bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparison on Physical, Structural, and Photocatalytical Properties of TiO2 Nanopowders Produced Using Sol‐Gel and Flame Spray Pyrolysis
Authors: Erol Mustafa , Sancakoglu Orkut , Yurddaskal Metin , Yildirim Serdar , Çelik Erdal
Published: April 2013

In this study, nanoscale photocatalyst TiO2 powders were synthesized via sol‐gel and flame spray pyrolysis (FSP). Phase structures and ratios were analyzed by X‐ray diffractometer (XRD). Size, specific surface area, and morphologies were determined using particle size analyzer, Brunauer‐Emmett‐Teller theory, and scanning electron microscope, respectively. Anatase phase with some rutile together was obtained in XRD analysis. The degradation rates of aqueous methylene blue (MB) by TiO2 nanopowders were calculated using UV–vis spectrophotometer. It was found that MB decomposition was successfully achieved with significantly high efficiencies for both sol‐gel and FSP‐derived powders with small differences.
Assessing salivary osmolality as a caries risk indicator in cerebral palsy children
Authors: Santos Maria Teresa Botti Rodrigues , Ferreira Maria Cristina Duarte , Mendes Fausto M. , de Oliveira Guaré Renata
Published: April 2013

Background

Salivary osmolality reflects the hydration status of individuals with cerebral palsy (CP) necessary for an adequate unstimulated salivary flow rate.

Aim

To investigate whether salivary osmolality could serve as a potential indicator of caries risk in children with spastic CP by displaying a stronger association with caries occurrence than salivary flow rate.

Design

The convenience sample consisted of 65 children with CP aged 6–13 years old. Unstimulated whole saliva was collected using cotton roll, and salivary osmolality was measured using a freezing point depression osmometer. The children's oral motor performance was evaluated during the feeding process using the Oral Motor Assessment Scale. Caries occurrence was also evaluated according the World Health Organization criteria.

Results

Motor skills were significantly associated with caries experience. Regarding the salivary parameters, osmolality presented a stronger association with caries experience than did the salivary flow rate. Children with worse oral motor performance presented a higher rate of caries occurrence.

Conclusion

Osmolality exhibited a stronger association with caries occurrence than did salivary flow rate. This parameter, therefore, could be a potential caries risk indicator for spastic cerebral palsy children.
Margins, Liquidity, and the Cost of Hedging
Authors: Mello Antonio S. , Parsons John E.
Published: April 2013

Recent financial reforms, such as the Dodd‐Frank Act in the U.S. and the European Market Infrastructure Regulation, encourage greater use of clearing and therefore increased margining of derivative trades. They also impose margining requirements on noncleared derivative trades. Such requirements have sparked a debate about whether a margin mandate increases the cost of hedging by nonfinancial corporations—the so‐called end‐users of derivatives.

The authors argue that it does not. They show that a nonmargined derivative is equivalent to a package of (1) a margined derivative and (2) a contingent line of credit. The main effect of a margin mandate is to require that this package be marketed as two distinct products. But it does not change the total financing or capital required to hedge. Nor does it raise the cost to banks or other dealers of offering the package, at least not directly.

Nevertheless, there may be indirect effects if, for example, the clearing mandate succeeds in lowering total counterparty exposures and therefore systemic risk. Although the authors do not explore these effects, they do offer one explanation for the popularity of over‐the‐counter, and thus noncleared, derivatives: accounting rules and bank regulations that treat the implicit lines‐of‐credit embedded in nonmargined derivatives differently from explicit lines of credit used to fund margins.
The Effects of Cash, Debt, and Insiders on Open Market Share Repurchases
Authors: Feng Liang , Pukthuanthong Kuntara , Thiengtham Dolruedee , Turtle H. J. , Walker Thomas J.
Published: April 2013

The findings of the authors' recent study suggest, on balance, that stock repurchases function much like tax‐efficient special dividends, increasing when free cash flow is large and when debt levels are low, but not replacing regularly scheduled dividends. Repurchasing companies experience median event returns of about 2% around the repurchase announcements, with a related mean effect of roughly 3%. Companies with greater free cash flow and less debt are more likely than otherwise comparable companies to repurchase their shares. Furthermore, repurchasing companies that exhibit substandard preannouncement stock price returns and seek to buy back higher percentages of shares tend to elicit more positive stock price reactions.

At the same time, the study provides some evidence that corporate managers attempt to use their inside information to profit from buybacks. For example, managing insiders in repurchasing firms decrease their selling activity and increase their buying activity two weeks before repurchase announcements to a greater extent than non‐managing insiders. But perhaps the most remarkable finding from this part of the study is how little insiders as a group seem to profit from their short‐term trading behavior—a finding that suggests that the market appears to anticipate much of this behavior.
Transparency, Value Creation, and Financial Crises
Authors: Silva Ana C. , Chavez Gonzalo A. , Lopez‐Lubian Francisco J.
Published: April 2013

This article reports the findings of the authors' recent study of the impact of the level of corporate transparency on shareholder value creation during periods of financial crisis. Their sample consists of the companies comprising Spain's IBEX 35 stock index during the ten‐year period 2000–2010. The study uses three different measures of earnings management (EM) as inverse indicators of the quality of disclosure and carries out fixed effects regressions that adjust for firm and industry characteristics, two periods of financial crises, and the passage of time. The main findings of the study are that (1) companies with lower disclosure quality have generated less value for their shareholders over long time periods and that (2) the shareholders of companies that were more aggressive in managing their earnings experienced greater wealth destruction during the two financial crises of the last decade.

