bluuebunny/crossref_metadata_2025_split huggingface dataset:
Domestication and lowland adaptation of coastal preceramic maize from Paredones, Peru
Authors: Vallebueno-Estrada Miguel , Hernández-Robles Guillermo G. , González-Orozco Eduardo , López-Valdivia Iván , Tham Teresa Rosales , Sánchez Víctor Vásquez , Swarts Kelly , Dillehay Tom D. , Vielle-Calzada Jean-Philippe , Montiel Rafael 
Published: February 2022

AbstractArchaeological cobs from Paredones and Huaca Prieta (Peru) are phenotypically indistinguishable from modern maize. This contrasts with the earliest Mexican macro-specimens from Guila Naquitz and San Marcos, which are phenotypically intermediate even though they date more recently in time. These observations suggest at least two alternative scenarios, one in which maize was domesticated earlier than previously thought in the lowland Mesoamerica, followed by rapid lowland dispersal to Peru, and another in which maize was independently domesticated in South America and subsequently lost, as current evidence supports a single origin for all modern maize. To gain insights into the origins of ancient Peruvian maize, we sequenced DNA from three Paredones specimens dating 6775 to 5000 calibrated years before present (BP) and conducted comparative analyses with two teosinte subspecies (Zea maysssp.mexicanaandparviglumis) and extant maize, including highland and lowland landraces from Mesoamerica and South America. We show that Paredones maize originated from the same domestication event as Mexican maize and was domesticated by 6775 BP, implying rapid dispersal followed by improvement. Paredones maize show minimal levels of gene flow frommexicana, smaller than those observed in teosinteparviglumis. It also harbors significantly fewer alleles previously found to be adaptive to highlands, but not of alleles adaptive to lowlands, supporting a lowland migration route. Our overall results imply that Paredones maize originated in Mesoamerica, arrived in Peru withoutmexicanaintrogression through a rapid lowland migration route, and underwent improvements in both Mesoamerica and South America.Significance StatementThe coastal Peruvian preceramic sites of Paredones and Huaca Prieta provide the earliest known maize macro-remains. Found more than 3,800 km away from the maize center of origin and presenting a phenotypically modern cob constitution relative to their antiquity, these specimens represent a paradox for understanding maize evolution and dispersal. We show that Paredones maize originated in Mesoamerica, like all known maize, and arrived in South America without introgression from the teosintemexicana. Since modern maize has substantial contributions frommexicana, it raises the question of whenmexicanaintrogression spread to South America. Paredones maize preferentially shares adaptive allelic diversity with lowland Mesoamerican samples, suggesting a migration route probably associated with a coastal corridor previously identified with archeological findings.
Age influences audiovisual speech processing in multi-talker scenarios – Evidence from cortical oscillations
Authors: Begau Alexandra , Klatt Laura-Isabelle , Schneider Daniel , Wascher Edmund , Getzmann Stephan 
Published: February 2022

AbstractAge-related differences in the processing of audiovisual speech in a multi-talker environment were investigated analyzing event-related spectral perturbations (ERSPs), focusing on theta, alpha, and beta oscillations that are assumed to reflect conflict processing, multisensory integration, and attentional mechanisms, respectively. Eighteen older and 21 younger healthy adults completed a two-alternative forced-choice word discrimination task, responding to audiovisual speech stimuli. In a cocktail-party scenario with two competing talkers (located at-15° and 15° azimuth), target words (/yes/ or /no/) appeared at a pre-defined (attended) position, distractor words at the other position. In two audiovisual conditions, acoustic speech was combined either with congruent or uninformative visual speech. While a behavioral benefit for congruent audiovisual speech occurred for both age groups, differences between audiovisual conditions in the theta and beta band were only present for older adults. A stronger increase in theta perturbations for stimuli containing uninformative visual speech could be associated with early conflict processing, while a stronger suppression in beta perturbations for congruent audiovisual speech could be associated to audiovisual integration. Compared to the younger group, the older group showed generally stronger beta perturbations. No condition differences in the alpha band were found. Overall, the findings suggest age-related differences in audiovisual speech integration in a multi-talker environment. While the behavioral benefit of congruent audiovisual speech was unaffected by age, older adults had a stronger need for cognitive control when processing conflicting audiovisual speech input. Furthermore, mechanisms of audiovisual integration are differently activated depending on the informational content of the visual information.
Chloroplast genome assemblies and comparative analyses of major Vaccinium berry crops
Authors: Fahrenkrog Annette M. , Matsumoto Gabriel , Toth Katalin , Jokipii-Lukkari Soile , Salo Heikki M. , Häggman Hely , Benevenuto Juliana , Munoz Patricio 
Published: February 2022

