bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial and temporal dynamics of phytoplankton community in the Sviyaga River, the Volga River basin, Russia
Authors: Tarasova N G 
Published: July 2021

Abstract
The phytoplankton communities of the Sviyaga River, the right-bank tributary of the Volga River, were studied. It was characterized by high taxonomic diversity. In total, 365 taxa of microalgae with a rank below genus were registered during the study period. Green algae and diatoms were the most diverse groups. The data obtained in 1984 and 2016 were compared; by the XXI century, the role of Planktotrichet-type algae has increased, as well as their share in the total species richness (by 10%). The distribution of the Ponto-Caspian invading diatom species Skeletonema subsalsum and Actinocyclus variabilis within the Volga River basin has been checked. These species were found in the estuarine phytoplankton communities of the Sviyaga River.
Micro-scale spatial distribution of bacterioplankton in the Priplotinny (Near-dam) Reach of the Kuibyshev Reservoir in the early autumn period 2020
Authors: Umanskaya M V , Krasnova E S , Yu Gorbunov M 
Published: July 2021

Abstract
A detailed study of the distribution of bacterioplankton and photosynthetic pigments of the Priplotinny Reach of the Kuibyshev Reservoir was carried out in early autumn 2020. The bacterioplankton cell numbers were 0.8-2.1 106 cells ml−1, and the biomass varied from 7 to 56 μg C L−1. The average chlorophyll a concentration of in the integral samples was 2.91 μg L−1, varying in the range of 1.1-9.6 μg L−1 (CV 30.7%). The pheophytin content was relatively low, 19.2 ± 10.4% of chlorophyll concentration, indicating the continued active phytoplankton development in the seston in the fall of 2020. From September 17 to October 3, a weak trend for an increase in bacterioplankton abundance as well as for a decrease in the chlorophyll a concentration and in the average cell volume was revealed. A significant (p < 0.05) correlation between the Chl a concentration in the total biomass of heterotrophic bacteria (r = 0.48) was observed. Under conditions of intense wind mixing, anthropogenic sources of pollution and the inflow of the inflow did not have a significant effect on the size structure of bacterioplankton. No pronounced local spatial complexes of stations were revealed in terms of quantitative and structural parameters of bacterioplankton and chlorophyll concentrations in the investigated part of the reservoir. In general, the concentration of pigments and the abundance and biomass of bacterioplankton correspond to the mesotrophic status of the Reach. Both the total number of bacterioplankton and the chlorophyll content in Pryplotinny Reach at the beginning of autumn 2020 are within the range of long-term monitoring values. While in the summer there is a clear long-term increasing trend of the bacterioplankton abundance, in the autumn the bacterioplankton numbers remain stable throughout the entire reservoir existence period.
Towards engineering heart tissues from bioprinted cardiac spheroids
Authors: Polonchuk Liudmila , Surija Lydia , Lee Min Ho , Sharma Poonam , Liu Chung Ming Clara , Richter Florian , Ben-Sefer Eitan , Rad Maryam Alsadat , Mahmodi Sheikh Sarmast Hadi , Shamery Wafa Al , Tran Hien A , Vettori Laura , Haeusermann Fabian , Filipe Elysse C , Rnjak-Kovacina Jelena , Cox Thomas , Tipper Joanne , Kabakova Irina , Gentile Carmine 
Published: July 2021

Abstract
Current in vivo and in vitro models fail to accurately recapitulate the human heart microenvironment for biomedical applications. This study explores the use of cardiac spheroids (CSs) to biofabricate advanced in vitro models of the human heart. CSs were created from human cardiac myocytes, fibroblasts and endothelial cells (ECs), mixed within optimal alginate/gelatin hydrogels and then bioprinted on a microelectrode plate for drug testing. Bioprinted CSs maintained their structure and viability for at least 30 d after printing. Vascular endothelial growth factor (VEGF) promoted EC branching from CSs within hydrogels. Alginate/gelatin-based hydrogels enabled spheroids fusion, which was further facilitated by addition of VEGF. Bioprinted CSs contracted spontaneously and under stimulation, allowing to record contractile and electrical signals on the microelectrode plates for industrial applications. Taken together, our findings indicate that bioprinted CSs can be used to biofabricate human heart tissues for long term in vitro testing. This has the potential to be used to study biochemical, physiological and pharmacological features of human heart tissue.
Long-term research reveals potential role of hybrids in climate-change adaptation. A commentary on ‘Expansion of the rareEucalyptus risdoniiunder climate change through hybridisation with a closely related species despite hybrid inferiority’
Authors: Bush David 
Published: July 2021

