bluuebunny/crossref_metadata_2025 huggingface dataset:
Regional temperature change over the Huang‐Huai‐Hai Plain of China: the roles of irrigation versus urbanization
Authors: Shi Wenjiao , Tao Fulu , Liu Jiyuan
Published: June 2013

Irrigation and urbanization, two widely occurring land‐use/land‐cover changes, have important influences on regional climate, especially on temperature. The effect of irrigation and urbanization on temperature is separately documented in several studies. However, there are few studies analysing the combined effects of irrigation and urbanization on temperature. In this study, changes in surface temperature were analysed in relation to irrigation and urbanization on the Huang‐Huai‐Hai Plain of China from 1955 to 2007. To better characterize the combined effects of these two processes on temperatures, long‐term weather observations are used along with irrigation and urbanization data sets. The results indicated that irrigation had a significant cooling effect of 0.17–0.20 °C decade−1 on average daily maximum temperature of the hottest 1, 5, and 30 d of each year on the Huang‐Huai‐Hai Plain. Compared with the reference conditions, irrigation also indicated a cooling effect of 0.12 °C decade−1 on summertime daily maximum temperature. In contrast to its effect on maximum temperature, irrigation appeared to induce a warming effect of 0.43 °C/decade on average daily minimum temperature of the coldest 1 d of each year. Where irrigation interfaced with urbanization, the urbanization warming of extreme daily maximum temperature seemed to only partly counteract the irrigation cooling effect. The findings of this study deepen our insight into the effects of irrigation and urbanization on temperature dynamics, and the combined implications for regional climate change. Further efforts to understand irrigation and urbanization effects on climate should not only use observations, but should also be coupled with dynamic land‐use and regional climate models to understand the complex processes and controlling mechanisms.
Precise 14C ages of the Vedde and Saksunarvatn ashes and the Younger Dryas boundaries from western Norway and their comparison with the Greenland Ice Core (GICC05) chronology
Authors: LOHNE ØYSTEIN S. , MANGERUD JAN , BIRKS HILARY H.
Published: June 2013

The Greenland ice cores with the GICC05 chronology represent a standard for late Quaternary climate events and their ages, whereas many other palaeoclimatic archives are dependent on 14C dates. It is therefore critical to know if the ice‐core and the calibrated 14C chronologies are identical, and if not to quantify the offset between them. We present Bayesian age–depth modelling of 118 accelerator mass spectrometry 14C dates from Kråkenes Lake, calibrated using INTCAL09, that provide high precision ages of 12 066 ± 42 and 10 210 ± 35 cal a BP for the Vedde and Saksunarvatn ashes, respectively. The lower and upper Younger Dryas boundaries have ages of 12 710 ± 52 and 11 546 ± 59 cal a BP, respectively. The four dated levels coincide with correlative levels in GICC05 within the dating uncertainties, but are all consistently younger at Kråkenes. The ages of the tephra chronostratigraphic markers suggest a mean offset of ∼70 years to older ages in the GICC05 compared with the INTCAL09 time scale. Responses to small climate changes ∼30 years before the Younger Dryas boundaries at Kråkenes are suggested to correspond to the defined Greenland Stadial 1 boundaries. This suggested difference in timing (30 years) and time scale offset (70 years) mean that the Greenland Stadial 1 boundaries appear ∼100 years older than the Younger Dryas boundaries.
Separation of somatropin charge variants by multiple‐injection CZE with Polybrene/chondroitin sulfate A double‐coated capillaries
Authors: Amini Ahmad
Published: June 2013

The performance of dynamic double‐coated fused‐silica capillaries with Polybrene and chondroitin sulfate A has been compared with uncoated fused‐silica capillaries for the determination of recombinant human growth factor (somatropin) charge variants. The separations were carried out under the same electrophoretic conditions as described in the European Pharmacopoeia, i.e. at pH 6.0 and 30°C. The coating significantly reduced the interactions between the proteins and the surface of the fused‐silica capillary. The first five separations performed in a new bare fused‐silica capillary were discarded because of very poor separation performance as a result of protein–surface interactions. There was an approximate twofold increase in the interday migration time precision (%RSD ≤ 6.5%) in the double‐coated capillaries. The method was successfully transferred to a multiple CZE mode where two samples were analyzed in a single electrophoretic run. The average purity of somatropin certified reference standard was 98.0% (%RSD ≤ 0.3%) determined by using uncoated and coated capillaries.
Pleomorphic adenoma of the major salivary glands: Diagnostic utility of FNAB and MRI
Authors: Heaton Chase M. , Chazen J. Levi , van Zante Annemieke , Glastonbury Christine M. , Kezirian Eric J. , Eisele David W.
Published: June 2013

Objectives/Hypothesis

Pleomorphic adenoma (PA) is the most common, benign tumor of the major salivary glands. Surgical resection is the treatment of choice. Initial preoperative workup of major salivary gland neoplasms often includes fine needle aspiration biopsy (FNAB) and magnetic resonance imaging (MRI) of the head and neck. Our objective was to assess the positive predictive value of FNAB and MRI in the evaluation of PA arising from within the major salivary glands.

Study Design

Retrospective chart review.

