bluuebunny/crossref_metadata_2025_split huggingface dataset:
ESTIMATES FOR APPROXIMATE SOLUTIONS TO A FUNCTIONAL DIFFERENTIAL EQUATION MODEL OF CELL DIVISION
Authors: TAYLOR STEPHEN , YANG XUESHAN 
Published: March 2021

AbstractThe functional partial differential equation (FPDE) for cell division, $$ \begin{align*} &\frac{\partial}{\partial t}n(x,t) +\frac{\partial}{\partial x}(g(x,t)n(x,t))\\ &\quad = -(b(x,t)+\mu(x,t))n(x,t)+b(\alpha x,t)\alpha n(\alpha x,t)+b(\beta x,t)\beta n(\beta x,t), \end{align*} $$is not amenable to analytical solution techniques, despite being closely related to the first-order partial differential equation (PDE) $$ \begin{align*} \frac{\partial}{\partial t}n(x,t) +\frac{\partial}{\partial x}(g(x,t)n(x,t)) = -(b(x,t)+\mu(x,t))n(x,t)+F(x,t), \end{align*} $$which, with known $F(x,t)$, can be solved by the method of characteristics. The difficulty is due to the advanced functional terms $n(\alpha x,t)$ and $n(\beta x,t)$, where $\beta \ge 2 \ge \alpha \ge 1$, which arise because cells of size x are created when cells of size $\alpha x$ and $\beta x$ divide.The nonnegative function, $n(x,t)$, denotes the density of cells at time t with respect to cell size x. The functions $g(x,t)$, $b(x,t)$ and $\mu (x,t)$ are, respectively, the growth rate, splitting rate and death rate of cells of size x. The total number of cells, $\int _{0}^{\infty }n(x,t)\,dx$, coincides with the $L^1$ norm of n. The goal of this paper is to find estimates in $L^1$ (and, with some restrictions, $L^p$ for $p>1$) for a sequence of approximate solutions to the FPDE that are generated by solving the first-order PDE. Our goal is to provide a framework for the analysis and computation of such FPDEs, and we give examples of such computations at the end of the paper.
A Multi‐Hydrogeophysical Study of a Watershed at Kaiwi Coast (Oʻahu, Hawaiʻi), using Seismic Ambient Noise Surface Wave Tomography and Self‐Potential Data
Authors: Grobbe Niels , Mordret Aurélien , Barde‐Cabusson Stéphanie , Ellison Lucas , Lach Mackenzie , Seo Young‐Ho , Viti Taylor , Ward Lauren , Zhang Haozhe 
Published: March 2021

AbstractWe study a watershed containing an old stream valley at the Kaiwi Coast on Oʻahu, Hawaiʻi. The study site has undergone significant hydrogeological changes throughout its history, and at present displays complex interactions of a variety of geological formations. We highlight an innovative and efficient combination of two hydrogeophysical methodologies for studying groundwater systems: ambient noise surface wave tomography (ANSWT), and self‐potential (SP) measurements. We collected (1) 5 days of continuous seismic data, using a total of 54 autonomous seismic nodes, exploiting both ocean wave and traffic noise sources and (2) 386 SP measurements with an average 20 m spacing, in the same area. We showcase how these two data sets complement each other in a joint‐interpretation framework. The SP data display the distribution of groundwater in the region, as well as zones of higher infiltration and/or flow rates. Using ANSWT, we identify the structural contact between the older Koʻolau basalt formation and the younger post‐erosional Honolulu volcanics, as well as the distribution of sedimentary valley fill and coastal deposits. The joint interpretation of the SP and seismic data clearly illustrates that groundwater flow occurs in the identified paleo‐channels at the erosional surface of the basaltic bedrock. Furthermore, it highlights that the basaltic bedrock of the ridges likely forms an important groundwater flow unit. Some flow may occur in the shallower valley fill material. Complementing SP data with seismic data enables us to place groundwater flow inferences, as made from SP data, at depth.
EHF suppresses cancer progression by inhibiting ETS1-mediated ZEB expression
Authors: Sakamoto Kaname , Endo Kaori , Sakamoto Kei , Kayamori Kou , Ehata Shogo , Ichikawa Jiro , Ando Takashi , Nakamura Ryosuke , Kimura Yujiro , Yoshizawa Kunio , Masuyama Keisuke , Kawataki Tomoyuki , Miyake Kunio , Ishii Hiroki , Kawasaki Tomonori , Miyazawa Keiji , Saitoh Masao 
Published: March 2021

