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Children show a distinct presentation of COVID‐19, characterized by a lower incidence and mild phenotype, but the reason for this is still unknown. The angiotensin‐converting enzyme 2 (ACE2) functions as the primary cell entry receptor for Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and is thought to cause distinct clinical features between children and old people. The primary purpose of this study was to determine whether differences exist in the level of expression and distribution of ACE2 between neonatal and adult rat lungs. The lung tissues from rats of various ages were used to investigate the expression patterns of ACE2. Western blot, immunohistochemistry, and immunofluorescence were used to quantify or identify the localization of ACE2 in rat lungs. ACE2 was homogenously expressed in fewer alveolar type II (AT2) cells in the neonatal lung, with no polarization to the alveolar space and additional expression in pulmonary endothelium when compared to adult rat lungs. These findings suggest that the patterns of ACE2 distribution and cellular localization in rat lungs change with age., Here, we examined whether differences exist in the level of expression and distribution of ACE2 between neonatal and adult rat lungs. We found that ACE2 was homogenously expressed in fewer alveolar type II cells in the neonatal lung, with no polarization to the alveolar space and additional expression in pulmonary endothelium when compared to the adult rat lung.

This is the first paper to study the options written on the Invesco Currency Shares Australian Dollar Trust (FXA) exchange‐traded fund (ETF). We quantify the empirical characteristics of the FXA option implied volatility (IV) curve showing that it exhibits a smirk shape, as in US equity options, and the curves become more negatively sloped and exhibit more convexity as the time to maturity increases. During the Global Financial Crisis (GFC) period and a bullish period, IV dramatically increased and the slope became even steeper across all maturities indicating that downside insurance is relatively expensive. Further, the information in the quantified IV curve factors has some predictive power for monthly FXA returns.

This paper proposes a comprehensive jump‐to‐default extended two‐factor stochastic volatility plus asymmetry jumps model for the valuation of VXX derivatives. The model provides a more flexible modeling of the time variation in VXX options smirk and VXX options volatility term structure compared with previous model alternatives. Empirical results indicate that our model outperforms Bao et al.'s model by 28.19% in‐sample and 23.38% out‐of‐sample. Moreover, our model improves the probability that the estimated prices fall inside the quoted option bid‐ask spread and has a better fitting capacity for the term structure of VXX implied volatility, especially for out‐of‐the‐money options.

This paper studies the implied volatility (IV) smirks in four commodity markets by adopting Zhang and Xiang's methodology. First, we document the term structure and dynamics of IV smirks. Overall, the commodity IV curves are negatively skewed with a positive curvature. Then we analyze the commodity and S&P 500 returns' predictability based on in‐sample and out‐of‐sample tests and find that the information embedded in IV smirks can significantly predict monthly commodity and S&P 500 returns. For example, the risk‐neutral fourth cumulant (FC) from the crude oil market outperforms all of the standard predictors in predicting the S&P 500 returns.

This paper studies the New Zealand (NZ) dairy derivatives, specifically, whole milk powder (WMP) options, which have been the most actively traded options in NZ since their inception in November 2011. Using the methodology of Zhang and Xiang, the dynamics of the implied volatility smirk of WMP options is documented. Overall, the level, slope and curvature were found to be 0.2625, −0.0194 and 0.0756, respectively. Modifying the CBOE VIX methodology, the NZ Dairy Volatility Index is created; this exhibits a downward trend and is the second‐best predictor of WMP returns, after curvature, in the latest subsample – after 26 June 2017.

We develop a model for the VXX, the most actively traded VIX futures exchange‐traded note, using Duffie, Pan, and Singleton's affine jump diffusion framework, where the volatility process has jumps and a stochastic long‐term mean. We calibrate the model parameters using the VIX term structure data and show that our model provides the theoretical link between the VIX, VIX futures, and the VXX. Our model can be used for pricing VIX futures, the VXX and other short‐term VIX futures exchange‐traded products (ETPs). Our model could be extended to price options on the VXX and other short‐term VIX futures ETPs.

