bluuebunny/crossref_metadata_2025 huggingface dataset:
HAESA, an Arabidopsis leucine-rich repeat receptor kinase, controls floral organ abscission
Authors: Jinn Tsung-Luo , Stone Julie M. , Walker John C.
Published: November 2021

Abcission, the natural shedding of leaves, flowers and fruits, is a fundamental component of plant development. Abscission is a highly regulated process that occurs at distinct zones of cells that undergo enlargement and subsequent separation. Although some components of abscission, including accumulation of the hormone ethylene and cell wall-degrading enzymes, have been described, the regulatory pathways remain largely unknown. In this paper we describe a critical component required for floral organ abscission in Arabidopsis thaliana, the receptor-like protein kinase HAESA. Histochemical analysis of transgenic plants harboring a HAESA promoter:: β-glucuronidase reporter gene and in situ RNA hybridization experiments show HAESA expression in the abscission zones where the sepals, petals, and stamens attach to the receptacle, at the base of pedicels, and at the base of petioles where leaves attach to the stem. Immunodetection, immunoprecipitation, and protein kinase activity assays reveal HAESA is a plasma membrane serine/threonine protein kinase. The reduction of function of HAESA in transgenic plants harboring an antisense construct results in delayed abscission of floral organs, and the severity of the phenotype is directly correlated with the level of HAESA protein. These results demonstrate that HAESA functions in developmentally regulated floral organ abscission.
Notch signaling is essential for vascular morphogenesis in mice
Authors: Krebs Luke T. , Xue Yingzi , Norton Christine R. , Shutter John R. , Maguire Maureen , Sundberg John P. , Gallahan Daniel , Closson Violaine , Kitajewski Jan , Callahan Robert , Smith Gilbert H. , Stark Kevin L. , Gridley Thomas
Published: November 2021

The Notch gene family encodes large transmembrane receptors that are components of an evolutionarily conserved intercellular signaling mechanism. To assess the role of theNotch4gene, we generatedNotch4-deficient mice by gene targeting. Embryos homozygous for this mutation developed normally, and homozygous mutant adults were viable and fertile. However, theNotch4mutation displayed genetic interactions with a targeted mutation of the relatedNotch1gene. Embryos homozygous for mutations of both theNotch4andNotch1genes often displayed a more severe phenotype thanNotch1homozygous mutant embryos. BothNotch1mutant andNotch1/Notch4double mutant embryos displayed severe defects in angiogenic vascular remodeling. Analysis of the expression patterns of genes encoding ligands for Notch family receptors indicated that only theDll4gene is expressed in a pattern consistent with that expected for a gene encoding a ligand for theNotch1andNotch4receptors in the early embryonic vasculature. These results reveal an essential role for the Notch signaling pathway in regulating embryonic vascular morphogenesis and remodeling, and indicate that whereas theNotch4gene is not essential during embryonic development, theNotch4andNotch1genes have partially overlapping roles during embryogenesis in mice.
Aberrant cell cycle checkpoint function and early embryonic death in Chk1−/− mice
Authors: Takai Hiroyuki , Tominaga Kaoru , Motoyama Noboru , Minamishima Yohji A. , Nagahama Hiroyasu , Tsukiyama Tadasuke , Ikeda Kyoji , Nakayama Keiko , Nakanishi Makoto , Nakayama Kei-ichi
Published: November 2021

The recent discovery of checkpoint kinases has suggested the conservation of checkpoint mechanisms between yeast and mammals. In yeast, the protein kinase Chk1 is thought to mediate signaling associated with the DNA damage checkpoint of the cell cycle. However, the function of Chk1 in mammals has remained unknown. Targeted disruption of Chk1 in mice showed thatChk1−/− embryos exhibit gross morphologic abnormalities in nuclei as early as the blastocyst stage. In culture, Chk1−/− blastocysts showed a severe defect in outgrowth of the inner cell mass and died of apoptosis. DNA replication block and DNA damage failed to arrest the cell cycle before initiation of mitosis inChk1−/− embryos. These results may indicate that Chk1 is indispensable for cell proliferation and survival through maintaining the G2 checkpoint in mammals.
Xenopus Cdc7 function is dependent on licensing but not on XORC, XCdc6, or CDK activity and is required for XCdc45 loading
Authors: Jares Pedro , Blow J. Julian
Published: November 2021

The assembly and disassembly of protein complexes at replication origins play a crucial role in the regulation of chromosomal DNA replication. The sequential binding of the origin recognition complex (ORC), Cdc6, and the minichromosome maintenance (MCM/P1) proteins produces a licensed replication origin. Before the initiation of replication can occur, each licensed origin must be acted upon by S phase-inducing CDKs and the Cdc7 protein kinase. In the present report we describe the role of Xenopus Cdc7 (XCdc7) in DNA replication using cell-free extracts of Xenopus eggs. We show that XCdc7 binds to chromatin during G1 and S phase. XCdc7 associates with chromatin only once origins have been licensed, but this association does not require the continued presence of XORC or XCdc6 once they have fulfilled their essential role in licensing. Moreover, XCdc7 is required for the subsequent CDK-dependent loading of XCdc45 but is not required for the destabilization of origins that occurs once licensing is complete. Finally, we show that CDK activity is not necessary for XCdc7 to associate with chromatin, induce MCM/P1 phosphorylation, or perform its essential replicative function. From these results we suggest a simple model for the assembly of functional initiation complexes in the Xenopus system.
Cooperative effects of genes controlling the G2/M checkpoint
Authors: Chan Timothy A. , Hwang Paul M. , Hermeking Heiko , Kinzler Kenneth W. , Vogelstein Bert
Published: November 2021

