bluuebunny/crossref_metadata_2025 huggingface dataset:
Profiling of innervations of mimetic muscles in fresh human cadavers using a modified Sihler's technique
Authors: Liu An‐Tang , Yu Da‐Zhi , Chen Gang , Dang Rui‐Shan , Zhang Ying‐Fan , Zhang Wen‐Jun , Liu Ben‐Li , Jiang Hua
Published: April 2010

The nerve map of the human face, although important in guiding facial surgery, has not been well defined. In this study we applied a modified Sihler's technique to profile intramuscular innervation of human mimetic muscles. Six fresh cadaveric heads were used. The intramuscular distribution of the facial nerve in human mimetic muscles was visualized using a modified Sihler's technique. Modified Sihler's staining revealed a three‐dimensional picture of the clearly purple‐black intramuscular facial and sensory nerves. The nerve branching patterns of both facial halves were asymmetrical. None of the fine nerve branches crossed over the midline. The facial nerve branches divided into secondary rami and formed a mesh‐like plexus before entering the target muscles at a right angle. The modified Sihler's technique can profile intramuscular innervation of human mimetic muscles. Our nerve map of the face offers valuable guidance for facial reanimation surgery, facial cosmetic surgery, and parotid surgery. Muscle Nerve, 2010
Quantification of sudomotor innervation: A comparison of three methods
Authors: Gibbons Christopher H. , Illigens Ben M.W. , Wang Ningshan , Freeman Roy
Published: April 2010

Peripheral sudomotor dysfunction is present in many peripheral neuropathies, but structural assessments of sudomotor fibers rarely occur. We evaluated 36 diabetic and 72 healthy control subjects who underwent detailed neurologic examinations and punch skin biopsies. Physical exam findings were quantified by neuropathy impairment score in the lower limb. Skin biopsies quantified intraepidermal nerve fiber density (IENFD) and sweat gland nerve fiber density (SGNFD) by a manual, automated, and semiquantitative method. The automated and manual SGNFD correlated with the IENFD at the same site (r = 0.62, P < 0.05 automated method, r = 0.67, P < 0.05 manual method). As neuropathy worsened, the SGNFD at the distal leg declined (automated counting r = −0.81, P < 0.001; manual counting r = −0.88, P < 0.001). The semiquantitative method displayed poor inter‐ and intrareviewer reliability and correlated poorly with standard neuropathy evaluation scores. Our results suggest that sudomotor fibers can be rapidly and reproducibly quantified, and results correlate well with physical exam findings. Muscle Nerve, 2010
Diaphragm displays early and progressive functional deficits in dysferlin‐deficient mice
Authors: Barton Elisabeth R. , Wang Bing Jing , Brisson Becky K. , Sweeney H. Lee
Published: April 2010

Mouse lines with dysferlin deficiency are accepted animal models for limb girdle muscular dystrophy 2B and Miyoshi myopathy, yet slow progression of pathology prevents rapid screening of potential therapies for this disease. Our goal was to define a functional signature for skeletal muscles that lack dysferlin. Force generation and susceptibility to eccentric contractile injury measurements were performed in isolated limb muscles and the diaphragm from 10‐ and 36‐week‐old A/J and age‐matched control mice. Limb muscles had normal specific force at both 10 and 36 weeks, whereas the diaphragm had significant deficits in both specific force and susceptibility to eccentric contractile injury. Membrane ruptures in the diaphragm during eccentric contractions occurred predominantly in myosin heavy chain 2A‐expressing fibers. Dysferlin content did not vary significantly between wildtype muscles, suggesting that there was no correlation between disease severity and normal endogenous levels of the protein. These studies show that, unlike limb muscles, the diaphragm from the A/J mouse displays early deficits in function that may lower the age needed for evaluating potential therapies for dysferlinopathies. Muscle Nerve, 2010
Quadriceps low‐frequency fatigue and muscle pain are contraction‐type‐dependent
Authors: Iguchi Masaki , Shields Richard K.
Published: April 2010

Eccentric contractions are thought to induce greater low‐frequency fatigue (LFF) and delayed‐onset muscle soreness (DOMS) than concentric contractions. In this study we induced a similar amount of eccentric quadriceps muscle fatigue during either a concentric or eccentric fatigue task to compare LFF and DOMS. Subjects (n = 22) performed concentric or eccentric fatigue tasks using 75% of the pre‐fatigue maximal voluntary contraction (MVC) torque, and both tasks ended when the MVC eccentric torque decreased by 25% pre‐fatigue. When subjects reached the failure criterion during the eccentric and concentric tasks, the concentric MVC was 78 ± 9.8% and 64 ± 8.4% of initial, respectively. LFF was greater after the concentric than the eccentric protocols (22 ± 12.4% and 15 ± 7.6% increase, respectively; P < 0.01). DOMS was over 100% greater for the eccentric protocol. These results indicate that DOMS is not dependent on the events that contribute to LFF. Muscle Nerve, 2010
Can a patient‐centred approach to epilepsy improve outcomes?
Authors: Sander Ley , Jacoby Ann , Leach John Paul
Published: April 2010

It is recognised that antiepileptic drug choice is driven by the desire for seizure control, but patient quality of life and consideration of other factors are also important for the treatment of the individual as a whole. In this expert panel discussion, three specialists discuss the benefits and potential for improved outcomes of a patient‐centred approach to epilepsy management. Copyright © 2010 Wiley Interface Ltd
Data assimilation with regularized nonlinear instabilities
Authors: Abarbanel Henry D. I. , Kostuk Mark , Whartenby William
Published: April 2010

In variational formulations of data assimilation, the estimation of parameters or initial state values by a search for a minimum of a cost function can be hindered by the numerous local minima in the dependence of the cost function on those quantities. We argue that this is a result of instability on the synchronization manifold where the observations are required to match the model outputs in the situation where the data and the model are chaotic. The solution to this impediment to estimation is given as controls moving the positive conditional Lyapunov exponents on the synchronization manifold to negative values and adding to the cost function a penalty that drives those controls to zero as a result of the optimization process implementing the assimilation. This is seen as the solution to the proper size of ‘nudging’ terms: they are zero once the estimation has been completed, leaving only the physics of the problem to govern forecasts after the assimilation window.

