bluuebunny/crossref_metadata_2025 huggingface dataset:
trans Influence and Steric Effect on the Distortions in Planar NiS4, NiS2PN, and NiS2P2 Chromophores
Authors: Srinivasan Subramaniam , Ramalingam Kuppukkannu , Rizzoli Corrado
Published: July 2012

The planar diamagnetic complexes [Ni(achdtc)2] (1),[Ni(achdtc)(PPh3)(NCS)] (2), and [Ni(achdtc)(PPh3)2]ClO4·0.5EtOAc (3) (achdtc = allylcyclohexylcarbodithioate) were prepared, characterized by elemental analysis, electronic, IR, NMR (1H, 13C, and 31P) spectroscopy and the crystal structures were determined by single‐crystal X‐ray crystallography. The characteristic thioureide bands occur at 1478, 1503, and 1507 cm–1 for 1, 2, and 3, respectively and the corresponding 13C chemical shifts are observed at 207.67, 204.16, and 202.31 ppm. 31P chemical shifts are observed at δ = 29.24 and 22.73 ppm for 2 and 3, respectively, indicating a strong interaction. Electronic spectral bands are observed at 480, 483, and 475 nm for 1, 2, and 3, corresponding to d → dxy/d transitions. Ni–S distances are asymmetric. The trans influence of PPh3 elongates the Ni–S bonds. The decrease in the S–Ni–S bite angle in 2 [78.80(16)°] and in 3 [78.36(2)°] compared to that observed in 1 [79.42(3)°] is due to the steric crowding of PPh3 around the central metal atom. A comparison of the bond parameters of compounds 1–3 shows a change in the arrangement from a planar NiS4 chromophore to distorted planar NiS2P2 chromophores. The observed distortion from planar to tetrahedral arrangement is influenced by the bulky triphenylphosphine ligand.
[VO(dien)]2GeS4: Solvothermal Synthesis and Crystal Structure with an Ortho‐Thiogermanate as Tetradentate Ligand
Authors: Wang Jing , Näther Christian , Djamil John , Bensch Wolfgang
Published: July 2012

The compound [VO(dien)]2GeS4 (1, dien = diethylenetriamine) features an ortho‐thiogermanate anion [GeS4]4–, which acts as tetradentate ligand joining [VO(dien)]2– complexes. The compound was obtained under solvothermal conditions crystallizing in thenon‐centrosymmetric orthorhombic space group Pna21 with a =19.8310(11), b = 8.0814(5), c = 12.0889(9) Å, V = 1937.4(2) Å3 and Z = 4. The V4+ cations are in a distorted octahedral environment of a tridentate dien molecule, one oxygen atom and two sulfur atoms from the [GeS4]4– anion. A three‐dimensional network is generated by hydrogen bonding interactions.
Regenerative Surgery: Tissue Engineering in General Surgical Practice
Authors: Wong Victor W. , Wan Derrick C. , Gurtner Geoffrey C. , Longaker Michael T.
Published: July 2012

Tissue engineering is a broad interdisciplinary field that aims to develop complex tissue and organ constructs through a combination of cell‐, biomaterial‐, and molecular‐based approaches. This approach has the potential to transform the surgical treatment for diseases including trauma, cancer, and congenital malformations. A fundamental knowledge of key concepts in regenerative medicine is imperative for surgeons to maintain a leading role in developing and implementing these technologies. Researchers have started to elucidate the biologic mechanisms that maintain organ homeostasis throughout life, indicating that humans may have the latent capacity to regenerate complex tissues. By exploiting this intrinsic potential of the body, we can move even closer to developing functional, autologous replacement parts for a wide range of surgical diseases.
Imprimeurs parisiens, libraires, fondeurs de caractères et correcteurs d'imprimerie, depuis l'introduction de l'imprimerie a Paris (1470) jusqu'a la fin du XVIe siècle
Authors: Renouard Philippe
Published: July 2012

Philippe Renouard (1862–1934) published this biographical directory of members of the Parisian book trade from the introduction of printing in 1470 until the sixteenth century in 1898. It replaced the only other existing catalogue, by Augustin-Martin Lottin, published more than a century earlier. Renouard corrected many of the errors in Lottin's catalogue and filled in gaps in information, extending his directory to include names and addresses of booksellers and printers, and the dates during which they were active, and family genealogies. The book also includes a map of the university quarter and city of Paris marked with the locations of former publishing houses. It remained the authoritative source on the topic until the 1960s, when the Bibliothèque Nationale published a newly revised and enlarged version.
Leçons sur les maladies du système nerveux
Authors: Charcot Jean-Martin
Published: July 2012

Jean-Martin Charcot (1825–93) was a professor of anatomical pathology at the Pitié-Salpêtrière Hospital in Paris, and one of the founders of modern neurology. Numerous disorders are named after him, and he was one of the best known doctors in nineteenth-century France. He was the first to describe and name multiple sclerosis, and undertook crucial research into what became known as Parkinson's Disease. He also worked on hysteria, and was one of Freud's teachers. These two volumes of lectures on neurological illnesses, first published in Paris in 1872–3 and 1877, were based on extensive clinical studies at the Salpêtrière, and edited by Désiré Magloire Bourneville. Detailed analysis of symptoms, sometimes using photography, combined with post-mortem analyses, allowed Charcot to produce classic descriptions of different neurological disorders. Volume 2 includes methods of clinical observation, and notes on spinal compression, infantile paralysis, Ménière's Disease, and epilepsy caused by syphilis.
JOINT UNIVERSALITY OF HURWITZ ZETA-FUNCTIONS
Authors: LAURINČIKAS ANTANAS
Published: July 2012

