bluuebunny/crossref_metadata_2025 huggingface dataset:
Similar effects on sediment structure and infaunal community of two competitive intertidal soft-bottom burrowing crab species
Authors: Martinetto Paulina , Palomo Gabriela , Bruschetti Martin , Iribarne Oscar
Published: March 2011

The intertidal crabs Neohelice granulata and Cyrtograpsus angulatus are common on the south-west Atlantic coast but they rarely share the same microhabitat. They are similar in size and in several life history traits which promote competition. Neohelice granulata is the dominant species in intertidal soft-sediment and salt-marsh areas from southern Brazil to northern Patagonia Argentina, where it forms extensive burrowing beds. Its burrowing activity affects sediment characteristics as well as the infaunal community. When both species coexist N. granulata constrains the distribution and modifies some population characteristics and burrowing behaviour of C. angulatus. However, C. angulatus live in burrows forming dense burrowing beds in soft-bottom intertidal areas where N. granulata is absent. Where both species coexist, C. angulatus rarely constructs burrows and N. granulata clearly dominate soft-sediment areas forming conspicuous burrowing beds. This suggests that these crab species could have similar ecological roles in some effects on sediments related to burrowing activities. In this study, we experimentally compare their effects on sediment characteristics and infaunal community. The results of the experiment showed that C. angulatus modify sediment water and organic matter contents and grain size–frequency distributions similarly to N. granulata. Neither N. granulata nor C. angulatus affected the mean abundance of infaunal organisms during the experiment but their variances showed the same patterns in many cases, indicating similar effects. These results indicate that C. angulatus can modify sediment characteristics similarly to N. granulata, and has similar interactions with infaunal species.
ANOTHER COMPLETELY INTERESTING OPERA: ‘THE MOTHER OF US ALL’ PART 2
Authors: Lister Rodney
Published: March 2011

In his introduction to Gertrude Stein's Four In America, Thornton Wilder quotes Stein's answer to someone who had asked for an explanation of her well-known line ‘a rose is a rose is a rose’
AMBIGUOUS MODERNISM: THE EARLY ORCHESTRAL WORKS OF SERGEI PROKOFIEV
Authors: Guillaumier Christina K
Published: March 2011

Sergei Prokofiev's association with modernism was a curious one: on the one hand, he thought his technically innovative, bold and challenging music positioned him as a modernist but on the other, he remained wary of aligning himself with any specific movement. Such a combination of reluctance and ambiguity in the face of a movement that was engaging interwar Europe with such intensity stems from what can be viewed as an overly protective attitude to his own purity of idiom. Prokofiev was keenly aware of his own prodigious talent and simultaneously anxious of possible musical influence. Nonetheless, he continued to be watchful of cutting-edge developments in music even if he was not particularly sympathetic to the accompanying philosophical debates on modern music.
SAMUEL BARBER'S ORGAN MUSIC
Authors: Quinn Iain
Published: March 2011

The publication of three previously unpublished early organ works of Samuel Barber (1910–1981) in the hundredth year since his birth allows an opportunity to consider his output afresh for an instrument he knew well from his childhood years. Known to millions through the broadcast, concert and film media, Barber's most-played work, the Adagio from the String Quartet, op. 11 (1936) has remained a familiar voice to contemporary ears 75 years after its composition. Indeed it could be fairly suggested that it has become to America what Elgar's Nimrod has to the British; a piece that can summon up the rawest of emotions within its first bars whilst being imbued with an unquestionable national identity.
Why do humans reason? Arguments for an argumentative theory
Authors: Mercier Hugo , Sperber Dan
Published: March 2011

Reasoning is generally seen as a means to improve knowledge and make better decisions. However, much evidence shows that reasoning often leads to epistemic distortions and poor decisions. This suggests that the function of reasoning should be rethought. Our hypothesis is that the function of reasoning is argumentative. It is to devise and evaluate arguments intended to persuade. Reasoning so conceived is adaptive given the exceptional dependence of humans on communication and their vulnerability to misinformation. A wide range of evidence in the psychology of reasoning and decision making can be reinterpreted and better explained in the light of this hypothesis. Poor performance in standard reasoning tasks is explained by the lack of argumentative context. When the same problems are placed in a proper argumentative setting, people turn out to be skilled arguers. Skilled arguers, however, are not after the truth but after arguments supporting their views. This explains the notorious confirmation bias. This bias is apparent not only when people are actually arguing, but also when they are reasoning proactively from the perspective of having to defend their opinions. Reasoning so motivated can distort evaluations and attitudes and allow erroneous beliefs to persist. Proactively used reasoning also favors decisions that are easy to justify but not necessarily better. In all these instances traditionally described as failures or flaws, reasoning does exactly what can be expected of an argumentative device: Look for arguments that support a given conclusion, and, ceteris paribus, favor conclusions for which arguments can be found.
When reasoning is persuasive but wrong
Authors: Sternberg Robert J.
Published: March 2011

Mercier and Sperber (M&S) are correct that reasoning and argumentation are closely related. But they are wrong in arguing that this relationship is one of evolutionary adaptation. In fact, persuasive reasoning that is not veridical can be fatal to the individual and to the propagation of his or her genes, as well as to the human species as a whole.
Query theory: Knowing what we want by arguing with ourselves
Authors: Weber Elke U. , Johnson Eric J.
Published: March 2011