Methods

All patients with a FNAB diagnosis of PA of the major salivary glands and who underwent surgical excision at our institution from 2001 to 2011 were identified. FNAB slides from these cases were reviewed by a cytopathologist for findings suggestive of PA: fibrillary stroma, mesenchymal elements, plasmacytoid myoepithelial cells, epithelial cells forming ducts or tubules, and the absence of nuclear atypia. For those patients with a preoperative MRI, the MRI studies were reviewed by a neuroradiologist for findings suggestive of PA, including homogenous T2 hyperintensity, well‐circumscribed borders, and solid contrast enhancement. Positive predictive value (PPV) of these specific FNAB and MRI findings were calculated using chi‐squared testing.

Results

One hundred forty‐six patients met inclusion criteria, and 68 had preoperative MRI. PPV of a FNAB diagnosis of PA was 97.8%. Characteristic features of PA on FNAB (fibrillary stroma, mesenchymal elements, plasmacytoid myoepithelial cells, epithelial cells forming ducts or tubules, and the absence of nuclear atypia) and MRI (homogenous T2 hyperintensity, well‐circumscribed borders, and solid contrast enhancement) all demonstrated PPVs of 95% or greater in patients with FNA diagnosis of PA.

Conclusions

PPV of a FNAB diagnosis of PA in the major salivary glands is high. Among patients with a FNAB diagnosis of PA, specific MRI characteristics also have a high PPV. The diagnostic accuracy of these studies in combination allows for the confident preoperative diagnosis of PA.

Level of Evidence

4. Laryngoscope, 123:3056–3060, 2013
Elevated intracranial pressure in patients with spontaneous cerebrospinal fluid otorrhea
Authors: Allen Kyle P. , Perez Carlos L. , Kutz J. Walter , Gerecci Deniz , Roland Peter S. , Isaacson Brandon
Published: June 2013

Objectives/Hypothesis

To determine the prevalence of elevated intracranial hypertension in patients with spontaneous cerebrospinal fluid otorrhea (SCSFO).

Study Design

Case series with chart review at a tertiary care academic medical center following institutional review board approval.

Methods

A retrospective review was performed of patients undergoing operative repair of SCSFO between January 2007 and May 2012.

Results

Thirty‐eight patients underwent operative repair of SCSFO. Of these, 22 underwent postoperative lumbar puncture with measurement of opening pressure. The opening pressure was elevated (> 20 cm/H20) in eight patients (36.4%). Preoperative magnetic resonance imaging was available for review by a neuroradiologist in 27 patients. Radiographic evidence of elevated intracranial pressure (ICP) was present in 48.1% of patients.

Conclusion

Elevated ICP is common in patients with SCSFO. However, as only a minority of patients have elevated ICP, it is not the sole factor in the development of SCSFO.

Level of Evidence

4. Laryngoscope, 124:251–254, 2014
Range image of the velopharynx produced using a 3‐D endoscope with pattern projection
Authors: Mishima Katsuaki , Nakano Asuka , Shiraishi Ruriko , Ueyama Yoshiya
Published: June 2013

Objectives/Hypothesis

To measure movements of the velopharynx in detail, a novel method of producing range images of the velopharynx was developed using a 3‐D endoscope. The purpose of this paper is to introduce this system and to clarify its accuracy.

Study Design

The standard errors of repeated measurements, intraclass correlation coefficients (ICC), ICC(1,1) for intrarater reliability, and ICC(2,1) for interrater reliability were measured using a phantom of the nasopharynx.

Methods

An endoscopic measuring system was developed in which a pattern projection system was incorporated into a commercially available 3‐D endoscope. Right and left images of the endoscope were integrated into one video file and digitized at a horizontal and vertical resolution of 640 × 480 pixels, as odd and even scanning lines, respectively. After separation of the video file into right and left images by interlace interpolation, correcting the distortion of the camera images, rectifying, and stereo‐matching range images of the velopharynx were produced. The distances between two points, which were marked at an interval of 5 mm on the uvula and the pharynx of the phantom, were measured.

Results

The standard errors of repeated measurements were 0.02 horizontally and 0.01 vertically. The ICC(1,1) and ICC(2,1) were 0.83 and 0.94, and both correlation coefficients were considered to be “almost perfect.”

Conclusion

The present endoscopic measuring system provided relatively accurate and reliable range images of the velopharynx, and enabled quantitative analysis of movements of the velopharynx.

Level of Evidence

N/A. Laryngoscope, 123:E122–E126, 2013
Success of endoscopic pharyngoesophageal dilation after head and neck cancer treatment
Authors: Chapuy Claudia I. , Annino Donald J. , Tishler Roy B. , Haddad Robert I. , Snavely Anna , Goguen Laura A.
Published: June 2013

Objectives/Hypothesis

To assess clinical success and safety of endoscopic pharyngoesophageal dilation after chemoradiation or radiation for head and neck cancer and to identify variables associated with dilation failure.

Study Design

Case series with chart review.

Methods

Between 2000 and 2008, a total of 111 patients treated with chemoradiation or radiation for head and neck cancer with subsequent pharyngoesophageal stenosis requiring endoscopic dilation were identified. Patients were evaluated for endoscopic dilation technique, severity of stenosis, technical and clinical success, and intra‐ and postoperative complications. The Diet/GT score (range, 1–5) was utilized to measure swallow success. Variables associated with dilation failure were analyzed by univariate and multivariate logistic regression.