We show how this procedure, called Dynamical State and Parameter Estimation (DSPE), works in the case of the Lorenz96 model with nine dynamical variables. Using DSPE, we are able to accurately estimate the fixed parameter of this model and all of the state variables, observed and unobserved, over an assimilation time interval [0, T]. Using the state variables at T and the estimated fixed parameter, we are able to accurately forecast the state of the model for t > T to those times where the chaotic behaviour of the system interferes with forecast accuracy. Copyright © 2010 Royal Meteorological Society
Capillary electrophoresis/mass spectrometry for the separation and characterization of bovine Cu,Zn‐superoxide dismutase
Authors: Borges‐Alvarez Marta , Benavente Fernando , Barbosa José , Sanz‐Nebot Victoria
Published: April 2010

The native form of Cu,Zn‐superoxide dismutase (SOD‐1) is a homodimer that coordinates one Cu2+ and one Zn2+ per monomer. Cu2+ and Zn2+ ions play crucial roles in enzyme activity and structural stability, respectively. In addition, dimer formation is essential for SOD‐1 functionality, and in humans several SOD‐1 mutant isoforms have been associated with certain types of amyotrophic lateral sclerosis (ALS), a progressive neurodegenerative disorder. In this paper we used capillary electrophoresis and mass spectrometry to study the different structures of bovine SOD‐1. The metal ions of the native enzyme (Cu2,Zn2‐dimer SOD‐1) were released in acidic medium in order to obtain apo‐SOD‐1, which is a monomer. Both substances were analyzed by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) and capillary electrophoresis with ultraviolet and electrospray ionization mass spectrometry detection (CE/UV and CE/ESI‐MS, respectively). With MALDI‐TOF‐MS, using matrices of sinapinic acid (SA) or 2,5‐dihydroxybenzoic acid (DHB) with or without trifluoroacetic acid (TFA), similar mass spectra were obtained for the metalated and non‐metalated samples. In both cases, an average molecular mass corresponding to the apo‐monomer SOD‐1 was calculated. This finding indicated that the metals were released from the Cu2,Zn2‐dimer SOD‐1 during sample preparation or ionization. For CE/UV and CE/ESI‐MS, two background electrolytes (BGEs) potentially compatible with ESI‐MS detection were used, namely 1 M of acetic acid (pH 2.3) and 10 mM of ammonium acetate (pH 7.3). Using a sheath liquid of 2‐propanol/water (60:40 v/v), with or without 0.1% v/v of formic acid, CE/ESI‐MS sensitivity was enhanced when the acidic BGE and the acidic sheath liquid were used. However, the electrophoretic profiles and the mass spectra obtained suggested that the metals of Cu2,Zn2‐dimer SOD‐1 were released, which generated the apo‐monomer during the electrophoretic separation. The neutral BGE provided enhanced conditions for the detection of the native enzyme. The differences between the mass spectra obtained for the Cu2,Zn2‐dimer and the apo‐monomer forms were significant and the presence of formic acid in the sheath liquid affected only sensitivity. Our results highlight the importance of selecting appropriate non‐denaturing separation and detection conditions to obtain reliable structural information about non‐covalent protein complexes by CE/ESI‐MS. Copyright © 2010 John Wiley & Sons, Ltd.
Shapes and morphologies of inkjet‐printed nanosilver dots on glass substrates
Authors: Lee Dong Jun , Oh Je Hoon
Published: April 2010

We investigated the effects of surface wettability, substrate temperature, and overprinting on the shapes and morphologies of dried and sintered inkjet‐printed dots of nanosilver suspensions. The surface wettability was modified by two different plasma surface treatments: C4F8 plasma treatment for hydrophobic surface and O2 plasma treatment for hydrophilic surface. The substrate temperature was varied from 25 to 85 °C with an interval of 20 °C. In order to change the dot thickness, dots were overprinted up to three times after complete drying of the ones previously printed. Printed dots were sintered for 1 h at 210 °C. The shapes and morphologies of dried dots including both single and overprinted dots were strongly influenced by the surface wettability of the substrate. The cross‐sectional profile was more convex on the hydrophobic surface at lower substrate temperature, but stack‐like morphologies of overprinted dots were obtained on both surfaces at higher substrate temperature due to the fast evaporation of solvent and coffee ring effect. Dots on hydrophilic surfaces experienced more shrinkage after sintering, and the shrinkage ratio of sintered dots tended to decrease with an increase in the number of overprints. The microstructure of sintered dots showed that nanoparticle clusters were more closely packed on hydrophobic surfaces. Copyright © 2010 John Wiley & Sons, Ltd.
Localised corrosion on 2219 aluminium alloy coated with a titanium based conversion coating
Authors: Grilli R. , Watts J. F. , Baker M. A. , Dunn B.
Published: April 2010