Atorvastatin (ATV) is frequently prescribed and generally well tolerated, but can lead to myotoxicity, especially at higher doses. A genome-wide association study of circulating levels of ATV, 2-hydroxy (2-OH) ATV, ATV lactone (ATV L), and 2-OH ATV L was performed in 590 patients who had been hospitalized with a non-ST elevation acute coronary syndrome 1 month earlier and were on high-dose ATV (80 mg or 40 mg daily). The UGT1A locus (lead single nucleotide polymorphism, rs887829) was strongly associated with both increased 2-OH ATV/ATV (P = 7.25 × 10-16 ) and 2-OH ATV L/ATV L (P = 3.95 × 10-15 ) metabolic ratios. Moreover, rs45446698, which tags CYP3A7*1C, was nominally associated with increased 2-OH ATV/ATV (P = 6.18 × 10-7 ), and SLCO1B1 rs4149056 with increased ATV (P = 2.21 × 10-6 ) and 2-OH ATV (P = 1.09 × 10-6 ) levels. In a subset of these patients whose levels of ATV and metabolites had also been measured at 12 months after hospitalization (n = 149), all of these associations remained, except for 2-OH ATV and rs4149056 (P = 0.057). Clinically, rs4149056 was associated with increased muscular symptoms (odds ratio (OR) 3.97; 95% confidence interval (CI) 1.29-12.27; P = 0.016) and ATV intolerance (OR 1.55; 95% CI 1.09-2.19; P = 0.014) in patients (n = 870) primarily discharged on high-dose ATV. In summary, both novel and recognized genetic associations have been identified with circulating levels of ATV and its major metabolites. Further study is warranted to determine the clinical utility of genotyping rs4149056 in patients on high-dose ATV.

In this paper, we propose a parsimonious and efficient model to price derivatives written on VIXs with different horizons. Our model is built on Luo and Zhang's (2012, J Futures Markets, 32, 1092–1123) concept of the instantaneous squared VIX (ISVIX) that is the sum of instantaneous diffusive and jump variances of the SPX return. Modeling the ISVIX as a mean‐reverting jump‐diffusion process with a stochastic long‐term mean, we obtain analytical formulas for VIX options and futures. Estimation with VIX term structure and calibration with VIX options data show that our model performs well in matching both time series and cross‐sectional VIX derivatives market prices.

Aims and objectives To compare the differences in psychosocial behaviour reactions, psychosocial needs, anxiety and depression before and after colostomy surgery and to explore the predictors of psychosocial behaviour reactions. Background Colorectal cancer is increasing worldwide. Abdominoperineal resection accompanied by permanent colostomy can cause complicated psychosocial reactions and needs. However, colostomy patients' trajectories of psychosocial adjustment at different time points must be discussed. Design A longitudinal study. Methods Using a convenience sampling method, 67 patients planning to undergo colostomy surgery were recruited from a tertiary cancer centre in southern China from January 2013-January 2014. Data collection consisted of two phases, conducted 1-2 days before surgery and 1-2 days prior to discharge. The Ostomy Psychosocial Behaviour Reaction Questionnaire, the Ostomy Psychosocial Needs Questionnaire, the Hospital Anxiety and Depression Scale and a self-designed demographic questionnaire were used to collect data. STROBE guidelines were followed. Results The participants had a moderate level of psychosocial behaviour reactions, a deep and wide range of psychosocial needs and a high incidence of anxiety and depression before and after surgery. Anxiety before surgery was significantly higher than that after surgery. Psychosocial needs and anxiety were significant predictors of psychosocial behaviour reactions. Conclusions Patients' anxiety was alleviated after surgery. The combination of ascertaining and meeting various psychosocial needs and managing negative emotions was helpful in alleviating patients' stress responses before and after surgery. Relevance to clinical practice An increased focus on the relationships among psychosocial behaviour reactions, psychosocial needs, anxiety and depression at different time points in colostomy patients is necessary for future research and practice.

In this paper, we study the implied volatility smirk (IVS) of options written on the FXI, the Financial Times Stock Exchange/Xinhua China 50 Index exchange‐traded fund (ETF). Using the methodology of Zhang and Xiang (2008, Quant Financ, 8, pp. 263–284), we document the empirical characteristics of the level, slope, and curvature of IVS of the FXI options. We find that, on average, IVS becomes steeper and more convex as time to maturity increases. The level and curvature are usually positive, and the slope is negative. We provide evidence that the information in the quantified IV factors has some predictive power for the future monthly FXI ETF returns.

