bluuebunny/crossref_metadata_2025 huggingface dataset:
Innate Immune Regulation by Toll-Like Receptors in the Brain
Authors: Mallard Carina
Published: October 2012

The innate immune system plays an important role in cerebral health and disease. In recent years the role of innate immune regulation by toll-like receptors in the brain has been highlighted. In this paper the expression of toll-like receptors and endogenous toll-like receptor ligands in the brain and their role in cerebral ischemia will be discussed. Further, the ability of systemic toll-like receptor ligands to induce cerebral inflammation will be reviewed. Finally, the capacity of toll-like receptors to both increase (sensitization) and decrease (preconditioning/tolerance) the vulnerability of the brain to damage will be disclosed. Studies investigating the role of toll-like receptors in the developing brain will be emphasized.
Modification of the Corrosion Properties of a Model Fe-8Ni-18Cr Steel Resulting from Plastic Deformation and Evaluated by Impedance Spectroscopy
Authors: Girardin Pierre-Yves , Frigerio Adrien , Berthod Patrice
Published: October 2012

A model {minor elements}-free Fe-8Ni-18Cr alloy (wt%) was elaborated by foundry, then cut in several cylindrical parts which were subjected to compression tests leading to different plastic deformation rates. The axis surface of the obtained samples were characterized in corrosion by impedance spectroscopy in an acid sulphuric solution. The obtained EIS results were plotted in the complex plan of Nyquist and the diagrams were all semicircular but with an average radius decreasing when the deformation rate increased. The plastic deformation obviously induced a decrease in charge transfer resistance, revealing a detrimental effect of the corrosion behaviour as the most often reported in studies involving stationary methods of electrochemical characterization of corrosion. It was also found that the capacitance tends to increase with the rate of plastic deformation by compression.
Recent Developments in Home Sleep-Monitoring Devices
Authors: Kelly Jessica M. , Strecker Robert E. , Bianchi Matt T.
Published: October 2012

Improving our understanding of sleep physiology and pathophysiology is an important goal for both medical and general wellness reasons. Although the gold standard for assessing sleep remains the laboratory polysomnogram, there is an increasing interest in portable monitoring devices that provide the opportunity for assessing sleep in real-world environments such as the home. Portable devices allow repeated measurements, evaluation of temporal patterns, and self-experimentation. We review recent developments in devices designed to monitor sleep-wake activity, as well as monitors designed for other purposes that could in principle be applied in the field of sleep (such as cardiac or respiratory sensing). As the body of supporting validation data grows, these devices hold promise for a variety of health and wellness goals. From a clinical and research standpoint, the capacity to obtain longitudinal sleep-wake data may improve disease phenotyping, individualized treatment decisions, and individualized health optimization. From a wellness standpoint, commercially available devices may allow individuals to track their own sleep with the goal of finding patterns and correlations with modifiable behaviors such as exercise, diet, and sleep aids.
Essential Oils of Plants as Biocides against Microorganisms Isolated from Cuban and Argentine Documentary Heritage
Authors: Borrego Sofía , Valdés Oderlaise , Vivar Isbel , Lavin Paola , Guiamet Patricia , Battistoni Patricia , Gómez de Saravia Sandra , Borges Pedro
Published: October 2012

Natural products obtained from plants with biocidal activity represent an alternative and useful source in the control of biodeterioration of documentary heritage, without negative environmental and human impacts. In this work, we studied the antimicrobial activity of seven essential oils against microorganisms associated with the biodeterioration of documentary heritage. The essential oils were obtained by steam distillation. The antimicrobial activity was analyzed using the agar diffusion method against 4 strains of fungi and 6 bacterial strains isolated from repositories air and documents of the National Archive of the Republic of Cuba and the Historical Archive of the Museum of La Plata, Argentina. Anise and garlic oils showed the best antifungal activity at all concentrations studied, while oregano oil not only was effective against fungi tested but also prevented sporulation of them all. Orange sweet and laurel oils were ineffective against fungi. Clove, garlic, and oregano oils showed the highest antibacterial activity at 25% against Enterobacter agglomerans and Streptomyces sp., while only clove and oregano oils were effective against Bacillus sp. at all concentrations studied. This study has an important implication for the possible use of the natural products from plants in the control of biodeterioration of documentary heritage.
Inflammatory Malignant Fibrous Histiocytoma Associated with Leukemoid Reaction or Leukocytosis: A Comprehensive Review
Authors: Hurtado-Cordovi Jorge , Pathak Prajwol , Avezbakiyev Boris , Frieri Marianne
Published: October 2012