High strength aluminium alloys are widely employed in aerospace applications. However, specific environmental conditions may trigger corrosion and therefore these alloys require additional protection. Most current conversion coatings used for this purpose are Cr(VI) based, and thus environmentally undesirable. A possible replacement is a Ti‐based coating, Nabutan STI/310. The aim of this work is to gain a better understanding of corrosion mechanisms of the Al alloy surfaces coated with Nabutan, focusing on the role of intermetallic precipitates in pitting corrosion. The second‐phase precipitates in Al 2219 alloy were characterised by means of Auger electron spectroscopy (AES), scanning Auger microscopy (SAM) and energy dispersive X‐ray spectroscopy (EDX). The surface was then coated and the same precipitate was analysed to observe how the coating had deposited on the intermetallics and the matrix. Subsequently, the behaviour of the precipitate in a 3.5% NaCl solution was investigated as a function of exposure time: 15 min, 45 min, 2 h, 4 h and 8 h. At the end of each exposure, the sample was returned to the microscope and the same precipitates reanalysed. The results showed how the coating deposited preferentially on the matrix. During the immersions, the coating itself suffered a progressive degradation. Corrosion products rich in aluminium and oxygen were found to increasingly accumulate in a random manner over the matrix, as a function of time. Fe and Mn from the alloy and Ti from the conversion coating did not show any major activity. Cu deposits were found after 8 h of immersion. Copyright © 2010 John Wiley & Sons, Ltd.
Surface modification of polymer films with a remote atmospheric pressure d.c. glow discharge: influence of substrate location
Authors: Jacobs T. , Carbone E. , Morent R. , De Geyter N. , Reniers F. , Leys C.
Published: April 2010

This study focuses on the surface treatment of polymer films (polypropylene and polyethylene terephthalate) with a remote atmospheric pressure d.c. glow discharge operating in ambient air. The set‐up used can be easily upgraded to industrial dimensions and simulates in‐line processing due to the rotating drum used to mount the samples on. The discharge was characterized by measuring the voltage–current curve. From this curve, three regimes can be distinguished: corona regime, glow regime and spark regime. The voltage is adjusted so that the plasma operates in the glow regime and the treatment effects are analyzed by water contact angle and XPS measurements. It is shown that the remote plasma source is capable of reducing the contact angle and making the surface of the polymers more hydrophilic. The influence of the distance of the sample to the electrodes and the power is studied. By XPS measurements, the chemical composition of the surface after treatment is determined for different operating conditions. On none of the analyzed samples, nitrogen was detected. The main effect of the treatment is the incorporation of oxygen. Angle‐resolved XPS measurements show that the composition of the top atomic layers is significantly different from that of the underlying layers. The functional groups grafted by the plasma treatment were identified by the deconvolution of the C1s peak. Copyright © 2010 John Wiley & Sons, Ltd.
Structuring polycrystalline Fe‐Si‐Al steel surfaces by means of ion beam–the role of grain orientation
Authors: Šetina Batič Barbara , Jenko Monika
Published: April 2010

Electrical steel (Fe‐Si‐Al alloy) surfaces were subjected to Ar+ ion beam irradiation at 10 keV beam energy and off‐normal sputtering conditions. The morphologies present were visualized by SEM and can be roughly divided into four classes: ripples oriented parallel to the ion beam direction, ripples oriented perpendicular to ion beam direction, smooth surfaces and rough faceted surfaces. Energy dispersive spectroscopy (EDS) results show that individual grains are compositionally homogebeous, therefore, the different patterns originate from differences in crystal orientations. The grain orientation was correlated to the pattern formed with electron backscatter diffraction (EBSD) technique and the results show that grains with similar orientation in the normal (Z) direction behave in a similar way. XPS analysis showed some Si enrichment of the surface layers. Copyright © 2010 John Wiley & Sons, Ltd.
Inhibition of Notch Signaling in Glioblastoma Targets Cancer Stem Cells via an Endothelial Cell Intermediate
Authors: Hovinga Koos E. , Shimizu Fumiko , Wang Rong , Panagiotakos Georgia , Van Der Heijden Maartje , Moayedpardazi Hamideh , Correia Ana Sofia , Soulet Denis , Major Tamara , Menon Jayanthi , Tabar Viviane
Published: April 2010

Glioblastoma multiforme (GBM) is a highly heterogeneous malignant tumor. Recent data suggests the presence of a hierarchical organization within the GBM cell population that involves cancer cells with stem-like behavior, capable of repopulating the tumor and contributing to its resistance to therapy. Tumor stem cells are thought to reside within a vascular niche that provides structural and functional support. However, most GBM studies involve isolated tumor cells grown under various culture conditions. Here, we use a novel three-dimensional organotypic “explant” system of surgical GBM specimens that preserves cytoarchitecture and tumor stroma along with tumor cells. Notch inhibition in explants results in decreased proliferation and self-renewal of tumor cells but is also associated with a decrease in endothelial cells. When endothelial cells are selectively eliminated from the explants via a toxin conjugate, we also observed a decrease in self-renewal of tumor stem cells. These findings support a critical role for tumor endothelial cells in GBM stem cell maintenance, mediated at least in part by Notch signaling. The explant system further highlighted differences in the response to radiation between explants and isolated tumor neurospheres. Combination treatment with Notch blockade and radiation resulted in a substantial decrease in proliferation and in self-renewal in tumor explants while radiation alone was less effective. This data suggests that the Notch pathway plays a critical role in linking angiogenesis and cancer stem cell self-renewal and is thus a potential therapeutic target. Three-dimensional explant systems provide a novel approach for the study of tumor and microenvironment interactions.
Nuclear winter
Authors: Robock Alan
Published: April 2010

