bluuebunny/crossref_metadata_2025 huggingface dataset:
Exhaled breath condensate purines correlate with lung function in infants and preschoolers
Authors: Patel Kavita , Davis Stephanie D. , Johnson Robin , Esther Charles R.
Published: May 2012

Rationale

Although airway inflammation begins early in life in children with chronic respiratory diseases, current methods to assess this inflammation are invasive and entail significant risk. Measurement of exhaled breath condensate (EBC) purines and other biomarkers offers a less invasive method to assess airway inflammation; however, the feasibility and utility of EBC biomarkers in young children has not been established.

Methods

EBC was collected from children <3 years old with cystic fibrosis or other lung diseases during clinically indicated infant pulmonary function tests (iPFTs). EBC concentrations of the purine biomarkers adenosine (Ado), adenosine monophosphate (AMP), and the dilution marker urea were measured using mass spectrometry.

Results

EBC was successfully collected (average volume 330 ± 170 µl) from preschool children (age 2.3 ± 0.8 years) in 15 of 17 iPFTs. No significant changes in oxygen saturation (96.9 ± 1.6 start, 96.8 ± 1.7 end, P = 0.389) or respiratory rate (35.2 ± 7.5 start, 34.6 ± 7.9 end, P = 0.443) were observed during collection. Ado and AMP were successfully measured in 13/15 samples [8 cystic fibrosis (CF)]. EBC AMP to Ado ratio (AMP/Ado) negatively correlated with forced expiratory volume at 0.5 sec (FEV0.5, r = −0.71, P < 0.01) and positively with the ratio of residual volume to total lung capacity (RV/TLC, r = 0.66, P = 0.015). These correlations remained statistically significant in the subset with CF.

Conclusions

EBC can be safely collected and analyzed in preschool children using commercially available equipment. The EBC AMP/Ado ratio correlates with measures of infant lung function and may be a less invasive means of monitoring airway inflammation in this population. Pediatr Pulmonol. 2013; 48:182–187. © 2012 Wiley Periodicals, Inc.
Cycle Ergometer Tests in Children With Cystic Fibrosis: Reliability and Feasibility
Authors: Kent Lisa , O'Neill Brenda , Davison Gareth , Nevill Alan , Murray Joyce , Reid Alastair , Elborn J. Stuart , Bradley Judy M.
Published: May 2012

The aim of this study was to assess the reliability and feasibility of cycle ergometer tests in young children with cystic fibrosis (CF). Children with CF aged 6–11 years and with stable lung disease performed two cycle ergometry tests (intermittent sprint and continuous incremental) on two occasions 1 week apart. Reliability was assessed using repeated‐measures ANOVA. Bias was considered to be significant at P < 0.05 level and a coefficient of variation (CV) below 10% was considered acceptable. Feasibility and acceptability data were also collected. Sixteen children with CF completed the study: (9M:7F), 8.7(1.8) years, FEV1%predicted: 88.1(17.4). Power measurements recorded during the intermittent sprint test demonstrated significant bias over days (P < 0.05) and CVs were between 10% and 15%. Peak work capacity recorded during the continuous incremental test was reliable (bias P < 0.05, CV < 10%), as was heart rate and SpO2 recorded during both tests (bias P < 0.05, CV < 10%). No problems were experienced in administering the tests and all children completed both tests on two separate occasions. There was a mixed response to questions on acceptability of tests. This is the first study to provide information on the reliability of performance measures recorded during an intermittent sprint protocol (peak power) and a continuous incremental cycle ergometry (peak work capacity) in children with CF. Pediatr Pulmonol. 2012; 47:1226–1234. © 2012 Wiley Periodicals, Inc.
A comparison of different bedside techniques to determine endotracheal tube position in a neonatal piglet model
Authors: Schmölzer Georg M. , Bhatia Risha , Davis Peter G. , Tingay David G.
Published: May 2012

Rationale

Endotracheal tube (ETT) malposition is common and an increasing number of non‐invasive techniques to aid rapid identification of tube position are available. Electrical impedance tomography (EIT) is advocated as a tool to monitor ventilation.

Objective

This study aimed to compare EIT with five other non‐invasive techniques for identifying ETT position in a piglet model.

Methodology

Six saline lavage surfactant‐depleted piglets were studied. Periods of ventilation with ETT placed in the oesophagus or a main bronchus (MB) were compared with an appropriately placed mid‐tracheal ETT. Colorimetric end‐tidal CO2 (Pedi‐Cap®), SpO2 and heart rate, tidal volume (${\rm V}_{{\rm T}_{{\rm ao}} } $) using a hot‐wire anemometer at the airway opening, tidal volume using respiratory inductive plethysmography (${\rm V}_{{\rm T}_{{\rm RIP}} } $) and regional tidal ventilation within each hemithorax (EIT) were measured.

Results

Oesophageal ventilation: Pedi‐Cap® demonstrated absence of color change. ${\rm V}_{{\rm T}_{{\rm ao}} } $, ${\rm V}_{{\rm T}_{{\rm RIP}} } $, and EIT correctly demonstrated no tidal ventilation. SpO2 decreased from mean (SD) 96 (2)% to 74 (12)% (P < 0.05; Bonferroni post‐test), without heart rate change. MB ventilation: SpO2, heart rate and Pedi‐Cap® were unchanged compared with mid‐tracheal position. ${\rm V}_{{\rm T}_{{\rm ao}} } $ and ${\rm V}_{{\rm T}_{{\rm RIP}} } $ decreased from a mean (SD) 10.8 (5.6) ml/kg and 14.6 (6.2) ml/kg to 5.5 (1.9) ml/kg and 6.4 (2.6) ml/kg (both P < 0.05; Bonferroni post‐test). EIT identified the side of MB ventilation, with a mean (SD) 95 (3)% reduction in tidal volume in the unventilated lung.