Mercier and Sperber (M&S) argue that reasoning is social and argumentative, and that this explains many apparently irrational judgment phenomena. We look at the relationship between interpersonal and intrapersonal argumentation and discuss parallels and differences from the perspective of query theory, a memory-based model of constructive preferences. We suggest an important goal is to integrate models across inference and preference.
What people may do versus can do
Authors: Kuhn Deanna
Published: March 2011

It warrants examining how well people can come to argue under supportive conditions, not only what they do under ordinary conditions. Sustained engagement of young people in dialogic argumentation yields more than the temporary “contextual effect” that Mercier & Sperber (M&S) identify in the target article. If such engagement were to become the norm, who can say what the argumentive potential of future generations is?
The chronometrics of confirmation bias: Evidence for the inhibition of intuitive judgements
Authors: Stupple Edward J. N. , Ball Linden J.
Published: March 2011

Mercier & Sperber (M&S) claim that the phenomenon of belief bias – which they consider to be an archetypal manifestation of a general confirmation bias in human reasoning – provides fundamental support for their argumentative theory and its basis in intuitive judgement. We propose that chronometric evidence necessitates a more nuanced account of belief bias that is not readily captured by argumentative theory.
Putting reasoning and judgement in their proper argumentative place
Authors: Oaksford Mike
Published: March 2011

This commentary agrees with Mercier and Sperber's (M&S's) thesis on the argumentative function of reasoning but suggests that an account of argument strength is required. A Bayesian account of argument strength (Hahn & Oaksford 2007) shows how the deployment of deductive fallacies, weak inductive arguments, and judgment fallacies such as base-rate neglect, can all be rationally defended in the right argumentative context.
Reasoning as deliberative in function but dialogic in structure and origin
Authors: Godfrey-Smith Peter , Yegnashankaran Kritika
Published: March 2011

Mercier and Sperber (M&S) claim that the main function of reasoning is to generate support for conclusions derived unconsciously. An alternative account holds that reasoning has a deliberative function even though it is an internalized analogue of public discourse. We sketch this alternative and compare it with M&S's in the light of the empirical phenomena they discuss.
The argumentative theory of reasoning applies to scientists and philosophers, too
Authors: Johnson John A.
Published: March 2011

Logical consistency demands that Mercier and Sperber's (M&S's) argumentative theory of reasoning apply to their own reasoning in the target article. Although they hint that their argument applies to professional reasoners such as scientists and philosophers, they do not develop this idea. In this commentary, I discuss the applicability of argumentative theory to science and philosophy, emphasizing the perils of moral reasoning.
Reasoning, argumentation, and cognition
Authors: Frankish Keith
Published: March 2011

This commentary does three things. First, it offers further support for the view that explicit reasoning evolved for public argumentation. Second, it suggests that promoting effective communication may not be the only, or even the main, function of public argumentation. Third, it argues that the data Mercier and Sperber (M&S) cite are compatible with the view that reasoning has subsequently been co-opted to play a role in individual cognition.
Argumentation: Its adaptiveness and efficacy
Authors: Mercier Hugo , Sperber Dan
Published: March 2011

Having defended the usefulness of our definition of reasoning, we stress that reasoning is not only for convincing but also for evaluating arguments, and that as such it has an epistemic function. We defend the evidence supporting the theory against several challenges: People are good informal arguers, they reason better in groups, and they have a confirmation bias. Finally, we consider possible extensions, first in terms of process-level theories of reasoning, and second in the effects of reasoning outside the lab.
Bridging the gap between methods research and the needs of policy makers: A review of the research priorities of the National Institute for Health and Clinical Excellence
Authors: Longworth Louise , Sculpher Mark J. , Bojke Laura , Tosh Jonathan C.
Published: March 2011

Objectives: The aim of this study was to establish a list of priority topics for methods research to support decision making at the National Institute for Health and Clinical Excellence (NICE).

Methods: Potential priorities for methods research topics were identified through a focused literature review, interviews, an email survey, a workshop and a Web-based feedback exercise. Participants were members of the NICE secretariat and its advisory bodies, representatives from academia, industry, and other organizations working closely with NICE. The Web exercise was open to anyone to complete but publicized among the above groups.

Results: A list of potential topics was collated. Priorities for further research differed according to the type of respondent and the extent to which they work directly with NICE. Priorities emerging from the group closest to NICE included: methodology for indirect and mixed treatment comparisons; synthesis of qualitative evidence; research relating to the use of quality-adjusted life-years (QALYs) in decision making; methods and empirical research for establishing the cost-effectiveness threshold; and determining how data on the uncertainty of effectiveness and cost-effectiveness data should be taken into account in the decision-making process. Priorities emerging from the broadest group of respondents (through the Web exercise) included: methods for extrapolating beyond evidence observed in trials, methods for capturing benefits not included in the QALY and methods to assess when technologies should be recommended in the context of further evidence gathering.

Conclusions: Consideration needs to be given to the needs of those who use the outputs of research for decision making when determining priorities for future methods research.
Cost-effectiveness analysis of cast versus splint in children with acceptably angulated wrist fractures
Authors: von Keyserlingk Camilla , Boutis Kathy , Willan Andrew R. , Hopkins Robert Borden , Goeree Ron
Published: March 2011

Objectives: In a practice setting where casting is considered the standard of care, the aim of this study was to assess the cost-effectiveness of wrist splints compared with routine casting in children with acceptably angulated distal radius greenstick or transverse fractures.

