bluuebunny/crossref_metadata_2025 huggingface dataset:
A two‐step process in the emergence of neurogenesis
Authors: Galliot Brigitte , Quiquand Manon
Published: September 2011

Cnidarians belong to the first phylum differentiating a nervous system, thus providing suitable model systems to trace the origins of neurogenesis. Indeed corals, sea anemones, jellyfish and hydra contract, swim and catch their food thanks to sophisticated nervous systems that share with bilaterians common neurophysiological mechanisms. However, cnidarian neuroanatomies are quite diverse, and reconstructing the urcnidarian nervous system is ambiguous. At least a series of characters recognized in all classes appear plesiomorphic: (1) the three cell types that build cnidarian nervous systems (sensory‐motor cells, ganglionic neurons and mechanosensory cells called nematocytes or cnidocytes); (2) an organization of nerve nets and nerve rings [those working as annular central nervous system (CNS)]; (3) a neuronal conduction via neurotransmitters; (4) a larval anterior sensory organ required for metamorphosis; (5) a persisting neurogenesis in adulthood. By contrast, the origin of the larval and adult neural stem cells differs between hydrozoans and other cnidarians; the sensory organs (ocelli, lens‐eyes, statocysts) are present in medusae but absent in anthozoans; the electrical neuroid conduction is restricted to hydrozoans. Evo‐devo approaches might help reconstruct the neurogenic status of the last common cnidarian ancestor. In fact, recent genomic analyses show that if most components of the postsynaptic density predate metazoan origin, the bilaterian neurogenic gene families originated later, in basal metazoans or as eumetazoan novelties. Striking examples are the ParaHox Gsx, Pax, Six, COUP‐TF and Twist‐type regulators, which seemingly exert neurogenic functions in cnidarians, including eye differentiation, and support the view of a two‐step process in the emergence of neurogenesis.
HUMAN AND ANIMAL RESEARCH GUIDELINES: ALIGNING ETHICAL CONSTRUCTS WITH NEW SCIENTIFIC DEVELOPMENTS
Authors: FERDOWSIAN HOPE
Published: September 2011

Both human research and animal research operate within established standards and procedures. Although the human research environment has been criticized for its sometimes inefficient and imperfect process, reported abuses of human subjects in research served as the impetus for the establishment of the Nuremberg Code, Declaration of Helsinki, and the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research and the resulting Belmont Report. No similar, comprehensive and principled effort has addressed the use of animals in research. Although published policies regarding animal research provide relevant regulatory guidance, these policies have not emerged from the process of specifying consistent and reasoned ethical principles. The lack of a fundamental effort to explore the ethical issues and principles regarding the use of animals in research has led to unclear and disparate policies. Recent studies have increased our understanding of animal cognition and emotion, suggesting that animals' potential for experiencing a wide variety of harms, such as pain and fear, is greater than has been previously appreciated. Furthermore, relationships between methods of captivity and certain laboratory procedures and the resulting adverse physical, social and psychological effects have been established. In light of this information, current protections may need to be reconsidered and modified. This paper explores the historical convergence and divergence in the creation of human and animal research guidelines, as well as opportunities to align ethical frameworks with new scientific discoveries.
THE THOUGHT SPACE OF GOD: THE HAUNTING BELOW THE I‐THOU RELATION
Authors: BERMAN MICHAEL
Published: September 2011

This essay attempts a phenomenological analysis of Descartes' statement, ‘my perception of God is prior to my perception of myself,’ and Buber's claim that God ‘is also the mystery of the self‐evident, nearer to me than my I.’ I radicalize the implications of Descartes' and Buber's claims by drawing on the thought of Husserl and Levinas, and couching the analysis in terms of Merleau‐Ponty's experiential notions of haunting and reversibility. This forces us to interrogate the subjective space in which we think God qua recognize the other, and shows us a kind of necessity that underlies the I‐Thou relation. My conclusion leaves us in a place of powerless subjective inwardness and awe.
The Authority of Scripture and the Triune God
Authors: PADDISON ANGUS
Published: September 2011

Consideration of what is meant by authority is a vital task for theology, and especially for those involved in theologically engaging with Scripture. After some general reflections on the nature of authority this article turns specifically to examine biblical authority. The challenges facing those who would offer an account of biblical authority are presented. The generating question for the positive proposals advanced in this essay is: what difference does the doctrine of the Trinity make to the account we render of biblical authority? The action of the triune God is the appropriate context for locating Scripture's salvific ministry. Moreover, Scripture is space that God gives us without violating our creatureliness. Scripture is both part of the created order and a participant within God's saving history. The doctrine of the Trinity invites us to articulate an account of biblical authority that is historical and timeful.
From Letter to Spirit
Authors: RENO R. R.
Published: September 2011

Reformation polemics and modern historical‐critical scholarship has encouraged us to see the spiritual sense of Scripture as remote from the literal sense. However, a close examination of the traditional methods of spiritual interpretation shows that the literal sense plays an important role in expositions of the spiritual sense. Traditional methods both anchor and motivate spiritual readings by recourse to the letter of Scripture, and as a consequence the speculative stretch toward the spiritual is saturated with the literal.
The hand structure of Carnotaurus sastrei (Theropoda, Abelisauridae): implications for hand diversity and evolution in abelisaurids
Authors: RUIZ JAVIER , TORICES ANGÉLICA , SERRANO HUMBERTO , LÓPEZ VALLE
Published: September 2011