Conclusions

EIT not only correctly identified oesophageal ventilation but also localized the side of MB ventilation. At present, no one technique is without limitations and clinicians should utilize a combination in addition to clinical judgement. Pediatr Pulmonol. 2013; 48:138–145. © 2012 Wiley Periodicals, Inc.
Ambulatory blood pressure monitoring in chinese children with obstructive sleep apnea/hypopnea syndrome
Authors: Xu Zhifei , Li Bei , Shen Kunling
Published: May 2012

Objective

Obstructive sleep apnea/hypopnea syndrome (OSAHS) is a common sleep problem. The aim of this study is to investigate the association between OSAHS and blood pressure (BP) in snoring children.

Methods

Snoring children were recruited from January 2009 to December 2010. Clinical history was taken accompanied by a physical examination and polysomnography were performed. A child with an apnea/hypopnea index (AHI) greater than 5 hr−1 or obstructive apnea index (OAI) greater than 1 hr−1 was diagnosed as having OSAHS. Ambulatory BP monitoring was performed for each child. BP load, BP index and nocturnal BP dipping were calculated for each child.

Results

One hundred forty‐five children with snoring were recruited and 107 of them were diagnosed with OSAHS. There were no differences between those with or without OSA in age or gender distribution. The OSAHS children had higher mean nighttime systolic and diastolic BP, increased BP load, and decreased nocturnal BP dipping compared to the non‐OSAHS children (SBP: P = 0.03, DBP: P < 0.001, BP load: P = 0.001, SBP dipping: P = 0.03, DBP dipping: P = 0.04). Multiple regression analysis showed that mean nighttime systolic BP was related to age, obesity, and oxygen desaturation index (ODI) (P = 0.04, 0.03, and 0.02 respectively), while mean nighttime diastolic BP was related to obesity and ODI (P = 0.03 and 0.04, respectively).

Conclusions

OSAHS children had a higher nocturnal BP than non‐OSAHS children and dysregulation of BP control reflected by decreased nocturnal BP dipping. Frequency of oxygen desaturation, apneas, and obesity were related to BP. Pediatr Pulmonol. 2013; 48:274–279. © 2012 Wiley Periodicals, Inc.
Effect of C60 as an electron buffer layer in polythiophene‐methanofullerene based bulk heterojunction solar cells
Authors: Elumalai Naveen Kumar , Yin Leung Man , Chellappan Vijila , Jie Zhang , Peining Zhu , Ramakrishna Seeram
Published: May 2012

The effect of C60 interlayer on charge transport and device performance in bulk heterojunction solar cells with active layer of poly3‐hexylthiophene (P3HT) and l‐3‐methoxycarbonyl‐propyl‐l‐phenyl‐6,6 methanofullerene (PCBM) have been studied. The C60 layer of different thicknesses (5 nm, 10 nm, 15 nm, and 20 nm) was introduced between the cathode and the photoactive layer of the solar cell. The solar cell performance was found to be maximized at an optimum C60 thickness of about 5 nm. Subsequent increase in C60 interlayer thickness promotes charge transfer near the Al‐C60 interface due to increased diffusion of Al atoms into the interstitials of C60. This results in the formation of s‐shaped kink in J–V spectra. To further investigate the cause of this detrimental effects, photoinduced charge extraction by linearly increasing voltage (PhotoCELIV) and CELIV studies were performed on the real solar cell devices. The CELIV transients obtained from the device with 5 nm C60 interlayer shows no charge extraction peak whereas the devices with C60 layer of thicknesses from 10 nm to 20 nm shows characteristic maxima due to the transferred charge carriers from the Al‐C60 interface. The PhotoCELIV studies performed on the devices showed characteristic single peak for the device with 5 nm C60 interlayer whereas the other devices exhibited dual peaks due to charges generated from photo excitation and injection at the interface respectively. The charge mobility values calculated from the dual photoCELIV transients indicates the charge mobility imbalance between the carriers in the devices.
Spectrally resolved cathodoluminescence imaging study of periodic [001]/[00‐1] GaAs structures for nonlinear optical conversion
Authors: Hortelano V. , Martínez O. , Jiménez J. , Lynch C. , Snure M. , Bliss D.
Published: May 2012

Orientation patterned (OP)‐GaAs crystals are very promising as nonlinear optical materials. They are suitable for mid‐infrared and terahertz laser sources, by frequency conversion of shorter wavelength pump sources. OP‐GaAs crystals must contain low concentrations of defects and must be homogeneous to reduce fluctuations, in the refractive index and the concomitant optical propagation losses. Understanding of the defects with electrooptic signature is crucial to improve the growth conditions for reducing their presence. Spectrally resolved cathodoluminescence imaging is used to study the main defects and how they are distributed throughout the OP‐GaAs crystal (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Formation of GaP nanostructures on GaAs (100) by droplet molecular beam epitaxy
Authors: Prongjit P. , Pankaow N. , Thainoi S. , Panyakeow S. , Ratanathammaphan S.
Published: May 2012