It is believed that multiple effectors independently control the checkpoints permitting transitions between cell cycle phases. However, this has not been rigorously demonstrated in mammalian cells. The p53-induced genes p21 and 14-3-3ς are each required for the G2 arrest and allow a specific test of this fundamental tenet. We generated human cells deficient in bothp21 and 14-3-3ς and determined whether the double knockout was more sensitive to DNA damage than either single knockout.p21−/−14-3-3ς−/− cells were significantly more sensitive to DNA damage or to the exogenous expression of p53 than cells lacking only p21 or only 14-3-3ς. Thus, p21 and 14-3-3ς play distinct but complementary roles in the G2/M checkpoint, and help explain why genes at the nodal points of growth arrest pathways, like p53, are the targets of mutation in cancer cells.
Novel gene expressed in nasal region influences outgrowth of olfactory axons and migration of luteinizing hormone-releasing hormone (LHRH) neurons
Authors: Kramer P.R. , Wray Susan
Published: November 2021

Although a variety of cues have been implicated in axonal targeting during embryogenesis and regeneration, the precise mechanisms guiding olfactory axons remain unclear. Appropriate olfactory axon pathfinding is essential for functional chemoreceptive and pheromone receptive systems. Olfactory axon pathfinding is also necessary for establishment of the neuroendocrine LHRH system, cells critical for reproductive function. LHRH cells exhibit neurophilic migration moving from the nasal region along olfactory axons into the brain. Factors involved in the migration of these neuroendocrine cells are as yet unresolved. We report identification of a novel factor termed nasal embryonic LHRH factor (NELF) that was discovered in a differential screen of migrating versus nonmigrating primary LHRH neurons. NELF is expressed in PNS and CNS tissues during embryonic development, including olfactory sensory cells and LHRH cells. NELF antisense experiments indicate that a reduction in NELF expression decreases olfactory axon outgrowth and the number of LHRH neurons that migrate out of the nasal tissue. These results demonstrate that NELF plays a role as a common guidance molecule for olfactory axon projections and subsequently, either directly or indirectly, in the neurophilic migration of LHRH cells.
A C. elegans patched gene, ptc-1, functions in germ-line cytokinesis
Authors: Kuwabara Patricia E. , Lee Min-Ho , Schedl Tim , Jefferis Gregory S.X.E.
Published: November 2021

Patched (Ptc), initially identified in Drosophila, defines a class of multipass membrane proteins that control cell fate and cell proliferation. Biochemical studies in vertebrates indicate that the membrane proteins Ptc and Smoothened (Smo) form a receptor complex that binds Hedgehog (Hh) morphogens. Smo transduces the Hh signal to downstream effectors. The Caenorhabditis elegans genome encodes two Ptc homologs and one related pseudogene but does not encode obvious Hh or Smo homologs. We have analyzed ptc-1 by RNAi and mutational deletion and find that it is an essential gene, although the absence of ptc-1 has no detectable effect on body patterning or proliferation. Therefore, the C. elegans ptc-1 gene is functional despite the lack of Hh and Smo homologs. We find that the activity and expression of ptc-1 is essentially confined to the germ line and its progenitors. ptc-1 null mutants are sterile with multinucleate germ cells arising from a probable cytokinesis defect. We have also identified a surprisingly large family of PTC-related proteins containing sterol-sensing domains, including homologs of Drosophila dispatched, in C. elegans and other phyla. These results suggest that the PTC superfamily has multiple functions in animal development.
Pan-neural Prospero terminates cell proliferation during Drosophila neurogenesis
Authors: Li Ling , Vaessin Harald
Published: November 2021

Organogenesis requires coordination between developmental specific regulators and genes governing cell proliferation. Here we show thatDrosophila prospero encodes a critical regulator of the transition from mitotically active cells to terminal differentiated neurons. Loss of pros results in aberrant expression of multiple cell-cycle regulatory genes and ectopic mitotic activity. In contrast, ectopic pros expression causes transcriptional suppression of multiple cell-cycle regulatory genes and premature termination of cell division. pros activity, hence, provides a critical regulatory link between neuronal lineage development and transcriptional regulation of cell cycle regulatory genes.
Direct regulation of nacre, a zebrafish MITF homolog required for pigment cell formation, by the Wnt pathway
Authors: Dorsky Richard I. , Raible David W. , Moon Randall T.
Published: November 2021