ABSTRACTBackgroundVaccinium is an economically important genus of berry crops in the family Ericaceae. Given the numerous hybridizations and polyploidization events among Vaccinium species, the taxonomy of this genus has remained uncertain and the subject of long debate. Therefore, the availability of more genomic resources for Vaccinium can provide useful tools for phylogenetic resolution, species identification, authentication of berry food products, and a framework for genetic engineering.ResultsIn this study, we assembled five Vaccinium chloroplast sequences representing the following berry types: northern highbush blueberry (V. corymbosum), southern highbush blueberry (V. corymbosum hybrids), rabbiteye blueberry (V. virgatum), lowbush blueberry (V. angustifolium), and bilberry (V. myrtillus). Two complete plastid genomes were achieved using long-read PacBio sequencing, while three draft sequences were obtained using short-read Illumina sequencing. Comparative analyses also included other previously available Vaccinium chloroplast sequences, especially the commercially important species V. macrocarpon (cranberry). The Vaccinium chloroplast genomes exhibited a circular quadripartite structure, with an overall highly conserved synteny and sequence identity among them. Despite their high similarity, we identified some polymorphic regions in terms of expansion/contraction of inverted repeats, gene copy number variation, simple sequence repeats, and single nucleotide polymorphisms. Phylogenetic analysis revealed multiple origins of highbush blueberry plastomes, likely due to the hybridization events during northern and southern highbush blueberry domestication.ConclusionsOur results enrich the genomic data availability for new Vaccinium species by sequencing and assembling the chloroplast DNA of major economically important berry types. Additional whole plastome analyses including more samples and wild species will be useful to obtain a refined knowledge of the maternal breeding history of blueberries and increase phylogenetic resolution at low taxonomic levels.
Inhibitory effect of EGCG-AgNPs and their lysozyme bioconjugates on biofilm formation and cytotoxicity
Authors: Meesaragandla Brahmaiah , Hayet Shahar , Fine Tamir , Janke Una , Chai Liraz , Delcea Mihaela 
Published: February 2022

ABSTRACTBiofilms are multicellular communities of microbial cells that grow on natural and synthetic surfaces. They have become the major cause for hospital-acquired infections because once they form, they are very difficult to eradicate. Nanotechnology offers a new approach to fight biofilm-associated infections. Here, we report on the synthesis of silver nanoparticles (AgNPs) with antibacterial ligand epigallocatechin gallate (EGCG) and the formation of lysozyme protein corona on AgNPs as shown by UV-Vis, dynamic light scattering, and circular dichroism analyses. We further tested the activity of EGCG-AgNPs and their lysozyme bioconjugates on the viability of Bacillus subtilis cells and biofilm formation. Our results showed that, although EGCG-AgNPs presented no antibacterial activity on planktonic Bacillus subtilis cells, they inhibited B. subtilis biofilm formation at concentrations larger than 40 nM and EGCG-AgNP-lysozyme bioconjugates inhibited biofilms at concentrations above 80 nM. Cytotoxicity assays performed with human cells showed a reverse trend, where EGCG-AgNPs barely affected human cell viability, while EGCG-AgNP-lysozyme bioconjugates severely hampered viability. Our results therefore demonstrate that EGCG-AgNPs may be used as non-cytotoxic antibiofilm agents.
Chloride ions evoke taste sensations by binding to the extracellular ligand-binding domain of sweet/umami taste receptors
Authors: Atsumi Nanako , Yasumatsu Keiko , Takashina Yuriko , Ito Chiaki , Yasui Norihisa , Margolskee Robert F. , Yamashita Atsuko 
Published: February 2022