Given the still unfolding impact of the recent global financial crisis, as reflected in the current debt crisis in Western European countries, the authors' study reinforces the importance of the current debate over the benefits and costs of increasing the regulation of financial markets, especially in the areas of transparency and disclosure requirements.
The first confirmed cases of full albinism in rajid species
Authors: Ball R. E. , Jones C. S. , Lynghammar A. , Noble L. R. , Griffiths A. M.
Published: April 2013

Three albino skate specimens (Rajidae) were captured from the North Sea and English Channel between 2008 and 2011. UsingDNAbarcoding (COIgene) and morphometric analyses, species were identified as a spotted rayRaja montagui, a blonde rayRaja brachyuraand a thornback rayRaja clavata. This finding represents the first record of full albinism (a lack of skin and retinal pigmentation) in rajid species.
Low‐Dose Dexamethasone Treatment Promotes the Pro‐Survival Signalling Pathway in the Adult Rat Prefrontal Cortex
Authors: Drakulić D. , Veličković N. , Stanojlović M. , Grković I. , Mitrović N. , Lavrnja I. , Horvat A.
Published: April 2013

Synthetic glucocorticoid dexamethasone (DEX), a highly potent anti‐inflammatory and immunosuppressive agent, is widely used in the treatment of brain cancer, as well as for inflammatory and autoimmune diseases. The present study aimed to determine whether low‐dose subchronic DEX treatment (100 μg/kg for eight consecutive days) exerts long‐term effects on apoptosis in the adult rat prefrontal cortex (PFC) by examining the expression of cell death‐promoting molecules [poly(ADP‐ribose) polymerase (PARP), p53, procaspase 3, cleaved caspase 3, Bax] and cell‐survival molecules (AKT, Bcl‐2). The results obtained revealed that body, thymus and adrenal gland weights, as well corticosterone levels, in the serum and PFC were reduced 1 day after the last DEX injection. In the PFC, DEX caused activation of AKT, augmentation of pro‐survival Bcl‐2 protein and an enhanced Bcl‐2/Bax protein ratio, as well Bcl‐2 translocation to the mitochondria. An unaltered profile with respect to the protein expression of apoptotic molecules PARP, procaspase 3 and Bax was detected, whereas p53 protein was decreased. Reverse transcriptase ‐polymerase chain reaction analysis showed a decrease of p53 mRNA levels and no significant difference in Bcl‐2 and Bax mRNA expression in DEX‐treated rats. Finally, a DNA fragmentation assay and Fluoro‐Jade staining demonstrated no considerable changes in apoptosis in the rat PFC. Our findings support the concept that low‐dose DEX creates a hypocorticoid state in the brain and also indicate that subchronic DEX treatment activates the pro‐survival signalling pathway but does not change apoptotic markers in the rat PFC. This mechanism might be relevant for the DEX‐induced apoptosis resistance observed during and after chemotherapy of patients with brain tumours.
Differences in the effect of maternal smoking during pregnancy for childhood overweight before and after 5 years of age
Authors: Suzuki Kohta , Sato Miri , Ando Daisuke , Kondo Naoki , Yamagata Zentaro
Published: April 2013

Aim

This study aimed to clarify the association between maternal smoking during pregnancy and childhood overweight during different periods using two cohort studies from the same population: the birth cohort (the 1st cohort) and the non‐overweight children at 5 years of age cohort (the 2nd cohort) by sex.

Material and Methods

The study population comprised children born between 1 April 1991 and 31 March 1999 in Koshu City, Yamanashi Prefecture, Japan, and their mothers. The dependent variables were diagnosis of overweight in each cohort. The primary independent variable was maternal smoking during pregnancy. Multiple logistic regression models were applied for these statistical analyses.

Results

Mothers who answered the questionnaire during early pregnancy gave birth to a total of 1644 babies during the study period. The 1st cohort consisted of these babies and were followed until 5 years of age. The 2nd cohort consisted of 1131 children who were diagnosed as normal weight at 5 years of age and followed until 9–10 years of age. There was an association between maternal smoking during pregnancy and overweight only in boys in the 1st cohort analysis (adjusted odds ratio, 4.5; 95% confidence interval, 2.0–10.2).

Conclusions

These results suggest that the effects of maternal smoking during pregnancy on childhood overweight tend to appear before 5 years of age, especially in boys. It is necessary for children whose mother smoked during pregnancy, especially in boys, to be careful with their diet and physical activity in order to prevent childhood obesity.
Complications Associated with Retained Foreign Bodies from Infected Penile Implants: Proposal for the Use of an Implant-Specific Checklist at the Time of Device Removal
Authors: Kava Bruce R. , Burdick-Wil Joshua
Published: April 2013

Introduction

Infection of a penile prosthesis requires that all device hardware and associated foreign materials are removed, irrespective of whether a salvage procedure will be performed. Failure to remove all foreign bodies from the operative field may result in persistent infection, necessitating surgical intervention.

Aim

To review our experience with complications arising from retained foreign bodies following removal of an infected penile prosthesis. We highlight the clinical features that should raise suspicion of retained device-associated materials, and also the role of imaging in evaluating these patients. Finally, a rational approach to prevent these occurrences is proposed with the implementation of an implant-specific checklist.