It is well known that Hurwitz zeta-functions with algebraically independent parameters over the field of rational numbers are universal in the sense that their shifts approximate simultaneously any collection of analytic functions. In this paper we introduce some classes of universal composite functions of a collection of Hurwitz zeta-functions.
DEGREE DISTANCE AND MINIMUM DEGREE
Authors: MUKWEMBI S. , MUNYIRA S.
Published: July 2012

Let G be a finite connected graph of order n, minimum degree δ and diameter d. The degree distance D′(G) of G is defined as ∑ {u,v}⊆V (G)(deg u+deg v) d(u,v), where deg w is the degree of vertex w and d(u,v) denotes the distance between u and v. In this paper, we find an asymptotically sharp upper bound on the degree distance in terms of order, minimum degree and diameter. In particular, we prove that \[ D^\prime (G)\le \frac {1}{4}\,dn\biggl (n-\frac {d}{3}(\delta +1)\biggr )^2+O(n^3). \] As a corollary, we obtain the bound D′ (G)≤n4 /(9(δ+1) )+O(n3) for a graph G of order n and minimum degree δ. This result, apart from improving on a result of Dankelmann et al. [‘On the degree distance of a graph’, Discrete Appl. Math.157 (2009), 2773–2777] for graphs of given order and minimum degree, completely settles a conjecture of Tomescu [‘Some extremal properties of the degree distance of a graph’, Discrete Appl. Math.98(1999), 159–163].
Pointwise-recurrent dendrite maps
Authors: NAGHMOUCHI ISSAM
Published: July 2012

Let $D$ be a dendrite and $f:D\rightarrow D$ a continuous map. Denote by $E(D)$ and $B(D)$ the sets of endpoints and branch points of $D$, respectively. We show that if $E(D)$ is countable, then $f$ is pointwise-recurrent if and only if $f$ is a pointwise-periodic homeomorphism; also, if $B(D)$ is discrete, then $f$ is pointwise-recurrent if and only if every point in $D\backslash E(D)$is periodic.
Perception of audio-visual speech synchrony in Spanish-speaking children with and without specific language impairment
Authors: PONS FERRAN , ANDREU LLORENÇ , SANZ-TORRENT MONICA , BUIL-LEGAZ LUCÍA , LEWKOWICZ DAVID J.
Published: July 2012

Speech perception involves the integration of auditory and visual articulatory information, and thus requires the perception of temporal synchrony between this information. There is evidence that children with specific language impairment (SLI) have difficulty with auditory speech perception but it is not known if this is also true for the integration of auditory and visual speech. Twenty Spanish-speaking children with SLI, twenty typically developing age-matched Spanish-speaking children, and twenty Spanish-speaking children matched for MLU-w participated in an eye-tracking study to investigate the perception of audiovisual speech synchrony. Results revealed that children with typical language development perceived an audiovisual asynchrony of 666 ms regardless of whether the auditory or visual speech attribute led the other one. Children with SLI only detected the 666 ms asynchrony when the auditory component followed the visual component. None of the groups perceived an audiovisual asynchrony of 366 ms. These results suggest that the difficulty of speech processing by children with SLI would also involve difficulties in integrating auditory and visual aspects of speech perception.
Functional characterization of the rod visual pigment of the echidna (Tachyglossus aculeatus), a basal mammal
Authors: BICKELMANN CONSTANZE , MORROW JAMES M. , MÜLLER JOHANNES , CHANG BELINDA S.W.
Published: July 2012

Monotremes are the most basal egg-laying mammals comprised of two extant genera, which are largely nocturnal. Visual pigments, the first step in the sensory transduction cascade in photoreceptors of the eye, have been examined in a variety of vertebrates, but little work has been done to study the rhodopsin of monotremes. We isolated the rhodopsin gene of the nocturnal short-beaked echidna (Tachyglossus aculeatus) and expressed and functionally characterized the proteinin vitro. Three mutants were also expressed and characterized: N83D, an important site for spectral tuning and metarhodopsin kinetics, and two sites with amino acids unique to the echidna (T158A and F169A). Theλmaxof echidna rhodopsin (497.9 ± 1.1 nm) did not vary significantly in either T158A (498.0 ± 1.3 nm) or F169A (499.4 ± 0.1 nm) but was redshifted in N83D (503.8 ± 1.5 nm). Unlike other mammalian rhodopsins, echidna rhodopsin did react when exposed to hydroxylamine, although not as fast as cone opsins. The retinal release rate of light-activated echidna rhodopsin, as measured by fluorescence spectroscopy, had a half-life of 9.5 ± 2.6 min−1, which is significantly shorter than that of bovine rhodopsin. The half-life of the N83D mutant was 5.1 ± 0.1 min−1, even shorter than wild type. Our results show that with respect to hydroxylamine sensitivity and retinal release, the wild-type echidna rhodopsin displays major differences to all previously characterized mammalian rhodopsins and appears more similar to other nonmammalian vertebrate rhodopsins such as chicken and anole. However, our N83D mutagenesis results suggest that this site may mediate adaptation in the echidna to dim light environments, possiblyviaincreased stability of light-activated intermediates. This study is the first characterization of a rhodopsin from a most basal mammal and indicates that there might be more functional variation in mammalian rhodopsins than previously assumed.
A school-based supplementary food programme in rural Kenya did not reduce children's intake at home
Authors: Gewa Constance A , Murphy Suzanne P , Weiss Robert E , Neumann Charlotte G
Published: July 2012

Objective

To examine changes in energy intake along with markers of dietary quality (animal-source energy and protein intakes) among household members in the presence of supplementary school feeding in rural Kenya.

