bluuebunny/crossref_metadata_2025 huggingface dataset:
Extranodal natural killer/T‐cell lymphoma, nasal type: Clinical and computed tomography findings in the head and neck region
Authors: Hung Liang‐Yueh , Chang Po‐Hung , Lee Ta‐Jen , Hsu Yin‐Ping , Chen Yi‐Wei , Fu Chia‐Hsiang , Huang Chi‐Che
Published: September 2012

Objectives/Hypothesis:

In patients with nasal natural killer/T‐cell lymphoma (NKTL), it is commonly without an obvious mass found in the nasal cavity by clinical or computed tomography (CT) findings. As a result, it takes longer to make a definite diagnosis when compared with other nasal malignancy. This study was designed to investigate clinical and CT findings of nasal NKTL.

Study Design:

Forty‐three patients with nasal NKTL were enrolled. The patients' data were collected retrospectively.

Methods:

All patients underwent contrast‐enhanced CT scans and endoscopic examinations. Symptoms were noted and recorded in detail.

Results:

Patients with lymphoma limited to their nasal cavity or paranasal sinus (N/PN) presented symptoms similar to chronic rhinosinusitis, such as nasal obstruction and purulent nasal discharge. Patients with lymphoma of the nasopharynx or oropharynx (NPx/OPx) tended to present more frequently with epistaxis or blood‐tinged sputum. On CT, NKTL was usually nonenhanced (79.1%), homogenous (100%), unilateral (61.9%), infiltrative (67.4%), and without central necrosis. Only 30.2% of the patients presented with a prominent mass. One disease‐specific sign, different from patients with chronic rhinosinusitis, was that the mucosa of the nasal cavity was thickened without involvement of the mucosa of the paranasal sinus (40.6%).

Conclusions:

The thickening of the mucosa of the nasal cavity without similar involvement of the paranasal sinuses is easily overlooked in patients with NKTL. In addition, the imaging findings of thickened mucosa of the nasal floor and/or nasal septum near the inferior meatus, a prominent mass, and bony destruction should raise suspicion of this diagnosis. Laryngoscope, 2012
Development of ocular vestibular‐evoked myogenic potentials in small children
Authors: Wang Shou‐Jen , Hsieh Wu‐Shiun , Young Yi‐Ho
Published: September 2012

Objectives/Hypothesis:

This study investigated the development of otolithic–ocular reflex in small children (<3 years old) via the ocular vestibular‐evoked myogenic potential (oVEMP) test.

Study Design:

Prospective study.

Methods:

Twenty full‐term newborns (group A), 15 children aged 1 to 3 years (group B), and 15 children aged 4 to 13 years (group C) were enrolled in this study. All children underwent auditory brainstem response testing or audiometry, and the oVEMP test.

Results:

All subjects had normal hearing. Typical biphasic oVEMP waveforms were not observed in the 20 newborns, but were present in six (40%) of 15 children aged 1 to 3 years and all (100%) children aged 4 to 13 years, exhibiting a significant difference. In group B, except for the nine children aged 12 to 24 months, the remaining six children, aged 25 to 47 months, had clear oVEMPs, with the mean nI latency and nI–pI amplitude resembling those in children aged 4 to 13 years, indicating that the otolithic–ocular reflex is mature in children aged >2 years.

Conclusions:

Despite the well‐developed caloric and cervical VEMP responses in early life, oVEMPs are not present in newborns, but are present in children aged >2 years who can walk with a gait resembling an adult. Maturation of the otolithic–ocular reflex is important to balance control, which is necessary in small children for independent gait. Laryngoscope, 2012
Acute ischemia of the parotid gland and auricle following embolization for epistaxis
Authors: Yilmaz Mehmet , Mamanov Marlen , Yener Murat , Aydin Faruk , Kizilkilic Osman , Eren Abdulkadir
Published: September 2012

We report a case of ischemia of the auricle and acute parotitis that developed following embolization for epistaxis. A 53‐year‐old male was previously conservatively treated for epistaxis with bilateral posterior nasal packing due to hypertension. As the bleeding, continued the patient underwent bilateral embolization of the internal maxillary arteries. The bleeding was controlled but the patient developed acute ischemia of the ipsilateral parotid gland and the auricle that regressed with medical treatment. Laryngoscope, 2012
Role of circulating MSCs in vocal fold wound healing
Authors: Ohno Satoshi , Hirano Shigeru , Kanemaru Shin‐ichi , Mizuta Masanobu , Ishikawa Seiji , Tateya Ichiro , Nakamura Tatsuo , Ito Juichi
Published: September 2012

Objectives/Hypothesis:

Vocal fold injury can cause intractable scarring resulting in dysphonia. Mesenchymal stem cells (MSCs) have great therapeutic potential in wound healing. They continuously circulate in the peripheral blood and migrate into wound sites where they induce regenerative effects. However, their roles in vocal fold wound healing are poorly understood because few MSCs exist in the peripheral blood and there is no specific marker to identify them. The present study evaluates how intravenously injected MSCs affect vocal fold wound healing using Green Fluorescent Protein (GFP) ‐labeled MSCs.

Study Design:

Prospective study using animal model.

Methods:

GFP‐labeled MSCs were obtained from femurs of GFP transgenic Sprague‐Dawley rats and incubated in culture. Sprague‐Dawley rats underwent intravenous injection of GFP‐labeled MSCs (1.0 × 106 cells) immediately after vocal fold injury. Histological examination was performed.