Inflammatory malignant fibrous histiocytoma (IMFH) associated with leukemoid reaction (LR)/leukocytosis is a rare entity. In this paper, we search PubMed for all known cases of IMFH associated with LR/leukocytosis in an attempt to draw conclusions about this variant’s response to treatments and its pathophysiology. Medline electronic database was searched using key words such as malignant fibrous histiocytoma, leukemoid reaction, and leukocytosis. A total of 16 patients were found, twelve males (75%) and 4 female (25%), with a mean age of 62.6 years, ranging from 47 to 77. The mean survival was 770 days, ranging from 14 to 6570 days. Four patients were alive at last follow-up: 6570 days, 1095 days, 335 days, and 180 days, respectively. Of the 12 patients that expired, death occurred approximately 92 days after the onset of LR or leukocytosis, ranging from 3 to 334 days. We conclude that IMFH associated with LR/leukocytosis does not completely respond to chemoradiation. Overproduction of growth factors and cytokines by IMFH cells and their interactions with the inflammatory infiltrate seem to promote immunological effector cell’s dysfunction and substantiate the development and growth of this neoplasm. A clear understanding of these molecular pathways is crucial in order to identify targets for potential therapy.
Formation of the Ions of Methylindoles in APCI Mass Spectrometry
Authors: Liu David Q. , Sun Mingjiang
Published: October 2012

Indoles are common building blocks of new pharmacologically active chemical entities in drug discovery and development. Due to their poor ionization in electrospray ionization mass spectrometry, atmospheric pressure chemical ionization (APCI) is the method of choice for LC-MS analysis of simple indoles. Three types of ions, including [M − 1]+, , and [M + H]+, can be observed in APCI but the relative intensities of these ions may vary depending upon the structural properties of the indoles and the mass spectral source conditions. We report in this paper the observation of [M − 1]+ ions for methylindoles in an Agilent multimode ion source and the investigation into their formation. By means of tandem mass spectrometric experiments performed on a Thermo Fisher Scientific LTQ ion trap mass spectrometer equipped with an APCI source, it was found that [M − 1]+ ions can be generated from ions upon-collision induced dissociation. This suggests that the [M − 1]+ ions might be the in-source fragmentation product of ions. It was proposed that both [M − 1]+ and ions are probably generated through a charge transfer mechanism while [M + H]+ ions are the product of proton transfer. The basicity of the analytes might play an important role in dictating which ionization mechanism is operative. For 3-methylindole, the charge transfer process appears to be more dominant than for 2-methylindole since the former is less basic. As expected, substituting electron withdrawing groups on 3-methylindole, such as fluorine, promotes charge transfer and vice versa. Therefore, it is expected that formation of the [M − 1]+ ions is more pronounced for less basic methylindoles.
A review of Bennelongia De Deckker & McKenzie, 1981 (Crustacea, Ostracoda) species from eastern Australia with the description of three new species
Authors: Shearn Rylan , Koenders Annette , Halse Stuart , Schön Isa , Martens Koen
Published: October 2012

Australia is predicted to have a high number of currently undescribed ostracod taxa. The genus Bennelongia De Deckker & McKenzie, 1981 (Crustacea, Ostracoda) occurs in Australia and New Zealand, and has recently shown potential for high speciosity, after the description of nine new species from Western Australia. Here, we focus on Bennelongia from eastern Australia, with the objectives of exploring likely habitats for undiscovered species, genetically characterising published morphological species and scanning classical species for cryptic diversity. Two traditional (morphological) species are confirmed to be valid using molecular evidence (B. harpago De Deckker & McKenzie, 1981 and B. pinpi De Deckker, 1981), while three new species are described using both morphological and molecular evidence. Two of the new species belong to the B. barangaroo lineage (B. dedeckkeri sp. nov. and B. mckenziei sp. nov.), while the third is a member of the B. nimala lineage (B. regina sp. nov.). Another species was found to be genetically distinct, but is not formally described here owing to a lack of distinguishing morphological features from the existing species B. cuensis Martens et al., 2012. Trends in diversity and radiation of the genus are discussed, as well as implications these results have for the conservation of temporary pool microfauna and our understanding of Bennelongia’s evolutionary origin.
Diplomacia do pé: o Brasil e as competições esportivas sul-americanas de 1919 e 1922
Authors: Santos João Manuel Casquinha Malaia
Published: October 2012

O presente artigo pretende discutir o papel das primeiras competições esportivas internacionais sediadas no Brasil, em 1919 e 1922, nas relações internacionais do país. Através da análise da política externa, das ações diplomáticas e da repercussão desses eventos pela imprensa, dentro e fora do país, pretende-se trazer uma primeira aproximação para o entendimento desses eventos como marcos importantes, tanto para a trajetória do país como sede de competições esportivas internacionais, quanto da própria política externa brasileira.
Revisando livros didáticos de História: ação da diplomacia cultural em nome da paz
Authors: Leite Juçara Luzia
Published: October 2012