BACKGROUND: Electroconvulsive therapy (ECT) is an effective treatment for older patients with severe psychiatric disorders, but their knowledge and attitudes regarding ECT have not been well studied. This study examined the knowledge and attitudes of older Chinese patients and their caregivers towards ECT. METHOD: A total of 216 participants comprising older patients treated with ECT (n = 108) and their caregivers (n = 108) were recruited. Their knowledge and attitudes regarding ECT were assessed using self-reported questionnaires. RESULTS: Most caregivers received sufficient information on the therapeutic effects of ECT, but inadequate information about the ECT process, its adverse effects, and risks was provided to caregivers and patients before treatment. Although ECT was generally viewed as beneficial, effective, and safe, around two-thirds of patients and caregivers believed that ECT should be used only for critically ill patients. Over half of the patients reported adverse effects caused by ECT, with memory impairment being the most commonly reported. CONCLUSIONS: Clinicians in Chinese psychiatric hospitals need to provide sufficient information on ECT to older patients and their caregivers before treatment, particularly regarding the treatment process and adverse effects.

Background Although stomas are necessary for disease treatment, they unavoidably affect patients' lives from physical, psychological, social, spiritual, and familial perspectives and contribute to feelings of embarrassment and shame. This study explored the current status and factors influencing stigma among Chinese patients with stoma. Methods A total of 209 patients with stoma at the stoma clinic of a tertiary cancer centre in Guangzhou, China, were recruited and investigated by using the Social Impact Scale, the Coping Self-Efficacy Scale, the State Self-Esteem Scale, and a demographic questionnaire. Multivariate linear regression was used to identify the factors influencing stigma. Results The mean Social Impact Scale score was 69.65 ± 13.18, which represents a moderate effect; specifically, 44% of the patients experienced high levels of stigma. Stoma patients with the following characteristics had high levels of stigma: young, low coping self-efficacy, low stoma acceptance by one's spouse or other family members, poor perceived body image, stool leakage, and no experience of participating in activities with other stoma patients. Conclusions Medical staff members should pay more attention to stigma in stoma patients. Coping self-efficacy, family members' acceptance of the stoma, and participation in activities with other stoma patients are influencing factors that protect these patients against stigma, whereas body image loss and stool leakage place them at higher risk for stigma. Interventions aimed at improving protective factors and decreasing risk factors should be considered to reduce the level of stigma in patients with stoma.

Background Diffusion-weighted imaging (DWI) has been studied in breast imaging and can provide more information about diffusion, perfusion and other physiological interests than standard pulse sequences. The stretched-exponential model has previously been shown to be more reliable than conventional DWI techniques, but different diagnostic sensitivities were found from study to study. Purpose This work investigated the characteristics of whole-lesion histogram parameters derived from the stretched-exponential diffusion model for benign and malignant breast lesions, compared them with conventional apparent diffusion coefficient (ADC), and further determined which histogram metrics can be best used to differentiate malignant from benign lesions. Study type This was a prospective study. Population Seventy females were included in the study. Field strength/sequence Multi-b value DWI was performed on a 1.5T scanner. Assessment Histogram parameters of whole lesions for distributed diffusion coefficient (DDC), heterogeneity index (α), and ADC were calculated by two radiologists and compared among benign lesions, ductal carcinoma in situ (DCIS), and invasive carcinoma confirmed by pathology. Statistical tests Nonparametric tests were performed for comparisons among invasive carcinoma, DCIS, and benign lesions. Comparisons of receiver operating characteristic (ROC) curves were performed to show the ability to discriminate malignant from benign lesions. Results The majority of histogram parameters (mean/min/max, skewness/kurtosis, 10-90th percentile values) from DDC, α, and ADC were significantly different among invasive carcinoma, DCIS, and benign lesions. DDC10% (area under curve [AUC] = 0.931), ADC10% (AUC = 0.893), and αmean (AUC = 0.787) were found to be the best metrics in differentiating benign from malignant tumors among all histogram parameters derived from ADC and α, respectively. The combination of DDC10% and αmean , using logistic regression, yielded the highest sensitivity (90.2%) and specificity (95.5%). Data conclusion DDC10% and αmean derived from the stretched-exponential model provides more information and better diagnostic performance in differentiating malignancy from benign lesions than ADC parameters derived from a monoexponential model. Level of evidence 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1701-1710.