Results:

Injected MSCs were distributed throughout the vocal fold wound site from day 1 up to day 56. These vocal folds showed increased hepatocyte growth factor (HGF)‐positive cells within the wound and improved wound healing compared with sham‐treated folds.

Conclusion:

Circulating MSCs can migrate to vocal fold wound sites and upregulate the expression of HGF during wound healing; thus, they are considered to play a significant role in wound healing within the vocal folds. Laryngoscope, 2012
Quantitative airway analysis during drug‐induced sleep endoscopy for evaluation of sleep apnea
Authors: Borek Ryan C. , Thaler Erica R. , Kim Christopher , Jackson Nicholas , Mandel Jeff E. , Schwab Richard J.
Published: September 2012

Objectives/Hypothesis:

To quantitatively measure changes in airway caliber at multiple anatomical levels during drug‐induced sleep endoscopy (DISE) for evaluation of sleep apnea. We hypothesize that patients undergoing DISE will show: 1) collapse at multiple upper airway regions (retropalatal, retroglossal, and retroepiglottic), with greater collapse in the retropalatal region; and 2) greater anterior‐posterior dimensional narrowing than the lateral.

Study Design:

Case series.

Methods:

Patients underwent DISE employing propofol as part of a nonrandomized prospective trial assessing candidacy for transoral robotic surgery intervention for sleep apnea. Images of the retropalatal, retroglossal, and retroepiglottic regions were captured during an initial period of light sedation and again in a period of deep sedation. Images were analyzed using software to measure the percent change in regional airway measurements as a result of DISE.

Results:

Thirty‐seven sleep endoscopy videos were analyzed from patients with obstructive sleep apnea (apnea‐hypopnea index: 42.9 ± 27.0 events/hour). Analyzable images were in the retropalatal (n = 24), retroglossal (n = 27), and retroepiglottic (n = 29) regions. The patients demonstrated mean reductions in airway area in the retropalatal (84.1 ± 18.7%), retroglossal (39.3 ± 37.5%), and retroepiglottic region (44.6 ± 42.8%). No statistically significant differences were found between lateral and anterior‐posterior airway dimensional changes.

Conclusions:

Patients undergoing DISE had significant reductions in airway area at multiple regions under deep sedation with propofol. We conclude that collapse in the retropalatal region is greater than the hypopharyngeal region. This method can be used to quantitatively measure DISE upper airway changes, which could potentially be used as a means for understanding surgical outcomes in patients with sleep apnea. Laryngoscope, 2012
Mechanical analysis of cartilage graft reinforced with PDS plate
Authors: Conderman Christian , Kinzinger Michael , Manuel Cyrus , Protsenko Dmitry , Wong Brian J.F.
Published: September 2012

Objectives/Hypothesis:

This study attempts to characterize the biomechanical properties of a PDS‐cartilage composite graft for use in septorhinoplasty.

Study Design:

Experimental Study.

Methods:

This study used a PDS analog, porcine cartilage cut to 1 × 5 × 20 mm, and a mechanical testing platform to measure flexure of a composite graft. Samples were assessed in four groups based on variations in suture pattern and orientation. The platform measured the force required to deflect the sample 2 mm in single cantilever beam geometry before and after the polymer was affixed to the specimen. Elastic Moduli were calculated before and after application of the polydioxanone polymer.

Results:

The average modulus of the cartilage alone was 17 ± 0.9 MPa. The modulus of the composite cartilage‐polymer graft with 2 suture fixation was 21.2 ± 1.5 MPa. The 3‐suture configuration produced an increase to 25.8 ± 2.23 MPa. The four‐suture configuration produced 23.1 ± 3.19 MPa. The five‐suture configuration produced 25.7 ± 2.6 MPa. The modulus of the analog alone was 170 ± 30 MPa. The modulus of the 0.5 mm PDS was 692 ± 37.4 MPa. The modulus of the 0.15 mm perforated PDS was 447 ± 34.8 MPa.

Conclusions:

The study found that suturing a polymer plate to cartilage resulted in enhanced stiffness of the composite. Under the conditions of the study, there was no significant difference in elastic moduli between suture configurations, making the two‐suture linear configuration optimal in the one‐plane cantilever deflection model. Laryngoscope, 2012
Audioprofiles and antioxidant enzyme genotypes in presbycusis
Authors: Angeli Simon I. , Bared Anthony , Ouyang Xiaomei , Du Li Lin , Yan Denise , Zhong Liu Xue
Published: September 2012

Objectives/Hypothesis:

Audiometric patterns have been shown to indirectly provide information regarding the pathophysiology of presbycusis and be useful in the phenotyping of hereditary deafness.

Study Design and Methods:

Hospital‐based cohort study of adults with presbycusis, comparing the association of audiometric patterns and polymorphisms of antioxidant enzymes that have been linked to presbycusis: GSTT1, GSTM1 and NAT2. All subjects underwent a clinical evaluation and completed questionnaires regarding ototoxicity and noise exposure. Pure‐tone threshold audiometry was obtained and subjects' audiograms were classified into specific patterns. DNA was extracted from blood and the polymorphisms of GSTT1, GSTM1, and the NAT2 variants (NAT2* 5A; NAT2* 6A,B) were analyzed by PCR.