In this contribution, we have demonstrated the fabrication of tensile strained GaP nanostructures on GaAs (100) substrates by droplet epitaxy using molecular beam epitaxy. The GaP nanostructures are ring‐like structure due to crystallization with low P2 pressure. The density of GaP ring‐like nanostructures varies between 8.92×108‐2.17×109 cm‐2 and the average of diameter varies between 88.4‐133 nm with increasing the Ga amount deposition in the range of 2.4‐4.8 ML. The photoluminescence result shows the tensile strain‐modified band gap effect of GaP nanostructure in GaAs matrix and it also confirms the high‐quality of GaP nanocrystal (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Role of Diallyl Sulfides and Dipropyl Sulfides in the In Vitro Antimicrobial Activity of the Essential Oil of Garlic, Allium sativum L., and Leek, Allium porrum L.
Authors: Casella Sergio , Leonardi Michele , Melai Bernardo , Fratini Filippo , Pistelli Luisa
Published: May 2012

The in vitro antibacterial activity of essential oils (EOs) obtained from fresh bulbs of garlic, Allium sativum L., and leek, Allium porrum L. ( Alliaceae), was studied. A. sativum (garlic) EO showed a good antimicrobial activity against Staphylococcus aureus (inhibition zone 14.8 mm), Pseudomonas aeruginosa (inhibition zone 21.1 mm), and Escherichia coli (inhibition zone 11.0 mm), whereas the EO of A. porrum (leek) had no antimicrobial activity. The main constituents of the garlic EO were diallyl monosulfide, diallyl disulfide (DADS), diallyl trisulfide, and diallyl tetrasulfide. The EO of A. porrum was characterized by the presence of dipropyl disulfide (DPDS), dipropyl trisulfide, and dipropyl tetrasulfide. The antimicrobial activities of the DADS and DPDS were also studied. The results obtained suggest that the presence of the allyl group is fundamental for the antimicrobial activity of these sulfide derivatives when they are present in Allium or in other species (DADS inhibition zone on S. aureus 15.9 mm, P. aeruginosa 21.9 mm, E. coli 11.4 mm). Copyright © 2012 John Wiley & Sons, Ltd.
THE SOLAR‐TO‐STREAM POWER RATIO: A DIMENSIONLESS NUMBER EXPLAINING DIEL FLUCTUATIONS OF TEMPERATURE IN MESOSCALE RIVERS
Authors: Link O. , Huerta A. , Stehr A. , Monsalve A. , Meier C. , Aguayo M.
Published: May 2012

The diel variation of temperature in mesoscale river reaches (catchment area > 1000 km2) is analysed using concurrent measurements of water temperature and of those meteorological (incident short‐wave radiation, air temperature, relative humidity and wind speed variables) and hydraulic variables (streamflow, top width, channel slope and flow depth) controlling the thermal regime. Measurements were taken along two river reaches located in central Chile, on the Itata (11 290 km2, Strahler's order 6, reach length 30 km,Qbankfull = 400 m3s−1) and Vergara (4340 km2, Strahler's order 5, reach length 20 km,Qbankfull = 85 m3s−1) rivers. The measuring frequency was 15 min. The relevant energy fluxes at the air–water interface, that is, atmospheric long‐wave radiation, net short‐wave radiation, radiation emitted by the water body, evaporation (latent heat) and conduction heat are computed and analysed for four scenarios of 12 days duration each, representing typical conditions for the austral winter, spring, summer and autumn. We find large differences in the diel river temperature range between the two sites and across seasons (and thus, flows and meteorological conditions), as reported in previous studies, but no clear relationship with the controlling variables is overtly observed. Following a dimensional analysis, we obtain a dimensionless parameter corresponding to the ratio of solar‐to‐stream power, which adequately explains the diel variation of water temperature in mesoscale rivers. A number of our own measurements as well as literature data are used for preliminary testing of the proposed parameter. This easy‐to‐compute number is shown to predict quite well all of the cases, constituting a simple and useful criterion to estimatea priorithe magnitude of temperature diel variations in a river reach, given prevailing meteorological (daily maximum solar radiation) and hydrologic–hydraulic (streamflow, mean top width) conditions. Copyright © 2012 John Wiley & Sons, Ltd.
Reaction of (PPh3)2C→CO2 with Halogenated Hydrocarbons; Formation and Crystal Structure of a Cationic Ester with 1, 2‐Dichloroethane
Authors: Petz Wolfgang , Neumüller Bernhard
Published: May 2012

The carbodiphosphorane CO2 adduct (2) reacts slowly with 1, 2‐dichloroethane to give (HC{PPh3}2)Cl (5) as result of HCl abstraction along with the ester‐like salt (ClCH2CH2O(O)CC{PPh3}2)Cl (4) from nucleophilic substitution of one Cl– by 2. Both compounds could be separated by fractional crystallization. Attempts to dissolve 2 in 1, 2‐difluorobenzene leads to small amounts of the hydrolysis product (HC{PPh3}2)(HCO3)·H2O (6·H2O) caused by some humidity in the solvent. All compounds could be crystallized and the structures studied by X‐ray analyses and 31P NMR spectroscopy.
Time series data for Canadian arctic vertebrates: IPY contributions to science, management, and policy
Authors: Ferguson S. H. , Berteaux D. , Gaston A. J. , Higdon J. W. , Lecomte N. , Lunn N. , Mallory M. L. , Reist J. , Russell D. , Yoccoz N. G. , Zhu X.
Published: May 2012