Three new metal coordination complexes, namely [Co(BPY)2(H2O)2](BPY)(BS)2(H2O)4 (1), [Co(BPY)2(H2O)4](ABS)2(H2O)2 (2) and [Co(BPY)(H2O)4](MBS)2 (3) (BPY = 4,4′-bipyridine, BS = phenylsulfonic acid, ABS = p-aminobenzenesulfonic acid, MBS = p-methylbenzenesulfonic acid), were obtained under hydrothermal conditions. Complexes 1, 2, 3 were structurally characterized using single-crystal X-ray diffraction and infrared spectroscopy. All of them display low-dimensional motifs: complex 1 displays a two-dimensional structure; and complexes 2 and 3 exhibit a one-dimensional tape structure. Through strong intermolecular hydrogen bonding interactions and weak packing interactions, all of them further stack to generate a three-dimensional supramolecular architecture. Catalysts 1, 2, 3 were involved in the green synthesis of a variety of 3,4-dihydropyrimidin-2(1H)-ones under solvent-free conditions through Biginelli reactions. The corresponding catalytic product was obtained in quantitative yields (99%) under eco-friendly synthesis conditions for the variety of reactions. Catalysts 1, 2, 3 exhibit excellent efficiency for the desired product, and their catalytic performance shows the following order: 2 > 1 ≈ 3, which can be ascribed to the hydrophobic interactions of different phenylsulfonate groups. The catalytic performance for the Biginelli reaction is not only dependent on the selected solvents, but also inversely proportional to the polarities of the solvents. Copyright © 2016 John Wiley & Sons, Ltd.

Dermatomyositis (DM) is a polygenic disorder characterized by inflammation of skeletal muscle and skin. To date, the exact etiopathogenesis of DM remains elusive. To explore the genetic basis of DM, we conducted genome-wide genotyping analysis of 127 patients and 1566 healthy controls by Illumina Human OmniZhongHua-8 BeadChips in the Chinese Han population. We investigated whether the three SNP (rs7750458, rs9501251 and rs9500928) at 6p21.32 in the HLA-DPB1 gene were significantly associated with DM (P < 5 × 10-8 ) and identified two susceptibility loci at 7q34 (PIP, rs9986765, P = 7.45 × 10-7 , odds ratio [OR] = 2.71) and 10q24.2 (CPN1, rs3750716, P = 9.04 × 10-7 , OR = 4.39) with suggestive evidence. We imputed 6674 classical human leukocyte antigen (HLA) alleles, amino acids and SNP from the discovery dataset, and stepwise analysis revealed that HLA-DPB1*17 in class II HLA genes were significantly associated with DM susceptibility. This study represents the first genome-wide association study (GWAS) of DM in the Chinese Han population. For the first time, HLA-DPB1 was found to be associated with DM in this population. Moreover, we identified two novel suggestive susceptibility loci (PIP and CPN1) and confirmed four previously reported genes (DMB, DQA1, DQB1 and DRB1) having potential associations with DM in the Chinese Han population. Our GWAS results in this population should provide important information regarding the genetic etiopathogenesis of DM and facilitate the development of new therapies for the treatment of DM and the prevention of DM progression.

In this paper, we develop an equilibrium asset pricing model for market excess returns, variance and the third cumulant by using a jump‐diffusion process with stochastic variance and jump intensity in Cox et al. (1985) production economy. Empirical evidence with the S&P 500 index and options from January, 1996 to December, 2005 strongly supports our model prediction that the lower the third cumulant, the higher the market excess returns. Consistent with existing literature, the theoretical mean–variance relation is supported only by regressions on risk‐neutral variance. We further demonstrate empirically that the third cumulant explains significantly the variance risk premium.