Results:

The audiometric patterns that were more prevalent in our cohort were “High‐Frequency Steeply Sloping” or HFSS (33%), “High‐Frequency Gently Sloping” or HFGS (31%), and “Flat” (27%), with other patterns being rare. We did not find a statistical significant effect of gender, age, hearing level, and ear side on the audiometric pattern. Subjects with mutant alleles for GSTT1 were more likely to have a HFSS audiogram than subjects with the wild type genotype.

Conclusions:

In this cohort, there was a similar prevalence for the three audiometric configurations HFSS, HFGS, and Flat, with other configurations being rare. Subjects with mutant alleles for GSTT1 were more likely to have a HFSS audiogram than subjects with the wild type genotype, suggesting that the basal turn of the cochlea is susceptible to GSTT1 regulated oxidative stress. However, further studies of audioprofiles with larger sample sizes may be needed to establish phenotype‐genotype correlations in presbycusis. Laryngoscope, 2012
Endoscopic trans(naso)orbital management of supraorbital mucoceles with biliary T‐tube stenting
Authors: Man Li‐Xing , McLean Caitlin C. , Pierce Matthew L. , Fakhri Samer
Published: September 2012

The objective of this article is to describe our surgical technique for accessing orbital and supraorbital ethmoid sinus mucoceles and the novel application of a biliary T‐tube to stent and redirect mucociliary flow into the frontal recess. We describe in technical terms our surgical approach and the use of an 8‐Fr pediatric biliary T‐tube as a paranasal sinus stent with demonstrative case reports. Four patients have been successfully managed employing the endoscopic trans(naso)orbital approach to access and marsupialize supraorbital and superiorly located orbital mucoceles without egress to the frontal recess. Patency of drainage was maintained by utilizing a flexible, pediatric, biliary T‐tube that is inserted via an above (trephination) and below (endoscopic) approach in three patients, and without the need for stenting in one patient (median follow‐up, 14.5 months). The presented surgical strategy is safe and effective in accessing and maintaining long‐term patency of problematic supraorbital and superiorly located intraorbital mucoceles without communication to the frontal recess. Laryngoscope, 2012
Effects of aging on thyroarytenoid muscle regeneration
Authors: Lee Kyungah , Kletzien Heidi , Connor Nadine P. , Schultz Edward , Chamberlain Connie S. , Bless Diane M.
Published: September 2012

Objectives/Hypothesis:

Regenerative properties of age‐associated changes in the intrinsic laryngeal muscles following injury are unclear. The purpose of this study was to investigate the regenerative properties of the thyroarytenoid (TA) muscle in an aging rat model. The hypothesis was that following myotoxic injury, old animals would exhibit a decrease in mitotic activities of muscle satellite cells when compared with younger rats, suggesting reduced regenerative potential in the aging rat TA muscle.

Study Design:

Animal group comparison.

Methods:

Regeneration responses following injury to the TA muscle were examined in 18 young adult, middle‐aged, and old Fischer 344/Brown Norway rats. TA muscle fiber cross‐sectional area (CSA), satellite cell mitosis (number/fiber), and regeneration index (CSA injured side/CSA noninjured side) were measured and compared across age groups.

Results:

Young adult animals had a significantly higher regeneration index than the middle‐aged and old groups. Within the lateral region of the TA muscle (LTA), the regeneration index was significantly higher in the young adult animals than in the middle‐aged and old animals. The regeneration index of the medial TA was significantly higher than the LTA across all age groups.

Conclusions:

The regenerative capacity of the TA muscle is impaired with increasing age. Laryngoscope, 2012
Development of Protein‐Cage‐Based Delivery Nanoplatforms by Polyvalently Displaying β‐Cyclodextrins on the Surface of Ferritins Through Copper(I)‐Catalyzed Azide/Alkyne Cycloaddition
Authors: Kwon Chanho , Kang Young Ji , Jeon Sangbin , Jung Seunho , Hong Sung You , Kang Sebyung
Published: September 2012

Protein cages are spherical hollow macromolecules that are attractive platforms for the construction of nanoscale cargo delivery vehicles. Human heavy‐chain ferritin (HHFn) is modified genetically to control the number and position of functional groups per cage. 24 β‐CDs are conjugated precisely to the modified HHFn in specific locations through thiol‐maleimide Michael‐type addition followed by copper(I)‐catalyzed azide/alkyne cycloaddition (CuAAC). The resulting human ferritins displaying β‐CDs (β‐CD‐C90 HHFn) can form inclusion complexes with FITC‐AD, which can slowly release the guest molecule reversibly in a buffer solution via non‐covalent β‐CD/AD interactions. β‐CD‐C90 HHFn can potentially be used as delivery vehicles for insoluble drugs.

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Onium‐functionalised Polymers in the Design of Non‐leaching Antimicrobial Surfaces
Authors: Nigmatullin Rinat , Gao Fengge
Published: September 2012

Biocides are widely explored in the design of materials and surfaces in order to address a variety of problems, such as biodeterioration, biofouling or infections. Materials with migrating biocides are under scrutiny due to potential health and environmental risks, as well as instability of the antimicrobial activity in time. This paper focuses on the onium‐functionalised polymers in the design of bioactive materials and surfaces, which are capable to kill micro‐organism or efficiently inhibit their growth on contact. The review highlights synthetic and processing routes towards the integration of onium functionalities into solid materials. The influence of materials structure on the antimicrobial activity and possible applications are discussed.

