bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is categorization in visual working memory a way to reduce mental effort? A pupillometry study
Authors: Zhou Cherie , Lorist Monicque M. , Mathôt Sebastiaan 
Published: November 2021

AbstractRecent studies on visual working memory (VWM) have shown that visual information can be stored in VWM as continuous (e.g., a specific shade of red) as well as categorical representations (e.g., the general category red). It has been widely assumed, yet never directly tested, that continuous representations require more VWM mental effort than categorical representations; given limited VWM capacity, this would mean that fewer continuous, as compared to categorical, representations can be maintained simultaneously. We tested this assumption by measuring pupil size, as a proxy for mental effort, in a delayed estimation task. Participants memorized one to four ambiguous (boundaries between adjacent color categories) or prototypical colors to encourage continuous or categorical representations, respectively; after a delay, a probe indicated the location of the to-be-reported color. We found that, for set size 1, pupil size was larger while maintaining ambiguous as compared to prototypical colors, but without any difference in memory precision; this suggests that participants relied on an effortful continuous representation to maintain a single ambiguous color, thus resulting in pupil dilation while preserving precision. In contrast, for set size 2 and higher, pupil size was equally large while maintaining ambiguous and prototypical colors, but memory precision was now substantially reduced for ambiguous colors; this suggests that participants now also relied on categorical representations for ambiguous colors (which are by definition a poor fit to any category), thus reducing memory precision but not resulting in pupil dilation. Taken together, our results suggest that continuous representations are more effortful than categorical representations, and that very few continuous representations (perhaps only one) can be maintained simultaneously.Significance statementVisual working memory (VWM) can store visual information in two more-or-less distinct formats: continuous and categorical representations. It is widely assumed that VWM capacity for continuous representations is more limited than for categorical representations, yet this assumption has never been explicitly tested. Here we address this crucial question of whether continuous representations cost more resources, and as a consequence limits VWM capacity, as compared to categorical representations. To do so, we measured pupil size (as a proxy for mental effort) and memory performance in a delayed estimation task. Crucially, our results suggest that continuous representations are more effortful than categorical representations, and that only one continuous representation can be maintained in VWM at one time.
Global Structure of the Intrinsically Disordered Protein Tau Emerges from its Local Structure
Authors: Stelzl Lukas S. , Pietrek Lisa M. , Holla Andrea , Oroz Javier , Sikora Mateusz , Köfinger Jürgen , Schuler Benjamin , Zweckstetter Markus , Hummer Gerhard 
Published: November 2021

AbstractThe paradigmatic disordered protein tau plays an important role in neuronal function and neurodegenerative diseases. To disentangle the factors controlling the balance between functional and disease-associated conformational states, we build a structural ensemble of the tau K18 fragment containing the four pseudorepeat domains involved in both microtubule binding and amyloid fibril formation. We assemble 129-residue-long tau K18 chains at atomic resolution from an extensive fragment library constructed with molecular dynamics simulations. We introduce a reweighted hierarchical chain growth (RHCG) algorithm that integrates experimental data reporting on the local structure into the assembly process in a systematic manner. By combining Bayesian ensemble refinement with importance sampling, we obtain well-defined ensembles and overcome the problem of exponentially varying weights in the integrative modeling of long-chain polymeric molecules. The resulting tau K18 ensembles capture nuclear magnetic resonance (NMR) chemical shift and J-coupling measurements. Without further fitting, we achieve excellent agreement with measurements of NMR residual dipolar couplings. The good agreement with experimental measures of global structures such as singlemolecule Förster resonance energy transfer (FRET) efficiencies is improved further by ensemble refinement. By comparing wild-type and mutant ensembles, we show that pathogenic single-point P301 mutations shift the population from the turn-like conformations of the functional microtubule-bound state to the extended conformations of disease-associated tau fibrils. RHCG thus provides us with an atomically resolved view of the population equilibrium between functional and aggregation-prone states of tau K18, and demonstrates that global structural characteristics of this intrinsically disordered protein emerge from its local structure.
Zika virus-specific IgM elicited during pregnancy exhibits ultrapotent neutralization
Authors: Singh Tulika , Hwang Kwan-Ki , Miller Andrew S. , Jones Rebecca L. , Lopez Cesar A. , Giuberti Camila , Gladden Morgan A. , Miller Itzayana , Webster Helen S. , Eudailey Joshua A. , Luo Kan , Holle Tarra Von , Edwards Robert J. , Valencia Sarah , Burgomaster Katherine E. , Zhang Summer , Mangold Jesse F. , Tu Joshua J. , Dennis Maria , Alam S. Munir , Premkumar Lakshmanane , Dietze Reynaldo , Pierson Theodore C. , Ooi Eng Eong , Lazear Helen M. , Kuhn Richard J. , Permar Sallie R. , Bonsignori Mattia 
Published: November 2021