Objective The mechanisms by which histamine increases microvascular permeability remain poorly understood. We tested the hypothesis that H1 receptor activation disrupts the endothelial barrier and investigated potential downstream signals. Methods We used confluent EC monolayers, assessing TER as an index of barrier function. HUVEC, HCMEC, and HDMEC were compared. Receptor expression was investigated using Western blotting, IF confocal microscopy and RT-PCR. Receptor function and downstream signaling pathways were tested using pharmacologic antagonists and inhibitors, respectively. Results We identified H1–H4 receptors on all three EC types. H1 antagonists did not affect basal TER but prevented the histamine-induced decrease in TER. Blockade of H2 or H3 attenuated the histamine response only in HDMEC, while inhibition of H4 attenuated the response only in HUVEC. Combined inhibition of both PKC and PI3K caused exaggerated histamine-induced barrier dysfunction in HDMEC, whereas inhibition of p38 MAP kinase attenuated the histamine response in all three EC types. Inhibition of RhoA, ROCK, or MLCK also prevented the histamine-induced decrease in TER in HDMEC. Conclusion The data suggest that multiple signaling pathways contribute to histamine-induced endothelial barrier dysfunction via the H1 receptor.

Variance swaps are natural instruments for investors taking directional bets on volatility and are often used for portfolio protection. The empirical observation on skewness research suggests that derivative professionals may also desire to hedge beyond volatility risk and there exists the need to hedge higher-moment market risks, such as skewness and kurtosis risks. We study two derivative contracts – skewness swap and kurtosis swap – which trade the forward realized third and fourth cumulants. Using S&P 500 index options data from 1996 to 2005, we document the returns of these swap contracts, i.e., skewness risk premium and kurtosis risk premium. We find that the both skewness and kurtosis risk premiums are significantly negative.

In this study, we extend the Chicago Board Options Exchange volatility index, VIX, from 30-day to any arbitrary time-to-maturity, and study the term structure of VIX. We propose new concepts of instantaneous and long-term squared VIXs as the limits at the short and long ends of the term structure respectively. Modeling the volatility process with instantaneous and long-term squared VIXs, we establish a parsimonious approach to capture information contained in the term structure of VIX. Our study provides an efficient setup to further study the pricing of VIX derivatives and their relation with S&P 500 options.

Pear scab (Venturia nashicola Tanaka et Yamamoto or Venturia pirina Aderhold) is one of the most important diseases of pears. Two hybrids, 03-04-034 and 03-08-080, highly resistant to pear scab were selected from interspecific reciprocal crosses of Pyrus × bretschneideri cv. Yali and Pyrus × ussuriensis cv. Jingbaili. The content of salicylic acid (SA) and polyphenols in the leaves of 03-04-034 and a highly susceptible hybrid individual were tested by high-performance liquid chromatography. The two scab-resistant individuals 03-04-034 and 03-08-080 were backcrossed with both of their parents, and the progenies were used for inheritance analysis of the resistance trait. The results indicated that diseased and non-diseased progenies segregated qualitatively and that diseased was dominant over non-diseased. The ratio of diseased/non-diseased progenies in all of the backcross populations was not significantly different from 1 : 15 indicating the segregation of four major gene loci was involved in the variation of resistance in these hybrid populations. When susceptible subpopulations from the two crosses were assessed for the severity of infection as measured by the ratio of lesion area to total leaf area, resistance was identified as a quantitative trait. Endogenous SA content in the leaves was extensively induced as early as 3 h after inoculation of the highly resistant individual 03-04-034, but no significant change in leaf SA content was found in the highly susceptible individual 03-19-136. Polyphenolic compounds, such as phlorhizin, catechol, quercetin and rutin, began to accumulate in leaves of 03-04-034 several hours earlier than that 03-19-136. The lignin content increased 45 h after inoculation in the resistant individual 03-04-034, but not in the susceptible individual 03-19-136. These observations indicated that the genetic resistance to pear scab of this interspecific population was correlated to SA induction, earlier polyphenol accumulation and the subsequent lignification of leaf tissue.