Design

A 2-year, longitudinal, randomized controlled feeding intervention study.

Setting

Kyeni South Division, Embu District, Kenya.

Subjects

A total of 182 schoolchildren and selected household members.

Results

There was no evidence that schoolchildren who received supplementary snacks at school experienced reduced intakes at home or that intakes by other family members were increased at the expense of the schoolchild's intake.

Conclusions

This analysis highlights a number of factors useful in planning for supplementary feeding interventions in rural Kenya and similar communities.
SCRIPT WITHOUT BUDDHISM: BURMESE INFLUENCE ON THE TAY (SHAN) SCRIPT OF MÄNG2 MAAW2 AS SEEN IN A CHINESE SCROLL PAINTING OF 1407
Authors: Daniels Christian
Published: July 2012

This article substantiates for the first time that Tay (Shan) script was written on a Ming dynasty scroll dated 1407. In the past, Tay scholars have assumed that early Tay script exhibited uniquely Tay characteristics from the outset, and only gradually acquired Burmese features after the eighteenth and nineteenth centuries. The data presented here demonstrates beyond doubt that the Tay borrowed heavily from the Burmese script to create their writing system before the fifteenth century. It also shows that the 1407 Tay script resembled the Ahom script more than the lik6 tho3 ngök6 script, and on the basis of this similarity concludes that lik6 tho3 ngök6 was not the progenitor of Tay scripts, as previously thought, and that the Ahom script preceded it.

The impact of Burmese script on the Tay writing system from the outset raises the broader issue of borrowing from Burman culture during the Pagan and early Ava periods. The Tay of Mäng2 Maaw2 and surrounding polities turned to Pagan and Ava for a written script, but shunned Theravada Buddhism, the religious apparatus that we assume always accompanied the spread of writing. Their adoption of a writing system stands out as a rare case of script without Buddhism in northern continental Southeast Asia. To the Tay, Pagan and Ava were dominant political powers worthy of emulation, and the adoption of their writing system attests the magnitude of its influence. It is hypothesized that such borrowing arose out of Tay aspirations for self-strengthening their polities, possibly in an endeavour to rival the Burman monarchy. Tay script emerged in an age when the Burman language had just become predominant among the elites of Pagan and early Ava. Two features of this case stand out. First, the Tay borrowed at a time when Burmese script was relatively novel and still the preserve of the Burman elite, a fact which reinforces the notion of borrowing for prestige value as well as practical utility. Second, the Tay gravitated towards the northern parts of Pagan and Ava, rather than the southern areas where Mon language retained predominance in inscriptions.
When What We Get Is Not What We Want
Authors: Gleibs Ilka H. , Täuber Susanne , Viki G. Tendayi , Giessner Steffen R.
Published: July 2012

By integrating an intergroup perspective on mergers with discrepancy theories, we argue that merger partners aim for merger patterns that best benefit their group’s standing. Importantly, we hypothesize and show that the discrepancy between what merger partners want and what they actually get affects outcomes essential to merger success. Specifically, we demonstrate that perceived fit between the implemented and the desired merger pattern predicts support for the merger. We further show that this effect is mediated by perceived fairness (Study 1) and emotional reactions to the merger (Study 2). Our findings are generalized across a field study that investigate a real merger between two institutions of higher education (Study 1) and an experiment (Study 2).
Reduction in Cognitive Dissonance According to Normative Standards in the Induced Compliance Paradigm
Authors: Voisin Dimitri , Fointiat Valérie
Published: July 2012

This study investigated the influence of the assessment of the discrepant act on dissonance reduction. In particular, we tested the influence of normative standards on a trivialization of the discrepant act and the assessment of research topic importance. The results suggest that dissonance reduction varies depending on whether the discrepant act is assessed as violating normative standards or not. In the cognitive dissonance state and in the absence of standards, performing a discrepant act leads individuals to trivialize it. However, when individuals perceive that the discrepant act violates normative standards, they reduce cognitive dissonance by overestimating the research topic. This result is interpreted in terms of the avoidance of negative consequences of social control reactions and the protection of self-concept.
Traveling magnetopause distortion related to a large‐scale magnetosheath plasma jet: THEMIS and ground‐based observations
Authors: Dmitriev A. V. , Suvorova A. V.
Published: July 2012