Methods

Medical records and imaging studies of patients presenting to our center with retained foreign bodies following removal of an infected penile prosthesis were reviewed.

Main Outcome Measures

Clinical and radiologic details of each of these cases were abstracted, including patient demographics, presenting symptoms, characteristics of retained materials, bacterial cultures, treatment, and follow-up.

Results

Presenting symptoms included: (i) persistent and relapsing drainage from cutaneous fistulae; (ii) cellulitis overlying an infected reservoir; (iii) persistent penile pain; and (iv) an asymptomatic individual requesting elective placement of a second implant. Infected foreign materials retrieved included: two rear-tip extenders, a tubing connector, two infected reservoirs, and nonabsorbable mesh. Preoperative computerized tomography scan confirmed the presence and the location of all of these materials. Using this data, we propose using an implant-specific checklist to insure removal of all device-related foreign bodies when explanting an infected penile prosthesis.

Conclusions

A number of adverse sequelae may result from inadvertently leaving behind device-related materials when an infected implant is removed. Ultimately it is the responsibility of the surgeon removing an infected implant to insure that all device components and associated materials are removed. We believe that implementing a two-step implant-specific checklist is a rational prevention strategy.
Studies of the Thermal and Haline Influences on Growth and Survival of Litopenaeus vannamei and Litopenaeus setiferus
Authors: Perez‐Velazquez Martin , González‐Félix Mayra L. , Davis D. A. , Roy Luke A. , Zhu Xuezhi
Published: April 2013

A series of experiments were conducted to examine the effects of salinity (1–48 g/L) on the biological performance, as evaluated by growth and survival, of the Pacific white shrimp, Litopenaeus vannamei, and the Atlantic white shrimp, Litopenaeus setiferus, reared at temperatures of 20, 24 or 28 C. Poor growth and survival of L. vannamei was observed after 21–28 d of culture at low salinity (2 and 4 g/L) at 20 C. Raising salinity to 8 and up to 32 g/L significantly increased survival at this temperature, indicating that avoiding low temperatures is critical for survival of this species when reared at low salinity. A major improvement in the growth rate of L. vannamei was observed at 24 C, but it still was sub‐optimal compared to growth observed at 28 C. Irrespective of salinity, high survival rates were observed at both 24 and 28 C, but variable growth rates were recorded. Contrary to L. vannamei, the Atlantic white shrimp, L. setiferus, which was reared for 28 d at 24 C only, had better growth performance at 8 g/L compared to 2, 16 and 32 g/L. Under equal experimental conditions, L. setiferus had considerably lower weight gain and survival than L. vannamei.
Ethicists’ and Nonethicists’ Responsiveness to Student E‐mails: Relationships Among Expressed Normative Attitude, Self‐Described Behavior, and Empirically Observed Behavior
Authors: Rust Joshua , Schwitzgebel Eric
Published: April 2013

Do professional ethicists behave any morally better than other professors do? Do they show any greater consistency between their normative attitudes and their behavior? In response to a survey question, a large majority of professors (83 percent of ethicists, 83 percent of nonethicist philosophers, and 85 percent of nonphilosophers) expressed the view that “not consistently responding to student e‐mails” is morally bad. A similarly large majority of professors claimed to respond to at least 95 percent of student e‐mails. These professors, and others, were sent three e‐mails designed to look like queries from students. Ethicists’ e‐mail response rates were not significantly different from the other two groups’. Expressed normative view correlated with self‐estimated rate of e‐mail responsiveness, especially among the ethicists. Empirically measured e‐mail responsiveness, however, was at best weakly correlated with self‐estimated e‐mail responsiveness; and professors’ expressed normative attitude was not significantly correlated with empirically measured e‐mail responsiveness for any of the three groups.
Sonata Form and the Problem of Second‐Theme Beginnings
Authors: Richards Mark
Published: April 2013

Although the second theme (ST) group is a crucial landmark in Classical sonata form, where it is usually articulated with great clarity, in many instances its beginning cannot be so easily discerned, especially in Beethoven. The problem is that no matter how powerful a single rule may be, none by itself can identify all those locations which may be considered an ST beginning. This article therefore proposes that an ST beginning depends on the presence of several musical signals, each of which contributes to its expression. These include: (1) tonic harmony of the new key, (2) beginning and end functions in the manner of one of Caplin's theme types, (3) preparation by a phrase‐ending chord, (4) the textural gap of Hepokoski and Darcy's medial caesura (MC) and, at the ST beginning itself, (5) a change in texture, (6) a change in dynamic and (7) characteristic melodic material. A sonata deformation in any of the first three signals sets off a teleologicalST process, which attempts to compensate for the deficiencies of the signal. By contrast, the deformation of an absent MC gap can produce anintegrated STor, if combined with an absent preparatory chord, aspontaneous ST.
Deconstructing Ixodes ricinus: a partial matrix model allowing mapping of tick development, mortality and activity rates
Authors: ESTRADA‐PEÑA A. , ESTRADA‐SÁNCHEZ D.
Published: April 2013