This article comments on:T. R. Pfeilsticker, R. C. Jones, D. A. Steane, P. A. Harrison, R. E. Vaillancourt and B. M. Potts, Expansion of the rare Eucalyptus risdonii under climate change through hybridization with a closely related species despite hybrid inferiority, Annals of Botany, Volume 129, Issue 1, 1 January 2022, Pages 1–14 https://doi.org/10.1093/aob/mcab103
LINADMIX: evaluating the effect of ancient admixture events on modern populations
Authors: Agranat-Tamir Lily , Waldman Shamam , Rosen Naomi , Yakir Benjamin , Carmi Shai , Carmel Liran 
Published: July 2021

AbstractMotivationThe rise in the number of genotyped ancient individuals provides an opportunity to estimate population admixture models for many populations. However, in models describing modern populations as mixtures of ancient ones, it is typically difficult to estimate the model mixing coefficients and to evaluate its fit to the data.ResultsWe present LINADMIX, designed to tackle this problem by solving a constrained linear model when both the ancient and the modern genotypes are represented in a low-dimensional space. LINADMIX estimates the mixing coefficients and their standard errors, and computes a P-value for testing the model fit to the data. We quantified the performance of LINADMIX using an extensive set of simulated studies. We show that LINADMIX can accurately estimate admixture coefficients, and is robust to factors such as population size, genetic drift, proportion of missing data and various types of model misspecification.Availability and implementationLINADMIX is available as a python code at https://github.com/swidler/linadmix.Supplementary informationSupplementary data are available at Bioinformatics online.
Sleep and longitudinal cognitive performance in preclinical and early symptomatic Alzheimer’s disease
Authors: Lucey Brendan P , Wisch Julie , Boerwinkle Anna H , Landsness Eric C , Toedebusch Cristina D , McLeland Jennifer S , Butt Omar H , Hassenstab Jason , Morris John C , Ances Beau M , Holtzman David M 
Published: July 2021

Abstract
Sleep monitoring may provide markers for future Alzheimer’s disease; however, the relationship between sleep and cognitive function in preclinical and early symptomatic Alzheimer’s disease is not well understood. Multiple studies have associated short and long sleep times with future cognitive impairment. Since sleep and the risk of Alzheimer’s disease change with age, a greater understanding of how the relationship between sleep and cognition changes over time is needed. In this study, we hypothesized that longitudinal changes in cognitive function will have a non-linear relationship with total sleep time, time spent in non-REM and REM sleep, sleep efficiency and non-REM slow wave activity.
To test this hypothesis, we monitored sleep-wake activity over 4–6 nights in 100 participants who underwent standardized cognitive testing longitudinally, APOE genotyping, and measurement of Alzheimer’s disease biomarkers, total tau and amyloid-β42 in the CSF. To assess cognitive function, individuals completed a neuropsychological testing battery at each clinical visit that included the Free and Cued Selective Reminding test, the Logical Memory Delayed Recall assessment, the Digit Symbol Substitution test and the Mini-Mental State Examination. Performance on each of these four tests was Z-scored within the cohort and averaged to calculate a preclinical Alzheimer cognitive composite score. We estimated the effect of cross-sectional sleep parameters on longitudinal cognitive performance using generalized additive mixed effects models. Generalized additive models allow for non-parametric and non-linear model fitting and are simply generalized linear mixed effects models; however, the linear predictors are not constant values but rather a sum of spline fits.
We found that longitudinal changes in cognitive function measured by the cognitive composite decreased at low and high values of total sleep time (P &lt; 0.001), time in non-REM (P &lt; 0.001) and REM sleep (P &lt; 0.001), sleep efficiency (P &lt; 0.01) and &lt;1 Hz and 1–4.5 Hz non-REM slow wave activity (P &lt; 0.001) even after adjusting for age, CSF total tau/amyloid-β42 ratio, APOE ε4 carrier status, years of education and sex. Cognitive function was stable over time within a middle range of total sleep time, time in non-REM and REM sleep and &lt;1 Hz slow wave activity, suggesting that certain levels of sleep are important for maintaining cognitive function.
Although longitudinal and interventional studies are needed, diagnosing and treating sleep disturbances to optimize sleep time and slow wave activity may have a stabilizing effect on cognition in preclinical or early symptomatic Alzheimer’s disease.
Assessing the Full Burden of Respiratory Syncytial Virus in Young Infants in Low- and Middle-Income Countries: The Importance of Community Mortality Studies
Authors: Srikantiah Padmini , Vora Prachi , Klugman Keith P 
Published: July 2021

