in different regions of the United States and Europe to construct nine synthetic microbial communities consisting of distinct strains of the same three bacterial species. Comparative genomics identified distinct phylogenetic clusters and significant variation in genome content across the nine synthetic communities. When we assembled each synthetic community with initially identical compositions, community structure diverged over time, resulting in communities with different dominant taxa. The taxonomically identical communities showed differing responses to abiotic (high salt) and biotic (the fungus Penicillium) perturbations, with some communities showing no response and others substantially shifting in composition. Functional differences were also observed across the nine communities, with significant variation in pigment production (light yellow to orange) and in composition of volatile organic compound profiles emitted from the rinds (nutty to sulfury). IMPORTANCE Our work demonstrated that the specific microbial strains used to construct a microbiome could impact the species composition, perturbation responses, and functional outputs of that system. These findings suggest that 16S rRNA gene taxonomic profiles alone may have limited potential to predict the dynamics of microbial communities because they usually do not capture strain-level diversity. Observations from our synthetic communities also suggest that strain-level diversity has the potential to drive variability in the aesthetics and quality of surface-ripened cheeses
Utveckling av web-baserad hantering avhandböcker och utrustningslager för operations- och anestesikliniken viduniversitetssjukhuset i Linköping
Denna rapporten behandlar hur ett webbaserat system för hantering av handböcker och utrustningslager, for operation- och anestesikliniken vid universitetssjukhuset i Linköping, kan realiseras. Den behandlar också hur man kan arbeta i grupp där kunskapsnivan varierar kraftigt mellan gruppmedlemmar. För att skapa systemet så togs en kravspecikation fram av projektgruppen tillsammans med kunden genom studiebesök och diskussion. Efter det skapades en arkitekturbeskrivning. Denna låg sedan som grund till utvecklingsarbetet. Resultatet blev ett system där alla plocklistor i handböckerna kopplades ihop med artiklar i artikeldatabasen. Pa detta sätt uppdateras lagerplats i alla handböcker då de ändras i kartoteket. Flera kan också plocka på samma lista då det uppdateras kontinuerligt mellan olika enheter. Det finns ocksåa en översiktsvy som visar hur långt operationsförberedelserna har kommit. Back-end på systemet gjordes med hjälp av CMS-plattformen KeystoneJS och front-end med hjälp av Handlebars, jQuery och less. Realtidsuppdateringen gjordes med hjälp av Socket.IO. Resultatet var lyckat och blev mycket uppskattat av kunden. Under utvecklingstiden sa undersöktes det hur ett projekt kan utvecklas effektivt då medlemmar i projektgruppen har olika nivåer av kunskap. Resultatet av denna undersökning var att dela in arbetet i roller och att arbeta nära varandra för att underlätta kommunikation och få snabba svar på frågor
Physical effort exertion for peer feedback reveals evolving social motivations from adolescence to young adulthood
Peer relationships and social belonging are particularly important during adolescence. Using a willingness-to-work paradigm to quantify incentive motivation, we examined whether evaluative information holds unique value for adolescents. Participants (N=102; 12–23y) rated peers, predicted how peers rated them, and exerted physical effort to view each peer’s rating. We measured grip force, speed, and opt-out behavior to examine the motivational value of peer feedback relative to a control condition of money, and how peer desirability and participants’ expectations modulated motivated effort across age. Overall, when compared to adolescents, adults were relatively less motivated for feedback compared against money. While adults exerted less force and speed for feedback when expecting rejection, adolescents exerted greater force and speed when they expected to be more strongly liked or disliked. Findings suggest the transition into adulthood is accompanied by a self-protective focus, whereas adolescents are motivated to consume highly informative feedback, even if negative
How adolescents and adults translate motivational value to action: Age-related shifts in strategic physical effort exertion for monetary rewards
Adults titrate the degree of physical effort they are willing to expend according to the magnitude of reward they expect to obtain, a process guided by incentive motivation. However, it remains unclear whether adolescents, who are undergoing normative developmental changes in cognitive and reward processing, translate incentive motivation into action in a way that is similarly tuned to reward value and economical in effort utilization. The present study adapted a classic physical effort paradigm to quantify age-related changes in motivation-based and strategic markers of effort exertion for monetary rewards from adolescence to early adulthood. One hundred and three participants aged 12-23 years completed a task that involved exerting low or high amounts of physical effort, in the form of a hand grip, to earn low or high amounts of money. Adolescents and young adults exhibited highly similar incentive-modulated effort for reward according to measures of peak grip force and speed, suggesting that motivation for monetary reward is consistent across age. However, young adults expended energy more economically and strategically: whereas adolescents were prone to exert excess physical effort beyond what was required to earn reward, young adults were more likely to strategically prepare before each grip phase and conserve energy by opting out of low reward trials. This work extends theoretical models of development of incentive-driven behavior by demonstrating that layered on similarity in motivational value for monetary reward, there are important differences in the way behavior is flexibly adjusted in the presence of reward from adolescence to young adulthood