AbstractETS homologous factor (EHF) belongs to the epithelium-specific subfamily of the E26 transformation-specific (ETS) transcription factor family. Currently, little is known about EHF’s function in cancer. We previously reported that ETS1 induces expression of the ZEB family proteins ZEB1/δEF1 and ZEB2/SIP1, which are key regulators of the epithelial–mesenchymal transition (EMT), by activating the ZEB1 promoters. We have found that EHF gene produces two transcript variants, namely a long form variant that includes exon 1 (EHF-LF) and a short form variant that excludes exon 1 (EHF-SF). Only EHF-SF abrogates ETS1-mediated activation of the ZEB1 promoter by promoting degradation of ETS1 proteins, thereby inhibiting the EMT phenotypes of cancer cells. Most importantly, we identified a novel point mutation within the conserved ETS domain of EHF, and found that EHF mutations abolish its original function while causing the EHF protein to act as a potential dominant negative, thereby enhancing metastasis in vivo. Therefore, we suggest that EHF acts as an anti-EMT factor by inhibiting the expression of ZEBs, and that EHF mutations exacerbate cancer progression.
DNA methylation predicts age and provides insight into exceptional longevity of bats
Authors: Wilkinson Gerald S. , Adams Danielle M. , Haghani Amin , Lu Ake T. , Zoller Joseph , Breeze Charles E. , Arnold Bryan D. , Ball Hope C. , Carter Gerald G. , Cooper Lisa Noelle , Dechmann Dina K. N. , Devanna Paolo , Fasel Nicolas J. , Galazyuk Alexander V. , Günther Linus , Hurme Edward , Jones Gareth , Knörnschild Mirjam , Lattenkamp Ella Z. , Li Caesar Z. , Mayer Frieder , Reinhardt Josephine A. , Medellin Rodrigo A. , Nagy Martina , Pope Brian , Power Megan L. , Ransome Roger D. , Teeling Emma C. , Vernes Sonja C. , Zamora-Mejías Daniel , Zhang Joshua , Faure Paul A. , Greville Lucas J. , Herrera M. L. Gerardo , Flores-Martínez José J. , Horvath Steve 
Published: March 2021

AbstractExceptionally long-lived species, including many bats, rarely show overt signs of aging, making it difficult to determine why species differ in lifespan. Here, we use DNA methylation (DNAm) profiles from 712 known-age bats, representing 26 species, to identify epigenetic changes associated with age and longevity. We demonstrate that DNAm accurately predicts chronological age. Across species, longevity is negatively associated with the rate of DNAm change at age-associated sites. Furthermore, analysis of several bat genomes reveals that hypermethylated age- and longevity-associated sites are disproportionately located in promoter regions of key transcription factors (TF) and enriched for histone and chromatin features associated with transcriptional regulation. Predicted TF binding site motifs and enrichment analyses indicate that age-related methylation change is influenced by developmental processes, while longevity-related DNAm change is associated with innate immunity or tumorigenesis genes, suggesting that bat longevity results from augmented immune response and cancer suppression.
A Model of the Cosmos in the ancient Greek Antikythera Mechanism
Authors: Freeth Tony , Higgon David , Dacanalis Aris , MacDonald Lindsay , Georgakopoulou Myrto , Wojcik Adam 
Published: March 2021