A stage‐structured Leslie matrix model of a partial, discrete population of Ixodes ricinus (Linnaeus) (Ixodida: Ixodidae) ticks was developed to elucidate the impact of climate trends on the distribution and phenology of this species in the western Palaearctic. The model calculates development and mortality rates for each instar and evaluates recruitment rates based on the development of the tick population. The model captures the changes in development and mortality rates, providing a coherent index of performance correlated with the tick's geographic range. Maximum development rates are recorded for latitudes south of 36 °N and are spatially correlated with sites of maximum temperature, highest saturation deficit and highest mortality. The maximum available developmental time (the total annual time during which temperature allows development) for I. ricinus in the western Palaearctic is < 45% of the total year. North of 60 °N, available developmental time decreases sharply to only 15% of the year. The latitudinal boundary at which survival rates sharply drop is 43–46 °N, clearly delimiting the classically recognized extent of the main tick populations. The pattern of activity for larval–nymphal synchrony shows a clear west–east pattern. The model demonstrates the impact of climate according to tick stage and geographic location, and provides a practical framework for testing how the tick's lifecycle is affected by climate change.
Gene loss, thermogenesis, and the origin of birds
Authors: Newman Stuart A. , Mezentseva Nadezhda V. , Badyaev Alexander V.
Published: April 2013

Compared to related taxa, birds have exceptionally enlarged and diversified skeletal muscles, features that are closely associated with skeletal diversification and are commonly explained by a diversity of avian ecological niches and locomotion types. The thermogenic muscle hypothesis (TMH) for the origin of birds proposes that such muscle hyperplasia and the associated skeletal innovations are instead the consequence of the avian clade originating from an ancestral population that underwent several successive episodes of loss of genes associated with thermogenesis, myogenesis, and skeletogenesis. Direct bird ancestors met this challenge with a combination of behavioral strategies (e.g., brooding of nestlings) and acquisition of a variety of adaptations for enhanced nonshivering thermogenesis in skeletal muscle. The latter include specific biochemical alterations promoting muscle heat generation and dramatic expansion of thigh and breast muscle mass. The TMH proposes that such muscle hyperplasia facilitated bipedality, freeing upper limbs for new functions (e.g., flight, swimming), and, by altering the mechanical environment of embryonic development, generated skeletal novelties, sometimes abruptly, that became distinctive features of the avian body plan.
Efficient development of Haynaldia villosa chromosome 6VS‐specific DNA markers using a CISP‐IS strategy
Authors: He Huagang , Zhu Shanying , Sun Weihong , Gao Derong , Bie Tongde
Published: April 2013

Development of effective molecular markers linked to Pm21 deriving from Haynaldia villosa is critical for wheat breeding of powdery mildew resistance. In this study, we designed 12 pairs of conserved‐intron scanning primers (CISPs), using intron‐containing conserved genes located on the short arm of Brachypodium distachyon chromosome 3 (3BdS) aligned with cDNA or expressed sequence tags (ESTs) of Triticeae crops. Of 12 CISP primer pairs, 11 amplified DNA both in H. villosa and in wheat, and four displayed H. villosa chromosome 6VS‐specific polymorphisms. Six non‐polymorphic DNAs were further sequenced for designing internal primers, and five additional 6VS‐specific markers were obtained. Of the total nine 6VS‐specific co‐dominant markers, six could effectively trace Pm21 in F2 population derived from the hybrid between the T6AL.6VS line and ‘Yangmai 158’. This study demonstrated that Brachypodium genomic information could be powerfully utilized to develop molecular markers in H. villosa or other Triticeae species.
Decision Making for Group Risk Reduction: Dealing with Epistemic Uncertainty
Authors: Bedford Tim
Published: April 2013

Group risk is usually represented by FN curves showing the frequency of different accident sizes for a given activity. Many governments regulate group risk through FN criterion lines, which define the tolerable location of an FN curve. However, to compare different risk reduction alternatives, one must be able to rank FN curves. The two main problems in doing this are that the FN curve contains multiple frequencies, and that there are usually large epistemic uncertainties about the curve. Since the mid 1970s, a number of authors have used the concept of “disutility” to summarize FN curves in which a family of disutility functions was defined with a single parameter controlling the degree of “risk aversion.” Here, we show it to be risk neutral, disaster averse, and insensitive to epistemic uncertainty on accident frequencies. A new approach is outlined that has a number of attractive properties. The formulation allows us to distinguish between risk aversion and disaster aversion, two concepts that have been confused in the literature until now. A two‐parameter family of disutilities generalizing the previous approach is defined, where one parameter controls risk aversion and the other disaster aversion. The family is sensitive to epistemic uncertainties. Such disutilities may, for example, be used to compare the impact of system design changes on group risks, or might form the basis for valuing reductions in group risk in a cost‐benefit analysis.
Vibronic fine structure in high-resolution x-ray absorption spectra from ion-bombarded boron nitride nanotubes
Authors: Petravic Mladen , Peter Robert , Varasanec Marijana , Li Lu Hua , Chen Ying , Cowie Bruce C. C.
Published: April 2013