We have shown that Wnt signals are necessary and sufficient for neural crest cells to adopt pigment cell fates. nacre, a zebrafish homolog of MITF, is required for pigment cell differentiation. We isolated a promoter region of nacre that contains Tcf/Lef binding sites, which can mediate Wnt responsiveness. This promoter binds to zebrafish Lef1 protein in vitro, and a nacre reporter construct is strongly repressed by dominant-negative Tcf in melanoma cells. Mutation of Tcf/Lef sites abolishes Lef1 binding and reporter function in vivo. Wnt signaling therefore directly activatesnacre, which in turn leads to pigment cell differentiation.
Chk2/hCds1 functions as a DNA damage checkpoint in G1by stabilizing p53
Authors: Chehab Nabil H. , Malikzay Asra , Appel Michael , Halazonetis Thanos D.
Published: November 2021

Chk2/hcds1, the human homolog of theSaccharomyces cerevisiae RAD53/SPK1andSchizosaccharomyces pombe cds1DNA damage checkpoint genes, encodes a protein kinase that is post-translationally modified after DNA damage. Like its yeast homologs, the Chk2/hCds1 protein phosphorylates Cdc25C in vitro, suggesting that it arrests cells in G2in response to DNA damage. We expressed Chk2/hCds1 in human cells and analyzed their cell cycle profile. Wild-type, but not catalytically inactive, Chk2/hCds1 led to G1arrest after DNA damage. The arrest was inhibited by cotransfection of a dominant-negative p53 mutant, indicating that Chk2/hCds1 acted upstream of p53. In vitro, Chk2/hCds1 phosphorylated p53 on Ser-20 and dissociated preformed complexes of p53 with Mdm2, a protein that targets p53 for degradation. In vivo, ectopic expression of wild-type Chk2/hCds1 led to increased p53 stabilization after DNA damage, whereas expression of a dominant-negative Chk2/hCds1 mutant abrogated both phosphorylation of p53 on Ser-20 and p53 stabilization. Thus, in response to DNA damage, Chk2/hCds1 stabilizes the p53 tumor suppressor protein leading to cell cycle arrest in G1.
The p23 molecular chaperones act at a late step in intracellular receptor action to differentially affect ligand efficacies
Authors: Freeman Brian C. , Felts Sara J. , Toft David O. , Yamamoto Keith R.
Published: November 2021

Multiple molecular chaperones, including Hsp90 and p23, interact with members of the intracellular receptor (IR) family. To investigate p23 function, we compared the effects of three p23 proteins on IR activities, yeast p23 (sba1p) and the two human p23 homologs, p23 and tsp23. We found that Sba1p was indistinguishable from human p23 in assays of seven IR activities in both animal cells and in yeast; in contrast, certain effects of tsp23 were specific to that homolog. Transcriptional activation by two IRs was increased by expression of any of the p23 species, whereas activation by five other IRs was decreased by Sba1p or p23, and unaffected by tsp23. p23 was expressed in all tissues examined except striated and cardiac muscle, whereas tsp23 accumulated in a complementary pattern; hence, p23 proteins might contribute to tissue-specific differences in IR activities. Unlike Hsp90, which acts on IR aporeceptors to stimulate ligand potency (i.e., hormone-binding affinity), p23 proteins acted on IR holoreceptors to alter ligand efficiencies (i.e., transcriptional activation activity). Moreover, the p23 effects developed slowly, requiring prolonged exposure to hormone. In vitro, p23 interacted preferentially with hormone–receptor–response element ternary complexes, and stimulated receptor–DNA dissociation. The dissociation was reversed by addition of a fragment of the GRIP1 coactivator, suggesting that the two reactions may be in competition in vivo. Our findings suggest that p23 functions at one or more late steps in IR-mediated signal transduction, perhaps including receptor recycling and/or reversal of the response.
Homeodomain and winged-helix transcription factors recruit activated Smads to distinct promoter elements via a common Smad interaction motif
Authors: Germain Stéphane , Howell Michael , Esslemont Graeme M. , Hill Caroline S.
Published: November 2021

We have investigated the regulation of the activin-inducible distal element (DE) of the Xenopus goosecoid promoter. The results show that paired-like homeodomain transcription factors of the Mix family, Mixer and Milk, but not Mix.1, mediate activin/TGF-β-induced transcription through the DE by interacting with the effector domain of Smad2, thereby recruiting active Smad2/Smad4 complexes to the Mixer/Milk-binding site. We identify a short motif in the carboxyl termini of Mixer and Milk, which is demonstrated to be both necessary and sufficient for interaction with the effector domain of Smad2 and is required for mediating activin/TGF-β-induced transcription. This motif is not confined to these homeodomain proteins, but is also present in the Smad2-interacting winged-helix proteins Xenopus Fast-1, human Fast-1, and mouse Fast-2. We demonstrate directly that transcription factors of different DNA-binding specificity recruit activated Smads to distinct promoter elements via a common mechanism. These observations, together with the temporal and spatial expression patterns ofMixer and Milk, lead us to propose a model for mesoendoderm formation in Xenopus in which these homeodomain transcription factor/Smad complexes play a role in initiating and maintaining transcription of target genes in response to endogenous activin-like signals.
The MAR-binding protein SATB1 orchestrates temporal and spatial expression of multiple genes during T-cell development
Authors: Alvarez John D. , Yasui Dag H. , Niida Hiroyuki , Joh Tadashi , Loh Dennis Y. , Kohwi-Shigematsu Terumi
Published: November 2021