Abstract
The Bill & Melinda Gates Foundation supported respiratory syncytial virus (RSV) mortality surveillance studies in several low- and middle-income countries to address the striking gap in community mortality burden data from these geographies. The compelling findings generated from these studies reveal a high unmeasured burden of community RSV mortality, particularly among infants aged &lt;6 months who are the target population for RSV immunization products currently in late-stage clinical development. These findings should inform revised global RSV mortality estimates and inform policy decisions on RSV vaccine financing and prioritization at the global and national levels.
Effect of radiographer-led intervention on reassurance, treatment satisfaction, and recurring chest pain in patients with a normal coronary computed tomography angiography—a randomized controlled trial
Authors: Krohn Isabel L , Rygh Cecilie B , Larsen Terje H , Wentzel-Larsen Tore , Norekvål Tone M 
Published: July 2021

Abstract

Background
Chest pain is a common complaint in the general practitioner’s (GP) office. Computed tomography (CT) is one of the main diagnostic tools available for assessing coronary artery disease (CAD), with a low probability of a false-negative result (&lt;1%). Despite normal CT findings, many patients with non-coronary chest pain believe they suffer from CAD.

Aims
To determine the effect of an intervention on reassurance, treatment satisfaction, and recurring chest pain in patients with non-coronary chest pain at follow-up after 1 month.

Methods
Patients with chest pain, but with normal coronary CT angiography, i.e., no CAD, were randomized into two groups. The intervention group received extended information about the CT examination, including visualization of their individual coronary calcium score images, before the radiographer conveyed the final examination result. The control group received standard care, i.e., neither extended information nor the examination result and were encouraged to consult their referring cardiologist or GP after 1 week. Items from the Seattle Angina Questionnaire and a question regarding reassurance measured the effect of the intervention at follow-up after 1 month.

Results
The study included 92 patients, 63 female and 29 male, with a follow-up response rate of 80%. Reassurance and overall treatment satisfaction were significantly higher in the intervention group (P = 0.016 and P = 0.046 respectively). The incidence of chest pain was significantly reduced in the intervention group (P = 0.042).

Conclusion
This study demonstrated that the intervention group showed significantly higher reassurance, overall treatment satisfaction, and experienced significantly less chest pain at follow-up after 1 month.

Clinical Trials Database ID
NCT03781661
The RAD52 Recombinational Repair Pathway is Essential in pol30 (PCNA) Mutants That Accumulate Small Single-Stranded DNA Fragments During DNA Synthesis
Authors: Merrill Bradley J , Holm Connie 
Published: July 2021

Abstract
To identify in vivo pathways that compensate for impaired proliferating cell nuclear antigen (PCNA or Pol30p in yeast) activity, we performed a synthetic lethal screen with the yeast pol30-104 mutation. We identified nine mutations that display synthetic lethality with pol30-104; three mutations affected the structural gene for the large subunit of replication factor C (rfc1), which loads PCNA onto DNA, and six mutations affected three members of the RAD52 epistasis group for DNA recombinational repair (rad50, rad52, and rad57). We also found that pol30-104 displayed synthetic lethality with mutations in other members of the RAD52 epistasis group (rad51 and rad54), but not with mutations in members of the RAD3 nor the RAD6 epistasis group. Analysis of nine different pol30 mutations shows that the requirement for the RAD52 pathway is correlated with a DNA replication defect but not with the relative DNA repair defect caused by pol30 mutations. In addition, mutants that require RAD52 for viability (pol30-100, pol30-104, rfc1-1 and rth1Δ) accumulate small single-stranded DNA fragments during DNA replication in vivo. Taken together, these data suggest that the RAD52 pathway is required when there are defects in the maturation of Okazaki fragments.
Genetic Analysis of Flagellar Length Control in Chlamydomonas reinhardtii: A New Long-Flagella Locus and Extragenic Suppressor Mutations
Authors: Asleson Catherine M , Lefebvre Paul A 
Published: July 2021