Nuclear winter is the term for a theory describing the climatic effects of nuclear war. Smoke from the fires started by nuclear weapons, especially the black, sooty smoke from cities and industrial facilities, would be heated by the Sun, lofted into the upper stratosphere, and spread globally, lasting for years. The resulting cool, dark, dry conditions at Earth's surface would prevent crop growth for at least one growing season, resulting in mass starvation over most of the world. In addition, there would be massive ozone depletion, allowing enhanced ultraviolet radiation. More people could die in the noncombatant countries than in those where the bombs were dropped, because of these indirect effects. Nuclear proliferation is now expanding the threat. A nuclear war between India and Pakistan could produce so much smoke that it would produce global environmental change unprecedented in recorded human history. Although the number of nuclear weapons in the world has fallen from 70,000 at its peak in the 1980s to less than 10,000 currently deployed, a nuclear war between the United States and Russia could still produce nuclear winter. This theory cannot be tested in the real world. However, analogs can inform us about parts of the theory, and there are many that give support to the theory. They include the seasonal cycle, the diurnal cycle, forest, fires, volcanic eruptions, and dust storms on Mars. The only way to be sure to prevent the climatic effects of nuclear war is to rid the world of nuclear weapons. Copyright © 2010 John Wiley & Sons, Ltd.

This article is categorized under:

Climate Models and Modeling > Knowledge Generation with Models

Assessing Impacts of Climate Change > Evaluating Future Impacts of Climate Change
Malignant Melanoma Amongst Maori and New Zealand Europeans, 2000–2004
Authors: Hore Todd , Robinson Elizabeth , Martin Richard C. W.
Published: April 2010

Background

Although cutaneous melanoma (CM) is rare among dark‐skinned populations, it has been found that dark‐skinned patients diagnosed with CM tend to have greater Breslow thickness and therefore a worse prognosis.

Methods

Data was obtained from the New Zealand Cancer Registry pertaining to CM ICD‐10 codes from 2000 to 2004. This data was used to compare different ethnicities. We compared New Zealand Europeans with those identifying themselves as Maori. Incorrect or absent data, benign nevi, and melanoma in situ were all excluded from analysis. Only one data entry was accepted per patient to avoid the inclusion of metastases.

Results

Overall, 9004 patients were registered as being diagnosed with CM during 2000–2004, and 7120 with complete ethnicity data were analyzed. A total of 69 cases were identified as Maori. The incidence of CM among Maori is 2.7 per 100,000. Maori had significantly greater Breslow thickness compared with New Zealand Europeans (1.3 vs. 0.80 mm, P < 0.0001). There were differences in type of CM between the two groups (P < 0.00001); in particular, Maori had more acral CM (2.9% vs. 0.8%).

Conclusions

Cutaneous melanoma is much less common among Maori than among New Zealand Europeans, but Maori have a greater Breslow depth and therefore have a worse prognosis. Increased awareness on behalf of these groups and health care practitioners should assist in ensuring early detection, thereby improving the overall outcome in Maori.
“The Cancer Bond”: Exploring the Formation of Cancer Risk Perception in Families with Lynch Syndrome
Authors: Palmquist Aunchalee E. L. , Koehly Laura M. , Peterson Susan K. , Shegog Margarette , Vernon Sally W. , Gritz Ellen R.
Published: April 2010

This study explores the social context of hereditary cancer risk perception in three families, an African‐American family, a Mexican‐American family, and a Caucasian family, each with Lynch Syndrome documented by a mismatch repair gene mutation. Communication network assessments measured family communication about cancer experiences and genetic testing information among a total of 26 participants. Participant narratives were evaluated to gain insight into how family cancer experiences and genetic testing information have shaped perceptions of cancer risk. Analysis of communication networks indicated that some families discussed cancer experiences to a greater extent than genetic testing information, and vice‐versa. Interviews elucidated that sharing both types of health information led participants to conceptualize linkages among a strong family history of cancer, genetic testing information, and cancer prevention strategies. Understanding how different types of family communication influence the formation of perceived hereditary disease risk may enhance efforts to tailor genetic counseling services for families.
Sniffing out social signals
Authors: Spehr M.
Published: April 2010

In most mammals, conspecific chemical com­munication strategies control complex social and sexual behavior. Just a few years ago, our concept of how the olfactory system is orga­nized to ensure faithful transmission of so­cial information built on the rather simplis­tic assumption that two fundamentally dif­ferent classes of stimuli - ‘general’ odors ver­sus ‘pheromones’ - are exclusively detected by either of two sensory structures: the main olfactory epithelium or the vomeronasal or­gan. A number of exciting recent findings, however, revealed a much more complex and functionally diverse organizational struc­ture of the sense of smell. At least four ana­tomically segregated olfactory subsystems, some remarkably heterogeneous in their cel­lular composition, detect distinct, but partial­ly overlapping populations of sensory stimuli. Discerning how subsystem-specific receptor architectures and signaling pathways orches­trate the coding logic of social chemosignals, will ultimately shed new light on the neuro­physiological basis of social behavior.
Convective instability in steady stenotic flow: optimal transient growth and experimental observation
Authors: GRIFFITH M. D. , THOMPSON M. C. , LEWEKE T. , HOURIGAN K.
Published: April 2010