Results

There were 271 dilations analyzed, with 42 combined antegrade retrograde dilations, 208 dilations over a guidewire, and 21 dilations without guidewire. Intraoperative patency and successful dilation of the stenotic segment was achieved in 95% of patients. A Diet/GT score of 5 (gastrostomy tube removed and soft/regular diet) was attained in 84 of 111 (76%) patients. Safety analysis showed complications occurred in 9% of all dilations. Perforations were noted in 4% of all procedures, with only two esophageal perforations requiring significant intervention. Multiple dilations were associated with an increased risk for perforations. Further logistic regression analyses revealed that the number of dilations was indicating a poor outcome and low Diet/GT score.

Conclusions

Pharyngoesophageal stenosis, occurring after chemoradiation and radiation treatment, can be successfully and safely treated with endoscopic dilation techniques. Patients with restenosis, requiring multiple dilations, have a higher risk of persistent dysphagia.

Level of Evidence

4 Laryngoscope, 123:3066–3073, 2013
Preformed class II donor-specific antibodies are associated with an increased risk of early rejection after liver transplantation
Authors: O'Leary Jacqueline G. , Kaneku Hugo , Jennings Linda W. , Bañuelos Nubia , Susskind Brian M. , Terasaki Paul I. , Klintmalm Göran B.
Published: June 2013

Preformed donor-specific human leukocyte antigen antibodies (DSAs) are considered a contraindication to the transplantation of most solid organs other than the liver. Conflicting data currently exist on the importance of preformed DSAs in rejection and patient survival after liver transplantation (LT). To evaluate preformed DSAs in LT, we retrospectively analyzed prospectively collected samples from all adult recipients of primary LT without another organ from January 1, 2000 to May 31, 2009 with a pre-LT sample available (95.8% of the patients). Fourteen percent of the patients had preformed class I and/or II DSAs with a mean fluorescence intensity (MFI) ≥ 5000. Preformed class I DSAs with an MFI ≥ 5000 remained persistent in only 5% of patients and were not associated with rejection. Preformed class II DSAs with an MFI of 5000 to 10,000 remained persistent in 23% of patients, and this rate increased to 33% for patients whose MFI was ≥10,000 (P < 0.001). Preformed class II DSAs in multivariable Cox proportional hazards modeling were associated with an increased risk of early rejection [hazard ratio (HR) = 1.58; p = 0.004]. In addition, multivariate modeling showed that in comparison with no DSAs (MFI < 1000), preformed class I and/or II DSAs with an MFI ≥ 5000 were independently correlated with the risk of death (HR = 1.51; p = 0.02). Liver Transpl 19:973–980, 2013. © 2013 AASLD.
Mathematical Modeling of Bivariate Distributions of Polymer Properties Using 2D Probability Generating Functions. Part II: Transformation of Population Mass Balances of Polymer Processes
Authors: Brandolin Adriana , Asteasuain Mariano
Published: June 2013

This is the second of two works presenting a new mathematical method for modeling bivariate distributions of polymer properties. It is based on the transformation of population balances using 2D probability generating functions (pgf) and a posteriori recovery of the distribution from the transform domain by numerical inversion. Part I of this work was devoted to the numerical inversion step. Here the transformation of the population balances to the pgf domain is analyzed. A 2D pgf transform table is developed, which allows a simple transformation of any typical polymer balance equation. Three copolymerization examples are used to show the application of the complete procedure of this modeling technique.
Genetic variants at chromosome 8q24, colorectal epithelial cell proliferation, and risk for incident, sporadic colorectal adenomas
Authors: Yang Baiyu , Thyagarajan Bharat , Gross Myron D. , Goodman Michael , Sun Yan V. , Bostick Roberd M.
Published: June 2013

Three polymorphic sites at chromosome 8q24 (rs7837328, rs10808555, rs6983267) have been associated with risk for colorectal adenomas. It was also previously reported that the single nucleotide polymorphism (SNP) rs6983267 may enhance Wnt signaling, which regulates cell proliferation. To investigate associations between the 8q24 variants and colorectal epithelial cell proliferation in the normal‐appearing colorectal mucosa, as well as with colorectal adenoma, we analyzed data from a previously conducted pilot, colonoscopy‐based case–control study of incident, sporadic colorectal adenoma (n = 90 cases, 132 controls). Proliferation was measured in biopsies of the normal‐appearing mucosa of the rectum, sigmoid colon, and cecum using immunohistochemistry for proliferating cell nuclear antigen (PCNA). The direct associations of each SNP with colorectal adenoma were consistent with those in previous reports. For all three SNPs, proliferation tended to be higher among those homozygous for the risk alleles compared to those heterozygous or homozygous for the nonrisk alleles combined; among the controls, proliferation was 32.1% higher (P = 0.23) for those with the rs10808555 GG genotype, 16.4% higher (P = 0.16) for those with the rs7837328 AA genotype, and 6.5% higher (P = 0.52) for those with the rs6983267 GG genotype. These preliminary findings, which are consistent with previously reported direct associations between genetic variants at chromosome 8q24 and risk for colorectal adenoma, suggest that the genetic variants may also be associated with higher levels of colorectal epithelial cell proliferation, thus providing support for further investigation of the hypothesis that 8q24 variants may increase risk via enhanced Wnt signaling. © 2013 Wiley Periodicals, Inc.
Genetic polymorphisms in RAD23B and XPC modulate DNA repair capacity and breast cancer risk in Puerto Rican women
Authors: Pérez‐Mayoral Julyann , Pacheco‐Torres Alba L. , Morales Luisa , Acosta‐Rodríguez Heidi , Matta Jaime L. , Dutil Julie
Published: June 2013

