Commodity spot prices tend to revert to some long-term mean level and most commodity derivatives are based on futures prices, not on spot prices. So, we consider spread options on futures instead of spot or spot index, where the log spot price follows a mean-reverting process. The volatility of the mean-reverting process is driven by two different (fast and slow) scale factors. We use asymptotic analysis to obtain a closed-form approximation of the futures prices and a closed-form formula for the approximate prices of spread options on the futures. The overall improvement of our analytic formula over the classical Kirk–Bjerksund–Sternsland (KBS) formula is discussed via numerical experiments.

The double-mean-reverting model, introduced by Gatheral [(2008). Consistent modeling of SPX and VIX options. In The Fifth World Congress of the Bachelier Finance Society London, July 18], is known to be a successful three-factor model that can be calibrated to both CBOE Volatility Index (VIX) and S&P 500 Index (SPX) options. However, the calibration of this model may be slow because there is no closed-form solution formula for European options. In this paper, we use a rescaled version of the model developed by Huh et al. [(2018). A scaled version of the double-mean-reverting model for VIX derivatives. Mathematics and Financial Economics 12: 495–515] and obtain explicitly a closed-form pricing formula for European option prices. Our formulas for the first and second-order approximations do not require any complicated calculation of integral. We demonstrate that a faster calibration result of the double-mean revering model is available and yet the practical implied volatility surface of SPX options can be produced. In particular, not only the usual convex behavior of the implied volatility surface but also the unusual concave down behavior as shown in the COVID-19 market can be captured by our formula.

For decades, fructose intake has been recognised as an environmental risk for metabolic syndromes and diseases. Here we comprehensively examined the effects of fructose intake on mice liver transcriptomes. Fructose-supplemented water (34 %; w/v) was fed to both male and female C57BL/6N mice at their free will for 6 weeks, followed by hepatic transcriptomics analysis. Based on our criteria, differentially expressed genes (DEG) were selected and subjected to further computational analyses to predict key pathways and upstream regulator(s). Subsequently, predicted genes and pathways from the transcriptomics dataset were validated via quantitative RT-PCR analyses. As a result, we identified eighty-nine down-regulated and eighty-eight up-regulated mRNA in fructose-fed mice livers. These DEG were subjected to bioinformatics analysis tools in which DEG were mainly enriched in xenobiotic metabolic processes; further, in the Ingenuity Pathway Analysis software, it was suggested that the aryl hydrocarbon receptor (AhR) is an upstream regulator governing overall changes, while fructose suppresses the AhR signalling pathway. In our quantitative RT-PCR validation, we confirmed that fructose suppressed AhR signalling through modulating expressions of transcription factor (AhR nuclear translocator; Arnt) and upstream regulators (Ncor2, and Rb1). Altogether, we demonstrated that ad libitum fructose intake suppresses the canonical AhR signalling pathway in C57BL/6N mice liver. Based on our current observations, further studies are warranted, especially with regard to the effects of co-exposure to fructose on (1) other types of carcinogens and (2) inflammation-inducing agents (or even diets such as a high-fat diet), to find implications of fructose-induced AhR suppression.

