"Ubiquitous uncertainties": spillovers across economic policy uncertainty and cryptocurrency uncertainty indices

PurposeThe purpose of this paper is to extend the literature on the spillovers across economic policy uncertainty (EPU) and cryptocurrency uncertainty indices.Design/methodology/approachThis paper uses cross-country economic policy uncertainty indices and the novel data measuring the cryptocurrency price uncertainties over the period 2013–2021 to construct a sample of 946 observations and applies the time-varying parameter vector autoregression (TVP-VAR) model to do an empirical study.FindingsThe findings suggest that there are cross-country spillovers of economic policy uncertainty. In addition, the total uncertainty spillover between economic policies and cryptocurrency peaked in 2015 before gradually decreasing in the following periods. Concomitantly, the cryptocurrency uncertainty has acted as the "receiver." More importantly, the authors found the predictive power of economic policy uncertainty to predict the cryptocurrency uncertainty index. This paper's results hold robust when using alternative measurement of cryptocurrency policy uncertainty.Originality/valueThis study is the first research that deeply investigates the association between two uncertainty indicators, namely economic policy uncertainty and the cryptocurrency uncertainty index. We provide fresh evidence about the dynamic connectedness between country-level economic policy uncertainty and the cryptocurrency index. Our work contributes a new channel driving the variants of uncertainties in the cryptocurrency market

Tail dependence structure and extreme risk spillover effects between the international agricultural futures and spot markets

This paper combines the Copula-CoVaR approach with the ARMA-GARCH-skewed Student-t model to investigate the tail dependence structure and extreme risk spillover effects between the international agricultural futures and spot markets, taking four main agricultural commodities, namely soybean, maize, wheat, and rice as examples. The empirical results indicate that the tail dependence structures for the four futures-spot pairs are quite different, and each of them exhibits a certain degree of asymmetry. In addition, the futures market for each agricultural commodity has significant and robust extreme downside and upside risk spillover effects on the spot market, and the downside risk spillover effects for both soybeans and maize are significantly stronger than their corresponding upside risk spillover effects, while there is no significant strength difference between the two risk spillover effects for wheat, and rice. This study provides a theoretical basis for strengthening global food cooperation and maintaining global food security, and has practical significance for investors to use agricultural commodities for risk management and portfolio optimization.Comment: 37 pages, 7 figure

Mediterranean diet during pregnancy and infant neurodevelopment: A prospective birth cohort study

BackgroundEmbryonic neural development is associated with intrauterine nutritional status. However, few cohort studies estimated the relationship between maternal dietary patterns during pregnancy and offspring's early neurodevelopment.ObjectiveTo examine the impact of the Mediterranean diet (MD) during pregnancy on infant neurodevelopment, including the potential mediating role of cord blood metabolites.MethodsAmong 1,471 mother–child pairs in a prospective birth cohort study in Hefei, China, we investigated the associations between maternal MD score [calculated based on a validated food frequency questionnaire (FFQ)] and child neurodevelopment at infancy [assessed using Ages and Stages Questionnaires, Third Edition (ASQ-3)]. The cord blood metabolic markers (including C-peptide, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, total cholesterol, and triglycerides) were measured.ResultsThe MD score was negatively associated with communication domain developmental delays in infants [relative risk (RR) with 95% CI: 0.34 (0.16, 0.72)]. Compared with girls, boys born from mothers with lower MD scores during pregnancy were inclined to the failure of the communication domain [RRs with 95% CI for boys: 0.34 (0.14, 0.84); for girls: 0.26 (0.06, 1.18)]. Mediation analysis showed that the association between the maternal MD score and failure of communication domain mediated by C-peptide was 19.4% in boys but not in girls.ConclusionAdhering to the MD during pregnancy was associated with a decreased risk of poor neurodevelopment, possibly mediated by lower levels of cord blood C-peptide

25-hydroxyvitamin D levels in children of different ages and with varying degrees of Helicobacter pylori infection and immunological features

BackgroundHelicobacter pylori (HP) is a major cause of upper digestive tract diseases. However, the relationship between HP infection and 25-hydroxyvitamin D [25(OH)D] levels in children has not been fully elucidated. This study investigated the levels of 25(OH)D in children of different ages and with varying degrees of HP infection and immunological features as well as the correlations between 25(OH)D levels in children infected with HP and their ages and degrees of infection.Materials and methodsNinety-four children who underwent upper digestive endoscopy were divided into an HP-positive group without peptic ulcers (Group A), an HP-positive group with peptic ulcers (Group B) and an HP-negative control group (Group C). The serum levels of 25(OH)D and immunoglobulin and the percentages of lymphocyte subsets were determined. HP colonization, the degree of inflammation, and the degree of activity were further evaluated by HE staining and immunohistochemical staining in gastric mucosal biopsy.ResultsThe 25(OH)D level of the HP-positive groups (50.93 ± 16.51 nmol/L) was significantly lower than that of the HP-negative group (62.89 ± 19.18 nmol/L). The 25(OH)D level of Group B (47.79 ± 14.79 nmol/L) was lower than that of Group A (51.53 ± 17.05 nmol/L) and was significantly lower than that of Group C (62.89 ± 19.18 nmol/L). The 25(OH)D level decreased with increasing age, and there was a significant difference between Group C subjects who were ≤5 years old and those who were aged 6–9 years and ≥10 years. The 25(OH)D level was negatively correlated with HP colonization (r = −0.411, P < 0.01) and the degree of inflammation (r = −0.456, P < 0.01). The percentages of lymphocyte subsets and immunoglobulin levels among Groups A, B and C were not significantly different.ConclusionsThe 25(OH)D level was negatively correlated with HP colonization and the degree of inflammation. As the age of the children increased, the level of 25(OH)D decreased, and the susceptibility to HP infection increased

