Mechanism of Germ Cell Specification in Early Zebrafish Embryogenesis

Reproduction is an essential feature of life that ensures the perpetuation and survival in many multicellular organisms while passing the genetic information to the next generation. The zebrafish germline is specified during early embryogenesis by maternal RNP granules collectively called germ plasm. It has been discovered that the zebrafish bucky ball gene, which is a key gene responsible for germ plasm formation and encodes a novel vertebrate-specific protein with unknown biochemical function. Overexpression experiments revealed that Buc induces ectopic primordial germ cells (PGCs) in vivo. So far, only the Oskar protein in Drosophila shows equivalent activities. Remarkably, we recently revealed that Oskar induces ectopic PGCs in zebrafish, albeit Oskar does not share sequence homology with Buc. Moreover, zebrafish Vasa is also sufficient to induce PGCs in vivo suggesting that Buc and Vasa act in the same molecular process involving in germ cell specification. This conserved activity between Oskar and Buc suggests that both proteins share a similar biochemical interactome, whose molecular identity is unknown. In this study, I characterize the interaction of Buc and the RNA helicase Vasa investigating their binding motifs. I identified a peptide encoding amino acids 372-394 in Buc as Vasa Binding Motif (VBM) and a peptide encoding amino acids 600-625 in Vasa as Buc Binding Motif (BBM) using bimolecular fluorescence complementation (BiFC). Further, I show that the Buc-VBM is highly conserved in vertebrates. Moreover, Buc and Vasa directly interact in vitro and independent of RNA. The Buc-VBM encodes an intrinsically disordered peptide, but CD spectroscopy reveals that a crowding agent induces formation of an alpha-helix. Fascinatingly, I discovered that Buc activates Vasa ATPase activity annotating the first biochemical function of Buc as a helicase activator. Collectively, these results propose a model in which the activity of Vasa helicase is a central regulator of PGC formation, which is tightly controlled by the germ plasm organizer Buc

Monetary policy rules in practice: Evidence for Sri Lanka

The paper seeks to characterise the monetary policy decision making process for Sri Lanka using standard Taylor-type monetary policy rules. Alternative monetary policy reaction functions are estimated for Sri Lanka over the period 1996Q1 to 2013Q2. An open economy reaction function is used in the analysis where the central bank is assumed to respond to changes in inflation, the output gap and the exchange rate. A forward looking specification of the reaction function is found to provide the most appropriate characterisation of policy making at the Central Bank of Sri Lanka. The results indicate that the size of the coefficient on the inflation gap has increased over time reflecting a greater focus on price stability. However, the response of monetary policy to fluctuations in output has been greater than the response to deviations in inflation reflecting the central bank’s preference and the lower sensitivity of output to interest rate changes

Monetary policy rules in practice: Evidence for Sri Lanka

The paper seeks to characterise the monetary policy decision making process for Sri Lanka using standard Taylor-type monetary policy rules. Alternative monetary policy reaction functions are estimated for Sri Lanka over the period 1996Q1 to 2013Q2. An open economy reaction function is used in the analysis where the central bank is assumed to respond to changes in inflation, the output gap and the exchange rate. A forward looking specification of the reaction function is found to provide the most appropriate characterisation of policy making at the Central Bank of Sri Lanka. The results indicate that the size of the coefficient on the inflation gap has increased over time reflecting a greater focus on price stability. However, the response of monetary policy to fluctuations in output has been greater than the response to deviations in inflation reflecting the central bank’s preference and the lower sensitivity of output to interest rate changes

Empirical studies on the performance of banks: A systematic literature review for future research

This paper intends to review research on the performance of banks to identify gaps in the current body of knowledge to justify future research directions. We use a systematic literature review method and review 164 articles from refereed journals. Content analysis reveals that most of the studies are empirical focusing on two aspects i.e. financial performance and efficiency of banks. These studies consider the impact of particular events and contexts on performance and efficiency while testing research hypotheses. However, often there is a lack of a theoretical backing for these studies. We argue that the considered events and contexts affect the risk transformation process under the financial intermediation theory. The efficiency of banks reflects the risk transformation process and causes performance. On the other hand, traditional performance indicators were based on financial measures that do not reflect the components of the risk transformation process. A sound comprehensive risk-based composite measure is required to fill this gap