SummaryCongenital Zika virus (ZIKV) infection results in neurodevelopmental deficits in up to 14% of infants born to ZIKV-infected mothers. Neutralizing antibodies are a critical component of protective immunity. Here, we demonstrate that plasma IgM responses contribute to ZIKV immunity in pregnancy, mediating neutralization up to three months post symptoms. From a ZIKV-infected pregnant woman, we established a B cell line secreting a pentameric ZIKV-specific IgM (DH1017.IgM) that exhibited ultrapotent ZIKV neutralization dependent on the IgM isotype. DH1017.IgM targets a novel envelope dimer epitope within Domain II. The arrangement of this epitope on the virion is compatible with concurrent engagement of all ten antigen-binding sites of DH1017.IgM, a solution not achievable by IgG antibodies. DH1017.IgM protected against lethal ZIKV challenge in mice. Our findings identify a unique role of antibodies of the IgM isotype in protection against ZIKV and posit DH1017.IgM as a safe and effective candidate immunoprophylactic, particularly during pregnancy.Key pointsPlasma IgM contributes to early ZIKV neutralization during pregnancyUltrapotent neutralization by pentameric DH1017.IgM mAb depends on isotypeDH1017.IgM can engage all binding sites concurrently through different angles of approachDH1017.IgM protects mice against lethal ZIKV challenge
High-quality reference genome for an arid-adapted mammal, the banner-tailed kangaroo rat (Dipodomys spectabilis)
Authors: Harder Avril M. , Walden Kimberly K.O. , Marra Nicholas J. , Willoughby Janna R. 
Published: November 2021

AbstractKangaroo rats in the genus Dipodomys are found in a variety of habitat types in western North America, including deserts, arid and semi-arid grasslands, and scrublands. Many Dipodomys species are experiencing strong population declines due to increasing habitat fragmentation, with two species listed as federally endangered. The precarious state of many Dipodomys populations, including those occupying extreme environments, make species of this genus valuable subjects for studying the impacts of habitat degradation and fragmentation on population genomic patterns and for characterizing the genomic bases of adaptation to harsh conditions. To facilitate exploration of such questions, we assembled and annotated a reference genome for the banner-tailed kangaroo rat (D. spectabilis) using PacBio HiFi sequencing reads, providing a more contiguous genomic resource than two previously assembled Dipodomys genomes. Using the HiFi data for D. spectabilis and publicly available sequencing data for two other Dipodomys species (D. ordii and D. stephensi), we demonstrate the utility of this new assembly for studies of congeners by conducting inference of historic effective population sizes (Ne) and linking these patterns to the species’ current extinction risk statuses. The genome assembly presented here will serve as a valuable resource for population and conservation genomic studies of Dipodomys species, comparative genomic research within mammals and rodents, and investigations into genomic adaptation to extreme environments and changing landscapes.Significance statementKangaroo rats in the genus Dipodomys occur in a wide variety of habitat types, ranging from scrublands to arid deserts, and are increasingly impacted by habitat fragmentation with populations of many species in strong decline. To facilitate population and conservation genomic studies of Dipodomys species, we generated the first reference genome assembly for the extensively studied banner-tailed kangaroo rat (D. spectabilis) from long read PacBio sequencing data. The genome assembly presented here will serve as a valuable resource for studies of Dipodomys species—which have long served as ecological and physiological models for the study of osmoregulation—comparative genomic surveys of mammals and rodents, and investigations into genomic adaptation to extreme environments and changing landscapes.
The Flowering Repressor SVP recruits the TOPLESS co-repressor to control flowering in chrysanthemum and Arabidopsis
Authors: Zhang Zixin , Hu Qian , Zhu Yuqing , Gao Zheng , Shang Erlei , Liu Gaofeng , Liu Weixin , Hu Rongqian , Chong Xinran , Guan Zhiyong , Fang Weimin , Chen Sumei , Sun Bo , He Yuehui , Jiang Jiafu , Chen Fadi 
Published: November 2021