AbstractSalt taste sensation is multifaceted: NaCl at low or high concentrations is preferably or aversively perceived through distinct pathways. Cl−is thought to participate in taste sensation through an unknown mechanism. Here we describe Cl−ion binding and the response of taste receptor type 1 (T1r), a receptor family composing sweet/umami receptors. The T1r2a/T1r3 heterodimer from the medaka fish, currently the sole T1r amenable to structural analyses, exhibited a specific Cl−binding in the vicinity of the amino-acid-binding site in the ligand-binding domain (LBD) of T1r3, which is likely conserved across species, including human T1r3. The Cl−binding induced a conformational change in T1r2a/T1r3LBD at sub-to low-mM concentrations similar to canonical taste substances. Furthermore, oral Cl−application to mice increased impulse frequencies of taste nerves connected to T1r-expressing taste cells and promoted their behavioral preferences attenuated by a T1r-specific blocker or T1r3 knock-out. These results suggest that the Cl−evokes taste sensations by binding to T1r, thereby serving as another preferred salt taste pathway at a low concentration.
Dynamic genetic adaptation of Bacteroides thetaiotaomicron murine gut colonization
Authors: Zhang Manjing , Kennedy Megan , DeLeon Orlando , Bissell Jacie , Trigodet Florian , Lolans Karen , Temelkova Sara , Carroll Katherine T. , Fiebig Aretha , Deutschbauer Adam , Sidebottom Ashley M. , Henry Chris , Rice Phoebe A. , Bergelson Joy , Chang Eugene B. 
Published: February 2022

AbstractTo understand how a bacterium ultimately succeeds or fails in adapting to a new environment, it is essential to assess the temporal dynamics of its fitness over the course of colonization. The mammalian gut, into which exogenous microorganisms are regularly introduced, represents a biologically and clinically relevant system to explore microbial adaptational processes. In this study, we introduce a human-derived commensal organism, Bacteroides thetaiotaomicron, into the guts of germ-free mice to 1) determine whether the genetic requirements for colonization shift over time and, if so, 2) characterize the biological functions required for microbial survival at different points of colonization. The results of a high-throughput functional genetics assay (BarSeq), transcriptomics, and metabolomics converge on several conclusions. First, adaptation to the host gut occurs in distinct stages. We observed drastic changes in gene usage during the first week, shifting from high expression of amino acid biosynthesis to polysaccharide utilization genes. These changes were sustained thereafter, except for the continued upregulation of a single polysaccharide utilization locus responsible for the degradation of raffinose-family oligosaccharides rich in the standard chow diet fed to our mice. Spontaneous mutations in wildtype Bt also evolve around this locus, highlighting the importance of efficient carbohydrate metabolism in long-term persistence within a monoassociated gut. To improve microbiome-based therapies, it will be important to appreciate and meet the distinct needs of the organism during each stage of colonization.ImportanceMicrobes regularly disperse across and adapt to new environments and ecological niches. A clinically significant microbial niche home to trillions of microbes is the mammalian gut. Temporal processes of microbial adaptation over the course of gut colonization are poorly understood on a genetic, transcriptional, and metabolite level. In this study, we leverage a three-pronged approach to characterize gut colonization as a dynamic process with shifting genetic determinants of microbial fitness. This study sheds light on host colonization by Bacteroides thetaiotaomicron, an organism that is prevalent and dominant across healthy human microbiomes, and not only identifies key pathways involved in colonization, but determines the timing of when these pathways are most vital to colonization success. By demonstrating that the key determinants of colonization success in the gut change over time, the results of this study highlight the importance of considering ecological dynamics in developing more effective microbiome-based therapies.
Autonomic dysfunction is associated with the development of arterial stiffness: The Whitehall II cohort
Authors: Schaarup Jonas , Christensen Martin S. , Hulman Adam , Hansen Christian Stevns , Vistisen Dorte , Tabák Adam G. , Witte Daniel R. , Bjerg Lasse 
Published: February 2022