New genes originate frequently across diverse taxa. Given that genetic networks are typically comprised of robust, co-evolved interactions, the emergence of new genes raises an intriguing question: how do new genes interact with pre-existing genes? Here, we show that a recently originated gene rapidly evolved new gene networks and impacted sex-biased gene expression in Drosophila. This 4–6 million-year-old factor, named Zeus for its role in male fecundity, originated through retroposition of a highly conserved housekeeping gene, Caf40. Zeus acquired male reproductive organ expression patterns and phenotypes. Comparative expression profiling of mutants and closely related species revealed that Zeus has recruited a new set of downstream genes, and shaped the evolution of gene expression in germline. Comparative ChIP-chip revealed that the genomic binding profile of Zeus diverged rapidly from Caf40. These data demonstrate, for the first time, how a new gene quickly evolved novel networks governing essential biological processes at the genomic level.

Aim. The aim of this study was to explore and describe the content of telephone intervention conversations conducted by an enterostomal nurse with patients discharged home with a colostomy. Background. People discharged home with a new colostomy often encounter stoma-related difficulties. Postdischarge care with telephone follow-up by an enterostomal nurse is a helpful way to provide support for patients and ensure continuity of care. There is a paucity of studies reporting the content of telephone follow-up of colostomy patients. Information on the content of such follow-up is important in helping to formulate telephone call protocols that can help these patients. Design. A qualitative exploratory study conducted in a university-based cancer centre in China. Methods. The contents of 25 intervention phone calls to colostomy patients from January–August 2009 were subject to qualitative content analysis. Results. Five themes emerged from the qualitative content analysis: ‘education for stoma care’, ‘access to stoma care’, ‘encouraging stoma self-care’, ‘resuming normal living’ and ‘general postoperative problems’. Conclusions. Colostomy patients experienced stoma-related problems and difficulties after discharge, most of which could be effectively managed via telephone follow-up by an enterostomal nurse. The telephone follow-up satisfied patients’ need for information and facilitated their adjustment to the permanent stoma. The findings suggested that patients had unmet needs after discharge and needed follow-up on returning home. Relevance to clinical practice. This study provides important information to guide practice and education. The themes extracted from the qualitative content analysis provide a useful framework to guide the nurse in discussing care with the stoma patients and ensuring patients’ adjustment to the permanent stoma. Further work can be done using this framework to develop protocols as standards of care and education materials when educating nurse specialists in stoma care.

Literature on responsibility of adult children for aging parents reflects lack of conceptual clarity. We examined filial concepts across five cultural groups: African-, Asian-, Euro-, Latino-, and Native Americans. Data were randomly divided for scale development (n = 285) and cross-validation (n = 284). Exploratory factor analysis on 59 items identified three filial concepts: Responsibility, Respect, and Care. Confirmatory factor analysis on a 12-item final scale showed data fit the three-factor model better than a single factor solution despite substantial correlations between the factors (.82, .82 for Care with Responsibility and Respect, and .74 for Responsibility with Respect). The scale can be used in cross-cultural research to test hypotheses that predict associations among filial values, filial caregiving, and caregiver health outcomes. © 2011 Wiley Periodicals, Inc. Res Nurs Health 34:310–326, 2011

This study examines the price-discovery function and information efficiency of a fast growing volatility futures market: the Chicago Board of Option Exchange VIX futures market. A linear Engle–Granger cointegration test with an error correction mechanism (ECM) shows that during the full sample period, VIX futures prices lead spot VIX index, which implies that the VIX futures market has some price-discovery function. But a modified Baek and Brock nonlinear Granger test detects bi-directional causality between VIX and VIX futures prices, suggesting that both spot and futures prices react simultaneously to new information. Quarter-by-quarter investigations show that, on average, the estimated parameters are not significantly different from zero, thus providing further evidence supporting information efficiency in the VIX futures market. © 2011 Wiley Periodicals, Inc. Jrl Fut Mark

This paper develops an equilibrium asset and option pricing model in a production economy under jump diffusion. The model provides analytical formulas for an equity premium and a more general pricing kernel that links the physical and risk-neutral densities. The model explains the two empirical phenomena of the negative variance risk premium and implied volatility smirk if market crashes are expected. Model estimation with the S&P 500 index from 1985 to 2005 shows that jump size is indeed negative and the risk aversion coefficient has a reasonable value when taking the jump into account.