An optimal transient growth analysis is compared with experimental observation for the steady flow through an abrupt, axisymmetric stenosis of varying stenosis degree. Across the stenosis range, a localized sinuous convective shear-layer instability type is predicted to dominate. A comparison of the shape and development of the optimal modes is made with experimental dye visualizations. The presence of the same sinuous-type disturbance immediately upstream of the highly chaotic region observed in the experimental flow is consistent with the optimal growth predictions. This, together with the fact that the flow is unstable globally only at much higher Reynolds numbers, suggests bypass transition.
Delivering Public Services in the Mixed Economy of Welfare: Perspectives from the Voluntary and Community Sector in Rural England
Authors: HARDILL IRENE , DWYER PETER
Published: April 2010

The voluntary and community sector in England is playing an increasingly important role in the delivery of public services to older adults and in doing so they rely on unpaid volunteers. In this article, we draw on the findings of a recent qualitative study of the impact on the voluntary and community sector of delivering ‘low-level’ public services that promote independent living and wellbeing in old age. The fieldwork focused on services that help older adults aged 70+ living in remote rural communities across three English regions. Those charged with service delivery, which is increasingly the voluntary and community sector, face particular challenges, such as uncertain funding regimes and reliance on volunteer labour.
Algorithmic path planning of static robots in three dimensions using configuration space metrics
Authors: Roy Debanik
Published: April 2010

Collision-free path planning for static robots is a demanding manifold of contemporary robotics research, vastly due to the growing industrial applications. In this paper, a novel ‘visibility map’-based heuristic algorithm is used to generate near-optimal safe path for a three-dimensional congested robot workspace. The final path is obtainable in terms of joint configurations, by considering the Configuration Space of the task space. The developed algorithm has been verified initially by considering representative 2D workspaces, cluttered with different obstacles with regular geometries and then after with the spatial endeavour. A case study reveals the effectiveness of the developed modules of the configuration space mapping, pertaining to a five degrees-of-freedom low payload articulated robot.
Decentralized control for mobile robotic sensor network self-deployment: barrier and sweep coverage problems
Authors: Cheng Teddy M. , Savkin Andrey V.
Published: April 2010

This paper addresses the problems of barrier coverage and sweep coverage in a corridor environment with a network of self-deployed mobile autonomous robotic sensors. Using the ideas of nearest neighbor rules and information consensus, we propose a decentralized control law for the robotic sensors to solve the coverage problems. Numerical simulations illustrate the effectiveness of the proposed algorithm. The results in this paper demonstrate that such simple motion coordination rules can play a significant role in addressing the issue of coverage in a mobile robotic sensor network.
Typological implications of Kalam predictable vowels
Authors: Blevins Juliette , Pawley Andrew
Published: April 2010

Kalam is a Trans New Guinea language of Papua New Guinea. Kalam has two distinct vowel types: full vowels /a e o/, which are of relatively long duration and stressed, and reduced central vowels, which are shorter and often unstressed, and occur predictably within word-internal consonant clusters and in monoconsonantal utterances. The predictable nature of the reduced vowels has led earlier researchers, e.g. Biggs (1963) and Pawley (1966), to suggest that they are a non-phonemic ‘consonant release’ feature, leading to lexical representations with long consonant strings and vowelless words. Here we compare Kalam to other languages with similar sound patterns and assess the implications for phonological theory in the context of Hall's (2006) typology of inserted vowels. We suggest that future work on predictable vowels should explore the extent to which clusters of properties are explained by evolutionary pathways.
Near surface climate of the traverse route from Zhongshan Station to Dome A, East Antarctica
Authors: Ma Yongfeng , Bian Lingen , Xiao Cunde , Allison Ian , Zhou Xiuji
Published: April 2010

Seasonal variation of temperature, pressure, snow accumulation, winds, and their harmonic analysis are presented by using the data from Zhongshan Station and three Automatic Weather Stations deployed between the East Antarctic coast and the summit of the ice sheet at Dome A for the period 2005–07. Results show that: 1) temperature, snow accumulation and specific humidity decrease with increasing elevation and distance from the coast, with snow accumulation decreasing from 199 mm water equivalent (w.e.) yr-1 at LGB69 (180 km from the coast) to 31 mm w.e. yr-1 at Dome A, 2) Dome A experiences an extremely low minimum temperature of -82.5°C with the monthly mean temperature below -50°C for eight months in contrast to Zhongshan Station which does not show any monthly mean temperatures below -20°C, 3) mean surface wind speed increases from the coast to the escarpment region, and then reduces rapidly towards the interior plateau with the strongest winds occurring at katabatic sites with the greatest surface slopes, 4) temperature and pressure all shows a distinct biannual oscillation with a main minimum in spring and a secondary minimum in autumn, differing slightly from station to station, and 5) winter temperature corelessness increases as a function of elevation and distance from the coast, from 0.260 at the coastal Zhongshan Station to 0.433 at Dome A.
THE ESSENTIAL SPECTRUM OF A PERTURBED OPERATOR ARISING IN TWO-DIMENSIONAL MAGNETOHYDRODYNAMICS
Authors: FAIERMAN M. , MENNICKEN R.
Published: April 2010

Descloux and Geymonat considered a model problem in two-dimensional magnetohydrodynamics and conjectured that the essential spectrum has an explicitly given band structure. This conjecture was recently proved by Faierman, Mennicken, and Möller by reducing the problem to that for a 2×2 block operator matrix. In a subsequent paper Faierman and Mennicken investigated the essential spectrum for the problem arising from a particular type of perturbation of precisely one of the operator entries in the matrix representation cited above of the original problem considered by Descloux and Geymonat. In this paper we extend the results of that work by investigating the essential spectrum for the problem arising from particular types of perturbations of all but one of the aforementioned operators. It remains an open question whether one can perturb the exceptional operator in such a way as to leave the essential spectrum unchanged.
Kognitive Basiskompetenzen und ihr Einfluss auf die Rechtschreib- und Rechenleistung
Authors: Knievel Julia , Daseking Monika , Petermann Franz
Published: April 2010