Abstract:  Carnotaurus sastrei is an abelisaurid dinosaur from the Late Cretaceous of Argentina that has very reduced, but robust, forelimbs and derived hands with four digits, including a large, conical‐shaped metacarpal IV lacking an articulation for a phalanx. The analysis presented in this work highlights a series of additional autapomorphies of C. sastrei. For example, the proximal phalanges are longer than the metacarpals in digits II and III, and digit III includes only one phalanx besides the ungual. The hand of Carnotaurus shares several features with those of Aucasaurus and Majungasaurus, but the hands of the latter genera also display autapomorphies, indicating that the diversity in abelisaurid hand structure is similar to the diversity of cranial protuberances of these dinosaurs.
New remains ofEgatochoerus jaegeri(Mammalia, Suoidea) from the late Eocene of Peninsular Thailand
Authors: ORLIAC MAEVA , GUY FRANCK , CHAIMANEE YAOWALAK , JAEGER JEAN‐JACQUES , DUCROCQ STEPHANE
Published: September 2011

Abstract: We report here additional remains referred toEgatochoerus jaegerifrom the late Eocene locality of Ban Mark in the Krabi basin, Thailand. The new material described, comprising upper and lower cheek teeth, deciduous premolars and partial cranial remains, makesE. jaegerithe best‐documented Eocene representative of Old World Suoidea at present. Detailed study and comparison of their cheek teeth structure reveal a homogeneity of the molar crest and groove patterns of Old World and New World Palaeogene suoids.
Naming Migraine and Those Who Have It
Authors: Young William B. , Kempner Joanna , Loder Elizabeth W. , Roberts Jason , Segal Judy Z. , Solomon Miriam , Cady Roger K. , Janoff Laura , Sheeler Robert D. , Robert Teri , Yocum Jennifer , Sheftell Fred D.
Published: September 2011

Medical language has implications for both public perception of and institutional responses to illness. A consensus panel of physicians, academics, advocates, and patients with diverse experiences and knowledge about migraine considered 3 questions: (1) What is migraine: an illness, disease, syndrome, condition, disorder, or susceptibility? (2) What ought we call someone with migraine? (3) What should we not call someone with migraine? Although consensus was not reached, theresponses were summarized and analyzed quantitatively and qualitatively. Panelists participated in writing and editing the paper. The panelists agreed that “migraine,” not “migraine headache,” was generally preferable, that migraine met the dictionary definition for each candidate moniker, terms with psychiatric valence should be avoided, and “sufferer” should be avoided except in very limited circumstances. Overall, while there was no consensus, “disease” was the preferred term in the most situations, and illness the least preferred. Panelists disagreed strongly whether one ought to use the term “migraineur” at all or if “person with migraine” was preferable. Panelists drew upon a variety of principles when considering language choices, including the extent to which candidate monikers could be defended using biomedical evidence, the cultural meaning of the proposed term, and the context within which the term would be used. Panelists strove to balance the need for terms to describe the best science on migraine, with the desire to choose language that would emphasize the credibility of migraine. The wide range of symptoms of migraine and its diverse effects may require considerable elasticity of language.
Hydration Degree of Alkali‐Activated Slags: A 29Si NMR Study
Authors: Le Saoût Gwenn , Ben Haha Mohsen , Winnefeld Frank , Lothenbach Barbara
Published: September 2011

A commercial blast furnace slag was activated using either sodium hydroxide or hydrous sodium metasilicate, and the degree of hydration was determined by 29Si magic angle spinning nuclear magnetic resonance (NMR). The results are compared with measurements made using scanning electron microscopy image analysis (SEM‐IA). The results from both 29Si NMR and the SEM‐IA measurements indicated a fast initial reaction with the alkali, and similar degrees of hydration throughout the reaction. The 29Si NMR results were analyzed using two different methods for fitting the residual slag in the decomposition of the 29Si NMR spectra: the first method used the spectrum of the anhydrous slag, whereas the second method used the spectrum of the dissolution residue of the hydrated sample. Only the first method provided a satisfactory simulation. The degree of hydration and the Al/Si atomic ratio within the C–S–H, deduced by 29Si NMR were in agreement with SEM‐IA and EDX analyses.
Balancing nurturance, cost and time: complementary feeding in Accra, Ghana
Authors: Pelto Gretel H. , Armar‐Klemesu Margaret
Published: September 2011

This paper presents a picture of the general patterns of complementary feeding behaviours in urban Ghana. A focused ethnographic study protocol for assessing complementary feeding developed for the Global Alliance for Improved Nutrition was used to collect data from caregivers of children 6–24 months of age. We examined the multiple factors that influence the selection of foods for infants and young children in this urban setting, and found that economic factors, health beliefs and other nurturing‐related values, access to food and issues of convenience all play important roles. We conclude that the interactions of nurturance, cost and time are vectors that affect feeding decisions.
Legislation should support optimal breastfeeding practices and access to low‐cost, high‐quality complementary foods: Indonesia provides a case study
Authors: Soekarjo Damayanti , Zehner Elizabeth
Published: September 2011