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Integrated Continuous Processing and Flow Characterization of RAFT Polymerization in Tubular Flow Reactors
Authors: Hornung Christian H. , Nguyen Xuan , Dumsday Geoff , Saubern Simon
Published: September 2012

Several unit operations are combined in series to form an integrated, continuous polymerization process; namely inline degassing of monomer stock solution prior to reaction, polymerization using the RAFT approach and precipitation after reaction to form a solid polymeric product. The polymerization is conducted at 70–80 °C with reaction times of 30–90 min in a stainless steel tubular flow reactor, yielding poly(acrylamide) at high conversion (typically >90%) and with a low polydispersity of 1.14–1.23. The axial dispersion occurring inside the tubular flow reactor during polymerization is characterized by reaction profiling using a series of NMR samples. The process can be scaled up to a total output of 1.36 kg of polymer per day on this laboratory‐scale reactor.

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Effects of poss nanoparticles on ABS‐g‐Ma thermo oxidation resistance
Authors: Ramirez Narciso Vilà , Sanchez‐Soto Miguel
Published: September 2012

Thermo oxidative degradation at and beyond processing temperatures has been carried out on ABS copolymer grafted with Maleic Anhydride (ABS‐g‐Ma) and three nanocomposites with the above material melt‐blended with different types of POSS, being amino‐propyl isobutyl (APOSS), glycidyl (GPOSS), and trisilanol (TPOSS). The incorporation adequacy of the nanofillers into the matrix has been assessed with scanning electron microscopy (SEM) and differential scanning calorimetry (DSC), whereas the quantification of the thermal degradation behavior of each sample was carried out through infrared spectrography (FTIR), thermogravimetric analysis (TGA) including the degradation kinetics and color spectrophotometry (Cielab). Although the results show adequate incorporation and miscibility of the nanofillers into the matrix, the GPOSS and the TPOSS nanocomposites provided no relevant improvements in thermal stability when compared with the base ABS‐g‐Ma, and the APOSS blend exhibits a very slight decay in almost all the quantitative analysis carried out in this work. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Self‐concept in Arab American adolescents: Implications of social support and experiences in the schools
Authors: Tabbah Rhonda , Miranda Antoinette Halsell , Wheaton Joe E.
Published: September 2012

The purpose of this study was to investigate three domains (Scholastic Competence, Social Acceptance, and Global Self‐Worth) of self‐concept in Arab American adolescents in relation to their school experiences, including discrimination, self‐perceived teacher social support, and self‐perceived classmate social support. Half of the sample either experienced some form of discrimination or knew someone who had. An experience of discrimination was significantly related to students' Scholastic Competence. Self‐perceived classmate support was significantly related to all domains of self‐concept; however, self‐perceived teacher support was not significantly related to any of the self‐concept domains. Implications of these results are discussed, as well as strategies for how to provide positive relationships for Arab American students and their families.
Unusual conformational preferences of 1,3‐dimethyl‐3‐isopropoxy‐3‐silapiperidine
Authors: Kirpichenko Svetlana V. , Shainyan Bagrat A. , Kleinpeter Erich
Published: September 2012

The conformational analysis of the first representative of the Si‐alkoxy substituted six‐membered Si,N‐heterocycles, 1,3‐dimethyl‐3‐isopropoxy‐3‐silapiperidine, was performed by low‐temperature 1H and 13C NMR spectroscopy and DFT theoretical calculations. In contrast to the expectations from the conformational energies of methyl and alkoxy substituents, the Meaxi‐PrOeq conformer was found to predominate in the conformational equilibrium in the ratio Meaxi‐PrOeq : Meeqi‐PrOax of ca. 2 : 1 as from the 1H and 13C NMR study. The thermodynamic parameters obtained by the complete line shape analysis showed that the main contribution to the barrier to ring inversion originates from the entropy term of the free energy of activation. Copyright © 2012 John Wiley & Sons, Ltd.
Structural and magnetic properties of Mg‐doped nano‐α‐Fe2O3 particles synthesized by surfactant mediation–precipitation technique
Authors: Mohapatra M. , Layek Samar , Anand S. , Verma H. C. , Mishra B. K.
Published: September 2012

Nanosized hematite with 1.53% Mg well dispersed in the crystal could be prepared using a wet chemical method. The chemical reaction followed by aging at 60 °C for 12 h produced Mg‐doped hematite of mean crystallite size (MCD) 78 nm as shown by X‐ray diffraction. Transmission electron microscopy measurement showed that particles are nearly spherical in shape. However, FTIR and differential thermal analysis results indicated presence of ferric hydroxide phase which was also confirmed from Mössbauer spectroscopy. The sample annealed at 400 °C did not show any extra phase other than α‐Fe2O3. Mg‐doped α‐Fe2O3 showed a weak ferromagnetism with a hysteresis loop superimposed on antiferromagnetic M–H curve. The saturation magnetization and coercivity decreased when the sample was annealed at 400 °C. The presence of ferrihydrite in α‐Fe2O3 matrix seems to provide pinning centers for domain walls, increasing the coercivity showing that this composite can also be an interesting magnetic material.

Mössbauer spectrum of (a) as‐prepared and (b) annealed sample of Mg‐doped hematite recorded in transmission geometry at 300 K. Black circles are the experimental data points and solid blue line is the Lorentzian fit.