Bovine spongiform encephalopathy (BSE) involves insertion/deletion (in/del) polymorphisms in the prion protein gene (PRNP) promoter region that are associated with vulnerability to disease progression. Recently, a second member of the prion gene family, prion-like protein gene (PRND), has been reported to show the PRND R132Q polymorphism, which is associated with the susceptibility to BSE in German Fleckvieh breeds. The objective of this study was to examine the genotype, allele, and haplotype frequencies of PRND gene in Korean cattle and evaluate their susceptibility to BSE. We did this in 277 Korean native cattle (Hanwoo) and 124 Korean dairy cattle (Holstein) by direct sequencing and compared the R132Q genotype frequency between BSE-affected German cattle and Korean cattle. The results indicated a total of 5 single nucleotide polymorphisms (SNPs) including PRND c.149G > A (p.50Arg > His; R50H), PRND c.285C > T (C4819T), PRND c.395G > A (p.132Arg > Gln; R132Q) and PRND c.528T > A (T5063A) in the open reading frame (ORF) and c.602C > G in the 3′ untranslated region (UTR) of exon 2 in Korean Holstein and Hanwoo cattle. Except for c.149G > A, the remaining 4 SNPs showed significantly different genotype and allele frequencies between the Korean Holstein and Hanwoo (P < 0·01). There were no significant differences in genotype distribution of c.395G > A SNP between BSE-affected German and Korean Holstein cattle (P = 0·6778), but a significant difference was detected between BSE-affected German cattle and Hanwoo cattle (P = 0·0028). The results suggest that Hanwoo cattle may possess a relatively more BSE-resistant genotype than Korean Holstein cattle.

In this study, we propose a Se-incorporated Ge10Sb90 as a phase-change material for phase-change memory (PCM) with high reliability and low operation power. We investigated the effect of the Se concentration on the thermal and electrical properties of Se-doped Ge10Sb90 films by varying the Se concentration from 0 to 20 at.%. The crystallization temperature, crystallization activation energy, and maximum ten-year data retention temperature increased with the increasing Se, thus demonstrating the improved thermal stability of Se-doped Ge10Sb90 films with higher Se contents. More Se also increased the rate factor, band gap, threshold voltage, and load resistance. In addition, the crystallization speed, programming window, and resistances of both the amorphous and crystalline states increased with the increasing Se concentration. In contrast, the reset current decreased with the increasing Se concentration. These results demonstrate that Se-doped Ge10Sb90 is a highly promising material for PCM applications.

Blackberry is a fruiting berry species with very high nutrient contents. With the recent increasing consumer demand for blackberries, new sources of germplasm and breeding techniques are required to improve blackberry production. This study was carried out to evaluate the genetic diversity (GD) and relationship among 55 blackberry (Rubus fruticosus) mutants derived from γ-ray treatment (52 lines) and N-methyl-N′-nitrosourea (MNU) treatment (three lines) using an inter-simple sequence repeat marker. A total of 18 bands were amplified with an average of 3.6 bands per primer. Among them, eight bands were identified to be polymorphic with a rate of 44.4%. In addition, the GD information content values were highest in the 60 Gy treatment population and the GD values were higher in the γ-ray treatment populations than in the MNU treatment population. According to a cluster analysis, all the mutant lines can be classified into five categories, and the genetic distance was greatest between the 80 Gy-irradiated population and other populations. These results indicate that mutant lines have high GD and can be effectively utilized for improving blackberry breeding.

Yoon H-K, Kim Y-K, Han C, Ko Y-H, Lee H-J, Kwon D-Y, Kim L. Paliperidone in the treatment of delirium: results of a prospective open-label pilot trial.

Objective: Delirium is a life-threatening neuropsychiatric syndrome characterised by disturbances in consciousness, attention, cognition and perception. Antipsychotics are considered the drugs of choice in managing the symptoms of delirium. Paliperidone is a benzisoxazole derivative and the principal active metabolite of risperidone. In this study, we aimed to evaluate the efficacy of paliperidone for the treatment of delirium.

Methods: A prospective open-label study of paliperidone for delirium treatment was performed with 6-day follow-up. Fifteen patients who met Diagnostic and Statistical Manual of Mental disorders, Fourth Edition criteria for delirium and had a score of 13 on the Delirium Rating Scale were recruited. The starting dose was 3 mg once a day and the dose was adjusted depending on the status of delirium. Daily assessments of the severity of delirium were evaluated using Memorial Delirium Assessment Scale (MDAS).