AbstractPlant flowering time is a consequence of the perception of environmental and endogenous signals. The MCM1-AGAMOUSDEFICIENS-SRF-box (MADS-box) gene SHORT VEGETATIVE PHASE (SVP) is a pivotal repressor that negatively regulates the floral transition during the vegetative phase. The transcriptional corepressor TOPLESS (TPL) plays critical roles in many aspects of plant life. An interaction first identified between the second LXLXLX motif (LRLGLP) of CmSVP with CmTPL1-2, which can repress the expression of a key flowering factor CmFTL3 by binding its promotor CArG element in chrysanthemum. Genetic analysis suggested that the CmSVP-CmTPL1-2 transcriptional complex is a prerequisite for SVP to act as a floral repressor, which reduces CmFTL3 transcriptional activity. CmSVP rescued the phenotype of the svp-31 mutant in Arabidopsis, and overexpression of AtSVP or CmSVP in the Arabidopsis dominant negative mutation tpl-1 led to a loss-of-function in late flowering, which confirmed the highly conserved function of SVP in the two completely different species. Thus, we have validated a conserved machinery wherein SVP relies on TPL to inhibit flowering through the direct regulation of FT, which is more meaningful for the evolution of species and could be translated to high-quality cultivation and breeding of crops.
Demyelination induces transcriptional reprograming in proprioceptive and Aβ rapidly adapting low-threshold-mechanoreceptor neurons
Authors: Elbaz Benayahu , Yang Lite , Rader Braesen Lee , Kawaguchi Riki , Traka Maria , Woolf Clifford J , Renthal William , Popko Brian 
Published: November 2021

SummarySchwann cells, the main glial cell in the peripheral nervous system (PNS), ensheath bundles of small unmyelinated axons or form myelin on larger axons. PNS injuries initiate transcriptional reprograming in both Schwann cells and sensory neurons that promotes regeneration. While the factors that initiate the transcriptional reprograming in Schwann cells are well characterized, the full range of stimuli that initiate this reprograming in sensory neurons remain elusive. Here, using a genetic model of Schwann cell ablation, we find that Schwann cell loss results in transient PNS demyelination without overt axonal loss. By profiling sensory ganglia at single-cell resolution we show that this demyelination induces transcriptional reprogramming preferably in proprioceptive and Aβ RA-LTMR neurons. Transcriptional reprograming is assumed to be a cell autonomous response of sensory neurons to mechanical axonal injury. By identifying similar reprograming in non-injured, demyelinated neurons, our study suggests that this reprograming represents a non-cell autonomous transcriptional response of sensory neurons to the loss of axon-Schwann cell interactions.HighlightsAblation of Schwann cells results in transient PNS demyelination, without overt axonal loss.Schwann cell loss results in transcriptional reprograming in specific sensory neurons.Spinal nerve transection (mechanical injury of axons) and demyelination (intact axons) induces similar transcriptional responses in DRG neurons.The transcriptional response to demyelination among DRG neurons is specific to the large myelinated proprioceptive and Aβ RA-LTMR neurons.
Aquaglyceroporin AQP7’s affinity for its substrate glycerol
Authors: Falato Michael , Chan Ruth , Chen Liao Y. 
Published: November 2021