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Electronic structure of the nitrogen donors in 6H SiC as studied by pulsed ENDOR and TRIPLE ENDOR spectroscopy
Authors: Savchenko Dariya V. , Kalabukhova Ekaterina N. , Pöppl Andreas , Shanina Bela D.
Published: September 2012

The nitrogen (N) donors in 6H SiC were investigated by field sweep electron spin echo (FS ESE), pulsed electron nuclear double resonance (ENDOR) and pulsed General TRIPLE ENDOR spectroscopy. The 29Si and 13C superhyperfine (shf) lines observed in the FS ESE and ENDOR spectra of N in n‐type 6H SiC were assigned by pulsed General TRIPLE resonance spectroscopy to the specific carbon (C) and silicon (Si) atoms located in the environment of N donors residing at two quasi‐cubic lattice sites (Nk1, Nk2) in 6H SiC. As a result, the largest value of the shf interaction was found with Si atoms for the N donors at the hexagonal (Nh) and quasi‐cubic site Nk1, while for Nk2 the largest value of the shf interaction was found with C atoms. It gives us the argument to consider that N substitute different lattice sites in 6H SiC lattice. The relative signs of the shf interaction (shfi) constants for Nk1 and Nk2 with 29Si and 13C nuclei located in the nearest‐neighbor, next nearest‐neighbor, and outer shells are found from the TRIPLE ENDOR spectra to be positive for C atoms and negative for Si atoms. From the comparison of the experimentally obtained shfi constants with the theory, the electronic spin‐density distribution over the 29Si and 13C nuclei located in the nearest neighbor shells of N donors has been obtained taking into account the Kohn–Luttinger interference effect. The position of the conduction band minimum along the ML‐line was determined to be at k0z/kmax = 0.2 ± 0.05.
Capturing the re‐entrant behavior of one‐dimensional Bose–Hubbard model
Authors: Pino M. , Prior J. , Clark S. R.
Published: September 2012

The Bose–Hubbard model (BHM) is an archetypal quantum lattice system exhibiting a quantum phase transition between its superfluid (SF) and Mott‐insulator (MI) phase. Unlike in higher dimensions the phase diagram of the BHM in one dimension possesses regions in which increasing the hopping amplitude can result in a transition from MI to SF and then back to a MI. This type of re‐entrance is well known in classical systems like liquid crystals yet its origin in quantum systems is still not well understood. Moreover, this unusual re‐entrant character of the BHM is not easily captured in approximate analytical or numerical calculations.

Here we study in detail the predictions of three different and widely used approximations; a multi‐site mean‐field decoupling, a finite‐sized cluster calculation, and a real‐space renormalization group (RG) approach. It is found that mean‐field calculations do not reproduce re‐entrance while finite‐sized clusters display a precursor to re‐entrance. Here we show for the first time that RG does capture the re‐entrant feature and constitutes one of the simplest approximation able to do so. The differing abilities of these approaches reveals the importance of describing short‐ranged correlations relevant to the kinetic energy of a MI in a particle‐number symmetric way.
Carrier trapping and recombination in TlGaSe2 layered crystals
Authors: Grivickas Vytautas , Odrinski Andrei , Bikbajevas Vitalijus , Gulbinas Karolis
Published: September 2012

In nominally undoped layered TlGaSe2 crystals the trapping centers have been investigated by photo‐induced current transient spectroscopy (PICTS). Five acceptor and donor traps have been detected. Quite large magnitudes of capture cross‐sections for donor traps at 0.23 and 0.45 eV have been determined. The depth‐resolved free‐carrier absorption (FCA) technique has been applied for the investigation of the majority hole lifetime, τR, at 295 and 77 K. The pronounced τR reduction with increasing injection level is attributed to the trapping effect of the minority electrons which provides a way of estimating trap centers concentration. A moderate τR variation across layer planes is observed but no carrier diffusion related to the recombination on the external crystal surfaces is detected. Moreover, abnormally sharp τR drop is found for carrier concentration above 1017 cm−3. The possibility of excess hole and electron special separation due to compositional stacking faults and the successive their enhanced recombination at high excess carrier concentrations is discussed.
Top management team nationality diversity and firm performance: A multilevel study
Authors: Nielsen Bo Bernhard , Nielsen Sabina
Published: September 2012

This research reexamines the equivocal relationship between top management team (TMT) diversity and firm performance. Combining upper echelons theory with insights from institutional theory, we establish a new, timely dimension of TMT diversity—nationality diversity—and develop an integrated multilevel framework explaining how its performance implications vary across contextual settings. We find that nationality diversity is positively related to performance; and this effect is stronger in (a) longer tenured teams, (b) highly internationalized firms, and (c) munificent environments. More generally, our research demonstrates that the consequences of TMT diversity depend on the (1) specific attributes of diversity being considered and (2) firm and industry conditions under which strategic decisions take place. Copyright © 2012 John Wiley & Sons, Ltd.
An Assessment of Fluorescence‐ and Absorbance‐Based Assays to Study Metal‐Oxide Nanoparticle ROS Production and Effects on Bacterial Membranes
Authors: Horst Allison M. , Vukanti Raja , Priester John H. , Holden Patricia A.
Published: September 2012