AbstractThe Antikythera Mechanism, an ancient Greek astronomical calculator, has challenged researchers since its discovery in 1901. Now split into 82 fragments, only a third of the original survives, including 30 corroded bronze gearwheels. Microfocus X-ray Computed Tomography (X-ray CT) in 2005 decoded the structure of the rear of the machine but the front remained largely unresolved. X-ray CT also revealed inscriptions describing the motions of the Sun, Moon and all five planets known in antiquity and how they were displayed at the front as an ancient Greek Cosmos. Inscriptions specifying complex planetary periods forced new thinking on the mechanization of this Cosmos, but no previous reconstruction has come close to matching the data. Our discoveries lead to a new model, satisfying and explaining the evidence. Solving this complex 3D puzzle reveals a creation of genius—combining cycles from Babylonian astronomy, mathematics from Plato’s Academy and ancient Greek astronomical theories.
Real-time seroprevalence and exposure levels of emerging pathogens in infection-naive host populations
Authors: Pinotti Francesco , Obolski Uri , Wikramaratna Paul , Giovanetti Marta , Paton Robert , Klenerman Paul , Thompson Craig , Gupta Sunetra , Lourenço José 
Published: March 2021

AbstractFor endemic pathogens, seroprevalence mimics overall exposure and is minimally influenced by the time that recent infections take to seroconvert. Simulating spatially-explicit and stochastic outbreaks, we set out to explore how, for emerging pathogens, the mix of exponential growth in infection events and a constant rate for seroconversion events could lead to real-time significant differences in the total numbers of exposed versus seropositive. We find that real-time seroprevalence of an emerging pathogen can underestimate exposure depending on measurement time, epidemic doubling time, duration and natural variation in the time to seroconversion among hosts. We formalise mathematically how underestimation increases non-linearly as the host’s time to seroconversion is ever longer than the pathogen’s doubling time, and how more variable time to seroconversion among hosts results in lower underestimation. In practice, assuming that real-time seroprevalence reflects the true exposure to emerging pathogens risks overestimating measures of public health importance (e.g. infection fatality ratio) as well as the epidemic size of future waves. These results contribute to a better understanding and interpretation of real-time serological data collected during the emergence of pathogens in infection-naive host populations.
Loss-of-function mutations in the histone methyltransferase EZH2 promote chemotherapy resistance in AML
Authors: Kempf Julia M. , Weser Sabrina , Bartoschek Michael D. , Metzeler Klaus H. , Vick Binje , Herold Tobias , Völse Kerstin , Mattes Raphael , Scholz Manuela , Wange Lucas E. , Festini Moreno , Ugur Enes , Roas Maike , Weigert Oliver , Bultmann Sebastian , Leonhardt Heinrich , Schotta Gunnar , Hiddemann Wolfgang , Jeremias Irmela , Spiekermann Karsten 
Published: March 2021

AbstractChemotherapy resistance is the main impediment in the treatment of acute myeloid leukaemia (AML). Despite rapid advances, the various mechanisms inducing resistance development remain to be defined in detail. Here we report that loss-of-function mutations (LOF) in the histone methyltransferase EZH2 have the potential to confer resistance against the chemotherapeutic agent cytarabine. We identify seven distinct EZH2 mutations leading to loss of H3K27 trimethylation via multiple mechanisms. Analysis of matched diagnosis and relapse samples reveal a heterogenous regulation of EZH2 and a loss of EZH2 in 50% of patients. We confirm that loss of EZH2 induces resistance against cytarabine in the cell lines HEK293T and K562 as well as in a patient-derived xenograft model. Proteomics and transcriptomics analysis reveal that resistance is conferred by upregulation of multiple direct and indirect EZH2 target genes that are involved in apoptosis evasion, augmentation of proliferation and alteration of transmembrane transporter function. Our data indicate that loss of EZH2 results in upregulation of its target genes, providing the cell with a selective growth advantage, which mediates chemotherapy resistance.
A general framework and practical procedure for improving pxrf measurement accuracy with integrating moisture content and organic matter content parameters
Authors: Chen Zengsiche , Xu Ya , Lei Guoyuan , Liu Yuqiang , Liu Jingcai , Yao Guangyuan , Huang Qifei 
Published: March 2021