SATB1 is expressed primarily in thymocytes and can act as a transcriptional repressor. SATB1 binds in vivo to the matrix attachment regions (MARs) of DNA, which are implicated in the loop domain organization of chromatin. The role of MAR-binding proteins in specific cell lineages is unknown. We generated SATB1-null mice to determine how SATB1 functions in the T-cell lineage. SATB1-null mice are small in size, have disproportionately small thymi and spleens, and die at 3 weeks of age. At the cellular level, multiple defects in T-cell development were observed. Immature CD3−CD4−CD8−triple negative (TN) thymocytes were greatly reduced in number, and thymocyte development was blocked mainly at the DP stage. The few peripheral CD4+single positive (SP) cells underwent apoptosis and failed to proliferate in response to activating stimuli. At the molecular level, among 589 genes examined, at least 2% of genes including a proto-oncogene, cytokine receptor genes, and apoptosis-related genes were derepressed at inappropriate stages of T-cell development in SATB1-null mice. For example,IL-2RαandIL-7Rαgenes were ectopically transcribed in CD4+CD8+double positive (DP) thymocytes. SATB1 appears to orchestrate the temporal and spatial expression of genes during T-cell development, thereby ensuring the proper development of this lineage. Our data provide the first evidence that MAR-binding proteins can act as global regulators of cell function in specific cell lineages.
CLOCK, an essential pacemaker component, controls expression of the circadian transcription factor DBP
Authors: Ripperger Jürgen A. , Shearman Lauren P. , Reppert Steven M. , Schibler Ueli
Published: November 2021

DBP, the founding member of the PAR leucine zipper transcription factor family, is expressed according to a robust daily rhythm in the suprachiasmatic nucleus and several peripheral tissues. Previous studies with mice deleted for the Dbp gene have established that DBP participates in the regulation of several clock outputs, including locomotor activity, sleep distribution, and liver gene expression. Here we present evidence that circadian Dbptranscription requires the basic helix–loop–helix–PAS protein CLOCK, an essential component of the negative-feedback circuitry generating circadian oscillations in mammals and fruit flies. Genetic and biochemical experiments suggest that CLOCK regulates Dbpexpression by binding to E-box motifs within putative enhancer regions located in the first and second introns. Similar E-box motifs have been found previously in the promoter sequence of the murine clock genemPeriod1. Hence, the same molecular mechanisms generating circadian oscillations in the expression of clock genes may directly control the rhythmic transcription of clock output regulators such asDbp.
Ro ribonucleoproteins contribute to the resistance of Deinococcus radiodurans to ultraviolet irradiation
Authors: Chen Xinguo , Quinn Anne Marie , Wolin Sandra L.
Published: November 2021

The genome of the radiation-resistant eubacterium Deinococcus radiodurans contains an ortholog of an RNA-binding protein known as the Ro 60-kD autoantigen. This protein, which was previously identified only in higher eukaryotes, is normally bound to small RNAs known as Y RNAs. We show that the Ro protein ortholog Rsr contributes to the resistance of D. radiodurans to UV irradiation. Rsr binds several small RNAs, encoded upstream of rsr, that accumulate following UV irradiation. One of these RNAs resembles a Y RNA. These results suggest that Ro RNPs could similarly contribute to the recovery of higher cells following UV irradiation.
Ribosome shunting in the cauliflower mosaic virus 35S RNA leader is a special case of reinitiation of translation functioning in plant and animal systems
Authors: Ryabova Lyubov A. , Hohn Thomas
Published: November 2021

The shunt model predicts that small ORFs (sORFs) within the cauliflower mosaic virus (CaMV) 35S RNA leader and downstream ORF VII are translated by different mechanisms, that is, scanning–reinitiation and shunting, respectively. Wheat germ extract (WGE) and rabbit reticulocyte lysate (RRL) in vitro translation systems were used to discriminate between these two processes and to study the mechanism of ribosomal shunt. In both systems, expression downstream of the leader occurred via ribosomal shunt under the control of a stable stem and a small ORF preceding it. Shunting ribosomes were also able to initiate quite efficiently at non-AUG start codons just downstream of the shunt landing site in WGE but not in RRL. The short sORF MAGDIS from the mammalian AdoMetDC RNA, which conditionally suppresses reinitiation at a downstream ORF, prevented shunting if placed at the position of sORF A, the 5′-proximal ORF of the CaMV leader. We have demonstrated directly that sORF A is translated and that proper termination of translation at the 5′-proximal ORF is absolutely required for both shunting and linear ribosome migration. These findings strongly indicate that shunting is a special case of reinitiation.
The Drosophila HEM-2/NAP1 homolog KETTE controls axonal pathfinding and cytoskeletal organization
Authors: Hummel Thomas , Leifker Karin , Klämbt Christian
Published: November 2021