Abstract
Flagellar length in the biflagellate alga Chlamydomonas reinhardtii is under constant and tight regulation. A number of mutants with defects in flagellar length control have been previously identified. Mutations in the three long-flagella (lf) loci result in flagella that are up to three times longer than wild-type length. In this article, we describe the isolation of long-flagellar mutants caused by mutations in a new LF locus, LF4. lf4 mutations were shown to be epistatic to lf1, while lf2 was found to be epistatic to lf4 with regard to the flagellar regeneration defect. Mutations in lf4 were able to suppress the synthetic flagella-less phenotype of the lf1, lf2 double mutant. In addition, we have isolated four extragenic suppressor mutations that suppress the long-flagella phenotype of lf1, lf2, or lf3 double mutants.
An Insulin-like Signaling Pathway Affects Both Longevity and Reproduction in Caenorhabditis elegans
Authors: Tissenbaum Heidi A , Ruvkun Gary 
Published: July 2021

Abstract
Mutations in daf-2 and age-1 cause a dramatic increase in longevity as well as developmental arrest at the dauer diapause stage in Caenorhabditis elegans. daf-2 and age-1 encode components of an insulin-like signaling pathway. Both daf-2 and age-1 act at a similar point in the genetic epistasis pathway for dauer arrest and longevity and regulate the activity of the daf-16 gene. Mutations in daf-16 cause a dauer-defective phenotype and are epistatic to the diapause arrest and life span extension phenotypes of daf-2 and age-1 mutants. Here we show that mutations in this pathway also affect fertility and embryonic development. Weak daf-2 alleles, and maternally rescued age-1 alleles that cause life span extension but do not arrest at the dauer stage, also reduce fertility and viability. We find that age-1(hx546) has reduced both maternal and zygotic age-1 activity. daf-16 mutations suppress all of the daf-2 and age-1 phenotypes, including dauer arrest, life span extension, reduced fertility, and viability defects. These data show that insulin signaling, mediated by DAF-2 through the AGE-1 phosphatidylinositol-3-OH kinase, regulates reproduction and embryonic development, as well as dauer diapause and life span, and that DAF-16 transduces these signals. The regulation of fertility, life span, and metabolism by an insulin-like signaling pathway is similar to the endocrine regulation of metabolism and fertility by mammalian insulin signaling.
hold up Is Required for Establishment of Oocyte Positioning, Follicle Cell Fate and Egg Polarity and Cooperates with Egfr during Drosophila Oogenesis
Authors: Rotoli Deborah , Andone Silvia , Tortiglione Claudia , Manzi Andrea , Malva Carla , Graziani Franco 
Published: July 2021

Abstract
In Drosophila the posterior positioning of the oocyte within the germline cluster defines the initial asymmetry during oogenesis. From this early event, specification of both body axes is controlled through reciprocal signaling between germline and soma. Here it is shown that the mutation hold up (hup) affects oocyte positioning in the egg chamber, follicle cell fate and localization of different markers in the growing oocytes. This occurs not only in dicephalic egg chambers, but also in oocytes normally located at the posterior. Generation of mosaic egg chambers indicates that hup has to be at least somatically required. Possible interactions of hup with Egfr, the Drosophila epidermal growth factor receptor homolog, have been investigated in homozygous double mutants constructed by recombination. Stronger new ovarian phenotypes have been obtained, the most striking being accumulation of follicle cells in multiple layers posteriorly to the oocyte. It is proposed that the hup gene product is a component of the molecular machinery that leads to the establishment of polarity both in follicle cell layer and oocyte, acting in the same or in a parallel pathway of Egfr.
Mitochondrial Genotype Segregation During Preimplantation Development in Mouse Heteroplasmic Embryos
Authors: Meirelles Flávio V , Smith Lawrence C 
Published: July 2021