Studies have shown that DNA repair capacity (DRC) is significantly decreased in breast cancer patients, but the molecular causes of inter‐individual variation in DRC are unknown. We hypothesized that genetic variation in the nucleotide excision repair pathway genes can modulate DRC and breast cancer risk in Puerto Rican women. A total of 228 breast cancer cases and 418 controls were recruited throughout Puerto Rico. For all study participants, eight single nucleotide polymorphisms (SNPs) in the genes XPC, XPD, and RAD23B were genotyped using a TaqMan PCR, and the DRC levels of UV induced‐DNA damage was measured in peripheral lymphocytes using a host cell reactivation assay. After adjustment for confounders, RAD23B rs1805329 (Ala249Val) was found to be significantly associated with breast cancer risk under all models tested (P < 0.001). There was also a significant association between breast cancer risk and RAD23B rs10739234 (intronic) under the recessive model (P = 0.003, OR: 2.72, 95% CI: 1.40–5.30). In cases, there was a statistically significant difference in mean DRC per genotype for RAD23B rs1805329 (P < 0.001) and XPC rs2607775 (P = 0.002). When we modeled the combined effect of multiple SNPs that each independently affected DRC on cancer risk, we observed incremental augmentations in risk with increasing number of risk genotypes at those loci (P overall model <0.001). The increase in adverse genotypes was also correlated with a progressive decrease in DRC values. Our data indicate an additive effect of the NER SNPs on DRC and breast cancer risk in Puerto Rican women. © 2013 Wiley Periodicals, Inc.
Securities Fraud and Corporate Finance: Recent Developments
Authors: Yu Xiaoyun
Published: June 2013

In this paper, I survey the recent research in corporate finance on financial securities frauds. I structure my review around the three subjects in this literature: studies of internal and external factors that elicit managerial incentives for fraudulent activities, studies on regulatory and market‐based mechanisms that help to deter or detect fraud and on what affects the efficiency of such mechanisms, and studies on the economic and social consequences of financial fraud. I outline the empirical challenges related to this line of research and discuss opportunities for future studies. Copyright © 2013 John Wiley & Sons, Ltd.
The Hanes‐Woolf linear QUESP method improves the measurements of fast chemical exchange rates with CEST MRI
Authors: Randtke Edward A. , Chen Liu Qi , Corrales L. Rene , Pagel Mark D.
Published: June 2013

Purpose

Contrast agents for chemical exchange saturation transfer MRI often require an accurate measurement of the chemical exchange rate. Many analysis methods have been reported that measure chemical exchange rates. Additional analysis methods were derived as part of this study. This report investigated the accuracy and precision of each analysis method.

Methods

Chemical exchange saturation transfer spectra were simulated using the Bloch‐McConnell equations modified for chemical exchange. Chemical exchange saturation transfer spectra of iopromide were obtained with a range of saturation times, saturation powers, and concentrations. These simulated and experimental results were used to estimate the chemical exchange rate using the QUESP, QUEST, Omega Plot (LB‐QUESP), EH‐QUESP, HW‐QUESP, LB‐Conc, EH‐Conc, and HW‐Conc methods.

Results

Bloch fitting produced the most precise estimates of chemical exchange rates, although substantial expertise and computation time were required to achieve these results. Of the more simplistic analysis methods, the HW‐QUESP method produced the most accurate and precise estimates of fast exchange rates. The QUEST and LB‐QUESP methods produced the most accurate estimates of slow exchange rates, especially with samples that have short T1w relaxation times.

Conclusions

HW‐QUESP is a simplistic analysis method that should be used when fast chemical exchange rates need to be estimated from chemical exchange saturation transfer MRI results. Magn Reson Med 71:1603–1612, 2014. © 2013 Wiley Periodicals, Inc.
A comprehensive non‐invasive framework for automated evaluation of acute renal transplant rejection using DCE‐MRI
Authors: Khalifa Fahmi , Abou El‐Ghar Mohamed , Abdollahi Behnaz , Frieboes Hermann B. , El‐Diasty Tarek , El‐Baz Ayman
Published: June 2013

The objective was to develop a novel and automated comprehensive framework for the non‐invasive identification and classification of kidney non‐rejection and acute rejection transplants using 2D dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI).

The proposed approach consists of four steps. First, kidney objects are segmented from the surrounding structures with a geometric deformable model. Second, a non‐rigid registration approach is employed to account for any local kidney deformation. In the third step, the cortex of the kidney is extracted in order to determine dynamic agent delivery, since it is the cortex that is primarily affected by the perfusion deficits that underlie the pathophysiology of acute rejection. Finally, we use an analytical function‐based model to fit the dynamic contrast agent kinetic curves in order to determine possible rejection candidates. Five features that map the data from the original data space to the feature space are chosen with a k‐nearest‐neighbor (KNN) classifier to distinguish between acute rejection and non‐rejection transplants. Our study includes 50 transplant patients divided into two groups: 27 patients with stable kidney function and the remainder with impaired kidney function. All of the patients underwent DCE‐MRI, while the patients in the impaired group also underwent ultrasound‐guided fine needle biopsy.