Results: The mean daily maintenance dose of paliperidone was 3.75 ± 1.06. The MDAS scores before and after treatment (day 7) were 23.60 ± 6.31 and 11.33 ± 5.45 (t = 6.78, p < 0.001), respectively. The intensity of delirium showed a statistically significant reduction in MDAS scores from the first day of treatment. No serious adverse effects were observed, and none of the patients discontinued paliperidone because of adverse effects.

Conclusions: This study shows that low-dose paliperidone is effective in reducing behavioural disturbances and symptoms in delirium and is well tolerated in delirious patients. This trial is an open-label study with a small sample size, and further controlled studies will be necessary.

The hardness changes caused by formation of the metastable and stable phases were examined and correlated with the microstructural changes in grain interior and grain boundary during aging at 350 °C to clarify the age-hardening and softening mechanism of a low-gold Au-Cu-Ag-Pd dental alloy. Aging in this context refers to the time-delay that occurs wherein such alloys are kept at elevated temperatures for periods upto many hours to allow precipitation or ordering to take place. During the period of increasing hardness, the matrix was separated into the Ag-rich α1 and AuCu I phases through the metastable phases, forming block-like structure. The apparent hardening was attributed primarily to lattice strain due to the tetragonality of AuCu I′ [the primer (′) here indicates a metastable phase; likewise (I) and (I′) indicate stable AuCu I and metastable AuCu I′ phases, respectively] and AuCu I phases along the c-axis, secondarily to the coherency or semicoherency strain between the metastable α1′ and AuCu I′ phases and between the α0 and AuCu I phases along the a-axis. The apparent softening was caused primarily by growth and coarsening of the lamellar structure in the grain boundaries, secondarily by coarsening of the block-like structure in the grain interior.

Resistance degradation of zirconium (Zr)-doped barium titanate (BaTiO3) was investigated. A series of Ba(Ti1−yZry)O3 powders and coarse-grained ceramics ranging y from 0 to 0.1 were prepared. The increase of Zr concentration systematically increased the time to as well as electric field to degradation. Such behaviors directly corresponded to those of ionic conduction contribution as evaluated by the Warburg impedance. The magnitude of Warburg impedance decreased with the increase of Zr concentration, which demonstrates that the Zr incorporation inhibits the ionic conduction caused by oxygen vacancies. The prototype multilayer ceramic capacitor (MLCC) samples were also prepared by applying these Ba(Ti1−yZry)O3 base powders and formulated X5R additives of commercial application. In this case, however, such distinct difference in degradation behavior with the variation of Zr concentration did not appear. It is supposed that the influence of additives far outweighs the effect of relative difference in the ionic conduction of Ba(Ti1−yZry)O3 under the MLCC test condition where the applied electric field strength is much higher than those for the coarse-grained bulk ceramics. Resistance degradation of MLCC under such high field might not be explained by only oxygen vacancy-related behavior alone.

Aim: To determine whether or not the change in cervical length (CL) over time is valuable in predicting spontaneous preterm delivery (SPTD) in asymptomatic twin pregnancies with a normal mid-trimester CL (>25 mm). Methods: This was a prospective study including 190 consecutive asymptomatic twin gestations with a CL > 25 mm at 20–24 weeks. The women underwent an initial CL measurement at the time of routine ultrasound examination between 20 and 24 weeks’ gestation, followed 4–5 weeks later by a repeat CL measurement. The primary outcome measure was SPTD at <32 completed weeks’ gestation. Multicollinearity was a concern in the multivariable model since change in CL and follow-up CL were highly correlated. Results: The rate of SPTD at <32 weeks was 4.2%. Multiple logistic regression analyses demonstrated that the change in CL and the follow-up CL were significantly associated with SPTD before 32 weeks after adjusting for baseline covariate such as in vitro fertilization. The best cut-off values for the prediction of SPTD at <32 weeks’ gestation were 13% for the change in CL with a sensitivity of 87.5% and a specificity of 63.2%. There was no significant difference in the area under the receiver operating characteristic curves between the change in CL and the follow-up CL. Conclusions: A greater change in CL is a good predictor of SPTD in asymptomatic twin pregnancies with a normal mid-trimester CL. However, the change in CL cannot provide data beyond the follow-up CL. In the setting of a normal mid-trimester CL, a follow-up CL measurement should be considered in asymptomatic twin pregnancies.