Methods: A cost-effectiveness analysis was conducted alongside a randomized controlled trial (RCT). One hundred children with acceptably angulated distal radius greenstick or transverse fractures received either a wrist splint or cast. Information on health care provider and patient and family resource use as well as productivity cost was collected. Resource use was costed using unit costs from local administrative data sources and expense diaries. Effectiveness was assessed at 6 weeks using the performance version of the Activities Scale for Kids (ASKp) questionnaire. Cost-effectiveness analysis related differential costs to differential ASKp scores.

Results: Mean total cost was $877.58 in the splint group and $950.35 in the cast group, with a mean difference of $−72.76 (standard error [SE] 45.88). Mean total healthcare cost was $670.66 in the splint group and $768.22 in the cast group, with a mean difference of $−97.56 (SE 9.24). Mean (SE) ASKp was 92.8 in the splint group and 91.4 in the cast group, with a mean difference of 1.439 (SE 1.585). Therefore, splint management was more effective and cheaper. After accounting for uncertainty, the probability of splint being cost-effective compared with cast was 94 percent for a willingness-to-pay threshold value of $0 for one-unit gain in ASKp score and exceeded 82 percent for all threshold values.

Conclusions: In this RCT, splint management was cost-effective compared with casting in children with acceptably angulated distal radius greenstick or transverse fractures. This study challenges the existing standard of care for children with this type of fracture and provides justification on clinical and economic grounds for a change in routine practice.
Average Frobenius distribution for elliptic curves defined over finite Galois extensions of the rationals
Authors: JAMES KEVIN , SMITH ETHAN
Published: March 2011

Let K be a fixed number field, assumed to be Galois over ℚ. Let r and f be fixed integers with f positive. Given an elliptic curve E, defined over K, we consider the problem of counting the number of degree f prime ideals of K with trace of Frobenius equal to r. Except in the case f = 2, we show that ‘on average,’ the number of such prime ideals with norm less than or equal to x satisfies an asymptotic identity that is in accordance with standard heuristics. This work is related to the classical Lang–Trotter conjecture and extends the work of several authors.
The non-equivalence between the trigonometric system and the system of functions with pointwise restrictions on values in the uniform and L1 norms
Authors: WOJCIECHOWSKI MICHAŁ
Published: March 2011

Let n denote the space of trigonometric polynomials of degree n i.e. n = span(e−ikt : |k| ≤ n) ⊂ Lp() and let (Ω, dx) be any mesurable space with finite measure. In this paper we use the quantitative version of the Helson-Rudin-Cohen idempotent theorem due to Green and Sanders (cf. [3]) to prove the following.
A novel rhodopsin-like gene expressed in zebrafish retina
Authors: MORROW JAMES M. , LAZIC SAVO , CHANG BELINDA S.W.
Published: March 2011

The visual pigment rhodopsin (rh1) constitutes the first step in the sensory transduction cascade in the rod photoreceptors of the vertebrate eye, forming the basis of vision at low light levels. In most vertebrates, rhodopsin is a single-copy gene whose function in rod photoreceptors is highly conserved. We found evidence for a second rhodopsin-like gene (rh1-2) in the zebrafish genome. This novel gene was not the product of a zebrafish-specific gene duplication event and contains a number of unique amino acid substitutions. Despite these differences, expression ofrh1-2in vitroyielded a protein that not only bound chromophore, producing an absorption spectrum in the visible range (λmax≈ 500 nm), but also activated in response to light. Unlikerh1,rh1-2is not expressed during the first 4 days of embryonic development; it is expressed in the retina of adult fish but not the brain or muscle. Similarrh1-2sequences were found in two otherDaniospecies, as well as a more distantly related cyprinid,Epalzeorhynchos bicolor. While sequences were only identified in cyprinid fish, phylogenetic analyses suggest an older origin for this gene family. Our study suggests thatrh1-2is a functional opsin gene that is expressed in the retina later in development. The discovery of a new previously uncharacterized opsin gene in zebrafish retina is surprising given its status as a model system for studies of vertebrate vision and visual development.
From the German Schoolmaster's Psychology to the Psychology of the Child: Evolving Rationales for the Teaching of History in U.S. Schools in the 1890s
Authors: Fallace Thomas D.
Published: March 2011

The rationale for teaching history proposed by most professional historians in the 1890s was based on faculty psychology—the theory that the mind was composed of mental faculties such as memory and will that could be strengthened like muscles. However, over the course of the decade this approach was gradually replaced by a functional approach to mind and society, which had roots in the new psychology of Wilhelm Wundt. This development was accompanied by a pedagogical shift in learning theory from an emphasis on exertion of the students' will to engaging students' interest. John Dewey, William James, and the American followers of German pedagogical theorist, Johann Frederich Herbart, directly challenged the faculty psychology of the German-inspired professional historians but still placed history at the center of their pedagogical schemes. As a result, history gained a central place in U.S. elementary and secondary curriculum during these years, but paradoxically the new psychology gradually eroded the influence of professional historians on the curriculum, because they failed to acknowledge these emerging pedagogical and psychological theories.
“Great Injustice”: Social Status and the Distribution of Military Pensions after the Civil War
Authors: Johnson Russell L.
Published: March 2011