AbstractRapid, accurate detection of heavy-metal content is extremely important for precise risk control and targeted remediation. Herein, a general modeling method and process based on the relationship between Pxrf measured values and site parameters are explored to construct a Pxrf correction model suitable to improve each site’s measurement accuracy. Results show a significant correlation between Pb, Mn, and Zn Pxrf measured values and actual concentrations, with correlation coefficients between 0.8 and 0.93. Through the correlation analysis, the correlation coefficient between the water content and the measured value of pxrf is in the range of 0.2–0.5. Pxrf measurement of all heavy metals was weakly affected by soil organic matter content, with correlation coefficients all lower than 0.5. Model transformation effectively improved the correlation between measured Pxrf value and actual concentration, and transformation increased the correlations of Sr, Mn, and Cu by around 0.11. Model verification results showed that the Pb, Zn, Fe, and Mn models can be used to improve Pxrf method detection accuracy.
Dual-specificity phosphatase 3 deletion promotes obesity, non-alcoholic steatohepatitis and hepatocellular carcinoma
Authors: Jacques Sophie , Arjomand Arash , Perée Hélène , Collins Patrick , Mayer Alice , Lavergne Arnaud , Wéry Marie , Mni Myriam , Hego Alexandre , Thuillier Virginie , Becker Guillaume , Bahri Mohamed Ali , Plenevaux Alain , Di Valentin Emmanuel , Oury Cécile , Moutschen Michel , Delvenne Philippe , Paquot Nicolas , Rahmouni Souad 
Published: March 2021

AbstractNon-alcoholic fatty liver disease (NAFLD) is the most common chronic hepatic pathology in Western countries. It encompasses a spectrum of conditions ranging from simple steatosis to more severe and progressive non-alcoholic steatohepatitis (NASH) that can lead to hepatocellular carcinoma (HCC). Obesity and related metabolic syndrome are important risk factors for the development of NAFLD, NASH and HCC. DUSP3 is a small dual-specificity protein phosphatase with a poorly known physiological function. We investigated its role in metabolic syndrome manifestations and in HCC using a mouse knockout (KO) model. While aging, DUSP3-KO mice became obese, exhibited insulin resistance, NAFLD and associated liver damage. These phenotypes were exacerbated under high fat diet (HFD). In addition, DEN administration combined to HFD led to rapid HCC development in DUSP3-KO compared to wild type (WT) mice. DUSP3-KO mice had more serum triglycerides, cholesterol, AST and ALT compared to control WT mice under both regular chow diet (CD) and HFD. The level of fasting insulin was higher compared to WT mice, though, fasting glucose as well as glucose tolerance were normal. At the molecular level, HFD led to decreased expression of DUSP3 in WT mice. DUSP3 deletion was associated with increased and consistent phosphorylation of the insulin receptor (IR) and with higher activation of the downstream signaling pathway. In conclusion, our results support a new role for DUSP3 in obesity, insulin resistance, NAFLD and liver damage.
Intracranial baroreflex is attenuated in an ovine model of renovascular hypertension
Authors: Vari Sydney , Guild Sarah-Jane , George Bindu , Ramchandra Rohit 
Published: March 2021