Long-term data are critically important to science, management, and policy formation. Here we describe a number of data collections from arctic Canada that monitor vertebrate population trends of freshwater and marine fish, marine birds, marine and terrestrial mammals. These time series data cover the last ca. 30 years and capture a period from the onset of global changes affecting the Arctic up to recent years with a rapid increase in temperature. While many of these data collections were initiated through a variety of government and university programs, they also include a surge in polar research launched with the recent International Polar Year (2007–2008). We estimated the long-term vertebrate index from our data that summarizes various taxa abundance trends within a global context and observed a continuous decline of about 30 % in population abundance since the 1990s. Though most data collections are biased towards few taxa, we conduct time-series analyses to show that the potential value of long-term data emerges as individual monitoring sites can be spread across space and time scales. Despite covering a handful of populations, the different time series data covered a large spectrum of dynamics, cyclic to non-cyclic, including coherence with the North Atlantic Oscillation, lag effects, and density dependence. We describe a synthesis framework to integrate ecological time-series research and thereby derive additional benefits to management, science, and policy. Future requirements include: (1) continuation of current observation systems; (2) expansion of current monitoring sites to include additional trophic links and taxonomic indicators; (3) expansion beyond the existing program to include greater spatial coverage into less-sampled ecosystems and key representative locations; and (4) integration of circumpolar observations and comprehensive analyses. Development of a circumpolar observation system is necessary for innovative science, large-scale adaptive management, and policy revision essential to respond to rapid global change.
PME aiming for quality, originality and peer recognition
Authors: Peeraer Griet
Published: May 2012

None
Redesigning the single‐chain variant of the restriction endonuclease PvuII by circular permutation
Authors: Schierling Benno , Wende Wolfgang , Pingoud Alfred
Published: May 2012

The restriction endonuclease PvuII has been introduced as a sequence‐specific cleavage module in highly‐specific nucleases for gene targeting. Here, a structural reorganization of the single‐chain variant of PvuII (scPvuII) was performed by circular permutation as a proof‐of‐concept in order to find out whether the relocated, new termini next to structural elements important for DNA recognition and catalysis could be used for the fusion with other regulatory protein domains. Three circularly permuted variants of scPvuII were obtained that all maintain the specific endonucleolytic activity of scPvuII.
The optimal threshold values for the severity of urinary incontinence based on the 1‐hour pad test
Authors: Li Bin , Zhu Lan , Xu Tao , Lang Jinghe
Published: May 2012

Objective

To explore the correlation between the 1‐hour pad test and Stamey incontinence grading and to obtain the optimal threshold values for the severity of urinary incontinence.

Methods

In a cross‐sectional retrospective study at Peking Union Medical College Hospital, 1‐hour pad test results and Stamey grades of female patients who had undergone therapy for urinary incontinence between June 2005 and December 2010 were reviewed. The correlation between the objective and subjective measurements was assessed via a Spearman rank correlation test. The optimal diagnostic threshold was evaluated by ROC curve, and areas under the ROC curve reflected the accuracy of the 1‐hour pad test.

Results

A strong positive correlation was found between the 1‐hour pad test results and the subjective grades of 320 patients (correlation coefficient 0.757, P < 0.001). On the basis of the 1‐hour pad test, the optimal diagnostic cutoff points for the severity of urinary incontinence were 3.4 g and 10.2 g.

Conclusion

The 1‐hour pad test could assess the severity of urinary incontinence accurately. The threshold values should be, approximately, less than 3 g for mild, 3–10 g for moderate, and more than 10 g for severe urinary incontinence.
Does the Leader's Ethnicity Matter? Ethnic Favoritism, Education, and Health in Sub-Saharan Africa
Authors: FRANCK RAPHAËL , RAINER ILIA
Published: May 2012

In this article we reassess the role of ethnic favoritism in sub-Saharan Africa. Using data from 18 African countries, we study how the primary education and infant mortality of ethnic groups were affected by changes in the ethnicity of the countries’ leaders during the last 50 years. Our results indicate that the effects of ethnic favoritism are large and widespread, thus providing support for ethnicity-based explanations of Africa's underdevelopment. We also conduct a cross-country analysis of ethnic favoritism in Africa. We find that ethnic favoritism is less prevalent in countries with one dominant religion. In addition, our evidence suggests that stronger fiscal capacity may have enabled African leaders to provide more ethnic favors in education but not in infant mortality. Finally, political factors, linguistic differences, and patterns of ethnic segregation are found to be poor predictors of ethnic favoritism.
Social anxiety disorder and shame cognitions in psychosis
Authors: Michail M. , Birchwood M.
Published: May 2012

Background

Social anxiety disorder (SAD) is surprisingly prevalent among people with psychosis and exerts significant impact on social disability. The processes that underlie its development remain unclear. The aim of this study was to investigate the relationship between shame cognitions arising from a stigmatizing psychosis illness and perceived loss of social status in co-morbid SAD in psychosis.

Method

This was a cross-sectional study. A sample of individuals with SAD (with or without psychosis) was compared with a sample with psychosis only and healthy controls on shame proneness, shame cognitions linked to psychosis and perceived social status.

Results

Shame proneness (p < 0.01) and loss of social status (p < 0.01) were significantly elevated in those with SAD (with or without psychosis) compared to those with psychosis only and healthy controls. Individuals with psychosis and social anxiety expressed significantly greater levels of shame (p < 0.05), rejection (p < 0.01) and appraisals of entrapment (p < 0.01) linked to their diagnosis and associated stigma, compared to those without social anxiety.