It is important to support women to exclusively breastfeed for 6 months and continue breastfeeding for 24 months and beyond. It is also necessary to provide the poor with access to affordable ways to improve the quality of complementary foods. Currently, many countries do not have the legal and policy environment necessary to support exclusive and continued breastfeeding. Legislative and policy changes are also necessary for introducing complementary food supplements, allowing them to be marketed to those who need them, and ensuring that marketing remains appropriate and in full compliance with the International Code of Marketing of Breastmilk Substitutes. This paper aims to illustrate the above with examples from Indonesia and to identify legislative requirements for supporting breastfeeding and enabling appropriate access to high‐quality complementary food supplements for children 6–24 months of age. Requirements include improved information, training, monitoring and enforcement systems for the International Code of Marketing of Breastmilk Substitutes; implementation and monitoring of the Baby‐Friendly Hospital Initiative; establishment of a registration category for complementary food supplements to enhance availability of high‐quality, low‐cost fortified products to help improve young child feeding; clear identification and marketing of these products as complementary food supplements for 6–24‐month‐olds so as to promote proper use and not interfere with breastfeeding.
Hydrofluoric acid poisoning: Data from the Victorian Poisons Information Centre
Authors: Wong Anselm , Greene Shaun , Robinson Jeff
Published: September 2011

Objective: To determine the epidemiology of hydrofluoric acid (HF) exposures, over an extended time period, in Victoria, Australia.

Methods: Retrospective case review of all HF exposures from calls to the Victorian Poisons Information Centre (VPIC) from June 2005 to February 2011.

Results: The VPIC received calls regarding 75 separate HF exposures (approximately 12 per year). The majority 68 (91%) of calls related to male patients. Sixty‐nine (92%) calls related to adults, six (8%) to children (<12 years) and none to the elderly (>65 years age). Fifty‐three per cent of exposures occurred at the workplace. Dermal exposures comprised 54 (72%). Forty‐six (85%) of these resulted from hand contact, six (11%) arm and two (4%) legs. The second most common exposure was ocular 11 (15%). More than half of exposures involved HF concentrations of 10% or less. Of the dermal exposures treated in EDs, 16% required calcium treatment in a form other than gel. Overall poisoning severity was mild (79% of cases Poisoning Severity Score of 0 or 1). Health professionals were the most frequent callers (53% of all cases).

Conclusions: Calls to the VPIC regarding HF are relatively rare, but almost all calls regarding HF taken by the VPIC required hospital evaluation. The majority of exposures were accidental occupational dermal exposures in male adults and most of these were minor, requiring topical calcium gel only. Small exposures with higher concentrated HF can be fatal; however, there were no cases of severe toxicity in the present study.
Climate Aridity and Land Use Changes: A Regional‐Scale Analysis
Authors: SALVATI L. , PERINI L. , SABBI A. , BAJOCCO S.
Published: September 2011

In recent years, aridity and drought have become crucial issues at the global scale because of their environmental and socio‐economic implications. On the one hand, aridity causes a reduction in the biological and economic productivity of terrestrial ecosystems, and represents a serious threat to ecological, biogeochemical, and hydrological processes. On the other hand, human use (and abuse) of vulnerable dry land ecosystems may lead to unsustainable land management. Based on these considerations, this paper analyses the recent land cover changes observed in Latium (Italy) during the exceptionally dry period 2000–2007. More than 50% of the area investigated was classified as dry in 2004–2007 compared with 0% in 2000–2003. Moreover, climatic aridity impacted differently on semi‐natural, agricultural, and built‐up land. These findings illustrate a possible scenario for suburban Mediterranean regions: increasing aridity (mainly due to rising temperatures) mainly impacting on peri‐urban land.
A Semi‐Analytical Solution Based on a Numerical Solution of the Solute Transport of a Conservative and Nonreactive Tracer
Authors: Zhang Jim , Clare Jay , Guo Jia
Published: September 2011

In the evaluation of potential risk from ingestion of groundwater near an impacted site, numerical simulation of fate and transport processes of chemicals of concern is often required. If there is potential concern about multiple chemicals, numerical simulation of each chemical separately is often needed. In this paper, a semi‐analytical solution is presented based on a numerical solution of the transport of a conservative and nonreactive tracer. When multiple chemicals undergoing sorption and first‐order degradation need to be modeled, we can avoid performing individual numerical simulations for each chemical by applying the semi‐analytical solution. Numerical test runs were conducted to verify the semi‐analytical solution; simulation results reveal that the concentrations derived from the semi‐analytical solution are identical to those derived from the individual numerical fate and transport model simulations. The semi‐analytical solution requires steady‐state flow conditions, no continuing contaminant source, and similar initial source concentration distributions.
Uniformity as response to soft law: Evidence from compliance and non‐compliance with the Dutch corporate governance code
Authors: Hooghiemstra Reggy , van Ees Hans
Published: September 2011