In Drosophila, the correct formation of the segmental commissures depends on neuron–glial interactions at the midline. The VUM midline neurons extend axons along which glial cells migrate in between anterior and posterior commissures. Here, we show that the genekette is required for the normal projection of the VUM axons and subsequently disrupts glial migration. Axonal projection defects are also found for many other moto- and interneurons. In addition,kette affects the cell morphology of mesodermal and epidermal derivatives, which show an abnormal actin cytoskeleton. The KETTE protein is homologous to the transmembrane protein HEM-2/NAP1 evolutionary conserved from worms to vertebrates. In vitro analysis has shown a specific interaction of the vertebrate HEM-2/NAP1 with the SH2–SH3 adapter protein NCK and the small GTPase RAC1, which both have been implicated in regulating cytoskeleton organization and axonal growth. Hypomorphickette mutations lead to axonal defects similar to mutations in the Drosophila NCK homolog dreadlocks. Furthermore, we show that kette and dock mutants genetically interact. NCK is thought to interact with the small G proteins RAC1 and CDC42, which play a role in axonal growth. In line with these observations, akette phenocopy can be obtained following directed expression of mutant DCDC42 or DRAC1 in the CNS midline. In addition, thekette mutant phenotype can be partially rescued by expression of an activated DRAC1 transgene. Our data suggest an important role of the HEM-2 protein in cytoskeletal organization during axonal pathfinding.
CIITA is a transcriptional coactivator that is recruited to MHC class II promoters by multiple synergistic interactions with an enhanceosome complex
Authors: Masternak Krzysztof , Muhlethaler-Mottet Annick , Villard Jean , Zufferey Madeleine , Steimle Viktor , Reith Walter
Published: November 2021

By virtue of its control over major histocompatibility complex class II (MHC-II) gene expression, CIITA represents a key molecule in the regulation of adaptive immune responses. It was first identified as a factor that is defective in MHC-II deficiency, a hereditary disease characterized by the absence of MHC-II expression. CIITA is a highly regulated transactivator that governs all spatial, temporal, and quantitative aspects of MHC-II expression. It has been proposed to act as a non-DNA-binding transcriptional coactivator, but evidence that it actually functions at the level of MHC-II promoters was lacking. By means of chromatin immunoprecipitation assays, we show here for the first time that CIITA is physically associated with MHC-II, as well asHLA–DM,Ii, MHC-I, andβ2mpromoters in vivo. To dissect the mechanism by which CIITA is recruited to the promoter, we have developed a DNA-dependent coimmunoprecipitation assay and a pull-down assay using immobilized promoter templates. We demonstrate that CIITA recruitment depends on multiple, synergistic protein–protein interactions with DNA-bound factors constituting the MHC-II enhanceosome. CIITA therefore represents a paradigm for a novel type of regulatory and gene-specific transcriptional cofactor.
Smad3 recruits the anaphase-promoting complex for ubiquitination and degradation of SnoN
Authors: Stroschein Shannon L. , Bonni Shirin , Wrana Jeffrey L. , Luo Kunxin
Published: November 2021

Smad proteins mediate transforming growth factor-β (TGF-β) signaling to regulate cell growth and differentiation. SnoN is an important negative regulator of TGF-β signaling that functions to maintain the repressed state of TGF-β target genes in the absence of ligand. On TGF-β stimulation, Smad3 and Smad2 translocate into the nucleus and induce a rapid degradation of SnoN, allowing activation of TGF-β target genes. We show that Smad2- or Smad3-induced degradation of SnoN requires the ubiquitin-dependent proteasome and can be mediated by the anaphase-promoting complex (APC) and the UbcH5 family of ubiquitin-conjugating enzymes. Smad3 and to a lesser extent, Smad2, interact with both the APC and SnoN, resulting in the recruitment of the APC to SnoN and subsequent ubiquitination of SnoN in a destruction box (D box)-dependent manner. In addition to the D box, efficient ubiquitination and degradation of SnoN also requires the Smad3 binding site in SnoN as well as key lysine residues necessary for ubiquitin attachment. Mutation of either the Smad3 binding site or lysine residues results in stabilization of SnoN and in enhanced antagonism of TGF-β signaling. Our studies elucidate an important mechanism and pathway for the degradation of SnoN and more importantly, reveal a novel role of the APC in the regulation of TGF-β signaling.
Does the monetary policy have any short-run and long-run effect on economic growth? A developing and a developed country perspective
Authors: Islam Md. Sayemul , Hossain Md. Emran , Chakrobortty Sudipto , Ema Nishat Sultana
Published: November 2021

Purpose

The study aims to empirically examine the relationship between monetary policy and economic growth, as well as to explore the long-run and the short-run effect of monetary policy on the economic growth of a developing country (Bangladesh) and a developed country (the United Kingdom).

Design/methodology/approach

Depending on data availability, the study employed secondary data covering the period of 1980–2019. The augmented Dickey–Fuller test and the Phillips–Perron test were used for the stationarity test. Further, the F-bounds test was run to justify the long-run relationship between monetary policy and economic growth. Thereafter, long-run coefficients were revealed from the auto-regressive distributed lag (ARDL) model and short-run coefficients from the error correction model. Furthermore, the vector error correction model (VECM) Granger causality approach was employed to demonstrate the causality of studied variables. Lastly, different diagnostics tests ensured the robustness of the models.