Conclusions

These findings suggest that shame cognitions arising from a stigmatizing illness play a significant role in social anxiety in psychosis. Psychological interventions could be enhanced by taking into consideration these idiosyncratic shame appraisals when addressing symptoms of social anxiety and associated distress in psychosis. Further investigation into the content of shame cognitions and their role in motivating concealment of the stigmatized identity of being ‘ill’ is needed.
GLOBAL IDENTIFICATION IN NONLINEAR MODELS WITH MOMENT RESTRICTIONS
Authors: Komunjer Ivana
Published: May 2012

This paper derives sufficient conditions for global identification in nonlinear models characterized by a finite number of unconditional moment restrictions. The main contribution of this paper is to provide a set of assumptions that are alternative to those of Gale-Nikaidô-Fisher-Rothenberg, and which when satisfied guarantee that the moment conditions globally identify the parameters of interest.
SPECIFICATION TEST FOR MISSING FUNCTIONAL DATA
Authors: Bugni Federico A.
Published: May 2012

Economic data are frequently generated by stochastic processes that can be modeled as realizations of random functions (functional data). This paper adapts the specification test for functional data developed by Bugni, Hall, Horowitz, and Neumann (2009, Econometrics Journal12, S1–S18) to the presence of missing observations. By using a worst case scenario approach, our method is able to extract the information available in the observed portion of the data while being agnostic about the nature of the missing observations. The presence of missing data implies that our test will not only result in the rejection or lack of rejection of the null hypothesis, but it may also be inconclusive.

Under the null hypothesis, our specification test will reject the null hypothesis with a probability that, in the limit, does not exceed the significance level of the test. Moreover, the power of the test converges to one whenever the distribution of the observations conveys that the null hypothesis is false.

Monte Carlo evidence shows that the test may produce informative results (either rejection or lack of rejection of the null hypothesis) even under the presence of significant amounts of missing data. The procedure is illustrated by testing whether the Burdett–Mortensen labor market model is the correct framework for wage paths constructed from the National Longitudinal Survery of Youth, 1979 survey.
STRUCTURAL CHANGE TESTS BASED ON IMPLIED PROBABILITIES FOR GEL CRITERIA
Authors: Guay Alain , Lamarche Jean-François
Published: May 2012

This paper proposes Pearson-type statistics based on implied probabilities to detect structural change. The class of generalized empirical likelihood estimators (see Smith 1997,The Economic Journal107, 503–519) assigns a set of implied probabilities to each observation such that moment conditions are satisfied. The proposed test statistics for structural change are based on the information content in these implied probabilities. We consider cases of structural change with unknown breakpoint that can occur in the parameters of interest or in the overidentifying restrictions used to estimate these parameters. We also propose a structural change test based on implied probabilities that is robust to weak identification or cases in which parameters are completely unidentified. The test statistics considered here have competitive size and power properties. Moreover, they are computed in a single step, which eliminates the need to compute the weighting matrix required for generalized method of moments estimation.
Consent in psychiatric biobanks for pharmacogenetic research
Authors: van der Baan Frederieke H. , Bernabe Rose D. C. , Bredenoord Annelien L. , Gregoor Jochem G. , Meynen Gerben , Knol Mirjam J. , van Thiel Ghislaine J. M. W.
Published: May 2012

In psychiatric practice, pharmacogenetics has the potential to identify patients with an increased risk of unsatisfactory drug responses. Genotype-guided treatment adjustments may increase benefits and reduce harm in these patients; however, pharmacogenetic testing is not (yet) common practice and more pharmacogenetic research in psychiatric patients is warranted. An important precondition for this type of research is the establishment of biobanks. In this paper, we argue that, for the storage of samples in psychiatric biobanks, waiving of consent is not ethically justifiable since the risks cannot be considered minimal and the argument of impracticability does not apply. An opt-out consent procedure is also not justifiable, since it presumes competence while the decisional competence of psychiatric patients needs to be carefully evaluated. We state that an enhanced opt-in consent procedure is ethically necessary, i.e. a procedure that supports the patients’ decision-making at the time when the patient is most competent. Nevertheless, such a procedure is not the traditional exhaustive informed consent procedure, since this is not feasible in the case of biobanking.
Computational intelligence with applications to general insurance: a review
Authors: Parodi Pietro
Published: May 2012

This paper argues that most of the problems that actuaries have to deal with in the context of non-life insurance can be usefully cast in the framework of computational intelligence (a.k.a. artificial intelligence), the discipline that studies the design of agents which exhibit intelligent behaviour. Finding an adequate framework for actuarial problems has more than a simply theoretical interest: it also allows a technological transfer from the computational intelligence discipline to general insurance, wherever techniques have been developed for problems which are common to both contexts. This has already happened in the past (neural networks, clustering, data mining have all found applications to general insurance) but not in a systematic way. One of the objectives of this paper will therefore be to introduce some useful techniques such as sparsity-based regularisation and dynamic decision networks that are not yet known to the wider actuarial community.