AbstractWe have previously shown that elevations in intracranial pressure (ICP) within physiological ranges in normotensive animals increase arterial pressure; termed the intracranial baroreflex. Hypertension is associated with alterations in reflexes which maintain arterial pressure however, whether the intracranial baroreflex is altered is not known. Hence, in the present study, we tested the hypothesis that in hypertension, physiological increases in ICP would not be accompanied with an increase in arterial pressure. Renovascular hypertension was associated with no change in heart rate, renal blood flow or ICP levels compared to the normotensive group. ICV infusion of saline produced a ramped increase in ICP of 20 ± 1 mmHg. This was accompanied by an increase in arterial pressure (16 ± 2 mmHg) and a significant decrease in renal vascular conductance. ICV infusion of saline in the hypertensive group also increased ICP (19 ± 2 mmHg). However, the increase in arterial pressure was significantly attenuated in the hypertensive group (5 ± 2 mmHg). Ganglionic blockade abolished the increase in arterial pressure in both groups to increased ICP. Our data indicates that physiological increases in ICP lead to increases in arterial pressure in normotensive animals but this is severely attenuated in renovascular hypertension.
CT assessment of the increased density of cerebral vessels in plateau region
Authors: Zhou Haiting , Tashi Tsering , Zhao Deli , Tsring Sonam , Liang Hongwei , Zhang Jinling 
Published: March 2021

AbstractIn this study, the relationship between the brain parenchymal density, the cerebral vessel density, the mean corpuscular hemoglobin (MCH) content, the mean corpuscular hemoglobin concentration (MCHC), and the morbidity associated with lacunar infarction of residents living in either the plains or the plateau regions were analyzed and compared for their potential clinical implications. Clinical data from the brain CT scans of individuals living in either the plain or plateau regions (129 each) were collected. Specifically, the CT values for basal ganglia, the middle cerebral artery, and the superior sagittal sinus, along with the number of patients with lacunar infarction, were collected. In addition, the MCH and MCHC values were measured in blood samples collected within 48 h following the CT scans. For statistical analysis, an independent sample t-test, Pearson's correlation test (permutation test), and Chi-squared test were employed. The inhabitants of the plateau had a significantly higher CT value of basal ganglia, the middle cerebral artery, and superior sagittal sinus and also higher levels of MCH and MCHC in the blood (ps < 0.001) than the inhabitants of the plains region. Further, there was a significant positive correlation between the three aforementioned CT values and the MCH and MCHC findings. However, no significant differences were found in the morbidity of lacunar infarction between these two regions (p > 0.05). The inhabitants in the plateau have a significantly higher brain parenchymal density, higher CT value for cerebral vessels density, and higher blood MCH and MCHC levels in comparison with individuals occupying the plains. Concurrently, the parenchymal density and the CT values are shown to be positively correlated with the MCH and MCHC content in the blood.
Transcriptional regulation of dosage compensation in Carica papaya
Authors: Liu Juan , Han Jennifer , Sharma Anupma , Wai Ching Man , Ming Ray , Yu Qingyi 
Published: March 2021

AbstractSex chromosome evolution results in the disparity in gene content between heterogametic sex chromosomes and creates the need for dosage compensation to counteract the effects of gene dose imbalance of sex chromosomes in males and females. It is not known at which stage of sex chromosome evolution dosage compensation would evolve. We used global gene expression profiling in male and female papayas to assess gene expression patterns of sex-linked genes on the papaya sex chromosomes. By analyzing expression ratios of sex-linked genes to autosomal genes and sex-linked genes in males relative to females, our results showed that dosage compensation was regulated on a gene-by-gene level rather than whole sex-linked region in papaya. Seven genes on the papaya X chromosome exhibited dosage compensation. We further compared gene expression ratios in the two evolutionary strata. Y alleles in the older evolutionary stratum showed reduced expression compared to X alleles, while Y alleles in the younger evolutionary stratum showed elevated expression compared to X alleles. Reduced expression of Y alleles in the older evolutionary stratum might be caused by accumulation of deleterious mutations in regulatory regions or transposable element-mediated methylation spreading. Most X-hemizygous genes exhibited either no or very low expression, suggesting that gene silencing might play a role in maintaining transcriptional balance between females and males.
The catalytic subunit of Plasmodium falciparum casein kinase 2 is essential for gametocytogenesis
Authors: Hitz Eva , Grüninger Olivia , Passecker Armin , Wyss Matthias , Scheurer Christian , Wittlin Sergio , Beck Hans-Peter , Brancucci Nicolas M. B. , Voss Till S. 
Published: March 2021