Findings

F-bounds test outcomes suggest that monetary policy has a long-run relationship with economic growth in both countries. Long-run coefficients revealed that money supply has a positive long-run impact on economic growth in both countries. Unlike the UK, the exchange rate exhibits an adverse effect on the economic growth of Bangladesh. The bank rate seems to promote economic growth for the UK. Findings also depict that increase in lending interest rates hurts the economic growth for both countries. Besides, the short-run coefficients portray random effects at different lags in both cases. Lastly, causality among studied variables is revealed using the VECM Granger causality approach.

Originality/value

The novelty of this study lies in consideration of both developing and developed countries in the same study.
A unified optimal power flow modeling for VSC-HVDC converter: a novel methodology for optimal installation based on average loadability index
Authors: Agrawal Sunilkumar , Kundu Prasanta
Published: November 2021

Purpose

This paper aims to propose a novel methodology for optimal voltage source converter (VSC) station installation in hybrid alternating current (AC)/direct current (DC) transmission networks.

Design/methodology/approach

In this analysis, a unified power flow model has been developed for the optimal power flow (OPF) problem for VSC-based high voltage direct current (VSC-HVDC) transmission network and solved using a particle swarm optimization (PSO) algorithm. The impact of the HVDC converter under abnormal conditions considering N-1 line outage contingency is analyzed against the congestion relief of the overall transmission network. The average loadability index is used as a severity indicator and minimized along with overall transmission line losses by replacing each AC line with an HVDC line independently.

Findings

The developed unified OPF (UOPF) model converged successfully with (PSO) algorithm. The OPF problem has satisfied the defined operational constraints of the power system, and comparative results are obtained for objective function with different HVDC test configurations represented in the paper. In addition, the impact of VSC converter location is determined on objective function value.

Originality/value

A novel methodology has been developed for the optimal installation of the converter station for the point-to-point configuration of HVDC transmission. The developed unified OPF model and methodology for selecting the AC bus for converter installation has effectively reduced congestion in transmission lines under single line outage contingency.
Undoing disaster colonialism: a pilot map of the pandemic's first wave in the Mapuche territories of Southern Chile
Authors: Carraro Valentina , Kelly Sarah , Vargas José Luis , Melillanca Patricio , Valdés-Negroni José Miguel
Published: November 2021

Purpose

The authors use media research and crowdsourced mapping to document how the first wave of the pandemic (April–August 2020) affected the Mapuche, focussing on seven categories of events: territorial control, spiritual defence, food sovereignty, traditional health practices, political violence, territorial needs and solidarity, and extractivist expansion.

Design/methodology/approach

Research on the effects of the pandemic on the Mapuche and their territories is lacking; the few existing studies focus on death and infection rates but overlook how the pandemic interacts with ongoing processes of extractivism, state violence and community resistance. The authors’ pilot study addresses this gap through a map developed collaboratively by disaster scholars and Mapuche journalists.

Findings

The map provides a spatial and chronological overview of this period, highlighting the interconnections between the pandemic and neocolonialism. As examples, the authors focus on two phenomena: the creation of “health barriers” to ensure local territorial control and the state-supported expansion of extractive industries during the first months of the lockdown.

Research limitations/implications

The authors intersperse our account of the project with reflections on its limitations and, specifically, on how colonial formations shape the research. Decolonising disaster studies and disaster risk reduction practice, the authors argue, is an ongoing process, bound to be flawed and incomplete but nevertheless an urgent pursuit.

Originality/value

In making this argument, the paper responds to the Disaster Studies Manifesto that inspires this special issue, taking up its invitation to scholars to be more reflexive about their research practice and to frame their investigations through grounded perspectives.
A critical examination of policy objectives and instruments for a sustainable and inclusive post-pandemic recovery
Authors: Tran-Nam Binh , Le-Van Cuong , Nguyen Ngoc-Anh
Published: November 2021

Purpose

This paper aims to provide rigor and clarity to the current coronavirus disease 2019 (COVID-19) policy debate in Vietnam. It is intended to serve a three-fold purpose. First, it critically examines the framing of policy objectives and the utilization of policy instruments for controlling COVID-19 in Vietnam. Second, it goes beyond policy design to consider the coordination and implementation of COVID-19 policies in Vietnam. Third, it discusses policy measures needed for post-COVID sustainable and inclusive growth, especially the sharing of the public costs of COVID-19 policies.

Design/methodology/approach

The paper employs a positivist research framework that emphasizes the causal relationships between the variables under study. The method of analysis is mixed, combining both qualitative and quantitative techniques. In particular, a simple, theoretical model is constructed to evaluate the welfare effects of alternative vaccine strategies. No primary data were collected.