The objective of the paper is to examine how firms have dealt with the trade‐off between flexibility and uncertainty that is characteristic for the decision‐making of firms in coping with self‐regulatory initiatives in general and the comply‐or‐explain principle in corporate governance in particular. Using unique data for 126 listed Dutch firms, we find that firms respond to this self‐regulatory initiative by largely complying with the code recommendation, possibly out of fear that the firm's reputation may be damaged. Furthermore, we find evidence suggesting that firms confine themselves to adopting a specific set of code recommendations and use similar arguments to explain non‐compliance. Our findings indicate uniformity in adopting the standard of good governance which is not in line with the logic of corporate governance codes and casts doubt on the effectiveness of this form of soft law. Overall, the paper's findings indicate that more restrictive (regulatory) instruments may be necessary to make firms conform to the spirit of codes.
Antimicrobial Activity of Natural Agents Coated on Starch‐Based Films against Staphylococcus aureus
Authors: Kuorwel Kuorwel K. , Cran Marlene J. , Sonneveld Kees , Miltz Joseph , Bigger Stephen W.
Published: September 2011

Abstract:  This study investigated the antimicrobial (AM) activity of starch‐based films coated with linalool, carvacrol, or thymol against Staphylococcus aureus in vitro or inoculated on the surface of Cheddar cheese. In solid media using the agar diffusion method, the inhibitory effect of linalool, carvacrol, or thymol coated onto the films increased significantly (P≤ 0.05) with the increase in concentration of each AM agent. All the coated films effectively inhibited the growth of S. aureus on the surface of Cheddar cheese. The sensitivity of S. aureus to the AM agents tested in the concentration range of the study is in the order of thymol > carvacrol > linalool.
Evaluating the Effect of Temperature on Microbial Growth Rate—The Ratkowsky and a Bělehrádek‐Type Models
Authors: Huang Lihan , Hwang Cheng‐An , Phillips John
Published: September 2011

Abstract:  The objective of this paper to conduct a parallel comparison of a new Bělehrádek‐type growth rate (with an exponent of 1.5, or the Huang model), Ratkowsky square‐root, and Ratkowsky square equations as secondary models for evaluating the effect of temperature on the growth of microorganisms. Growth rates of psychrotrophs and mesophiles were selected from the literature, and independently analyzed with the 3 models using nonlinear regression. Analysis of variance (ANOVA) was used to compare the means of growth rate (μ), estimated minimum temperature (Tmin), approximate standard errors (SE) of Tmin, model mean square errors (MSE), accuracy factor (Af), bias factor (Bf), relative residual errors (δ), Akaike information criterion (AICc), and Bayesian information criterion (BIC). Based on the estimated Tmin values, the Huang model distinctively classified the bacteria into 2 groups (psychrotrophs and mesophiles). No significant difference (P > 0.05) was observed among the means of the μ values reported in the literature or estimated by the 3 models, suggesting that all 3 models were suitable for curve fitting. Nor was there any significant difference in MSE, SE, δ, Af, Bf, AICc, and BIC. The Tmin values estimated by the Huang model were significantly higher than those estimated by the Ratkowsky models, but were in closer agreement with the biological minimum temperatures for both psychrotrophs and mesophiles. The Tmin values estimated by the Ratkowsky models systematically underestimated the minimum growth temperatures. In addition, statistical estimation showed that the mean exponent for the new Bělehrádek‐type growth rate model may indeed be 1.5, further supporting the validity of the Huang model.
Lysimachia vietnamensis and L. verbascifolia spp. nov. (Primulaceae) from Vietnam
Authors: Loc Phan Ke , Chi‐Ming Hu
Published: September 2011

Two new species of Lysimachia (Primulaceae), L. vietnamensis L. K. Phan & C. M. Hu and L. verbascifolia C. M. Hu & K. L. Phan from Vietnam are described and illustrated.
DETERMINANTS OF INFLATION IN GHANA: AN EMPIRICAL INVESTIGATION
Authors: ADU GEORGE , MARBUAH GEORGE
Published: September 2011

This paper provides an empirical analysis of the factors accounting for inflation dynamics in Ghana using the bounds test and other econometric approaches. We find that real output, nominal exchange rate, broad money supply, nominal interest rate and fiscal deficit play a dominant role in the inflationary process in Ghana. To the extent that output growth by far has the strongest impact on inflation, targeting supply‐side constraints will help moderate price inflation. The paper concludes that inflation in Ghana is explained by a combination of structural and monetary factors consistent with prior studies.
Efficient estimation for a multiple matrix sample design
Authors: Goldstein Harvey , James Anthony N.
Published: September 2011

A generalized least squares method is proposed for estimation in multiple matrix sampling designs. It is shown that this provides efficient estimates, is flexible, and makes fewer assumptions than other procedures.
A scale invariant model for three‐mode factor analysis
Authors: Lee Sik‐Yum , Fong Wai‐Kwan
Published: September 2011

The statistical model for three‐mode factor analysis developed by Bentler & Lee (1979) represents a model for the covariance structure of random variables. In this model, arbitrary rescalings of the variables will destroy the covariance structure. A slightly modified model is proposed in this paper to handle the problem. A statistical development of the model is discussed based on the generalized least squares approach. Estimates, standard error estimates and a goodness‐of‐fit statistic are obtained via the Gauss‐Newton algorithm. It is shown that either the sample correlation matrix or the sample covariance matrix can be used for estimation. An example is presented to illustrate the theory.
‘Much more at home with 3.999 pupils than with four’1: The contributions to psychometrics of Sir Godfrey Thomson
Authors: Sharp Stephen
Published: September 2011

