Actuarial Model Assumptions for Australian Inflation, Equity Returns, and Interest Rates

Though actuaries have developed several types of stochastic investment models for inflation, stock market returns, and interest rates, there are two commonly used in practice: autoregressive time series models with normally distributed errors, and autoregressive conditional heteroscedasticity (ARCH) models. ARCH models are particularly suited when there is heteroscedasticity in inflation and interest rate series. In such cases nonnormal residuals are found in the empirical data. This paper examines whether Australian univariate inflation and interest rate data are consistent with autoregressive time series and ARCH model assumptions

Delithation, Exfoliation, and Transformation of Rock-Salt-Structured Li₂TiO₃ to Highly Exposed {010}-Faceted Anatase

{010}-Facet-exposed anatase TiO₂ crystals exhibit the highest photoreactivity among the exposed facets. To obtain a higher exposure rate of this facet, the work investigated the transformation of the nanosheets with cavities within the layers derived from a rock-salt-structured Li₂TiO₃ precursor. All the lithium ions were extracted from the precursor by H⁺/Li⁺ ion exchange in HCl aqueous solutions, and after tetramethylammonium ions were intercalated, the precursor can delaminated into the nanosheets. The [TiO₃]^2– nanosheets were hydrothermally treated under different temperatures and pH values. The results showed that the anatase phase was formed in a wider range of pH and temperature, compared with using nanoribbons of [Ti₄O₉]^2– and nanosheets of [Ti_1.73O₄]^1.07–. At low pH, [111]-faceted nanorod-shaped anatase nanocrystals were formed preferentially, and the nanocrystals preferentially grow along the [001] direction with the increase of solution pH, leading to a large percentage of {010} facets on their surface. The photocatalytic activity increases with the increase of exposure rate of {010} facets

Associations of Physical Activity, Screen Time with Depression, Anxiety and Sleep Quality among Chinese College Freshmen

<div><p>Objectives</p><p>To investigate the independent and interactive associations of physical activity (PA) and screen time (ST) with depression, anxiety and sleep quality among Chinese college students.</p><p>Methods</p><p>A cross-sectional study was conducted in Wuhan University, China from November to December 2011. The students reported their PA, ST and socio-economic characteristics using self-administered questionnaires. Sleep quality was measured by the Pittsburgh Sleep Quality Index (PSQI). Depression and anxiety were assessed using the Self-rating Depression Scale (SDS) and Self-rating Anxiety Scale (SAS), respectively. Multivariate logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of the independent and interactive relationships of PA and ST with depression, anxiety and sleep quality.</p><p>Results</p><p>A total of 1106 freshmen (471 females and 635 males) aged 18.9±0.9 years were included in the study. After adjustment for potential confounders, high PA and low ST were independently associated with significantly lower risks for poor sleep quality (OR: 0.48, 95% CI: 0.30–0.78) and depression (OR: 0.67, 95%CI: 0.44–0.89), respectively. An interactive inverse association was observed for combined effects of PA and low ST on depression (OR: 0.62, 95%CI: 0.40–0.92) and sleep quality (OR: 0.51, 95%CI: 0.27–0.91). No statistically significant associations were found between PA, ST and anxiety among the participants.</p><p>Conclusions</p><p>These findings suggest an independent and interactive relationship of high PA and low ST with significantly reduced prevalence of depressive problems and favorable sleep quality among Chinese college freshmen.</p></div

Associations between physical activity, screen time and depression, anxiety, sleep quality among Chinese college freshmen.

<p>Adjusted for age, gender, BMI, and maternal education.</p><p>*: p<0.05; **: p<0.01.</p><p>OR: odd ratio. CI: confidence interval. PA: physical activity. ST: screen time.</p

Tuning Solid-State Fluorescence of a Twisted π‑Conjugated Molecule by Regulating the Arrangement of Anthracene Fluorophores

1-(5-(Anthracen-9-yl)-3-(4-methoxyphenyl)-4,5-dihydropyrazol-1-yl)­ethanone was synthesized and crystallized to provide three types of crystals with different fluorescent colors and host–guest structures. Crystal structure analysis reveals that this compound possesses twisted π-conjugated structure and different degrees of distortion depending on guest molecules in the three crystal structures. The anthracene fluorophore stacking modes are regulated from monomer arrangement to face-to-face π-stacked arrangement by means of the entrapment of organic acid molecules in the lattice. The vibrational spectroscopy, thermal behaviors, diffuse reflectance absorption spectroscopy, solid-state fluorescence properties, and fluorescence quantum yields and lifetimes of the three types of crystals were investigated. Such properties are closely related to the fluorophore stacking modes and intermolecular electronic interactions in crystals. The π-stacked geometries of anthracene fluorophores are responsible for the red-shifted emissions and longer fluorescence lifetimes. It indicates that the optical properties of organic materials could be modulated by entrapping different guest molecules in lattice

Basic characteristics of the study subjects.