We extracted the kidney objects and the renal cortex from DCE‐MRI for accurate medical evaluation with an accuracy of 0.97 ± 0.02 and 0.90 ± 0.03, respectively, using the Dice similarity metric. In a cohort of 50 participants, our framework classified all cases correctly (100%) as rejection or non‐rejection transplant candidates, which is comparable to the gold standard of biopsy but without the associated deleterious side‐effects.

Both the 95% confidence interval (CI) statistic and the receiver operating characteristic (ROC) analysis document the ability to separate rejection and non‐rejection groups. The average plateau (AP) signal magnitude and the gamma‐variate model functional parameter α have the best individual discriminating characteristics. Copyright © 2013 John Wiley & Sons, Ltd.
Saponin Inventory from Argania spinosa Kernel Cakes by Liquid Chromatography and Mass Spectrometry
Authors: Henry Max , Kowalczyk Mariusz , Maldini Mariateresa , Piacente Sonia , Stochmal Anna , Oleszek Wiesław
Published: June 2013

Introduction

Argania spinosa kernel cakes, obtained from argan oil extraction process, are known to contain large amounts of saponins. Only a few have been characterised previously, due to the use of pure ethanol as extracting solvent. The use of aqueous 50% ethanol improved the extraction of more polar saponins.

Objective

Identification of polar saponins in kernel cakes of Argania spinosa by liquid chromatography–mass spectrometry and NMR techniques.

Methods

Defatted kernel cakes were first extracted with ethanol and then twice with 50% aqueous ethanol. Individual crude extracts were analysed with an ion‐trap mass spectrometer in negative mode electrospray MS and MS/MS modes. NMR experiments were run under standard conditions at 300 K on a Bruker DRX‐600 spectrometer.

Results

The LC–MS base peak chromatogram of saponins from pure ethanol extract was dominated by 11 large and several small peaks but the UV chromatogram showed only two peaks, corresponding to the main neutral saponins found previously in Argania: arganine A and B. In 50% aqueous ethanol extracts, numerous other saponins were detected. Many of them were glucuronide oleanane‐type triterpene carboxylic acid 3,28‐O‐bidesmosides (GOTCAB saponins). The assignments of 1H‐ and 13C‐NMR spectra of the four most abundant GOTCAB saponins confirmed the MS results.

Conclusion

Four GOTCAB saponins were structurally identified by NMR analysis in the 50% aqueous ethanol extract. Furthermore, LC–MS analyses showed the presence of at least 19 additional polar saponins in these kernel cakes. Copyright © 2013 John Wiley & Sons, Ltd.
Reactivity studies of carbon, phosphorus and sulfur‐based acyl sites with tertiary oximes in gemini surfactants
Authors: Gupta Bhanushree , Sharma Rahul , Singh Namrata , Karpichev Yevgen , Satnami Manmohan L. , Ghosh Kallol K.
Published: June 2013

Kinetic studies of the reactions of tertiary oximes (monoisonitroso acetone; MINA and butane 2,3 dione monooxime; BDMO) with some carboxylate (p‐nitrophenyl acetate and p‐nitrophenyl benzoate), phosphate (p‐nitrophenyl diphenyl phosphate and bis (2,4‐dinitrophenyl) phosphate) and sulfonate (p‐nitrophenyl p‐toluene sulphonate) esters in gemini surfactants have been conducted. The observed first‐order rate constant versus surfactant profiles show micelle‐assisted bimolecular reactions involving interfacial ion exchange between bulk aqueous media and micellar pseudophase. Experimental results showed that MINA exhibited better nucleophilic activity towards ester cleavage than BDMO. Pseudophase model has been applied in order to determine micellar second‐order rate constants and binding constants. Copyright © 2013 John Wiley & Sons, Ltd.
Substituent effects on the formation and nucleophile selectivity of ring‐substituted phenonium ions in aqueous solution
Authors: Tsuji Yutaka , Ogawa Shin , Richard John P.
Published: June 2013

The reaction of 2‐(4‐methyphenyl)ethyl tosylate (Me-1-OTs) in 50/50 (v/v) trifluoroethanol/water at 25 °C is first order in the concentration of azide anion nucleophile. A carbon‐13 NMR analysis of the products of the reactions of Me‐1‐[α‐13C]OTs in 50/50 (v/v) trifluoroethanol/water at 25 °C shows the formation of Me‐1‐[β‐13C]OH, Me‐1‐[β‐13C]OCH2CF3 and Me-1-[β-13C]N3 from the trapping of a symmetrical 4‐methylphenonium ion reaction intermediate Me‐2+. The formation of Me-1-[α-13C]N3 by concerted bimolecular displacement of azide ion at Me‐1‐[α‐13C]OTs (kN = 3.8 × 10−6 M−1 s−1) and of Me‐1‐[α‐13C]OH and Me‐1‐[α‐13C]OCH2CF3 by concerted bimolecular displacement of solvent (ksolv = 1.8 × 10−8 s−1) is also observed. An analysis of the rate and product data provides a value of kaz/ks = 32 M−1 for partitioning of Me‐2+ between addition of azide ion and solvent that is nearly three‐fold smaller than kaz/ks = 83 M−1 reported in an earlier study on the partitioning of MeO‐2+ [J. Org. Chem. 2011, 76, 9568]. This change is attributed to a decrease in nucleophile selectivity with increasing electrophile reactivity for the activation‐limited addition of solvent and azide anion to X‐2+. These data set a limit of 1/ks ≥ 10−7 s for the lifetime of Me-2+ in aqueous solution. Copyright © 2013 John Wiley & Sons, Ltd.
Specific airway resistance in children: Panting or tidal breathing?
Authors: Coutier Laurianne , Varechova Silvia , Demoulin Bruno , Bonabel Claude , Roman‐Amat Clotilde , Tuan Thanh Le , Ioan Iulia , Schweitzer Cyril , Marchal François
Published: June 2013

Background

The measurement of specific airway resistance during tidal breathing (sRawtb) has gained popularity in children, but methodological concerns have been raised regarding the electronic compensation for the thermal artifact. The panting method (sRawp) is efficient in minimizing the latter, but may be associated with a change in end expiratory lung volume if the effort is not properly balanced. The aim of the study was to compare sRawtb with sRawp in children.