The authors have applied high-resolution near-edge x-ray absorption fine structure measurements around the nitrogen K-edge to study the effects of ion-bombardment on near-surface properties of boron nitride nanotubes. A notable difference has been observed between surface sensitive partial electron yield (PEY) and bulk sensitive total electron yield (TEY) fine-structure measurements. The authors assign the PEY fine structure to the coupling of excited molecular vibrational modes to electronic transitions in NO molecules trapped just below the surface. Oxidation resistance of the boron nitride nanotubes is significantly reduced by low energy ion bombardment, as broken B-N bonds are replaced by N-O bonds involving oxygen present in the surface region. In contrast to the PEY spectra, the bulk sensitive TEY measurements on as-grown samples do not exhibit any fine structure while the ion-bombarded samples show a clear vibronic signature of molecular nitrogen.
Electron-injecting properties of Rb2CO3-doped Alq3 thin films in organic light-emitting diodes
Authors: Park Jin Woo , Lim Jong Tae , Oh Jong Sik , Kim Sung Hee , Viet Phuong Pham , Jhon Myung S. , Yeom Geun Young
Published: April 2013

Rubidium carbonate (Rb2CO3)-doped tris(8-quinolinolato)aluminum (III) (Alq3) thin films have been investigated as electron-injecting materials for organic light-emitting diodes (OLEDs). Electron-only devices consisting of glass/tin-doped indium oxide (ITO)/Rb2CO3-doped Alq3 (10 nm)/aluminum (Al) showed an electron-ohmic contact property between the electrode and the organic layer at the doping concentration of 10% and higher. The electron-injecting ability of these contacts was largely enhanced by the n-doping effect of Rb2CO3 into the Alq3 layer. The ultraviolet photoemission spectra revealed that when the doping concentration was increased, the n-doping effect reduced the carrier-injecting barrier height by lowering the work function at the Rb2CO3-doped Alq3 interfaces. Also, the x-ray photoemission spectra showed that as the doping concentration was increased at the interfaces, Alq3 molecules decomposed in a chemical reaction with Rb2CO3. The OLED device, having the glass/ITO/molybdenum oxide (MoOx, 25%)-doped N,N′-diphenyl-N,N′-bis(1-naphthyl)-1,1′-biphenyl-4,4′-diamine (NPB, 5 nm)/NPB (63 nm)/Alq3 (32 nm)/Rb2CO3-doped Alq3 (10%, 10 nm)/Al (100 nm) structure, showed the best performance at the optimal doping concentration of Rb2CO3-doped Alq3, both the maximum luminance of 114 400 cd/m2 at the bias voltage of 9.8 V and the power efficiency of 2.7 lm/W at the luminance of 1000 cd/m2 were obtained.
Preparation of a clean Ge(001) surface using oxygen plasma cleaning
Authors: Ponath Patrick , Posadas Agham B. , Hatch Richard C. , Demkov Alexander A.
Published: April 2013

The authors demonstrate a method to obtain a clean and smooth Ge (001) surface using oxygen plasma cleaning without sputtering or Ge regrowth. The preparation of the germanium surface consists of four cycles of ex situ wet etching using hydrochloric acid as the etchant and H2O2 as the oxidant. Subsequently, the sample is outgassed and exposed to an oxygen plasma for 30 min followed by thermal desorption of the newly formed oxide layer. Reflection high-energy electron diffraction shows a clear 2 × 1 reconstruction of the germanium surface. In situ x-ray photoelectron spectroscopy measurements confirm that the cleaned surface is free of carbon contamination and that no GeO2 remains. Angle-resolved photoemission spectra of the cleaned Ge show the peak associated with the Ge surface state indicating a very clean surface. Atomic force microscope images further indicate a smooth germanium surface with a mean surface roughness of approximately 3 Å after plasma cleaning.
Fabrication of 3D charged particle trap using through-silicon vias etched by deep reactive ion etching
Authors: Verma Ankita , Jennings Joshah , Johnson Ryan D. , Weber Marc H. , Lynn Kelvin G.
Published: April 2013

Positrons are charged antiparticles that annihilate upon contact with electrons or any form of matter. Two of the authors (Lynn and Weber) have proposed a new approach to store large numbers of charged particles such as positrons. The proposed structure consists of thousands of 0.1-mm-diameter holes etched through silicon wafers, which are then stacked axially to form cylindrical microtubes to store a large number of positrons. The authors used deep reactive ion etching on the wafers to create the through-holes with smooth and straight sidewalls. To produce the best possible etching results, they iteratively modified the etching parameters, including the chamber pressure, temperature, radio frequency power, inductively coupled plasma power, SF6/O2 gas flow, and O2 gas content. These iterations addressed the fabrication issues that were encountered, such as bowing, notching, undercutting, nonuniform etch rates across the wafer, and preferential etching along certain crystal planes. The trench widths were calibrated to match the etch rates between all the wafer features. The final results enabled the etching of through-wafer vias with straight sidewalls (89.9–90.1°), smooth surfaces, and high aspect ratios (≥5:1) with minimal defects. This paper describes the etching process used to produce these vias.
Weighted cross‐correlation based variational optical flow for gastric flow analysis in ultrasonic videos
Authors: Chen Chaojie , Wang Yuanyuan , Yu Jinhua , Zhou Zhuyu , Shen Li , Chen Yaqing
Published: April 2013

Purpose:

Estimating the fluid motion in ultrasonic videos is a crucial step in the analysis of duodenogastric reflux. Severe image noise and illumination changes in the pyloric region (the region of interest) challenge the accurate estimation of gastric flow. In this paper, the authors propose an illumination‐robust optical flow method based on the weighted cross‐correlation.