Here, we present a case study of THEMIS and ground‐based observations of the perturbed dayside magnetopause and the geomagnetic field in relation to the interaction of an interplanetary directional discontinuity (DD) with the magnetosphere on 16 June 2007. The interaction resulted in a large‐scale local magnetopause distortion of an “expansion – compression – expansion” (ECE) sequence that lasted for ∼15 min. The compression was caused by a very dense, cold, and fast high‐βmagnetosheath plasma flow, a so‐called plasma jet, whose kinetic energy was approximately three times higher than the energy of the incident solar wind. The plasma jet resulted in the effective penetration of magnetosheath plasma inside the magnetosphere. A strong distortion of the Chapman‐Ferraro current in the ECE sequence generated a tripolar magnetic pulse “decrease – peak– decrease” (DPD) that was observed at low and middle latitudes by some ground‐based magnetometers of the INTERMAGNET network. The characteristics of the ECE sequence and the spatial‐temporal dynamics of the DPD pulse were found to be very different from any reported patterns of DD interactions with the magnetosphere. The observed features only partially resembled structures such as FTE, hot flow anomalies, and transient density events. Thus, it is difficult to explain them in the context of existing models.
Dual‐spacecraft radio occultation measurement of the electron density near the lunar surface by the SELENE mission
Authors: Ando H. , Imamura T. , Nabatov A. , Futaana Y. , Iwata T. , Hanada H. , Matsumoto K. , Mochizuki N. , Kono Y. , Noda H. , Liu Q. , Oyama K.‐I. , Yamamoto Z. , Saito A.
Published: July 2012

During the SELENE (Kaguya) mission the dual‐spacecraft radio occultation technique was used to investigate the electron population in the vicinity of the lunar surface. One pair of coherent S‐band radio signals from one spacecraft was used to probe the possible electron density enhancement near the Moon, and another signal pair from the other spacecraft measured the solar wind and the terrestrial ionosphere plasma fluctuations, which also exist in the measurement by the former signal pair. The results suggest that any stable ionosphere with densities comparable to the ones observed by the Soviet Luna 19 and 22 missions does not exist near the terminator at high latitudes, although the occurrence of temporal or localized density enhancements cannot be ruled out.
Web site lets solar scientists inform and inspire students
Authors: Hauck Karin
Published: July 2012

Where on the Web can a middle school girl ask a female solar scientist about solar storms, the course and behavior of charged solar particles, and the origin of the Sun's dynamo—and also find out what the scientist was like as a child, whether the scientist has tattoos or enjoys snowboarding, what she likes and dislikes about her career, and how she balances her energy for work and family life? These kinds of exchanges happen at Solar Week (http://www.solarweek.org; see Figure 1). Established in 2000, Solar Week is an online resource for middle and lower high school students about the science of the Sun, sponsored by the Center for Science Education at the Space Sciences Laboratory (CSE@SSL) at the University of California, Berkeley (UC Berkeley). The Web site's goals are to educate students about the Sun and solar physics and to encourage future careers in science—especially for girls. One way is by giving solar scientists the chance to be relatable role models, to answer students' questions, and to share their experiences in an online forum.
Exploring the vents, ridges, rocks, and geothermal spas of the Reykjanes Peninsula
Authors: Ramsayer Kate
Published: July 2012

Renting a submarine to explore the deepsea basalt lava flows of the Mid‐Atlantic Ridge is a pricey proposition. But on a field trip to Iceland's Reykjanes Peninsula following the Chapman Conference on Volcanism and the Atmosphere, participants were able to stay on dry land to explore the volcanic features of the ridge where the Eurasian and North American plates are spreading apart. “If you're interested in ocean ridge basalt, the Reykjanes Ridge is your place,” said Karl Grönvold, a geochemist with the Institute of Earth Sciences at the University of Iceland. Grönvold led the daylong field trip to geologic sites of interest in southwest Iceland, including the ridge, fumaroles, boiling hot pots, and the geothermal spa and power plant at the Blue Lagoon.
Scientists and education professionals can present at Geophysical Information for Teachers Workshop
Authors: Adamec Bethany , Asher Pranoti
Published: July 2012

As many members know, every year at the Fall Meeting, the AGU Education and Public Outreach department collaborates with the National Earth Science Teachers Association (NESTA) to hold a workshop for K–12 Earth and space science teachers and informal educators. These Geophysical Information for Teachers (GIFT) workshops allow science teachers to hear about the latest Earth and space research from the scientists making the discoveries, explore new classroom resources for their students, and visit exhibits and technical sessions during the meeting for free. Successful GIFT workshops were held at the December 2010 and 2011 meetings, where excellent teams of presenters discussed a range of topics that addressed AGU's science and society and education goals and objectives (see http://www.agu.org/about/strategic_plan.shtml).
Outstanding Student Paper Awards
Authors: Anonymous
Published: July 2012

The following members received Outstanding Student Paper Awards at the 2011 AGU Fall Meeting in San Francisco, Calif. See also “Outstanding Student Paper Awards” published previously (Eos, 93(27), 253–254) and in future issues of Eos.
Intraseasonal temperature variability in the upper troposphere and lower stratosphere from the GPS radio occultation measurements
Authors: Tian Baijun , Ao Chi O. , Waliser Duane E. , Fetzer Eric J. , Mannucci Anthony J. , Teixeira Joao
Published: July 2012