Findings

The Vietnamese government’s dual goals of containing the pandemic and maintaining economic growth, while being reasonable, need clarification and updating. It is argued that in the longer term, there is no trade-off between saving lives and protecting the economy. The downward revision of the projected growth rate and commitment to a coherent and transparent vaccination strategy is the best way to move forward in Vietnam. The choice of vaccine rollout order involves a consideration of ethics. It is suggested that it is appropriate to vaccinate elderly people and people with underlying medical conditions first. Complementary policy measures to stimulate aggregate demand and supply need to be expanded but also more targeted. Effective coordination and implementation of COVID-19 policies remain a serious challenge for Vietnam. Finally, inclusive growth and sustainable development should take account of human capital development and distributive justice.

Social implications

The paper proposes a number of policy measures which have social impact. These include the government's formal commitment to a vaccine first strategy and a relief package of essential goods to poor and disadvantaged households.

Originality/value

The paper contributes positively to the current COVID-19 policy formulation by providing rigor and clarity to the framing of policy objectives and the utilization of policy instruments. While vaccination has been adopted as a national policy instrument, its design and implementation can be much improved. The paper recommends an appropriate vaccine strategy for Vietnam. It also draws attention to other dimensions of successful policies, namely, communication, coordination, implementation and distributive justice.
Reference effects and customer engagement in a museum visit
Authors: Siu Noel Yee Man , Zhang Tracy Junfeng , Kwan Ho Yan
Published: November 2021

Purpose

By extending the expectancy-disconfirmation theory and integrating the elaboration likelihood model, this study aims to explore the reference effects (i.e. disconfirmation and self-identity) and customer engagement that affect customer experience on satisfaction with a museum visit. The study is designed to test a dual-mediator mechanism involving disconfirmation and self-identity. The moderating role of cognitive, affective or behavioral engagements is also examined with the overall purpose to advance the understanding of customer experience in cultural consumption such as museum visits.

Design/methodology/approach

A self-administered field survey in two stages was carried out on visitors to the Hong Kong Museum of Art. A total of 465 valid response sets were used for analysis. Hypotheses were tested using confirmatory factor analysis, three-step mediation test, structural equation modeling and moderation regressions.

Findings

Disconfirmation and self-identity are found to be dual mediators in the experience–satisfaction relationship. Cognitive engagement reduces the effect of knowledge experience on disconfirmation and self-identity but increases that of the entertainment experience on disconfirmation and self-identity. Affective engagement amplifies the effect of knowledge experience on self-identity but mitigates the importance of entertainment evaluations.

Practical implications

Findings highlight the importance of both perceived knowledge and entertainment experiences in visitors’ evaluation of a cultural experience. Managers are suggested to craft promotional messages with the psychological appeal that connects visitors with museum services. Appropriate engagement tactics for museums can be developed to avoid overloading visitors with information.

Originality/value

Previous studies treat disconfirmation as the dominant reference effect in the formation of customer satisfaction. This study shows both disconfirmation and self-identity as dual reference effects that link the customer experience to satisfaction in the museum context, serving as a pioneer in defining how the influence of experience on reference effects varies depending on how customers are cognitively and affectively engaged in such context.
Do non-financial performance and accrual-based cost information affect public sector budgeting?
Authors: Kuroki Makoto , Motokawa Katsuhiro
Published: November 2021

Purpose

This study aims to provide evidence of how budget officers use non-financial and accrual-based cost information in the budgeting process and how the usage of this information is influenced by financial constraints.

Design/methodology/approach

A randomized survey-based field experiment investigating budget officers in 546 Japanese local governments (LGs) was conducted. This allowed us to identify the budget officers' decision-making in the public sector budgeting process by creating and analyzing primary data with regression models.

Findings

We found that budget officers suppress budget amounts based on non-financial information of good performances. Under fiscal constraints, officers further reduce budget amounts using information on high accrual-based costs and poor non-financial performance.

Originality/value

Our survey-based field experiment allowed us to obtain primary data from officers making budget decisions. To the best of our knowledge, this study provides the first evidence that non-financial good and poor performance information and accrual-based cost information affect budget officers' decision-making under financial constrain.
Money supply, exchange rates and office market dynamics: comparative evidence from the UK and Germany
Authors: Coën Alain , Lefebvre Benoit
Published: November 2021

Purpose

The aim of this study is to shed light on the relative importance of money supply and exchange rates variations on office markets prices dynamics.

Design/methodology/approach

Using a parsimonious real estate asset pricing model, the authors focus on the two biggest European office markets; namely the United Kingdom and Germany. The authors use a panel approach based on a robust econometric methodology (GMM with correction errors-in-variables). The authors take into account the variations of exchange rates and money supplies for the most important currencies.

Findings

The results highlight the impact of money supplies and exchange rates on office prices after the Global Financial Crisis. The authors report that the monetary policies in the UK and in Germany (Euro zone) have had significant influences in the real estate sector after the Global Financial Crisis. However, the authors identified significant differences between British and German office markets for the 2009–2019 period regarding the impact of money supply and exchange rates variations on the office prices dynamics.

Practical implications

The results highlight the impact of money supplies and exchange rates on office prices after the Global Financial Crisis. The detailed and exclusive database (composed of the main office markets in the United Kingdom and in Germany) allows the authors to identify significant differences and opportunities for investors.

