A Double-threshold GARCH Model for the French Franc/Deutschmark exchange rate

This paper combines and generalizes a number of recent time series models of daily exchange rate series by using a SETAR model which also allows the variance equation of a GARCH specification for the error terms to be drawn from more than one regime. An application of the model to the French Franc/Deutschmark exchange rate demonstrates that out-of-sample forecasts for the exchange rate volatility are also improved when the restriction that the data it is drawn from a single regime is removed. This result highlights the importance of considering both types of regime shift (i.e. thresholds in variance as well as in mean) when analysing financial time series

Study on conjugate heat transfer in a photovoltaic wall

2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Early Treatment of Nevus of Ota in Children is More Effective and Beneficial to Mental Health: Observation on the Efficacy of Q-Switched Ruby Laser in Treating 159 Cases of Nevus of Ota in Children

Ji-Cong Jiang,&ast; Ying-Wei Wang,&ast; Yu Gao, Qi-Shuang Zhou Department of Dermatology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, 325027, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Qi-Shuang Zhou; Yu Gao, Email [email protected]; [email protected] and Objective: Nevus of Ota (NO), also known as “brownish-blue nevus of the palate of the eye”, is a benign dermal pigmentation that increases skin disease. The Q-switched ruby laser is a classic treatment for nevus of Ota in children, but the optimal age for treatment is still controversial. The aim of this study was to investigate the treatment effect of Q-switched ruby laser in children with nevus of Ota at different ages and the effect on psychological health status.Materials and Methods: Children with nevus of Ota treated with Q-switched ruby laser in the Department of Dermatology of the Second Affiliated Hospital of Wenzhou Medical University from June 2015 to June 2019 were retrospectively analysed. And the mental health status was assessed using the CDI scale.Results: In the preschool children group (0– 7 year age), the significant efficacy rates was 93.1%, the average number of treatments was 3.6, and the overall incidence of adverse reactions was 4.7%. The significant efficacy rates in the school-age children group (7– 14 year age) was 90.3%, the average number of treatments was 5.1, and the overall incidence of adverse reactions was 13.7%. The mean post-treatment CDI score in the preschool children group was 10.8, and 9.7% of children exceeding 19 points. The mean pre-treatment CDI score in the school-age children group was 17.3, and 24.6% of children exceeding 19 points. The mean post-treatment CDI score was 13.6 and 15.1% of children exceeded 19 points. The chi-square test for the significant efficacy rate of the two groups showed P> 0.05, which was not statistically significant. The significant efficacy rate of the preschool group and that of the school-age children group. The t-test for the number of treatments in the two groups showed P< 0.05, which was statistically significant. Adverse reactions in the two groups showed a statistically significant P< 0.05. The mean CDI scores and the percentage of depressed individuals in the school-age children group were significantly lower after treatment than before treatment (p< 0.05).Conclusion: Q-switched ruby laser is safe and effective in treating nevus of Ota in children. Early treatment can reduce the number of treatments and the incidence of adverse reactions. In addition, early treatment can reduce children’s depression, which is beneficial to mental health.Keywords: nevus of Ota, children, Q-switched ruby laser, early treatment, mental healt

Electron shuttle-mediated microbial Fe(III) reduction under alkaline conditions

Purpose: Extracellular Fe(III) reduction plays an important role in a variety of biogeochemical processes. Several mechanisms for microbial Fe(III) reduction in pH-neutral environments have been proposed, but pathways of microbial Fe(III) reduction within alkaline conditions have not been clearly identified. Alkaline soils are vastly distributed; thus, a better understanding of microbial Fe(III) reduction under alkaline conditions is of significance. The purpose of this study is to explore the dominant mechanism of bacterial iron reduction in alkaline environments. Materials and methods: We used antraquinone-2,6-disulfonate (AQDS) as a representative of quinone moities of humic substances and elemental sulfur and sulfate as sulfur species to investigate the potential role of humic substances and sulfur species in mediating microbial Fe(III) reduction in alkaline environments. We carried out thermodynamic calculations to predict the ability of bacteria to reduce Fe(III) (oxyhydr)oxides under alkaline conditions and the ability of AQDS and sulfur species to serve as electron acceptors for microbial anaerobic respiration in an assumed alkaline soil environments. A series of incubation experiments with two model dissimilatory metal reducing bacteria, Shewanella oneidensis MR-1 and Geobacter sulfurreducens PCA as well as mixed bacteria enriched from a soil were performed to confirm the contribution of AQDS and sulfur species to Fe(III) reduction under alkaline conditions. Results and discussion: Based on thermodynamic calculations, we predicted that, under alkaline conditions, the enzymatic reduction of Fe(III) (oxyhydr)oxides would be thermodynamically feasible but very weak. In our incubation experiments, the reduction of ferrihydrite by anaerobic cultures of Shewanella oneidensis MR-1, Geobacter sulfurreducens PCA or microbes enriched from a soil was significantly increased in the presence of S0 or AQDS. Notably, AQDS contributed more to promoting Fe(III) reduction as a soluble electron shuttle than S0 did under the alkaline conditions probably because of different mechanisms of microbial utilization of AQDS and S0. Conclusions: These results suggest that microbial reduction of Fe(III) (oxyhydr)oxides under alkaline conditions may proceed via a pathway mediated by electron shuttles such as AQDS and S0. Considering the high ability of electron shuttling and vast distribution of humic substances, we suggest that humic substance-mediated Fe(III) reduction may potentially be the dominant mechanism for Fe(III) reduction in alkaline environments

