Cell type-specific regulation of choline acetyltransferase gene expression - Role of the neuron-restrictive silencer element and cholinergic-specific enhancer

This study demonstrates the presence of positive and negative regulatory elements within a 2336-base pair-long region of the rat choline acetyltransferase (ChAT) gene promoter that cooperate to direct cell type-specific expression in cholinergic cells. A 21-base pair-long neuron-restrictive silencer element (NRSE) was identified in the proximal part of this region. This element was recognized by the neuron-restrictive silencer factor (NRSF), previously shown to regulate expression of other neuron-specific genes. The ChAT NRSE was inactive in both cholinergic and non-cholinergic neuronal cells, but repressed expression from a heterologous promoter in non-neuronal cells. Specific deletion of this element allowed ChAT gene promoter activity in non-neuronal cells, and overexpression of NRSF repressed ChAT gene promoter activity in cholinergic cells. The distal part of the ChAT gene promoter showed cholinergic-specific enhancing activity, which stimulated promoter activity in cholinergic cells, but was inactive in non-cholinergic neuronal and non-neuronal cells. This enhancer region suppressed the activity of the ChAT NRSE in cholinergic cells, even after NRSF overexpression. Thus, at least two kinds of regulatory elements cooperate to direct ChAT gene expression to cholinergic neurons, namely a neuron-restrictive silencer element and a cholinergic-specific enhancer

Oct4/Sox2 binding sites contribute to maintaining hypomethylation of the maternal Igf2/H19 imprinting control region

A central question in genomic imprinting is how parental-specific DNA methylation of imprinting control regions (ICR) is established during gametogenesis and maintained after fertilization. At the imprinted Igf2/H19 locus, CTCF binding maintains the unmethylated state of the maternal ICR after the blastocyst stage. In addition, evidence from Beckwith-Wiedemann patients and cultured mouse cells suggests that two Sox-Oct binding motifs within the Igf2/H19 ICR also participate in maintaining hypomethylation of the maternal allele. We found that the Sox and octamer elements from both Sox-Oct motifs were required to drive hypomethylation of integrated transgenes in mouse embryonic carcinoma cells. Oct4 and Sox2 showed cooperative binding to the Sox-Oct motifs, and both were present at the endogenous ICR. Using a mouse with mutations in the Oct4 binding sites, we found that maternally transmitted mutant ICRs acquired partial methylation in somatic tissues, but there was little effect on imprinted expression of H19 and Igf2. A subset of mature oocytes also showed partial methylation of the mutant ICR, which suggested that the Sox-Oct motifs provide some protection from methylation during oogenesis. The Sox-Oct motifs, however, were not required for erasure of paternal methylation in primordial germ cells, which indicated that the oocyte methylation was acquired post-natally. Maternally inherited mutant ICRs were unmethylated in blastocysts, which suggested that at least a portion of the methylation in somatic tissues occurred after implantation. These findings provide evidence that Sox-Oct motifs contribute to ICR hypomethylation in post-implantation embryos and maturing oocytes and link imprinted DNA methylation with key stem cell/germline transcription factors

Short-term versus long-term benefits: balanced sustainability framework and research propositions

Sustainability research has been expanding rapidly during recent decades. Such research takes various forms with the identification of mixed results. Even though there are several review articles on sustainability with valuable insights, the time dimension aspect of sustainability is totally missing in addition to lack of well-developed framework. This paper systematically reviews previous sustainability studies published in the refereed scientific journals for the past two decades to understand the evolution of sustainability issues in the business context and solutions proposed until now. The study categorizes the popular sustainability practices into short- and long-term practices based on the time effect, and link them with different forms of organizational capabilities and sustainability performance. The paper further proposes a two-dimensional sustainability framework that incorporates practices, capabilities and performance, and the balancing issues between short- and long-term sustainability. At the end, it suggests potential research directions for future research as well

Can Big Data and Predictive Analytics Improve Social and Environmental Sustainability?

Although literature indicates that big data and predictive analytics (BDPA) convey a distinct organisational capability, little is known about their performance effects in particular contextual conditions. Grounding our investigation in the dynamic capability views and organisational culture and based on sample of 205 Indian manufacturing organisations, we empirically investigate the effects of BDPA on social performance (SP) and environmental performance (EP) using variance based structural equation modelling (i.e. PLS). We find that BDPA has significant impact on SP/EP. However, we did not find evidence for moderating role of flexible orientation and control orientation in the links between BDPA and SP/EP. Our findings offer a more nuanced understanding of the performance implications of BDPA, thereby addressing the crucial questions of how and when BDPA can enhance social/environmental sustainability in supply chains

Recommendations for the Generation, Quantification, Storage, and Handling of Peptides Used for Mass Spectrometry-Based Assays

BACKGROUND: For many years, basic and clinical researchers have taken advantage of the analytical sensitivity and specificity afforded by mass spectrometry in the measurement of proteins. Clinical laboratories are now beginning to deploy these work flows as well. For assays that use proteolysis to generate peptides for protein quantification and characterization, synthetic stable isotope-labeled internal standard peptides are of central importance. No general recommendations are currently available surrounding the use of peptides in protein mass spectrometric assays. CONTENT: The Clinical Proteomic Tumor Analysis Consortium of the National Cancer Institute has collaborated with clinical laboratorians, peptide manufacturers, metrologists, representatives of the pharmaceutical industry, and other professionals to develop a consensus set of recommendations for peptide procurement, characterization, storage, and handling, as well as approaches to the interpretation of the data generated by mass spectrometric protein assays. Additionally, the importance of carefully characterized reference materials-in particular, peptide standards for the improved concordance of amino acid analysis methods across the industry-is highlighted. The alignment of practices around the use of peptides and the transparency of sample preparation protocols should allow for the harmonization of peptide and protein quantification in research and clinical care

Three essays in financial economics

This thesis contains three chapters that study different aspects of financial economics. The first part of the thesis studies the effect of weakening creditor rights on distress risk premia via a bankruptcy reform that shifts bargaining power in financial distress toward shareholders. We find that the reform reduces risk factor loadings and returns of distressed stocks. The effect is stronger for firms with lower firm-level shareholder bargaining power. An increase in credit spreaids of riskier relative to safer firms, in particular for firms with lower firm-level shareholder bargaining power, confirms a shift in bargaining power fro bondholders toshareholders. Out-of-sample tests reveal that a reversal of the reform's effects leads to a reversal of factor loadings and returns. The second part of the thesis examines how social connections in elite networks affect the allocation of bank credit. We employ a unique dataset on members of an elite service club in Germany to study this question. Specifically, we investigate credit allocation decision of banks to firms inside the network. Using a quasi-experimental research design, we document misallocation of bank credit inside the network, with bankser with weakly-alinged incentives engaging most actively in crony lending. Our findings thus resonate with existing theories of elite networks as rent-extractive coalitions that stifle economic prosperity. The third part of the thesis exploits a unique institutional setting in Korea to assess the effects of firms' political connections on the allocation of government procurement contracts. After winning the election, the new president appoints several members of his networks as CEOs of state-owned firms. In turn, these state firms allocate significantly more procurement contracts to private firms with a CEO from the same network. Contracts allocated to connected private firms suffer from systematically worse execution and more frequent cost increases through renegotiations

Microflora manipulation of artificially reared piglets

Typescript (photocopy).Digitized by Kansas Correctional Industrie