Methods

Fifty‐five children aged 6.5–11.5 years were studied. sRawtb was measured in a commercial plethysmograph. sRawp was measured with a home made equipment that allowed breath by breath analysis (sRawp1) as well as with the commercial body box (sRawp2).

Results

sRawtb was significantly larger than either sRawp1 or sRawp2 (P < 0.0001). The mean (95% CI) difference sRawp1 − sRawtb was −0.374 (−0.835 to 0.088) kPa s. The difference between sRawp1 and sRawp2 was significant (P < 0.005) but not clinically relevant, and mean (95% CI) difference sRawp1 − sRawp2 was 0.115 (−0.094 to 0.324) kPa s. The breath by breath analysis showed small but significant increase in sRawp1 throughout the maneuver (P < 0.001), whatever the pattern of end expiratory level.

Conclusion

Tidal breathing is associated with an overestimation of sRaw compared with panting in children. Although the latter results in small increase throughout the panting maneuver, sRawp is probably more trustful than sRawtb. Pediatr Pulmonol. 2014; 49:245–251. © 2013 Wiley Periodicals, Inc.
Apixaban: new anticoagulant for stroke prevention
Authors: Chaplin Steve , Manning Lisa , Lam Man Yee , Robinson Thompson
Published: June 2013

Apixaban is a new oral anticoagulant licensed for the prevention of stroke and systemic embolism. In our New products review, Steve Chaplin presents the clinical data relating to its efficacy and adverse events compared with warfarin and aspirin, and hospital specialists discuss its place in stroke prevention.
Observations of the chemical composition of stratospheric aerosol particles
Authors: Murphy D. M. , Froyd K. D. , Schwarz J. P. , Wilson J. C.
Published: June 2013

Recent instrumentation can distinguish various types of aerosol particles in the stratosphere and determine their relative abundance. In the background lower stratosphere between major volcanic eruptions, most particles are either relatively pure sulphuric acid, sulphuric acid with material from ablated meteoroids or mixed organic‐sulphate particles that originated in the troposphere. The meteoritic iron and magnesium appear to be dissolved whereas the aluminum and silicon appear to be inclusions. Most stratospheric aerosol mass is liquid sulphuric acid and associated water, but a large fraction of particles contain either inclusions of meteoritic elements such as silicon or organic material that is probably effloresced or glassy. These solid phases could have large but unknown implications for the ability of particles to act as freezing nuclei for polar stratospheric clouds. Internally mixed black carbon is a measurable but very small component of the stratospheric aerosol by mass. Despite their importance for heterogeneous chemistry, there are few quantitative measurements of halogens in stratospheric particles.
Smart Nanomachines Based on DNA Self‐Assembly
Authors: Song Chen , Wang Zhen‐Gang , Ding Baoquan
Published: June 2013

DNA‐based nanomachines are self‐assembled DNA superstructures that harness chemical free energy to perform mechanical work. The development of DNA machines has benefited greatly from the achievements in both structural and dynamic DNA nanotechnology. In this review, the configurations of DNA machines, fuel systems, and operations are discussed to outline the evolving paths of DNA machines. The focus is on the smart mechanical behavior of DNA machines, from the standpoint of upgrading the complexity of DNA nanostructures, cooperative activation of multimachinary systems, and the establishment of a network of the mechanical states. In the end, the challenges are highlighted and possible solutions are proposed to push forward smart DNA nanomachines, with the goal of creating biomimicking systems. Insights are also provided into the potential applications of the DNA machines with designable intelligence.
Incorporating a Measure of Uncertainty into Systems of Systems Development Performance Measures
Authors: Volkert Richard , Stracener Jerrell , Yu Junfang
Published: June 2013

Technical Performance Measures (TPMs) historically are used to help the Program Manager in predicting if a program is on a path to achieve required performance. When extended over a developmental timeline, TPMs have provided a deterministic approach for predicting expected operational performance. However, TPMs are difficult to derive for a complex acknowledged system of systems (SoS). An SoS Performance Measure (SPM) has been developed that is equivalent in purpose to TPMs and demonstrated for a deterministic state similar to TPM usage. However, reality indicates that many of the SoS component variables have significant uncertainty associated with them during the SoS development. Therefore, to more accurately account for the ability of an SoS to achieve its desired performance, this variability needs to be accounted for. This paper extends the deterministic SPM concept to a stochastic SPM to account for this uncertainty. An Antisubmarine Warfare (ASW) mission example is used, and demonstrates how this extension improves the effectiveness of the SPM methodology.
Targeting and tailoring climate change communications
Authors: Bostrom Ann , Böhm Gisela , O'Connor Robert E.
Published: June 2013