The production and inevitable release of engineered nanoparticles requires rapid approaches to screen for their potential effects in environmental organisms, including bacteria. In bacteria, engineered nanoparticle effects can initiate at the cell membrane, for example by structurally damaging membranes or inhibiting energy transduction. Commercially available fluorescence‐ and absorbance‐based assays could allow for rapidly assaying engineered nanoparticle effects on bacterial membranes, but there are limitations, including that: 1) assays are not currently configured to operate as part of a comprehensive high‐throughput screening system, since assay conditions vary widely and formats are mostly high‐volume and thus low‐throughput, and; 2) engineered nanoparticles can interfere with assay reagents or function, yielding false‐negative or ‐positive outcomes. Here, key assays to study reactive oxygen species (total ROS, and superoxide) production, and impacts on bacterial membrane integrity, membrane potential, and electron transport chain activity, are assessed for their potential use as a comprehensive system to test for nanoparticle effects in bacteria. To address (1), assays are adapted for simultaneous use in 96‐well microplates under harmonized conditions. To address (2), a general scheme to test for engineered nanoparticle interferences with assay reagents and function is conceived, and used to study assay interferences by three nanoscale metal‐oxides: nano‐TiO2, nano‐CeO2, and nano‐ZnO. The results show that the selected assays can be used as a suite, and that nanoparticle interferences, when they occur, can be systematically investigated and often accounted for.
Associational resistance in a multiple herbivore system: differential effects of mammal versus insect herbivores
Authors: Axelsson E. P. , Stenberg J. A.
Published: September 2012

Recent studies have suggested that associational resistance (AR) should be more effective in protecting plants from grazing by mammals than by herbivorous insects. We tested this hypothesis in a multiple‐herbivore system by comparing herbivory on, and reproductive success of, fireweed plants growing within meadowsweet stands with fireweeds growing outside meadowsweet stands in abandoned fields in Northern Sweden. We showed that meadowsweet mediates AR against shared mammal grazers, but not against shared insect herbivores. The risk of fireweed plants being browsed by mammals when growing in the absence of meadowsweet was at least double (41 % affected) that of plants growing within meadowsweet patches (17.5 % affected). We also showed that whereas mammal browsing had a negative effect on fireweed performance, the effect of insect herbivory was negligible. Our results support the hypothesis that AR is more effective against grazing mammals than against herbivorous insects.
Baseline time accounting: Considering global land use dynamics when estimating the climate impact of indirect land use change caused by biofuels
Authors: Kløverpris Jesper Hedal , Mueller Steffen
Published: September 2012

Purpose

Current estimations of the climate impact from indirect land use change (ILUC) caused by biofuels are heavily influenced by assumptions regarding the biofuel production period. The purpose of this paper is to propose a new method (baseline time accounting) that takes global land use dynamics into account that is consistent with the global warming potential, that is applicable to any phenomenon causing land use change, and that is independent of production period assumptions.

Methods

We consider ILUC in two forms. The first is called “accelerated expansion” and concerns ILUC in regions with an expanding agricultural area. The second is called “delayed reversion” and concerns ILUC in regions with a decreasing agricultural area. We use recent trends in international land use and projections of future land use change to assess how ILUC from biofuels will alter the development in global agricultural land use dynamics compared to the existing trend (i.e., the baseline development). We then use the definition of the global warming potential to determine the CO2 equivalence of the change in land use dynamics.

Results and discussion

We apply baseline time accounting to two existing ILUC studies in the literature. With current trends in global agricultural land use, the method significantly reduces the estimated climate impact in the previous ILUC studies (by more than half). Sensitivity analyses show that results are somewhat sensitive to assumptions regarding carbon sequestration and assumptions regarding postreversion ecosystems.

Conclusions

The global dynamic development in land use has important implications for the time accounting step when estimating the climate impact of ILUC caused by biofuel production or other issues affecting land use. Ignoring this may lead to erroneous conclusions about the actual climate impact of ILUC. Several land use projections indicate that the global agricultural area will keep expanding up to and beyond 2050. We therefore recommend to apply the baseline time accounting concept as an integrated part of future ILUC studies and to update the results on a regular basis.
Microstructures and Compositional Variation in the Intra-volcanic Bole Clays from the Eastern Deccan Volcanic Province: Palaeoenvironmental Implications and Duration of Volcanism
Authors: Shrivastava J. P. , Ahmad Mansoor , Srivastava Surabhi
Published: September 2012

Clay minerals associated with intra-volcanic bole horizons of varied colours and thicknesses contain montmorillonite, halloysite and kaolinite, show distinct microstructures and microaggregates. In kaolinite, Fe3+ ions substitute for Al3+ at octahedral sites. Most of these clays are dioctahedral type, show balance between net layer and interlayer charges. The interstratified illite - smectite (I/S) mixed layers containing variable proportions of montmorillonite. Illite contains sheet-like, well oriented microaggregates. The parallel stacks of chlorite sheets show chlorite/smectite (C/S) mixed layers. Progressive enrichment of Fe and depletion of Al ions with the advancement of kaolinization process is observed. High order of structural and compositional maturity observed in these bole clays, indicate long hiatus between the two volcanic episodes.