AbstractBackground and aimTo examine the association between baseline level and change of autonomic nervous function with subsequent development of arterial stiffness.MethodsAutonomic nervous function was assessed of 4,901 participants of the Whitehall II occupational cohort by heart rate variability (HRV) indices and resting heart rate (rHR) three times between 1997-2009, while arterial stiffness was assessed by carotid-femoral pulse wave velocity (PWV) measured twice between 2007-2013. First, individual HRV/rHR levels and annual changes were estimated. Then, we modelled the development of PWV by HRV/rHR using linear mixed effect models. First, we adjusted for sex and ethnicity (model 1), and then for socioeconomic and lifestyle factors, various clinical measurements, and medications (model 2).ResultsA decrease in HRV and unchanged rHR was associated with subsequent higher levels of PWV, but the effect of a change in HRV was less pronounced at higher ages. A typical individual aged 65 years with a SDNN level of 30 ms and a 2% annual decrease in SDNN had 1.32 (0.95; 1.69) higher PWV compared to one with the same age and SDNN level but with a 1% annual decrease in SDNN. Further adjustment had no major effect on the results.ConclusionPeople who experience a steeper decline of autonomic nervous function have higher levels of arterial stiffness. However, the association was weaker at higher ages.
Epigenetic aging and perceived psychological stress in old age
Authors: Vetter Valentin Max , Drewelies Johanna , Sommerer Yasmine , Kalies Christian Humberto , Regitz-Zagrosek Vera , Bertram Lars , Gerstorf Denis , Demuth Ilja 
Published: February 2022

AbstractAdverse effects of psychological stress on physical and mental health, especially in older age, are well documented. How perceived stress relates to the epigenetic clock measure, DNA methylation age acceleration (DNAmAA), is less well understood and existing studies reported inconsistent results.DNAmAA was estimated from five epigenetic clocks (7-CpG, Horvath’s, Hannum’s, PhenoAge and GrimAge DNAmAA). Cohen’s Perceived Stress Scale (PSS) was used as marker of psychological stress.We analyzed data from 1,100 Berlin Aging Study II (BASE-II) participants assessed as part of the GendAge study (mean age = 75.6 years, SD = 3.8 years, 52.1% women).In a first step, we replicated well-established associations of perceived stress with morbidity, frailty, and symptoms of depression in the BASE-II cohort studied here. In a second step, we did not find any statistically significant association of perceived stress with any of the five epigenetic clocks in multiple linear regression analyses that adjusted for covariates.Although the body of literature suggests an association between higher DNAmAA and stress or trauma during early childhood, the current study found no evidence for an association of perception of stress with DNAmAA in older people. We discuss possible reasons for the lack of associations and highlight directions for future research.
Female gender, depressive symptoms, manual job, and higher physical disability predict long term low back pain persistence
Authors: Gomes Luís Antunes , Rodrigues Ana Maria , Branco Jaime C. , Canhão Helena , Cruz Eduardo Brazete 
Published: February 2022