Originality/value

The authors use a parsimonious model and apply a panel approach based on a robust econometric methodology to analyse the impact of exchange rates and money supply variations on the office prices dynamics. The detailed and exclusive database (composed of the main office markets in the United Kingdom and in Germany) allows the authors to identify significant differences for investors.
Characteristics of owners and managers in different countries: a meta-analytical investigation of SMEs' growth
Authors: Marconatto Diego Antônio Bittencourt , Teixeira Emidio Gressler , Santini Fernando de Oliveira , Ladeira Wagner Junior
Published: November 2021

Purpose

The paper aims to provide robust evidence about the relationships between key individual characteristics of owners and managers (OMs) and small and medium enterprises (SMEs)' growth and the moderating influence of the country context on these relationships.

Design/methodology/approach

The authors meta-analyzed 62 studies presenting a cumulative sample of 175 effect-sizes and 174,590 SMEs.

Findings

The authors found that SMEs led by more experienced men with higher levels of education are more likely to grow. While the relationship between OMs' experience and SMEs' growth is significant for differing country contexts, national characteristics affect the magnitude of the influence that OMs' education and gender specifically exert on SME expansion. The authors also found that the positive impact of OMs' human capital on SMEs' growth increases when these firms are focused on technology.

Research limitations/implications

The study yielded small-effect sizes for the impact of OMs' human capital and gender on SMEs' growth. Researchers can assess the influence of these characteristics on SMEs' growth along with other individual dimensions.

Originality/value

The current study is the first meta-analytical investigation about the influence of OMs' gender on SMEs' growth. The study focuses solely on SME OMs, as SMEs are not simply larger businesses on a smaller scale. The authors employ a wide set of country-level moderators in the research going beyond most empirical examinations of the topic that have given only marginal attention to moderators.
An overview: characterization of natural fiber reinforced hybrid composites
Authors: Balasubramanian M. , Loganathan Thozhuvur Govindaraman , Srimath R.
Published: November 2021

Purpose

The purpose of this study is to understand the behavior of hybrid bio-composites under varied applications.

Design/methodology/approach

Fabrication methods and material characterization of various hybrid bio-composites are analyzed by studying the tensile, impact, flexural and hardness of the same. The natural fiber is a manufactured group of assembly of big or short bundles of fiber to produce one or more layers of flat sheets. The natural fiber-reinforced composite materials offer a wide range of properties that are suitable for many engineering-related fields like aerospace, automotive areas. The main characteristics of natural fiber composites are durability, low cost, low weight, high specific strength and equally good mechanical properties.

Findings

The tensile properties like tensile strength and tensile modulus of flax/hemp/sisal/Coir/Palmyra fiber-reinforced composites are majorly dependent on the chemical treatment and catalyst usage with fiber. The flexural properties of flax/hemp/sisal/coir/Palmyra are greatly dependent on fiber orientation and fiber length. Impact properties of flax/hemp/sisal/coir/Palmyra are depended on the fiber content, composition and orientation of various fibers.

Originality/value

This study is a review of various research work done on the natural fiber bio-composites exhibiting the factors to be considered for specific load conditions.
Counterintuitive scaling between population abundance and local density: Implications for modelling transmission of infectious diseases in bat populations
Authors: Lunn Tamika J. , Peel Alison J. , Eby Peggy , Brooks Remy , Plowright Raina K. , Kessler Maureen K. , McCallum Hamish
Published: November 2021

Models of host–pathogen interactions help to explain infection dynamics in wildlife populations and to predict and mitigate the risk of zoonotic spillover. Insights from models inherently depend on the way contacts between hosts are modelled, and crucially, how transmission scales with animal density.

Bats are important reservoirs of zoonotic disease and are among the most gregarious of all mammals. Their population structures can be highly heterogeneous, underpinned by ecological processes across different scales, complicating assumptions regarding the nature of contacts and transmission. Although models commonly parameterise transmission using metrics of total abundance, whether this is an ecologically representative approximation of host–pathogen interactions is not routinely evaluated.

We collected a 13‐month dataset of tree‐roosting Pteropus spp. from 2,522 spatially referenced trees across eight roosts to empirically evaluate the relationship between total roost abundance and tree‐level measures of abundance and density—the scale most likely to be relevant for virus transmission. We also evaluate whether roost features at different scales (roost level, subplot level, tree level) are predictive of these local density dynamics.

Roost‐level features were not representative of tree‐level abundance (bats per tree) or tree‐level density (bats per m2 or m3), with roost‐level models explaining minimal variation in tree‐level measures. Total roost abundance itself was either not a significant predictor (tree‐level 3D density) or only weakly predictive (tree‐level abundance).

This indicates that basic measures, such as total abundance of bats in a roost, may not provide adequate approximations for population dynamics at scales relevant for transmission, and that alternative measures are needed to compare transmission potential between roosts. From the best candidate models, the strongest predictor of local population structure was tree density within roosts, where roosts with low tree density had a higher abundance but lower density of bats (more spacing between bats) per tree.

Together, these data highlight unpredictable and counterintuitive relationships between total abundance and local density. More nuanced modelling of transmission, spread and spillover from bats likely requires alternative approaches to integrating contact structure in host–pathogen models, rather than simply modifying the transmission function.