No cenário internacional do pós-primeira guerra, gradualmente, os objetivos morais somavam-se aos objetivos cívicos do ensino de História. A década de 1920, especialmente, foi marcada por uma discussão ampla sobre o papel da educação – especialmente do ensino de História – na construção de um mundo de paz. O livro didático esteve no centro desse debate e educadores de tendências opostas manifestaram-se. Ao longo desses debates, o papel da Commission Internationale de Coopération Intellectuelle (CICI) se destacou na Liga das Nações, procurando facilitar a colaboração de intelectuais no serviço de promoção da paz mundial dentro dos objetivos da Liga. O presente artigo reflete sobre esse contexto, destacando o papel do Brasil na adoção de uma diplomacia cultural válida tanto para os países europeus quanto para os vizinhos latino-americanos, considerando a dinâmica da transição do foco de interesses da Liga das Nações para a União Panamericana. Ressaltamos a atuação do Ministério das Relações Exteriores nesse processo ao empreender uma diplomacia cultural sobre a História a ser ensinada, que, incólume às oscilações políticas do período, culmina na manutenção de publicação da “Bibliografia de História do Brasil”.
Cidadania e migração: da integração nacional à participação local
Authors: Mattiazzi Giulio
Published: October 2012

O artigo apresenta uma breve reflexão acerca das profundas transformações da noção de cidadania na modernidade e na pós-modernidade, tanto à luz da crítica pós-colonial quanto em função dos desafios políticos que estas mudanças apresentam.  Uma atenção crítica é reservada ao uso do dispositivo da concessão da cidadania como forma de integração dos migrantes na Europa.
Um diplomata na Revolta da Armada: as impressões políticas e a atuação do Conde de Paço D'Arcos
Authors: Santos Júnior João Júlio Gomes dos
Published: October 2012

Carlos Eugênio Corrêa da Silva, o Conde de Paço D’Arcos, foi o primeiro diplomata a representar Portugal na República brasileira. Sua Missão Diplomática compreendeu o período entre 2 de Junho de 1891 e 20 de Novembro de 1893. Em seus relatórios sobre a situação política brasileira os argumentos de defesas da ordem social e da hierarquia militar são recorrentes, com especial destaque durante a Revolta da Armada. A proposta desse artigo é analisar fontes diplomáticas para compreender as impressões e a atuação desse diplomata durante esse conflito.
A cidade como projeto coletivo: impressões sobre a experiência de Medellín
Authors: Oliveira Lúcia Maciel Barbosa de
Published: October 2012

Reflete-se sobre a possibilidade de recriação da ideia de cidade como projeto coletivo a partir de impressões da experiência de Medellín, Colômbia, ainda em processo, que tem conseguido criar uma nova trama urbana e cidadã em decorrência de um projeto de concertação que tem a cultura como eixo de sua ação.
Effect of Spacer Length on the Specificity of Counterion-Cationic Gemini Surfactant Interaction
Authors: Sood Rohit , Alakoskela Juha-Matti , Sood Anjali , Vitovic Pavol , Kinnunen Paavo K.J.
Published: October 2012

Aqueous solutions of three dicationic quaternary N,N-dimethylammonium gemini surfactants with identical hydrocarbon tails (N-hexadecyl) separated by flexible two, four, and six carbon atom spacers (di-, tetra-, and hexamethylene), abbreviated as G2, G4, and G6, respectively, were characterized using dynamic light scattering (DLS), Langmuir balance, differential scanning calorimetry (DSC), and microscopy in the presence of varying concentrations of sodium salts of fluoride, chloride, bromide, and iodide. Clear dependence on the counterion species was evident in the surface activity of the geminis, as follows. In 0.1 mM salt minima in surface tension and hence presumably the highest affinity for G2, G4, and G6 were observed with fluoride/chloride, bromide, and iodide, respectively. This same ion specificity of G2, G4, and G6 was evident also in the changes of average hydrodynamic diameters (Zav) with temperature. More specifically, maximum in Zav for G2 was observed in 100 mM NaCl, for G4 in 100 mM NaBr, and for G6 in 1 mM NaI. Our results demonstrate that spacer length has a profound impact on the interaction of these surfactants with halide counter-ions of different sizes, controlling the organization of these cationic geminis in the presence of salt. Importantly, our studies show that adjusting the headgroup structure it is possible to design amphiphiles, which can be used to bind specific metal ions in solution, for purposes such as water purification and mineral enrichment.
Determining the Characteristics of Sodium Benzoate (E211) Production Using Mathematical Method
Authors: Kovac Kralj Anita
Published: October 2012

The productivity of a particular product is highly effective if we know the chemical kinetics. Determining chemical kinetics requires a fundamental knowledge of reactants' declining concentrations or the formation of product concentration. Concentration can be determined by double-linear extrapolation, using the conductivity measurement of strong electrolytes. This method is based on two linear sloped-lines from which the linear constants from different diagrams can be read:
1) The first diagram represents linear time dependence regarding difference in conductivity2) The second diagram represents linear difference in conductivity dependence regarding concentration.
Sodium benzoate (NaC6H5CO2) is a preservative. It is produced by the neutralization of benzoic acid (C7H6O2) with sodium hydroxide (NaOH) in a stirred batch reactor under different room temperatures:
NaOHÂ  + C7H6O2 <--> NaC6H5CO2 + H2O
The kinetic parameters and characteristics of sodium benzoate production (activated energy, reaction rate constant, rate order) were determined.
Thermodynamic Database Update to Model Synthetic Chelating Agents in Soil Systems
Authors: Yunta Felipe , López-Rayo Sandra , Lucena Juan J
Published: October 2012