Bibliometric analysis on the impact of COVID-19 on corporate governance

The COVID-19 pandemic has created a severe impact on the business field in the world as a whole. Nevertheless, there is a dearth of studies that synthesize the literature on the COVID-19 impact on corporate governance. The purpose of this study is to highlight the key issues and current trends in the area of COVID-19’s effects on corporate governance and to offer suggestions for future research paths. This study performs a bibliometric analysis using a sample of 137 studies from the SCOPUS database to ascertain the volume of research on COVID-19 and corporate governance between 2020 and 2022. Based on their citations and the number of publications, researchers in this study identified the most significant authors, sources, countries and documents using Biblioshiny software. Additionally, evaluate the themes that already exist, point out any barriers to the literature’s expansion, and offer suggestions for future research directions. There is a dearth of research studies conducted on this area, but China and India published the highest number of articles. The majority of research on COVID-19’s impact on corporate governance focuses on the qualitative approach and is frequently investigated based on agency theory. Finally, the research suggests potential directions for future studies by the researchers and helps practitioners and policymakers to understand the impact of the COVID-19 pandemic on corporate governance and take necessary actions

Non-intrusive load monitoring based on low frequency active power measurements

A Non-Intrusive Load Monitoring (NILM) method for residential appliances based on ac- tive power signal is presented. This method works e ectively with a single active power measurement taken at a low sampling rate (1 s). The proposed method utilizes the Karhunen Lo ́ eve (KL) expan- sion to decompose windows of active power signals into subspace components in order to construct a unique set of features, referred to as signatures, from individual and aggregated active power signals. Similar signal windows were clustered in to one group prior to feature extraction. The clustering was performed using a modified mean shift algorithm. After the feature extraction, energy levels of signal windows and power levels of subspace components were utilized to reduce the number of possible ap- pliance combinations and their energy level combinations. Then, the turned on appliance combination and the energy contribution from individual appliances were determined through the Maximum a Pos- teriori (MAP) estimation. Finally, the proposed method was modified to adaptively accommodate the usage patterns of appliances at each residence. The proposed NILM method was validated using data from two public databases: tracebase and reference energy disaggregation data set (REDD). The pre- sented results demonstrate the ability of the proposed method to accurately identify and disaggregate individual energy contributions of turned on appliance combinations in real households. Furthermore, the results emphasise the importance of clustering and the integration of the usage behaviour pattern in the proposed NILM method for real household

The MacGyver effect: alive and well in health services research?

<p>Abstract</p> <p>Background</p> <p>In a manner similar to the television action hero MacGyver, health services researchers need to respond to the pressure of unpredictable demands and constrained time frames. The results are often both innovative and functional, with the creation of outputs that could not have been anticipated in the initial planning and design of the research.</p> <p>Discussion</p> <p>In the conduct of health services research many challenges to robust research processes are generated as a result of the interface between academic research, health policy and implementation agendas. Within a complex and rapidly evolving environment the task of the health services researcher is, therefore, to juggle sometimes contradictory pressures to produce valid results.</p> <p>Summary</p> <p>This paper identifies the MacGyver-type dilemmas which arise in health services research, wherein innovation may be called for, to maintain the intended scientific method and rigour. These 'MacGyver drivers' are framed as opposing issues from the perspective of both academic and public policy communities. The ideas expressed in this paper are illustrated by four examples from research projects positioned at the interface between public policy strategy and academia.</p

Spatial analysis of COVID-19 and socio-economic factors in Sri Lanka

Using data from the Epidemiological Department of Sri Lanka, a cluster analysis was carried out based on COVID-19 data and demographic data of districts, towards developing a mathematical model that can identify and describe socio-economic factors related to pandemic measures. Population and population density, monthly expenditure, and education level are suggested as main factors for policy makers consideration. Findings can support future evidence-based COVID-19 policies, and further utilized as a foundation for other epidemiological models. A challenge in the study was the presumed disparity between actual COVID-19 cases and observed COVID-19 cases, thereby depicting an inaccurate measure of COVID-19 severity