Whilst in the first part of this paper we dealt mainly with data-driven loss modelling under the assumption that all the data were accurate and fully relevant to the exercise, in this second part of the paper we explore how to deal with uncertain knowledge, whether this uncertainty comes from the fact that the data are not fully reliable (e.g. they are estimates) or from the fact that the knowledge is “soft” (e.g. expert beliefs) or not fully relevant (e.g. market information on a given risk). Most importantly, we will deal with the problem of making pricing, reserving and capital decisions under uncertainty. It will be concluded that a Bayesian framework is the most adequate for dealing with uncertainty, and we will present a number of computational intelligence techniques to do this in practice.
Mixtures of stratospheric and overshooting air measured using A‐Train sensors
Authors: Iwasaki S. , Shibata T. , Okamoto H. , Ishimoto H. , Kubota H.
Published: May 2012

Synergetic spaceborne observations of overshooting air, defined as cloud intrusion through the level of neutral buoyancy above deep convection, are analyzed using various thresholds introduced in previous studies to detect overshooting. The brightness temperature of the overshooting air measured by the Moderate Resolution Imaging Spectroradiometer (MODIS) is generally 2 K higher than that retrieved by the radiative transfer model, in which the size distribution of ice cloud particles is estimated from Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP) and CloudSat data and the vertical temperature profile of cloud is assumed to follow that of the European Centre for Medium Range Weather Forecast (ECMWF). The lapse rate of overshooting whose cloud top is higher than the level of the cold‐point temperature (CPT) is lower than that of an adiabatic expansion. These observations can be rationalized as being due to the overshooting air being locally warmed by a mixture of warmer stratospheric air. Analysis of CALIOP and CloudSat data by using a radar‐lidar algorithm shows that the mode of averaged ice water content of the overshoot above the CPT height is 6.3–10 mg/m3. Therefore, if 5% or more of ice particles in the overshoot are sublimated and mixed into the lower stratosphere, the lower stratospheric air will be hydrated. The difference between the brightness temperatures of 6.7 and 11 μm channels observed with MODIS demonstrates that the overshoot enhances stratospheric water vapor. These results indicate that the warm stratospheric air moves downward at and around the overshoot and mixes with the overshooting air and that the overshooting hydrates the lower stratosphere.
While China's dominance in rare earths dips, concerns remain about these and other elements
Authors: Showstack Randy
Published: May 2012

China's dominance in the production of rare earth elements (REEs) peaked with that nation producing 97% of them in 2010; this number already has dipped to 90% in 2012 as mines in other nations are coming online, according to REE expert Karl Gschneidner Jr., a professor at Iowa State University's Ames Laboratory. Chinese production could drop to 60% by 2014, with production increasing at mines in the United States and other countries, he said. However, this reduction in China's share of REE production does not signal an end to the production crisis in REEs and other critical minerals, Gschneidner and others noted during a 1 May panel discussion on critical materials shortages at the AGU Science Policy Conference in Washington, D. C. REEs are a group of 17 chemically similar metallic elements used in a variety of electronic, optical, magnetic, and catalytic applications, and despite their name, they are relatively plentiful in the Earth's crust. China's control of known REE reserves has dropped from 75% in 1975 to 30.9% in 2012, with other regions also having large reserves, including the Commonwealth of Independent States (some former Soviet Republic states), the United States, and Australia, according to Gschneidner. Critical minerals are mineral commodities that are particularly important for a nation's economy or national defense that could potentially face supply disruptions.
Uranus's auroras observed from Hubble Space Telescope
Authors: Balcerak Ernie
Published: May 2012

New observations from the Hubble Space Telescope provide the first ever images of Uranus's auroras. The new observations, described by Lamy et al., are also the first unambiguous detections of Uranus's auroras since they were first discovered using the Voyager 2 spacecraft, which few by the planet in 1986. Auroras arise from the solar wind's interaction with a planet's magnetosphere. Uranus's magnetosphere, which is not well studied, is unusual because the planet's magnetic axis is both offset and sharply tilted with respect to the planet's spin axis. The newly detected auroras, seen on the dayside of the planet in November 2011, are quite different from Earth's—Uranus's auroras were faint dots of light that lasted online a few minutes, unlike the dancing colored curtains organized along rings of emissions around Earth's magnetic poles, intensified on the nightside and lasting for hours. (Geophysical Research Letters, doi:10.1029/ 2012GL051312, 2012)
Undulations in MeV solar energetic particle fluxes in Earth's magnetosphere associated with substorm magnetic field reconfigurations
Authors: Rodriguez J. V.
Published: May 2012

East‐west anisotropies in GOES solar energetic particle (SEP) flux observations provide evidence of a time‐varying radial gradient between L ≈ 4 and L ≈ 7. During elevated auroral activity, the gradient, represented by the ratio of inner (eastward‐observed) to outer (westward‐observed) fluxes, exhibits undulations lasting 1–3 h. A superposed epoch analysis based on 85 geosynchronous field dipolarizations observed during 19 SEP events between 1998 and 2006 shows that >4 MeV inner proton fluxes increase as the geosynchronous field stretches during substorm growth phase, then decrease gradually following field dipolarization at substorm onset. This behavior is distinct from the sharp increase of outer belt electrons and protons at the time of the dipolarization. The undulations indicate that substorm‐related field changes in the near‐Earth magnetotail enhance access of SEPs to the inner magnetosphere (down to L ≈ 4). The observation of undulations at geosynchronous orbit is suppressed during high solar wind dynamic pressure (Pdyn > 5 nPa) or strong geomagnetic storm conditions (Dst∗ < −100 nT) because the radial gradient is greatly reduced under these conditions and the interplanetary flux level provides an upper limit to the SEP fluxes in the magnetosphere. A sequence of 10 SEP undulations was observed during and following the 18 April 2002 sawtooth event. Analysis of this sequence shows that undulations observed at all local times are associated with substorm‐related field changes on the nightside. GOES eastward SEP observations at all local times can thus serve as global trace particle sensing of substorm‐related field reconfigurations in the near‐Earth magnetotail.
The role of phase compatibility in martensite
Authors: Salman Oğuz Umut , Finel Alphonse , Delville Rémi , Schryvers Dominique
Published: May 2012