ABSTRACTAQP7 is one of the four human aquaglyceroporins that facilitate glycerol transport across the cell membrane, a biophysical process that is essential in human physiology. Therefore, it is interesting to compute AQP7’s affinity for its substrate (glycerol) with reasonable certainty to compare with the experimental data suggesting high affinity in contrast with most computational studies predicting low affinity. In this study aimed at computing the AQP7-glycerol affinity with high confidence, we implemented a direct computation of the affinity from unbiased equilibrium molecular dynamics (MD) simulations of three all-atom systems constituted with 0.16M, 4.32M, and 10.23M atoms, respectively. These three sets of simulations manifested a fundamental physics law that the intrinsic fluctuations of pressure in a system are inversely proportional to the system size (the number of atoms in it). These simulations showed that the computed values of glycerol-AQP7 affinity are dependent upon the system size (the inverse affinity estimations were, respectively, 47.3 mM, 1.6 mM, and 0.92 mM for the three model systems). In this, we obtained a lower bound for the AQP7-glycerol affinity (an upper bound for the dissociation constant). Namely, the AQP7-glycerol affinity is stronger than 1087/M (the dissociation constant is less than 0.92 mM). Additionally, we conducted hyper steered MD (hSMD) simulations to map out the Gibbs free-energy profile. From the free-energy profile, we produced an independent computation of the AQP7-glycerol dissociation constant being approximately 0.18 mM.Table of contents entry
How increased cognitive load affects the dual-task cost in healthy young adults? A randomized, double-blind sham-controlled study
Authors: Behrangrad Shabnam , Zoghi Maryam , Mansouri Farshad , Jaberzadeh Shapour 
Published: November 2021

AbstractOur ability to interact flexibly with the surrounding environment and achieve an adaptive goal-directed response is one of the necessities of balance control. This study aimed to examine the interaction between cognitive demand and the necessity for keeping balance in unstable conditions. We examined the effects of performing two cognitive tasks, namely the Stroop test and Wisconsin Card Sorting Test (WCST), on postural balance in healthy young adults. Stroop and the WCST test assess selective attention and cognitive flexibility in shifting between rules, respectively. Thirty-two healthy adults were included in two experimental conditions (control and treatment) in random order, separated by at least seven days. Standing balance was evaluated by the Sway Medical Mobile application in eyes open (EO) and eyes closed (EC) in different stance positions: feet apart, feet together, semi-tandem, tandem, and single-leg stance (SLS). Balance was evaluated before and after the cognitive test in each experimental condition. Our findings indicate that performing cognitively demanding tasks adversely affected the balance ability in more demanding balance tests such as the SLS with EC (P □ 0.05). However, no significant changes were seen in other balance tests (P □ 0.05). Additionally, no significant changes were seen in balance ability after the Stroop or Wisconsin card sorting test alone. These results confirm that performing cognitively demanding tasks significantly reduced the ability to keep balance in less stable conditions. These findings have significant implications in understanding and preventing falls and incidents resulting from an impaired balance in complex and cognitively demanding conditions.
Rare alternative second line injectable drug resistance markers identified by gene-wise genome wide association in M. tuberculosis with unexplained resistance
Authors: Conkle-Gutierrez Derek , Kim Calvin , Ramirez-Busby Sarah M. , Modlin Samuel J. , Mansjö Mikael , Werngren Jim , Rigouts Leen , Hoffner Sven E. , Valafar Faramarz 
Published: November 2021