Abstract
Mitochondrial DNA content remains constant between the mature egg and the blastocyst stage in mammals, making this the only period in development when genotypes segregate to daughter cells without the confounding effect of genotype replication. To analyze the segregation patterns of mitochondrial DNA during preimplantation development, we introduced polymorphic mitochondria either peripherally (cytoplast transplantation) or in the perinuclear vicinity (karyplast transplantation) into zygotes. Genotype ratios were significantly more variable among blastomeres from cytoplast (coefficient of variation = 83.8%) than karyoplast (coefficient of variation = 34.7%) reconstructed zygotes. These results suggest that heteroplasmy caused by polymorphic mitochondria positioned in the periphery of oocytes at the time of fertilization shows a more stringent segregation pattern than when the organelle is in the vicinity of the nucleus. Moreover, donor-to-host mitochondrial genotype ratios in karyoplast-derived groups increased significantly during development, particularly in the C57BL/6 group, where the ratio practically doubled between the four-cell (17.3%) and the blastocyst stage (29.6%). Although the mechanisms controlling this preferential replication of nuclear-type mitochondrial DNA are unknown, it is suggested that access to nuclear-derived transcription and replication factors could lead to the preferential replication of perinuclear mitochondrial genotypes during morula and blastocyst formation.
The Laschamps geomagnetic excursion recorded in continental sediments from southern Germany
Authors: Kirscher U , Dallanave E , Weissbrodt V , Stojakowits P , Grau M , Bachtadse V , Mayr C 
Published: July 2021

SUMMARYWe present palaeo- and rock magnetic results from a well-dated, 21 m-thick, Late Pleistocene continental sedimentary section located in southern Germany. Rock magnetic measurements reveal a complex magnetic mineralogy dominated by low coercivity minerals likely related to single domain biogenic magnetite and biogenic or early diagenetic greigite. In the lower part of the section also detrital haematite is present. The stable remanence shows predominantly normal polarity with two marked deviations at ∼1280-1200 cm and at 886 cm profile depth. Whereas the lower excursion is well established by several samples and documented also by detrital haematite, the upper one is only represented by a single sample and revealed by magnetite and greigite. Using the radiocarbon-based age model for the section, the lower excursion yields an age of 42.8–41.3 ka cal BP and is interpreted to represent the Laschamps geomagnetic excursion. The increased abundance of greigite in the upper part of the section, especially in the sample responsible for the upper anomalous direction, renders the interpretation of an actual excursion problematic due to the reducing environment necessary for the greigite formation.
Synergistic role of retinoic acid signaling and Gata3 during primitive choanae formation
Authors: Kurosaka Hiroshi , Mushiake Jin , Saha Mithun , Wu Yanran , Wang Qi , Kikuchi Masataka , Nakaya Akihiro , Yamamoto Sayuri , Inubushi Toshihiro , Koga Satoshi , Sandell Lisa L , Trainor Paul A , Yamashiro Takashi 
Published: July 2021

Abstract
Developmental defects of primitive choanae, an anatomical path to connect the embryonic nasal and oral cavity, result in disorders called choanal atresia (CA), which are associated with many congenital diseases and require immediate clinical intervention after birth. Previous studies revealed that reduced retinoid signaling underlies the etiology of CA. In the present study, by using multiple mouse models which conditionally deleted Rdh10 and Gata3 during embryogenesis, we showed that Gata3 expression is regulated by retinoid signaling during embryonic craniofacial development and plays crucial roles for development of the primitive choanae. Interestingly, Gata3 loss of function is known to cause hypoparathyroidism, sensorineural deafness and renal disease (HDR) syndrome, which exhibits CA as one of the phenotypes in humans. Our model partially phenocopies HDR syndrome with CA, and is thus a useful tool for investigating the molecular and cellular mechanisms of HDR syndrome. We further uncovered critical synergy of Gata3 and retinoid signaling during embryonic development, which will shed light on novel molecular and cellular etiology of congenital defects in primitive choanae formation.