It is observed that the bole horizons suffered rigorous weathering, approximately 5 fold higher than the respective parent lava flows under the alternate wet and dry spells of climatic changes. Translating the production time estimates of clays associated with the 21 bole horizons, found in the eastern Deccan volcano-sedimentary succession, it is assessed that the minimum time required for their formation is approximately 7 my. Clay minerals that occur across the stratigraphic sequence show cyclic changes in the climate, favouring longer duration of volcanic activity. Late Maastrichtian Lameta beds post-date Deccan volcanism to 70 Ma or earlier to this. Considering the formation of bole clays in terms of time, it is possible that the volcanic activity started much earlier in the late Maastrichtian, and continued after 65 Ma or even later. Thus, the clay stratigraphy based estimates lend support to a prolong duration.
Geo-microbial Prospecting Studies of Surface Sediments from Petroliferous Region of the Mehsana Block, North Cambay Basin
Authors: Rasheed M. A. , Prasanna M. Veena , Lakshmi M. , Madhavi T. , Kalpana M. S. , Patil D. J. , Dayal A. M.
Published: September 2012

Surface adsorbed gas surveys and geo-microbiological surveys are well known techniques of petroleum exploration and aim towards risk reduction in exploration by way of identifying the areas warm with hydrocarbons and to establish inter-se exploration priorities amongst the identified warm areas. The thermogenic surface adsorbed gaseous hydrocarbons distribution patterns in petroliferous areas are considered to be a credible evidence for the upward migration of hydrocarbons. The present investigation aims to explore correlation between the adsorbed gas distribution pattern and microbial oxidizers in identifying the upward migration of hydrocarbons especially in the tropical black soil terrain of known petroliferous Mehsana Block of North Cambay Basin, India. A set of 135 sub-soil samples collected, were analyzed for indicator hydrocarbon oxidizing bacteria, adsorbed light gaseous hydrocarbons and carbon isotope ratios (δ13Cmethane and δ13 Cethane). The microbial prospecting studies showed the presence of high bacterial population for methane (5.4 x 106 cfu/gm), ethane (5.5 x 106 cfu/gm), propane (4.6 x 106 cfu/gm) and butane oxidizing bacteria (4.6 x 106 cfu/gm) in soil samples. The light gaseous hydrocarbon analysis showed that the concentration ranges of C1, C2, C3, iC4 and nC4 are 402 ppb, 135 ppb, 70 ppb, 9 ppb and 18 ppb, respectively, and the value of carbon isotope ranges of methane -29.5 to -43.0‰ (V-PDB) and ethane -19.1 to -20.9‰ (V-PDB). The existence of un-altered petroliferous microseep (δ13C, -43‰) of catagenetic origin is observed in the study area. Geo-microbial prospecting method and adsorbed soil gas and carbon isotope studies have shown good correlation with existing oil/ gas fields of Mehsana. Microbial surveys can independently precede other geochemical and geophysical surveys to delineate area warm with hydrocarbons, and mapped microbiological anomalies may provide focus for locales of hydrocarbon accumulation in the Mehsana Block of Cambay Basin.
Automatic generation of Brazilian sign language windows for digital TV systems
Authors: de Araújo Tiago Maritan Ugulino , Ferreira Felipe Lacet Silva , dos Santos Silva Danilo Assis Nobre , Lemos Felipe Hermínio , Neto Gutenberg Pessoa , Omaia Derzu , de Souza Filho Guido Lemos , Tavares Tatiana Aires
Published: September 2012

Deaf people have serious difficulties accessing information. The support for sign language (their primary means of communication) is rarely addressed in information and communication technologies. Furthermore, there is a lack of works related to machine translation for sign language in real-time and open-domain scenarios, such as TV. To minimize these problems, in this paper, we propose an architecture for machine translation to Brazilian sign language (LIBRAS) and its integration, implementation and evaluation for digital TV systems, a real-time and open-domain scenario. The system, called LibrasTV, allows the LIBRAS windows to be generated and displayed automatically from a closed caption input stream in Brazilian Portuguese. LibrasTV also uses some strategies, such as low time consuming, text-to-gloss machine translation and LIBRAS dictionaries to minimize the computational resources needed to generate the LIBRAS windows in real-time. As a case study, we implemented a prototype of LibrasTV for the Brazilian digital TV system and performed some tests with Brazilian deaf users to evaluate it. Our preliminary evaluation indicated that the proposal is efficient, as long as its delays and bandwidth are low. In addition, as previously mentioned in the literature, avatar-based approaches are not the first choice for the majority of deaf users, who prefer human translation. However, when human interpreters are not available, our proposal is presented as a practical and feasible alternative to fill this gap.
Fast Strategies In Maker–Breaker Games Played on Random Boards
Authors: CLEMENS DENNIS , FERBER ASAF , KRIVELEVICH MICHAEL , LIEBENAU ANITA
Published: September 2012

In this paper we analyse classical Maker–Breaker games played on the edge set of a sparse random boardG~n,p. We consider the Hamiltonicity game, the perfect matching game and thek-connectivity game. We prove that forp(n) ≥ polylog(n)/nthe boardG~n,pis typically such that Maker can win these games asymptotically as fast as possible,i.e., withinn+o(n),n/2+o(n) andkn/2+o(n) moves respectively.
Offspring ADHD as a Risk Factor for Parental Marital Problems: Controls for Genetic and Environmental Confounds
Authors: Schermerhorn Alice C. , D'Onofrio Brian M. , Slutske Wendy S. , Emery Robert E. , Turkheimer Eric , Harden K. Paige , Heath Andrew C. , Martin Nicholas G.
Published: September 2012