In recent years, historians have paid increased attention to the Civil War pension system created for Union army soldiers and their families. It has come to be seen as a milestone in the evolution of U.S. social policy. Despite the overall appearance of generosity and of unbiased treatment for applicants, however, individuals actually experienced the system very differently based on the social status of the soldier involved. Looking at pension legislation, its implementation, and nearly one thousand pension claim files, this article argues that three types of status discrimination appeared in the distribution of pensions: Pension laws paid larger amounts to officers and their families, the Pension Bureau used ability to perform manual labor to determine the level of disability regardless of the applicants' true ability to earn a living, and claims based on the service of officers generally were decided more quickly and more favorably than those of enlisted men. Because military ranks reflected the soldiers' civilian social position—most manual laborers served as enlisted men, for example—these biases meant that individuals of higher social status received significantly better treatment than those of lower civilian status.
Individual Differences in Sensitivity to Reward
Authors: Van den Berg Ivo , Franken Ingmar H. A. , Muris Peter
Published: March 2011

Reward, such as monetary gain, and punishment, such as monetary loss, are capable of modifying the electrophysiological signals of the brain. Further, it is known that there are individual differences in the sensitivity for reward and punishment. This study set out to test the relationship between self-reported sensitivity to reward and sensitivity to punishment and electrophysiological brain responses to monetary gains and losses. Subjects filled out the modified Behavioral Inhibition System/Behavioral Activation System scales for measuring responsiveness to reward (RR) and responsiveness to punishment (RP), and performed a gambling task. The results showed that there was a significant positive correlation between scores on the RR scale and P3 amplitudes on the Fz electrode location to win, loss, and break even outcomes. There was no significant correlation, however, between scores on the RP scale and the P3 amplitudes to all outcomes. For the feedback-related negativity, no significant correlations with both the RR and RP scales were present. Thus individuals scoring high on RR seem to be generally more sensitive to outcomes (either positive or negative) during a task where they might receive a reward.
The Effects of Valence and Arousal on Hemispheric Asymmetry of Emotion
Authors: Zhang Jing , Zhou Renlai , Oei Tian P. S.
Published: March 2011

The independent influence of valence and arousal on emotional hemispheric brain asymmetry was investigated to decide between three contrasting hypotheses: the right hemisphere hypothesis, the valence hypothesis, and the integrative hypothesis. Event-related potentials (ERPs) were recorded while participants (N = 20) viewed positive high arousal, positive low arousal, negative high arousal, and negative low arousal pictures, following a baseline measure of ERPs while viewing gray squares. Self-ratings of emotional state in terms of valence and arousal were taken after each of the four emotion blocks. Valence and arousal effects on hemispheric asymmetry were analyzed for the time windows 130–170, 170–280, 280–450, and 450–600 ms. Right dominance on N2 during negative high arousal and left dominance on P3 and late positive potentials during negative low arousal were found over the frontal lobe. Right dominance on P2, P3, and late positive potentials over the parietal lobes appeared during high arousal. No frontal asymmetry was found in positive emotion. Our result partly supported the integrative hypothesis and did not provide evidence for the right hemisphere hypothesis or the valence hypothesis. These results suggested that arousal plays the main role in the ERPs’ hemispheric asymmetry.
Microsegregation rates of liquid Fe‐Ni‐S metal in natural silicate‐metal systems: A combined experimental and numerical study
Authors: Rushmer Tracy , Petford Nick
Published: March 2011

We present results of an image‐based numerical model aimed at quantifying the microsegregation and flow of liquid metal in meteorites prior to the onset of silicate melting. The sample material is the H6 chondrite Kernouvé. The model utilizes the observed geometry of two distinct chondrite textures associated with grain‐scale melt segregation in the following: (1) the undeformed (natural) state and (2) during deformation and partial melting under controlled (laboratory) conditions. The numerical simulations recover liquid metal segregation rates of ∼10−6to 10−4m s−1for matrix permeabilities (k) of 10−12<k< 10−10m2and pressure gradients of ∼1 and 104Pa m−1. The velocity flow field is position‐dependent across the sample, reflecting initial grain‐scale heterogeneity and anisotropy in the spatial distribution of metal prior to melting. In addition to porous flow, we use a coupled Brinkman‐Navier‐Stokes solution to quantify liquid metal segregation through deformation‐induced microscale veins. Melt flow velocities in veins are several orders faster than matrix flow, implying that a combination of porous (grain‐scale) flow feeding into a network of small‐scale cracks and veins during the initial stages of partial melting may be an extremely efficient mechanism for segregating liquid metal from silicate matrix in planetesimals undergoing deformation. This mechanism may be temporary and confined only to the earliest stages of melt microsegregation because with increasing temperature, the onset of silicate melting shuts off liquid metal segregation by creeping matrix flow. The point at which this occurs marks an important transition in the mode and style of internal differentiation.
Preferential Langerhans cell differentiation from CD34+ precursors upon introduction of ABCG2 (BCRP)
Authors: van de Ven Rieneke , Lindenberg Jelle J , Reurs Anneke W , Scheper Rik J , Scheffer George L , de Gruijl Tanja D
Published: March 2011

