Negotiating the information-rich sensory world often requires the concurrent management of multiple tasks. Despite this requirement, humans are thought to be poor at multitasking because of the ...processing limitations of frontoparietal and subcortical (FP-SC) brain regions. Although training is known to improve multitasking performance, it is unknown how the FP-SC system functionally changes to support improved multitasking. To address this question, we characterized the FP-SC changes that predict training outcomes using an individual differences approach. Participants (n= 100) performed single and multiple tasks in pre- and posttraining magnetic resonance imaging (fMRI) sessions interspersed by either a multitasking or an active-control training regimen. Multivoxel pattern analyses (MVPA) revealed that training induced multitasking improvements were predicted by divergence in the FP-SC blood oxygen level-dependent (BOLD) response patterns to the trained tasks. Importantly, this finding was only observed for participants who completed training on the component (single) tasks and their combination (multitask) and not for the control group. Therefore, the FP-SC system supports multitasking behavior by segregating constituent task representations.
Redox processes are at the heart of numerous functions in chemistry and biology, from long-range electron transfer in photosynthesis and respiration to catalysis in industrial and fuel cell research. ...These functions are accomplished in nature by only a limited number of redox-active agents. A long-standing issue in these fields is how redox potentials are fine-tuned over a broad range with little change to the redox-active site or electron-transfer properties. Resolving this issue will not only advance our fundamental understanding of the roles of long-range, non-covalent interactions in redox processes, but also allow for design of redox-active proteins having tailor-made redox potentials for applications such as artificial photosynthetic centres or fuel cell catalysts for energy conversion. Here we show that two important secondary coordination sphere interactions, hydrophobicity and hydrogen-bonding, are capable of tuning the reduction potential of the cupredoxin azurin over a 700 mV range, surpassing the highest and lowest reduction potentials reported for any mononuclear cupredoxin, without perturbing the metal binding site beyond what is typical for the cupredoxin family of proteins. We also demonstrate that the effects of individual structural features are additive and that redox potential tuning of azurin is now predictable across the full range of cupredoxin potentials.
Abstract
Leptin exerts its effects on energy balance by inhibiting food intake and increasing energy expenditure via leptin receptors in the hypothalamus. While LepR neurons in the arcuate nucleus of ...the hypothalamus, the primary target of leptin, have been extensively studied, LepR neurons in other hypothalamic nuclei remain understudied. LepR neurons in the lateral hypothalamus contribute to leptin's effects on food intake and reward, but due to the low abundance of this population it has been difficult to study their molecular profile and responses to energy deficit. We here explore the transcriptome of LepR neurons in the LH and their response to energy deficit. Male LepR-Cre mice were injected in the LH with an AAV carrying Cre-dependent L10:GFP. Few weeks later the hypothalami from fed and food-restricted (24-h) mice were dissected and the TRAP protocol was performed, for the isolation of translating mRNAs from LepR cells in the LH, followed by RNA sequencing. After mapping and normalization, differential expression analysis was performed with DESeq2. We confirm that the isolated mRNA is enriched in LepR transcripts and other known neuropeptide markers of LepR
LH
neurons, of which we investigate the localization patterns in the LH. We identified novel markers of LepR
LH
neurons with association to energy balance and metabolic disease, such as
Acvr1c
,
Npy1r, Itgb1
, and genes that are differentially regulated by food deprivation, such as
Fam46a
and
Rrad
. Our dataset provides a reliable and extensive resource of the molecular makeup of LH LepR neurons and their response to food deprivation.
Current prominent models of identity face challenges in bridging across divergent perspectives and apparent dichotomies such as personal or social-collective, conscious or unconscious, and epigenetic ...or discursive-relational, and affording pursuit of research questions that allows integrative answers. This article presents a coherent theoretical perspective on the integrative nature of identity and its developmental mechanisms. Adopting the contextual social role as a primary unit of analysis, the Dynamic Systems Model of Role Identity (DSMRI) conceptualizes role identity as a Complex Dynamic System (CDS) anchored in action that comprises the actor's ontological and epistemological beliefs, purpose and goals, self-perceptions and self-definitions, and perceived action possibilities in the role. These system components are conceptualized as interdependent, and identity development is viewed as emergent, continuous, nonlinear, contextualized, and given to influences from within and without the system. The role identity itself constitutes an element within a multilevel hierarchy, which at the unit of analysis of the individual reflects a CDS of the multiple roles that constitute the person's psychosocial identity. Identity development involves the formation and restructuring of relations within and among role identities through intra- and interpersonal processes that are mediated by sociocognitive and cultural means, and framed by the context as well as by implicit dispositions. The DSMRI provides a framework to conceptualize and investigate the nature of the identity system, its development, and the relationship between identity development and psychological functioning at different units of-analysis, across different developmental stages and contexts, and using quantitative and qualitative methodologies.