Godfrey Thomson's writings cover many areas of psychology, education and statistics but the most influential aspects of his work were at the interfaces between these three fields. His work revolved around the concept of intelligence: its nature, how to measure it, how far it was genetically determined and whether on average it was increasing or decreasing in society over time. His earlier work on the factorial nature of intelligence was dominated by a debate with Charles Spearman, who promoted the notion of general intelligence not only as one explanation of test data but as the only permissible explanation. It was this claim of uniqueness which Thomson contested. Initially the debate was conducted in terms of alternative competing theories but subsequently it was overtaken by the development of factor analysis as a statistical technique and a recognition that the debate concerned the merits of different methods of analysing data rather than deciding empirically between mutually exclusive theories. Thomson's views on the role which selective tests should play in education are contrasted with the role which he did play as the author of the Moray House tests, which were widely used by education authorities throughout Britain. The development of these tests enabled Thomson to collect data to show that larger families score lower on standardised tests, suggesting that there might be a long‐term decline in national intelligence. His role in the 1932 and 1947 Scottish Mental Surveys illustrates his concern with this possibility, though the surveys did not produce evidence of any such decline.
Generalization of Improved General Approximation tests to split‐plot designs with multiple between‐subjects factors and/or multiple within‐subjects factors
Authors: Algina James
Published: September 2011

Huynh developed the Improved General Approximation (IGA) tests of the between × within interaction and the within‐subjects main effect in a split‐plot design with one within‐subjects and one between‐subjects factor. These tests were designed to control the Type I error rate when multisample sphericity is violated. In Huynh's development the within‐subjects main effect on weighted means is tested. Algina adapted the IGA test to test the within‐subjects main effect on unweighted means in a split‐plot design with one within‐subjects and one between‐subjects factor. Both Huynh's original development and Algina's adaptation are generalized for use with repeated measures designs with multiple between‐subjects factors and/or multiple within‐subjects factors. SAS/IML (SAS Institute Inc., 1989) modules for implementing the generalized test are made available.
On scoring ordered classifications
Authors: Fielding Antony
Published: September 2011

Methods for scoring ordered classifications in a variety of methodological situations are reviewed. These contrast with model‐based approaches through such foci as generalized linear models. The practical empirical advantages of scoring functions are discussed. In developing and extending previous work on axiomatic frameworks for scoring functions it is suggested that conditional mean scoring functions have a logical and intuitive appeal. Extensions to axiom‐based criteria are suggested and their form is suggested by a convexity theorem. This is extended to other useful properties. The debate surrounding choices of arbitrary scores is discussed and some application areas are reviewed. It is concluded that some minimal attention be given to forms of scores whilst recognizing that scoring will continue in practice and that controversy will continue.
Electrochemical determination of cadmium(II) using dithizone assisted ion transfer and eletrolyte dropping electrode
Authors: Shu Feifei , Xie Shaoai , Jia Jinping
Published: September 2011

The transfer of Cd(II) assisted by dithizone (DzH2) present in methyl isobutyl ketone (MIBK) at water–MIBK interface was systematically investigated by novel electrolyte dropping electrode (EDE) using cyclic voltammetry (CV) and square wave voltammetry (SWV). The protonation of DzH2 at polarized liquid–liquid interface was studied. The stoichiometry of resulting metal ligand complex was formulated. Transfer peak current was proportional to the bulk concentration of the Cd(II) varied between 1 μM to 0.1 mM and the maximum value of relative standard deviation was about 3.17%. The presented procedure was successfully applied for determination of Cd(II) in real samples.
INSTANTON FLOER HOMOLOGY FOR TWO-COMPONENT LINKS
Authors: HARPER ERIC , SAVELIEV NIKOLAI
Published: September 2011

For any oriented link of two components in an integral homology 3-sphere, we define an instanton Floer homology whose Euler characteristic is twice the linking number between the components of the link. We show that, for two-component links in the 3-sphere, this Floer homology does not vanish unless the link is split. We also relate our Floer homology to the Kronheimer–Mrowka instanton Floer homology for links.
ON NON-SELF LOCAL MOVES
Authors: NAKANISHI YASUTAKA , SHIBUYA TETSUO , TSUKAMOTO TATSUYA , YASUHARA AKIRA
Published: September 2011

Gusarov and Habiro introduced a Cm move, that is strongly related to Vassiliev invariants. In this note, we study a special kind of Cm move, called a non-self Cm move. We show that two links can be transformed into each other by a finite sequence of non-self Cm moves if and only if (1) the two links can be transformed into each other by a finite sequence of Cm moves, and (2) the knot types of corresponding components coincide.
FOURIER APPROXIMATION OF SYMMETRIC IDEAL KNOTS
Authors: CARLEN M. , GERLACH H.
Published: September 2011

Enforcing a specific symmetry group on a curve, knotted or not, is not trivial using standard interpolations such as polygons or splines. For a prescribed symmetry group we present a symmetrization process based on a Fourier description of a knot. The presence of symmetry groups implies a characteristic pattern in the Fourier coefficients. The relations between the coefficients are shown for five ideal knot shapes with their proposed symmetry groups.
(Invited) Random Telegraph Noise: From a Device Physicist's Dream to a Designer's Nightmare
Authors: Simoen Eddy , Kaczer Ben , Toledano-Luque Maria , Claeys Cor
Published: September 2011