Epidermal Langerhans cells (LC) and dermal interstitial dendritic cells (IDC) were found to express the ATP‐binding cassette (ABC) transporter breast cancer resistance protein (BCRP; ABCG2). Also, low BCRP expression was present on CD34+ blood DC precursors and expression was increased upon their differentiation to LC. The CD34+ acute myeloid leukemia‐derived DC cell line MUTZ3 can be cultured into LC or IDC, depending on the cytokine cocktail used. Introduction of functional BCRP in MUTZ3 progenitor cells through retroviral transduction resulted in the emergence of typical LC‐characteristics in IDC cultures; the majority of cells remained negative for the IDC‐specific C‐type lectin DC‐SIGN, but rather displayed enhanced expression of the LC‐specific C‐type lectin Langerin and characteristic high expression levels of CD1a. BCRP‐induced skewing toward LC‐like differentiation coincided with early RelB expression in ‘IDC’, derived from MUTZ3‐BCRP, and depended on endogenous transforming growth factor beta (TGF‐β) production. Intriguingly, cellular BCRP localization differed between skin LC and IDC, and a more cytoplasmic BCRP localization, as observed in primary skin LC, seemed to relate to LC‐like differentiation in IDC cultures upon BCRP introduction in MUTZ3 progenitors. Together these data support a role for BCRP in preferential LC differentiation from CD34+ myeloid DC progenitors.
A metalloporphyrin functionalized metal–organic framework for selective oxidization of styrene
Authors: Xie Ming-Hua , Yang Xiu-Li , Wu Chuan-De
Published: March 2011

A functional metal–organic framework assembled from palladium-porphyrin struts and cadmium(ii) nodes presents interesting topological network structure, high stability and significant catalytic activity.
Coercivity enhancement in L11 Co50-xCuxPt50 thin films
Authors: Yuan Fu-Te , Sun An-Cheng , Hsu Jen-Hwa , Tan C. S. , Kuo P. C. , Liao W. M. , Lee H. Y.
Published: March 2011

This study investigates structural and magnetic properties of the (Co50-xCux)Pt50 films deposited on the MgO(111) substrate. Experimental results indicate that adding Cu significantly improves the alignment of L11[111] and decreases the structural defects of the epitaxial films. Additionally, a large increment of an order of magnitude in out-of-plane coercivity (Hc⊥) from 0.2 to 2.2 kOe is achieved when x is increased from 0 to 23. Such an increase accompanies a reduction of in-plane coercivity (Hc||) from 1.5 to less than 0.1 kOe. The enhancement in Hc⊥ is attributed to the domain wall pinning effect induced by compositional segregation of Cu and Co. This study provides an effective approach to optimize the perpendicular magnetic properties of L11 CoPt.
Characterization of oxidation resistant Fe@M (M=Cr, Ni) core@shell nanoparticles prepared by a modified reverse micelle reaction
Authors: Naik Sweta H. , Carroll Kyler J. , Carpenter Everett E.
Published: March 2011

Iron-based nanoparticles are the forerunners in the field of nanotechnology due to their high magnetization saturation and biocompability which affords them use in a variety of applications. However, iron-based nanoparticles, due to a high surface-to-volume ratio, suffer from oxidation and limit its practicality by lowering the magnetic moment significantly. To avoid this oxidation, the surfaces of the particles have to be passivated. One such way to accomplish this passivation is to synthesize core@shell nanoparticles that have a surface treatment of chromium or nickel. These core@shell nanoparticles have been synthesized using a reverse micelle technique. The Cr and Ni passivated iron nanoparticles were characterized by x-ray diffraction, transmission electron microscopy, vibrating sample magnetometry, and x-ray photoelectron spectroscopy to determine their phase, morphology, surface properties, and magnetization saturation. A high magnetization saturation of 160 and 165 emu/g for Cr and Ni passivated iron core@shell nanoparticles was achieved.
The effects of size and orientation on magnetic properties and exchange bias in Co3O4 mesoporous nanowires
Authors: Zeng R. , Wang J. Q. , Chen Z. X. , Li W. X. , Dou S. X.
Published: March 2011

Co3O4 mesoporous nanowires with average single crystalline grain sizes of about 8 nm, 12nm, 25 nm, and 45 nm were synthesized by sintering of microwave-assisted hydrothermal processed belt-Co(OH)2 precursors at 300–500 °C for 2 h. Microstructure analysis was conducted by x-ray diffraction, x-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), field emission SEM (FESEM), transmission electron microscopy (TEM), and high resolution TEM (HRTEM) to confirm the composition, structure, and orientation in the nanowires. Systematic magnetic measurements have also been conducted on the nanowires. It was found that the size and orientation have significant effects on the magnetic and exchange bias properties. The interesting finding was made that room temperature ferromagnetism appeared at 350 °C in the high orientation samples. Systematic comparison and analysis of the relationships among the grain size, microstructure, orientation (texture), surface electric structure (O vacancies), and defects with magnetic properties (ferromagnetism, coercive field, exchange bias, etc.) are presented in this work.
An approach for analysis of magnetostatic volume waves in magnonic crystals
Authors: Chi Kai H. , Zhu Yun , Mao Rong W. , Dolas James P. , Tsai Chen S.
Published: March 2011