<p>Values are presented as mean (SD) or number (percentage) when appropriate.</p><p>BMI: body mass index. PA: physical activity. ST: screen time.</p

Ferroelectric Mesocrystalline BaTiO₃/SrTiO₃ Nanocomposites with Enhanced Dielectric and Piezoelectric Responses

A platelike mesocrystalline BaTiO₃/SrTiO₃ (BT/ST) nanocomposite is prepared via a clever two-step solvothermal soft chemical process. First a protonated titanate H_1.07Ti_1.73O₄·<i>n</i>H₂O (HT) crystal with a layered structure and platelike morphology is solvothermally treated in a Ba­(OH)₂ solution to generate a homogeneous platelike BaTiO₃/HT (BT/HT) nanocomposite. Second the generated BT/HT nanocomposite is solvothermally treated in a Sr­(OH)₂ solution to generate the mesocrystalline BT/ST nanocomposite with platelike particle morphology. The transformation reactions from the HT precursor to the mesocrystalline BT/ST nanocomposite are topochemical conversion reactions, and the formed BT/ST nanocomposite is constructed from well-aligned BT and ST nanocrystals in the same crystal-axis orientation. The BT/ST nanocomposite annealed at 900 °C shows a ferroelectric behavior and drastically enhanced piezoelectric and dielectric responses owing to the introduction of a lattice strain at a three-dimensional heteroepitaxial interface between the BT and ST nanocrystals in the mesocrystal. The nanostructure of the BT/ST mesocrystal is suitable for simultaneous application of the strain engineering and the orientation engineering to develop high performance piezoelectric and dielectric materials

Regulation of Arrangements of Pyrene Fluorophores via Solvates and Cocrystals for Fluorescence Modulation

1-Acetyl-3-phenyl-5-(1-pyrenyl)-pyrazoline (APPP) was synthesized and formed four types of different crystals under different crystallization conditions: guest-free crystal (<b>I</b>, α polymorph), APPP·chloroform solvate (<b>II</b>), APPP·phenol cocrystal (<b>III</b>), and APPP·acetic acid solvate (<b>IV</b>). Twisted structures and different stacking modes of APPP molecules were found in the four crystals. Single crystal X-ray analyses revealed pyrene fluorophores adopt an edge-to-face π-stacked arrangement in crystal <b>I</b>, mononer arrangement in crystals <b>II </b>and <b>III</b>, and face-to-face slipped π-stacked arrangement in crystal <b>IV</b>. Another phase (β polymorph) was discovered during DSC experiments of crystals <b>II</b> and <b>IV</b> and obtained by desolvation of crystal <b>II</b>. However, solvent-mediated phase transitions revealed β polymorph is a metastable phase at room temperature, and no single crystal could be isolated. The optical–physical properties of these solids were investigated. Crystal <b>I</b> shows a broad emission band (λ_max = 419 nm) with a red shift of about 40 nm relative to its flurescence in solvents, in which the vibrational features are less clear. The spectra of crystals <b>II</b> and <b>III</b> and β polymorph are similar to each other, exhibiting the shortest λ_em (λ_max = 399–400 nm), and the fluorescence spectra with vibrational features are close to pyrene fluorescence in solvents. In contrast, crystal <b>IV</b> shows structureless and broad emission spectrum with the longest λ_em (λ_max = 452 nm) among these crystals. The difference in their optical–physical properties is closely related to the different arrangements of pyrene fluorophores. The monomer arrangements of pyrene fluorophores may be responsible for the shortest λ_em, higher emission quantum yields, and longer lifetimes. For a given organic luminescent material, the strategy based on the solvates and cocrystals can not only tune the optical–physical properties but also be helpful to find suitable polymorphic phases

Tuning Solid-State Fluorescence of a Twisted π‑Conjugated Molecule by Regulating the Arrangement of Anthracene Fluorophores

1-(5-(Anthracen-9-yl)-3-(4-methoxyphenyl)-4,5-dihydropyrazol-1-yl)­ethanone was synthesized and crystallized to provide three types of crystals with different fluorescent colors and host–guest structures. Crystal structure analysis reveals that this compound possesses twisted π-conjugated structure and different degrees of distortion depending on guest molecules in the three crystal structures. The anthracene fluorophore stacking modes are regulated from monomer arrangement to face-to-face π-stacked arrangement by means of the entrapment of organic acid molecules in the lattice. The vibrational spectroscopy, thermal behaviors, diffuse reflectance absorption spectroscopy, solid-state fluorescence properties, and fluorescence quantum yields and lifetimes of the three types of crystals were investigated. Such properties are closely related to the fluorophore stacking modes and intermolecular electronic interactions in crystals. The π-stacked geometries of anthracene fluorophores are responsible for the red-shifted emissions and longer fluorescence lifetimes. It indicates that the optical properties of organic materials could be modulated by entrapping different guest molecules in lattice

Tuning Solid-State Fluorescence of a Twisted π‑Conjugated Molecule by Regulating the Arrangement of Anthracene Fluorophores

1-(5-(Anthracen-9-yl)-3-(4-methoxyphenyl)-4,5-dihydropyrazol-1-yl)­ethanone was synthesized and crystallized to provide three types of crystals with different fluorescent colors and host–guest structures. Crystal structure analysis reveals that this compound possesses twisted π-conjugated structure and different degrees of distortion depending on guest molecules in the three crystal structures. The anthracene fluorophore stacking modes are regulated from monomer arrangement to face-to-face π-stacked arrangement by means of the entrapment of organic acid molecules in the lattice. The vibrational spectroscopy, thermal behaviors, diffuse reflectance absorption spectroscopy, solid-state fluorescence properties, and fluorescence quantum yields and lifetimes of the three types of crystals were investigated. Such properties are closely related to the fluorophore stacking modes and intermolecular electronic interactions in crystals. The π-stacked geometries of anthracene fluorophores are responsible for the red-shifted emissions and longer fluorescence lifetimes. It indicates that the optical properties of organic materials could be modulated by entrapping different guest molecules in lattice