Poliaminocarboxylate and polyaminophenolcarboxylate chelating agents, being the most representatives EDTA and o,o-EDDHA, have been profusely studied by our research team during the last 25 years because they are synthetized to be mainly used as micronutrient fertilizers to correct nutritional disorders affecting largely on crop yields placed under Mediterranean conditions. In the last years new chelating agents were designed and synthesized and the most of them were proposed to be included in the current European Directive on Fertilizers. Overall chelating agent properties, including equilibrium in soil by modeling, should be taken in account in order to check the iron chlorosis correction ability. Chemical speciation programs such as MINTEQA2, and most recently VMinteq, are being successfully used as tools to predict the behavior of each novel chelating agent in soil-plant system. Nowadays just one polyaminophenolcarboxylate chelating agent (o,o-EDDHA) is available into a VMinteq-compatible database (Lindsay's database) whereas more than seven of these type of products are authorized by European fertilizers normative to be used as micronutrient fertilizers. Therefore the aim of this work was the database updating to include all chelating agents related to o,o-EDDHA and EDTA whose complete characterization is performed and published elsewhere. Once database is updated, further modelization studies such as equilibrium reactions and adsorption isotherms with solid phase may be readily performed to get fundamental information and understand the reactivity of these recalcitrant polyaminophenolcarboxylates in soils.
Extended Stern Model
Authors: Pradhan Rangadhar , Mitra Analava , Das Soumen
Published: October 2012

In this paper, a theoretical approach of extended Stern model is formulated to represent the electric double layer (EDL) for biochemical as well as biological samples. The existing Stern model is used for several decades to describe the phenomena of electric double layer of electrode/electrolyte interface. In the conventional stern model the double layer which is formed between the electrode and electrolyte interface is described by double layer capacitance. Using the existing Stern model, the equivalent circuit model is not valid for electrical double layer capacitance of electrode/electrolyte interface in Î² dispersion range. The protein molecules form chemical coupling and chemical adsorption along with classical ionic bonding with gold electrodes. Thus, the compactness of EDL decreases and the double layer capacitance is replaced by a constant phase element (CPE). In the present paper, a three-electrode based ECIS device was used to measure the impedance of various enzymatic solutions for practical realization of theoretical approach. The results obtained from experimental work, were simulated by equivalent circuit simulator, ZsimpWin to validate the extended Stern model by comparing Ï‡2 value. Finally the electrical parameters were extracted and compared for Stern model and extended Stern model. The results obtained by practical experiment and equivalent circuit simulation showed the effectiveness of extended Stern model over Stern model.
Use of Magnetic Resonance Imaging as Well as Clinical Disease Activity in the Clinical Classification of Multiple Sclerosis and Assessment of Its Course
Authors: Cook Stuart D. , Dhib-Jalbut Suhayl , Dowling Peter , Durelli Luca , Ford Corey , Giovannoni Gavin , Halper June , Harris Colleen , Herbert Joseph , Li David , Lincoln John A. , Lisak Robert , Lublin Fred D. , Lucchinetti Claudia F. , Moore Wayne , Naismith Robert T. , Oehninger Carlos , Simon Jack , Sormani Maria Pia
Published: October 2012

It has recently been suggested that the Lublin-Reingold clinical classification of multiple sclerosis (MS) be modified to include the use of magnetic resonance imaging (MRI). An international consensus conference sponsored by the Consortium of Multiple Sclerosis Centers (CMSC) was held from March 5 to 7, 2010, to review the available evidence on the need for such modification of the Lublin-Reingold criteria and whether the addition of MRI or other biomarkers might lead to a better understanding of MS pathophysiology and disease course over time. The conference participants concluded that evidence of new MRI gadolinium-enhancing (Gd+) T1-weighted lesions and unequivocally new or enlarging T2-weighted lesions (subclinical activity, subclinical relapses) should be added to the clinical classification of MS in distinguishing relapsing inflammatory from progressive forms of the disease. The consensus was that these changes to the classification system would provide more rigorous definitions and categorization of MS course, leading to better insights as to the evolution and treatment of MS.
Effect of a Single Bout of Intermittent versus Continuous Walking on Perceptions of Fatigue in People with Multiple Sclerosis
Authors: Karpatkin Herb , Rzetelny Adam
Published: October 2012