In this study, we examine the detailed spatiotemporal patterns and vertical structure of the intraseasonal temperature variability in the upper troposphere and lower stratosphere (UTLS) associated with the Madden‐Julian Oscillation (MJO) using the temperature profiles from the recent Global Positioning System radio occultation (GPS RO) measurements including the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) mission. The MJO‐related temperature anomalies in the UTLS are smaller near the equator (<0.6 K) than over the subtropics and extratropics (>1.2 K). Near the equator, the temperature anomalies exhibit an eastward tilt with height from the upper troposphere (UT) to the lower stratosphere (LS) and their magnitudes and signs are determined by the strength of convective anomalies and vertical pressure level. The subtropical temperature anomalies have similar magnitudes and patterns at a given location between the UT (250 hPa to 150 hPa) and the LS (150 hPa to 50 hPa) except for opposite signs that change around 150 hPa. The subtropical warm (cold) anomalies in the UT and cold (warm) anomalies in the LS are typically collocated with the subtropical positive (negative) tropopause height anomalies/cyclones (anticyclones) and flank or lie to the west of equatorial enhanced (suppressed) convection. We also compare the intraseasonal temperature variability in the UTLS related to the MJO between the GPS RO and Atmospheric Infrared Sounder (AIRS) measurements to highlight the new features of the GPS RO temperature anomalies and to evaluate the quality of the AIRS temperature in the UTLS considering the GPS RO temperature in the UTLS as the benchmark. Both AIRS and GPS RO have a very consistent vertical structure in the subtropical UTLS with a high correlation coefficient 0.92 and similar magnitudes. Both AIRS and GPS RO also show a generally consistent vertical structure of the intraseasonal temperature anomalies in the equatorial UTLS. However, GPS RO reveals many detailed fine‐scale vertical structures of the equatorial temperature anomalies between 150 and 50 hPa that are not well captured by AIRS. Furthermore, the equatorial temperature anomalies are about 40% underestimated in AIRS in comparison to GPS RO, over the equatorial Indian and western Pacific Oceans for 250 hPa and over all longitudes for 100 hPa. The low sampling within the optically thick clouds and low vertical resolution near the tropopause may both contribute to these deficiencies of AIRS.
Comparing the impacts of mitigation versus non‐intervention scenarios on future temperature and precipitation extremes in the HadGEM2 climate model
Authors: Caesar John , Lowe Jason A.
Published: July 2012

Although international climate change negotiations focus on global mean temperature targets, it is also important to assess the impact of emission scenarios on climate extremes at the global and regional scale. This paper examines how temperature and precipitation extremes indices are projected to change around the globe during the 21st Century under an aggressive climate change mitigation scenario in the United Kingdom Met Office Hadley Centre HadGEM2‐AO coupled climate model, and how these changes might differ from a mid‐range non‐intervention scenario. Even under an aggressive mitigation strategy there are projected increases in warm temperature extremes on a global and regional scale up to the mid‐21st Century, and temperature extremes tend to follow a similar trajectory to the projected global mean temperature change associated with each scenario. Changes in precipitation‐related extremes are projected to be more variable. There are regional differences in the direction of changes and it appears that the aerosol forcing associated with the scenarios could have an important influence. The regions which are projected to benefit most from mitigation vary depending on the index being considered, but in general absolute increases in temperature extremes are reduced in the northern midlatitudes, whereas for frequency based indices it is northern South America, parts of the USA, Africa and Asia which see the largest avoided increases. For precipitation indices, northern South America sees the most consistent signal toward avoided drying conditions, along with the Mediterranean and parts of Russia and central Asia.
Study of chemoresistant CD133+ cancer stem cells from human glioblastoma cell line U138MG using multiple assays
Authors: Warrier Sudha , Pavanram Prathyusha , Raina Dhruv , Arvind Milan
Published: July 2012

Glioblastoma is one of the most common malignant tumours in adults, with an average life expectancy of less than 1 year. The high mortality of glioblastomas is attributed to its resistance to conventional chemotherapeutic agents. Numerous studies have established the presence of a cancer stem population within glioblastomas. These CSC (cancer stem cell) populations express the cell‐surface marker, CD133, and are tumorigenic and chemoresistant. Hence, CSCs make a potential target for anticancer therapies. We have focused on techniques that can reliably identify and isolate a viable CSC population, and studied their chemoresistant attributes. We show the presence of a CSC population within a slowly proliferating glioblastoma cell line, U138MG. An improvised neurosphere enrichment culture technique was developed for the isolation of CSC population. Stem cell neurospheres obtained by this protocol maintained their viability for several weeks, and could be redispersed for deriving colony‐forming units and secondary spheres from single‐cell suspensions. RT‐PCR (reverse transcription–PCR), cell surface localization by immunofluorescence and enumeration by FACS analysis showed that the sphere cultures of U138MG grown on agarose‐coated plates had elevated CD133 levels. Drug sensitivity assays indicated that these enriched spheres were more resistant to drug treatment than their non‐CSC controls. Drug‐resistant CSC had an increased expression of ABC (ATP‐binding‐cassette) drug transporters, such as ABCC2, ABCC4, ABCG2 and p‐glycoprotein, indicative of their role in the resistance mechanisms. These studies will facilitate the development of in vitro assays for the sparse CSC population and strategies for improved treatment regimens for glioblastomas.
Spoken Persuasive Discourse Abilities of Adolescents With Acquired Brain Injury
Authors: Moran Catherine , Kirk Cecilia , Powell Emma
Published: July 2012

Purpose

The aim of this study was to examine the performance of adolescents with acquired brain injury (ABI) during a spoken persuasive discourse task. Persuasive discourse is frequently used in social and academic settings and is of importance in the study of adolescent language.

Method

Participants included 8 adolescents with ABI and 8 peers without ABI who were matched for age, gender, and education. A spoken persuasive discourse task requiring participants to express their opinion on a topic was administered, and the 2 groups were compared on measures of language productivity, syntactic complexity, and language content. In addition, the relationship between working memory and discourse production was explored.