AbstractPoint mutations in the rrs gene and eis promoter are known to confer resistance to second-line injectable drugs (SLIDs) amikacin (AMK), capreomycin (CAP), and kanamycin (KAN). While mutations in these canonical genes confer a majority of SLID-resistance, alternative mechanisms of resistance are not uncommon and threaten effective treatment decisions when using conventional molecular diagnostics. In total, 1184 clinical M. tuberculosis isolates from 7 countries were studied for genomic markers associated with phenotypic resistance. The markers rrs:A1401G and rrs:G1484T were associated with resistance to all three SLIDs, and three known markers in the eis promoter (eis:G-10A, eis:C-12T, and eis:C-14T) were similarly associated with kanamycin resistance (KAN-R). Among 325, 324, 270 AMK-R, CAP-R, and KAN-R isolates, 264 (81.2%), 250 (77.2%), and 249 (92.3%) harbored canonical mutations, respectively. Thirteen isolates harbored more than one canonical mutation. Canonical mutations did not account for 111 of the phenotypically resistant isolates. A gene-wise method identified three genes and promoters with mutations that, on aggregate, associated with unexplained resistance to at least one SLID. Our analysis associated whiB7 promoter mutations with KAN resistance, supporting clinical relevance for the previously demonstrated role of whiB7 overexpression in KAN resistance. We also provide evidence for the novel association of ppe51 (a gene previously associated with various antimicrobial compounds) with AMK resistance, and for the novel association of thrB with AMK and CAP resistance. The use of gene-wise association can provide additional insight, and therefore is recommended for identification of rare mechanisms of resistance when individual mutations carry insufficient statistical power.
Government data governance framework based on a data middle platform
Authors: Mao Zijun , Wu Jingyi , Qiao Yali , Yao Hong 
Published: November 2021

PurposeThe present paper constructed a new framework for government data governance based on the concept of a data middle platform to elicit the detailed requirements and functionalities of a government data governance framework.Design/methodology/approachFollowing a three-cycle activity, the design science research (DSR) paradigm was used to develop design propositions. The design propositions are obtained based on a systematic literature review of government data governance and data governance frameworks. Cases and experts further assessed the effectiveness of the implementation of the artifacts.FindingsThe study developed an effective framework for government data governance that supported the digital service needs of the government. The results demonstrated the advantages of the framework in adapting to organizational operations and data, realized the value of data assets, improved data auditing and oversight and facilitated communication. From the collection of data to the output of government services, the framework adapted to the new characteristics of digital government.Originality/valueKnowledge of the “data middle platforms” generated in this study provides new knowledge to the design of government data governance frameworks and helps translate design propositions into concrete capabilities. By reviewing earlier literature, the article identified the core needs and challenges of government data governance to help practitioners approach government data governance in a structured manner.
Value co-creation for developing cultural and creative virtual brand communities
Authors: Chen Longshan , Yuan Leping , Zhu Zhangxiang 
Published: November 2021

PurposeThis study aims to explore the value co-creation for developing cultural and creative virtual brand communities (CCVBCs) by developing a conceptual framework based on the stimulus-organism-response framework, social cognition theory (SCT) and social exchange theory (SET).Design/methodology/approachThe proposed conceptual framework was developed from a comprehensive review of the related literature. This study tested and validated the proposed framework using partial least square structural equation model based on the data collected through a survey.FindingsFirst, perceived hedonic benefit was positively affected by content personalization, user interaction design and technological innovation. Perceived social benefit and perceived self-achievement benefit were positively affected by user interaction design and technological innovation. Second, user content creation behavior was affected by perceived social benefit and perceived self-achievement benefit; user browsing behavior was significantly affected only by perceived hedonic benefit, and interaction behavior was significantly affected by perceived hedonic benefit, perceived social benefit and perceived self-achievement benefit. Third, perceived social benefit and perceived self-achievement benefit partially mediated the relationship between user interaction design and interaction behavior. As for the influence of technological innovation on interaction behavior, however, and the influence of user interaction design and technological innovation on content creation behavior, both perceived social benefit and perceived self-achievement benefit had complete mediation.Originality/valueThis study found that the characteristics of developing CCVBCs affected perceived benefit in participating in the value co-creation process. The results contributed to the value creation research by enriching the understanding of user value co-creation in developing CCVBCs.