Methods:

Cross‐correlation was combined with the variational optical method framework as an illumination‐robust local feature identifier. In consideration of accuracy near edges, they constructed visual similarity weights according to the characteristics of ultrasonic images. A processing procedure containing coarse‐to‐fine step and refinement was designed to get the final results. They tested the proposed method on synthetic and real ultrasonic images and compared it with other three optical flow methods. For quantitative evaluation, two metrics of angular and amplitude error were used.

Results:

The synthetic results demonstrate that the proposed method performs better on ultrasonic images, with angular error of 4.1° and amplitude error of 3.3%. In qualitative comparison, the proposed method kept the motion field smooth in the homogeneous region while preserving edge information. When they used the results of the proposed method to judge the gastric flow direction, the automatic judgments agreed well with visual observation.

Conclusions:

The proposed method is a good tool for image velocimetry in ultrasonic images. It provides promising results to estimate the motion of gastric flow in ultrasonic videos.
Basilar-membrane interference patterns from multiple internal reflection of cochlear traveling waves
Authors: Shera Christopher A. , Cooper Nigel P.
Published: April 2013

At low stimulus levels, basilar-membrane (BM) mechanical transfer functions in sensitive cochleae manifest a quasiperiodic rippling pattern in both amplitude and phase. Analysis of the responses of active cochlear models suggests that the rippling is a mechanical interference pattern created by multiple internal reflection within the cochlea. In models, the interference arises when reverse-traveling waves responsible for stimulus-frequency otoacoustic emissions (SFOAEs) reflect off the stapes on their way to the ear canal, launching a secondary forward-traveling wave that combines with the primary wave produced by the stimulus. Frequency-dependent phase differences between the two waves then create the rippling pattern measurable on the BM. Measurements of BM ripples and SFOAEs in individual chinchilla ears demonstrate that the ripples are strongly correlated with the acoustic interference pattern measured in ear-canal pressure, consistent with a common origin involving the generation of SFOAEs. In BM responses to clicks, the ripples appear as temporal fine structure in the response envelope (multiple lobes, waxing and waning). Analysis of the ripple spacing and response phase gradients provides a test for the role of fast- and slow-wave modes of reverse energy propagation within the cochlea. The data indicate that SFOAE delays are consistent with reverse slow-wave propagation but much too long to be explained by fast waves.
Point vortex model for prediction of sound generated by a wing with flap interacting with a passing vortex
Authors: Manela A. , Huang L.
Published: April 2013

Acoustic signature of a rigid wing, equipped with a movable downstream flap and interacting with a line vortex, is studied in a two-dimensional low-Mach number flow. The flap is attached to the airfoil via a torsion spring, and the coupled fluid-structure interaction problem is analyzed using thin-airfoil methodology and application of the emended Brown and Michael equation. It is found that incident vortex passage above the airfoil excites flap motion at the system natural frequency, amplified above all other frequencies contained in the forcing vortex. Far-field radiation is analyzed using Powell-Howe analogy, yielding the leading order dipole-type signature of the system. It is shown that direct flap motion has a negligible effect on total sound radiation. The characteristic acoustic signature of the system is dominated by vortex sound, consisting of relatively strong leading and trailing edge interactions of the airfoil with the incident vortex, together with late-time wake sound resulting from induced flap motion. In comparison with the counterpart rigid (non-flapped) configuration, it is found that the flap may act as sound amplifier or absorber, depending on the value of flap-fluid natural frequency. The study complements existing analyses examining sound radiation in static- and detached-flap configurations.
Experimental investigation of the piano hammer-string interaction
Authors: Birkett Stephen
Published: April 2013

Experimental techniques for investigating the piano hammer-string interaction are described. It is argued that the accuracy, consistency, and scope of conclusions of previous studies can be compromised by limitations of the conventional methods relating to key inputs; physical distortion; numerical distortion, particularly when differentiation or integration of measured signals is used to derive primary response variables; contact identification; and synchronization issues. These problems are discussed, and experimental methods that have been devised to avoid them are described and illustrated by detailed results from a study of the hammer-string interaction in a vertical piano. High resolution displacements are obtained directly by non-contact high-speed imaging and quantitative motion tracking. The attention focused on achieving very accurate and consistent temporal and spatial alignment, including the objective procedure used for contact identification, allows meaningful comparisons of responses from separate tests. String motion at the strike point and on each side of it, as well as hammer motion, is obtained for eight dynamic levels from 1.06 to 2.98 m/s impact velocity. Detailed observations of the force-compression behavior of the hammer interacting with real strings are presented. The direct effects of hammer shank deflection and agraffe string pulses on the interaction are also highlighted.
Transient ultrasound propagation in porous media using Biot theory and fractional calculus: Application to human cancellous bone
Authors: Fellah M. , Fellah Z. E. A. , Mitri F. G. , Ogam E. , Depollier C.
Published: April 2013

A temporal model based on the Biot theory is developed to describe the transient ultrasonic propagation in porous media with elastic structure, in which the viscous exchange between fluid and structure are described by fractional derivatives. The fast and slow waves obey a fractional wave equation in the time domain. The solution of Biot's equations in time depends on the Green functions of each of the waves (fast and slow), and their fractional derivatives. The reflection and transmission operators for a slab of porous materials are derived in the time domain, using calculations in the Laplace domain. Their analytical expressions, depend on Green's function of fast and slow waves. Experimental results for slow and fast waves transmitted through human cancellous bone samples are given and compared with theoretical predictions.
Effect of mismatched place-of-stimulation on the salience of binaural cues in conditions that simulate bilateral cochlear-implant listening
Authors: Goupell Matthew J. , Stoelb Corey , Kan Alan , Litovsky Ruth Y.
Published: April 2013