An overview is given on Random Telegraph Noise (RTN) in MOS-based devices. First, the basic properties and physics are briefly outlined, emphasizing the stochastic nature of its main parameters: the capture and emission time constant, while its amplitude is fixed and specific for each trap. Different techniques exist to characterize RTN in MOS devices, either by time or frequency domain measurements. A distinction can also be made between dynamic equilibrium methods like noise spectroscopy or transient measurements, based on a Deep-Level Transient Spectroscopy approach. While single-device based RTN measurements are still of high value, for modern circuit applications, techniques are being developed allowing a fast assessment of RTN in a large number of transistors. The scaling of CMOS technologies to the 32 nm and below raises the issue of variability induced either by random dopant fluctuations or in general, by random charge fluctuations, both spatially and in time. As will be seen, the presence of traps responsible for RTN brings about an additional source of variability which may become dominant in future memories. Finally, it will be shown that RTN is not only a fundamental component of 1/f noise but the same oxide traps are also largely responsible for the Bias Temperature Instability (BTI) in scaled MOSFETs. This leads to a self-consistent model for BTI and a stochastic approach towards the reliability prediction of deep submicron CMOS technologies.
(Invited) Radiation Hardness of SiGe and Ge-Based CMOS Technologies
Authors: Claeys Cor , Iacvo S. , Mitard J. , Arora R. , Zhang C. X. , Galloway K. F. , Fleetwood D. M. , Schrimpf R. D. , Poizat M. , Simoen Eddy
Published: September 2011

To cope with the devices requirements imposed with the ITRS roadmap, several technique are implemented to boost up the drive current. Two possible approaches are the introduction of SiGe channels and the use of Ge-based devices. This paper reviews the radiation hardness of both CMOS technologies, based on an experimental study of state-of-the-art devices, for potential use in space applications.
Quantum Hall Effect as an Electrical Resistance Standard
Authors: Boudinov Henri I. , Boff Marco
Published: September 2011

A special modulation doped Al_0.3Ga_0.7As/GaAs sample was used inthis manuscript with a main objective to demonstrate the application of the integer quantum Hall effect as an universal standard for electrical resistance measurements. The n-type impurities are introduced at a distance of 20 nm from the hetero interface. Some of the electrons are captured in the potential well, far from the impurity atoms. Extremely high carrier mobility (meff = 480000 cm2/Vs at T = 4.2 K) is obtained due to this separation through a significant reduction in ionized impurity scattering.
Comparison between SOI nMOSFET's under Uniaxial and Biaxial Mechanical Stress in Analog Applications
Authors: Souza Márcio S. , Souza Felipe N. , De Souza Michelly , Pavanello Marcelo A.
Published: September 2011

This work presents a study comparing the analog performance of uniaxially and biaxially strained planar Silicon-on-Insulator nMOSFETs for a wide range of channel lengths. The study is performed via two-dimensional numerical and process simulation and supported by experimental measurements. The comparison between devices from the same technology with these two strained techniques demonstrated that higher intrinsic voltage gain is obtained for biaxial mechanical stress. However, the transconductance is higher for uniaxial mechanical stress for shorter devices (below 550 nm) leading to larger unity gain frequency. On the other hand, despite both strain techniques degrades the output conductance, this degradation with channel length shortening is less pronounced for devices under biaxial mechanical stress.
Platinum to Kill Lifetime in Power Diode Design
Authors: Rojas-Hernandez A. , Swart J. W. , Marzano W. , Garcia-Juarez A.
Published: September 2011

An ultrafast power diode is designed and simulated aiming a simple and low cost fabrication process. It is limited to use not implantation process and to use a deep diffusion. The main parameters to fabricate this structure were studied using SRH and Auger recombination models for the lifetime, Crowell model for impact and high injection current considerations to lifetime. The lifetime reduction was performed by adjusting the parameters of capture cross section and density and Energy-level position of platinum. A breakdown voltage of more than 600 V and reverse recovery times less than 35 ns were obtained for a p+nn+ structure, with an epilayer of 50 μm thickness and doping of 2 to 3 x 1014 cm-3.
Low-Frequency Noise Study of p-Channel Bulk MuGFETs
Authors: Simoen Eddy , Aoulaiche Marc , Collaert Nadine , Claeys Cor
Published: September 2011

The low-frequency (LF) noise in p-channel bulk Multiple-Gate Field-Effect Transistors (MuGFETs) with 2.5 nm SiON gate oxide has been investigated in the ohmic regime from weak to strong inversion. It is shown that both 1/f-like noise and Generation-Recombination (GR) noise are present, giving rise to a wide device-to-device scatter in the spectral density. The 1/f noise is dominated by number fluctuations from which an effective trap density in the range 5×1017 cm-3eV-1 has been derived. At the same time, it is demonstrated that the GR noise originates from traps in the gate oxide.
Temperature Influence on Tunnel Field Effect Transistors (TFETs) with Low Ambipolar Currents
Authors: Martino Marcio D. , Der Agopian Paula G. , Dos Santos Filho Sebastião G. , Martino João A.
Published: September 2011

