Generation of mice harbouring a conditional loss-of-function allele of Gata6

The zinc finger transcription factor GATA6 is believed to have important roles in the development of several organs including the liver, gastrointestinal tract and heart. However, analyses of the contribution of GATA6 toward organogenesis have been hampered because Gata6(-/- )mice fail to develop beyond gastrulation due to defects in extraembryonic endoderm function. We have therefore generated a mouse line harbouring a conditional loss-of-function allele of Gata6 using Cre/loxP technology. LoxP elements were introduced into introns flanking exon 2 of the Gata6 gene by homologous recombination in ES cells. Mice containing this altered allele were bred to homozygosity and were found to be viable and fertile. To assess the functional integrity of the loxP sites and to confirm that we had generated a Gata6 loss-of-function allele, we bred Gata6 'floxed' mice to EIIa-Cre mice in which Cre is ubiquitously expressed, and to Villin-Cre mice that express Cre in the epithelial cells of the intestine. We conclude that we have generated a line of mice in which GATA6 activity can be ablated in a cell type specific manner by expression of Cre recombinase. This line of mice can be used to establish the role of GATA6 in regulating embryonic development and various aspects of mammalian physiology

Development of the mammalian liver and ventral pancreas is dependent on GATA4

<p>Abstract</p> <p>Background</p> <p>In the mouse, the parenchyma of both the liver and ventral pancreas is specified from adjacent domains of the ventral foregut endoderm. GATA4, a zinc finger transcription factor, is strongly expressed in these endodermal domains and molecular analyses have implicated GATA4 in potentiating liver gene expression during the onset of hepatogenesis. We therefore hypothesized that GATA4 has an integral role in controlling the early stages of pancreatic and liver development.</p> <p>Results</p> <p>To determine whether GATA4 contributes to development of either the pancreas or liver we characterized the formation of pancreatic and hepatic tissues in embryos derived from <it>Gata4</it>^-/-ES cells by tetraploid embryo complementation. In the absence of GATA4, development of the liver and ventral pancreas was disrupted. At embryonic day (E) 9.5, the liver bud failed to expand although, contrary to expectations, the hepatic endoderm was able to form a pseudo-stratified epithelial liver bud that expressed hepatic genes. Moreover, as we had shown previously, the embryos lacked septum transversum mesenchyme suggesting that liver defects may be cell non-autonomous. Analyses of pancreatic development revealed a complete absence of the ventral but not the dorsal pancreas in <it>Gata4</it>^-/-embryos. Moreover, <it>Gata6</it>^-/-embryos displayed a similar, although less dramatic phenotype, suggesting a critical role for multiple GATA factors at the earliest stages of ventral pancreas development.</p> <p>Conclusion</p> <p>This study defines integral roles for GATA factors in controlling early development of the mammalian liver and pancreas.</p

Federated Meta-Learning for Few-Shot Fault Diagnosis with Representation Encoding

Deep learning-based fault diagnosis (FD) approaches require a large amount of training data, which are difficult to obtain since they are located across different entities. Federated learning (FL) enables multiple clients to collaboratively train a shared model with data privacy guaranteed. However, the domain discrepancy and data scarcity problems among clients deteriorate the performance of the global FL model. To tackle these issues, we propose a novel framework called representation encoding-based federated meta-learning (REFML) for few-shot FD. First, a novel training strategy based on representation encoding and meta-learning is developed. It harnesses the inherent heterogeneity among training clients, effectively transforming it into an advantage for out-of-distribution generalization on unseen working conditions or equipment types. Additionally, an adaptive interpolation method that calculates the optimal combination of local and global models as the initialization of local training is proposed. This helps to further utilize local information to mitigate the negative effects of domain discrepancy. As a result, high diagnostic accuracy can be achieved on unseen working conditions or equipment types with limited training data. Compared with the state-of-the-art methods, such as FedProx, the proposed REFML framework achieves an increase in accuracy by 2.17%-6.50% when tested on unseen working conditions of the same equipment type and 13.44%-18.33% when tested on totally unseen equipment types, respectively

Generation of single-copy transgenic mouse embryos directly from ES cells by tetraploid embryo complementation

BACKGROUND: Transgenic mice have been used extensively to analyze gene function. Unfortunately, traditional transgenic procedures have only limited use in analyzing alleles that cause lethality because lines of founder mice cannot be established. This is frustrating given that such alleles often reveal crucial aspects of gene function. For this reason techniques that facilitate the generation of embryos expressing such alleles would be of enormous benefit. Although the transient generation of transgenic embryos has allowed limited analysis of lethal alleles, it is expensive, time consuming and technically challenging. Moreover a fundamental limitation with this approach is that each embryo generated is unique and transgene expression is highly variable due to the integration of different transgene copy numbers at random genomic sites. RESULTS: Here we describe an alternative method that allows the generation of clonal mouse embryos harboring a single-copy transgene at a defined genomic location. This was facilitated through the production of Hprt negative embryonic stem cells that allow the derivation of embryos by tetraploid embryo complementation. We show that targeting transgenes to the hprt locus in these ES cells by homologous recombination can be efficiently selected by growth in HAT medium. Moreover, embryos derived solely from targeted ES cells containing a single copy LacZ transgene under the control of the α-myosin heavy chain promoter exhibited the expected cardiac specific expression pattern. CONCLUSION: Our results demonstrate that tetraploid embryo complementation by F3 hprt negative ES cells facilitates the generation of transgenic mouse embryos containing a single copy gene at a defined genomic locus. This approach is simple, extremely efficient and bypasses any requirement to generate chimeric mice. Moreover embryos generated by this procedure are clonal in that they are all derived from a single ES cell lines. This facilitates the comparative analysis of lethal alleles and thereby advances our ability to analyze gene function in mammals