ABSTRACTBackgroundLow Back Pain (LBP) is a long-term health condition with distinct clinical courses. The characterization of these courses together with the identification of prognostic factors of a persistent disabling LBP course has the potential to enable a better identification of patients in high-risk and ultimately allow the development of personalized interventions to change their long-term prognosis. This study aimed to assess the course of chronic LBP (CLBP) over 5 years in a large population-based study, its cumulative impact on disability and health-related quality of life (HRQoL) and the indicators for persistent CLBP course.Material and methodsActive CLBP participants were identified from a representative sample of 10.661 adults randomly recruited from the dwelling population of EpiDoC. Pain, disability and HRQoL were assessed at three time-points. According to their pain symptoms over time, participants were classified as having a persistent or relapsing pain course. A General Linear Model was used to compare mean differences between and within groups. The relation between baseline variables and persistent CLBP was modulated through logistic regression.ResultsAmong the 1.201 adults with active CLBP at baseline, 634 completed the three time-points of data collection (52.8%) and 400 (63.1%) were classified as having a persistent course. Statistically significant interactions were found between the group and time on disability (F (2.126)= 23.78, p<0.001) and HRQoL (F (2.125)= 82.78, p<0.001). In the adjusted model, the persistent course was associated with the disability level (OR: 1.84, CI95% 1.4 to 2.4), presence of depressive symptoms (OR: 1.96, CI95% 1.2 to 3.2), female gender (OR: 1.9, CI95% 1.26-2.87), and having a manual job (OR: 1.46, CI95% 1.02 to 2.1).ConclusionIn the long-term, CLBP patients have distinct clinical courses. Being female, presenting depressive symptoms, having a manual job and a higher disability at baseline predict a CLBP persistent outcome.
A central protein complex essential for Invasion inToxoplasma gondii
Authors: Singer Mirko , Simon Kathrin , Forné Ignasi , Meissner Markus 
Published: February 2022

Apicomplexa are obligate intracellular parasites. While most species are restricted to specific hosts and cell types,Toxoplasma gondiican invade every nucleated cell derived from warm-blooded animals. This broad host range suggests that this parasite can recognize multiple host cell ligands or structures, leading to the activation of a central protein complex, which should be conserved in all apicomplexans. During invasion, the unique secretory organelles (micronemes and rhoptries) are sequentially released and several micronemal proteins have been suggested to be required for host cell recognition and invasion. However, to date only few micronemal proteins have been demonstrated to be essential for invasion.Cysteine Repeat Modular Proteins (CRMPs) are a family of apicomplexan specific proteins. In Toxoplasma gondii, two CRMPs are present in the genome. The Kringle domain containing protein (CRMPA) and the GCC2 GCC3 domain containing protein (CRMPB). Here we demonstrate that both proteins form a complex that contains additional micronemal proteins. Disruption of this complex results in a block of rhoptry secretion and parasites being unable to invade the host cell. In conclusion, this complex is a central invasion complex conserved in all apicomplexans.
Tropical hummingbird pollination networks are resistant to short-term experimental removal of a common flowering plant
Authors: Leimberger Kara G. , Hadley Adam S. , Frey Sarah J.K. , Betts Matthew G. 
Published: February 2022

ABSTRACTTheory predicts that the structure of plant-pollination networks should withstand disturbance, but experiments testing this prediction remain uncommon. In this study, we simulated the local extinction of a hummingbird-pollinated understory plant,Heliconia tortuosa, from tropical forest fragments using a replicated Before-After-Control-Impact design while quantifying hummingbird abundance and space use (383 hummingbird captures and 72 radio-tagged individuals), floral visitation rates (>19,000 observation hours), and pollination success (529 flowers). We expected thatH. tortuosaremoval would either result in (i) network collapse, in which hummingbirds vacate fragments and compromise the reproductive success of other flowering plants, or (ii) increased hummingbird reliance on alternative resources (rewiring), leading to sustained fragment use. In our experiment, hummingbird behavior and pollination were remarkably resistant to loss ofH. tortuosa, a locally common plant species representing 30-40% of the available nectar resources on average. The exact mechanisms enabling short-term hummingbird persistence after resource removal remain unclear, as we did not discover evidence of rewiring. We hypothesize that physiological adaptations (e.g., torpor and insectivory) may have allowed hummingbird persistence, perhaps alongside high movement ability. With the important caution that short-term experiments may not emulate natural extinction processes, our study provides support for predictions that pollination networks may be robust to plant species loss.