This work presents a study of the temperature impact on tunnel field effect transistors performance. After design considerations regarding undesirable ambipolar currents, TFETs were simulated for temperatures ranging from 100 to 400 K. Bearing this objective in mind, the influence of each one of the most relevant transport mechanisms was analyzed and the resulting subthreshold slope was compared to the 60 mV/dec limit at room temperature for CMOS technology. At first, the device structure was defined based on the subthreshold swing extracted for different gate lengths. Sub-60mV/dec slopes were obtained by reducing ambipolar currents with an underlapped gate at the channel-drain junction. Finally, TFETs were simulated for different temperatures, individually focusing on mechanisms such as band-to-band tunneling, Shockley-Read-Hall generation and traps-assisted tunneling components. Therefore, only when all the components were joined together, it became more clear the advantages of operating devices under low temperature.
Alpha Radiation Incidence Angle Influence on Planar FDSOI nMOSFET
Authors: Magalhães Robson A. , Agopian Paula G. , Silveira Marcilei A. , Giacomini Renato C.
Published: September 2011

This work addresses the dependence of the incidence angle of alpha radiation on nMOSFET FDSOI transistor. The incidence angle ranged from -90 to 90 degrees in the two main symmetry planes of the device. The transitory effects were analyzed through three dimensional numerical simulations. The results showed considerable directivity to single event effects susceptibility. The generalized directivity can be used in the shielding engineering of electronic equipment subjected to isotropic radiation environments.
Structural Characterization of Si1-xCx Nanolayers Synthesized by C Implantation into SiO2/Si
Authors: Dos Reis Roberto M. , Maltez Rogerio L. , Boudinov Henri I.
Published: September 2011

We report the conversion of Si layer in 40 nm SiC by 40 keV carbon (C) implantation into SiO2/Si structure. SiC layer is revealed to the sample surface after final SiO2 etching. Two distinct methods were carried out: a) by sequential C implantations followed by 1250°C annealing after each implantation step (under a flux consisting of a mixture of 99% Ar with 1% O2) and, b) by single-step implantation followed by the same annealing. Rutherford Backscattering Spectrometry was employed to measure layer composition evolution after each sequential implantation step and annealing. Transmission electron microscopy (TEM) has shown that single-step implantation, up to the same minimum fluence, results in better structural quality and granular nature layer in the case of sequential synthesis
Si Nanocrystals Embedded in SiO2 Produced by Reactive Sputtering for Light Emission
Authors: De Mattos Antônio Eudócio P. , Sombrio Guilherme , Franzen Paulo L. , Pereira Marcelo B. , Boudinov Henri I.
Published: September 2011

In the present work, we confectioned light emitting SiOx (x<2) samples using reactive sputtering. By controlling the oxygen concentration in the deposition chamber (range from 0.5% up to 10), an excess of silicon was created in the formed silicon oxide films. Only after a thermal annealing (temperatures from 1050ºC to 1100ºC), the samples showed the photoluminescence (PL) effect. Silicon nanocrystals formed during the thermal annealing were the responsible for the observed PL signal when excited with the 488nm line of argon laser. We also performed thermal annealing at 450ºC, using forming gas ambient to passivate the silicon nanocrystals interface. The result was a significant improvement in PL signal. Furthermore, the Rutherford Backscattering Spectrometry experiment showed that the deposition time is an important parameter to create the silicon excess and achieve light emission.
Study on the Performance Enhancement of ZnO Nanoparticles Thin-Film Transistors
Authors: Vidor Fábio Fedrizzi , Wirth Gilson Inácio , Wolff Karsten , Hilleringmann Ulrich
Published: September 2011

Due to the electrical, sensory and optical properties the interest on ZnO-based devices including thin-film transistors (TFT) aroused. The main concerns, when using ZnO nanoparticles (NP-ZnO) in TFT, are the low charge carrier mobility and the hysteresis when poly(4-vinylphenol) (PVP) is used as gate dielectric. It is well-known that the mobility in NP-ZnO films can be enhanced by the subsequent hydrothermal decomposition of zinc salts. The electrical behavior as a function of time and temperature is investigated, taking the NP-ZnO without addition of zinc acetate as reference. The addition of zinc acetate leads to a device with better performance, with increased drain current level and without the presence of the hysteresis in the transfer characteristic. The formation reaction was performed at a temperature of 200°C, which enables process compatibility to some plastic substrates.
Production and Characterization of Bi2O3-WO3-TeO2 Thin Films with Au Nanoparticles for Applications with Micro and Nanoelectronic Devices
Authors: Izumi Fábio , Kassab Luciana R. , Dos Santos Filho Sebastião G. , Martinelli José R.
Published: September 2011

In the present work we report the production and characterization of Bi2O3-WO3-TeO2 (BWT) thin films with Au nanoparticles. RF co-sputttering technique was used for the deposition of the amorphous films on substrates. A target of BWT was RF-sputtered simultaneously with pure Au target using argon plasma; O2 flow was also used in order to replenish oxygen of BWT lost in process. Nucleation was obtained by means of heat treatment and also using heat treatment together with ultraviolet irradiation. Elipsometry, perfilometry, X-ray fluorescence, transmission electron microscopy, atomic force and optical absorption technique were used to evaluate the applications for micro and nanoelectronic devices.
Production of TiO2 Nanotubes and Nanoparticles
Authors: Fraga Tiago M. , Pereyra Inés , Albertin Katia F.
Published: September 2011