Although bilateral cochlear implantation has the potential to improve sound localization and speech understanding in noise, obstacles exist in presenting maximally useful binaural information to bilateral cochlear-implant (CI) users. One obstacle is that electrode arrays may differ in cochlear position by several millimeters, thereby stimulating different neural populations. Effects of interaural frequency mismatch on binaural processing were studied in normal-hearing (NH) listeners using band-limited pulse trains, thereby avoiding confounding factors that may occur in CI users. In experiment 1, binaural image fusion was measured to capture perceptual number, location, and compactness. Subjects heard a single, compact image on 73% of the trials. In experiment 2, intracranial image location was measured for different interaural time differences (ITDs) and interaural level differences (ILDs). For larger mismatch, locations perceptually shifted towards the ear with the higher carrier frequency. In experiment 3, ITD and ILD just-noticeable differences (JNDs) were measured. JNDs increased with decreasing bandwidth and increasing mismatch, but were always measurable up to 3 mm of mismatch. If binaural-hearing mechanisms are similar between NH and CI subjects, these results may explain reduced sensitivity of ITDs and ILDs in CI users. Large mismatches may lead to distorted spatial maps and reduced binaural image fusion.
Room acoustics analysis using circular arrays: An experimental study based on sound field plane-wave decomposition
Authors: Torres Ana M. , Lopez Jose J. , Pueo Basilio , Cobos Maximo
Published: April 2013

Plane-wave decomposition (PWD) methods using microphone arrays have been shown to be a very useful tool within the applied acoustics community for their multiple applications in room acoustics analysis and synthesis. While many theoretical aspects of PWD have been previously addressed in the literature, the practical advantages of the PWD method to assess the acoustic behavior of real rooms have been barely explored so far. In this paper, the PWD method is employed to analyze the sound field inside a selected set of real rooms having a well-defined purpose. To this end, a circular microphone array is used to capture and process a number of impulse responses at different spatial positions, providing angle-dependent data for both direct and reflected wavefronts. The detection of reflected plane waves is performed by means of image processing techniques applied over the raw array response data and over the PWD data, showing the usefulness of image-processing-based methods for room acoustics analysis.
Spin current-induced by a sound wave
Authors: Lyapilin Igor. I.
Published: April 2013

The interaction of conduction electrons with a longitudinal sound wave propagating in a crystal in a constant magnetic field is investigated. It is shown that the transverse spin current arises when the longitudinal sound wave propagation through the system. The average power absorbed by the spin subsystem of the conduction electrons and the spin-Hall conductivity have a resonant character.
Speech intelligibility among modulated and spatially distributed noise sources
Authors: Culling John F. , Mansell Elizabeth R.
Published: April 2013

At a cocktail party, listeners are faced with multiple, spatially distributed interfering voices. The dominant interfering voice may change from moment to moment and, consequently, change in spatial location. The ability of the binaural system to deal with such a dynamic scene has not been systematically analyzed. Spatial release from masking (SRM) was measured in simple spatial scenes, simulated over headphones with a frontal speech source. For a single noise at 105°, SRM was reduced if that noise modulated (10 Hz square wave, 50% duty cycle, 20 dB modulation depth), but, for two noises in symmetrical locations, SRM increased if the noises were modulated in alternation, suggesting that the binaural system can “switch” between exploiting different spatial configurations. Experiment 2 assessed the contributions of interaural time and level differences as a function of modulation rate (1–20 Hz). Scenes were created using the original head-related impulse responses and ones that had been manipulated to isolate each cue. SRM decreased steeply with modulation rate. The combined effects of interaural time and level differences were consistent with additive contributions. The results indicate that binaural sluggishness limits the contribution of binaural switching to speech understanding at a cocktail party.
Translational Repression and eIF4A2 Activity Are Critical for MicroRNA-Mediated Gene Regulation
Authors: Meijer H. A. , Kong Y. W. , Lu W. T. , Wilczynska A. , Spriggs R. V. , Robinson S. W. , Godfrey J. D. , Willis A. E. , Bushell M.
Published: April 2013

MicroRNA Mechanism

MicroRNAs are small noncoding RNAs that regulate gene expression by binding complementary target messenger RNAs (mRNAs) and repressing their expression through repression of protein translation and mRNA degradation.

Meijer
et al.

(p.
82
) show that in a HeLa cell system mRNA degradation is a consequence of translational inhibition via the initiation factor eIF4A2.
Great Refresher or First Course
Naked Statistics
Stripping the Dread from the Data

by Charles Wheelan

Norton, New York, 2013. 302 pp. $26.95, C$28.50. ISBN 9780393071955.
Authors: Lamb Evelyn J.
Published: April 2013

To help readers evaluate claims in our data-saturated world, Wheelan's survey stresses what statistical concepts mean for members of the public.
Climate Change Conversations
Authors: Shakhashiri Bassam Z. , Bell Jerry A.
Published: April 2013