Young elephants in a large herd maintain high levels of elephant endotheliotropic herpesvirus-specific antibodies and do not succumb to fatal haemorrhagic disease

Elephant endotheliotropic herpesviruses (EEHVs) have co-existed with elephants for millions of years, yet may cause fatal haemorrhagic disease (EEHV-HD), typically in elephants between 1 and 10 years of age. EEHV is omnipresent in (sub)adult elephants, and young elephants with low EEHV-specific antibody levels are at risk for EEHV-HD, suggesting that fatal disease may occur due to an insufficiently controlled primary infection. To further address this hypothesis, sera of three large elephant cohorts were subjected to a multiple EEHV species ELISA: (I) 96 Asian elephants between 0 and 57 years, including 13 EEHV-HD fatalities, from European zoo herds typically sized five to six elephants, (II) a herd of 64 orphaned elephants aged 0–15 years at the Elephant Transit Home in Sri Lanka and (III) 31 elephants aged 8–63 years, part of a large herd of 93 elephants at Pinnawala Elephant Orphanage, Sri Lanka. All Sri Lankan elephants showed high EEHV-specific antibody levels regardless of their age. While antibody levels of most European zoo elephants were comparable to those of Sri Lankan elephants, the average antibody level of the European juveniles (1–5 years of age) was significantly lower than those of age-matched Sri Lankan individuals. Moreover, the European juveniles showed a gradual decrease between 1 and 4 years of age, to be attributed to waning maternal antibodies. Maintenance of high levels of antibodies in spite of waning maternal antibodies in young Sri Lankan elephants is likely due to the larger herd size that increases the likelihood of contact with EEHV-shedding elephants. Together with the observation that low levels of EEHV-specific antibodies correlate with increased numbers of EEHV-HD fatalities, these results suggest that infection in presence of high maternal antibody levels may protect calves from developing EEHV-HD, while at the same time activating an immune response protective in future encounters with this virus.http://wileyonlinelibrary.com/journal/tbedhj2022Veterinary Tropical Disease

Young elephants in a large herd maintain high levels of elephant endotheliotropic herpesvirus-specific antibodies and do not succumb to fatal haemorrhagic disease

Elephant endotheliotropic herpesviruses (EEHVs) have co-existed with elephants for millions of years, yet may cause fatal haemorrhagic disease (EEHV-HD), typically in elephants between 1 and 10 years of age. EEHV is omnipresent in (sub)adult elephants, and young elephants with low EEHV-specific antibody levels are at risk for EEHV-HD, suggesting that fatal disease may occur due to an insufficiently controlled primary infection. To further address this hypothesis, sera of three large elephant cohorts were subjected to a multiple EEHV species ELISA: (I) 96 Asian elephants between 0 and 57 years, including 13 EEHV-HD fatalities, from European zoo herds typically sized five to six elephants, (II) a herd of 64 orphaned elephants aged 0–15 years at the Elephant Transit Home in Sri Lanka and (III) 31 elephants aged 8–63 years, part of a large herd of 93 elephants at Pinnawala Elephant Orphanage, Sri Lanka. All Sri Lankan elephants showed high EEHV-specific antibody levels regardless of their age. While antibody levels of most European zoo elephants were comparable to those of Sri Lankan elephants, the average antibody level of the European juveniles (1–5 years of age) was significantly lower than those of age-matched Sri Lankan individuals. Moreover, the European juveniles showed a gradual decrease between 1 and 4 years of age, to be attributed to waning maternal antibodies. Maintenance of high levels of antibodies in spite of waning maternal antibodies in young Sri Lankan elephants is likely due to the larger herd size that increases the likelihood of contact with EEHV-shedding elephants. Together with the observation that low levels of EEHV-specific antibodies correlate with increased numbers of EEHV-HD fatalities, these results suggest that infection in presence of high maternal antibody levels may protect calves from developing EEHV-HD, while at the same time activating an immune response protective in future encounters with this virus