Results

There were no statistically significant group differences on measures of language productivity or syntactic complexity, with the exception of the use of mazes, which was more prevalent in the discourse of the group with ABI. However, there were significant differences in language content, with age-matched peers producing more than twice as many supporting reasons and far fewer tangentially related utterances than the adolescents with ABI.

Conclusions

Persuasive discourse production was affected following ABI. Given the importance of persuasive discourse in social and academic situations, further investigations into factors that influence discourse production in adolescents with ABI are warranted.
Auditory Training for Children With Auditory Processing Disorder and Language Impairment: A Response to Bellis, Chermak, Weihing, and Musiek
Authors: Fey Marc E. , Kamhi Alan G. , Richard Gail J.
Published: July 2012

Purpose

We respond to Bellis, Chermak, Weihing, and Musiek’s (2012) criticisms of the evidence-based systematic review of Fey et al. (2011) on the effects of auditory training on auditory, spoken, and written language performance of children with auditory processing disorder or language impairment. In general, we argue that the conceptualizations and methods on which our review was based were well motivated, and that our original conclusions are valid given the limited evidence that is currently available from clinical studies of auditory training with school-age children with auditory processing disorder or language impairment.
Salivary Gland Trauma: A Review of Diagnosis and Treatment
Authors: Lazaridou Maria , Iliopoulos Christos , Antoniades Kostas , Tilaveridis Ioannis , Dimitrakopoulos Ioannis , Lazaridis Nicolas
Published: July 2012

Salivary gland trauma is uncommon. Parotid gland and duct injuries are far more common than injuries to submandibular and sublingual glands due to anatomic position. Several methods of treating salivary duct injuries and their complications have been advocated. Optimal treatment outcomes can be achieved with early diagnosis, adequate evaluation, and proper management. This article presents current diagnostic and treatment protocols of salivary gland trauma. The anatomy of the salivary glands is briefly described and clinical cases are also presented to illustrate the treatment options described.
Correcting for atmospheric distortion in telescopes
Authors: Levi Barbara G.
Published: July 2012

Optical astronomers are frequently hampered by atmospheric turbulence that distorts telescopic images by causing random phase shifts in the incoming light. These distortions often reduce the resolution of a telescope far below its diffraction limit. But the outlook may be brightened by new techniques now being developed to detect and correct for the phase error in real time. Until now most techniques to correct for atmospheric distortions have been post-detection compensation techniques: The effects of turbulence are extracted after the image data has been recorded. Three of the groups that are conducting major development efforts on real-time compensation described their work at a conference on Optical Propagation Through Turbulence that was sponsored by the Optical Society of America at the University of Colorado, 9–11 July. These three groups are from Hughes Research Laboratories, from Itek Corporation and from Lawrence Berkeley Laboratory and the Institute for Advanced Studies.
Microwave resonances of ultrathin hexagonally symmetric microcavity arrays
Authors: Brown J. R. , Hibbins A. P. , Lawrence C. R. , Lockyear M. J. , Sambles J. R.
Published: July 2012

A metamaterial surface formed by three slot gratings at 60° to each other has two possible high-symmetry arrangements. One forms equilateral triangular metal patches, the other a combination of hexagons and small equilateral triangles. When spaced above a ground plane with a thin dielectric spacer both structures give strong microwave absorption at certain resonant frequencies, which is largely angle independent. The results of microwave reflectivity measurements are here presented for the two distinct sample geometries and compared with predictions from finite element method models.
Photomechanical bending mechanics of polydomain azobenzene liquid crystal polymer network films
Authors: Cheng Liang , Torres Yanira , Min Lee Kyung , McClung Amber J. , Baur Jeffery , White Timothy J. , Oates William S.
Published: July 2012

Glassy, polydomain azobenzene liquid crystal polymer networks (azo-LCNs) have been synthesized, characterized, and modeled to understand composition dependence on large amplitude, bidirectional bending, and twisting deformation upon irradiation with linearly polarized blue-green (440–514 nm) light. These materials exhibit interesting properties for adaptive structure applications in which the shape of the photoresponsive material can be rapidly reconfigured with light. The basis for the photomechanical output observed in these materials is absorption of actinic light by azobenzene, which upon photoisomerization dictates an internal stress within the local polymer network. The photoinduced evolution of the underlying liquid crystal microstructure is manifested as macroscopic deformation of the glassy polymer film. Accordingly, this work examines the polarization-controlled bidirectional bending of highly concentrated azo-LCN materials and correlates the macroscopic output (observed as bending) to measured blocked stresses upon irradiation with blue-green light of varying polarization. The resulting photomechanical output is highly dependent on the concentration of crosslinked azobenzene mesogens employed in the formulation. Experiments that quantify photomechanical bending and photogenerated stress are compared to a large deformation photomechanical shell model to quantify the effect of polarized light interactions with the material during static and dynamic polarized light induced deformation. The model comparisons illustrate differences in internal photostrain and deformation rates as a function of composition and external mechanical constraints.
Linearized potential vorticity mode and its role in transition to baroclinic instability
Authors: Pieri A. B. , Cambon C. , Godeferd F. S. , Salhi A.
Published: July 2012