The thousands of presentations at next week's meeting of The American Chemical Society (ACS) in New Orleans exemplify one of the many ways scientists converse among themselves about the most recent advances in science. Science and technology continue to reshape the world we live in, and appreciating how these changes, both intended and unintended, come about is a necessity for all citizens in a democratic society. Scientists have a responsibility to help their fellow citizens understand what science and technology can and cannot do for them.
Disparate Host Immunity to Mycobacterium avium subsp.paratuberculosisAntigens in Calves Inoculated with M. avium subsp.paratuberculosis, M. avium subsp.avium, M. kansasii, and M. bovis
Authors: Stabel J. R. , Waters W. R. , Bannantine J. P. , Palmer M. V.
Published: April 2013

The cross-reactivity of mycobacterial antigens in immune-based diagnostic assays has been a major concern and a criticism of the current tests that are used for the detection of paratuberculosis. In the present study,Mycobacterium aviumsubsp.paratuberculosisrecombinant proteins were evaluated for antigenic specificity compared to a whole-cell sonicate preparation (MPS). Measures of cell-mediated immunity toM. aviumsubsp.paratuberculosisantigens were compared in calves inoculated with liveM. aviumsubsp.paratuberculosis,M. aviumsubsp.avium(M. avium),Mycobacterium kansasii, orMycobacterium bovis. Gamma interferon (IFN-γ) responses to MPS were observed in all calves that were exposed to mycobacteria compared to control calves at 4 months postinfection. Pooled recombinantM. aviumsubsp.paratuberculosisproteins also elicited nonspecific IFN-γ responses in inoculated calves, with the exception of calves infected withM. bovis.M. aviumsubsp.paratuberculosisproteins failed to elicit antigen-specific responses for the majority of immune measures; however, the expression of CD25 and CD26 was upregulated on CD4, CD8, gamma/delta (γδ) T, and B cells for the calves that were inoculated with eitherM. aviumsubsp.paratuberculosisorM. aviumafter antigen stimulation of the cells. Stimulation with MPS also resulted in the increased expression of CD26 on CD45RO+CD25+T cells from calves inoculated withM. aviumsubsp.paratuberculosisandM. avium. Although recombinant proteins failed to elicit specific responses for the calves inoculated withM. aviumsubsp.paratuberculosis, the differences in immune responses toM. aviumsubsp.paratuberculosisantigens were dependent upon mycobacterial exposure. The results demonstrated a close alignment in immune responses between calves inoculated withM. aviumsubsp.paratuberculosisand those inoculated withM. aviumthat were somewhat disparate from the responses in calves infected withM. bovis, suggesting that the biology of mycobacterial infection plays an important role in diagnosis.
Analytical Evaluation of GeneXpert CT/NG, the First Genetic Point-of-Care Assay for Simultaneous Detection of Neisseria gonorrhoeae and Chlamydia trachomatis
Authors: Tabrizi Sepehr N. , Unemo Magnus , Golparian Daniel , Twin Jimmy , Limnios Athena E. , Lahra Monica , Guy Rebecca
Published: April 2013

GeneXpert CT/NG was evaluated with 372 characterized bacterial strains. Sensitivity of 10 genome copies/reaction was obtained for both agents. Four
Neisseria mucosa
and two
Neisseria subflava
isolates were positive for one of two gonococcal targets; however, the assay flagged all as negative. The assay was analytically highly sensitive and specific.
Tropism of and Innate Immune Responses to the Novel Human Betacoronavirus Lineage C Virus in Human
Ex Vivo
Respiratory Organ Cultures
Authors: Chan Renee W. Y. , Chan Michael C. W. , Agnihothram Sudhakar , Chan Louisa L. Y. , Kuok Denise I. T. , Fong Joanne H. M. , Guan Y. , Poon Leo L. M. , Baric Ralph S. , Nicholls John M. , Peiris J. S. Malik
Published: April 2013

Since April 2012, there have been 17 laboratory-confirmed human cases of respiratory disease associated with newly recognized human betacoronavirus lineage C virus EMC (HCoV-EMC), and 7 of them were fatal. The transmissibility and pathogenesis of HCoV-EMC remain poorly understood, and elucidating its cellular tropism in human respiratory tissues will provide mechanistic insights into the key cellular targets for virus propagation and spread. We utilized
ex vivo
cultures of human bronchial and lung tissue specimens to investigate the tissue tropism and virus replication kinetics following experimental infection with HCoV-EMC compared with those following infection with human coronavirus 229E (HCoV-229E) and severe acute respiratory syndrome coronavirus (SARS-CoV). The innate immune responses elicited by HCoV-EMC were also investigated. HCoV-EMC productively replicated in human bronchial and lung
ex vivo
organ cultures. While SARS-CoV productively replicated in lung tissue, replication in human bronchial tissue was limited. Immunohistochemistry revealed that HCoV-EMC infected nonciliated bronchial epithelium, bronchiolar epithelial cells, alveolar epithelial cells, and endothelial cells. Transmission electron microscopy showed virions within the cytoplasm of bronchial epithelial cells and budding virions from alveolar epithelial cells (type II). In contrast, there was minimal HCoV-229E infection in these tissues. HCoV-EMC failed to elicit strong type I or III interferon (IFN) or proinflammatory innate immune responses in
ex vivo
respiratory tissue cultures. Treatment of human lung tissue
ex vivo
organ cultures with type I IFNs (alpha and beta IFNs) at 1 h postinfection reduced the replication of HCoV-EMC, suggesting a potential therapeutic use of IFNs for treatment of human infection.