A theoretical approach, based on Walker’s equation, to analyze the propagation characteristics of magnetostatic volume waves in magnonic crystals with periodic variation in magnetic layer thickness is presented. The properties of bandgaps versus the thickness parameters of the magnetic layer and the magnetically tuned bandgaps are verified experimentally.
Compositional dependence of antiferromagnetic anisotropy in IrMn/CoFe exchange bias systems
Authors: Aley N. P. , O’Grady K.
Published: March 2011

We report on a study of the effect of Ir content on the loop shift (HEX) and anisotropy constant (KAF) in the CoFe/IrMn system. The sample structure investigated was Si/NiCr(5 nm)/Ru(5 nm)/IrxMn1-x/CoFe(2 nm)/Ta(3 nm). All samples were produced by sputtering and the Ir and Mn levels were varied using a specially made composite target and deposited at ∼120 °C. The composition of the samples was analyzed using energy dispersive x-ray analysis. KAF was calculated from thermal activation measurements using the York Protocols. A plateau in HEX was found for Ir levels between 16– 20.5 at. %. HEX was found to decrease by 50% on either side of this window. This result is consistent with previous studies where the enhancement of HEX was attributed to an increase in the atomic ordering of the IrMn alloy. However, KAF decreases linearly with increasing Ir concentration and does not appear to correlate with the change in HEX.
Soft magnetism and microwave magnetic properties of Fe-Co-Hf films deposited by composition gradient sputtering
Authors: Li Shandong , Liu Ming , Xu Feng , Lou J. , Tian Zongjun , Wu Jianpeng , Hu Yi , Cai Xinle , Duh Jenq-Gong , Sun Nian X.
Published: March 2011

A composition gradient sputtering method was employed to deposit a series of (FexCo1-x)1-yHfy alloy films with different Fe/Co atomic ratios and Hf-doping. At Fe/Co = 70/30, the magnetically annealed (Fe0.7Co0.3)1-yHfy films with y = 0.087 – 0.124 showed a very high uniaxial anisotropy and an ultrahigh ferromagnetic resonance frequency over 7 GHz after the films were annealed at 350 °C, while at Fe/Co = 50/50, the as-deposited (Fe0.5Co0.5)1-yHfy films with y = 0.074 – 0.168 showed an excellent in-plane uniaxial anisotropy and high ferromagnetic resonance frequency over 3 GHz. These Fe-Co-Hf films deposited by the composition gradient sputtering method exhibited ahigh saturation magnetization of 1.8 – 2.2 T, a large uniaxial anisotropy field of 200 – 500 Oe, and a high ferromagnetic resonance frequency over 7 GHz, which provides great opportunities for integrated magnetic devices.
An evolutionary computation approach for time-harmonic field problems involving nonlinear magnetic media
Authors: Adly A. A. , Abd-El-Hafiz S. K.
Published: March 2011

Recently, the particle swarm optimization evolutionary approach has been successfully utilized in field computation for devices involving nonlinear magnetic media. The purpose of this paper is to extend the aforementioned approach toward the solution of time-harmonic field problems. More specifically, unknown time-step vector magnetic potentials leading to the minimization of the energy functional are computed in an evolutionary mechanism to determine instantaneous field components. The proposed approach has been implemented and utilized for different supply frequencies, field amplitudes, and media characteristics. Details of the approach as well as comparisons with finite-element computations demonstrating the accuracy of the approach are given in the paper.
Estimation of heat loss in thermal wave experiments
Authors: Straube Hilmar , Breitenstein Otwin
Published: March 2011

The theoretical description of thermal wave experiments assumes harmonic heat introduction (sinusoidally modulated heating and cooling) and an adiabatic (thermally insulated from the environment) sample. In most experimental setups, however, only pulsed heat is introduced, and the mean sample temperature stabilizes at a value above ambient determined by the strength of the heat loss to the surroundings. The question arises as to what conditions have to be satisfied such that the assumption of an adiabatic sample is applicable to the experimental situation. In this contribution we present a treatment of heat-loss mechanisms (radiation, conduction/convection to air, and conduction to the sample holder) together with their implications for signal shape and temperature control of the sample. The treatment leads to a general mathematical criterion to decide whether heat conduction inside the sample can be considered to be adiabatic or not, depending on excitation frequency and spatial frequency content of the heating power distribution. The theoretical considerations are applied experimentally to typical situations of thermally thin samples (where heat loss to the sample holder is critical) and thermally thick samples (where temperature control can be a problem).
Edge shape effect on vibrational modes in graphene nanoribbons: A numerical study
Authors: Mazzamuto F. , Saint-Martin J. , Valentin A. , Chassat C. , Dollfus P.
Published: March 2011

The phonon dispersion and the vibrational density of states (VDOS) of graphene nanoribbons (GNR) of various widths and edge shapes are calculated using the force constant model including the fifth-nearest neighbor atoms. Among typical graphene peaks like E2g (or G) and D peaks, several distinctive ribbon peaks are identified in the VDOS depending on the edge shape. According to our calculation, the edge nature of a GNR can be identified by several characteristic peaks in the VDOS: many out-of-plane edge localized modes are detected at about 630 cm−1 in armchair GNRs and many in-plane edge modes are detected at about 480 cm−1 in zigzag GNRs. In mixed-edge GNRs the intensity of these peaks is strongly correlated to the armchair-to-zigzag edge ratio.
Deformation mechanisms in silicon nanoparticles
Authors: Zhang Ning , Deng Qian , Hong Yu , Xiong Liming , Li Shi , Strasberg Matthew , Yin Weiqi , Zou Yongjie , Taylor Curtis R. , Sawyer Gregory , Chen Youping
Published: March 2011