Background: Previous studies have found that child attention-deficit/hyperactivity disorder (ADHD) is associated with more parental marital problems. However, the reasons for this association are unclear. The association might be due to genetic or environmental confounds that contribute to both marital problems and ADHD. Method: Data were drawn from the Australian Twin Registry, including 1,296 individual twins, their spouses, and offspring. We studied adult twins who were discordant for offspring ADHD. Using a discordant twin pairs design, we examined the extent to which genetic and environmental confounds, as well as measured parental and offspring characteristics, explain the ADHD–marital problems association. Results: Offspring ADHD predicted parental divorce and marital conflict. The associations were also robust when comparing differentially exposed identical twins to control for unmeasured genetic and environmental factors, when controlling for measured maternal and paternal psychopathology, when restricting the sample based on timing of parental divorce and ADHD onset, and when controlling for other forms of offspring psychopathology. Each of these controls rules out alternative explanations for the association. Conclusion: The results of the current study converge with those of prior research in suggesting that factors directly associated with offspring ADHD increase parental marital problems.
The climate‐water‐health nexus in emerging megacities
Authors: Akanda Ali Shafqat , Hossain Faisal
Published: September 2012

Today a handful of developing nations (India, China, Nigeria, Brazil, Bangladesh, Indonesia, and Pakistan) account for more than half of the world's population. A majority of these nations are rapidly urbanizing, as people from remote regions migrate in search of economic prosperity [Cohen, 2003]. Such a rural‐to‐urban migratory trend has been the leading cause of cities expanding to megacities, which are defined by the United Nations as cities with a population greater than 10 million. By 2025 a greater proportion of the world's megacities, most of them situated in low‐lying coastal areas, will be in developing nations in Asia and Africa (Figure 1a) [Asian Development Bank, 2012].
Easing food waste could reduce pressure on natural resources
Authors: Showstack Randy
Published: September 2012

Calls to reduce food waste and enhance agricultural water efficiency were among the points raised during the 27 August opening session of World Water Week in Stockholm, Sweden. “More than one fourth of all the water we use worldwide is taken to grow over one billion tons of food that nobody eats. That water, together with the billions of dollars spent to grow, ship, package, and purchase the food, is sent down the drain,” said Torgny Holmgren, executive director of the Stockholm International Water Institute, which organizes World Water Week. “Reducing the waste of food is the smartest and most direct route to relieve pressure on water and land resources. It's an opportunity we cannot afford to overlook,” he added.
Carbon dioxide drove climate change during longest interglacial
Authors: Bhattacharya Atreyee
Published: September 2012

Known as the marine isotope stage 11 (MIS 11), the interglacial period that occurred from approximately 425,000 years ago to approximately 375,000 years ago was the longest and possibly the warmest interglacial in the past 500,000 years. Because the orbital configurations, atmospheric greenhouse gas concentrations, climate, and faunal characteristics during MIS 11 closely resemble those of the past 5000 years, paleoclimatologists use MIS 11 as a geological analogue of the present and the near future. Several high‐ resolution records document almost all aspects of terrestrial and marine climate through MIS 11. However, there is neither a clear understanding about how climatic parameters such as atmospheric carbon dioxide (CO2), sea surface temperature, the isotopic makeup of carbon in marine and terrestrial reservoirs, and annual air temperature interact, nor a consensus regarding the major drivers of climate change during this interval.
Dipolarization fronts and associated auroral activities: 2. Acceleration of ions and their subsequent behavior
Authors: Zhou X.‐Z. , Ge Y. S. , Angelopoulos V. , Runov A. , Liang J. , Xing X. , Raeder J. , Zong Q.‐G.
Published: September 2012

We present case studies of THEMIS multipoint observations of ion distributions in the magnetotail plasma sheet at various locations upstream of earthward‐propagating dipolarization fronts. Observations made near the neutral sheet show a characteristic signature, enhancements of earthward‐moving ion fluxes about 30 s before dipolarization front arrival. In previous studies, this signature has been well explained as front‐reflected ions confined to a region characterized by their gyroradii over the background Bz field that coexist with the ambient population. However, at higher latitudes near the plasma sheet boundary layer, observations suggest that earthward‐moving ions appear a few minutes earlier than at the central plasma sheet, indicating that the ions reflected at the same dipolarization front could access farther toward the Earth at higher latitudes. These observed phenomena, as also stated in our companion paper, are associated with transient intensifications of proton auroral brightness, which suggests a direct connection between magnetospheric and ionospheric signatures during geomagnetic disturbed conditions. We carry out numerical simulations and theoretical analysis of ion dynamics to interpret and reproduce these observations, to improve our understanding of interactions between earthward‐propagating fronts and the ambient plasma in the near‐Earth magnetotail, and to establish the proton auroral effects of dipolarization fronts.
AKR‐like emissions observed at low altitude by the DEMETER satellite
Authors: Parrot Michel , Berthelier Jean‐Jacques
Published: September 2012

This paper reports observations of Auroral Kilometric Radiation (AKR) by the low altitude satellite DEMETER (700 km) during the super magnetic storm of November 2004. AKR is generated along auroral field lines at altitudes above ∼3000 km and escapes from the Earth so that most observations have been made close to the source regions or at large distances from the Earth. However, EM waves with AKR‐like frequency spectra detected by the low altitude EXOS‐C satellite were interpreted by Oya et al. (1985) as AKR emissions propagating toward the Earth in the whistler mode. During the large magnetic storm of November 8–10, 2004, numerous events have been observed by DEMETER and, in one case, the emissions were recorded when DEMETER was flying over an intense aurora observed by the UVI (Ultra Violet Imager) of the POLAR spacecraft. During this event, density depletions have been observed at the satellite altitude. Similar AKR‐like EM waves were also recorded by DEMETER at other times showing that these emissions are a common phenomenon at low altitudes in the auroral regions during periods of sustained magnetic activity.