With the recent global surge of SARS-CoV-2 Delta variant, there continues to be high demand for COVID-19 diagnostic testing. Abbott ID NOW is a rapid, CLIA-waived, COVID-19 diagnostic test ideally ...suited for use in urgent care settings or where access to diagnostic testing is limited. In this study we describe the results of rigorous validation of ID NOW and post-implementation study of POC test utilization patterns within community hospitals and clinics. Performance of ID NOW was validated by comparison of the results from 207 consecutive, paired, specimens tested on the ID NOW and on the m2000/Alinity m platforms. Once validated, ID NOW devices were placed for clinical use at four regional hospitals and clinics.
We found that the ID NOW and m2000/Alinity m positive and negative percent agreement were 94.5% (95% CI, 85.1% to 98.1%) and 99.3% (95% CI, 96.4% to 99.9%), respectively. As of August 2021, a total of 2,301 tests were performed by ID NOW at individual regional network sites. The population tested consisted of 55.5% White and 42.9% Black patients, with Black patients presenting predominantly in the hospitals, while White patients were more evenly distributed between hospital and clinic sites. Disease prevalence observed among patients tested by ID NOW (12.3%) was aligned with overall prevalence seen at regional sites (11.3%).
In summary, the ID NOW test can provide rapid and accurate results in a variety of near-to-patient and POC settings. If used correctly, it could serve as a valuable diagnostic tool to enable equal access to care and improve healthcare delivery within large health network systems.
Area of muscle, fat, and bone is often measured in thigh CT scans when tissue composition is a key outcome. SliceOmatic software is commonly referenced for such analysis but published methods may be ...insufficient for new users. Thus, a quick start guide to calculating thigh composition using SliceOmatic has been developed.
CT images of the thigh were collected from older (69 ± 4 yrs, N = 24) adults before and after 12-weeks of resistance training. SliceOmatic was used to segment images into seven density regions encompassing fat, muscle, and bone from -190 to +2000 Hounsfield Units HU. The relative contributions to thigh area and the effects of tissue density overlap for skin and marrow with muscle and fat were determined.
The largest contributors to the thigh were normal fat (-190 to -30 HU, 29.1 ± 7.4%) and muscle (35 to 100 HU, 48.9 ± 8.2%) while the smallest were high density (101 to 150 HU, 0.79 ± 0.50%) and very high density muscle (151 to 200 HU, 0.07 ± 0.02%). Training significantly (P<0.05) increased area for muscle in the very low (-29 to -1 HU, 5.5 ± 7.9%), low (0 to 34 HU, 9.6 ± 16.8%), normal (35 to 100 HU, 4.2 ± 7.9%), and high (100 to 150 HU, 70.9 ± 80.6%) density ranges for muscle. Normal fat, very high density muscle and bone did not change (P>0.05). Contributions to area were altered by ~1% or less and the results of training were not affected by accounting for skin and marrow.
When using SliceOmatic to calculate thigh composition, accounting for skin and marrow may not be necessary. We recommend defining muscle as -29 to +200 HU but that smaller ranges (e.g. low density muscle, 0 to 34 HU) can easily be examined for relationships with the health condition and intervention of interest.
Clinicaltrials.gov NCT02261961.
The abilities to select appropriate responses and suppress unwanted actions are key executive functions that enable flexible and goal-directed behavior. However, to date it has been unclear whether ...these two cognitive operations tap a common action control resource or reflect two distinct processes. In the present study, we used an individual differences approach to examine the underlying relationships across seven paradigms that varied in their response selection and response inhibition requirements: stop-signal, go–no-go, Stroop, flanker, single-response selection, psychological refractory period, and attentional blink tasks. A confirmatory factor analysis suggested that response inhibition and response selection are separable, with stop-signal and go–no-go task performance being related to response inhibition, and performance in the psychological refractory period, Stroop, single-response selection, and attentional blink tasks being related to response selection. These findings provide evidence in support of the hypothesis that response selection and response inhibition reflect two distinct cognitive operations.
How does the brain combine information predictive of the value of a visually guided task (incentive value) with information predictive of where task-relevant stimuli may occur (spatial certainty)? ...Human behavioural evidence indicates that these two predictions may be combined additively to bias visual selection (
Additive Hypothesis
), whereas neuroeconomic studies posit that they may be multiplicatively combined (
Expected Value Hypothesis
). We sought to adjudicate between these two alternatives. Participants viewed two coloured placeholders that specified the potential value of correctly identifying an imminent letter target if it appeared in that placeholder. Then, prior to the target’s presentation, an endogenous spatial cue was presented indicating the target’s more likely location. Spatial cues were parametrically manipulated with regard to the information gained (in bits). Across two experiments, performance was better for targets appearing in high versus low value placeholders and better when targets appeared in validly cued locations. Interestingly, as shown with a Bayesian model selection approach, these effects did not interact, clearly supporting the Additive Hypothesis. Even when conditions were adjusted to increase the optimality of a multiplicative operation, support for it remained. These findings refute recent theories that expected value computations are the singular mechanism driving the deployment of endogenous spatial attention. Instead, incentive value and spatial certainty seem to act independently to influence visual selection.
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