Zusammenfassung. In dieser Arbeit werden vorschulische kognitive Basiskompetenzen untersucht, die zur Prognose der kombinierten Rechtschreib- und der Rechenleistung beitragen sollen. 119 Kinder nahmen im letzten Kindergartenjahr an einem Screening für kognitive Basiskompetenzen (BASIC-Preschool) teil. Die vorschulischen Leistungen in den Bereichen Sprachverständnis, auditive Merkspanne, visuell-räumliche Wahrnehmung, sowie selektive Aufmerksamkeit wurden auf ihre Vorhersagekraft für die Rechtschreibleistung (DRT 1) und die Rechenleistung (DEMAT 1+) zu Beginn der zweiten Klasse überprüft. Korrelative Zusammenhänge und regressionsanalytische Betrachtungen weisen auf die besondere Bedeutung des vorschulischen Sprachverständnisses für die Schulleistung hin. Die Ergebnisse belegen die Relevanz, sprachliche Fähigkeiten im letzten Kindergartenjahr zu erfassen und zu fördern.
Wie sich die Werte ändern
Authors: Hofer Manfred , Reinders Heinz , Fries Stefan
Published: April 2010

Zusammenfassung. Ein zieltheoretisches Modell zur Erklärung von Veränderungen in individuellen und gesellschaftlichen Werten wird vorgeschlagen. Die Theorie besagt im Kern, dass Menschen ihre Werte durch alltägliche Handlungserfahrungen, die sie in ihrem kulturellen Umfeld machen, verändern. Handeln wird als zielgerichtet angesehen und es wird angenommen, dass die affektiven und kognitiven Begleiterscheinungen und Ergebnisse von Handlungen wahrgenommen und verarbeitet werden. Aus den kumulierten Erfahrungen im Sinne von inneren und äußeren Rückmeldungen in einem Handlungsbereich schließen Personen auf die Werte, die sie mit den in diesem Bereich angestrebten Zielen verbinden. Gesellschaftliche Werteänderungen ergeben sich dann, wenn hinreichend viele Personen innerhalb der jeweiligen Kultur ähnlich gerichtete Erfahrungen machen. Wir spezifizieren Auftretensbedingungen und nehmen eine Einordnung in bestehende Theorien vor. Es wird illustriert, wie die Theorie den Inter-Kohorten-Wandel von Werten bei Jugendlichen erklären kann.
Vorhersage früher Schriftsprachleistungen aus vorschulischen Kompetenzen der Sprache und der phonologischen Informationsverarbeitung
Authors: von Goldammer Ariane , Mähler Claudia , Bockmann Ann-Katrin , Hasselhorn Marcus
Published: April 2010

Zusammenfassung. Im deutschen Sprachraum werden seit vielen Jahren Kompetenzen im Bereich der phonologischen Informationsverarbeitung im Zusammenhang mit dem Schriftspracherwerb untersucht. Als stärkster Prädiktor von frühen Lese- und Rechtschreibkompetenzen gilt die vorschulische phonologische Bewusstheit. Studien aus dem angloamerikanischen und skandinavischen Sprachraum deuten jedoch darauf hin, dass auch breitere sprachliche Kompetenzen (Wortschatz, Grammatik) den Erwerb der Schriftsprache vorhersagen. An der vorliegenden Längsschnittstudie nahmen 53 Kinder teil, die im Alter von 5 Jahren hinsichtlich ihrer Kompetenzen im Bereich der Sprache und der phonologischen Informationsverarbeitung sowie im Alter von 8 Jahren hinsichtlich ihrer Lese-Rechtschreibleistungen untersucht wurden. Als stärkster Prädiktor der frühen Lese- und Rechtschreibkompetenz konnte dabei die vorschulische Satzgedächtnisleistung identifiziert werden. Diese wiederum lässt sich durch die Größe des Wortschatzes und die Kapazität des phonologischen Arbeitsgedächtnisses erklären. Mit dem Nachsprechen von Sätzen liegt damit ein ökonomisches Maß vor, mit dem bereits im Vorschulalter Schriftsprachleistungen vorhergesagt werden können.
The Divergence of Implicit and Explicit Consumer Evaluations
Authors: Summerville Amy , Hsieh Brendon , Harrington Nick
Published: April 2010

This research extends findings that implicit and explicit attitudes may diverge to a consumer evaluation task using multiple measures of implicit evaluation: Evaluative Movement Assessment (EMA; Brendl, Markman, & Messner, 2005) and Evaluative Priming (Fazio, Jackson, Dunton, & Williams,1995). These measures were significantly associated with each other for both positive and negative implicit attitudes. Neither measure predicted explicit liking of the product or explicit intention to purchase the product. We believe this to be the first such demonstrated divergence in a naturalistic, unconditioned consumer evaluation context. Implicit activation of the product’s emotional benefit (e.g., “relaxation”), as assessed in a lexical decision task (LDT), was not associated with the EMA or evaluative priming, but was significantly associated with both explicit emotional state (e.g., relaxation) and explicit purchase intention; the latter effect was not mediated by explicit emotion.
Using Community Data to Test the Discriminant Validity of Ethnic/Racial Group IATs
Authors: Blair Irene V. , Judd Charles M. , Havranek Edward P. , Steiner John F.
Published: April 2010