The objectives of this study were to evaluate fish guild compositions and national river health using a multi-metric model of the Korean index of biological integrity using fishes (K-IBIF) in four major Korean watersheds along with water chemistry and habitat quality. Tolerant and omnivore fish species dominated all the watersheds, and the proportions of tolerance guilds and trophic guilds reflected water chemistry and habitat quality. The number of sensitive species and insectivore species had negative correlations (r < −0.42, P < 0.01) with chemical water quality (biological oxygen demand (BOD)), while tolerant species and omnivore species had positive correlation (r > 0.27, P < 0.05) with BOD values. Physical habit conditions, based on qualitative habitat evaluation index (QHEI) model, indicated a “good” condition (mean = 68.9; range = 45–105) in three watersheds, except for the Yeongsan River watershed. Values of QHEI were significantly correlated (R2 > 0.4, P < 0.01) with nitrogen and phosphorus levels in all watersheds, suggesting that habitat degradation is associated with eutrophication. Model values of K-IBIF in the watersheds averaged 18.2, indicating a “fair” condition, and about 37% of all observations in K-IBIF model values were judged as a “poor” health condition, indicating severe health impairment. Overall, our data suggest that degradation of the river health was due to a combined effect of chemical pollution and physical habitat modifications. This research provides valuable information on Korean river conservation and restoration in the future.

The levels and distribution of polychlorinated biphenyl (PCB) congeners were analysed in fourteen soil and eight lichen (Usnea aurantiaco-atra) samples from King George Island, West Antarctica. A total of 32 PCB congeners were found in five soil samples collected in 2006, and the mean concentration of total PCBs was 20.4 pg g-1 dry weight (range, 8.0−33.8 pg g-1 dry weight). The most abundant PCB isomers in soil samples were di-, tri-, and penta-CBs, which accounted for more than 75% of the total residues. Twelve dioxin-like PCBs were also detected in nine soil and eight lichen samples, and the levels of dioxin-like PCBs were 5-fold higher in lichens than in soil. PCBs were detected at very low levels in most soil and lichen samples. The highest congener concentrations were found for PCB 118 (6.63 and 21.93 pg g-1 in soil and lichen, respectively) among dioxin-like PCBs. PCB levels in air samples were highly correlated with those in soil and lichen samples, as were PCB levels in soil and lichen samples collected at the same site. Long-range atmospheric transport is thought to be the main source of PCBs on King George Island. However, PCB levels in soil and lichen samples were also apparently influenced by local sources of PCBs.

The incubation-limitation hypothesis suggests that clutch size in some birds is limited by incubation capacity. However, this remains disputed amongst ornithologists. This study aimed to test whether incubation capacity limits the maximum clutch size to two eggs in south polar skuas (Catharacta maccormicki Saunders) by comparing the egg and nest temperatures as well as hatchability between two-egg and three-egg clutches. Although the vast majority of clutches contained one or two eggs, four naturally occurring three-egg clutches were found at Barton Peninsula, King George Island over three breeding seasons (2004–2005, 2005–2006 and 2006–2007). Regardless of clutch size, all incubating parents exhibited two discernible brood patches. The mean egg and nest temperatures of the three-egg clutches were significantly lower than were those of the two-egg clutches. The accumulated time that egg temperature decreased below 30°C in three-egg clutches was approximately eight times longer than that in two-egg clutches. The hatchability of natural one-egg (89.5%) and two-egg clutches (95.4%) were significantly higher than that of the three-egg clutches, which was zero. Our results suggest that the maximum clutch size in south polar skuas is probably restricted by incubation capacity.