Social marketing studies suggest that targeting segments of the population, by assessing and addressing their values and motives for actions in the design of communications, can improve the effectiveness of health and environmental communications efforts. Guidance for climate change communication now routinely proposes targeting specific audience segments as a fundamental principle, despite ambiguity regarding what specific behaviors to target and a lack of empirical evidence for specific strategies. Audience segmentation strategies proposed to date for climate change communications resemble those used in other social marketing efforts, but can be proprietary or opaque, with little data on the effects of implementing them. Insufficient evidence exists to systematically demonstrate the effectiveness of targeting or tailoring climate change communications per se, other than by reference to related research on health and environmental risk communications. Meta‐analyses with systematic literature reviews, however, demonstrate that health risk communications can be more effective at changing attitudes and behaviors if they are tailored to the individual recipients' beliefs about their self‐efficacy. The advent of technology‐enabled microtargeting is rapidly expanding the opportunities for tailoring and targeting climate change communications and for adding to what we know from using them to make them effective. WIREs Clim Change 2013, 4:447–455. doi: 10.1002/wcc.234

This article is categorized under:

Perceptions, Behavior, and Communication of Climate Change > Communication
Enhancement of FK506 production by engineering secondary pathways of Streptomyces tsukubaensis and exogenous feeding strategies
Authors: Huang Di , Xia Menglei , Li Shanshan , Wen Jianping , Jia Xiaoqiang
Published: June 2013

FK506 is a clinically important macrocyclic polyketide with immunosuppressive activity produced by Streptomyces tsukubaensis. However, the low titer at which it is produced is a bottleneck to its application and use in industrial processes. We have overexpressed five potential targets associated with FK506 production (fkbO, fkbL, fkbP, fkbM, fkbD) which were identified in our previous study, with the aim to improve FK506 production. The results of the analysis showed that the constructed strains with an additional copy of each gene increased FK506 production by approximately 10–40 % compared with the wild-type strain D852. The results of the gene expression analysis indicated that each gene was upregulated. Combinatorial overexpression of the five genes resulted in a 146 % increase in the FK506 titer to 353.2 mg/L, in comparison with the titer produced by D852. To further improve the production of FK506 by the engineered strain HT-FKBOPLMD, we supplemented the medium with various nutrients, including soybean oil, lactate, succinate, shikimate, chorismate, lysine, pipecolate, isoleucine and valine. Optimization of feeding concentrations and times resulted in HT-FKBOPLMD being able to produce approximately 70 % more FK506, thereby reaching the maximal titer of 457.5 mg/L, with lower amounts of by-products (FK520 and 37,38-dihydro-FK506). These results demonstrate that the combination of the metabolically engineered secondary pathways and the exogenous feeding strategies developed here was able to be successfully applied to improve the production of industrially and clinically important compounds.
Improving robot manipulation with data-driven object-centric models of everyday forces
Authors: Jain Advait , Kemp Charles C.
Published: June 2013

Based on a lifetime of experience, people anticipate the forces associated with performing a manipulation task. In contrast, most robots lack common sense about the forces involved in everyday manipulation tasks. In this paper, we present data-driven methods to inform robots about the forces that they are likely to encounter when performing specific tasks. In the context of door opening, we demonstrate that data-driven object-centric models can be used to haptically recognize specific doors, haptically recognize classes of door (e.g., refrigerator vs. kitchen cabinet), and haptically detect anomalous forces while opening a door, even when opening a specific door for the first time. We also demonstrate that two distinct robots can use forces captured from people opening doors to better detect anomalous forces. These results illustrate the potential for robots to use shared databases of forces to better manipulate the world and attain common sense about everyday forces.
PARTICIPATING PAYOUT LIFE ANNUITIES: LESSONS FROM GERMANY
Authors: Maurer Raimond , Rogalla Ralph , Siegelin Ivonne
Published: June 2013

This paper analyzes the framework of German participating payout life annuities (PLAs), which offer guaranteed minimum benefits as well as participation in insurers' surpluses. We show that the process of sharing surpluses between shareholders and policyholders follows transparent and consistent rules. Subsequently, we develop an asset-liability model for a stylized German life insurer that offers PLAs to evaluate benefit variability and insurer stability given stochastic mortality and capital market developments. Our results suggest that guaranteed benefits can be provided with high credibility via PLAs, while, at the same time, annuitants receive attractive money's worth ratios. Moreover, we show that it might be difficult to offer a fixed benefit annuity providing the same lifetime utility as a PLA for the same premium and a comparably low insolvency risk. Overall, PLA schemes may be an efficient way to deal with risk factors that are highly unpredictable and difficult to hedge over the long run, such as systematic longevity and investment risks.
HEDGING MORTALITY CLAIMS WITH LONGEVITY BONDS
Authors: Biagini Francesca , Rheinländer Thorsten , Widenmann Jan
Published: June 2013

We study mean–variance hedging of a pure endowment, a term insurance and general annuities by trading in a longevity bond with continuous rate payments proportional to the survival probability. In particular, we discuss the introduction of a gratification annuity as an interesting insurance product for the life insurance market. The optimal hedging strategies are determined via their Galtchouk–Kunita–Watanabe decompositions under specific, yet sufficiently general model assumptions. The results are then further illustrated by assuming a general affine structure of the mortality intensity process. The optimal hedging strategies as well as the residual hedging error of a gratification annuity and a simple life annuity are finally investigated with numerical simulations, which illustrate the nice features of the gratification annuity for the insurance industry.
MULTIVARIATE TAIL ESTIMATION WITH APPLICATION TO ANALYSIS OF COVAR
Authors: Nguyen Tilo , Samorodnitsky Gennady
Published: June 2013