Differential effects of neurotrophins and schwann cell-derived signals on neuronal survival/growth and synaptogenesis

Recent studies have shown that the survival of mammalian motoneurons in vitro is promoted by neurotrophins (NTs) and cAMP. There is also evidence that neurotrophins enhance transmitter release.Wethus investigated whether these agents also promote synaptogenesis. Cultured Xenopus spinal cord neurons were treated with a mixture of BDNF, glia-derived neurotrophic factor, NT-3, and NT-4, in addition to forskolin and IBMX or the cell-permeant form of cAMP, to elevate the cAMP level. The outgrowth and survival of neurons were dramatically increased by this trophic stimulation. However, when these neurons were cocultured with muscle cells, the trophic agents resulted in a failure of synaptogenesis. Specifically, the induction ofAChreceptor (AChR) clustering in cultured muscle cells was inhibited at nerve–muscle contacts, in sharp contrast to control, untreated cocultures. Because AChR clustering induced by agrin or growth factor-coated beads in muscle cells was unaffected by trophic stimulation, its effect on synaptogenesis is presynaptic in origin. In the control, agrin was deposited along the neurite and at nerve–muscle contacts. This was significantly downregulated in cultures treated with trophic stimuli. Reverse transcriptase-PCR analyses showed that this decrease in agrin deposition was caused by an inhibition of agrin synthesis by trophic stimuli. Both agrin synthesis and induction of AChR clustering were restored under trophic stimulation when Schwann cell-conditioned medium was introduced. These results suggest that trophic stimulation maintains spinal neurons in the growth state, and Schwann cell-derived factors allow them to switch to the synaptogenic state

Notch1 is required for hypoxia-induced proliferation, invasion and chemoresistance of T-cell acute lymphoblastic leukemia cells

Background Notch1 is a potent regulator known to play an oncogenic role in many malignancies including T-cell acute lymphoblastic leukemia (T-ALL). Tumor hypoxia and increased hypoxia-inducible factor-1α (HIF-1α) activity can act as major stimuli for tumor aggressiveness and progression. Although hypoxia-mediated activation of the Notch1 pathway plays an important role in tumor cell survival and invasiveness, the interaction between HIF-1α and Notch1 has not yet been identified in T-ALL. This study was designed to investigate whether hypoxia activates Notch1 signalling through HIF-1α stabilization and to determine the contribution of hypoxia and HIF-1α to proliferation, invasion and chemoresistance in T-ALL. Methods T-ALL cell lines (Jurkat, Sup-T1) transfected with HIF-1α or Notch1 small interference RNA (siRNA) were incubated in normoxic or hypoxic conditions. Their potential for proliferation and invasion was measured by WST-8 and transwell assays. Flow cytometry was used to detect apoptosis and assess cell cycle regulation. Expression and regulation of components of the HIF-1α and Notch1 pathways and of genes related to proliferation, invasion and apoptosis were assessed by quantitative real-time PCR or Western blot. Results Hypoxia potentiated Notch1 signalling via stabilization and activation of the transcription factor HIF-1α. Hypoxia/HIF-1α-activated Notch1 signalling altered expression of cell cycle regulatory proteins and accelerated cell proliferation. Hypoxia-induced Notch1 activation increased the expression of matrix metalloproteinase-2 (MMP2) and MMP9, which increased invasiveness. Of greater clinical significance, knockdown of Notch1 prevented the protective effect of hypoxia/HIF-1α against dexamethasone-induced apoptosis. This sensitization correlated with losing the effect of hypoxia/HIF-1α on Bcl-2 and Bcl-xL expression. Conclusions Notch1 signalling is required for hypoxia/HIF-1α-induced proliferation, invasion and chemoresistance in T-ALL. Pharmacological inhibitors of HIF-1α or Notch1 signalling may be attractive interventions for T-ALL treatment

Magneto-Orientation of Magnetic Double Stacks for Patterned Anisotropic Hydrogels with Multiple Responses and Modulable Motions

Reported here is a multi‐response anisotropic poly(N‐isopropylacrylamide) hydrogel developed by using a rotating magnetic field to align magnetic double stacks (MDSs) that are fixed by polymerization. The magneto‐orientation of MDSs originates from the unique structure with γ‐Fe(2)O(3) nanoparticles sandwiched by two silicate nanosheets. The resultant gels not only exhibit anisotropic optical and mechanical properties but also show anisotropic responses to temperature and light. Gels with complex ordered structures of MDSs are further devised by multi‐step magnetic orientation and photolithographic polymerization. These gels show varied birefringence patterns with potentials as information materials, and can deform into specific configurations upon stimulations. Multi‐gait motions are further realized in the patterned gel through dynamic deformation under spatiotemporal light and friction regulation by imposed magnetic force. The magneto‐orientation assisted fabrication of hydrogels with anisotropic structures and additional functions should bring opportunities for gel materials in biomedical devices, soft actuators/robots, etc