In addition to the effect of stable stratification and uniform shear in turbulent flows, a case which has already been modelled using linear approaches (rapid distortion theory) and direct numerical simulations, we introduce the effect of uniform rotation. Assuming the rotation axis to be vertical, and aligned with the gradients of density and mean velocity, an enslaved horizontal stratification is forced and baroclinic instability can occur. In that case, the linear analysis shows an extension of the unstable domain up to a gradient Richardson number \documentclass[12pt]{minimal}\begin{document}$\textit {Ri}$\end{document}Ri of 1 for kx = 0 modes. First, we extend this asymptotic analysis at t → ∞ to kx ≠ 0 modes. We show that these modes lead asymptotically to oscillating bounded solutions whose frequency depend only on the rotation number \documentclass[12pt]{minimal}\begin{document}$R=1/\textit {Ro}$\end{document}R=1/Ro. The analysis of the transition to baroclinic instability is then completed with a discussion of the role of kx ≈ 0 modes—small streamwise wavenumbers—and of the importance of coupling with the potential vorticity mode \documentclass[12pt]{minimal}\begin{document}$u^{(\Omega _{pot})}$\end{document}u(Ωpot) or Ertel's mode. The latter is shown to be determinant for dramatic transient growth at intermediate times. The structure of the stratified, sheared, rotating flow is predicted using a stochastic linear approach (referred to as kinematic simulation) to complete the rapid distortion theory analysis.
The high-pressure electronic structure of the [Ni(ptdt)2] organic molecular conductor
Authors: Tulip P. R. , Bates S. P. , Clark S. J.
Published: July 2012

The electronic structure of the single component molecular crystal [Ni(ptdt)2] (ptdt = propylenedithiotetrathiafulvalenedithiolate) is determined at ambient and high pressure using density functional theory. The electronic structure of this crystal is found to be of the “crossing bands” type with respect to the dispersion of the HOMO and LUMO, resulting in a small, non-zero density of states at the Fermi energy at ambient pressure, indicating that this crystal is a “poor quality” metal, and is consistent with the crystal's resistivity exhibiting a semiconductor-like temperature dependence. The ambient pressure band structure is found to be predominantly one-dimensional, reflecting enhanced intermolecular interactions along the [100] stacking direction. Our calculations indicate that the band structure becomes two-dimensional at high pressures and reveals the role of shortened intermolecular contacts in this phenomenon. The integrity of the molecular structure is found to be maintained up to at least 22 GPa. The electronic structure is found to exhibit a crossing bands nature up to 22 GPa, where enhanced intermolecular interactions increase the Brillouin zone centre HOMO-LUMO gap from 0.05 eV at ambient pressure to 0.15 eV at 22 GPa; this enhanced HOMO-LUMO interaction ensures that enhancement of a metallic state in this crystal cannot be simply achieved through the application of pressure, but rather requires some rearrangement of the molecular packing. Enhanced HOMO-LUMO interactions result in a small density of states at the Fermi energy for the high pressure window 19.8–22 GPa, and our calculations show that there is no change in the nature of the electronic structure at the Fermi energy for these pressures. We correspondingly find no evidence of an electronic semiconducting-metal insulator transition for these pressures, contrary to recent experimental evidence [Cui et al., J. Am. Chem. Soc. 131, 6358 (2009)]10.1021/ja901553z.
Determination of optical damage cross-sections and volumes surrounding ion bombardment tracks in GaAs using coherent acoustic phonon spectroscopy
Authors: Steigerwald A. , Hmelo A. B. , Varga K. , Feldman L. C. , Tolk N.
Published: July 2012

We report the results of coherent acoustic phonon spectroscopy analysis of band-edge optical modification of GaAs irradiated with 400 keV Ne++ for doses between 1011–1013 cm−2. We relate this optical modification to the structural damage density as predicted by simulation and verified by ion channeling analysis. Crystal damage is observed to cause optical modification that reduces the amplitude of the optoacoustic signal. The depth-dependent nature of the optoacoustic measurement allows us to determine optical damage cross-sections along the ion track, which are found to vary as a function of position along the track. Unexpectedly, we find that this optical modification is primarily dependent on the structural damage density and insensitive to the specific defect configuration along the ion track, suggesting that a simple model of defect density along the track is sufficient to characterize the observed optical changes. The extent of optical modification is strongly probe frequency-dependent as the frequency is detuned from the GaAs band edge. As determined from the experimental measurements, the spatial extent of optical modification exceeds the spatial extent of the structural disorder by an order of magnitude.
Response to “Comment on ‘Dynamics of glass-forming liquids. XIII. Microwave heating in slow motion'” [J. Chem. Phys. 137, 027101 (2012)]
Authors: Huang Wei , Richert Ranko
Published: July 2012

A dielectric cell with a Teflon spacer covering the entire perimeter is advantageous for impedance experiments performed at electric fields of 450 kV/cm or more using a 10 μm electrode separation. While the large spacer surface makes a correction to the infinite frequency dielectric constant necessary if reliable permittivity data are desired, field induced relative changes are extremely insensitive to this problem. It is demonstrated that the field induced relative changes of the loss factor, tan δ, with and without correcting for the excess parallel capacitance are practically the same.
Strong enhancement of magnetoelectric coupling in Dy3+ doped HoMnO3
Authors: Magesh J. , Murugavel P. , Mangalam R. V. K. , Singh K. , Simon Ch. , Prellier W.
Published: July 2012