Pressure-induced amorphous-to-amorphous configuration change in Ca-Al metallic glasses

Pressure-induced amorphous-to-amorphous configuration changes in Ca-Al metallic glasses (MGs) were studied by performing in-situ room-temperature high-pressure x-ray diffraction up to about 40 GPa. Changes in compressibility at about 18 GPa, 15.5 GPa and 7.5 GPa during compression are detected in Ca80Al20, Ca72.7Al27.3, and Ca66.4Al33.6 MGs, respectively, whereas no clear change has been detected in the Ca50Al50 MG. The transfer of s electrons into d orbitals under pressure, reported for the pressure-induced phase transformations in pure polycrystalline Ca, is suggested to explain the observation of an amorphous-to-amorphous configuration change in this Ca-Al MG system. Results presented here show that the pressure induced amorphous-to-amorphous configuration is not limited to f electron-containing MGs

The Antioxidant Protein Peroxiredoxin 4 Is Epigenetically Down Regulated in Acute Promyelocytic Leukemia

The antioxidant peroxiredoxin (PRDX) protein family comprises 6 members, which are implicated in a variety of cellular responses, including growth factor signal transduction. PRDX4 resides in the endoplasmic reticulum (ER), where it locally controls oxidative stress by reducing H2O2levels. We recently provided evidence for a regulatory function of PRDX4 in signal transduction from a myeloid growth factor receptor, the granulocyte colony-stimulating factor receptor (G-CSFR). Upon activation, the ligand-induced G-CSFR undergoes endocytosis and routes via the early endosomes where it physically interacts with ER-resident PRDX4. PRDX4 negatively regulates G-CSFR mediated signaling. Here, we investigated whether PRDX4 is affected in acute myeloid leukemia (AML); genomic alterations and expression levels of PRDX4 were investigated. We show that genomic abnormalities involving PRDX4 are rare in AML. However, we find a strong reduction in PRDX4 expression levels in acute promyelocytic leukemia (APL) compared to normal promyelocytes and different molecular subtypes of AML. Subsequently, the possible role of DNA methylation and histone modifications in silencing of PRDX4 in APLs was investigated. We show that the reduced expression is not due to methylation of the CpG island in the promoter region of PRDX4 but correlates with increased trimethylation of histone 3 lysine residue 27 (H3K27me3) and lysine residue 4 (H3K4me3) at the transcriptional start site (TSS) of PRDX4, indicative of a bivalent histone code involved in transcriptional silencing. These findings suggest that the control of G-CSF responses by the antioxidant protein PRDX4 may be perturbed in APL

Multi-Constellation Signal Design Aided Affine Frequency Division Multiplexing for 6G Communication Systems

As one of the novel waveforms recently proposed for future 6G communications, affine frequency division multiplexing (AFDM) is capable of combating the effects of the high Doppler and achieving full diversity over high mobility wireless channels. In this paper, hybrid multi-constellations for AFDM systems are proposed. A hybrid multi-constellation is obtained by eliminating points with the largest energy and by geometric interpolation among the signal points of the traditional single constellation. Two types of hybrid multi-constellation schemes, namely multiconstellation aided AFDM-Type 1 (MC-AFDM-T1) and multiconstellation aided AFDM-Type 2 (MC-AFDM-T2), are designed to improve AFDM system reliability. Monte Carlo simulations demonstrate that the proposed MC-AFDM-T1 and MC-AFDMT2 schemes are capable of achieving better symbol error rate (SER) compared to that of the original-AFDM (Ori-AFDM)

A genetic cause of Alzheimer disease: mechanistic insights from Down syndrome

Down syndrome, caused by an extra copy of chromosome 21, is associated with a greatly increased risk of early onset Alzheimer disease. It is thought that this risk is conferred by the presence of three copies of the gene encoding amyloid precursor protein (APP), an Alzheimer risk factor, although the possession of extra copies of other chromosome 21 genes may also play a role. Further study of the mechanisms underlying the development of Alzheimer disease in Down syndrome could provide insights into the mechanisms that cause dementia in the general population

Polymorphisms of toll-like receptors 2 and 9 and severity and prognosis of bacterial meningitis in Chinese children

Toll-like receptors (TLRs) play a crucial role in innate immunity, protecting the host from bacterial pathogens. We investigated whether bacterial meningitis (BM) in children was associated with gene polymorphisms in TLR2 (rs3804099), TLR3 (rs3775291 and rs3775290) and TLR9 (rs352139 and rs352140). Blood samples were taken from 218 child patients with confirmed BM and 330 healthy adult controls (HC) and polymorphisms of these genes were analyzed by PCR-based sequencing. For TLR2 rs3804099, frequencies of the minor allele C were markedly higher in patients with severe BM (defined as CSF glucose concentration <= 1.5 mmol/L and seizures) than those without (43.5% and 40.1% vs. 30.1% and 29.1%, p = 0.008 and p = 0.016, respectively). For TLR9 rs352139, patients who carried genotype AA and minor allele A developed seizures less often than those without (OR = 0.289, p = 0.003 and OR = 0.568, p = 0.004, respectively). However, for TLR9 rs352140, patients who carried genotype TT and minor allele T developed seizures more often than those without (OR = 3.385, p = 0.004 and OR = 1.767, p = 0.004, respectively). Our finding suggested that genetic variations in TLR2 and TLR9 are associated with severity and prognosis of bacterial meningitis in Chinese children. However, the results should be interpreted with caution since the number of subjects included was limited