The quality of estimation of multivariate tails depends significantly on the portion of the sample included in the estimation. A simple approach involving sequential statistical testing is proposed in order to select which observations should be used for estimation of the tail and spectral measures. We prove that the estimator is consistent. We test the proposed method on simulated data, and subsequently apply it to analyze CoVaR for stock and index returns.
The Animal Kingdom
Authors: Cuvier Georges
Published: June 2013

Georges Cuvier (1769–1832), made a peer of France in 1819 in recognition of his work, was perhaps the most important European scientist of his day. His most famous work, Le Règne Animal, was published in French in 1817; Edward Griffith (1790–1858), a solicitor and amateur naturalist, embarked on in 1824, with a team of colleagues, an English version which resulted in this illustrated sixteen-volume edition with additional material, published between 1827 and 1835. Cuvier was the first biologist to compare the anatomy of fossil animals with living species, and he named the now familiar 'mastodon' and 'megatherium'. However, his studies convinced him that the evolutionary theories of Lamarck and St Hilaire were wrong, and his influence on the scientific world was such that the possibility of evolution was widely discounted by many scholars both before and after Darwin. Volume 4 is the last of four books on mammals.
The Animal Kingdom
Authors: Cuvier Georges
Published: June 2013

Georges Cuvier (1769–1832), made a peer of France in 1819 in recognition of his work, was perhaps the most important European scientist of his day. His most famous work, Le Règne Animal, was published in French in 1817; Edward Griffith (1790–1858), a solicitor and amateur naturalist, embarked on in 1824, with a team of colleagues, an English version which resulted in this illustrated sixteen-volume edition with additional material, published between 1827 and 1835. Cuvier was the first biologist to compare the anatomy of fossil animals with living species, and he named the now familiar 'mastodon' and 'megatherium'. However, his studies convinced him that the evolutionary theories of Lamarck and St Hilaire were wrong, and his influence on the scientific world was such that the possibility of evolution was widely discounted by many scholars both before and after Darwin. Volume 6 is the first of three books on birds.
Lock-in and quasiperiodicity in a forced hydrodynamically self-excited jet
Authors: Li Larry K. B. , Juniper Matthew P.
Published: June 2013

The ability of hydrodynamically self-excited jets to lock into strong external forcing is well known. Their dynamics before lock-in and the specific bifurcations through which they lock in, however, are less well known. In this experimental study, we acoustically force a low-density jet around its natural global frequency. We examine its response leading up to lock-in and compare this to that of a forced van der Pol oscillator. We find that, when forced at increasing amplitudes, the jet undergoes a sequence of two nonlinear transitions: (i) from periodicity to${ \mathbb{T} }^{2} $quasiperiodicity via a torus-birth bifurcation; and then (ii) from${ \mathbb{T} }^{2} $quasiperiodicity to 1:1 lock-in via either a saddle-node bifurcation with frequency pulling, if the forcing and natural frequencies are close together, or a torus-death bifurcation without frequency pulling, but with a gradual suppression of the natural mode, if the two frequencies are far apart. We also find that the jet locks in most readily when forced close to its natural frequency, but that the details contain two asymmetries: the jet (i) locks in more readily and (ii) oscillates more strongly when it is forced below its natural frequency than when it is forced above it. Except for the second asymmetry, all of these transitions, bifurcations and dynamics are accurately reproduced by the forced van der Pol oscillator. This shows that this complex (infinite-dimensional) forced self-excited jet can be modelled reasonably well as a simple (three-dimensional) forced self-excited oscillator. This result adds to the growing evidence that open self-excited flows behave essentially like low-dimensional nonlinear dynamical systems. It also strengthens the universality of such flows, raising the possibility that more of them, including some industrially relevant flames, can be similarly modelled.
Nonlinear stratified spindown over a slope
Authors: Benthuysen Jessica A. , Thomas Leif N.
Published: June 2013

Nonlinear stratified spindown of an along-isobath current over an insulated slope is shown to develop asymmetries in the vertical circulation and vertical relative vorticity field. During spindown, cyclonic vorticity is weakened to a greater extent than anticyclonic vorticity near the boundary because of buoyancy advection. As a consequence, Ekman pumping is weakened over Ekman suction. Momentum advection can weaken Ekman pumping and strengthen Ekman suction. Time-dependent feedback between the geostrophic flow and the frictional secondary circulation induces asymmetry in cyclonic and anticyclonic vorticity away from the boundary. Buoyancy advection over a slope can modify the secondary circulation such that anticyclonic vorticity decays faster than cyclonic vorticity outside the boundary layer. In contrast, momentum advection can cause cyclonic vorticity to spin down faster than anticyclonic vorticity. A scaling and analytical solutions are derived for when buoyancy advection over a slope can have a more significant impact than momentum advection on these asymmetries. In order to test this scaling and analytical solutions, numerical experiments are run in which both buoyancy and momentum advection are active. These solutions are contrasted with homogeneous or stratified spindown over a flat bottom, in which momentum advection controls the asymmetries. These results are applied to ocean currents over continental shelves and slopes.