The magnetoelectric effect in Ho0.9Dy0.1MnO3 is found 31 times stronger than HoMnO3 which could be due to strong lattice frustration arises out of the structural distortion on doping. The TN observed from magnetic measurement reveals a double peak corresponding to the in-plane and inter-planar ordering leading to assignment of Γ4 structure. The antiferromagnetic transition at TN indeed drives dielectric transition mediated by the lattice strain whereas at the TSR, lattice strain drives the spin reorientation of Mn3+. In contrary to the long held belief, the magnetic structure changes from Γ4 to Γ1 at TSR instead of Γ4 to Γ3.
Heating and flooding: A unified approach for rapid generation of free energy surfaces
Authors: Chen Ming , Cuendet Michel A. , Tuckerman Mark E.
Published: July 2012

We propose a general framework for the efficient sampling of conformational equilibria in complex systems and the generation of associated free energy hypersurfaces in terms of a set of collective variables. The method is a strategic synthesis of the adiabatic free energy dynamics approach, previously introduced by us and others, and existing schemes using Gaussian-based adaptive bias potentials to disfavor previously visited regions. In addition, we suggest sampling the thermodynamic force instead of the probability density to reconstruct the free energy hypersurface. All these elements are combined into a robust extended phase-space formalism that can be easily incorporated into existing molecular dynamics packages. The unified scheme is shown to outperform both metadynamics and adiabatic free energy dynamics in generating two-dimensional free energy surfaces for several example cases including the alanine dipeptide in the gas and aqueous phases and the met-enkephalin oligopeptide. In addition, the method can efficiently generate higher dimensional free energy landscapes, which we demonstrate by calculating a four-dimensional surface in the Ramachandran angles of the gas-phase alanine tripeptide.
Anomalous low temperature stair like coercivity decrease due to magnetostatic coupling between superconducting and ferromagnetic particles in mixed powders
Authors: Marín P. , Aragón A. M. , Lieblich M. , García Escorial A. , Crespo P. , Hernando A.
Published: July 2012

Magnetization curves of mixed Nb and FeSi based micrometric particles have been analyzed. The influence of the dispersion of Nb particles on the mixture remanence and coercivity has been studied above and below the Nb superconducting critical temperature. The hysteresis loop shows, at 5 K and low applied fields, a decrease of both remanence and coercivity with respect to the one of pure ferromagnetic powders as well as a stair like profile. These features are explained as a consequence of the diamagnetic hysteresis loop of Nb giving rise to local stray fields acting on the ferromagnetic particles at its nearest neighboring.
Confinement of vacancies during annealing of H implanted GaN sandwiched between two {InGaN/GaN} superlattices
Authors: Cherkashin N. , Claverie A. , Sotta D. , Bethoux J.-M. , Capello L. , Kononchuk O.
Published: July 2012

Using transmission electron microscopy techniques, we identify the extended defects of interstitial and vacancy types found after H implantation and annealing in GaN. We statistically analyze the effect of boarding or sandwiching GaN between strained superlattices on these populations of defects. We finally demonstrate the possibility to use compressively strained layers to localize and favour the precipitation of vacancy type defects in GaN. The source of excess vacancies, the mechanism responsible for the cavity localization, and the drastic increase of their volume fraction are discussed.
Electrical and thermal spin accumulation in germanium
Authors: Jain A. , Vergnaud C. , Peiro J. , Le Breton J. C. , Prestat E. , Louahadj L. , Portemont C. , Ducruet C. , Baltz V. , Marty A. , Barski A. , Bayle-Guillemaud P. , Vila L. , Attané J.-P. , Augendre E. , Jaffrès H. , George J.-M. , Jamet M.
Published: July 2012

In this letter, we first show electrical spin injection in the germanium conduction band at room temperature and modulate the spin signal by applying a gate voltage to the channel. The corresponding signal modulation agrees well with the predictions of spin diffusion models. Then, by setting a temperature gradient between germanium and the ferromagnet, we create a thermal spin accumulation in germanium without any charge current. We show that temperature gradients yield larger spin accumulations than electrical spin injection but, due to competing microscopic effects, the thermal spin accumulation remains surprisingly unchanged under the application of a gate voltage.
Electronic effect of Na on Cu(In,Ga)Se2 solar cells
Authors: Cho Dae-Hyung , Lee Kyu-Seok , Chung Yong-Duck , Kim Ju-Hee , Park Soo-Jeong , Kim Jeha
Published: July 2012

We report the effect of Na on the electronic properties of Cu(In,Ga)Se2 (CIGS) thin-film solar cells with a structure of grid/ITO/i-ZnO/CdS/CIGS/Mo/SiOx/soda-lime glass (SLG). The diffusion of Na from the SLG into the CIGS layer was systematically controlled by varying the thickness of SiOx. As the Na content increased, the hole concentration of CIGS was enhanced, while the band-gap was nearly constant, which led to a lower Fermi level in the CIGS towards its valence-band edge. The Na-induced increment in the built-in potential (Vbi) across the n-(ITO/i-ZnO/CdS)/p-CIGS junction yielded an increment of open-circuit voltage that well agreed with the calculated Vbi.
Phonon conductivity in graphene
Authors: Alofi A. , Srivastava G. P.
Published: July 2012

The phonon conductivity in suspended graphene and in graphene nanoribbons has been studied within the framework of Callaway’s effective relaxation time theory. The conductivity expression has been computed by employing analytical expressions for phonon dispersion relations and vibrational density of states based on the semicontinuum model by Nihira and Iwata. It is found that the Normal-drift contribution to the conductivity, arising from the consideration of the momentum conserving nature of three-phonon Normal processes, is very important for explaining the magnitude as well as the temperature dependence of the experimentally measured results for suspended graphene.