We report here on the observation of dislocation nucleation and glide in silicon nanoparticles, after phase transformation from diamond cubic to β-tin crystal structure, within the formed β-tin metallic phase region in atomistic simulations of indentation. The simulation results provide an explanation of the super-high hardness of silicon nanoparticles measured in experiments. By comparing the simulation results with experimental measurement of hardness, we are able to evaluate the performance of two widely used interatomic potential functions: Stillinger–Weber and Tersoff potentials. Through simulations, we have found a critical size of silicon nanoparticles where there is a change in deformation mechanisms, strength, and hardness. The effect of the applied strain rate on simulation results is also investigated.
The role of nonlinearity in computing graph-theoretical properties of resting-state functional magnetic resonance imaging brain networks
Authors: Hartman D. , Hlinka J. , Paluš M. , Mantini D. , Corbetta M.
Published: March 2011

In recent years, there has been an increasing interest in the study of large-scale brain activity interaction structure from the perspective of complex networks, based on functional magnetic resonance imaging (fMRI) measurements. To assess the strength of interaction (functional connectivity, FC) between two brain regions, the linear (Pearson) correlation coefficient of the respective time series is most commonly used. Since a potential use of nonlinear FC measures has recently been discussed in this and other fields, the question arises whether particular nonlinear FC measures would be more informative for the graph analysis than linear ones. We present a comparison of network analysis results obtained from the brain connectivity graphs capturing either full (both linear and nonlinear) or only linear connectivity using 24 sessions of human resting-state fMRI. For each session, a matrix of full connectivity between 90 anatomical parcel time series is computed using mutual information. For comparison, connectivity matrices obtained for multivariate linear Gaussian surrogate data that preserve the correlations, but remove any nonlinearity are generated. Binarizing these matrices using multiple thresholds, we generate graphs corresponding to linear and full nonlinear interaction structures. The effect of neglecting nonlinearity is then assessed by comparing the values of a range of graph-theoretical measures evaluated for both types of graphs. Statistical comparisons suggest a potential effect of nonlinearity on the local measures—clustering coefficient and betweenness centrality. Nevertheless, subsequent quantitative comparison shows that the nonlinearity effect is practically negligible when compared to the intersubject variability of the graph measures. Further, on the group-average graph level, the nonlinearity effect is unnoticeable.
Modeling, design, and analysis of interferometric cantilevers for time-resolved force measurements in tapping-mode atomic force microscopy
Authors: Sarioglu A. F. , Solgaard O.
Published: March 2011

Cantilevers with interferometric high bandwidth force sensors can resolve nonlinear tip-sample interaction forces in tapping-mode atomic force microscopy. In this paper, we provide a detailed analysis of time-resolved force measurements using such cantilever. We first model the probe as a coupled spring-mass system and investigate its steady state dynamics under tapping-mode imaging conditions. Next, we analyze the optical response of the interferometric force sensor: Diffraction patterns as a function of tip displacement are obtained both analytically and by simulations. Finally, the frequency response of the force sensor is calculated, and the effects of the sensor geometry variations on the sensor mechanical response are analyzed.
Ab-initio calculation of magnetic properties of Gd-doped ZnGeN2
Authors: Rufinus J.
Published: March 2011

The current interest in the field of semiconductor spintronics is mostly focused on transition metal-doped and rare-earth metal-doped binary materials. Recently, however, the explorations of metal-doped ternary semiconductors have gained attention due to experimental confirmations of possible high transition temperature in chalcopyrite compounds. Since the chalcopyrites are ternary materials, there are possibilities of having ferromagnetic or antiferromagnetic configurations, depending on which metal site was substituted by the dopant. Mn-doped ZnGeN2, for example, was found to be antiferromagmetic for MnZn and ferromagnetic for MnGe. A density functional theory study is performed on Gd-doped ternary material ZnGeN2. Our results show Gd-doped ZnGeN2 to be ferromagnetic, independent of the substitution sites. The formation of half-metallic ferromagnetism is possible in this type of material.
Highly Hk-graded perpendicular media with [CoB/Pt]n+O multilayer film
Authors: Nemoto Hiroaki , Nakagawa Hiroyuki , Tanahashi Kiwamu , Nakatani Ryo-ichi
Published: March 2011

Novel media with deeper vertical gradation in the anisotropy field, Hk, were developed by adding a granular [Co/Pt]n multilayer film with oxide grain boundaries to a conventional perpendicular media structure. While the novel graded media had equivalent writability and on-track recording performance to the conventional media, they showed enhanced thermal stability particularly under the influence of magnetic fields. The enhanced thermal stability contributed to a smaller erase-band width and better tolerance to adjacent track erasure. The highly Hk-graded media thus provided the capability for a higher track density, which is a promising solution to achieve high areal recording density.
Experimental write margin analysis of bit patterned media
Authors: Saga Hideki , Shirahata Kazuki , Mitsuzuka Kaname , Shimatsu Takehito , Aoi Hajime , Muraoka Hiroaki
Published: March 2011