The π electronic delocalization in trans-C4H6 and cis-C4H6 has been investigated in the frame of ab initio valence bond theory with 6–31G basis set. The result shows that the Csp2-Csp2 single bond length (1.506 A) is only about 0.024 A shorter than the Csp3-Csp3 bond, thus the central bond length shortening would be mainly due to π conjugation. The theoretical resonance energies of the trans-C4H6 and cis-C4H6 are 8.48 and 7.44 kcal/mol, respectively.

A modern valence bond approach, namely bonded tableau unitary group approach, is applied to ozone, sulphur dioxide and nitrite systems, respectively. It is shown that the biradical structure is in the primary position in describing the molecular structure of ozone. Thus three instead of two resonance structures are needed to describe the ground state of ozone. The case of sulphur dioxide is similar to that of ozone. It is found that, however, for the nitrite anion four resonance structures are needed.

Monochorionic pregnancies present unique challenges for selective fetal reduction, as vaso-occlusive procedures are required to ablate blood flow, usually in the umbilical cord, to achieve asystole in the selected fetus. We describe a case series of 35 monochorionic pregnancies (27 twins and eight triplets) undergoing selective fetal reduction using radiofrequency ablation. All procedures were performed under local anaesthesia. The procedure was technically successful in all cases. The live born rate was 88.6%. One (2.9%) woman miscarried within 2 weeks of the procedure, and two (5.7%) babies were stillborn. The median gestation at delivery was 36 weeks of gestation (range 24-41 weeks). There were no maternal complications. The median gestational age at procedure was 17 + 3 weeks (range from 12 + 5 to 27 + 4 weeks). All women had antenatal magnetic resonance imaging (MRI) post procedure. There were two (5.7%) cases of abnormal brain imaging. Our experience suggests that radiofrequency ablation is a safe and effective procedure for fetal reduction in complicated monochorionic pregnancies.

This paper studies the critical stock price of American options with continuous dividend yield. We solve the integral equation and derive a new analytical formula in a series form for the critical stock price. American options can be priced and hedged analytically with the help of our critical-stock-price formula. Numerical tests show that our formula gives very accurate prices. With the error well controlled, our formula is now ready for traders to use in pricing and hedging the S&P 100 index options and for the Chicago Board Options Exchange to use in computing the VXO volatility index.

In this article, we look at study the dynamics of forward rates with maturities longer than 14 years. We re-document the phenomenon of the downward sloping long forward rate term structure using U.S. Treasury STRIPS data over the period 1988 to 2007. By calibrating Diebold F. X. and Li C.-L.'s (2006) dynamic Nelson C. R. and Siegel A. F. (1987) and Christensen J. H. E., Diebold F. X., and Rudebusch G. D.'s (2007) arbitrage-free Nelson-Siegel models, we find that both models explain the empirical phenomenon very well. Out-of-sample comparison shows that imposing no-arbitrage restriction indeed improves the forecasting performance. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark 30:957–982, 2010

We conducted a comprehensive study of 15 cultivars of Chinese barley and one cultivar of European barley to examine and compare the activity and heat stability of limit dextrinase (LD) among them. Our results revealed that the enzymatic activity of LD drops dramatically at incubation temperatures >65°C, indicating that 65°C is the point of incubation temperature sensitivity for this enzyme. Compared with the European barley cultivar Triumph, the levels of enzymatic activity and heat stability of LD in most Chinese barley cultivars included in this study were low, except for Jipi 2 and 92001, which were nearly equal to Triumph. We also found that the activity and heat stability of LD were strongly influenced by the genotype and growth environment of the cultivar, which suggests that genetic manipulation and optimal cultivation conditions may be useful in producing high-quality barley for the brewing industry.

It is very difficult to produce thin wall complex castings of the Ni3Al-based alloy by investment casting. Defects such as incomplete mold filling and hot tears appear commonly. In this paper, physical parameters of Ni3Al-based alloy are obtained by experiments and simulations using JmatPro software. The calculation results of physical parameters are credible by comparing with test results and can be used in the pre-processing of casting simulaton software ProCAST of thin wall castings. Gating and feeding system is optimized to decrease hot tearing tendentiousness and ensure filling ability according to casting simulation results.