The present study used a multi-method, multi-measure, multi-group approach to investigate the discriminant validity of prejudice-related Implicit Association Tests (IATs). Community members from three ethnic/racial groups in the US completed IATs and explicit measures of attitudes toward African Americans and Latinos, with Whites used as the comparison group. The results of this study provided strong support for the discriminant validity of the IATs by showing, (a) expected patterns of variation among the three participant groups that were unique to each IAT, (b) unique relations between responses on each IAT and corresponding (same-group) explicit measures of prejudice, and (c) invariance across the three participant groups in the degree to which the attitude measures loaded on two latent factors, indicating distinct attitudes toward African Americans and Latinos.
Solar cycle signal in a general circulation and chemistry model with internally generated quasi‐biennial oscillation
Authors: Schmidt H. , Brasseur G. P. , Giorgetta M. A.
Published: April 2010

Simulations with the HAMMONIA general circulation and chemistry model are analyzed to improve the understanding of the atmospheric response to solar cycle variations and the role of the quasi‐biennial oscillation of equatorial winds (QBO) for this response. The focus is on the Northern Hemisphere winter stratosphere. Owing to the internally produced QBO, albeit with a too short period of 24 months, the model is particularly suited for such an exercise. The simulation setup with only solar and QBO forcing allows an unambiguous attribution of the simulated signals. Two separate simulations have been performed for perpetual solar maximum and minimum conditions. The simulations confirm the plausibility of dynamical mechanisms, suggested earlier, that propagate the solar signal from the stratopause region downward to the troposphere. One feature involved in this propagation is a response maximum of temperature and ozone in the lower equatorial stratosphere. In our model, this maximum appears as a pure solar signal independent of the QBO and of other forcings. As observed, the simulated response of the stratospheric polar vortex to solar cycle forcing depends on the QBO phase. However, in the model this is statistically significant only in late winter. The simulation for early and mid winter suffers probably from a too strong internal variability of the polar vortex in early winter.
Step‐pool stability: Testing the jammed state hypothesis
Authors: Zimmermann André , Church Michael , Hassan Marwan A.
Published: April 2010

We investigate the stability of step‐pool channels by examining how the traditional approach to bed stability based on the critical Shields number is modified by particles jamming across the width of the channel. Experiments were conducted in a flume with slopes ranging between 3% and 18% and either smooth or rough walls. By varying the size of sediment and width of the flume we observed that the stability of the bed increases as the jamming ratio (channel width/D84step is the diameter at which 84% of the step stones are smaller) decreases for jamming ratios less than six. At low jamming ratios both grain‐on‐grain structuring and sediment entrainment phenomena affect the stability of the bed. Actual bed failure, however, depends upon the history of bed development and the chance arrangement of the stone structures in the bed. Thus, the experiments also demonstrate that the inherently stochastic nature of sediment transport affects not only the movement of individual grains but also the stability of the channel as a whole. Since stochastic processes affect the stability of the entire channel, there is no clearly defined separation between stable and unstable beds, rather, an overlapping field where both stable and unstable bed states can exist. This field was modeled using logistic regression to derive a probability of bed failure. A comparison of data from experiments with rough banks and smooth banks showed that rough banks significantly increase the stability of the bed.
Nonclassical crystallization of amorphous iron nanoparticles by radio frequency methods
Authors: Carroll K. J. , Pitts J. A. , Zhang Kai , Pradhan A. K. , Carpenter E. E.
Published: April 2010

Amorphous iron nanoparticles were synthesized using an aqueous reduction in iron(II) sulfate with sodium borohydride and sodium citrate. Various radio frequency (rf) exposure times were investigated in order to determine trends in nonclassical crystallization. RF times from 15 to 300 s revealed an increase in crystallite size from 5 to 60 nm, as determined by powder x-ray diffraction. Also, solvent optimization revealed that ethanol produced the largest trends for increasing crystallite size without total oxidation of the samples. Magnetic characterization by room temperature vibrating sample magnetometry and high resolution transmission microscopy was performed to verify magnetic properties and particle morphology.
Annealing of amorphous FexCo100−x nanoparticles synthesized by a modified aqueous reduction using NaBH4
Authors: Carroll K. J. , Hudgins D. M. , Brown L. W. , Yoon S. D. , Heiman D. , Harris V. G. , Carpenter E. E.
Published: April 2010

Fe x Co 100 − x nanoparticles were synthesized by aqueous reduction in iron (II) sulfate and cobalt (II) sulfate using sodium borohydride and sodium citrate. The initial concentrations of iron and cobalt were varied while maintaining an overall metal concentration of 4.60 mM. Increasing the cobalt content from 0 to 100 at. % decreased the magnetization saturation from 152 to 48 emu/g, as determined by room temperature vibrating sample magnetometry. Annealing the samples at 450 and 600 °C showed an increase in crystallite size. Powder x-ray diffraction and transmission electron microscopy was performed to determine the phases and morphology of the materials.
Observations of oxidation mechanisms and kinetics in faceted FeCo magnetic nanoparticles
Authors: Jones N. J. , McNerny K. L. , Wise A. T. , Sorescu M. , McHenry M. E. , Laughlin D. E.
Published: April 2010