Write margin analysis of the bit patterned media (BPM) was experimentally carried out using a static tester. Sample BPM were fabricated from hard/soft-stacked (exchange-coupled composite; ECC) base media with a Pt/Co multilayer hard layer and a Co soft layer. Write margins of 60-nm-dot (140 nm period) and 40-nm-dot (100 nm period) media were confirmed to be 80 nm and 50 nm, respectively. An analysis of the margin loss factor found a large residual margin loss. The loss factors of 60-nm-dot and 40-nm-dot media were 57 nm and 44 nm, respectively, and these values almost correspond to the dot diameter. The residual margin loss was identified as due to the formation of a multi-domain structure within some dots under certain recording conditions.
Coalescence-free L1 ordering of embedded CoPt nanoparticles
Authors: Tournus F. , Blanc N. , Tamion A. , Dupuis V. , Epicier T.
Published: March 2011

We have synthesized diluted samples of CoPt clusters and investigated by various techniques the effect of a 2 h anneal at 750 K. Transmission electron microscopy observations have put into evidence L10 chemical ordering without any detectable coalescence upon annealing. Magnetic measurements on CoPt clusters embedded in amorphous carbon have been used to provide additional and stronger evidence of the absence of coalescence. We show how the analysis of normalized ZFC curves can be used as a convenient and powerful technique to detect subtle variations in the cluster size distribution.
Loss separation in soft magnetic composites
Authors: de la Barrière O. , Appino C. , Fiorillo F. , Ragusa C. , Ahmed H. Ben , Gabsi M. , Mazaleyrat F. , LoBue M.
Published: March 2011

We report and discuss significant results on the magnetic losses and their frequency dependence insoft magnetic composites. Two types of bonded Fe-based materials have been characterized atdifferent inductions from dc to 10 kHz and analyzed by extending the concept of loss separation and the related statistical theory to the case of heterogeneous materials. Starting from the experimental evidence of eddy current confinement inside the individual particles, the classical losscomponent is calculated for given particle size distribution. Taking then into account thecontribution of the experimentally determined quasistatic (hysteresis) loss, the excess losscomponent is obtained and quantitatively assessed. Its behavior shows that the dynamichomogenization of the magnetization process with frequency, a landmark feature of magnetic laminations, is restrained in these materials. This results into a partial offset of the loss advantage offered by the eddy current confinement.
Reversal of patterned Co/Pd multilayers with graded magnetic anisotropy
Authors: Davies J. E. , Morrow P. , Dennis C. L. , Lau J. W. , McMorran B. , Cochran A. , Unguris J. , Dumas R. K. , Greene P. , Liu Kai
Published: March 2011

Magnetization reversal and the effect of patterning have been investigated in full-film and dot arrays of Co/Pd multilayers, using the first-order reversal curve and scanning electron microscopy with polarization analysis techniques. The effect of patterning is most pronounced in low sputtering pressure films, where the size of contiguous domains is larger than the dot size. Upon patterning, each dot must have its own domain nucleation site and domain propagation is limited within the dot. In graded anisotropy samples, the magnetically soft layer facilitates the magnetization reversal, once the reverse domains have nucleated.
Magnetic properties of Gd2C: Experiment and first principles calculations
Authors: Mudryk Y. , Paudyal Durga , Pecharsky V. K. , Gschneidner K. A.
Published: March 2011

We report the crystal structure, magnetic properties, and electronic structure of Gd2C. The compound crystallizes in the rhombohderal CdCl2–type structure and has a Curie temperature of 351 K, which decreases to ∼340 K after heat treatment at 1000 °C for 1 week. The magnetic ordering transition is of second order, and the saturation magnetic moment measured at 2 K in 70 kOe magnetic field is 7.26 µB/Gd which compares well with 7.34 µB/Gd calculated from first principles. The electronic structure calculations performed using the tight bonding linear muffin tin orbital method within the non local exchange correlation potentials show stronger exchange interactions compared to the local exchange correlation potentials leading to the high Curie temperature of Gd2C.
Thermoelectric properties of Co0.9Fe0.1Sb3-based skutterudite nanocomposites with FeSb2 nanoinclusions
Authors: Zhou Chen , Sakamoto Jeffrey , Morelli Donald , Zhou Xiaoyuan , Wang Guoyu , Uher Ctirad
Published: March 2011

Bulk thermoelectric nanocomposite materials have great potential to exhibit higher figure of merit due to effects arising from the nanostructure. In this paper, we report thermoelectric properties from 80 K to 800 K of Co0.9Fe0.1Sb3 based skutterudite nanocomposites containing FeSb2 nanoinclusions. The nanoscale FeSb2 precipitates are well dispersed in the skutterudite matrix and reduce the lattice thermal conductivity due to additional phonon scattering from the nanoscopic interfaces. Moreover, the nanocomposite samples also exhibit enhanced Seebeck coefficients relative to the regular iron substituted skutterudite samples. As a result, our best nanocomposite sample reached a dimensionless figure of merit of 0.59 at 788 K, a factor of two higher than that of the control sample Co0.9Fe0.1Sb3.