Acrossocheilus spinifer sp. nov. is described from the river basins in Fujian Province and the Han Jiang basin in Guangdong Province, south China. It is one of the barred Acrossocheihis species sharing five or six vertical bars on the flanks, with each bar being two scales in width. Acrossocheilus spinifer sp. nov. is morphologically most similar to Acrossocheilus wenchowensis. but distinguished from it by: a colour pattern of all vertical bars extending ventrally to the second scale row below the lateral line, and having the second bar placed posterior to the base of the last simple dorsal-fin ray, a blunt snout; and a stout, last simple dorsal-fin ray. Acrossocheilus spinifer sp. nov. resembles Acrossocheilus kreyenbergii and Acrossocheilus stenotaeniatus with which it shares a stout, last simple dorsal-fin ray with a serrated posterior edge, but is separated from both species by having a narrow median interruption in the lower lip, a lower jaw fully covered by the lower lip when viewed ventrally and the second vertical bar placed posterior to the base of the last simple dorsal-fin ray. The absence of a longitudinal stripe extending along the lateral line on the flanks in males readily distinguishes A. spinifer sp. nov. from Four other species, namely Acrossocheilus fasciatus, Acrossocheilus paradoxus, Acrossocheilus parallens, and Acrossocheilus jishouensis. (c) 2006 The Authors Journal compilation (c) 2006 The Fisheries Society of the British Isles.

This study investigates the relative performance of various historical volatility estimators that incorporate daily trading range: M. Parkinson (1980), M. Garman and M. Klass (1980), L. C. G. Rogers and S. E. Satchell (1991), and D. Yang and Q. Zhang (2000). It is found that the range estimators all perform very well when an asset price follows a continuous geometric Brownian motion. However, significant differences among various range estimators are detected if the asset return distribution involves an opening jump or a large drift. By adding microstructure noise to the Monte Carlo simulation, the finding of S. Alizadeh, M. W. Brandt, and F. X. Diebold (2002)—that range estimators are fairly robust toward microstructure effects—is confirmed. An empirical test with S&P 500 index return data shows that the variances estimated with range estimators are quite close to the daily integrated variance. The empirical results support the use of range estimators for actual market data. © 2006 Wiley Periodicals, Inc. Jrl Fut Mark 26:297–313, 2006

Ubiquitous computing environment is defined by the shift of computing technology from the desktop to the background. One of its most notable attributes is its potential to extend the scope of service and personal mobility. This paper describes an agent-based architecture that brings personal and service mobility to the ubiquitous computing environment. A software agent, running on a portable device carried by the user, leverages the existing service discovery protocols to learn about all services available in the vicinity of the user. Short-range wireless technology such as Bluetooth can be used to build a personal area network connecting only devices that are close enough to the user. Acting on behalf of the user and based on a number of aspects, the software agent runs a quality of service (QoS) negotiation and selection algorithm to select the most appropriate available service(s) to be used for a given communication session. The software agent selects as well the configuration parameters for each service. The proposed architecture supports also service hand-off to recompense for service volatility during user movement. Copyright © 2004 John Wiley & Sons, Ltd.

This article explores the price of continuously sampled Asian options. For geometric Asian options, we present pricing formulas for both backward-starting and forward-starting cases. For arithmetic Asian options, we demonstrate that the governing partial differential equation (PDE) cannot be transformed into a heat equation with constant coefficients; therefore, these options do not have a closed-form solution of the Black–Scholes type, that is, the solution is not given in terms of the cumulative normal distribution function. We then solve the PDE with a perturbation method and obtain an analytical solution in a series form. Numerical results show that as compared with Zhang's (2001) highly accurate numerical results, the series converges very quickly and gives a good approximate value that is more accurate than any other approximate method in the literature, at least for the options tested in this article. Graphical results determine that the solution converges globally very quickly especially near the origin, which is the area in which most of the traded Asian options fall. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:535–560, 2003