Fatigue may limit the ability of people with multiple sclerosis (MS) to participate in walking exercises, which could ultimately reduce their benefit from physical therapy. An exercise program that minimizes the fatigue experienced by people with MS during exercise may lead to an increase in the amount of exercise being performed. The purpose of this study was to determine whether subjective feelings of fatigue differ in people with MS depending on whether they exercised intermittently or continuously. Using a within-subjects, counterbalanced crossover design, a sample of 30 individuals with MS performed 6 minutes of continuous and 6 minutes of intermittent walking 1 week apart. Fatigue was measured on the Visual Analogue Scale of Fatigue (VASF) and recorded before and after the walking conditions. A 2 × 2 repeated-measures analysis of variance was used to assess the potential effects of intermittent versus continuous walking on self-reported fatigue. A significant interaction revealed that pre-post mean self-ratings of fatigue on the VASF increased less in the intermittent condition (from 37.93 mm to 44.83 mm; difference = 6.90 mm) compared with the continuous condition (from 34.33 mm to 54.43 mm: difference = 20.10 mm) (P < .001), suggesting that patients experienced less fatigue in the intermittent condition despite walking an equivalent total duration. The interaction effect was not influenced by age, gender, disease severity or duration, use of antispasticity medication, use of assistive devices, or mood. The results suggest that people with MS may be more tolerant of, and able to perform, greater amounts of exercise if they exercise intermittently.
Barriers and Facilitators Related to Participation in Aquafitness Programs for People with Multiple Sclerosis
Authors: Brown Cara , Kitchen Kaitlyn , Nicoll Kaley
Published: October 2012

Exercise and leisure activities provide physical and psychosocial benefits to people with multiple sclerosis (MS) and can enhance their quality of life. In Winnipeg, Manitoba, Canada, people with MS have reported barriers to their participation in local MS-specific aquafitness (AF) programs. Therefore, a formal exploration of the accessibility of local AF programs for people with MS was undertaken. The purpose of this phenomenological study was to identify factors that facilitate or impede participation in AF programs by individuals with MS living in Winnipeg. Qualitative data were collected from a total of eight participants through one focus group (n = 7) and one in-depth interview (n = 1). The sample consisted of individuals with MS who were currently participating in AF programming as well as those who were not. Data were audio-recorded and transcribed verbatim, and thematic analysis was completed. Seven themes emerged regarding factors affecting participation in local AF programs. Barriers to participation included inadequate transportation, lack of one-on-one support, environmental inaccessibility, and fears associated with participation in the programs. Facilitators of participation included a knowledgeable instructor and experiencing physical and psychosocial benefits from the program. Information from this study was used locally to advocate for people with MS in order to increase participation in local AF programming.
Relationship Between Expanded Health Belief Model Variables and Mammography Screening Adherence in Women with Multiple Sclerosis
Authors: Paraska Karen
Published: October 2012

People with disabilities often find it more difficult to access health-care services than the general population, further jeopardizing their health and well-being. The purpose of this descriptive pilot study was to explore the relationship between variables of the Expanded Health Belief Model (EHBM) and adherence to mammography screening in a sample of homebound women with MS after completion of a National Multiple Sclerosis Society (NMSS) intervention, known as the “Home-Based Health Maintenance Program for Women with MS,” that was conducted in Allegheny County, Pennsylvania. The intervention was conducted in the patients' homes and included education of the women and their partners on risk factors for breast cancer and instruction in breast examination techniques. The patients were also helped to make appointments for mammograms. This study derived its sample from the intervention program and used data on adherence recorded by the NMSS. After completion of the intervention, telephone interviews were conducted with women who met the inclusion criteria (N = 11). Descriptive statistics indicate that adherence can be successfully described using variables of the EHBM, including perceived susceptibility, perceived severity, perceived benefits, and self-efficacy. The instruments chosen for the research were well tolerated, useful, and efficient to administer and allowed for immediate assessment.
A bacterial sulfonolipid triggers multicellular development in the closest living relatives of animals
Authors: Alegado Rosanna A , Brown Laura W , Cao Shugeng , Dermenjian Renee K , Zuzow Richard , Fairclough Stephen R , Clardy Jon , King Nicole
Published: October 2012

Bacterially-produced small molecules exert profound influences on animal health, morphogenesis, and evolution through poorly understood mechanisms. In one of the closest living relatives of animals, the choanoflagellate Salpingoeca rosetta, we find that rosette colony development is induced by the prey bacterium Algoriphagus machipongonensis and its close relatives in the Bacteroidetes phylum. Here we show that a rosette inducing factor (RIF-1) produced by A. machipongonensis belongs to the small class of sulfonolipids, obscure relatives of the better known sphingolipids that play important roles in signal transmission in plants, animals, and fungi. RIF-1 has extraordinary potency (femtomolar, or 10−15 M) and S. rosetta can respond to it over a broad dynamic range—nine orders of magnitude. This study provides a prototypical example of bacterial sulfonolipids triggering eukaryotic morphogenesis and suggests molecular mechanisms through which bacteria may have contributed to the evolution of animals.
The starvation hormone, fibroblast growth factor-21, extends lifespan in mice
Authors: Zhang Yuan , Xie Yang , Berglund Eric D , Coate Katie Colbert , He Tian Teng , Katafuchi Takeshi , Xiao Guanghua , Potthoff Matthew J , Wei Wei , Wan Yihong , Yu Ruth T , Evans Ronald M , Kliewer Steven A , Mangelsdorf David J
Published: October 2012