( Fe 50 Co 50 ) 97 V 2 Nb 1 nanoparticles were synthesized in an induction plasma torch and oxidized isochronally at temperatures between room temperature (RT) and 900 °C. The particles exhibited three stages of oxidation present at different temperatures. The initial oxide layer was nearly Co-free, beginning at 3 nm at RT, and Co appeared to oxidize separately from the iron. Iron cations were determined to be the mobile species during oxidation, yielding a progressively more Co-rich core as oxidation progressed, decreasing from an average diameter of 42 to 25 nm, while the oxide tripled in size. At 350 °C, the particles exhibited a less dense core, and at 900 °C the particles were observed to have changed morphology completely with some sintering, forming completely oxidized particles with an average diameter three times the as received size.
Effects of particle size and composition on coercivity of Sm–Co nanoparticles prepared by surfactant-assisted ball milling
Authors: Poudyal Narayan , Rong Chuan-bing , Liu J. Ping
Published: April 2010

The SmCox (x=3.5, 4, 5, 6, 8.5, and 10) magnetic nanoparticles with different composition have been prepared by surfactant-assisted ball milling technique. By controlling the settle-down time and the centrifugation conditions, the SmCox nanoparticles with different particle size and narrow size distribution were successfully obtained. It was observed that the SmCo nanoparticles become unstable with increasing Sm content. It was also observed that the coercivity of the SmCox nanoparticles increases with Co content and particle size, indicating a complex effect of the particle size and composition on magnetic hardening of the hard magnetic nanoparticles.
Thermal stability and magnetocaloric effect of the Gd65Fe20Al15−xBx (x=–7) glassy ribbons
Authors: Fang Y. K. , Lai C. H. , Hsieh C. C. , Zhao X. G. , Chang H. W. , Chang W. C. , Li W.
Published: April 2010

The thermal stability, magnetocaloric effect, and refrigeration capacity (RC) of Gd-based Gd65Fe20Al15−xBx (x=0–7) glassy ribbons have been investigated. A relatively wide supercooled liquid region ΔTx(ΔTx=Tx−Tg) (50–80 K) and large reduced glass transition temperature Trg(Trg=Tg/Tm) (>0.63) are found in Gd65Fe20Al15−xBx glassy ribbons. The distinctive glass transition and sharp crystalline events as well as large values of ΔTx and Trg confirm the excellent glass forming ability of these alloys. The maximal magnetic entropy changes, −ΔSMmax, and RC values of the specimens are about 4.80–5.21 J/kg K and 700–800 J/kg under 50 kOe, respectively. These −ΔSMmax values are comparable to or even higher than that of some reported bulk metallic glasses. Moreover, the larger RC values are due to the broad ΔSM peak (∼200 K), which is caused by the glassy structure. The large ΔSM and RC values make the Gd-based Gd65Fe20Al15−xBx glassy ribbons attractive candidates for magnetic refrigeration materials.
Field dependence of the magnetocaloric effect in core-shell nanoparticles
Authors: Franco V. , Conde A. , Sidhaye Deepti , Prasad B. L. V. , Poddar P. , Srinath S. , Phan M. H. , Srikanth H.
Published: April 2010

The field dependence of the magnetic entropy change peak at the low temperature surface spin freezing transition in chemically synthesized, monodispersed Co, Co–Ag, and Ni–Ag core-shell nanoparticles is studied, with the aim of gaining insight into the critical exponents of this transition. It is evidenced that although the magnitude of the peak entropy change and position of the peak can be tuned by changing the composition and nature (metallic or organic) of the shell and surfactant layers, the characteristics of the spin freezing transition are not altered. The field dependence of the refrigerant capacity also confirms this finding.
Magnetocaloric effects in Er1−xTbxAl2 alloys
Authors: Khan Mahmud , Gschneidner K. A. , Pecharsky V. K.
Published: April 2010

The magnetocaloric properties of the (Er1−xTbx)Al2 alloys have been evaluated by magnetization and heat capacity measurements. It is shown that by partial substitution of Er by Tb the ferromagnetic ordering temperature of (Er1−xTbx)Al2 can be tuned over a wide range of temperatures, that is from 13 K (ErAl2) to 110 K (TbAl2). Over the entire temperature range the alloy system exhibits large magnetocaloric effect. For a field change of 5 T, the observed magnetic entropy changes peaks from −18 J/kg K (x=0.20) to −12 J/kg K (x=0.90). The adiabatic temperature changes measured for selected alloys in the series show a maximum value of 6 K when the magnetic field is changed from 0 to 5 T.
Magnetism and magnetocaloric effects in Ni50Mn35−xCoxIn15 Heusler alloys
Authors: Pathak Arjun K. , Dubenko Igor , Pueblo Christopher , Stadler Shane , Ali Naushad
Published: April 2010

The effects of the partial substitution of Mn by Co on the magnetic, magnetoelastic, and magnetocaloric properties of Ni50Mn35In15 Heusler alloys were studied using x-ray diffraction, temperature and field dependences of the magnetization [M(T,H)], and strain gauge techniques. It was observed that the presence of ≈3% Co atoms in Mn sites strongly affected the magnetic and magnetoelastic behaviors of Ni50Mn35In15. At H=5 T, a maximum magnetoelastic strain of ≈0.6% was observed for Ni50Mn35In15. It was found that Co substituted into the Mn position does not affect the ΔSM in the vicinity of the second order transitions (SOTs), however ΔSM near the first order transitions (FOTs) it slightly decreases. The net refrigeration capacities in the vicinity of both the FOT and SOT were found to significantly increase by introducing Co into Mn sites. The net refrigeration capacity in the vicinity of the FOT and SOT was found to be 167 J/kg (T=277–293 K) and 229 J/kg (T=305–354 K), respectively, at a magnetizing field of 5 T. These values of the magnetocaloric parameters are comparable to that of the largest values reported for metallic magnets near room temperature.