AbstractCasein kinase 2 (CK2) is a pleiotropic kinase phosphorylating substrates in different cellular compartments in eukaryotes. In the malaria parasite Plasmodium falciparum, PfCK2 is vital for asexual proliferation of blood-stage parasites. Here, we applied CRISPR/Cas9-based gene editing to investigate the function of the PfCK2α catalytic subunit in gametocytes, the sexual forms of the parasite that are essential for malaria transmission. We show that PfCK2α localizes to the nucleus and cytoplasm in asexual and sexual parasites alike. Conditional knockdown of PfCK2α expression prevented the transition of stage IV into transmission-competent stage V gametocytes, whereas the conditional knockout of pfck2a completely blocked gametocyte maturation already at an earlier stage of sexual differentiation. In summary, our results demonstrate that PfCK2α is not only essential for asexual but also sexual development of P. falciparum blood-stage parasites and encourage studies exploring PfCK2α as a potential target for dual-active antimalarial drugs.
High-contrast photochromic Eu-doped K0.5Na0.5NbO3 ceramics with prominent pellucidity
Authors: Zhou Yang , Wang Peng , Lin Jinfeng , Lu Qiling , Wu Xiao , Gao Min , Lin Tengfei , Lin Cong , Zheng Xinghua 
Published: March 2021

Eu-doped K0.5Na0.5NbO3 pellucid ceramics, with light illumination-induced high-contrast photochromic behaviors of both optical transmittance and photoluminescence, exhibit potential in the application of optical data storage.
COVID-19: Risikofaktor Adipositas – seine Relevanz und die ursächlichen pathophysiologischen Mechanismen
Authors: Balfanz Paul , Marx Nikolaus , Müller-Wieland Dirk 
Published: March 2021

ZusammenfassungDie Frage nach einer Assoziation von Risikofaktoren mit der „Coronavirus Disease 2019“ (COVID-19), die durch die Infektion mit dem Virus SARS-CoV-2 ausgelöst wird, kann aktuell nicht relevanter sein.In der ersten deutschen Analyse der Uniklinik Aachen, aber auch in weiteren internationalen Studien konnte eine erhöhte Prävalenz an Übergewicht bzw. Adipositas unter den Erkrankten gezeigt werden. Eine Korrelation der Höhe des BMI mit der Schwere der Erkrankung und der Dauer und Notwendigkeit der Therapie wird deutlich. Zudem sorgt das Vorliegen einer Adipositas für das Erkranken von Patienten mit jüngerem Lebensalter.Pathophysiologisch bieten zahlreiche Mechanismen eine mögliche Begründung. Hierunter zählen die Veränderung und Einschränkung der Organfunktion durch Akkumulation von Fettgewebe, aber auch die erhöhte Expression von ACE-2-Rezeptoren, die als Bindeprotein des SARS-CoV-2 das Eindringen in die Zelle ermöglichen. Durch die Freisetzung von Adipokinen kommt es zu einer chronischen pro-inflammatorischen Situation mit veränderter immunozellulären Abwehr und über eine veränderte Insulinreaktion zu einer höheren Prävalenz eines Diabetes mellitus mit daraus folgender schlechterer Krankheitsprognose. Dies erzeugt einen negativen Effekt auf die Lungenfunktion. Es kommt dort durch die Fettablagerung zu einer reduzierten systemischen Compliance und zu einer erhöhten Sensibilität für respiratorische Infektionen. Zudem zeigen sich im Rahmen einer Adipositas ein erniedrigtes exspiratorisches Reservevolumen, „gas trapping“ und eine resultierende systemische Hypoxie.Der spezifische Tropismus unterschiedlicher Viren hin zu Adipozyten unterstreicht durch den Aspekt der Viruspersistenz und chronischen Immunaktivität zusätzlich zu den anderen genannten Punkten die Bedeutung des Risikofaktors Adipositas im Zusammenhang mit dem Progress und der Therapie von COVID-19, aber auch anderer viraler Erkrankungen.