Fibroblast growth factor-21 (FGF21) is a hormone secreted by the liver during fasting that elicits diverse aspects of the adaptive starvation response. Among its effects, FGF21 induces hepatic fatty acid oxidation and ketogenesis, increases insulin sensitivity, blocks somatic growth and causes bone loss. Here we show that transgenic overexpression of FGF21 markedly extends lifespan in mice without reducing food intake or affecting markers of NAD+ metabolism or AMP kinase and mTOR signaling. Transcriptomic analysis suggests that FGF21 acts primarily by blunting the growth hormone/insulin-like growth factor-1 signaling pathway in liver. These findings raise the possibility that FGF21 can be used to extend lifespan in other species.
Indirect routes to reproductive success
Authors: Pickett John
Published: October 2012

By comparing wild-type and transgenic tobacco plants in a natural ecosystem, researchers have confirmed that the indirect defence mechanisms employed by plants to fend off herbivorous insects can increase Darwinian fitness.
New twists in the unfolded protein response
Authors: Cross Benedict C S , Ron David
Published: October 2012

The response of S. pombe, also known as fission yeast, to misfolded proteins involves mechanisms that have not been observed in other species.
Launching eLife, Part 1
Authors: Schekman Randy , Patterson Mark , Watt Fiona , Weigel Detlef
Published: October 2012

The new open-access journal eLife has launched, making its first content available in PubMed Central. In addition to publishing science of the highest quality, the journal aims to improve both the peer-review process and the presentation of new research results.
Could a hormone point the way to life extension?
Authors: Kenyon Cynthia
Published: October 2012

Mice that have been genetically modified to produce high levels of fibroblast growth factor-21 live longer than mice with normal levels of this hormone.
Common Concepts in Materials Characterization, Introduction
Authors: Kaufmann Elton N.
Published: October 2012

One may view this chapter as a preparatory entrance to subsequent chapters of Characterization of Materials. We expect that each article of this chapter will be separately valuable to readers as they refer to it for concepts and procedures underlying many of those covered in articles about specific measurement methods in subsequent chapters.

Of course, not every topic covered by an article in this chapter will be relevant to every measurement method covered later. However, the concepts in this chapter are sufficiently common to appear repeatedly in a materials research context.
Thermometry
Authors: Dollimore David , Samuels Alan C.
Published: October 2012

Thermometry is the science of measuring temperature, and thermometers are the instruments used to measure temperature. Temperature must be regarded as the scientific measure of “hotness” or “coldness.” This article is concerned with the measurement of temperatures in materials of interest to materials science, and the notion of temperature is thus limited in this discussion to that which applies to materials in the solid, liquid, or gas state (as opposed to the so‐called temperature associated with ion gases and plasmas, which is no longer limited to a measure of the internal kinetic energy of the constituent atoms).

A brief excursion into the history of temperature measurement will reveal that measurement of temperature actually preceded the modern definition of temperature and a temperature scale.

The simple expedient of sealing the instrument so that the liquid and gas were contained in the tube really marks the invention of a glass thermometer. By making the diameter of the tube small, so that the volume of the gas was considerably reduced, the liquid dilation in these sealed instruments could be used to indicate the temperature. Fahrenheit eventually substituted mercury for the “spirits of wine” earlier used as the working liquid fluid, because mercury's thermal expansion with temperature is more nearly linear. Temperature scales were then invented using two selected fixed points—usually the ice point and the blood point or the ice point and the boiling point.

The starting point for the thermodynamic treatment of temperature is to state that it is a property that determines in which direction energy will flow when it is in contact with another object. Heat flows from a higher temperature object to a lower temperature object. When two objects have the same temperature, there is no flow of heat between them and the objects are said to be in thermal equilibrium. Heat transfer is an important consideration for many materials engineering applications, and thermal conductivity measurements rely on accurate and precise temperature measurement and control. Development of the International Temperature Scale of 1990 is detailed. Various types of thermometer are discussed as well as the need, sometimes, to control the temperature. Recent developments in the measurement of temperature and thermal properties at the microscopic scale are also reviewed.
Symmetry in Crystallography
Authors: Steinfink Hugo , Peterca Mihai
Published: October 2012

The study of crystals has fascinated humanity for centuries, with motivations ranging from scientific curiosity to the belief that they had magical powers. Early crystal science was devoted to descriptive efforts, limited to measuring interfacial angles and determining optical properties. Some investigators such as Haüy attempted to deduce the underlying atomic structure from the external morphology. These efforts were successful in determining the symmetry operations relating crystal faces and led to the theory of point groups, the assignment of all known crystals to only seven crystal systems, and extensive compilations of axial ratios and optical indices. Roentgen's discovery of x‐rays and Laue's subsequent discovery of the scattering of x‐rays by crystals revolutionized the study of crystallography: crystal structures—that is, the relative location of atoms in space—could now be determined unequivocally. Shechtman's finding of quasicrystals in 1984 expanded further the family of crystal structures and led to a revised definition of the term crystal. The benefits derived from these advances have enhanced fundamental science, technology, and medicine ever since and have directly contributed to the welfare of human society

This article introduces basic symmetry operators, space groups, and crystallographic notation, and concludes with two examples from each category of materials with long‐range order: crystalline and quasicrystalline.
Introduction to Computation
Authors: Stan Marius
Published: October 2012