Shape memory alloys inherit their macroscopic properties from their mesoscale microstructure originated from the martensitic phase transformation. In a cubic to orthorhombic transition, a single variant of martensite can have a compatible (exact) interface with the austenite for some special lattice parameters in contrast to conventional austenite/twinned martensite interface with a transition layer. Experimentally, the phase compatibility results in a dramatic drop in thermal hysteresis and gives rise to very stable functional properties over cycling. Here, we investigate the microstructures observed in Ti50Ni50−xPdx alloys that undergo a cubic to orthorhombic martensitic transformation using a three-dimensional phase field approach. We will show that the simulation results are in very good agreement with transmission electron microscopy observations. However, the understanding of the drop in thermal hysteresis requires the coupling of phase transformation with plastic activity. We will discuss this point within the framework of thermoelasticity, which is a generic feature of the martensitic transformation.
Spatially periodical poling of silica glass
Authors: Sokolov K. , Melehin V. , Petrov M. , Zhurikhina V. , Lipovskii A.
Published: May 2012

The process of poling of silica glass using periodical anodic electrode, or, the same, electric field imprinting of periodical structure in silica glass is modeled. We studied the influence of the electrode periodicity and the magnitude of applied voltage on the thickness of poled (charge carriers depleted) region and on the smearing of the relief of the poled region. It is shown that the smearing is mainly limited by charge carriers drift induced by lateral components of electric field formed by the anodic electrode. The modeling also shows that if high, order of kilovolts, voltage is used for poling, the atmosphere and the type of anodic electrode (blocking or non-blocking) do not essentially influence the results of the processing.
Ion acceleration in a helicon source due to the self-bias effect
Authors: Wiebold Matt , Sung Yung-Ta , Scharer John E.
Published: May 2012

Time-averaged plasma potential differences up to 165 V over several hundred Debye lengths are observed in low pressure (pn < 1 mTorr) expanding argon plasmas in the Madison Helicon eXperiment (MadHeX). The potential gradient leads to ion acceleration greater than that predicted by ambipolar expansion, exceeding Ei ≈ 7 kTe in some cases. RF power up to 500 W at 13.56 MHz is supplied to a half-turn, double-helix antenna in the presence of a nozzle magnetic field, adjustable up to 1 kG. A retarding potential analyzer (RPA) measures the ion energy distribution function (IEDF) and a swept emissive probe measures the plasma potential. Single and double probes measure the electron density and temperature. Two distinct mode hops, the capacitive-inductive (E-H) and inductive-helicon (H-W) transitions, are identified by jumps in density as RF power is increased. In the capacitive (E) mode, large fluctuations of the plasma potential (Vp-p≳140V, Vp-p/Vp¯≈150%) exist at the RF frequency and its harmonics. The more mobile electrons can easily respond to RF-timescale gradients in the plasma potential whereas the inertially constrained ions cannot, leading to an initial flux imbalance and formation of a self-bias voltage between the source and expansion chambers. In the capacitive mode, the ion acceleration is not well described by an ambipolar relation, while in the inductive and helicon modes the ion acceleration more closely follows an ambipolar relation. The scaling of the potential gradient with the argon flow rate and RF power are investigated, with the largest potential gradients observed for the lowest flow rates in the capacitive mode. The magnitude of the self-bias voltage agrees with that predicted for RF self-bias at a wall. Rapid fluctuations in the plasma potential result in a time-dependent axial electron flux that acts to “neutralize” the accelerated ion population, resulting in a zero net time-averaged current through the acceleration region when an insulating upstream boundary condition is enforced. Grounding the upstream endplate increases the self-bias voltage compared to a floating endplate.
Enhancing hole mobility in III-V semiconductors
Authors: Nainani Aneesh , Bennett Brian R. , Brad Boos J. , Ancona Mario G. , Saraswat Krishna C.
Published: May 2012

Transistors based on III-V semiconductor materials have been used for a variety of analog and high frequency applications driven by the high electron mobilities in III-V materials. On the other hand, the hole mobility in III-V materials has always lagged compared to group-IV semiconductors such as germanium. In this paper, we explore the use of strain and heterostructure design guided by bandstructure modeling to enhance the hole mobility in III-V materials. Parameters such as strain, valence band offset, effective masses, and splitting between the light and heavy hole bands that are important for optimizing hole transport are measured quantitatively using various experimental techniques. A peak Hall mobility for the holes of 960 cm2/Vs is demonstrated and the high hole mobility is maintained even at high sheet charge.
Enhancement in magnetic field sensitivity and reduction in equivalent magnetic noise by magnetoelectric laminate stacks
Authors: Li Menghui , Gao Junqi , Wang Yaojin , Gray David , Li Jiefang , Viehland D.
Published: May 2012

We have investigated the equivalent magnetic noise and magnetic field sensitivity for a magnetoelectric (ME) sensor unit of N numbers of ME laminates stacked together. Our results show with increasing N that the modeled and measured equivalent magnetic noises decreased by a factor of N and that the magnetic field sensitivities increased by N. For Metglas/Pb(Mg1/3,Nb2/3)O3-PbTiO3 laminates, the equivalent magnetic noise decreased and the magnetic field sensitivity increased by a factors of 2.1 and 2.3, respectively, for N = 4 relative to that for N = 1.
Formation of iron nitride thin films with Al and Ti additives
Authors: Gupta Rachana , Tayal Akhil , Amir S. M. , Gupta Mukul , Gupta Ajay , Horisberger M. , Stahn J.
Published: May 2012