Amn1 governs post-mitotic cell separation in Saccharomyces cerevisiae

<div><p>Post-mitotic cell separation is one of the most prominent events in the life cycle of eukaryotic cells, but the molecular underpinning of this fundamental biological process is far from being concluded and fully characterized. We use budding yeast <i>Saccharomyces cerevisiae</i> as a model and demonstrate <i>AMN1</i> as a major gene underlying post-mitotic cell separation in a natural yeast strain, YL1C. Specifically, we define a novel 11-residue domain by which Amn1 binds to Ace2. Moreover, we demonstrate that Amn1 induces proteolysis of Ace2 through the ubiquitin proteasome system and in turn, down-regulates Ace2’s downstream target genes involved in hydrolysis of the primary septum, thus leading to inhibition of cell separation and clumping of haploid yeast cells. Using ChIP assays and site-specific mutation experiments, we show that Ste12 and the a1-α12 heterodimer are two direct regulators of <i>AMN1</i>. Specifically, a1-α2, a diploid-specific heterodimer, prevents Ste12 from inactivating <i>AMN1</i> through binding to its promoter. This demonstrates how the Amn1-governed cell separation is highly cell type dependent. Finally, we show that <i>AMN1</i>^<i>368D</i> from YL1C is a dominant allele in most strains of <i>S</i>. <i>cerevisiae</i> and evolutionarily conserved in both genic structure and phenotypic effect in two closely related yeast species, <i>K</i>. <i>lactis</i> and <i>C</i>. <i>glabrata</i>.</p></div

The long noncoding RNA lncNB1 promotes tumorigenesis by interacting with ribosomal protein RPL35

The majority of patients with neuroblastoma due to MYCN oncogene amplification and consequent N-Myc oncoprotein over-expression die of the disease. Here our analyses of RNA sequencing data identify the long noncoding RNA lncNB1 as one of the transcripts most over-expressed in MYCN-amplified, compared with MYCN-non-amplified, human neuroblastoma cells and also the&nbsp;most over-expressed in neuroblastoma compared with all other cancers. lncNB1 binds to the ribosomal protein RPL35 to enhance E2F1 protein synthesis, leading to DEPDC1B gene transcription. The GTPase-activating protein DEPDC1B induces ERK protein phosphorylation and N-Myc protein stabilization. Importantly, lncNB1 knockdown abolishes neuroblastoma cell clonogenic capacity in vitro and leads to neuroblastoma tumor regression in mice, while high levels of lncNB1 and RPL35 in human neuroblastoma tissues predict poor patient prognosis. This study therefore identifies lncNB1 and its binding protein RPL35 as key factors for promoting E2F1 protein synthesis, N-Myc protein stability and N-Myc-driven oncogenesis, and as therapeutic targets

Forecasting and Improving the Call Center Operations - Time Series approach and Queueing theory approach

This paper mainly aims to provide the data story to the call center to improve operations, assisting the Business Experience Team to make data-driven decisions. We intend to capture the pattern of current trends and seasonality, as well as the forecasting for the next peak season call volume by time series approach. More importantly, we would like to identify the optimum staffing levels needed to meet certain service goals by implementing queueing model. In order to predict the baseline and the peak season of the call volume, we compare 2 time series models: ARIMA (autoregressive integrated moving averages) model and Holt-Winters exponential smoothing model. The later one gives a better prediction of the call volume. Moreover, we employ 3 classical models (ErlangC, ErlangB and ErlangA models) to find the relationship between the number of operators needed and the wait time of customers in the queue. We end up with the conclusion that increasing 5 operators could achieve the target: 95% of phone calls are answered within 5 minutes

The Evaluation of the Low Income Housing Tax Credit Exploration of Allocation in Connecticut, Florida, Maryland, Mississippi and Wisconsin

Our study was inspired by a 2009 lawsuit in Texas, where a nonprofit organization, the Inclusive Communities Project (ICP), sued the Texas Department of Housing and Community Affairs for disproportionally allocating tax credits in minority-concentrated neighborhoods, while disproportionally withholding tax credits from predominantly Caucasian neighborhoods. Ultimately, the Supreme Court ruled that as long as the plan is not inherently racist then the plaintiff has the responsibility to develop an alternative plan that would ensure equality in impact. This ruling brings forth questions about the disparity in impact in other states besides Texas, and if there are specific features of state allocation plans that may be contributing to any observed disparity in impact along racial lines. In this context, we sought to examine and answer the following questions: 1. What are the trends in situating LIHTC properties in minority-concentrated neighborhoods? 2. What are the features of states’ plans that affect the disparity in impact in locating LIHTC units?United States Government Accountability Offic

Does low-carbon pilot policy in China improve corporate profitability? The role of innovation and subsidy

In an effort to aggressively combat climate change, China mplemented a low-carbon city pilot policy (LCCP) in 2010. This study analyzes the impact LCCP, which is a specific environmental regulation on firms' profitability and innovation performance. The study argues that LCCP has an impact on corporate profitability by enhancing corporate innovation. Based on the data of A-share listed enterprises from 2005 to 2020, this study employ a multi-period Differences-in-Differences (DID) method to explore whether and how the LCCP affects the profitability of enterprises. The study finds that: (1) LCCP can greatly increase enterprise profitability; (2) LCCP has a more prompt effect on the profitability of large companies; (3) LCCP increases innovation investment and financial subsidies, which in turn increases company profitability. The study enriches the body of knowledge on the effects of LCCP on large companies and SMEs, and provides crucial evidence base for the consequences of government's strategy to assist firms in achieving the low carbon growth