Understanding and controlling materials requires coupled experimental andcomputational characterization methods. The paper reviews the main characteristics of computational methods and the benefits of using them for materials characterization. Several concepts such as models, simulations, predictability, verification and validation are briefly discussed in the context of materials characterization at various scales: atomistic, meso‐scale and continuum. New developments in high performance computing are also mentioned, as they pertain to improving the computational tools for materials characterization. The author predicts that in a few years, the concept of materials characterization will be defined as a strongly coupled experimental and computational methodology.
Prediction of Phase Diagrams
Authors: de Fontaine Didier
Published: October 2012

A phase diagram is a graphical object, usually determined experimentally, indicating phase relationships in thermodynamic space. Usually, one coordinate axis represents temperature; the others may represent pressure, volume, concentrations of various components, and so on. This unit is concerned only with temperature‐concentration diagrams, limited to binary (two‐component) and ternary (three‐component) systems. Since more than one component is considered, the relevant thermodynamic systems are alloys, by definition, of metallic, ceramic, or semiconductor materials. The emphasis here is placed primarily on metallic alloys.

Phase diagrams can be classified broadly into two main categories: experimentally and theoretically determined. The object of the present unit is the theoretical determination—i.e., the calculation of phase diagrams, meaning ultimately their prediction. But calculation of phase diagrams can mean different things: there are prototype, fitted, and first‐principles approaches. Prototype diagrams are calculated under the assumption that energy parameters are knowna priorior given arbitrarily. Fitted diagrams are those whose energy parameters are fitted to known, experimentally determined diagrams or to empirical thermodynamic data. First‐principles diagrams are calculated on the basis of energy parameters calculated from essentially only the knowledge of the atomic numbers of the constituents, hence by actually solving the relevant Schrödinger equation.

Theory also enters in the experimental determination of phase diagrams, as these diagrams not only indicate the location in thermodynamic space of existing phases but also must conform to rigorous rules of thermodynamic equilibrium (stable or metastable). The fundamental rule of equality of chemical potentials imposes severe constraints on the graphical representation of phase diagrams, while also permitting an extraordinary variety of forms and shapes of phase diagrams to exist, even for binary systems.

That is one of the attractions of the study of phase diagrams, experimental or theoretical: their great topological diversity subject to strict thermodynamic constraints. In addition, phase diagrams provide essential information for the understanding and designing of materials, and so are of vital importance to materials scientists. For theoreticians, first‐principles (orab initio) calculations of phase diagrams provide enormous challenges, requiring the use of advanced techniques of quantum and statistical mechanics.
Simulating Microstructural Evolution using the Phase Field Method
Authors: Wang Y. , Chen L.‐Q. , Zhou N.
Published: October 2012

The key to predict material properties is the state of microstructure. Because microstructural evolution is a typical nonlinear, nonlocal, and multiparticle dynamic problem, computer simulations play an ever increasingly important role in predicting key microstructural features and their time evolution during various processes such as phase transformations, domain coarsening, and plastic deformation. A plethora of computational methods and algorithms have been developed in recent years to complement theoretical and experimental studies to explore the high dimensional material‐ and processing‐parameter space, which would not only lower the cost but also increase the efficiency of optimizing existing materials and developing new ones. In this article, a brief account of the basic features of each method, including the conventional front‐tracking methods and techniques without front‐tracking (such as Continuum/Microscopic/Coarse‐Grained Phase Field Method; Mesoscopic/Atomistic Monte Carlo; Cellular Automata; Discrete Lattice Model; Phase Field Crystal Model; Diffusive Molecular Dynamics; Microscopic Master Equations; Inhomogeneous Path Probability Method; and Molecular Dynamics) will be presented first, followed by detailed descriptions of the fundamentals of various phase‐field methods at different length scales and their model formulations. The applications of the phase field methods will be demonstrated by examples of coherent precipitation, grain growth, ferroelectric domain structure formation, dislocation core structures, and dislocation‐precipitate interactions. Existing challenges and future trends of the phase‐field methods are discussed at the end of the article.
Binary and Multicomponent Diffusion
Authors: Ågren John
Published: October 2012

The theoretical basis for multicomponent diffusion is reviewed with special emphasis on the development of models and databases for practical calculations.
Tension Testing
Authors: Antolovich Stephen D.
Published: October 2012

Of all mechanical properties, perhaps the most fundamental are related to what happens when a material is subjected to simple uniaxial tension. In its essence, a tensile test is carried out by attaching a specimen to a load‐measuring device, applying a load (or imposing a given deformation), and measuring the load and corresponding deformation.