In this work, we investigate the process of iron nitride (Fe-N) phase formation using 2 at. % Al or 2 at. % Ti as additives. The samples were prepared with a magnetron sputtering technique using different amount of nitrogen during the deposition process. The nitrogen partial pressure (RN2) was varied between 0% and 50% (rest argon) and the targets of pure Fe, [Fe + Ti] and [Fe + Al] were sputtered. The addition of small amount of Ti or Al results in improved soft-magnetic properties when sputtered using RN2≤ 10%. It was found that the thermal stability of soft-magnetic phase increases considerably when Al or Ti additives were used. When RN2 is increased to 50% non-magnetic Fe-N phases are formed. We found that iron mononitride (FeN) phases (N at. % ∼50) are formed with Al or Ti addition at RN2 = 50% whereas in the absence of such addition ϵ-Fe3-xN phases (N at. % ∼30) are formed. It was found that the overall nitrogen content can be increased significantly with Al or Ti additions. On the basis of obtained result, we propose a mechanism describing formation of Fe-N phases with Al and Ti additives.
Characterization of low temperature InGaAs-InAlAs semiconductor photo mixers at 1.55 μm wavelength illumination for terahertz generation and detection
Authors: Kostakis I. , Saeedkia D. , Missous M.
Published: May 2012

The structural, optical, and electrical properties of undoped and Be doped lattice matched InGaAs–InAlAs multiple quantum well structures, grown by molecular beam epitaxy (MBE) at low (∼250 °C) and normal (∼450 °C) growth temperatures, have been investigated in detail. Double crystal x-ray diffraction studies showed that the thickness of the low temperature (LT) grown quantum well (QW) layers decrease with post growth annealing, while the normal temperature grown QW layers retain their initial thickness. This behaviour is associated with the As precipitation and is the first evidence and report of a direct observation of this phenomenon in LT InGaAs–InAlAs QWs. Room temperature photoluminescence (PL) measurements revealed signs of optical activities in the LT undoped and lower doped structures suggesting that the native defects in LT InGaAs–InAlAs are not sufficient to completely inhibit band to band recombination. Optimal combination of doping, including a modulation doped structure, and post growth annealing temperature results in materials with sub-picoseconds lifetimes (<200 fs) and a resistivity of ∼107 Ω/sq, which is a high value for this material. The results imply the possibility of fabricating efficient photo-mixers operating at the telecom wavelength of 1.55 μm for THz imaging or other optoelectronic applications.
Density functional theory analysis of dopants in cupric oxide
Authors: Peng Yuan , Zhang Zhen , Viet Pham Thien , Zhao Yang , Wu Ping , Wang Junling
Published: May 2012

Fabrication of both p-type and n-type cupric oxide is of great importance for the large-scale photovoltaic application. Our first-principles density functional theory calculations confirm that copper vacancy can lead to good p-type conduction in CuO, while oxygen vacancy is a deep donor. To investigate electrical conduction in CuO, we calculated the defect formation energies as well as their ionization levels for several potential acceptors and donors. Our results indicate that Li and Na are shallow acceptors and their formation energies are low in oxygen rich environment. However, it is also found that n-type conduction is relatively hard to induce by donors, as most donors have deep transition levels in the band gap and/or high formation energies. Hf and Zr have the shallowest ionization levels of around 0.2 eV below the conduction band minimum, but their formation energies are relatively high, limiting the electrical conductivity of doped CuO. Our study explains why it is hard to obtain n-type conduction in CuO.
On accurate capacitance characterization of organic photovoltaic cells
Authors: Carr J. A. , Chaudhary S.
Published: May 2012

Capacitance measurements, widely used to characterize numerous semiconductor properties, have been recently adopted to characterize organic photovoltaic (OPV) devices. It is known that certain challenges are associated with capacitance measurements. Of upmost importance is the employment of a proper measurement model (series or parallel). Owing to larger capacitive impedances and low series resistances, the parallel model is typically employed in inorganics. However, we find that for characteristically thinner organic films, a hybrid model should be used. We highlight the inconsistencies in OPV literature due to indiscriminate usage of parallel model and show how proper model selection can rectify any artifacts.
Characteristics of indium incorporation in InGaN/GaN multiple quantum wells grown on a-plane and c-plane GaN
Authors: Song Keun-Man , Kim Jong-Min , Kang Bong-Kyun , Yoon Dae-Ho , Kang S. , Lee Sang-Won , Lee Sung-Nam
Published: May 2012

We investigated the characteristics of InGaN-based multiple quantum wells (MQWs) grown on a-plane and c-plane GaN templates, which were grown by metal-organic chemical vapor deposition onto r-plane and c-plane sapphire, respectively. A shorter photoluminescence peak wavelength and peaks with larger full-width at half-maximum are observed for MQWs grown on an a-plane GaN template compared with a c-plane GaN template, despite the same growth conditions used. A growth model based on the atomic configuration of the growing surfaces is proposed to explain the difference in optical emission properties and indium incorporation between a-plane and c-plane MQWs.
Inverted bi-prism phononic crystals for one-sided elastic wave transmission applications
Authors: Hwan Oh Joo , Woong Kim Hoe , Sik Ma Pyung , Min Seung Hong , Young Kim Yoon
Published: May 2012

This work presents the realization of one-sided wave transmission by using a specially engineered phononic crystal structure. It is an inverted bi-prism phononic crystal engineered for a horizontally incident elastic wave at a specific frequency. The incident wave along one direction is shown to be totally reflected by the bi-prism while the incident wave along the opposite direction transmitted through it with refraction, also evident from experiments. An application of the proposed bi-prism may be found in thin elastic strips.