TiO2 nanotubes and nanoparticles were obtained by anodization of metallic Ti foil in a 0.5% HF, 1:7 acetic acid aqueous solution. Voltages of 23 and 35 V were applied and the anodization time was varied. Scanning Electron Microscope (SEM) and Raman scattering spectroscopy were utilized to analyze the obtained structures. It was observed that nanotubes with larger diameter are obtained for higher anodization voltages, also a morphology and crystalline phase dependency on anodization time, for a given voltage, were observed. Nanotubes with diameters in the 20nm to 90 nm range were obtained for different anodization times and voltages.
Analytical Model for the Threshold Voltage in Junctionless Nanowire Transistors of Different Geometries
Authors: Trevisoli Renan D. , Doria Rodrigo T. , Pavanello Marcelo A.
Published: September 2011

Junctionless nanowire transistors (JNTs) are considered promising for the sub-20 nm era. As these devices have a constant doping profile from source to drain, they have a great scalability without the need for rigorously controlled doping and activation techniques. These devices also present a flexible threshold voltage, which strongly depends on the device cross section. This work proposes an analytical model for JNTs. The model is derived from the solution of the Poisson equation with the appropriate boundary conditions. The quantum confinement for devices of reduced dimensions has also been accounted. The threshold voltage in cylindrical and trigate JNTs are analyzed. Tridimensional numerical simulations were performed to validate the model.
Modeling Electromigration Lifetimes of Copper Interconnects
Authors: De Orio Roberto L. , Ceric Hajdin , Selberherr Siegfried
Published: September 2011

A model for early failure due to electromigration in copper dual-damascene interconnects is proposed. The model is based on analytical expressions obtained from solutions of electromigration stress build-up assuming slit void growth under the interconnect vias. It is demonstrated that the model satisfactorily describes the complex physics of void nucleation and growth of the electromigration damage. Furthermore, it is shown that the simulation results provide reasonable estimates for early electromigration failures.
Characterization of Thin-Film SOI PIN Diodes from Cryogenic to Above Room Temperatures Using an Explicit I-V Multi-Branch Model
Authors: Lugo-Muñoz Denise , Muci Juan , Ortiz-Conde Adelmo , García-Sanchez Francisco , De Souza Michelly , Flandre Denis , Pavanello Marcelo A.
Published: September 2011

A multi-branch model is proposed to describe multiple conduction mechanisms in thin-film SOI PIN diodes with parasitic series resistance over a wide operating temperature range, from 90 to 390 K. The model is composed of the parallel combination of three branches, each of them incorporating a diode and a series resistance. The model's unique advantage is its explicit nature which allows the terminal current to be continuously expressed as an explicit analytical function of the applied terminal voltage. The resulting explicit equation is convenient for repetitive simulation applications as well as for analytic differentiation and integration, in contrast to conventional models which only allow numerical solutions. The model's suitability has been assessed by parameter extraction and subsequent playback on real SOI PIN diode forward I-V characteristics.
A Simple Electron Mobility Model Considering the Impact of Silicon-Dielectric Interface Orientation for Surrounding Gate Devices
Authors: Perin André L. , Pereira Arianne S. , Agopian Paula G. , Martino João A. , Giacomini Renato C.
Published: September 2011

In this work, we present a simple mobility model that takes into account the variation of the carrier's mobility according to crystallographic orientations of the silicon-dielectric interface. The effective mobility of simulated devices was compared to experimental data for several interface orientations and showed good agreement. The model has been applied to a CYNTHIA nMOS transistor and allowed the observation of non-uniform current density around the silicon pillar due to electron mobility variation.
Model and Fitting Results for the Filamentary Conduction in MIM Resistive Switching Devices
Authors: Palumbo Felix , Miranda Enrique , Ghibaudo Gerard , Jousseaume Vincent
Published: September 2011

Experimental results for the resistive switching effect occurring in Pt/HfO2/Pt devices are analyzed within the framework of the twoterminal Landauer theory for mesoscopic conducting systems. It is shown that the magnitude of the current and the voltage dependence of the switching conduction characteristic are mainly dictated by the size of the filamentary path generated after electroforming. The temperature dependence of the high resistance conduction characteristics is also modeled in a consistent manner with the proposed picture.
(Invited) Boosting ION/IOFF Ratio in Ultimate Sub-Decananometer Transistors: The Case of FDSOI Multi-gate MOSFETs and Multi-barrier Enhanced Gate Modulated Resonant Tunneling-FETs
Authors: Afzalian Aryan
Published: September 2011

Using efficient NEGF methods, we explore and optimize here ION/IOFF ratios and slope characteristics of ultra scaled nanotransistors. Those depend on the gate-to-channel coupling and carrier statistics that dictate the way carriers are made available to drive a current when increasing VG. We first investigate the gateto- channel coupling. Quantum effects and their impact on ultrascaled nanowires are enlightened when optimizing ION/IOFF ratios vs. the cross-section size in a 10nm nanowire. It is shown that an optimum cross-section of about 3x3 nm2 exist due to a trade-off between electrostatic and confinement. Also the fundamental limit of improving gate control by thinning gate oxide is shown and leads us to switch from EOT to the CET concept. As the density of state is about constant with VG in a standard transistor, when varying the gate voltage the current varies at a rate dictated by Fermi-Dirac statistics only. In order to further increase ION/IOFF ratios, we propose a new device concept, the gate-modulated resonant tunneling FET (RT-FET), that uses a multi-barrier gate controlled architecture to render this DoS non-constant with VG.