The result obtained from a tensile test is a so‐called stress/strain curve, a plot of stress (force/unit area) versus strain. The results of such a test (along with the results of other tests, to be sure) are basic to determination of the suitability of a given material for a particular load‐bearing application. In this regard the results obtained from such a test are of great engineering significance. Tensile‐test results also provide a great deal of information relative to the fundamental mechanisms of deformation that occur in the specimen. Coupled with microscopic examination, tensile test results are used to develop theories of hardening and to develop new alloys with improved properties. Tensile tests can be used to obtain information on the following types of properties: elastic properties, plastic properties, toughness.
Thermogravimetric Analysis
Authors: Vyazovkin Sergey
Published: October 2012

Thermogravimetric analysis (TGA) is an analytical technique for measuring changes in the mass of a material that occur in response to programmed temperature changes. The changes in the mass can be caused by a variety processes such as decomposition, degradation, sublimation, vaporization, adsorption, desorption, oxidation, and reduction. The article explains the principles of TGA and practical aspects of the method that include description of the apparatus, discussion of experimental variables, and applications. Among practical applications, a particular attention is paid to determining composition and thermal stability of materials, evaluating the kinetics of thermally stimulated processes, predicting lifetimes, and studying reactions of materials with gases. The article also addresses the issues of sample preparation as well as of basic analysis and interpretation of data. A special consideration is given to the sources of errors in the mass and temperature measurements as well as to the methods of calibrating both values.
Conductivity Measurement
Authors: Wentworth Stuart M. , Österbacka Ronald
Published: October 2012

Electrical conductivity (resistivity) is a fundamental materials property and as such finds its value incorporated in many complex and sophisticated treatments of materials behavior. In this article, we are presenting some techniques useful for the determination of the conductivity of materials.
Capacitance–Voltage (
C
–
V
) Characterization of Semiconductors
Authors: Barnes Peter A.
Published: October 2012

Hillibrand and Gold first described the use of capacitance ‐voltage (C–V) methods to determine the majority carrier concentration in semiconductors. C–V measurements are capable of yielding quantitative information about the diffusion potential and doping concentration in semiconductor materials. The technique employs p‐n junctions, metal‐semiconductor (MS) junctions (Schottky barriers), electrolyte‐semiconductor junctions, metal‐insulator‐semiconductor (MIS) capacitors, and MIS field effect transistors (MISFETSs). The discussions to follow will emphasize p‐n junctions and Schottky barrier techniques.

C–V measurements yield accurate information about doping concentrations of majority carriers as a function of distance (depth) from the junction. The major competing technique to C–V measurements is the Hall effect, which, while yielding added information about the carrier mobility, requires difficult, time‐consuming procedures to determine carrier‐depth profiles. In fact, C–V profiling and Hall measurements can be considered complementary techniques.

In concert with deep‐level transient spectroscopy (DLTS), C–V measurements can quantitatively describe the free carrier concentrations together with information about traps. Defects appearing as traps at energies deep within the forbidden gap of a semiconductor can add or remove free carriers. The same Schottky diode can be used for both C–V measurements and DLTS measurements. The C–V apparatus and the DLTS apparatus are often a “bundled” setup.

C–V profiling to determine the doping profile of the mobile majority carriers in a semiconductor is a powerful quantitative technique. Some precautions must be taken, especially in dealing with multiple‐layered structures such as high‐to‐low doping levels, quantum wells, and the presence of traps. However, most of the problems encountered have been addressed in the literature. Major considerations and precautions to be taken in dealing with C–V profiling data acquisition and reduction are also covered in the ASTM standard. The cost of assembling a C–V profiling apparatus will range between six thousand dollars for a simple, single temperature, manual apparatus to sixty thousand dollars for a fully automated apparatus. C–V profiling used in concert with deep‐level transient spectroscopy to identify traps, as well as with Hall effect, to address transport mechanisms, provides a powerful set of tools at reasonable cost.
Magnetism and Magnetic Measurement, Introduction
Authors: Chien C. L.
Published: October 2012

Magnetism and magnetic materials have a long and illustrious history from antiquity to the present. Devices and technologies based on magnetism, from loadstone in the ancient, to the spin‐valve GMR read‐heads in our computers now, to the new memories (e.g., STT‐MRAM) in the future, may be the longest running technology in human endeavor. A fundamental understanding of magnetism requires quantum mechanics and special relativity that have been advanced in the 20th century. In this Chapter, we describe the origin of the atomic magnetic moments, their mutual interaction that leads to magnetism, the generation of magnetic field, and the exploitation of magnetic materials for technological applications.
Magnetometry
Authors: Guertin Robert P. , Foner Simon
Published: October 2012

All materials possess a magnetic moment; techniques for measuring that bulk macroscopic property are defined here as magnetometry. This article reviews the most common techniques for measuring the total magnetic moments of small samples (volume <= 1cm3 and/or mass <=1 g). Several factors contribute to the bulk magnetic moment of a sample. Essentially all materials show weak diamagnetism from filled electronic core states of the atoms. Metallic materials show an additional contribution to their diamagnetism from the orbital motion of the otherwise degenerate spin‐up and spin‐down conduction electrons as well as Pauli paramagnetism from splitting of the conduction bands. The largest contribution to the magnetic moment of materials comes from unpaired localized spins of elemental constituents –unpaired 3d and sometimes 4d and 5d electrons in the case of the transition metal series, 4f electrons for the rare earths, and 5f electrons for the actinide constituents.